A high-Si content middle layer for ArF trilayer patterning

This work discusses the development and characterization of Honeywell's middle layer material, UVAS, for trilayer patterning. The UVAS polymer contains high Si content constructed by polymerizing multiple monomers selected to produce a film that meets the requirements as a middle layer for trilayer patterning. Results of ArF photoresist patterning evaluations, plasma and wet etch studies, and photoresist and full stack rework tests will be presented and discussed. ArF photoresist patterning tests show that UVAS exhibits organic BARC like performance with respect to MEEF (Mask Error Enhancement Factor), DOF (Depth of Focus) and EL (Exposure Latitude). Shelf life data shows that UVAS maintains very stable properties even after 6 months storage at room temperature. We will also briefly discuss investigation of amine or nitrogen-based contaminant blocking by the UVAS middle layer.