US5474651A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for filling via holes in a semiconductor layer structure
Assignee: Siemens AG
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Filing: 1994-08-11
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Granted: 1995-12-12
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Expires: 2014-08-11
Abstract
Abstract For filling via holes that extend onto interconnects to be contacted in a semiconductor layer structure, the interconnects are connected to a conductive layer through auxiliary via holes. The via holes are filled with metal by electro-deposition, whereby the interconnects are wired as a cooperating electrode in an electrolyte via an auxiliary contact to the conductive layer. Subsequently, the conductive layer is removed.
Inventors
- 👤 Holger Huebner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 05:46
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/071; H10W20/074; H10W20/076; H10W20/031; H10W20/056; H10W20/057; H05; H05K; H05K3/00; H05K3/40; H05K3/42; H05K3/423; H05K3/46; H05K3/4644
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
260 words
A method for filling at least one via hole in a semiconductor layer structure having an interconnect therein spaced from a first surface of the semiconductor layer structure, comprising the steps of: opening at least a first auxiliary via hole in said semiconductor layer structure from said first surface down to said interconnect so as to uncover a portion of said interconnect; applying a conductive layer having conforming edge coverage on said first surface and into said first auxiliary via hole so as to contact the uncovered portion of the interconnect; applying an insulating layer onto said conductive layer so as to fill the first auxiliary via hole; providing an opening through said insulating layer and conductive layer, and through said semiconductor layer structure from said first surface down to said interconnect so as to uncover another portion of said interconnect and form a first via hole thereto; covering sidewalls of the first via hole with an insulation structure; utilizing a portion of said conductive layer on said first surface of said semiconductor layer structure as an auxiliary contact; providing an electrolyte, immersing the semiconductor layer structure in the electrolyte, and connecting a power source for an electro-deposition between the electrolyte and said first interconnect by utilizing the auxiliary contact which is in electrical connection with said first interconnect via said conductive layer passing through said first auxiliary via hole; filling said first via hole with metal by electro-deposition in the electrolyte; and removing the insulating layer and conductive layer lying above the first surface of the semiconductor layer structure.
Claim 2
Independent Claim
260 words
A method for filling at least one via hole in a semiconductor layer structure having an interconnect therein spaced from a first surface of the semiconductor layer structure, comprising the steps of: opening at least a first auxiliary via hole in said semiconductor layer structure from said first surface down to said interconnect so as to uncover a portion of said interconnect; applying a conductive layer having conforming edge coverage on said first surface and into said first auxiliary via hole so as to contact the uncovered portion of the interconnect; applying an insulating layer onto said conductive layer so as to fill the first auxiliary via hole; providing an opening through said insulating layer and conductive layer, and through said semiconductor layer structure from said first surface down to said interconnect so as to uncover another portion of said interconnect and form a first via hole thereto; covering sidewalls of the first via hole with an insulation structure; utilizing a portion of said conductive layer on said first surface of said semiconductor layer structure as an auxiliary contact; providing an electrolyte, immersing the semiconductor layer structure in the electrolyte, and connecting a power source for an electro-deposition between the electrolyte and said first interconnect by utilizing the auxiliary contact which is in electrical connection with said first interconnect via said conductive layer passing through said first auxiliary via hole; filling said first via hole with metal by electro-deposition in the electrolyte; and removing the insulating layer and conductive layer lying above the first surface of the semiconductor layer structure.
Claim 3
Dependent Claim
22 words
A method according to claim 1 wherein the auxiliary contact to the conductive layer is connected to ground potential during the electro-deposition.
Claim 4
Dependent Claim
124 words
A method according to claim 1 including the steps of: providing in said semiconductor layer structure a second interconnect spaced from said first surface; opening at least a second auxiliary via hole from said first surface down to said second interconnect before application of said conductive layer; when applying said conductive layer in said first auxiliary via hole, also applying said conductive layer in said second auxiliary via hole so that the first and second interconnects are electrically shorted via the conductive layer; opening a second via hole from said first surface down to said second interconnect before said electro-deposition; covering sidewalls of said second via hole with a further insulation structure; and also filling said second via hole with metal during said electro-deposition.
Claim 5
Dependent Claim
73 words
A method according to claim 1 including the further steps of: forming said insulating layer in said first auxiliary via hole as a photoresist which also covers portions of said conductive layer overlying said first surface of said semiconductor layer structure; and after exposure and development of said insulating layer of photoresist, employing the photoresist as an etching mask for opening said first via hole with the assistance of an anisotropic dry-etching process.
