title: 3D LITHOGRAPHY. Atomic gold-enabled three-dimensional lithography for silicon mesostructures.
abstract: Three-dimensional (3D) mesostructured semiconductors show promising properties and applications; however, to date, few methods exist to synthesize or fabricate such materials. Metal can diffuse along semiconductor surfaces, and even trace amounts can change the surface behavior. We exploited the phenomena for 3D mesoscale lithography, by showing one example where iterated deposition-diffusion-incorporation of gold over silicon nanowires forms etchant-resistant patterns. This process is facet-selective, producing mesostructured silicon spicules with skeletonlike morphology, 3D tectonic motifs, and reduced symmetries. Atom-probe tomography, coupled with other quantitative measurements, indicates the existence and the role of individual gold atoms in forming 3D lithographic resists. Compared to other more uniform silicon structures, the anisotropic spicule requires greater force for detachment from collagen hydrogels, suggesting enhanced interfacial interactions at the mesoscale.
authors.affiliation: Department of Chemistry, the University of Chicago, Chicago, IL 60637, USA.
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Luo
authors.affiliation: Department of Chemistry, the University of Chicago, Chicago, IL 60637, USA.
authors.forename: Yuanwen
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208, USA. Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, Northwestern University, Evanston, IL 60208, USA.
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Myers
authors.affiliation: Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208, USA. The Northwestern University Center for Atom-Probe Tomography (NUCAPT), Northwestern University, Evanston, IL 60208, USA.
authors.forename: Dieter
authors.initials: D
authors.lastname: Isheim
authors.affiliation: Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208, USA. Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, Northwestern University, Evanston, IL 60208, USA.
authors.forename: Jinsong
authors.initials: J
authors.lastname: Wu
authors.affiliation: Department of Chemistry, the University of Chicago, Chicago, IL 60637, USA.
authors.forename: John F
authors.initials: JF
authors.lastname: Zimmerman
authors.affiliation: Department of Chemistry, the University of Chicago, Chicago, IL 60637, USA.
authors.forename: Zongan
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208, USA. Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, Northwestern University, Evanston, IL 60208, USA.
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Li
authors.affiliation: The James Franck Institute, the University of Chicago, Chicago, IL 60637, USA.
authors.forename: Yucai
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208, USA. Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, Northwestern University, Evanston, IL 60208, USA.
authors.forename: Xinqi
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208, USA. Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, Northwestern University, Evanston, IL 60208, USA.
authors.forename: Vinayak P
authors.initials: VP
authors.lastname: Dravid
authors.affiliation: Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208, USA. The Northwestern University Center for Atom-Probe Tomography (NUCAPT), Northwestern University, Evanston, IL 60208, USA.
authors.forename: David N
authors.initials: DN
authors.lastname: Seidman
authors.affiliation: Department of Chemistry, the University of Chicago, Chicago, IL 60637, USA. The James Franck Institute, the University of Chicago, Chicago, IL 60637, USA. The Institute for Biophysical Dynamics, Chicago, IL 60637, USA. btian@uchicago.edu.
authors.forename: Bozhi
authors.initials: B
authors.lastname: Tian