CN117998868A - Resistive random access memory with data retention capacity and preparation method of resistive random access layer - Google Patents

Abstract

The disclosure discloses a resistive random access memory with data retention capability and a preparation method of a resistive random access layer. The resistive random access memory includes: a resistive layer comprising a first metal oxide doped with a second metal; wherein the second metal has an activity lower than the activity of the first metal in the first metal oxide. According to the scheme of the embodiment of the disclosure, the diffusion of the conductive filament can be restrained by doping the doping element with lower activity than the metal element in the metal oxide of the resistive layer, so that the stability of the conductive filament is improved. Because the conductive filaments are not easily broken due to diffusion effect, the data stored in the resistive random access memory is not automatically changed, and the data holding capacity of the resistive random access memory is improved.

Description

Resistive random access memory with data retention capacity and preparation method of resistive random access layer

Technical Field

The present disclosure relates generally to the field of memory technology. More particularly, the present disclosure relates to a resistive random access memory having data retention capability and a method for fabricating a resistive random access layer of the resistive random access memory.

Background

The resistive random access memory has the advantages and characteristics of low writing voltage, short erasing and writing time, good memory property, nondestructive reading, multi-state storage property, simple structure, small area and the like.

The storage principle of the resistive random access memory is to cause ion movement and local structural change of the storage medium through external stimulus, thereby causing resistance change, and to store data by using the resistance difference. The principle of resistance change is as follows: under the action of external stimulus, oxygen ions or metal ions migrate in the resistive layer, so that nanoscale conductive filaments are formed in the resistive layer, the on-off state of the conductive filaments determines the high-low resistance state of the resistor, the high-resistance state is defined as binary data '0', and the low-resistance state is defined as binary data '1', and the function of the nonvolatile memory can be realized.

However, since such a nano-sized conductive filament is unstable, especially after waiting at high temperature or for a long time, the conductive filament may be tapered and even broken due to a diffusion effect, thereby causing errors in stored data.

In view of the foregoing, it is desirable to provide a resistive random access memory that suppresses the diffusion effect of the conductive filaments and increases the stability of the conductive filaments, thereby improving the data retention capability of the resistive random access memory.

Disclosure of Invention

To address at least one or more of the technical problems mentioned above, the present disclosure proposes, in various aspects, a resistive random access memory and a method of fabricating a resistive random access layer thereof.

In a first aspect, the present disclosure provides a resistive random access memory with data retention capability comprising: a resistive layer comprising a first metal oxide doped with a second metal; wherein the second metal has an activity lower than the activity of the first metal in the first metal oxide.

In some embodiments, wherein the doping proportion of the second metal in the resistive layer is less than or equal to 5%.

In some embodiments, wherein the doping ratio of the second metal in the resistive layer is less than or equal to 3%.

In some embodiments, wherein the doping proportion of the second metal in the resistive layer is less than or equal to 2%.

In some embodiments, wherein the second metal is uniformly doped in the first metal oxide.

In some embodiments, the resistive random access memory further comprises: a top electrode and a bottom electrode; wherein the bottom electrode comprises a third metal or a third metal compound, and the top electrode comprises an active metal for ionizing to form active metal ions in a pressurized state to form conductive filaments connecting the top electrode and the bottom electrode in the resistive layer.

In a second aspect, the present disclosure provides a method for preparing a resistive layer of a resistive memory comprising: obtaining a target material made of a first metal; doping a second metal in the target to obtain an alloy target; bombarding the alloy target material in a mode of reactive sputtering with oxygen so as to generate a resistive layer; the composition of the resistance change layer is a first metal oxide doped with a second metal, and the activity of the second metal is lower than that of the first metal.

In a third aspect, the present disclosure provides a method for preparing a resistive layer of a resistive memory comprising: obtaining a target material made of a first metal oxide; doping a second metal oxide in the target to obtain a doped oxide; bombarding the doped oxide by a radio frequency sputtering mode to generate a resistive layer; the composition of the resistance change layer is first metal oxide doped with second metal, and the activity of the second metal in the second metal oxide is lower than that of the first metal in the first metal oxide.

