High Temperature Performance and Low Frequency Noise Characteristics of AlGaN/GaN/AlGaN Double Heterostructure Metal-Oxide-Semiconductor Heterostructure Field-Effect-Transistors with Photochemical Vapor Deposition SiO 2 Layer

• Published in: Japanese Journal of Applied Physics Vol. 44; no. 4S; p. 2458
• Main Authors: Wang, Chun-Kai, Chang, Shoou-Jinn, Su, Yan-Kuin, Chiou, Yu-Zung, Kuo, Cheng-Huang, Chang, Chia-Sheng, Lin, Tien-Kun, Ko, Tsun-Kai, Tang, Jing-Jou
• Format: Journal Article
• Language: English
• Published: 01.04.2005
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.44.2458

High quality SiO 2 films were successfully deposited onto AlGaN using photochemical vapor deposition (photo-CVD). The interface state density, D it , of photo-CVD SiO 2 was estimated to be only 1.1×10 11 cm -2 eV -1 at room temperature and still only 3.5×10 12 cm -2 eV -1 even at 175°C. With a 1 µm gate length, it was found that the maximum saturated drain-source current ( I ds ), maximum transconductance ( g m ) and gate voltage swing (GVS) of the AlGaN/GaN/AlGaN double heterostructure metal-oxide-semiconductor heterostructure field-effect-transistors (MOS-HFETs) fabricated were 755 mA/mm, 95 mS/mm and 8 V, respectively. Even at 300°C, the maximum saturated I ds and maximum g m of the MOS-HFETs fabricated were still kept at 527 mA/mm and 77 mS/mm, respectively. Furthermore, from the low frequency noise power spectrum, it was found that noise power density of the AlGaN/GaN/AlGaN double heterostructure was lower and presented pure 1/f noise with smaller trapping effects than conventional structures.