Rotary electroplating cell with controlled current distribution

Abstract From the Canadian patent

Abstract of the Disclosure, An apparatus and a method for rotary electroplating a thin metallic film having a uniform thickness and composition throughout. The apparatus includes a flow-through jet plate having nozzles of radially increasing size and uniformly spaced radially therethrough, or nozzles of the same size with varying radial spacing therebetween so as to provide a differential flow distribution of the plating solution that impinges on the wafer-cathode where the film is deposited. The spacing and size of the nozzles are critical to obtaining a uniform thickness. The electrical currents to the wafer and to a thieving ring are controlled by variable resistors so as to keep the …