MEMS microphone having improved sensitivity and method for the production thereof
A MEMS microphone with improved sensitivity and a method for producing such a MEMS microphone are disclosed. In an embodiment the MEMS microphone includes a carrier substrate, a capacitor having two electrodes, a substrate-side anchor and an electrode anchor, wherein the substrate-side anchor connects the substrate to the capacitor, wherein the electrode anchor connects the two electrodes of the capacitor, wherein one of the electrodes is a backplate and the other electrode is the anchored membrane, and wherein the substrate-side anchor has a bearing area on the substrate which exceeds a minimum area necessary for a mechanical stability of the MEMS microphone by not more than the minimum area.
1. A method for producing a MEMS microphone, the method comprising:
providing a carrier substrate;
arranging a lower sacrificial layer on the carrier substrate;
producing a membrane on the lower sacrificial layer;
arranging an upper sacrificial layer on the membrane; and
producing a backplate on the upper sacrificial layer,
wherein an etching rate of the lower sacrificial layer in a region which is intended to adjoin a later substrate-side anchor and/or an etching rate of the upper sacrificial layer in a region which is intended to adjoin a later capacitor anchor are/is increased after arranging the corresponding sacrificial layer.
2. The method according to claim 1 , wherein, after producing the backplate, at least one region of increased etching rate of a sacrificial layer is removed by etching.
3. The method according to claim 1 , wherein the etching rate is an etching rate for etching using an etchant HF or VHF.
4. The method according to claim 1 , wherein the etching rate is increased by ion implantation.
5. The method according to the claim 1 , wherein the etching rate is increased by implantation of P ions.