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:10/10/2017)... ... October 10, 2017 , ... Dr. Bob Harman, founder ... local San Diego Rotary Club. The event entitled “Stem Cells and ... had 300+ attendees. Dr. Harman, DVM, MPVM was joined by two human doctors: ...
(Date:10/10/2017)... ... October 10, 2017 , ... USDM ... firm for the life sciences and healthcare industries, announces a presentation by Subbu ... , The presentation, “Automating GxP Validation for Agile Cloud Platforms,” will present a ...
(Date:10/9/2017)... ... , ... The award-winning American Farmer television series will feature 3 Bar Biologics ... at 8:30aET on RFD-TV. , With global population estimates nearing ten billion people ... to feed a growing nation. At the same time, many of our valuable resources ...
(Date:10/9/2017)... ... October 09, 2017 , ... ... medical journal, Epilepsia, Brain Sentinel’s SPEAC® System which uses the surface electromyography ... generalized tonic-clonic seizures (GTCS) using surface electromyography (sEMG). The prospective multicenter phase ...
Breaking Biology Technology:
(Date:5/16/2017)... DALLAS , May 16, 2017   ... for health organizations, and MD EMR Systems ... certified development partner for GE, have established a ... Patient Portal product and the GE Centricity™ products, ... Centricity EMR. These new integrations ...
(Date:4/24/2017)... Janice Kephart , former 9/11 ... Partners, LLP (IdSP) , today issues the following ... March 6, 2017 Executive Order: Protecting the ... be instilled with greater confidence, enabling the reactivation ... applications are suspended by until at least July ...
(Date:4/18/2017)... 18, 2017  Socionext Inc., a global expert in SoC-based imaging ... server, the M820, which features the company,s hybrid codec technology. A ... Tera Probe, Inc., will be showcased during the upcoming Medtec Japan ... at the Las Vegas Convention Center April ... Click here for ...
Breaking Biology News(10 mins):