Establishing proper safety systems is imperative in sophisticated industries such as the manufacture of semiconductors. Some of the most stringent requirements known in manufacturing are found in the laboratories and cleanroom areas in the field of semiconductors.
To eliminate dust, control vibration, humidity and temperature, the lab environment must be controlled. However, another area is also important. To etch and process the silicon wafers for the production of semiconductors, several highly corrosive and toxic chemicals are required. The use of these chemicals results in toxic gases and vapors and these require a sophisticated gas detector system to ensure laboratory safety. Gas detectors are crucial to safety systems and can also detect Asphyxiants, toxic and flammable gases. Usually, detectors are integrated into a sophisticated control/monitoring system. These can:
- Pinpoint the area of the gas emission
- Interface control systems to automatically shut down a process or area to contain the gas outflow
- Use an alarm to alert personnel to the area of gas concentration
Examples of Gases Used in Semiconductor Production
The cleanroom laboratories contain equipment for etching, photolithography, doping and cleaning. These processes require the use of toxic and corrosive chemicals. For example, the toxic gas hydrogen sulfide is used in gallium arsenide (GaAs) doping, to incorporate sulfur into the gallium arsenide. The toxic liquid carbon tetrachloride is used in plasma etching of silicon as a source of chlorine gas. Other examples of toxic chemicals used for etching and doping include diborane gas, phosphine gas, dichlorosilane and sulfur hexafluoride.