화학공학소재연구정보센터
Applied Surface Science, Vol.257, No.10, 4581-4585, 2011
Instability of nanostructures patterned in polystyrene under high electric field gradients
A nanolithography technique based on the lateral displacement of electrically biased AFM tip was developed for nanostructures formation of 30-100nm in width and 1-10nm in height in the polystyrene (PS) films. It was demonstrated that the nanostructures patterned in annealed PS films (90K Mw) show slow exponential relaxation between 55 and 265 h depending on their size. Relaxation of the nanostructures in non-annealed films usually occurred in minutes. It was observed that in the annealed samples a negative electric charge accumulated in the areas where the nanostructures formed while in the non-annealed samples only the positive charge in exposed areas was detected using the electric force microscopy. After 320 h of monitoring under the humidity maintained between 25 and 27% it was suggested that slow dynamical changes of the nanostructures can be attributed to the negative electric charge dissipation in the annealed samples. (C) 2011 Elsevier B.V. All rights reserved.