A bidirectional thyristor structure
By integrating back-to-back PNP transistors in a thyristor structure, the problem of difficulty in dealing with common mode current shock in the prior art is solved, and efficient ESD energy absorption and latchup protection are achieved.
Patent Information
- Application Number
- CN202510004001.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-02
- Publication Date
- 2025-04-08
AI Technical Summary
The existing thyristor structure is difficult to effectively deal with common mode current impact, resulting in possible latch effect and high current self-sustaining state, affecting the reliability of the chip.
A bidirectional structure is designed to highly integrate two back-to-back PNP transistors based on the traditional bidirectional SCR structure, and absorb ESD pulse energy using the high opening speed of the PNP transistor, and clamp the voltage through the SCR structure to prevent the occurrence of latchup.
The opening speed of the ESD device can effectively absorb the remaining ESD energy, prevent the occurrence of latchup, and when facing common mode current impact, it can absorb the high voltage peak first to protect the SCR structure.
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Figure CN119789536A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of semiconductor technology, and in particular to a bidirectional thyristor structure. Background Art
[0002] Electrostatic discharge (ESD) is currently one of the main causes of integrated circuit (IC) failure, especially in the field of high-voltage integrated circuits. With the rapid development of power semiconductor technology, high-voltage integrated circuits have become an important part of the IC industry and are widely used in power management, automotive electronics and other fields with extremely high reliability requirements. However, such circuits usually work in a relatively harsh high-voltage environment, which puts forward more stringent design requirements for the performance of ESD protection devices.
[0003] In the prior art, ESD protection devices not only need to be able to withstand high voltage and high current impacts, but also must have a high maintenance voltage to fundamentally eliminate the latch-up effect and prevent the chip from failing due to the triggering of parasitic structures and entering a high current self-sustaining state. In addition, the chip also needs to deal with the problems that may be caused by common mode current impact (CMC). CMC is usually caused by external transient interference (such as lightning strikes, power supply noise, static electricity, etc.), which will generate high transient currents through power pins or I / O interfaces, triggering internal parasitic components and causing latch-up effects.
[0004] Based on this, a thyristor structure with high holding voltage and common mode current resistance is needed. Summary of the invention
[0005] In view of this, an embodiment of the present invention provides a bidirectional thyristor structure to at least solve the problem that the existing bidirectional thyristor structure is difficult to handle the common mode current.
[0006] The embodiment of the present invention provides the following technical solutions:
[0007] An embodiment of the present invention provides a bidirectional thyristor structure, comprising a P-type epitaxial layer, wherein the middle portion of the P-type epitaxial layer is separated by a first N-type well-doped type well region and a first N-type deep well-doped type well region to form a first epitaxial layer region and a second epitaxial layer region, a first P-type high-voltage doped type well region is formed in a first injection region on the first epitaxial layer region, a first P-type well-doped type well region is provided in an injection structure on the first P-type high-voltage doped type well region, and a first P-type heavily doped active region and a first N-type heavily doped active region are provided at the top of the first P-type well-doped type well region;
[0008] A second P-type high-voltage doped type well region is formed in the second injection region on the second epitaxial layer region, a second P-type well-doped type well region is provided in the injection structure on the second P-type high-voltage doped type well region, and a second P-type heavily doped active region and a second N-type heavily doped active region are provided on the top of the second P-type well-doped type well region.
