Metal layer patterning method

Claim 2

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of aluminum; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the temperature of the electrolyte is set to a constant value Te (°C.) and the density of current flowing across the metal layer to the electrolyte is set to a constant value larger than a value Je (mA/cm 2 ) determined by the constant value Te (°C.) of the electrolyte temperature; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Je of the current density is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 3

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be pattern is formed of aluminum; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the density of current flowing across the metal layer to the electrolyte is set to a constant value Je (mA/cm 2 ) and the temperature of the electrolyte is set to a constant value smaller than a value Te (°C.) determined by the constant value Je (mA/cm 2 ) of the current density; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/ca 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Te is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 4

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be pattern is formed of aluminum; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the density of current flowing across the metal layer to the electrolyte is set to a constant value Je (mA/cm 2 ) and the temperature of the electrolyte is set to a constant value smaller than a value Te (°C.) determined by the constant value Je (mA/cm 2 ) of the current density; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/ca 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Te is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 5

A metal layer patterning method according to claim 1 or 2, whereinthe a and b are given by a=2.09 (1±0.1) b=17.5 (1±0.1).

Claim 6

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on he metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of aluminum; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid and nitric acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the temperature of the electrolyte is set to a constant value Te (°C.) and the density of current flowing across the metal layer to the electrolyte is set to a constant value larger than a value Je (mA/cm 2 ) determined by the constant value Te (°C.) of the electrolyte temperature; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Je of the current density is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) =[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increase suddenly.

Claim 7

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on he metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of aluminum; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid and nitric acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the temperature of the electrolyte is set to a constant value Te (°C.) and the density of current flowing across the metal layer to the electrolyte is set to a constant value larger than a value Je (mA/cm 2 ) determined by the constant value Te (°C.) of the electrolyte temperature; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Je of the current density is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) =[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increase suddenly.

Claim 8

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of aluminum; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid and nitric acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the density of current flowing access the metal layer to the electrolyte is set to a constant value Je (mA/cm 2 ) and the temperature of the electrolyte is set to a constant value smaller than Te (°C.) determined by the constant value Je (mA/cm 2 ) of the current density; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Te is given by Te=a×Je+b =[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 9

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of aluminum; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid and nitric acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the density of current flowing access the metal layer to the electrolyte is set to a constant value Je (mA/cm 2 ) and the temperature of the electrolyte is set to a constant value smaller than Te (°C.) determined by the constant value Je (mA/cm 2 ) of the current density; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Te is given by Te=a×Je+b =[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 10

A metal layer patterning method according to claim 4 or 5, wherein the a and b are given by a=2.09 (1+0.1) b=17.5 (1+0.1).

Claim 11

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of aluminum; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid, nitric acid and acetic acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the temperature of the electrolyte is set to a constant value Te (°C.) and the density of current flowing across the metal layer to the electrolyte is set to a constant value larger than a value Je (mA/cm 2 ) determined by the constant value Te (°C.) of the electrolyte temperature; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Je of the current density is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 12

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of aluminum; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid, nitric acid and acetic acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the temperature of the electrolyte is set to a constant value Te (°C.) and the density of current flowing across the metal layer to the electrolyte is set to a constant value larger than a value Je (mA/cm 2 ) determined by the constant value Te (°C.) of the electrolyte temperature; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Je of the current density is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 13

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; wherein the metal layer to be patterned is formed of aluminum; wherein the electrolyte is a basic aqueous solution including a solute consisting prinicipally of phosphoric acid, nitric acid and acetic acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the density of current flowing across the metal layer to the electrolyte is set to a constant value Je (mA/cm 2 ) and the temperature of the electrolyte is set to a constant value smaller than a value Te (°C.) determined by the constant value Je (mA/cm 2 ) of the current density; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent value of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etchig carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Te is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 14

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; wherein the metal layer to be patterned is formed of aluminum; wherein the electrolyte is a basic aqueous solution including a solute consisting prinicipally of phosphoric acid, nitric acid and acetic acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the density of current flowing across the metal layer to the electrolyte is set to a constant value Je (mA/cm 2 ) and the temperature of the electrolyte is set to a constant value smaller than a value Te (°C.) determined by the constant value Je (mA/cm 2 ) of the current density; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent value of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etchig carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Te is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 15

A metal layer patterning method according to claim 7 or 8, wherein the a and b are given by a=2.60 (1±0.1) b=17.5 (1±0.1).

