Five-Minute TSV Copper Electrodeposition

Abstract

© The Author(s) 2014. Published by ECS. TSV(Through Silicon Via) is a promising interconnection for the next generation smartphone, driving assistance and medical care system because of its high speed image processing and low energy consumption. Conventional TSV electrodeposition requires 15 minutes to 1.5 hour due to the application of a low current of less than 10 mA/cm 2 . Two shapes of vias have been used, columnar and conical shapes. Columnar shape via has acute edges at via mouth and the current lines concentrates at these edges, hence introducing void. In conical shape via, the acute angle at via bottom concentrates the current lines, hence improving bottom up filling. Using conical vias, we are able to electrodeposit a 6 μm diameter and 25 μm deep TSV via within 5 minutes. A very high on-current of 90 mA/cm 2 is able to be applied without any void formation.