To understand how the substrate temperature influences the deposition rate and spatial profile of deposits formed using laser chemical vapor deposition (LCVD), spatially resolved multi-wavelength pyrometry measurements of the substrate temperature have been made during LCVD of titanium nitride (TiN) on Ti-6Al-4V substrates. The precursors that have been used are TiCl$sb4,$ N$sb2,$ and H$sb2.$ Also, deposition has been studied as a function of the N$sb2$:H$sb2$ gas ratio, the TiCl$sb4$ partial pressure, the total chamber pressure, and the laser power. Also, film thickness has been measured by stylus profilometry, and film composition and microstructure have been determined by Scanning Electron Microscopy (SEM), Auger Electron Spectroscopy (AES), and X-ray Photoelectron Spectroscopy (XPS). While the substrate temperature and the gas composition have the greatest influence on TiN film growth, H$sb2$ exerts the greatest influence on TiN film growth. Also, enhanced mass transport associated with localized laser beam heating has led to film growth rates on the order of 1 $mu$m/sec; however, there is still evidence of reactant depletion at the center of the laser heated spot. In addition to calculating film growth rates based on film height, two new methods of characterizing the film growth rate have been developed. Using these growth rates, three insights have been obtained. First, the film growth rates are 1-1/2 orders of magnitude greater than typical CVD deposition rates. Second, radial growth of the films continues after reactant depletion occurs at the center of the deposit. Third, comparison of the growth rates with LIF measurements supports the concept of a temperature-dependent sticking coefficient. Based on the experiments, reaction rate equations have been postulated as a function of N$sb2$/H$sb2$ gas ratio and TiCl$sb4$ partial pressure. Also, the apparent activation energy for deposition is 108.9 kJ/mol when one calculates the deposition rate based on film height. Using alternate definitions of film growth rates, the apparent activation energies are 65.2 and 81.4 kl/mol. The discrepancy in these activation energies has occurred because part of the measured film volume is actually TiCl$sb4$ rather than TiN.

This report results from a contract tasking Technion as follows: Investigate the characteristics of thin silicon nitride films deposited on substrates via the use of chemical laser deposition techniques. This report summarized the research activities during the first year of work as was planned in the proposal. It completes the information which was given in the previous two progress reports. Basically, the aim of the first year was to study the possibility of deposition of silicon nitride thin films from silane and ammonia at low temperatures. The investigation was carried out by studying the effect of substrate temperature on deposition rate and film quality. In addition, the photochemical reaction was studied by analyzing the composition of gas molecules prior and during laser irradiation. At the end of the first year it was also possible to start doing experiments for deposition of silicon carbide from silane and acetylene.