Integrating high-κ dielectrics with a small equivalent oxide thickness (EOT) with two-dimensional (2D) semiconductors for low-power consumption van der Waals (vdW) heterostructure electronics remains challenging in meeting both interface quality and dielectric property requirements. Here, we demonstrate the integration of ultrathin amorphous HfO_x sandwiched within vdW heterostructures by the selective thermal oxidation of HfSe₂ precursors. The self-cleaning process ensures a high-quality interface with a low interface state density of 10¹¹–10¹² cm^–2 eV^–1. The synthesized HfO_x displays excellent dielectric properties with an EOT of ∼1.5 nm, i.e., a high κ of ∼16, an ultralow leakage current of 10^–6 A/cm², and an impressively high breakdown field of 9.5 MV/cm. This facilitates low-power consumption vdW heterostructure MoS₂ transistors, demonstrating steep switching with a low subthreshold swing of 61 mV/decade. This one-step integration of high-κ dielectrics into vdW sandwich heterostructures holds immense potential for developing low-power consumption 2D electronics while meeting comprehensive dielectric requirements.

中文翻译：

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超薄氧化铪与洁净范德华界面的集成，用于二维三明治异质结构电子器件

将具有小等效氧化物厚度 (EOT) 的高 K 电介质与二维 (2D) 半导体集成以实现低功耗范德华 (vdW) 异质结构电子器件在满足界面质量和介电性能要求方面仍然具有挑战性。在这里，我们展示了通过 HfSe ₂前驱体的选择性热氧化将超薄非晶 HfO _x夹在 vdW 异质结构中。自清洁工艺确保了高质量的界面，界面态密度低至10 ¹¹ –10 ¹² cm ^–2 eV ^–1。合成的 HfO _x显示出优异的介电性能，EOT 约为 1.5 nm，即 κ 约为 16，超低漏电流为 10 ^–6 A/cm ²，以及令人印象深刻的高击穿电场为 9.5 MV/cm。这有利于低功耗 vdW 异质结构 MoS ₂晶体管，展示了具有 61 mV/十倍频程的低亚阈值摆幅的陡峭开关。这种将高 κ 电介质一步集成到 vdW 夹层异质结构中的做法，在满足综合电介质要求的同时，具有开发低功耗二维电子器件的巨大潜力。