Growth of Al doped ZnO thin films by a synchronized two laser system

We report the deposition of Al doped ZnO thin films with the aid of a synchronised two laser system. The laser system consists of an ArF* excimer laser (λ = 193 nm, τ ∼ 12 ns) and a Nd:YAG laser (λ = 355 nm, τ ∼ 10 ns), for the time-matched ablation of the host (Zn) and dopant (Al) targets in oxygen atmosphere. Our approach allows for the independent and accurate setting of the laser fluences of the two lasers, in accordance with the energy requirements of the host and dopant materials. The method proposed by us permits also an in situ change of the doping conditions throughout the thin film growth process. The controlled modification of the dopant profile inside the growing film can be obtained relatively easily by the appropriate variation of the Nd:YAG laser fluence and/or number of pulses applied to the Al dopant target during the deposition process.