Preparation method of resistive layer of variable resistance type memory

Abstract

The invention relates to the field of semiconductor device preparation, and provides a preparation method of a resistive layer of a variable resistive memory, which comprises the following steps: depositing a seed layer on a bottom electrode of a pre-prepared variable resistive memory; a resistive layer material is deposited on the seed layer in a co-sputtering mode, target materials used in the co-sputtering process at least comprise a first target material and a second target material, the first target material comprises any one of scandium, titanium, strontium, yttrium, lanthanum and barium, and the second target material is aluminum nitride; and performing low-temperature cooling on the resistive layer material to form a resistive layer. In order to solve the defect of low read-write speed of the variable resistance type memory in the related technology, the scheme of the application can improve the read-write speed of the variable resistance type memory by preparing the resistive layer by using aluminum nitride.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor device preparation, and particularly to a method for preparing a resistive switching layer of a resistive random access memory. Background Art

[0002] A resistive random access memory (RRAM) is a non-volatile memory that realizes information storage and release through changes in internal resistance values.

[0003] The resistive switching performance of RRAM determines the quality of RRAM, and the resistive switching performance mainly depends on the internal resistive switching layer. Therefore, the material and preparation method of the resistive switching layer play a decisive role in the overall performance of RRAM.

[0004] In the related art, the RRAM applied has the disadvantage of slow data read / write speed due to the limitation of the resistive switching layer performance, and cannot meet the usage requirements. Summary of the Invention

[0005] The present invention provides a method for preparing a resistive switching layer of a resistive random access memory to solve the defect of slow read / write speed of the resistive random access memory in the related art. The solution of the present application can improve the read / write speed of the resistive random access memory by using aluminum nitride to prepare the resistive switching layer.

[0006] The present invention provides a method for preparing a resistive switching layer of a resistive random access memory, including:

[0007] Depositing a seed layer on a bottom electrode of a pre-prepared resistive random access memory;

[0008] Depositing a resistive switching layer material on the seed layer by co-sputtering. The target materials used in the co-sputtering process include at least a first target material and a second target material. The first target material includes any one of scandium, titanium, strontium, yttrium, lanthanum, and barium, and the second target material is aluminum nitride;

[0009] Performing low-temperature cooling on the resistive switching layer material to form a resistive switching layer.

[0010] According to the method for preparing a resistive switching layer of a resistive random access memory provided by the present invention, the target materials used in the co-sputtering process include a first target material and a second target material. The first target material includes any one of scandium, titanium, strontium, yttrium, lanthanum, and barium, and the second target material is aluminum nitride.

[0011] According to the method for preparing the resistive switching layer of the variable resistive memory provided by the present invention, the targets used in the co-sputtering process include a first target, a second target, and a third target. The first target is any one of scandium, titanium, strontium, yttrium, lanthanum, and barium. The second target is any one of scandium, titanium, strontium, yttrium, lanthanum, and barium. The third target is aluminum nitride.

[0012] According to the method for preparing the resistive switching layer of the variable resistive memory provided by the present invention, the sputtering particles used in the co-sputtering process are argon particles.

[0013] According to the method for preparing the resistive switching layer of the variable resistive memory provided by the present invention, the temperature in the co-sputtering process is 100 degrees Celsius to 400 degrees Celsius.

[0014] According to the method for preparing the resistive switching layer of the variable resistive memory provided by the present invention, the material of the seed layer includes any one or more of platinum, molybdenum, aluminum, ruthenium, and phosphorus.

[0015] The present invention also provides a variable resistive memory, including a resistive switching layer prepared by the preparation method described in any of the above embodiments.

[0016] According to the variable resistive memory provided by the present invention, the content of aluminum nitride in the resistive switching layer is 40% to 98% by mass.

[0017] According to the variable resistive memory provided by the present invention, the thickness of the resistive switching layer is 10 nanometers to 50 nanometers.

[0018] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, it implements the method for preparing the resistive switching layer of any of the above variable resistive memories.

