Calibration apparatus for capacitance height gauges
US4539835A · kind A · utility
11Cited by
4References
11Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 14, 1984 |
| Grant date | Sep 10, 1985 |
| Priority date | — |
| Expiry date | Mar 14, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J37/304
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In an electron beam lithography apparatus a capacitance height gauge is used to determine the distance between a reticule and electron optics. In order to calibrate the capacitance gauge an optical interferometer, including a mirror are mounted on the same axis as the capacitance gauge. The mirror is moved a predetermined distance so that the movement distance measured by the capacitance gauge and the interferometer can be compared.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.