In a fourth aspect, the present disclosure provides a method for preparing a resistive layer of a resistive memory comprising: acquiring a target material made of a first metal and a target material made of a second metal to serve as the first target material and the second target material respectively; bombarding the first target material and the second target material in a common oxidation reaction sputtering mode to generate a resistance change layer; the composition of the resistance change layer is a first metal oxide doped with a second metal, and the activity of the second metal is lower than that of the first metal.

In a fifth aspect, the present disclosure provides a method for preparing a resistive layer of a resistive memory comprising: acquiring a target material made of a first metal oxide and a target material made of a second metal oxide to serve as the first target material and the second target material respectively; bombarding the first target material and the second target material in a radio frequency sputtering mode to generate a resistive layer; the composition of the resistance change layer is first metal oxide doped with second metal, and the activity of the second metal in the second metal oxide is lower than that of the first metal in the first metal oxide.

In a sixth aspect, the present disclosure provides a method for preparing a resistive layer of a resistive memory comprising: growing a first preset number of thin films of a first metal oxide by an atomic layer deposition method; growing a second preset number of thin films of a second metal oxide on the thin films of the first metal oxide by an atomic layer deposition method; repeating the growth step of the film of the first metal oxide and the growth step of the film of the second metal oxide until a resistance change layer with a preset film layer number is obtained; the composition of the resistance change layer is first metal oxide doped with second metal, and the activity of the second metal in the second metal oxide is lower than that of the first metal in the first metal oxide.

By the resistive random access memory having the data retention capability provided as above, the embodiments of the present disclosure suppress diffusion of the conductive filaments by doping the doping element in the resistive random access layer having lower reactivity than the metal element in the metal oxide of the resistive random access layer, thereby increasing the stability of the conductive filaments. Because the conductive filaments are not easily broken due to diffusion effect, the data stored in the resistive random access memory is not automatically changed, and the data holding capacity of the resistive random access memory is improved.

Drawings

The above, as well as additional purposes, features, and advantages of exemplary embodiments of the present disclosure will become readily apparent from the following detailed description when read in conjunction with the accompanying drawings. Several embodiments of the present disclosure are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar or corresponding parts and in which:

FIG. 1 illustrates an exemplary block diagram of a resistive random access memory according to some embodiments of the present disclosure;

FIG. 2 illustrates an exemplary flow chart of a method of fabricating a resistive switching layer according to some embodiments of the present disclosure;

FIG. 3 illustrates an exemplary flow chart of a method of fabricating a resistive switching layer according to further embodiments of the present disclosure;

FIG. 4 illustrates an exemplary flow chart of a method of fabricating a resistive switching layer according to further embodiments of the present disclosure;

FIG. 5 illustrates an exemplary flow chart of a method of fabricating a resistive switching layer according to further embodiments of the present disclosure;

fig. 6 illustrates an exemplary flow chart of a method of fabricating a resistive switching layer according to further embodiments of the present disclosure.

Detailed Description

The following description of the embodiments of the present disclosure will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are some, but not all embodiments of the disclosure. Based on the embodiments in this disclosure, all other embodiments that may be made by those skilled in the art without the inventive effort are within the scope of the present disclosure.

It should be understood that the terms "comprises" and "comprising," when used in this specification and the claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It is also to be understood that the terminology used in the description of the present disclosure is for the purpose of describing particular embodiments only, and is not intended to be limiting of the disclosure. As used in the specification and claims of this disclosure, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should be further understood that the term "and/or" as used in the present disclosure and claims refers to any and all possible combinations of one or more of the associated listed items, and includes such combinations.

As used in this specification and the claims, the term "if" may be interpreted as "when..once" or "in response to a determination" or "in response to detection" depending on the context. Similarly, the phrase "if a determination" or "if a [ described condition or event ] is detected" may be interpreted in the context of meaning "upon determination" or "in response to determination" or "upon detection of a [ described condition or event ]" or "in response to detection of a [ described condition or event ]".

Specific embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

Exemplary application scenarios

The storage principle of the resistive random access memory is that the ion movement and the local structural change of the storage medium are caused by external stimulus, and under the action of the external stimulus, oxygen ions or metal ions migrate in a resistive random access layer, so that nanoscale conductive filaments are formed in the resistive random access layer, the on-off state of the conductive filaments determines the high-low resistance state of the resistor, and the difference of the resistor can be used for storing data, so that the function of the nonvolatile memory is realized.

