450mm Standards Update: October 2014
By Kevin Nguyen, SEMI
While the timing of a transition to 450mm wafers remains unclear, the industry is continuing to develop the standards that will be essential to high-volume manufacturing on larger substrates. The first standard proposal was submitted in 2007, and SEMI has since published nearly nineteen 450mm-related Standards. New standards are being developed as the industry identifies new requirements, and revisions to published standards are being made as areas for improvement are recognized.
The International Advanced Wafer Geometry Task Force issued ballot 5654 in cycle 2-14, revision to SEMI M49-0613, Guide for Specifying Geometry Measurement Systems for Silicon Wafers for the 130 nm to 16 nm Technology Generations, reducing 450mm wafer edge exclusion from 2 mm to 1.5 mm for 16 nm technology generation. This ballot passed at the SEMICON West meeting in San Francisco, California and is waiting for processing for publication.
While doc. 5654 is aiming to revise measurement system standard, doc. 5655 is balloting to increase the Fixed Quality Area (FQA) from 223 mm to 223.5 mm for 450mm polished wafers in SEMI M1-0414, Specification for Polished Single Crystal Silicon Wafers. These changes are significant since there may be limitations in verifying the quality of wafers close to the wafer edge due to limitations of measurement equipment. No time table is set, but doc. 5655 may be issued in cycle 7-2014 for review at SEMICON Japan in December, 2014.
450mm notchless wafer standardization effort has been in the discussions for over a year. The International Polished Wafer and International 450mm Wafer Task Forces proposed adding a 450mm notchless wafer specification in SEMI M1-0414 via ballot 5604. Driven by the G450C, the proposed changes will improve the wafer symmetry and increase the utilization of wafer surface. However, eliminating the notch will require replacement with several fiducial marks scribed on the back of the wafer’s surface. Doc. 5604 recently completed adjudication during the European Silicon Wafer TC Chapter meeting on October 8, 2014 in Grenoble, France during SEMICON Europa and will next undergo procedural review.
In addition, other physical interfaces and carriers standardization efforts are underway including doc. 5069B, Specification for 450mm Wafer Shipping System. SEMI has a 300mm wafer shipping system standard (M45), but a 450mm wafer version is not yet available. The International 450mm Shipping Box Task Force is currently drafting doc. 5069B for the third time after it failed at the April 2014 meeting.
For complete listing of revisions and new standards efforts, visit (http://www.semi.org/node/42416)
If your company is not yet involved in these efforts to shape the future, learn more about SEMI Standards by visiting www.semi.org/en/Standards. Note that participation in the SEMI Standards Program is free, but requires registration. To learn more, contact your local SEMI Standards staff or register at: www.semi.org/standardsmembership.
For additional 450 information (PPTs, viewpoints, Standards revisions, etc.), visit 450 Central at www.semi.org/450.