| 摘要 |
The present invention relates to a plasma etching method capable of forming a taper-shaped recessed portion in a wide gap semiconductor substrate. In the plasma etching method, first, a mask (M) having an opening is formed on the surface of a wide gap semiconductor substrate (K). Then, the wide gap semiconductor substrate (K) having the mask (M) formed thereon is placed on a base, the wide gap semiconductor substrate (K) is heated at 200°C or more, and etching gas and protective film forming gas supplied into a process chamber are converted into plasma while a bias potential is applied to the base. Thereby the etching of the wide gap semiconductor substrate (K) with the etching gas converted into a plasma is performed in parallel with the forming of a protective film with the protective film forming gas converted into a plasma. Thus, the taper-shaped recessed portion is formed in the silicon carbide substrate (K) by driving the etching of the silicon carbide substrate (K) while protecting the same with the protective film. |