However, since such a nano-sized conductive filament is unstable, especially after waiting at high temperature or for a long time, the conductive filament may be tapered and even broken due to a diffusion effect, thereby causing errors in stored data.

Exemplary application scenario

In view of this, the embodiments of the present disclosure provide a resistive random access memory with data retention capability, which can inhibit the diffusion of conductive filaments by doping a doping element with lower activity than a metal element in a metal oxide of a resistive random access layer, and effectively reduce the probability of data errors caused by breakage of the conductive filaments when data is unchanged.

Fig. 1 illustrates an exemplary block diagram of a resistive random access memory 100 of some embodiments of the present disclosure, as illustrated in fig. 1, the resistive random access memory of the embodiments of the present disclosure sequentially includes: a top electrode 101, a resistive layer 102 and a bottom electrode 103. The resistive layer 102 includes a first metal oxide 1021 doped with a second metal 1022, and the second metal 1022 has an activity lower than that of the first metal in the first metal oxide 1021.

Taking the case that the resistive layer is made of alumina as an example, the aluminum conductive filament is unstable after formation, and particularly after waiting at high temperature or for a long time, a part of aluminum atoms can diffuse into the alumina resistive layer under the action of heat, so that the volume of the original conductive filament is reduced, the resistance value is increased, and even the conductive filament is disconnected and finally becomes in a cut-off state, thereby causing errors of stored data. In order to prevent the conductive filaments from becoming finer due to diffusion effects, a metal having lower reactivity than aluminum, such as sodium, magnesium, calcium, or the like, may be doped in the resistive layer.

The principle of suppressing breakage of the conductive filaments by doping a metal having a lower reactivity is as follows, and for convenience of explanation, a case where magnesium is doped in the alumina resistive layer will be described as an example below:

The valence state of magnesium in the oxide is 2+, the valence state of aluminum in the alumina is 3+, and after the alumina is doped with magnesium in the resistance change layer, due to the existence of valence state difference, the alumina material can generate some oxygen vacancies to keep electric neutrality. Oxygen vacancies accelerate the diffusion of oxygen ions in the metal oxide while inhibiting the diffusion of metal ions. Therefore, the conductive filaments can be effectively prevented from breaking due to diffusion effect after doping magnesium in alumina.

Based on the above principle, the metal doped into the resistive layer needs to have a lower valence state. Further, the radius of the ion or atom of the selected second metal is close to that of the metal in the first metal oxide in the resistance change layer, so that the whole material structure can be ensured not to be distorted or collapsed in a large range. Therefore, in the case where the resistive layer is made of alumina, magnesium having a radius closer to that of aluminum atoms may be preferably selected as the second metal among metals such as sodium, magnesium, and calcium.

Illustratively, the first metal oxide may be aluminum oxide, perovskite oxide, nickel oxide, tantalum-containing oxide, hafnium-containing oxide, or tantalum-and hafnium-containing metal oxide, without limitation herein.

In this embodiment, the top electrode 101 comprises an active metal and the bottom electrode 103 comprises a third metal or a third metal compound. Illustratively, the active metal may be one or more of aluminum, copper, silver, and the like, the third metal may be one or more of platinum, tungsten, ruthenium, and the like, and the third metal compound may be one or more of titanium nitride, tantalum nitride, and the like, without limitation herein.

In some embodiments of the present disclosure, the conductive filament pattern of the resistive random access memory includes two types: a conductive filament mode and an oxygen hole mode. The resistive random access memory adopting the conductive wire mode is called CBRAM, the English of the resistive random access memory is called Conductive Bridge ReRAM, the resistive random access memory adopting the oxygen hole mode is called OxRAM, and the English of the resistive random access memory is called Oxygen Vacancy based ReRAM.

In the case of the CBRAM, the top electrode ionizes in a pressurized state to form active metal ions, which move in the resistive layer under the action of an electric field and reach the bottom electrode, thereby forming conductive filaments connecting the top and bottom electrodes within the resistive layer.

