Electrostatic discharge protection device

Abstract

The invention relates to the technical field of chip electrostatic discharge protection, and provides an electrostatic discharge protection device. The electrostatic discharge protection device comprises a P-type substrate; the P-type well layer is arranged on the P-type substrate, the surface of the P-type well layer is provided with an N-type doped region, a first P-type doped region and a second P-type doped region, the first P-type doped region is arranged at the position adjacent to the N-type doped region, and the second P-type doped region is arranged at the middle position of the N-type doped region; and the output end of the ESD trigger circuit is electrically connected with the second P-type doped region, and the ESD trigger circuit is configured to output high potential during electrostatic discharge, so that injection current is injected into the P-type substrate through the second P-type doped region. According to the invention, the turn-on voltage of the field oxide parasitic device used for ESD protection can be effectively reduced, and a better ESD protection effect is achieved.

Description

Technical Field

[0001] The present invention generally relates to the field of chip electrostatic discharge (ESD) protection technology. Specifically, the present invention relates to an electrostatic discharge protection device. Background Art

[0002] A field oxide device is a parasitic structure formed near the field oxide layer during chip manufacturing, which can play a role in ESD protection.

[0003] Figure 1 FIG. 4 shows a cross-sectional schematic diagram of a field oxygen parasitic device in the prior art. Figure 1 As shown, the existing field oxygen parasitic device, when performing ESD protection, mainly relies on the avalanche breakdown of the PN junction formed by the N+ doped region and the P well, triggering the parasitic NPN structure to turn on to discharge the ESD charge. However, since the avalanche breakdown voltage of the PN junction is usually relatively high, it will affect the ESD protection effect of the field oxygen parasitic device. Summary of the invention

[0004] In order to at least partially solve the above problems in the prior art, the present invention provides an electrostatic discharge protection device, comprising:

[0005] P-type substrate;

[0006] A P-type well layer is arranged on the P-type substrate, and a surface of the P-type well layer has an N-type doping region, a first P-type doping region and a second P-type doping region, wherein the first P-type doping region is arranged at a position adjacent to the N-type doping region, and the second P-type doping region is arranged at a middle position of the N-type doping region; and

[0007] An ESD trigger circuit has an output end electrically connected to the second P-type doped region, wherein the ESD trigger circuit is configured to output a high potential during electrostatic discharge so that an injection current is injected into the P-type substrate through the second P-type doped region.

[0008] In one embodiment of the present invention, it is provided that the N-type doping region includes a first N-type doping region located in the middle and a second N-type doping region located around the first N-type doping region.

[0009] In one embodiment of the present invention, it is provided that the second P-type doping region is disposed at a middle position of the first N-type doping region.

[0010] In one embodiment of the present invention, it is provided that the electrostatic discharge protection device further includes:

[0011] A shallow trench isolation is arranged between the first N-type doping region and the second N-type doping region.

[0012] In one embodiment of the present invention, it is provided that the electrostatic discharge protection device further includes:

[0013] An N-type well is disposed below the second N-type doping region, wherein the N-type well is configured to inhibit the injection current from flowing toward the first P-type doping region.

[0014] In one embodiment of the present invention, it is provided that the ESD trigger circuit includes an RC detection circuit.

[0015] In one embodiment of the present invention, the RC detection circuit includes a resistor, a capacitor, and an inverter.

[0016] In one embodiment of the present invention, it is provided that a common point between the first end of the resistor and the first input end of the inverter is a power supply end of the RC detection circuit.

[0017] In one embodiment of the present invention, the second end of the resistor is connected to the first end of the capacitor and the second input end of the inverter, and the common point of the second end of the capacitor and the third input end of the inverter is the ground end of the RC detection circuit.

[0018] In one embodiment of the present invention, it is provided that the output end of the inverter is connected to the second P-type doped region.

