Design and Fabrication of BaTiO₃ Crystal Thin-Film Waveguides

Abstract:

BaTiO₃ crystal film has the very high electro-optic effect, so it has important research value for thin film waveguide electro-optic modulators. In this work, BPM software is used to simulate the single-mode condition of ridge waveguide at first, then BaTiO₃ film waveguide structure is designed with suitable film thickness.BaTiO₃ waveguide thin films are grown by pulsed laser deposition on single crystal MgO substrate. The BaTiO₃ thin-film crystalline structures grown at different temperature sand different laser powers were analyzed by using X ray diffraction , which showed the BaTiO₃ films have a priority crystallization direction and good crystallization quality at 750°C grown temperature. For the optimally-designed waveguide structures, the PECVD technique and ICP plasma etching method are employed to coat and etch Si₃N₄ films, respectively. Through the optimization of main process parameters, 60 sccm reaction gas flow and 150 nm/min etching speed are finally selected to create the ridge waveguides, and consequently, the surface roughness of Si₃N₄ film waveguide reaches 2.3 nm.

• Periodical: Key Engineering Materials (Volumes 609-610)
• Pages: 201-207
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.609-610.201
• Online since: April 2014
• Authors: Jing Zhang, Xiu Hua Fu, Li Jun Guo, Jian Hong Zhou, Dong Mei Liu, Deg Gui Sun
• Keywords: BaTiO₃ Crystal Thin-Film, ICP Etching, PECVD Deposition, Priority Crystallization Quality, Pulsed Laser Deposition, Ridge Waveguide

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DOI: 10.1063/1.360126