Laser-stimulated processes in metal carbonyls for metal-based film synthesis

The laser induced decomposition chemistry of metal carbonyls has been the subject of numerous investigations. In the area of metal film deposition, the gas-phase photolysis of carbonyls is an area of current interest, owing to their large absorption cross sections in the UV wavelength range. However, detailed analysis showed that the film composition reflects additional thermal and photochemical surface processes, which need to be further elucidated. Although leading to higher film purities, the thermal decomposition of carbonyls in the presence of a laser heated substrate was less explored. Examples of laser-stimulated deposition processes from metal carbonyls are presented, including the UV photolysis of Mo(CO)(6) at long exposure times and the thermal decomposition of Cr(CO)(6). Some aspects related to Mo(CO)(6) decomposition in presence of silane are discussed, in connection with the synthesis of new metal-modified polymers. A comparative analysis of the properties of films obtained from Fe(CO)(5) by photolytic and thermal laser-induced processes indicates that specific growth mechanisms influence the film structure and chemical composition.