Meeting the challenges of 157-nm microstepper technology

Osamu Yamabe; Noboru Uchida; Toshiro Itani

doi:10.1117/12.474554

30 July 2002 Meeting the challenges of 157-nm microstepper technology

Osamu Yamabe, Noboru Uchida, Toshiro Itani

Proceedings Volume 4691, Optical Microlithography XV; (2002) https://doi.org/10.1117/12.474554
Event: SPIE's 27th Annual International Symposium on Microlithography, 2002, Santa Clara, California, United States

Abstract

For the aim of fabricating next-generation semiconductor devices, researchers are now attempting to enhance 157-nm lithography so as to achieve 70-nm node level various circuit designs. Many of the challenges for 157-nm technology such as contamination and purge control, calcium fluoride intrinsic birefringence, finding resists with suitable performance characteristics, have been performed. The major challenge, in terms of stability of tool performance, has been the apparent accumulation of contamination on the bottom of the objective. This has been evidenced by a reduction in resolution performance and an increase in the non-uniformity of the illumination intensity across the image plane. Uniformity over the entire imaging field has increased from 0.58% to as much as 18.5% through the use of the tool. This paper reports our demonstration that loss of uniformity due to contamination from resist outgassing can be reversed by cleaning the bottom surface of the lens of 157-nm microstepper (Ultratech Stepper Inc.) in- situ using 157-nm light and a small concentration of O₂ in the N₂ purging for exposure area. With an in-situ oxygen (O₂) and vacuum ultra violet (VUV) cleaning, the uniformity of over the full imaging field has been improved from 18.5% to 6.0%. The edges of the imaging field do not recover as well during a cleaning as the center of the field, as the central 0.5 mm diameter of the field uniformity has been improved to more or less 2.0%. The procedure of this in-situ O₂ cleaning will also be introduced, and in addition to this in-situ O₂ cleaning, some recent results in system performance will be shown and many of these challenges will be discussed.

Citation Download Citation

Osamu Yamabe, Noboru Uchida, and Toshiro Itani "Meeting the challenges of 157-nm microstepper technology", Proc. SPIE 4691, Optical Microlithography XV, (30 July 2002); https://doi.org/10.1117/12.474554

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

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
10 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Contamination

Photomasks

Birefringence

Nitrogen

Oxygen

Image resolution

Lithography

Show All Keywords

Keywords/Phrases

Search In:

Publication Years