Apparatus for calibrating a surface scanner
US4512659A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 10, 1983 |
| Grant date | Apr 23, 1985 |
| Priority date | — |
| Expiry date | Aug 10, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/9501
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A test device for calibrating an optical scanner wherein microscopic patterns of light scattering elements simulate the scattering of light from particles or flaws of different sizes. Simulation of different particles sizes is achieved by means of clusters or arrays of these light scattering elements having different areawise densities. Patterns of such clusters or arrays are disposed on a surface with intervening spaces where a random assortment of foreign particles may be expected. In this manner, the foreign particles may be directly compared to a test pattern. The test surface may be a semiconductor wafer having a thin, inert coating with openings therein forming the light scattering elements. The openings may be made by photolithographic techniques, i.e., masking and etching, so that various patterns on a surface may be all created simultaneously by the same process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.