[0009] Further, a third P-type high-voltage doping type well region is formed in the third injection region on the first epitaxial layer region, the third injection region is located on a side of the first injection region away from the second injection region, a third P-type well-doping type well region is formed in the injection structure on the third P-type high-voltage doping type well region, and a third P-type heavily doped active region is formed in the injection structure on the third P-type well-doping type well region;
[0010] A second N-type well-doping type well region is formed in the fourth injection region on the first epitaxial layer region, the fourth injection region is located on a side of the third injection region away from the first injection region, and a fourth P-type heavily doped active region is formed in the injection structure on the second N-type well-doping type well region;
[0011] A fourth P-type high-voltage doping type well region is formed in the fifth injection region on the first epitaxial layer region, the fifth injection region is located on a side of the fourth injection region away from the third injection region, a fourth P-type well-doping type well region is formed in the injection structure on the fourth P-type high-voltage doping type well region, and a fifth P-type heavily doped active region is formed in the injection structure on the second P-type well-doping type well region;
[0012] A second N-type deep well-doping type well region is formed in the sixth implantation region on the first epitaxial layer region, a third N-type well-doping type well region is formed in the implantation region on the second N-type deep well-doping type well region, and a third N-type heavily doped active region is provided on the top of the third N-type well-doping type well region;
[0013] A fifth P-type high-voltage doping type well region is formed in the seventh injection region on the second epitaxial layer region, the seventh injection region is located on a side of the second injection region away from the first injection region, a fifth P-type well-doping type well region is formed in the injection structure on the fifth P-type high-voltage doping type well region, and a sixth P-type heavily doped active region is formed in the injection structure on the fifth P-type well-doping type well region;
[0014] A fourth N-type well-doped well region is formed in the eighth implantation region on the second epitaxial layer region, the eighth implantation region is located on a side of the seventh implantation region away from the second implantation region, and a seventh P-type heavily doped active region is formed in the implantation structure on the fourth N-type well-doped well region;
[0015] A sixth P-type high-voltage doping type well region is formed in the ninth implantation region on the second epitaxial layer region, the fifth implantation region is located on a side of the fourth implantation region away from the third implantation region, a sixth P-type well doping type well region is formed in the implantation structure on the sixth P-type high-voltage doping type well region, and an eighth P-type heavily doped active region is formed in the implantation structure on the sixth P-type well doping type well region;
[0016] A third N-type deep well doping type well region is formed in the tenth implantation region on the second epitaxial layer region, a fifth N-type well doping type well region is formed in the implantation region on the third N-type deep well doping type well region, and a fourth N-type heavily doped active region is provided on the top of the fifth N-type well doping type well region;
[0017] The third N-type heavily doped active region, the fourth P-type heavily doped active region, the seventh P-type heavily doped active region and the fourth N-type heavily doped active region are connected to each other through metal wires.
[0018] Furthermore, it also includes a plurality of SAB silicide barrier layers, which are respectively arranged at the top of the first epitaxial layer region and the second epitaxial layer region, and are respectively located between the fifth P-type heavily doped active region and the fourth P-type heavily doped active region, between the fourth P-type heavily doped active region and the third P-type heavily doped active region, between the sixth P-type heavily doped active region and the seventh P-type heavily doped active region, and between the seventh P-type heavily doped active region and the eighth P-type heavily doped active region.
[0019] Furthermore, it also includes a deep N-type heavily doped well region, which is arranged at the bottom of the P-type epitaxial layer region, the third N-type deep well doping type well region, the third N-type deep well doping type well region, and the first N-type deep well doping type well region.
[0020] Furthermore, the third N-type heavily doped active region and the fifth P-type heavily doped active region, the third P-type heavily doped active region and the first P-type heavily doped active region, the first P-type heavily doped active region and the first N-type heavily doped active region, the first N-type heavily doped active region and the second P-type heavily doped active region, the second P-type heavily doped active region and the second N-type heavily doped active region, the second N-type heavily doped active region and the sixth P-type heavily doped active region, and the eighth P-type heavily doped active region and the fourth N-type heavily doped active region are isolated by shallow trench isolation (STI) regions.
[0021] Further, the first N-type heavily doped active region, the first P-type well doping type well region, the first P-type high voltage doping type well region, the first epitaxial layer region, the N-type well doping type well region, and the N-type deep well doping type well region form a first triode;
[0022] The second N-type heavily doped active region, the second P-type well doping type well region, the second P-type high voltage doping type well region, the second epitaxial layer region, the N-type well doping type well region, and the N-type deep well doping type well region form a second triode;
[0023] The first P-type heavily doped active region, the first P-type well doping type well region, the first P-type high voltage doping type well region, the first epitaxial layer region, the N-type well doping type well region, the N-type deep well doping type well region, the second epitaxial layer region, the second P-type high voltage doping type well region, the second P-type well doping type well region, and the second P-type heavily doped active region form a third triode;
[0024] The fourth P-type heavily doped active region, the second N-type well doping type well region, the third N-type well doping type well region, the third N-type heavily doped active region, the fifth P-type heavily doped active region, the fourth P-type well doping type well region, the fourth P-type high voltage doping type well region, the third P-type heavily doped active region, the third P-type well doping type well region, and the third P-type high voltage doping type well region form a fourth transistor Q4;
[0025] The seventh P-type heavily doped active area, the fourth N-type well doping type well area, the fifth N-type well doping type well area, the fourth N-type heavily doped active area, the sixth P-type heavily doped active area, the fifth P-type well doping type well area, the fifth P-type high-voltage doping type well area, the eighth P-type heavily doped active area, the sixth P-type well doping type well area, and the sixth P-type high-voltage doping type well area form a fifth triode;
[0026] Among them, the first transistor and the second transistor are NPN transistors, the third transistor is a bidirectional PNP transistor, and the fourth transistor Q4 and the fifth transistor are both PNP transistors.
