In-trench capacitor merged structure

An integrated circuit device, comprising:

• a substrate;
• a trench capacitor structure within the substrate, comprising:
• a plurality of electrode layers comprising a first material,
• wherein the first material has a first coefficient of thermal expansion;
• a plurality of insulator layers interspersed with the plurality of electrode layers;
• and
• a merged dielectric layer comprising a second material in a merge region between co-facing surfaces of a top-most layer of the plurality of electrode layers,
• wherein the second material has a second coefficient of thermal expansion that is lesser relative to the first coefficient of thermal expansion.

A method, comprising:

• forming an insulator layer of a trench capacitor structure on a device region including a first material having a first coefficient of thermal expansion;
• forming an electrode layer of the trench capacitor structure on the insulator layer from a second material having a second coefficient of thermal expansion that is greater relative to the first coefficient of thermal expansion;
• and
• forming a merged dielectric layer in a gap between co-facing surfaces of the electrode layer from a third material having a third coefficient of thermal expansion that is lesser relative to the first coefficient of thermal expansion.