Limiting and Enhancement Effects in Laser Chemical Vapor Deposition

ABSTRACTLaser chemical vapor deposition (LCVD) is a modification of conventional CVD using a laser heat source. The film growth characteristics differ considerably from conventional CVD in several ways, however. The use of an optical heat source means that the optical properties of the film/substrate system must be considered, e.g., for metals deposited on absorbing substrates, the film thickness and diameter may “self-limit” in some cases because the deposited film reflects most of the laser energy. On the other hand, the small area heated in LCVD results in a different diffusion geometry and access to higher surface temperatures than are achievable when large areas are heated. For favorable reactant systems, these enhancement effects can yield fast deposition rates and line deposition scan speeds greater than 10 cm/sec. This paper will review results of pulsed and cw LCVD of predominantly metal films using visible and infrared lasers.