UC Berkeley

The conventional projection-type photolithography approach to nanoscale manufacturing is facing possibly insurmountable challenges, especially to invent novel technical solutions that remain economical for the next generation of semi-conductor integrated circuits. Although extreme ultra violet (EUV) lithography with the next generation photo-masks and 193-nm immersion lithography with double patterning are expected to deliver 22 nm and smaller nodes, it still cannot effectively address the reliability and cost issues required for mass production. Maskless nanolithography is a potentially agile and cost effective approach, but most of the current solutions have throughputs that are too low for manufacturing purposes.

This dissertation reports a new low-cost high-throughput approach to maskless nanolithography that uses an array of plasmonic lenses (PL) that "fly" above the rotating surface to be patterned, concentrating short wavelength surface plasmons into sub-100 nm spots. However, these nanoscale spots are only formed in the near field (within a few nanometers of the surface), which makes it very difficult to scan the array above the surface at high speeds. To overcome this problem a self-spacing air-bearing surface was designed and fabricated that can fly the array just nanometers above a disk that is spinning at speeds on the order of 10 meter/second, and patterning with feature sizes far smaller than the far-field diffraction limit have been experimentally demonstrated . Using this plasmonic nanolithography (PNL) approach, a 22-nm half-pitch direct pattern writing was successfully demonstrated using ultra-fast laser assisted nanoscale heat management and advanced PL designs.

This nano-fabrication scheme has the potential of a few orders of magnitude higher throughput than current maskless techniques, and it opens the way for a new cost effective approach towards the next generation lithography for nano-manufacturing.