==General Film Characteristics==
PVD films in generaly are dominated by island nucleation with low diffusion that then transforms into vertical fibers or columnar growth. Unless there is heating to temperatures that approach 50-70% of the melting point, the growth will not be crystalline with large grains.
Evaporation typically grows with fibrous, domed structures while sputtering, which has a bit more energy, has a little more energy and resputtering and approaches columnar growth.
This, combined with other factors (source size, gas collisions/mean free path and deposition angle) lead to general trends in the film:
|'''Higher Ion Energy'''
*Often denser films, better adhesion, smaller grain size
*Easier to make reactive gas
|'''High Vacuum Process'''
|'''Larger source''' - better uniformity
|Rates dependent on melting point + vapor pressure - difficult to do alloys (co-dep recommended. Some compounds dissociate with heating. |Components typically sputter at similar rates when targets are alloyed to start with. Often knock off compounds as molecules.