Multi-tier deep trench capacitor and methods of forming the same

A method of forming a capacitor structure, comprising:

• forming a first-tier capacitor assembly comprising a first substrate having a first front surface and a first backside surface that are parallel to each other, and a first alternating layer stack embedded within the first substrate and including at least two first metallic electrode layers interlaced with at least one first node dielectric layer;
• forming a second-tier capacitor assembly comprising a second substrate having a second front surface and a second backside surface that are parallel to each other, and a second alternating layer stack embedded within the second substrate and including at least two second metallic electrode layers interlaced with at least one second node dielectric layers;
• and
• attaching the second substrate to the first substrate such that one of the at least two second metallic electrode layers directly contacts one of the at least two first metallic electrode layers.

A method of forming a capacitor structure, comprising:

• forming a first deep trench in a first substrate;
• forming a first alternating layer stack embedded within the first substrate and including at least two first metallic electrode layers interlaced with at least one first node dielectric layer in the first deep trench;
• removing portions of the first alternating stack from above a horizontal plane including a first front surface of the first substrate;
• forming a second deep trench in a second substrate having a second front surface and a second backside surface;
• forming a second alternating layer stack embedded within the second semiconductor substrate and including at least two second metallic electrode layers interlaced with at least one second node dielectric layer in the second deep trench;
• removing a portion of the second alternating layer stack from outside the second deep trench;
• and
• attaching the second substrate to the first substrate such that one of the at least two second metallic electrode layers directly contacts one of the at least two first metallic electrode layers.