Abstract: Systems, apparatuses, and methods for routing traffic through vertically stacked semiconductor dies are disclosed. A first semiconductor die has a second die stacked vertically on top of it in a three-dimensional integrated circuit. The first die includes a through silicon via (TSV) interconnect that does not traverse the first die. The first die includes one or more metal layers above the TSV, which connect to a bonding pad interface through a bonding pad via. If the signals transferred through the TSV of the first die are shared by the second die, then the second die includes a TSV aligned with the bonding pad interface of the first die. If these signals are not shared by the second die, then the second die includes an insulated portion of a wafer backside aligned with the bonding pad interface.

Abstract: A technique for alleviating the problems of defects caused by stress applied to bond pads (32) includes, prior to actually making an integrated circuit (10), adding dummy metal lines (74, 76) to interconnect layers (18, 22, 26) to increase the metal density of the interconnect layers. These problems are more likely when the interlayer dielectrics (16, 20, 24) between the interconnect layers are of a low-k material. A critical area or force area (64) around and under each bond pad defines an area in which a defect may occur due to a contact made to that bond pad. Any interconnect layer in such a critical area that has a metal density below a certain percentage can be the cause of a defect in the interconnect layers. Any interconnect layer that has a metal density below that percentage in the critical area has dummy metal lines added to it.