Resistive switching memory device including diode-type thin film for controlling hydrogen ions, driving method thereof, and manufacturing method thereof

Abstract

The present invention relates to a resistive switching memory device that can exhibit the characteristics of a non-volatile memory, due to an internal electric field of a diode-type thin film, even when an external electric field is removed, a driving method thereof, and a manufacturing method thereof. In particular, the resistive switching memory device may include: a first electrode; a resistive switching layer disposed on the first electrode; a diode-type thin film disposed on the resistive switching layer; a hydrogen supply layer disposed on the diode-type thin film; and a second electrode disposed on the hydrogen supply layer.

Description

Resistance change memory device including diode-type thin film for hydrogen ion control, driving method thereof, and manufacturing method thereof

[0001] The present invention relates to a resistance change memory element capable of having non-volatile memory characteristics due to an internal electric field of a diode-type thin film even when an external electric field is removed, a driving method thereof, and a manufacturing method thereof.

[0002] Nonvolatile memory, which electrically controls data input and output, possesses the advantage of retaining information even after power is removed. The fundamental principle for storing information is charge storage, and for input and output, fast operating speed, low operating voltage, high durability, and high integration are essential.

[0003] Oxide-based resistive switching memory (RRAM) has recently attracted attention, recording information by generating and erasing conductive filaments formed between upper and lower electrodes. However, this oxide-based resistive memory exhibits volatility. When the external voltage is removed, the conductive path naturally disappears, or the conductive path is destroyed by changes in the concentration of oxygen vacancies or Joule heat generated by reapplied voltage, returning to its original state. This makes it difficult to maintain non-volatile data and limits memory reliability.

[0004] While the precise mechanisms underlying the formation and destruction of conductive pathways remain unclear, recent research has revealed that ion movement and concentration gradient-driven diffusion occur competitively around conductive pathways. This diffusion can persist even after the electric field is removed, leading to the spontaneous loss of the stored state.

[0005] Therefore, various structural approaches are being attempted to overcome the volatility limitations of oxide-based resistive memory and realize memory devices with true non-volatile characteristics by implementing structures that stabilize the positions of ions and physically maintain conductive paths even in the absence of voltage application, but practical solutions are still lacking.

[0006] The background technology of the invention has been prepared to facilitate a better understanding of the present invention. It should not be construed as an admission that the matters described in the background technology of the invention constitute prior art.

[0007] Conventional resistive memory devices have attracted attention as next-generation non-volatile memory devices due to their relatively simple structure, low manufacturing costs, and fast response speeds. In particular, devices utilizing oxide-based resistive layers store information by utilizing conductive filaments that can be formed and destroyed by applying voltage between upper and lower electrodes.

[0008] However, this structure has a limitation in that it cannot stably maintain the conductive path even after the external voltage is removed, which leads to the problem of volatility characteristics appearing due to the collapse of the conductive path by rearrangement of oxygen vacancies or residual diffusion.

[0009] To solve this problem, various material combinations and structural improvements have been attempted, but there are still factors that hinder practical application, such as state instability due to ion diffusion when the external electric field is removed, failure to maintain data, and increased resistance deviation due to repeated use of the device.

[0010] In particular, the conductive paths in oxide-based resistive memory are formed in an extremely unstable manner. This is the primary cause of memory state loss, as hydrogen ions or oxygen vacancies spontaneously rearrange according to Joule heat and concentration gradients within the material when a voltage is applied. Therefore, the need for a structure capable of stabilizing ion positions and irreversibly maintaining the resistive state even after the electric field is removed has been raised.

[0011] Accordingly, the inventors of the present invention have noticed that by laminating a diode-type thin film capable of controlling the movement of hydrogen ions on a resistance conversion layer, a polarization state induced when a voltage is applied is maintained even after the electric field is removed, and an internal electric field caused by this polarization effectively suppresses ion diffusion, thereby realizing non-volatile characteristics.

[0012] Accordingly, the inventors of the present invention have invented a resistance change memory device, a method of driving the same, and a method of manufacturing the same, which uses a ferroelectric or polarizable oxide series material in a diode-type thin film, thereby forming its own internal electric field even after an electric field is applied, and enabling the internal electric field to function as an electrical barrier for fixing hydrogen ions.

[0013] Accordingly, the problem to be solved by the present invention is to provide a resistance change memory device including a diode-type thin film for hydrogen ion control, a driving method thereof, and a manufacturing method thereof, which overcomes the volatility problems, low data retention, and device-to-device variation problems that occur in traditional oxide-based memory structures, and which can stably maintain a resistance state even after an external power source is removed by combining a hydrogen ion-based resistance transition mechanism and an internal electric field-based ion movement suppression structure.

[0014] The problems to be solved by the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

[0015] In order to solve the above-described problem, a resistance change memory device including a diode-type thin film for hydrogen ion control according to an example of the present invention is provided. The resistance change memory device may include a first electrode; a resistance change layer disposed on the first electrode; a diode-type thin film disposed on the resistance change layer; a hydrogen supply layer disposed on the diode-type thin film; and a second electrode disposed on the hydrogen supply layer.

