A fast-opening bidirectional symmetrical electrostatic protection device

Abstract

The present invention provides a fast-opening bidirectional symmetrical electrostatic protection device, comprising a first conductive type substrate, and more than one bidirectional SCR structural unit arranged above the first conductive type substrate, wherein the bidirectional SCR structural unit comprises three electrostatic discharge modules arranged in parallel and non-contact, wherein the electrostatic discharge modules are respectively provided with a first conductive type heavily doped region and a second conductive type heavily doped region, wherein the first conductive type heavily doped region of the second electrostatic discharge module and the second conductive type heavily doped region of the first electrostatic discharge module can construct a first direction conduction path of electrostatic discharge, and the first conductive type heavily doped region of the third electrostatic discharge module and the second conductive type heavily doped region of the second electrostatic discharge module can construct a second direction conduction path opposite to the first direction, wherein the length and conduction path of the first direction conduction path and the second direction conduction path are consistent. The present invention can achieve a faster conduction opening speed.

Description

Technical Field

[0001] The invention relates to the field of electrostatic protection device structures, and in particular to a fast-opening bidirectionally symmetrical electrostatic protection device. Background Art

[0002] Electronic circuit systems are easily damaged by transient energies such as electrical over stress (EOS) and electrostatic discharge (ESD). As one of the mainstream protection devices, electrostatic protectors play an important role in the electrostatic protection of circuits and chips. According to the protection type, electrostatic protection devices can be divided into unidirectional and bidirectional devices, both of which have bidirectional ESD discharge capabilities. However, unidirectional protection devices only have unilateral blocking capabilities, while bidirectional protection devices have bidirectional blocking capabilities. For some port signals where there are both positive and negative voltages, bidirectional protection devices must be selected for ESD protection.

[0003] Among the existing various bidirectional electrostatic protection components, the bidirectional silicon controlled rectifier (SCR) has symmetrical IV characteristics, stronger discharge capability, lower clamping voltage, and can provide better protection against bidirectional electrostatic shock.

[0004] With the continuous evolution of integrated circuit process nodes, the integration of chips is getting higher and higher, but the corresponding voltage resistance is constantly decreasing. At this time, for fast electrostatic discharge events, such as IEC discharge, CDM mode (Charged Device Model), the first discharge pulse is usually around 1ns. At this time, if you want to provide timely and reliable electrostatic protection for the protected circuit, the electrostatic protection device is required to have a sufficiently fast opening response speed to quickly discharge static charges. Usually for SCR devices, their opening speed is related to the distance between the positive and negative electrodes, which is usually related to the base length of the two parasitic BJTs (Bipolar Junction Transistor): the shorter the base length of the two BJTs, the shorter the carrier transit time, and the positive feedback establishment time is also shortened accordingly, making the device turn on faster as a whole.

[0005] Figure 1(a) and Figure 1(b) show the typical bidirectional SCR device structure and circuit diagram, respectively. As shown in Figure 1(a) and Figure 1(b), a P-well resistor R is connected in series on both the forward and reverse conduction paths. P阱 , the ESD discharge path is long, so the SCR turn-on speed is usually poor and cannot provide timely and effective voltage clamping capability for fast electrostatic discharge events.

[0006] Figure 2Another existing bidirectional SCR device structure is shown. Figure 2 As shown, the forward and reverse conduction paths go through a BJT with a longer base region (L B-PNP and L B-NPN ), and it is also impossible to open it faster.

[0007] In summary, for the existing bidirectional SCR structure, the turn-on speed is usually slow and cannot provide timely and effective voltage clamping capability for fast electrostatic discharge events. Therefore, for the bidirectional SCR structure, how to optimize the turn-on speed while maintaining the symmetrical IV characteristics is worth studying. Summary of the invention

[0008] In order to solve the problem of slow turn-on speed of bidirectional SCR structure in the prior art, the present invention provides a fast-on bidirectional symmetrical electrostatic protection device, which optimizes the structural layout to reduce the base region length to shorten the carrier transit time, thereby achieving a faster turn-on speed.

