Research has been conducted to develop alternatives to chemically amplified 193 nm photoresist materials that will be
able to achieve the requirements associated with sub-32 nm device technology. New as well as older photoresist design
concepts for non-chemically amplified 193 nm photoresists that have the potential to enable improvements in line edge
roughness while maintaining adequate sensitivity, base solubility, and dry etch resistance for high volume manufacturing
are being explored. The particular platforms that have been explored in this work include dissolution inhibitor
photoresist systems, chain scissioning polymers, and photoresist systems based on polymers incorporating
formyloxyphenyl functional groups. In studies of two-component acidic polymer/dissolution inhibitor systems, it was
found that compositions using ortho-nitrobenzyl cholate (NBC) as the dissolution inhibitor and poly norbornene
hexafluoro alcohol (PNBHFA) as the base resin are capable of printing 90 nm dense line/space patterns upon exposure to
a 193 nm laser. Studies of chain scission enhancement in methylmethacrylate copolymers showed that incorporating
small amounts of absorptive a-cleavage monomers significantly enhanced sensitivity with an acceptable increase in
absorbance at 193 nm. Specifically, it was found that adding 3 mol% of α-methyl styrene (α-MS) reduced the dose to
clear of PMMA-based resist from 1400 mJ/cm2 to 420 mJ/cm2. Preliminary data are also presented on a direct
photoreactive design concept based on the photo-Fries reaction of formyloxyphenyl functional groups in acrylic copolymers.
As an option in the creation of a synthetic bio-optic lens, we propose that spatial modulation of refractive index can be realized in polymer composites containing a colloidal ionophoric phase. The variation of refractive index could result from electric field induced orientation or polarization of the dispersed phase. Devices are envisioned in which the refractive index gradient will be controlled by variation of the local applied field with matrix-addressed microelectrode arrays. Of particular utility in the demonstration of this phenomena are ionophoric and ionomeric block copolymers containing poly(ethylene oxide), PEO, poly(acrylic acid), PAA, and poly(methylmethacrylate), PMMA, chain segments. Systems that will be discussed relative to the provision of options in the creation of a synthetic biooptic lens are: (1) Electric field induced polarization of electrorefractive moieties localized in nanoscopic, salt-doped PEO domains of PS-b-PEO composites and (2.) localized deformation of salt-doped elastomeric PDMS-b-PEO composites.