Claim 16

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of a aluminum; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of hydrochloric acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the temperature of the electrolyte is set to a constant value Te (°C.) and the density of current flowing across the metal layer to the electrolyte is set to a constant value larger than a value Je (mA/cm 2 ) determined by the constant value Te (°C.) of the electrolyte temperature; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent value of the densities of current flowing across the metal layer of the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Je of the current density is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 17

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of a aluminum; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of hydrochloric acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the temperature of the electrolyte is set to a constant value Te (°C.) and the density of current flowing across the metal layer to the electrolyte is set to a constant value larger than a value Je (mA/cm 2 ) determined by the constant value Te (°C.) of the electrolyte temperature; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent value of the densities of current flowing across the metal layer of the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Je of the current density is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 18

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of aluminum; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of hydrochloric acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the density of current flowing across the metal layer to the electrolyte is set to a constant value Je (mA/cm 2 ) and the temperature of the electrolyte is set to a constant value smaller than a value Te (°C.) determined by the constant value Je (mA/cm 2 ) of the current density; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Te is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 19

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of aluminum; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of hydrochloric acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the density of current flowing across the metal layer to the electrolyte is set to a constant value Je (mA/cm 2 ) and the temperature of the electrolyte is set to a constant value smaller than a value Te (°C.) determined by the constant value Je (mA/cm 2 ) of the current density; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Te is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 20

A metal layer patterning method according to claim 10 or 11, wherein the a and b are given by a=3.33 (1±0.1) b=16.5 (1±0.1).

Claim 21

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of aluminun; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of potassium hydroxide; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the temperature of the electrolyte is set to a constant value Te (°C.) and the density of current flowing across the metal layer to the electrolyte is set to a constant value larger than a value Je (mA/cm 2 ) determined by the constant value Te (°C.) of the electrolyte temperature; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Je of the current density is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 22

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of aluminun; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of potassium hydroxide; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the temperature of the electrolyte is set to a constant value Te (°C.) and the density of current flowing across the metal layer to the electrolyte is set to a constant value larger than a value Je (mA/cm 2 ) determined by the constant value Te (°C.) of the electrolyte temperature; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Je of the current density is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 23

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of aluminum; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of potassium hydroxide; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the density of current flowing across the mental layer to the electrolyte is set to a constant value Je (mA/cm 2 ) and the temperature of the electrolyte is set to a constant value smaller than a value Te (°C.) determined by the constant value Je (mA/cm 2 ) of the current density; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Te is given by Te=a×je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 24

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of aluminum; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of potassium hydroxide; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the density of current flowing across the mental layer to the electrolyte is set to a constant value Je (mA/cm 2 ) and the temperature of the electrolyte is set to a constant value smaller than a value Te (°C.) determined by the constant value Je (mA/cm 2 ) of the current density; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Te is given by Te=a×je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 25

A metal layer patterning method according to claim 1 or 14, wherein the a and the b are given by a=4.34 (1±0.1) b=15.6 (1±0.1).

Claim 26

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of aluminum; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of sodium hydroxide; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the temperature of the electrolyte is set to a constant value Te (°C.) and the density of current flowing across the metal layer to the electrolyte is set to a constant value larger than a value Je (mA/cm 2 ) determined by the constant value Te (°C.) of the electrolyte temperature; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Je of the current density is given by Te=a×je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out util voltage between the metal layer and the electrode increases suddenly.

Claim 27

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of aluminum; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of sodium hydroxide; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the temperature of the electrolyte is set to a constant value Te (°C.) and the density of current flowing across the metal layer to the electrolyte is set to a constant value larger than a value Je (mA/cm 2 ) determined by the constant value Te (°C.) of the electrolyte temperature; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Je of the current density is given by Te=a×je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out util voltage between the metal layer and the electrode increases suddenly.

Claim 28

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of aluminum; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of sodium hydroxide; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the density of current flowing across the metal layer to the electrolyte is set to a constant value Je (mA/cm 2 ) and the temperature of the electrolyte is set to a constant value smaller than a value Te (°C.) determined by the constant value Je (mA/cm 2 ) of the current density; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Te is given by Te=a×je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 29

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of aluminum; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of sodium hydroxide; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the density of current flowing across the metal layer to the electrolyte is set to a constant value Je (mA/cm 2 ) and the temperature of the electrolyte is set to a constant value smaller than a value Te (°C.) determined by the constant value Je (mA/cm 2 ) of the current density; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Te is given by Te=a×je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 30

A metal layer patterning method according to claim 16 or 17, wherein the a and the b are given by a=3.57 (1±0.1) b=17.1 (1±0.1).

