When it comes to building semiconductors and microchips, one of the most common materials used is silicon. If you want to take a closer look at the silicon wafer manufacturing process, check this out:
An ingot is grown by heating the silicon to about 1420˚C which is way above the element’s melting point. The liquefaction of the polycrystalline and dopant combination would result in the formation of a single silicon crystal which is called the seed. The seed barely touches the surface as it is positioned right on top of the melt. The finished ingot has to have the same crystal orientation as the seed.Since the goal is to attain doping uniformity, the crucible of molten silicon and the seed have to be rotated in opposite directions until the proper conditions for crystal growth are reached. At this point, the number of crystal defects is minimized and the seed can be slowly lifted out of the melt. Next, the crystal’s diameter is increased by reducing the pull speed.As soon as the desired diameter is attained, it needs to be maintained by stabilizing the growth conditions. Upon lifting the seed above the melt, a thin film of the silicon adheres to the seed because of the surface tension. While cooling, the melted silicon orients itself to the seed’s crystal structure.
The fully-grown ingot is then ground to a diameter that’s a bit bigger than the desired diameter of the silicon wafer. To indicate the ingot’s orientation, a flat cut or notch is cut into it before it passes a series of inspections and proceeds to the second stage of the manufacturing process – slicing. A diamond edge saw is used to slice the wafers. The wafers are lapped and etched to remove saw marks and other defects.
The wafer is polished in a cleanroom by workers who are wearing special cleanroom suits. A fan is over their heads to blow away unwanted particles that may come in contact with the silicon wafers.
Wafer World offers high-quality silicon wafers that would be perfect for your next project. Contact us today for inquiries!
