Wafer Carriers and Fire Safety

Wafer carriers (i.e., boxes and pods) have historically been constructed of plastic materials with high heat and smoke release rate when burning. Modern semiconductor fabrication plants include materials management systems that can result in large concentrations of wafer carriers, such as in stockers. In case of a fire in a stocker, the resulting property damage and business interruption can have a very serious impact to fab operations. The fab layout schemes now under development for 300m fabs offer different challenges, and tend to increase inherent fire hazards as compared with present fab layouts. The concept of the fire risk as associated with wafer carriers is explored. The interaction of work in progress automatic transport systems, vertical and horizontal fab layout schemes, and stockers are considered. Mitigation strategies are discussed, including the development of carriers constructed of inherently non-fire propagating materials, passive fire protection, active fire suppression systems, and fire detection methods.