Abstract This paper reports a novel ALD-AlOx/PECVD-SiNx bi-layer structure to passivate the surface channels of the hydrogen terminated diamond transistors. The upper SiNx was selectively etched to fabricate the robust T-shaped gates, while the lower thin AlOx with high quality was retained as the gate insulator. The fabricated device with gate length of 0.3 μm demonstrated a high current density of 715 mA/mm, a low on-resistance of 8 Ω·mm, and an extrinsic fT/fmax of 10/20 GHz. RF power output characteristics were investigated at 2 GHz and a maximum output power density of 703 mW/mm was obtained at a low drain voltage of −15 V. It reveals that it is a promising solution for high stable and high power diamond RF transistors and microwave integrated circuits by using the AlOx/SiNx passivation structure.

中文翻译：

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具有 AlOx/SiNx 双层钝化和选择性蚀刻 T 形栅极的 H 端金刚石 RF MOSFET

摘要 本文报道了一种新型 ALD-AlOx/PECVD-SiNx 双层结构，用于钝化氢端金刚石晶体管的表面通道。上部 SiNx 被选择性蚀刻以制造坚固的 T 形栅极，而下部高质量的薄 AlOx 被保留作为栅极绝缘体。制造的栅极长度为 0.3 μm 的器件显示出 715 mA/mm 的高电流密度、8 Ω·mm 的低导通电阻和 10/20 GHz 的外在 fT/fmax。研究了 2 GHz 下的射频功率输出特性，在 -15 V 的低漏电压下获得了 703 mW/mm 的最大输出功率密度。采用 AlOx/SiNx 钝化结构的微波集成电路。