Bidirectional low-capacitance low-clamping voltage suppression protection device
By filling the doped polysilicon in the deep trench to form an isolation region, the leakage problem of TVS devices when implementing bidirectional low-capacitance low-clamp voltage structure is solved, and the trigger voltage, clamp voltage and capacitance are achieved, reducing the power leakage problem of TVS devices when implementing bidirectional low-capacity low-clamp voltage structure, thus achieving lower trigger voltage, clamp voltage and capacitance, reducing the The leakage point improves the performance and reliability of the transient voltage suppression protection device.
Patent Information
- Application Number
- CN202420456580.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-08
- Publication Date
- 2025-02-25
- Estimated Expiration
- 2034-03-08
AI Technical Summary
When existing TVS devices realize bidirectional low-capacity and low-clamp voltage PNPN, PNP, and NPN structures, there is a leakage problem, which causes the product to be unable to be used normally.
By filling the deep trench with doped polycrystalline silicon to form an isolation region, the leakage problem of PNPN, PNP, and NPN structures is solved, thereby obtaining transient voltage suppression protection with lower trigger voltage, low clamp voltage, small capacitance and low leakage point Device.
Lower trigger voltage, clamp voltage and capacitance are achieved, reducing leakage points and improving the performance and reliability of transient voltage suppression protection devices.
Smart Images
Figure CN222532103U_ABST
Abstract
Description
Technical Field
[0001] The embodiments of the present application belong to the field of semiconductor technology, and specifically relate to a bidirectional low-capacitance and low-clamping voltage suppression protection device. Background Art
[0002] As the signal transmission rate of electronic products continues to increase, the process technology of back-end IC devices is becoming more and more advanced, and the tolerance of electronic products to ESD (electrostatic discharge) and EOS (electrical overstress) is becoming weaker and weaker. This requires the addition of transient voltage suppression protection devices (TVS) to protect the back-end IC of electronic products. At the same time, higher requirements are placed on TVS devices, requiring lower clamping voltage and smaller capacitance. In order to achieve bidirectional low-capacitance and low-clamping voltage PNPN, PNP, and NPN structures, existing TVS devices will have leakage problems, resulting in the product being unable to be used normally. Summary of the invention
[0003] The purpose of the embodiments of the present application is to solve or alleviate the technical problems existing in the above-mentioned prior art. The present invention provides a new structure to solve the leakage problem of TVS devices in the prior art in order to achieve bidirectional low-capacitance and low-clamping voltage PNPN, PNP, and NPN structures.
[0004] The embodiment of the present application provides a bidirectional low-capacitance low-clamping voltage suppression protection device, including a first injection region and a second injection region;
[0005] The first injection region and the second injection region have the same doping type, both of which are the first doping type; the first injection region and the second injection region are arranged in an epitaxial layer, the epitaxial layer is arranged on a substrate, and the substrate and the epitaxial layer have the same doping type, both of which are the second doping type;
[0006] Deep trenches are provided on the sides of the first implantation region and the second implantation region, the deep trenches are filled with doped polysilicon, the doped polysilicon is of the second doping type, and the bottom of the deep trenches extends into the substrate; or,
[0007] The first injection region and the second injection region have the same doping type, both of which are the first doping type; the first injection region and the second injection region are arranged in an epitaxial layer, the epitaxial layer is arranged on a substrate, the substrate and the epitaxial layer have the same doping type, both of which are the second doping type; a third injection region is arranged on the side of the first injection region and the second injection region, and the bottom of the third injection region extends into the substrate; or,
[0008] The doping types of the first injection region and the second injection region are the same and are both the first doping type. The first injection region and the second injection region are directly arranged in the substrate, and the substrate is the second doping type. Deep trenches are arranged on the sides of the first injection region and the second injection region, and the deep trenches are filled with doped polysilicon, and the doped polysilicon is the second doping type. The bottom of the deep trench extends into the substrate, and a fourth injection region is arranged in the substrate along the horizontal direction, and the fourth injection region is connected to the deep trench.
[0009] As a preferred embodiment of the present application, the doping concentration of the substrate is greater than that of the epitaxial layer.
[0010] As a preferred embodiment of the present application, it further includes: a fifth injection region and a sixth injection region;
[0011] The fifth injection region is adjacent to the first injection region, the sixth injection region is adjacent to the second injection region, the fifth injection region is arranged in the first well region, and the sixth injection region is arranged in the second well region; the fifth injection region and the sixth injection region are of the second doping type, and the first well region and the second well region are of the first doping type; or,
[0012] The first injection region and the fifth injection region are both arranged in the first well region, the second injection region and the sixth injection region are both arranged in the second well region, the fifth injection region and the sixth injection region are of the second doping type, and the first well region and the second well region are of the first doping type.
