Wet chemical etching processes are employed in the manufacturing of a variety of microelectronic components. These processes use etchants that generally contain aggressive and toxic chemicals, generate hazardous waste and have limited resolution. Electrochemical metal removal is an evolving alternate processing technique that involves controlled metal shaping by an external current, thereby requiring less aggressive and nontoxic electrolytes. The application of controlled electrochemical metal removal in the fabrication of microstructures and microcomponents is referred to as electrochemical micromachining (EMM). In this paper a recently developed EMM process and tool for metal mask fabrication is discussed. EMM performance is compared to that obtained by the conventional chemical etching process. Obtained results demonstrate the opportunities offered by EMM particularly as a high-speed, environmentally friendly processing technology.
Dr. Madhav Datta and Harris, D., “Electrochemical micromachining: An environmentally friendly, high speed processing technology”, Electrochimica Acta, vol. 42, pp. 3007–3013, 1997.