The Not So Clean Business of Making Silicon Chips
Think of the images associated with the modern semiconductor industry, most prominently associated with Silicon Valley in California. Workers with white gowns, head coverings and gloves manufacturing chips in a well-lighted, dust free workplace replete with the latest ventilation systems are the pictures which come to mind.
Now a report has just been published in Technology Review, a journal edited at the Massachusetts Institute of Technology in Cambridge, Massachusetts, which will send shock waves through this fast-growing industry’s complacency over the safety of its operations.
The lengthy article, entitled “The Not-So-Clean Business of Making Chips,” is by Dr. Joseph LaDou of the University of California-San Francisco School of Medicine. Here is his overall conclusion: “…the semiconductor industry, which uses large quantities of toxic metals, chemicals, and gases, max be creating significantly greater health and safety problems for its workers than heretofore realized. Some health and safety professionals are particularly concerned about the effects of these materials on the reproductive health of the industry’s largely female workforce, many of whom are of childbearing age. The use of highly toxic and flammable materials also poses a serious threat to the safety of residents in surrounding communities. For instance, the rupture of one cylinder containing a toxic gas such as arsine could cause widespread acute exposures among local residents. Recent findings also show that the industry is contaminating the groundwater of nearby communities and polluting the air with photochemical smog.” The author also included mention of dangers such as explosion, fire and electrocution.
Technology Review does not sound industrial alarms easily. When it does, the criticized industry has better take heed. With detail and precision, Dr. LaDou makes the following points:
- California Department of Industrial Relations’ surveys show high relative rates of worker illnesses compared to other manufacturing industries and the use of strikingly large quantities of toxic materials, including the deadly arsine, phosphine and diborane
- He and reporter, Alison Bass, take apart the semiconductor industry’s statistical rebuttals including its redefinition of “illness” so that “one-time” chemical exposures are instead re-classified as “injuries” (usually of the no-work-time-lost variety) without clarifying what “one-time” means.
- Because of alleged trade secret restrictions and just plain indifference, manufacturers of these chemicals and do not provide adequate information that would be helpful to both semiconductor companies and health professionals in case of accidents or human exposures.
- New semiconductor chip manufacturing processes, as in the replacement of “wet etching” by a called “dry plasma etching”, are introducing new perils that are more difficult to evaluate. Also, an expanded use of advanced techniques for doping silicon wafers with arsenic, phosphorus, or boron is associated with an increasing number of health complaints of workers.
- What is unknown about the toxicity and exposure to these gases and chemicals must not be assumed to be safe. For example, scientists from the National Institute for Occupational Safety and Health found workers, who repeatedly inhaled arsine gas at less than one-tenth the federal standard, still excreted enough arsenic to suggest possible cancerous results. Such chronic arsine exposure “may occur without visible signs of red-cell destruction or kidney damage,” according to Dr. LaDou.
- Silicon Valley is a serious source of underground leaks of toxic materials from storage, waste and fuel tanks and piping systems. These seepage are contaminating underground drinking water sources.
- While there are not belching smokestacks, like some industrial factories, semiconductor companies are emitting tons of “reactive organic gases” every day that are invisible contributors to the formation of photochemical smog.
- As the Environmental Protection Agency languishes over environmental problems of this industry, an “even larger danger” looms: no community’s emergency facilities are able to handle “the major disaster that could result from the rupture of a metal cylinder containing arsine gas.”
- A good physician should prescribe as well as diagnose. Dr. LaDou recommends more engineering safety prevention through safer materials substitution, the up-to-date training of police, fire and medical personnel to deal with these hazards, and comprehensive follow—up studies of workers’ and communities’ health and safety.
It will be interesting to see whether this modern industry has a modern response to these charges or whether it will adopt the stonewall posture of a General Motors. Either way, the silicon chip is going to be very controversial long before it reaches the consumer.