Recent Advances in GaN‐Based Power HEMT Devices

Abstract

The ever‐increasing power density and operation frequency in electrical power conversion systems require the development of power devices that can outperform conventional Si‐based devices. Gallium nitride (GaN) has been regarded as the candidate for next‐generation power devices to improve the conversion efficiency in high‐power electric systems. GaN‐based high electron mobility transistors (HEMTs) with normally‐off operation is an important device structure for different application scenarios. In this review, an overview of a series of effective approaches to improve the performance of GaN‐based power HEMT devices is given. Modified epistructures are presented to suppress defects and current leakage, and low‐damage recess‐free processes are discussed in fabricating normally‐off HEMTs. Possible effects of dielectrics on a metal–insulator–semiconductor (MIS) structure are also intensively introduced. Metal/semiconductor contact engineering is investigated, and fabrication of Au‐free ohmic contact and graphene insertion layer to enhance the device performance is emphasized. Finally, the effects of field plates are studied through the use of simulated and fabricated devices.

Lattice Location Studies of the Amphoteric Nature of Implanted Mg in GaN

“…Note that in Figure 2(c) the interstitial fractions measured at 500°C and 600°C start at similar values around ~9%. While at 500°C a drop to 4-5% is visible once more than ~5×106 events have accumulated on this beam spot, for 600°C no data is available for this number of events; however, it is clear from Figure5(c) that for prolonged implantations also 4-5% are reached at this temperature. Finally, at 800°C interstitial Mg reaches values that are a few per cent only or practically 0% [Figure2(c) and 5].…”

“…During the last decades, optoelectronic devices based on the wide band gap semiconductor gallium nitride have revolutionized solid state lighting. Currently a field of applications where GaN based devices are also entering everyday life and replacing Si on a massive scale, is related to power electronics, [1][2][3][4][5][6] with applications as voltage transformers or inverters, ranging from power distribution grids, electrical vehicles, photovoltaic inverters, to simple household items such as power supplies. [7] The vast majority of GaN-based devices require besides ntype also p-type doping, and it is well-known that the group-II element Mg is the only technologically feasible acceptor dopant in GaN.…”

Diamond as the heat spreader for the thermal dissipation of GaN-based electronic devices

“…Benefitted from the high breakdown voltages (10 times higher than Si), high switching speed (over GHz), compact size, and tunable electronic architecture [1][2][3][4][5][6][7], III-V nitride semiconductor is becoming one of the best candidates for high-power electronics to enable the increasing power density and high conversion efficiency. The commercialized AlGaN/GaN high electron mobility transistors (HEMTs) have led to the entry into the mediumpower market, and play a central role for the RF and millimeter-wave applications [8][9][10][11]. In the applications of 5 G communications, radar, and electronic warfare, the HEMTs devices can offer more than 10 times higher power density than the existing Si technologies [12].…”

Releasable AlGaN/GaN 2D Electron Gas Heterostructure Membranes for Flexible Wide‐Bandgap Electronics

“…

In recent years, AlGaN/GaN technology has shown its rapid development trend, opening a wide range of potential applications for consumer electronics, medical healthcare, and robotics. [9][10][11] However, due to the limitation of growth kinetics, AlGaN/ GaN heterostructures are grown on rigid substrates such as Si, SiC, and sapphire, causing significant difficulty in realizing flexible devices and circuits.Transfer-printing technology has offered a new strategy, of which AlGaN/ GaN heterojunction membranes can be released from the growth substrate and subsequently transferred onto arbitrary substrates. Various approaches have been used to fabricate flexible AlGaN/ GaN HEMTs.

…”

“…In recent years, AlGaN/GaN technology has shown its rapid development trend, opening a wide range of potential applications for consumer electronics, medical healthcare, and robotics. [9][10][11] However, due to the limitation of growth kinetics, AlGaN/ GaN heterostructures are grown on rigid substrates such as Si, SiC, and sapphire, causing significant difficulty in realizing flexible devices and circuits.…”