US 2023/0141491 A1 · SYMMETRIC BI-DIRECTIONAL SILICON-CONTROLLED RECTIFIER FOR ELECTROSTATIC DISCHARGE PROTECTION

Abstract

Disclosed is a semiconductor structure including a semiconductor substrate (e.g., a P-substrate) and a symmetric BDSCR. The BDSCR includes, within the substrate, a first well (e.g., a low-doped deep Nwell) and, within the first well, symmetric side sections and a middle section positioned laterally between the side sections. Each side section includes: second and third wells (e.g., Pwells), where the third well is shallower than and has a higher conductivity level than the second well. Each middle section includes multiple floating wells including: two fourth wells (e.g., Nwells), which have a higher conductivity level than the first well, and a fifth well (e.g., another Pwell), which is positioned laterally between and shallower than the fourth wells. By incorporating the floating wells into the middle section, high current tolerance is improved.

Claims20

Dependent claims

A structure comprising:

a semiconductor substrate with a first type conductivity;
and
a device on the substrate and comprising:
a first well within the substrate and having a second type conductivity;
and
within the first well, side sections and a middle section positioned laterally between the side sections,
wherein each side section comprises:
a second well with the first type conductivity;
and
a third well immediately adjacent to the second well and having the first type conductivity at a higher conductivity level than the second well, and
wherein the middle section comprises:
two fourth wells having the second type conductivity at a higher conductivity level than the first well;
and
a fifth well positioned laterally between the fourth wells and having the first type conductivity.

11 more elements

A structure comprising:

a semiconductor substrate with a first type conductivity;
and
a device on the substrate and comprising:
a first well within the substrate and having a second type conductivity;
and
within the first well, side sections and a middle section positioned laterally between the side sections,
wherein each side section comprises:
a second well with the first type conductivity;
and
a third well having the first type conductivity at a higher conductivity level than the second well, wherein the third well is partially within the second well at an interface between the second well and the first well, and
wherein the middle section comprises:
two fourth wells having the second type conductivity at a higher conductivity level than the first well;
and
a fifth well positioned laterally between the fourth wells and having the first type conductivity.

11 more elements

A structure comprising:

a semiconductor substrate with a first type conductivity, wherein the substrate has a first surface and a second surface opposite the first surface;
and
a device on the substrate and comprising:
a first well within the substrate and having a second type conductivity;
and
within the first well, side sections and a middle section positioned laterally between the side sections,
wherein each side section comprises:
a second well with the first type conductivity;
a third well having the first type conductivity at a higher conductivity level than the second well, wherein the third well is partially within the second well at an interface between the second well and the first well;
a first contact region at the second surface adjacent to the third well and having the first type conductivity at a higher conductivity level than the second well;
and
a second contact region at the second surface adjacent to the third well and having the second type conductivity, and
wherein the middle section comprises:
two fourth wells having the second type conductivity at a higher conductivity level than the first well;
and
a fifth well positioned laterally between the fourth wells and having the first type conductivity, wherein the fourth wells and the fifth well are all floating wells.

13 more elements

Dependencies are inferred from the claim text.

Symmetric bi-directional silicon-controlled rectifier for electrostatic discharge protection

Life of this patent

Symmetric bi-directional silicon-controlled rectifier for electrostatic discharge protection

Life of this patent

Abstract

Claims20