Robust, scalable self-aligned platinum silicide process

A robust, scalable PtSix process is developed. The process consists of two consecutive annealing steps in a single run; the first is silicidation of Pt films on Si substrates carried out in N-2, whereas the second is surface oxidation of the resultant PtSix in O-2. By adequately adjusting the temperature during the oxidation step, a protective SiOx hard mask forms on PtSix of different thicknesses and compositions. Such a surface oxidation is absent for Pt on SiO2 isolation, which is crucial for the subsequent selective wet etch for a self-aligned process. Ultralong PtSix nanowires are fabricated using this robust self-aligned process. (c) 2006 American Institute of Physics.