Publication

Abstract : Hexamethyldisilazane (HMDS) vapor treatment of plasma-damaged nanoporous organosilicate thin films has been studied as a function of treatment temperature in this work. Although, the {HMDS} vapor treatment facilitated incorporation of methyl (CH3) groups subsequent to the removal of free hydroxyl (OH) groups in the damaged films at treatment temperature as low as 55 °C, the bonded {OH} groups were not removed. More significantly, detailed analysis of the results reveals that {HMDS} vapor modified only the surface of the plasma-damaged samples and not the entire film as expected. This is attributed to the formation of a thin solid layer on the surface, which effectively prevents penetration of {HMDS} vapors into the bulk. The Fourier transform-infrared (FT-IR) absorption and dielectric constant measurements confirm that the vapor treatment assists only partial curing of the plasma-damaged films. Alternative processes of curing the films with {HMDS} dissolved in supercritical carbon dioxide (SCCO2) as a medium of reaction in static and pulsed modes were also attempted and the results are presented in this paper.