Dual trench isolation structures

A structure, comprising:

• a first well region in a substrate;
• a second well region in the substrate;
• a dual trench isolation region in the first well region, the dual trench isolation region composed of a shallow trench isolation structure and a deep trench isolation structure on a side adjacent to and connecting with the shallow trench isolation structure;
• and
• a gate structure spanning over the first well region and the second well region, the gate structure extending to the dual trench isolation region.

A method, comprising:

• forming a doped well region in a substrate;
• forming a dual trench isolation region within the doped well region, the dual trench isolation region comprising a first isolation region of a first depth and a second isolation region of a second depth, different than the first depth;
• and
• forming a gate structure on the substrate and extending over a portion of the dual trench isolation region.