Surface modification of thin tetrahedral amorphous carbon films by means of UV direct laser interference patterning

In this work, direct laser interference patterning of hydrogen-free tetrahedral amorphous carbon (ta-C) thin films using an ultraviolet (UV) nanosecond pulsed laser is investigated. Using this method, line-like arrays with submicrometer resolution were fabricated. In particular, a 180 nm grating period was successfully produced. In addition, it was found that depending on the laser energy density, the tetrahedral carbon film either graphitizes or crystallizes locally at the interference maxima positions. Furthermore, the crystallization is accompanied with a delamination of the film and even the formation of carbon fiber-like structures. The electrical properties of graphitized and delaminated ta-C were measured.