MEMS Device

A method, comprising:

• depositing a first conductive material over an etch stop layer over a substrate;
• patterning the first conductive material to form an electrode;
• depositing a dielectric layer over the electrode;
• depositing a second conductive material over the dielectric layer;
• patterning the second conductive material to form a deflectable membrane, wherein an overlapping area of a fixed portion of the deflectable membrane with the electrode is less than a maximum overlapping;
• forming a backside cavity in the substrate to expose a surface of the etch stop layer;
• and
• removing portions of the etch stop layer and portions of the dielectric layer disposed between central portions of the deflectable membrane and the electrode.

A method, comprising:

• depositing an etch stop layer over a substrate;
• depositing a first nitride layer over the etch stop layer;
• depositing a first electrically conductive layer over the first nitride layer;
• depositing a second nitride layer over the first electrically conductive layer, wherein the first nitride layer, the first electrically conductive layer, and the second nitride layer form a first multilayer arrangement;
• etching a plurality of first openings in the first multilayer arrangement to expose an upper surface of the etch stop layer;
• depositing a first oxide layer into the plurality of first openings and over the first multilayer arrangement;
• depositing a second electrically conductive layer over the first oxide layer;
• depositing a second oxide layer over the first oxide layer and over the second electrically conductive layer;
• depositing a third nitride layer over the second oxide layer;
• depositing a third electrically conductive layer over the third nitride layer;
• depositing a fourth nitride layer over the third electrically conductive layer, wherein the third nitride layer, the third electrically conductive layer, and the fourth nitride layer form a second multilayer arrangement;
• etching a plurality of second openings in the second multilayer arrangement to expose an upper surface of the second oxide layer;
• forming a backside cavity in the substrate;
• and
• removing portions of the etch stop layer, the first oxide layer, and the second oxide layer that are disposed over the backside cavity.