Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
155 words
A method for pattern-wise etching of a metal film on the surface of a substrate which comprises the steps of: (a) forming a film of a metal on the substrate; (b) forming a subsidiary masking layer mainly composed of silicon dioxide on the film of the metal; (c) forming a layer of an organic resist material sensitive to actinic rays on the subsidiary masking layer; (d) patterning of the layer of the organic resist material, thereby forming a patterned organic resist layer; (e) pattern-wise etching of the subsidiary masking layer through the patterned organic resist layer as the mask, thereby forming a patterned subsidiary masking layer; (f) pattern-wise etching of the film of the metal through the patterned subsidiary masking layer as the mask with a chlorine-containing etching gas, thereby forming a patterned layer of the metal; and (g) removing the patterned subsidiary masking layer from the surface of the patterned layer of the metal.
Claim 2
Independent Claim
155 words
A method for pattern-wise etching of a metal film on the surface of a substrate which comprises the steps of: (a) forming a film of a metal on the substrate; (b) forming a subsidiary masking layer mainly composed of silicon dioxide on the film of the metal; (c) forming a layer of an organic resist material sensitive to actinic rays on the subsidiary masking layer; (d) patterning of the layer of the organic resist material, thereby forming a patterned organic resist layer; (e) pattern-wise etching of the subsidiary masking layer through the patterned organic resist layer as the mask, thereby forming a patterned subsidiary masking layer; (f) pattern-wise etching of the film of the metal through the patterned subsidiary masking layer as the mask with a chlorine-containing etching gas, thereby forming a patterned layer of the metal; and (g) removing the patterned subsidiary masking layer from the surface of the patterned layer of the metal.
Claim 3
Dependent Claim
31 words
The method as claimed in claim 1, wherein the pattern-wise etching of the subsidiary masking layer in the step (e) is performed by a dry process with a fluorine-containing etching gas.
Claim 4
Dependent Claim
33 words
The method as claimed in claim 1, wherein the removal of the patterned subsidiary masking layer in the step (g) is performed by a process of dry etching with a fluorine-containing etching gas.
Claim 5
Dependent Claim
16 words
The method as claimed in claim 1, wherein the subsidiary masking layer comprises a phosphosilicate glass.
Claim 6
Dependent Claim
39 words
The method as claimed in claim 2, wherein the fluorine-containing etching gas is selected from the group consisting of trifluoromethane, carbon tetrafluoride, hexafluoroethane, octafluoropropane, a mixture of carbon tetrafluoride and oxygen, and a mixture of carbon tetrafluoride and hydrogen.
Claim 7
Dependent Claim
32 words
The method as claimed in claim 1, wherein the pattern-wise etching of the film of the metal in the step (f) is performed in a plasma atmosphere of the chlorine-containing etching gas.
Claim 8
Dependent Claim
26 words
The method as claimed in claim 6, wherein the chlorine-containing etching gas is selected from the group consisting of carbon tetrachloride, boron trichloride and silicon tetrachloride.
Claim 9
Dependent Claim
30 words
The method as claimed in claim 1, wherein the removal of the patterned subsidiary masking layer in the step (g) is preceded by removal of the patterned organic resist layer.
Claim 10
Dependent Claim
25 words
The method as claimed in claim 8, wherein the patterned organic resist layer is removed by dry etching in a plasma atmosphere of oxygen gas.
Claim 11
Dependent Claim
21 words
The method as claimed in claim 8, wherein the patterned organic resist layer is removed between the steps (f) and (g).
Claim 12
Dependent Claim
21 words
The method as claimed in claim 8, wherein the patterned organic resist layer is removed between the steps (e) and (f).
Claim 13
Dependent Claim
37 words
The method as claimed in claim 1, wherein the subsidiary masking layer mainly composed of silicon dioxide is resistant to dry etching with a chlorine-based etching gas, but susceptible to dry etching with a fluorine-based etching gas.