L_G 55 nm T-gate InGaN/GaN channel based high electron mobility transistors for stable transconductance operation

Nonlinearity operation and early gain suppression limit the high-frequency operation of GaN-HEMTs. Nonlinear transconductance and resistance drop-off at relatively large V_GS are the major sources for the nonlinear operation of the high electron mobility transistors (HEMTs). In this article, we present the In_0.1Ga_0.9N channel-based HEMTs for stable transconductance operation. The device performance is evaluated for both Al_0.3Ga_0.7N, and In_0.17Al_0.83N barrier materials with silicon nitride passivation. The In_0.17Al_0.83N/In_0.1Ga_0.9N/GaN heterostructure device shows remarkable improvement in gate voltage swing than Al_0.3Ga_0.7N/In_0.1Ga_0.9N/GaN. L_G 55 nm T-gate In_0.17Al_0.83N/In_0.1Ga_0.9N HEMT exhibited 5 A/mm of maximum drain current density (I_{DS, max}) for 1 V gate bias, 0.72 S/mm of stable transconductance (g_m,max), 43.5 V of off-state breakdown voltage (V_BR), and 275/289 GHz of f_T/f_max. The HEMT with AlGaN/InGaN/GaN heterostructure showed 2.81 A/mm of maximum drain current density for 1 V gate bias, 0.66 S/mm of stable transconductance, 55.3 V of V_BR, and 252/263 GHz of f_T/f_max. Moreover, a highest theoretical OIP3 value of 61.2 and 67.6 dBm obtained for AlGaN and InAlN barrier HEMTs, respectively. The proposed InGaN/GaN channel-based HEMTs are more reliable for high-frequency linear operation.