Selective etch of silicon nitride
US8956980B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 25, 2013 |
| Grant date | Feb 17, 2015 |
| Priority date | — |
| Expiry date | Nov 25, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/334
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of etching silicon nitride on patterned heterogeneous structures is described and includes a remote plasma etch formed from a fluorine-containing precursor and a nitrogen-and-oxygen-containing precursor. Plasma effluents from two remote plasmas are flowed into a substrate processing region where the plasma effluents react with the silicon nitride. The plasmas effluents react with the patterned heterogeneous structures to selectively remove silicon nitride while very slowly removing silicon, such as polysilicon. The silicon nitride selectivity results partly from the introduction of fluorine-containing precursor and nitrogen-and-oxygen-containing precursor using distinct (but possibly overlapping) plasma pathways which may be in series or in parallel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.