Low temperature Cu/Cu direct bonding using formic gas in-situ treatment

摘要

A low temperature Cu/Cu direct bonding technology using formic acid vapor treatment was developed. Using this technology, 6mm×6mm Cu film chips were bonded at low temperature in N2 atmosphere. XPS surface analysis shows that Cu surface oxide was reduced after formic gas in-situ treatment. The bonding was conducted in N2 at 200°C after Cu surface was treated at 200°C for 10min.