TWI237243B - Magnetic recording material and method for making the same - Google Patents

Abstract

The present invention discloses a magnetic recording material and a method for making the same. The magnetic recording material includes a porous alumina substrate having a number of highly-ordered holes defined therein, and magnetic material of CoCrPtX alloy received in the holes. The CoCrPtX alloy is confinedly shaped as a number of cylinders by the holes. Thus, the cylindrical CoCrPtX alloy has perpendicular magnetic anisotropy and high coercivity along its axial direction. The resultant magnetic recording material has a recording density of 64.5 KGbit/in<2>.

Description

mmr- ------_ Case No. 92104611 V. Description of the invention (1) [Technical field to which the invention belongs]

The present invention relates to a kind of magnetic L finger: a kind of magnetic material with high memory density and a method for preparing the same, especially [previous technology] € a bulk material and a method for preparing the same. With the development of information technology, # 音 有 六 妙 6 increased, and the requirement of increasing the degree of Guzi on a limited area is related to the recording density and storage capacity of the bulk material. The key is to improve the record. The method of making each bit of information accounted for is the method of reducing the size of the memory material. This method is used to reduce the size of the memory material; m2 to hundreds, but the use of bismuth is a superparamagnetic phenomenon. In ancient times, it has a higher magnetization and superb power. Issues are published; 丨 In order to increase the information storage density of magnetic memory materials, it is necessary to find a way to deal with the coercive force of Chuanbei while reducing the median, n, and n7;; Small size magnetic

The sub = 1 operation is usually implemented by methods such as photolithography or self-assembly. Currently, ice ultraviolet (DUV) lithography can be extended to about 50 ° in lateral dimensions, but such expansion is unreliable and expensive. When the size is less than 50mm, X-ray lithography and far-ultraviolet lithography can be used, but both require huge capital investment, which is currently difficult to be practical. For a description of the 40-70ηπ particle self-assembly method made of rubber pulp or other compounds, see Micheletto Equal to Langmuir 11, 3333-3336 (1995), A Simple Method for the Production of a Two-Dimensional, Ordered Array of Small Latex Part icles — Text t. For a description of the orderly formation of 5-1 Onm-sized semiconductor particles, see Murray equal to Science 270, 1335-1338 (1995), nwm ':: Ί through Mifd) t. 92104611

Self-Organization of CdSe Nanocrystal 1 tes into Three-Dimensional Quantum Dot Super 1 a11ices — in the text ο IBM Corporation ’s publication number CN 1 2439 9 9A, published on February 9, 2000, published in Chinese patent application A memory material formed by nano-scale particle chemical self-assembly method. The memory material is composed of a nano-scale magnetic particle layer arranged on the substrate surface with a substantially uniform diameter and spacing. The particles have a diameter of not more than 50 nm and contain a magnetic material. The magnetic material includes elements Co, Fe, Ni, Mn, Sm, Nd, Pr, Pt, and Gd, and metal compounds of these elements, binary alloys and ternary alloys, and iron oxides including at least one of the foregoing elements in addition to barium ferric acid Salt or ferrite. The § area memory density of bit memory material is 100 Gbit / in2 per square inch, even close to i 000 Gbit / in2. However, the magnetic particles of the memory material are prepared using a self-assembly method. The uniform particle size of the magnetic particles is uncertain, and further reduction of the magnetic particle size will cause a superparamagnetic phenomenon, thereby limiting the storage surface of the memory material. The density is further increased. In view of this, it is necessary to provide a magnetic memory material with a highly ordered arrangement of magnetic materials and a higher density.发明 [Summary of the Invention] An object of the present invention is to provide a magnetic memory material having a highly ordered morphological arrangement and high density. 〃 The high-density magnetic memory material disclosed in the present invention is a porous alumina substrate, which has a uniformly arranged microporous array 歹 ^;

1237243 :: 丨 Case No. 92104611 V. Description of the invention (3) The magnetic material CoCrPtX is deposited in the microporous array, where χ represents boron, nitrogen or carbon; a protective coating, which is deposited on porous alumina The surface of the substrate, wherein the diameter of the micropores of the porous alumina substrate is 5 to 5 nanometers, and the distance between two adjacent micropores is 2 to 1 nanometer. Further, the present invention also provides a method for preparing the above-mentioned high-density magnetic memory material, the steps of which include: (1) providing a substrate, the surface of which is oxidized to form a uniform array of micropores;

(2) depositing a magnetic material CoCrPtX in the microporous array, where χ represents a side, nitrogen or carbon; (3) depositing a protective coating diamond-like carbon (DLC) on the microporous surface of the porous oxide substrate. Preferably, the surface of the protective coating diamond-like carbon is further deposited with a lubricant perfluoropolyether (PFPE).

