Silicon etch process with tunable selectivity to SiO2 and other materials
US9368364B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 10, 2014 |
| Grant date | Jun 14, 2016 |
| Priority date | — |
| Expiry date | Dec 10, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/334
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A tunable plasma etch process includes generating a plasma in a controlled flow of a source gas including NH3 and NF3 to form a stream of plasma products, controlling a flow of un-activated NH3 that is added to the stream of plasma products to form an etch gas stream; and controlling pressure of the etch gas stream by adjusting at least one of the controlled flow of the source gas and the flow of un-activated NH3 until the pressure is within a tolerance of a desired pressure. An etch rate of at least one of polysilicon and silicon dioxide by the etch gas stream is adjustable by varying a ratio of the controlled flow of the source gas to the flow of un-activated NH3.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.