W2W permanent stacking for 3D system integration

In this paper, we present advances in 300mm wafer-to-wafer (W2W) oxide-oxide bonding for high density 3D interconnect application. A CMOS compatible low temperature oxide-oxide bonding method has been developed which yields consistent void-free bonding. In addition, sub-micron W2W alignment accuracy has been demonstrated with standalone test materials using an integrated permanent bonding platform.