Improvement of $V_{\rm th}$ Instability in Normally-Off GaN MIS-HEMTs Employing ${\rm PEALD}\hbox{-}{\rm SiN}_{\rm x}$ as an Interfacial Layer

Abstract

In this letter, reduction of threshold voltage instability in gate recessed normally-off GaN metal insulator semiconductor high electron mobility transistors with SiN <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> gate insulator was investigated. A plasma enhanced atomic layer deposition technique was successfully employed for very thin SiN <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> (5 nm) as an interfacial layer. The hysteresis and drift of threshold voltage in transfer curve and the forward biased gate leakage current were effectively reduced.