Low Dynamic ON-Resistance in AlGaN/GaN Power HEMTs Obtained by AlN Thin Film Passivation

Abstract

An effective passivation technique for AlGaN/GaN-on-Si power HEMTs is presented. This technique features AlN ultra-thin film grown by plasma enhanced atomic layer deposition (PEALD). With low-surface-damage in situ remote plasma pretreatments prior to the AlN deposition, an atomically sharp PEALD-AlN/III-nitride interface as well as high-crystal-quality AlN film have been obtained. Effective current collapse suppression and dynamic ON-resistance reduction are demonstrated in the PEALD-AlN passivated AlGaN/GaN HEMTs under high drain bias switching conditions. An output power of 2.64 W/mm and a power added-efficiency of 33% are obtained at 2 GHz on the PEALD-AlN passivated HEMTs without the use of field-plate.