The advent of new technologies in the nanoscience arena require new and improved methods for the fabrication of multiscale features (e.g. from micro- to nanometer scales). Specifically, biological applications generally demand the use of transparent substrates to allow for the optical monitoring of processes of interest in cells and other biological materials. While wet etching methods commonly fail to produce essential nanometer scale features, plasma-based dry etching can produce features down to tens of nanometers. However, dry etching methods routinely require extreme conditions and extra steps to obtain features without residual materials such as sidewall deposits (veils). This work presents a significant improvement to previously developed methods utilizing dry etching. The etching of Au films can be carried out at room temperature and mild pressure producing features down to 50 nm. By controlling the oxygen percentage in the plasma features with aspect ratios of 2 can be obtained in one single step and without sidewall deposits. This method generates surfaces completely flat and ready for the deposition of other materials. The gold features that were produced by this method exhibited high conductivity when carbon nanotubes were deposited on top of patterned features (gold nanoelectrodes) providing a close circuit, hence demonstrating the functionality of the gold features after the dry etching process. The production of gold nano features on glass substrates open the possibility for the use of these biocompatible, high conductive and chemically stable materials in biological/biomedical applications.
Reactive Ion Etching, Nanofeatures, Gold nano electrodes, multi scale etching