A method for fabricating a micro structures with multi differential gap on silicon substrate

摘要

A method of forming a micro structure with vertical step height on a silicon substrate is provided to float the micro structure by forming the vertical step height and subjecting the substrate to wet etching. A first mask layer(120) is formed on a single crystal silicon substrate, and then a second mask layer is formed on the substrate. The substrate is etched by using the first or second mask layer. The mask layer is removed, and the substrate is etched by using the first mask layer to form a trench. A protective layer(140) is formed on a sidewall of the trench. The substrate is further etched by using the first mask and the protective layer as a mask. The substrate is subjected to wet etching to form a cavity on a bottom surface of the trench.