Improving GaN-based HEMTs Performance by Gate Recess Technique

Abstract

GaN-based electron mobility transistors (HEMTs) have been widely used in high-frequency or high-power device application. However, GaN-based HEMT is usually normally-on mode due to the high-density two-dimensional electron gas (2DEG) caused by its strong polarization effect, which has poor fail-safe operation and more difficult gate control. In this paper, we use gate recess technology combined with ICP-RIE to control the depth of gate penetration to achieve the purpose of controlling the threshold voltage. Measurements show that the threshold voltage (VTH) exhibits a positive shift of +1.9 V with the gate penetration.