WO2019177086A1 - MgO SINTERED BODY AND SPUTTERING TARGET - Google Patents

MgO SINTERED BODY AND SPUTTERING TARGET Download PDF

Info

Publication number
WO2019177086A1
WO2019177086A1 PCT/JP2019/010479 JP2019010479W WO2019177086A1 WO 2019177086 A1 WO2019177086 A1 WO 2019177086A1 JP 2019010479 W JP2019010479 W JP 2019010479W WO 2019177086 A1 WO2019177086 A1 WO 2019177086A1
Authority
WO
WIPO (PCT)
Prior art keywords
sintered body
mgo
mgo sintered
sputtering target
abnormal discharge
Prior art date
Application number
PCT/JP2019/010479
Other languages
French (fr)
Japanese (ja)
Inventor
寛明 久保
真樹 田中
敦志 三谷
宗佑 横山
正信 高巣
宏季 田中
Original Assignee
宇部マテリアルズ株式会社
日本タングステン株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 宇部マテリアルズ株式会社, 日本タングステン株式会社 filed Critical 宇部マテリアルズ株式会社
Publication of WO2019177086A1 publication Critical patent/WO2019177086A1/en

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
    • C04B35/03—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on magnesium oxide, calcium oxide or oxide mixtures derived from dolomite
    • C04B35/04—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on magnesium oxide, calcium oxide or oxide mixtures derived from dolomite based on magnesium oxide
    • C04B35/053—Fine ceramics
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/22—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating
    • C23C14/34—Sputtering
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N50/00—Galvanomagnetic devices
    • H10N50/01—Manufacture or treatment
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N50/00—Galvanomagnetic devices
    • H10N50/80—Constructional details
    • H10N50/85—Magnetic active materials

