Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
263 words
A process for producing a semiconductor device having a multilayer interconnection composed of a plurality of conductive layers electrically separated from each other by interlayer insulating layers inserted therebetween in an area other than sites at which the conductive layers are electrically interconnected via a through hole, at least one of the conductive layers having a layer formed thereon for preventing stress- and/or electro-migration thereof, the process comprising the steps of: forming a first conductive layer; forming on said first conductive layer a migration-preventing layer for preventing mechanical stress- and/or electro-migration in said first conductive layer; forming an opening through said migration-preventing layer, the opening having a width less than a width of said first conductive layer within a region surrounded by a periphery of the opening; forming an interlayer insulating layer on said migration-preventing layer and the exposed surface of said first conductive layer so as to cover said migration-preventing layer and said first conductive layer, and to fill the opening; forming a through hole having a width less than the width of the opening and extending through said interlayer insulating layer to the surface of said first conductive layer within the region of the filled opening so that the surface of said first conductive layer is exposed while not exposing a periphery of the opening; and forming a second conductive layer on said interlayer insulating layer so that, during the forming of said second conductive layer, the through hole is filled with a conductive substance of said second conductive layer to thereby electrically connect said first and the second conductive layers.
Claim 2
Dependent Claim
263 words
A process for producing a semiconductor device having a multilayer interconnection composed of a plurality of conductive layers electrically separated from each other by interlayer insulating layers inserted therebetween in an area other than sites at which the conductive layers are electrically interconnected via a through hole, at least one of the conductive layers having a layer formed thereon for preventing stress- and/or electro-migration thereof, the process comprising the steps of: forming a first conductive layer; forming on said first conductive layer a migration-preventing layer for preventing mechanical stress- and/or electro-migration in said first conductive layer; forming an opening through said migration-preventing layer, the opening having a width less than a width of said first conductive layer within a region surrounded by a periphery of the opening; forming an interlayer insulating layer on said migration-preventing layer and the exposed surface of said first conductive layer so as to cover said migration-preventing layer and said first conductive layer, and to fill the opening; forming a through hole having a width less than the width of the opening and extending through said interlayer insulating layer to the surface of said first conductive layer within the region of the filled opening so that the surface of said first conductive layer is exposed while not exposing a periphery of the opening; and forming a second conductive layer on said interlayer insulating layer so that, during the forming of said second conductive layer, the through hole is filled with a conductive substance of said second conductive layer to thereby electrically connect said first and the second conductive layers.
Claim 3
Dependent Claim
66 words
A process according to claim 1, wherein said forming of a through hole is carried out by an etching, the process further comprising the following two steps: isotropically etching an upper portion of said interlayer insulating layer from a free surface thereof; anisotropically etching a remainder of said interlayer insulating layer until the through hole is completed to expose the surface of said first conductive layer.
Claim 4
Dependent Claim
17 words
A process according to claim 2, wherein said isotropic etching is carried out by a dry etching.
Claim 5
Dependent Claim
22 words
A process according to any one of claim 1 to 3, wherein said migration-preventing layer comprises a layer substantially composed of TiN.
Claim 6
Dependent Claim
34 words
A process according to claim 4, wherein said TiN migration-preventing layer is subjected to an etching treatment using a gaseous mixture of CHF 3 and CF 4 as an etchant to form the opening.
Claim 7
Dependent Claim
36 words
A process according to claim 2, wherein forming said interlayer insulating layer includes forming a hillock-preventing layer for preventing formation of hillocks in said first conductive layer and a phosphosilicate glass or a borophosphosilicate glass layer.
Claim 8
Dependent Claim
15 words
A process according to claim 6, wherein said hillock-preventing layer consists of SiO 2 .
Claim 9
Dependent Claim
72 words
A process according to claim 6, wherein said isotropic etching of the upper portion of said interlayer insulating layer is carried out by a plasma etching method using a first gaseous mixture comprising fluoromethane and/or fluoroethane as an etchant and said anisotropic etching of the remainder of said interlayer insulation layer is carried out by a reactive ion etching method using a second gaseous mixture comprising fluoromethane and/or fluoroethane as an etchant.
Claim 10
Dependent Claim
14 words
A process according to claim 8, wherein said first gaseous mixture further comprises oxygen.
Claim 11
Dependent Claim
51 words
A process according to any one of claims 1 to 3, wherein said first and/or second conductive layers are composed of any material selected from the group consisting of Al and an aluminum-based alloy containing at least one alloying element selected from the group consisting of silicon, copper, titanium and tungsten.