Claim 31

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of an aluminum-silicon alloy; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the temperature of the electrolyte is set to a constant value Te (°C.) and the density of current flowing across the metal layer to the electrolyte is set to a constant value larger than a value Je (mA/cm 2 ) determined by the constant value Te (°C.) of the electrolyte temperature; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Je of the current density is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 32

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of an aluminum-silicon alloy; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the temperature of the electrolyte is set to a constant value Te (°C.) and the density of current flowing across the metal layer to the electrolyte is set to a constant value larger than a value Je (mA/cm 2 ) determined by the constant value Te (°C.) of the electrolyte temperature; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Je of the current density is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 33

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of an aluminum-silicon alloy; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the density of current flowing across the metal layer to the electrolyte is set to a constant value Je (mA/cm 2 ) and the temperature of the electrolyte is set to a constant value smaller than a value Te (°C.) determined by the constant value Je (mA/cm 2 ) of the current density: wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Te is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 34

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of an aluminum-silicon alloy; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the density of current flowing across the metal layer to the electrolyte is set to a constant value Je (mA/cm 2 ) and the temperature of the electrolyte is set to a constant value smaller than a value Te (°C.) determined by the constant value Je (mA/cm 2 ) of the current density: wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Te is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 35

A metal layer patterning method according to claim 19 or 20, wherein the a and the b are given by a=2.09 (1±0.1) b=17.5 (1±0.1).

Claim 36

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of an aluminum silicon alloy; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid and nitric acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the temperature of the electrolyte is set to a constant value Te (°C.) and the density of current flowing across the matal layer to the electrolyte is set to a constant value larger than a value Je (mA/cm 2 ) determined by the constant value Te (°C.) of the electrolyte temperature; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Je of the current density is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic ethching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 37

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of an aluminum silicon alloy; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid and nitric acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the temperature of the electrolyte is set to a constant value Te (°C.) and the density of current flowing across the matal layer to the electrolyte is set to a constant value larger than a value Je (mA/cm 2 ) determined by the constant value Te (°C.) of the electrolyte temperature; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Je of the current density is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic ethching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 38

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of an aluminum-silicon alloy; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid and nitric acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the density of current flowing across the metal layer to the electrolyte is set to a constant value Je (mA/cm 2 ) and the temperature of the electrolyte is set to a constant value smaller than a value Te (°C.) determined by the constant value Je (mA/cm 2 ) of the current density; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Te is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 39

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of an aluminum-silicon alloy; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid and nitric acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the density of current flowing across the metal layer to the electrolyte is set to a constant value Je (mA/cm 2 ) and the temperature of the electrolyte is set to a constant value smaller than a value Te (°C.) determined by the constant value Je (mA/cm 2 ) of the current density; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Te is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 40

A metal layer patterning method according to claim 22 or 23, wherein the a and the b the are given by a=2.09 (1±0.1) b=17.5 (1±0.1).

Claim 41

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of an aluminum-silicon alloy; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid, nitric acid and acetic acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the temperature of the electrolyte is set to a constant value Te (°C.) and the density of current flowing across the metal layer to the electrolyte is set to a constant value larger than a value Je (mA/cm 2 ) determined by the constant value Te (°C.) of the electrolyte temperature; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Je of the current density is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increasses suddenly.

Claim 42

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of an aluminum-silicon alloy; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid, nitric acid and acetic acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the temperature of the electrolyte is set to a constant value Te (°C.) and the density of current flowing across the metal layer to the electrolyte is set to a constant value larger than a value Je (mA/cm 2 ) determined by the constant value Te (°C.) of the electrolyte temperature; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Je of the current density is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increasses suddenly.

Claim 43

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of an aluminum-silicon alloy; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid, nitric acid and acetic acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the density of current flowing across the metal layer to the electrolyte is set to a constant value Je (mA/cm 2 ) and the temperature of the electrolyte is set to a constant value smaller than a value Te (°C.) determined by the constant value Je (mA/cm 2 ) of the current density; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Te is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increasses suddenly.

Claim 44

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of an aluminum-silicon alloy; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid, nitric acid and acetic acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the density of current flowing across the metal layer to the electrolyte is set to a constant value Je (mA/cm 2 ) and the temperature of the electrolyte is set to a constant value smaller than a value Te (°C.) determined by the constant value Je (mA/cm 2 ) of the current density; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Te is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increasses suddenly.

Claim 45

A metal layer patterning method according to claim 25 or 26, wherein the a and the b are given by a=2.09 (1±0.1) b=17.5 (1±0.1).

Claim 46

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of an aluminum-copper alloy; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the temperature of the electrolyte is set to a constant value Te (°C.) and the density of current flowing across the metal layer to the electrolyte is set to a constant value larger than a value Je (mA/cm 2 ) determined by the constant value Te (°C.) of the electrolyte temperature; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Je of the current density is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 47

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of an aluminum-copper alloy; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the temperature of the electrolyte is set to a constant value Te (°C.) and the density of current flowing across the metal layer to the electrolyte is set to a constant value larger than a value Je (mA/cm 2 ) determined by the constant value Te (°C.) of the electrolyte temperature; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Je of the current density is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 48

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of an aluminum-copper alloy; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the density of current flowing across the metal layer to the electrolyte is set to a constant value Je (mA/cm 2 ) and the temperature of the electrolyte is set to a constant value smaller than a value Te (°C.) determined by the constant value Je (mA/cm 2 ) of the current density; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Te is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 49

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of an aluminum-copper alloy; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the density of current flowing across the metal layer to the electrolyte is set to a constant value Je (mA/cm 2 ) and the temperature of the electrolyte is set to a constant value smaller than a value Te (°C.) determined by the constant value Je (mA/cm 2 ) of the current density; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Te is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 50

A metal layer patterning method according to claim 28 or 29, wherein the a and the b are given by a=2.40 (1±0.1) b=18.5 (1±0.1).

