The wider bandgap AlGaN (Eg > 3.4 eV) channel-based high electron mobility transistors (HEMTs) are more effective for high voltage operation. High critical electric field and high saturation velocity are the major advantages of AlGaN channel HEMTs, which push the power electronics to a greater operating regime. In this article, we present the DC characteristics of 0.8 µm gate length (LG) and 1 µm gate-drain distance (LGD) AlGaN channel-based high electron mobility transistors (HEMTs) on ultra-wide bandgap β-Ga2O3 Substrate. The β-Ga2O3 substrate is cost-effective, available in large wafer size and has low lattice mismatch (0 to 2.4%) with AlGaN alloys compared to conventional SiC and Si substrates. A physics-based numerical simulation was performed to investigate the DC characteristics of the HEMTs. The proposed HEMT exhibits sheet charge density (ns) of 1.05 × 1013 cm−2, a peak on-state drain current (IDS) of 1.35 A/mm, DC transconductance (gm) of 277 mS/mm. The ultra-wide bandgap AlGaN channel HEMT on β-Ga2O3 substrate with conventional rectangular gate structure showed 244 V off-state breakdown voltage (VBR) and field plate gate device showed 350 V. The AlGaN channel HEMTs on β-Ga2O3 substrate showed an excellent performance in ION/IOFF and VBR. The high performance of the proposed HEMTs on β-Ga2O3 substrate is suitable for future portable power converters, automotive, and avionics applications.

Nonlinearity operation and early gain suppression limit the high‐frequency operation of GaN‐HEMTs. Nonlinear transconductance and resistance drop‐off at relatively large VGS are the major sources for the nonlinear operation of the high electron mobility transistors (HEMTs). In this article, we present the In0.1Ga0.9N channel‐based HEMTs for stable transconductance operation. The device performance is evaluated for both Al0.3Ga0.7N, and In0.17Al0.83N barrier materials with silicon nitride passivation. The In0.17Al0.83N/In0.1Ga0.9N/GaN heterostructure device shows remarkable improvement in gate voltage swing than Al0.3Ga0.7N/In0.1Ga0.9N/GaN. LG 55 nm T‐gate In0.17Al0.83N/In0.1Ga0.9N HEMT exhibited 5 A/mm of maximum drain current density (IDS, max) for 1 V gate bias, 0.72 S/mm of stable transconductance (gm,max), 43.5 V of off‐state breakdown voltage (VBR), and 275/289 GHz of fT/fmax. 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 VBR, and 252/263 GHz of fT/fmax. 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.

In this work, we present the high performance of composite channel based In 0.17 Al 0.83 N/In 0.1 Ga 0.9 N/GaN/Al 0.04 Ga 0.96 N high electron mobility transistors (HEMTs) on a sapphire substrate. A numerical simulation is carried out for the proposed and conventional GaN channel-based HEMTs using TCAD. Due to the strong polarization of InAlN/InGaN, enhanced electron confinement and high electron mobility of composite channel based proposed device shows excellent DC and RF characteristics with improved linearity than conventional GaN channel based HEMTs. A 55 nm T-gate device demonstrates 4.45 A/mm drain current density (I DS ) at V GS = 0 V, 0.7 S/mm stable transconductance (G M ) for a wide range of gate bias, and excellent F T /F max of 274/288 GHz.Benefiting from the Al 0.04 Ga 0.96 N buffer (back-barrier), the device shows a very low sub-threshold drain leakage current and high breakdown voltage (V BR ) of 43.5 V. The combination of high F T /F max , stable transconductance, and high breakdown voltage of the proposed HEMTs shows the great promise for high power and wide-bandwidth millimeter-wave applications.