[0019] The present invention has at least the following beneficial effects: the present invention proposes an electrostatic discharge protection device, which can effectively reduce the turn-on voltage of the field oxygen parasitic device when used for ESD protection, thereby achieving a better ESD protection effect and improving the ESD protection level of the chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] To further illustrate the advantages and features of various embodiments of the present invention, a more detailed description of various embodiments of the present invention will be presented with reference to the accompanying drawings. It will be understood that these drawings only depict typical embodiments of the present invention and are therefore not to be considered as limiting the scope thereof. In the accompanying drawings, for clarity, identical or corresponding parts will be represented by identical or similar reference numerals.

[0021] Figure 1 A cross-sectional schematic diagram of a field oxygen parasitic device in the prior art is shown.

[0022] Figure 2 A schematic cross-sectional view of an electrostatic discharge protection device according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0023] It should be noted that the components in the figures may be shown exaggeratedly for the sake of illustration and are not necessarily true to scale. In the figures, identical or functionally identical components are provided with the same reference numerals.

[0024] In the present invention, unless otherwise specified, "arranged on...", "arranged above..." and "arranged above..." do not exclude the existence of an intermediate between the two. In addition, "arranged on or above..." merely indicates the relative positional relationship between two components, and in certain cases, such as after reversing the product direction, it can also be converted into "arranged below or below...", and vice versa.

[0025] In the present invention, each embodiment is only intended to illustrate the aspects of the present invention and should not be construed as limiting.

[0026] In the present invention, unless otherwise specified, the quantifiers "a", "an" and "an" do not exclude the presence of a plurality of elements.

[0027] It should also be noted that in the embodiments of the present invention, for the sake of clarity and simplicity, only a portion of the parts or components may be shown, but those of ordinary skill in the art will understand that under the teachings of the present invention, the required parts or components may be added according to the needs of the specific scenario. In addition, unless otherwise specified, the features in different embodiments of the present invention may be combined with each other. For example, a feature in the second embodiment may be used to replace a corresponding or functionally identical or similar feature in the first embodiment, and the resulting embodiment also falls within the disclosure scope or recorded scope of the present application.

[0028] It should also be noted that within the scope of the present invention, the terms "same", "equal", "equal to" and the like do not mean that the values ​​of the two are absolutely equal, but allow a certain reasonable error, that is, the terms also cover "substantially the same", "substantially equal", "substantially equal to". By analogy, in the present invention, the terms "perpendicular to", "parallel to" and the like indicating directions also cover the meanings of "substantially perpendicular to" and "substantially parallel to".

[0029] In the present application, the term "configuration" refers to the setting of the shape, structure, material and / or function of the target object to achieve the desired technical effect, wherein "configuration" includes a variety of alternative technical means for achieving the technical effect, which become obvious under the teaching of the present application.

[0030] In addition, the numbering of the steps of the methods of the present invention does not limit the execution order of the method steps. Unless otherwise specified, the method steps can be executed in different orders.

[0031] The present invention will be further described below in conjunction with specific embodiments with reference to the accompanying drawings.

[0032] Figure 2 FIG. 4 is a cross-sectional schematic diagram of an electrostatic discharge protection device according to an embodiment of the present invention. Figure 2 As shown, the electrostatic discharge protection device includes a P-type substrate 201, a P-type well layer 202, a first N-type doped region 2031, a second N-type doped region 2032, a first P-type doped region 2041, a second P-type doped region 2042, an N-type well 205 and an ESD trigger circuit 206.

[0033] In some embodiments, the P-type well layer 202 is disposed on the surface of the P-type substrate 201 .

[0034] In some embodiments, the surface of the P-type well layer 202 has an N-type doping region and a first P-type doping region 2041 , wherein the first P-type doping region 2041 is arranged adjacent to the N-type doping region.

[0035] In some embodiments, the N-type doped region includes a first N-type doped region 2031 located in the middle position and a second N-type doped region 2032 located around the first N-type doped region 2031, wherein a shallow trench isolation (STI) 2033 is provided between the first N-type doped region 2031 and the second N-type doped region 2032.