Definitions

  • the present invention relates to a MgO sintered body and a sputtering target.
  • a magnetic tunnel junction (MTJ) element has attracted attention as an element for improving the recording density of a magnetic recording apparatus, and is expected to be applied to a magnetic head of a hard disk, a high-performance nonvolatile memory, or the like.
  • the MTJ element has an insulating thin film called a tunnel barrier layer between two ferromagnetic layers.
  • MgO manganesium oxide
  • the MgO thin film is formed by, for example, a sputtering method using an MgO sintered body as a sputtering target.
  • various MgO sintered bodies have been proposed.
  • Patent Document 1 describes a MgO sintered body having a dense and fine crystal structure with a relative density of 99% or more and an average crystal grain size of 30 ⁇ m or less.
  • This MgO sintered body exhibits excellent mechanical properties. Furthermore, when an MgO sintered body having a porosity of 0.5% or less is used as a sputtering target, impurity contamination in the apparatus during sputtering is improved. Furthermore, when a (111) -oriented MgO sintered body is used as a sputtering target, secondary electron emission during sputtering is promoted and sputtering efficiency is improved.
  • the purity is 99.99% or more, the relative density is more than 98%, the average crystal grain size is 8 ⁇ m or less, and the peak intensity ratio I (111) / I (200 ) Is 8% or more and less than 25%.
  • An MgO thin film formed by a sputtering method using this MgO sintered body as a sputtering target exhibits excellent insulating properties, small surface roughness, and excellent homogeneity.
  • An object of some aspects of the present invention is to provide an MgO sintered body and a sputtering target that can sufficiently reduce abnormal discharge during sputtering, which is a cause of generation of particles during film formation.
  • a first aspect of the present invention is an MgO sintered body characterized by having an average crystal particle diameter of more than 10 ⁇ m and not more than 100 ⁇ m and a surface having a center line average roughness Ra of not more than 1.6 ⁇ m. About.
  • An MgO sintered body having an average crystal particle diameter of more than 10 ⁇ m and not more than 100 ⁇ m has a reduced grain boundary triple point that tends to be the starting point of chipping. Therefore, in the sputtering method using this MgO sintered body as a sputtering target, the average abnormal discharge due to chipping can be reduced.
  • the MgO sintered body according to the first aspect of the present invention further has a surface having a center line average roughness Ra of 1.6 ⁇ m or less, surface chipping and deposits are reduced.
  • the MgO sintered body according to the first aspect of the present invention can reduce both the average abnormal discharge and the initial abnormal discharge because both the average crystal particle size is increased and the surface is smoothened. it can.
  • the first aspect of the present invention it is preferable to have a density of 3.569 g / cm 3 or more.
  • a density of 3.569 g / cm 3 or more In order to increase the density of the MgO sintered body, it is conceivable to promote the sintering of the MgO sintered body. When the sintering of the MgO sintered body is promoted, the crystal particle diameter generally increases, so that it becomes difficult to smooth the surface as described above.
  • both increasing the density and smoothing the surface are compatible. As the density of the MgO sintered body increases, the pores at the grain boundaries that tend to become the starting point of chipping decrease. Therefore, in the sputtering method using this MgO sintered body as a sputtering target, the average abnormal discharge due to chipping can be reduced.
  • a second aspect of the present invention relates to a sputtering target comprising the MgO sintered body according to the first aspect.
  • the sputtering target including the MgO sintered body of the first aspect can reduce abnormal discharge during sputtering, generation of particles during film formation can be reduced, and a good MgO thin film can be formed. be able to.
  • MgO sintered body (1-1) Average crystal particle diameter, centerline average roughness Ra, density of MgO sintered body
  • the MgO sintered body of the present embodiment has an average crystal particle of more than 10 ⁇ m and not more than 100 ⁇ m
  • the surface has a diameter and a center line average roughness Ra of 1.6 ⁇ m or less.
  • the MgO sintered body of the present embodiment may further have a density of 3.569 g / cm 3 or more.
  • An MgO sintered body having an average crystal particle diameter of more than 10 ⁇ m and not more than 100 ⁇ m has a reduced grain boundary triple point that tends to be the starting point of chipping. Therefore, in the sputtering method using this MgO sintered body as a sputtering target, the average abnormal discharge due to chipping can be reduced.
  • the average crystal particle diameter exceeds 10 ⁇ m, preferably 12 ⁇ m or more, more preferably 14 ⁇ m or more, still more preferably 17 ⁇ m or more, and particularly preferably 20 ⁇ m or more.
  • the grain boundary triple points that tend to become the starting point of chipping decrease.
  • minute strains are generated in the particles. Chipping is less likely to occur due to internal stress generated by this strain.
  • the strength generally decreases as the average crystal particle size increases.
  • there is also an effect of the above-mentioned distortion and if it is up to 100 ⁇ m, it can resist thermal stress and thermal shock during bonding. Therefore, in the sputtering method using this MgO sintered body as a sputtering target, the average abnormal discharge can be further reduced.
  • the initial abnormal discharge on the surface of the MgO sintered body can be reduced.
  • the center line average roughness Ra of the surface is preferably 1 ⁇ m or less, and more preferably 0.6 ⁇ m or less. As the center line average roughness Ra is further reduced, surface chipping and deposits are further reduced. In addition, fluctuations in the electric field are less likely to occur. Therefore, in the sputtering method using this MgO sintered body as a sputtering target, the initial abnormal discharge on the surface of the MgO sintered body can be further reduced.
  • the center line average roughness Ra is preferably as small as possible, it is technically not 0 ⁇ m.
  • An MgO sintered body having a density of 3.569 g / cm 3 or more has reduced grain boundary pores that tend to be the starting point of chipping. Therefore, in the sputtering method using this MgO sintered body as a sputtering target, the average abnormal discharge due to chipping can be reduced.
  • the density is preferably 3.575 g / cm 3 or more. As the density further increases, the grain boundary pores that tend to become the starting point of chipping further decrease. Therefore, in the sputtering method using this MgO sintered body as a sputtering target, the average abnormal discharge can be further reduced.
  • the average crystal particle diameter of the MgO sintered body when the average crystal particle diameter of the MgO sintered body is increased, the crystal particles that are separated during surface polishing and grinding are increased, and thus it is difficult to smooth the surface.
  • the crystal particle diameter When the sintering of the MgO sintered body is promoted, the crystal particle diameter generally increases, so that it becomes difficult to smooth the surface as described above. For this reason, chipping and deposits on the surface increase, and in the sputtering method using this MgO sintered body as a sputtering target, the initial abnormal discharge on the surface of the MgO sintered body may increase.
  • the MgO sintered body of the present embodiment has both a large average crystal particle size and a smooth surface, both the average abnormal discharge and the initial abnormal discharge can be reduced.
  • the MgO sintered body of the present embodiment can further reduce the average abnormal discharge by further increasing the density.
  • the MgO sintered body of the present embodiment is an MgO sintered body that further includes a uniaxial pressure sintering process in the manufacturing process, and (111) ) Surface X-ray diffraction intensity ratio ⁇ (111) is (Equation 1), ⁇ (111) of the uniaxially pressed surface is ⁇ V (111), and ⁇ (111) of the surface perpendicular to the uniaxially pressed surface ) Is ⁇ H (111), ⁇ V (111) / ⁇ H (111)> 1.5 is preferable.
  • the uniaxially pressed surface is equal to a surface having a center line average roughness Ra of 1.6 ⁇ m or less.
  • ⁇ (111) ⁇ 0.4434 ⁇ R 2 + 1.4434 ⁇ R ⁇ (Formula 1)
  • R I (111) / (I (111) + I (200))
  • the manufacturing method of the MgO sintered body of this embodiment includes (a) a step of obtaining MgO particles by refining MgO raw material powder, and (b) uniaxial pressure firing of MgO particles. And obtaining a MgO sintered body, and (c) a step of heat-treating the MgO sintered body in an oxygen-containing atmosphere.
  • the method of manufacturing the MgO sintered body according to the present embodiment includes a process of obtaining MgO particles by refining the MgO raw material powder.
  • the purity of the MgO raw material powder is preferably as high as possible in order to reduce contamination of the usage environment of the MgO sintered body, and is preferably 99.99% (4N) or more.
  • the MgO sintered body obtained by sintering the refined MgO particles to the MgO sintered body obtained by sintering the non-miniaturized MgO particles has a large proportion of the (111) plane, that is, the (111) plane orientation. It is easy to obtain a MgO sintered body. Therefore, the particle diameter of MgO particles obtained by refining the MgO raw material powder is preferably 1 ⁇ m or less, and more preferably 0.5 ⁇ m or less.
  • using MgO particles produced by a production method for example, a gas phase oxidation method that directly obtains fine particles can prevent a decrease in purity during miniaturization and is reactive during sintering. Is preferable because it is high and it is easy to obtain higher purity.
  • the manufacturing method of the MgO sintered body of the present embodiment includes a process of obtaining MgO sintered body by uniaxial pressure sintering of MgO particles.
  • Sintering temperature can be lowered because sintering can be promoted by applying pressure during sintering.
  • the sintering temperature is lowered, the growth of crystal grains can be suppressed, so that a denser sintered body can be obtained while controlling the particle diameter.
  • the pressing is limited to the uniaxial direction, the (111) plane increases on the uniaxially pressed surface, and the (111) plane orientation of the MgO sintered body becomes strong.
  • the uniaxial pressure is preferably 5 MPa or more.
  • the pressurizing method may be a known method, for example, a hot press method is preferable, and a method of applying a load with a weight or the like on the press body may be used.
  • HIP sintering may be further performed after uniaxial pressure sintering.
  • the manufacturing method of the MgO sintered body of the present embodiment includes a step of heat-treating the MgO sintered body in an oxygen-containing atmosphere.
  • the MgO sintered body contains many oxygen defects, and its structure has a grayish white color tone and becomes non-uniform. Furthermore, oxygen defects become a factor that hinders the formation of the (111) plane. Therefore, when the MgO sintered body is heat-treated in an oxygen-containing atmosphere, the oxygen defects of the MgO sintered body are reduced, and the structure exhibits a white color tone and becomes uniform, thus promoting the (111) plane orientation of the MgO sintered body. can do.
  • the oxygen concentration in the oxygen-containing atmosphere may be 0.05% by volume or more, and preferably 0.1% by volume or more.
  • the balance of the oxygen-containing atmosphere may be a reducing gas such as nitrogen or Ar.
  • the temperature of the heat treatment is preferably 1273K or higher, more preferably 1423K or higher, and further preferably 1673K or higher.
  • the heat treatment time is required to be 1 minute or longer, and preferably 1 hour or longer. For example, when the MgO sintered body is heat-treated for 1 hour or more in an air atmosphere at 1673 K or more, oxygen defects are reduced and the (111) plane orientation of the MgO sintered body can be further promoted.
  • the manufacturing method of the MgO sintered body may further include a step of processing the MgO sintered body into a desired shape.
  • a processing method known methods such as cutting, grinding, and polishing can be used.
  • the MgO sintered body of the present embodiment can be further subjected to a sputtering method as a sputtering target by further bonding a backing plate. Since the sputtering target of the present embodiment includes the MgO sintered body of the present embodiment, abnormal discharge during sputtering can be reduced. Therefore, when the sputtering target of this embodiment is used for the sputtering method, generation of particles can be reduced, and a good MgO thin film can be formed. Furthermore, since the sputtering target of this embodiment is (111) -oriented, secondary electron emission during sputtering is promoted, and the sputtering efficiency can be improved.
  • the use of the MgO sintered body of the present embodiment is not limited to the sputtering method.
  • a known method such as a resistance heating vapor deposition method, an electron beam vapor deposition method, a molecular beam epitaxy method, an ion plating vapor deposition method, or a laser ablation method.
  • Those skilled in the art will readily understand that they can be used in physical vapor deposition.
  • MgO sintered body An MgO raw material powder having a purity of 4N and an average particle diameter of 0.2 ⁇ m, methanol as a solvent, and a nylon ball are placed in a nylon pot, and dispersed and mixed for 20 hours to obtain an MgO raw material powder. Refined to obtain an MgO slurry mainly composed of MgO particles. The MgO slurry was taken out from the nylon pot and granulated using a closed spray dryer in a nitrogen atmosphere to obtain MgO granulated powder. The MgO granulated powder was molded with a mold press to obtain an MgO molded body.
  • the MgO compact is sintered under atmospheric pressure (primary sintering) in an air atmosphere at 773 to 1673K, and then uniaxial pressure sintering (secondary sintering) at 20 MPa in an Ar atmosphere and 1623 to 1923K in a hot press apparatus.
  • primary sintering primary sintering
  • secondary sintering uniaxial pressure sintering
  • an MgO sintered body was obtained.
  • some MgO molded bodies were further subjected to HIP sintering (tertiary sintering) at 100 MPa, Ar atmosphere, 1473-1823 K after uniaxial pressure sintering. ) To obtain a MgO sintered body.
  • An MgO sintered body obtained by uniaxial pressure sintering (secondary sintering) or HIP sintering (tertiary sintering) is heat-treated for 5 hours at 1823 K in an oxygen-containing atmosphere having an oxygen concentration of 18% by volume, and MgO sintering. Got the body.
  • the uniaxially pressed surface of the MgO sintered body was finished using a # 230 to # 2000 grindstone to obtain a sample.
  • Table 1 shows the treatment performed on each sample.
  • the X-ray diffraction intensity ratio ⁇ (111) of the (111) plane in the X-ray diffraction pattern is set to (Equation 1), and ⁇ (111) of the uniaxially pressed surface is ⁇ V (111), uniaxially pressed.
  • ⁇ V (111) / ⁇ H (111) was calculated when ⁇ (111) on the surface perpendicular to the surface was ⁇ H (111).
  • ⁇ (111) ⁇ 0.4434 ⁇ R 2 + 1.4434 ⁇ R ⁇ (Formula 1)
  • R I (111) / (I (111) + I (200))
  • Evaluation results Table 2 shows the measurement results. Samples 1 to 8 are examples of the present invention, and sample 9 is a comparative example of the present invention.
  • Sample 9 of the comparative example had an average crystal particle diameter of 5 ⁇ m, a center line average roughness Ra of 1.1 ⁇ m, and a density of 3.560 g / cm 3 .
  • the initial abnormal discharge was 0.5 times / minute and the average abnormal discharge was 0.14 times / minute.
  • Samples 1 to 8 of the Examples had an average crystal particle diameter of 11 ⁇ m or more, a center line average roughness Ra of 1.6 ⁇ m or less, and a density of 3.569 g / cm 3 or more.
  • the initial abnormal discharge was 0.1 to 0.6 times / minute and the average abnormal discharge was 0.04 to 0.11 times / minute, and the abnormal discharge was sufficiently reduced. This is presumably because the average crystal particle size was increased and / or the density was increased.
  • the average abnormal discharge of Sample 1 having an average crystal particle size of 14 ⁇ m and a density of 3.569 g / cm 3 is 0.09 times / min, whereas the average crystal particle size of 20 ⁇ m and the density is 3.580 g / cm 3.
  • sample 3 cm 3, sample 7 of the average crystal grain size of 42 ⁇ m and density 3.578g / cm 3 respectively mean abnormal discharge of the sample 8 of 70 ⁇ m and density average crystal grain size of 3.580g / cm 3 0 Reduced to 0.06 times / minute, 0.04 times / minute, and 0.04 times / minute. This is presumably because the average crystal particle size was increased and / or the density was increased.
  • the initial abnormal discharge of the sample 1 with the center line average roughness Ra of 1.6 ⁇ m is 0.6 times / min
  • the sample 2 with the center line average roughness Ra of 0.2 to 0.9 ⁇ m is 2 to 0.9 ⁇ m.
  • the initial abnormal discharge of 8 was reduced to 0.1 to 0.4 times / min. This is presumably because the center line average roughness Ra is small.
  • the peak intensity ratio I (111) / I (200) was 15 to 19% for the H plane, and 39 to 75% for the V plane. Furthermore, ⁇ V (111) / ⁇ H (111) was 1.8 to 2.9. From the above, it can be seen that the (111) plane orientation of the uniaxially pressed surface is strong.
  • Comparative sample 9 had an average crystal particle size of 5 ⁇ m and a strain of 0.000.
  • the strains of Samples 1 to 8 in Examples were 0.005 to 0.053. Since the strain becomes larger as the value of strain becomes larger, it can be seen that minute strain is generated as the MgO crystal grains grow.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Ceramic Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Structural Engineering (AREA)
  • Physical Vapour Deposition (AREA)
  • Compositions Of Oxide Ceramics (AREA)

Abstract

This MgO sintered body has an average crystal particle diameter that is greater than 10 µm but is no more than 100 µm, and has a surface with a center line average roughness Ra of 1.6 µm or less.

