scholarly journals AlGaN/GaN MIS-HEMT with PECVD SiNx, SiON, SiO2 as Gate Dielectric and Passivation Layer

Electronics ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 416 ◽  
Author(s):  
Kuiwei Geng ◽  
Ditao Chen ◽  
Quanbin Zhou ◽  
Hong Wang

Three different insulator layers SiNx, SiON, and SiO2 were used as a gate dielectric and passivation layer in AlGaN/GaN metal–insulator–semiconductor high-electron-mobility transistors (MIS-HEMT). The SiNx, SiON, and SiO2 were deposited by a plasma-enhanced chemical vapor deposition (PECVD) system. Great differences in the gate leakage current, breakdown voltage, interface traps, and current collapse were observed. The SiON MIS-HEMT exhibited the highest breakdown voltage and Ion/Ioff ratio. The SiNx MIS-HEMT performed well in current collapse but exhibited the highest gate leakage current density. The SiO2 MIS-HEMT possessed the lowest gate leakage current density but suffered from the early breakdown of the metal–insulator–semiconductor (MIS) diode. As for interface traps, the SiNx MIS-HEMT has the largest shallow trap density and the lowest deep trap density. The SiO2 MIS-HEMT has the largest deep trap density. The factors causing current collapse were confirmed by Photoluminescence (PL) spectra. Based on the direct current (DC) characteristics, SiNx and SiON both have advantages and disadvantages.

2019 ◽  
Vol 9 (17) ◽  
pp. 3610 ◽  
Author(s):  
Hwang ◽  
Jang ◽  
Kim ◽  
Lee ◽  
Lim ◽  
...  

This study investigates metal-insulator-semiconductor high electron mobility transistor DC characteristics with different gate dielectric layer compositions and thicknesses, and lattice temperature effects on gate leakage current by using a two-dimensional simulation. We first compared electrical properties, including threshold voltage, transconductance, and gate leakage current with the self-heating effect, by applying a single Si3N4 dielectric layer. We then employed different Al2O3 dielectric layer thicknesses on top of the Si3N4, and also investigated lattice temperature across a two-dimensional electron gas channel layer with various dielectric layer compositions to verify the thermal effect on gate leakage current. Gate leakage current was significantly reduced as the dielectric layer was added, and further decreased for a 15-nm thick Al2O3 on a 5-nm Si3N4 structure. Although the gate leakage current increased as Al2O3 thickness increased to 35 nm, the breakdown voltage was improved.


Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1534
Author(s):  
Shun-Kai Yang ◽  
Soumen Mazumder ◽  
Zhan-Gao Wu ◽  
Yeong-Her Wang

In this paper, we have demonstrated the optimized device performance in the Γ-shaped gate AlGaN/AlN/GaN metal oxide semiconductor high electron mobility transistor (MOS-HEMT) by incorporating aluminum into atomic layer deposited (ALD) HfO2 and comparing it with the commonly used HfO2 gate dielectric with the N2 surface plasma treatment. The inclusion of Al in the HfO2 increased the crystalline temperature (~1000 °C) of hafnium aluminate (HfAlOX) and kept the material in the amorphous stage even at very high annealing temperature (>800 °C), which subsequently improved the device performance. The gate leakage current (IG) was significantly reduced with the increasing post deposition annealing (PDA) temperature from 300 to 600 °C in HfAlOX-based MOS-HEMT, compared to the HfO2-based device. In comparison with HfO2 gate dielectric, the interface state density (Dit) can be reduced significantly using HfAlOX due to the effective passivation of the dangling bond. The greater band offset of the HfAlOX than HfO2 reduces the tunneling current through the gate dielectric at room temperature (RT), which resulted in the lower IG in Γ-gate HfAlOX MOS-HEMT. Moreover, IG was reduced more than one order of magnitude in HfAlOX MOS-HEMT by the N2 surface plasma treatment, due to reduction of N2 vacancies which were created by ICP dry etching. The N2 plasma treated Γ-shaped gate HfAlOX-based MOS-HEMT exhibited a decent performance with IDMAX of 870 mA/mm, GMMAX of 118 mS/mm, threshold voltage (VTH) of −3.55 V, higher ION/IOFF ratio of approximately 1.8 × 109, subthreshold slope (SS) of 90 mV/dec, and a high VBR of 195 V with reduced gate leakage current of 1.3 × 10−10 A/mm.


