CN-121992503-A - Method for preparing monocrystalline manganese nitride film

Abstract

The invention provides a method for preparing a monocrystalline manganese nitride film, which comprises the following steps of (1) preprocessing a substrate to remove impurities adsorbed on the surface of the substrate, (2) taking a manganese source as an evaporation source, using a radio frequency plasma pyrolysis source to crack nitrogen into nitrogen atoms, and adopting a molecular beam epitaxy method to prepare the monocrystalline manganese nitride film, wherein the nitrogen partial pressure is 2X 10 ‑5 -4×10 ‑5 mbar, and the radio frequency power is 200-300W. The method can obtain a single crystal film with high quality and no impurity phase. The monocrystal manganese nitride film prepared by the invention has good stability in the atmosphere and water, good conductivity and good antiferromagnetic metal material.

Inventors

• JI ZHUANG
• GU MINGHUI
• GUO JIANDONG
• MENG MENG

Assignees

• 中国科学院物理研究所

Dates

Publication Date

20260508

Application Date

20241105

Claims (9)

1. 1. A method for preparing a single crystal manganese nitride film comprising the steps of: (1) Pretreating the substrate to remove impurities adsorbed on the surface of the substrate; (2) The method comprises the steps of taking a manganese source as an evaporation source, using a radio frequency plasma pyrolysis source to crack nitrogen molecules into nitrogen atoms with higher chemical activity, and adopting a molecular beam epitaxy method to prepare the single crystal manganese nitride film, wherein the nitrogen partial pressure is 2X 10 -5 -4×10 -5 mbar, and the radio frequency power is 200-300W.
2. 2. The method of claim 1, wherein the pre-treating the substrate in step (1) is performed by a method comprising: The substrate is placed in a chamber for molecular beam epitaxy and annealed at 900-1000 ℃ for 0.5-2 hours under vacuum of 10 -10 mbar or less.
3. 3. The method of claim 1, wherein the substrate is selected from magnesium oxide and/or strontium titanate.
4. 4. The method of claim 1, wherein the purity of the manganese source is 99.9998 wt% or greater.
5. 5. The method of claim 1, wherein the nitrogen has a purity of 99.9999 wt% or greater.
6. 6. The method of claim 1, wherein the temperature of the evaporation source is set to 730-770 ℃.
7. 7. The method of claim 1, wherein the single crystal manganese nitride thin film prepared by molecular beam epitaxy in the step (2) is performed under the following conditions: The growth temperature is 300-350 ℃ and the growth time is 15-120 minutes.
8. 8. The method of claim 1, wherein the method further comprises the following step after step (2): and (3) carrying out in-situ annealing treatment on the monocrystalline manganese nitride film prepared in the step (2) to obtain the monocrystalline manganese nitride film with higher quality.
9. 9. The method of claim 9, wherein the in situ annealing treatment is performed under the following conditions: The annealing temperature is 300-350 ℃, the nitrogen partial pressure is 2X 10 -5 -4×10 -5 mbar, and the annealing time is 25 minutes-1 hour.

Description

Method for preparing monocrystalline manganese nitride film Technical Field The invention belongs to the field of materials. In particular, the present invention relates to a method for preparing a single crystal manganese nitride film. Background With the development of the internet of things and the high-speed development of artificial intelligence application, the human society continuously puts higher demands on the application field and range of computers. Traditional von neumann computer architecture relies on logical linear logic communication between the arithmetic control unit and each memory, and a large number of data accesses, transmissions and operations make its development face the limitations of "memory walls" and "power consumption walls". Aiming at the current requirement of the data-intensive application, the new generation of logic storage devices needs to have the following characteristics that 1, the non-volatile memory devices need to have coping capability for emergency situations and cannot cause data loss due to the emergency situations, 2, the power consumption is low, the power consumption of the devices is required to be small for mass data operation, unnecessary energy waste and interference to device operation are avoided, 3, the storage capacity is large, and the operation and storage of mass data can be met. Magnetic Random Access Memory (MRAM) has the potential to be a next generation new logic memory device that represents the logical relationship of "0" and "1" by two different states of the ferromagnetic layer, has good non-volatility and near zero static power consumption compared to conventional charge storage, and also has the characteristic of large storage density, which simultaneously meets the need for a large number of data storage operations. Through many years of research and development, MRAM has gradually entered a commercial state from the first generation of Toggle-MRAM that manipulates magnetic moment based on a strong external magnetic field to the new generation of STT and SOT-MRAM devices that manipulates magnetic moment based on spin-polarized current, but these devices still face some unavoidable problems, such as data loss caused by the interference of the strong external magnetic field, power consumption caused by the large manipulation current, auxiliary external field participation, limiting the miniaturization of the device size, etc., which all need further research and improvement on the current MRAM devices. One path to solve the above problems is further research into antiferromagnetic materials whose crystal lattice is composed of a staggered arrangement of magnetic atoms having opposite magnetic moments, which do not show magnetism outward as a whole, are insensitive to external disturbing magnetic fields, and have spin response speeds on the order of terahertz, which makes antiferromagnetic materials have potential as cores of new-generation logic memory devices. On one hand, the change of the high-low resistance state in the antiferromagnetic material can be electrically controlled by manipulating the direction of the Nel vector in the antiferromagnetic material, and an important thought is provided for the antiferromagnetic material to be used as a magnetic memory material, on the other hand, the exchange bias effect existing at the interface of the antiferromagnetic material and the ferromagnetic material can be used as an effective field to assist the decisive turning of the magnetic moment of the MRAM device, and under a certain write current, the exchange bias field can turn over, so that a new thought is provided for the application of the antiferromagnetic material to the MRAM device. However, conventional IrMn, ptMn, etc. metal antiferromagnetic materials, although well-developed in technology, are suitable for industrial manufacture of current GMR, TMR, etc. devices, there are still a number of problems in the use of these materials, such as the use of a large amount of rare noble metal materials, which are disadvantageous for reduction of industrial cost, high formation temperature of antiferromagnetic ordered structures, and disadvantageous for practical industrial preparation and application, etc. It is desirable to find material systems suitable for use as anti-ferromagnetic spintronics research and applications, and to add fundamental research, in an effort to become the core of next generation logic memory devices. Among the many antiferromagnetic material systems, manganese nitride (MnN) material is an alternative antiferromagnetic material that can be used for magnetic storage, and there have been some reports on its antiferromagnetic spintronics applications. In summary, the antiferromagnetic manganese nitride material has research and application potential as a new generation antiferromagnetic spintronics device, but the preparation of the film still has the problems of hetero-phase or poor crystallization quality and t