材料化学-纳米材料4.pdfVIP

Scanning Probe Microscope (SPM) Lithography Or Scanning Probe Lithography (SPL) A Scanning Probe Microscope tip, such as an Atomic Force Microscope (AFM) or Scanning Tunneling Microscope (STM) tip, is used to locally modify a surface, much like a pen or knife Scanning Probe Lithography (SPL) • Mechanical scratching •Anodization of Si surface • Electrochemical decomposition of self-assembled monolayer • Electrofield induced chemical reaction • Electrochemical reaction in solution using protected STM tips •Optical or Optical-Assisted Lithography • AFM Dip-Pen Nanolithography (DPN) Mechanical Modification of Surface modification by STM Surface with AFM Tip tip with a voltage and current, line spacing is 3nm Line pattern created by Surface oxidation of silicon NSOM-based Lithography surface by STM Ag line obtained by electrochemical reduction SEM image of Chromium of Ag+ in solution with Lines created by… STM Dip-Pen Nanolithography Dip-Pen Nanolithography (DPN) is an AFM lithography technique where molecules are transported from AFM tip to surface to form nanostructures Water meniscus spontaneously condenses between AFM tip and surface, which facilitates transport of the molecules from tip to surface. Deposition occurs due to surface affinity of the solutes. From Piner et. al, Science 283, 661. Previous efforts (by Chad Mirkin, NWU): • serial patterning of alkanethiols on gold • parallel patterning using several AFM tips • patterning alkanethiol-based etch resists •Patterning hexamethyldithilathane on semiconductor surfaces Dip-Pen Nanolithography Richard D. Piner, Jin