title: Vertical Si nanowire arrays fabricated by magnetically guided metal-assisted chemical etching.
abstract: In this work, vertically aligned Si nanowire arrays were fabricated by magnetically guided metal-assisted directional chemical etching. Using an anodized aluminum oxide template as a shadow mask, nanoscale Ni dot arrays were fabricated on an Si wafer to serve as a mask to protect the Si during the etching. For the magnetically guided chemical etching, we deposited a tri-layer metal catalyst (Au/Fe/Au) in a Swiss-cheese configuration and etched the sample under the magnetic field to improve the directionality of the Si nanowire etching and increase the etching rate along the vertical direction. After the etching, the nanowires were dried with minimal surface-tension-induced aggregation by utilizing a supercritical CO2drying procedure. High-resolution transmission electron microscopy (HR-TEM) analysis confirmed the formation of single-crystal Si nanowires. The method developed here for producing vertically aligned Si nanowire arrays could find a wide range of applications in electrochemical and electronic devices.
authors.affiliation: Materials Science and Engineering, University of California at San Diego, 9500 Gilman Dr, La Jolla, CA 92093, USA. Biomaterials Center, Korea Institute of Science and Technology (KIST), Hwarang-ro 14-gil, Seongbuk-gu, Seoul, 02792, Korea.
authors.forename: Dong Won
authors.initials: DW
authors.lastname: Chun
authors.forename: Tae Kyoung
authors.initials: TK
authors.lastname: Kim
authors.forename: Duyoung
authors.initials: D
authors.lastname: Choi
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Caldwell
authors.forename: Young Jin
authors.initials: YJ
authors.lastname: Kim
authors.forename: Jae Cheol
authors.initials: JC
authors.lastname: Paik
authors.forename: Sungho
authors.initials: S
authors.lastname: Jin
authors.forename: Renkun
authors.initials: R
authors.lastname: Chen