Deprotection kinetic monitoring of a 193nm positive tone resist by ellipsometry

Abstract: Optical changes in thin films of model photoresist materials were measured in real time with ellipsometry during UV exposure and heating. A critique change in the optical parameters of the film is detected if the sample is heated during EUV exposure, showing that deprotection reaction initiation can be measured by ellipsometry. Hence the kinetic of deprotection reaction is measured at various temperatures for different doses. Simulation of the optical changes of the film shows a rapid film compaction during the deprotection, and final compaction is linked to the deprotection ratio of the resist. [Copyright &y& Elsevier]