Methods of etching polysilicon and methods of forming pluralities of capacitors
US7902081B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 11, 2006 |
| Grant date | Mar 8, 2011 |
| Priority date | — |
| Expiry date | Aug 27, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/32134
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of etching polysilicon includes exposing a substrate comprising polysilicon to a solution comprising water, HF, and at least one of a conductive metal nitride, Pt, and Au under conditions effective to etch polysilicon from the substrate. In one embodiment, a substrate first region comprising polysilicon and a substrate second region comprising at least one of a conductive metal nitride, Pt, and Au is exposed to a solution comprising water and HF. The solution is devoid of any detectable conductive metal nitride, Pt, and Au prior to the exposing. At least some of the at least one are etched into the solution upon the exposing. Then, polysilicon is etched from the first region at a faster rate than any etch rate of the first region polysilicon prior to the etching of the at least some of the conductive metal nitride, Pt, and Au.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.