siliciumwafers

Siliciumwafers, also known as silicon wafers, are thin round discs of highly pure crystalline silicon that serve as the foundational substrates for most semiconductor devices and photovoltaic cells. They come primarily in two forms: monocrystalline wafers, which provide a uniform crystal lattice, and polycrystalline wafers, used mainly in solar cells. Common crystal orientations include the <100>, <110>, and <111> planes. Diameters range from about 25 mm to 300 mm, with 150 mm, 200 mm, and 300 mm being widespread in industry. Typical thicknesses are around 0.2 to 0.8 mm, and wafers are doped to become p-type or n-type.

Manufacturing starts with a silicon ingot grown by methods such as Czochralski (CZ) or float-zone (FZ). The ingot is sliced into wafers, edges are trimmed, and the surfaces are polished to a mirror finish, often using chemical-mechanical polishing. Wafers undergo thorough cleaning and may receive surface treatments or passivation. Doping can occur during crystal growth or later by diffusion or ion implantation to adjust electrical properties. The surface chemistry forms a native oxide (SiO2) when exposed to air, and thermal oxidation is commonly used in device fabrication.

Applications span the electronics and energy sectors. Most integrated circuits and MEMS devices are fabricated on silicon wafers, while photovoltaic cells use larger-area wafers of silicon. Wafers are specified by diameter, thickness, crystal orientation, resistivity, and defect density.

Quality control follows industry standards from organizations such as SEMI, JEDEC, and IEC, governing properties like bow, warp, roughness, defect density, and wafer purity. Wafers require careful handling and cleanroom processing due to their brittleness.