Wafer Level 3D Stacking Using Smart Cut and Metal-Metal Direct Bonding Technology

While significant research effort on various planar approaches, the 3D vertical IC stacking is undoubtedly gaining increasing momentum as a leading contender in the challenge to meet performance, cost, and size demands through this decade and beyond. The Smart CutTM technology allowing the stack of very thin layers with direct bonding is one of the emerging technologies in this field. In this paper, the Smart CutTM technology using low temperature metal direct bonding (allowing direct vertical integration) is demonstrated.