Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
205 words
A method of forming a multilayer interconnection structure, comprising the steps of: providing a first conductive layer; forming a first insulating layer on said first conductive layer; forming a second conductive layer on said first insulating layer; forming a second insulating layer on said second conductive layer; forming a through hole in said second insulating, said second conductive and said first insulating layers so as to expose a portion of said first conductive layer and a portion of said second conductive layer, said through hole having sidewalls extending through said second insulating, second conductive and first insulating layers; masking at least the exposed portion of the second conductive layer with a masking film effective to prevent deposit thereon of a metal which has a strong and selective adhesion on said first and second conductive layers; partially filling the through hole with a metal which contacts the exposed portion of said first conductive layer; re-exposing said portion of said second conductive layer masked by said masking film by removing said masking film from said portion of said second conductive layer; and substantially filling a remainder of said through hole with said metal so that said first and second conductive layers are electrically interconnected with each other.
Claim 2
Independent Claim
205 words
A method of forming a multilayer interconnection structure, comprising the steps of: providing a first conductive layer; forming a first insulating layer on said first conductive layer; forming a second conductive layer on said first insulating layer; forming a second insulating layer on said second conductive layer; forming a through hole in said second insulating, said second conductive and said first insulating layers so as to expose a portion of said first conductive layer and a portion of said second conductive layer, said through hole having sidewalls extending through said second insulating, second conductive and first insulating layers; masking at least the exposed portion of the second conductive layer with a masking film effective to prevent deposit thereon of a metal which has a strong and selective adhesion on said first and second conductive layers; partially filling the through hole with a metal which contacts the exposed portion of said first conductive layer; re-exposing said portion of said second conductive layer masked by said masking film by removing said masking film from said portion of said second conductive layer; and substantially filling a remainder of said through hole with said metal so that said first and second conductive layers are electrically interconnected with each other.
Claim 3
Dependent Claim
17 words
A method according to claim 1, wherein said first and second conductive layers are made of polysilicon.
Claim 4
Dependent Claim
19 words
A method according to claim 1, wherein said first and second insulating layers are made of SiO 2 .
Claim 5
Dependent Claim
16 words
A method according to claim 1, wherein said masking film is made of SiO 2 .
Claim 6
Dependent Claim
11 words
A method according to claim 1, wherein said metal is tungsten.
Claim 7
Dependent Claim
17 words
A method according to claim 1, wherein said through-hole is formed by photolithography and dry etching techniques.
Claim 8
Dependent Claim
37 words
A method according to claim 1, wherein said masking film is initially deposited on an upper exposed surface of said second insulating layer, the sidewalls of said through-hole and the exposed portions of said first conductive layer.
Claim 9
Dependent Claim
50 words
A method according to claim 7, wherein in the step of re-exposing said masked portion of said conductive layer, said masking film deposited on the upper exposed surface of said second insulating layer and the exposed portion of said first conductive layer is removed by an ion reactive etching step.
Claim 10
Dependent Claim
41 words
A method according to claim 8, wherein two portions of said masking film deposited on the opposed wall portions of said through-hole are removed by an isotropic etching so as to expose the two opposed surfaces of said second conductive layer.
Claim 11
Dependent Claim
43 words
A method according to claim 1, wherein the deposition of said metal on the surface of said first conductive layer is continued until an end surface of the deposited metal reaches a position close to the opposed surfaces of said second conductive layer.
Claim 12
Independent Claim
243 words
A method of forming a multilayer interconnection structure, comprising the steps of: providing a first conductive layer made of polysilicon; forming a first insulating layer made of SiO 2 on said first conductive layer; forming a second conductive layer made of polysilicon on said first insulating layer; forming a second insulating layer made of SiO 2 on said second conductive layer; forming a through hole in said second insulating, said second conductive and said first insulating layers so as to expose a portion of said first conductive layer and a portion of said second conductive layer, said through hole having sidewalls extending through said second insulating, second conductive and first insulating layers; masking at least the exposed portion of the second conductive layer with a masking film effective to prevent deposit thereon of a metal which has a strong and selective adhesion on said first and second conductive layers by oxidizing or nitriding said exposed portion of said second conductive layer; partially filling the through hole with a metal which contacts the exposed portion of said first conductive layer by depositing said metal by chemical vapor disposition; re-exposing said portion of said second conductive layer masked by said masking film by removing said making film from said portion of said second conductive layer; and substantially filling a remainder of said through hole with said metal by chemical vapor deposition so that said first and second conductive layers are electrically interconnected with each other.
Claim 13
Independent Claim
243 words
A method of forming a multilayer interconnection structure, comprising the steps of: providing a first conductive layer made of polysilicon; forming a first insulating layer made of SiO 2 on said first conductive layer; forming a second conductive layer made of polysilicon on said first insulating layer; forming a second insulating layer made of SiO 2 on said second conductive layer; forming a through hole in said second insulating, said second conductive and said first insulating layers so as to expose a portion of said first conductive layer and a portion of said second conductive layer, said through hole having sidewalls extending through said second insulating, second conductive and first insulating layers; masking at least the exposed portion of the second conductive layer with a masking film effective to prevent deposit thereon of a metal which has a strong and selective adhesion on said first and second conductive layers by oxidizing or nitriding said exposed portion of said second conductive layer; partially filling the through hole with a metal which contacts the exposed portion of said first conductive layer by depositing said metal by chemical vapor disposition; re-exposing said portion of said second conductive layer masked by said masking film by removing said making film from said portion of said second conductive layer; and substantially filling a remainder of said through hole with said metal by chemical vapor deposition so that said first and second conductive layers are electrically interconnected with each other.