From raw materials to finished products processing and production of the main links? Construction technology? Key issues of safety in production? What security measures are generally taken?
(4): end shoulder growth after a long thin neck, to reduce the temperature and casting speed, the crystal diameter gradually increased to the desired size. (5) the diameter growth: after a long neck and shoulder end, by continuously adjusting casting speed and temperature, the crystal diameter maintained at between 2mm positive and negative, the diameter of fixed part is called the diameter part. Monocrystalline silicon wafer from the equal diameter part. (6) tail growth: if the rod is separated from the liquid surface, the effect force will cause the dislocation and slip line of the crystal rod. So in order to avoid the occurrence of this problem, the diameter of the crystal rod must be gradually reduced until it is a sharp point and separated from the liquid surface. This process is called tail growth. After a long period of time, the crystal rod is taken out of the furnace chamber for cooling for a period of time to complete a growth cycle.
Another reason is that CZ is easier to produce large size single crystal silicon rods than FZ method. At present, using the method of CZ CZ main equipment: CZ growth furnace growth furnace by CZ components can be divided into four parts: (1) the furnace body comprises a quartz crucible, graphite crucible, heating and insulating element in the furnace wall (2) crystal and crucible for rotary mechanism: including seed chuck, hanging and pulled the rotating element (3) atmosphere pressure control: including gas flow control, vacuum system and pressure control valve (4) control system: including the detection sensor and computer control system processing: charging, melting, necking, shoulder growth, growth, growth and diameter growth of the tail (1) charging: the polysilicon raw materials and impurities in the quartz crucible, the type of impurity depends on the N or P type resistance. Boron, phosphorus, antimony, arsenic. (2): after the melting quartz crucible for polysilicon feedstock after long crystal furnace must be closed and vacuum filling in high purity argon to maintain a certain pressure range, and then open the graphite heater power supply, heating to the melting temperature (1420 DEG C) above, the polysilicon raw material melting. (3) necking growth: when the temperature of the silicon melt is stable, the seed is slowly immersed in the silicon melt. Because of the thermal stress in the contact between the seed and the silicon melt, the seeds will be dislocation, which must be used to reduce the growth of the crystal. Necking is the seed growth will rapidly upward, the seed crystal grows to a certain size of the reduced diameter (4-6mm) due to the dislocation line and growth axis into a corner, as long as the neck is long enough, the dislocation can grow the crystal surface, zero crystal dislocation.
At present, more than 98% of the electronic components are all made of monocrystalline silicon. Among them, the CZ method accounts for about 85%, and the other part is the FZ growth method. Monocrystalline silicon grown by the CZ method for the production of low power integrated circuit components. The FZ method is mainly used in the growth of monocrystalline silicon in high power electronic components. The CZ method is more commonly used than the FZ method in the semiconductor industry, mainly because of its high oxygen content provides the advantages of wafer strengthening.
The monocrystalline silicon processed into silicon polished wafer processes: crystal growth, cutting, grinding, flat or rolling diameter V groove processing, chamfering, grinding slice polishing, cleaning, corrosion - Packaging: the purpose is to cut off the head and tail of the monocrystalline silicon removal and exceed customer specifications of the parts will be segmented into monocrystalline silicon slicing device can handle the length of cut specimen resistivity measurement of oxygen content in silicon rods. Cut off equipment: in the park outside the park by cutting or cutting machine mainly imported materials cutting machine: blade od grinding: because the surface diameter of the monocrystalline silicon and uneven diameter than the diameter specification final polishing wafer, the outer diameter of rolling mill can accurately obtain diameter. Outer diameter grinding equipment: grinding flat edge or V type groove processing: refers to the designated position and processing, with the specific direction of the crystal silicon on the flat side or V. Processing equipment: grinding machines and X - RAY diffractometer. Slice: a single crystal silicon rod is cut into a thin wafer with an exact geometric size.
