Enhancement Mode AlGaN/GaN MOS High-electron-mobility Transistors with ZrO2 Gate Dielectric Deposited by Atomic Layer Deposition

Applied Physics Express, Vol. 9, No. 7, June 2016, doi: 10.7567/APEX.9.071003/meta

Enhancement Mode AlGaN/GaN MOS High-electron-mobility Transistors with ZrO2 Gate Dielectric Deposited by Atomic Layer Deposition

Travis J. Anderson¹, Virginia D. Wheeler¹, David I. Shahin², Marko J. Tadjer¹, Andrew D. Koehler¹, Karl D. Hobart¹, Aris Christou², Francis J. Kub¹, and Charles R. Eddy Jr.¹
¹ U.S. Naval Research Laboratory, Washington, D.C. 20375, U.S.A.
² University of Maryland, College Park, MD 20742, U.S.A.

Abstract:

Advanced applications of AlGaN/GaN high-electron-mobility transistors (HEMTs) in high-power RF and power switching are driving the need for insulated gate technology. We present a metal–oxide–semiconductor (MOS) gate structure using atomic-layer-deposited ZrO2 as a high-k, highbreakdown gate dielectric for reduced gate leakage and a recessed barrier structure for enhancement mode operation. Compared to a Schottky metal-gate HEMT, the recessed MOS-HEMT structure demonstrated a reduction in the gate leakage current by 4 orders of magnitude and a threshold voltage shift of +6V to a record +3.99V, enabled by a combination of a recessed barrier structure and negative oxide charge. © 2016 The Japan Society of Applied Physics

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