Buffer-related gate lag in AlGaN/GaN HEMTs

Two-dimensional analysis of gate lag in AlGaN/GaN HEMTs is performed by considering a deep donor and a deep acceptor in a buffer layer. It is shown that relatively large gate lag can arise due to traps in the buffer layer. It is also shown that the buffer-related gate lag becomes smaller when the gate length becomes longer. Dependence of buffer-related gate lag on trap parameters such as a deep-acceptor density and a deep-donor's energy level is also studied.