Morphology characterization and growth of GaAs nanowires on Selective-area substrates

• Published in: Chemical physics letters 2021-09, Vol.779, p.138887, Article 138887
• Main Authors: Zeng, Li-Na, Li, Lin, Yang, Yun-fan, Liu, Zhao-yue, Li, Zai-Jin, Zhao, Zhi-bin, Chen, Hao, Qiao, Zhong-Liang, Qu, Yi, Liu, Guo-Jun
• Format: Article
• Language: English
• Subjects: Epitaxial growth; Microstructure; Nanowires; Semiconductors
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/j.cplett.2021.138887

The nanowires are influenced by the patterned substrate and the distribution of alloy particles, showing a distribution of “one hole with one particle” along the circular holes of the substrate. [Display omitted] •Two nanowire epitaxial growth methods, a catalyzed and selective-area epitaxial.•Incorporates the controllability of the selective-area growth method.•GaAs nanowires having "one hole with one nanowire" controllable distribution. Gold (Au)-catalyzed and catalyst-free gallium arsenide (GaAs) nanowires (NWs) were grown on GaAs substrates with mask patterns by metal–organic chemical vapor deposition (MOCVD). Catalyst-free GaAs NWs with hexagonal prism morphology were observed by scanning electron microscopy (SEM). The growth rate of catalyst-free GaAs NWs was reduced to nearly 5.5% of that of NWs grown using a vapor–liquid–solid (VLS) mechanism. By coating Au as a catalyst on selective-area substrates with the same thickness of Au film, an increased growth was observed. The diameter of the Au-catalyzed NWs grown on selective-area substrates was roughly reduced to 40%, resulting in multiple NWs being squeezed into the same hole. GaAs NWs with cylindrical geometry on selective-area substrates were produced by adjusting the thickness of the Au film, and thus, a single NW could be contained in one hole as the Au film thickness increased.