Patent EP0100736A2 successfully refreshed from Google Patents.
EP0100736A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Structure and process for lift-off wafer processing
Assignee: Fairchild Semiconductor Corp
•
Filing: 1983-08-01
•
Granted: —
•
Expires: 2003-08-01
Abstract
Abstract An improved lift-off process for forming metallized interconnections between various regions on a semiconductor device relies on the use of a particular polyimide in forming a protective mask over the device. The polyimide is a copolymer of an aromatic cycloaliphatic. diamine and a dianhydride which allows the resulting structure to withstand particularly high temperatures in the fabrication process. In particular, the polyimide when subjected to high temperature metallization under vacuum remains sufficiently soluble to be substantially completely removed from the device by immersion in common organic solvents. This allows high temperature metallization as interconnects for integrated circuits.
Inventors
- 👤 Alvin Milgram
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 17:05
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/004; G03F7/09; G03F7/094; H; H10; H10P; H10P76/00; H10P76/20; H10P76/202; Y; Y10; Y10S; Y10S438/00; Y10S438/942; Y10S438/948; Y10S438/951
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
143 words
A lift-off process for depositing a metallization pattern on a surface of a semiconductor device, said process including the steps of : forming a composite structure including the semiconductor device (10), a protective layer (12, 14) over the surface (11) of the semiconductor device, and a masking layer (16) over the protective layer ; defining the desired metallization pattern in the mask layer (16) ; etching the protective layer (12, 14) to expose the surface (11) of the semiconductor device in a pattern corresponding to the desired metallization pattern ; metallizing (18) the exposed surface of the semiconductor device ; and removing the protective layer (12, 14) whereby only the metallized pattern is left on the surface ; characterized by comprising : forming the protective layer (12, 14) from a polyimide which is a copolymer of an aromatic cycloaliphatic diamine and' a dianhydride.
Claim 2
Dependent Claim
143 words
A lift-off process for depositing a metallization pattern on a surface of a semiconductor device, said process including the steps of : forming a composite structure including the semiconductor device (10), a protective layer (12, 14) over the surface (11) of the semiconductor device, and a masking layer (16) over the protective layer ; defining the desired metallization pattern in the mask layer (16) ; etching the protective layer (12, 14) to expose the surface (11) of the semiconductor device in a pattern corresponding to the desired metallization pattern ; metallizing (18) the exposed surface of the semiconductor device ; and removing the protective layer (12, 14) whereby only the metallized pattern is left on the surface ; characterized by comprising : forming the protective layer (12, 14) from a polyimide which is a copolymer of an aromatic cycloaliphatic diamine and' a dianhydride.
Claim 3
Dependent Claim
68 words
A process as in Claim 1 characterized in that said step of forming the protective layer (12, 14) comprises : applying a layer (12) of said polyimide on the surface of the semiconductor (10) ; and applying a barrier layer (14) over the polyimide layer (12) ; said step of removing tne protective layer comprising dissolving said polyimide and barrier layers (12, 14) in a substantially nonpolar solvent.
Claim 4
Dependent Claim
134 words
A process as in Claims 1 or 2, characterized in that the polyimide consists essentially of the recurring unit having the formula wnerein Y is a divalent organic radical selected from carbocyclic-aromatic, aliphatic, araliphatic, cycloaliphatic, and heterocyclic radicals, combinations of these, and radicals with heteroatom-containing bridging groups where the heteroatom in the bridge is oxygen, sulfur, nitrogen, silicon or phosphorus, provided that, out of the total number of polyamide-imide recurring units, 1 to 100 percent of such units have Y equal to a phenylindane radical of the structural formula -wherein R 1 is hydrogen or lower alkyl, and R 2 , R 3 , R 4 and R 5 are independently hydrogen, halogen or lower alkyl, and either aromatic ring of the unsymmetrical phenylindane radical may be bonded to an amide or imide nitrogen.
Claim 5
Dependent Claim
28 words
A process as in Claim 1 to 3 characterized in that the metallizing step is carried out at a temperature in the range from about 250 to 325°C.
Claim 6
Dependent Claim
20 words
A process as in Claim 1 to 4 characterized in that the metallizing step is accomplished with an aluminum-silicon-copper alloy.
Claim 7
Dependent Claim
19 words
A semiconductor device characterized by being fabricated according to the process of any one of Claims 1 to 5.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.