Method and apparatus for evaluating surface and subsurface and subsurface features in a semiconductor
US5042952A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 9, 1990 |
| Grant date | Aug 27, 1991 |
| Priority date | — |
| Expiry date | Jul 9, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/2656
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus are disclosed for evaluating surface and subsurface features in a semiconductor sample. In operation, a periodic energy source is applied to the surface of the semiconductor sample to generate a periodic electron-hole plasma. This plasma interacts with features in the sample as it diffuses. The plasma affects the index of refraction of the sample and the changing plasma density is monitored using a radiation probe. In the preferred embodiment, the radiation probe measures the plasma induced periodic changes of reflectivity of the surface of the sample to yield information about the sample, such as ion dopant concentrations, residue deposits and defects.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.