Excimer Laser Crystallization of SnO2:Sb Sol-Gel Films

Instead of classical or rapid thermal annealing, KrF excimer laser irradiation has been successfully applied to crystallize dried SnO2:Sb films elaborated by a sol-gel process. The penetration of the crystallization front below the film surface, as imaged by transmission electron microscopy, is controlled by the laser fluence and the number of pulses and can thus be confined in the film itself without affecting sensitive substrates. All films laser irradiated at fluences higher than 40 mJ/cm2 become conductive. At constant laser fluence, the electrical sheet resistance goes through a minimum with increasing number of pulses. The consequence of film's densification and morphology on electrical properties is discussed.