PLD

The generation of thin films by means of particle beams due to irradiation of solid targets using high energetic pulsed UV excimer laser radiation is called PLD (Pulse Laser Deposition). Fig. 1 shows an example of a schematic PLD set-up. As an alternative lasers with wavelengths in the visible or infrared spectrum can be used, even the superposition of different light sources can be realized.
The PLD technique combines opportunities and advantages of other deposition processes. Almost any kind of target material, conducting or non-conducting, can be used for film deposition, including materials with very high evaporation temperatures or rather complicated stoichiometry. Moreover the generation of multi-layer films is possible.
Film properties like thickness, stoichiometry or structure can be controlled by specific manipulation of process (mainly laser) parameters. High instantaneous ablation rates per laser pulse cause an oversaturation of particles within the plasma, a high deposition rate and, thus, a specific kinetic of film growth. This enables the generation of optical dense thin films with accurate thickness.





Fig.: Principle of PLD set-up