标题： 直接X射线测量单层MoS$_{2}$中来自覆盖层和几何特征的应变 显示英文标题

标题： Direct X-Ray Measurements of Strain in Monolayer MoS$_{2}$ from Capping Layers and Geometrical Features

摘要： 通过制造过程中图案化和覆盖层引起的应变可以用来改变二维（2D）材料或其他薄膜的特性。 在这里，我们探讨覆盖层如何通过直接的X射线衍射测量晶格来对单层MoS$_{2}$施加应变。 我们首先观察到自然氧化金属层（$\sim$1.5 nm Al）和随后沉积的Al$_{2}$O$_{3}$（厚度为15 nm至25 nm）对二维材料的影响，并发现施加到MoS$_{2}$上的应变主要由种子层的界面粘附性以及基底粘附性控制。 然后，使用模拟晶体管接触的测试结构，我们测量到这种图案相比整体薄膜产生的应变有所增强。 此外，我们观察到显著的拉伸应变——在单层MoS$_{2}$中高达2%，这是迄今为止在刚性基底上记录的最大实验值之一——这是由于高度应力的整体金属覆盖层引起的。 这些结果提供了直接证据，支持了之前关于二维材料器件中应变效应的报告。 显示英文摘要

摘要： Strain induced through fabrication, both by patterning and capping, can be used to change the properties of two-dimensional (2D) materials or other thin films. Here, we explore how capping layers impart strain to monolayer MoS$_{2}$ using direct x-ray diffraction measurements of the lattice. We first observe the impact of naturally-oxidized metal layers ($\sim$1.5 nm Al) and subsequently-deposited Al$_{2}$O$_{3}$ (15 nm to 25 nm thick) on the 2D material, and find that the strain imparted to MoS$_{2}$ is mainly controlled by the interfacial adhesion of the seed layer in addition to the substrate adhesion. Then, using test structures which mimic transistor contacts, we measure enhanced strain from such patterns compared to blanket films. Furthermore, we observe significant tensile strain - up to 2% in monolayer MoS$_{2}$, one of the largest experimental values to date on a rigid substrate - due to highly-stressed blanket metal capping layers. These results provide direct evidence supporting previous reports of strain effects in 2D material devices.