Contactless real-time in-situ monitoring of a chemical etching process
US5338390A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 4, 1992 |
| Grant date | Aug 16, 1994 |
| Priority date | — |
| Expiry date | Dec 4, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A contactless method and apparatus for real-time in-situ monitoring of a chemical etching process for the etching of at least one wafer in a wet chemical etchant bath are disclosed. The method comprises the steps of providing at least two conductive electrodes in the wet chemical bath, said at least two electrodes being proximate to but not in contact with the at least one wafer; and monitoring an electrical characteristic between the at least two electrodes, wherein a prescribed change in the electrical characteristic is indicative of a prescribed condition of the etching process. Such a method and apparatus are particularly useful in a wet chemical etch station.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.