Structure of micro-electro-mechanical-system microphone and method for fabricating the same

A structure of micro-electro-mechanical-system (MEMS) microphone, comprising:

• a substrate, having a first opening;
• a dielectric layer, disposed on the substrate, wherein the dielectric layer has a second opening aligned to the first opening;
• a diaphragm, disposed within the second opening of the dielectric layer, wherein a peripheral region of the diaphragm is embedded into the dielectric layer at sidewall of the second opening;
• and
• a backplate layer, disposed on the dielectric layer and covering over the second opening, wherein the backplate layer includes a plurality of acoustic holes arranged into a regular array pattern, the regular array pattern includes a hexagon unit, each hexagon unit has six of the acoustic holes at corners and one of the acoustic holes at a center.

A method for fabricating micro-electro-mechanical-system (MEMS) microphone, comprising:

• providing a substrate;
• forming a dielectric layer on the substrate, wherein the dielectric layer is embedded with a diaphragm;
• forming a backplate layer on the dielectric layer, wherein the backplate layer includes a plurality of acoustic holes arranged into a regular array pattern, the regular array pattern includes a hexagon unit, each hexagon unit has six of the acoustic holes at corners and one of the acoustic holes at a center;
• patterning the substrate to have a first opening;
• and
• performing an etching process to etch a portion of the dielectric layer to form a second opening for releasing a sensing region of the diaphragm, wherein the etching process includes etching the dielectric layer through the acoustic holes at one side of the diaphragm.