The surface morphology of the as deposited films was checked using
Atomic Force Microscopy (AFM) (VEECO 3100). The AFM images show very
smooth surfaces for the SiO2 and TiO2 films as shown in figures 5.1 and 5.2
respectively. The SiO2 film demonstrates an optically flat surface with an
average and RMS values for the surface roughness of 8.77 and 11.05 Å
respectively. As for TiO2 film, a smother film was deposited with an average
and RMS values for the surface roughness of 3.34 Å and 4.18 Å respectively.
However, from the roughness measurements the surface is smooth enough for
the desired application. From these observations it is expected that in
multilayer structures the interfaces are likely to be sharp, minimizing the
effect of absorption or scattering at the surface or interfaces.