Abstract:
A semiconductor wafer, including a substrate, at least one via formed in the substrate, and copper electroplating inside the at least one via, where the copper electroplating comprises a first layer of nanotwin copper, and a second layer of bulk copper. Further, a method of making a semiconductor wafer, the method comprising providing a substrate; etching the substrate to form at least one via; and depositing copper electroplating inside the at least one via, wherein the copper electroplating comprises a first layer of nanotwin copper, and a second layer of bulk copper.
Abstract:
A method for electroplating a wafer detects plating bath failure based on a voltage change. The method is useful in plating wafers having TSV features. Voltage of each anode of a plating processor may be monitored. An abrupt drop in voltage signals a bath failure resulting from conversion of an accelerator such as SPS to it's by products MPS. Bath failure is delayed or avoided by current pulsing or current ramping. An improved plating bath has a catholyte with a very low acid concentration.