Oxidation layering produces a thin layer of silicon dioxide, or oxide, on the substrate by exposing the wafer to a mixture of high-purity oxygen and hydrogen at ± 1000°C (1800°F).
Oxide is used to provide insulating and passivation layers and form transistor gates. Insulating oxide layers are usually about ± 1500 Å (angstroms). Gate layers are usually between 200 Å and 500 Å .