[0016] According to a feature of the present invention, the diode-type thin film may include at least one selected from the group consisting of Al, Zr, In, Bi, La, Y, Sr, Zn, Ti, Ta, Gd and Hf.

[0017] According to a feature of the present invention, the diode-type thin film may have a thickness of 1 nm to 20 nm or less.

[0018] According to a feature of the present invention, the resistance change layer may include any one selected from the group consisting of IGZO (InGaZnO), ITZO (InSnZnO), ZnO, AZO (Al-doped ZnO), and TaOx.

[0019] According to a feature of the present invention, the resistance change layer may have a thickness of 20 nm to 80 nm.

[0020] According to a feature of the present invention, the hydrogen supply layer is 10 20 atoms / cm 3 10 inland 22 atoms / cm 3 may contain hydrogen concentrations.

[0021] According to a feature of the present invention, the hydrogen supply layer may be composed of an insulating film with a controlled hydrogen content to facilitate the movement of hydrogen ions.

[0022] According to a feature of the present invention, the diode-type thin film may be composed of a ferroelectric material to form an electrical barrier that maintains residual polarization even after the electric field is removed, thereby suppressing reverse diffusion of hydrogen ions.

[0023] According to a feature of the present invention, when the first electrode is connected to ground and a positive voltage is applied to the second electrode, the resistance change layer may exhibit a first resistance state in which it is set to a low resistance state, and when the first electrode is connected to ground and a negative voltage is applied to the second electrode, the resistance change layer may exhibit a second resistance state in which it is reset to a high resistance state.

[0024] According to a feature of the present invention, when a positive voltage is removed from the second electrode, the first resistance state can be maintained by the internal electric field of the diode-type thin film.

[0025] According to a feature of the present invention, when a negative voltage is removed from the second electrode, the second resistance state can be maintained by the internal electric field of the diode-type thin film.

[0026] According to a feature of the present invention, in the first resistance state, hydrogen ions in the hydrogen supply layer can move to the resistance change layer.

[0027] According to a feature of the present invention, in the second resistance state, hydrogen ions in the resistance change layer can move to the hydrogen supply layer.

[0028] In order to solve the above-described problem, a method for driving a resistance change memory element including a diode-type thin film for hydrogen ion control according to an example of the present invention is provided. The driving method of the resistance change memory element including a first electrode, a resistance change layer, a diode-type thin film, a hydrogen supply layer, and a second electrode may include a step of inducing a first movement of hydrogen ions by connecting the first electrode to ground and applying a positive voltage to the second electrode.

[0029] According to a feature of the present invention, in the step of inducing the first movement, hydrogen ions in the hydrogen supply layer can move to the resistance change layer.

[0030] According to a feature of the present invention, after the step of inducing the first movement, a step of inducing the second movement of hydrogen ions by connecting the first electrode to ground and applying a negative voltage to the second electrode may be further included.

[0031] According to a feature of the present invention, in the step of inducing the second movement, hydrogen ions in the resistance change layer can move to the hydrogen supply layer.

[0032] According to a feature of the present invention, in the step of inducing the first movement, the resistance change layer can be set to a low resistance state.

[0033] According to a feature of the present invention, in the step of inducing the second movement, the resistance change layer can be reset to a high resistance state.

[0034] In order to solve the above-described problem, a method for manufacturing a resistance variable memory device including a diode-type thin film for hydrogen ion control according to an example of the present invention is provided. The method may include the steps of forming a first electrode on a substrate; depositing a resistance change layer on the first electrode; depositing a diode-type thin film made of a ferroelectric material on the resistance change layer; depositing a hydrogen supply layer containing hydrogen on the diode-type thin film; and forming a second electrode on the hydrogen supply layer.

[0035] Specific details of other embodiments are included in the detailed description and drawings.

[0036] The resistance-variable memory device according to the present invention can function as a diode or blocking layer even when an external electric field is removed due to the internal electric field of the diode-type thin film. Accordingly, the reliability of the non-volatile memory can be improved by controlling the movement of ions between layers.

[0037] In addition, improved response speed and low-voltage operation are possible by inducing resistance change within the resistance change layer through the movement of hydrogen ions that are light in weight and have a fast movement speed.

[0038] In addition, the polarization characteristics of the diode-type thin film facilitate the movement of hydrogen ions, which can help lower the driving voltage and improve the response speed.

[0039] In addition, the resistance change memory element according to one embodiment of the present invention has a 2-terminal structure, enabling high integration.

[0040] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

[0041] FIG. 1 is a cross-sectional view of a resistance change memory element according to one embodiment of the present invention.

[0042] FIG. 2 is a cross-sectional view showing an initial state in which no voltage is applied or removed to a resistance change memory element according to one embodiment of the present invention.

