Construction
Integrated circuits came at a time when technology was reaching its physical limitations. Advanced forms of circuits built with vacuum tubes filled entire rooms. With the advent of the transistor, things became a little easier, but all of the soldering had to be done by hand which still meant a single error would cause the entire circuit to fail. Of course, the logical solution was to create an entire circuit in one solid piece. As the field of engineering goes, the feat of imagining an idea on paper is only half the battle. Once the design is all set, the complex process of construction actually begins. Perhaps complex isn’t the right word, however, as modern transistors are smaller than a grain of rice. In fact, meticulous is a much better description. Construction of integrated circuits has to occur in a completely isolated and cleaned room without any chance of contamination (Intersil Corporation).
As mentioned before, design comes first. Once a design is decided upon, a mask, the equivalent of a cutout for a flashlight, is made from the design. At this point, a silicone crystal has to be acquired through purchase or growing. This crystal is then cut into thin slices, known as wafers, by a precise saw. After these wafers are thoroughly cleaned, they are covered with another wafer of insulator followed by another photosensitive film-like layer. This sandwich of layers is then placed subjected to UV rays that are shot through the mask. The layers break down wherever the UV light hits which directly corresponds to the mask built from the design. After the wafer is washed with chemicals to break away the spots the UV light started, all that is left is a maze-like piece on which some silicon peaks through channels in the insulation material. This process can be repeated as many times as needed to build layer upon layer of circuit (MadeHow.com).
At this point, the rest of the process deals with making the wafer into the best...