Semi cleanrooms getting the lead out
10/01/2005
BY HANK HOGAN
Semiconductor makers and tool suppliers, as well as cleanroom builders and operators, are beginning to understand the implications of what it will mean to “think green” in the near future. European Union (EU) directives scheduled to go into effect on July 1, 2006, are part of a broad effort to lessen the environmental impact of the semi industry, and as a result, environmental changes are likely in store for cleanrooms and the tools within them.
The EU’s Restriction of Hazardous Substances (RoHS) mandates that manufacturers get lead, cadmium, mercury, bromine-containing flame-retardants, and other substances out of their process and products. The Waste Electrical and Electronic (WEEE) directive also aims to keep electronic gear out of landfills by setting criteria for collection, treatment, and recycling.
James Beasley, senior environment, health, and safety (ESH) program manager at the manufacturing research consortium SEMATECH (www.sematech.org), predicts, “Our initial assessment is that the greatest [cleanroom] impact can be on materials of construction, such as coatings, which may have restricted or banned materials in them currently.”
Under RoHS, manufacturers of hazardous construction materials may be facing some tough choices. Plastics suppliers, for example, will have to come up with an acceptable alternative to bromine for fire resistance. On the whole, however, Beasley believes material manufacturers are already doing a good job of understanding the new directives and are preparing for them.
As for tools in a semiconductor fab, most are classified as large industrial equipment that will not end up in a landfill; in which case, the WEEE directive doesn’t apply. But that doesn’t mean that the tools escape all consequences. Aimee Bordeaux, senior director of the EHS division at the semiconductor industry association SEMI (www.semi.org), notes that a tool may contain thousands of subcomponents with suspect elements-lead, for example-and that manufacturers of those subcomponents may need to implement what could be far-reaching changes to meet RoHS and WEEE. “If a critical component is now lead-free, then you’ve got to requalify that,” cautions Bordeaux.
And semiconductor makers could be challenged to simply comply in a timely fashion with the RoHS directives. In July, for example, AMD (www.amd.com) announced that it had begun offering microprocessors with reduced lead content that were RoHS-compliant. While the company noted that it had begun working on getting the lead out in 2001, and was now shipping product a year ahead of the EU deadline, it has been four years in the making.
Philips Semiconductors (www.philips-semiconductors.com), part of Royal Philips Electronics of the Netherlands, which has semiconductor fabs throughout Europe, is also well aware of RoHS and WEEE. But Andrew Whittard, global process improvement manager at Philips Semiconductors, notes that cleanrooms currently aren’t the main area of concern when it comes to meeting the directives.
Instead, Whittard says, “We have been focusing on the removal of the lead content from our semiconductors.” Achieving this, he notes, occurs either with the selection of the right early stage materials or with the use of lead-free coatings.
As is the case with AMD, getting the lead out has taken years, as Whittard reports that Philips has just now almost completed the transition.
Meanwhile, RoHS compliance by semi manufacturers is expected to bring about environmental changes in cleanrooms and their equipment and furnishings. For example, changes to equipment that maintain and monitor the contamination-controlled area could be required if internal components need to be altered to meet the RoHS mandate and WEEE directive. Cleanroom operators would then be faced with the need to requalify or, perhaps, even make a lifetime buy.
Editor’s note: The SEMI Web site offers additional information and FAQs on RoHS and WEEE. To learn more, visit: http://wps2a.semi.org, click on “Advocacy.”