A Distributed Bulk-Oxide Trap Model for $\hbox{Al}_{2} \hbox{O}_{3}$ InGaAs MOS Devices

This paper presents a distributed circuit model for bulk-oxide traps based on tunneling between the semiconductor surface and trap states in the gate dielectric film. The model is analytically solved at dc. It is shown that the distributed bulk-oxide trap model correctly depicts the frequency dispersion in the capacitance- and conductance-voltage data of Al
₂
O
₃
-InGaAs MOS devices that do not fit the conventional interface state model. The slope degradation or stretch-out of the measured capacitance-voltage curve near flatband can be also explained by the distributed bulk-oxide trap model.