FORMING METHOD FOR SOI BOARD BY LASER RECRYSTALLIZATION METHOD

摘要

PURPOSE:To eliminate peeling of a recrystallized silicon film from a positioning mark and recrystallized silicon residue in the recess of the mark by removing part of a single crystalline film after a laser recrystallization is ended, exposing part of an insulating film, and forming the mark on the exposed part. CONSTITUTION:A polycrystalline silicon 3 is irradiated with a laser light 4, the entire substrate is scanned, melted, and recrystallized to form a single crystalline silicon film 6. The recrystallized (single crystalline) film 6 is selectively etched to expose the positioning mark forming region of an insulating film 2. Then, after a resist mask is removed, another resist mask 8 is formed. The mask 8 is provided on an insulating film region exposed with a pattern opening 9 corresponding to the positioning mark. With it as a mask, a recess of a positioning mark 1 is formed on the insulating film (SiO2 film) 2 by anisotropic RIE using CF4-H2 mixture gas as etching gas.