Method and apparatus for contactless real-time in-situ monitoring of a chemical etching process
US5456788A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 31, 1995 |
| Grant date | Oct 10, 1995 |
| Priority date | — |
| Expiry date | Mar 31, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/32135
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A contactless method and apparatus for in-situ chemical etch monitoring of an etching process during etching of a workpiece with a wet chemical etchant are disclosed. The method comprises steps of providing a base member having a reference surface; releasably securing the workpiece to the base member; providing at least two sensors disposed on the base member to be proximate to but not in contact with the outer perimeter of the workpiece surface; and monitoring an electrical characteristic between said at least two sensors, wherein a prescribed change in the electrical characteristic is indicative of a prescribed condition of the etching process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.