Researchers Create Enhanced Light Sources For Lithography

Jul 09, 2008
Researchers Create Enhanced Light Sources For Lithography
Mirrors are used in scientist Mark Tillack's UC San Diego photonics lab to guide light into laser amplifiers.

A breakthrough discovery at UC San Diego may help aid the semiconductor industry’s quest to squeeze more information on chips to accelerate the performance of electronic devices. So far, the semiconductor industry has been successful in its consistent efforts to reduce feature size on a chip. Smaller features mean denser packing of transistors, which leads to more powerful computers, more memory, and hopefully lower costs.

In an effort to help create faster, better and cheaper light sources for chips, UC San Diego researchers, in collaboration with Cymer, Inc., are developing laser-produced light sources for next generation Extreme Ultraviolet Lithography (EUVL).

The researchers, led by mechanical and aerospace engineering scientist Mark Tillack, filed a patent in May 2008 for their latest discovery indicating that longer pulse lengths can provide similar performance as short pulse lengths. Tillack and his team found that employing a long pulse in a CO2 laser system used in an EUVL source could make the system significantly more efficient, simpler, and cheaper compared to that using a shorter pulse. Their research findings were recently published in Applied Physics Letters.

Today’s semiconductor companies are diligently working on developing EUVL as the leading candidate for next generation lithography tools to produce microchips with features of 32 nanometers or less. While great progress has been made in this field, several challenges still exist to cost effectively field EUVL in high volume manufacturing. Nowadays, the light source in semiconductor lithography is applied directly from a laser through a mask to a wafer. In EUVL, a laser is used to produce extreme ultraviolet light that is sent to a mask and then the wafer. This indirect process is more inefficient, and could require a very large and very expensive laser source, Tillack said.

“CO2 lasers, which we use in our lab, have two advantages – they are inherently cheaper to build and operate, and they give better conversion efficiency from the laser to EUV light,” he said. “Our discovery that long pulses work well enough means that the CO2 laser system can be built and operated more cheaply.”

Tillack pointed to possible future applications for EUVL, such as flash memory chips, which will become denser and denser. “Imagine in the future being able to make a 200 gigabyte flash disk memory stick cheaply,” he said. “EUVL could make hard disks obsolete”.

“We didn’t know how to make a powerful source of light in this part of the spectrum before,” added Tillack, also an associate director of the UC San Diego Jacobs School of Engineering’s Center for Energy Research. “We might be opening new avenues for advanced light sources. We need to continue our research and begin to look at other possible applications.”

Source: University of California, San Diego

Explore further: Quick-change materials break the silicon speed limit for computers

add to favorites email to friend print save as pdf

Related Stories

Scientists Shed 'Light' on Semiconductor Quandry

Jul 14, 2009

(PhysOrg.com) -- UC San Diego scientists are using laser plasma-produced light sources to explore performance improvements of critical inspection tools for the semiconductor industry, which ultimately will ...

Recommended for you

Oculus unveils new prototype VR headset

35 minutes ago

Oculus has unveiled a new prototype of its virtual reality headset. However, the VR company still isn't ready to release a consumer edition.

Wireless sensor transmits tumor pressure

7 hours ago

The interstitial pressure inside a tumor is often remarkably high compared to normal tissues and is thought to impede the delivery of chemotherapeutic agents as well as decrease the effectiveness of radiation ...

Tim Cook puts personal touch on iPhone 6 launch

8 hours ago

Apple chief Tim Cook personally kicked off sales of the iPhone 6, joining in "selfies" and shaking hands with customers Friday outside the company's store near his Silicon Valley home.

Team improves solar-cell efficiency

23 hours ago

New light has been shed on solar power generation using devices made with polymers, thanks to a collaboration between scientists in the University of Chicago's chemistry department, the Institute for Molecular ...

Calif. teachers fund to boost clean energy bets

23 hours ago

The California State Teachers' Retirement System says it plans to increase its investments in clean energy and technology to $3.7 billion, from $1.4 billion, over the next five years.

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

guiding_light
4.8 / 5 (5) Jul 09, 2008
They can build any kind of EUV source, it will hardly be used. EUVL has too many problems in other areas.
plasma_guy
4.7 / 5 (3) Jul 09, 2008
Gigaphoton (the laser company) already covered this last year.