Assisted Nanopatterning of Tin-based Inorganic Resist: Effect of Peripheral Functional Group Population on Resolution and Sensitivity

While inorganic resists are emerging as possible potential candidates for sub-10 nm node semiconductor fabrication, fundamental understanding on such promising chemical compositions is inevitably paramount to confront the concerning challenges associated with inorganic resists. Given that assisted nanopatterning of inorganic resists may significantly improve the patterning capability of inorganic resists along with addressing the vertical shrinkage issue of resist film during processing and patterning to a greater extent, we present an interesting fundamental aspect of matrix parameters on the sensitivity, resolution and extent of film shrinkage. We have shown that the population of peripheral functional groups on the organic matrix plays a major role in determining the resolution and sensitivity of the resist composition, and highly balanced presence of functional groups per matrix unit is very critical. Also, the structural features of the matrix play an important role in governing the overall sensitivity. Using calix-arene scaffold as a matrix and tin oxohydroxide as inorganic component, the new resist compositions have been explored for sub-20 nm patterning with sharp features using electron beam lithography. We successfully printed ~22 nm line/space (L/S) patterns with LER of 2.10 ± 0.03. Finally, we have established through structure-performance relationship studies that matrix assisted nanopatterning has potential to address the shrinkage of inorganic resist film. The radar chart diagram established the co-relation between matrix structure and resist performance.