1.1.5 Oxidation

Oxidation is used to generate silicon dioxide layers as insulators (e.g. field oxide between devices), as scattering layers or masks for ion implantation. In the oxidation process oxygen (dry oxidation) or H$_2$O (wet oxidation) molecules convert silicon layers on top of the wafer to silicon dioxide. To enhance the oxidation this is performed at elevated temperatures. Beside the temperature the oxidation process is influenced by the pressure.

Compared to deposited silicon dioxide, thermally grown silicon dioxide has excellent mechanical and electrical properties and especially a very good sticking coefficient with the underlying silicon. The high quality and the properties of the silicon dioxide is the most important reason why silicon is still the dominating material in IC fabrication.