Capacitance height gage applied in reticle position detection system for electron beam lithography apparatus
US4538069A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 28, 1983 |
| Grant date | Aug 27, 1985 |
| Priority date | — |
| Expiry date | Oct 28, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J37/304
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method of calibrating a capacitance height gage for an electron beam lithography machine. The electron beam apparatus having the capacitance height gage to be calibrated is first mounted in a calibration fixture wherein the distance between the gage and a calibration reticle is adjusted using a laser interferometer. The electron beam is directed to a center high backscatter point, and then deflected to a predetermined high backscatter point. The capacitance gage readings and deflection voltages are measured to define a calibration plane. The electron beam apparatus is then repositioned to the lithography station having a reticle positioned below the electron beam. The distance to the reticle is measured with the capacitance gage, and the deflection of the electron beam during lithography operations is adjusted according to the variation of the reticle plane from the calibration plane.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.