Smart stackingTM technology: An industrial solution for 3D layer stacking

Abstract

Smart Stacking™ is a wafer-to-wafer stacking technology of partially or fully processed wafers. This technology enables transferring very thin layers in a high volume manufacturing environment. The core technologies are surface conditioning, low temperature direct bonding and wafer thinning (figure 1). This technology is adapted for advanced semiconductor applications such as Back Side Illumination (BSI) CMOS Image Sensors (CIS) as well as 3D integration approaches [1,2].