Effect of treatment in nitrogen plasma on the electrical parameters of AlGaN/GaN heterostructures

Abstract

In this work, the influence of deep levels formed at the SiON/AlGaN interface under the nitrogen plasma action during the deposition of a SiON film on the electrical parameters of SiON/AlGaN/GaN structures were studied. The concentration and mobility of free carriers in 2DEG and the capacitance parameters of the structures were measured. It has been experimentally established that short-term action of nitrogen plasma (25 and 50 sec.) does not change the concentration of free carriers in 2DEG, but leads to a decrease in their mobility. The value of the charge that can form at the SiON/AlGaN interface has been calculated. With the help of C–V measurements, it was experimentally shown how the charge in the SiON/AlGaN/GaN system changes during one measurement cycle at different voltage ranges. Based on the consideration of the energy band diagrams of the system, possible explanations for the charge redistribution processes in the analyzed system under certain actions are proposed.