Measurement in situ of thickness and optical properties of transparent films by optical spectrometry

Optical emission spectroscopy is a commonly used technique for controlling the reactive sputtering process which however doesn't allow the in situ det ermination of the critical reactive gas flow rate for high rate deposition of stoichiometrie ceramic coatings. We present here a method consisting in exploiting the transmission interferometric phenomena occurring during the growth of a transparent film on a transparent substrate. This method allows both the in situ determination of the critical reactive gas flow rate for high rate deposition of stoichiometric films and the in situ or ex situ det ermination of the thickness and of the Optical indexes of the deposited fil m.