6 "153mm ≤φ≤158mm
6.2 inches159mm ≤φ≤164mm
6.5 inches168mm ≤φ≤173mm
8 "203mm ≤φ≤ 208mm
In addition, because the four corners of the monocrystalline silicon wafer are bent into arcs, there is such a standard:
Is chord length (mm) the length of radian?
6? Inch 28.24~3 1.30
6.5 inches 10.93~ 13.54
8? Inch 20.46~23. 18
The diameter (mm) is the length of the diagonal.
6? Inch 150.0 0.5
6.5 inches 165.0 0.5
8? Inch 200.0 0.5
Silicon wafer:
Insert a Si seed crystal (seed crystal, usually a small crystal rod) rod with a certain crystal orientation into molten Si, and slowly pull the crystal rod to produce a crystal column with the same crystal orientation as the seed crystal. The diameter of the crystal column can be controlled by controlling the pulling speed and other process variables. Cut the crystal column into many small pieces. Make a chip. The part of the pillar that cannot be cut into usable wafers can be called head and tail material. The surface of the initially cut wafer is usually rough and cannot be used for wafer production, so it is usually polished in the subsequent process, hence the name polished wafer. According to different wafer manufacturing requirements, it is usually necessary to dope some impurities, such as P and B, into the coarse wafer to change its resistance, so it has a lower resistance. Terms such as high resistance and heavy doping. Coating wafer can be understood as Epitaxial wafer epi, which is a wafer made for semiconductor devices with specific requirements. It is usually used in high-end integrated circuits and special integrated circuits, such as silicon on insulator (SOI). In the production process of wafer integrated circuits, it is necessary to test the process state of production equipment for some wafers, such as particle grade, etching rate and defect rate. These wafers are usually called control wafers, and control wafers are also used to process with normal production batches to test the quality of a certain process, such as CVD film thickness. After maintenance or repair, the production equipment immediately handles the batch of wafers, which is easy to cause scrapping, so it is usually necessary to use some very low-cost wafers to run the process to determine the quality of maintenance or repair work. This kind of wafer is usually called a virtual wafer. Of course, fake wafers are sometimes used in normal production. For example, some machines must process a certain number of wafers, and if the wafers are insufficient, they will be supplemented by virtual wafers, while some machines must perform some form of virtual operation after processing a certain number of wafers. Otherwise, the process quality cannot be guaranteed, and so on. Many wafers can be called dummy wafers. The baffle can basically be regarded as a virtual wafer. Fake wafers, control wafers, baffles, etc. can usually be recycled.
Silicon wafer is an important material for making integrated circuits, and various semiconductor devices can be made by photolithography and ion implantation. Chips made of silicon wafers have amazing computing power. The development of science and technology constantly promotes the development of semiconductors. With the development of automation and computer technology, the cost of silicon chip (integrated circuit), a high-tech product, has dropped to a very low level. This makes silicon chips widely used in aerospace, industry, agriculture and national defense, and even quietly enters every family.