In the case of OxRAM of the resistive random access memory, after the top electrode is pressurized, oxygen ions in the resistive random access layer migrate under the action of an electric field to form oxygen vacancies, and then a large number of oxygen vacancies are connected at a certain interval, thereby forming conductive filaments connecting the top electrode and the bottom electrode.

It should be noted that, doping the second metal in the resistive layer of the CBRAM can inhibit the conductive filament from breaking due to diffusion effect, and doping the second metal in the resistive layer of OXRAM can also increase or adjust the concentration of oxygen vacancies in the resistive layer, so as to adjust parameters such as operating voltage and leakage current.

Further, in some embodiments, to ensure uniformity of diffusion of metal ions or oxygen ions in the resistive layer, the second metal is uniformly doped in the first metal oxide.

An exemplary doping method of the resistive layer of the resistive memory is described above, and the doping ratio of the second metal in the resistive layer of the resistive memory is further described below.

In the resistive layer, the doping proportion of the second metal is less than or equal to 5%. Optionally, the doping proportion of the second metal is less than or equal to 3%. Further alternatively, the doping proportion of the second metal is less than or equal to 2%.

In practical applications, the doping ratio of the second metal may be between 0.01% and 2%, for example, the doping ratio of magnesium in the aluminum oxide resistive layer may be between 0.01% and 1%, and for example, the doping ratio of magnesium atoms to aluminum atoms in the doped resistive layer is 1:1000, that is, the doping ratio of magnesium is 0.1%.

It should be noted that, the operator may adjust the doping ratio of the second metal in the resistive layer within the doping ratio range described in any of the foregoing embodiments according to actual requirements, which is not limited herein.

In order to fabricate the resistive layer of the resistive random access memory described in any of the above embodiments, some embodiments of the present disclosure provide a variety of fabrication methods, which are described below in conjunction with the accompanying drawings.

Fig. 2 illustrates an exemplary flowchart of a method 200 for preparing a resistive layer according to some embodiments of the present disclosure, and in step S201, a target material made of a first metal is obtained as shown in fig. 2. The target is a sputtering source for forming various functional films on the substrate by magnetron sputtering, multi-arc ion plating or other types of coating systems under proper process conditions. It is understood that the target is a target material bombarded by high-speed energetic particles in the thin film preparation process.

In step S202, a second metal is doped in the target to obtain an alloy target. In this step, the doped second metal is less active than the first metal. For example, when the aluminum target is obtained in step S201, a metal having a lower reactivity such as sodium, calcium, magnesium, or the like needs to be selected as the second metal. Magnesium may be preferred as the second metal in step S202 based on atomic radius considerations and the like.

Further, the proportion of the doped second metal in step S202 is less than or equal to 5%. Optionally, the proportion of doped second metal is less than 3%. Further alternatively, the proportion of doped second metal is less than 2%. In some embodiments, the doping ratio of the second metal may be in the following range, such as 0.01% to 2%.

In step S203, the alloy target is bombarded by reactive sputtering with oxygen to generate a resistive layer. In the step, the reactive sputtering method with oxygen adopts a reactive magnetron sputtering technology, which is one of the main processes for depositing the compound film, and by using the technology, certain reactive gas, such as oxygen, can be introduced when sputtering a pure metal or alloy target material, and the compound film is obtained by reactive deposition.

It should be noted that, in some embodiments, assuming that the first metal is aluminum and the second metal is magnesium, the alloy target is a magnesium-aluminum alloy target. Bombarding the magnesium-aluminum alloy target material in a mode of reactive sputtering with oxygen, and growing to obtain the film of aluminum oxide magnesium as a resistance variable layer. The composition of the resistive layer is a first metal oxide doped with a second metal, wherein the doped second metal can effectively inhibit the diffusion of the conductive filaments in the resistive layer, thereby improving the data retention capacity of the resistive memory with the resistive layer.

Fig. 3 is a flowchart illustrating an exemplary method 300 for preparing a resistive layer according to other embodiments of the present disclosure, and in step S301, a target made of a first metal oxide is obtained as shown in fig. 3. The target is a target material bombarded with high-speed energetic particles, which may include: metal-based targets, alloy-based targets, oxide-based targets, and the like. In this embodiment, an oxide-based target, such as an alumina target, is used.

