Preliminary Survey Report: Control Technology for Gallium Arsenide Processing at M/A-COM, Lowell, Massachusetts, Report No. CT-163-13A.
An evaluation was made of technology employed at M/A-COM (SIC-3674) in Lowell, Massachusetts, for controlling hazardous substances encountered during use of gallium-arsenide (1303000) in production of semiconductor devices. While toxicity of gallium-arsenide has not been evaluated, it is suggested that stringent controls for arsenic (7440382) be met (10 micrograms/cubic meter). The building under study was built exclusively for gallium-arsenide production, housing about 160 workers. Crystals were grown using the Liquid Encapsulated Czochralski technique. Some experimental work with Electro Dynamic Gradient crystal growth was also done. In manufacture of products other than wafers, additional production steps were needed including epitaxial growth, ion implantation, photolithography, etching, metallization, wafer thinning or scribing, and packaging. Potential hazards existed mainly in numerous solvents, acids, and gases used. Engineering measures (material substitution, process/equipment modification, isolation or automation, and ventilation), work practices, personal protection (safety goggles and protective clothing for crystal growth, epitaxy, and wafer fabrication areas and use of respirators during crystal puller cleaning), and workplace and medical monitoring were used to limit exposures. Since M/A-COM appears to be using state of the art control methods in crystal growth, it will likely be recommended for in depth study to evaluate the effectiveness of these methods.
Division of Physical Sciences and Engineering, Engineering Control Technology Branch, NIOSH, Cincinnati, Ohio, Report No. CT-163-13A, 9 pages, 3 references