Characterization and observation of Cu-Cu Thermo-Compression Bonding using 4-point bending test system

The quantitative interfacial adhesion energy of the Cu-Cu direct bonding layers was evaluated in terms of the bonding temperature and Ar+ plasma treatment on Cu surface by using a 4-point bending test. The interfacial adhesion energy and bonding quality depend on increased bonding temperature and post-annealing temperature. With increasing bonding temperature from to , the interfacial adhesion energy increase from to . The Ar+ plasma treatment on Cu surface drastically increase the interfacial adhesion energy form to . The plasma pre-treatment successfully reduces processing temperature of Cu to Cu direct bonding.