[0043] FIG. 3 is a drawing for explaining a driving method when a positive voltage is applied to a resistance change memory element according to one embodiment of the present invention.

[0044] FIG. 4 is a drawing for explaining a driving method when a positive voltage is applied to a resistance change memory element according to one embodiment of the present invention and then removed.

[0045] FIG. 5 is a drawing for explaining a driving method when a negative voltage is applied to a resistance change memory element according to one embodiment of the present invention.

[0046] FIG. 6 is a drawing for explaining a driving method when a negative voltage is applied to a resistance change memory element according to one embodiment of the present invention and then removed.

[0047] FIG. 7 is a diagram illustrating the structure and operating characteristics of a resistance change memory device that does not include a diode-type thin film according to a comparative example of the present invention.

[0048] FIG. 8 is a drawing illustrating the structure and operating characteristics of a resistance change memory device including a diode-type thin film according to one embodiment of the present invention.

[0049] FIG. 9 is a flowchart showing a method for manufacturing a resistance change memory device including a diode-type thin film according to one embodiment of the present invention.

[0050] Specific structural and step-by-step descriptions of embodiments according to the concepts of the present invention disclosed in this specification or application are merely illustrative for the purpose of explaining embodiments according to the concepts of the present invention. Embodiments according to the concepts of the present invention may be implemented in various forms and should not be construed as limited to the embodiments described in this specification or application.

[0051] Embodiments according to the concept of the present invention can be modified in various ways and take on various forms. Therefore, specific embodiments are illustrated in the drawings and described in detail in this specification or application. However, this is not intended to limit embodiments according to the concept of the present invention to a specific disclosed form, and it should be understood that all modifications, equivalents, and alternatives fall within the spirit and technical scope of the present invention.

[0052] While terms such as "first" and / or "second" may be used to describe various components, these components should not be limited by these terms. These terms are intended solely to distinguish one component from another. For example, without departing from the scope of the invention, a first component may be referred to as a "second component," and similarly, a second component may also be referred to as a "first component."

[0053] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components in between. Conversely, when a component is referred to as being "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between. Other expressions that describe the relationship between components, such as "between" and "immediately between" or "adjacent to" and "directly adjacent to," should be interpreted similarly.

[0054] In the present invention, expressions such as "A or B," "at least one of A and / or B," or "one or more of A or / and B" can include all possible combinations of the listed items. For example, "A or B," "at least one of A and B," or "at least one of A or B" can all refer to cases where (1) at least one A is included, (2) at least one B is included, or (3) both at least one A and at least one B are included.

[0055] The expressions "first," "second," "first," or "second," used in the present invention can describe various components, regardless of order and / or importance, and are only used to distinguish one component from another, but do not limit the components. For example, a first user device and a second user device can represent different user devices, regardless of order or importance. For example, without departing from the scope of the rights set forth in this document, a first component can be referred to as a second component, and similarly, a second component can also be referred to as a first component.

[0056] The terms used herein are solely for the purpose of describing specific embodiments and may not be intended to limit the scope of other examples. Singular expressions may include plural expressions unless the context clearly dictates otherwise. Terms used herein, including technical or scientific terms, have the same meaning as commonly understood by those skilled in the art described herein.

[0057] Terms used in this invention, including those defined in general dictionaries, may be interpreted as having the same or similar meaning within the context of the relevant technology. Unless explicitly defined herein, they shall not be interpreted in an idealized or overly formal sense. In some cases, even if a term is defined herein, it cannot be interpreted to exclude embodiments of this document.

[0058] The terminology used herein is merely used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In the present invention, terms such as "comprise" or "have" indicate the presence of a described feature, number, step, operation, component, part, or combination thereof. Therefore, it should be understood that they do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0059] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0060] The individual features of the various examples of the present invention can be partially or fully combined or combined with one another. Therefore, as those skilled in the art will readily understand, the various examples are capable of various technical connections and operations. Each example can be implemented independently of the other or together in a related manner.

[0061] In describing one embodiment of the present invention, descriptions of technical details that are well-known in the technical field to which the present invention pertains and are not directly related to the present invention may be omitted. This is to avoid obscuring the gist of the present invention by omitting unnecessary explanations and to convey the gist more clearly.

[0062]

[0063] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.

[0064] First, a resistance change memory element according to one embodiment of the present invention will be described with reference to FIG. 1.

[0065] Fig. 1 is a cross-sectional view of a resistance change memory element according to one embodiment of the present invention. (In Fig. 1, each layer does not represent an actual thickness, but is arbitrarily depicted for the purpose of explaining the resistance change memory element of the present invention.)

