System and method for measuring germanium concentration for manufacturing control of BiCMOS films
US7508531B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 4, 2007 |
| Grant date | Mar 24, 2009 |
| Priority date | — |
| Expiry date | Oct 4, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/213
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system and method is disclosed for measuring a germanium concentration in a semiconductor wafer for manufacturing control of BiCMOS films. Germanium is deposited over a silicon substrate layer to form a silicon germanium film. Then a rapid thermal oxidation (RTO) procedure is performed to create a layer of thermal oxide over the silicon germanium film. The thickness of the layer of thermal oxide is measured in real time using an interferometer, an ellipsometer, or a spectroscopic ellipsometer. The measured thickness of the layer of thermal oxide is correlated to a germanium concentration of the silicon germanium film using an approximately linear correlation. The correlation enables a value of the germanium concentration in the silicon germanium film to be provided in real time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.