Ultrathin PtSi layers patterned by scanned probe lithography

A process for patterning ultrathin layers of PtSi with high spatial resolut ion is presented. In this process, scanned probe anodic oxidation is used t o pattern a surface oxide layer on a H-passivated Si surface. This oxide pa ttern prevents the reaction of a deposited Pt film with the underlying Si i n the formation of PtSi. The unreacted Pt on the oxide is removed by a sele ctive etch before any annealing. This process greatly reduces lateral diffu sion and produces a 2-nm-thick PtSi layer with good electrical properties t hat maintains the fidelity of the patterned oxide mask. Such nanostructured PtSi films are a good candidate for use in constructing lateral Si-based q uantum devices. (C) 2001 American Institute of Physics.