Zener diode
By forming a first sub-doped region and a second sub-doped region spaced apart in the Zener diode, the problem of inconsistent forward and reverse breakdown voltages is solved, achieving bidirectional breakdown voltage consistency and broadening the application range.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-19
- Publication Date
- 2026-03-24
AI Technical Summary
In existing Zener diodes, the forward and reverse breakdown voltages are difficult to match, which limits their application scenarios.
By forming a first sub-doped region and a second sub-doped region spaced apart within a first conductivity type doped region, the second sub-doped region is electrically connected to the first conductivity type substrate, forming a third PN junction region, so that its breakdown voltage is the same as that of the first PN junction region, thus achieving bidirectional breakdown voltage consistency.
This achieves high consistency in bidirectional breakdown voltage of Zener diodes, broadening their application scenarios.
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Figure CN121728786A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of semiconductor devices, in particular to a zener diode. BACKGROUND
[0002] A zener diode, also known as a Zener diode, is a diode that utilizes the reverse breakdown characteristics of a PN junction to function as a voltage regulator. The current of the zener diode can vary within a wide range while the voltage remains essentially constant. The zener diode has a very high resistance until the critical reverse breakdown voltage is reached. At the critical breakdown point, the reverse resistance suddenly decreases to a very small value, and the current increases while the voltage remains essentially constant in this low resistance region. Due to this characteristic, the zener diode can be used as a voltage regulator, a voltage reference element, or an overvoltage protector, etc.
[0003] In the prior art, a silicon substrate is first subjected to P-type impurity diffusion to form a PN junction, and then N-type impurities are diffused in the P-type impurity diffusion region to form another PN junction, thereby realizing a bidirectional zener diode with vertical structure and positive and negative zener breakdown. However, due to the large difference in the junction region impurity concentration of the two PN junctions, it is difficult to achieve consistent breakdown voltages of the two PN junctions, thereby limiting the application of the zener diode. SUMMARY
[0004] In view of the above-mentioned shortcomings of the prior art, the present application aims to provide a zener diode to achieve consistent positive and negative breakdown voltages of the zener diode.
[0005] To achieve the above-mentioned objects and other related objects, the present application provides a zener diode, which comprises:
[0006] a first conductivity type substrate comprising a first surface and a second surface;
[0007] a second conductivity type doped region extending from a middle region of the first surface of the first conductivity type substrate to the inside of the first conductivity type substrate in the direction of the second surface, defining a depth extending to the inside of the first conductivity type substrate as a first depth;
[0008] a first conductivity type doped region formed at least partially in the second conductivity type doped region, and the portion located in the second conductivity type doped region extends to the inside of the second conductivity type doped region in the direction from the first surface to the second surface of the first conductivity type substrate, defining a depth extending to the inside of the second conductivity type doped region as a second depth; the first conductivity type doped region comprises a first sub-doped region and a second sub-doped region arranged at intervals, and the second sub-doped region is electrically connected to the first conductivity type substrate.
[0009] Compared with the prior art, the voltage stabilizing diode has at least the following beneficial effects:
[0010] The voltage stabilizing diode of the present application comprises a first conductive type substrate, a second conductive type doped region and a first conductive type doped region, the first conductive type substrate comprises a first surface and a second surface. The second conductive type doped region extends to the interior of the first conductive type substrate from the middle region of the first surface of the first conductive type substrate to the direction of the second surface, and the depth extending to the interior of the first conductive type substrate is defined as the first depth. The first conductive type doped region is at least partially formed in the second conductive type doped region, and the part located in the second conductive type doped region extends to the interior of the second conductive type doped region from the first surface of the first conductive type substrate to the direction of the second surface, and the depth extending to the interior of the second conductive type doped region is defined as the second depth; the first conductive type doped region comprises a first sub-doped region and a second sub-doped region arranged at intervals, and the second sub-doped region is electrically connected with the first conductive type substrate.
