| 摘要 |
PURPOSE:To accurately and readily control to etch, to improve the reliability of an element and to improve the yield by utilizing a silicon nitride film and a silicon oxide nitride film grown at a low temperature by a plasma CVD method as a diffused protective film. CONSTITUTION:A silicon nitride film 2 of 300-500Angstrom is grown by a plasma CVD method with monosilane and ammonia on a GaAsP layer 1b laminated on a GaAs layer 1a of a substrate 1, a silicon oxide nitride film 3 of 1,000-2,000Angstrom is then grown by a plasma CVD method with monosilane, ammonia and laughing gas, a resist pattern 4 is formed to expose a portion 3a. With the pattern 4 as a mask it is etched by dry etching method to form a selectively diffusing diffusion window 6 and a diffused protective film 5, and the pattern 4 is removed. |
