Laboratoire Nanotechnologies Nanosystèmes (LN2) - CNRS UMI-3463, Institut Interdisciplinaire d'Innovation Technologique (3IT), Université de Sherbrooke, 3000 Boulevard Université, Sherbrooke, J1K OA5, Québec, Canada.
Nanoelectronics-Nanophotonics INRS-EMT, 1650, Boul. Lionel-Boulet, Varennes, J3X 1S2, Québec, Canada.
Small. 2017 May;13(18). doi: 10.1002/smll.201603269. Epub 2017 Mar 15.
The ultimate performance of a solid state device is limited by the restricted number of crystalline substrates that are available for epitaxial growth. As a result, only a small fraction of semiconductors are usable. This study describes a novel concept for a tunable compliant substrate for epitaxy, based on a graphene-porous silicon nanocomposite, which extends the range of available lattice constants for epitaxial semiconductor alloys. The presence of graphene and its effect on the strain of the porous layer lattice parameter are discussed in detail and new remarkable properties are demonstrated. These include thermal stability up to 900 °C, lattice tuning up to 0.9 % mismatch, and compliance under stress for virtual substrate thicknesses of several micrometers. A theoretical model is proposed to define the compliant substrate design rules. These advances lay the foundation for the fabrication of a compliant substrate that could unlock the lattice constant restrictions for defect-free new epitaxial semiconductor alloys and devices.
固态器件的最终性能受到可用的外延生长晶态衬底数量的限制。因此，只有一小部分半导体是可用的。本研究描述了一种基于石墨烯-多孔硅纳米复合材料的可调谐顺应衬底的新概念，该复合材料扩展了外延半导体合金可用的晶格常数范围。详细讨论了石墨烯的存在及其对多孔层晶格参数应变的影响，并展示了新的显著特性。这些特性包括高达 900°C 的热稳定性、高达 0.9%的晶格调谐不匹配以及在数微米的虚拟衬底厚度下的应力下的顺应性。提出了一个理论模型来定义顺应衬底的设计规则。这些进展为制造顺应衬底奠定了基础，该衬底可以为无缺陷的新外延半导体合金和器件释放晶格常数限制。
