scholarly journals Effects of Recessed-Gate Structure on AlGaN/GaN-on-SiC MIS-HEMTs with Thin AlOxNy MIS Gate

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1538 ◽  
Author(s):  
Hyun-Seop Kim ◽  
Myoung-Jin Kang ◽  
Jeong Jin Kim ◽  
Kwang-Seok Seo ◽  
Ho-Young Cha

This study investigated the effects of a thin aluminum oxynitride (AlOxNy) gate insulator on the electrical characteristics of AlGaN/GaN-on-SiC metal-insulator-semiconductor high electron mobility transistors (MIS-HEMTs). The fabricated AlGaN/GaN-on-SiC MIS-HEMTs exhibited a significant reduction in gate leakage and off-state drain currents in comparison with the conventional Schottky-gate HEMTs, thus enhancing the breakdown voltage. The effects of gate recess were also investigated while using recessed MIS-HEMT configuration. The Johnson’s figures of merit (= fT × BVgd) for the fabricated MIS-HEMTs were found to be in the range of 5.57 to 10.76 THz·V, which is the state-of-the-art values for GaN-based HEMTs without a field plate. Various characterization methods were used to investigate the quality of the MIS and the recessed MIS interface.

2022 ◽  
Author(s):  
Xinchuang Zhang ◽  
Mei Wu ◽  
Bin Hou ◽  
Xuerui Niu ◽  
Hao Lu ◽  
...  

Abstract In this work, the N2O radicals in-situ treatment on gate region has been employed to improve device performance of recessed-gate AlGaN/GaN high-electron-mobility transistors (HEMTs). The samples after gate recess etching were treated by N2O radicals without physical bombardment. After in-situ treatment (IST) processing, the gate leakage currents decreased by more than one order of magnitude compared to the sample without IST. The fabricated HEMTs with the IST process show a low reverse gate current of 10-9 A/mm, high on/off current ratio of 108, and high fT×Lg of 13.44 GHz·μm. A transmission electron microscope (TEM) imaging illustrates an oxide layer with a thickness of 1.8 nm exists at the AlGaN surface. X-ray photoelectron spectroscopy (XPS) measurement shows that the content of the Al-O and Ga-O bonds elevated after IST, indicating that the Al-N and Ga-N bonds on the AlGaN surface were broken and meanwhile the Al-O and Ga-O bonds formed. The oxide formed by a chemical reaction between radicals and the surface of the AlGaN barrier layer is responsible for improved device characteristics.


2007 ◽  
Vol 46 (2) ◽  
pp. 478-484 ◽  
Author(s):  
Chih-Yuan Chan ◽  
Ting-Chi Lee ◽  
Shawn S. H. Hsu ◽  
Leaf Chen ◽  
Yu-Syuan Lin

2011 ◽  
Vol 1324 ◽  
Author(s):  
Takuma Nanjo ◽  
Misaichi Takeuchi ◽  
Akifumi Imai ◽  
Yousuke Suzuki ◽  
Muneyoshi Suita ◽  
...  

ABSTRACTA channel layer substitution of a wider bandgap AlGaN for a conventional GaN in high electron mobility transistors (HEMTs) is an effective method of enhancing the breakdown voltage. Wider bandgap AlGaN, however, should also increase the ohmic contact resistance. Si ion implantation doping technique was utilized to achieve sufficiently low resistive source/drain contacts. The fabricated AlGaN channel HEMTs with the field plate structure demonstrated good pinch-off operation with sufficiently high drain current density of 0.5 A/mm without noticeable current collapse. The obtained maximum breakdown voltages was 1700 V in the AlGaN channel HEMT with the gate-drain distance of 10 μm. These remarkable results indicate that AlGaN channel HEMTs could become future strong candidates for not only high-frequency devices such as low noise amplifiers but also high-power devices such as switching applications.


2008 ◽  
Vol 155 (12) ◽  
pp. H987 ◽  
Author(s):  
Jung-Hun Oh ◽  
Min Han ◽  
Sung-Woon Moon ◽  
Seokhun Lee ◽  
In-Seok Hwang ◽  
...  

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