Compared with the prior art, the present invention provides a magnetic memory material with a memory density of up to 64.5KGbit / in2, which greatly improves the memory density of the magnetic material. In addition, in this memory material, the magnetic material is deposited on the oxidized micropore array 10 to form a columnar body, the diameter of which is limited by the size of the micropore pore size, only 5nm, so the magnetic memory material has a high vertical difference. The coercivity of the magnetite in the axial direction of the cascade is as high as 8000 ~ 20, 000e, so it does not appear superparamagnetization due to the influence of temperature changes. [Embodiment] Please refer to the first figure. The base material of the memory used in the present invention is the oxidized oxide substrate 10, and the formation of the porous oxidized junction substrate 10 can be performed first.

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The GF6 gas selectively etched the surface of the aluminum substrate to generate nano-points. Then, the aluminum substrate was placed in a high-temperature oven with a high oxygen flow chamber, and was oxidized by the two B cells to form a microporous array 1 2 . The micropore array has a uniform pore size of 5nm, and a preferred range is 3nm; the micropores are closely spaced with a spacing of 2 ~ 1 Onm, preferably a spacing of 2 ~ 5nm; each of the microwell arrays 2 The depth of the micropores is 2.5 to 7.5 nm. The microwell array 12 is columnar, uniformly distributed and arranged in an orderly manner, and the pores are independent of each other. Therefore, the phenomenon of mutual staggering due to the inclination of the microwells does not occur. Alternatively, the aluminum substrate can also be selected for silicon. A thickness of 2.5 to 7.5 nm aluminum film is deposited on the surface of the glass. The thickness of the aluminum substrate can be controlled by controlling the strength of the deposition and the time of deposition. In addition, the gas of the substrate with inscriptions can also be a mixed gas of ch4 and CF4. Please refer to the second figure. After the porous alumina matrix is formed, the magnetic material CoCrPtX is deposited into the micropore array 12, where χ represents any one of boron, nitrogen, and carbon. The deposition process can be called sputtering. In the present invention, in the present invention, first, coCrPtx is made into a thin film, and then the porous alumina substrate 10 is placed directly opposite to it, and then a CoCrPtX thin film target is bombarded with an argon plasma, and coCrPtX is deposited. Into the microporous array 12 of the porous alumina film 10. In addition to ion deposition, the magnetic material and CoCrPtX can also be deposited by ion beam deposition (Ion Beain).

Deposition) or ion plating. In addition to the aforementioned CoCrPtX, the magnetic material also includes CoCrPtTax, where X also represents any one of boron, nitrogen, or carbon.

After the CoCrPtX deposition is completed, the surface of the porous alumina substrate 10 is washed with hydrofluoric acid so that the non-porous portion of the surface of the alumina substrate

1237243 __ 銮 号 92104611_year month day_correction _ 5. Description of the invention (5)

CoCrPtX was removed. CoCrPtX deposited in the oxide chain microwell array 12 is restricted by the shape of the microwells to form a columnar body 14. The diameter of the columnar body 1 4 is limited to the size of the micropore diameter and is only 1 ~ 5nm. Therefore, the columnar body 14 has a high perpendicular anisotropy and a high coercive force in the vertical direction. Between ~ 20,000 〇e, so there is no superparamagnetization phenomenon affected by temperature changes. Referring to the third figure, a protective coating layer 16 is deposited on the surface of the porous alumina substrate to protect the columnar body 14 and fix it in the microporous array 12. The protective coating layer 16 Must be strong and adhere to the surface of the porous alumina substrate (not shown). Suitable materials for protective coatings include diamond-like carbon (DLC) and amorphous carbon. The preferred material of the protective coating 16 is diamond-like carbon (DLC), which can be deposited by mixing argon with hydrogen, methyl or ethyl sintering = gas reactive sputtering, and the thickness of the protective coating 16 The thickness is 5 to 10 nm, and the thickness is preferably 7.5 nm. Protective i, 6 'can be shot by any suitable method known to those skilled in the art ^ 2gu = i using electro-enhanced chemical vapor deposition (PE CVD) or sputtering, or heating porous oxide Base body 10 to 150 ~ 3. Generation: Make the sample blast in hexane or similar carbon source molecular plasma for dazzling glance. It can be protective; ':: guaranteed; after the coating 16 is completed ... The degree is 0.5 ~ 2 ... It is preferable to coat a layer of lubricant 18 on the surface of the household sound, which is (PFPE), lubricant Lu 丨 / Xingji ^ 0 · 7 ~ hhm, the material is perfluoropolyfluorene

Coating), the deposition method of the body is the dip coating method (Dip is the red coating method (SPin Coating).

