How are semiconductors manufactured?
Today’s semiconductors are usually composed of silicon, and they are manufactured in a procedure that combines the familiar with the bizarre; some steps that are involved in the process are as everyday as developing a roll of photographic film while others seem as if they would be better suited to take place on a spaceship. These semiconductors appear to the naked eye as being small and flat, but they are actually three-dimensional “sandwiches” that are ten to twenty layers thick. It can take more than two dozen steps and up to two full months to produce a single one of these silicon sandwiches. Some of the basic and more essential steps involved in the manufacturing process of silicon chips are briefly detailed below. First, silicon crystals are melted in a vat and purified to 99.9999% purity. The molten silicon is drawn into long, heavy, cylindrical ingots, which are then cut into thin slices called wafersabout the thickness of a business card. One side of each wafer must be polished
