Understanding nanomechanical and surface ellipsometry of optical F-doped SnO₂ thin films by in-line APCVD

In this paper, a production-type chemical vapour deposition (CVD) is utilized to deposit fluorine doped tin oxide thin films of different thicknesses and dopant levels. Deposited films showed a preferred orientation along the (200) plane of a tetragonal structure due to the formation of halogen rich polar molecules during the process. A holistic approach studying elastic modulus and hardness of resulting films by a high-throughput atmospheric-pressure CVD process is described. The hardness values determined lie between 8 and 20 GPa. For a given load, the modulus generally increased slightly with the thickness. The average elastic recovery for the coatings was found to be between 45 and 50%. Refractive index and thickness values derived from the fitted ellipsometry data were in excellent agreement with independent calculations from transmission and reflection data.