Chang L.-CHsu K.-CHo Y.-TTzeng W.-CHo Y.-LCHAO-HSIN WU2021-09-022021-09-02202021686734https://www.scopus.com/inward/record.uri?eid=2-s2.0-85084924058&doi=10.1109%2fJEDS.2020.2987597&partnerID=40&md5=b71c5983fa049fa96d10fb8e706598f2https://scholars.lib.ntu.edu.tw/handle/123456789/580568In this letter, we successfully demonstrated a AlGaN/GaN high-electron mobility transistor on silicon substrate with high product of maximum oscillation frequency (fmax) and gate length (LG) by reducing the gate resistance (Rg) using a thick, high aspect ratio rectangular gate (R-gate) structure with an LG of 265 nm and thickness of 315 nm which was fabricated using a thick polymethyl methacrylate lift-off process. The maximum drain current is over 1 A/mm, and the peak transconductance is 291 mS/mm. The values of cutoff frequency and fmax are 43.7 GHz and 126.5 GHz at a drain voltage (Vd) of 12 V, respectively. Rg is extracted through the small-signal model, and the value is given as 0.21-{Omega } -mm which is comparable to devices with the T-gate structure. This low Rg results in a high fmax and high text{f}{max }times {mathrm{ L}}{mathrm{ G}} product of 33.52 GHz- mu text{m} , comparable to previously reported GaN-on-Si transistors for both R-gate and T-gate structures. ? 2013 IEEE.Aluminum gallium nitride; Aspect ratio; Cutoff frequency; Drain current; Gallium nitride; III-V semiconductors; Polymethyl methacrylates; Silicon; AlGaN/GaN high electron mobility transistors; High aspect ratio; Lift-off process; Maximum drain current; Maximum oscillation frequency; Peak transconductance; Silicon substrates; Small signal model; High electron mobility transistorsjournal article10.1109/JEDS.2020.29875972-s2.0-85084924058