[0027] Further, the emitter of the first triode is connected to the port T1, the emitter of the second triode is connected to the port T2, the collectors of the first triode and the second triode are connected and then connected to the base of the third triode, the two emitters of the third triode are respectively connected to the base of the first triode and the base of the second triode, the base of the first triode is connected to the port T1 through a first resistor, and the base of the second triode is connected to the port T2 through a second resistor;
[0028] The base of the fourth transistor Q4 is connected to the emitter of the fourth transistor Q4 through the third resistor, the collector of the fourth transistor Q4 is connected to the port T1, the emitter of the fourth transistor Q4 is connected to the emitter of the fifth transistor, the base of the fifth transistor is connected to the emitter of the fifth transistor through the fourth resistor, and the collector of the fifth transistor is connected to the port T2.
[0029] Further, the port T1 is respectively connected to the fifth P-type heavily doped active area, the third P-type heavily doped active area, the first P-type heavily doped active area, and the first N-type heavily doped active area, and the port T2 is respectively connected to the eighth P-type heavily doped active area, the sixth P-type heavily doped active area, the second P-type heavily doped active area, and the second N-type heavily doped active area.
[0030] Compared with the prior art, the at least one technical solution adopted in the embodiment of the present invention can achieve the following beneficial effects:
[0031] A bidirectional thyristor structure of the present invention can meet the design requirements of high maintenance voltage in actual ESD protection, and has extremely high current discharge efficiency, and through the highly integrated structure of two back-to-back PNP transistors based on the structure of traditional bidirectional SCR (thyristor), when ESD pulse, especially IEC pulse, is applied, PNP can be turned on first due to its extremely high turn-on speed, and absorb a certain amount of pulse energy, and as the voltage continues to increase, the SCR structure is turned on, and hysteresis occurs at this time, the voltage is clamped, PNP is turned off, and SCR absorbs the remaining energy of ESD. Thereby improving the turn-on speed of the entire ESD device; in addition, when the energy of CMC comes at this time, PNP will absorb its high voltage peak first, thereby preventing the problem of latchup in the SCR structure. BRIEF DESCRIPTION OF THE DRAWINGS
[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0033] Figure 1 A side cross-sectional view of a bidirectional thyristor structure according to an embodiment of the present invention;
[0034] Figure 2 A partial top view of a bidirectional thyristor structure according to an embodiment of the present invention;
[0035] Figure 3 A circuit diagram of a bidirectional thyristor structure according to an embodiment of the present invention;
[0036] Figure 4 This is a simulation diagram of a bidirectional thyristor structure according to an embodiment of the present invention.
[0037] The accompanying drawings of the present invention are as follows:
[0038] 100, substrate structure; 101, second N-type deep well doping type well region; 102, third N-type well doping type well region; 103, third N-type heavily doped active region; 104, fifth P-type heavily doped active region; 105, fourth P-type well doping type well region; 106, fourth P-type high voltage doping type well region; 107, fourth P-type heavily doped active region; 108, second N-type well doping type well region; 109, third P-type heavily doped active region; 110, third P-type well doping type well region; 111, third P-type high voltage doping type well region; 112, first P-type heavily doped active region; 113, first N-type heavily doped active region; 114, first P-type well doping type well region; 115, first P-type high voltage doping type well region; 116, first epitaxial layer region;
[0039] 201, third N-type deep well doping type well region; 202, fifth N-type well doping type well region; 203, fourth N-type heavily doped active region; 204, eighth P-type heavily doped active region; 205, sixth P-type well doping type well region; 206, sixth P-type high voltage doping type well region; 207, seventh P-type heavily doped active region; 208, fourth N-type well doping type well region; 209, sixth P-type heavily doped active region; 210, fifth P-type well doping type well region; 211, fifth P-type high voltage doping type well region; 212, second P-type heavily doped active region; 213, second N-type heavily doped active region; 214, second P-type well doping type well region; 215, second P-type high voltage doping type well region; 216, second epitaxial layer region;
[0040] 301, deep N-type heavily doped well region; 302, shallow trench isolation STI region; 303, N-type well doping type well region; 304, N-type deep well doping type well region;
[0041] 400. SAB silicide barrier layer. DETAILED DESCRIPTION
[0042] The embodiments of the present application are described in detail below with reference to the accompanying drawings.
[0043] The following describes the implementation methods of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present application.
[0044] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on the present application, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspect described herein can be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this device and / or practice this method.
[0045] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application. The drawings only show components related to the present application rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.
[0046] Additionally, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, it will be understood by those skilled in the art that the examples can be practiced without these specific details.
