Review of compound semiconductor devices for RF power applications

Abstract

The progress of RF power devices based on compound semiconductor materials are reviewed. Two major application of those devices are the handy terminals and the base stations. The highest poweradded-efficiency is the major concern for the mobile terminals, while the latter one requires the high power transmitting capability with sufficient linearity. Compound semiconductor devices are suited for those applications. The present paper reviews the recent developments of those RF power devices.

Reconfigurable Physical Reservoir in GaN/α-In2Se3 HEMTs Enabled by Out-of-Plane Local Polarization of Ferroelectric 2D Layer

“…Gallium nitride (GaN) high-electron-mobility transistors (HEMTs) are attractive for high-frequency applications owing to their high electron mobility (>2000 cm 2 /(V s)). − Recently, ferroelectric-based GaN metal–oxide–semiconductor (MOS) HEMTs using HZO, PZT, and HfO 2 dielectrics have been proposed to reduce the device dimensions and achieve lower power consumption via a negative capacitance effect. − However, it has been still challenging for ferroelectric-GaN MOS-HEMTs to achieve ideal performance of a large hysteresis (Δ V ) and low subthreshold slope ( SS ) owing to the depolarization effect caused by the interface charge trapping and polarization of the AlGaN barrier layer. − To maximize the Δ V and steep SS , the integration of a ferroelectric material with strong ferroelectric polarization and without dangling bonds is ideal for ferroelectric-GaN MOS-HEMTs. Therefore, in this study, we employed a highly crystalline two-dimensional (2D) ferroelectric material, α-In 2 Se 3 , as a ferroelectric gate heterostructure in GaN MOS-HEMTs because it is free from the charge-trapping effect in dangling bonds and has a high carrier concentration.…”

Reduction in the Interfacial Trap Density of Al2O3/GaAs Gate Stack by Adopting High Pressure Oxidation

“…On the other hand, the commercialization of GaAs MOSFETs is still limited because of the high density of interfacial states (D it ) between the channel and gate dielectric layer, whereas RF electronics and optoelectronics products are available based on the GaAs semiconductor. 2,3 In the case of Si MOSFETs, the thermal SiO 2 film has excellent interfacial properties and thermal stability with respect to the silicon substrate, which allows a low D it and low subthreshold gate swing of the resulting FETs. On the other hand, the high quality gate dielectric, such as Al 2 O 3 , have been grown directly on the GaAs substrate by atomic layer deposition (ALD) or molecular beam epitaxy (MBE) because the high D it distribution of the thermal oxide (Ga 2 O 3 )/GaAs substrate is unacceptable for MOS-FET applications.…”