Inverted Semiconductor Insulator Semiconductor Field Effect Transistor
Original Publication Date: 1988-Nov-01
Included in the Prior Art Database: 2005-Feb-15
A technique is described whereby an inverted semiconductor insulator semiconductor (ISIS) field-effect transistor (SISFET) with an inverted interface provides a high mobility channel on top of an AlGaAs barrier, so as to obtain improved ohmic contacts and self-alignment. The GaAs gate or SISFET high speed transistor devices typically have the carrier accumulation at a hetero-interface channel accomplished by the application of a positive voltage on an n-type GaAs gate separated from the channel by a thin AlGaAs barrier. The structure is usually grown by molecular beam epitaxy (MBE) and the AlGaAs is grown on top of an undoped GaAs layer, forming a "normal interface". This interface is usually smooth and the 2DEG (the accumulated carriers) have high mobilities.