Analysis of hydrogenated amorphous carbon films deposited by middle frequency pulsed unbalanced magnetron sputtering

► a-C:H films were synthesized by middle frequency pulsed unbalanced magnetron sputtering technique. ► Working pressure plays an important role in the microstructure and properties of the a-C:H films. ► The AES depth profile exhibited that the transitional layer width decreases with increasing working pressure. ► a-C:H films exhibit quite higher transmission in near IR region. ► a-C:H films can resist rain erosion.