Use of a rapid anneal to improve CaF2:Si (100) epitaxy

Post‐anneals of short duration at high temperature are shown to improve significantly the quality of CaF2 films on Si (100). An anneal at 1100 °C for 20 s in an Ar ambient reduced χmin, the ratio of backscattered 1.8‐MeV 4He+ ions in the aligned to random direction, from 0.26 for an as‐grown CaF2 film to 0.03 following the post‐anneal. This is the best χmin yet reported for the CaF2:Si (100) system. The post‐anneal films also show improved chemical, mechanical, and electrical properties.