Atomic force microscope tip-induced anodization of titanium film for nanofabrication of oxide patterns

Nanometer-scale oxide patterns were fabricated on Ti films deposited on Si( 100) surface by means of atomic force microscope tip-induced anodization. T he application of a negative bias voltage to a heavily doped silicon tip re lative to the sample substrate permitted nanoscale lines and dots of titani um oxide to be formed directly on the titanium surfaces. Their sizes were d ependent on the relative humidity, the scanning rate of the tip, and the pu lse duration time. The spatial resolution of titanium oxide patterns was im proved by increasing the tip scan rate and also by lowering the relative hu midity. The smallest linewidth obtained in this experiment was about 18 nm. With increasing pulse duration time, the growth rate of oxide rapidly decr eased. This result can be attributed to the decrease of the transport rate of ionic species through the existing oxide layer due to a reduction of ele ctric field strength with increasing the oxide thickness. (C) 2000 American Vacuum Society.