Performance enhancement for AlGaN/GaN HEMTs with dual discrete field-plate

We propose optimized field plate structures to improve the performance of AlGaN / GaN HEMT under electrical stress. The two structures are T-gate AlGaN / GaN HEMT with dual discrete field plates (DDFP-HEMT) and single discrete field-plate (SDFP-HEMT). Benefiting from the modulation effects of the field plate on the electric field, the DDFP-HEMT and SDFP-HEMT exhibit better breakdown characteristics and current collapse suppression. The performance of the two structure devices and no-discrete-field-plate devices (NDFP- HEMT) is explored in Silvaco TCAD. The DDFP-HEMT and SDFP-HEMT achieve the highest off-state breakdown voltage (VBD) of 1188 V and 1120 V in the experiment, respectively, being 33 % and 25 % higher than that of NDFP-HEMT, respectively. In particular, the current collapse in DDFP-HEMT and SDFP- HEMT is reduced by 24 % and 9 % under 200 V stress bias, respectively, when compared to NDFP-HEMT. The DDFP-HEMT shows greatest reliability improvement in the three samples.