Substrate Bias Effect on Ion-Implanted GaAs MESFETs

Abstract

Decrease in drain current caused by negative bias on the substrate (substrate bias effect) is observed in MESFETs fabricated from ion-implanted GaAs. Illumination of IR light enhances the effect in a similar manner to VPE GaAs. From photoconductivity measurement on the FIT, the substrate bias effect is found to be dominated by the same deep levels as those located in the semi-insulating GaAs substrate.