[0047] In high-voltage applications, it is often necessary to resist pulses generated by CMC common-mode inductors. When an ESD pulse is applied to the chip, the ESD device unit is turned on. At this time, if there is a CMC common-mode inductor, when the ESD pulse ends, the ESD device remains in the turned-on state, which can easily cause a latch-up phenomenon.
[0048] Based on this, the present application provides a bidirectional thyristor structure. The technical solutions provided by the embodiments of the present application are described below in conjunction with the accompanying drawings.
[0049] The bidirectional thyristor structure of the present invention can be used in a BCD process based on common sizes, such as 130nm and 180nm BCD process sizes.
[0050] Specifically, it includes a P-type epitaxial layer, the middle part of the P-type epitaxial layer is separated by a first N-type well-doped type well region 303 and a first N-type deep well-doped type well region 304 to form a first epitaxial layer region 116 and a second epitaxial layer region 216, a first P-type high-voltage doped type well region 115 is formed in a first injection region on the first epitaxial layer region 116, a first P-type well-doped type well region 114 is provided in an injection structure on the first P-type high-voltage doped type well region 115, and a first P-type heavily doped active region 112 and a first N-type heavily doped active region 113 are provided at the top of the first P-type well-doped type well region 114; a second P-type high-voltage doped type well region 215 is formed in a second injection region on the second epitaxial layer region 216, a second P-type well-doped type well region 214 is provided in an injection structure on the second P-type high-voltage doped type well region 215, and a second P-type heavily doped active region 212 and a second N-type heavily doped active region 213 are provided at the top of the second P-type well-doped type well region 214.
[0051] The P-type epitaxial layer is formed on the P-type substrate structure 100 .
[0052] The methods for forming each level structure in the present application include but are not limited to deposition, etching and other process flows.
[0053] Among them, the first N-type well-doping type well region 303 and the first N-type deep well-doping type well region 304 are a stacked structure, the first N-type well-doping type well region 303 is located at the top of the first N-type deep well-doping type well region 304, and the first N-type well-doping type well region 303 and the first N-type deep well-doping type well region 304 both have a certain length.
[0054] Among them, the first P-type high voltage doping type well region 115, the first P-type well doping type well region 114, the second P-type high voltage doping type well region 215 and the first P-type well doping type well region 114 all have a certain length.
[0055] The implantation region is a specific region in the single crystal silicon structure where N-type or P-type ions are implanted under a high energy electric field. The N-type or P-type ions are mainly implanted by ion doping implantation.
[0056] Further, a third P-type high-voltage doped type well region 111 is formed in the third injection region on the first epitaxial layer region 116, the third injection region is located on the side of the first injection region away from the second injection region, a third P-type well doped type well region 110 is formed in the injection structure on the third P-type high-voltage doped type well region 111, and a third P-type heavily doped active region 109 is formed in the injection structure on the third P-type well doped type well region 110; a second N-type well doped type well region 108 is formed in the fourth injection region on the first epitaxial layer region 116, the fourth injection region is located on the side of the third injection region away from the first injection region, and a fourth P-type heavily doped active region 107 is formed in the injection structure on the second N-type well doped type well region 108; the first epitaxial layer region A fourth P-type high-voltage doping type well region 106 is formed in the fifth injection region on the domain 116, the fifth injection region is located on the side of the fourth injection region away from the third injection region, a fourth P-type well doping type well region 105 is formed in the injection structure on the fourth P-type high-voltage doping type well region 106, and a fifth P-type heavily doped active region 104 is formed in the injection structure on the fourth P-type well doping type well region 105; a second N-type deep well doping type well region 101 is formed in the sixth injection region on the first epitaxial layer region 116, a third N-type well doping type well region 102 is formed in the injection region on the second N-type deep well doping type well region 101, and a third N-type heavily doped active region 103 is provided at the top of the third N-type well doping type well region 102;
[0057] The third injection region, the fourth injection region, the fifth injection region and the sixth injection region all have a certain length and are arranged in parallel and at intervals, so that the structure formed therein also has a certain length dimension.
