ESD protection device with SCR structure

Abstract

According to the ESD protection device with the SCR structure provided by the invention, blocky second heavily doped regions (N +) and blocky third heavily doped regions (P +) in a first well region (PW) are arranged in a staggered manner, blocky fifth heavily doped regions (P +) and blocky sixth heavily doped regions (N +) in a second well region (NW) are arranged in a staggered manner, and the SCR structure is formed by coupling PNP and NPN, so that the reliability of the device is improved. A fifth heavily doped region (P +) in the second well region (NW) is an emitter of a PNP, and a second heavily doped region (N +) in the first well region (PW) is an emitter of an NPN, so that the structure reduces the area of the emitter of a bipolar junction transistor (BJT), reduces the transport efficiency of a base region, can effectively reduce the current gain beta of the PNP and NPN transistors, and improves the reliability of the transistor. And finally, the maintaining voltage Vh of the SCR structure in the ESD protection device is improved.

Description

Technical Field

[0001] This application relates to the field of semiconductor manufacturing technology, and specifically to an ESD protection device with an SCR structure. Background Technology

[0002] In human life and manufacturing processes, the accumulation and release of electric charge occur constantly, a phenomenon known as static electricity. The instantaneous release of charge, in particular, is extremely harmful to industrial manufacturing due to its short duration and large instantaneous current, especially in the advanced integrated circuit industry. As integrated circuits advance towards advanced processes, the thickness of their gate oxide layers has been reduced to the nanometer scale, making them highly susceptible to damage during static discharge.

[0003] Conventional ESD (Electrostatic Discharge Protection) devices, such as GGNMOS (Gate-Grounded NMOS) and GDPMOS (Gate-to-Drain PMOS), have inherently low robustness. To achieve higher ESD protection levels, the area of ​​these devices needs to be increased, reducing their economic benefits. While conventional SCR devices offer higher robustness, their holding voltage Vh is relatively low, making them susceptible to latch-up effects and chip damage. Summary of the Invention

[0004] This application provides an ESD protection device with an SCR structure, which can solve the problem that the holding voltage Vh of traditional SCR devices is too low, which can easily induce latch-up effect and cause chip damage.

[0005] This application provides an ESD protection device with an SCR structure, including: Substrate; A first well region, wherein the first well region is located in the substrate; A first shallow trench isolation structure in the form of a ring is located in the substrate and is disposed around the first well region; A second well region in the form of a ring is located in the substrate and is disposed around the first shallow trench isolation structure; A first heavily doped region of a first conductivity type, in the form of a strip, is located in the first well region; Multiple block-shaped second-conductivity type second-doped regions; Multiple block-shaped third doped regions of the first conductivity type, the second doped regions and the third doped regions are arranged alternately, and the alternately arranged second doped regions and the third doped regions are located in the first well regions on both sides of the first doped regions; A fourth doped region of the second conductivity type is ring-shaped, the fourth doped region being located in the second well region and close to the edge of the second well region; The fifth doped region of the first conductivity type is in a blocky form; The sixth doped region of the second conductivity type is in the form of a block, and the fifth and sixth doped regions are arranged alternately, and the alternately arranged fifth and sixth doped regions are located in the second well region between the fourth doped region and the first shallow trench isolation structure; The first, second, and third heavily doped regions are all connected to a low level; the fourth, fifth, and sixth heavily doped regions are all connected to a high level.

[0006] Optionally, in the ESD protection device with the SCR structure, in the staggered arrangement of the second and third heavily doped regions, there is a certain distance between each pair of adjacent second and third heavily doped regions.

[0007] Optionally, in the ESD protection device with the SCR structure, in the staggered fifth and sixth doped regions, there is a certain distance between each pair of adjacent fifth and sixth doped regions.

[0008] Optionally, in the ESD protection device with the SCR structure, each of the third doped regions is connected to the first doped region; each of the second doped regions is at a certain distance from the first doped region.

