Spectroscopic ellipsometry study of thin film thermo-optical properties

• Published in: Thin solid films Vol. 517; no. 17; pp. 5066 - 5069
• Main Authors: Xie, H., Ng, F.L., Zeng, X.T.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.07.2009; Elsevier
• Subjects: Annealing; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Deposition by sputtering; Ellipsometry; Exact sciences and technology; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Optical properties; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of specific thin films; Optical thin films; Physics; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Titanium oxide; Annealing; Titanium oxide; Optical properties; Optical thin films; Ellipsometry; Temperature dependence; Scanning electron microscopy; Data analysis; Spectroscopic ellipsometry; Refractive index; XRD; Thin films; Wafers; Physical vapor deposition; Silicon; Optical films; Microstructure
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2009.03.159

Spectroscopic ellipsometry (SE) was employed to realize in-situ monitoring and the determination of thermo-optic coefficients (TOC) of thin films by integrating a temperature controlled hot stage to the ellipsometer and applying the empirical relationship of Cauchy between the refractive index and wavelength in the data analysis. Magnetron sputtered titanium oxide thin films of 350 nm thick both as-deposited and post-deposition annealed were prepared on silicon wafers for this investigation. Results of ellipsometric analysis show that as-deposited TiO 2 films have a negative TOC of − 1.21 × 10 − 4  K − 1 at 630 nm over the test temperature range 304–378 K. The post-deposition annealing at 923 K for 2 hours leads an increase in film refractive index to 2.29 from 2.17 for as-deposited TiO 2 films, and an enhancement in TOC up to − 2.14 × 10 − 4  K − 1 . X-ray diffraction (XRD) and scanning electron microscopy (SEM) cross-sectional analysis were performed for film structure characterization.