Investigation of Enhancement-Mode AlGaN/GaN MIS-HEMT with Recessed Gate Structure

The enhancement-mode AlGaN/GaN metal insulator semiconductor high electron mobility transistor (MIS-HEM) with recessed gate structure is comprehensively studied by using Silvaco TCAD software. The effects of etching depth of AlGaN barrier layer, gate length, sort and thickness of gate dielectric layer on device performance are explored. The outcomes from the simulation indicate that the enhanced device is capable of attaining a threshold voltage of +1 V, a substantial drain saturation current of 1.38 A/mm, and an elevated peak transconductance of 498 mS/mm. It has been observed that the gate recess depth substantially boosts the transconductance, achieving a maximum value of g_mmax at 498 mS/mm.The value significantly surpasses that exhibited by the traditional AlGaN/GaN MIS-HEMT. The threshold voltage of Al0.18Ga0.82N TBL recessed gate MIS-HEMT is +1 V. Furthermore, in comparison to the conventional MIS-HEMT device, the drain saturation current experiences an augmentation by about 9.5%. TCAD simulation results show that this HEMT structure is more effective than conventional HEMT in terms of enhanced mode operation and device parameters.