Variable thickness self-aligned photoresist process
US4231811A · kind A · utility
82Cited by
9References
11Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 13, 1979 |
| Grant date | Nov 4, 1980 |
| Priority date | — |
| Expiry date | Sep 13, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/948
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A process for forming with a single masking step regions of different thicknesses in a photo-sensitive layer is disclosed. A masking member or reticle includes opaque and transparent areas and areas with a grating. The pitch of the periodic grating is of a lesser dimension than can be resolved by the masking projection apparatus. The photo-sensitive region illuminated by the grating receives uniform illumination at an intermediate intensity, thereby providing, after developing, a layer with regions of intermediate thickness.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.