Recent Reliability Progress of GaN HEMT Power Amplifiers

2012 ◽  
Vol 1432 ◽  
Author(s):  
Toshihiro Ohki ◽  
Masahito Kanamura ◽  
Yoichi Kamada ◽  
Kozo Makiyama ◽  
Yusuke Inoue ◽  
...  

ABSTRACTIn this paper, we describe highly reliable GaN high electron mobility transistors (HEMTs) for high-power and high-efficiency amplifiers. First, we present the reliability mechanisms and progress on the previously reported GaN HEMTs. Next, we introduce our specific device structure of GaN HEMTs for improving reliability. An n-GaN cap and optimized buffer layer were used to suppress the trap-related phenomena, such as a current collapse. Gate edge oxidation is effective for reducing the gate leakage current. A Ta-based barrier metal was inserted between an ohmic electrode and interconnection metal for preventing increase in contact resistance. SiN of passivation film was optimized for reducing the current collapse of short-gatelength HEMTs.

Electronics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 942
Author(s):  
Wei Lin ◽  
Maojun Wang ◽  
Haozhe Sun ◽  
Bing Xie ◽  
Cheng P. Wen ◽  
...  

Carbon doping in the buffer of AlGaN/GaN high-electron-mobility transistors (HEMTs) leads to the notorious current collapse phenomenon. In this paper, an HEMT structure with a source-connected p-GaN (SCPG) embedded in the carbon-doped semi-insulating buffer is proposed to suppress the buffer-induced current collapse effect. Two-dimensional transient simulation was carried out to show the successful suppression of buffer-induced current collapse in the SCPG-HEMTs compared with conventional HEMTs. The mechanism of suppressing dynamic on-resistance degradation by ejecting holes from the SCPG into the high resistive buffer layer after off-state stress is illustrated based on energy band diagrams. This paper contributes an innovative device structure to potentially solve the buffer-induced degradation of the dynamic on-resistance in GaN power devices.


2003 ◽  
Vol 764 ◽  
Author(s):  
B. Luo ◽  
F. Ren ◽  
M. A. Mastro ◽  
D. Tsvetkov ◽  
A. Pechnikov ◽  
...  

AbstractHigh quality undoped AlGaN/GaN high electron mobility transistors(HEMTs) structures have been gorwn by Hydride Vapor Phase Epitaxy (HVPE). The morphology of the films grown on Al2O3 substrates is excellent with root-mean-square roughness of ∼0.2nm over 10×10μm2 measurement area. Capacitance-voltage measurements show formation of dense sheet of charge at the AlGaN/GaN interface. HEMTs with 1μm gate length fabricated on these structures show transconductances in excess of 110 mS/mm and drain-source current above 0.6A/mm. Gate lag measurements show similar current collapse characteristics to HEMTs fabricated in MBE- or MOCVD grown material.


Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 400
Author(s):  
Van Cuong Nguyen ◽  
Kwangeun Kim ◽  
Hyungtak Kim

We investigated the sensing characteristics of NO2 gas sensors based on Pd-AlGaN/GaN high electron mobility transistors (HEMTs) at high temperatures. In this paper, we demonstrated the optimization of the sensing performance by the gate bias, which exhibited the advantage of the FET-type sensors compared to the diode-type ones. When the sensor was biased near the threshold voltage, the electron density in the channel showed a relatively larger change with a response to the gas exposure and demonstrated a significant improvement in the sensitivity. At 300 °C under 100 ppm concentration, the sensor’s sensitivities were 26.7% and 91.6%, while the response times were 32 and 9 s at VG = 0 V and VG = −1 V, respectively. The sensor demonstrated the stable repeatability regardless of the gate voltage at a high temperature.


1999 ◽  
Vol 4 (S1) ◽  
pp. 775-780 ◽  
Author(s):  
Shangli Wu ◽  
Richard T. Webster ◽  
A. F. M. Anwar

DC and intrinsic small signal parameters are reported for AlGaN/GaN high electron mobility transistors. The calculations are based upon a self-consistent solution of Schrödinger and Poisson’s equation to model the quantum well formed in GaN. Transport parameters are obtained from an ensemble Monte Carlo simulation.


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