[0036] In some embodiments, a second P-type doping region 2042 is disposed at a middle position of the first N-type doping region 2031 .

[0037] In some embodiments, the output end of the ESD trigger circuit 206 is connected to the second P-type doped region 2042, wherein the ESD trigger circuit 206 is configured to output a high potential during electrostatic discharge so that the injection current I1 is injected into the P-type substrate 201 through the second P-type doped region 2042.

[0038] In some embodiments, the ESD trigger circuit 206 is an RC detection circuit, wherein the RC detection circuit includes a resistor R, a capacitor C, and an inverter, wherein the common point of the first end of the resistor R and the first input end of the inverter is the power supply end (VDD) of the RC detection circuit, the second end of the resistor R is connected to the first end of the capacitor C and the second input end of the inverter, the common point of the second end of the capacitor C and the third input end of the inverter is the ground end of the RC detection circuit, and the output end of the inverter is connected to the second P-type doped region 2042.

[0039] In some embodiments, an N-type well 205 is provided below the second N-type doped region 2032, and the junction depth of the N-type well 205 is deeper than that of the N-type doped region, wherein the N-type well 205 is configured to suppress the injection current I1 from flowing toward the first P-type doped region 2041, making it easier to form a positive bias voltage at the second P-type doped region 2042, causing the parasitic NPN to be more easily turned on, thereby achieving a lower ESD trigger voltage and a better ESD protection effect.

[0040] Although various embodiments of the present invention are described above, it should be understood that they are presented as examples only and not as limitations. It is obvious to those skilled in the relevant art that various combinations, modifications and changes can be made thereto without departing from the spirit and scope of the present invention. Therefore, the breadth and scope of the present invention disclosed herein should not be limited by the exemplary embodiments disclosed above, but should only be defined according to the attached claims and their equivalents.

Claims

1. An electrostatic discharge protection device, characterized in that: include: P-type substrate; A P-type well layer is arranged on the P-type substrate, and a surface of the P-type well layer has an N-type doping region, a first P-type doping region and a second P-type doping region, wherein the first P-type doping region is arranged at a position adjacent to the N-type doping region, and the second P-type doping region is arranged at a middle position of the N-type doping region; as well as An ESD trigger circuit has an output end electrically connected to the second P-type doped region, wherein the ESD trigger circuit is configured to output a high potential during electrostatic discharge so that an injection current is injected into the P-type substrate through the second P-type doped region.

2. The electrostatic discharge protection device according to claim 1, characterized in that: The N-type doping region includes a first N-type doping region located in the middle and a second N-type doping region located around the first N-type doping region.

3. The electrostatic discharge protection device according to claim 2, characterized in that: The second P-type doping region is disposed at a middle position of the first N-type doping region.

4. The electrostatic discharge protection device according to claim 2, characterized in that: Also includes: A shallow trench isolation is arranged between the first N-type doping region and the second N-type doping region.

5. The electrostatic discharge protection device according to claim 3, characterized in that: Also includes: An N-type well is disposed below the second N-type doping region, wherein the N-type well is configured to inhibit the injection current from flowing toward the first P-type doping region.

6. The electrostatic discharge protection device according to claim 1, characterized in that: The ESD trigger circuit includes an RC detection circuit.

7. The electrostatic discharge protection device according to claim 6, characterized in that: The RC detection circuit includes a resistor, a capacitor and an inverter.

8. The electrostatic discharge protection device according to claim 7, characterized in that: A common point between the first end of the resistor and the first input end of the inverter is a power supply end of the RC detection circuit.

9. The electrical discharge protection device according to claim 7, characterized in that: The second end of the resistor is connected to the first end of the capacitor and the second input end of the inverter, and the common point of the second end of the capacitor and the third input end of the inverter is the ground end of the RC detection circuit.

10. The electrical discharge protection device according to claim 7, characterized in that: The output end of the inverter is connected to the second P-type doping region.

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