Cu-Cu Die to Die Surface Activated Bonding in Atmospheric Environment Using Ar and Ar/N2 Plasma

Abstract

Surface activated bonding (SAB) method is an attractive option for Cu-Cu bonding as the force application duration is considerably shorter as compared to thermocompression bonding. Die to die SAB allows 3D heterogeneous integration to be done with lesser energy consumption compared to thermocompression. In this report, blanket and patterned Cu-Cu die to die SAB are demonstrated. Two different types of plasma were used for the surface activation of Cu. Both Ar and Ar/N2 plasma activation were performed on the Cu surfaces enabling direct bonding at room temperature, ambient air, and atmospheric pressure without any wet chemical process.