A New Highly-Conductive (AlGa)As/GaAs/(AlGa)As Selectively-Doped Double-Heterojunction Field-Effect Transistor (SD-DH-FET)

Abstract

A new type of field-effect transistor (SD-DH-FET) has been successfully fabricated in which very-high-density electrons (∼1.27×10 12 /cm 2 ) are supplied from a selectively-doped (AlGa)As/GaAs/(AlGa)As double-heterojunction structure grown by molecular beam epitaxy. The structure showed an extremely high sheet conductivity of 24 mS/□ at 77 K with a Hall mobility of 119,000 cm 2 /Vs. A depletion-mode FET with this structure showed high channel mobility of more than 35,000 cm 2 /Vs at 77 K, suggesting that SD-DH-FETs have potential for applications to extremely high-speed microwave devices and integrated circuits.