High Si content BARC for applications in dual BARC systems such as tri-layer patterning

This work discusses the requirements and performance of Honeywell's middle layer material, UVAS, for trilayer patterning. UVAS is a high Si content polymer synthesized directly from Si containing starting monomer components. The monomers are selected to produce a film that meets the requirements as a middle layer for trilayer patterning and gives us a level of flexibility to adjust the properties of the film to meet the customer's specific photoresist and patterning requirements. Results of simulations of the substrate reflectance versus numerical aperture, UVAS thickness, and under layer film are presented. Immersion lithographic patterning of ArF photoresist line space and contact hole features will be presented. A sequence of SEM images detailing the plasma etch transfer of line space photoresist features through the middle and under layer films comprising the TLP film stack will presented. Excellent etch selectivity between the UVAS and the organic under layer film exists as no edge erosion or faceting is observed as a result of the etch process. The results of simulations of Rsub versus NA, and the thickness of each film comprising a two layer antireflective film stack will also be discussed.