MEMS microphone and method for manufacturing the same
A semiconductor device includes a substrate having an opening extending through the substrate and at least one support member on a sidewall of the opening, a vibration membrane on the substrate, a cover layer on the vibration membrane. The substrate, the vibration membrane, and the cover layer define a cavity. The opening exposes a lower surface portion of the vibration membrane. The at least one support member on the sidewall of the opening provides support to the vibration membrane in a deformation of the vibration membrane to prevent breakage.
1. A semiconductor device, comprising:
a substrate having an opening extending through the substrate and at least one support member on a sidewall of the opening, the at least one support member having a thickness substantially equal to a thickness of the substrate and comprising a plurality of square-shaped protrusions each having a lateral width equal to a lateral length;
a vibration membrane on the substrate;
a cover layer on the vibration membrane; and
a cavity delineated by the substrate, the vibration membrane, and the cover layer;
wherein the opening exposes a lower surface portion of the vibration membrane.
2. The semiconductor device of claim 1 , wherein the at least one support member comprises a plurality of support members symmetrically arranged on the sidewall of the opening.
3. The semiconductor device of claim 1 , wherein the lateral width of a square-shaped protrusion is smaller than a lateral width of the opening.
4. The semiconductor device of claim 1 , wherein the at least one support member has an upper surface flush with an upper surface of the substrate.
5. The semiconductor device of claim 1 , wherein the vibration membrane comprises polysilicon.
6. The semiconductor device of claim 1 , wherein the cover layer comprises at least one through-hole in communication with the cavity.
7. The semiconductor device of claim 6 , wherein the cover layer further comprises an electrode layer on a lower surface of the cover layer.
8. The semiconductor device of claim 1 , wherein the plurality of square-shaped protrusions are evenly spaced on the sidewall of the opening.
9. The semiconductor device of claim 1 , wherein the plurality of square-shaped protrusions are symmetrically disposed on the sidewall of the opening.
10. The semiconductor device of claim 1 , wherein the opening comprises a square-shaped cross section having four curved corners.
11. The semiconductor device of claim 10 , wherein the plurality of square-shaped protrusions comprise four protrusions, each of the four protrusions being arranged between two adjacent curved corners at an equal distance.