Description

ＭｇＯ焼結体及びスパッタリングターゲットMgO sintered body and sputtering target
　本発明は、ＭｇＯ焼結体及びスパッタリングターゲットに関する。 The present invention relates to a MgO sintered body and a sputtering target.
　近年、磁気記録装置の記録密度を向上させる素子として磁気トンネル接合（ＭＴＪ）素子が注目され、ハードディスクの磁気ヘッドや高性能不揮発メモリ等への応用が期待されている。ＭＴＪ素子は、２つの強磁性体層の間にトンネルバリア層と呼ばれる絶縁性の薄膜を有する。この薄膜の材料として、優れた絶縁性、熱伝導率、耐熱性、化学的安定性及び耐酸化性を備えるＭｇＯ（酸化マグネシウム）が注目されている。 Recently, a magnetic tunnel junction (MTJ) element has attracted attention as an element for improving the recording density of a magnetic recording apparatus, and is expected to be applied to a magnetic head of a hard disk, a high-performance nonvolatile memory, or the like. The MTJ element has an insulating thin film called a tunnel barrier layer between two ferromagnetic layers. As a material for this thin film, MgO (magnesium oxide) having excellent insulating properties, thermal conductivity, heat resistance, chemical stability, and oxidation resistance has attracted attention.
　ＭｇＯ薄膜は、例えば、ＭｇＯ焼結体をスパッタリングターゲットとして用いたスパッタリング法によって形成される。良好なＭｇＯ薄膜を得るため、様々なＭｇＯ焼結体が提案されている。 The MgO thin film is formed by, for example, a sputtering method using an MgO sintered body as a sputtering target. In order to obtain a good MgO thin film, various MgO sintered bodies have been proposed.
特開２００９－１７３５０２号公報JP 2009-173502 A ＷＯ２０１３／０６５５６４号WO2013 / 065564
　特許文献１には、相対密度が９９％以上、平均結晶粒子径が３０μｍ以下の緻密で微細な結晶組織を有するＭｇＯ焼結体が記載されている。このＭｇＯ焼結体は優れた機械的性質を示す。更に、気孔率が０．５％以下のＭｇＯ焼結体をスパッタリングターゲットとして用いると、スパッタリング時の装置内の不純物汚染が改善される。更に、（１１１）面配向のＭｇＯ焼結体をスパッタリングターゲットとして用いると、スパッタリング時の二次電子放出が促進され、スパッタリング効率が向上する。 Patent Document 1 describes a MgO sintered body having a dense and fine crystal structure with a relative density of 99% or more and an average crystal grain size of 30 μm or less. This MgO sintered body exhibits excellent mechanical properties. Furthermore, when an MgO sintered body having a porosity of 0.5% or less is used as a sputtering target, impurity contamination in the apparatus during sputtering is improved. Furthermore, when a (111) -oriented MgO sintered body is used as a sputtering target, secondary electron emission during sputtering is promoted and sputtering efficiency is improved.
　特許文献２には、純度が９９．９９％以上であり、相対密度が９８％を超え、平均結晶粒径が８μｍ以下であり、Ｘ線回折パターンにおけるピーク強度比Ｉ（１１１）／Ｉ（２００）が８％以上２５％未満であるＭｇＯ焼結体が記載されている。このＭｇＯ焼結体をスパッタリングターゲットとして用いたスパッタリング法によって形成されるＭｇＯ薄膜は、優れた絶縁性と、表面粗さが小さく、優れた均質性とを示す。 In Patent Document 2, the purity is 99.99% or more, the relative density is more than 98%, the average crystal grain size is 8 μm or less, and the peak intensity ratio I (111) / I (200 ) Is 8% or more and less than 25%. An MgO thin film formed by a sputtering method using this MgO sintered body as a sputtering target exhibits excellent insulating properties, small surface roughness, and excellent homogeneity.
　しかし、従来のＭｇＯ焼結体をスパッタリングターゲットとして用いたスパッタリング法では、成膜時のパーティクルの発生要因である、スパッタリング時の異常放電を十分低減することができなかった。 However, in the sputtering method using a conventional MgO sintered body as a sputtering target, abnormal discharge during sputtering, which is a cause of generation of particles during film formation, cannot be sufficiently reduced.
　本発明の幾つかの態様は、成膜時のパーティクルの発生要因である、スパッタリング時の異常放電を十分低減することができるＭｇＯ焼結体及びスパッタリングターゲットを提供することを目的とする。 An object of some aspects of the present invention is to provide an MgO sintered body and a sputtering target that can sufficiently reduce abnormal discharge during sputtering, which is a cause of generation of particles during film formation.
（１）本発明の第１の態様は、１０μｍを超え、１００μｍ以下の平均結晶粒子径と、中心線平均粗さＲａが１．６μｍ以下の表面とを有することを特徴とするＭｇＯ焼結体に関する。 (1) A first aspect of the present invention is an MgO sintered body characterized by having an average crystal particle diameter of more than 10 μm and not more than 100 μm and a surface having a center line average roughness Ra of not more than 1.6 μm. About.
　１０μｍを超え、１００μｍ以下の平均結晶粒子径を有するＭｇＯ焼結体は、チッピングの起点になりやすい粒界三重点が減少する。したがって、このＭｇＯ焼結体をスパッタリングターゲットとして用いたスパッタリング法では、チッピングによる平均異常放電を低減することができる。ところで、ＭｇＯ焼結体の平均結晶粒子径が大きくなると、表面研磨、研削の際にはく離する結晶粒子が大きくなるため、表面を平滑にすることが難しくなる。しかし、本発明の第１の態様のＭｇＯ焼結体は、更に、中心線平均粗さＲａが１．６μｍ以下の表面を有するため、表面のチッピングや付着物が減少する。したがって、このＭｇＯ焼結体をスパッタリングターゲットとして用いたスパッタリング法では、ＭｇＯ焼結体表面の初期異常放電を低減することができる。つまり、本発明の第１の態様のＭｇＯ焼結体は、平均結晶粒子径が大きくなることと表面を平滑にすることが両立するため、平均異常放電と初期異常放電の両方を低減することができる。 An MgO sintered body having an average crystal particle diameter of more than 10 μm and not more than 100 μm has a reduced grain boundary triple point that tends to be the starting point of chipping. Therefore, in the sputtering method using this MgO sintered body as a sputtering target, the average abnormal discharge due to chipping can be reduced. By the way, when the average crystal particle diameter of the MgO sintered body is increased, the crystal particles that are separated during surface polishing and grinding are increased, so that it is difficult to smooth the surface. However, since the MgO sintered body according to the first aspect of the present invention further has a surface having a center line average roughness Ra of 1.6 μm or less, surface chipping and deposits are reduced. Therefore, in the sputtering method using this MgO sintered body as a sputtering target, the initial abnormal discharge on the surface of the MgO sintered body can be reduced. In other words, the MgO sintered body according to the first aspect of the present invention can reduce both the average abnormal discharge and the initial abnormal discharge because both the average crystal particle size is increased and the surface is smoothened. it can.
（２）本発明の第１の態様では、３．５６９ｇ／ｃｍ３以上の密度を有することが好ましい。ＭｇＯ焼結体の密度を大きくするためは、ＭｇＯ焼結体の焼結を促進させることが考えられる。ＭｇＯ焼結体の焼結を促進させると、一般に結晶粒子径が大きくなるため、上記のように表面を平滑にすることが難しくなる。しかし、本発明の第１の態様では密度を大きくすることと表面を平滑にすることが両立する。ＭｇＯ焼結体の密度が大きくなると、チッピングの起点になりやすい粒界の気孔が減少する。したがって、このＭｇＯ焼結体をスパッタリングターゲットとして用いたスパッタリング法では、チッピングによる平均異常放電を低減することができる。 (2) In the first aspect of the present invention, it is preferable to have a density of 3.569 g / cm 3 or more. In order to increase the density of the MgO sintered body, it is conceivable to promote the sintering of the MgO sintered body. When the sintering of the MgO sintered body is promoted, the crystal particle diameter generally increases, so that it becomes difficult to smooth the surface as described above. However, in the first aspect of the present invention, both increasing the density and smoothing the surface are compatible. As the density of the MgO sintered body increases, the pores at the grain boundaries that tend to become the starting point of chipping decrease. Therefore, in the sputtering method using this MgO sintered body as a sputtering target, the average abnormal discharge due to chipping can be reduced.
