Inversion layer transport and properties of oxides on InAs

Inversion layer transport in p-type InAs at 77 K using Van der Pauw samples has been investigated with anodic oxides and sputtered SiO2 as the gate insulators. It has been found that there is a correlation between the surface transport measurements, the fixed charge in the oxide, and possibly the insulating properties of the oxide. An attempt is made to develop a model to interrelate these measurements. It is found that fixed oxide charge appears to be the dominant mechanism in limiting the mobility at low surface carrier concentrations, while at higher concentrations surface roughness is the dominant mechanism.