Chromium Nanodot-array Deposition using Atomic Force Microscopy

Chromium nanodot deposition by atomic force microscopy (AFM) is demonstrated for the first time. An oscillating Cr-coated AFM cantilever is brought close to the substrate surface by the engage process in a wavemode operation and a negative tip voltage is applied to form a strong electrical field to transport the Cr atoms from the tip to the surface. An array of nine Cr nanodots around 90nm in diameter and 0.2nm to 0.3nm in height is fabricated by changing the tip positions at room temperature and in ambient conditions. It is found that the deposition is an intermittent contact process, which is avoided by most researchers for other metal nanoscale dot depositions, such as gold. A deposition mechanism is proposed, with supporting results from further experiments. Our research shows that it is possible to obtain much smaller features for application of nanoelectronics with this method by controlling the deposition time and the applied voltage.