EFFECT OF PRESSURE ON THE OUTPUT CHARACTERISTICS OF P-GAAS ALGAAS HETEROJUNCTION FIELD-EFFECT TRANSISTOR/

We report current-voltage measurements on p-channel GaAs/AlGaAs hetero junction field effect transistor as a function of pressure up to 1.3 G Pa at room temperature. Under high pressure conditions, the main effec t observed is an increase in the saturated current (I-dss). This incre ase in I-dss is associated with a change in the threshold voltage (V-t ), and carrier mobility in the two dimensional hole gas at the interfa ce. The shift in V-t with pressure can be interpreted in terms of the increase in the Valence band offset due to the relative change in the bandgap of the materials. Through model fits to the device characteris tics at various pressures, the pressure dependence of mobility was ext racted.