The reduction in size of field-effect transistors (FETs) comprised of 3D semiconductors is confronted with the issues such as short-channel effects, tunneling effects and thermal dissipation. The emergence of transition metal dichalcogenides (TMDCs) atomic layers has opened up unprecedented opportunities for scaling down of the electronics in view of their unique layered-structure and excellent properties. TMDCs grown directly on high-k dielectric substrates are beneficial for fabricating high-performance FETs. Here, we demonstrate the direct growth of atomically thin MoS2 flakes on high-κ dielectric (HfO2) substrates via a chemical vapor deposition process. The morphology and structure of the as-grown materials were systemically investigated by optical microscope, atomic force microscope, Raman spectroscopy, photoluminescence, transmission electron microscope and X-ray photoelectron spectroscopy. The MoS2 flakes are approximately 5–10 µm in size with polycrystalline monolayer structure. The optical properties of the MoS2 flakes are also found to be substrate-dependent due to optical interference. In addition, back-gate FETs based on the as-grown MoS2 were fabricated and their performance was investigated. The results indicate that the n-type FETs show high on/off current ratio of ~ 106 and a carrier mobility of 9.75 cm2 V−1 s−1.

中文翻译：

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通过化学气相沉积在高 κ 衬底上生长原子级薄的 MoS2 薄片

由 3D 半导体组成的场效应晶体管 (FET) 的尺寸减小面临着诸如短沟道效应、隧道效应和热耗散等问题。鉴于其独特的层状结构和优异的性能，过渡金属二硫属化物（TMDC）原子层的出现为缩小电子器件的尺寸开辟了前所未有的机会。直接在高 k 介电基板上生长的 TMDC 有利于制造高性能 FET。在这里，我们展示了通过化学气相沉积工艺在高 κ 电介质 (HfO2) 衬底上直接生长原子级薄的 MoS2 薄片。通过光学显微镜、原子力显微镜、拉曼光谱、光致发光、透射电子显微镜和 X 射线光电子能谱。MoS2 薄片大小约为 5-10 µm，具有多晶单层结构。由于光学干涉，还发现 MoS2 薄片的光学性质与基材有关。此外，还制造了基于生长的 MoS2 的背栅 FET，并研究了它们的性能。结果表明，n 型 FET 显示出~106 的高开/关电流比和 9.75 cm2 V-1 s-1 的载流子迁移率。制造了基于生长的 MoS2 的背栅 FET，并研究了它们的性能。结果表明，n 型 FET 显示出~106 的高开/关电流比和 9.75 cm2 V-1 s-1 的载流子迁移率。制造了基于生长的 MoS2 的背栅 FET，并研究了它们的性能。结果表明，n 型 FET 显示出~106 的高开/关电流比和 9.75 cm2 V-1 s-1 的载流子迁移率。