[0011] The first PN junction region is formed between the second conductive type doped region and the first sub-doped region, the second PN junction region is formed between the first conductive type substrate and the second conductive type doped region, and the third PN junction region is formed between the second conductive type doped region and the second sub-doped region. Since the first sub-doped region and the second sub-doped region are formed at intervals by the first conductive type doped region, they have the same doping concentration, and the doping concentrations of the first PN junction region and the third PN junction region formed thereby are also the same, so they have the same breakdown voltage. When a forward voltage is applied, the first PN junction region is reversely broken down, and the current flows through the second PN junction region and the third PN junction region and flows out in a forward direction. When a reverse voltage is applied, that is, a reverse voltage is applied to the second PN junction region and the third PN junction region, the breakdown voltage of the third PN junction region is lower and its voltage clamping effect, the current will pass through the third PN junction region and be reversely broken down, and will not pass through the second PN junction region, and then the current will pass through the first PN junction region and flow out in a forward direction. Since the first PN junction region and the third PN junction region are formed based on the same diffusion of N-type impurities in the same first conductive type doped region, they have the same junction depth and impurity distribution, so the first PN junction region and the third PN junction region have the same breakdown voltage, that is, the above-mentioned voltage stabilizing diode has a completely consistent bidirectional breakdown voltage. Thus, the bidirectional breakdown voltage of the voltage stabilizing diode of the present application has high consistency, and further widens its application scenarios. BRIEF DESCRIPTION OF DRAWINGS
[0012] Figure 1 The structure of the voltage stabilizing diode in the embodiment of the present application is shown in the figure;
[0013] Figure 2 The equivalent circuit diagram of the voltage stabilizing diode in the embodiment of the present application is shown in the figure; Figure 1
[0014] Figure 3 A structure diagram of a zener diode in an embodiment of the present application;
[0015] Figure 4 A structure diagram of a zener diode in an embodiment of the present application; Figure 3 An equivalent circuit diagram of the zener diode;
[0016] Figure 5 A structure diagram of a zener diode in an embodiment of the present application;
[0017] Figure 6 A structure diagram of a zener diode in an embodiment of the present application.
[0018] Reference signs are shown as follows:
[0019] 100, a first conductive type substrate; 101, a first surface; 102, a second surface; 200, a second conductive type doped region; 300, a first conductive type doped region; 301, a first sub-doped region; 302, a second sub-doped region; 401, a first insulating layer; 402, a second insulating layer; 501, a first electrode; 502, a second electrode; 600, a connecting layer; 701, a first PN junction region; 702, a second PN junction region; 703, a third PN junction region. DETAILED DESCRIPTION
[0020] The present application will be described in detail by the following specific embodiments, and those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in the specification. The present application can also be implemented or applied by different specific embodiments, and various modifications or changes can be made to the details in the specification without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.
[0021] It should be understood that the diagrams provided in the embodiments of the present application only illustrate the basic concepts of the present application in a schematic manner, and although only the components related to the present application are shown in the diagrams, the actual implementation does not draw the components according to the number, shape and size of the components in the actual implementation, and the shape, number and proportion of each component in the actual implementation can be changed at will, and the component layout form can also be more complex. The structure, proportion, size, etc. shown in the drawings of the specification are only used to cooperate with the content disclosed in the specification for those skilled in the art to understand and read, and are not used to limit the implementation conditions of the present application, so they do not have technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effects and purposes that can be achieved by the present application, should still fall within the scope of the technical content disclosed in the present application.
[0022] The inventor found that, referring to Figure 1 and Figure 2, a p-type impurity is diffused first to form a second PN junction region 702 on a silicon substrate, and then an n-type impurity is diffused in the p-type impurity diffusion region to form a first PN junction region 701, so as to realize a bidirectional Zener diode with vertical structure and reverse Zener breakdown. However, since the first PN junction region 701 is formed by diffusing an n-type impurity in a p-type impurity diffusion region, the impurity concentration of the junction region must be much higher than that of the second PN junction region 702, and the impurity concentration largely determines the breakdown voltage of the PN junction. Therefore, it is difficult to achieve consistent breakdown voltages of the first PN junction region 701 and the second PN junction region 702, which limits the application scenarios of the Zener diode.
[0023] To solve the above technical problems, the embodiment provides a voltage stabilizing diode which solves the problem that the forward and reverse breakdown voltages are difficult to be consistent.
[0024] The embodiment provides a voltage stabilizing diode, which comprises:
[0025] A first-conductivity-type substrate comprising a first surface and a second surface;
[0026] A second-conductivity-type doped region extending from a middle region of the first surface of the first-conductivity-type substrate to the inside of the first-conductivity-type substrate in the direction from the first surface to the second surface, and defining a first depth as the depth extending to the inside of the first-conductivity-type substrate;
[0027] A first-conductivity-type doped region formed at least partially in the second-conductivity-type doped region, and the part in the second-conductivity-type doped region extending to the inside of the second-conductivity-type doped region in the direction from the first surface to the second surface of the first-conductivity-type substrate, and defining a second depth as the depth extending to the inside of the second-conductivity-type doped region; the first-conductivity-type doped region comprises a first sub-doped region and a second sub-doped region arranged at intervals, and the second sub-doped region is electrically connected to the first-conductivity-type substrate. Thus, the embodiment forms the first sub-doped region and the second sub-doped region arranged at intervals in the first-conductivity-type doped region, and leads out the second sub-doped region to contact the first-conductivity-type substrate to form a third PN junction region, the breakdown voltage of which is the same as that of the first PN junction region, so as to obtain a voltage stabilizing diode with the same forward breakdown voltage through the two PN junction regions.