[0009] Optionally, in the ESD protection device with the SCR structure, each of the sixth doped regions is connected to the fourth doped region; each of the fifth doped regions is at a certain distance from the fourth doped region.

[0010] Optionally, in the ESD protection device with the SCR structure, the ESD protection device further includes: a second shallow trench isolation structure in the form of a ring, the second shallow trench isolation structure being located in the substrate and disposed around the second well region.

[0011] Optionally, in the ESD protection device with the SCR structure, the ESD protection device further includes: a ring-shaped third well region located in the substrate and disposed around the second shallow trench isolation structure.

[0012] Optionally, in the ESD protection device with the SCR structure, the ESD protection device further includes: a ring-shaped seventh doped region located in the third well region, and the seventh doped region is grounded.

[0013] Optionally, in the ESD protection device with the SCR structure, the conductivity type of the first well region is P-type; and the conductivity type of the second well region is N-type.

[0014] Optionally, in the ESD protection device with the SCR structure, the first conductivity type is P-type; the second conductivity type is N-type.

[0015] The technical solution of this application has at least the following advantages: This application provides an ESD protection device with an SCR structure. In the first well region (PW), the blocky second heavily doped region (N+) and the blocky third heavily doped region (P+) are arranged alternately, and in the second well region (NW), the blocky fifth heavily doped region (P+) and the blocky sixth heavily doped region (N+) are arranged alternately. Since the SCR structure is formed by coupling PNP and NPN, the fifth heavily doped region (P+) in the second well region (NW) is the emitter of the PNP, and the second heavily doped region (N+) in the first well region (PW) is the emitter of the NPN. Therefore, this structure reduces the emitter area of ​​the BJT (bipolar junction transistor), reduces the transport efficiency of the base region, and can effectively reduce the current gain β of the PNP and NPN transistors, ultimately leading to an increase in the sustaining voltage Vh of the SCR structure in the ESD protection device. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a top view schematic diagram of an ESD protection device with an SCR structure according to an embodiment of the present invention; Figure 2 yes Figure 1 A cross-sectional schematic diagram of an ESD protection device with an SCR structure along the AA' tangent line; Figure 3 yes Figure 1 A cross-sectional schematic diagram of an ESD protection device with an SCR structure below the BB' tangent line; Figure 4 This is a schematic diagram of the measured TLP (transmission line pulse) data of an ESD protection device with an SCR structure according to an embodiment of the present invention; The reference numerals in the attached figures are explained as follows: 10-Substrate, 11-Buried layer, 12-Deep well region, 13-Deep base region, 21-First well region, 22-Second well region, 23-Third well region, 31-First heavily doped region, 32-Second heavily doped region, 33-Third heavily doped region, 34-Fourth heavily doped region, 35-Fifth heavily doped region, 36-Sixth heavily doped region, 37-Seventh heavily doped region, 41-First shallow trench isolation structure, 42-Second shallow trench isolation structure, 43-Third shallow trench isolation structure, 44-Fourth shallow trench isolation structure. Detailed Implementation

