The work pace in cleanrooms is deliberately slow. Limited movement keeps the air in cleanrooms as free as possible of dust and other particles, which can destroy semiconductors during their production. Because the machinery sets the operatorsí rate of work in the largely automated production process, workers maintain an easygoing pace. Although workers spend some time alone monitoring equipment, operators and technicians spend much of their time working in teams.
Technicians are on their feet most of the day, walking through the cleanroom to oversee production activities. Operators spend a great deal of time sitting or standing at workstations, monitoring computer readouts and gauges. Sometimes, they must retrieve wafers from one station and take them to another.
The temperature in the cleanrooms must be kept within a narrow range: usually, it is set at a comfortable 72 degrees Fahrenheit. Although bunny suits cover virtually the entire body, except perhaps the eyes (over which workers wear protective glasses), their lightweight fabric keeps the temperature inside fairly comfortable as well. Entry and exit of workers in bunny suits from the cleanroom are controlled to minimize contamination, and workers must be reclothed in a clean suit and decontaminated each time they return to the cleanroom.
Several highly toxic chemicals are used at various points in the process of manufacturing semiconductors. Workers who are exposed to such chemicals can be seriously harmed. However, semiconductor fabrication plants are designed with safeguards to ensure that these chemicals are handled, used, and disposed of without exposure to workers or the surrounding environment. Toxic chemicals are applied to wafers by computer-controlled machine tools in sealed chambers and there is normally little risk of workers coming into contact with them.
Semiconductor-fabricating plants operate around the clock. For this reason, night and weekend work is common. In some plants, workers maintain standard 8-hour shifts, 5 days a week. In other plants, employees are on duty for 12-hour shifts to minimize the disruption of cleanroom operations brought about by changes in shift. In some plants, managers allow workers to alternate schedules, thereby distributing the overnight shift equitably.