In step S302, a second metal oxide is doped in the target to obtain a doped oxide. In this step, the second metal in the doped second metal oxide needs to be less active than the first metal in the first metal oxide. For example, when the alumina target is obtained in step S201, it is necessary to select an oxide of a metal such as sodium, calcium, magnesium, or the like having lower activity as the second metal oxide. Based on atomic radius considerations, magnesium oxide may be preferred as the second metal oxide in step S202. And doping to obtain the magnesia aluminum as doped oxide.

Further, in step S302, the doping ratio of the second metal in the second metal oxide is less than or equal to 5%. Optionally, the doping proportion of the second metal is less than 3%. Further alternatively, the doping proportion of the second metal is less than 2%. In some embodiments, the doping ratio of the second metal may be in the following range, such as 0.01% to 2%.

In step S303, the doped oxide is bombarded by means of radio frequency sputtering to generate a resistive layer. The mode of radio frequency sputtering is also one of the main processes for depositing compound films, which uses positive ions in radio frequency discharge plasma to bombard a target material, and sputtering target material atoms to deposit on the surface of a substrate to form a film.

In the practical application process, when step S303 is executed, the two electrodes are indirectly connected to the rf power supply, and electrons in the plasma between the two electrodes that continuously oscillate are obtained enough energy from the rf electric field to collide with gas molecules more effectively and ionize the latter, thereby generating a large amount of ions and electrons. At this time, secondary electrons no longer need to be generated at high pressure to sustain the discharge process, and rf sputtering can be performed at low pressure instead. The radio frequency sputtering can generate a self-bias effect on the target, namely, the target can be automatically under a larger negative potential under the action of a radio frequency electric field, so that gas ions spontaneously bombard the target and sputter the target, and sputtered target atoms deposit to form a film.

The magnesium aluminum oxide is bombarded by a radio frequency sputtering mode, and a film of the magnesium aluminum oxide can be grown to be obtained to be used as a resistance variable layer. The composition of the resistive layer is a first metal oxide doped with a second metal, wherein the doped second metal can effectively inhibit the diffusion of the conductive filaments in the resistive layer, thereby improving the data retention capacity of the resistive memory with the resistive layer.

Fig. 4 illustrates an exemplary flowchart of a method 400 for preparing a resistive layer according to further embodiments of the present disclosure, and in step S401, a target made of a first metal and a target made of a second metal are obtained as a first target and a second target, respectively, as shown in fig. 4. In this step, the second metal needs to be less active than the first metal. Taking the case where the first metal is aluminum as an example, it is necessary to select a metal having a lower activity such as sodium, calcium, magnesium, or the like as the second metal. Magnesium may be preferred as the second metal in step S401 based on atomic radius considerations and the like.

In step S402, the first target and the second target are bombarded by co-oxidation reactive sputtering to generate a resistive layer. In this step, when the target material is sputtered by co-oxidation reactive sputtering, the target material reacts with oxygen to form a metal oxide, and since a plurality of target materials are sputtered simultaneously in this embodiment, the preparation of a thin film of the composite metal oxide can be realized.

Taking the case that the first metal is aluminum and the second metal is magnesium as an example, bombarding the aluminum target material and the magnesium target material in a common oxidation reaction sputtering mode, combining sputtered aluminum ions and magnesium ions with ionized oxygen ions to form magnesium aluminum oxide, and finally growing to obtain a film of aluminum magnesium oxide serving as a resistance change layer. The composition of the resistive layer is understood to be aluminum oxide doped with magnesium, i.e. a first metal oxide doped with a second metal.

Further, in some embodiments, a multi-target copolymerization Jiao Jianshe process may be employed to achieve simultaneous sputtering of multiple targets.

Fig. 5 illustrates an exemplary flowchart of a method 500 for preparing a resistive layer according to still other embodiments of the present disclosure, and in step S501, a target made of a first metal oxide and a target made of a second metal oxide are obtained as a first target and a second target, respectively, as shown in fig. 5. In this step, the second metal in the second metal oxide is less active than the first metal in the first metal oxide, and for example, an alumina target may be used as the first target and magnesia as the second target.

