Researchers working at JILA at the University of Colorado have created an extreme ultraviolet (EUV) light source that can be used to measure and manipulate objects at the nanoscale.

The team, led by Margaret Murnane and Henry Kapteyn, will describe its findings in a paper by team member Randy Bartels in the July 19 issue of Science. JILA is an interdisciplinary institute for research and graduate education in the physical sciences operated jointly by the University of Colorado and NIST.

By developing a sharply focused laser-like beam of ultraviolet light using a device that could fit on a dining room table, the team has potentially broken one of the barriers to ever-shrinking chip sizes. One of the limits on size is a result of objects being smaller than the waves of light illuminating them. Critical measurements that require optical microscopes have been limited by the wavelength of their light sources.

The EUV light has a wavelength of only 10 nm, and it can pulse in shorter bursts than any existing system, which will allow it to measure fast interactions between small particles. Unlike most EUV light sources, this breakthrough has a tight focus; in the right system it could produce the smallest diameter laser-like beam in the world.

In the electronics sector, the light source could help measure chip components as they continue to shrink. Right now, the tools for measuring and characterizing components are behind the fabrication tools, said Filbert Bartoli, a program manager in the Division of Electrical and Communications Systems at the NSF, which funded the research.

"The design rules for electronic chips are down to a little more than 100 nanometers," Bartoli said. "What happens when you get to 10 nanometers?"

It's a question that has been in search of an answer. Measurement using an AFM is a relative measurement, and there are limitations to any scanning technique, according to Bartoli.

"You really need to have characterization techniques that keep pace with fabrication technologies," he said. "I would think that the project managers at Intel that want to keep Moore's Law going would be interested in such characterization technologies."

The EUV light is produced in a process called high harmonic generation (HHG), where researchers fire a visible-light laser into a gas, creating a strong electromagnetic field. The field ionizes the gas, separating the electrons from their parent atoms. When the electrons recollide with the ionized gas atoms and oscillate back and forth within the electromagentic field, a well-synchronized stream of photons fires out of the system, boosted up to a high-energy, extreme ultraviolet wavelength.

The real breakthrough development is the team's "structured waveguide" that confines the target gas and keeps the EUV beam tightly focused. So focused, in fact, that a beam that begins at the earth 1 cm in diameter would be 30 m when it reached the moon. A conventional laser would be about 1 km in diameter when it reached the moon.

"Being able to demonstrate that they have a high-quality, coherent beam is quite an accomplishment," Bartoli told NanotechPlanet. But before the light source can find work helping extend Moore's Law, more work has to be done. "There are a number of technologies that are complementary that have to developed."

Among the developments needed to complement the light source are advanced optics such as aberration-corrected lenses for the deep UV, and a detector or imaging system sensitive to the UV signal so images of whatever is being measured can be displayed (because humans can't see light at this wavelength).

"The work is quite visionary, and it's going to be a while before it's readily available," Bartoli said.