New Al 0.25 Ga 0.75 N/GaN HEMTs structure with the partial silicon doping

Abstract

By applying the theory of two-dimensional electron gas (2DEG) formed in the AlGaN/GaN high electron mobility transistors, two 2DEG concentration regions are realised by doping partial silicon into the AlGaN layer for the first time. A new electric field peak is introduced in the surface electric field by the electric field modulation effect due to the partial silicon positive charge. The high electric fields near the gate and drain electrodes are decreased effectively, and the surface electric field is uniform. The proposed structure with the partial silicon doping is better than the conventional structures with the electric field plate near the drain, which is due to the absence of the adding capacitance. The breakdown voltage is improved from 308 V for the conventional structure to 400 V for the proposed one resulting from the uniform surface electric field.