[0066] Referring to FIG. 1, a resistance change memory device according to an embodiment of the present invention may include a first electrode (10), a resistance change layer (active layer) (20) disposed on the first electrode (10), a diode-type thin film (30) disposed on the resistance change layer (20), a hydrogen supply layer (hydrogen layer) (40) disposed on the diode-type thin film (30), and a second electrode (50) disposed on the hydrogen supply layer (40). The resistance change memory device of the present invention has a 2-terminal structure and may be driven by utilizing the movement of hydrogen ions induced to the resistance change layer (20). When having a 2-terminal structure like this, high integration may be possible. In addition, the resistance change memory device of the present invention may have a horizontal structure in which the first electrode (10), the resistance change layer (20), the diode-type thin film (30), the hydrogen supply layer (40), and the second electrode (50) are disposed horizontally.

[0067] The first electrode (10) of the present invention may include a metal or a doped semiconductor. Specifically, the first electrode (10) may include any one selected from the group consisting of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), palladium (Pd), tantalum (Ta), platinum (Pt), titanium (Ti), nickel (Ni), and copper (Cu), or an alloy thereof, or doped silicon (Si). However, the materials mentioned above are merely exemplary, and any other conductive material that can generate an electric field may be used as the first electrode (10) of the present invention.

[0068] The resistance change layer (20) of the present invention may be disposed on the first electrode (10). In the present invention, the resistance change layer (20) may mean a layer whose resistance is changed by an external electric field. The resistance change layer (20) of the present invention may include an oxide semiconductor or a material whose resistance is changed by an external electric field, such as hydrogen ions or oxygen vacancies. Specifically, the oxide semiconductor or the material whose resistance is changed may be any one selected from the group consisting of IGZO (InGaZnO), ITZO (InSnZnO), ZnO, AZO (Al-doped ZnO), TiO2, HfO2, CeO2, LAO (LaAlO3), SrTiO3, NiO, and ZnSnO3. Preferably, it may include IGZO (InGaZnO). However, the materials mentioned above are merely exemplary, and any other material whose resistance is changed by an external electric field may be used as the resistance change layer (20) of the present invention.

[0069] The thickness of the resistance change layer (20) may be 20 nm to 80 nm.

[0070] The diode-type thin film (30) of the present invention may be disposed on the resistance conversion layer (20). In the present invention, the diode-type thin film (30) may be a thin film that allows movement of particles (electrons, ions, etc.) in one direction, similar to a diode, but blocks movement of particles (electrons, ions, etc.) in the opposite direction. In one example, the diode-type thin film (30) may include a ferroelectric material having polarization characteristics. The diode-type thin film (30) of the present invention may include at least one selected from the group consisting of Al, Zr, Cu, In, Bi, Pb, Mn, Fe, Ni, La, Y, Sr, Zn, Ti, Ta, Gd, and Hf. Specifically, the diode-type thin film (30) is PZT (Pb(Zr,Ti)O3), PTO (PbTiO3), SBT (SrBi2Ti2O3), BLT (Bi(La,Ti)O3), PLZT (Pb(La,Zr)TiO3), BST (Bi(Sr,Ti)O3), barium titanate (BaTiO3), PVDF, HfO2, ZrO2, TiO2, Al2O3, Ta2O5, MnO x , BiFeO x , BaTiO x , ZrO x , NiO x , AlO x , ZnO x , TiO x , TaO x , WO x , CuO x , InO x and HfO x It may include at least one oxide selected from the group consisting of. Preferably HfO x, and in this case, x is a positive number greater than 0 and less than or equal to 2, and may have crystallinity. However, the materials mentioned above are merely exemplary, and any ferroelectric material that has a dipole, exhibits polarization characteristics, and has crystallinity may be used as the diode-type thin film (30) of the present invention.

[0071] The thickness of the diode-type thin film (30) may be 1 nm to 20 nm or less. If the thickness of the diode-type thin film (30) is thicker than the above range, even if an external voltage is applied, the influence of the electric field applied to the diode-type thin film (30) is weakened, so that the dipole alignment of the material within the diode-type thin film (30) is lowered and the polarization characteristics may not be well exhibited.

[0072] When an external voltage is applied to a resistance change memory device according to the present invention and then removed, the diode-type thin film (30) can function as a blocking layer like a diode due to an internal electric field existing within the diode-type thin film (30). Accordingly, it can have the characteristics of a non-volatile memory. The mechanism by which the diode-type thin film (30) behaves like a blocking layer will be described in detail later together with a description of a driving method of the resistance change memory device according to the present invention.

[0073] The hydrogen supply layer (40) of the present invention may be placed on a diode-type thin film (30). The hydrogen supply layer (40) may include hydrogen or hydrogen ions. The hydrogen supply layer (40) may be 10 20 atoms / cm 3 10 inland 22 atoms / cm 3The hydrogen concentration may be included. When the resistance change memory element is driven, hydrogen ions in the hydrogen supply layer (40) may move to the resistance change layer (20) by an applied external voltage. The hydrogen supply layer (40) may be an insulating film containing hydrogen. At this time, the hydrogen supply layer (40) may be composed of an insulating film in which the hydrogen content is controlled to facilitate the movement of hydrogen ions. Specifically, the hydrogen supply layer (40) may be formed of an oxide nitride (SiN) that can effectively contain or fix hydrogen. x ) may be included.