（３）本発明の第２の態様は、第１の態様のＭｇＯ焼結体を備えることを特徴とするスパッタリングターゲットに関する。 (3) A second aspect of the present invention relates to a sputtering target comprising the MgO sintered body according to the first aspect.
　第１の態様のＭｇＯ焼結体を備えたスパッタリングターゲットは、スパッタリング時の異常放電を低減することができるため、成膜時のパーティクルの発生を低減することができ、良好なＭｇＯ薄膜を形成することができる。 Since the sputtering target including the MgO sintered body of the first aspect can reduce abnormal discharge during sputtering, generation of particles during film formation can be reduced, and a good MgO thin film can be formed. be able to.
　以下、本発明の好適な実施形態について詳細に説明する。なお、以下に説明する本実施形態は、請求の範囲に記載された本発明の内容を不当に限定するものではなく、本実施形態で説明される構成のすべてが本発明の解決手段として必須であるとは限らない。 Hereinafter, preferred embodiments of the present invention will be described in detail. The present embodiment described below does not unduly limit the contents of the present invention described in the claims, and all the configurations described in the present embodiment are indispensable as means for solving the present invention. Not always.
（１）ＭｇＯ焼結体
（１－１）ＭｇＯ焼結体の平均結晶粒子径、中心線平均粗さＲａ、密度
　本実施形態のＭｇＯ焼結体は、１０μｍを超え、１００μｍ以下の平均結晶粒子径と、中心線平均粗さＲａが１．６μｍ以下の表面とを有する。本実施形態のＭｇＯ焼結体は、更に３．５６９ｇ／ｃｍ３以上の密度を有してもよい。 (1) MgO sintered body (1-1) Average crystal particle diameter, centerline average roughness Ra, density of MgO sintered body The MgO sintered body of the present embodiment has an average crystal particle of more than 10 μm and not more than 100 μm The surface has a diameter and a center line average roughness Ra of 1.6 μm or less. The MgO sintered body of the present embodiment may further have a density of 3.569 g / cm 3 or more.
　１０μｍを超え、１００μｍ以下の平均結晶粒子径を有するＭｇＯ焼結体は、チッピングの起点になりやすい粒界三重点が減少する。したがって、このＭｇＯ焼結体をスパッタリングターゲットとして用いたスパッタリング法では、チッピングによる平均異常放電を低減することができる。 An MgO sintered body having an average crystal particle diameter of more than 10 μm and not more than 100 μm has a reduced grain boundary triple point that tends to be the starting point of chipping. Therefore, in the sputtering method using this MgO sintered body as a sputtering target, the average abnormal discharge due to chipping can be reduced.
　平均結晶粒子径は１０μｍを超え、１２μｍ以上が好ましく、１４μｍ以上がより好ましく、１７μｍ以上が更に好ましく、２０μｍ以上が特に好ましい。平均結晶粒子径が大きくなると、チッピングの起点になりやすい粒界三重点が減少する。更に、ＭｇＯ結晶粒子の成長に伴い、粒子内に微小な歪が生じる。この歪により発生する内部応力により、チッピングが生じにくくなる。一方、一般に平均結晶粒子径が大きくなるに従い、強度は低下する。しかし、本発明においては、上記歪の効果もあり、１００μｍまでであれば、ボンディング時の熱応力、熱衝撃に抗することができる。したがって、このＭｇＯ焼結体をスパッタリングターゲットとして用いたスパッタリング法では、平均異常放電を更に低減することができる。 The average crystal particle diameter exceeds 10 μm, preferably 12 μm or more, more preferably 14 μm or more, still more preferably 17 μm or more, and particularly preferably 20 μm or more. As the average crystal grain size increases, the grain boundary triple points that tend to become the starting point of chipping decrease. Further, with the growth of MgO crystal particles, minute strains are generated in the particles. Chipping is less likely to occur due to internal stress generated by this strain. On the other hand, the strength generally decreases as the average crystal particle size increases. However, in the present invention, there is also an effect of the above-mentioned distortion, and if it is up to 100 μm, it can resist thermal stress and thermal shock during bonding. Therefore, in the sputtering method using this MgO sintered body as a sputtering target, the average abnormal discharge can be further reduced.
　中心線平均粗さＲａが１．６μｍ以下の表面を有するＭｇＯ焼結体は、表面のチッピングや付着物が減少する。したがって、このＭｇＯ焼結体をスパッタリングターゲットとして用いたスパッタリング法では、ＭｇＯ焼結体表面の初期異常放電を低減することができる。 In the MgO sintered body having a surface with a center line average roughness Ra of 1.6 μm or less, chipping and deposits on the surface are reduced. Therefore, in the sputtering method using this MgO sintered body as a sputtering target, the initial abnormal discharge on the surface of the MgO sintered body can be reduced.
　表面の中心線平均粗さＲａは１μｍ以下が好ましく、０．６μｍ以下が更に好ましい。中心線平均粗さＲａが更に小さくなると、表面のチッピングや付着物が更に減少する。また、電界のゆらぎが生じにくくなる。したがって、このＭｇＯ焼結体をスパッタリングターゲットとして用いたスパッタリング法では、ＭｇＯ焼結体表面の初期異常放電を更に低減することができる。中心線平均粗さＲａは可能な限り小さいほど好ましいが、技術的に０μｍになることはない。 The center line average roughness Ra of the surface is preferably 1 μm or less, and more preferably 0.6 μm or less. As the center line average roughness Ra is further reduced, surface chipping and deposits are further reduced. In addition, fluctuations in the electric field are less likely to occur. Therefore, in the sputtering method using this MgO sintered body as a sputtering target, the initial abnormal discharge on the surface of the MgO sintered body can be further reduced. Although the center line average roughness Ra is preferably as small as possible, it is technically not 0 μm.
　３．５６９ｇ／ｃｍ３以上の密度を有するＭｇＯ焼結体は、チッピングの起点になりやすい粒界の気孔が減少する。したがって、このＭｇＯ焼結体をスパッタリングターゲットとして用いたスパッタリング法では、チッピングによる平均異常放電を低減することができる。 An MgO sintered body having a density of 3.569 g / cm 3 or more has reduced grain boundary pores that tend to be the starting point of chipping. Therefore, in the sputtering method using this MgO sintered body as a sputtering target, the average abnormal discharge due to chipping can be reduced.
　密度は３．５７５ｇ／ｃｍ３以上が好ましい。密度が更に大きくなると、チッピングの起点になりやすい粒界の気孔が更に減少する。したがって、このＭｇＯ焼結体をスパッタリングターゲットとして用いたスパッタリング法では、平均異常放電を更に低減することができる。 The density is preferably 3.575 g / cm 3 or more. As the density further increases, the grain boundary pores that tend to become the starting point of chipping further decrease. Therefore, in the sputtering method using this MgO sintered body as a sputtering target, the average abnormal discharge can be further reduced.
　ここで、ＭｇＯ焼結体の平均結晶粒子径が大きくなると、表面研磨、研削の際にはく離する結晶粒子が大きくなるため、表面を平滑にすることが難しくなる。また、ＭｇＯ焼結体の密度を大きくするために、ＭｇＯ焼結体の焼結を促進させることが考えられる。ＭｇＯ焼結体の焼結を促進させると、一般に結晶粒子径が大きくなるため、上記のように表面を平滑にすることが難しくなる。このため、表面のチッピングや付着物が増加し、このＭｇＯ焼結体をスパッタリングターゲットとして用いたスパッタリング法では、ＭｇＯ焼結体表面の初期異常放電が増加するおそれがある。しかし、本実施形態のＭｇＯ焼結体は、平均結晶粒子径が大きくなることと、表面を平滑にすることとが両立するため、平均異常放電と初期異常放電の両方を低減することができる。 Here, when the average crystal particle diameter of the MgO sintered body is increased, the crystal particles that are separated during surface polishing and grinding are increased, and thus it is difficult to smooth the surface. In order to increase the density of the MgO sintered body, it is conceivable to promote the sintering of the MgO sintered body. When the sintering of the MgO sintered body is promoted, the crystal particle diameter generally increases, so that it becomes difficult to smooth the surface as described above. For this reason, chipping and deposits on the surface increase, and in the sputtering method using this MgO sintered body as a sputtering target, the initial abnormal discharge on the surface of the MgO sintered body may increase. However, since the MgO sintered body of the present embodiment has both a large average crystal particle size and a smooth surface, both the average abnormal discharge and the initial abnormal discharge can be reduced.
