CMP variable angle in situ sensor
US5838448A · kind A · utility
38Cited by
16References
26Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 11, 1997 |
| Grant date | Nov 17, 1998 |
| Priority date | — |
| Expiry date | Mar 11, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/0683
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A chemical-mechanical polishing (CMP) optical process monitor apparatus allows in situ measurement of the thickness of a thin film being polished. As the incidence angle of the incident light on the wafer being polished is changed, the reflected intensity of the light from the thin film on the wafer undergoes a variation in local maxima and minima. The angle at which the light intensity is a maximum or minimum determined by the thin film interference equation, thus providing a measurement of the thin film thickness and/or the change in the thin film thickness.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.