High Drain Current Density E-Mode ${\rm Al}_{2}{\rm O}_{3}$/AlGaN/GaN MOS-HEMT on Si With Enhanced Power Device Figure-of-Merit $(4\times 10^{8}~{\rm V}^{2}\Omega^{-1}{\rm cm}^{-2})$

Joseph Jesudass Freedsman,Toshiharu Kubo,Takashi Egawa

doi:10.1109/ted.2013.2276437

Abstract

In this paper, we report on the enhancement-mode (E-mode) Al 2 O 3 /AlGaN/GaN metal-oxide-semiconductor high-electron mobility transistors (MOS-HEMTs) on Si. The E-mode operation is due to the negative charges in the atomic layer deposited Al 2 O 3 layer. The unrecessed E-mode MOS-HEMTs exhibit high drain current density with a low specific ON-state resistance (R ON , sp ) of 0.7 mΩ·cm 2 . A low gate leakage current showed enhancements in the subthreshold characteristics such as ION/IOFF ratio ~10 8 and subthreshold slope of 75 mV/decade. This E-mode device showed good retention characteristics of threshold voltage upto 10 5 s. Furthermore, the E-mode MOS-HEMT exhibits an OFF-state breakdown voltage of 532 V for short gate-to-drain distance (L gd =4 μm) that records a high power device figure of merit (FOM=BV 2 /R ON,sp ) value of 4×10 8 V 2 Ω -1 cm -2 .

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