[0028] Optionally, in the direction parallel to the first surface of the first-conductivity-type substrate, one end of the second sub-doped region extends to the edge of the second-conductivity-type doped region to contact the first-conductivity-type substrate.
[0029] Optionally, the second sub-doped region comprises a protruding portion located at the edge of the second-conductivity-type doped region, and the length of the protruding portion in the direction parallel to the first surface of the first-conductivity-type substrate is greater than the first depth.
[0030] Optionally, the second sub-doped region is not in contact with the first conductive type substrate, and the second sub-doped region is electrically connected to the first conductive type substrate through the connecting layer.
[0031] Optionally, the voltage stabilizing diode further comprises:
[0032] Optionally, the voltage stabilizing diode further comprises:
[0033] Optionally, the interval between the first sub-doped region and the second sub-doped region is greater than twice the second depth.
[0034] Optionally, the interval between the first sub-doped region and the second sub-doped region is greater than 5 μm.
[0035] Optionally, the doping concentration of the first conductive type substrate is less than the doping concentration of the first conductive type doped region, the doping concentration of the first conductive type substrate is less than the doping concentration of the second conductive type doped region, and the doping concentration of the second conductive type doped region is less than the doping concentration of the first conductive type doped region.
[0036] Optionally, the second conductive type doped region and the first sub-doped region form a first PN junction region, the first conductive type substrate and the second conductive type doped region form a second PN junction region, and the second conductive type doped region and the second sub-doped region form a third PN junction region.
[0037] Optionally, the doping concentration of the second PN junction region is less than the doping concentration of the first PN junction region, and the doping concentration of the first PN junction region is equal to the doping concentration of the third PN junction region.
[0038] Optionally, the breakdown voltage of the second PN junction region is greater than the breakdown voltage of the first PN junction region, and the breakdown voltage of the first PN junction region is equal to the breakdown voltage of the third PN junction region.
[0039] Optionally, the doping concentration of the first conductive type substrate is between 1E17 atoms / cm 3 and 1E18 atoms / cm 3 .
[0040] Optionally, the doping concentration of the second conductive type doped region is between 1E18 atoms / cm 3 and 1E20 atoms / cm 3 .
[0041] Optionally, the doping concentration of the first conductive type doped region is between 1E18 atoms / cm 3 and 1E21 atoms / cm 3 .
[0042] Optionally, the Zener diode also includes:
[0043] The first electrode is electrically connected to a substrate of a first conductivity type;
[0044] The second electrode is electrically connected to the first sub-doped region.
[0045] The present invention will now be described in detail with reference to specific embodiments.
[0046] This embodiment provides a Zener diode, see reference. Figure 3 The Zener diode includes a substrate 100 of a first conductivity type, a doped region 200 of a second conductivity type, and a doped region 300 of a first conductivity type.
[0047] Among them, reference Figure 3 The first conductivity type substrate 100 can be silicon (Si), germanium (Ge), or silicon-germanium (SiGe), or it can be other layers containing semiconductor materials, such as silicon-on-insulator (SiInsulator) or germanium-on-insulator (GrFeInsulator). This first conductivity type substrate 100 is doped with impurities to form the first conductivity type. It should be noted that the conductivity of the first conductivity type in this embodiment is opposite to that of the second conductivity type described below. For example, if the first conductivity type is N-type, then the second conductivity type is P-type, and vice versa. In this embodiment, the first conductivity type substrate 100 is a silicon substrate doped with an N-type impurity element to form an N-type conductivity type. Optionally, the N-type impurity element is antimony; of course, the N-type impurity can also be other Group V elements such as phosphorus or arsenic. In other embodiments, the first conductivity type substrate 100 can also be a P-type substrate.