2011 ◽  
Vol 88 (7) ◽  
pp. 1309-1311 ◽  
Author(s):  
C.H. Fu ◽  
K.S. Chang-Liao ◽  
Y.A. Chang ◽  
Y.Y. Hsu ◽  
T.H. Tzeng ◽  
...  

2015 ◽  
Vol 815 ◽  
pp. 30-35
Author(s):  
Ling Yan Shen ◽  
Xin Hong Cheng ◽  
Zhong Jian Wang ◽  
Duo Cao ◽  
Li Zheng ◽  
...  

Metal-insulator-semiconductor (MIS) diodes with Si3N4/Al2O3 bilayer gate dielectric films deposited on an AlGaN/GaN heterostructure were fabricated, where the Si3N4 layer played a role of etching stopped layer to protect the Al2O3 film from being damaged. Compared with traditional Schottky diodes, a distinct suppression of gate leakage current was achieved for the MIS diodes both at forward and reverse bias, and the dominant leakage current mechanism is Fowler–Nordheim tunneling. The 2DEG density extracted from C-V curves was 3~7 ́1013cm-2, in the same order of magnitude as Schottky diodes and hall measurement. Although the existence of the bilayer dielectric did not affect the 2DEG density at the interface of AlGaN/GaN, Si3N4 layer shared more gate bias and led to more gate bias required to deplete 2DEG and turn down the devices, moreover, Si3N4 layer had no effect on suppressing the forward or reverse gate leakage current due to its narrow band gap width and band bending compared with a single Al2O3 film. The experimental results provided a reference for the design of gate dielectric film structure for AlGaN/GaN high-electron-mobility transistors (HEMTs).


2013 ◽  
Vol 103 (14) ◽  
pp. 142903 ◽  
Author(s):  
Hai-Dang Trinh ◽  
Yueh-Chin Lin ◽  
Minh-Thuy Nguyen ◽  
Hong-Quan Nguyen ◽  
Quoc-Van Duong ◽  
...  

2018 ◽  
Vol 11 (6) ◽  
pp. 061501 ◽  
Author(s):  
Eiji Kojima ◽  
Kenta Chokawa ◽  
Hiroki Shirakawa ◽  
Masaaki Araidai ◽  
Takuji Hosoi ◽  
...  

2011 ◽  
Vol 335-336 ◽  
pp. 1079-1085
Author(s):  
Li Liu ◽  
Xiao Hua Ma ◽  
Yin Tang Yang

SiC MIS structure with ultra-thin Al2O3as gate dielectric deposited by Atomic Layer Deposition(ALD) on epitaxial layer of 4H-SiC(0001)80N-/N+ substrate is fabricated. The experimental results indicate that the prepared ultra Al2O3gate dielectric exhibits good physical and electrical characteristics, including a high breakdown electrical field of 25MV/cm, excellent interface properties(2×1013cm-2•eV-1) and low gate-leakage current (IG=1×10-3A/㎝-2@EOX=8MV/cm). Analysis of current conduction mechanism in deposited Al2O3gate dielectric has also been systematically performed. The confirmed conduction mechanisms consisted of FP emission, FN tunneling, DT and Schottky emission. And the dominance of these current conduction mechanisms depended on applied electrical field, When the gate leakage current mechanism is dominated by FN tunneling, the barrier height of SiC/Al2O3is 1.4eV, which can meet the requirement of SiC MISFET devices.


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