Conformal Open-Air Electroplating of Through-Wafer Vias

A method is described for depositing high-density metal in through-wafer vias. This method requires that the cathode end of the via be left open to the air to facilitate electrolyte diffusion, especially in the early stages of the electroplating process. An open-air electroplating process is of value in high aspect-ratio settings. The process is demonstrated by electroplating copper through a crack with an aspect ratio of 6.8.