Electrostatic discharge protection device and electrostatic discharge protection circuit

Abstract

The invention provides an electrostatic discharge protection device and an electrostatic discharge protection circuit, and the device comprises a first electrode; the functional layer is located on the surface of one side of the first electrode, and the functional layer can be switched between a high resistance state and a low resistance state under the action of voltage; the second electrode is located on the surface of the side, away from the first electrode, of the functional layer. The electrostatic discharge protection device is usually connected with a main circuit in parallel, and due to a phase change or resistance change structure in the electrostatic discharge protection device, when the main circuit works normally, resistance is high, and normal functions of the main circuit cannot be affected. When the main circuit is subjected to the ESD pulse, the resistance of the phase change or resistance change structure in the semiconductor device can be rapidly reduced, so that the ESD pulse in the main circuit is discharged, and the damage to the device in the main circuit is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of electrostatic discharge protection for integrated circuits, and more specifically, to an electrostatic discharge protection device and an electrostatic discharge protection circuit. Background Art

[0002] During the manufacturing, testing, transportation and use of integrated circuits, a certain amount of charge will accumulate in the environment around or inside the chip. When these chip pins form a path with the ground, the charge will be transferred, resulting in a transient large current. This transient large current will cause the performance of the chip to degrade, or even fail and burn. This transient large current is a typical electrostatic discharge (ESD) pulse. Summary of the invention

[0003] In view of this, the present application provides an electrostatic discharge protection device and an electrostatic discharge protection circuit, and the scheme is as follows:

[0004] An electrostatic discharge protection device, comprising:

[0005] a first electrode;

[0006] A functional layer located on a surface of one side of the first electrode, wherein the functional layer can be switched between a high resistance state and a low resistance state under the action of a voltage;

[0007] The second electrode is located on a surface of the functional layer that is away from the first electrode.

[0008] Preferably, in the electrostatic discharge protection device described above, the functional layer is one or more resistive switching layers.

[0009] Preferably, in the electrostatic discharge protection device described above, the functional layer includes:

[0010] A first insertion layer located on a surface of the first electrode facing the second electrode;

[0011] One or more resistive switching layers located on a surface of the first insertion layer facing away from the first electrode;

[0012] A second insertion layer is located on a surface of the resistive layer facing away from the first electrode.

[0013] Preferably, in the electrostatic discharge protection device described above, the thickness of the resistive switching layer is 10nm-500nm;

[0014] The material of the resistive switching layer is any one of OTS, MIEC and IMT.

[0015] Preferably, in the electrostatic discharge protection device described above, the material of the first insertion layer is a metal insertion layer or a metal oxide insertion layer;

[0016] The second insertion layer is a metal insertion layer or a metal oxide insertion layer.

[0017] Preferably, in the electrostatic discharge protection device described above, the thickness of the first insertion layer is 2nm-30nm;

[0018] The thickness of the second insertion layer is 2nm-30nm.

[0019] Preferably, in the electrostatic discharge protection device described above, the thickness of the first electrode is 10nm-5um;

[0020] The thickness of the second electrode is 10nm-5um.

[0021] Preferably, in the electrostatic discharge protection device described above, the first electrode, the functional layer and the second electrode are arranged in sequence in the first direction;

[0022] The functional layer is a resistive switching functional layer;

[0023] The first direction is perpendicular to the first electrode and the second electrode, and parallel to the resistive switching functional layer.

[0024] Preferably, in the electrostatic discharge protection device described above, the length of the resistive switching functional layer is 1 μm-10 μm, and the thickness is 20 nm-200 nm.

[0025] The present application also provides an electrostatic discharge protection circuit, comprising:

[0026] An electrostatic discharge protection device as described in any one of the above descriptions;

[0027] A main circuit is connected in parallel with the electrostatic discharge protection device.

