Etch methods to form anisotropic features for high aspect ratio applications
US7368394B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 27, 2006 |
| Grant date | May 6, 2008 |
| Priority date | — |
| Expiry date | Feb 27, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/76814
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Methods for forming anisotropic features for high aspect ratio application in etch process are provided in the present invention. The methods described herein advantageously facilitates profile and dimension control of features with high aspect ratios through a sidewall passivation management scheme. In one embodiment, sidewall passivations are managed by selectively forming an oxidation passivation layer on the sidewall and/or bottom of etched layers. In another embodiment, sidewall passivation is managed by periodically clearing the overburden redeposition layer to preserve an even and uniform passivation layer thereon. The even and uniform passivation allows the features with high aspect ratios to be incrementally etched in a manner that pertains a desired depth and vertical profile of critical dimension in both high and low feature density regions on the substrate without generating defects and/or overetching the underneath layers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.