气相沉积技术在原子制造领域的发展与应用

随着未来信息器件朝着更小尺寸、更低功耗和更高性能方向的发展,构建器件的材料尺寸将进一步缩小.传统的"自上而下"技术在信息器件发展到纳米量级时遇到瓶颈,而气相沉积技术由于其能在原子尺度构筑纳米结构引起极大关注,被认为是最有潜力突破现有制造极限进而在原子尺度构造、搭建物质形态的"自下而上"方法.本文重点讨论适用于低维材料的原子尺度制造的分子束外延技术和原子层沉积/刻蚀技术.简要介绍相关技术中蕴含的科学原理及其在纳米信息器件加工和制造领域的应用,并探讨如何在原子尺度实现对低维功能材料厚度和微观形貌的精密控制.

Development and application of vapor deposition technology in atomic manufacturing

With the development of future information devices towards smaller size,lower power consumption and higher performance,the size of materials used to build devices will be further reduced.Traditional"top-down"technology has encountered a bottleneck in the development of information devices on a nanoscale,while the vapor deposition technology has attracted great attention due to its ability to construct nanostructures on an atomic scale,and is considered to have the most potential to break through the existing manufacturing limits and build nano-structures directly with atoms as a"bottom-up"method.During molecular beam epitaxy,atoms and molecules of materials are deposited on the surface in an"atomic spray painting"way.By such a method,some graphene-like two-dimensional materials(e.g.,silicene,germanene,stanene,borophene)have been fabricated with high quality and show many novel electronic properties,and the ultrathin films(several atomic layers)of other materials have been grown to achieve certain purposes,such as NaCl ultrathin layers for decoupling the interaction of metal substrate with the adsorbate.In an atomic layer deposition process,which can be regarded as a special modification of chemical vapor deposition,the film growth takes place in a cyclic manner.The self-limited chemical reactions are employed to insure that only one monolayer of precursor(A)molecules is adsorbed on the surface,and the subsequent self-limited reaction with the other precursor(B)allows only one monolayer of AB materials to be built.And the self-assembled monolayers composed of usually long-chain molecules can be introduced as the active or inactive layer for area-selective atomic layer deposition growth,which is very useful in fabricating nano-patterned structures.As the reverse process of atomic layer deposition,atomic-layer etching processes can remove certain materials in atomic precision.In this paper we briefly introduce the principles of the related technologies and their applications in the field of nano-electronic device processing and manufacturing,and find how to realize the precise control of the thickness and microstructure of functional materials on an atomic scale.