SURFACE MORPHOLOGY OF MgF 2/YF 3 MULTI LAYER THIN FILMS BY THERMAL EVAPORATION METHOD

Magnesium fluoride and Yttrium fluoride antireflec tion multilayer thin films have been deposited on t o well cleaned BK-7 Glass substrate in Vacuum of 2x10 -5 mbar using physical vapour deposition technique. S urface morphology analysis by AFM of different multilayer structures deposited by thermal evaporat ion method i.e., Single layer, double layer, three layer and four layer thin films were presented in this study. The main object ive of this study was to investigate the influence of thickness of various antireflection multilayer thin films on the effect of surface roughness and grain size of the particle s. The thickness of the films has been determined by quartz crystal monitor method. T he surface morphology studies are performed using A tomic force Microscopy (AFM) techniques. AFM was the best tool to investig ate the surface smoothness and to find the grain si ze of the particles. The grain size is calculated for all the films of different thickness. Index Terms: Multilayer’s, AFM, MgF 2/YF 3, Roughness, Grain size, BK-7, Antireflection