title: Formation mechanism of SiGe nanorod arrays by combining nanosphere lithography and Au-assisted chemical etching.
abstract: The formation mechanism of SiGe nanorod (NR) arrays fabricated by combining nanosphere lithography and Au-assisted chemical etching has been investigated. By precisely controlling the etching rate and time, the lengths of SiGe NRs can be tuned from 300 nm to 1  μm. The morphologies of SiGe NRs were found to change dramatically by varying the etching temperatures. We propose a mechanism involving a locally temperature-sensitive redox reaction to explain this strong temperature dependence of the morphologies of SiGe NRs. At a lower etching temperature, both corrosion reaction and Au-assisted etching process were kinetically impeded, whereas at a higher temperature, Au-assisted anisotropic etching dominated the formation of SiGe NRs. With transmission electron microscopy and scanning electron microscopy analyses, this study provides a beneficial scheme to design and fabricate low-dimensional SiGe-based nanostructures for possible applications.
authors.affiliation: Institute of Materials Science and Engineering, National Central University, Jhongli, 32001, Taiwan. phyeh331@mail.tku.edu.tw.
authors.forename: Chih-Chung
authors.initials: CC
authors.lastname: Lai
authors.forename: Yun-Ju
authors.initials: YJ
authors.lastname: Lee
authors.forename: Ping-Hung
authors.initials: PH
authors.lastname: Yeh
authors.forename: Sheng-Wei
authors.initials: SW
authors.lastname: Lee