Temporary Bonding Process is joining wafers during processing using temporary adhesive, enabling backside access while protecting frontside — enables thinning, via formation. Adhesive low-melting-point polymer (LMPT) thermally activated. Cost-effective, widely available. Carrier temporary substrate (glass, dummy silicon) provides mechanical support. Bond Strength ~0.1-1 MPa adequate for processing forces but weak for easy de-bonding. De-Bonding heating adhesive above Tg (~120-150°C) loses strength. Wafer separates. Residue adhesive remains post-debond. Chemical cleaning removes (compatible solvents). Mechanical wedge/peel alternative to heating. Higher risk of circuit damage. Electrostatic ESD bonding via Coulomb attraction. Low residue. Fusion Van der Waals bonding (cleaned flat surfaces). No adhesive. Strong; difficult de-bonding. Smart Cut hydrogen implantation enables layer transfer via cleavage plane. Adhesive Selection cost, de-bonding ease, thermal stability, solvent compatibility. Wafer Cleanliness particles between wafers cause voids. Pre-bond cleaning critical. Bonding Fixtures ensure parallel, aligned contact. Vacuum chucks typical. Pressure Control uniform pressure ~0.5-2 MPa over entire wafer. Temporary Bonding enables advanced processing otherwise impossible; backside access essential.