Method of producing diffraction grating
US5368992A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 19, 1993 |
| Grant date | Nov 29, 1994 |
| Priority date | — |
| Expiry date | Mar 19, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/001
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In a method of producing a .lambda./4-shifted diffraction grating, a positive type photoresist is applied to a substrate so that the surface level of the photoresist is in the vicinity of the node of the nodes in a standing wave light intensity distribution in the thickness direction of the photoresist that is nearest to the substrate, the light intensity distribution is produced by interference between incident light in the film and light reflected by the substrate. Then, the photoresist is subjected to two-luminous-flux interference exposure, followed by development, providing a pattern of photoresist films regions each having an over-hanging portion. Thereafter, an insulating film is deposited on the photoresist and exposed parts of the substrate, a first protective resist is selectively formed on the photoresist, the insulating film which is not covered with the first resist is removed, the substrate is etched using the photoresist, which is not covered with the first resist, as a mask, the photoresist is removed together with the first resist and the insulating film on the photoresist by lift-off, leaving the insulating film on the substrate, a second protective resist is sele…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.