Hetero junction field effect transistor device

Abstract

Abstract A high-mobility semiconductor device having a GaAs/AlGaAs hetero junction comprises a GaAs active layer (5) 10-300 nm thick and a GaAs contact layer (9), 50-300 nm thick with a high-carrier concentration AlGaAs barrier layer (7) 5-30 nm thick interposed therebetween. These layers are formed by epitaxial growth on a semi-insulating GaAs substrate (1) bearing an AlGaAs buffer layer (3), at least 500 nm thick. On the contact layer are attached a source electrode and a drain electrode; a gate electrode is formed in the contact layer by selective etching. The effective carrier concentration of the active layer is increased by the barrier layer and the thick­ness of the active layer is reduced, resulting in an increase in the trans-conductance and improvement in the high frequency characteristics. Since the presence of the barrier layer enables selecting etching of the contact layer, element characteristics such as the plane uniformity and reproducibility can be improved.

Inventors

• 👤 Hideki Mitsubishi Monsanto Chem. Comp. Goto
• 👤 Masanori Mitsubishi Monsanto Chem. Comp. Kato
• 👤 Tatsuhiko Mitsubishi Monsanto Chem. Comp Kawakami

Bibliographic Details