[0009] The fast-opening bidirectional symmetrical electrostatic protection device of the present invention comprises a first conductive type substrate, and more than one bidirectional SCR structural unit arranged above the first conductive type substrate, wherein the bidirectional SCR structural unit comprises three electrostatic discharge modules arranged in parallel and non-contact, namely a first electrostatic discharge module, a second electrostatic discharge module and a third electrostatic discharge module, wherein the first electrostatic discharge module, the second electrostatic discharge module and the third electrostatic discharge module are respectively provided with a first conductive type heavily doped region and a second conductive type heavily doped region, wherein the first electrostatic discharge module and the third electrostatic discharge module are respectively arranged on both sides of the second electrostatic discharge module, and the first conductive type heavily doped region and the second conductive type heavily doped region of the first electrostatic discharge module and the third electrostatic discharge module are respectively connected to the first port through metal interconnects, and the first conductive type heavily doped region of the second electrostatic discharge module is connected to the first port through metal interconnects. A heavily doped region of a first conductive type and a heavily doped region of a second conductive type are respectively connected to the second port through metal interconnects, the heavily doped region of the second conductive type of the first electrostatic discharge module is arranged close to the heavily doped region of the first conductive type of the second electrostatic discharge module, the heavily doped region of the first conductive type of the third electrostatic discharge module is arranged close to the heavily doped region of the second conductive type of the second electrostatic discharge module, the heavily doped region of the first conductive type of the second electrostatic discharge module and the heavily doped region of the second conductive type of the first electrostatic discharge module can construct a first direction conduction path for electrostatic discharge, the heavily doped region of the first conductive type of the third electrostatic discharge module and the heavily doped region of the second conductive type of the second electrostatic discharge module can construct a second direction conduction path opposite to the first direction, and the length and conduction path of the first direction conduction path and the second direction conduction path are consistent.

[0010] Furthermore, the number of the bidirectional SCR structural units is more than 2, and all the bidirectional SCR structural units are arranged in parallel on the first conductive type substrate. When the adjacent electrostatic discharge modules of two SCR structural units are connected to the first port through metal interconnections, the two adjacent SCR structural units can share the electrostatic discharge module.

[0011] Furthermore, a second conductive type large well region is provided on the first conductive type substrate, and all bidirectional SCR structural units are arranged in parallel on the surface of the second conductive type large well region.

[0012] Furthermore, the first electrostatic discharge module, the second electrostatic discharge module and the third electrostatic discharge module have the same structure and are isolated by a shallow trench isolation structure. The first conductive type heavily doped region and the second conductive type heavily doped region of the first electrostatic discharge module are contacted and arranged in parallel. The first electrostatic discharge module also includes a first conductive type ESD protection layer arranged on the lower surface of the first conductive type heavily doped region and the second conductive type heavily doped region.

[0013] Furthermore, the first electrostatic discharge module, the second electrostatic discharge module and the third electrostatic discharge module have the same structure and are isolated by a shallow trench isolation structure. The first conductive type heavily doped region and the second conductive type heavily doped region of the first electrostatic discharge module are arranged in parallel on the upper surface of the second conductive type large well region, and the first conductive type heavily doped region and the second conductive type heavily doped region are isolated by a shallow trench isolation structure. The first electrostatic discharge module also includes a first conductive type ESD protection layer arranged on the lower surface of the second conductive type heavily doped region.

[0014] Furthermore, a second conductive type deep well region is provided on the first conductive type substrate, all bidirectional SCR structural units are arranged in parallel in the second conductive type deep well region, the electrostatic discharge module includes a first conductive type well region arranged in the second conductive type deep well region, and the first conductive type heavily doped region and the second conductive type heavily doped region are arranged non-contactly on the surface of the first conductive type well region.

[0015] Furthermore, the electrostatic discharge module includes a second conductive type well region disposed on a first conductive type substrate, and the first conductive type heavily doped region and the second conductive type heavily doped region are disposed non-contactingly on a surface of the first conductive type well region.

[0016] Furthermore, it also includes an auxiliary trigger module, the output end of the auxiliary trigger module is connected to the control end of the bidirectional SCR structure unit.

[0017] Furthermore, it also includes a diversion module arranged on the first port and / or the second port.