[0018] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0020] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components; and they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0021] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0022] This application provides an ESD protection device with an SCR structure, referenced... Figures 1-3 , Figure 1 This is a top view schematic diagram of an ESD protection device with an SCR structure according to an embodiment of the present invention. Figure 2 yes Figure 1 A cross-sectional schematic diagram of an ESD protection device with an SCR structure along the AA' tangent line. Figure 3 yes Figure 1 A cross-sectional schematic diagram of an ESD protection device with an SCR structure along the BB' tangent line. The ESD protection device with an SCR structure includes: Substrate 10; A first well region 21 is located in the substrate 10; A first shallow trench isolation structure 41 in the form of a ring is located in the substrate 10 and is disposed around the first well region 21. A second well region 22 is annular in shape, located in the substrate 10 and surrounding the first shallow trench isolation structure 41; A first heavily doped region 31 of the first conductivity type in the form of a strip, the first heavily doped region 31 being located in the first well region 21; Multiple block-shaped second heavily doped regions of the second conductivity type 32; Multiple block-shaped third doped regions 33 of the first conductivity type, the second doped regions 32 and the third doped regions 33 are arranged alternately, and the alternately arranged second doped regions 32 and the third doped regions 33 are located in the first well region 21 on both sides of the first doped region 31. A fourth heavily doped region 34 of the second conductivity type is ring-shaped and is located in the second well region 22 and close to the edge of the second well region 22. The fifth doped region 35 is in the form of a blocky first conductivity type; The sixth doped region 35 of the second conductivity type is in the form of a block. The fifth doped region 35 and the sixth doped region 36 are arranged alternately, and the alternately arranged fifth doped region 35 and the sixth doped region 36 are located in the second well region 22 between the fourth doped region 34 and the first shallow trench isolation structure 41. The first heavily doped region 31, the second heavily doped region 32, and the third heavily doped region 33 are all connected to a low level; the fourth heavily doped region 34, the fifth heavily doped region 35, and the sixth heavily doped region 36 are all connected to a high level.

[0023] In this embodiment, the first well region 21 has a P-type conductivity and the second well region 22 has an N-type conductivity.

[0024] Furthermore, the first conductivity type is P-type; the second conductivity type is N-type.

[0025] Preferably, the top layer of the substrate 10 can be an epitaxial layer.

[0026] Preferably, the ESD protection device further includes: a second shallow trench isolation structure 42 in the form of an annular shape, the second shallow trench isolation structure 42 being located in the substrate 10 and surrounding the second well region 22.

[0027] Furthermore, the ESD protection device also includes a ring-shaped third well region 23, which is located in the substrate 10 and surrounds the second shallow trench isolation structure 42.

[0028] Preferably, the ESD protection device further includes: a ring-shaped seventh doped region 37, the seventh doped region 37 being located in the third well region 23, and the seventh doped region 37 being grounded (GND).

[0029] In this embodiment, the third well region 23 has a P-type conductivity, and the seventh doped region 37 has a P-type conductivity.

[0030] In this embodiment, the ESD protection device further includes: a buried layer 11, an annular deep well region 12, and an annular deep base region 13. The deep well region 12 is located in the substrate 10, and further, the deep well region 12 is located at the bottom of the second well region 22 and is in contact with the second well region 22. The buried layer 11 is located in the substrate 10 and at the bottom of the deep well region 12, and the buried layer 11 is in contact with the deep well region 12. The deep base region 13 is located in the substrate, and the deep base region 13 is located at the bottom of the third well region 23 and is in contact with the third well region 23.

[0031] In this embodiment, the substrate 10 has a P-type conductivity, the buried layer 11 has an N-type conductivity, the deep well region 12 has an N-type conductivity, and the deep base region 13 has a P-type conductivity.

[0032] Preferably, in the staggered arrangement of the second doped region 32 and the third doped region 33, there is a certain distance between each pair of adjacent second doped regions 32 and third doped regions 33.

[0033] Furthermore, in the staggered arrangement of the fifth doped region 35 and the sixth doped region 36, there is a certain distance between each pair of adjacent fifth doped regions 35 and sixth doped regions 36.

[0034] Preferably, each of the third doped regions 33 is connected to the first doped region 31; each of the second doped regions 32 has a certain distance from the first doped region 31, specifically, refer to Figure 3 The ESD device further includes a third shallow trench isolation structure 43, which isolates the second heavily doped region 32 and the first heavily doped region 31.

[0035] Preferably, each of the sixth doped regions 36 is connected to the fourth doped region 34; each of the fifth doped regions 35 has a certain distance from the fourth doped region 34, specifically, refer to Figure 3 The ESD device further includes a fourth shallow trench isolation structure 44, which isolates the fifth heavily doped region 35 and the fourth heavily doped region 34.

[0036] refer to Figure 4 , Figure 4 This is a schematic diagram of the measured TLP data of the ESD protection device with SCR structure according to an embodiment of the present invention. It can be seen that the measured sustaining voltage Vh of the ESD protection device with SCR structure provided in this application can be increased to 25V.

