Plasma activating and spin-cleaning create -OH-rich wafer surfaces for pre-bonding at room temperature via van der Waals forces, followed by annealing to achieve high-strength dielectric bonds and Cu-Cu interconnects. Applications include POI/SOI substrates, InP/GaAs-SiO₂ heterointegration, MEMS wafer-level capping, and 3D-stacking CIS, memories and Micro-LEDs.