Investigating the process latitude of a low temperature metalorganic chemical vapor deposition TiNitride process

A design of experiments was used to characterize a metalorganic chemical va por deposition (MOCVD) TiN production process and hardware. The factors eva luated included pedestal temperature, tetrakis diethylamido titanium (TDEAT ) flow, reactor pressure, ammonia flow, and nitrogen purge flow. Responses include density, resistivity, deposition tate, thickness uniformity, step c overage, stress. resistance stability, and particles. All factors studied b ut the nitrogen purge had some first order effect on the responses investig ated. Temperature has the most significant effect on the overall film quali ty and step coverage. Increasing temperature increases the density and lowe rs the resistivity of the film while reducing the step coverage: Pressure i s a dominant factor and effects all the responses studied. Increasing the p ressure serves to improve the film quality and step coverage. Ammonia used at high rates increases the density of: the film while reducing the deposit ion rate and thickness nonuniformity. The TDEAT flow primarily controls the deposition rate of the system; too high a flow can result in an increase i n the resistivity and a drop in film density. Characterization of the CVD T IN process indicated that for the factor ranges studied the center point pr ocess is manufacturable and controllable. All of the responses were found t o be within acceptable ranges. (C) 1999 American Vacuum Society. [S0734-211 X(99)10102-1].