Laser-induced direct formation of C54 TiSi2 films with fine grains on c-Si substrates

Abstract

In this letter, we report on the direct synthesis of C54 TiSi2 films with fine grains by pulsed-laser irradiation from Ti deposited on Si substrates, using a Q-switched Nd:YAG laser. The films were characterized using micro-Raman spectroscopy, high-resolution transmission electron microscopy, and atomic force microscopy. In comparison with the C54 TiSi2 using the conventional rapid thermal annealing (RTA) of 35 nm thick Ti/Si, which has an average grain size of about 110 nm and film thickness of 50 nm, the laser-induced C54 TiSi2 films vary from 13 to about 42 nm in thickness with different laser scanning speed and the grain size is 85 nm on average. The TiSi2/substrate Si interface is smooth on the atomic scale. Our results demonstrate the unique advantages of the laser-induced formation technique and its potential in deep submicron semiconductor technology. We propose that the C54 phase is formed by solid-state diffusion, rather than melting. © 1999 American Institute of Physics.