Method of etching high aspect ratio openings
US6743727B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 5, 2001 |
| Grant date | Jun 1, 2004 |
| Priority date | — |
| Expiry date | Sep 6, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/76224
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of etching a deep, high aspect ratio opening in a silicon substrate includes etching the substrate with a first plasma formed using a first gaseous mixture including a bromine containing gas, an oxygen containing gas and a first fluorine containing gas. The etching process with the first gaseous mixture produces a sidewall passivating deposit, which builds up near the opening entrance. To reduce this buildup, and to increase the average etching rate, the sidewall passivating deposit is periodically thinned by forming a second plasma using a mixture containing silane and a second fluorine containing gas. The substrate remains in the same plasma reactor chamber during the entire process and the plasma is continuously maintained during the thinning step. Holes of a depth greater than 40 times the width may be produced using repeated cycles of etching and thinning.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.