Patent ID: 7615452

Claim:
A method of fabricating a normally-off field-effect semiconductor device utilizing a two-dimensional carrier gas layer created by a heterojunction between layers of dissimilar semiconducting materials as a channel, comprising the steps of: (a) covering part of a major surface of a substrate with an antigrowth mask; (b) epitaxially growing a first semiconducting material on the masked major surface of the substrate until there is created a first semiconductor layer which comprises a first and a second flat-surfaced section and a slant-surfaced section therebetween, at least the slant-surfaced section of the first semiconductor layer being formed on the antigrowth mask by lateral overgrowth of the first semiconducting material; (c) epitaxially growing a second semiconducting material on the first semiconductor layer thereby creating a second semiconductor layer having a first and a second flat-surfaced section and a slant-surfaced section which are formed respectively on the first and the second flat-surfaced section and the slant-surfaced section of the first semiconductor layer; (d) creating a first major electrode which is electrically coupled to a two-dimensional carrier gas layer due to a heterojunction between the first flat-surfaced sections of the first and the second semiconductor layer; (e) creating a second major electrode which is electrically coupled to the two-dimensional carrier gas layer due to a heterojunction between the second flat-surfaced sections of the first and the second semiconductor layer; and (f) creating gating means on the slant-surfaced section of the second semiconductor layer for control of conduction between the first and the second major electrode.