Laser chemical vapor deposition of TiN dots: A comparison of theoretical and experimental results

摘要

A mathematical model for the concentration profile of TiCl4at the top surface of an Incoloy 800H substrate placed inside a laser chemical vapor deposition (LCVD) reactor is developed by using the threehyphen;dimensional transient mass diffusion equation. The model is used for studying the spatial variation of the thickness of TiN dots deposited by LCVD, using a CO2laser and a reactive atmosphere consisting of TiCl4, N2, and H2. By assuming that the chemical reaction is firsthyphen;order with respect to TiCl4, and that the sticking coefficient of TiN at the substrate surface is temperature dependent, the deposited TiN film is found to have a volcanic profile under certain conditions, which is in good agreement with experimental results.