Mechanisms of contamination in photochemical deposition or thin metal films

Systematic investigations of thin Cr, Mo and W films deposited from the hexacarbonyls with low power, cw UV light have been carried out in order to learn about sources of contamination by C and O during film growth. Dissociative chemisorption of CO from the precursor, reactions with oxygen-containing background gases during deposition and air alter deposition all affect film compositions. Laser heating can also he important. General aspects of film contamination are discussed for other precursors such as the alkyls and acetylacetonates, and compared to the present data. © 1990 SPIE.