[0074] The second electrode (50) of the present invention may be disposed on the hydrogen supply layer (40). The second electrode (50) may include a metal or a doped semiconductor. Specifically, the second electrode (50) may include any one selected from the group consisting of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), palladium (Pd), tantalum (Ta), platinum (Pt), titanium (Ti), nickel (Ni), and copper (Cu), or an alloy thereof, or doped silicon (Si). However, the materials mentioned above are merely exemplary, and any other conductive material that can generate an electric field may be used as the second electrode (50) of the present invention.

[0075] Meanwhile, the types or values ​​(thickness, concentration, etc.) of each layer are not limited to those mentioned above, and various modifications that can be easily changed or substituted and applied by a person having ordinary skill in the art are also included in the scope of the present invention. The resistance change memory device of the present invention can change its resistance state by inducing the movement of hydrogen ions. Specifically, when the first electrode (10) is connected to the ground and a positive voltage is applied to the second electrode (50), the resistance change layer (20) can exhibit a first resistance state in which it is set to a low resistance state. In the first resistance state, hydrogen ions in the hydrogen supply layer (40) can move to the resistance change layer (20) along the (external) electric field. Accordingly, the resistance of the resistance change layer (20) can be in a low state, and can exhibit memory characteristics by being set to this low resistance state. In the first resistance state, materials in the diode-type thin film (30) can exhibit a constant polarization direction according to the (external) electric field. Specifically, in the first resistance state, dipoles contained in the materials in the diode-type thin film (30) are arranged according to the electric field, so that positive (+) charges can be induced on the surface of the resistance change layer (20) side, and negative (-) charges can be induced on the surface of the hydrogen supply layer (40) side.

[0076] Meanwhile, when the positive voltage is removed from the second electrode (50) while the first electrode (10) is connected to the ground, the resistance change memory element of the present invention can maintain the first resistance state due to the internal electric field of the diode-type thin film (30). This is due to the polarization characteristics of the diode-type thin film (30). Even when the external voltage is removed, the diode-type thin film (30) can maintain the aligned polarization state due to the electric field when the external voltage is applied, and this is because an internal electric field can be formed within the diode-type thin film (30). In this way, the diode-type thin film (30) of the present invention can efficiently control the movement of ions between layers by acting as a diode or a blocking layer due to the internal electric field. Through this, the characteristics of a non-volatile memory can be implemented and the reliability can be improved.

[0077] The resistance change memory element of the present invention can exhibit a second resistance state in which the resistance change layer (20) is reset to a high resistance state when the first electrode (10) is connected to ground and a negative voltage is applied to the second electrode (50). In the second resistance state, hydrogen ions in the resistance change layer (20) can move to the hydrogen supply layer (40) along the (external) electric field. Accordingly, the resistance of the resistance change layer (20) can become high, and can be reset to this high resistance state to exhibit memory characteristics. Meanwhile, even in the second resistance state, materials in the diode-type thin film (30) can exhibit a constant polarization direction depending on the (external) electric field. Specifically, in the second resistance state, dipoles contained in the materials in the diode-type thin film (30) are arranged according to the electric field, so that a negative (-) charge can be induced on the surface of the resistance change layer (20) side, and a positive (+) charge can be induced on the surface of the hydrogen supply layer (40) side.

[0078] Similar to what was described above, when a positive voltage is removed from the second electrode (50) while the first electrode (10) is connected to the ground, the resistance change memory element of the present invention can maintain the second resistance state by the internal electric field of the diode-type thin film (30). This is due to the polarization characteristics of the diode-type thin film (30), and even when the external voltage is removed, the diode-type thin film (30) can maintain the aligned polarization state by the electric field when the external voltage is applied, and this is because an internal electric field can be formed within the diode-type thin film (30).

[0079] Through these resistance state changes, a data writing process (writing; set state) or a data erasing process (erasing; reset state) can be performed, and high reliability can be achieved by controlling ion movement through a diode-type thin film (30).

[0080] Hereinafter, a method for driving a resistance change memory device according to various embodiments of the present invention will be described with reference to FIGS. 2 to 6. The resistance change memory device described below is identical to the one described above, and thus a detailed description thereof will be omitted. Meanwhile, in FIGS. 2 to 6, hydrogen ions are represented as circles.

[0081] FIG. 2 is a cross-sectional view showing an initial state in which no voltage is applied or removed to a resistance change memory element according to one embodiment of the present invention.

[0082] Referring to Figure 2, it can be seen that hydrogen ions are arranged in a disorderly manner throughout the device without any directionality, and the polarization direction within the diode-type thin film (30) is also disordered.

[0083] FIG. 3 is a drawing for explaining a driving method when a positive voltage is applied to a resistance change memory element according to one embodiment of the present invention.