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No. 92104611 correction Ι2 # 7343 said tf--five-ι * · hair ^ Ming-say-ming, the memory material of the present invention, the columnar body 14 preferably has a diameter of 3 ππ, and the distance is preferably 2 to 5 nm, If the memorized information density is expressed by 1 magnetic particle / bit, the memory density is about 64.5KGbit / in2, and the memory density of the magnetic film obtained by the previous technology is 1G ~ 10Gbit / in2, which greatly improves the magnetic memory of South Its recording density. In summary, this creation meets the requirements for an invention patent, and a patent application is filed in accordance with the law. However, the above is only a preferred embodiment of this creation. For those who are familiar with the skills of this case, equivalent modifications or changes made in accordance with the spirit of this case should be included in the scope of patent application below.

Page 10 Case No. 92104611_ 年月 日 __ ΐ ·… simple explanation of the formula [Simplified illustration of the diagram] The first diagram is a cross-sectional view of the porous alumina substrate of the present invention. The second figure is a cross-sectional view of a magnetic material deposited in the microwell array of the first figure. The third figure is a schematic view of a protective coating deposited on the surface of the second figure. The fourth diagram is a schematic diagram of a lubricant layer deposited on the surface of the protective coating. [Description of main component symbols] Porous alumina substrate 10 Microporous array 12 Columnar body 14 Protective coating 16 Lubricant layer 18

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Claims (1)

1237243 __ Case No. 92104611 6. Scope of patent application 1. A magnetic memory material, including: Xiong oxide oxide substrate 'The substrate has a uniform array of micropores;' a magnetic material CoCrPtX, where X represents boron, nitrogen or carbon The magnetic material CoCrPtX is deposited in the microporous array; a protective coating is deposited on the surface of the porous samarium substrate; wherein the diameter of the micropore is 1 to 5 nanometers and two adjacent micropores The interval is 2 ~ work. 2 · The magnetic memory material according to item 1 of the scope of patent application, wherein the pore depth of the micropores is 2.5 to 7. 5 nm. ′, Person • The magnetic memory material described in item 1 of the declared patent scope, wherein the magnetic material further includes CoCrPtTaX, where X represents boron, nitrogen, or hindrance. 4. The magnetic memory material according to item 1 of the patent application scope, wherein the protective coating material includes diamond-like carbon or amorphous fracture. 5. The magnetic memory material according to item 1 or 4 of the scope of patent application, wherein the thickness of the protective coating is 5 to 10 nm. 6 · The magnetic memory material according to item 1 of the scope of patent application, wherein The surface of the creeping coating is also coated with a lubricant layer, and the material is ρ ρ p e. 7 · The magnetic memory material according to item 6 of the scope of patent application, wherein the thickness of the lubricant layer is 0.5 to 2 nm. 8. A method for preparing a magnetic memory material, the steps of which include: providing a matrix, the surface of which is oxidized to form a uniform array of micropores; Case No. 92104611 1237243 on page 12 Amendment date: June 6th, patent application scope (2) Deposit magnetic material CoCrPtX in the microporous array ten, where X represents boron, nitrogen or carbon; (3) Deposit protective coatings Diamond structured carbon (DLC) is on the microporous surface of the porous oxide substrate. 9-The method for preparing a magnetic memory material as described in item 8 of the scope of the patent application ', wherein the method for depositing the magnetic material includes sputtering, ion beam deposition, or iontophoresis. 1 · Method for preparing magnetic memory material as described in item 8 of the scope of patent application 'wherein a protective coating of diamond-like diamond is deposited; 5 carbon method includes reactive sputtering with argon and hydrogen, methane or ethane mixed gas (Reactive Sputtering). 1 1. The method for preparing a magnetic memory material as described in item 8 of the scope of the patent application, wherein the method for depositing a protective coating of diamond-like fracture includes plasma enhanced chemical vapor deposition method, sputtering coating. 1 2 · The method for preparing magnetic memory materials as described in item 8 of the scope of the patent application. / The surface of the diamond-like carbon with a protective coating is also deposited with a lubricant layer. The material is PFPE. 1 3. The method for preparing a magnetic memory material as described in item 12 of the scope of the patent application, wherein the method for depositing the lubricant layer includes a dip coating method or a spin coating method. Page 13