Structure and method of latchup robustness with placement of through wafer via within CMOS circuitry
A method of manufacturing a semiconductor structure includes: forming a trench in a back side of a substrate; depositing a dopant on surfaces of the trench; forming a shallow trench isolation (STI) structure in a top side of the substrate opposite the trench; forming a deep well in the substrate; out-diffusing the dopant into the deep well and the substrate; forming an N-well and a P-well in the substrate; and filling the trench with a conductive material.
1. A semiconductor structure, comprising:
an NFET device having a P-well at a top side of a substrate;
a PFET device having an N-well at the top side of the substrate;
a substrate contact comprising a through wafer via extending from a backside of the substrate to a bottom surface of an isolation structure located between the NFET device and the PFET device; and
a dopant out-diffused from surfaces of a via opening of the through wafer via into the substrate and a deep well,
wherein the substrate contact is arranged to prevent formation of a parasitic circuit.
2. A semiconductor structure, comprising:
an NFET device having a P-well at a top side of a substrate;
a PFET device having an N-well at the top side of the substrate;
a deep well formed in the substrate below the N-well and the P-well;
a through wafer via extending from a backside of the substrate to a bottom surface of an isolation structure;
an electrical connection region between the through wafer via and the deep well; and
a high voltage junction between the through wafer via and the substrate.
3. The semiconductor structure of claim 2 , wherein a top portion of the through wafer via contacts a bottom portion of the isolation structure.
4. The semiconductor structure of claim 3 , wherein the isolation structure comprises one of:
a shallow trench isolation (STI) structure,
a trench isolation (TI) structure formed through a shallow trench isolation (STI) structure, and
a deep trench (DT) structure formed below a shallow trench isolation (STI) structure.
5. The semiconductor structure of claim 2 , wherein the through wafer via contacts the bottom surface of the isolation structure.
6. The semiconductor structure of claim 5 , wherein the electrical connection region and the high voltage junction comprise a dopant out-diffused from surfaces of a via opening of the through wafer via.