Manufacture of recrystallized silicon substrate

Abstract

Abstract PURPOSE:To form an SOI substrate with a flat surface, and to shape an excellent semiconductor device by forming an amorphous silicon layer onto a polysilicon layer, to which layers are shaped, forming a cap film composed of an silicon dioxide layer and an silicon nitride layer onto the amorphous silicon layer and changing the polysilicon layer and the amorphous silicon layer into a single crystal through laser scanning. CONSTITUTION:An SiO2 layer 2 is formed onto an Si substrate 1 through thermal oxidation, and a poly Si layer 3 is shaped through a decompression CVD method, and an amorphous Si layer 8 is formed further through the decompression CVD. The Si substrate is thermally treated, a flat SiO2 layer 4 is shaped, and an Si3N4 layer 5 is formed through a plasma CVD method. The poly Si layer 3 and the amorphous Si layer 8 are melted and recrystallized through scanning while partially superposition-applying a laser, thus forming a single crystal layer 9. The Si3N4 layer 5 is removed by using hot phosphoric acid, and the SiO2 layer 4 is gotten rid of by a hydrofluoric acid group treating liquid, thus acquiring the recrystallized Si substrate flat in microscopic inspection.

Inventors

• 👤 Yoshihiro Boku

Bibliographic Details