[0019] The present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements the method for preparing the resistive switching layer of any of the above variable resistive memories.

[0020] The present invention also provides a computer program product, including a computer program. When the computer program is executed by a processor, it implements the method for preparing the resistive switching layer of any of the above variable resistive memories.

[0021] In the preparation method provided by the present application, aluminum nitride is used to prepare the resistive switching layer of the variable resistive memory. By utilizing the high resistivity and good resistive switching characteristics of aluminum nitride, the resistive switching performance of the resistive switching layer can be improved. At the same time, rare elements such as scandium, titanium, strontium, yttrium, lanthanum, and barium are doped into the resistive switching layer to further enhance the resistive switching performance. The co-sputtering preparation method can also avoid the adverse effects of high temperature during the preparation process on the product performance, thereby preparing a resistive switching layer of a variable resistive memory with excellent performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0023] Figure 1 is one of the flow diagrams of the preparation method provided by the embodiment of the present invention;

[0024] Figure 2 is the second flow diagram of the preparation method provided by the embodiment of the present invention;

[0025] Figure 3 is the third flow diagram of the preparation method provided by the embodiment of the present invention;

[0026] Figure 4 is the fourth flow diagram of the preparation method provided by the embodiment of the present invention;

[0027] Figure 5 is the structural diagram of the variable resistive memory provided by the embodiment of the present invention;

[0028] Figure 6 is the physical structure diagram of the electronic device provided by the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] To make the objectives, technical solutions, and advantages of the present invention clearer, the following will clearly and completely describe the technical solutions in the present invention with reference to the accompanying drawings in the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0030] Figure 1 is one of the flow diagrams of the preparation method provided by the embodiment of the present invention.

[0031] Such as Figure 1As shown in the figure, this embodiment provides a method for preparing a resistive switching layer of a variable resistor memory, including:

[0032] Step 101: Deposit a seed layer on the bottom electrode of the pre-prepared variable resistor memory.

[0033] The method for pre-preparing the bottom electrode of the variable resistor memory can refer to the implementation of related technologies. For example, a bottom electrode can be deposited on a substrate of a Complementary Metal Oxide Semiconductor (CMOS) structure. The substrate can be a wafer substrate, and the wafer substrate is provided with a driving transistor. The driving transistor can be an FDSOI driving transistor, a FinFET driving transistor, a GAA-type driving transistor, and an HKMG / Poly SiON-type driving transistor, etc. The composition materials of the deposited bottom electrode can include any one or more of tungsten, titanium, tantalum, tungsten nitride, titanium nitride, and tantalum nitride. In practical applications, physical vapor deposition (PVD) or chemical vapor deposition (CVD) can be used to deposit the bottom electrode on the wafer substrate. The thickness of the bottom electrode can be 20 nanometers to 100 nanometers, preferably 60 nanometers.

[0034] The seed layer refers to a thin film deposited on the bottom electrode. The seed layer can play roles such as providing a conductive path, enhancing adhesion, and blocking diffusion. Specifically, the seed layer can provide a conductive path for the subsequent metal layer or wire to ensure the normal operation of the circuit, and can also enhance the adhesion between the subsequently deposited metal layer or wire and the substrate to avoid problems such as peeling off. It can also prevent the substrate material from diffusing into the metal layer during subsequent processing, ensuring the stability and reliability of the device.

[0035] In practical applications, the material of the seed layer includes any one or more of platinum, molybdenum, aluminum, ruthenium, and phosphorus. The seed layer can also be deposited by co-sputtering.

[0036] Step 102: Deposit a resistive switching layer material on the seed layer by co-sputtering. The targets used in the co-sputtering process include at least a first target and a second target. The first target includes any one of scandium, titanium, strontium, yttrium, lanthanum, and barium, and the second target is aluminum nitride.