It should be noted that the above selection of the first target and the second target is only one example in the present embodiment. In practical applications, an alumina target may be used as the first target and calcium oxide as the second target, without undue limitation.

In step S502, the first target and the second target are bombarded by means of radio frequency sputtering to generate a resistive layer. The manner of rf sputtering in this embodiment is described in detail in the foregoing embodiment in connection with fig. 3, and will not be described here again.

Further, in some embodiments, a multi-target copolymerization Jiao Jianshe process may be employed to achieve simultaneous sputtering of the first and second targets, with the sputtered target atoms depositing to form a thin film.

Taking the case that an alumina target is taken as a first target and magnesia is taken as a second target as an example, under the action of a radio frequency electric field, the alumina target and the magnesia target are automatically positioned at a larger negative potential, so that spontaneous bombardment and sputtering are generated on the alumina target by gas ions, and sputtered target atoms are deposited to form a magnesia-alumina film. The film can be used as a resistive layer, the composition of which can also be understood as aluminum oxide doped with magnesium, i.e. a first metal oxide doped with a second metal.

The above examples describe alternatives for preparing the resistive layer in a physical chemical vapor deposition process. In other embodiments, a chemical vapor deposition process may also be used to fabricate the resistive layer of the resistive memory, as described below in conjunction with fig. 6.

Fig. 6 illustrates an exemplary flowchart of a method 600 of fabricating a resistive switching layer according to further embodiments of the present disclosure, as shown in fig. 6, in which a first preset number of thin films of a first metal oxide are grown by an atomic layer deposition method in step S601. An atomic layer deposition method is a method in which a substance can be plated on a substrate surface layer by layer in the form of a monoatomic film, and in the atomic layer deposition process, a chemical reaction of a new atomic film is directly associated with a previous layer, so that only one atom is deposited per reaction.

By means of sequential deposition of monoatomic layers in the atomic layer deposition method, the deposited layers can have uniform thickness and excellent consistency, and therefore doping uniformity of the finally obtained resistive layer is guaranteed.

Illustratively, n atomic layer films of aluminum oxide may be grown by different reactive precursors in step S601, where n is between 1 and 100.

In step S602, a second preset number of thin films of a second metal oxide are grown on the thin films of the first metal oxide by an atomic layer deposition method. Taking the case that the first metal oxide is alumina as an example, after growing an n-layer atomic layer film of alumina in step S601, step S602 is performed to grow a second predetermined number of atomic layer films of a second metal oxide, such as an atomic layer film of magnesium oxide, on the atomic layer film of alumina.

In this embodiment, the second metal in the second metal oxide has an activity lower than that of the first metal in the first metal oxide, so when the first metal oxide is alumina, the second metal oxide may be an oxide of a metal such as sodium, magnesium, or calcium. Magnesium oxide may be preferred as the second metal oxide in view of the atomic radius and the like.

In step S603, it is determined whether the number of layers of the film reaches a preset number of layers of the film. If yes, step S604 is executed, and if no, step S601 is returned. In this embodiment, step S601 and step S602 are repeatedly performed, and atomic layer films of the first metal oxide and the second metal oxide are grown at intervals until a film with a preset film layer number is finally obtained, and the growth process of the atomic layer film is ended, so as to obtain the resistive layer.

In step S604, a film with a preset number of film layers is used as a resistive layer. In this embodiment, the composition of the resistive layer may be understood as a first metal oxide doped with a second metal, wherein the second metal has a lower activity than the first metal in the first metal oxide.

The foregoing embodiments in connection with fig. 2 to 6 describe various methods for preparing a resistive layer of a resistive memory, and in practical application, a user may select different methods to complete the preparation of the resistive layer according to practical situations and requirements, which is not limited in any way.

Further, the preparation methods described in fig. 2 and fig. 4 may be preferably selected based on the consideration of process complexity, which is difficult to implement and has high doping flexibility.

