| 摘要 |
PROBLEM TO BE SOLVED: To avoid abnormal lateral diffusion and form second conductivity type semiconductor regions at a high density on a first conductivity type semiconductor layer. SOLUTION: The manufacturing method comprises forming an Al2 O3 film 2 (diffusion mask film) on a semiconductor substrate having an n-type AlGaAs layer 1a epitaxially grown on a semi-insulative GaAs substrate 1b, forming diffusion openings 2a in the Al2 O3 film 2, forming a ZnO-SiO2 diffusion source film 3 thereon, forming an AlN anneal cap film 4 thereon, and annealing the substrate to diffuse Zn into the AlGaAs layer 1a through the openings 2a from the AlN film to form p-type semiconductor regions 5. The Al2 O3 film 2 has a good adhesion to the AlGaAs layer 1a and nearly the same thermal expansion coefficient as that of the AlGaAs layer 1a, thereby avoiding a poor adhesion at annealing and abnormal lateral diffusion due to stress. |
