Semiconductor structure having an integrated double-wall capacitor for embedded dynamic random access memory (edram) and method to form the same

A semiconductor structure, comprising:

• a plurality of semiconductor devices disposed in or above a substrate;
• one or more dielectric layers disposed above the plurality of semiconductor devices;
• metal wiring disposed in each of the dielectric layers and electrically coupled to one or more of the semiconductor devices;
• and
• an embedded double-wall capacitor disposed in one or more of the dielectric layers and adjacent to the metal wiring of the one or more dielectric layers, the capacitor comprising:
• a trench disposed in the one or more of the dielectric layers, the trench having a bottom and sidewalls;
• a U-shaped metal plate disposed at the bottom of the trench, spaced apart from the sidewalls;
• an insulator layer disposed on and conformal with the sidewalls of the trench and the U-shaped metal plate;
• and
• a top metal plate layer disposed on and conformal with the insulator layer.

A method of forming an embedded double-wall capacitor for a semiconductor device, the method comprising:

• etching a trench in a first dielectric layer formed above a substrate, the trench having a bottom and sidewalls;
• forming a U-shaped metal plate at the bottom of the trench, spaced apart from the sidewalls of the trench;
• depositing a second dielectric layer disposed on and conformal with the sidewalls of the trench and the U-shaped metal plate;
• and
• depositing a top metal plate layer disposed on and conformal with the second dielectric layer.