HEMT structure with passivated structure

Abstract

Abstract A channel layer (44), a donor layer (48), Schottky layer (50, 54), and cap layer (56) are formed on a substrate (42). A source (60) and drain (62) are formed on the cap layer (56). A gate (64) is formed on the cap layer (56), or at the bottom of a recess (58) which is formed through the cap layer (56) and partially extends into the Schottky layer (54). The donor (48) and Schottky (50, 54) layers are formed of a semiconductive material which includes an oxidizable component such as aluminum. A passivation or stop layer (52) of a lattice-matched, non-oxidizable material is formed underlying the source (60), drain (62), and gate (64), and sealingly overlying the donor layer (48). The stop layer (52) may be formed between the Schottky layer (54) and the donor layer (48), or constitute a superlattice in combination with the Schottky layer consisting of alternating stop and Schottky sublayers. Alternatively, the stop layer (52) may sealingly overlie the Schottky layer (50), and further constitute the cap layer.

Inventors

• 👤 Loi D. Nguyen
• 👤 Michael J. Delaney
• 👤 Lawrence E. Larson
• 👤 Umesh K. Mishra

Bibliographic Details