Lasers have attracted considerable interest world wide because of their versatility as a tool for many scientific and engineering applications such as processing and synthesis of materials. Among various applications of laser, Laser Chemical Vapor Deposition (LCVD) and Laser Physical Vapor Deposition (LPVD) techniques can be used to synthesize thin layers of materials with precise spatial control. Although the potential of Laser Induced Deposition (LID) processes as a superior technique to produce thin films has been demonstrated, little has been done to understand the fundamentals of such processes. For this reason, a research project encompassing experimental studies and development of mathematical models for the film forming process during LID for a compound such as Titanium Nitride (TIN) is researched in order to understand the mechanism of such processes, and to develop a science base for laser-aided materials processing. Morphology and stoichiometry of TiN deposits for both LPVP and LCVD will be a major interest. TiN is chosen as the model material for the study for its wide application in various industries such as microelectronics, opto electronics, tool and aerospace industries. Applications of TiN thin films as a diffusion barrier between Si and Al (for VLSI) is often observed. The experimental studies include the determination of optical and electronic properties and characterization by various electron-optical techniques for TiN films formed by LID. The surface temperature and chemical composition near the point of deposition will also be determined. These results will be used to obtain information about the surface-decomposition fraction and the cluster size in the film. The chemical kinetic data will shed light on the reaction rate law in the vapor phase during LPVD and at the gas-solid interface during LCVD, and on the question of enhanced reaction rate during LID. Along with the experimental works, mathematical studies will be carried out by considering continuum mechanics for deposition at a high ambient pressure, and by using the Monte Carlo (MC) simulation or molecular dynamics (MD) technique for deposition at a low ambient pressure (Ultra High Vacuum, UHV) to model particle transport with chemical reaction during LID. MC or MD simulation can also be utilized to predict the cluster size, and its effect on the film quality. Such models will be useful to determine the important process parameters, to predict the performance of the LID systems, to design and optimum LID system with optimum control. The researched work may allow the improved control laser- based thin film deposition processes for semiconductor processing and the production of wear-resistant coatings.
