First, a 99.9999% pure silicon crystal ingot is sliced into thin wafers.
Polishing the wafer removes surface scratches and impurities, leaving a near-perfect base for building chips.
Portions of the silicon are chemically altered to create the source and drain regions of the transistor, which control the flow defined by photolithography, where the wafer is coated with a light-sensitive material called photoresist. Next, light is shined through a patterned mask onto a chip-size section of the wafer -- a process similar to printing a photograph from a negative. A machine called a stepper repeats this process for each chip on the wafer.