US Patent 11239315 Dual trench isolation structures

The present disclosure generally relates to semiconductor structures and, more particularly, to dual trench isolation structures and methods of manufacture. The structure includes: a doped well region in a substrate; 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 a gate structure on the substrate and extending over a portion of the dual trench isolation region.