Estimating Local Deposition Conditions and Kinetic Parameters Using Film Profiles

Abstract

ABSTRACTEVREST, a program which uses film profile data in features obtained from low pressure chemical vapor deposition (LPCVD) processes to estimate the local partial pressures, temperature, and kinetic parameters is demonstrated for blanket tungsten deposition by the hydrogen reduction of tungsten hexafluoride. EVREST uses EVOLVE, a physically based process simulator for ballistic transport and heterogeneous reactions in features on patterned wafers, to compute film profiles for a given set of deposition conditions and kinetic parameters. Calculated film profiles are compared with the experimental film profile and the free parameters are adjusted to minimize the sum of squared differences between points on the calculated and experimental profiles. EVREST uses Marquardt's method to determine the set of deposition parameters which provide the best calculated profile. Simulated and experimental profiles are in very good agreement.