Nanoscale characterization of unintentional doping of atomically thin layered semiconductors by scanning nonlinear dielectric microscopy
Nanoscale characterization of unintentional doping of atomically thin layered semiconductors by scanning nonlinear dielectric microscopy
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DOI：
10.1063/5.0016462
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发表时间：
2020-08
影响因子：
3.2
通讯作者：
K. Yamasue;Yasuo Cho
中科院分区：
文献类型：
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作者：
K. Yamasue;Yasuo Cho
我们使用扫描非线性介电显微镜（SNDM）观察了在二氧化硅上机械剥离的少层铌掺杂MoS 2的无意载流子掺杂。SNDM可以在纳米尺度上对脱落样品中的大多数载流子分布进行成像。我们发现，与厚的MoS 2层不同，随着厚度的减小，原子薄层表现出p到n型的转变。观察到的无意n掺杂水平估计为1 × 10 13 cm−2，与先前独立研究的结果一致。此外，还研究了紫外-臭氧处理对多数载流子分布的影响。n型掺杂随加工时间的增加而发展。SNDM可以很容易地应用于原子薄层半导体，即使在制造过程的早期阶段，也将促进对器件特性的理解和预测能力。
We use scanning nonlinear dielectric microscopy (SNDM) to visualize unintentional carrier doping of few-layer Nb-doped MoS 2 mechanically exfoliated on SiO 2. SNDM enables imaging of the majority carrier distribution in as-exfoliated samples at the nanoscale. We show that, unlike thick MoS 2 layers, atomically thin layers exhibit a p- to n-type transition as the thickness decreases. The level of the observed unintentional n-doping is estimated to be 1 × 10 13 cm − 2, in agreement with the results of previous independent studies. In addition, the influence of ultraviolet–ozone treatment on the majority carrier distribution is also investigated. The n-type doping is observed to progress with increasing processing time. SNDM can be readily applied to atomically thin layered semiconductors and will advance understanding of and the ability to predict device characteristics even at an early stage of the fabrication process.