Operation of spatial light modulators in DUV light

The Fraunhofer Institute for Microelectronic Circuits and Systems (FhG-IMS) has developed spatial light modulators (SLM), which are used in a pattern generator for DUV laser mask writing developed by Micronic Laser Systems. They consist of micromirror arrays and allow massive parallel writing in UV mask writers. The chip discussed here consists of 2048 × 512 individually addressable mirrors and can be run at a frame rate of 1 to 2 kHz. For this application it is necessary that the SLMs can be operated under DUV light without changing their performance. This paper discusses a failure mechanism of the SLMs when operated in DUV light and countermeasures to eliminate this effect.