Patent EP0165513A2 successfully refreshed from Google Patents.
EP0165513A2
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EP
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Semiconductor contact metal protection
Assignee: International Business Machines Corp
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Filing: 1985-05-29
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Granted: —
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Expires: 2005-05-29
Abstract
Abstract In a photoresist lift-off process for depositing metal on a semiconductor substrate, a protective coating (40) of silicon is applied to an etched via hole (32) prior to the contact metal (42) deposition step. This prevents the formation of contaminant trapping voids and contaminated chemical residues which would otherwise occur at the base (42) of the metal line subsequently deposited in the bottom of the via hole. The protective silicon layer (40), which has a thickness of from 10 to 30 nanometers, remains intact as a permanent part of the structure.
Inventors
- 👤 Edward C. Fredericks
- 👤 Madan M. Nanda
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 11:50
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/40; H10W20/41; H10W20/44; H10W20/4451; H10P; H10P76/00; H10P76/20; H10P76/202; H10W20/01; H10W20/031; H10W20/056; Y; Y10; Y10S; Y10S438/00; Y10S438/942; Y10S438/948; Y10S438/951
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
67 words
In a semiconductor fabrication process, a method for protecting the sides of a contact metal structure from attack by chemicals used in subsequent process steps, characterized by the step of: depositing a film (40) of protective material, which is resistant to attack by chemicals, on the sides (32) of an etched via hole; depositing a contact metal (42) in the via hole on a semiconductor substrate (38).
Claim 2
Dependent Claim
33 words
The process of claim 1, including the step of depositing an additional film over the interface between the metal contact and the via holes so as to seal the structure against chemical attack.
Claim 3
Dependent Claim
50 words
In a metal lift-off process for the deposition of a metal structure for an integrated circuit, a method for protecting the sides of the metal structure from attack by chemicals used in subsequent process steps, comprising the steps of applying a layer of photoresist (30) to an insulator film (36);
Claim 4
Dependent Claim
21 words
forming a window with sidewalls (32) through the photoresist and insulating film on top of a semiconductor substrate (38); characterized by:
Claim 5
Dependent Claim
25 words
depositing a layer (40) of protective material, which is resistant to attack by said chemicals, on the surface (32) of said sidewalls of said window;
Claim 6
Dependent Claim
32 words
depositing contact lift-off metal (42) in the bottom of said window with the sides of the metal structure conforming to said surface of said protective layer covering said sides of said window;
Claim 7
Dependent Claim
20 words
applying etching chemicals by photoresist removal whereby the sides of said metal structure are not in contact with the chemicals.
Claim 8
Independent Claim
26 words
The method of a previous claim, wherein said protective material (40) is selected from the group consisting of silicon, germanium, nitride, molybdenum silicide, and tungsten silicide.
Claim 9
Independent Claim
61 words
The method of a previous claim, wherein said substrate (38) is selected from the group consisting of silicon and gallium arsenide; said metal (42) is selected from the group consisting of aluminum, molybdenum, tungsten and titanium; and said photoresist (30) is selected from the group consisting of optical photoresist, electron beam photoresist, positive photoresist and negative photoresist, wet or dry developable.
Claim 10
Independent Claim
16 words
The method of a previous claim, wherein said subsequently applied chemical is an alkali photoresist developer.
Claim 11
Dependent Claim
81 words
An electrical contact structure (42, 37) for an integrated circuit, formed through a window (32) in an insulator layer (36) on a silicon substrate (38), characterized by: a thin layer (40) of silicon coating the sidewalls (32) of said window in said insulator layer; a metal contact structure (42) deposited on said silicon (40) in said window, having its edges in contact with the surface of said silicon in said window and in electrical contact with said silicon substrate (38, 37).
References Cited (Backward Citations)
No citation records indexed.
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