Improvement in GaAs MESFET performance due to piezoelectric effect

Abstract

This paper describes the possibility of improving the performance of GaAs MESFET's by using piezoelectric effects. It is shown that piezoelectric charges, induced in the FET channel region due to the stressed dielectric overlayer, can be used to compensate for the deep tail of carrier distribution in the channel region. As a result, transconductance of short-channel GaAs FET's can be improved with a smaller shift in threshold voltage. The experimental results obtained for WSi <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> - gate self-aligned MESFET's are qualitatively in good agreement with the theoretical values.