Compound semiconductor field effect transistor having a controlled diffusion profile of impurity elements

摘要

A field effect transistor includes a substrate of a compound semiconductor material, source and drain regions formed in the substrate, a channel region defined between the source and said drain regions, a gate electrode provided on the substrate so as to cover the channel region, and a pair of diffusion suppressing regions provided in the substrate respectively at both lateral ends of the channel region, each of the diffusion suppressing regions containing an electrically inert element that suppresses a diffusion of a dopant element therethrough.