[0048] Continue to refer to Figure 3 The first conductivity type substrate 100 has a first surface 101 and a second surface 102 disposed opposite to each other. A second conductivity type doped region 200 extends from the first surface 101 towards the second surface 102 into the interior of the first conductivity type substrate 100, and the depth extending into the interior of the first conductivity type substrate 100 is defined as a first depth H1. In this embodiment, the second conductivity type doped region 200 is a P-type doped region. The doping element of this P-type doped region can be boron, or it can be aluminum or gallium.
[0049] Continue to refer to Figure 3The first conductivity type doped region 300 is at least partially formed within the second conductivity type doped region 200, and extends from the first surface 101 to the second surface 102 of the first conductivity type substrate 100 into the interior of the second conductivity type doped region 200. The depth extending into the second conductivity type doped region 200 is defined as the second depth H2. The first conductivity type doped region 300 includes at least a first sub-doped region 301 and a second sub-doped region 302 spaced apart. The first sub-doped region 301 is formed inside the second conductivity type doped region 200, and is spaced apart from the first conductivity type substrate 100 by the second conductivity type doped region 200. The second sub-doped region 302 is electrically connected to the first conductivity type substrate 100, specifically through contact or through a connecting layer. The first conductivity type doped region 300 is an N-type doped region, and the doping element of the N-type doped region is phosphorus.
[0050] Optionally, continue to refer to Figure 3 The second conductivity type doped region 200 is formed by diffusing P-type impurities in the middle region of the first conductivity type substrate 100. The first conductivity type doped region 300 is formed by diffusing N-type impurities in the second conductivity type doped region 200. Therefore, the doping concentration of the first conductivity type substrate 100 is less than the doping concentration of the first conductivity type doped region 300, and the doping concentration of the first conductivity type substrate 100 is less than the doping concentration of the second conductivity type doped region 200. The doping concentration of the second conductivity type doped region 200 is less than the doping concentration of the first conductivity type doped region 300.
[0051] Reference Figure 3 Simultaneously refer to Figure 4 In this embodiment, a first PN junction region 701 is formed between the second conductivity type doped region 200 and the first sub-doped region 301, a second PN junction region 702 is formed between the first conductivity type substrate 100 and the second conductivity type doped region 200, and a third PN junction region 703 is formed between the second conductivity type doped region 200 and the second sub-doped region 302. Since the first sub-doped region 301 and the second sub-doped region 302 are formed by the first conductivity type doped region 300 with intervals, they have the same doping concentration. Therefore, the first PN junction region 701 and the third PN junction region 703 also have the same doping concentration and thus the same breakdown voltage. When a forward voltage is applied, refer to the attached diagram. Figure 3 The vertical dashed arrow from top to bottom indicates that the first PN junction region 701 has reversed breakdown, and the current then flows through the second PN junction region 702 and the third PN junction region 703 in the forward direction. When a reverse voltage is applied, refer to the attached diagram. Figure 3The dashed line arrow pointing upwards indicates that a reverse voltage is applied to the second PN junction region 702 and the third PN junction region 703. Due to the lower breakdown voltage of the third PN junction region 703 and its voltage clamping effect, the current will flow through the third PN junction region 703 in the reverse breakdown direction, bypassing the second PN junction region 702. The current then flows out through the first PN junction region 701 in the forward direction. Since the first PN junction region 701 and the third PN junction region 703 are formed in the same first conductivity type doped region 300 based on the same primary diffusion of N-type impurities, they have the same junction depth and impurity distribution. Therefore, the first PN junction region 701 and the third PN junction region 703 have the same breakdown voltage, meaning the aforementioned Zener diode has a completely consistent bidirectional breakdown voltage. Figure 1 Compared with existing solutions, this embodiment only requires making a few intervals in the first conductivity type doped region 300 and optimizing the formation position of the second sub-doped region 302, or forming a connecting layer 600 when forming the electrode. The process is simple and conducive to industrialization.
[0052] Among them, continue to refer to Figure 3 The doping concentration within the first conductivity type substrate 100 is uniformly distributed along the thickness direction. Optionally, the doping concentration of the first conductivity type substrate 100 is between 1E17 atoms / cm². 3 ~1E18 atoms / cm 3 The doping concentration of the second conductivity type doped region 200 gradually decreases from the first surface 101 to the second surface 102. Optionally, the doping concentration of the second conductivity type doped region 200 is between 1E18 atoms / cm². 3 ~1E20 atoms / cm 3 The doping concentration of the first conductivity type doped region 300 also gradually decreases from the first surface 101 to the second surface 102. Optionally, the doping concentration of the first conductivity type doped region 300 is between 1E18 atoms / cm². 3 ~1E21 atoms / cm 3 .
