Method and device for inspecting micromask patterns
US4465350A · kind A · utility
Inventor
Key dates
| Filing date | Dec 8, 1981 |
| Grant date | Aug 14, 1984 |
| Priority date | — |
| Expiry date | Dec 8, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/84
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Inspection of micromask patterns occurs by both moving an inspecting laser beam relative to a micromask and varying the intensity of said beam in the same manner that occurs during pattern generation. The pattern modulates the inspecting laser beam by one of reflecting or transmitting a modulated laser beam therefrom. The modulated beam then is sensed and used to produce a modulation signal. The modulated signal is compared to a control signal, which controls both the relative movement between a writing laser beam and the micromask and varies the beam intensity during pattern generation. Agreement between the modulation and control signals indicates correct pattern generation and a difference therebetween indicates a pattern inaccuracy.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.