[0058] Further, a fifth P-type high-voltage doping type well region 211 is formed in the seventh injection region on the second epitaxial layer region 216, the seventh injection region is located on the side of the second injection region away from the first injection region, a fifth P-type well-doping type well region 210 is formed in the injection structure on the fifth P-type high-voltage doping type well region 211, and a sixth P-type heavily doped active region 209 is formed in the injection structure on the fifth P-type well-doping type well region 210; a fourth N-type well-doping type well region 208 is formed in the eighth injection region on the second epitaxial layer region 216, the eighth injection region is located on the side of the seventh injection region away from the second injection region, and a seventh P-type heavily doped active region 207 is formed in the injection structure on the fourth N-type well-doping type well region 208; the second epitaxial layer region A sixth P-type high-voltage doping type well region 206 is formed in the ninth injection region on the domain 216, the fifth injection region is located on the side of the fourth injection region away from the third injection region, a sixth P-type well-doping type well region 205 is formed in the injection structure on the sixth P-type high-voltage doping type well region 206, and an eighth P-type heavily doped active region 204 is formed in the injection structure on the sixth P-type well-doping type well region 205; a third N-type deep well-doping type well region 201 is formed in the tenth injection region on the second epitaxial layer region 216, a fifth N-type well-doping type well region 202 is formed in the injection region on the third N-type deep well-doping type well region 201, and a fourth N-type heavily doped active region 203 is provided at the top of the fifth N-type well-doping type well region 202.
[0059] Among them, the seventh injection region, the eighth injection region, the ninth injection region and the tenth injection region all have a certain length and are arranged in parallel and at intervals, so that the structures formed therein also have a certain length dimension.
[0060] The third N-type heavily doped active region 103 , the fourth P-type heavily doped active region 107 , the seventh P-type heavily doped active region 207 and the fourth N-type heavily doped active region 203 are interconnected by metal wires.
[0061] Furthermore, the bidirectional thyristor structure also includes a plurality of SAB silicide barrier layers 400, which are respectively arranged at the top of the first epitaxial layer region 116 and the second epitaxial layer region 216, and are respectively located between the fifth P-type heavily doped active region 104 and the fourth P-type heavily doped active region 107, between the fourth P-type heavily doped active region 107 and the third P-type heavily doped active region 109, between the sixth P-type heavily doped active region 209 and the seventh P-type heavily doped active region 207, and between the seventh P-type heavily doped active region 207 and the eighth P-type heavily doped active region 204.
[0062] Furthermore, the bidirectional thyristor structure also includes a deep N-type heavily doped well region 301, which is arranged at the bottom of the P-type epitaxial layer region, the third N-type deep well doping type well region 201, the third N-type deep well doping type well region 201, and the first N-type deep well doping type well region 304.
[0063] Furthermore, the third N-type heavily doped active region 103 and the fifth P-type heavily doped active region 104, the third P-type heavily doped active region 109 and the first P-type heavily doped active region 112, the first P-type heavily doped active region 112 and the first N-type heavily doped active region 113, the first N-type heavily doped active region 113 and the second P-type heavily doped active region 212, the second P-type heavily doped active region 212 and the second N-type heavily doped active region 213, the second N-type heavily doped active region 213 and the sixth P-type heavily doped active region 209, and the eighth P-type heavily doped active region 204 and the fourth N-type heavily doped active region 203 are isolated by shallow trench isolation STI regions 302.
[0064] The shallow trench isolation STI region 302 between the third N-type heavily doped active region 103 and the fifth P-type heavily doped active region 104 extends downward to the top of the third N-type well-doping type well region 102 and the fourth P-type well-doping type well region 105 .
[0065] Among them, the shallow trench isolation STI region 302 between the third P-type heavily doped active area 109 and the first P-type heavily doped active area 112 extends downward to the top of the third P-type well-doped type well area 110 and the first P-type well-doped type well area 114; the shallow trench isolation STI region 302 between the first P-type heavily doped active area 112 and the first N-type heavily doped active area 113 extends downward to the inside of the top of the embedded first P-type well-doped type well area 114.
[0066] Among them, the shallow trench isolation STI region 302 between the second P-type heavily doped active area 212 and the second N-type heavily doped active area 213 extends downward to the top of the second P-type well-doped type well region 214 embedded in it; the shallow trench isolation STI region 302 between the second N-type heavily doped active area 213 and the sixth P-type heavily doped active area 209 extends downward to the top of the fifth P-type well-doped type well region 210 and the second P-type well-doped type well region 214; the shallow trench isolation STI region 302 between the eighth P-type heavily doped active area 204 and the fourth N-type heavily doped active area 203 extends downward to the top of the fifth N-type well-doped type well region 202 and the sixth P-type well-doped type well region 205.
[0067] The shallow trench isolation (STI) region 302 is used to isolate the structures on both sides of the region from being connected to each other.
