Method for detecting end point in plasma etching by impedance change
US6599759B2 · kind B2 · utility
3Cited by
3References
16Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 2, 2001 |
| Grant date | Jul 29, 2003 |
| Priority date | — |
| Expiry date | Jul 14, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J37/32935
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method for detecting end-point in a plasma etching process by monitoring plasma impedance changes on a time scale is disclosed. In the method, a plasma etching process is first conducted in a process chamber, while changes in a parameter of plasma impedance in the chamber occurring during the etching process is recorded in a curve on a time scale. An end-point of the plasma etching process is then defined for the etching of a specific material layer at a point where the direction of a slope of the curve changes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.