Aluminum alloy line resistive to stress migration formed in semiconductor integrated circuit

Claim 2

An aluminum alloy connecting means of a type which has resistance to stress migration formed in a semiconductor integrated circuit, comprising: an insulating layer formed on a semiconductor substrate wherein circuit devices are constructed; an alloy line layer which includes crystal grains, each of which has crystal faces, and comprising aluminum as a constituent of the alloy and formed on said insulating layer such that the crystal faces of the crystal grains of said alloy line layer are mainly oriented in the (111) plane, and the grain size of the crystal being regulated so as to satisfy the following relationship: (W/14)<l<W where l is the grain size of the alloy crystal, and W is the line width; and a protection film of a type which has internal stresses therein, protecting at least said alloy line layer and formed on or above at least part of said alloy line layer so that said internal stresses of the protection film acts thereon, wherein an occurrence of stress migration due to the tensile stress of said protection film is prevented.

Claim 3

The aluminum alloy line according to claim 1, wherein said protection film is of a type which has internal stresses sufficient to cause stress migration in said alloy layer.

Claim 4

The aluminum alloy line according to claim 2, wherein the grain size of the alloy crystal is regulated so that the relationship between the grain size l of the alloy crystal and the width W of the line satisfies the following formula: (W/4)≦l≦(W/1.5).

Claim 5

The aluminum alloy line according to claim 3, wherein said alloy line layer comprises aluminum and silicon.

Claim 6

The aluminum alloy line according to claim 4, wherein the crystal faces of the crystal grains of said alloy line layer are disposed in the (111) plane in such a way that the x-ray diffraction intensity at the (111) plane is greater than at other planes and satisfies the following relationship: I.sub.111 /I.sub.abc >2 wherein I 111 is the x-ray diffraction intensity in the (111) plane, and I abc is the highest diffraction intensity at the other planes.

Claim 7

The aluminum alloy line according to claim 5, wherein said protection film is a surface protection film.

Claim 8

The aluminum alloy line according to claim 5, wherein said protection film is formed of a silicon nitride film.

Claim 9

The aluminum alloy line according to claim 7, wherein said protection film is a surface protection film.

Claim 10

An aluminum alloy connecting means according to claim 8, wherein said insulating layer is formed of an oxide and said alloy line layer is formed on said insulating layer.

Claim 11

The aluminum alloy line according to claim 1, wherein said alloy line layer comprises aluminum and silicon.

Claim 12

The aluminum alloy line according to claim 10, wherein the crystal faces of the crystal grains of said alloy line layer are disposed in the (111) plane in such a way that the x-ray diffraction intensity at the (111) plane is greater than at other planes and satisfies the following relationships: I.sub.111 /I.sub.abc >2 wherein I 111 is the x-ray diffraction intensity in the (111) plane, and I abc is the highest diffraction intensity at the other planes.

Claim 13

The aluminum alloy line according to claim 11, wherein said protection film is formed of a silicon nitride film.

Claim 14

The aluminum alloy line according to claim 12, wherein said protection film is a surface protection film.

Claim 15

The aluminum alloy line according to claim 11, wherein said protection film is a surface protection film.

Claim 16

The aluminum alloy line according to claim 1, wherein said protection film is formed of a silicon nitride film.

Claim 17

The aluminum alloy line according to claim 15, wherein said protection film is a surface protection film.

Claim 18

The aluminum alloy line according to claim 1, wherein said protection film is a surface protection film.

