Modeling for sub-50-nm x-ray application with phase masks

James W. Taylor; Daniel H. Malueg; Franco Cerrina; Mumit Khan; Don Thielman

doi:10.1117/12.535422

20 May 2004 Modeling for sub-50-nm x-ray application with phase masks

James W. Taylor, Daniel H. Malueg, Franco Cerrina, Mumit Khan, Don Thielman

Proceedings Volume 5374, Emerging Lithographic Technologies VIII; (2004) https://doi.org/10.1117/12.535422
Event: Microlithography 2004, 2004, Santa Clara, California, United States

Abstract

The CNTech Advanced Lithography Toolset uses a beam propagation method to calculate the intensity profile as it propagates through the mask and into the photoresist. One can construct the membrane, absorber, gap, and resist, each as a series of n-slices to achieve unusually precise calculations. Here a clear X-ray phase mask is modeled with silicon nitride in a configuration called a Bright Peak Enhanced X-ray Phase Mask (BPEXPM). For the optimized structure of this mask, which relies on both diffraction and phase shifting to produce the reduced wafer image, four factors must be controlled; these are: absorber thickness - material and wavelength dependent, absorber wall slope, gap, and resist threshold. A central composite experimental design showed that a 100 nm mask would print a wafer at 35 nm CD using the 70% maximum intensity threshold when the wall slope was 0.5° from the vertical. Additionally: 1) a 100 nm increase in absorber thickness decreased the CD by 1.0 nm; 2) every 1.0 um increase in gap decreased the CD 0.8 nm; and 3) every 1.0 nm increase in mask CD increased the linewidth only 0.1 nm. Other mask processing materials were examined in addition to the 180° (π) phase-shift absorber thickness. Experimental verifications of the modeling results are in progress to demonstrate device construction for devices with lower wafer coverage than would be required for memory devices.

Citation Download Citation

James W. Taylor, Daniel H. Malueg, Franco Cerrina, Mumit Khan, and Don Thielman "Modeling for sub-50-nm x-ray application with phase masks", Proc. SPIE 5374, Emerging Lithographic Technologies VIII, (20 May 2004); https://doi.org/10.1117/12.535422

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
5 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Photomasks

X-rays

Semiconducting wafers

Phase shifts

Silicon

Lithography

Silicon carbide

Show All Keywords

Keywords/Phrases

Search In:

Publication Years