Highly-conformal plasma-enhanced atomic-layer deposition silicon dioxide liner for high aspect-ratio through-silicon via 3D interconnections

Increasing the TSV aspect ratio is a manufacturable approach to meet the requirements of high density 3D interconnections. A good control on the overall cost of ownership of the 3D interconnections clearly points towards the direction of highly conformal thin film deposition techniques for liner, barrier, and seed processing. The SiO2 liner process, developed within ASM and implemented into imec 3D test vehicles, exhibits near-ideal conformality obtained for deposition temperature as low as 200ºC. This is making this liner process a very versatile candidate for integration into via-middle process flow.