[0037] Co-sputtering refers to sputtering using multiple targets simultaneously in the same sputtering system. The basic principle of co-sputtering is that in a vacuum environment, high-energy particles bombard the surface of the target, causing target atoms or molecules to escape from the surface and deposit on the substrate to form a thin film. During co-sputtering, multiple targets are activated simultaneously, and target atoms or molecules deposit on the substrate according to their respective sputtering rates, thereby forming a thin film with a specific composition and structure. In this step, at least a first target and a second target are used to complete co-sputtering. The first target can be any one of rare metals such as scandium, titanium, strontium, yttrium, lanthanum, and barium, and the second target can be aluminum nitride. Since aluminum nitride is a compound semiconductor material, at high temperatures, the resistivity of aluminum nitride may decrease significantly. For example, when the temperature exceeds 300 degrees Celsius, the resistivity of aluminum nitride may decrease by three orders of magnitude. This resistive switching property gives it unique advantages as a material for the resistive switching layer. In addition, aluminum nitride also has a response mechanism under the action of an electric field. For example, electrons inside aluminum nitride are excited under the action of the electric field to form an electron conduction channel, enabling current to pass through the material more easily, resulting in a change in the resistance state. And there may be trap energy levels inside aluminum nitride, and the trap energy levels can capture or release electrons under the action of the electric field. During this process, the resistance state of aluminum nitride can change rapidly. The grain boundaries of aluminum nitride may also change under the action of the electric field, thereby affecting the resistance state. In summary, in this embodiment, by adding aluminum nitride to the resistive switching layer, a rapid change in the resistance value of the resistive switching layer can be achieved, that is, the beneficial effect of improving the reverse speed and thus the read / write speed can be achieved.

[0038] In addition, in this step, by means of co-sputtering, the effect of doping rare metals such as scandium, titanium, strontium, yttrium, lanthanum, and barium into aluminum nitride is achieved, which can further improve the resistive switching performance of aluminum nitride.

[0039] Step 103, perform low-temperature cooling on the resistive switching layer material to form a resistive switching layer.

[0040] During cooling, cryo cooling can be used. Specifically, based on the principle of thermoelectric cooling (TEC), that is, using the Peltier Effect generated by semiconductor materials when current passes through. When current passes through a thermocouple composed of two different semiconductor materials, one end will absorb heat and become cold, while the other end will release heat and become hot. By controlling the direction and magnitude of the current, cooling or heating of an object can be achieved.

[0041] Figure 2 It is the second schematic flow chart of the preparation method provided by the embodiment of the present invention.

[0042] As Figure 2As shown, in an exemplary embodiment, the target materials used in the co-sputtering process include a first target material and a second target material. The first target material is any one of scandium, titanium, strontium, yttrium, lanthanum, and barium, and the second target material is aluminum nitride.

[0043] Figure 2 An example of a co-sputtering method using two target materials is illustrated. The first target material can be any one of scandium, titanium, strontium, yttrium, lanthanum, and barium. Exemplarily, the first target material can be scandium, and the second target material is aluminum nitride. During Figure 2 In the illustrated co-sputtering process, argon particles can be used to strike the first target material and the second target material. The elements on the first target material and the second target material fall off onto the bottom electrode to form a resistive switching layer.

[0044] Figure 3 It is the third schematic flow diagram of the preparation method provided by the embodiments of the present invention.

[0045] In an exemplary embodiment, the target materials used in the co-sputtering process include a first target material, a second target material, and a third target material. The first target material is any one of scandium, titanium, strontium, yttrium, lanthanum, and barium, the second target material is any one of scandium, titanium, strontium, yttrium, lanthanum, and barium, and the third target material is aluminum nitride.

[0046] Figure 3 An example of a co-sputtering method using three target materials is illustrated. The first target material can be any one of scandium, titanium, strontium, yttrium, lanthanum, and barium. Exemplarily, the first target material can be scandium, the second target material can be any one of scandium, titanium, strontium, yttrium, lanthanum, and barium. Exemplarily, the second target material can be titanium, and the third target material is aluminum nitride. During Figure 3 In the illustrated co-sputtering process, argon particles can be used to strike the first target material, the second target material, and the third target material. The elements on the first target material, the second target material, and the third target material fall off onto the bottom electrode to form a resistive switching layer.

