AlGaN/GaN‐based normally‐off GaN MOSFET with stress controlled 2DEG source and drain

Abstract

AlGaN/GaN‐based normally‐off GaN MOSFET with stress controlled 2DEG source and drain was proposed and fabricated using Al2O3 gate oxide deposited on the fully recessed gate region. The proposed normally‐off Al2O3/GaN MOSFET utilized AlGaN/GaN heterostructure source and drain with extremely high 2DEG density of 1.87×1014 cm2 with mobility of 120 cm2V‐1s‐1 and the device results were compared to those obtained from the reference device with normal AlGaN/GaN heterostructure source and drain with 2DEG density of 1.33×1013 cm2 and mobility of 1070 cm2V‐1s‐1. The maximum drain current and maximum transconductance of the proposed device were 263 mA/mm and 72 mS/mm, respectively, about 7.3‐times and 5‐times larger than those of the reference device, which are comparable to or even higher than one of the best results obtained from various GaN MOSFETs reported by others. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

GaN MOSHEMT employing HfO2as a gate dielectric with partially etched barrier

“…Compared with traditional GaN HEMTs, the gate voltage forward swing range increases more than 10 times and the reverse gate leakage is significantly suppressed for the GaN MOSHEMT. The forward breakdown voltage of gate junction of GaN MOSHEMT is V gs =22 V, and the reverse breakdown voltage is V gs =−90 V, the breakdown criterion being > ´-| | I 1 10 gs 5 A mm −1 . The MOS junction behaves like a Schottky junction with a barrier height of 1.1 V and the ideality factor is 2.5 after breakdown, which indicates that the breakdown of the junction is the breakdown of the gate dielectric.…”

“…Max Ids/mA•mm −1 Max Gm/mS•mm −1 Gate length/μm [5] 263, (Vgs=6 V, Vds=10 V) 72 0.25 [6] 230,(Vgs=10 V, Vds=7 V) 100 2 [7] 660, (Vgs=2 V, Vds=6 V) 250 1.4 This work 900, (Vgs=2 V, Vds=10 V) 250 0.5 Test results show that high current density, high tranconductance, negligible gate current, large gate voltage swing range and comparable RF characteristics of GaN MOSHEMT with traditional GaN HEMT have been obtained.…”

“…In the related research of GaN MOSHEMTs, the GaN MOSHEMT with Al 2 O 3 gate dielectric developed by Ki-Sik et al uses a full wet etching of barrier layer under the gate to adjust the device threshold voltage and improve the device gate control [5], so the MOS interface is in direct contact with the GaN channel, as a result electrons are seriously scattered by the interface and the electron transport characteristics of the channel are degraded, so the current density and gain cutoff of the device is decreased.…”

Performance Enhancement in N2 Plasma Modified AlGaN/AlN/GaN MOS-HEMT Using HfAlOX Gate Dielectric with Γ-Shaped Gate Engineering

“…However, Ki-Sik et al and Zhe at al. reported that the electron transport characteristics could be seriously affected by the interface states in fully recessed HEMTs, due to the completely etched AlGaN barrier layer [ 7 , 8 ].…”

Influence of V/III Ratio of Low Temperature Grown AlN Interlayer on the Growth of GaN on Si<111> Substrate

“…In the past decade, the field of semiconductor has seen tremendous technological and commercial progress, such as optoelectronic devices, 1,2) solar cells, 3) and high power electronic devices. 4) Otherwise, the research of GaN growth on Si substrate attracted extensive attentions because of its great potential in cost-effective industry applications. However, high quality GaN epilayer is hard to be obtained on Si substrate due to the existence of the large lattice mismatch and thermal expansion mismatch between GaN and Si.…”