Self-formation of hexagonal nanotemplates for growth of pyramidal quantum dots by metalorganic vapor phase epitaxy on patterned substrates

作     者：Alessandro Surrente Romain Carron Pascal Gallo Alok Rudra Benjamin Dwir Eli Kapon 

作者机构：Laboratory of Physics of Nanostructures Ecole Polytechnique Federale de Lausanne CH- 1015 Lausanne Switzerland 

出 版 物：《Nano Research》 (纳米研究（英文版）)

年 卷 期：2016年第9卷第11期

页      面：3279-3290页

核心收录：

学科分类：080903[工学-微电子学与固体电子学] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

基　　金：The authors gratefully acknowledge funding from the Swiss National Science Foundation 

主　　题：metalorganic vapor phaseepitax kinetic Monte Carlosimulations epitaxial growth onpatterned substrates symmetry elevation adatom diffusion 

摘      要：We demonstrate the self-formation of hexagonal nanotemplates on GaAs （111）B substrates patterned with arrays of inverted tetrahedral pyramids during metal-organic vapor phase epitaxy and its role in producing high-symmetry, site-controlled quantum dots （QDs）. By combining atomic force microscopy measurements on progressively thicker GaAs epitaxial layers with kinetic Monte Carlo growth simulations, we demonstrate self-maintained symmetry elevation of the QD formation sites from three-fold to six-fold symmetry. This symmetry elevation stems from adatom fluxes directed towards the high-curvature sites of the template, resulting in the formation of a fully three-dimensional hexagonal template after the deposition of relatively thin GaAs layers. We identified the growth conditions for consistently achieving a hexagonal pyramid bottom, which are useful for producing high-symmetry QDs for efficient generation of entangled photons.