Thin film patterning

The most common patterning technology has been lithography process. In this process patterns are created by using multi step process, masks and chemicals. However, there are many issues in this process such as high investment cost, time consuming/ multi step process, inflexibility and environmental problems. Different kinds of laser technologies have been introduced into patterning process. This process is often called direct laser writing process. Lasers seem to have potential to overcome some of the issues introduces by the other traditional tools because of lower investment cost, no mechanical stress to the work piece and no chemicals involved. However, conventional lasers don’t seem to solve all related problems because they create large heat affected zones (HAZ), which has an affect to the processing quality. The use of green or UV-lasers has reduced this problem, but has not eliminated the problem totally.

It has been demonstrated that with ultra short laser pulses materials can be processed with excellent quality and high precision. This is due the fact that shortening the pulse length to ultra short regime permits a drastic reduction of the HAZ and shock affected zone (SAZ), which are the main reasons for quality issues. However, processing speed has been a problem with these lasers. Furthermore, ultra short pulse lasers have been complex, large, expensive systems and difficult to control, thus being unsuitable for integration with production lines.

At Corelase, we have developed a laser concept operating at MHz repetition rate regime, X-LASE, which combines the processing benefits of ultra short laser pulses with high processing speeds. The new concept is based on fiber laser technology, which enables packaging of the laser to small footprint. Furthermore this enables easy integration to automation and production lines. Also all-fiber-delivery design improves the robustness of the system against any vibration or other environmental issues.

 
Lithography vs laser direct writing