Enhanced lift-off techniques for use with dielectric optical coatings and light sensors produced therefrom
US8836064B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 22, 2012 |
| Grant date | Sep 16, 2014 |
| Priority date | — |
| Expiry date | Jun 22, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/0272
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Light sensors including dielectric optical coatings to shape their spectral responses, and methods for fabricating such light sensors in a manner that accelerates lift-off processes and increases process margins, are described herein. In certain embodiments, a short duration soft bake is performed. Alternatively, or additionally, temperature cycling is performed. Alternatively, or additionally, photolithography is performed using a photomask that includes one or more dummy corners, dummy islands and/or dummy rings. Each of the aforementioned embodiments form and/or increase a number of micro-cracks in the dielectric optical coating not covering the photodetector sensor region, thereby enabling an accelerated lift-off process and an increased process margin. Alternatively, or additionally, a portion of the photomask can include chamfered corners so that the dielectric optical coating includes chamfered corners, which improves the thermal reliability of the dielectric optical coating.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.