Uniform electroplating of wafers

An electroplating device for wafer metallization of a wafer for interconnection comprising:

• a reservoir for electrolyte,
• a holder adapted to hold the wafer above said reservoir,
• a counter-electrode in said reservoir, said counter-electrode disposed concentrically with said holder,
• means adapted for passing current between said counter-electrode and the wafer in said holder,
• a pump adapted for pumping electrolyte from said reservoir against the wafer in said holder, and
• wherein the diameter of said counter-electrode is smaller than the diameter of said wafer holder.

An electroplating device for wafer metallization of a wafer for interconnection comprising:

• a reservoir for electrolyte,
• a holder adapted to hold the wafer above said reservoir,
• a counter-electrode in said reservoir,
• means adapted for passing current between said counter-electrode and the wafer in said holder,
• a pump adapted for pumping electrolyte from said reservoir against the wafer in said holder, and
• a distributor positioned in said reservoir and formed with holes at an angle to the flow direction of the electrolyte whereby electrolyte causes rotation of said distributor and emerges from said distributor in the form of multiple submerged jets adapted to contact a face of said wafer held in such holder.

An electroplating device for wafer metallization of a wafer for interconnection comprising:

• a reservoir for electrolyte,
• a holder adapted to hold the wafer above said reservoir,
• a counter-electrode in said reservoir,
• means adapted for passing current between said counter-electrode and the wafer in said holder,
• a pump adapted for pumping electrolyte from said reservoir against the wafer in said holder, and
• means for periodically reversing current adapted to remove excess electroplating metal from areas on the wafer in said holder where the electroplating is thicker than the average and wherein the total electrical charge passed during the reversed current period is smaller than the total charge passed during the forward current period.

An electroplating device for wafer metallization of a wafer for interconnection comprising:

• a reservoir for electrolyte,
• a holder adapted to hold the wafer above said reservoir,
• a counter-electrode in said reservoir,
• means adapted for passing current between said counter-electrode and the wafer in said holder,
• a pump adapted for pumping electrolyte from said reservoir against the wafer in said holder, and
• means for applying pulsed current to said pump during the electroplating process.

An electroplating device for metallization of a wafer coated with a thin barrier layer and a thin seed layer of a metal to be electroplated over the barrier layer with an electrolyte containing an electroplated metal in solution for interconnection comprising:

• a reservoir for electrolyte,
• a holder adapted to hold the wafer above said reservoir,
• a counter-electrode in said reservoir,
• means adapted for passing current between said counter-electrode and the wafer in said holder,
• a pump adapted for pumping electrolyte from said reservoir against the wafer in said holder,
• means for adjusting the plating parameter B.sup.2 of the electrolyte wherein:
• B.sup.2 =(.rho./.rho..sub.el)(R.sup.2 /Wd).ltoreq.1
• where .rho. and .rho..sub.el are the resistivities of the metal to be electroplated and the electrolyte, respectively, R is the radius of the wafer, W is the thickness of the electroplated metal and d is the distance between said wafer and said counter-electrode.

An electroplating device of wafers for interconnection comprising:

• a reservoir for electrolyte,
• a holder adapted to hold a wafer above said reservoir,
• a counter-electrode in said reservoir,
• means for passing current between said counter-electrode and a wafer in said holder,
• a pump for pumping electrolyte from said reservoir against said wafer, and
• a distributor positioned in said reservoir including a disk having a plurality of holes adapted to provide a flow of electrolyte through the disk that is uniform along a radius of the disk.

A method of electroplating for the metallization of wafers for interconnection comprising:

• providing a reservoir containing a counter-electrode,
• providing a holder above said reservoir,
• providing a wafer coated with a thin barrier layer and a thin seed layer of the metal to be electroplated over said barrier layer in said holder,
• placing an electrolyte containing an electroplated metal in solution in said reservoir and adjusting the plating parameter B.sup.2 of said electrolyte wherein:
• B.sup.2 =(.rho./.rho..sub.el)(R.sup.2 /Wd).ltoreq.1
• where .rho. and .rho..sub.el are the resistivities of said metal to be electroplated and said electrolyte, respectively, R is the radius of said wafer, W is the thickness of the electroplated metal and d is the distance between said wafer and said counter-electrode,
• a pump to pump said electrolyte upward against said wafer, and
• passing a current between said counter-electrode and said wafer.