Method for producing thin bistable membranes

Abstract

The subject of the application is a method for manufacturing a thin bi-stable membrane, characterized in that it comprises the following steps: a) creating at least one masking layer on a substrate wafer made of a semiconductor material, having etching selectivity with respect to the substrate wafer material; b) shaping at least one membrane region in the masking layer using a lithography and selective etching process; c) etching the substrate wafer material in the membrane region to create a recess with a predetermined geometry; d) removing the masking layer; e) carrying out at least one cycle comprising oxidizing the substrate wafer material and removing the resulting oxide layer, wherein this cycle is repeated many times to controllably shape the profile of the walls and bottom of the recess for the buffer layer; f) creating a layer of membrane material over the shaped recess;g) etching the backing plate material from the side opposite the membrane layer to selectively remove the backing material and release the membrane, wherein the geometry of the recess and the thickness of the membrane layer are selected such that the membrane exhibits two stable mechanical states after release.;

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