New ISO cleanroom standards for nanotechnology under discussion
The rapid rise in the use of nanoscale materials has prompted various ISO standards committees to look at amending current cleanroom standards.The existing set of ISO 14644 cleanroom standards enables users to manage production facilities down to 100 nanometres in airborne particulate terms and 5 microns on surfaces. These levels may not, however, be adequate for nano medical or nano MEMS device production. As a consequence, the ISO working group TC 209, the body responsible for cleanroom standards, has set up a new working group to examine future requirements.
This new working group was launched in Seattle, in mid-June, with the objective of either modifying the existing standards or preparing a new one exclusively for nano production. While Dr Peter Hatto, of IonBond Ltd, remains the leader of the International ISO TC 229 nanotechnology group, the new working group will have a US-based chair, supported by BSI secretariat Dr David Michael. Dick Gibbons, the SEE contamination focus group chairman, will be the UK representative, with the rest of Europe providing vital team members from its existing working clean room groups.
Gibbons says the work plan agreed in Seattle is for road maps to be produced to map out the team progress over the next three years and that an early start should be made to consider supplements to two key documents: ISO 14644 part 4 Design and 14644 part 5 Operations. The group considers that a condensation nucleus counter (CNC) technique could be used for measurements of airborne particulate down to 5 nanometres, requiring changes to parts 1, 2 and 3 covering Validation and Test Methods. However, since parts 1 and 2 are currently the object of significant change, further changes are likely to be subject to delay, according to Gibbons.
Operator and material safety are considered to be key issues within the nano technology work groups and some protocols will need to be inserted into the Part 5 cleanroom document, said Gibbons. “We anticipate new sections to protect the operator, additional to its current role in protecting the product and the facility. This was assessed as a top priority in Seattle.
“We understand that US facility constructors are working to unusual demands in terms of vibration control and electromagnetic or static precaution (EMI / ESS). Neither of these requirements is fully developed in the existing part 4 Design guide, but they are understood properly by constructors building for semiconductor fabrication. Clearly these issues need to be strengthened in ISO 14644 part 4, while retaining the standard’s nature as a non-industry specific document.”
The SEE focus group therefore requests that the cleanroom industries make the group aware of their capabilities in terms of Vibration and EMI control relating to nanotechnology. “This will help to ensure that the planned documentation can be met by European as well as Asian and US industries,” said Gibbons. The group would also welcome contact with garment and consumable suppliers that are working in these industries. Please respond to Dick Gibbons at richard.gibbons@environmental.org.uk