Influence of field plate on surface-state-related lag characteristics of AlGaN/GaN HEMT

The relationship between AlGaN/GaN HEMT gate field plate (FP) and surface-state-related gate lag phenomena is investigated by two-dimensional numerical transient simulations to study the mechanism of the influence of FPs on current collapse. The simulations reveal that adding a field plate has a noticeable impact on the extent of current collapse while it has no influence on lapsed time. The FP is found to suppress current collapse through reducing the ionization probability of surface states by enhancing free hole accumulation next to the AlGaN surface between gate and drain.