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 method of manufacturing a semiconductor structure, comprising:
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.
2. The method of claim 1 , further comprising removing excess dopant from the trench.
3. The method of claim 1 , wherein the out-diffusing creates an electrical contact at an interface of the trench and the deep well, and a high voltage junction at an interface of the trench and the substrate.
4. The method of claim 1 , wherein the trench extends to a bottom surface of the shallow trench isolation structure.
5. The method of claim 4 , wherein:
the deep well is a deep N-well, and
the trench extends through the N-well, the deep N-well, and the substrate.
6. The method of claim 1 , further comprising forming a trench isolation (TI) structure through the STI structure.
7. The method of claim 6 , wherein the TI structure extends between the N-well and the P-well, into the deep well, and to an upper surface of the trench.
8. The method of claim 1 , further comprising lining surfaces of the trench with a barrier material before the filling.
9. A method of manufacturing a semiconductor structure, comprising:
forming a deep trench (DT) structure in a substrate;
forming a shallow trench isolation (STI) structure over the DT structure;
forming a trench in a back side of the substrate opposite the STI structure;
depositing a dopant on surfaces of 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.
10. The method of claim 9 , wherein the DT structure extends between the N-well and the P-well, into the deep well, and to the trench.
11. The method of claim 9 , wherein the STI structure, the DT structure, and the trench are substantially aligned.
12. The method of claim 9 , wherein the out-diffusing creates an electrical contact region at an interface of the trench and the deep well, and a high voltage junction at an interface of the trench and the substrate.
13. The method of claim 9 , further comprising:
removing excess dopant from the trench; and
lining surfaces of the trench with a barrier material before the filling.