Solid State Technology: Notchless wafer standard approved
Published:
Wednesday, March 18, 2015 - 09:49
450mm notchless wafer standardization has been under
discussion for over a year. Driven by the G450C
Consortium, the proposed changes will improve wafer
symmetry, but more importantly, increase the utilization of
wafer surface area. The International Polished Wafer and International 450mm Wafer Task Forces (TF) led
the effort to add a 450mm notchless wafer specification via
ballot 5604. The document was
completed late last year and is now published in the latest
edition of SEMI M1-0215 Specification for Polished Single
Crystal Silicon Wafers.
SEMI T7-0709 - Specification for Back Surface Marking of Double-Side Polished Wafers with a Two-Dimensional Matrix Code Symbol, is an important specification, which provides marking symbology with no intrusion in the fixed quality area of the wafer. This standard is applicable for various size of wafers, and not limited to 450mm notchless wafers. In alignment with SEMI M1, the Fiducial Mark Interoperability TF, in cooperation with the International 450mm Wafer TF, balloted and successfully received committee approval for doc. 5752, Revision of SEMI T7 to cover 450mm wafers. (See figure below for the primary location of the SEMI T7 mark on the polished wafer.) The document was approved at the Traceability Committee meeting during SEMICON Japan in December 2014. The new version of SEMI T7 is currently being processed for publication and will be available in Spring 2015. When the revision of the T7 is published, SEMI will have a total of 20 SEMI standards for 450mm manufacturing.
[caption id="" align="alignnone" width="379"]
450mm Diameter Wafer with Location of Orientation
Fiducial Marks (Source: SEMI M1 -Figure 6)[/caption]
By Kevin Nguyen, SEMI
