A state-of-art review on gallium oxide field-effect transistors

Abstract

As a promising ultra-wide bandgap (UWBG) semiconductor, gallium oxide (Ga2O3) has recently aroused increasing attention in the area for high-power electronics, power switch for radio frequency (RF) operation, and solar blind UV detectors. The β-phase of Ga2O3 is deemed as a potential candidate for next generation high-power electronics due to its high theoretical breakdown electric field (8 MV cm−1), UWBG (4.8 eV), and large Baliga’s figure of merit. Owing to the intensive research efforts across the world since 2013, gallium oxide transistors recently make rapid advances in device design and performance. Until now, high quality large-size bulk Ga2O3 and n-type epi products are successively coming onto the market, as well as there are gratifying progress worldwide to develop more complex epi structures, including β-(Al x Ga1−x )2O3/Ga2O3, β-(In x Ga1−x )2O3/Ga2O3, n-Ga2O3/p-NiO, β-Ga2O3/4H-SiC heterostructures et al. In this paper, the basic physical properties of Ga2O3, and the recent research process of Ga2O3 based transistors field-effect transistor (FET) for high-power electronics and RF are introduced. Furthermore, various state-of-the-art structures and process used in Ga2O3 based FETs have been summarized and compared, including planar/vertical metal-oxide-semiconductor field-effect transistor (MOSFET), trench MOSFET, FinFET, modulation-doped FET or called it high electron mobility transistors with two-dimensional electron gas channel, SOI MOSFET, thus the potential of Ga2O3 FETs is preliminary revealed. Finally, the prospect of the Ga2O3 based FET for high-power and RF application will be also analyzed.

A Review of β-Ga2O3 Power Diodes

“…Calculations suggest the absence of shallow acceptors in Ga 2 O 3 , and holes exhibit self-trapping effects within the material [31,32]. Consequently, current research is primarily focused on unipolar Ga 2 O 3 power electronic devices, including field-effect transistors (FETs) and Schottky barrier diodes (SBDs) [33][34][35]. Compared to traditional p-n junction diodes, SBDs exhibit lower turn-on voltages and faster recovery times, making them commonly employed in low-power and high-speed switching applications.…”

Indium doping-assisted monolayer Ga2O3 exfoliation for performance-enhanced MOSFETs

“…Recently, 2D Ga 2 O 3 with a wide bandgap (4.69-6.42 eV) and extraordinary properties 2,3 have shown superior device performance over the bulk counterpart β-Ga 2 O 3 for applications of photodetectors, [4][5][6][7] gas sensors, 8,9 and field-effect transistors (FET). [10][11][12][13][14] Subsequent theoretical studies predict that the electron mobility of ML Ga 2 O 3 is as high as 2684 cm 2 V −1 s −1 , which can be further tuned up to ∼10 4 cm 2 V −1 s −1 by the layer thickness and surface passivation, 15,16 and high stability is maintained in the ambient atmosphere. In addition, defect-free oxygen vacancy and valid p-type doping ML Ga 2 O 3 is expected to achieve through valence band modification, which breaks the obstruction of bulk β-Ga 2 O 3 caused by the serious self-compensating effect; 17,18 hence, the development of complementary logic applications based on ML Ga 2 O 3 is expected to be realized.…”

Progress in Gallium Oxide Field-Effect Transistors for High-Power and RF Applications

“…Previous review articles on β-Ga 2 O 3 FETs have reported the chronological development in device design and performance [10], or focused specifically on RF FETs [7], E-mode FETs [11], or vertical GaN and β-Ga 2 O 3 FETs [9]. Other review papers have covered FETs designed for both high-power and RF applications [12,13]. This review is formatted to aid current and future β-Ga 2 O 3 high-power and RF FET researchers by separately discussing the different steps of FET fabrication, ranging from structures, materials, ohmic contacts, gate dielectrics, and material preparation.…”