Selective etch of silicon by way of metastable hydrogen termination
US9418858B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 25, 2014 |
| Grant date | Aug 16, 2016 |
| Priority date | — |
| Expiry date | Jun 25, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/32137
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Methods of etching exposed silicon on patterned heterogeneous structures is described and includes a remote plasma etch formed from a fluorine-containing precursor and a hydrogen-containing precursor. Plasma effluents from the remote plasma are flowed into a substrate processing region where the plasma effluents react with the exposed regions of silicon. The plasmas effluents react with the patterned heterogeneous structures to selectively remove silicon while very slowly removing other exposed materials. The silicon selectivity results, in part, from a preponderance of hydrogen-containing precursor in the remote plasma which hydrogen terminates surfaces on the patterned heterogeneous structures. A much lower flow of the fluorine-containing precursor progressively substitutes fluorine for hydrogen on the hydrogen-terminated silicon thereby selectively removing silicon from exposed regions of silicon. The silicon selectivity also results from the presence of an ion suppressor positioned between the remote plasma and the substrate processing region. The ion suppressor reduces or substantially eliminates the number of ionically-charged species that reach the substrate. The methods may…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.