　また、本実施形態のＭｇＯ焼結体は、密度を更に大きくすることにより、平均異常放電を更に低減することができる。 Moreover, the MgO sintered body of the present embodiment can further reduce the average abnormal discharge by further increasing the density.
（１－２）ＭｇＯ焼結体の配向性
　本実施形態のＭｇＯ焼結体は、更に、製造工程に一軸加圧焼結工程を含むＭｇＯ焼結体であって、Ｘ線回折パターンにおける（１１１）面のＸ線回折強度比率α（１１１）を（式１）とし、一軸加圧された面のα（１１１）をαＶ（１１１）、一軸加圧された面に垂直な面のα（１１１）をαＨ（１１１）としたとき、αＶ（１１１）／αＨ（１１１）＞１．５であることが好ましい。なお、一軸加圧された面は、中心線平均粗さＲａが１．６μｍ以下の表面に等しい。
　α（１１１）＝｛－０．４４３４×Ｒ２＋１．４４３４×Ｒ｝　　（式１）
　ここで、Ｒ＝Ｉ（１１１）／（Ｉ（１１１）＋Ｉ（２００））
　　　　　Ｉ（１１１）：ＭｇＯ（１１１）面のＸ線回折強度
　　　　　Ｉ（２００）：ＭｇＯ（２００）面のＸ線回折強度 (1-2) Orientation of MgO Sintered Body The MgO sintered body of the present embodiment is an MgO sintered body that further includes a uniaxial pressure sintering process in the manufacturing process, and (111) ) Surface X-ray diffraction intensity ratio α (111) is (Equation 1), α (111) of the uniaxially pressed surface is αV (111), and α (111) of the surface perpendicular to the uniaxially pressed surface ) Is αH (111), αV (111) / αH (111)> 1.5 is preferable. The uniaxially pressed surface is equal to a surface having a center line average roughness Ra of 1.6 μm or less.
α (111) = {− 0.4434 × R 2 + 1.4434 × R} (Formula 1)
Here, R = I (111) / (I (111) + I (200))
I (111): X-ray diffraction intensity of MgO (111) plane I (200): X-ray diffraction intensity of MgO (200) plane
　等方的に結晶成長する通常の焼結と比較して、一軸加圧焼結によって（１１１）面の結晶成長、即ち、原子の再配列が促進される。このため、ＭｇＯ焼結体は緻密になると同時に、気孔が粒界に沿って焼結体の外に出やすくなる。上記のように異常放電の原因となる気孔が減少するため、このＭｇＯ焼結体をスパッタリングターゲットとして用いたスパッタリング法では平均異常放電を低減することができる。 Compared with normal sintering in which crystal growth isotropic, uniaxial pressure sintering promotes crystal growth on the (111) plane, that is, rearrangement of atoms. For this reason, the MgO sintered body becomes dense, and at the same time, the pores easily come out of the sintered body along the grain boundary. Since pores that cause abnormal discharge are reduced as described above, average abnormal discharge can be reduced by sputtering using this MgO sintered body as a sputtering target.
（２）ＭｇＯ焼結体の製造方法
　本実施形態のＭｇＯ焼結体の製造方法は、（ａ）ＭｇＯ原料粉末を微細化してＭｇＯ粒子を得る工程と、（ｂ）ＭｇＯ粒子を一軸加圧焼結してＭｇＯ焼結体を得る工程と、（ｃ）ＭｇＯ焼結体を酸素含有雰囲気で熱処理する工程とを有する。 (2) Manufacturing method of MgO sintered body The manufacturing method of the MgO sintered body of this embodiment includes (a) a step of obtaining MgO particles by refining MgO raw material powder, and (b) uniaxial pressure firing of MgO particles. And obtaining a MgO sintered body, and (c) a step of heat-treating the MgO sintered body in an oxygen-containing atmosphere.
（２－１）ＭｇＯ原料粉末の微細化工程
　本実施形態のＭｇＯ焼結体の製造方法は、ＭｇＯ原料粉末を微細化してＭｇＯ粒子を得る工程を有する。 (2-1) MgO raw material powder refinement process The method of manufacturing the MgO sintered body according to the present embodiment includes a process of obtaining MgO particles by refining the MgO raw material powder.
　ＭｇＯ原料粉末の純度は、ＭｇＯ焼結体の使用環境の汚染を低減するため、極力高くすることが好ましく、好ましくは９９．９９％（４Ｎ）以上である。 The purity of the MgO raw material powder is preferably as high as possible in order to reduce contamination of the usage environment of the MgO sintered body, and is preferably 99.99% (4N) or more.
　微細化されていないＭｇＯ粒子を焼結したＭｇＯ焼結体に対し、微細化されたＭｇＯ粒子を焼結したＭｇＯ焼結体は、（１１１）面の割合が多い、つまり、（１１１）面配向のＭｇＯ焼結体が得られやすい。したがって、ＭｇＯ原料粉末を微細化して得られるＭｇＯ粒子の粒子径は１μｍ以下が好ましく、０．５μｍ以下がより好ましい。また、直接微細粒子が得られる製造方法（例えば気相酸化法）で作製されたＭｇＯ粒子を用いることは、微細化の際の純度低下を防ぐことができ、かつ、焼結の際の反応性が高く、より高純度を得やすいため、好ましい。 The MgO sintered body obtained by sintering the refined MgO particles to the MgO sintered body obtained by sintering the non-miniaturized MgO particles has a large proportion of the (111) plane, that is, the (111) plane orientation. It is easy to obtain a MgO sintered body. Therefore, the particle diameter of MgO particles obtained by refining the MgO raw material powder is preferably 1 μm or less, and more preferably 0.5 μm or less. In addition, using MgO particles produced by a production method (for example, a gas phase oxidation method) that directly obtains fine particles can prevent a decrease in purity during miniaturization and is reactive during sintering. Is preferable because it is high and it is easy to obtain higher purity.
（２－２）一軸加圧焼結工程
　本実施形態のＭｇＯ焼結体の製造方法は、ＭｇＯ粒子を一軸加圧焼結してＭｇＯ焼結体を得る工程を有する。 (2-2) Uniaxial pressure sintering process The manufacturing method of the MgO sintered body of the present embodiment includes a process of obtaining MgO sintered body by uniaxial pressure sintering of MgO particles.
　焼結時に圧力を加えると焼結を促進することができるため、焼結温度を下げることができる。焼結温度を下げると結晶粒子の成長を抑制することができるため、粒子径を制御しながらより緻密な焼結体を得ることができる。更に、加圧を一軸方向に限定すると、一軸加圧された面に（１１１）面が増加し、ＭｇＯ焼結体の（１１１）面配向が強くなる。この配向を強く発現させるため、一軸加圧は５ＭＰａ以上が好ましい。加圧方法は公知の方法でよく、例えば、ホットプレス法が好ましく、プレス体上にウェイト等で荷重を加える方法でもよい。 Sintering temperature can be lowered because sintering can be promoted by applying pressure during sintering. When the sintering temperature is lowered, the growth of crystal grains can be suppressed, so that a denser sintered body can be obtained while controlling the particle diameter. Further, when the pressing is limited to the uniaxial direction, the (111) plane increases on the uniaxially pressed surface, and the (111) plane orientation of the MgO sintered body becomes strong. In order to express this orientation strongly, the uniaxial pressure is preferably 5 MPa or more. The pressurizing method may be a known method, for example, a hot press method is preferable, and a method of applying a load with a weight or the like on the press body may be used.
　ＭｇＯ焼結体の中の気孔をより確実に除去するため、一軸加圧焼結後、更にＨＩＰ焼結を行ってもよい。 In order to more reliably remove pores in the MgO sintered body, HIP sintering may be further performed after uniaxial pressure sintering.
（２－３）酸素含有雰囲気熱処理工程
　本実施形態のＭｇＯ焼結体の製造方法は、ＭｇＯ焼結体を酸素含有雰囲気で熱処理する工程を有する。 (2-3) Oxygen-containing atmosphere heat treatment step The manufacturing method of the MgO sintered body of the present embodiment includes a step of heat-treating the MgO sintered body in an oxygen-containing atmosphere.
　一軸加圧焼結及びＨＩＰ焼結は通常還元雰囲気で行われるため、ＭｇＯ焼結体は酸素欠陥を多く含み、その組織は灰白色の色調を呈し、不均一になる。更に、酸素欠陥は（１１１）面の形成を妨げる要因となる。そこで、ＭｇＯ焼結体を酸素含有雰囲気で熱処理すると、ＭｇＯ焼結体の酸素欠陥が減少し、組織は白色の色調を呈し、均一になるため、ＭｇＯ焼結体の（１１１）面配向を促進することができる。 Since uniaxial pressure sintering and HIP sintering are usually carried out in a reducing atmosphere, the MgO sintered body contains many oxygen defects, and its structure has a grayish white color tone and becomes non-uniform. Furthermore, oxygen defects become a factor that hinders the formation of the (111) plane. Therefore, when the MgO sintered body is heat-treated in an oxygen-containing atmosphere, the oxygen defects of the MgO sintered body are reduced, and the structure exhibits a white color tone and becomes uniform, thus promoting the (111) plane orientation of the MgO sintered body. can do.
