RF Performance of Ultra-wide Bandgap HEMTs

Abstract

In the current scenario of high-speed electronics technology, many application areas—broadband Internet access, fifth-generation (4G/5G) mobile systems, and cutting-edge military applications—are realizing very-fast to reality. To cater these ever-increasing demands, radio-frequency (RF) and microwave power amplifiers are in prime-attention, and will be constantly evaluated on price versus performance metrics. Ultra-wide bandgap (UWBG) high electron mobility transistors (HEMTs) are promising candidates for switching power applications owing to very-high breakdown strength of the material. And higher values of energy band gap (Eg) and electron mobility enabled low on-resistance (RON) guarantees superior power handling capability. UWBG HEMTs having two-dimensional electron gas (2DEG) channel with high carrier concentration and high electron mobility are fast gaining space in high frequency and power switching applications. Also, these UWBG materials having large optical phonon energy, Eop ~92 meV (GaN), ~45 meV (β-Ga2O3) make them most suitable semiconductor materials for the imminent terahertz (THz, 1012 Hz) frequency applications: THz imaging and spectroscopy. In this paper, we present latest technological developments of the gallium nitride (GaN)- and beta-phase of gallium oxide (β-Ga2O3)-based HEMTs, with careful and quantitative investigation of their suitability toward radio frequency (RF), high power device applications, and THz emerging applications.