Laserscribing of Thin Films Using Top-Hat Laser Beam Profiles

We present a comparative study of laser scribing different thin solid films using nanosecond laser pulses with different wavelengths and laser beam profiles. In particular, we show the influence of the used laser beam profile for the processing of a 150nm thin Indium Tin Oxide transparent conductive film and a multilayer system, consisting of different metal and transparent conductive oxide (TCO) layers deposited on a soda lime glass substrate. For laser scribing the wavelengths 1064nm, 532nm and 355nm were used with a Gaussian and a Top-Hat beam profile. The homogenous Top-Hat beam profile is generated with both, a refractive and diffractive beam shaper. The results show several advantages of using a Top-Hat laser beam shape for thin film laser scribing, such as less energy consumption, high rim quality with simultaneous small pulse overlap and protection of the underlying substrate, respectively. Our results prove that the application of beam shapers can improve the process quality and increase the scribing speed for the investigated materials.