Lattice-Matched AlInN/GaN/AlGaN/GaN Heterostructured-Double-Channel Metal-Oxide-Semiconductor High-Electron Mobility Transistors with Multiple-Mesa-Fin-Channel Array

Abstract

Multiple-mesa-fin-channel array patterned by a laser interference photolithography system and gallium oxide (Ga2O3) gate oxide layer deposited by a vapor cooling condensation system were employed in double-channel Al0.83In0.17N/GaN/Al0.18Ga0.82N/GaN heterostructured-metal-oxide-semiconductors (MOSHEMTs). The double-channel was constructed by the polarized Al0.18Ga0.82N/GaN channel 1 and band discontinued lattice-matched Al0.83In0.17N/GaN channel 2. Because of the superior gate control capability, the generally induced double-hump transconductance characteristics of double-channel MOSHEMTs were not obtained in the devices. The superior gate control capability was contributed by the side-wall electrical field modulation in the fin-channel. Owing to the high-insulating Ga2O3 gate oxide layer and the high-quality interface between the Ga2O3 and GaN layers, low noise power density of 8.7 × 10−14 Hz−1 and low Hooge’s coefficient of 6.25 × 10−6 of flicker noise were obtained. Furthermore, the devices had a unit gain cutoff frequency of 6.5 GHz and a maximal oscillation frequency of 12.6 GHz.

Performance Comparison of Lattice-Matched AlInN/GaN/AlGaN/GaN Double-Channel Metal–Oxide–Semiconductor High-Electron Mobility Transistors with Planar Channel and Multiple-Mesa-Fin-Channel Array

“…Regarding the simulation of a one-dimensional (1D) Schrödinger–Poisson solver, double two-dimensional electron gas (2-DEG) channels were formed at the polarized Al 0.18 Ga 0.82 N/GaN interface and the band-discontinued lattice-matched Al 0.83 In 0.17 N/GaN interface [ 29 ]. Using a Hall measurement (Ecopia Crop., Anyang, Korea) at room temperature, the equivalent electron mobility of 1770 cm 2 /V-s and the equivalent sheet electron density of 1.11 × 10 13 cm −2 were measured.…”

“…In addition to the 500-nm-wide strip channel array patterned using an He-Cd laser interference photolithography system, similar fabrication processes of planar devices were utilized for fabricating devices with multiple-mesa-fin-channel array. However, within the same channel width of 50 μm, the total real channel width in the multiple-mesa-fin-channel array was 25.2 μm [ 29 ].…”

“…It was worth noting that the real drain–source current in the devices with multiple-mesa-fin-channel array was less than that of the planar devices. When the on-resistance (R on ) of the devices was defined as the inverse slope of the I DS −V DS characteristics at V DS = 0 V and V GS = 5 V, the R on = 10.2 Ω-mm of the planar devices was calculated and compared with the R on = 6.1 Ω-mm of the devices with multiple-mesa-fin-channel array [ 29 ].…”

“…The extrinsic unit gain cutoff frequency (f T ) of 5.7 GHz and the maximum oscillation frequency (f max ) of 10.5 GHz of the planar devices were obtained. For the MOSHEMTs with multiple-mesa-fin-channel array, the f T and f max were 6.5 GHz and 12.6 GHz, respectively [ 29 ].…”

“…In this study, before depositing the Ga 2 O 3 gate oxide layer, an (NH 4 ) 2 S x chemical solution was used to treat the sample surface to completely remove the undesired native oxide residing on the surface of the GaN-based semiconductors [ 28 ]. Recently, lattice-matched double-channel AlInN/GaN/AlGaN/GaN MOSHEMTs with multiple-mesa-fin-channel array were reported [ 29 ]. Although the compared performances of signal-channel MOSHEMTs with planar channel and multiple-mesa-fin-channel array were reported previously [ 30 , 31 ], a comparison of the performances of the multiple-channel MOSHEMTs with planar channel and multiple-mesa-fin-channel array has not yet been carried out.…”