SiO₂ + Si (thermal oxide silicon wafer)

The silicon dioxide layer forms on the wafer during thermal oxidation, a process typically carried out in a horizontal tube furnace at temperatures between 900 to 1200°C, using either wet or dry methods. This oxide layer, grown directly on the wafer, offers superior uniformity and dielectric strength compared to layers deposited by CVD. It acts as a dielectric insulator, essential for most silicon-based devices, providing surface smoothing, acting as a doping barrier, and serving as surface dielectric protection. Thermal oxidation wafers are used as substrates for various applications, including PVD/CVD coatings, magnetron sputtering, molecular beam epitaxy, and analytical techniques such as XRD, SEM, AFM.