[0028] Based on the above introduction, the present application provides an electrostatic discharge protection device and an electrostatic discharge protection circuit. The electrostatic discharge protection device is usually connected in parallel with the main circuit. Due to the phase change or resistive change structure in the electrostatic discharge protection device, when the main circuit is working normally, the resistance is high and will not affect the normal function of the main circuit. When the main circuit is subjected to an ESD pulse, the resistance of the phase change or resistive change structure in the semiconductor device will drop rapidly, thereby discharging the ESD pulse in the main circuit, thereby reducing damage to the devices in the main circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0030] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not used to limit the conditions under which this application can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size, without affecting the effects and purposes that can be achieved by this application, should still fall within the scope of the technical contents disclosed in this application.

[0031] Figure 1 A schematic diagram of the structure of an electrostatic discharge protection device provided in an embodiment of the present application;

[0032] Figure 2 A schematic diagram of the structure of another electrostatic discharge protection device provided in an embodiment of the present application;

[0033] Figure 3 A schematic diagram of the structure of another electrostatic discharge protection device provided in an embodiment of the present application;

[0034] Figure 4 A top view of an electrostatic discharge protection device provided in an embodiment of the present application;

[0035] Figure 5 A circuit diagram of an electrostatic discharge protection circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the embodiments in 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 making creative work are within the scope of protection of this application.

[0037] In order to achieve ESD protection, an ESD protection device is provided, which realizes electrostatic discharge by setting active devices such as PN junctions on a silicon base, thereby protecting the core devices in the main circuit. This type of electrostatic discharge protection device includes devices such as Zener diodes, GGNMOS (gate grounded N-channel field effect transistors), SCRs (silicon controlled rectifiers), etc. The core components for realizing electrostatic discharge in the above-mentioned devices are all PN junctions, but the devices that use PN junctions to realize electrostatic discharge protection are large in size and will produce parasitic parameters, as well as large area overhead of Si materials and difficulty in integrated circuit (IC) layout. In theory, the best ESD protection structure can be any ideal state that meets the above conditions and will not cause additional problems.

[0038] Based on the problems of the electrostatic discharge protection device introduced above, the present application provides an electrostatic discharge protection device, which includes: a first electrode; a functional layer located on one side surface of the first electrode, and the functional layer can be switched between a high resistance state and a low resistance state under the action of voltage; a second electrode, located on the side surface of the functional layer away from the first electrode.

[0039] Among them, the functional layer has natural phase change and resistance change characteristics. When the voltage reaches a certain threshold, it will generate a large on-state current. When it is lower than the threshold, it is in the off state and the leakage current is small. By adjusting the structure and size of the functional layer, an electrostatic discharge protection device with low leakage current, high failure current, fast disconnection, low parasitic capacitance, high integration and simple structure can be formed.

[0040] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0041] refer to Figure 1 , Figure 1 A schematic diagram of the structure of an electrostatic discharge protection device provided in an embodiment of the present application, the electrostatic discharge protection device includes: a first electrode 10; a functional layer 11 located on one side surface of the first electrode 10, the functional layer 11 can switch between a high resistance state and a low resistance state under the action of voltage; a second electrode 12, located on the side surface of the functional layer 11 away from the first electrode 10.

[0042] The electrostatic discharge protection device is usually connected in parallel with the main circuit. Due to the phase change or resistance change structure in the electrostatic discharge protection device, when the main circuit is working normally, the resistance is high and will not affect the normal function of the main circuit. When the main circuit is subjected to an ESD pulse, the resistance of the phase change or resistance change structure in the semiconductor device will drop rapidly, thereby discharging the ESD pulse in the main circuit, thereby reducing damage to the devices in the main circuit.

[0043] The resistance of the functional layer 11 when it is in a high resistance state is higher than the resistance of the functional layer 11 when it is in a low resistance state.

[0044] refer to Figure 2 , Figure 2 A schematic diagram of the structure of another electrostatic discharge device provided in an embodiment of the present application. Figure 1 and Figure 2 As shown, in the electrostatic discharge protection device provided by the present application, the functional layer 11 is one or more resistive switching layers 111 .

[0045] The thickness of the functional layer 11 is related to the threshold voltage of the electrostatic discharge protection device. The thicker the functional layer 11 is, the higher the threshold voltage is, and the thinner the functional layer 11 is, the lower the threshold voltage is. However, the thickness of a single-layer resistive layer 111 is limited. Therefore, one or more layers of resistive layer 111 can be selected to form the functional layer 11 according to the situation to meet the usage requirements.

