We make a two-dimensional transient analysis of field-plate AlGaN/GaN HEMTs with a semi-insulating buffer layer, where a deep acceptor above the midgap is considered. It is studied how the deep-acceptor density and the field plate affect buffer-related lag phenomena and current collapse. It is shown that the introduction of field plate is effective to reduce the lags and current collapse. It is also shown that without a field plate the drain lag and current collapse increase with increasing the deep-acceptor density as expected because the deep acceptors act as electron traps, But with a field plate, surprisingly, the lags and current collapse are shown to be smaller when the deep-acceptor density becomes higher. This indicates that the field plate on the device surface is effective to reduce the buffer-related current collapse when the acceptor density in the buffer layer is high and electrons are not so diffused into the buffer layer.
Journal: TechConnect Briefs
Volume: 4, Informatics, Electronics and Microsystems: TechConnect Briefs 2017
Published: May 14, 2017
Pages: 27 - 30
Industry sectors: Advanced Materials & Manufacturing | Sensors, MEMS, Electronics
Topics: Informatics, Modeling & Simulation