Selective Removal of SiOxNy Semitransparent Film over SiO2 Film in the Heat Retaining Enhanced Crystallization Method for Fabrication of TFTs

摘要

A selective removal process of semitransparent SiOxNy film on SiO2 buffer film was developed for heat retaining layer enhanced crystallization (HREC). The ratio of the etching rate between SiOxNy film and SiO2 film was 7.5:1. After excimer laser annealing and selective removal of SiOxNy film, the SiO2 film showed improved breakdown voltage and the fixed oxide charge when compared to that without ELA. The surface of SiO2 buffer film on crystallized Si film after SiOxNy removal was shown to be flat from SEM measurement.