Numerical simulation of stress-dependent oxide growth at convex and concave corners of trench structures

A numerical simulation of oxide thinning at convex and concave corners of trench structures is discussed. The stress effect on the oxide growth is modeled by solving oxidation kinetic equations including stress-dependent physical parameters. The different mechanism for oxide thinning at both corners has been clearly revealed by a comparison of oxide shapes obtained by cross-sectional transmission electron microscope (TEM) photographs and simulations. The oxide thinning at convex corners is caused by the stress-dependent surface reaction, and the oxide thinning at concave corners is caused by the stress-dependent oxidant diffusion.<>