Optical Measurement for Deposition Thickness using a Thin Glass Vibrator Installed in Fiber Coupling

We propose a thin glass vibrator which is installed with micro-ball lens in FC connector as a photothermal vibrating type sensor. The vibrator was fabricated from a cover glass with accuracy of about 50 μm by ultrasound. In deposition process using an ion sputtering apparatus, continuous measurements of the resonance frequencies were possible without adjustments of an optical system. Resonance frequencies of the vibrator with 5 mm in length and 2 mm in width decreased from 3.280 kHz to 3.243 kHz during deposition thickness increase of 500 nm of Au. Possibility of practical use of a low price optical sensor was shown for measurement of depositon thickness.