Scalability of Direct Silicon Bonded (DSB) technology for 32nm node and beyond

Direct Silicon Bonded (DSB) technology is shown to be scalable for 32nm node and beyond for two integration schemes: Solid Phase Epitaxy (SPE)-before-Shallow Trench Isolation (STI) and STI-before-SPE. For SPE-before-STI, 32nm node ground rules can be met by thinning DSB thickness to ∼70nm, which ensures complete removal of boundary defects by STI. For STI-before-SPE, a scaling-independent solution is provided by the use of 45° rotated (100) base wafers which allow trench-defect-free SPE at the STI edges.