According to the use classification, semiconductor silicon wafer can be divided into polishing wafer, annealing wafer, epitaxial wafer, junction spacer and high-end silicon wafer represented by SOI wafer. So what's the difference between silicon wafer polishing and epitaxial wafer?
Polished wafers can be used as substrate materials for memory chips, power devices and epitaxial wafers. Epitaxial wafer is a layer of monocrystalline silicon grown on the basis of polished wafer, which is generally used to manufacture general processor chips, diodes and igbt power devices. Because the original polished particles are fine and the particle size is smaller than the wavelength of visible light, a transparent or translucent polished film is formed after uniform distribution.
2. Where is the silicon wafer polishing pad used?
Polished wafer is the most used product, and other silicon wafer products are produced by secondary processing on the basis of polished wafer.
Polished silicon wafer is the most basic and widely used silicon wafer. Polished wafers can be directly used to make semiconductor devices, widely used in memory chips and power devices, and can also be used as substrate materials for other types of silicon wafers such as epitaxial wafers and SOI wafers.
With the continuous narrowing of the characteristic linewidth of integrated circuits, the lithography accuracy is getting finer and finer, and the tiny unevenness on the silicon wafer will cause the deformation and dislocation of integrated circuit graphics, so the manufacturing technology of silicon wafer is facing higher and higher requirements and challenges. The surface granularity and cleanliness of silicon wafers also directly affect the output of semiconductor products.
Therefore, polishing process is very important to improve the flatness and cleanliness of silicon wafer surface. The main principle is to flatten the surface of semiconductor silicon wafer and reduce the roughness by removing the residual damaged layer on the machined surface.