Manipulation of nanocracks on silicon based thin film and its application as large area nanopatterning

Abstract

Generally, a fracture is considered as an uncontrollable phenomenon due to its highly random nature. The aim of this study is to investigate straight, random, and highly ordered cracks such as oscillatory cracks and to manipulate via elaborate control of mechanical properties of the cracking medium including thickness, geometry, and elastic mismatch. Utilizing semiconductor fabrication and laser technology, a specific thin film with micro-sized notches fabricated on a silicon based substrate generates various types of self-propagating nano-cracks in large area including optical wave-like nano-cracks resembling refraction, total internal reflection and evanescent wave. These novel properties are utilized to fabricate complex and large areal nano/micro patterns which is extremely difficult to fabricate using conventional nano/micro patterning process. The nano/micro patterns made in this study are directly implementable into a nano/micro-channel application since the cracks naturally have a form of channel-like shape. In addition, a flexible transparent conductor fabrication using the nano/micro patterns as template is demonstrated.