　酸素含有雰囲気の酸素濃度は０．０５体積％以上であればよく、０．１体積％以上が好ましい。酸素含有雰囲気の残部は窒素やＡｒ等の還元ガスでもよい。熱処理の温度は１２７３Ｋ以上が好ましく、１４２３Ｋ以上がより好ましく、１６７３Ｋ以上が更に好ましい。熱処理の時間は１分以上が必要であり、１時間以上が好ましい。例えば、大気雰囲気、１６７３Ｋ以上で、１時間以上ＭｇＯ焼結体を熱処理すると、酸素欠陥は減少し、ＭｇＯ焼結体の（１１１）面配向をより促進することができる。 The oxygen concentration in the oxygen-containing atmosphere may be 0.05% by volume or more, and preferably 0.1% by volume or more. The balance of the oxygen-containing atmosphere may be a reducing gas such as nitrogen or Ar. The temperature of the heat treatment is preferably 1273K or higher, more preferably 1423K or higher, and further preferably 1673K or higher. The heat treatment time is required to be 1 minute or longer, and preferably 1 hour or longer. For example, when the MgO sintered body is heat-treated for 1 hour or more in an air atmosphere at 1673 K or more, oxygen defects are reduced and the (111) plane orientation of the MgO sintered body can be further promoted.
（２－４）加工工程
　ＭｇＯ焼結体の製造方法は、更に、ＭｇＯ焼結体を所望の形状に加工する工程を有してもよい。加工の方法は、切断、研削、研磨等、公知の方法を用いることができる。 (2-4) Processing Step The manufacturing method of the MgO sintered body may further include a step of processing the MgO sintered body into a desired shape. As a processing method, known methods such as cutting, grinding, and polishing can be used.
（３）スパッタリングターゲット
　本実施形態のＭｇＯ焼結体は、更にバッキングプレートをボンディングし、スパッタリングターゲットとしてスパッタリング法に供することができる。本実施形態のスパッタリングターゲットは、本実施形態のＭｇＯ焼結体を備えるため、スパッタリング時の異常放電を低減することができる。したがって、本実施形態のスパッタリングターゲットをスパッタリング法に用いると、パーティクルの発生を低減することができ、良好なＭｇＯ薄膜を形成することができる。更に、本実施形態のスパッタリングターゲットは（１１１）面配向しているため、スパッタリング時の二次電子放出が促進され、スパッタリング効率を向上させることができる。 (3) Sputtering target The MgO sintered body of the present embodiment can be further subjected to a sputtering method as a sputtering target by further bonding a backing plate. Since the sputtering target of the present embodiment includes the MgO sintered body of the present embodiment, abnormal discharge during sputtering can be reduced. Therefore, when the sputtering target of this embodiment is used for the sputtering method, generation of particles can be reduced, and a good MgO thin film can be formed. Furthermore, since the sputtering target of this embodiment is (111) -oriented, secondary electron emission during sputtering is promoted, and the sputtering efficiency can be improved.
　本実施形態のＭｇＯ焼結体の用途はスパッタリング法に限定されるものではなく、例えば、抵抗加熱蒸着法、電子ビーム蒸着法、分子線エピタキシー法、イオンプレーティング蒸着法、レーザアブレーション法といった公知の物理蒸着法に使用できることは当業者には容易に理解される。 The use of the MgO sintered body of the present embodiment is not limited to the sputtering method. For example, a known method such as a resistance heating vapor deposition method, an electron beam vapor deposition method, a molecular beam epitaxy method, an ion plating vapor deposition method, or a laser ablation method. Those skilled in the art will readily understand that they can be used in physical vapor deposition.
　以下、本発明の実施例について詳細に説明する。 Hereinafter, embodiments of the present invention will be described in detail.
（１）ＭｇＯ焼結体の製造
　純度が４Ｎ、平均粒子径が０．２μｍのＭｇＯ原料粉末と、溶媒としてメタノールと、ナイロンボールとをナイロンポットに入れ、２０時間分散混合してＭｇＯ原料粉末を微細化し、ＭｇＯ粒子を主成分とするＭｇＯスラリーを得た。ＭｇＯスラリーをナイロンポットから取り出し、窒素雰囲気のクローズドスプレードライヤーを用いて造粒し、ＭｇＯ造粒粉を得た。ＭｇＯ造粒粉を金型プレスで成形し、ＭｇＯ成形体を得た。 (1) Production of MgO sintered body An MgO raw material powder having a purity of 4N and an average particle diameter of 0.2 μm, methanol as a solvent, and a nylon ball are placed in a nylon pot, and dispersed and mixed for 20 hours to obtain an MgO raw material powder. Refined to obtain an MgO slurry mainly composed of MgO particles. The MgO slurry was taken out from the nylon pot and granulated using a closed spray dryer in a nitrogen atmosphere to obtain MgO granulated powder. The MgO granulated powder was molded with a mold press to obtain an MgO molded body.
　ＭｇＯ成形体を、大気雰囲気、７７３～１６７３Ｋで常圧焼結（一次焼結）した後、ホットプレス装置にて２０ＭＰａ、Ａｒ雰囲気、１６２３～１９２３Ｋで一軸加圧焼結（二次焼結）して、ＭｇＯ焼結体を得た。ＭｇＯ焼結体の中の気孔をより確実に除去するため、一部のＭｇＯ成形体については、一軸加圧焼結後、更に、１００ＭＰａ、Ａｒ雰囲気、１４７３～１８２３ＫでＨＩＰ焼結（三次焼結）を行い、ＭｇＯ焼結体を得た。 The MgO compact is sintered under atmospheric pressure (primary sintering) in an air atmosphere at 773 to 1673K, and then uniaxial pressure sintering (secondary sintering) at 20 MPa in an Ar atmosphere and 1623 to 1923K in a hot press apparatus. Thus, an MgO sintered body was obtained. In order to more reliably remove pores in the MgO sintered body, some MgO molded bodies were further subjected to HIP sintering (tertiary sintering) at 100 MPa, Ar atmosphere, 1473-1823 K after uniaxial pressure sintering. ) To obtain a MgO sintered body.
　一軸加圧焼結（二次焼結）又はＨＩＰ焼結（三次焼結）で得られたＭｇＯ焼結体を、酸素濃度１８体積％の酸素含有雰囲気、１８２３Ｋで５時間熱処理し、ＭｇＯ焼結体を得た。ＭｇＯ焼結体の一軸加圧された面を、＃２３０～＃２０００番砥石を用いて仕上げ加工を行い、試料を得た。 An MgO sintered body obtained by uniaxial pressure sintering (secondary sintering) or HIP sintering (tertiary sintering) is heat-treated for 5 hours at 1823 K in an oxygen-containing atmosphere having an oxygen concentration of 18% by volume, and MgO sintering. Got the body. The uniaxially pressed surface of the MgO sintered body was finished using a # 230 to # 2000 grindstone to obtain a sample.
　各試料に対して行った処理を表１に示す。
Figure JPOXMLDOC01-appb-T000001
 Table 1 shows the treatment performed on each sample.
Figure JPOXMLDOC01-appb-T000001
（２）評価方法
　得られた試料について、以下の項目の測定を行った。 (2) Evaluation method The obtained sample was measured for the following items.
（２－１）中心線平均粗さＲａ
　仕上げ加工された面を、触針式表面粗さ計を用いて測定し、ＪＩＳ　Ｂ　０６０１に準拠して中心線平均粗さＲａを算出した。 (2-1) Centerline average roughness Ra
The finished surface was measured using a stylus type surface roughness meter, and the center line average roughness Ra was calculated in accordance with JIS B 0601.
（２－２）平均結晶粒子径
　試料を鏡面研磨加工後、走査電子顕微鏡（ＳＥＭ：日本電子製　ＪＳＭ－７０００Ｆ）で観察し、得られたＳＥＭ像においてＪＩＳ　Ｒ　１６７０に準拠して平均結晶粒子径を算出した。 (2-2) Average crystal particle diameter After the sample was mirror-polished, the sample was observed with a scanning electron microscope (SEM: JSM-7000F, manufactured by JEOL Ltd.). In the obtained SEM image, the average crystal particle diameter was based on JIS R 1670 Was calculated.
（２－３）密度
　試料の密度（ｇ／ｃｍ３）をアルキメデス法で算出した。 (2-3) Density The density (g / cm 3 ) of the sample was calculated by the Archimedes method.
（２－４）スパッタリング時の異常放電
　試料にバッキングプレートをボンディングし、以下の条件でスパッタ装置（ＵＬＶＡＣ製　ＣＳ－Ｌ）を用いてスパッタリングを行い、異常放電を、放電開始直後（初期異常放電）と放電安定化後（平均異常放電）についてカウントした。スパッタリングの条件は、チャンバーの到達真空度１×１０－４Ｐａ以下、Ａｒガス圧０．１４Ｐａ、投入電力ＲＦ１００Ｗとした。 (2-4) Abnormal discharge during sputtering A backing plate is bonded to the sample, sputtering is performed using a sputtering device (ULVAC CS-L) under the following conditions, and abnormal discharge occurs immediately after the start of discharge (initial abnormal discharge). And after discharge stabilization (average abnormal discharge). The sputtering conditions were such that the ultimate vacuum in the chamber was 1 × 10 −4 Pa or less, the Ar gas pressure was 0.14 Pa, and the input power was RF 100 W.
