Method of using hydrogen plasma to pre-clean copper surfaces during Cu/Cu or Cu/metal bonding

A method of bonding a copper wire to a copper bonding pad, comprising the steps of:

• providing a semiconductor die structure having an exposed copper bonding pad within a chamber;
• said copper bonding pad having an upper surface;
• producing a hydrogen-plasma within said chamber from a plasma source;
• pre-cleaning and passivating said copper bonding pad with said hydrogen-plasma to remove any copper oxide formed on said copper bonding pad upper surface;
• and
• bonding a copper wire to said passivated copper bonding pad.

A method of bonding a copper wire to a copper bonding pad, comprising the steps of:

• providing a semiconductor die structure having an exposed copper bonding pad within a chamber;
• said copper bonding pad having an upper surface;
• producing a hydrogen-plasma within said chamber from a plasma source;
• said hydrogen-source being selected from the group comprising NH3, H2, N2+H2, He+H2, and Ar+H2;
• pre-cleaning and passivating said copper bonding pad with said hydrogen-plasma to remove any copper oxide formed on said copper bonding pad upper surface;
• and
• bonding a copper wire to said passivated copper bonding pad.