Measurement set-up for low-frequency noise characterization of GaN HEMT transistors

Gallium Nitride (GaN) based High Electron Mobility Transistors (HEMTs) have an excellent potential for high temperature and high-frequency electronics because of the wide energy band gap and high peak and saturation velocities. The level of low-frequency noise is one of the important parameters determining the device potential for microwave and switching applications. In this paper we report on an experimental set-up for measurement and investigations of low-frequency (LF) noise in advanced electronic devices such as GaN HEMTs. The set-up allows realization of the low-frequency noise measurements under optical and/or thermal excitation in the UV/VIS region and temperature range from 25 to 300 °C. Functionality of the set-up is demonstrated by measurement of low-frequency drain noise spectral density of HEMT transistor under conventional dark conditions and UV illumination. Spectral decomposition has been used for identification of noise sources in HEMT transistor and influence of the UV illumination to low-frequency noise sources has been investigated.