Nanoimprinting of TiO2-SiO2 photocurable materials with high titanium concentration for CF4/O2 etch selectivity

The nanofabrication of nanometre-scale multiple-level structures by nanoimprint lithography and CF₄/O₂ etching rates was investigated for nanoelectro mechanical systems and three-dimensional (3D) wafer-level packaging. A TiO₂-SiO₂ sol-gel photocurable material with high titanium concentration of 20.9 wt- was developed for CF₄/O₂ etch selectivity with a pattern transferring carbon layer in a bi-layer process. The nanostructures of 3D micropatterns, holes with 200 nm diameter and 130 nm-wide dense lines with line edge roughness of ~10 nm were provided. The CF₄/O₂ etching rate of the TiO₂-SiO₂ photocurable material was ~3.7 times lower than that of the referenced SiO₂ sol-gel photocurable material. The CF₄/O₂ etch rates of titanium-based photocurable materials were confirmed for deep plasma etching processes.