In summary, the embodiments of the present disclosure provide a resistive random access memory that suppresses diffusion of conductive filaments by doping a doping element in a resistive random access layer that is less active than a metal element in a metal oxide of the resistive random access layer, thereby reducing the risk of errors in data stored in the resistive random access memory due to breakage of the conductive filaments, and further improving the data retention capability of the resistive random access memory.

In addition, some embodiments of the present disclosure also provide various methods for preparing a resistive layer of a resistive memory, which prepares a uniformly doped resistive layer for the resistive memory through a physical chemical vapor deposition process or an atomic layer deposition process, thereby improving data retention capability of the resistive memory.

While various embodiments of the present disclosure have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous modifications, changes, and substitutions will occur to those skilled in the art without departing from the spirit and scope of the present disclosure. It should be understood that various alternatives to the embodiments of the disclosure described herein may be employed in practicing the disclosure. The appended claims are intended to define the scope of the disclosure and are therefore to cover all equivalents or alternatives falling within the scope of these claims.

Claims (11)

1. A resistive random access memory having data retention capability, comprising: a resistive layer comprising a first metal oxide doped with a second metal;

Wherein the second metal has an activity lower than the activity of the first metal in the first metal oxide.

2. The resistive random access memory according to claim 1, wherein a doping ratio of the second metal in the resistive layer is less than or equal to 5%.

3. The resistive random access memory according to claim 2, wherein a doping ratio of the second metal in the resistive layer is less than or equal to 3%.

4. A resistive random access memory according to claim 3, wherein the doping proportion of the second metal in the resistive layer is less than or equal to 2%.

5. A resistive-switching memory as defined in any one of claims 1-4, wherein the second metal is uniformly doped in the first metal oxide.

6. The resistive random access memory of any one of claims 1-4, further comprising: a top electrode and a bottom electrode;

Wherein the bottom electrode comprises a third metal or a third metal compound, and the top electrode comprises an active metal for ionizing in a pressurized state to form active metal ions to form conductive filaments connecting the top electrode and the bottom electrode in the resistive layer.

7. A method for preparing a resistive layer of a resistive memory, comprising:

obtaining a target material made of a first metal;

Doping a second metal in the target to obtain an alloy target; and

Bombarding the alloy target material in a mode of reactive sputtering with oxygen so as to generate the resistive layer;

The composition of the resistive layer is a first metal oxide doped with a second metal, and the activity of the second metal is lower than that of the first metal.

8. A method for preparing a resistive layer of a resistive memory, comprising:

obtaining a target material made of a first metal oxide;

Doping a second metal oxide in the target to obtain a doped oxide; and

Bombarding the doped oxide in a radio frequency sputtering mode to generate the resistive layer;

The composition of the resistive layer is a first metal oxide doped with a second metal, and the activity of the second metal in the second metal oxide is lower than that of the first metal in the first metal oxide.

9. A method for preparing a resistive layer of a resistive memory, comprising:

acquiring a target material made of a first metal and a target material made of a second metal to serve as the first target material and the second target material respectively; and

Bombarding the first target material and the second target material in a common oxidation reaction sputtering mode to generate the resistance change layer;

The composition of the resistive layer is a first metal oxide doped with a second metal, and the activity of the second metal is lower than that of the first metal.

10. A method for preparing a resistive layer of a resistive memory, comprising:

Acquiring a target material made of a first metal oxide and a target material made of a second metal oxide to serve as the first target material and the second target material respectively; and

Bombarding the first target material and the second target material in a radio frequency sputtering mode to generate the resistance change layer;

The composition of the resistive layer is a first metal oxide doped with a second metal, and the activity of the second metal in the second metal oxide is lower than that of the first metal in the first metal oxide.

11. A method for preparing a resistive layer of a resistive memory, comprising:

growing a first preset number of thin films of a first metal oxide by an atomic layer deposition method;

Growing a second preset number of thin films of a second metal oxide on the thin films of the first metal oxide by an atomic layer deposition method;

Repeating the growth step of the first metal oxide film and the growth step of the second metal oxide film until a resistive layer with a preset film layer number is obtained;

The composition of the resistive layer is a first metal oxide doped with a second metal, and the activity of the second metal in the second metal oxide is lower than that of the first metal in the first metal oxide.