Low-resistance ohmic contacts in AlGaN/GaN high-electron-mobility transistor (HEMT) devices require high-temperature (HT) annealing (> 800 °C) which can deteriorate material quality, surface morphology, and edge acuity of the metal stacks. This article demonstrates the high-frequency and high-power performance of the AlGaN/GaN HEMT devices with low-temperature metal-organic chemical vapor deposition (MOCVD) regrown degenerately doped InGaN ohmic contacts compared with GaN-based regrown contacts. Ohmic contacts fabricated by regrowth methods could be a valuable alternative for both metal-based alloyed ohmic contacts and implantation-based ohmic contacts. Using a T-gate and MOCVD regrown InGaN ohmic contacts, the AlGaN/GaN HEMT with an ${L}_{g}$ of 150 nm and S-D spacing of $2.5~\mu \text{m}$ demonstrated a maximum drain current of 0.94 A/mm and a peak transconductance of 337 mS/mm. The same device exhibited a forward current gain frequency ${f}_{t}$ of 36.8 GHz and a maximum frequency of oscillation ${f}_{\text {max}}$ of 75.0 GHz. A power density of 3.07 W/mm with a 60% drain efficiency was measured at 35 GHz with a ${V}_{\text {ds}}$ of 20 V and a quiescent current of 100 mA/mm.

中文翻译：

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具有InGaN的MOCVD再生的AlGaN / GaN HEMT中的非合金欧姆接触 K a-频段应用

AlGaN / GaN高电子迁移率晶体管（HEMT）器件中的低电阻欧姆接触需要高温（HT）退火（> 800°C），这会降低材料质量，表面形态和金属堆叠的边缘敏锐度。本文展示了与基于GaN的再生长触点相比，具有低温金属有机化学气相沉积（MOCVD）再生长的简并掺杂InGaN欧姆接触的AlGaN / GaN HEMT器件的高频和高功率性能。对于基于金属的合金欧姆接触和基于植入的欧姆接触，通过再生长方法制造的欧姆接触可能是有价值的替代方法。使用T栅极和MOCVD再生长的InGaN欧姆接触，AlGaN / GaN HEMT具有 $ {L} _ {g} $ 150 nm和SD间距 $ 2.5〜\ mu \ text {m} $ 最大漏极电流为0.94 A / mm，峰值跨导为337 mS / mm。同一器件表现出正向电流增益频率 $ {f} _ {t} $ 36.8 GHz和最大振荡频率 $ {f} _ {\ text {max}} $ 75.0 GHz。在35 GHz频率下测得的功率密度为3.07 W / mm，漏极效率为60％ $ {V} _ {\ text {ds}} $ 20 V的静态电流和100 mA / mm的静态电流。