CO2 laser-induced chemical vapor deposition of titanium silicide films

We have developed a CO2 laser-induced chemical vapor deposition (CVD) process to deposit films of titanium silicide from a gaseous mixture of SiH4 and TiCl4. Such films are suitable for gate electrodes, interconnects, and contacts on present and future generations of very large scale integrated circuits. Films deposited at a 400 °C substrate temperature are amorphous and have a resistivity of 300 μΩ cm. Annealing at 800 °C converts the films to polycrystalline TiSi2 with a resistivity of 20 μΩ cm. The initial film composition can be varied by changing the SiH4/TiCl4 gas ratio. The CO2 laser induces thermal chemical reactions in the CVD reactor. Observed gas phase reaction products are those predicted by thermodynamics.