Improving wafer level CD uniformity for logic applications utilizing mask level metrology and process

Avi Cohen; Thomas Trautzsch; Ute Buttgereit; Erez Graitzer; Ori Hanuka

doi:10.1117/12.2027348

9 September 2013 Improving wafer level CD uniformity for logic applications utilizing mask level metrology and process

Avi Cohen, Thomas Trautzsch, Ute Buttgereit, Erez Graitzer, Ori Hanuka

Proceedings Volume 8880, Photomask Technology 2013; 888025 (2013) https://doi.org/10.1117/12.2027348
Event: SPIE Photomask Technology, 2013, Monterey, California, United States

Abstract

Critical Dimension Uniformity (CDU) is one of the key parameters necessary to assure good performance and reliable functionality of any integrated circuit (IC). The extension of 193nm based lithography usage combined with design rule shrinkage makes process control, in particular the wafer level CDU control, an extremely important and challenging task in IC manufacturing. In this study the WLCD-CDC closed loop solution offered by Carl Zeiss SMS was examined. This solution aims to improve the wafer level intra-field CDU without the need to run wafer prints and extensive wafer CD metrology. It combines two stand-alone tools: The WLCD tool which measures CD based on aerial imaging technology while applying the exact scanner-used illumination conditions to the photomask and the CDC tool which utilizes an ultra-short femto-second laser to write intra-volume shading elements (Shade-In Elements™) inside the photomask bulk material. The CDC process changes the dose going through the photomask down to the wafer, hence the wafer level intra-field CDU improves. The objective of this study was to evaluate how CDC process is affecting the CD for different type of features and pattern density which are typical for logic and system on chip (SOC) devices. The main findings show that the linearity and proximity behavior is maintained by the CDC process and CDU and CDC Ratio (CDCR) show a linear behavior for the different feature types. Finally, it was demonstrated that the CDU errors of the targeted (critical) feature have been effectively eliminated. In addition, the CDU of all other features have been significantly improved as well.

Citation Download Citation

Avi Cohen, Thomas Trautzsch, Ute Buttgereit, Erez Graitzer, and Ori Hanuka "Improving wafer level CD uniformity for logic applications utilizing mask level metrology and process", Proc. SPIE 8880, Photomask Technology 2013, 888025 (9 September 2013); https://doi.org/10.1117/12.2027348

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available