Low warpage high density trench capacitor

A semiconductor die, comprising:

• a substrate;
• a trench array having a plurality of trenches defined therein, wherein the plurality of trenches are rotationally symmetric about a center (CNTR) of the trench array and have a predetermined length extending along a surface of the substrate;
• a first dielectric layer disposed in a bottom region of the plurality of trenches, along sidewalls of the plurality of trenches, and over the surface of the substrate;
• a first conducting layer disposed over the first dielectric layer and over the surface of the substrate, wherein the first conducting layer is insulated from the substrate by the first dielectric layer and has an outermost perimeter that is symmetric about the center of the trench array;
• and
• a second conducting layer disposed over the first conducting layer and insulated from the first conducting layer by a second dielectric layer.

A semiconductor die, comprising:

• a substrate;
• a trench array having a plurality of trenches defined therein, wherein the plurality of trenches are rotationally symmetric about a center (CNTR) of the trench array and extend along a surface of the substrate;
• a first dielectric layer disposed in a bottom region of the plurality of trenches, along sidewalls of the plurality of trenches, and over the surface of the substrate;
• a first conducting layer disposed over the first dielectric layer and over the surface of the substrate, wherein the first conducting layer is insulated from the substrate by the first dielectric layer;
• a second conducting layer disposed over the first conducting layer and over the surface of the substrate, wherein the second conducting layer is insulated from the first conducting layer by a second dielectric layer, and further wherein an air gap is present between inner sidewalls of the second conducting layer;
• and
• a capping layer disposed over the second conducting layer, wherein the air gap extends to the capping layer.