A voltage bias between a sharp probe tip and a sample generates an intense electric field at the tip. The high field can be used to locally oxidize silicon in a process known as electric-field-enhanced oxidation. The high field desorbes the hydrogen passivation on the silicon surface, allowing the exposed silicon to oxidize in air (the oxidation rate is enhanced by the presence of the accelerating field). Both single-crystal silicon and amorphous silicon may be locally oxidized in such a way. This local oxidation process is powerful because of its fine resolution (sub-50-nm) and the resistant oxide etch mask that is created. Our work involves characterizing the oxidation process, increasing pattering reliability and throughput, and fabricating structures and devices using this local oxidation technique.
oxidation of silicon