Risk Assessment and Mitigation of Energetic Events in the Semiconductor Industry
Zhang, Shasha ; Sharfstein, Susan ; Begley, Thomas
(College of Nanoscale Science and Engineering, 257 Fuller Road, Albany, NY 12203)
Wafer fabrication is a procedure bearing substantial risks due to many chemically intensive processes involved. A survey conducted in early 2013 was analyzed to provide integrated overviews of seventy incidents that occurred in the past three years. The most significant risks lie in the film deposition process, including atomic layer deposition (ALD) and chemical vapor deposition (CVD). Such risks are not only associated with upstream precursors that are pyrophoric, unstable or water sensitive, but also exist in downstream byproducts. For many of the new precursors, there is a general lack of material property information for conducting process hazard review. During the process, chemical byproducts may form and accumulate in the exhaust system or forelines. Many of these reaction byproducts are uncharacterized, but it is certain that they consist of energetic substances. In this work, a new effort is initiated to assess and mitigate the hazards associated with both poorly characterized pyrophoric precursors and unknown byproducts. A wide variety of experimental methods are introduced to evaluate the hazards and understand the reaction chemistry. Differential scanning calorimeter and adiabatic calorimeter are used to evaluate stability, reactivity and runaway potential of materials and mixtures. The data will assist not only in developing control measures to eliminate or minimize the level of the risks, but also in predicting the incidents in a worst-case scenario. A series of solid phase characterization methods, such as scanning electron microscopy, differential scanning calorimetry, Fourier transform infrared spectroscopy and X-ray diffraction, are proposed to characterize solid byproducts in order to identify root causes and retrieve reaction history. A combustion experiment is designed to acquire flame characteristics for various materials, providing information for engineering design of fire sensing systems. Detailed information will be presented and discussed in this talk.