（２－５）配向性
　試料の一軸加圧された面と、一軸加圧された面に垂直な面について、Ｘ線回折装置（ＢｕｒｕｋｅｒＡｘｓ製　Ｄ８　ＡＤＶＡＮＣＥ）を用いてＸ線回折パターンを測定し、ＭｇＯ（１１１）面及び（２００）面のそれぞれのＸ線回折のピーク強度Ｉ（１１１）及びＩ（２００）を求めた。得られたピーク強度からピーク強度比Ｉ（１１１）／Ｉ（２００）を、一軸加圧された面（Ｖ）と、一軸加圧された面に垂直な面（Ｈ）について算出した。更に、Ｘ線回折パターンにおける（１１１）面のＸ線回折強度比率α（１１１）を（式１）とし、一軸加圧された面のα（１１１）をαＶ（１１１）、一軸加圧された面に垂直な面のα（１１１）をαＨ（１１１）としたときのαＶ（１１１）／αＨ（１１１）を算出した。
　α（１１１）＝｛－０．４４３４×Ｒ２＋１．４４３４×Ｒ｝　　（式１）
　Ｒ＝Ｉ（１１１）／（Ｉ（１１１）＋Ｉ（２００）） (2-5) Orientation An X-ray diffraction pattern was measured using a X-ray diffractometer (D8 ADVANCE manufactured by BurkerAxs) for a uniaxially pressed surface of the sample and a surface perpendicular to the uniaxially pressed surface. The X-ray diffraction peak intensities I (111) and I (200) of the MgO (111) plane and the (200) plane were determined. From the obtained peak intensity, the peak intensity ratio I (111) / I (200) was calculated for the uniaxially pressed surface (V) and the surface (H) perpendicular to the uniaxially pressed surface. Further, the X-ray diffraction intensity ratio α (111) of the (111) plane in the X-ray diffraction pattern is set to (Equation 1), and α (111) of the uniaxially pressed surface is αV (111), uniaxially pressed. ΑV (111) / αH (111) was calculated when α (111) on the surface perpendicular to the surface was αH (111).
α (111) = {− 0.4434 × R 2 + 1.4434 × R} (Formula 1)
R = I (111) / (I (111) + I (200))
（２－６）歪
　ＭｇＯ粒子に生じた歪の指標として、リーベルト解析をＢｒｕｋｅｒＡｘｓ製ＴＯＰＡＳにてＦｕｎｄａｍｅｎｔａｌパラメータを用いて行った。その結果をｓｔｒａｉｎにて表示する。 (2-6) Strain As an index of strain generated in MgO particles, Liberty analysis was performed with TOPAS manufactured by BrukerAxs using Fundamental parameters. The result is displayed in strain.
（３）評価結果
　測定結果を表２に示す。試料１～８が本発明の実施例、試料９が本発明の比較例である。
Figure JPOXMLDOC01-appb-T000002
 (3) Evaluation results Table 2 shows the measurement results. Samples 1 to 8 are examples of the present invention, and sample 9 is a comparative example of the present invention.
Figure JPOXMLDOC01-appb-T000002
　比較例の試料９は平均結晶粒子径が５μｍ、中心線平均粗さＲａが１．１μｍ、密度が３．５６０ｇ／ｃｍ３であった。このとき、初期異常放電が０．５回／分、平均異常放電が０．１４回／分であった。これに対し、実施例の試料１～８は平均結晶粒子径が１１μｍ以上、中心線平均粗さＲａが１．６μｍ以下、密度が３．５６９ｇ／ｃｍ３以上であった。このとき、初期異常放電が０．１～０．６回／分、平均異常放電が０．０４～０．１１回／分であり、異常放電を十分低減した。これは、平均結晶粒子径が大きくなったため、及び／又は、密度が高くなったためと考えられる。 Sample 9 of the comparative example had an average crystal particle diameter of 5 μm, a center line average roughness Ra of 1.1 μm, and a density of 3.560 g / cm 3 . At this time, the initial abnormal discharge was 0.5 times / minute and the average abnormal discharge was 0.14 times / minute. In contrast, Samples 1 to 8 of the Examples had an average crystal particle diameter of 11 μm or more, a center line average roughness Ra of 1.6 μm or less, and a density of 3.569 g / cm 3 or more. At this time, the initial abnormal discharge was 0.1 to 0.6 times / minute and the average abnormal discharge was 0.04 to 0.11 times / minute, and the abnormal discharge was sufficiently reduced. This is presumably because the average crystal particle size was increased and / or the density was increased.
　更に、平均結晶粒子径が１４μｍ及び密度が３．５６９ｇ／ｃｍ３の試料１の平均異常放電は０．０９回／分であるのに対し、平均結晶粒子径が２０μｍ及び密度が３．５８０ｇ／ｃｍ３の試料３、平均結晶粒子径が４２μｍ及び密度が３．５７８ｇ／ｃｍ３の試料７、平均結晶粒子径が７０μｍ及び密度が３．５８０ｇ／ｃｍ３の試料８の平均異常放電はそれぞれ０．０６回／分、０．０４回／分、０．０４回／分に低減した。これは、平均結晶粒子径が大きくなったため、及び／又は、密度が高くなったためと考えられる。 Furthermore, the average abnormal discharge of Sample 1 having an average crystal particle size of 14 μm and a density of 3.569 g / cm 3 is 0.09 times / min, whereas the average crystal particle size of 20 μm and the density is 3.580 g / cm 3. sample 3 cm 3, sample 7 of the average crystal grain size of 42μm and density 3.578g / cm 3, respectively mean abnormal discharge of the sample 8 of 70μm and density average crystal grain size of 3.580g / cm 3 0 Reduced to 0.06 times / minute, 0.04 times / minute, and 0.04 times / minute. This is presumably because the average crystal particle size was increased and / or the density was increased.
　更に、中心線平均粗さＲａが１．６μｍの試料１の初期異常放電は０．６回／分であるのに対し、中心線平均粗さＲａが０．２～０．９μｍの試料２～８の初期異常放電は０．１～０．４回／分に低減した。これは、中心線平均粗さＲａが小さくなったためと考えられる。 Further, the initial abnormal discharge of the sample 1 with the center line average roughness Ra of 1.6 μm is 0.6 times / min, whereas the sample 2 with the center line average roughness Ra of 0.2 to 0.9 μm is 2 to 0.9 μm. The initial abnormal discharge of 8 was reduced to 0.1 to 0.4 times / min. This is presumably because the center line average roughness Ra is small.
　試料１～８の配向性については、ピーク強度比Ｉ（１１１）／Ｉ（２００）はＨ面が１５～１９％であったのに対しＶ面は３９～７５％であった。更に、αＶ（１１１）／αＨ（１１１）は１．８～２．９であった。以上より、一軸加圧された面の（１１１）面配向が強いことがわかる。 Regarding the orientation of Samples 1 to 8, the peak intensity ratio I (111) / I (200) was 15 to 19% for the H plane, and 39 to 75% for the V plane. Furthermore, αV (111) / αH (111) was 1.8 to 2.9. From the above, it can be seen that the (111) plane orientation of the uniaxially pressed surface is strong.
　比較例の試料９は平均結晶粒子径が５μｍ、ｓｔｒａｉｎが０．０００であった。これに対し、実施例の試料１～８のｓｔｒａｉｎは０．００５～０．０５３であった。ｓｔｒａｉｎは値が大きいほど歪が大きいことから、ＭｇＯ結晶粒子の成長に従い、微小な歪が生じていることがわかる。 Comparative sample 9 had an average crystal particle size of 5 μm and a strain of 0.000. On the other hand, the strains of Samples 1 to 8 in Examples were 0.005 to 0.053. Since the strain becomes larger as the value of strain becomes larger, it can be seen that minute strain is generated as the MgO crystal grains grow.
　なお、上記のように本実施形態について詳細に説明したが、本発明の新規事項及び効果から実体的に逸脱しない多くの変形が可能であることは当業者には容易に理解できるであろう。したがって、このような変形例はすべて本発明の範囲に含まれる。例えば、明細書において、少なくとも一度、より広義又は同義な異なる用語とともに記載された用語は、明細書のいかなる箇所においても、その異なる用語に置き換えられることができる。また、物理蒸着用ターゲット部材、物理蒸着膜及び層構造等の構成及び動作も本実施形態で説明したものに限定されず、種々の変形が可能である。 Although the present embodiment has been described in detail as described above, it will be easily understood by those skilled in the art that many modifications can be made without departing from the novel matters and effects of the present invention. Therefore, all such modifications are included in the scope of the present invention. For example, in the specification, a term described at least once together with a different term having a broader meaning or the same meaning can be replaced with the different term anywhere in the specification. Further, the configuration and operation of the physical vapor deposition target member, the physical vapor deposition film, the layer structure, and the like are not limited to those described in the present embodiment, and various modifications are possible.

