Nanotechnology Now

Our NanoNews Digest Sponsors



Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Exposing the Sensitivity of Extreme Ultraviolet Photoresists

NIST researchers exposed a 300 mm silicon wafer with incrementally increasing doses of extreme ultraviolet light (EUV) in 15 areas. After the wafer was developed, the team determined that the seventh exposure was the minimum dose required (E0) to fully remove the resist.

Credit: NIST
NIST researchers exposed a 300 mm silicon wafer with incrementally increasing doses of extreme ultraviolet light (EUV) in 15 areas. After the wafer was developed, the team determined that the seventh exposure was the minimum dose required (E0) to fully remove the resist.

Credit: NIST

Abstract:
Researchers at the National Institute of Standards and Technology (NIST) have confirmed that the photoresists used in next-generation semiconductor manufacturing processes now under development are twice as sensitive as previously believed. This finding, announced at a workshop last month,* has attracted considerable interest because of its implications for future manufacturing. If the photoresists are twice as sensitive as previously thought, then they are close to having the sensitivity required for high volume manufacturing, but the flip side is that the extreme ultraviolet optical systems in the demonstration tools currently being used are only about half as effective as believed.

Exposing the Sensitivity of Extreme Ultraviolet Photoresists

GAITHERSBURG, MD | Posted on June 26th, 2008

Extreme ultraviolet lithography (EUVL) is a process analogous to film photography. A silicon wafer is coated with photoresist and exposed to EUV light that reflects off a patterned "photomask." Where the light strikes the resist it changes the solubility of the coating. When developed, the soluble portions wash away leaving the same pattern exposed on the silicon surface for the processing steps that ultimately create microcircuits.

The drive to make circuits with ever smaller features has pushed manufacturers to use shorter and shorter wavelengths of light. EUVL is the next step in this progression and requires developing both suitable light sources and photoresists that can retain the fine details of the circuit, balancing sensitivity, line edge roughness and spatial resolution. NIST researcher Steve Grantham says that optical lithography light sources in use today emit light with a wavelength of about 193 nanometers, which borders on optical wavelengths. EUVL sources produce light with wavelengths about an order of magnitude smaller, around 13.5 nanometers. Because this light does not travel through anything—including lenses—mirrors have to be used to focus it.

Until recently, EUV photoresist sensitivity was referenced to a measurement technique developed at Sandia National Labs in the 1990s. Late in 2007, scientists at the Advanced Light Source at Lawrence Berkeley National Laboratory in Berkeley, Calif., used a NIST-calibrated photodetector to check the standard. Their detector-based measurements indicated that the resist's sensitivity was about twice that of the resist-based calibration standard.

Following on the intense interest that these results generated when the Berkeley group presented them at a conference in February, the Intel Corporation asked scientists at NIST to make their own independent determination of the EUVL resist sensitivity to validate the results. Measurements conducted at the NIST SURF III Synchrotron Ultraviolet Radiation Facility agreed with those of the Berkeley group. The fact that the photoresist is now known to be twice as sensitive to the EUV light implies that half as much light energy as had been expected is arriving at the wafer.

"These results are significant for a technology that faces many challenges before it is slated to become a high-volume manufacturing process in 2012," Grantham says. "It should open the eyes of the industry to the need for accurate dose metrology and the use of traceable standards in their evaluations of source and lithography tool performance."

* S. Grantham, C. Tarrio, R. E. Vest, T. B. Lucatorto, A. Novembre, M. Cangemi, V. Prabhu, K.W. Choi, M. Chandhok, T. Younkin and J. S. Clarke. SEMATECH EUV Source Workshop, Bolton Landing, N.Y., May 12, 2008.

####

About NIST
Founded in 1901, NIST is a non-regulatory federal agency within the U.S. Department of Commerce. NIST's mission is to promote U.S. innovation and industrial competitiveness by advancing measurement science, standards, and technology in ways that enhance economic security and improve our quality of life.

For more information, please click here

Contacts:
Mark Esser

(301) 975-8735

Copyright © NIST

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

The Pocket Project will develop a low-cost and accurate point-of-care test to diagnose Tuberculosis: ICN2 holds a follow-up meeting of the Project on September 18th - 19th September 18th, 2014

New non-invasive technique could revolutionize the imaging of metastatic cancer September 17th, 2014

Toward making lithium-sulfur batteries a commercial reality for a bigger energy punch September 17th, 2014

Recruiting bacteria to be technology innovation partners: September 17th, 2014

Chip Technology

‘Small’ transformation yields big changes September 16th, 2014

UT Arlington research uses nanotechnology to help cool electrons with no external sources September 11th, 2014

Excitonic Dark States Shed Light on TMDC Atomic Layers: Berkeley Lab Discovery Holds Promise for Nanoelectronic and Photonic Applications September 11th, 2014

Researchers Create World’s Largest DNA Origami September 11th, 2014

Nanoelectronics

Rice rolls 'neat' nanotube fibers: Rice University researchers' acid-free approach leads to strong conductive carbon threads September 15th, 2014

Excitonic Dark States Shed Light on TMDC Atomic Layers: Berkeley Lab Discovery Holds Promise for Nanoelectronic and Photonic Applications September 11th, 2014

Researchers Create World’s Largest DNA Origami September 11th, 2014

Material development on the nanoscale: Doped graphene nanoribbons with potential September 8th, 2014

Discoveries

The Pocket Project will develop a low-cost and accurate point-of-care test to diagnose Tuberculosis: ICN2 holds a follow-up meeting of the Project on September 18th - 19th September 18th, 2014

Scientists refine formula for nanotube types: Rice University theorists determine factors that give tubes their chiral angles September 17th, 2014

Toward making lithium-sulfur batteries a commercial reality for a bigger energy punch September 17th, 2014

Recruiting bacteria to be technology innovation partners: September 17th, 2014

Announcements

The Pocket Project will develop a low-cost and accurate point-of-care test to diagnose Tuberculosis: ICN2 holds a follow-up meeting of the Project on September 18th - 19th September 18th, 2014

Scientists refine formula for nanotube types: Rice University theorists determine factors that give tubes their chiral angles September 17th, 2014

New non-invasive technique could revolutionize the imaging of metastatic cancer September 17th, 2014

Toward making lithium-sulfur batteries a commercial reality for a bigger energy punch September 17th, 2014

Photonics/Optics/Lasers

The Pocket Project will develop a low-cost and accurate point-of-care test to diagnose Tuberculosis: ICN2 holds a follow-up meeting of the Project on September 18th - 19th September 18th, 2014

'Squid skin' metamaterials project yields vivid color display: Rice lab creates RGB color display technology with aluminum nanorods September 15th, 2014

Fonon at Cutting-Edge of 3D Military Printing: Live-Combat Scenarios Could See a Decisive Advantage with 3D Printing September 15th, 2014

Simple, Cost-Effective Method Proposed for Synthesizing Zinc Oxide Nanopigments September 15th, 2014

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More














ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE