Reducing the impact of reticle CD-non-uniformity of multiple structures by dose corrections based on aerial image measurements

Ute Buttgereit; Robert Birkner; Thomas Scheruebl; Sander de Putter; Bernardo Kastrup; Jo Finders

doi:10.1117/12.848053

1 April 2010 Reducing the impact of reticle CD-non-uniformity of multiple structures by dose corrections based on aerial image measurements

Ute Buttgereit, Robert Birkner, Thomas Scheruebl, Sander de Putter, Bernardo Kastrup, Jo Finders

Author Affiliations +

Proceedings Volume 7638, Metrology, Inspection, and Process Control for Microlithography XXIV; 76380D (2010) https://doi.org/10.1117/12.848053
Event: SPIE Advanced Lithography, 2010, San Jose, California, United States

Abstract

For many critical lithography applications the main contributor to wafer intra-field CD variation is the reticle CD variation. Current practice is that the input data needed to correct the effect of the reticle on the wafer CD is gathered using wafer exposures and SEM or scatterometry analysis. This approach consumes valuable scanner time and adds wafer costs. In this work we evaluate the potential for Intra-Field CD non-uniformity (CDU) correction based on aerial image reticle measurements for a complex 2D structure, including peripheral structures. The application selected is a 45nm rotated brick wall structure (active area DRAM). A total of 10 line / space structures (both horizontal and vertical) through pitch represent the periphery. Mask qualification has been performed using the newly developed Zeiss WLCD32 metrology tool, which measures wafer level CD on masks using aerial imaging technology. Excellent correlation is shown between intra-field wafer data and WLCD32 data. Furthermore, a comparison is made between the correction potential of ASML DoseMapper recipes based on wafer data and on WLCD32 mask data, indicating that the potential CDU improvement via both approaches is similar. Exposures with the resulting dose recipes have been used to confirm this predicted correction potential in a realistic setting.

Citation Download Citation

Ute Buttgereit, Robert Birkner, Thomas Scheruebl, Sander de Putter, Bernardo Kastrup, and Jo Finders "Reducing the impact of reticle CD-non-uniformity of multiple structures by dose corrections based on aerial image measurements", Proc. SPIE 7638, Metrology, Inspection, and Process Control for Microlithography XXIV, 76380D (1 April 2010); https://doi.org/10.1117/12.848053

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