Previous studies of methacrylate based nanoparticle have demonstrated the excellent pattern forming capability of these hybrid materials when used as photoresists under 13.5 nm EUV exposure. HfO 2 and ZrO 2 methacrylate resists have achieved high resolution (~22 nm) at a very high EUV sensitivity (4.2 mJ/cm 2 ). Further investigations into the patterning process suggests a ligand displacement mechanism, wherein, any combination of a metal oxide with the correct ligand could generate patterns in the presence of the suitable photoactive compound. The current investigation extends this study by developing new nanoparticle compositions with transdimethylacrylic acid and o-toluic acid ligands. This study describes their synthesis and patterning performance under 248 nm KrF laser (DUV) and also under 13.5 nm EUV exposures (dimethylacrylate nanoparticles) for the new resist compositions.

In the past few years, industry has made significant progress to deliver a stable high power EUV scanner and a 100 W light source is now being tested on the manufacuring scale. The success of a high power EUV source demands a fast and high resolution EUV resist. However, chemcially amplied resists encounter unprecedented challenges beyond the 22 nm node due to resolution, roughness and sensitivity tradeoffs. Unless novel solutions for EUV resists are proposed and further optimzed, breakthroughs can hardly be achieved. Oxide nanoparticle EUV (ONE) resists stablized by organic ligands were originally proposed by Ober et al. Recently this work attracts more and more attention due to its extraordinanry EUV sensitivity. This new class of photoresist utilizes ligand cleavage with a ligand exchange mechanism to switch its solubilty for dual-tone patterning. Therefore, ligand selection of the nanoparticles is extremely important to its EUV performance.

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Methacrylate based nanoparticle materials have been investigated for their negative-tone patterning with DUV (248nm, 254nm), e-beam and EUV lithography, and show promising EUV sensitivity and resolution. In order to further extend the application of this novel class of materials and understand more about the underlying mechanism, we continue to study its dual-tone behavior and the tone-switching process. Catalyzed by a photoradical generator, we have been able to print positive tone line-space patterns with both DUV and e-beam exposure enabled patterning of features with a wide range of line-widths. By monitoring the patterning process, the PEB conditions have been found to be a crucial factor, which determines the solubility and core-ligand interactions.