Contactless Measurement of Electron Mobility in Ferroelectric Gate High-Electron-Mobility Transistor Structures

We have evaluated the electron mobility in BaMgF 4 /AlGaAs/GaAs(100) high-electron-mobility transistor (HEMT) structures using a contactless mobility measurement system. It has been found that the HEMT structure can be prevented from deteriorating when the BaMgF 4 layer is properly deposited, and that dependence of the electron mobility on the N-AlGaAs layer thickness is explained using a simple parallel conduction theory. It has also been found that the electron mobility in the structures is decreased from 6300 cm 2 /(V·s) to 3300 c m 2 /( V · s ) at room temperature as the r m B a M g F 4 growth temperature is increased from 550° C to 650° C.