[0047] In an exemplary embodiment, the sputtering particles used in the co-sputtering process are argon particles.

[0048] Argon particles are particles with extremely inactive chemical properties and hardly react with any substance. Therefore, using argon particles to strike the target materials can avoid contamination.

[0049] In practical applications, argon particles can strike the target materials under the protection of nitrogen. Specifically, nitrogen can be mixed with argon particles in a set ratio and then sprayed onto the target materials at a set flow rate. For example, the mixing ratio of nitrogen to argon particles can be 10% - 90%, that is to say, the volume ratio of nitrogen to argon particles can be 1 / 10 - 9 / 10, and the set flow rate can be 100 sccm to 2000 sccm.

[0050] In an exemplary embodiment, the temperature during the co-sputtering process is 100 degrees Celsius to 400 degrees Celsius.

[0051] In an exemplary embodiment, the purity of the target used during the co-sputtering process is 4N9, that is, the purity can reach 99.9999%.

[0052] In an exemplary embodiment, the deposition power during the co-sputtering process can be 100 W to 2000 W. For example, the deposition power can be 500 W or 1000 W; the deposition pressure during the co-sputtering process can be 2 mTorr to 40 mTorr. For example, the deposition pressure can be 10 mTorr or 20 mTorr.

[0053] In an exemplary embodiment, the material of the seed layer includes any one or more of platinum, molybdenum, aluminum, ruthenium, and phosphorus.

[0054] In an exemplary embodiment, after the resistive switching layer is prepared, a top electrode can be deposited on the resistive switching layer. The material of the top electrode can be any one or more of tungsten, titanium, tantalum, tungsten nitride, titanium nitride, and tantalum nitride. In practical applications, the deposition method of the top electrode can be the same as that of the bottom electrode, and physical vapor deposition (Physical Vapor Deposition, PVD) or chemical vapor deposition (Chemical Vapor Deposition, CVD) can be used for the deposition of the top electrode.

[0055] In practice, the thickness of the top electrode can be 20 nanometers to 100 nanometers. Exemplarily, it can be 60 nanometers.

[0056] Figure 4 It is the fourth flow diagram of the preparation method provided by the embodiments of the present invention.

[0057] As Figure 4 shown, after depositing the resistive switching layer material on the bottom electrode, the material can be cooled to room temperature by a low-temperature cooling method to obtain the resistive switching layer.

[0058] Next, the variable resistive memory provided by the present invention will be described. As Figure 5 shown, the variable resistive memory provided by this embodiment includes a resistive switching layer, and the resistive switching layer can be prepared by the preparation method of the resistive switching layer of the variable resistive memory described above.

[0059] In an exemplary embodiment, the content of aluminum nitride in the resistive switching layer is 40% to 98% by mass.

[0060] In an exemplary embodiment, the thickness of the resistive switching layer is 10 nanometers to 50 nanometers.

[0061] Figure 6Illustrates a schematic diagram of the physical structure of an electronic device, as Figure 6 shown. The electronic device may include: a processor 610, a communications interface 620, a memory 630, and a communication bus 640. Among them, the processor 610, the communications interface 620, and the memory 630 complete communication with each other through the communication bus 640. The processor 610 may call logic instructions in the memory 630 to execute a method for preparing a resistive switching layer of a resistive random access memory. The method includes:

[0062] Depositing a seed layer on a bottom electrode of a pre-prepared resistive random access memory;

[0063] Depositing a resistive switching layer material on the seed layer by co-sputtering. The target materials used in the co-sputtering process include at least a first target material and a second target material. The first target material includes any one of scandium, titanium, strontium, yttrium, lanthanum, and barium, and the second target material is aluminum nitride;

[0064] Performing low-temperature cooling on the resistive switching layer material to form a resistive switching layer.

