Pre-endpoint techniques in photoresist etching
US7001529B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 27, 2003 |
| Grant date | Feb 21, 2006 |
| Priority date | — |
| Expiry date | Aug 11, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/31144
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method for controlling a photoresist etch step in a plasma processing chamber is disclosed. The photoresist etch step being configured to etch back a photoresist layer deposited on a substrate surface to a thinner photoresist layer having predefined photoresist thickness. The method includes etching the photoresist layer using a plasma etch process and detecting interference patterns coming from the photoresist layer. The method further includes terminating the photoresist etch step when an analysis of the interference patterns indicates that the predefined photoresist thickness is achieved, whereby the predefined photoresist thickness is greater than zero.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.