Pulsed Laser Deposition
Pulsed laser deposition is a method for fabricating thin films of various materials. Within an ultrahigh vacuum chamber, a solid (typically ceramic) target is illuminated with short high-energy laser pulses, which ablate some material via thermal or non-thermal processes. The ablated material is deposited on a substrate as a thin film of amorphous or crystalline material. The number of laser pulses is adjusted to obtain the required material thickness.
Ideally, the laser pulses should have a short wavelength in the ultraviolet spectral region. Therefore, one typically uses either Q-switched lasers in combination with nonlinear frequency converters, or excimer lasers which directly generate UV light.
Pulses with a rise time of only a few nanoseconds allow not only efficient non-thermal ablation, but also precise preservation of the stoichiometry of the target material. This is an important advantage of pulsed laser deposition over other deposition techniques. It is important e.g. for the production of complex ceramic materials such as high-temperature superconductors or magnetic materials.