Copper-to-Copper Direct Bonding Process Using Current-Induced Enhancement Method

In this paper, an alternative copper-to-copper direct bonding method is investigated through electric current-induced bonding, which is the enhancement method for forming copper-to-copper bonding using electric current. Electric current has two driving forces for copper-to-copper bonding: joule heat caused by electric current and electron wind force. These factors influenced the bonding formation by momentum transfer and additional diffusivity to copper atoms, so the interface of each copper pad quickly disappeared.