ESH Consideration for Using Pyrophoric or Water-reactive Materials in Semiconductor Manufacturing Facility
(Taiwan Semiconductor Industry Association)
Pyrophoric and water-reactive materials like Trimethyl Aluminum, PDMAT or TDMAT have been used in advanced semiconductor manufacturing processes widely. These chemicals can ignite spontaneously while contacting air, or moisture in the air, or water, therefore they cannot be exposed to the atmosphere by all means. For semiconductor company, all work incorporating new pyrophoric or water-reactive materials must be reviewed by EHS experts in advance, The purpose is to eliminate or well control hazards. In order to have effective ESH review, material suppliers should provide sufficient and accurate ESH information to users. At least, following information must be well collected before use, like physical and chemical characteristics, health effects in the worst case, water reactivity, instability, by-products contained, and engineering control measures. All these information can help us to simulate the possible hazardous emissions and work out adequate abatement and control systems. After doing these, risk of fire, cleanroom contamination, external environmental pollution or other facility-related events can be reduced. Besides that, due to pyrophoric or water-reactive materials often have low vapor pressure, so their supplying systems are normally different from traditional hazardous gases, PH3 or SiH4. Most of time, the containers of pyrophoric and water-reactive materials were located inside or close to process tools, so special considerations are required. For example, the supplying system should be designed with good isolation, gas capacity should be limited and dual or real time monitoring should be in place. This paper will share our consideration, management principles and some design practices as the minimum criteria of pyrophoric and water-reactive material storages, transportation, use and disposal. By following those rules, we hope to well protect both of company’s assets and workers.