Pulsed laser deposition (PLD) — an advanced state for technical applications

The conventional thin-film deposition equipment of pulsed laser deposition (PLD) has been modified for the preparation of individual thin solid films and nanometer-layer stacks of uniform thickness across 100-mm substrates. The planar target configuration was replaced by a cylindrical one and the target motion regime has been improved to provide precise spatial control of the plasma plume orientation. During thin-film deposition, substrate translation is preferred instead of the usual rotation technique. With this arrangement the emission characteristic of the plasma source can be computer controlled and the desired coating can be tailored via a stepper-motor-driven manipulator for the desired layer thickness profile across an extended substrate. Thus, for example, a homogeneous film thickness is obtained even for lower target/substrate distances, and an appropriate deposition rate can be maintained. In a second version, this cylinder geometry principle of plasma plume control by target surface morphology is extended to a spatial solution. The hemispherical target surface becomes the basic element for inside-wall coating of tubes or even of more complex hollow bodies. First applications of the equipment are explained and compared with typical results of the conventional technique.