Metal-insulator-metal (MIM) capacitor with deep trench (DT) structure and method in a silicon-on-insulator (SOI)

A method of forming a capacitor structure, said method comprising:

• forming a substrate comprising:
• a metal layer;
• and
• at least one other layer;
• forming a trench in said substrate;
• forming a metal sidewall within said trench such that said metal sidewall is in contact with said metal layer, said metal layer comprising a first node of said capacitor structure;
• lining said metal sidewall with a dielectric material;
• and
• filling said trench with a conductive fill material such that said conductive fill material in said trench is not in contact with said metal layer, said conductive fill material comprising a second node of said capacitor structure,
• said substrate comprising a dielectric layer above said metal layer, said method further comprising:
• after said filling said trench with conductive fill material, recessing said conductive fill material in said trench;
• capping said conductive fill material;
• recessing said dielectric layer and said metal sidewall above said metal layer;
• depositing another dielectric layer on said metal layer over said conductive fill material and said cap;
• and
• bonding a Silicon-on-insulator layer (SOI) on said another dielectric layer.

A method comprising:

• forming a substrate comprising:
• providing a first silicon layer,
• depositing a metal layer on said first silicon layer,
• depositing a dielectric layer on said metal layer, and
• bonding a Silicon-on-insulator (SOI) layer on said dielectric layer;
• forming a trench in said substrate through said metal layer, said dielectric layer, and said SOI layer;
• forming a metal sidewall within said trench such that said metal sidewall is in contact with said metal layer, said metal layer comprising a first node of a capacitor structure;
• lining said metal sidewall with a dielectric material;
• filling said trench with a conductive fill material such that said conductive fill material in said trench is not in contact with said metal layer, said conductive fill material comprising a second node of said capacitor structure;
• after said filling said trench with conductive fill material, recessing said conductive fill material in said trench so as to expose at least an upper section of said trench;
• removing said metal sidewall from said upper section of said trench;
• depositing additional conductive fill material such that said conductive fill material is in contact with said SOI layer;
• and
• capping said conductive fill material.