Apparatus for controlling output of an excimer laser device
US5463650A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 28, 1994 |
| Grant date | Oct 31, 1995 |
| Priority date | — |
| Expiry date | Dec 28, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S3/225
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An apparatus used for elimination of the influence of spiking in an excimer laser device. The values of predetermined parameters which contribute to the spiking such as oscillation suspension time in a successive pulse oscillation are obtained. Discharge voltage for each of the successive laser beam pulses is changed on the basis of the obtained parameter values such that subsequent successive laser beam pulses have the same energy. The discharge voltage is stored according to time elapsed after the start of the successive pulse oscillation, and discharge voltage is controlled such that stored discharge voltage corresponds to the measured elapsed time. During the time when a stepper is not performing processing using the laser beam, the laser beam pulse is oscillated under predetermined conditions and the energy of the resulting pulses is detected. The stored discharge voltage is corrected on the basis of the detected magnitude of the pulse energy, a desired magnitude of the pulse energy and the predetermined conditions. The discharge voltage is controlled such that the corrected discharge voltage is obtained during the time when the stepper performs the processing using the laser …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.