Drain current drift by holes trapped in Schottky contact in WSi gate GaAs MESFETs

Hysteretic drain current (Id) drift phenomena observed in the high power operation of WSi gate GaAs MESFETs were studied. The existence of a thin insulating layer at WSi-GaAs interface originated by the native oxide on GaAs surface was revealed by XPS and X-ray reflection. Id drift phenomena can be explained as the effect of holes being trapped in the insulating layer at the WSi-GaAs Schottky contact interface.