Analysis of Gate-Length Dependence of Lags and Current Collapse in Field-Plate AlGaN/GaN HEMTs

摘要

We make 2-D transient simulations of field-plate AlGaN/GaN HEMTs with a semi-insulating buffer layer,where a deep acceptor above the midgap is considered.We particularly study how the gate lag,drain lag and current collapse in AlGaN/GaN HEMTs are influenced by the gate length and field-plate length.As a result,it is shown that the gate lag increases as the gate length becomes short,but the drain lag is not so dependent on the gate length.Then,the current collapse,which is a combined effect of gate lag and drain lag,tends to increase as the gate length becomes short due to the gate-lag effect.