Normally-off AlGaN/AlN/GaN/Si oxide-passivated HEMTs and MOS-HEMTs by using CF₄ plasma and ozone water oxidization treatment

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• 作者：Ching-Sung Lee^a ; ^{cslee@fcu.edu.tw} ; Han-Yi Liu^a ; Wei-Chou Hsu^b ; Si-Fu Chen^a
• 关键词：AlGaN/AlN/GaN ; Normally-off ; Oxide passivation ; MOS-HEMT ; Al2O3 ; Ozone water oxidization ; CF4 plasma treatment
• 刊名：Materials Science in Semiconductor Processing
• 出版年：2017
• 出版时间：1 March 2017
• 年：2017
• 卷：59
• 期：Complete
• 页码：1-4
• 全文大小：545 K
• 卷排序：59

文摘

The letter reports normally-off device characteristics of Al0.26Ga0.74N/AlN/GaN oxide-passivated high electron mobility transistors (HEMTs) and metal-oxide-semiconductor HEMTs (MOS-HEMTs) grown on a Si substrate. Al2O3 was formed as the surface passivation oxide or gate dielectric on a thin AlGaN barrier layer by using a cost-effective ozone water oxidization technique. CF4 plasma was used to enable normally-off operation. For the gate dimensions of 1×100 µm2, the present oxide-passivated HEMT and MOS-HEMT (a control Schottky-gate HEMT) have demonstrated superior on/off-current ratio (Ion/Ioff) of 2.5×106 and 1×107 (3.9×103), maximum extrinsic transconductance (gm, max) of 154 and 175 (120) mS/mm, maximum drain-source current density (IDS, max) of 312 and 349 (300) mA/mm, two-terminal gate-drain breakdown voltage (BVGD) of −80 and −140 (−36) V, turn-on voltage (Von) of 1.2 and 1.3 (1) V, and three-terminal on-state breakdown voltage (BVDS) of 93 and 109 (48) V. Excellent BVGD and BVDS enhancements of 122% (288%) and 94% (127%) are achieved in the present oxide-passivated HEMT (MOS-HEMT) design.