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EP-4432356-B1 - ELECTROSTATIC DISCHARGE PROTECTION DEVICE

EP4432356B1EP 4432356 B1EP4432356 B1EP 4432356B1EP-4432356-B1

Inventors

  • SONG, JONGKYU
  • HEO, JIN
  • KIM, MINHO
  • SONG, JOOYOUNG
  • LEE, EUNSUK
  • JEON, CHANHEE

Dates

Publication Date
20260513
Application Date
20240110

Claims (11)

  1. An electrostatic discharge protection device (100) comprising: a substrate (101) having a first conductivity type; a first well (121) formed on the substrate and having the first conductivity type; a second well (123) formed on the substrate surrounding the first well in a plan view, the second well having a second conductivity type; a first diffusion region (131) formed on the first well and having the first conductivity type; a second diffusion region (132) formed on the first well surrounding the first diffusion region in the plan view, the second diffusion region having the second conductivity type; a third diffusion region (133) formed on the first well and having the first conductivity type; a fourth diffusion region (134) formed on the first well surrounding the third diffusion region in the plan view, the fourth diffusion region having the second conductivity type; a fifth diffusion region (135) formed on the first well surrounding the second diffusion region and the fourth diffusion region in the plan view, the fifth diffusion region having the first conductivity type; a sixth diffusion region (136) formed on the second well (123) to surround the fifth diffusion region in the plan view, the sixth diffusion region having the first conductivity type; and a seventh diffusion region (137) formed on the second well surrounding the sixth diffusion region in the plan view, the seventh diffusion region having the second conductivity type, wherein the sixth diffusion region (136) and the seventh diffusion region (137) are to be connected to a first electrode (E1), and the first diffusion region to the fifth diffusion region are to be connected to a second electrode (E3, E4).
  2. The electrostatic discharge protection device (100) of claim 1, wherein the first conductivity type is a P-type conductivity, and the second conductivity type is an N-type conductivity.
  3. The electrostatic discharge protection device (100) of claim 1 or 2, further comprising: a first resistor (R1) connected between the second diffusion region and the fifth diffusion region; and a second resistor (R2) connected between the fourth diffusion region and the fifth diffusion region.
  4. The electrostatic discharge protection device (100) of any preceding claim, further comprising: a gate polysilicon pattern (GP) formed on at least one from among: a region between the second diffusion region and the fifth diffusion region, a region between the fourth diffusion region and the fifth diffusion region, and a region between the fifth diffusion region and the sixth diffusion region.
  5. The electrostatic discharge protection device (100) of any preceding claim, wherein the substrate (101) further includes: an epitaxial layer (104) of the second conductivity type; and a buried layer (102) formed on a lower portion of the epitaxial layer.
  6. The electrostatic discharge protection device (100) of any preceding claim, further comprising: a first drift region (111) formed on a lower portion of the first well (121) and having the first conductivity type; a second drift region (113) formed on a lower portion of the second well (123) and having the second conductivity type; and a first deep-well (122) formed under the fifth diffusion region in the first well (121) and in the first drift region, the first deep-well having the first conductivity type.
  7. The electrostatic discharge protection device (100) of claim 6, wherein a doping concentration of the first well (121) is higher than a doping concentration of the first drift region, wherein a doping concentration of the second well (123) is higher than a doping concentration of the second drift region (113), and wherein a doping concentration of the first deep-well (122) is lower than the doping concentration of the first drift region (111).
  8. The electrostatic discharge protection device (100) of any preceding claim, further comprising: a first resistor connected between the second diffusion region (132) and the fifth diffusion region (135); and a second resistor connected between the fourth diffusion region (134) and the fifth diffusion region (135).
  9. The electrostatic discharge protection device (100) of any preceding claim, further comprising a gate polysilicon pattern formed on at least one from among: a region between the second diffusion region (132) and the fifth diffusion region (135), a region between the fourth diffusion region (134) and the fifth diffusion region (135), and a region between the fifth diffusion region (135) and the sixth diffusion region (136).
  10. The electrostatic discharge protection device (100) of claim 5 and preferably any one of claims 6 and 7, wherein the epitaxial layer (104) is a first epitaxial layer, and the buried layer is a first buried layer (102), wherein the substrate (101) further includes: a second epitaxial layer (105) of the second conductivity type; a second buried layer (103) formed on a lower portion of the second epitaxial layer; a second deep-well (115) formed on the second epitaxial layer and having the first conductivity type; and a seventh well (125) formed on the second deep-well and having the first conductivity type.
  11. The electrostatic discharge protection device (100) of any preceding claim, wherein the first electrode (E1) is an anode electrode, and the second electrode (E3, E4) is a cathode electrode, and preferably comprising the first and second electrodes (E1, E3, E4).

