Non-contact optical techniques for measuring surface conditions
US5490728A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 12, 1994 |
| Grant date | Feb 13, 1996 |
| Priority date | — |
| Expiry date | Jan 12, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/4742
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Thermal, optical, physical and chemical characteristics of a substrate (11) surface are determined with non-contact optical techniques that include illuminating (23) the surface with radiation having a ripple intensity characteristic (51), and then measuring the combined intensities (53) of that radiation after modification by the substrate surface and radiation emitted from the surface. Precise determinations of emissivity, reflectivity, temperature, changing surface composition, the existence of any layer formed on the surface and its thickness are all possible from this measurement. They may be made in situ and substantially in real time, thus allowing the measurement to control (39, 41) various processes of treating a substrate surface. This has significant applicability to semiconductor wafer processing and metal processing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.