Semiconductor wafer bonding

Abstract When mirror‐polished, flat, and clean wafers are brought into contact, they are locally attracted to each other and adhere or bond. This phenomenon is known as semiconductor wafer bonding. Different adhesion forces (van der Waals forces, hydrogen bonding) are the reason for the bonding effect at room temperature. The different bonding mechanisms acting in dependence on the surface conditions (hydrophilic, hydrophobic) are reviewed. Variations of the properties of bonded interfaces (structural, mechanical, electrical) during annealing are discussed. The focus is on low‐temperature bonding techniques. Reasons for the formation of interface defects are presented. Applications of semiconductor wafer bonding for future developments are briefly summarized. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)