Effects of gate width variation on the performance of Normally-OFF dual-recessed gate MIS AlGaN/GaN HEMT

Discovery of wideband gap semiconductor materials has boosted the field of power electronics. Fabrication of HEMT has overcome the drawback of lower mobility and ON-state current of wide bandgap materials. However, due to lower ON-state current earlier proposed devices suffer from poor ON-state resistance; hence, in this work dual gate technique has been proposed. To further switch the device characteristics from Normally-ON to Normally-OFF state, recessed gate technique is used. Device physics, analog parameters of Normally-OFF dual-recessed gate metal insulator semiconductor AlGaN/GaN HEMT (DRG-MIS-HEMT) are analyzed and compared with conventional DG-MIS-HEMT. To solidify the analysis, width of recessed gate has been varied from 2 nm to 28 nm. At recessed gate width (=28 nm), proposed device resulted R-ON = 1.98 omega-cm(2), threshold voltage 1.25 V, I-DS of 1100 mA/mm, I-ON/I-OFF = 10(14) and f(t) = 10 GHz. Proposed device also resulted in improved linearity characteristics over single gate structure. In future, the proposed device can be used for RF applications.