Claims (3)

  1. 　１０μｍを超え、１００μｍ以下の平均結晶粒子径と、中心線平均粗さＲａが１．６μｍ以下の表面とを有することを特徴とするＭｇＯ焼結体。 MgO sintered body characterized by having an average crystal particle diameter of more than 10 μm and not more than 100 μm and a surface having a center line average roughness Ra of not more than 1.6 μm.
  2. 　３．５６９ｇ／ｃｍ３以上の密度を有することを特徴とする請求項１に記載のＭｇＯ焼結体。 The MgO sintered body according to claim 1, having a density of 3.569 g / cm 3 or more.
  3. 　請求項１又は２に記載のＭｇＯ焼結体を備えることを特徴とするスパッタリングターゲット。 A sputtering target comprising the MgO sintered body according to claim 1 or 2.
PCT/JP2019/010479 2018-03-15 2019-03-14 MgO SINTERED BODY AND SPUTTERING TARGET WO2019177086A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2018-048363 2018-03-15
JP2018048363 2018-03-15

Publications (1)

Publication Number Publication Date
WO2019177086A1 true WO2019177086A1 (en) 2019-09-19

Family

ID=67907842

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2019/010479 WO2019177086A1 (en) 2018-03-15 2019-03-14 MgO SINTERED BODY AND SPUTTERING TARGET

Country Status (1)

Country Link
WO (1) WO2019177086A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020075750A1 (en) * 2018-10-10 2020-04-16 Ｊｘ金属株式会社 Magnesium oxide sputtering target

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10130827A (en) * 1996-10-28 1998-05-19 Mitsubishi Materials Corp Mgo target and its production
JP2000169956A (en) * 1998-12-03 2000-06-20 Japan Energy Corp Magnesium oxide target for sputtering and its production
WO2000040769A1 (en) * 1998-12-28 2000-07-13 Japan Energy Corporation Sputtering target
JP2000313655A (en) * 1999-04-28 2000-11-14 Kyocera Corp High-density magnesium oxide-based sintered compact and its production, and member for plasma treatment apparatus
JP2008189493A (en) * 2007-02-02 2008-08-21 Sumitomo Electric Ind Ltd POLYCRYSTALLINE MgO SINTERED BODY
WO2009096384A1 (en) * 2008-01-28 2009-08-06 Nippon Tungsten Co., Ltd. POLYCRYSTALLINE MgO SINTERED COMPACT, PROCESS FOR PRODUCING THE POLYCRYSTALLINE MgO SINTERED COMPACT, AND MgO TARGET FOR SPUTTERING
WO2013065564A1 (en) * 2011-11-04 2013-05-10 株式会社フェローテックセラミックス Sputtering target and method for producing same
CN106587940A (en) * 2016-12-02 2017-04-26 有研亿金新材料有限公司 High-purity compact magnesium oxide target material and preparation method thereof
JP2018141202A (en) * 2017-02-28 2018-09-13 株式会社高純度化学研究所 Ceramic sputtering target and manufacturing method of the same

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10130827A (en) * 1996-10-28 1998-05-19 Mitsubishi Materials Corp Mgo target and its production
JP2000169956A (en) * 1998-12-03 2000-06-20 Japan Energy Corp Magnesium oxide target for sputtering and its production
WO2000040769A1 (en) * 1998-12-28 2000-07-13 Japan Energy Corporation Sputtering target
JP2000313655A (en) * 1999-04-28 2000-11-14 Kyocera Corp High-density magnesium oxide-based sintered compact and its production, and member for plasma treatment apparatus
JP2008189493A (en) * 2007-02-02 2008-08-21 Sumitomo Electric Ind Ltd POLYCRYSTALLINE MgO SINTERED BODY
WO2009096384A1 (en) * 2008-01-28 2009-08-06 Nippon Tungsten Co., Ltd. POLYCRYSTALLINE MgO SINTERED COMPACT, PROCESS FOR PRODUCING THE POLYCRYSTALLINE MgO SINTERED COMPACT, AND MgO TARGET FOR SPUTTERING
WO2013065564A1 (en) * 2011-11-04 2013-05-10 株式会社フェローテックセラミックス Sputtering target and method for producing same
CN106587940A (en) * 2016-12-02 2017-04-26 有研亿金新材料有限公司 High-purity compact magnesium oxide target material and preparation method thereof
JP2018141202A (en) * 2017-02-28 2018-09-13 株式会社高純度化学研究所 Ceramic sputtering target and manufacturing method of the same

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
"JIS Handbook 35 Ceramics", JAPANESE STANDARDS ASSOCIATION, January 2003 (2003-01-01), pages 249 - 250 *
NAGAKURA, SABUROU ET AL., IWANAMI DICTIONARY OF PHYSICS AND CHEMISTRY, 20 February 1998 (1998-02-20), pages 538 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020075750A1 (en) * 2018-10-10 2020-04-16 Ｊｘ金属株式会社 Magnesium oxide sputtering target

Similar Documents

Publication Publication Date Title
JP5121268B2 (en) Aluminum nitride sintered body and member for semiconductor manufacturing apparatus
JP4987238B2 (en) Aluminum nitride sintered body, semiconductor manufacturing member, and aluminum nitride sintered body manufacturing method
US8158544B2 (en) Yttria sintered body and component used for plasma processing apparatus
JP6037415B2 (en) Magnetic material sputtering target and manufacturing method thereof
JP5231823B2 (en) Polycrystalline MgO sintered body, method for producing the same, and MgO target for sputtering
JP6069214B2 (en) Sputtering target and manufacturing method thereof
JP7062229B2 (en) Plate-shaped silicon nitride sintered body and its manufacturing method
WO2017030360A1 (en) Silicon nitride sintered compact with high thermal conductivity, and method for manufacturing same
JP7062230B2 (en) Plate-shaped silicon nitride sintered body and its manufacturing method
WO2016088867A1 (en) MgO SPUTTERING TARGET MATERIAL AND THIN FILM
CN116018329A (en) Ceramic sintered body comprising magnesium aluminate spinel
JPH10236866A (en) Aluminium bearing sintered compact
JP5406565B2 (en) Aluminum oxide sintered body, manufacturing method thereof, and semiconductor manufacturing apparatus member
WO2019177086A1 (en) MgO SINTERED BODY AND SPUTTERING TARGET
JP5998712B2 (en) IGZO sintered body, sputtering target, and oxide film
JP2017193477A (en) Oxide sintered body and sputtering target, and methods for producing same
WO2004026790A1 (en) Aluminum nitride sintered compact
JP7108046B2 (en) magnesium oxide sputtering target
JPWO2019163710A1 (en) Manufacturing method of composite sintered body, semiconductor manufacturing equipment member and composite sintered body
JP7201103B2 (en) Plate-like silicon nitride sintered body and manufacturing method thereof
WO2018013387A1 (en) Magnesium oxide sputtering target and method of making same
JP7165023B2 (en) magnesium oxide sputtering target
JP2013193932A (en) Method for producing ceramic material, ceramic material, and sputtering target member
JP5698568B2 (en) Aluminum oxide sintered body and method for producing the same
JP7110175B2 (en) MgAl2O4 sintered body, sputtering target using said sintered body, and method for producing MgAl2O4 sintered body

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 19767560

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 19767560

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: JP