Paper
2 April 2014 Compensating process non-uniformity to improve wafer overlay by RegC
Author Affiliations +
Abstract
The introduction of double and triple patterning tightened the Overlay current nodes’ specifications across the industry to levels of 5nm and 3nm respectively. Overlay error is a combination of Intra-field and field-to-field errors. The Intra-field error includes several systematic signatures, such as overlay magnitude differences between X and Y axes, field center vs edge and more. The recent developments in scanner technology improved the intra-field Overlay to high orders. In this work we have quantified the state-of-the-art residual overlay errors and applied the RegC® (registration/overlay control) process, a new solution of deep sub-nanometer pattern shift, to further improve the overlay process control, in addition to the current lithography’s state-of-the-art capabilities. As a result we managed to reduce the baseline overlay error by more than one nanometer and reduced systematic intrafield non-uniformities, by removing the 3 sigma difference between X and Y to zero. The combination of intra-field control by RegC® with high order correction per exposure (CPE) by the scanner provides a new era of overlay control required for the 2x and 1x multiple patterning processes.
© (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Philippe Leray, Shaunee Cheng, Avi Cohen, Erez Graitzer, Vladimir Dmitriev, Shiran Rehtan, and Nadav Wertsman "Compensating process non-uniformity to improve wafer overlay by RegC", Proc. SPIE 9050, Metrology, Inspection, and Process Control for Microlithography XXVIII, 905015 (2 April 2014); https://doi.org/10.1117/12.2048081
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Semiconducting wafers

Photomasks

Scanners

Overlay metrology

Process control

Optical lithography

Data modeling

Back to Top