| 摘要 |
PURPOSE:To enable to finish the diffusion process by one time, and to prevent the penetration of electrodes through the diffusion layer of an InP/InGaAsP photodetector by a method wherein an InGaAs layer is used as a selective mask to form a P-N junction by selective diffusion, and metal electrodes are provided thereon. CONSTITUTION:An SiO2 film 7 is formed on multilayers made to grow epitaxially on a substrate, and patterning is performed to provide a diffusion layer 8. Diffusion of Cd is performed making the SiO2 film 7 and the InGaAs layer 6 as the mask for selective diffusion to form a convex P<+> type InP diffusion layer 10 and the P<+> type shallow diffusion layer 10''. Then etching off is performed reserving only the 3 elements layers 6' at the electrode parts. Accordingly the diffusion process can be finished by one time, and thrust through of the P<+> type diffusion layer 10'' is not generated when alloying of electrodes is to be performed. |