[0065] In addition, when the logic instructions in the above-mentioned memory 630 are implemented in the form of software functional units and sold or used as an independent product, they may be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of this technical solution, may be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The foregoing storage medium includes: various media such as a USB flash drive, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk, or an optical disc that can store program codes.

[0066] On the other hand, the present invention also provides a computer program product. The computer program product includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the method for preparing a resistive switching layer of a resistive random access memory provided by the above-mentioned various methods. The method includes:

[0067] Depositing a seed layer on a bottom electrode of a pre-prepared resistive random access memory;

[0068] Deposit the resistive switching layer material on the seed layer by co-sputtering. The target materials used in the co-sputtering process include at least a first target material and a second target material. The first target material includes any one of scandium, titanium, strontium, yttrium, lanthanum, and barium, and the second target material is aluminum nitride;

[0069] Perform low-temperature cooling on the resistive switching layer material to form a resistive switching layer.

[0070] In another aspect, the present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it is configured to execute the method for preparing the resistive switching layer of the variable resistive memory provided by the above-mentioned various methods. The method includes:

[0071] Deposit a seed layer on the bottom electrode of a pre-prepared variable resistive memory;

[0072] Deposit the resistive switching layer material on the seed layer by co-sputtering. The target materials used in the co-sputtering process include at least a first target material and a second target material. The first target material includes any one of scandium, titanium, strontium, yttrium, lanthanum, and barium, and the second target material is aluminum nitride;

[0073] Perform low-temperature cooling on the resistive switching layer material to form a resistive switching layer.

[0074] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement it without creative efforts.

[0075] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on such an understanding, the above technical solutions, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods of each embodiment or some parts of the embodiments.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for preparing a resistive switching layer of a resistive memory, characterized in that: include: Depositing a seed layer on the bottom electrode of the previously prepared variable resistance memory; Depositing a resistive layer material on the seed layer by co-sputtering, wherein the target materials used in the co-sputtering process include at least a first target material and a second target material, wherein the first target material includes any one of scandium, titanium, strontium, yttrium, lanthanum and barium, and the second target material is aluminum nitride; The resistive switching layer material is cooled at a low temperature to form a resistive switching layer.

2. The method for preparing a resistive switching layer of a resistive memory according to claim 1, characterized in that: The target materials used in the co-sputtering process include a first target material and a second target material, the first target material is any one of scandium, titanium, strontium, yttrium, lanthanum and barium, and the second target material is aluminum nitride.

3. The method for preparing a resistive switching layer of a resistive memory according to claim 1, characterized in that: The target materials used in the co-sputtering process include a first target material, a second target material and a third target material. The first target material is any one of scandium, titanium, strontium, yttrium, lanthanum and barium. The second target material is any one of scandium, titanium, strontium, yttrium, lanthanum and barium. The third target material is aluminum nitride.

4. The method for preparing a resistive switching layer of a resistive memory according to any one of claims 1 to 3, characterized in that: The sputtering particles used in the co-sputtering process are argon particles.

5. The method for preparing a resistive switching layer of a resistive memory according to any one of claims 1 to 3, characterized in that: The temperature during the co-sputtering process is 100 degrees Celsius to 400 degrees Celsius.

6. The method for preparing a resistive switching layer of a resistive memory according to claim 1, characterized in that: The material of the seed layer includes any one or more of platinum, molybdenum, aluminum, ruthenium and phosphorus.

7. A variable resistance memory, characterized in that: The invention comprises a resistive switching layer prepared by the preparation method according to any one of claims 1 to 7.

8. The variable resistance memory according to claim 6, wherein: The content of aluminum nitride in the resistive layer is 40% to 98% by mass.

9. The variable resistance memory according to claim 6, wherein: The thickness of the resistive switching layer is 10 nanometers to 50 nanometers.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the method for preparing the resistive switching layer of the variable resistive memory according to any one of claims 1 to 6 is implemented.

Images