[0018] Furthermore, the second conductive type large well region, the first conductive type ESD protection layer, the second conductive type well region, and the first conductive type well region are replaced by a P-Base and N-Base process hierarchy structure with the same doping type.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: the length and conduction path of the first direction conduction path and the second direction conduction path of the present invention are consistent, and the symmetrical IV characteristics can be maintained; in addition, by optimizing the structural layout, the first conductive type heavily doped region and the second conductive type heavily doped region of both the first direction conduction path and the second direction conduction path are arranged adjacently, which effectively reduces the length of the base region, thereby shortening the transit time of the carriers, and thus achieving a faster turn-on speed. The present invention has flexible design, high degree of freedom, and a wide range of applications, and is particularly suitable for bidirectional symmetrical SCR structure design, providing a good bidirectional electrostatic protection solution for the protected circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the present invention or the solutions in the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 (a) is a schematic diagram of the structure of a typical bidirectional SCR device;

[0022] Figure 1(b) is a circuit diagram of a typical bidirectional SCR device;

[0023] Figure 2 It is a schematic diagram of the structure of another existing bidirectional SCR device;

[0024] Figure 3 A schematic diagram of the structure of a fast-opening bidirectionally symmetrical electrostatic protection device proposed in the first embodiment of the present invention;

[0025] Figure 4 A schematic diagram of the structure of a fast-opening bidirectionally symmetrical electrostatic protection device proposed in the second embodiment of the present invention;

[0026] Figure 5 A schematic diagram of the structure of a fast-opening bidirectionally symmetrical electrostatic protection device proposed in the third embodiment of the present invention;

[0027] Figure 6 This is a schematic structural diagram of a fast-opening bidirectionally symmetrical electrostatic protection device proposed in the fourth embodiment of the present invention. DETAILED DESCRIPTION

[0028] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs; the terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention; the terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of the present invention or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0029] Reference to "embodiments" in the present invention means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it mutually exclusive, independent, or alternative to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in the present invention may be combined with other embodiments.

[0030] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings.

[0031] like Figure 3-Figure 6 As shown, the fast-opening bidirectional symmetrical electrostatic protection device of the present invention includes a first conductive type substrate, and more than one bidirectional SCR structural unit arranged above the first conductive type substrate, wherein the bidirectional SCR structural unit includes three electrostatic discharge modules arranged in parallel and non-contact, namely, a first electrostatic discharge module, a second electrostatic discharge module and a third electrostatic discharge module, wherein the first electrostatic discharge module, the second electrostatic discharge module and the third electrostatic discharge module are respectively provided with a first conductive type heavily doped region and a second conductive type heavily doped region, wherein,

[0032] The first electrostatic discharge module and the third electrostatic discharge module are respectively arranged on both sides of the second electrostatic discharge module, the first conductive type heavily doped region and the second conductive type heavily doped region of the first electrostatic discharge module and the third electrostatic discharge module are respectively connected to the first port through metal interconnection lines, and the first conductive type heavily doped region and the second conductive type heavily doped region of the second electrostatic discharge module are respectively connected to the second port through metal interconnection lines.

[0033] The second conductive type heavily doped region of the first electrostatic discharge module is arranged close to the first conductive type heavily doped region of the second electrostatic discharge module, and the first conductive type heavily doped region of the third electrostatic discharge module is arranged close to the second conductive type heavily doped region of the second electrostatic discharge module. The first conductive type heavily doped region of the second electrostatic discharge module and the second conductive type heavily doped region of the first electrostatic discharge module can construct a first direction conduction path for electrostatic discharge, and the first conductive type heavily doped region of the third electrostatic discharge module and the second conductive type heavily doped region of the second electrostatic discharge module can construct a second direction conduction path opposite to the first direction, and the length and conduction path of the first direction conduction path and the second direction conduction path are consistent.

