Method and aparatus for determining surface profiles
US4748335A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 3, 1985 |
| Grant date | May 31, 1988 |
| Priority date | — |
| Expiry date | Jul 3, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2201/103
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system for determining surface profiles of specimens such as semiconductor wafers includes a drive for mounting the wafer for oscillatory movement along a line and an optical imaging system overlying the wafer for focusing a beam on a small sport on the wafer and including a photodetector for detecting the reflected sport from the wafer. The spot is scanned along the line on the wafer while the focal depth of the imaging system is progressively changed while the photodetector and connected digital circuitry generate a plurality of spaced output signals for each scan along the line so that data comprised of a series of spaced signals are provided at a plurality of focus levels extending through the surface profile of the wafer. Computer means are provided for analyzing the data and providing a graphical output of the surface profile.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.