Source-Connected p-GaN Gate HEMTs for Increased Threshold Voltage

Abstract

A pathway to increase the threshold voltage <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$(V_{\rm TH})$</tex></formula> of p-GaN gate high-electron-mobility transistors (HEMTs) is presented. The hole depletion width in the p-GaN layer at the gate interface is one of the key controlling factors of <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$V_{\rm TH}$</tex></formula> in p-GaN gate HEMTs. In order to increase the depletion width, we devise a new device structure of p-GaN gate HEMT having a source-connected p-GaN bridge. We demonstrate that a bridged p-GaN gate HEMT structure increases the <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$V_{\rm TH}$</tex></formula> from 0.93 to 2.44 V.