Surface passivation of AlN/GaN MOS-HEMTs using ultra-thin Al2O3 formed by thermal oxidation of evaporated aluminium

Taking, S. et al. (2010) Surface passivation of AlN/GaN MOS-HEMTs using ultra-thin Al2O3 formed by thermal oxidation of evaporated aluminium. Electronics Letters, 46(4), pp. 301-302. (doi: 10.1049/el.2010.2781)

Abstract

A simple method is reported for fabrication of AlN/GaN MOS-HEMTs. Ultra-thin Al2O3, which is formed using thermal oxidation of evaporated Al, was used for surface passivation and as a gate dielectric. Prior to formation of Al2O3, the Al protects the very sensitive AlN epilayer from exposure to processing liquid chemicals. Fabricated two-finger AlN/GaN MOS-HEMTs with 3 mm gate length and 200 mm gate width showed good gate control of drain currents up to a gate bias of 3 V and achieved a maximum drain current, I-DSmax, of similar to 900 mA/mm. The peak extrinsic transconductance, G(max), of the device is similar to 100 mS/mm at V-DS = 8 V. Capacitance-voltage (C-V) characteristics of Al2O3/AlN/GaN circular test MOS structures were observed and measured. They exhibited no hysteresis, indicating the good quality of the thermally grown Al2O3 for realising AlN/GaN MOS-HEMTs for high power and high frequency applications.

• Item Type: Articles
• Keywords: Device, fabrication, field-effect transistors, passivation, surface passivation
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Wasige, Professor Edward and Zhou, Dr Haiping and Thayne, Prof Iain and Bentley, Dr Steven and Banerjee, Mr Abhishek and Khokhar, Dr Ali and Rahman, Dr Faiz and Li, Dr Xu and Oxland, Dr Richard
• Authors: Taking, S., Banerjee, A., Zhou, H., Li, X., Khokhar, A.Z., Oxland, R., McGregor, I., Bentley, S., Rahman, F., Thayne, I.G., Dabiran, A.M., Wowchak, A.M., Cui, B., and Wasige, E.
• Subjects: T Technology > TK Electrical engineering. Electronics Nuclear engineering
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Journal Name: Electronics Letters
• Journal Abbr.: Electron. lett.
• Publisher: The Institution of Engineering & Technology
• ISSN: 0013-5194
• ISSN (Online): 1350-911X
• Published Online: 17 February 2010