US Patent 7242071 Semiconductor structure

A structure comprises a deep sub-collector buried in a first epitaxial layer and a near sub-collector buried in a second epitaxial layer. The structure further comprises a deep trench isolation structure isolating a region which is substantially above the deep sub-collector, a reach-through structure in contact with the near sub-collector, and a reach-through structure in contact with the deep sub-collector to provide a low-resistance shunt, which prevents COMS latch-up of a device. The method includes forming a merged triple well double epitaxy/double sub-collector structure.