Al₂O₃-Dielectric In_0.18Al_0.82N/AlN/GaN/Si Metal-Oxide-Semiconductor Heterostructure Field-Effect Transistors With Backside Substrate Metal-Trench Structure

Abstract

This paper investigates novel Al2O3-dielectric In0.18Al0.82N/AlN/GaN metal-oxidesemiconductor heterostructure field-effect transistors (MOS-HFETs) with backside metal-trench structure grown by using a non-vacuum ultrasonic spray pyrolysis deposition technique. 3-μm deep metal trenches coated with 150-nm thick Ni were formed on the backside of the Si substrate to improve the heat dissipation efficiency. The present In0.18Al0.82N/AlN/GaN MOS-HFET (Schottky-gate HFET) has demonstrated improved maximum drain-source current density (IDS,max) of 1.08 (0.86) A/mm at VDS = 8 V, gate-voltage swing of 4 (2) V, on/off-current ratio (Ion/Ioff) of 8.9 x 108 (7.4 x 104), subthreshold swing of 140 (244) mV/dec, two-terminal off-state gate-drain breakdown voltage (BVGD) of -191.1 (-173.8) V, turn-on voltage (Von) of 4.2 (1.2) V, and three-terminal on-state drain-source breakdown voltage (BVDS) of 155.9 (98.5) V. Enhanced power performances, including saturated output power (Pout) of 27.9 (21.5) dBm, power gain (Ga) of 20.3 (15.5) dB, and power-added efficiency (PAE) of 44.3% (34.8%), are achieved.

Keywords

• InAlN/AlN/GaN
• MOS-HFET
• Al₂O₃
• non-vacuum ultrasonic spray pyrolysis deposition
• backside metal-trench