Transient voltage suppression protection device

Abstract

The utility model relates to a transient voltage suppression protection device comprising a first metal electrode, the top of which is coated with a substrate; the epitaxial layer is located on the substrate, an insulating layer is arranged on the epitaxial layer, a second metal electrode is arranged on the insulating layer, and a passivation layer connected with the insulating layer is arranged in a partial region of the second metal electrode; the first doped region is arranged in the central region of the top of the epitaxial layer; the semiconductor device comprises a substrate layer, a first doped region and two second doped regions, the two second doped regions are symmetrically arranged on the left side and the right side of the first doped region, the two second doped regions are not connected with the second doped regions, and the second doped regions penetrate through the epitaxial layer through the semiconductor region to be connected with the substrate layer. The left side and the right side of the second metal electrode extend to the portion, above the second doping area, of the insulating layer, and an avoiding area is arranged in the center of the insulating layer and used for enabling the second metal electrode to be directly connected with the first doping area.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of semiconductor, especially relates to a transient voltage suppression protection device. BACKGROUND

[0002] With the electronic product size is smaller and smaller, in the set top box interface, display card interface, USB interface etc. Many kinds of application to transient voltage suppression protection device from parameter performance and product volume put forward the request, especially in various overvoltage alternating current protection circuit, no matter the voltage polarity that adds on both ends, as long as the voltage is greater than trigger voltage can be turned on, realize bidirectional overvoltage protection function, also to the voltage symmetry of two directions is higher requirement, the traditional diode is composed of N type substrate and P type epitaxial layer, with the function of forward conduction, reverse cut-off, usually as transient voltage suppression protection device is used in direct current circuit.But in alternating current circuit, transient voltage suppression protection device can work in positive and negative two directions, so the traditional diode can not meet this requirement. Among them, in order to realize the working application of alternating current, one scheme is to seal two diodes in a package, and the requirement of alternating current change is met by reverse connection of the two diodes, but this packaging form is large in size, with the development of product to light, convenient, small, this kind of sealing technical scheme is gradually no longer suitable for electronic products;A scheme is to use NPN triode composed of N type substrate, P type epitaxial layer and N type doped area, which can be regarded as two diodes " back to back " to form, so that the integration of the product is further improved, and the demand of product miniaturization is met. But because the collector region and the emitter region of NPN triode are formed respectively, the doping concentration of collector region and the doping concentration of emitter region cannot be completely the same, no matter how to adjust, it will affect the voltage of the upper and lower two diodes of " back to back " at the same time, resulting in that the voltage symmetry of the upper and lower two diodes is not optimal. CONTENT OF UTILITY MODEL

[0003] The utility model aims at providing a kind of transient voltage suppression protection device, to solve the problems existing in the prior art.

[0004] The above technical purpose of the utility model is realized by the following technical scheme:

[0005] A kind of transient voltage suppression protection device, comprising:

[0006] The top of the first metal electrode is coated with a substrate;

[0007] Epitaxial layer is located on the substrate, the epitaxial layer is provided with an insulating layer, the second metal electrode is provided on the insulating layer, and the second metal electrode is provided with a passivation layer connected with the insulating layer in part area;

[0008] The first doped region is disposed in the top center region of the epitaxial layer;

[0009] The first doped region has two second doped regions, which are symmetrically arranged on the left and right sides of the first doped region. Neither of the two second doped regions is connected to the first doped region. The second doped region is connected to the substrate layer through the epitaxial layer via the semiconductor region. The left and right sides of the second metal electrode extend to the insulating layer above the second doped region. A clearance area is provided at the center of the insulating layer. The clearance area is used to allow the second metal electrode to be directly connected to the first doped region.

[0010] By adopting the above technical solution, since the two second doped regions are located on the left and right sides of the first doped region, and the two second doped regions are not directly connected to the first doped region, and the two second doped regions are connected to the substrate through the epitaxial layer via the semiconductor region, so that the substrate is connected to the two second doped regions through the semiconductor region, and both ends of the second metal electrode extend to the insulating layer above the two second doped regions, by setting the doping type of each directly connected region to be opposite, the transient voltage suppression protection device can have bidirectional high symmetry, thereby making the transient voltage suppression protection device more suitable for AC protection circuits and providing very good protection for the back-end circuits.

[0011] In a further embodiment, an epitaxial layer is disposed at the bottom of the first metal electrode, and a substrate is disposed at the bottom of the epitaxial layer located at the bottom of the first metal electrode.

[0012] In a further embodiment, a connection region is also included, the top end of which passes through the first metal electrode and is connected to a substrate located on top of the first metal electrode, the bottom end of which passes through the first metal electrode and is connected to a substrate located at the bottom of the first metal electrode, and the bottom end of the connection region passes through an epitaxial layer located at the bottom of the first metal electrode.

[0013] In a further embodiment, the transient voltage suppression protection device is symmetrical.

[0014] In a further embodiment, an insulating sealing layer is provided on the top of the second metal electrode, and a contact point electrically connected to the second metal electrode is provided on the insulating sealing layer.

