论文标题
WS2原子层的生长蚀刻金属化学蒸气沉积方法
Growth-Etch Metal-Organic Chemical Vapor Deposition Approach of WS2 Atomic-Layers
论文作者
论文摘要
金属有机化学蒸气沉积（MOCVD）是当今半导体工业中用于薄膜制造的主要方法之一，被认为是实现大规模和高质量的2D过渡金属二核苷（TMDC）的最有希望的途径之一。但是，如果不采取特殊措施，MOCVD会遭受一些严重的缺点，例如小域的大小和碳污染，导致光学和晶体质量差，这可能会抑制其用于大规模制造原子 - 薄半导体的实施。在这里，我们提出了一种生长滋养MOCVD（GE-MOCVD）方法，其中在生长过程中引入了少量的水蒸气，而前体则以脉冲传递。描述了生长的演变与水蒸气量，循环的数量和类型和气体组成的变化。相对于我们的常规过程，我们显示出显着的域大小增加。通过拉曼光谱，光致发光（PL）光谱和HRTEM研究来证明WS2（和WSE2）结构域的晶体质量的提高。此外，时间分辨的PL研究显示出很长的激子寿命，与机械剥落的薄片中观察到的寿命相当。因此，此处介绍的GE-MOCVD方法可能有助于其整合到广泛的应用中。
Metal organic chemical vapor deposition (MOCVD) is one of the main methodologies used for thin film fabrication in the semiconductor industry today and is considered one of the most promising routes to achieve large-scale and high-quality 2D transition metal dichalcogenides (TMDCs). However, if not taken special measures, MOCVD suffers from some serious drawbacks, such as small domain size and carbon contamination, resulting in poor optical and crystal quality, which may inhibit its implementation for the large-scale fabrication of atomic-thin semiconductors. Here we present a Growth-Etch MOCVD (GE-MOCVD) methodology, in which a small amount of water vapor is introduced during the growth, while the precursors are delivered in pulses. The evolution of the growth as a function of the amount of water vapor, the number and type of cycles and the gas composition is described. We show a significant domain size increase is achieved relative to our conventional process. The improved crystal quality of WS2 (and WSe2) domains was demonstrated by means of Raman spectroscopy, photoluminescence (PL) spectroscopy and HRTEM studies. Moreover, time-resolved PL studies show very long exciton lifetimes, comparable to those observed in mechanically exfoliated flakes. Thus, the GE-MOCVD approach presented here may facilitate their integration into a wide range of applications.
