Kilovolt AlGaN/GaN HEMTs as Switching Devices

Abstract

Subject classification: 73.40.Qv; 85.30.Tv; S7.14 SiC devices have been the focus for several years as potential high voltage switches working at high temperature with very low on-resistance. Another competitive candidate for this application is the GaN HEMT (high electron mobility transistor). GaN has slightly wider bandgap, higher electric strength, and higher saturated velocity than SiC. The most prominent is that by utilizing the AlGaN/GaN heterojunction, the GaN HEMT has much higher charge density (up to 2 Â 10 13 cm --2 ) and mobility (up to 2200 cm 2 /Vs) in the channel compared to SiC MOSFET or JFET, yielding much lower on-resistance than SiC devices. GaN grown on SiC substrate also takes the advantage of high thermal conductivity of SiC. A GaN HEMT with a breakdown voltage of 1050 V was fabricated with a specific on-resistance of 3.4 mW cm 2 and current density of 4 kA cm --2 . State-of-art power device figure of merit of V 2 BR /R on = 3.24 Â 10 8 [V 2 W --1 cm --2 ] was achieved on this device. Projected performance of GaN HEMTs is also discussed and compared with SiC devices in this paper.

Monolithic integration of light-emitting diodes and power metal-oxide-semiconductor channel high-electron-mobility transistors for light-emitting power integrated circuits in GaN on sapphire substrate

“…1 GaN power switching field-effect transistors (FETs), such as metaloxide-semiconductor (MOS) FETs, high-electron-mobility transistors (HEMTs), and MOS-Channel HEMTs (MOSCHEMTs) have shown outstanding performance in terms of high breakdown voltage (BV), low specific on-resistance, and high operating frequency, [2][3][4] and can be very useful as output devices for emerging applications of high power-high voltage LED systems. Ultimately, monolithic integration of GaN-based LEDs and GaN power HEMTs can reduce the cost and the size of solid state lighting systems, improve system reliability, and serve as a technology platform for the development of light-emitting power integrated circuits (LEPICs).…”

Mass Transport Regrowth of GaN for Ohmic Contacts to AlGaN/GaN

“…Breakdown voltages exceeding 1 kV [1], and power densities of 9.8 W/mm at 8 GHz [2] have been demonstrated. The aluminum composition is typically in the range 30-40%, but a higher composition has inherent advantages for power performance, namely increased sheet carrier concentration and break down voltage.…”

AlGaN/GaN Heterostructure Field-Effect Transistors on Fe-Doped GaN Substrates with High Breakdown Voltage

“…The open squares represent the state-of-theart GaN-based devices reported by other groups. [15][16][17][18][19][20][21][22] Our results are still not highly developed compared with those of the state-of-the-art GaN-based devices. One of the reasons is that we used a mesa isolation technique.…”