[0037] In this application, the blocky second heavily doped region (N+) and the blocky third heavily doped region (P+) in the first well region (PW) are arranged alternately, and the blocky fifth heavily doped region (P+) and the blocky sixth heavily doped region (N+) in the second well region (NW) are arranged alternately. Since the SCR structure is formed by coupling PNP and NPN, the fifth heavily doped region (P+) in the second well region (NW) is the emitter of the PNP, and the second heavily doped region (N+) in the first well region (PW) is the emitter of the NPN. The alternate arrangement of the second heavily doped region (N+) and the blocky third heavily doped region (P+), as well as the alternate arrangement of the fifth heavily doped region (P+) and the blocky sixth heavily doped region (N+), reduces the emitter area of ​​the parasitic PNP and NPN, reduces the transport efficiency of the base region, and can effectively reduce the current gain β of the PNP and NPN transistors, ultimately leading to an increase in the sustaining voltage Vh of the SCR structure in the ESD protection device.

[0038] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this application.

Claims

1. An ESD protection device with an SCR structure, characterized in that, include: Substrate; A first well region, wherein the first well region is located in the substrate; A first shallow trench isolation structure in the form of a ring is located in the substrate and is disposed around the first well region; A second well region in the form of a ring is located in the substrate and is disposed around the first shallow trench isolation structure; A first heavily doped region of a first conductivity type, in the form of a strip, is located in the first well region; Multiple block-shaped second-conductivity type second-doped regions; Multiple block-shaped third doped regions of the first conductivity type, the second doped regions and the third doped regions are arranged alternately, and the alternately arranged second doped regions and the third doped regions are located in the first well regions on both sides of the first doped regions; A fourth doped region of the second conductivity type is ring-shaped, the fourth doped region being located in the second well region and close to the edge of the second well region; The fifth doped region of the first conductivity type is in a blocky form; The sixth doped region of the second conductivity type is in the form of a block, and the fifth and sixth doped regions are arranged alternately, and the alternately arranged fifth and sixth doped regions are located in the second well region between the fourth doped region and the first shallow trench isolation structure; The first, second, and third heavily doped regions are all connected to a low level; the fourth, fifth, and sixth heavily doped regions are all connected to a high level.

2. The ESD protection device with an SCR structure according to claim 1, characterized in that, In the staggered arrangement of the second and third doped regions, there is a certain distance between each pair of adjacent second and third doped regions.

3. The ESD protection device with an SCR structure according to claim 1, characterized in that, In the staggered arrangement of the fifth and sixth doped regions, there is a certain distance between each pair of adjacent fifth and sixth doped regions.

4. The ESD protection device with an SCR structure according to claim 1, characterized in that, Each of the third doped regions is connected to the first doped region; each of the second doped regions is at a certain distance from the first doped region.

5. The ESD protection device with an SCR structure according to claim 1, characterized in that, Each of the sixth doped regions is connected to the fourth doped region; each of the fifth doped regions is at a certain distance from the fourth doped region.

6. The ESD protection device with an SCR structure according to claim 1, characterized in that, The ESD protection device further includes: a second shallow trench isolation structure in the form of a ring, the second shallow trench isolation structure being located in the substrate and surrounding the second well region.

7. The ESD protection device with an SCR structure according to claim 1, characterized in that, The ESD protection device further includes a ring-shaped third well region located in the substrate and surrounding the second shallow trench isolation structure.

8. The ESD protection device with an SCR structure according to claim 7, characterized in that, The ESD protection device further includes: a ring-shaped seventh doped region located in the third well region, and the seventh doped region being grounded.

9. The ESD protection device with an SCR structure according to claim 1, characterized in that, The first well region has a P-type conductivity; the second well region has an N-type conductivity.

10. The ESD protection device with an SCR structure according to claim 1, characterized in that, The first conductivity type is P-type; the second conductivity type is N-type.

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