[0084] Referring to FIG. 3, a method for driving a resistance change memory element according to various embodiments of the present invention may include a step of inducing a first movement of hydrogen ions by connecting the first electrode (10) to ground and applying a positive voltage to the second electrode (50) in a resistance change memory element including a first electrode (10), a resistance change layer (20), a diode-type thin film (30), a hydrogen supply layer (40), and a second electrode (50). In the step of inducing the first movement, hydrogen ions in the hydrogen supply layer (40) may move to the resistance change layer (20). Specifically, in the step of inducing the first movement, the resistance change layer (20) may be set to a low resistance state, which may be a first resistance state of the resistance change memory element. Referring to Fig. 3, the materials within the diode-type thin film (30) exhibit a constant polarization direction depending on the (external) electric field, and a positive (+) charge may be induced on the surface of the resistance change layer (20) side, and a negative (-) charge may be induced on the surface of the hydrogen supply layer (40) side. A more detailed description of this first resistance state is replaced with the one described above.

[0085] FIG. 4 is a drawing for explaining a driving method when a positive voltage is applied to a resistance change memory element according to one embodiment of the present invention and then removed.

[0086] Referring to FIG. 4, it can be seen that even when the voltage is removed from the second electrode (50), the materials within the diode-type thin film (30) exhibit a constant polarization direction. This is due to the polarization characteristics of the diode-type thin film (30). Even when the external voltage is removed, the diode-type thin film (30) can maintain an aligned polarization state by the electric field when the external voltage is applied, and this is because an internal electric field can be formed within the diode-type thin film (30). The polarization characteristics of the diode-type thin film (30) facilitate the movement of hydrogen ions, which can help lower the driving voltage and improve the response speed. In this way, the diode-type thin film (30) of the present invention can efficiently control the movement of ions between layers by acting as a diode or a blocking layer due to the internal electric field, and can improve the reliability of the memory.

[0087] FIG. 5 is a drawing for explaining a driving method when a negative voltage is applied to a resistance change memory element according to one embodiment of the present invention.

[0088] Referring to FIG. 5, the driving method of the resistance change memory element according to various embodiments of the present invention may further include, after the step of inducing the first movement, a step of inducing the second movement of hydrogen ions by connecting the first electrode (10) to ground and applying a negative voltage to the second electrode (50). In the step of inducing the second movement, hydrogen ions in the resistance change layer (20) may move to the hydrogen supply layer (40). Specifically, in the step of inducing the second movement, the resistance change layer (20) may be reset to a high resistance state, which may be the second resistance state of the resistance change memory element. Referring to FIG. 5, materials in the diode-type thin film (30) exhibit a constant polarization direction according to an (external) electric field, and negative (-) charges may be induced on the surface of the resistance change layer (20) and positive (+) charges may be induced on the surface of the hydrogen supply layer (40). A more detailed description of this second resistance state is given in the previous section.

[0089] FIG. 6 is a drawing for explaining a driving method when a negative voltage is applied to a resistance change memory element according to one embodiment of the present invention and then removed.

[0090] Referring to FIG. 6, it can be seen that even though the voltage is removed from the second electrode (50), the materials within the diode-type thin film (30) exhibit a constant polarization direction. This is due to the polarization characteristics of the diode-type thin film (30), as described above, because the diode-type thin film (30) can form an electric field inside. The polarization characteristics of the diode-type thin film (30) facilitate the movement of hydrogen ions, which can help lower the driving voltage and improve the response speed. In this way, the diode-type thin film (30) of the present invention can efficiently control the movement of ions between layers and improve the reliability of the memory by acting as a diode or a blocking layer due to the internal electric field.

[0091] Through this driving method and ion movement induction, a data writing process (writing; set state) or a data erasing process (erasing; reset state) can be performed, and high reliability can be achieved by controlling ion movement through a diode-type thin film (30).

[0092] Hereinafter, with reference to FIGS. 7 and 8, an experimental example comparing the hydrogen ion behavior and current change characteristics of a resistance change memory device depending on whether a diode-type thin film is included will be described.

[0093] FIG. 7 is a diagram illustrating the structure and operating characteristics of a resistance change memory device that does not include a diode-type thin film according to a comparative example of the present invention.

[0094] As illustrated in (a) of Fig. 7, the resistance change memory element according to the comparative example does not include a diode-type thin film between the hydrogen supply layer (40) and the resistance change layer (20). In this structure, when an external electric field is applied, hydrogen ions contained within the hydrogen supply layer move along the direction of the electric field, but when the electric field is removed, since there is no internal electric field, the hydrogen ions spontaneously move in the opposite direction and tend to return to the initial state (position).

[0095] This phenomenon of rearrangement or redistribution of ions has a negative effect on the non-volatility of the memory, shortening the retention time of stored information / data and causing operational characteristics (endurance degradation) that make it difficult to reproduce the same resistance state even when repeatedly operated.

