不同源漏间距的AlN/GaN异质结场效应晶体管中极化库仑场散射的研究

Using the measured Capacitance-Voltage and Current-Voltage characteristics of the rectangular AlN/GaN Heterostructure Field-Effect Transistors (HFETs) with different distances between source and drain, we found that the polarization Coulomb field scattering has an important influence on the two-dimensional electron gas (2DEG) electron mobility. Moreover, comparing to the device in which the distance between source and drain is 100μm, the polarization Coulomb field scattering has an enhanced influence on the mobility of the device in which the distance source and drain was 20μm. This is attributed to the reinforced effect of the nonuniform stain distribution near the Ohmic contact region with the distance between Schottky contact area and Ohmic contact region decreasing, resulting in that the polarization Coulomb field scattering has stronger effect, which should be a significance problem we cannot neglect as the device scaling.