Tip etching system and method for etching platinum-containing wire

摘要

A tip and substrate preparation system for use with scanning probe microscopes (SPMs) includes a scanning tunneling microscope (STM) tip maker, STM tip coater, a substrate treatment method for producing clean, flat gold substrates for STM use and methods for preparing chemically activated substrates for use with an atomic force microscope (AFM). The tip maker includes a coater and an etcher which are preferably controlled by electronic controllers. The etcher provides fully automatic tip etching in a two-stage process in sodium hydroxide (NaOH) solution, permitting platinum alloys to be etched without the use of cyanide-containing chemicals. The coater is used to insulate the tips with soft polymer coatings so as to ensure very low tip leakage current (on the order of about 1 pA typical). The substrate treatment device comprises a quartz plate and a quartz torch for annealing substrates in a hydrogen flame. The chemically activated substrates for atomic force microscopy permit the surface of mica to be modified at will so as to be hydrophobic, hydrophilic, positively or negatively charged.