ScAIN etch mask for highly selective etching
US10651048B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 12, 2019 |
| Grant date | May 12, 2020 |
| Priority date | — |
| Expiry date | Aug 12, 2039 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/02266
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A fabrication process employing the use of ScAlN as an etch mask is disclosed. The ScAlN etch mask is chemically nonvolatile in fluorine-based etch chemistries and has a low sputter yield, resulting in greater etch mask selectivity and reduced surface roughness for silicon and other semiconductor materials. The ScAlN etch mask has an etch mask selectivity of greater than 200,000:1 relative to silicon compared to an etch mask selectivity of less than 40,000:1 for a prior art AlN etch mask relative to silicon. Further, due to reduced sputtering of the ScAlN etch mask, and thus reduced micromasking, the ScAlN etch mask yielded a surface roughness of 0.6 μm compared to a surface roughness of 2.8 μm for an AlN etch mask.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.