We have demonstrated a novel method of depositing ALD-Al ₂ O ₃ /PECVD-SiO ₂ bi-layer dielectric to passive the surface channels of the hydrogen-terminated diamond (H-diamond). After Al ₂ O ₃ /SiO ₂ passivation, the surface current increased with time and then tended to be saturated. Afterwards, it became much more stable and showed a larger current than an unpassivated counterpart. The H-diamond MOSFETs were fabricated by using this bi-layer passivation structure and an extremely low Ohmic contact resistance of $0.87~\Omega \cdot $ mm was obtained. The H-diamond RF MOSFET with gate length of $0.45~{\mu }\text{m}$ achieved a high current density of −549 mA/mm and an extrinsic ${f} _{\mathrm{ T}}/{f}_{\max }$ of 15/36 GHz. By load-pull measurement, a high output power density of 1.04 W/mm was obtained at frequency of 2 GHz. The results reveal that it is a promising solution for high-stable and high-power diamond transistors by using the Al ₂ O ₃ /SiO ₂ bi-layer passivation.

中文翻译：

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具有2 GHz的Al ₂ O ₃ / SiO ₂双层钝化的H端金刚石MOSFET的1 W / mm输出功率密度

我们已经展示了一种沉积ALD-Al ₂ O ₃ / PECVD-SiO ₂双层电介质以钝化氢封端金刚石（H-金刚石）的表面通道的新颖方法 。Al ₂ O ₃ / SiO ₂钝化后，表面电流随时间增加，然后趋于饱和。之后，它变得更加稳定，并且比未钝化的同类产品显示出更大的电流。通过使用这种双层钝化结构和极低的欧姆接触电阻，可以制造H金刚石MOSFET。 $ 0.87〜\ Omega \ cdot $ 获得毫米。栅极长度为H的H金刚石RF MOSFET $ 0.45〜{\ mu} \ text {m} $ 实现了−549 mA / mm的高电流密度和非本征 $ {f} _ {\ mathrm {T}} / {f} _ {\ max} $ 15/36 GHz。通过负载牵引测量，在2 GHz的频率下获得了1.04 W / mm的高输出功率密度。结果表明，通过使用Al ₂ O ₃ / SiO ₂双层钝化技术，它是用于高稳定性和高功率金刚石晶体管的有前途的解决方案 。