An emission Fourier transform infrared (E/FT-IR) technique for epifilm thickness measurement will be reported. The E/FT-IR technique takes advantage of the heated wafer as the source of IR radiation. It is a noncontact, nondestructive, real-time, and in situ epifilm thickness monitoring tool that we demonstrated to be useful for observing real-time growth rates and incubation times. In addition, this method is especially applicable to precise end point control when critical film thicknesses are required. Moreover, we have identified some limitations to this method, and found the operable temperature ranges. Furthermore, we have demonstrated, for the first time, a closed-loop feedback control of epitaxial silicon film thickness in a multichamber single-wafer chemical vapor deposition reactor.