Abstract: Methods of electrodeposition and electroless deposition are disclosed which afford super-filling of high-aspect ratio features on wafers by exposing wafers and electrolytic solutions in which they are immersed to conditions effective to induce reduction of metal ions in the electrolytic solution, preferably by a multiple step reduction, whereby electrodeposition of metal occurs at a bottom of each of the features until the features are substantially super-filled. Systems for performing such methods are described as are the resulting wafers produced thereby.

Abstract: The non-uniformity of electroplating on wafers is due to the appreciable resistance of the thin seed layer and edge effects. Mathematical analysis of the current distribution during wafer electroplating reveals that the ratio between the resistance of the thin deposited seed layer and the resistance of the electrolyte and the electrochemical reaction determines the uniformity of the electroplated layer. Uniform plating is critical-in-wafer metallization for the subsequent step of chemical mechanical polishing of the wafer. Based on the analysis, methods to improve the uniformity of metal electroplating over the entire wafer include increasing the resistance of the electrolyte, increasing the distance between the wafer and the anode, increasing the thickness of the seed layer, increasing the ionic resistance of a porous separator placed between the wafer and the anode, placement of a rotating distributor in front of the wafer, and establishing contacts at the center of the wafer.

Abstract: A flow-through porous electrode structure for electrochemical systems having flowing electrolytes is disclosed. The flow-through porous electrode structure includes a single porous electrode having two planar opposing faces, each of which provides a reaction surface for electrochemical electron-transfer reactions of the same polarity. The porous electrode features spaced passage means which extends at least in part through the electrode between the opposing faces for distributing the circulating electrolyte through the electrode. The passage means comprises a plurality of vertically spaced, generally horizontally disposed passageways extending from a first side of the porous member. These passageways having a generally circular cross section and extend substantially across the width of the porous electrode member.

Abstract: High current efficiency can be obtained in an electrolytic cell by inducing turbulence in the catholyte preferably by utilizing a gas-directing cathode and cation-permselective membrane combination. There is disclosed a process for electrolysis, particularly, the electrolysis of an alkali metal chloride such as sodium chloride to produce chlorine and sodium hydroxide. Said cell has a cathode and an anode divided into catholyte and anolyte compartments by a cation-permselective membrane. Turbulence inducing means such as a gas-directing cathode provides turbulence in said catholyte at the surface of said membrane by directing gas evolving on said cathode toward or away from said membrane. Multicell arrangements are also disclosed wherein said cells are connected in series.