Processing is so complex that it is controlled by computers. Here, computers control the flow of oxygen, water and inert gases. They also regulate the time and temperature cycle used to fire the wafers. Slight variations lead to differences in the quality and thickness of oxidized silicon. So the computers are also used to keep detailed, wafer batch by wafer batch, records of the exact process conditions measured during each step in the fabrication of the microchip. After the microchips are finished, these records can be analyzed to determine the source of errors or to improve the process.
