Wafer sensing apparatus for sensing wafer insertion
US5892240A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 20, 1996 |
| Grant date | Apr 6, 1999 |
| Priority date | — |
| Expiry date | Dec 20, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S414/137
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A wafer sensing apparatus for sensing whether a wafer is inserted in a wafer cassette. The wafer sensing apparatus includes a light emitting device for emitting light of a predetermined wavelength toward the inside of a wafer cassette, a light sensing device, positioned opposite to the light emitting device, for sensing the emitted light, and an optical filter device for passing light corresponding only to the predetermined wavelength of light emitted from the light emitting device. The light sensing device is not affected by interference light from outside sources that can cause a faulty wafer sensing function, since the interfering light is reflected or absorbed by the optical filter device. Equipment malfunctions caused by faulty sensing from the light sensing device are prevented, thereby improving the equipment operating efficiency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.