Comparison of mechanical stresses of Cu Through-Silicon Via (TSV) samples fabricated by Hynix vs. SEMATECH using synchrotron X-ray microdiffraction for 3-D integration and reliability

One key to enable the successful implementation of 3-D interconnects using Through-Silicon Via (TSV) is the control of the mechanical stresses. The synchrotron-sourced X-ray microdiffraction technique has been recognized to allow some important advantages compared to other techniques. Using this approach, we have studied Cu TSV samples from Hynix, Inc. as well as from SEMATECH and found interesting differences in the stress states of the Cu TSV. We proposed an explanation of the observed differences. This understanding could lead to improved stress control in Cu TSV as well as to reduce the impact to the silicon electron mobility.