Improving the resolution and the uniformity of AFM tip induced oxide patterns with pulsed voltages

Oxide line patterns were fabricated on the surface of titanium (Ti) film using atomic force microscopy (AFM) tip induced local oxidation technique. The growth behavior of the oxide under static voltages was studied. It was found the lateral growth of the oxide experienced two stages and the growth rate at the initial stage was very high. Pulsed voltages were employed and their effects on the controlling of the oxidation dynamics were examined. The results indicated that the high lateral and vertical growth rates of oxide at the initial stage could be suppressed with pulsed voltages. A minimum line width of 8 nm and highly uniform patterns were obtained with optimized voltage pulses. These results indicated that applying pulsed voltage is an effective method for improving both the resolution and the uniformity of the fabricated structures with scanning probe microscopy (SPM) tip induced local oxidation technique.