Polysilicon processing using an anti-reflective dual layer hardmask for 193 nm lithography
US6624068B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 24, 2001 |
| Grant date | Sep 23, 2003 |
| Priority date | — |
| Expiry date | Aug 24, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/32137
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A lithographic method of forming submicron polysilicon features on a semiconductor substrate, including the steps of coating said substrate with an anti-reflective coating (ARC) comprising two layers having matched indices of refraction (n) and extinction coefficient (k) selected to reduce reflection to less than 1% with 193 nm wavelength exposure. The ARC is subsequently patterned to serve as an etch hardmask. Preferably the ARC mask consists of a first layer of between 300 and 1500 angstroms of silicon rich silicon nitride having an extinction coefficient of from 0.77 to 1.07, and a second layer of between 170 and 320 angstroms of silicon oxynitride having an extinction coefficient of about 0.32.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.