Parallel patterning of indium tin oxide with ultra short pulses

Indium tin oxide (ITO) is a commonly used material in the manufacture of several photonic devices such as flat panel displays, solar cells and electronic ink. Direct laser patterning of ITO films offers a viable alternative to these methods. An ultrashort pulse laser system with pulse duration of 10 ps and variable repetition rate (5–50 kHz) was applied to ITO removal from a glass substrate. Removal of the film was achieved through determination of the ablation threshold (Φth) of both the ITO and glass. By varying the traverse speed, fluence and offset, a processing window was identified. In addition, a spatial light modulator was introduced into the optical path and used for diffractive multiple beam processing; this increased throughput by increasing the ‘effective’ repetition rate.