[0096] As confirmed by the current-probability distribution curve shown in (b) of Fig. 7, the current distributions of the low resistance state (LRS) and high resistance state (HRS) measured under a read voltage condition of approximately 0.5 V are very wide and overlap, showing a small current difference between each state and unstable operating characteristics.

[0097] This makes it difficult to distinguish between or within memory cells. Consequently, experimental results suggest that structures without diode-type thin films are unsuitable for practical non-volatile memory.

[0098] FIG. 8 is a drawing illustrating the structure and operating characteristics of a resistance change memory device including a diode-type thin film according to one embodiment of the present invention.

[0099] As shown in (a) of FIG. 8, a resistance change memory element according to one embodiment of the present invention has a structure including a diode-type thin film, and a diode-type thin film (30) is inserted between a hydrogen supply layer (40) and a resistance change layer (20).

[0100] Referring to Fig. 8, in the structure, when an electric field is applied, hydrogen ions move to the resistance conversion layer, and even when the electric field is removed, the internal electric field is maintained due to the polarization characteristics of the diode-type thin film, so that the moved hydrogen ions are fixed to the resistance conversion layer and do not redisperse. As a result, the memory state is stably maintained, ensuring non-volatile characteristics.

[0101] In other words, the internal electric field acts as an electric barrier to fix hydrogen ions, and this electric barrier is induced by the residual polarization formed within the ferroelectric material, and the polarization continuously forms an internal electric field, thereby preventing hydrogen ions from re-diffusion in the reverse direction even after the electric field is removed.

[0102] In particular, ferroelectrics possess the characteristic of maintaining polarization even after the electric field is removed. This residual polarization enables stable ion positioning, thereby maintaining the electrical barrier effect for a long period of time. Accordingly, the diode-type thin film of the present invention functions not as a simple blocking layer, but as a ferroelectric-based active memory state retention structure, playing a crucial role in the implementation of non-volatile memory.

[0103] As confirmed by the current-probability distribution curve illustrated in Fig. 8(b), under a read voltage condition of approximately 0.5 V, the current distributions in the storage state and high-resistance state are clearly distinguished, and the narrow distribution width demonstrates reliable data readout. Consequently, the experimental results suggest that the structure including the diode-type thin film is a nonvolatile memory device with significantly improved data retention and repeatable operation characteristics.

[0104] FIG. 9 is a flowchart showing a method for manufacturing a resistance change memory device including a diode-type thin film according to one embodiment of the present invention.

[0105] Referring to Fig. 9, first, a first electrode (10) to act as a lower electrode is formed on a substrate (S110), and a resistance change layer (20) is deposited on top of the first electrode (10) (S120).

[0106] Next, a diode-type thin film (30) made of a ferroelectric material is formed on the resistance change layer (20) (S130), and a hydrogen supply layer (40) containing hydrogen is laminated on top of the diode-type thin film (30) (S140).

[0107] Finally, a second electrode (50) to act as an upper electrode is deposited on the hydrogen supply layer (40) (S150).

[0108] This completes the stacked structure of a resistance-variable memory device. Each layer can be formed using thin-film processing techniques such as sputtering, atomic layer deposition (ALD), or chemical vapor deposition (CVD).

[0109] In particular, the diode-type thin film can be crystallized through an annealing process to have polarization characteristics, and the hydrogen supply layer can be composed of a material such as silicon nitride (SiNx:H), as an example. It was confirmed that the resistance state can be stably maintained by controlling the movement of hydrogen ions through the diode-type thin film and suppressing ion diffusion by the internal electric field even after the external voltage is removed.

[0110] Accordingly, it is experimentally supported that the resistance change memory device according to one embodiment of the present invention can effectively overcome the volatility problem of existing oxide-based memories and can be utilized as a non-volatile memory device that can exhibit excellent performance in data retention and repetitive operation characteristics.

[0111] The present invention has been described above, focusing on preferred embodiments thereof. Those skilled in the art will appreciate that the present invention can be implemented in modified forms without departing from its essential characteristics. Therefore, the disclosed embodiments should be considered illustrative rather than limiting. The scope of the present invention is set forth in the claims, not the foregoing description, and all differences within the scope equivalent thereto should be construed as being encompassed by the present invention.

[0112] [National Research and Development Project Supporting This Invention]

[0113] [Project ID] 2710006418

[0114] [Assignment Number] 00417600

[0115] [Ministry Name] Ministry of Science and ICT

[0116] [Name of Project Management (Specialist) Agency] Korea Science and Technology Commercialization Agency

[0117] [Research Project Name] Domestic Research Equipment Technology Competitiveness Enhancement Project

[0118] [Research Project Title] Observation of Micro-Energy Level Density Changes in Semiconductors Using a Thermal Reflection Microscope

[0119] [Name of the project performing organization] Daegu Gyeongbuk Institute of Science and Technology

[0120] Research Period: April 1, 2024 - December 31, 2024

[0121] [National Research and Development Project Supporting This Invention]

