Use of depolymerizable polymers in the fabrication of lift-off structure for multilevel metal processes
US4519872A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 11, 1984 |
| Grant date | May 28, 1985 |
| Priority date | — |
| Expiry date | Jun 11, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/951
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An improved lift-off process for multilevel metal structure in the fabrication of integrated circuits by employing lift-off layer formed from polymers which undergo clean depolymerization under the influence of heat or radiation and allow rapid and residue-free release of an "expendable mask". An embedded interconnection metallurgy system is formed by application of the lift-off layer of this invention over a cured polymer film or on an oxygen RIE barrier layer previously deposited on organic or inorganic substrate, followed by another barrier over which is then coated a radiation sensitive resist layer. After definition of the desired resist pattern by imagewise exposure and development, the image is replicated into the barrier by sputter etching in a fluorine containing ambient and subsequently into the base layer down to the substrate by oxygen reactive ion etching which is followed by blanket metal evaporation and finally the lift-off by brief heat treatment at the depolymerization temperature of the lift-off layer, and brief solvent soak.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.