阅读说明：本技术 氮化铝钪材料 (Aluminum scandium nitride material ) 是由 吴文斌 舒小敏 于 2019-10-13 设计创作，主要内容包括：本发明公开一种氮化铝钪材料,具体地说,是氮化铝钪靶材及氮化铝钪颗粒,氮化铝钪颗粒是由氮化铝钪靶材通过机械加工制备而成,用于蒸发镀膜制备氮化铝钪薄膜及器件。氮化铝钪材料化学表达式为：(Sc<Sub>x</Sub>Al<Sub>1-x</Sub>)N,其中2at%≤x≤50at%。氮化铝钪靶材相对密度可控范围70.0%-99.2%、纯度≥99.99%、主要杂质含量之和小于100μg/g、晶粒尺寸最大值可控范围20μm-200μm。可用于镀膜厂家通过磁控溅射直接制备氮化铝钪薄膜,可避免现有反应溅射法制备氮化铝钪薄膜过程中出现的不稳定现象,提高生产效率和改善薄膜质量。(The invention discloses an aluminum scandium nitride material, and particularly relates to an aluminum scandium nitride target material and aluminum scandium nitride particles. The chemical expression of the aluminum scandium nitride material is as follows: (Sc) x Al 1‑x ) N, wherein x is more than or equal to 2at percent and less than or equal to 50at percent. The controllable range of the relative density of the aluminum scandium nitride target material is 70.0-99.2%, the purity is more than or equal to 99.99%, the sum of the main impurity contents is less than 100 mu g/g, and the controllable range of the maximum value of the grain size is 20 mu m-200 mu m. Can be used for film plating manufacturers to directly prepare the aluminum scandium nitride film through magnetron sputtering, can avoid the unstable phenomenon in the process of preparing the aluminum scandium nitride film by the existing reactive sputtering method, improves the production efficiency and improves the film thicknessFilm quality.)

1. An aluminum scandium nitride material, which is characterized in that: the aluminum scandium nitride material is specifically an aluminum scandium nitride target material and aluminum scandium nitride particles, and the chemical expressions of the aluminum scandium nitride target material and the aluminum scandium nitride particles are (Sc)_xAl_1-x) N, wherein x is more than or equal to 2at percent and less than or equal to 50at percent, the aluminum scandium nitride target material has the relative density range of 70.0-99.2 percent, the purity is more than or equal to 99.99 percent, the sum of the main impurity content is less than 100 mu g/g, the controllable range of the maximum value of the grain size is 20 mu m-200 mu m, and the aluminum scandium nitride particles are prepared by the aluminum scandium nitride target material through mechanical processing and are used for preparing aluminum scandium nitride films and devices through evaporation coating.

2. The aluminum scandium nitride material of claim 1, wherein: the relative density of the aluminum scandium nitride target material is 70.0% or more in minimum value and 99.2% or less in maximum value, the actual value deviation is 0.5% or less, and the actual value of the relative density is 70.0-99.2% by controlling the production conditions.

3. The aluminum scandium nitride material of claim 1, wherein: the maximum value of the grain size of any aluminum scandium nitride target is a certain value within the range of 20-200 μm, the grain sizes of other grains of the target are smaller than or equal to the maximum value, and the maximum value of the grain size of the aluminum scandium nitride target can be controlled by adjusting process parameters.

4. The aluminum scandium nitride material of claim 1, wherein: the aluminum scandium nitride particles are prepared from an aluminum scandium nitride target material through machining and used for preparing an aluminum scandium nitride film and a device through evaporation coating, the aluminum scandium nitride particles are prepared from the aluminum scandium nitride target material through machining, the characteristics of the aluminum scandium nitride particles, such as relative density, purity, crystal size and the like, also inherit the corresponding characteristics of the aluminum scandium nitride target material, the controllable range of the relative density of the aluminum scandium nitride particles is 70.0-99.2%, the purity is more than or equal to 99.99%, the sum of the contents of main impurities is less than 100 mu g/g, and the controllable range of the maximum value of the crystal size is 20 mu m-200 mu m.

Technical Field

The invention relates to the field of materials, in particular to an aluminum scandium nitride target material and aluminum scandium nitride particles.

