In situ monitoring of atmospheric pressure tin oxide CVD using near-infrared diode laser spectroscopy

In situ near-IR diode laser absorption spectroscopy is a new technique whic h has been used to monitor reaction species involved in the atmospheric pre ssure tin oxide CVD deposition reaction. The system is entirely noninvasive and provides real-time analysis. Preliminary results obtained in the CVD d eposition reaction of tin oxide onto a glass substrate in a small laborator y scale reactor is described. These will illustrate how sensitive the syste m is to small changes in reaction conditions which can then lead to much gr eater control over film qualities. Additionally, the light is easily transm itted through optical fibres to the reactor region to pass directly through the quartz reactor walls.