[0034] In the embodiment of the present invention, 100, 200, 300, 400, 500 and 600 represent a first conductive type substrate of a semiconductor process; 130, 220, 240, 610, 620, 630, 640 and 650 represent a second conductive type well region, 310 and 410 represent a second conductive type large well region, 120, 140, 230, 520, 530 and 540 represent a first conductive type well region, 110, 210 and 510 represent a second conductive type deep well region, 122, 141, 231, 232, 311, 314, 317, 320, 323, 326, 329, 332, 412, 415, 418, 522, 532, 542, 611, 621, 631, 641 and 651 represent heavily doped regions of the second conductivity type (i.e., second conductivity type active regions), 121, 142, 221, 222, 312, 315, 318, 321, 324, 327, 330, 333, 411, 414, 417, 521, 531, 541, 612, 622, 632, 642 and 652 represent heavily doped regions of the first conductivity type (i.e., first conductivity type active regions), 313, 316, 319, 322, 325, 328, 331, 334, 413, 416 and 419 represent first conductivity type ESD protection layers, 335 and 420 represent STI (Shallow Electron Transistor). Trench Isolation (Shallow Trench Isolation) isolation structure, 150 represents the metal interconnection line of the first port, 160 represents the metal interconnection line of the second port, 170 represents the metal interconnection line of the third port, 180 represents the metal interconnection line of the Mth port, and 190 represents the metal interconnection line of the Kth port, wherein M and K are both positive integers greater than 3.

[0035] Next, the present invention takes the first conductivity type as P type and the second conductivity type as N type as an example, and describes the structure of the present invention in detail in combination with specific embodiments. It should be known that the present invention interchanges the doping types of all conductivity type regions (N type P-type, P-type N type), the solution of the present invention is still valid.

[0036] like Figure 3 As shown, as the first embodiment of the present invention, the present invention can realize bidirectional ESD discharge between N ports, wherein N is a positive integer, and the port in this example is an I / O port, and of course, it can also be a power port. Specifically, the present invention is provided with an N-type large well region on a P-type substrate, and N-1 bidirectional SCR structural units are arranged in parallel in the N-type large well region. The third electrostatic discharge module of the first bidirectional SCR structural unit in this example is arranged close to the second bidirectional SCR structural unit. Since the first electrostatic discharge module of the second bidirectional SCR structure in this example is also connected to the I / O port one through the metal interconnect line 150, the third electrostatic discharge module of the first bidirectional SCR structural unit in this example can be shared with the first electrostatic discharge module of the second bidirectional SCR structure, and set to one. Of course, if the I / O port M is different from the port connected to the third electrostatic discharge module of the previous bidirectional SCR structure, the two bidirectional SCR structures only need to be configured with three electrostatic discharge modules at the same time.

[0037] In the first bidirectional SCR structural unit of the present embodiment, the first electrostatic discharge module, the second electrostatic discharge module and the third electrostatic discharge module have the same structure and are isolated by the STI isolation structure. The P-type heavily doped region and the N-type heavily doped region of the first electrostatic discharge module are arranged in contact and parallel, and a P-type ESD protection layer (hereinafter referred to as P-ESD) isolated from the N-type large well region is also arranged on the lower surface of the P-type heavily doped region and the N-type heavily doped region. A forward conduction path from I / O port 1 to I / O port 2 is formed between the P-type heavily doped region of the first electrostatic discharge module and the N-type heavily doped region of the second electrostatic discharge module, a reverse conduction path from I / O port 2 to I / O port 1 is formed between the P-type heavily doped region of the second electrostatic discharge module and the N-type heavily doped region of the third electrostatic discharge module, and a positive phase conduction path from I / O port 1 to I / O port 3 is formed between the P-type heavily doped region of the third electrostatic discharge module and the N-type heavily doped region of the second electrostatic discharge module of the second bidirectional SCR structural unit, and so on.

[0038] pass Figure 3 It can be seen that the forward conduction path and the reverse conduction path of this embodiment are completely consistent, both passing through the path of P+ / P-ESD / N well / P-ESD / N+, and can maintain symmetrical IV characteristics. In addition, the distance between the positive and negative electrodes is only the length of an STI, and the STI length can usually take the minimum value of the process, which can enable the device to achieve extremely fast turn-on speed. And this design scheme can achieve bidirectional electrostatic discharge of N ports by repeating N bidirectional SCR structural units.

