Hot electrom degradation effects in 0.14 μm AlInAs//GaInAs/InP HEMTs

摘要

We report on hot electron stress emasurements on 0.14μm MOCVD grown AlInAs/GaInas/InP HEMTs. The stress measurements increase the drain-source current and hence induce a temporary negative shift in the threshold voltage in unpassivated HEMTs A permanent negative shift in the threshold voltage has been obtained in passivated HEMTs. The observed degradation (temporary/permanent) is due to the storage of positive charges (created by the impact ionization in the channel) in the Schottky AlInAs layer (temporary) or at the interface of semiconductor-passivation layer (permanent). For a given drain-source bias, a shift in the threshold voltage is larger in the gate-source bias region where the device has a mzximum transconductance value.