[0013] As a preferred embodiment of the present application, it further includes: a seventh injection region and an eighth injection region;
[0014] The seventh injection region is arranged at a side of the fifth injection region away from the first injection region, the eighth injection region is arranged at a side of the sixth injection region away from the second injection region, and the seventh injection region and the eighth injection region are of the first doping type; the first injection region, the fifth injection region and the seventh injection region are all arranged in the first well region, and the second injection region, the sixth injection region and the eighth injection region are all arranged in the second well region; or,
[0015] The seventh injection region is arranged on the side of the first injection region away from the fifth injection region, the eighth injection region is arranged on the side of the second injection region away from the sixth injection region, and the seventh injection region and the eighth injection region are of the second doping type; the first injection region, the fifth injection region and the seventh injection region are all arranged in the first well region, and the second injection region, the sixth injection region and the eighth injection region are all arranged in the second well region.
[0016] As a preferred embodiment of the present application, the first doping type is N-type, and the second doping type is P-type; or, the first doping type is P-type, and the second doping type is N-type.
[0017] Compared with the prior art, the embodiment of the present application provides a bidirectional low-capacitance and low-clamping voltage suppression protection device. The present application solves the leakage problem of PNPN, PNP, and NPN structures by filling doped polysilicon in deep trenches to form isolation regions, thereby obtaining a transient voltage suppression protection device with lower trigger voltage, low clamping voltage, small capacitance, and low leakage point. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 A schematic diagram of the structure of a bidirectional low-capacitance and low-clamping voltage suppression protection device provided in Embodiment 1 of the present application;
[0019] Figure 2-Figure 4 A schematic diagram of the structure of a bidirectional low-capacitance and low-clamping voltage suppression protection device provided in Embodiment 2 of the present application;
[0020] Figure 5 This is a schematic diagram of the structure of a bidirectional low-capacitance and low-clamping voltage suppression protection device provided in Example 3 of the present application.
[0021] Figure 6 This is a schematic diagram of the structure of a bidirectional low-capacitance and low-clamping voltage suppression protection device provided in Example 4 of the present application. DETAILED DESCRIPTION
[0022] In order to enable those skilled in the art to better understand the technical solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.
[0023] The embodiments of the present application provide a bidirectional low-capacitance and low-clamping voltage suppression protection device. The technical solution of the present application is described in detail below with specific embodiments.
[0024] Embodiment 1
[0025] like Figure 1 As shown, the embodiment of the present application provides a bidirectional low-capacitance low-clamping voltage suppression protection device, including a first injection region 03 and a second injection region 04;
[0026] The first injection region 03 and the second injection region 04 have the same doping type, both of which are the first doping type. The first injection region 03 and the second injection region 04 are arranged in the epitaxial layer 02. The epitaxial layer 02 is arranged on the substrate 01. The substrate 01 and the epitaxial layer 02 have the same doping type, both of which are the second doping type.
[0027] Deep trenches 05 are disposed on the sides of the first implantation region 03 and the second implantation region 04 . The deep trenches 05 are filled with doped polysilicon having the same doping type as the epitaxial layer 02 . The bottom of the deep trenches 05 extends into the substrate 01 .
[0028] Wherein, the first doping type is N-type, and the second doping type is P-type;
[0029] In the embodiment of the present application, the doping concentration of the substrate 01 is greater than that of the epitaxial layer 02 .
[0030] The following is a preparation process of the protection device provided in an embodiment of the present application. The device is a P-type epitaxial layer 02 (resistivity is about 400Ω) with a thickness of about 10um grown on a P-type substrate 01, and then an N-type first injection region 03 and an N-type second injection region 04 are implanted to form an interval. Deep trenches 05 are formed on the sides of the N-type first injection region 03 and the second injection region 04 on the P-type epitaxial layer 02 through deep trench technology, and then P-type polysilicon is filled in the deep trench 05 to form a low-capacitance and small leakage TVS.