Claim 51

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of an aluminum-copper alloy; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid and nitric acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the temperature of the electrolyte is set to a constant value Te (°C.) and the density of current flowing across the metal layer to the electrolyte is set to a constant value larger than a value Je (mA/cm 2 ) determined by the constant value Te (°C.) of the electrolyte temperature; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Je of the current density is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 52

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of an aluminum-copper alloy; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid and nitric acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the temperature of the electrolyte is set to a constant value Te (°C.) and the density of current flowing across the metal layer to the electrolyte is set to a constant value larger than a value Je (mA/cm 2 ) determined by the constant value Te (°C.) of the electrolyte temperature; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Je of the current density is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 53

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of an aluminum-copper alloy; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid and netric acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the density of current flowing across the metal layer to the electrolyte is set to a constant value Je (mA/cm 2 ) and the temperature of the electrolyte is set to a constant value samller than a value Te (°C.) determined by the constant value Je (mA/cm 2 ) of the current density; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Te is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 54

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of an aluminum-copper alloy; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid and netric acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the density of current flowing across the metal layer to the electrolyte is set to a constant value Je (mA/cm 2 ) and the temperature of the electrolyte is set to a constant value samller than a value Te (°C.) determined by the constant value Je (mA/cm 2 ) of the current density; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Te is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 55

A metal layer patterning method according to claim 31 or 32, wherein the a and the b are given by a=2.09 (1±0.1) b=18.5 (1±0.1).

Claim 56

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of an aluminum-copper alloy; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid, nitric acid and acetic acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the temperature of the electrolyte is set to a constant value Te(°C.) and the density of current flowing across the metal layer to the electrolyte is set to a constant value larger than a value Je (mA/cm 2 ) determined by the constant value Te (°C.) of the electrolyte temperature; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the sensities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 and (°C.), the value Je of the current density is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 57

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of an aluminum-copper alloy; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid, nitric acid and acetic acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the temperature of the electrolyte is set to a constant value Te(°C.) and the density of current flowing across the metal layer to the electrolyte is set to a constant value larger than a value Je (mA/cm 2 ) determined by the constant value Te (°C.) of the electrolyte temperature; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the sensities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 and (°C.), the value Je of the current density is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1); and wherein the electrolytic etching is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 58

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of an aluminum-copper alloy; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid, nitric acid and acetic acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the density of current flowing across the metal layer to the electrolyte is set to a constant value Je (mA/cm 2 )and the temperature of the electrolyte is set to a constant value smaller than a value Te (°C.) determined by the constant value Je (mA/cm 2 ) of the current density; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Te is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1 =[(1±0.1); and wherein the electrolytic ethcing is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 59

A metal layer patterning method comprising the steps of: forming a metal layer to be patterned on an insulating substrate; forming a mask layer of a desired pattern on the metal layer; and subjecting the metal layer to electrolytic etching by an electrolyte through the mask layer to form a patterned metal layer; wherein the metal layer to be patterned is formed of an aluminum-copper alloy; wherein the electrolyte is a basic aqueous solution including a solute consisting principally of phosphoric acid, nitric acid and acetic acid; wherein a DC constant-current source is connected between the metal layer and an electrode corresponding thereto; wherein the density of current flowing across the metal layer to the electrolyte is set to a constant value Je (mA/cm 2 )and the temperature of the electrolyte is set to a constant value smaller than a value Te (°C.) determined by the constant value Je (mA/cm 2 ) of the current density; wherein, letting J 1 (mA/cm 2 ) and J 2 (mA/cm 2 ) represent values of the densities of current flowing across the metal layer to the electrolyte in the case of the amount of side etching of the patterned metal layer being substantially zero when the electrolytic etching is carried out with the electrolyte temperature held at T 1 (°C.) and T 2 (°C.), the value Te is given by Te=a×Je+b a=[(T.sub.2 -T.sub.1)/(J.sub.2 -J.sub.1)]×(1±0.1) b=[(T.sub.1 J.sub.2 -T.sub.2 J.sub.1)/(J.sub.2 -J.sub.1 =[(1±0.1); and wherein the electrolytic ethcing is carried out until voltage between the metal layer and the electrode increases suddenly.

Claim 60

A metal layer patterning method according to claim 34 or 35, wherein the a and the b are given by a=2.40 (1±0.1) b=18.5 (1±0.1).