Isotropic etchback method of linewidth tailoring multilayer dielectric diffraction gratings for improvement of laser damage resistance and diffraction efficiency
US11079543B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 23, 2011 |
| Grant date | Aug 3, 2021 |
| Priority date | — |
| Expiry date | Jul 28, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S3/0057
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method of fabricating a multilayer dielectric (MLD) diffraction grating by providing a multilayer stack having a grating layer, and anisotropically etching the grating layer to form grating lines having an initial lineheight, an initial linewidth, and an initial grating duty cycle, that are greater than a target lineheight, a target linewidth, and a target grating duty cycle, respectively. An isotropic wet etch solution is then used to etch back the grating lines to the target lineheight, the target linewidth, and the target grating duty cycle so as to minimize electric field intensities and maximize diffraction efficiency for a given set of MLD illumination conditions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.