Effect of pulse CO2 laser annealing on the crystallization of Er3+ doped Al2O3 thin film to a silica-on-silicon substrate

We analyze the effect of the laser annealing on the crystallization of Er3+ doped amorphous Al2O3 thin films deposited on the silica-on-silicon substrate. These thin films were prepared by the microwave electron cyclotron resonance plasma source and were annealed by pulse CO2 laser. The Gauss intensity distribution of laser beam was mended at 3 × f position in the collimation system. Strong crystallization occurred in Al2O3 thin films and liquid phase crystallization was proposed to appear with the increase of laser powers. Photoluminescence intensity enhancement by a factor of 47 around 1.53 μm has been realized by laser annealing process and Raman spectra study has suggested that Er3+ emission centers excited by Si nanocrystal (Si-nc) were formed in the Al2O3–SiO2 materials. The dual wavelength energy transfer mechanism between 800 nm and 980 nm is proposed in Er-doped Si-nc in Al2O3–SiO2 thin films.