Laser Physical and Laser Chemical Vapor Deposition of TiN and TiNxOy Films

Abstract

ABSTRACTWe have investigated the formation of polycrystalline TiN and amorphous TiNxOy films using laser physical (LPVD) and laser chemical (LCVD) vapor deposition techniques. The LPVD method involved the ablation of a TiN hot pressed pellet and Ti in the presence of nitrogen plasma using nanosecond XeCl excimer laser pulses (wavelength 308nm, pulse duration 45×10−9 seconds, and energy density ∼4-5 Jcm−2). The films were polycrystalline (average grain size ∼100Å) with face-centered-cubic structure and lattice constant of 4.25Å. The average grain size remained constant as the substrate temperature ranged from 25 to 550°C. In the LCVD method, a pulsed CO2 laser beam was used to crack TiCl4 and NH3 and form TiN films. Amorphous TiNxOy films were formed under poor vacuum conditions in the LPVD techniques. These amorphous TiNxOy films often exhibited explosive recrystallization with characteristic star patterns. Resistivity and microhardness measurements were made on these films and these results have been correlated with microstructure and chemical composition.