[0039] like Figure 4 As shown, as the second embodiment of the present invention, compared with the first embodiment, this embodiment floats the P-ESD at the negative electrode of the SCR while maintaining the symmetrical IV characteristics and the shortest distance between the positive and negative electrodes, that is, by isolating the P-type heavily doped region and the N-type heavily doped region through a shallow trench isolation structure, and removing the P-ESD under the P-type heavily doped region, and only setting the P-ESD under the N-type heavily doped region, so that a very low trigger voltage can be obtained by using the vertical NPN. Such a design is suitable for low-voltage applications, and there is no need to design an additional trigger-on module.

[0040] like Figure 5 As shown, as the third embodiment of the present invention, this embodiment uses a P-type well region (P-well for short) and an N-type deep well region (deep N-well for short) to realize a bidirectional SCR structure. A deep N-well is provided on the P-type substrate, and all bidirectional SCR structural units are arranged in parallel in the deep N-well. The electrostatic discharge module includes a P-well arranged in the deep N-well, and the P-type heavily doped region and the N-type heavily doped region are arranged on the surface of the P-well in a non-contact manner.

[0041] In this embodiment, the distance between the positive and negative electrodes is L, which is composed of the sum of the "P-well spacing size", the "size of the P-type heavily doped region surrounded by the P-well", and the "size of the N-type heavily doped region surrounded by the P-well". In a typical planar process, the size of the above L is usually very small, so the bidirectional SCR device can obtain a very fast turn-on speed.

[0042] like Figure 6 As shown in the figure, as the fourth embodiment of the present invention, this embodiment uses an N-type well region (referred to as N-well) to directly form a bidirectional SCR structure on a P-type substrate. Specifically, a number of N-wells corresponding to the number of electrostatic discharge modules are provided on the P-type substrate, and then a group of non-contact P-type heavily doped regions and N-type heavily doped regions are provided on the upper surface of the N-well, thereby forming an electrostatic discharge module. The process level of this embodiment is the simplest.

[0043] Preferably, in the present invention, the P-ESD, P-well, and N-well regions can be replaced by P-Base, N-Base or other customized process hierarchical structures with the same doping type.

[0044] The present invention can also add some functional modules on the basis of the fast-opening bidirectional symmetrical electrostatic protection device to optimize the structural design of the present invention. As one of the embodiments of the present invention, this example can set an auxiliary trigger module, and the output end of the auxiliary trigger module is connected to the control end of the bidirectional SCR structural unit, so as to optimize the opening voltage of the electrostatic protection device of the present invention. In addition, the present invention can also set a shunt module on each port or part of the ports to optimize the maintenance voltage of the device, etc. The trigger module and the shunt module can adopt the general structure of the existing semiconductor device circuit, which will not be repeated here.

[0045] In summary, the length and conduction path of the forward conduction path and the reverse conduction path of the present invention are completely consistent, so that the symmetrical IV characteristics can be well maintained; in addition, by optimizing the structural layout, the positive and negative electrodes are arranged adjacent to each other in both the forward conduction path and the reverse conduction path, which effectively reduces the length of the base region, thereby shortening the transit time of the carriers, and thus achieving a faster turn-on speed. The present invention is flexible in design, has a high degree of freedom, and has a wide range of applications. It is particularly suitable for bidirectional symmetrical SCR structure design, and provides a good bidirectional electrostatic protection solution for the protected circuit.

[0046] The specific implementation modes described above are preferred implementation modes of the present invention, and are not intended to limit the specific implementation scope of the present invention. The scope of the present invention includes but is not limited to the specific implementation modes, and all equivalent changes made according to the present invention are within the protection scope of the present invention.

