Thermal oxidation is a process used to grow a layer of oxide on a material, typically silicon. This is achieved by exposing the material to high temperatures in the presence of oxygen or water vapor. The resulting oxide layer is crucial in semiconductor manufacturing, as it acts as an insulator and protects the underlying material. This technique is commonly employed in the production of integrated circuits and other electronic devices. The thickness and quality of the oxide layer can be controlled by adjusting the temperature and duration of the oxidation process, making it a vital step in the fabrication of components like MOSFETs and CMOS devices.