3D STACKED IC DEVICE WITH STEPPED SUBSTACK INTERLAYER CONNECTORS

摘要

A stepped substack interlayer connector structure on a multi-layer integrated circuit includes N steps on a substrate from a surface of the substrate at a first level to the surface of the substrate at a second level. A stack of active layers alternating with insulating layers includes a plurality of substacks which are arranged in relation to the N steps to form each of contact regions where the substacks are arranged at a common level. Interlayer connectors are formed by conductors in each region connected to landing regions on the active layers in each of the substacks. The maximum depth of the interlayer connectors is equal to or less than the thickness of the substacks.