Gold Wet Etch Optimization on 200mm Substrates for MEMS Applications

Thanks to relaxed pattern dimensions and friendly wet process cost, MEMS technology uses a great number of wet etch process steps during process flow. Nevertheless, as dimensions are downscaling, for the very used gold wet etch process, a limited under etch of the gold layer under photo resist mask is required. This paper makes a comparison between a gold wet etch process in immersion mode and a gold wet etch process with a single wafer spray tool.