Bhat Abhishek, Elleuch Omar, Cui Xiaorui, Guan Yingxin, Scott Shelley A, Kuech Thomas F, Lagally Max G
Department of Materials Science and Engineering, University of Wisconsin, Madison, Wisconsin 53706, United States.
Department of Chemical and Biological Engineering, University of Wisconsin, Madison, Wisconsin 53706, United States.
ACS Appl Mater Interfaces. 2020 May 6;12(18):20859-20866. doi: 10.1021/acsami.0c02747. Epub 2020 Apr 27.
The growth of single crystals of Ge-rich SiGe alloys in an extended composition range is demonstrated using the nanomembrane (NM) platform and III-V growth substrates. Thin films of high-Ge-content SiGe films are grown on GaAs(001) to below the kinetic critical thickness and released from the growth substrate by selectively etching a release layer to relax the strain. The resulting crystalline nanomembranes at the natural lattice constant of the alloy are transferred to a new host and epitaxially overgrown at similar compositions to make a thicker single crystal. Straightforward critical-thickness calculations demonstrate that a very wide range of group IV alloys, including those involving Sn, can be fabricated using the NM platform and the proper choice of III-V substrate. Motivations for making new group IV alloys center on band gap engineering for the development of novel group IV optoelectronic structures and devices.
利用纳米膜（NM）平台和III-V族生长衬底，展示了在扩展成分范围内生长富锗硅锗合金单晶的过程。高锗含量的硅锗薄膜在GaAs(001)上生长至低于动力学临界厚度，通过选择性蚀刻释放层从生长衬底上释放出来，以弛豫应变。所得具有合金自然晶格常数的晶体纳米膜被转移到新的衬底上，并在相似成分下外延过度生长以制成更厚的单晶。简单的临界厚度计算表明，使用NM平台和适当选择III-V族衬底，可以制造出非常广泛的IV族合金，包括那些涉及锡的合金。制造新型IV族合金的动机主要集中在带隙工程上，以开发新型IV族光电子结构和器件。
