SPIE Proceedings | Volume 10143 | Patterning I >

Full Content is available to subscribers

Subscribe/Learn More  >
Proceedings Article

Integrated approach to improving local CD uniformity in EUV patterning

[+] Author Affiliations
Andrew Liang, Timothy Tran, Chen-Wei Liang, Brandon Ward, Steven Chuang, Jengyi Yu, Greg Harm, Samantha Tan, Rich Wise, Sirish Reddy, Akhil Singhal, Bart van Schravendijk, Girish Dixit, Nader Shamma

Lam Research Corp. (United States)

Jan Hermans, Jelle Vandereyken

IMEC (Belgium)

Katja Viatkina, David Rio, Michael Kubis, Mircea Dusa

ASML Netherlands B.V. (Netherlands)

Proc. SPIE 10143, Extreme Ultraviolet (EUV) Lithography VIII, 1014319 (March 24, 2017); doi:10.1117/12.2258192
Text Size: A A A
From Conference Volume 10143

  • Extreme Ultraviolet (EUV) Lithography VIII
  • Eric M. Panning; Kenneth A. Goldberg
  • San Jose, California, United States | February 26, 2017
Abstract

abstract

Extreme ultraviolet (EUV) lithography is crucial to enabling technology scaling in pitch and critical dimension (CD). Currently, one of the key challenges of introducing EUV lithography to high volume manufacturing (HVM) is throughput, which requires high source power and high sensitivity chemically amplified photoresists. Important limiters of high sensitivity chemically amplified resists (CAR) are the effects of photon shot noise and resist blur on the number of photons received and of photoacids generated per feature, especially at the pitches required for 7 nm and 5 nm advanced technology nodes. These stochastic effects are reflected in via structures as hole-to-hole CD variation or local CD uniformity (LCDU). Here, we demonstrate a synergy of film stack deposition, EUV lithography, and plasma etch techniques to improve LCDU, which allows the use of high sensitivity resists required for the introduction of EUV HVM. Thus, to improve LCDU to a level required by 5 nm node and beyond, film stack deposition, EUV lithography, and plasma etch processes were combined and co-optimized to enhance LCDU reduction from synergies.

Test wafers were created by depositing a pattern transfer stack on a substrate representative of a 5 nm node target layer. The pattern transfer stack consisted of an atomically smooth adhesion layer and two hardmasks and was deposited using the Lam VECTOR PECVD product family. These layers were designed to mitigate hole roughness, absorb out-of-band radiation, and provide additional outlets for etch to improve LCDU and control hole CD. These wafers were then exposed through an ASML NXE3350B EUV scanner using a variety of advanced positive tone EUV CAR. They were finally etched to the target substrate using Lam Flex dielectric etch and Kiyo conductor etch systems. Metrology methodologies to assess dimensional metrics as well as chip performance and defectivity were investigated to enable repeatable patterning process development.

Illumination conditions in EUV lithography were optimized to improve normalized image log slope (NILS), which is expected to reduce shot noise related effects. It can be seen that the EUV imaging contrast improvement can further reduce post-develop LCDU from 4.1 nm to 3.9 nm and from 2.8 nm to 2.6 nm. In parallel, etch processes were developed to further reduce LCDU, to control CD, and to transfer these improvements into the final target substrate. We also demonstrate that increasing post-develop CD through dose adjustment can enhance the LCDU reduction from etch. Similar trends were also observed in different pitches down to 40 nm. The solutions demonstrated here are critical to the introduction of EUV lithography in high volume manufacturing. It can be seen that through a synergistic deposition, lithography, and etch optimization, LCDU at a 40 nm pitch can be improved to 1.6 nm (3-sigma) in a target oxide layer and to 1.4 nm (3-sigma) at the photoresist layer. © (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Citation

Andrew Liang ; Jan Hermans ; Timothy Tran ; Katja Viatkina ; Chen-Wei Liang, et al.
" Integrated approach to improving local CD uniformity in EUV patterning ", Proc. SPIE 10143, Extreme Ultraviolet (EUV) Lithography VIII, 1014319 (March 24, 2017); doi:10.1117/12.2258192; http://dx.doi.org/10.1117/12.2258192


Access This Proceeding
Sign in or Create a personal account to Buy this proceeding ($15 for members, $18 for non-members).

Figures

Tables

MultiMedia


NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).
Compression-Only CPR: Pushing the Science Forward
Cone
AAM 2010;304:1493-1495.
All you need to read in the other general jounals
BMJ 2010;341:c5893-c1494.

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging & repositioning the boxes below.

Related Book Chapters

Topic Collections

Advertisement
SPIE © 1962 - 2017. All Rights Reserved.
  • Don't have an account?
  • Subscribe to the SPIE Digital Library
  • Create a FREE account to sign up for Digital Library content alerts and gain access to institutional subscriptions remotely.
Access This Proceeding
Sign in or Create a personal account to Buy this proceeding ($15 for members, $18 for non-members).
Access This Proceeding
Sign in or Create a personal account to Buy this article ($15 for members, $18 for non-members).
Access This Chapter

Access to SPIE eBooks is limited to subscribing institutions and is not available as part of a personal subscription. Print or electronic versions of individual SPIE books may be purchased via SPIE.org.