Emergency Release Abatement of MOCVD Precursor Materials
Faller, Rebecca (ATMI, San Jose, California and )
Cheung, Beverly (SAME)
A commonly used manufacturing method for III-V compound semiconductor devices is metal organic chemical vapor deposition (MOCVD). Products resulting from MOCVD processes include light emitting diodes (LED's), high temperature semiconductors, and high frequency semiconductors for telecommunications devices. Typical precursor materials for MOCVD processes include arsine (AsH3) and phosphine (PH3). These materials are highly toxic and are generally packaged, stored, and delivered in high-pressure cylinders. The toxicity and pressure of the gases have the potential to create disastrous consequences if released in an uncontrolled manner. Although the gases are typically utilized within gas cabinets, should a release of the gas occur, the exhaust of these secondary containment devices ultimately flows to the atmosphere. Abatement devices are used to protect the surrounding community from exposure to hazardous materials, should an emergency situation arise. Several areas have requirements for facilities using arsine or phosphine pressurized gas cylinders to provide a mechanism to reduce exhaust concentrations to specified concentrations. Abatement tools must be highly effective in order to remove these hazardous materials to below one-half of immediate danger to life and health (IDLH). This paper describes a customized bed of dry scrubbing media that is installed at the exhaust of the secondary enclosure. This product is not only capable of abating arsine and phosphine to below one-half IDLH during an emergency release scenario, but it is also provides non-flammable and irreversible abatement of these gases. The emergency release scrubber described herein provides excellent technological advantages over the traditional carbon beds.
[abstract as .pdf]