[0068] Further, the first N-type heavily doped active region 113, the first P-type well doping type well region 114, the first P-type high voltage doping type well region 115, the first epitaxial layer region 116, the N-type well doping type well region 303, and the N-type deep well doping type well region 304 form a first transistor Q1; the second N-type heavily doped active region 213, the second P-type well doping type well region 214, the second P-type high voltage doping type well region 215, the second epitaxial layer region 216, the N-type well doping type well region 303, and the N-type deep well doping type well region 304 form a second transistor Q2; the first P-type heavily doped active region 112, the first P-type well doping type well region 114, the first P-type high voltage doping type well region 115, the first epitaxial layer region 116, the N-type The well-doped type well region 303, the N-type deep well-doped type well region 304, the second epitaxial layer region 216, the second P-type high-voltage doped type well region 215, the second P-type well-doped type well region 214, and the second P-type heavily doped active region 212 form a third transistor Q3; the fourth P-type heavily doped active region 107, the second N-type well-doped type well region 108, the third N-type well-doped type well region 102, the third N-type heavily doped active region 103, the fifth P-type heavily doped active region 104, the fourth P-type well-doped type well region 105, the fourth P-type high-voltage doped type well region 106, the third P-type heavily doped active region 109, the third P-type well-doped type well region 110, and the third P-type high-voltage doped type well region 111 form a fourth transistor Q4;
[0069] The seventh P-type heavily doped active region 207, the fourth N-type well doping type well region 208, the fifth N-type well doping type well region 202, the fourth N-type heavily doped active region 203, the sixth P-type heavily doped active region 209, the fifth P-type well doping type well region 210, the fifth P-type high-voltage doping type well region 211, the eighth P-type heavily doped active region 204, the sixth P-type well doping type well region 205, and the sixth P-type high-voltage doping type well region 206 form the fifth transistor Q5.
[0070] The first transistor Q1 and the second transistor Q2 are NPN transistors, the third transistor Q3 is a bidirectional PNP transistor, and the fourth transistor Q4 and the fifth transistor Q5 are both PNP transistors.
[0071] Among them, the emitter of the fourth transistor Q4 includes a fourth P-type heavily doped active area 107, the base includes a second N-type well-doped type well area 108, a third N-type well-doped type well area 102, and a third N-type heavily doped active area 103, the collector includes a fifth P-type heavily doped active area 104, a fourth P-type well-doped type well area 105, a fourth P-type high-voltage doped type well area 106 and a third P-type heavily doped active area 109, a third P-type well-doped type well area 110, and a third P-type high-voltage doped type well area 111.
[0072] Among them, it can be seen from the top view that the second N-type well-doped type well region 108 and the third N-type well-doped type well region 102 are an integral N injection. When the ESD forward pulse enters from port T1, it is equivalent to a PN junction and is turned on by path 1. For the fourth transistor Q4, its repeating structure includes a third P-type heavily doped active region 109, a third P-type well-doped type well region 110, a third P-type high-voltage doped type well region 111, a fourth P-type heavily doped active region 107 and a second N-type well-doped type well region 108.
[0073] Similarly, the fifth transistor Q5 and the fourth transistor Q4 are symmetrical structures, and their structural composition is the same as that of the fourth transistor Q4. When a forward pulse enters from the port T1, since the fourth transistor Q4 is a PN junction at this time, a high voltage is generated at the third N-type heavily doped active area 103. Along the wire, the seventh P-type heavily doped active area 207 and the fourth N-type heavily doped active area 203 are high voltage. At this time, the fifth transistor Q5 is turned on under the ESD pulse.
[0074] Further, the emitter of the first triode Q1 is connected to the port T1, the emitter of the second triode Q2 is connected to the port T2, the collectors of the first triode Q1 and the second triode Q2 are connected and then connected to the base of the third triode Q3, the two emitters of the third triode Q3 are respectively connected to the base of the first triode Q1 and the base of the second triode Q2, the base of the first triode Q1 is connected to the port T1 through the first resistor R1, and the base of the second triode Q2 is connected to the port T2 through the second resistor R2;
[0075] The base of the fourth triode Q4 is connected to the emitter of the fourth triode Q4 through the third resistor R3, the collector of the fourth triode Q4 is connected to the port T1, the emitter of the fourth triode Q4 is connected to the emitter of the fifth triode Q5, the base of the fifth triode Q5 is connected to the emitter of the fifth triode Q5 through the fourth resistor R4, and the collector of the fifth triode Q5 is connected to the port T2.
[0076] Further, port T1 is respectively connected to the fifth P-type heavily doped active region 104, the third P-type heavily doped active region 109, the first P-type heavily doped active region 112, and the first N-type heavily doped active region 113, and port T2 is respectively connected to the eighth P-type heavily doped active region 204, the sixth P-type heavily doped active region 209, the second P-type heavily doped active region 212, and the second N-type heavily doped active region 213.
