The manufacturing of CPUs is a complex and highly specialized process that involves many different steps. Here is a general overview of the process:
- Purification of silicon: The first step is to purify silicon, which is the main ingredient in CPUs. This is done by melting sand and then removing impurities from the molten silicon.
- Growing a silicon crystal: Once the silicon is purified, it is grown into a single crystal. This is done by pulling a seed crystal out of a molten silicon bath. The seed crystal is then pulled upward, while the molten silicon is added to the bottom of the bath. This process causes the silicon to solidify into a long, thin crystal.
- Slicing the silicon crystal: The silicon crystal is then sliced into thin wafers. These wafers are the starting point for the actual manufacturing of the CPU.
- Photolithography: The next step is to use photolithography to create the circuitry on the wafers. This is done by exposing the wafers to light through a mask. The light causes the photoresist, which is a light-sensitive material, to harden. The areas of the wafer that are not exposed to light are then washed away, leaving behind the circuitry.
- Ion implantation: In this step, dopants are implanted into the wafers to create the transistors. Dopants are atoms that have different electrical properties than silicon. By implanting dopants into the wafers, the electrical properties of the transistors can be controlled.
- Oxidation: The wafers are then oxidized, which creates a layer of silicon dioxide on the surface of the wafers. This layer of silicon dioxide protects the transistors from damage.
- Metalization: In this step, a layer of metal is deposited on the wafers. This layer of metal forms the connections between the transistors.
- Testing: The final step is to test the wafers to make sure that they are working properly. This is done by running a series of electrical tests on the wafers.
The manufacturing of CPUs is a complex and highly specialized process. It requires a lot of precision and a clean environment. The cost of manufacturing CPUs is also very high. However, the demand for CPUs is also very high, so the cost is justified.