Manufacturability issues with double patterning for 50-nm half-pitch single damascene applications using RELACS shrink and corresponding OPC

Maaike Op de Beeck; Janko Versluijs; Vincent Wiaux; Tom Vandeweyer; Ivan Ciofi; Herbert Struyf; Dirk Hendrickx; Jan Van Olmen

doi:10.1117/12.713393

26 March 2007 Manufacturability issues with double patterning for 50-nm half-pitch single damascene applications using RELACS shrink and corresponding OPC

Maaike Op de Beeck, Janko Versluijs, Vincent Wiaux, Tom Vandeweyer, Ivan Ciofi, Herbert Struyf, Dirk Hendrickx, Jan Van Olmen

Author Affiliations +

Proceedings Volume 6520, Optical Microlithography XX; 65200I (2007) https://doi.org/10.1117/12.713393
Event: SPIE Advanced Lithography, 2007, San Jose, California, United States

Abstract

A double patterning (DP) process is discussed for 50nm half pitch interconnects, using a litho-etch-litho-etch approach on metal hard mask (MHM). Since an 0.85NA immersion scanner is used, the small pitch of 100nm is obtained by DP, the small trenches are made by a Quasar exposure followed by a shrink technique. The RELACS^® process is used, realizing narrow trenches with larger DOF and less LER. For mask making, a design split is carried out, followed by adjustments of the basic design to make the patterns more litho-friendly. Assist features are placed next to isolated trenches to ensure sufficient DOF. Furthermore, an adjusted OPC calculation is carried out, taking into account proximity effects of both the exposure and the subsequent shrink process. After mask fabrication, this DP process is used for a single damascene application, with BDIIx as low-k material and TaN or TiN as MHM. Various problems are encountered, such as CD gain of the trenches during both MHM etch steps, poisoning and BARC thickness variations due to topography during the second litho step. For all these problems, solutions or work-arounds have been found, After the second MHM-etch, the 50nm half-pitch pattern is transferred successfully in the underlying low-k material.

Citation Download Citation

Maaike Op de Beeck, Janko Versluijs, Vincent Wiaux, Tom Vandeweyer, Ivan Ciofi, Herbert Struyf, Dirk Hendrickx, and Jan Van Olmen "Manufacturability issues with double patterning for 50-nm half-pitch single damascene applications using RELACS shrink and corresponding OPC", Proc. SPIE 6520, Optical Microlithography XX, 65200I (26 March 2007); https://doi.org/10.1117/12.713393

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