Claim 19

An aluminum alloy line structure formed in a semiconductor circuit comprising: a first oxide film layer formed on a semiconductor substrate wherein circuit devices are constructed and having a first contact opening in order to expose a portion of the substrate surface; a first aluminum alloy line layer comprising aluminum as a constituent of the alloy and formed as an electrical connecting means on said first oxide film to contact the substrate surface through said first contact opening; wherein the crystal faces of the crystal grains of said first alloy line layer are mainly oriented in the (111) plane; a nitride film layer formed on said first oxide film and said first alloy line layer having a surface flattened by a dry etching process and having a second contact opening to expose a surface portion of said first alloy line layer; a second oxide film layer formed on said nitride film layer except for said second contact opening to expose the surface portion of said first alloy line layer; a second aluminum alloy line layer comprising aluminum as the major constituent of the alloy and formed as an electrical connecting means on said second oxide film layer to contact said first aluminum alloy line layer via said second contact opening; and a protection film of a type which has internal stresses therein, protecting at least said alloy line layer and formed on or above at least part of said alloy line layer so that said internal stresses of the protection film acts thereon, wherein the crystal faces of the crystal grains of said second alloy line layer are mainly oriented in the (111) plane to prevent occurrence of stress migration due to the tensile stress of said protection film, and the grain size of the crystal being regulated so as to satisfy the following relationship: (W/14)<l<W where l is the grain size of the alloy crystal, and W is the line width.

Claim 20

An aluminum alloy line structure formed in a semiconductor circuit comprising: a first oxide film layer formed on a semiconductor substrate wherein circuit devices are constructed and having a first contact opening in order to expose a portion of the substrate surface; a first aluminum alloy line layer comprising aluminum as a constituent of the alloy and formed as an electrical connecting means on said first oxide film to contact the substrate surface through said first contact opening; wherein the crystal faces of the crystal grains of said first alloy line layer are mainly oriented in the (111) plane; a nitride film layer formed on said first oxide film and said first alloy line layer having a surface flattened by a dry etching process and having a second contact opening to expose a surface portion of said first alloy line layer; a second oxide film layer formed on said nitride film layer except for said second contact opening to expose the surface portion of said first alloy line layer; a second aluminum alloy line layer comprising aluminum as the major constituent of the alloy and formed as an electrical connecting means on said second oxide film layer to contact said first aluminum alloy line layer via said second contact opening; and a protection film of a type which has internal stresses therein, protecting at least said alloy line layer and formed on or above at least part of said alloy line layer so that said internal stresses of the protection film acts thereon, wherein the crystal faces of the crystal grains of said second alloy line layer are mainly oriented in the (111) plane to prevent occurrence of stress migration due to the tensile stress of said protection film, and the grain size of the crystal being regulated so as to satisfy the following relationship: (W/14)<l<W where l is the grain size of the alloy crystal, and W is the line width.

Claim 21

An aluminum alloy line structure formed in a semiconductor circuit comprising: a first oxide film layer formed on a semiconductor substrate wherein circuit devices are constructed and having a first contact opening in order to expose a portion of the substrate surface; a first aluminum alloy line layer comprising aluminum as a constituent of the alloy and formed as an electrical connecting means on said first oxide film to contact the substrate surface through said first contact opening; wherein the crystal faces of the crystal grains of said first alloy line layer are mainly oriented in the (111) plane; a nitride film layer formed laminarly on said first oxide film and said first alloy line layer and having a second contact opening to expose a surface portion of said first alloy line layer; a spin-on-glass layer formed in the recesses existing in said nitride film layer, and cured; a second oxide film layer formed on said nitride film layer and said spin-on-glass layer except for said second contact opening to expose the surface portion of said first alloy line layer; a second aluminum alloy line layer comprising aluminum as a constituent of the alloy and formed as an electrical connecting means on said second oxide film layer to contact said first aluminum alloy line layer via said second contact opening; and a protection film of a type which has internal stresses therein, protecting at least said alloy line layer and formed on or above at least part of said alloy line layer so that said internal stresses of the protection film acts thereon, wherein the crystal faces of the crystal grains of said second alloy line layer are mainly oriented in the (111) plane to prevent occurrence of stress migration due to the tensile stress of said protection film, and the grain size of the crystal being regulated so as to satisfy the following relationship: (W/14)<l<W where l is the grain size of the alloy crystal, and W is the line width.

