Nanoimprinting of TiO 2 –SiO 2 photocurable materials with high titanium concentration for CF 4 /O 2 etch selectivity

Abstract

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.