SRAF enhancement using inverse lithography for 32nm hole patterning and beyond

V. Farys; F. Chaoui; J. Entradas; F. Robert; O. Toublan; Y. Trouiller

doi:10.1117/12.829894

30 September 2009 SRAF enhancement using inverse lithography for 32nm hole patterning and beyond

V. Farys, F. Chaoui, J. Entradas, F. Robert, O. Toublan, Y. Trouiller

Proceedings Volume 7488, Photomask Technology 2009; 748813 (2009) https://doi.org/10.1117/12.829894
Event: SPIE Photomask Technology, 2009, Monterey, California, United States

Abstract

At 32 nm node and beyond, one of the most critical processes is the holes patterning due to the Depth of Focus (DOF) that becomes rapidly limited. Thus the use of Sub Resolution Assist Features (SRAF) becomes mandatory to keep DOF at a sufficient level through pitch. SRAF are generally generated using Rule Based OPC with a different cleaning step to avoid risk of SRAF printing or conflict with main feature. One of the key challenges of using such a technique is the ability of placing SRAF in random holes features. The rule based approach cannot treat all the configurations resulting in non-optimal SRAF placement for certain main feature. On the other hand, Inverse Lithography has shown the ability of generating SRAF at the ideal size and position (theoretically) 1 and interest of this technique has been proven experimentally 2,3. Nevertheless, this kind of technique is not yet ready for maskshop due to MRC limitation caused by the pixelated SRAF output, and the important mask writing time due to the shotcount 4. In this paper we propose to make a comparison of the two approaches on random 2D features. We will see that Inverse Lithography permits to keep a sufficient DOF on 2D features configurations where Rule based appears to be limited. Simulated and experimental results will be presented comparing Rule based, Ideal and MRC constraint SRAF in terms of DOF and Runtime performance for hole patterning

Citation Download Citation

V. Farys, F. Chaoui, J. Entradas, F. Robert, O. Toublan, and Y. Trouiller "SRAF enhancement using inverse lithography for 32nm hole patterning and beyond", Proc. SPIE 7488, Photomask Technology 2009, 748813 (30 September 2009); https://doi.org/10.1117/12.829894

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