Development of Next-Generation Distortion Correction Technologies for High-Precision Wafer-to-Wafer Bonding

A wafer bonder that stably achieves a bonding overlay accuracy of 50 nm is developed. Correction technologies for various bonding-induced distortion fingerprints, which are one of the key technologies, and the prospect for future improvements of bonding overlay accuracy are reported. These high-precision bonding technologies will be essential for the fabrication of future three-dimensional integrated circuits.