System for non-destructive measurement of samples
US6268916A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 11, 1999 |
| Grant date | Jul 31, 2001 |
| Priority date | — |
| Expiry date | May 11, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J4/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The surface of a doped semiconductor wafer is heated locally by means of a pump beam whose intensity is modulated at a first frequency. The heated area is sampled by a probe beam whose intensity is modulated at a second frequency. After the probe beam has been modulated (reflected or transmitted) at the first frequency by the wafer, the modulated probe beam is detected at a frequency equal to the difference between the harmonics of the first and second frequencies to determine dose of the dopants in the wafer. Such or similar type of instrument for measuring dose may be combined with an ellipsometer, reflectometer or polarimeter for measuring dose as well as thickness(es) and/or indices of refraction in a combined instrument for measuring the same sample.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.