Step and Flash Imprint Lithography Using UV-transparent, Electrically Conductive Templates
A. A. Talin, A. Hooper, J. H. Baker, D. J. Resnick, W. J. Dauksher, D. Mancini,
Motorola Labs, US
Keywords: Step, flash, imprint, lithography, ITO
Step and flash imprint lithography (SFIL) is a promising new technique capable of resolving sub 100nm features at a substantially lower cost than any other candidate method currently under development. Successful implementation of SFIL requires that the mold, or template, be highly transparent at the actinic wavelength, defect free, and be sufficiently electrically conductive such that no charging occurs during e-beam patterning to define the mold pattern or during post fabrication inspection, which requires a scanning electron microscope.
In this work we describe fabrication of SFIL templates that incorporate the above qualities, and demonstrate printing of 20 nm features. The electrical conductivity (~1ohm-cm)-1 and over 90% UV transparency (365 nm) is achieved by incorporating a specially designed indium tin oxide (ITO) film into the SFIL template structure, By placing the ITO layer below the SiO2 layer in which the template pattern is defined, charge imparted during electron beam patterning of the resist layer is bled to ground, thus eliminating electron beam blurring. In addition, the ITO layer serves as an etch stop during SiO2 layer patterning. The final template is readily inspectable in a SEM without any need for thin metal layers typically required for imaging insulating samples.
NSTI Nanotech 2003 Conference Technical Program Abstract