Background

Aluminum nitride is a good piezoelectric thin film material, has the advantages of high Acoustic Wave speed, high thermal conductivity, low dielectric loss, excellent temperature stability, compatibility with CMOS (complementary metal oxide semiconductor) process and the like, and is an ideal material for preparing high-frequency, high-power and high-integration Surface Acoustic Wave (SAW) devices. Compared with a single aluminum nitride (AlN) functional film, the scandium aluminum nitride [ (ScAl) N ] functional film prepared by doping ScN into AlN has the advantages that the piezoelectric coefficient and the electromechanical coupling coefficient are effectively improved, and the performance of AlN as a piezoelectric film material can be improved, so that an SAW (surface acoustic wave) device with more excellent performance is prepared. At present, aluminum scandium nitride [ (ScaL) N ] functional thin film and a preparation method thereof are hot spots of disputed research at home and abroad, and a plurality of research organizations obtain beneficial results through research, so that the aluminum scandium nitride [ (ScaL) N ] functional thin film is basically prepared in a reactive sputtering mode, specifically, an aluminum scandium metal target (or an aluminum metal target and a scandium metal target) is used as a sputtering coating raw material, the aluminum scandium metal target (or the aluminum metal target and the scandium metal target) is loaded into reactive sputtering equipment, and after vacuumizing, argon and nitrogen are introduced, wherein the argon is a working gas, and the nitrogen is a reaction gas. Under the action of electromagnetism, ionized argon positive ions bombard the surface of an aluminum-scandium metal target along a direction with a certain included angle, aluminum-scandium metal components escape from the surface of the target, fly out along the symmetrical direction of the bombardment direction and fly to the surface of a base material, and during sputtering, aluminum-scandium metal reacts with nitrogen to generate AlN and ScN which are deposited on the surface of the base material and crystallized to form a layer of aluminum-scandium nitride [ (ScAl) N ] functional film. The method for preparing the film in the reactive sputtering mode considers both sputtering coating and chemical combination reaction, the preparation conditions are difficult to control, such as the difference of the reaction conditions of aluminum, scandium and nitrogen, the difference of the reaction conditions and the sputtering conditions, the problem of nitrogen guest series working gas and the like, and the difference, the problem and the derived deep-level problem are comprehensively considered. Although a comprehensive optimal set of operating parameters can be obtained through research, the reaction and sputtering must be compatible, and certain disadvantages which are difficult to overcome are inevitable. Such as target poisoning during the preparation process, incomplete nitridation of metal impurities or low-valence nitrides in the film, partial amorphous state of the film, unsatisfactory film morphology, and reduced film quality with increased content of the dopant ScN, which results in increased cost, reduced production efficiency, and poor film performance.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides an aluminum scandium nitride material, in particular to an aluminum scandium nitride target material and aluminum scandium nitride particles.

The chemical expression of the aluminum scandium nitride target material and the aluminum scandium nitride particles is Sc_xAl_1-x) N, wherein x is more than or equal to 2at percent and less than or equal to 50at percent.

The controllable range of the relative density of the aluminum scandium nitride target material is 70.0-99.2%, the minimum value of the relative density of the aluminum scandium nitride target material is more than or equal to 70.0%, and the maximum value is less than or equal to 99.2%. By controlling the production conditions, the relative density of the produced aluminum scandium nitride can be any value in the range of 70.0-99.2%, the actual value deviation is less than or equal to 0.5%, and the actual value of the relative density is also in the range of 70.0-99.2%.

The purity of the aluminum scandium nitride target material is more than or equal to 99.99 percent, and the sum of the contents of main impurities is less than 100 mu g/g.

The controllable range of the maximum value of the grain size of the aluminum scandium nitride target material is 20-200 mu m, the maximum value of the grain size of any aluminum scandium nitride target material is a certain value within the range of 20-200 mu m, the sizes of other grains of the target material are less than or equal to the maximum value, and the maximum value of the grain size of the aluminum scandium nitride target material can be controlled by adjusting process parameters.

The aluminum scandium nitride particles are prepared by machining an aluminum scandium nitride target material and are used for preparing an aluminum scandium nitride film and a device by evaporation coating. The aluminum scandium nitride particles are prepared by machining an aluminum scandium nitride target material, the relative density, purity, crystal size and other characteristics of the aluminum scandium nitride particles also inherit the corresponding characteristics of the aluminum scandium nitride target material, the controllable range of the relative density of the aluminum scandium nitride particles is 70.0-99.2%, the purity is more than or equal to 99.99%, the sum of the main impurity contents is less than 100 mu g/g, and the controllable range of the maximum value of the crystal grain size is 20 mu m-200 mu m.

