'Solid immersion' probed for maskless litho

But researchers from the University of Arizona have put a new twist on the technology, by devising so-called "solid immersion." In a paper at the Bacus Symposium for Photomask Technology, the University of Arizona Wednesday (Sept. 15) is expected to describe the means of enabling maskless lithography, by using "solid immersion lens nano-probes."

With the technology, the university is said to achieve 20-nm designs and high numerical apertures in a maskless lithography tool of 2.3-to-2.4, with a possibility of reaching 3.4, according to industry sources.

Solid immersion does not use water as a means to boost the resolution in a lithography tool. Instead, the technology appears to be more related to novel and exotic approaches like atomic force microscopy (AFM) and dip-pen lithography.

"Solid immersion is a neat concept," said Walt Trybula, a senior fellow at International Sematech, who is familiar with the technology. "It uses solid material. It's solid immersion."

"In this paper, we discuss a new maskless lithography concept employing an array of solid immersion lens (SIL) nano-probes," according to researchers from the university. "The nano-probes are efficient near-field transducers. Each transducer is the combination of a SIL, a dielectric probe tip and an antenna structure."

The university has apparently produced the first results with the technology. "By combining these technologies, it should be possible to fabricate an efficient array of near-field transducers with optical spot dimensions of around 20-nm when illuminated by a 405 num laser diode source," according to the paper.