Production of a lift-off mask and its application
US4659650A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 17, 1986 |
| Grant date | Apr 21, 1987 |
| Priority date | — |
| Expiry date | Mar 17, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/2022
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A positive resist containing a weak base and polyvinyl phenol as a film forming component is deposited on a substrate, subsequently exposed imagewise, cured, blanket exposed and developed in a KOH solution at temperatures of less than 10.degree. C. The resist pattern thus obtained is exposed to light having a wavelength ranging from 300 to 320 nm and finally heat-treated at temperatures ranging from 150.degree. to 280.degree. C. The finished lift-off mask is dimensionally stable at temperatures of .ltoreq.280.degree. C. and does not emit liquid or volatile components when heated. During application of the lift-off mask, a material is blanket vapor deposited at a substrate temperature ranging from about 160.degree. to 250.degree. C. on the resist pattern having openings with overhanging walls. Subsequently, the resist pattern is dissolved in a sodium metasilicate solution, causing the material vapor deposited thereon to be lifted off, with the material deposited on the substrate directly remaining. The lift-off mask is particularly suitable for generating conductor patterns on semiconductor substrates if low and uniform contact resistances between the conductor and the semiconductor…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.