High-accuracy characterization of titanium films for LiNbO/sub 3/ guided wave devices by optical densitometry

An experimental study of optical densitometry as a technique for accurate determination of Ti film thickness for integrated optical devices on LiNbO/sub 3/ is discussed. Densitometric data, obtained with a simple instrument for photographic applications, are compared to conventional stylus profilometric measurements and to microgravimetric and Rutherford backscatter measurements; excellent linearity and a sensitivity of about 3 AA are evidenced, as well as capability of absolute calibration in terms of metal atoms per unit surface area, over the entire range of Ti thickness commonly used in integrated optics. The possibility of using this very simple, rapid, and nondestructive method for systematic sample testing, online deposition monitoring, and utilizing optimum coating area is also presented.<
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