PULSED-LASER DEPOSITION (PLD) - AN ADVANCED STATE FOR TECHNICAL APPLICATIONS

The conventional thin-film deposition equipment of pulsed laser deposi tion (PLD) has been modified for the preparation of individual thin so lid films and nanometer-layer stacks of uniform thickness across 100-m m substrates. The planar target configuration was replaced by a cylind rical one and the target motion regime has been improved to provide pr ecise spatial control of the plasma plume orientation. During thin-fil m 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 coatin g can be tailored via a stepper-motor-driven manipulator for the desir ed layer thickness profile across an extended substrate. Thus, for exa mple, a homogeneous film thickness is obtained even for lower target/s ubstrate distances, and an appropriate deposition rate can be maintain ed. In a second version, this cylinder geometry principle of plasma pl ume control by target surface morphology is extended to a spatial solu tion. The hemispherical target surface becomes the basic element for i nside-wall coating of tubes or even of more complex hollow bodies. Fir st applications of the equipment are explained and compared with typic al results of the conventional technique.