[0046] The functional layer 11 can be converted between a high resistance state and a low resistance state under the action of voltage. In the embodiment of the present application, the threshold voltage refers to the voltage value corresponding to the midpoint of the turning zone where the resistance state of the functional layer 11 changes sharply with the change of the input voltage. Under normal circumstances, it is believed that when the voltage is higher than the threshold voltage, the functional layer 11 is in a low resistance state; when the voltage is lower than the threshold voltage, the functional layer 11 is in a high resistance state.

[0047] refer to Figure 3 , Figure 3 A schematic diagram of the structure of another electrostatic discharge device provided in an embodiment of the present application, Figure 3 In the electrostatic discharge protection device shown, the functional layer 11 includes: a first insertion layer 131 located on the surface of the first electrode 10 facing the second electrode 12; one or more resistive layers 111 located on the surface of the first insertion layer 131 facing away from the first electrode 10; and a second insertion layer 132 located on the surface of the resistive layer 111 facing away from the first electrode 10.

[0048] By providing the first insertion layer 131 and the second insertion layer 132, the stability of the connection between the resistive layer 111 and the electrode can be improved, and the contact resistance between the resistive layer 111 and the electrode can be reduced, so that the total resistance of the electrostatic discharge protection device during operation is reduced. At the same time, the reduction in resistance can also reduce the time for the electrostatic discharge protection device to discharge ESD pulses.

[0049] In the electrostatic discharge protection device provided in the present application, the thickness of the resistive layer 111 is 10nm-500nm; the material of the resistive layer 111 is: any one of OTS (based on bidirectional threshold switching), MIEC (mixed ionic electronic conduction), and IMT (insulator to metal transition).

[0050] Among them, OTS materials are generally amorphous sulfur compounds and oxide materials. When the voltage is lower than the threshold voltage, this material has a low leakage current and is close to being closed. When the voltage reaches the threshold voltage, electrical breakdown will occur inside the OTS material. The electron breakdown may be caused by field emission, Zener tunneling or collision ionization of electrons from the valence band or occupied localized states to the conduction band. After breakdown, excess carriers fill traps and recombination centers, and the rapid increase in excess carrier drift mobility will lead to the generation of negative differential IV characteristics.

[0051] IMT materials usually refer to an oxide material that can reversibly and rapidly transform between a high-resistance insulating state and a low-resistance metallized state under the action of an electric field or Joule heat. The most common IMT materials are VO2 and NbO2. Taking NbO2 as an example, under the action of an applied voltage, the temperature of NbO2 will increase with the increase of voltage. When the temperature of NbO2 is higher than a certain value, NbO2 will transform from an insulating tetragonal phase to a metallic rutile phase, thereby causing the electrostatic discharge protection device to transform from a high-resistance state to a low-resistance state.

[0052] Under the influence of external factors, the electrons and ions inside the MIEC material will conduct together, thereby realizing the transition from a high resistance state to a low resistance state. When the influence of external factors disappears, the material can also realize the transition from a low resistance state to a high resistance state. It should be noted that the material of the resistive layer 111 can also be selected from other types of materials according to needs. This application takes the above three types as examples and does not limit the materials used in the resistive layer 111.

[0053] In the electrostatic discharge protection device provided in the present application, the material of the first insertion layer 131 is a metal insertion layer or a metal oxide insertion layer; the second insertion layer 132 is a metal insertion layer or a metal oxide insertion layer.

[0054] The materials of the first insertion layer 131 and the second insertion layer 132 used in the present application can be common metal materials such as copper, silver, aluminum, zinc, iron, nickel, chromium, tungsten, titanium, etc., and can also be made of oxides of certain metals such as: GaO x MgO x , ZrO x The materials of the first insertion layer 131 and the second insertion layer can be selected according to actual conditions, and this application does not limit this. Among them, the resistivity of the above-mentioned several conductive metal materials is different, and the resistance of the first insertion layer 131 and the second insertion layer 132 can be changed by changing the conductive metal material used, thereby changing to increase the trigger voltage threshold of the electrostatic discharge protection device that causes the resistance change.