The invention has the beneficial effects that the aluminum scandium nitride target material can be used as a magnetron sputtering coating raw material for preparing the aluminum scandium nitride functional film by SAW device manufacturers, is used for preparing the aluminum scandium nitride functional film by a magnetron sputtering method without a reactive sputtering method; the aluminum scandium nitride particles can be used as an evaporation coating raw material for preparing an aluminum scandium nitride functional film by an SAW equipment manufacturer, and can be used for preparing the aluminum scandium nitride functional film by an evaporation method. Therefore, the current situation that the aluminum scandium nitride functional film is prepared by singly relying on a reactive sputtering method at home and abroad at present can be improved, ways for preparing the aluminum scandium nitride functional film are enriched, the defects of difficult avoidance of the reactive sputtering method are overcome, and the problems that a target material poisoning phenomenon exists in the preparation process, metal impurities or low-price nitride which are not completely nitrided possibly exist in the film, the film possibly has a partially amorphous state, the appearance of the film is possibly unsatisfactory, the quality of the film is reduced along with the increase of the content of a dopant ScN, and the like are solved, so that the film performance is ensured, the production efficiency is improved, and the production cost is reduced.

Detailed Description

Process for synthesizing aluminium nitride and scandium nitride by temp. -programmed gas-solid synthesis

And (3) synthesizing AlN: cold-pressing aluminum powder with purity of more than 99.99% into loose blocks, placing into a crucible, transferring the crucible into a vacuum heating furnace, vacuumizing to 1-5Pa, introducing nitrogen to 100-200kPa, heating to 500-600 kPa⁰C, preserving the temperature for 0.5h, and removing the oxide on the surface of the aluminum powder. Continuously heating to 800-850⁰C, preserving heat for 1-2h to ensure that the aluminum powder and the nitrogen fully react, cooling to room temperature along with the furnace, taking out the synthesized product, crushing, ball-milling, repeating the process at 1100-1200⁰C is nitrided for 0.5h for the second time, cooled along with the furnace, and subjected to XRD test, and the product is qualified without impurity phases except AlN phases. And crushing and ball-milling the qualified product to-500-mesh AlN powder for later use.

Synthesis of ScN: cold-pressing scandium powder with purity of above 99.99% into loose block, placing into crucible, transferring the crucible into vacuum heating furnace, vacuumizing to 1-5Pa, introducing nitrogen gas to 100-200kPa, and heating to 800-900⁰And C, preserving heat for 1-2 hours to ensure that scandium powder and nitrogen fully react, cooling to room temperature along with the furnace, taking out a synthetic product, crushing, ball-milling, cooling along with the furnace, and performing XRD test, wherein no impurity phase except the ScN phase is qualified. If the metal scandium is not nitrided, secondary nitridation is needed. And crushing and ball-milling the qualified product to-500-mesh ScN powder for later use.

Hot pressed sintering forming

Calculating the dosage of AlN and ScN according to the mixing atomic ratio of AlN to ScN in each example in Table 1, mixing, placing into a mold, sintering in a vacuum hot pressing furnace at 1500-1600 deg.C⁰And C, applying pressure of 12-25MPa, and sintering for 30-80min to obtain the aluminum nitride scandium-doped target blank. Processing the blank by a grinding machine to obtain an aluminum scandium nitride target material, and packaging and warehousing the qualified aluminum scandium nitride target material after inspection; after the blank is processed by the grinding machine,And grinding, screening out aluminum scandium nitride particles, and packaging and delivering out of the warehouse after the aluminum scandium nitride particles are inspected to be qualified.

TABLE 1 atomic ratio of AlN to ScN mixed in each example

	Atomic ratio of AlN (at%)	Atomic ratio of ScN (at%)
			Example 1	98	2
example 2	90	10
			Example 3	80	20
Example 4	70	30
			Example 5	60	40
Example 6	50	50

The technical scope of the present invention is not limited to the contents of the specification, and must be determined according to the scope of the claims.