GaN schottky barrier MOSFET using indium-tin-oxide as source, drain and gate material

Abstract

We fabricated normally-off mode n-channel schottky barrier metal oxide semiconductor field effect transistor (SB-MOSFET) with ITO schottky barrier source/drain (S/D) on a highly resistive GaN layer grown on silicon substrate with low temperature AlN and high temperature GaN buffer layers. Fabricated SB-MOSFET exhibited a threshold voltage of 4.2 V, and a maximum transconductance of 2.9 mS/mm at V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DS</sub> = 3 V. The normalized on-current was 7.9 mA/mm and off-current was as low as 1×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-12</sup> A/mm. ITO is proved as a promising material for the gate metal as well as the source/drain in GaN schottky barrier MOSFET.