[0055] In the electrostatic discharge protection device provided in the present application, the thickness of the first insertion layer 131 is 2 nm-30 nm; the thickness of the second insertion layer 132 is 2 nm-30 nm.

[0056] The thickness of the first insertion layer 131 and the second insertion layer 132 is usually between 2nm and 30nm, and the thickness can be set according to the thickness of the resistive layer 111. The threshold voltage of the electrostatic discharge protection device can be changed by the thickness and material selection of the first insertion layer 131 and the second insertion layer 132 to meet the requirements of various circuits.

[0057] In the electrostatic discharge protection device provided in the present application, the thickness of the first electrode 10 is 10 nm-5 μm; the thickness of the second electrode 12 is 10 nm-5 μm.

[0058] The first electrode 10 and the second electrode 12 are usually metal electrodes. The thicker the metal electrode, the better the overall performance of the electrostatic discharge protection device and the worse the current carrying capacity. Therefore, in the electrostatic discharge protection device provided in the present application, the thickness of the first electrode 10 and the second electrode 12 are selected to be between 10nm-5μm. Metal electrodes within this range have higher current carrying capacity, smaller size, and better performance of electrostatic discharge protection devices.

[0059] refer to Figure 4 , Figure 4 A top view of an electrostatic discharge protection device provided in an embodiment of the present application, Figure 4 In the electrostatic discharge protection device shown, the first electrode 10, the functional layer 11 and the second electrode 12 are arranged in sequence in the first direction; the functional layer 11 is a resistive functional layer 112; wherein the first direction is perpendicular to the first electrode 10 and the second electrode 12, and parallel to the resistive functional layer 112.

[0060] In an embodiment of the present application, the first electrode 10, the resistive functional layer 112, and the second electrode are arranged in the same plane. The height of the electrostatic discharge protection device formed based on this structure is relatively low, so as to adapt to some devices with a relatively small vertical height inside the device. The electrostatic discharge protection device provided in the present application can extend the distance between the two electrodes and increase the threshold voltage by increasing the length of the resistive functional layer 112, which has a better effect for scenarios requiring ESD protection with higher threshold voltages. With this structure, a high threshold voltage can be achieved when the device thickness is relatively low, thereby adapting to the main circuit with a higher operating voltage.

[0061] In the electrostatic discharge protection device provided in the present application, the length of the resistive switching functional layer 112 is 1 μm-10 μm, and the thickness is 20 nm-200 nm.

[0062] The longer the length of the resistive functional layer 112, the greater the threshold voltage of the electrostatic discharge protection device. Normally, the length of the resistive functional layer 112 is between 1 μm and 10 μm. However, when the required threshold voltage is small, the length of the resistive functional layer 112 can be further shortened. If the threshold voltage required by the target device is large, the length of the resistive functional layer 112 can be appropriately increased, or a multilayer resistive functional layer 11 can be set to meet the requirements. The thickness of the resistive functional layer 112 between 20nm and 200nm can provide better structural strength, as well as high resistance of the resistive functional layer 112 in the high resistance state and low resistance in the low resistance state. Reduce the impact on the main circuit and quickly discharge the ESD pulse in the low resistance state.

[0063] refer to Figure 5 , Figure 5 A schematic diagram of an electrostatic discharge protection circuit provided in an embodiment of the present application, the electrostatic discharge protection circuit includes: an electrostatic discharge protection device 21 as in any of the above embodiments; a main circuit 22, the main circuit 22 is connected in parallel with the electrostatic discharge protection device.

[0064] During the normal operation of the main circuit 22, the electrostatic discharge protection device 21 is in a high impedance state, and the shunting of the main circuit 22 can be ignored, so as not to affect the normal function of the main circuit 22. When a certain position of the main circuit 22 is subjected to an ESD pulse, the electrostatic discharge protection device 21 can be turned on within a few nanoseconds or even tens of picoseconds to discharge the ESD pulse current, thereby preventing the components in the main circuit 22 from being damaged and protecting the internal core circuit.

