Method for leak detection in etching chambers
US5522957A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 22, 1993 |
| Grant date | Jun 4, 1996 |
| Priority date | — |
| Expiry date | Dec 22, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S148/162
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for detecting the presence of gaseous impurities, notably oxygen, in a gas mixture that flows over an IC wafer in an etcher during the etching process. The method is based upon the discovery that the ratio of the etch rate of spin-on-glass material to the etch rate of other materials, such as plasma-enhanced chemical vapor deposition (PECVD oxide) materials, varies in a predictable manner with the amount of oxygen contaminating the gas mixture. The standard ratio, in the absence of oxygen, is determined for a given set of processing conditions by first etching an SOG wafer, then etching a PECVD oxide material wafer, measuring the amount of material etched in each case, and from that calculating the respective etch rates, and finally taking the ratio of the two calculated etch rates. This standard ratio is used as the benchmark for future tests. When a production run is to be conducted on a new material, the above procedure is repeated when the equipment is otherwise ready for the run, and the new calculated etch rate ratio is compared with the standard ratio. If they are substantially equal, this indicates a lack of oxygen contamination. If the ratio has chan…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.