Optimization of align marks and overlay targets in VIA first dual damascene process

Dae-Ung Shin; Young-Bae Jeong; Jeong-Lyeol Park; Jae-Sung Choi; Jeong-Gun Lee; Dae-Hoon Lee

doi:10.1117/12.485032

2 June 2003 Optimization of align marks and overlay targets in VIA first dual damascene process

Dae-Ung Shin, Young-Bae Jeong, Jeong-Lyeol Park, Jae-Sung Choi, Jeong-Gun Lee, Dae-Hoon Lee

Proceedings Volume 5038, Metrology, Inspection, and Process Control for Microlithography XVII; (2003) https://doi.org/10.1117/12.485032
Event: Microlithography 2003, 2003, Santa Clara, California, United States

Abstract

Due to its low resistance and high electromigration performance, copper is now considered as a better metalization than the currently used aluminum based alloys. Dual damascene architecture is generally proposed for fabrication of multilevel copper interconnection. However, in the case of via first dual damascene scheme, we have great difficulties in M2 Trench photoprocess such as alignments and overlay measurements because this scheme makes too high topography of via patterns. Alignment marks and overlay targets made during via patterning process do not have good image contrasts after coating BARC and photoresist. Deteriorated image contrast of alignment marks and overlay targets increases the uncertainty in the alignment and overlay measurement. The image contrasts of alignment mark become worse after coating BARC and photoresist, resulting in weak, noisy, and asymmetric alignment signals. In this paper, we evaluated the impacts of mark structure, geometry, and BARC processing for the alignments and the overlay measurements using convex or concave structures, bar or slit structures, and special designed structures in M2 trench photo process. We also investigated the copper filled keys on M1 trench layer as alternative alignment targets.

Citation Download Citation

Dae-Ung Shin, Young-Bae Jeong, Jeong-Lyeol Park, Jae-Sung Choi, Jeong-Gun Lee, and Dae-Hoon Lee "Optimization of align marks and overlay targets in VIA first dual damascene process", Proc. SPIE 5038, Metrology, Inspection, and Process Control for Microlithography XVII, (2 June 2003); https://doi.org/10.1117/12.485032

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