TCAD Study of Leakage Current Suppression Mechanism by Deep P Layer and Additional Source Electrode in GaN High‐Electron‐Mobility Transistors

In the development of semiconductor power devices, leakage current sources are often a difficult problem because they cause transient fluctuations in electrical characteristics and adversely affect device reliability. The mechanism of leakage current increase and structures with deep P layer that reduce leakage current in AlGaN/GaN high‐electron‐mobility transistors (HEMT) are reported. Specifically, the cause of the leakage current increase is that the hole carriers accumulated under the gate reduce the function of the potential barrier of the negatively biased gate electrode. In this report, the quantitative and qualitative mechanism of leakage current reduction is explained in detail using technology CAD (TCAD). In the simulations, the mechanism can be effectively revealed using a new structure with a deep P layer connected to an additional source electrode.