SCIENTIFIC & TECHNICAL SERVICES
Thin Films Laboratory
The Service of Thin Films has been created to offer to the researchers the capability of fabrication of complex oxides thin films and heterostructures combining oxides and metals.
The deposition techniques are pulsed laser deposition (PLD) for oxides and sputtering for metals. Currently there are two PLD set-ups installed, and in short time both systems will be connected to a chamber with several sputtering units. PLD is a physical vapour deposition technique that uses ultraviolet laser radiation to vaporize material that is transferred to the substrate. The plot in Figure 1 is a sketch illustrating a PLD set-up.
Scientists in charge
Tel. 935801853 (ext. 323-262)
The technique is very suitable for oxides, and compared with other techniques is particularly useful to obtain films with complex stoichiometry and to grow epitaxial films and heterostructures. Moreover, PLD is highly versatile to optimize the deposition conditions of new materials, and the films can be grown in relatively fast processes. These characteristics favour the use of the technique by research groups having interest in different materials.
The pulsed beam of an ultraviolet laser (usually an excimer) is focused on a ceramic target placed in a vacuum chamber. The combination of pulsed irradiation, high photon energy, and high energy density can cause the ablation of the material. Ablation refers to the etching and emission of material under conditions totally out of the equilibrium. The plasma created expands fast along the perpendicular direction of the target (see the photography in Figure 2). A substrate is placed front the target, and inert or reactive gases are usually introduced during the deposition process.