Instability of the induced potential distribution in undoped AlGaN/GaN HEMTs and SiC transistor structures

In this work, we discuss the results of investigation of potential distribution instabilities in undoped AlGaN/GaN HEMTs and SiC transistor (FET) structures due to charge changes on the structure surface. An analysis of the state effects influence in the top layer of a passivated silicon nitride film reveals the possibility of the "memory effect" appearance due to electrons tunneling from an active area to different states in the silicon nitride film and AlGaN layer. All considerations are followed by device characterization. A technological process for silicon nitride film deposition and a precision method of hydrogen bond concentration measurement by FTIR were developed to carry out experiments with a high accuracy.