Simultaneous Measurement of Reflectance and Transmittance of Thin Films Using Optical Thickness Monitor

Abstract

An Optical Thickness Monitor (OTM) to measure the reflectance and transmittance simultaneously has been constructed. It uses inexpensive components for mechanical construction; prisms and lenses for optical path; simple electronic circuitry for detection unit and sampling the light beam. The entire system can be easily aligned. This system has a unique advantage in its being able to measure reflectance and transmittance simultaneously. Using the fabricated OTM, reflectance and transmittance are measured for Al film during evaporation and the results are given to illustrate its applicability.