An electroplating apparatus and method reduces oxidation of thermodynamically unstable and oxidizable ionic species in an electroplating solution to deposit complex magnetic alloy onto substrates. The electroplating apparatus comprises an electroplating cell (30) in which oxidation of oxidizable anions and cations is reduced. The cell comprises an anode compartment (110) with anolyte solution in contact with the anode (55), a cathode compartment (105) with catholyte solution containing oxidizable plating anions in contact with the cathode (50). A cation selective membrane (100) separates the electrode compartments. Upon application of a voltage or power supply (90) across the anode and cathode, the transport of oxidizable plating anions and to a lesser degree cations, to the anode is substantially blocked by the cation-selective semi-permeable membrane, thereby reducing oxidation of the oxidizable anions and cations at the anode. The concentration of the anolyte and catholyte solutions can be tailored, and an inert gas can be maintained above the electrolyte solution in an enclosed region (140) to further reduce oxidation.

Electroplating apparatus and process for reducing oxidation of oxidizable plating anions and cations

A plating system (10) and method are provided for electroplating silicon wafers with copper using an insoluble anode (13) wherein the electrolyte is agitated or preferably circulated through an electroplating tank (11) of the system and a portion of the electrolyte is removed from the system when a predetermined operating parameter is met. A copper-containing solution having a copper concentration greater than the copper concentration of the removed portion is added to the copper plating system (10) simultaneously or after electrolyte removal, in a substantially equal amount to the electrolyte removed from the system and balances the amount of copper plated and removed in the removal stream. In a preferred method and system, an electrolyte holding tank (19) is provided which serves as a reservoir for circulating electrolyte. The addition of the copper-containing solution and removal of working electrolyte is also preferably made from the holding tank (19). The preferred apparatus is preferably cylindrical and is specially configured so that recirculating electrolyte enters near the anode (13) and exits near the cathode (12) with the outlet of the apparatus having a substantially continuous opening around the periphery of the electroplating tank (11) so that electrolyte exiting the tank has a substantially uniform flow across the surface of the cathode (12). The anode (13) is preferably circular and has a central through opening (13a) through which the entering electrolyte passes.

Copper metallization of silicon wafers using insoluble anodes

A substrate plating device capable of using an insoluble anode and replenishing metal ions automatically; a substrate plating device capable of making uniform a primary current distribution between a cathode and an anode and downsizing the device itself; and a plating device with which black film turned into a particle form does not contaminate a substrate to be plated even when a soluble anode is used. A substrate plating device, wherein a substrate to be metal-plated and an insoluble anode are disposed opposite to each other in a plating tank containing a plating solution, wherein soluble anode and cathode are disposed opposite to each other in a circulation tank or a dummy tank provided separately from the plating tank and an anion exchange membrane or a cation selective exchange membrane are disposed between the anode and the cathode. Current is allowed to run between the separately disposed anode and cathode to thereby generate metal ions continuously for replenishing into the plating tank. In addition, an ion exchange membrane or a porous neutral barrier membrane is disposed between a substrate to be plated and an anode to provide a substrate-to-be-plated side area and an anode side area separated from each other.

Substrate plating device

A process and apparatus for electroplating metals in which the metal salt concentration within the electroplating bath is reduced by providing an insoluble anode assembly in the bath. The insoluble anode assembly includes an enclosure which defines a compartment around an insoluble anode and which is formed at least in part by an anion exchange membrane. The primary reaction at the insoluble anode during electroplating is electrolysis of water to produce predominantly oxygen and hydrogen ions. The flow of current through the insoluble anode assembly causes anions in the plating solution to travel through the anion membrane into the compartment, resulting in an increase in acid concentration within the compartment. Accumulated acid is periodically flushed from the compartment.

Process and apparatus for control of electroplating bath composition

An apparatus and method for electrochemical processing of microelectronic workpieces in a reaction vessel. In one embodiment, the reaction vessel includes: an outer container having an outer wall; a distributor coupled to the outer container, the distributor having a first outlet configured to introduce a primary flow into the outer container and at least one second outlet configured to introduce a secondary flow into the outer container separate from the primary flow; a primary flow guide in the outer container coupled to the distributor to receive the primary flow from the first outlet and direct it to a workpiece processing site; a dielectric field shaping unit in the outer container coupled to the distributor to receive the secondary flow from the second outlet, the field shaping unit being configured to contain the secondary flow separate from the primary flow through at least a portion of the outer container, and the field shaping unit having at least one electrode compartment through which the secondary flow can pass while the secondary flow is separate from the primary flow; an electrode in the electrode compartment; and an interface member carried by the field shaping unit downstream from the electrode, the interface member being in fluid communication with the secondary flow in the electrode compartment, and the interface member being configured to prevent selected matter of the secondary flow from passing to the primary flow.

Apparatus and methods for electrochemical processing of microelectronic workpieces

A process for electroplating metals in an electroplating bath having an anode and a cathode. The cathode is formed by a workpiece to be plated and the anode includes soluble material in the form of the metal to be plated and insoluble material in a proportion selected so that the anode efficiency equals the cathode efficiency. This avoids metal salt build-up in the bath. Metal salt solution carried out of the bath with the workpiece is recovered and recycled to the bath, avoiding loss of metal to the system and waste disposal problems.

Craig J. Brown

Papers

Process for electroplating metals