[0031] Embodiment 2
[0032] On the basis of the first embodiment, the device further comprises: a fifth injection region 06 and a sixth injection region 07;
[0033] like Figure 2 As shown, the fifth injection region 06 is adjacent to the first injection region 03, the sixth injection region 07 is adjacent to the second injection region 04, the fifth injection region 06 is arranged in the first well region 08, and the sixth injection region 07 is arranged in the second well region 09; the fifth injection region 06 and the sixth injection region 07 are of the second doping type, and the first well region 08 and the second well region 09 are of the first doping type; or,
[0034] like Figure 3 As shown, the first injection region 03 and the fifth injection region 06 are both arranged in the first well region 08, and the second injection region 04 and the sixth injection region 07 are both arranged in the second well region 09; the fifth injection region 06 and the sixth injection region 07 are of the second doping type, and the first well region 08 and the second well region 09 are of the first doping type.
[0035] The bottom of the device is isolated by growing a P epitaxial layer 02 on a P-type substrate 01, and the side of the device is isolated by filling P-type polysilicon into the deep trench 05; and the current path after the device is turned on is not affected. The isolation area formed in the present application solves the leakage problem of the bidirectional SCR structure, thereby obtaining a transient voltage suppression protection device with lower trigger voltage, low clamping voltage, small capacitance, and low leakage point. Using polysilicon to isolate the side of the device can not only reduce the capacitance, but also make the manufacturing process simpler because more injections are not required, and the resistivity of polysilicon is more uniform, so it has a better isolation effect on leakage and can improve the manufacturing yield.
[0036] Embodiment 3
[0037] like Figure 4 As shown, on the basis of the second embodiment, the device further includes: a seventh injection region 10 and an eighth injection region 11;
[0038] The seventh injection region 10 is arranged on the side of the fifth injection region 06 away from the first injection region 03 , and the eighth injection region 11 is arranged on the side of the sixth injection region 07 away from the second injection region 04 ; both the seventh injection region 10 and the eighth injection region 11 are of the first doping type.
[0039] The first injection region 03 , the fifth injection region 06 and the seventh injection region 10 are all arranged in the first well region 08 , and the second injection region 04 , the sixth injection region 07 and the eighth injection region 11 are all arranged in the second well region 09 .
[0040] like Figure 4 The structure shown in the figure has a specific preparation process as follows: the device is a P-type epitaxial layer 02 (resistivity is about 400Ω) with a thickness of about 10um grown on a P-type substrate 01, and then an N-type first well region 08 and an N-type second well region 09 are implanted on the P-type epitaxial layer 02, and then a P-type fifth implantation region 06 is formed in the N-type first well region 08, and a P-type sixth implantation region 07 is formed in the N-type second well region 09, and then an N-type first implantation region 03 and an N-type seventh implantation region 10 are formed in the N-type first well region 08, and an N-type second implantation region 04 and an N-type eighth implantation region 11 are formed in the N-type second well region 09, and deep trenches 05 are respectively formed on the sides of the N-type first implantation region 03 and the second implantation region 04 on the P-type epitaxial layer 02 by deep trench 05 technology, and then P-type polysilicon is filled in the deep trench 05 to form a TVS with low capacitance and small leakage.
[0041] Embodiment 4
[0042] As another embodiment of the present application, Figure 5As shown, the first injection region 03 and the second injection region 04 have the same doping type, and both are the first doping type. The first injection region 03 and the second injection region 04 are arranged in the epitaxial layer 02, and the epitaxial layer 02 is arranged on the substrate. The substrate and the epitaxial layer 02 have the same doping type, and both are the second doping type. The third injection region 12 is arranged on the side of the first injection region 03 and the second injection region 04, and the bottom of the third injection region 12 extends into the substrate 01.
[0043] The following is a preparation process of the protection device provided in an embodiment of the present application. The device is a P-type epitaxial layer 02 (resistivity is approximately 400Ω) with a thickness of approximately 4um grown on a P-type substrate 01, and then an N-type first injection region 03 and an N-type second injection region 04 are injected into the P-type epitaxial layer 02 to form an interval. A third injection region 12 is formed on the side surfaces of the N-type first injection region 03 and the second injection region 04 on the P-type epitaxial layer 02, thereby forming a low-capacitance and low-leakage TVS.
[0044] like Figure 6 As shown, the doping types of the first injection region 03 and the second injection region 04 are the same and are both of the first doping type. The first injection region 03 and the second injection region 04 are directly arranged in the substrate 01, and the substrate 01 is of the second doping type; deep trenches 05 are arranged on the sides of the first injection region 03 and the second injection region 04, and the deep trenches 05 are filled with doped polysilicon, and the doping type of the doped polysilicon is the second doping type. The bottom of the deep trench 05 extends to the substrate 01, and a fourth injection region 13 is arranged in the substrate 01 along the horizontal direction, and the fourth injection region 13 is connected to the deep trench 05.
