Method to increase the etch rate and depth in high aspect ratio structure
US6709917B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 13, 2002 |
| Grant date | Mar 23, 2004 |
| Priority date | — |
| Expiry date | Jul 25, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/3065
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of fabricating a high aspect ratio deep trench in a semiconductor substrate comprising reducing the formation of a passivation film during the etching of the trench by including a first step of contacting the substrate in which the deep trench is to be formed with a fluorine poor or low concentration of a fluorine gas in the plasma of etchant gases for etching the high aspect ratio deep trench, followed by a second step of increasing the concentration of the fluorine containing gas to create a fluorine-rich plasma while lowering the chamber pressure of the reactor and RF power. Preferably, the second step is introduced periodically during the etching of a deep trench in an alternating manner.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.