Apparatuses and methods for etching process

Abstract

A method is provided for an etching process. The method includes dispensing a liquid electrolyte layer over a layer-to-be-etched on a substrate. A first electrode is coupled to the substrate, and a second electrode is coupled to the liquid electrolyte layer. An alternating voltage is applied at different frequencies between these electrodes. Impedance data is collected in response to the alternating voltage. The etching process is then performed with an etching parameter selected based on the collected impedance data, allowing for precise control and improved uniformity of the layer-to-be-etched.

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