Field effect transistor

US5250822A · kind A · utility

Assignee

• Mitsubishi Electric Corporation · JP

Inventors

• Takuji Sonoda · Itami, JP
• Shinichi Sakamoto · Hitachinaka, JP
• Nobuyuki Kasai · Itami, JP

Key dates

• Filing date: Mar 25, 1992
• Grant date: Oct 5, 1993
• Expiry date: Mar 25, 2012

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D30/4732

Abstract

A field effect transistor includes a GaAs substrate on which an undoped GaAs layer is disposed. A doped electron supply layer is disposed on the undoped GaAs layer and has a negligible deep dopant level. A channel layer disposed on the electron supply layer has a larger electron affinity than the electron supply layer. The electron supply layer and the channel layer form a heterojunction. A third semiconductor layer having the same conductivity type as the electron supply layer is disposed on the electron supply layer. Gate, drain, and source electrodes are disposed on the third semiconductor layer. The dopant concentration of the third layer is smaller than the dopant concentration of the electron supply layer.