Etching method for silicon substrates and semiconductor sensor
US5949118A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 24, 1996 |
| Grant date | Sep 7, 1999 |
| Priority date | — |
| Expiry date | Apr 24, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/977
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An etching method for a silicon substrate, which can easily smooth the etching surface of the (110)-oriented silicon, is disclosed. A container is filled with KOH solution. In the KOH solution is immersed a (110)-oriented silicon wafer having a PN junction and is also disposed a platinum electrode plate to face the silicon wafer. To between a platinum electrode of the silicon wafer and the platinum electrode plate are connected a constant voltage power source, an ammeter and a contact in series. A controller starts etching from one surface on which the PN junction is formed, and terminates voltage application when the specified time lapses after the formation of an anodic oxide film is equilibrated with the etching of the anodic oxide film on the etching surface on the PN junction part. In this case, the controller detects flowing current through the ammeter, and the point of time when the equilibrium state is obtained is the point of inflection of the detected current to the constant current after the peak thereof.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.