Process for etching
US5110408A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 20, 1991 |
| Grant date | May 5, 1992 |
| Priority date | — |
| Expiry date | Feb 20, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/32139
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
The present invention relates to the etching of a gate film, a tungsten film, a silicon film, etc. In the present invention, use is made of an etching gas comprising a mixture composed of a reductive fluoride gas, a hydrocarbon gas and a halogen gas having a larger atomic diameter than a material to be etched, or a mixture composed of a reductive fluoride gas and a Cl-containing hydrocarbon gas, and the process comprises the step of conducting anisotropic etching of a material to be etched with an etching gas (a reductive fluoride gas), the step of forming a protective film by a depositing gas (a hydrocarbon gas), and the step of removing excess deposits formed as the protective film by means of a gas reactive with the protective film (a halogen gas or a Cl-containing hydrogen gas), wherein anisotropic etching is conducted by forming a protective film on a side wall while removing excess deposits formed as the protective film, thus enabling the anisotropic etching to be conducted with good accuracy.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.