The daily operations of semiconductor manufacturing and R&D departments involves a number of potential health and safety standards. Apart from laboratory-induced hazards, the most critical areas are silicon device and gallium arsenide fabrication.
Operators employed in semiconductor and R&D manufacturing plants are potentially exposed to an array of chemical agents including first and foremost acids such as acetic, chromic, hydrochloric, hydrofluoric, nitric, phosphoric, and sulphuric. Then there are caustic substances like ammonium hydroxide, hydrogen peroxide, and sodium hydroxide. The semiconductor manufacturing prices also depends on cryogens such as argon, carbon dioxide, oxygen and nitrogen, as well as chemical listed as cyanides.
Corrosive gases and solvents
The extensive list of gases used in these facilities include corrosive, flammable, explosive, pyrophoric and toxic gaseous substances such as arsine, boron, trifluoride, diborane, hydrogen chloride, phosphine, and silane. Chemicals vital to semiconductor manufacture include various solvents such as isopropyl alcohol, ethanol, acetone, glycol ether mixture, methanol, methylene chloride, methyl ethyl ketone, n-butyl acetate, 1,1,1-trichlorethane, and xylene.
Heavy metals and airborne irritants
Semiconductor industry relies on complex technological processes that include metals and their salts such as aluminium, antimony, arsenic, boron, chromium, gallium, gold, magnesium, mercury, nickel, silver, and phosphorus. In addition workers may be exposed to nanoparticles, manufacturing dust, eye and skin irritant photoresists and various forms of silica. The list of hazards presented here is not conclusive but serves it purpose to illustrate a wide range of exposures that are characteristic of semiconductor manufacturing and R&D.
Safety practices and standards
There is a number of national consensus standards aimed at regulating worker safety and health in the semiconductor industry. These standards propose process elements such as liquid heating systems, sizing and identifying flow-limiting devices for gas cylinder valves, equipment safety labelling, exhaust ventilation, equipment ergonomics, risk assessment, etc. Fire and smoke are one of the biggest health and safety concerns, due to the high density of highly-flammable and easily-ignitable plastics as well as highly-flammable liquids and gases.
Process hazard assessments need to be conducted for operations that involve additional risk, while employees need to attend periodical safety and chemical management training. Chemical hazards need to be identified by the potential routes of entry (dermal, inhalation, digestion), while permanently placed gas monitors in laboratory and manufacturing areas need to be tested periodically to make sure they are working properly. The safety and performance of storage tanks and machines can be additionally improved by coating them in special anti-rust paint that provides galvanic protection against corrosion.
EHS management approach
The distinctive nature of semiconductor industry calls for an EHS (Environment, Health, Safety) approach, which covers all potential types of hazards listed above. Such a management process requires trained and competent EHS professionals to conduct recognition and evaluation of occupational issues. Through the hierarchy of controls (elimination, substitution, engineering, administrative, and personal protection equipment) it’s possible to reduce the occurrence of these risks.
Environmental gas safety
The presence of highly toxic, flammable and explosive gases in semiconductor facilities poses a special safety challenge for health and safety managers. The first line of defence are flow-limiting orifices that are an industry standard for many of these gases. Special gas cylinders are usually placed in gas cabinets and piped into laboratories or manufacturing areas. Laboratory-specific gas cylinders, on the other hand, need to be placed in ventilated enclosures or gas cabinets. By using sub-atmospheric toxic gas cylinders there have been significant improvements in safe gas delivery.
Considering the immediate and delayed potential hazards in semiconductor manufacturing and R&D, companies have to rely on both national and industry specific health and safety standards. The highest level of employee safety can be achieved through managing the working environment, an applying solutions that protect the operators from liquid and airborne toxins and irritants.