Optical transmission spectroscopy of Al thin films deposited on glass substrates via thermal evaporation
Aluminum (Al) was deposited on glass substrate through thermal evaporation using the redesigned thermal evaporator chamber at the National Institute of Physics. Commercial-grade aluminum foil was placed on an alumina crucible heated by a tungsten basket inside a vacuum chamber maintained at 10-4 Torr. Evaporated films were grown at varied deposition time from 15 to 60 minutes with 15-min increments. Optical transmission spectroscopy was used to characterize the grown films. Transmission spectra measured at different sites of the films suggest that the deposition of thin film was concentrated at the center of the glass substrate. It was observed that as the deposition time increases, the transmittance of the film decreases. The setup proposed in this paper is suitable for experiments on thin film deposition in undergraduate physics laboratory.