Navigation Links
New paper reveals nanoscale details of photolithography process
Date:12/12/2007

Scientists at the National Institute of Standards and Technology (NIST) have made the first direct measurements of the infinitesimal expansion and collapse of thin polymer films used in the manufacture of advanced semiconductor devices. Its a matter of only a couple of nanometers, but it can be enough to affect the performance of next-generation chip manufacturing. The NIST measurements, detailed in a new paper,* offer a new insight into the complex chemistry that enables the mass production of powerful new integrated circuits.

The smallest critical features in memory or processor chips include transistor gates. In todays most advanced chips, gate length is about 45 nanometers, and the industry is aiming for 32-nanometer gates. To build the nearly one billion transistors in modern microprocessors, manufacturers use photolithography, the high-tech, nanoscale version of printing technology. The semiconductor wafer is coated with a thin film of photoresist, a polymer-based formulation, and exposed with a desired pattern using masks and short wavelength light (193 nm). The light changes the solubility of the exposed portions of the resist, and a developer fluid is used to wash the resist away, leaving the pattern which is used for further processing.

Exactly what happens at the interface between the exposed and unexposed photoresist has become an important issue for the design of 32-nanometer processes. Most of the exposed areas of the photoresist swell slightly and dissolve away when washed with the developer. However this swelling can induce the polymer formulation to separate (like oil and water) and alter the unexposed portions of the resist at the edges of the pattern, roughening the edge. For a 32-nanometer feature, manufacturers want to hold this roughness to at most about two or three nanometers.

Industry models of the process have assumed a fairly simple relationship in which edge roughness in the exposed latent image in the photoresist transfers directly to the developed pattern, but the NIST measurements reveal a much more complicated process. By substituting deuterium-based heavy water in the chemistry, the NIST team was able to use neutrons to observe the entire process at a nanometer scale. They found that at the edges of exposed areas the photoresist components interact to allow the developer to penetrate several nanometers into the unexposed resist. This interface region swells up and remains swollen during the rinsing process, collapsing when the surface is dried. The magnitude of the swelling is significantly larger than the molecules in the resist, and the end effect can limit the ability of the photoresist to achieve the needed edge resolution. On the plus side, say the researchers, their measurements give new insight into how the resist chemistry could be modified to control the swelling to optimal levels.


'/>"/>

Contact: Michael Baum
michael.baum@nist.gov
301-975-2763
National Institute of Standards and Technology (NIST)  
Source:Eurekalert

Related biology technology :

1. New White Paper Details Strategies for Biotechnology Companies to Improve EH&S Compliance
2. Free White Papers Detail Sterility Testing Essentials for Medical Device, Pharmaceutical Manufacturers
3. 454 Sequencing(TM): Science Paper Suggests That Structural Variation Plays an Important Role in Genetic Variation
4. New White Paper Details Six Steps to Investigate and Prevent Laboratory Accidents
5. Microtest Offers Free White Paper: Virus Testing for Biological Products: Partnering With a Contract Lab
6. Free White Paper Addresses Challenges of New FDA Regulations Awaiting Combo Product Manufacturers
7. New Survey Reveals Many Adults With High Cholesterol Fail to Take Necessary Steps to Improve Their Condition
8. CCMR gets $2.9M for training grad students in nanoscale science
9. Penn engineers design computer memory in nanoscale form that retrieves data 1,000 times faster
10. CCMR gets $2.9M for training grad students in nanoscale science
11. Penn engineers design computer memory in nanoscale form that retrieves data 1,000 times faster
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
New paper reveals nanoscale details of photolithography process
(Date:10/11/2017)... ... October 11, 2017 , ... A new study published ... frozen and fresh in vitro fertilization (IVF) transfer cycles. The multi-center ... success. , After comparing the results from the fresh and frozen transfer cohorts, ...
(Date:10/10/2017)... ... October 10, 2017 , ... Dr. Bob Harman, founder and CEO of ... Rotary Club. The event entitled “Stem Cells and Their Regenerative Powers,” ... Dr. Harman, DVM, MPVM was joined by two human doctors: Peter B. Hanson, ...
(Date:10/9/2017)... 9, 2017  BioTech Holdings announced today identification ... its ProCell stem cell therapy prevents limb loss ... Company, demonstrated that treatment with ProCell resulted in ... as compared to standard bone marrow stem cell ... in reduction of therapeutic effect.  ...
(Date:10/7/2017)... Phoenix, Arizona (PRWEB) , ... ... ... than 15 years’ experience providing advanced instruments and applications consulting for microscopy ... the in-house expertise in application consulting, Nanoscience Analytical offers a broad range ...
Breaking Biology Technology:
(Date:3/29/2017)... 29, 2017  higi, the health IT company that ... North America , today announced a Series B ... of EveryMove. The new investment and acquisition accelerates higi,s ... to transform population health activities through the collection and ... higi collects and secures data today on behalf ...
(Date:3/24/2017)... 2017 The Controller General of Immigration from Maldives ... Algeen have received the prestigious international IAIR Award for the most ... Reading ... Maldives ... Abdulla Algeen (small picture on the right) have received the IAIR award ...
(Date:3/23/2017)... 2017 Research and Markets has announced the ... Trends - Industry Forecast to 2025" report to their offering. ... The Global ... of around 8.8% over the next decade to reach approximately $14.21 ... market estimates and forecasts for all the given segments on global ...
Breaking Biology News(10 mins):