Excimer-Laser Removal of SiO2 Patterns from GaAs Substrates

Abstract

SiO₂ patterns on GaAs substrates can be completely removed by KrF excimer-laser irradiation in air. The substrate surface is found to be dean, without residual SiO₂ patterns or other contaminants. Free-standing SiO₂ microstripes can be formed by this method. This technique provides an efficient dry process to remove SiO₂ patterns on GaAs substrates, instead of the wet etching process. The mechanisms to peel off the SiO₂ patterns from the GaAs substrate are considered to involve direct momentum transfer, photodecomposition of the interface substance, and thermal expansion of the substrate.