Herein, a high-quality gate stack (native HfO₂ formed on 2D HfSe₂) fabricated via plasma oxidation is reported, realizing an atomically sharp interface with a suppressed interface trap density (D_it ≈ 5 × 10¹⁰ cm⁻² eV⁻¹). The chemically converted HfO₂ exhibits dielectric constant, κ ≈ 23, resulting in low gate leakage current (≈10⁻³ A cm⁻²) at equivalent oxide thickness ≈0.5 nm. Density functional calculations indicate that the atomistic mechanism for achieving a high-quality interface is the possibility of O atoms replacing the Se atoms of the interfacial HfSe₂ layer without a substitution energy barrier, allowing layer-by-layer oxidation to proceed. The field-effect-transistor-fabricated HfO₂/HfSe₂ gate stack demonstrates an almost ideal subthreshold slope (SS) of ≈61 mV dec⁻¹ (over four orders of I_DS) at room temperature (300 K), along with a high I_on/I_off ratio of ≈10⁸ and a small hysteresis of ≈10 mV. Furthermore, by utilizing a device architecture with separately controlled HfO₂/HfSe₂ gate stack and channel structures, an impact ionization field-effect transistor is fabricated that exhibits n-type steep-switching characteristics with a SS value of 3.43 mV dec⁻¹ at room temperature, overcoming the Boltzmann limit. These results provide a significant step toward the realization of post-Si semiconducting devices for future energy-efficient data-centric computing electronics.

中文翻译：

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适用于低功耗陡峭开关计算设备的高 K 电介质 (HfO2)/2D 半导体 (HfSe2) 门堆栈

在此，报道了通过等离子体氧化制造的高质量栅极堆叠（在2D HfSe _{2上形成的天然HfO 2}），实现了具有抑制的界面陷阱密度的原子级尖锐界面（D _it ≈ 5 × 10 ¹⁰ cm ^-2 eV ^-1）。化学转化的HfO ₂表现出介电常数κ ≈ 23，从而在等效氧化物厚度约0.5 nm时产生低栅极漏电流(约10 ^-3 A cm ^-2 )。密度泛函计算表明，实现高质量界面的原子机制是O原子在没有取代能垒的情况下取代界面HfSe ₂层中的Se原子，从而允许逐层氧化进行。场效应晶体管制造的 HfO ₂ /HfSe ₂栅极堆叠在室温 (300 K) 下表现出近乎理想的亚阈值斜率 (SS) 约 61 mV dec ^{-1 （超过}I _DS的四个数量级），以及高I_开/关_比≈10 ⁸和小滞后 ≈10 mV。此外，通过利用具有单独控制的HfO ₂ /HfSe ₂栅极堆叠和沟道结构的器件架构，制造了碰撞电离场效应晶体管，该晶体管表现出n型陡峭开关特性，在室温下SS值为3.43 mV dec ^-1室温下，克服了玻尔兹曼极限。这些结果为实现未来高能效、以数据为中心的计算电子设备的后硅半导体器件迈出了重要一步。