Correlation between channel mobility improvements and negative Vth shifts in III–V MISFETs: Dipole fluctuation as new scattering mechanism

摘要

Channel mobility µeff for InGaAs MISFETs is improved by using the (111)A surface orientation and (NH4)2S treatment. These µeff improvements are associated with negative shifts in Vth and Vfb. We propose that carrier scattering by fluctuated dipoles at the MIS interfaces contributes to µeff for the III–V MISFETs. For the InP MISFETs, the effects of the interface dipoles are not apparent due to their inferior interface quality.