Surface roughness prediction in SILAR coating process of ZnO thin films: Mathematical modelling and validation

This study aimed to evaluate the effect of SILAR coating parameters on the surface roughness of ZnO thin films with a chemometric approach and to develop a mathematical model that can be used to predict the surface roughness of the films depending on the coating parameters. The selected process parameters for the SILAR coating of ZnO are the ammonia solution amount, cycle number and stirring speed. The effect of coating pa-rameters on ZnO thin film roughness was investigated with the help of RSM. A statistical estimation model was developed and used to estimate the effect of parameters on roughness. The adequacy of the developed mathe-matical model was tested with ANOVA. When the data obtained were examined, it was understood that the amount of NH4OH played a decisive role in the morphology of ZnO coatings. The surface roughness of the optimized coating was measured as 213.4 nm for Rq and 177.8 nm for Ra, and the developed mathematical models estimated the surface roughness of the coating as 214.9 nm for Rq and 179.6 nm for Ra. The findings revealed that the mathematical models developed to predict the surface roughness of ZnO films are accurate and reliable in predicting the Rq and Ra values.