[0122] [Project ID] 2710013458

[0123] [Task Number] 2023R1A2C1004131

[0124] [Ministry Name] Ministry of Science and ICT

[0125] [Name of Project Management (Specialist) Institution] (New) National Research Foundation of Korea (Integrated)

[0126] [Research Project Name] (Type 1-1) Mid-career Research

[0127] [Research Project Title] Study of Memory Effects Implemented with Asymmetric Local Energy Levels for Multilayer Perceptron Implementation

[0128] [Name of the project performing organization] Daegu Gyeongbuk Institute of Science and Technology

[0129] [Research Period] March 1, 2024 - February 28, 2025

Claims

1. First electrode; A resistance change layer disposed on the first electrode; A diode-type thin film disposed on the above resistance conversion layer; A hydrogen supply layer disposed on the diode-type thin film; and A resistance change memory element comprising a second electrode disposed on the hydrogen supply layer.

2. In paragraph 1, A resistance change memory element characterized in that the diode-type thin film comprises at least one selected from the group consisting of Al, Zr, In, Bi, La, Y, Sr, Zn, Ti, Ta, Gd, and Hf.

3. In paragraph 1, A resistance change memory device characterized in that the diode-type thin film has a thickness of 1 nm to 20 nm or less.

4. In paragraph 1, A resistance change memory device characterized in that the resistance change layer includes any one selected from the group consisting of IGZO (InGaZnO), ITZO (InSnZnO), ZnO, AZO (Al-doped ZnO), and TaOx.

5. In paragraph 1, A resistance change memory element characterized in that the resistance change layer has a thickness of 20 nm to 80 nm.

6. In paragraph 1, The above hydrogen supply layer is 10 20 atoms / cm 3 10 inland 22 atoms / cm 3 A resistance change memory device characterized by including a hydrogen concentration of .

7. In paragraph 1, A resistance change memory device characterized in that the hydrogen supply layer is composed of an insulating film with controlled hydrogen content to facilitate the movement of hydrogen ions.

8. In paragraph 1, A resistance change memory device characterized in that the above diode-type thin film is composed of a ferroelectric material to form an electrical barrier that maintains residual polarization even after the electric field is removed, thereby suppressing reverse diffusion of hydrogen ions.

9. In paragraph 1, When the first electrode is connected to the ground and a positive voltage is applied to the second electrode, the resistance change layer exhibits a first resistance state set to a low resistance state, A resistance change memory element characterized in that when the first electrode is connected to ground and a negative voltage is applied to the second electrode, the resistance change layer exhibits a second resistance state in which it is reset to a high resistance state.

10. In paragraph 9, When the positive voltage is removed from the second electrode, A resistance change memory element characterized in that the first resistance state is maintained by the internal electric field of the diode-type thin film.

11. In paragraph 9, When the negative voltage is removed from the second electrode, A resistance change memory element characterized in that a second resistance state is maintained by an internal electric field of the diode-type thin film.

12. In paragraph 9, In the above first resistance state, A resistance change memory device characterized in that hydrogen ions in the hydrogen supply layer move to the resistance change layer.

13. In paragraph 9, In the above second resistance state, A resistance change memory element characterized in that hydrogen ions in the resistance change layer move to the hydrogen supply layer.

14. A method for driving a resistance change memory device including a first electrode, a resistance change layer, a diode-type thin film, a hydrogen supply layer, and a second electrode, A method for driving a resistance change memory element, comprising the step of connecting the first electrode to ground and applying a positive voltage to the second electrode to induce the first movement of hydrogen ions.

15. In paragraph 14, In the step of inducing the above first movement, A method for driving a resistance change memory element, characterized in that hydrogen ions in the hydrogen supply layer move to the resistance change layer.

16. In paragraph 14, After the step of inducing the above first movement, A method for driving a resistance change memory element, further comprising the step of connecting the first electrode to ground and applying a negative voltage to the second electrode to induce a second movement of hydrogen ions.

17. In paragraph 16, In the step of inducing the above second movement, A method for driving a resistance change memory element, characterized in that hydrogen ions in the resistance change layer move to the hydrogen supply layer.

18. In paragraph 14, In the step of inducing the above first movement, A method for driving a resistance change memory element, characterized in that the resistance change layer is set to a low resistance state.

19. In paragraph 16, In the step of inducing the above second movement, A method for driving a resistance change memory element, characterized in that the resistance change layer is reset to a high resistance state.

20. A method for manufacturing a resistance change memory element including a diode-type thin film for hydrogen ion control performed by a device, A step of forming a first electrode on a substrate; A step of depositing a resistance change layer on the first electrode; A step of depositing a diode-type thin film made of a ferroelectric material on the above resistance change layer; A step of laminating a hydrogen supply layer containing hydrogen on the diode-type thin film; and A method for manufacturing a resistance change memory device, characterized in that it comprises a step of forming a second electrode on the hydrogen supply layer.

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