Robert McLeod

The CU technology was developed by Associate Professor Robert McLeod of the electrical, computer and energy engineering department, Visiting Assistant Professor Tim Scott of the chemical and biological engineering department, and Professor Christopher Bowman of the chemical and biological engineering department. The three researchers, along with graduate students Benjamin Kowalski and Amy Sullivan (Sullivan is now a faculty member at Agnes Scott College in Decatur, Ga.) first published the details of the new technology in a 2009 issue of Science magazine.

Licensed to Heidelberg Instruments by the University of Colorado Technology Transfer Office, the patent pending method involves using a tightly focused beam of blue light to etch lines and dots thousands of times smaller than the width of a human hair into lithography patterns on a substrate such as silicon, said McLeod. A second beam of light, this one ultraviolet, is then used to "erase" the edges of the pattern, resulting in much smaller structures, he said.

"The University of Colorado is one of the leading R&D centers making major inroads in nanoscale technology development," said Alexander Forozan, head of global business development at Heidelberg Instruments. "We are thrilled to work with CU's outstanding staff and look forward to a continuing and long-lasting relationship."

Ted Weverka, a licensing manager at the CU Technology Transfer Office, said, "We are excited to have Heidelberg as a partner for this technology. Heidelberg's technical know-how and market savvy ensure a strong future for this invention."

To develop the technique, McLeod and his colleagues used a tabletop laser to project tightly focused beams of visible blue light onto liquid molecules known as monomers. A chemical reaction initiated a bonding of the monomers into a plastic-like polymer solid. Focusing the blue beam in one place inscribed a small, solid dot. If the beam moved the focus across the material, it created a thin thread, or line.

The CU researchers then added a second ultraviolet laser focused into a halo, or donut, which surrounded the blue light. The special monomer formulation was designed to be inhibited by the UV light, shutting down its transformation from a liquid to a solid, he said. This "halo of inhibition" prevented the edges of the spot or line from developing, resulting in a much finer final structure.

McLeod said the new technology has the potential to lead to the construction of a variety of nanotechnology devices, including electronic circuits and nanomechanical devices. "This is a new set of new tools that provide a new way to do nanotechnology," McLeod said.

The method offers the potential to shrink transistor circuitry, a process that drives the global electronic market that is continually pursuing smaller, more powerful microchips, said McLeod, whose research on the project was funded by the National Science Foundation and through the University of Colorado Innovative Seed Program. In 2010, McLeod received an NSF CAREER award for his achievements, one of the most prestigious honors directed toward young faculty.