Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


"Liquid lenses" may shrink feature sizes on microchips


New data from the National Institute of Standards and Technology (NIST) will assist in the design of optics for liquid immersion lithography, an old idea that recently has attracted new interest as a possible means of improving image resolution and thereby shrinking feature sizes of computer chips.

Conventional optical lithography has advanced sufficiently to achieve a resolution of 100 nanometers (billionths of a meter), but there are physical and technical limits to how much better it can get. By placing certain liquids between the final optical element and the silicon wafer, it may be possible to extend the resolution to 65 nanometers for state-of-the-art lithography using the 193-nanometer wavelength of light, or even 45 nanometers or below for future systems using the 157-nanometer wavelength.

A key characteristic of liquids to be used in immersion lithography is their refractive index, which affects how light bends as it crosses an interface, such as that between the liquid and a lens or a silicon wafer. Air has an index close to one. By contrast, water has a refractive index almost 50 percent higher. Placing this higher-index fluid between the lens and the silicon wafer reduces the resolution-limiting effects of diffraction, enabling imaging of smaller feature sizes.

NIST physicists recently presented preliminary measurements of the refractive index for high-purity water, considered the best candidate for a "liquid lens" at the 193-nanometer wavelength. They also determined that the index is very sensitive to temperature changes, a critical issue for optics design. A forthcoming paper describes the techniques used to make these technically difficult measurements.* Future work will focus on refining these measurements and collecting data on other liquids that may be useful in 157-nanometer lithography.

*Burnett, John H., and Simon Kaplan. In press. "Measurement of the refractive index and thermooptic coefficient of water near 193 nanometers." To appear in Proceedings of SPIE Optical Microlithography XVI (2003) 5040-188.0

Laura Ost | EurekAlert!
Further information:

More articles from Process Engineering:

nachricht Intelligent wheelchairs, predictive prostheses
20.12.2017 | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA

nachricht Jelly with memory – predicting the leveling of com-mercial paints
15.12.2017 | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Im Focus: ILA 2018: Laser alternative to hexavalent chromium coating

At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.

When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...

Im Focus: Radar for navigation support from autonomous flying drones

At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.

Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

International Virtual Reality Conference “IEEE VR 2018” comes to Reutlingen, Germany

08.03.2018 | Event News

Latest News

Wandering greenhouse gas

16.03.2018 | Earth Sciences

'Frequency combs' ID chemicals within the mid-infrared spectral region

16.03.2018 | Physics and Astronomy

Biologists unravel another mystery of what makes DNA go 'loopy'

16.03.2018 | Life Sciences

Science & Research
Overview of more VideoLinks >>>