Patent ID: 7276768

Claim:
A semiconductor structure comprising: a substrate of a semiconductor material having a top surface; a first doped well formed in the semiconductor material of the substrate, the first doped well having a first conductivity type; a first field effect transistor with source and drain regions in the first doped well; a second doped well formed in the semiconductor material of the substrate and disposed adjacent to the first doped well, the second doped well having a second conductivity type; a second field effect transistor with source and drain regions in the second doped well; and a dielectric-filled trench defined in the substrate between the first and second doped wells, the trench including a base, first sidewalls intersecting the top surface, and second sidewalls disposed between the base and the first sidewalls, the second sidewalls having a wider separation than the first sidewalls, and the wider separation of the second sidewalls operating to reduce latch-up of the first and second field effect transistors.