[0053] In one example, refer to Figure 3Along a direction parallel to the first surface 101 of the first conductivity type substrate 100, one end of the second sub-doped region 302 extends to the edge of the second conductivity type doped region 200 and contacts the first conductivity type substrate 100. The second sub-doped region 302 includes a protrusion (marked as L in the figure), located at the edge of the second conductivity type doped region 200. The length L of the protrusion along the direction parallel to the first surface of the first conductivity type substrate is greater than the first depth H1, which is also the diffusion depth of the second conductivity type doped region 200, to prevent lateral diffusion of second conductivity type impurities during the process, thus affecting the contact between the second sub-doped region 302 and the first conductivity type substrate 100. A third PN junction region 703 is formed between the first conductivity type substrate 100 and the second sub-doped region 302 of the first conductivity type doped region 300. In this example, refer to... Figure 3 The first conductivity type doped region 300 includes a first sub-doped region 301 and two second sub-doped regions 302 spaced apart. The first sub-doped region 301 is formed in the middle of the first conductivity type doped region 300, and the two second sub-doped regions 302 are distributed on both sides of the first sub-doped region 301, surrounding the first sub-doped region 301. In other examples, see... Figure 5 The first conductivity type doped region 300 includes a first sub-doped region 301 and a second sub-doped region 302 that are spaced apart, and the first sub-doped region 301 and the second sub-doped region 302 are symmetrically distributed.
[0054] In another example, refer to Figure 6 The second sub-doped region 302 is not in direct contact with the first conductivity type substrate 100, but is electrically connected to the first conductivity type substrate 100 through the connecting layer 600. In this example, the Zener diode also includes a first insulating layer 401, which is formed above the second sub-doped region 302 and a portion of the first conductivity type substrate 100 on the first surface 101, for electrically isolating the second sub-doped region 302 from the subsequently formed electrode. The connecting layer 600 is formed above the first insulating layer 401 and penetrates the first insulating layer 401, with one end connected to the second sub-doped region 302 and the other end connected to the first conductivity type substrate 100. Optionally, the connecting layer 600 is a metal connecting layer. Optionally, the first insulating layer 401 has an opening corresponding to the position of the first sub-doped region 301, which is used for the subsequent formation of an electrode on the first sub-doped region 301.
[0055] Optionally, refer to Figure 3 , Figure 5 or Figure 6The Zener diode also includes a first electrode 501 and a second electrode 502. The first electrode 501 is electrically connected to a first conductivity type substrate 100, and the second electrode 502 is electrically connected to a first sub-doped region 301. In this embodiment, the first electrode 501 is formed on the second surface 102 of the first conductivity type substrate 100, and the second electrode 502 is formed on the first surface 101 of the first conductivity type substrate 100 and on the first sub-doped region 301 to form a vertically structured Zener diode. In other embodiments, a horizontally structured Zener diode can also be formed by setting the position of the electrodes. Optionally, the connecting layer 600 and the second electrode 502 are formed using the same process, which helps to simplify the fabrication process and improve production efficiency. Optionally, the first insulating layer 401 is silicon dioxide or silicon nitride. In this embodiment, the first insulating layer 401 is silicon dioxide.
[0056] Optionally, refer to Figure 3 The spacing D between the first sub-doped region 301 and the second sub-doped region 302 is greater than twice the second depth H2. Optionally, the spacing D between the first sub-doped region 301 and the second sub-doped region 302 is greater than 5 μm. This avoids the formation of electrical connections between the first sub-doped region 301 and the second sub-doped region 302 due to impurity diffusion.
[0057] Optionally, refer to Figure 3 , Figure 5 or Figure 6 The Zener diode further includes a second insulating layer 402, which covers the first insulating layer 401 and partially covers the edge of the second electrode 502. Optionally, the second insulating layer 402 is silicon dioxide or silicon nitride; in this embodiment, the second insulating layer 402 is silicon nitride.