[0077] The working principle of the present invention is as follows:
[0078] When a forward ESD pulse enters from the left end port T1, the PN junction first epitaxial layer region 116 and the third N-type well-doped type well region 102 of the fourth transistor Q4 on its left side are first turned on. Since the third N-type heavily doped active region 103, the fourth N-type heavily doped active region 203, and the seventh P-type heavily doped active region 207 are connected by metal wires, the fourth N-type heavily doped active region 203 and the seventh P-type heavily doped active region 207 also generate a high potential. At this time, a PNP structure (fifth transistor Q5) is formed by the seventh P-type heavily doped active region 207, the fourth N-type heavily doped active region 203 to the sixth P-type heavily doped active region 209 and the eighth P-type heavily doped active region 204, and is turned on under the ESD pulse.
[0079] As the ESD pulse voltage increases, its forward voltage is applied to the first P-type heavily doped active region 112 and the first N-type heavily doped active region 113, causing the SCR structure from the first P-type heavily doped active region 112, the first N-type heavily doped active region 113 to the second N-type heavily doped active region 213, and the second P-type heavily doped active region 212 to turn on (the first transistor Q1, the second transistor Q2, and the third transistor Q3), and generate hysteresis, at which time the PNP structure is turned off.
[0080] In this specification, the same or similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the product embodiment described later, since it corresponds to the method, the description is relatively simple, and the relevant parts can be referred to the partial description of the system embodiment.
[0081] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.
Claims
1. A bidirectional thyristor structure, characterized in that: A P-type epitaxial layer is included, wherein the middle portion of the P-type epitaxial layer is separated by a first N-type well-doped type well region and a first N-type deep well-doped type well region to form a first epitaxial layer region and a second epitaxial layer region, a first P-type high-voltage doped type well region is formed in a first injection region on the first epitaxial layer region, a first P-type well-doped type well region is provided in an injection structure on the first P-type high-voltage doped type well region, and a first P-type heavily doped active region and a first N-type heavily doped active region are provided at the top of the first P-type well-doped type well region; A second P-type high-voltage doped type well region is formed in the second injection region on the second epitaxial layer region, a second P-type well-doped type well region is provided in the injection structure on the second P-type high-voltage doped type well region, and a second P-type heavily doped active region and a second N-type heavily doped active region are provided on the top of the second P-type well-doped type well region.
2. The bidirectional thyristor structure according to claim 1, characterized in that: A third P-type high-voltage doping type well region is formed in the third injection region on the first epitaxial layer region, the third injection region is located on a side of the first injection region away from the second injection region, a third P-type well-doping type well region is formed in the injection structure on the third P-type high-voltage doping type well region, and a third P-type heavily doped active region is formed in the injection structure on the third P-type well-doping type well region; A second N-type well-doping type well region is formed in the fourth injection region on the first epitaxial layer region, the fourth injection region is located on a side of the third injection region away from the first injection region, and a fourth P-type heavily doped active region is formed in the injection structure on the second N-type well-doping type well region; A fourth P-type high-voltage doping type well region is formed in the fifth injection region on the first epitaxial layer region, the fifth injection region is located on a side of the fourth injection region away from the third injection region, a fourth P-type well-doping type well region is formed in the injection structure on the fourth P-type high-voltage doping type well region, and a fifth P-type heavily doped active region is formed in the injection structure on the second P-type well-doping type well region; A second N-type deep well-doping type well region is formed in the sixth implantation region on the first epitaxial layer region, a third N-type well-doping type well region is formed in the implantation region on the second N-type deep well-doping type well region, and a third N-type heavily doped active region is provided on the top of the third N-type well-doping type well region; A fifth P-type high-voltage doping type well region is formed in the seventh injection region on the second epitaxial layer region, the seventh injection region is located on a side of the second injection region away from the first injection region, a fifth P-type well-doping type well region is formed in the injection structure on the fifth P-type high-voltage doping type well region, and a sixth P-type heavily doped active region is formed in the injection structure on the fifth P-type well-doping type well region; A fourth N-type well-doped well region is formed in the eighth implantation region on the second epitaxial layer region, the eighth implantation region is located on a side of the seventh implantation region away from the second implantation region, and a seventh P-type heavily doped active region is formed in the implantation structure on the fourth N-type well-doped well region; A sixth P-type high-voltage doping type well region is formed in the ninth implantation region on the second epitaxial layer region, the fifth implantation region is located on a side of the fourth implantation region away from the third implantation region, a sixth P-type well doping type well region is formed in the implantation structure on the sixth P-type high-voltage doping type well region, and an eighth P-type heavily doped active region is formed in the implantation structure on the sixth P-type well doping type well region; A third N-type deep well doping type well region is formed in the tenth implantation region on the second epitaxial layer region, a fifth N-type well doping type well region is formed in the implantation region on the third N-type deep well doping type well region, and a fourth N-type heavily doped active region is provided on the top of the fifth N-type well doping type well region; The third N-type heavily doped active region, the fourth P-type heavily doped active region, the seventh P-type heavily doped active region and the fourth N-type heavily doped active region are connected to each other through metal wires.
