Hardened photoresist master image mask process
US4201800A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 28, 1978 |
| Grant date | May 6, 1980 |
| Priority date | — |
| Expiry date | Apr 28, 1998 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/948
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An improved mask fabrication process is disclosed which may be broadly applied to ion-implantation, reactive plasma etching, or the etching of semiconductor structures. The process is based upon the deposition onto an oxide coated or bare semiconductor surface, of a first photoresist layer having formed therein a plurality of windows and which is hardened by a wet chemical technique so as to have an increased resistance to dissolution in solvents. A second photoresist layer is deposited over the surface and windows of the first layer and a subplurality of windows are formed therein over selected windows in the first photoresist layer so as to selectively block a portion of the plurality of windows in the first layer. This composite mask invention may then be employed to carry out an ion-implantation step, wet etching step or reactive plasma etching step on the oxide or semiconductor surface exposed through composite windows. The second layer of photoresist may then be removed and a substitute photoresist layer may be deposited on the surface and windows of the first, hardened photoresist layer and a different subplurality of windows in the substitute layer may be selectively formed…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.