Surface scaling evolution and dielectric properties of sputter-deposited low loss Mg2SiO4 thin films

The evolution of surface roughness and dielectric properties of sputter-deposited Mg2SiO4 thin films have been studied. Analysis of height–height correlation function and power spectrum densities of the atomic force microscope images revealed that the growth surface experiences a difference in short-range and global roughening, indicating an anomalous scaling (super-rough) behavior. The growth exponent β = 0.9 suggests that the growth instability due to the shadowing far outweighs the effects of a high substrate temperature (700 °C). The dielectric loss tangent showed a pronounced dependence on deposition time, while dielectric constant remained unchanged at the bulk value; the changes in the grain structure via the evolution of surface scaling are suggested as a contributing factor.