| 摘要 |
PURPOSE:To obtain the gate insulating FET of compound semiconductor which can be stably operated by a method wherein bias voltage is applied to a P type GaSa layer which is an active layer. CONSTITUTION:A compound semiconductor layer, having the same conductive type as the compound semiconductor substrate and a fixed voltage will be applied, is formed between the compound semiconductor substrate and a gate insulating field-effect transistor. To be more precise, 1 as shown in the diagram is a semi-insulating GaAs substrate, 2 is an N type GaAs layer, 3 is another N type GaAs layer, 4 is a P type layer, 5 is an insulating film, 6 is a metal, and 7 is a P type GaAs layer having the density higher than that of the P type GaAs layer 4. The high density P type GaAs layer 7 is connected to a substrate bias power supply VB. The bias voltage value of the substrate is to be properly set in accordance with the device characteristics. |
