Growing an ingot is the first step in silicon wafer manufacturing. Once the ingot is fully-grown, it will then be sliced to its specification, and a series of other steps will still be performed before coming up with the final product. Each of the steps must be done perfectly to not affect the quality of the wafers. To show you how the process of the growing ingot is carried out, here is the process of growing silicon ingots:
Growing a silicon ingot may take around a week up to a month, depending on various factors, including specification, size, and quality. Most single crystal silicon wafers are grown through the CZ method, while the rest is grown through the FZ method. To grow a silicon ingot, the first procedure is to heat the silicon to 1420°C, which is above the melting point of silicon. Once the crystal and dopant mixture has been dissolved, the single silicon crystal seed is put on top of the melt, hardly touching the surface.
Keep in mind that the seed must have the same crystal orientation in the accomplished ingot. The doping must also be uniform. To achieve this, the seed crystal and the container of molten silicon must rotate in opposite directions. Once it reaches the required conditions for crystal growth, the seed crystal can be taken out of the melt. The growth will then begin to take place with a fast pulling of the seed crystal. Doing this will reduce the number of crystal defects within the seed while it’s still at the beginning of the silicon wafer manufacturing.
After this, the pulling speed will be reduced to allow the size of the crystal to increase. Once the desired size is achieved, the growth conditions are maintained to control the diameter. After removing from the melt, and as it starts to cool, the atoms start to orient themselves to the crystal structure of the seed.
Growing silicon ingots is a crucial step to produce high-quality wafers. At Wafer World, our silicon wafer manufacturing process is carefully and meticulously carried out to guarantee high-quality wafers. Get all your wafer needs with us today! Call us for inquiries or purchase wafers online!
