Potential Step Coverage for Supercritical Fluid Deposition of TiO2 by Numerical Simulation and Microcavity Analysis

The potential step coverage for supercritical fluid deposition of TiO2 (TiO2-SCFD) was evaluated using numerical simulation based on kinetic parameters. A required parameter, the ratio of the surface reaction rate constant to the diffusivity, k(s)/D, was retrieved experimentally. The simulations revealed that a step coverage of 0.97 was possible on deep trenches (6.75-mu m depth, 125-nm width) without compromising the growth rate. Conformal deposition by TiO2-SCFD is possible on narrow trenches having the same aspect ratio. The simulations were validated experimentally. Our methodology for evaluating the potential step coverage is also equally applicable to SCFD of other metal oxides. (c) 2013 The Electrochemical Society. All rights reserved.