Method of etching a shallow trench
US9842743B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 22, 2016 |
| Grant date | Dec 12, 2017 |
| Priority date | — |
| Expiry date | Dec 22, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/67069
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of etching a shallow trench is disclosed in the present invention. By removing the photoresist layer immediately at the end point of the hard mask layer etching and further using the improved process conditions etch the top of the substrate at the same time of the hard mask layer over-etching, such as a lower bias power, a higher pressure and a bigger polymer gases flow rate, the present invention has formed a smooth morphology on the top of the shallow trench. Therefore, the sharp corner appeared in the prior art is avoided by changing the start point of the silicon substrate etching, so as to fundamentally eliminate the leakage current caused by the sharp corner.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.