Surprisingly, complex computer chips are made from something quite technically unimpressive: sand. Microprocessors are one of the most complicated products to manufacture, and creating these chips is a difficult and precise process. The steps, from isolating silicon from sand to silicon wafer dicing to layering interconnects, are the most basic stages in an amazingly sophisticated fabrication process.
Start With Sand
The process of creating a computer chip begins with silica sand, comprised of silicon dioxide. Silicon is the base material for semi-conductor manufacturing and must be isolated from the sand and pure before it can be used in manufacturing.
Multiple purification processes are performed to deliver electronic-grade silicon. A purified silicon ingot weighs around 100kg and is made ready for the next step.
Silicon Wafer Dicing
The circular silicon ingot is sliced into wafers as thin as possible. The silicon wafers are then refined and polished to provide the best possible surface for the next fabrication steps.
A layer of photoresist is spread thinly across the wafer, and this layer is then exposed to a UV light mask shaped in the pattern of the microprocessor’s circuits. The exposed photoresist becomes soluble and is washed off by a solvent. A pattern of hard material is applied to the wafer creating thin silicon ridges.
Using a process as complex as silicon wafer dicing, an insulation layer is applied to the surface, and holes are etched into it. Electroplating is used to deposit copper ions on the surface, forming a layer of copper on top.
The transistors are now connected in an architecture that allows the chip to function as a processor.
Test and Sliced Dies and Packaging
The chips are now ready to be tested, and the wafer is sliced into dies. Dies are packaged and assume the familiar form factor of a desktop processor. Processors are then tested for power efficiency, frequency, and other performance metrics.