Direct imprint of Al foil for metallization of high-aspect ratio Al lines in nano/micro patterned SiO2/Si

Patterning techniques of Al micro/nano-structures become more and more critical as optical components and microelectronic devices continue to be scaled down. In this work, we fabricated gap-filled Al lines in SiO2/Si masters by using the direct thermal imprint of molten Al. As a result, gap-filled Al lines with width ranging from 0.25 to 20 μm and depth ranging from 6 to 127 μm could be achieved without any further processing step such as CVD and PVD. The process studied here has shown the possibility to extend trench filling capability to 0.25 μm structures with 24:1 aspect ratio, which are difficult to be obtained by other conventional Al metallization methods.