Claim 6
Dependent Claim
20 words
A method according to claim 4 wherein an edge delacquering is implemented producing said auxiliary contact to the conductive layer.
Claim 7
Dependent Claim
20 words
A method according to claim 1 including the step of forming said conductive layer of tungsten in a CVD deposition.
Claim 8
Dependent Claim
20 words
A method according to claim 1 including the step of forming said conductive layer of gold in a current-less deposition.
Claim 9
Dependent Claim
43 words
A method according to claim 1 including the step of forming the insulation structure at the sidewalls of the first via hole by surface-wide deposition of an insulation layer which is substantially edge conforming followed by an anisotropic etching of the insulation layer.
Claim 10
Dependent Claim
161 words
A method according to claim 1 wherein a second surface via hole is filled at a second surface of the semiconductor substrate which lies opposite the first surface, and includes the steps of: opening a second surface auxiliary via hole from said second surface and extending to a surface of an interconnect to be contacted from said second surface; applying a further conductive layer onto the second surface and into said second surface auxiliary via hole at said second surface; applying a further insulating layer onto said further conductive layer which fills the second surface auxiliary via hole at tile second surface; opening a second surface via hole from said second surface to said further interconnect; covering sidewalls of the second surface via hole with an insulating structure; providing a contact to the further conductive layer; and filling the second surface via hole with metal by said electro-deposition in said electrolyte when filling the first via hole at tile first surface.
Claim 11
Dependent Claim
22 words
A method according to claim 9 wherein the contact of the further conductive layer is connected to ground potential during the electro-deposition.
Claim 12
Independent Claim
239 words
A method for filling at least one via hole in a semiconductor layer structure having an interconnect therein spaced from a first surface of the semiconductor layer structure, comprising the steps of: opening at least one auxiliary via hole from said first surface down to said interconnect so as to uncover a portion of the interconnect; applying a conductive layer on said first surface and into said auxiliary via hole so as to contact the uncovered portion of the interconnect; applying an insulating layer onto said conductive layer so as to fill the auxiliary via hole; providing an opening through said insulating layer, conductive layer and semiconductor layer structure to said interconnect so as to uncover another portion thereof and form a via hole thereto; covering sidewalls of the via hole with an insulation structure; utilizing a portion of said conductive layer on said first surface of said semiconductor layer structure as an auxiliary contact; providing an electrolyte, immersing the semiconductor layer structure in the electrolyte, and connecting a power source for an electro-deposition between the electrolyte and said first interconnect by utilizing the auxiliary contact which is in electrical connection with said first interconnect via said conductive layer passing through said auxiliary via hole; filling said via hole with metal by electro-deposition in the electrolyte; and stripping off said insulating layer and conductive layer at said first surface and planarizing the first surface of the semiconductor layer structure.
Claim 13
Independent Claim
239 words
A method for filling at least one via hole in a semiconductor layer structure having an interconnect therein spaced from a first surface of the semiconductor layer structure, comprising the steps of: opening at least one auxiliary via hole from said first surface down to said interconnect so as to uncover a portion of the interconnect; applying a conductive layer on said first surface and into said auxiliary via hole so as to contact the uncovered portion of the interconnect; applying an insulating layer onto said conductive layer so as to fill the auxiliary via hole; providing an opening through said insulating layer, conductive layer and semiconductor layer structure to said interconnect so as to uncover another portion thereof and form a via hole thereto; covering sidewalls of the via hole with an insulation structure; utilizing a portion of said conductive layer on said first surface of said semiconductor layer structure as an auxiliary contact; providing an electrolyte, immersing the semiconductor layer structure in the electrolyte, and connecting a power source for an electro-deposition between the electrolyte and said first interconnect by utilizing the auxiliary contact which is in electrical connection with said first interconnect via said conductive layer passing through said auxiliary via hole; filling said via hole with metal by electro-deposition in the electrolyte; and stripping off said insulating layer and conductive layer at said first surface and planarizing the first surface of the semiconductor layer structure.
References Cited (Backward Citations)
US4888087A
Cited
EP0517551A2
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-12-11 | 1999-06-12 | 1999-12-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-12-11 | 2003-06-12 | 2003-12-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-12-11 | 2007-06-12 | 2007-12-12 | $7700.00 | Window Closed / Lapsed |