Description

TECHNICAL FIELD The present invention generally relates to an electrostatic discharge protection device. In particular, embodiments of the present disclosure described herein relate to a thyristor-based electrostatic discharge protection device. BACKGROUND An electrostatic discharge protection device that is a silicon controlled rectifier (SCR) (or thyristor) is triggered by the reverse breakdown between an N-well and a P-well and has a trigger voltage of a relatively high level. In addition, a typical silicon controlled rectifier-based electrostatic discharge protection device has a holding voltage of a relatively low level due to an internal parasitic bipolar junction transistor (BJT). Meanwhile, in some cases, a trigger voltage of a high level may be required depending on the specifications of a required product. A method of adjusting a distance between the P-well and the N-well, in which the reverse breakdown occurs, may be used to design an electrostatic discharge protection device that has a trigger voltage of a high level. However, when a value of the trigger voltage is increased by increasing the distance between the P-well and the N-well, the electrostatic discharge protection device may not operate properly due to a decrease in a current gain. Accordingly, to meet product specifications, it is desirable to design an electrostatic discharge protection device which, e.g., operates stably at a trigger voltage of a high level, for example in terms of reliable protection of the electronic device. We refer to: CN108879632 A (Zheng; 23.11.18) relates to an electrostatic discharging protection circuit, and discloses such a circuit that comprises a silicon-controlled rectifier, a first diode and a second diode, wherein the silicon-controlled rectifier comprises two dual-carrier junction transistors.US2006/011939 A1 (Mohn, 19.1.06) relates to a two-dimensional silicon controlled rectifier, and disclosing such a rectifier having an anode and cathode forming a checkerboard pattern.US2009/166721 A1 (Denison; 2.7.09) relates to a quasi-vertical gated NPN-PNP ESD protection device, and discloses such a device that has a well having one conductivity type formed adjacent to a deep well having another conductivity type.US2012/199874 A1 (Salcedo; 9.8.12) relates to transient electrical overstress protection and discloses an apparatus including: an internal circuit electrically connected between a first node and a second node; and a protection circuit electrically connected between the first node and the second node.CN108807364 A (Hung; 13.11.08) relates to an electrostatic discharge protection device and circuit and method for manufacturing the device, and discloses such a device that includes: a base well of a first dopant type on a substrate, a first well of the first dopant type in the base well, a second well of a second dopant type in the base well, a first highly doped region of the first dopant type and a second highly doped region of the second dopant type in the first well, a third highly doped region of the second dopant type in the second well, and a fourth highly doped region of the first dopanttype in the third highly doped region. SUMMARY According to a first aspect of the present invention, there is provided an electrostatic discharge protection device according to claim 1. Preferred embodiments are defined by the dependent claims. BRIEF DESCRIPTION OF THE FIGURES The above and other objects and features of the present disclosure will become apparent by describing in detail embodiments thereof with reference to the accompanying drawings. FIG. 1 illustrates a plan view of an ESD protection device according to an embodiment of the claimed invention.FIG. 2 illustrates a cross-sectional view of an ESD protection device taken along line I-I' of FIG. 1.FIG. 3 illustrates a cross-sectional view of an ESD protection device taken along line II- II' of FIG. 1.FIG. 4 is a graph illustrating an operating characteristic of an ESD protection device of the present disclosure.FIG. 5 illustrates a cross-sectional view of an ESD protection device taken along line I-I' of FIG. 1.FIG. 6 illustrates a cross-sectional view of an ESD protection device taken along line I-I' of FIG. 1.FIG. 7 illustrates a cross-sectional view of an ESD protection device taken along line I-I' of FIG. 1.FIG. 8 illustrates a cross-sectional view of an ESD protection device taken along line I-I' of FIG. 1.FIG. 9 illustrates a cross-sectional view of an ESD protection device taken along line I-I' of FIG. 1.FIG. 10 illustrates a cross-sectional view of an ESD protection device taken along line I-I' of FIG. 1.FIG. 11 illustrates a cross-sectional view of an ESD protection device taken along line I-I' of FIG. 1.FIG. 12 illustrates a cross-sectional view of an ESD protection device taken along line I-I' of FIG. 1.FIG. 13 illustrates a cross-sectional view of an ESD protection device taken along line I-I' of FIG. 1.FIG. 14 illustrates a cross-sectional