An experimental study on the effect of film layer and annealing on morphology by AFM of tin dioxide thin film prepared by spin-coating method

Tin dioxide (SnO2) thin film having layers of 5, 20, 40 and 60 were deposited by spin-coating method onto glass substrate. It was found that the film thickness increases with increasing number of deposited film layers. The effect of number of deposited film layers and annealing on film morphology were investigated by atomic force microscopy. The SnO2 films of different layer were annealed at 673 K for 15 min in air. It was found that the surface morphology changes with film thickness and annealing. From the experimental study it was found that though the mean grain area of pre-annealed SnO2 films were increased with the increasing number of deposited film layers, after annealing the mean grain area of the same films were decreased almost to a constant value regardless of number of film layers. The root mean square roughness (rms) on the surface increases as a result of increasing number of film layers and was found to be greater for post-annealed films than those of pre-annealed films.