Exposure Assessment of Fluorides in University of California, Berkeley Microfabrication Laboratory

A new process to tech silicon isotropically with xenon difluoride (XeF2) for the manufacturing of Micro Electro Mechanical Systems (MEMS) components has recently been developed. Users of this equipment have reported odors associated with the process at the University of California (UC), Berkeley Microfabrication Laboratory. Air samples were collected form machine operators, maintenance personnel, and etched wafers to evaluate potential sources of fluoride exposure. In addition, the engineering design of this equipment and operational procedures were examined. Fluoride was not detected in the air samples, but potential sources of fluoride exposure were located due to improper engineering design. A maintenance procedure for a XeF2 source bottle change had not been established at the time of the evaluation presenting another potential safety hazard. As a result of this study, the engineering design was improved and maintenance procedures are being established.