Production and processing flow of single crystal silicon wafer:
Cut - diameter rolling - end grinding, polishing, grinding, slicing, chamfering polishing, cleaning and corrosion.
Cut off: the purpose is to obtain the product size required by the customer. The main use of silicon wafer thin cut, can effectively save the material.
Outside grinding: the diameter of the single crystal silicon rod is larger than the diameter of the final polishing wafer, and the diameter of the single crystal silicon rod is larger than that of the final polishing wafer.
End face grinding: the end face of the single crystal silicon is rough, and the grinding and polishing of the surface is required. The silicon wafer produced by our company has the high efficiency and high precision. (learn more about the information of thin grinding wheels)
Slicing: a thin wafer with a precise geometric size of a single crystal silicon wafer. The main use of silicon wafer thin cut, can effectively save the material. (learn more about thin slice of silicon wafer)
Chamfer: an edge of the wafer taxes will be cut into the dressing into the shape of a circular arc, prevent the wafer edge of the rupture and lattice defects, increase epitaxial layer and a photoresist layer of flatness.
Grinding: by grinding to remove slices and wheel grinding the kerf and surface damage layer, effectively improve the monocrystalline silicon wafer curvature, flatness and parallelism, reach a polishing process can deal with the specifications. The most commonly used equipment is double end grinding machine, supporting the use of double end grinding disc, has advantages of high efficiency, high precision and long service life. (for more information of the double end mill)
Corrosion: refers to the cutting and grinding and other mechanical processing, the surface of the wafer by the processing stress and the formation of the damage layer, usually by chemical etching.
Ways of corrosion:
(A) acid corrosion is the most commonly used. Corrosive acid by nitric acid (HNO3), hydrofluoric acid (HF), and some acid buffer (CH3COCH, H3PO4).
(B) alkaline corrosion, alkaline corrosion solution by NaOH or KOH plus pure water composition.
Polishing: refers to the surface of the silicon wafer to improve the micro defects, so as to obtain a high flatness of the wafer polishing.
Cleaning: in the process of processing a lot of steps need to be used in the process of processing a single crystal silicon wafer cleaning, cleaning is mainly in the final cleaning after polishing. The purpose of cleaning is to remove all the pollution sources on the surface of the wafer.