Dislocations as the origin of threshold voltage scatterings for GaAs MESFET on LEC-grown semi-insulating GaAs substrate

Abstract

This paper describes the extended results on the influence of dislocations in liquid-encapsulated Czochralski (LEC) grown semi-insulating GaAs substrates on threshold voltage of GaAs MESFET's. MESFET's located less than about 50 µm from a dislocation exhibit threshold voltage lower than those far from a dislocation and threshold voltage scatters at less than about 30 µm from a dislocation. The scattering is considered briefly from anisotropy of stress field around dislocations. Particular interest is devoted to the electrical properties around dislocations because of their detrimental influence on the FET threshold voltage.