[0058] In summary, the Zener diode of this embodiment forms a first sub-doped region and a second sub-doped region spaced apart within a first conductivity type doped region. The second sub-doped region is led out and electrically connected to the first conductivity type substrate to form a third PN junction region. The breakdown voltage of the third PN junction region is the same as that of the first PN junction region. When a forward voltage is applied, the first PN junction region breaks down in the reverse direction, and the current flows out through the second and third PN junction regions in the forward direction. When a reverse voltage is applied, that is, a reverse voltage is applied to the second and third PN junction regions, the third PN junction region has a lower breakdown voltage and a voltage clamping effect, so the current will pass through the third PN junction region in the reverse direction without passing through the second PN junction region. Then the current flows out through the first PN junction region in the forward direction. Since the first and third PN junction regions are formed in the same first conductivity type doped region based on the same first diffusion of N-type impurities, they have the same junction depth and impurity distribution. Therefore, the first and third PN junction regions have the same breakdown voltage, that is, the Zener diode has a completely consistent bidirectional breakdown voltage. Therefore, the bidirectional breakdown voltage of the Zener diode in this embodiment has a high degree of consistency, which broadens the application range of the Zener diode.
[0059] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.
Claims
1. A Zener diode, characterized in that, include: A substrate of a first conductivity type includes a first surface and a second surface; The second conductivity type doped region extends from the middle region of the first surface of the first conductivity type substrate toward the second surface into the interior of the first conductivity type substrate, and the depth extending into the interior of the first conductivity type substrate is defined as the first depth. A first conductivity type doped region is formed within the second conductivity type doped region and extends from the first surface of the first conductivity type substrate toward the second surface into the interior of the second conductivity type doped region. The depth extending into the interior of the second conductivity type doped region is defined as the second depth. The first conductivity type doped region includes a first sub-doped region and a second sub-doped region that are spaced apart. The second sub-doped region is electrically connected to the first conductivity type substrate.
2. The Zener diode according to claim 1, characterized in that, Along a direction parallel to the first surface of the first conductivity type substrate, one end of the second sub-doped region extends to the edge of the second conductivity type doped region and contacts the first conductivity type substrate.
3. The Zener diode according to claim 2, characterized in that, The second sub-doped region includes a protrusion located at the edge of the second conductivity type doped region, and the length of the protrusion along a direction parallel to the first surface of the first conductivity type substrate is greater than the first depth.
4. The Zener diode according to claim 1, characterized in that, The second sub-doped region is not in contact with the first conductivity type substrate, and the second sub-doped region is electrically connected to the first conductivity type substrate through a connecting layer.
5. The Zener diode according to claim 4, characterized in that, The Zener diode also includes: An insulating layer is formed on the first surface above the second sub-doped region and a portion of the first conductivity type substrate; the connecting layer is formed above the insulating layer and penetrates the insulating layer, with one end connected to the second sub-doped region and the other end connected to the first conductivity type substrate.
6. The Zener diode according to claim 1, characterized in that, The spacing between the first sub-doped region and the second sub-doped region is greater than twice the second depth.
7. The Zener diode according to claim 1, characterized in that, The spacing between the first sub-doped region and the second sub-doped region is greater than 5 μm.
8. The Zener diode according to claim 1, characterized in that, The doping concentration of the first conductivity type substrate is less than the doping concentration of the first conductivity type doped region, the doping concentration of the first conductivity type substrate is less than the doping concentration of the second conductivity type doped region, and the doping concentration of the second conductivity type doped region is less than the doping concentration of the first conductivity type doped region.
9. The Zener diode according to claim 1, characterized in that, A first PN junction region is formed between the second conductivity type doped region and the first sub-doped region, a second PN junction region is formed between the first conductivity type substrate and the second conductivity type doped region, and a third PN junction region is formed between the second conductivity type doped region and the second sub-doped region.
10. The Zener diode according to claim 9, characterized in that, The doping concentration of the second PN junction region is less than that of the first PN junction region, and the doping concentration of the first PN junction region is equal to that of the third PN junction region.
11. The Zener diode according to claim 9, characterized in that, The breakdown voltage of the second PN junction region is greater than the breakdown voltage of the first PN junction region, and the breakdown voltage of the first PN junction region is equal to the breakdown voltage of the third PN junction region.
12. The Zener diode according to claim 1, characterized in that, The doping concentration of the first conductivity type substrate is between 1E17 atoms / cm 3 ~1E18 atoms / cm 3 .
13. The Zener diode according to claim 1, characterized in that, The doping concentration of the second conductivity type doped region is between 1E18 atoms / cm². 3 ~1E20 atoms / cm 3 .
14. The Zener diode according to claim 1, characterized in that, The doping concentration of the first conductivity type doped region is between 1E18 atoms / cm 3 ~1E21 atoms / cm 3 .
15. The Zener diode according to claim 1, characterized in that, The Zener diode also includes: The first electrode is electrically connected to the substrate of the first conductivity type; The second electrode is electrically connected to the first sub-doped region.