title: Comparison of recessed gate-head structures on normally-off AlGaN/GaN high-electron-mobility transistor performance.
abstract: In this work, different gate-head structures have been compared in the context of AlGaN/GaN-based high-electron-mobility transistors (HEMTs). Field-plate (FP) technology self-aligned to the gate electrode leads to various gate-head structures, most likely gamma (γF)-gate, camel (see symbol)-gate, and mushroom-shaped (T)-gate. In-depth comparison of recessed gate-head structures demonstrated that key performance metrics such as transconductance, output current, and breakdown voltage are better with the T-gate head structure. The recessed T-gate with its one arm toward the source side not only reduces the source-access resistance (R(g) +R(gs)), but also minimizes the source-side dispersion and current leakage, resulting in high transconductance (G(m)) and output current (I(DS)). At the same time, the other arm toward the drain-side reduces the drain-side dispersion and tends to distribute electric field peaks uniformly, resulting in high breakdown voltage (V(BR)). DC and RF analysis showed that the recessed T-gate FP-HEMT is a suitable candidate not only for high-frequency operation, but also for high-power applications.
authors.forename: Mansoor Ali
authors.initials: MA
authors.lastname: Khan
authors.forename: Jun-Woo
authors.initials: JW
authors.lastname: Heo
authors.forename: Hyun-Seok
authors.initials: HS
authors.lastname: Kim
authors.forename: Hyun-Chang
authors.initials: HC
authors.lastname: Park
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry*; D004581:Electronics / Q000379:methods*; D005708:Gallium / Q000737:chemistry*
chemical_list: D017607:Aluminum Compounds; C513700:aluminum gallium nitride; C473348:gallium nitride; D005708:Gallium