It is said that under normal conditions, its application function will not fail.
To achieve this, the film must generally have strong adhesion, low internal stress, little pinhole density,
strong mechanical performance, uniform film thickness, and sufficient resistance to chemical erosion.
The characteristics of the film are mainly affected by the deposition process, film forming conditions,
the formation of interface layer and the substrate. subsequent heat treatment also plays an important
role.
1. Lattice mismatch between film and substrate
2. Difference in coefficient of thermal expansion between film and substrate
3. Inter extrusion between grain boundaries