A transportable bump plating fixture and method for holding a semiconductor wafer in a face up orientation in a plating bath while plating bumps on the metallized circuitry on the wafer face. The fixture includes an elastomer pad which contacts the back of the wafer and forms a seal which prevents the plating bath from coming into contact with the back of the wafer. The fixture also includes means for forming a cathodic electrical connection to the metallization on the face of the wafer, and further includes a plating anode disposed above the face of the wafer. The fixture is open to the flow of the plating bath over the face of the wafer and between the face of the wafer and the anode.
A process and apparatus for advanced semiconductor applications which involves the selective electrodeposition of metal on a semiconductor wafer is described. The present invention has significant economic and performance advantages over the current state of the art. It addresses problems associated with cleanliness (a major issue with sub-micron processing) , metal thickness uniformity, step coverage and environmental concerns. A metal with better device performance capabilities compared to the standard aluminum is also employed. The hardware allows the selective deposition to occur without allowing the electrolyte to contact the rear of the wafer or the electrodes contacting the front wafer surface. A virtual anode improves the primary current distribution improving the thickness uniformity while allowing optimization of other film parameters with the remaining deposition variables. Using this process and the associated hardware, metal lines are selectively deposited with contacts or vias completely filled without the need for plasma etching the deposited metal.
A method and an apparatus for uniform electroless plating of layers onto exposed metallizations in integrated circuits such as bond pads. The apparatus provides means for holding a plurality of wafers, and rotating each wafer at constant speed and synchronous within the plurality. Immersed in a plating solution flowing in substantially laminar motion and at constant speed, the method creates periodic superposition of directions and speeds of the motion of the wafers and the motion of the plating solution. The invention creates periodically changing wafer portions where the directions and speeds are additive and where the directions and speeds are opposed and subtractive. Consequently, highly uniformly layers are electrolessly plated onto the exposed metallizations of bond pads. If the plated layers are bondable metals, the process transforms otherwise unbondable pad metallization into bondable pads.
A plating device for a wafer employs an air bag 6, 20 as a holding means for downwardly depressing the wafer 8 upon performing plating on the wafer 8. The air bag 6, 20 constrain only the upper surface 13 of the circumferential edge of the wafer at an expanded state and releases the constraint by contracting to restore an initial configuration at a non-expanded state. By this, the holding means will not occupy the upper side space of the wafer both during plating process and during non-plating process so as to avoid adhering of dust and foreign matter onto the wafer 8.
An apparatus and method for electro-chemically depositing a uniform metal layer onto a substrate is provided. In one aspect, the apparatus includes a cathode connected to the substrate plating surface, an anode disposed above the substrate support member and an electroplating solution inlet supplying an electroplating solution fluidly connecting the anode and the substrate plating surface. In another aspect, the apparatus further includes a dual catch-cup system having an electroplating solution catch-cup and a rinse catch-cup. The dual catch-cup system provides separation of the electroplating solution and the rinse solutions during processing and provides re-circulating systems for the different solutions of the electroplating system.
A cage boat having easily replaceable parts utilizes removable spacer rails for holding semiconductor wafers contained within a cage formed from slats removably attached to end pieces perpendicular to the slats.
