Study of Electrophysical Characteristics of pHEMT Heterostructures by the Methods of Impedance Spectroscopy

The methods of impedance spectroscopy of (Al, In, Ga)As-based pHEMT heterostructures are developed using an LCR meter in the frequency range 0.1-2000 kHz and a vector network analyzer at higher frequencies of 0.01-3 GHz. These methods determine all the main parameters of the pHEMT heterostructures, including the threshold voltage, the channel resistance, the sheet density of electrons, and their mobility at operating biases.