Diffusion mask and fabrication method for forming PN-junction elements in a compound semiconductor substrate

摘要

A pn-junction element is formed in a compound semiconductor substrate by depositing an aluminum-nitride film on the surface of the substrate, patterning the aluminum-nitride film to form a diffusion mask, depositing a diffusion source film on the diffusion mask, diffusing an impurity from the diffusion source film into the substrate, and removing the diffusion source film with buffered hydrofluoric acid. Electrode lines can then be formed directly on the aluminum-nitride diffusion mask, which is not etched by buffered hydrofluoric acid.