Multi-step potentiostatic/galvanostatic plating control

A multistep electroplating process for electroplating a substrate containing a seed layer thereon with copper or other metal comprising the steps of:

• inserting the substrate having the seed layer thereon to initiate metal plating into an electroplating apparatus comprising a metal plating solution, an anode and multiple cathode electrical perimeter contacts to the seed layer;
• exposing the seed layer, anode and cathode perimeter contacts to the metal plating solution;
• and
• plating onto the seed layer and substrate by applying to the anode and cathode perimeter contacts a current preprogrammed to ramp up to a current value from a first current value which current produces during the ramping a voltage below a predetermined threshold voltage which was empirically determined to cause burn-through of the seed layer.

An apparatus for electroplating a substrate containing a seed layer thereon with copper or other metal which is immersed in an electroplating bath comprises:

• a tank containing a metal plating solution;
• an anode in the metal plating solution;
• a substrate positioned in the metal plating solution having a seed layer thereon facing the anode, the seed layer having multiple cathode perimeter electrical contacts;
• means for supplying a current to the anode and cathode perimeter electrical contacts in the apparatus to provide to the anode and perimeter contacts for a first time period a voltage below a predetermined threshold voltage which was empirically determined to cause burn-through of the seed layer;
• and
• means for supplying after the first time period a current to the anode and perimeter contacts for a second time period the current producing a voltage below the predetermined threshold voltage;
• wherein when the current is supplied the metal of the metal plating solution is plated onto the seed layer forming a metal plated substrate.

An apparatus for electroplating a substrate containing a seed layer thereon with copper or other metal comprises:

• a tank containing a metal plating solution;
• an anode in the metal plating solution;
• a substrate positioned in the metal plating solution having thereon a seed layer facing the anode, the seed layer having multiple cathode perimeter electrical contacts;
• and
• means for supplying a current to the anode and cathode perimeter contacts which current is preprogrammed to ramp up to a current value from a first current value and which current produces during the ramping a voltage below a predetermined threshold voltage which was empirically determined to cause burn-through of the seed layer;
• wherein when the current is supplied the metal of the metal plating solution is plated onto the seed layer forming a metal plated substrate.