Patent ID: 7812403

Claim:
An isolation structure in a semiconductor substrate of a first conductivity type, the isolation structure comprising: a floor isolation region of a second conductivity type submerged in the substrate; a filled trench extending downward from a surface of the substrate at least to the floor isolation region, the filled trench containing a dielectric material, the filled trench laterally surrounding an isolated pocket of the substrate, the floor isolation region and the filled trench together enclosing the isolated pocket of the substrate; a partition trench in the isolated pocket, the partition trench containing the dielectric material and extending downward from the surface of the substrate at least to the floor isolation region so as to separate the isolated pocket into first and second parts, the first and second parts not being in contact with each other; and a well of the second conductivity type in the first part of the isolated pocket, the well extending downward from the surface of the substrate to the floor isolation region.