Claims

1. A fast-opening bidirectional symmetrical electrostatic protection device, characterized in that: The invention comprises a first conductive type substrate, and one or more bidirectional SCR structural units arranged above the first conductive type substrate, wherein the bidirectional SCR structural unit comprises three electrostatic discharge modules arranged in parallel and non-contactly, namely a first electrostatic discharge module, a second electrostatic discharge module and a third electrostatic discharge module, wherein the first electrostatic discharge module, the second electrostatic discharge module and the third electrostatic discharge module are respectively provided with a first conductive type heavily doped region and a second conductive type heavily doped region, wherein: The first electrostatic discharge module and the third electrostatic discharge module are respectively arranged on both sides of the second electrostatic discharge module, the first conductive type heavily doped region and the second conductive type heavily doped region of the first electrostatic discharge module and the third electrostatic discharge module are respectively connected to the first port through metal interconnection lines, and the first conductive type heavily doped region and the second conductive type heavily doped region of the second electrostatic discharge module are respectively connected to the second port through metal interconnection lines. The second conductive type heavily doped region of the first electrostatic discharge module is arranged close to the first conductive type heavily doped region of the second electrostatic discharge module, and the first conductive type heavily doped region of the third electrostatic discharge module is arranged close to the second conductive type heavily doped region of the second electrostatic discharge module. The first conductive type heavily doped region of the second electrostatic discharge module and the second conductive type heavily doped region of the first electrostatic discharge module can construct a first direction conduction path for electrostatic discharge, and the first conductive type heavily doped region of the third electrostatic discharge module and the second conductive type heavily doped region of the second electrostatic discharge module can construct a second direction conduction path opposite to the first direction, and the length and conduction path of the first direction conduction path and the second direction conduction path are consistent.

2. The fast-opening bidirectional symmetrical electrostatic protection device according to claim 1, characterized in that: The number of the bidirectional SCR structural units is more than 2, and all the bidirectional SCR structural units are arranged in parallel on the first conductive type substrate. When the adjacent electrostatic discharge modules of two SCR structural units are connected to the first port through metal interconnections, the two electrostatic discharge modules are simplified into one setting, and the two adjacent SCR structural units can share the electrostatic discharge module.

3. The fast-opening bidirectional symmetrical electrostatic protection device according to claim 1 or 2, characterized in that: A second conductive type large well region is provided on the first conductive type substrate, and all bidirectional SCR structural units are arranged in parallel on the surface of the second conductive type large well region.

4. The fast-opening bidirectional symmetrical electrostatic protection device according to claim 3, characterized in that: The first electrostatic discharge module, the second electrostatic discharge module and the third electrostatic discharge module have the same structure and are isolated by a shallow trench isolation structure. The first conductive type heavily doped region and the second conductive type heavily doped region of the first electrostatic discharge module are contacted and arranged in parallel. The first electrostatic discharge module also includes a first conductive type ESD protection layer arranged on the lower surface of the first conductive type heavily doped region and the second conductive type heavily doped region.

5. The fast-opening bidirectional symmetrical electrostatic protection device according to claim 4, characterized in that: The second conductive type large well region and the first conductive type ESD protection layer are replaced by a P-Base and N-Base process hierarchy structure with the same doping type.

6. The fast-opening bidirectional symmetrical electrostatic protection device according to claim 3, characterized in that: The first electrostatic discharge module, the second electrostatic discharge module and the third electrostatic discharge module have the same structure and are isolated by a shallow trench isolation structure. The first conductive type heavily doped region and the second conductive type heavily doped region of the first electrostatic discharge module are arranged in parallel on the upper surface of the second conductive type large well region, and the first conductive type heavily doped region and the second conductive type heavily doped region are isolated by a shallow trench isolation structure. The first electrostatic discharge module also includes a first conductive type ESD protection layer arranged on the lower surface of the second conductive type heavily doped region.

7. The fast-opening bidirectional symmetrical electrostatic protection device according to claim 1 or 2, characterized in that: A second conductive type deep well region is provided on the first conductive type substrate, all bidirectional SCR structural units are arranged in parallel in the second conductive type deep well region, the electrostatic discharge module includes a first conductive type well region arranged in the second conductive type deep well region, and the first conductive type heavily doped region and the second conductive type heavily doped region are arranged non-contactly on the surface of the first conductive type well region.

8. The fast-opening bidirectional symmetrical electrostatic protection device according to claim 1 or 2, characterized in that: The electrostatic discharge module includes a second conductive type well region disposed on a first conductive type substrate, and the first conductive type heavily doped region and the second conductive type heavily doped region are disposed on a surface of the second conductive type well region without contact.

9. The fast-opening bidirectional symmetrical electrostatic protection device according to claim 1 or 2, characterized in that: It also includes an auxiliary trigger module, the output end of which is connected to the control end of the bidirectional SCR structure unit.

10. The fast-opening bidirectional symmetrical electrostatic protection device according to claim 1 or 2, characterized in that: It also includes a flow diversion module arranged on the first port and / or the second port.

Images