Nanoscale Ripples on Polymers Created by Focused Ion Beam

Myoung-Woon Moon, Jun Hyun Han, Ashkan Vaziri, Eun Kyu Her, Kyu-Hwan Oh, Kwang-Ryeol Lee, John W. Hutchinson
 

We show that focused ion beam irradiation results in creation of peculiar one- and twodimensional nanoscale features on the surface of polyimide - a common polymer in electronics, large scale structures, automobile industry, and biomedical applications. The role of ion beam incident angle, acceleration voltage and fluence on the morphology of the structural features is systematically investigated and insights into the mechanisms of formation of these nanoscale features are provided. Moreover, by using the maskless patterning method of the focused ion beam system, we have developed a robust technique for controlled modification of polymeric surface. The technique, which is analogous to using a grey glass with varying darkness to control the radiation from the sun but at a much smaller scale, enables the ion intensity and angle to be controlled at each surface point of the polymer giving rise to structural surface features with desired shape and morphology.