Claim 22

An aluminum alloy line structure formed in a semiconductor circuit comprising: a first oxide film layer formed on a semiconductor substrate wherein circuit devices are constructed and having a first contact opening in order to expose a portion of the substrate surface; a first aluminum alloy line layer comprising aluminum as a constituent of the alloy and formed as an electrical connecting means on said first oxide film to contact the substrate surface through said first contact opening; wherein the crystal faces of the crystal grains of said first alloy line layer are mainly oriented in the (111) plane; a nitride film layer formed laminarly on said first oxide film and said first alloy line layer and having a second contact opening to expose a surface portion of said first alloy line layer; a spin-on-glass layer formed in the recesses existing in said nitride film layer, and cured; a second oxide film layer formed on said nitride film layer and said spin-on-glass layer except for said second contact opening to expose the surface portion of said first alloy line layer; a second aluminum alloy line layer comprising aluminum as a constituent of the alloy and formed as an electrical connecting means on said second oxide film layer to contact said first aluminum alloy line layer via said second contact opening; and a protection film of a type which has internal stresses therein, protecting at least said alloy line layer and formed on or above at least part of said alloy line layer so that said internal stresses of the protection film acts thereon, wherein the crystal faces of the crystal grains of said second alloy line layer are mainly oriented in the (111) plane to prevent occurrence of stress migration due to the tensile stress of said protection film, and the grain size of the crystal being regulated so as to satisfy the following relationship: (W/14)<l<W where l is the grain size of the alloy crystal, and W is the line width.

Claim 25

A method as in claim 20, wherein said surface protection layer is of a type with internal stresses of the type which would lead to stress migration in said alloy line layer.

Claim 26

A semiconductor device of a type with resistance to stress migration, comprising: a substrate; a first insulating layer, formed on said substrate, and having a contact portion therein which does not cover said substrate over a terminal area; alloy line layer means, including aluminum as one constituent thereof, covering said first insulating layer and covering and in contact with said substrate at said terminal area, at least a surface portion of said alloy line layer means having crystal grains which have crystal faces which are mainly oriented in the (111) plane, wherein a grain size of said crystal grains are regulated so as to satisfy the following relationship: (W/14)≦l≦W where l is the grain size of the alloy crystal, and W is the line width; and surface protection layer means, covering at least said surface portion of said alloy line layer means, for protecting same, said surface protection layer means of a type which has internal stresses therein, which could cause stress migration in said alloy line layer means.

Claim 27

A semiconductor device of a type with resistance to stress migration, comprising: a substrate; a first insulating layer, formed on said substrate, and having a contact portion therein which does not cover said substrate over a terminal area; alloy line layer means, including aluminum as one constituent thereof, covering said first insulating layer and covering and in contact with said substrate at said terminal area, at least a surface portion of said alloy line layer means having crystal grains which have crystal faces which are mainly oriented in the (111) plane, wherein a grain size of said crystal grains are regulated so as to satisfy the following relationship: (W/14)≦l≦W where l is the grain size of the alloy crystal, and W is the line width; and surface protection layer means, covering at least said surface portion of said alloy line layer means, for protecting same, said surface protection layer means of a type which has internal stresses therein, which could cause stress migration in said alloy line layer means.

Claim 28

A device as in claim 22, wherein said alloy line layer means includes: a first alloy line layer, in contact with said terminal area and covering said first insulating layer, a second insulating layer, covering said first alloy line layer, and formed with a contact hole therein, and a second alloy line layer, covering at least part of said second insulating layer and in contact with said first alloy line layer through said contact hole, and including said surface portion, said surface protection layer means covering said second insulating layer and said second alloy line layer.

Claim 31

A method as in claim 24, wherein a grain size of said crystal grains are regulated so as to satisfy the following relationship: (W/14)≦l≦W where l is the grain size of the alloy crystal, and W is the line width; and surface protection layer means.