Mechanism of simultaneous formation of refractory-metal free C40 and C49 TiSi2 induced by Q-switched Nd: Yttrium-aluminum-garnet laser irradiation

Abstract

In this article, we demonstrate the usefulness of using a Q -switched Nd: Yttrium-aluminum-garnet laser to induce various phases of TiSi2 in 350 Å of Ti layer deposited onto (100) Si substrates by varying the pulse width, τ, and energy fluence of the laser. Two sets of experiments were carried out. In the first set of experiments, τ and energy fluence of the laser are set at 0.18 μs and approximately 1.5 J cm2, respectively. The laser annealed TiSi sample was then characterized using micro-Raman spectroscopy and it was found that C49 TiSi2 is formed at two different temperatures. One is formed at a nonmelting temperature, 680 °C, and the other formation temperature is at a high temperature of around 1975 °C. A mechanism is proposed to explain the formation of C49 under these two different conditions. In addition, we also note that C40 is formed between these two temperatures. In the second set of experiments, increasing τ to 1.6 μs and reducing the energy fluence to approximately 1.0 J cm2 resulted in the formation of pure refractory C40. This refractory metal free C40 phase is confirmed with glancing angle x-ray diffraction. © 2005 American Vacuum Society.