Transparent Conducting Oxide (TCO) coatings play a crucial role in both photovoltaic and display technologies. In the latter technology TCO's provide a conductive electrode that is also transparent to the light emitted from the underlying display while, in the former technology, TCO's allow light to pass through the electrode to the underlying semiconductor that converts the light into electron-hole pairs. Despite the commercial need, the process control has been limited by the traditional vacuum deposition method of reactive magnetron sputtering that is pretty much standard for TCO deposition in the industry. Sputtering is simple to implement and, in fact, generally produces higher quality TCO films than can be produced with traditional evaporation methods, but it is a very slow deposition rate process. Plasma injection designs analogous to the HAD process will be tested as a baseline condition. The ability to really drive the rate up is going to depend not just on the reactivity of the metal and oxygen species and available surface energy (i.e. the degree of ionization and radical density). It will also depend critically on the intimacy of the flux mixture as the combined flux strikes the substrate. This will require designing both the plasma and metal sources to direct the flux in very specific ways.
