The interface state of hydrogen-terminated (C–H) diamond metal–oxide–semiconductor field-effect transistor (MOSFET) is critical for device performance. In this paper, we investigate the fixed charges and interface trap states in C–H diamond MOSFETs by using different gate dielectric processes. The devices use Al₂O₃ as gate dielectrics that are deposited via atomic layer deposition (ALD) at 80 C and 300 C, respectively, and their C–V and I–V characteristics are comparatively investigated. Mott–Schottky plots (1/C ²–V _G) suggest that positive and negative fixed charges with low density of about 10¹¹ cm⁻² are located in the 80-C- and 300-C deposition Al₂O₃ films, respectively. The analyses of direct current (DC)/pulsed I–V and frequency-dependent conductance show that the shallow interface traps (0.46 eV–0.52 eV and 0.53 eV–0.56 eV above the valence band of diamond for the 80-C and 300-C deposition conditions, respectively) with distinct density (7.8 10¹³ eV⁻¹⋅cm⁻²–8.5 10¹³ eV⁻¹⋅cm⁻² and 2.2 10¹³ eV⁻¹⋅cm⁻²–5.1 10¹³ eV⁻¹⋅cm⁻² for the 80-C- and 300-C-deposition conditions, respectively) are present at the Al₂O₃/C–H diamond interface. Dynamic pulsed I–V and capacitance dispersion results indicate that the ALD Al₂O₃ technique with 300-C deposition temperature has higher stability for C–H diamond MOSFETs.

氢封端 (C-H) 金刚石金属氧化物半导体场效应晶体管 (MOSFET) 的界面态对器件性能至关重要。在本文中，我们通过使用不同的栅极介电工艺研究了 C-H 金刚石 MOSFET 中的固定电荷和界面陷阱态。这些器件使用 Al ₂ O ₃作为栅极电介质，分别在 80 C 和 300 C 下通过原子层沉积 (ALD) 沉积，并比较研究了它们的C - V和I - V特性。Mott–Schottky plots (1/ C ² – V _G ) 表明正负固定电荷密度约为 10¹¹ cm ^-2分别位于80-C-和300-C沉积Al ₂ O ₃膜中。直流 (DC)/脉冲I – V和频率相关电导的分析表明，在 80-C 和 300- C沉积条件，分别）具有不同的密度（7.8 10 ¹³ eV ^-1 ⋅cm ^-2 –8.5 10 ¹³ eV ^-1 ⋅cm ^-2和 2.2 10 ¹³ eV ^-1 ⋅cm ^-2 –5.1 10 ¹³ eV ^-1⋅cm ^-2分别用于 80-C 和 300-C 沉积条件）存在于 Al ₂ O ₃ /C-H 金刚石界面处。动态脉冲I - V和电容色散结果表明，沉积温度为 300-C 的 ALD Al ₂ O ₃技术对 C-H 金刚石 MOSFET 具有更高的稳定性。