三维金属和二维半导体之间的范德瓦尔斯接触
Yan Wang1,2, Jong Chan Kim3, Ryan J Wu4
1Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, UK.
Nature
|March 29, 2019
概括
研究人员为二维半导体如二硫化 (MoS2) 开发了超清德瓦尔斯接触器. 这种金属半导体接口的突破使得具有显著降低接触阻力的高性能场效晶体管成为可能.
科学领域:
- 材料科学
- 凝聚物质物理学
- 纳米技术
背景情况:
- 金属半导体接口的高接触电阻限制了电场效应晶体管的性能,特别是在缩小设备尺寸的情况下.
- 像二硫化 (MoS2) 这样的二维材料对于超薄晶体管来说是有前途的,但它们的接触电阻很高.
- 现有的范德瓦尔斯接触通常涉及转移材料或多层二维半导体,留下单层应用的空白.
研究的目的:
- 为了证明3D金属和单层2D过渡金属二二烯酸之间的超清范德瓦尔斯接触.
- 研究新型金属半导体连接点的接口特性和接触阻力.
- 使用二维材料实现高性能场效晶体管.
主要方法:
- 使用单层MoS2上覆盖100nm黄金的10nm制造接触器.
- 在200°C下火,形成金固溶液.
- 使用扫描传输电子显微镜 (STEM) 进行表征,以确认接口质量和粘合.
主要成果:
- 通过金属和单层MoS2之间的范德瓦尔斯型粘合,实现了原子利的超清接口.
- 单层MoS2的测量接触电阻为3000 ± 300 Ω·μm,少层MoS2的测量电阻为800 ± 200 Ω·μm.
- 在其他2D材料如NbS2,WS2和WSe2上显示出高场效晶体管移动性 (167±20cm2/Vs) 和低接触电阻.
结论:
- 在单层二维半导体上使用简单标准实验室方法成功实现超清德瓦尔斯接触.
- 开发的接触策略显著降低了接触阻力,为高性能二维电子设备铺平了道路.
- 这种方法为各种二维过渡金属二化物制造高质量接口提供了多功能途径.
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