Reticle quality control in wafer fabs is different from quality control in mask shops. Mask shop requirements are typically inspectability of mask-type, resolution and sensitivity, with the latter usually being the most important. Mask shop sensitivity requirements are also fairly absolute. All defects or imperfections of a certain specification have to be found 100 percent of the time, every time. Wafer fab requirements are an interplay between inspectability, sensitivity, and the economic cost of inspection versus the economic risk of not inspecting. Early warning and defect signatures versus absolute capture of all defects is a key distinction between wafer fabs and mask shops. In order to better understand the different strategies and approaches taken by wafer fabs for reticle quality control an industry-wide benchmark survey of leading wafer fabs was undertaken. This paper summarizes the results while retaining the different wafer fabs' anonymity and confidentiality. The approach taken for the survey was specifically designed to be impartial and independent of any tools, solutions or applications available from KLA-Tencor.

Date Published: 1 November 2007
PDF: 5 pages
Proc. SPIE 6730, Photomask Technology 2007, 67305B (1 November 2007); doi: 10.1117/12.745389

Published in SPIE Proceedings Vol. 6730:
Photomask Technology 2007
Robert J. Naber; Hiroichi Kawahira, Editor(s)