Process of forming graded aperture masks
US4303466A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 19, 1980 |
| Grant date | Dec 1, 1981 |
| Priority date | — |
| Expiry date | Jun 19, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J9/142
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A process for forming openings of varying sizes in an aperture mask by determining an over-etch factor wherein the over-etch factor is determined by the time of etching through an etchant resist pattern located on opposite sides of an aperture mask material to produce an opening of predetermined size and shape followed by individually sizing the opening in the etchant resist so that etching from both sides of the aperture mask material produces etched openings of various sizes throughout the aperture with the sizing of the opening in the etchant resist characterized by having substantially constant over-etch factor even though the final openings in the aperture masks are of various sizes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.