Thermal Oxidation is one of the most important process steps in semi­conductor fabrication to produce high quality isolation layers. A chemical reaction converts silicon into silicon dioxide which has more than twice of the original volume. This is the main source for stress and displacements in the oxidized structure. Stress in copper interconnects can be essential for the life time of an integrated circuit, because it can support material transport and lead to void formation. During the fabrication of sensors, where thin film deposition is often used, an intrinsic stress is generated in the layers which can cause unwanted deformation in free standing structures. After an introduction the author describes the advanced oxidation model and shows by means of pictures the verified simulation results. A highlight of this book is the chapter about the Finite Element Method (FEM) which is used to solve the mathematical formulation numerically. In a comprehensible way the author describes how to apply FEM in practice, so that the reader of this book should be able to discretize many other kinds of differential equations and solve them with a computer, which is basic for simulation.