Optical fiber-based sensor for in situ monitoring of cadmium sulfide thin-film growth.

This work presents a scheme for in situ monitoring of thin-film growth. A fiber-optic sensor based on Fabry-Perot interferometric technique has been established for the first time to monitor in situ growth of thin films. This was applied for determining thickness of cadmium sulfide (CdS) thin films during growth. The fabrication process of CdS film was carried out in 30 mM cadmium acetate and thioacetamide solution at 60°C temperature. The estimated thickness determined during the growth was verified by scanning electron microscopy. This study shows that in situ measurement of the thickness of thin films is feasible by this new technique, and a close match of the estimated thickness was achieved.