[0065] like Figure 5 The circuit shown is a circuit design diagram provided by an embodiment of the present application. In the electrostatic discharge protection circuit, the main circuit 23 includes: a first MOS tube 231 and a second MOS tube 232. When an ESD pulse enters the circuit from port 20, the electrostatic discharge protection device 21 will work, thereby discharging the ESD pulse to ground 22, thereby preventing the ESD pulse from entering the main circuit 25, thereby protecting the main circuit 25. It should be noted that the electrostatic discharge protection device 21 has a threshold voltage, so when the voltage at port 20 is less than the threshold voltage, the electrostatic discharge protection device 21 will not work, thereby avoiding short-circuiting the main circuit 23. Among them, Figure 5 The connection mode of the main circuit shown is only a circuit structure. The electrostatic discharge protection device 21 provided in this application only needs to be connected in parallel with the device to be protected to achieve ESD protection for the device. It should be noted that this application does not limit the main circuit device to be protected.

[0066] In this specification, each embodiment is described in a progressive, parallel, or progressive and parallel manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other. For the circuit disclosed in the embodiment, since it corresponds to the device disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part device.

[0067] It should be noted that in the description of the present application, it should be understood that the description of the drawings and embodiments is illustrative rather than restrictive. The same reference numerals throughout the embodiments of the specification identify the same structure. In addition, for the sake of understanding and ease of description, the drawings may exaggerate the thickness of some layers, films, panels, regions, etc. It is also understood that when an element such as a layer, film, region, or substrate is referred to as "on" another element, the element may be directly on the other element or there may be an intermediate element. In addition, "on" refers to positioning an element on or below another element, but does not essentially refer to positioning on the upper side of another element according to the direction of gravity.

[0068] The terms "upper", "lower", "top", "bottom", "inner", "outer", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. When a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be a centrally arranged component at the same time.

[0069] It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that an article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such article or device. In the absence of further restrictions, the elements defined by the sentence "comprising a ..." do not exclude the existence of other identical elements in the article or device including the above elements.

[0070] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An electrostatic discharge protection device, characterized in that: include: a first electrode; A functional layer located on a surface of one side of the first electrode, wherein the functional layer can be switched between a high resistance state and a low resistance state under the action of a voltage; The second electrode is located on a surface of the functional layer that is away from the first electrode.

2. The electrostatic discharge protection device according to claim 1, characterized in that: The functional layer is one or more resistive switching layers.

3. The electrostatic discharge protection device according to claim 1, characterized in that: The functional layer comprises: A first insertion layer located on a surface of the first electrode facing the second electrode; One or more resistive switching layers located on a surface of the first insertion layer facing away from the first electrode; A second insertion layer is located on a surface of the resistive layer facing away from the first electrode.

4. The electrostatic discharge protection device according to claim 3, characterized in that: The thickness of the resistive layer is 10nm-500nm; The material of the resistive switching layer is any one of OTS, MIEC and IMT.

5. The electrostatic discharge protection device according to claim 3, characterized in that: The first insertion layer is a metal insertion layer or a metal oxide insertion layer; The second insertion layer is a metal insertion layer or a metal oxide insertion layer.

6. The electrostatic discharge protection device according to claim 3, characterized in that: The thickness of the first insertion layer is 2nm-30nm; The thickness of the second insertion layer is 2nm-30nm.

7. The electrostatic discharge protection device according to claim 1, characterized in that: The thickness of the first electrode is 10nm-5μm; The thickness of the second electrode is 10nm-5um.

8. The electrostatic discharge protection device according to claim 1, characterized in that: The first electrode, the functional layer and the second electrode are arranged sequentially in a first direction; The functional layer is a resistive switching functional layer; The first direction is perpendicular to the first electrode and the second electrode, and parallel to the resistive switching functional layer.

9. The electrostatic discharge protection device according to claim 8, characterized in that: The resistive switching functional layer has a length of 1 μm-10 μm and a thickness of 20 nm-200 nm.

10. An electrostatic discharge protection circuit, characterized in that: include: The electrostatic discharge protection device according to any one of claims 1 to 9; A main circuit is connected in parallel with the electrostatic discharge protection device.

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