[0045] The following is a preparation process of the protection device provided in an embodiment of the present application. Ion implantation is performed in a P-type substrate 01 to form four injection regions 13 arranged horizontally, and then an N-type first injection region 03 and an N-type second injection region 04 arranged at intervals are formed above the sixth fourth injection region 0413. Deep trenches 05 are respectively formed on the sides of the N-type first injection region 03 and the second injection region 04 on the P-type substrate 01 through deep trench technology, and then P-type polysilicon is filled in the deep trench 05 to form a TVS with low capacitance and small leakage.
[0046] The fourth embodiment is only aimed at adjusting the isolation region formed by the deep trench, substrate and external delay in the structure of the first embodiment, and the other structures are the same as those of the second to third embodiments.
[0047] Although the present application has been described in detail herein with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements may be made to the present application. Therefore, these modifications or improvements made without departing from the spirit of the present application are within the scope of protection claimed by the present application.
Claims
1. A bidirectional low capacitance low clamping voltage suppression protection device, characterized in that: comprising a first injection region and a second injection region; The first injection region and the second injection region have the same doping type, both of which are the first doping type; the first injection region and the second injection region are arranged in an epitaxial layer, the epitaxial layer is arranged on a substrate, and the substrate and the epitaxial layer have the same doping type, both of which are the second doping type; Deep trenches are provided on the sides of the first injection region and the second injection region, the deep trenches are filled with doped polysilicon, the doped polysilicon is of the second doping type, and the bottom of the deep trenches extends into the substrate; or, The first injection region and the second injection region have the same doping type, both of which are the first doping type; the first injection region and the second injection region are arranged in an epitaxial layer, the epitaxial layer is arranged on a substrate, the substrate and the epitaxial layer have the same doping type, both of which are the second doping type; a third injection region is arranged on the side of the first injection region and the second injection region, and the bottom of the third injection region extends into the substrate; or, The doping types of the first injection region and the second injection region are the same and are both the first doping type. The first injection region and the second injection region are directly arranged in the substrate, and the substrate is the second doping type. Deep trenches are arranged on the sides of the first injection region and the second injection region, and the deep trenches are filled with doped polysilicon, and the doped polysilicon is the second doping type. The bottom of the deep trench extends into the substrate, and a fourth injection region is arranged in the substrate along the horizontal direction, and the fourth injection region is connected to the deep trench.
2. A bidirectional low capacitance low clamping voltage suppression protection device as claimed in claim 1, characterized in that: The doping concentration of the substrate is greater than that of the epitaxial layer.
3. A bidirectional low capacitance low clamping voltage suppression protection device as claimed in claim 1, characterized in that: Also includes: a fifth injection region and a sixth injection region; The fifth injection region is adjacent to the first injection region, the sixth injection region is adjacent to the second injection region, the fifth injection region is arranged in the first well region, and the sixth injection region is arranged in the second well region; the fifth injection region and the sixth injection region are of the second doping type, and the first well region and the second well region are of the first doping type; or, The first injection region and the fifth injection region are both arranged in the first well region, the second injection region and the sixth injection region are both arranged in the second well region, the fifth injection region and the sixth injection region are of the second doping type, and the first well region and the second well region are of the first doping type.
4. A bidirectional low capacitance low clamping voltage suppression protection device as claimed in claim 3, characterized in that: Also includes: a seventh injection region and an eighth injection region; The seventh injection region is arranged at a side of the fifth injection region away from the first injection region, the eighth injection region is arranged at a side of the sixth injection region away from the second injection region, and the seventh injection region and the eighth injection region are of the first doping type; the first injection region, the fifth injection region and the seventh injection region are all arranged in the first well region, and the second injection region, the sixth injection region and the eighth injection region are all arranged in the second well region; or, The seventh injection region is arranged on the side of the first injection region away from the fifth injection region, the eighth injection region is arranged on the side of the second injection region away from the sixth injection region, and the seventh injection region and the eighth injection region are of the second doping type; the first injection region, the fifth injection region and the seventh injection region are all arranged in the first well region, and the second injection region, the sixth injection region and the eighth injection region are all arranged in the second well region.
5. A bidirectional low capacitance low clamping voltage suppression protection device as claimed in claim 1, characterized in that: The first doping type is N-type, and the second doping type is P-type; or, the first doping type is P-type, and the second doping type is N-type.