3. The bidirectional thyristor structure according to claim 2, characterized in that: It also includes multiple SAB silicide blocking layers, which are respectively arranged at the top of the first epitaxial layer region and the second epitaxial layer region, and are respectively located between the fifth P-type heavily doped active region and the fourth P-type heavily doped active region, between the fourth P-type heavily doped active region and the third P-type heavily doped active region, between the sixth P-type heavily doped active region and the seventh P-type heavily doped active region, and between the seventh P-type heavily doped active region and the eighth P-type heavily doped active region.
4. The bidirectional thyristor structure according to claim 3, characterized in that: It also includes a deep N-type heavily doped well region, which is arranged at the bottom of the P-type epitaxial layer region, the third N-type deep well doping type well region, the third N-type deep well doping type well region, and the first N-type deep well doping type well region.
5. The bidirectional thyristor structure according to claim 4, characterized in that: The third N-type heavily doped active region and the fifth P-type heavily doped active region, the third P-type heavily doped active region and the first P-type heavily doped active region, the first P-type heavily doped active region and the first N-type heavily doped active region, the first N-type heavily doped active region and the second P-type heavily doped active region, the second P-type heavily doped active region and the second N-type heavily doped active region, the second N-type heavily doped active region and the sixth P-type heavily doped active region, and the eighth P-type heavily doped active region and the fourth N-type heavily doped active region are isolated by shallow trench isolation (STI) regions.
6. The bidirectional thyristor structure according to any one of claims 2 to 5, characterized in that: The first N-type heavily doped active region, the first P-type well doping type well region, the first P-type high voltage doping type well region, the first epitaxial layer region, the N-type well doping type well region, and the N-type deep well doping type well region form a first triode; The second N-type heavily doped active region, the second P-type well doping type well region, the second P-type high voltage doping type well region, the second epitaxial layer region, the N-type well doping type well region, and the N-type deep well doping type well region form a second triode; The first P-type heavily doped active region, the first P-type well doping type well region, the first P-type high voltage doping type well region, the first epitaxial layer region, the N-type well doping type well region, the N-type deep well doping type well region, the second epitaxial layer region, the second P-type high voltage doping type well region, the second P-type well doping type well region, and the second P-type heavily doped active region form a third triode; The fourth P-type heavily doped active region, the second N-type well doping type well region, the third N-type well doping type well region, the third N-type heavily doped active region, the fifth P-type heavily doped active region, the fourth P-type well doping type well region, the fourth P-type high voltage doping type well region, the third P-type heavily doped active region, the third P-type well doping type well region, and the third P-type high voltage doping type well region form a fourth transistor Q4; The seventh P-type heavily doped active area, the fourth N-type well doping type well area, the fifth N-type well doping type well area, the fourth N-type heavily doped active area, the sixth P-type heavily doped active area, the fifth P-type well doping type well area, the fifth P-type high-voltage doping type well area, the eighth P-type heavily doped active area, the sixth P-type well doping type well area, and the sixth P-type high-voltage doping type well area form a fifth triode; Among them, the first transistor and the second transistor are NPN transistors, the third transistor is a bidirectional PNP transistor, and the fourth transistor Q4 and the fifth transistor are both PNP transistors.
7. The bidirectional thyristor structure according to claim 6, characterized in that: The emitter of the first triode is connected to the port T1, the emitter of the second triode is connected to the port T2, the collectors of the first triode and the second triode are connected and then connected to the base of the third triode, the two emitters of the third triode are respectively connected to the base of the first triode and the base of the second triode, the base of the first triode is connected to the port T1 through a first resistor, and the base of the second triode is connected to the port T2 through a second resistor; The base of the fourth transistor Q4 is connected to the emitter of the fourth transistor Q4 through the third resistor, the collector of the fourth transistor Q4 is connected to the port T1, the emitter of the fourth transistor Q4 is connected to the emitter of the fifth transistor, the base of the fifth transistor is connected to the emitter of the fifth transistor through the fourth resistor, and the collector of the fifth transistor is connected to the port T2.
8. The bidirectional thyristor structure according to claim 7, characterized in that: The port T1 is respectively connected to the fifth P-type heavily doped active area, the third P-type heavily doped active area, the first P-type heavily doped active area, and the first N-type heavily doped active area, and the port T2 is respectively connected to the eighth P-type heavily doped active area, the sixth P-type heavily doped active area, the second P-type heavily doped active area, and the second N-type heavily doped active area.