[0015] In summary, this utility model has the following beneficial effects:

[0016] 1. By having two second doped regions located on the left and right sides of the first doped region, and the two second doped regions not directly connected to the first doped region, and by having the two second doped regions connected to the substrate through the epitaxial layer via the semiconductor region, the substrate is connected to the two second doped regions through the semiconductor region. Moreover, both ends of the second metal electrode extend to the insulating layer above the two second doped regions. Therefore, by setting the doping type of each directly connected region to be opposite, the transient voltage suppression protection device can have bidirectional high symmetry, thereby making the transient voltage suppression protection device more suitable for AC protection circuits and providing very good protection for the downstream circuits. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0018] In the figure, 1 is the first metal electrode; 2 is the substrate; 3 is the epitaxial layer; 4 is the insulating layer; 5 is the second metal electrode; 6 is the passivation layer; 7 is the first doped region; and 8 is the second doped region. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to the accompanying drawings.

[0020] Identical parts are indicated by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "upper," and "lower" used in the following description refer to the attached figures. Figure 1 In this specification, the terms "bottom surface" and "top surface," "inner" and "outer" refer to the direction toward or away from the geometry of a specific component. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this specification, "a plurality of" means two or more, unless otherwise explicitly and specifically defined by the direction of the center.

[0021] Example 1:

[0022] like Figure 1 As shown, a transient voltage suppression and protection device includes:

[0023] First metal electrode 1, the top of the first metal electrode 1 is coated with substrate 2;

[0024] An epitaxial layer 3 is located on a substrate 2. An insulating layer 4 is disposed on the epitaxial layer 3. A second metal electrode 5 is disposed on the insulating layer 4. A passivation layer 6 connected to the insulating layer 4 is disposed in a portion of the second metal electrode 5.

[0025] The first doped region 7 is disposed in the top center region of the epitaxial layer 3;

[0026] There are two second doped regions 8, which are symmetrically arranged on the left and right sides of the first doped region 7. Neither of the two second doped regions 8 is connected to the first doped region 8. The second doped regions 8 are connected to the substrate 2 through the epitaxial layer 3 via the semiconductor region. The left and right sides of the second metal electrode 5 extend to the insulating layer 4 above the second doped region 8. A clearance area is provided at the center of the insulating layer 4 to allow the second metal electrode 5 to be directly connected to the first doped region 7. An epitaxial layer 3 is provided at the bottom of the first metal electrode 1. A substrate 2 is provided at the bottom of the epitaxial layer 3 at the bottom of the first metal electrode 1. A connection area is also included. The top end of the connection area passes through the first metal electrode 1 and connects to the substrate 2 at the top of the first metal electrode 1. The bottom end of the connection area passes through the first metal electrode 1 and connects to the substrate 2 at the bottom of the first metal electrode 1. The bottom end of the connection area passes through the epitaxial layer 3 at the bottom of the first metal electrode 1. The transient voltage suppression protection device is symmetrical. An insulating sealing layer is provided at the top of the second metal electrode 5. A contact point electrically connected to the second metal electrode 5 is provided on the insulating sealing layer.

[0027] Specific implementation process: When the doping type of the substrate, the first doped region, the second doped region, and the semiconductor region is N-type, the doping type of the epitaxial layer is P-type, and the first doped region, the second doped region, and the epitaxial layer constitute a lateral NPN structure; when the doping type of the substrate, the first doped region, the second doped region, and the polysilicon layer is P-type, the doping type of the epitaxial layer is N-type, and the first doped region, the second doped region, and the epitaxial layer constitute a lateral PNP structure.

[0028] In the embodiments disclosed in this utility model, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "linking" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments disclosed in this utility model according to the specific circumstances.

[0029] This specific embodiment is merely an explanation of the present utility model and is not intended to limit the present utility model. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but as long as they are within the scope of the claims of the present utility model, they are protected by patent law.

Claims

1. A transient voltage suppression and protection device, characterized in that, include: A first metal electrode (1) is coated with a substrate (2) on its top; An epitaxial layer (3) is located on the substrate (2). An insulating layer (4) is disposed on the epitaxial layer (3). A second metal electrode (5) is disposed on the insulating layer (4). A passivation layer (6) connected to the insulating layer (4) is disposed in a portion of the second metal electrode (5). The first doped region (7) is disposed in the top center region of the epitaxial layer (3); There are two second doped regions (8), and the two second doped regions (8) are symmetrically arranged on the left and right sides of the first doped region (7). Neither of the two second doped regions (8) is connected to the first doped region (7). The second doped region (8) is connected to the substrate (2) through the semiconductor region through the epitaxial layer (3). The left and right sides of the second metal electrode (5) extend to the insulating layer (4) above the second doped region (8). A clearance area is provided at the center of the insulating layer (4). The clearance area is used to allow the second metal electrode (5) to be directly connected to the first doped region (7).

2. The transient voltage suppression and protection device according to claim 1, characterized in that: An epitaxial layer (3) is disposed at the bottom of the first metal electrode (1), and a substrate (2) is disposed at the bottom of the epitaxial layer (3) located at the bottom of the first metal electrode (1).

3. A transient voltage suppression and protection device according to claim 2, characterized in that, It also includes a connection region, the top end of which passes through the first metal electrode (1) and is connected to the substrate (2) located on top of the first metal electrode (1), the bottom end of which passes through the first metal electrode (1) and is connected to the substrate (2) located at the bottom of the first metal electrode, and the bottom end of the connection region passes through the epitaxial layer (3) located at the bottom of the first metal electrode (1).

4. The transient voltage suppression and protection device according to any one of claims 1-3, characterized in that: The transient voltage suppression and protection device is symmetrical.

5. A transient voltage suppression and protection device according to claim 1, characterized in that: An insulating sealing layer is provided on the top of the second metal electrode (5), and a contact point electrically connected to the second metal electrode (5) is provided on the insulating sealing layer.

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