Study of in-situ structural and chemical changes of ultrathin polymer films

Simulation of X-ray reflectivity (XRR) curves based on standard theoretical formalism has been performed by changing the structural parameters such as thickness, density, and roughness. Analysis of simulated curves shows that the density of thin films can be obtained within the specified range of thickness assuming chemical and physical changes occur in the system. Also along with this simulation, we have performed experimental XRR studies using polymer thin films of different thicknesses prepared by spin-coating method. In-situ XRR data were collected while chemical and structural changes occur in thin films. Results show that the instant density of the films can be determined during chemical and structural changes in the films as observed by comparison with simulated curves.