A custom double-lamella method is presented for electrochemically etchingtungsten wire for use as tips in scanning tunneling microscopy (STM). Forcomparison, tips were also manufactured in-house using numerous conventionalmethods and examined using an optical microscope. Both sets of tips were usedto obtain STM images of highly-oriented pyrolytic graphite, the quality ofwhich varied. The clarity of the STM images was found to be correlated to theoptically-measured cone angle of the STM tip, with larger cone anglesconsistently producing atomically resolved images. The custom etching proceduredescribed allows one to create larger cone angles and consequently provedsuperior in reliably producing high-quality tips.
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