Simultaneous in-situ optical sensing of pressure and etch rate in plasma etch chamber
US6021672A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 18, 1998 |
| Grant date | Feb 8, 2000 |
| Priority date | — |
| Expiry date | Sep 18, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J37/32972
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A non-intrusive method for in-situ measurement of etching chamber and optionally etch rate inside a plasma etching chamber is disclosed for use in the fabrication of semiconductor devices. The method includes the step of selecting at least one plasma species as a probe which can be F, CF.sub.2, or CO, then measuring the emission intensity at a predetermined wavelength corresponding to the plasma species so selected. Preferably, the emission intensity is measured at wavelength of 686 nm (corresponding to the transition of F from 3s.sup.3 P.sub.3 to 3p.sup.4 P.sub.3), 269 or 239 nm, corresponding to the transitions from A.sup.1 B.sub.1 (v'=0) to X.sup.1 A.sub.1 (v"=0) and from A.sup.1 B.sub.1 (v'=9) to X.sup.1 A.sub.1 (v"=0) for CF.sub.2, respectively, and 693 or 505 nm, corresponding to the transitions from d.sup.3 .PI.(v'=2) to a.sup.3 .PI.(v"=2) and from d.sup.3 .PI.(v'=7) to a.sup.3 .PI.(v"=2) for CO, respectively. By properly selecting the measurement site, etching rate and etching pressure can be obtained simultaneously.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.