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Active and Passive Electronic Components
Volume 2012 (2012), Article ID 459043, 10 pages
http://dx.doi.org/10.1155/2012/459043
Research Article

GaN-Based High-k Praseodymium Oxide Gate MISFETs with + UV Interface Treatment Technology

Department of Electronics Engineering, Chang Gung University, Taoyuan, Taiwan

Received 1 July 2012; Revised 28 September 2012; Accepted 26 October 2012

Academic Editor: Pei-Wen Li

Copyright © 2012 Chao-Wei Lin and Hsien-Chin Chiu. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

This study examines the praseodymium-oxide- (Pr2O3-) passivated AlGaN/GaN metal-insulator-semiconductor high electron mobility transistors (MIS-HEMTs) with high dielectric constant in which the AlGaN Schottky layers are treated with P2S5/(NH4)2 + ultraviolet (UV) illumination. An electron-beam evaporated Pr2O3 insulator is used instead of traditional plasma-assisted chemical vapor deposition (PECVD), in order to prevent plasma-induced damage to the AlGaN. In this work, the HEMTs are pretreated with P2S5/(NH4)2 solution and UV illumination before the gate insulator (Pr2O3) is deposited. Since stable sulfur that is bound to the Ga species can be obtained easily and surface oxygen atoms are reduced by the P2S5/(NH4)2 pretreatment, the lowest leakage current is observed in MIS-HEMT. Additionally, a low flicker noise and a low surface roughness (0.38 nm) are also obtained using this novel process, which demonstrates its ability to reduce the surface states. Low gate leakage current Pr2O3 and high-k AlGaN/GaN MIS-HEMTs, with P2S5/(NH4)2 + UV illumination treatment, are suited to low-noise applications, because of the electron-beam-evaporated insulator and the new chemical pretreatment.