Plasma spayed coating comprising y2o3-based composite and manufacturing method thereof

Abstract

The present invention provides a plasma sprayed coating comprising a composite of a magnesium compound and an yttrium compound, wherein the composite includes a monoclinic yttrium oxide.

Description

Y2O3-based composite spray coating and its manufacturing method

[0001] The present invention relates to a Y2O3 plasma sprayed coating, and more particularly, to a plasma sprayed coating containing a Y2O3 complex and a method for manufacturing the same.

[0002] Recent advancements in semiconductor process integration and ultra-fine linewidth technology require plasma etching processes under extreme environments such as high-density plasma, high cleanliness, and excessive electrical shock. In particular, plasma etching processes that utilize reactive gases containing halogen elements such as F, Cl, or Br with strong chemical reactivity etch various deposition materials on the wafer surface, and at the same time cause damage to the surface of metal or ceramic components inside the chamber and generate non-volatile contaminant particles through chemical and physical reactions.

[0003] Therefore, interest in coatings of ceramic materials that exhibit excellent plasma resistance on the surface of metal or ceramic parts has recently increased significantly, and yttrium oxide (Y2O3) coatings are widely applied as a representative example.

[0004] Yttrium oxide (Y2O3) exhibits a high melting point (2,450°C), chemical stability, and crystallographic stability up to 2,300°C. In particular, Y2O3 exhibits excellent plasma resistance due to excellent chemical stability against F radicals, high ion collision resistance due to the high atomic mass of yttrium, and excellent mechanical properties of the reaction product YF3.

[0005] However, when the upper surface of the Y2O3 coating layer reacts with plasma gases such as SF6, CF4, CHF3, and HF at the beginning of the etching process, a change in the concentration of fluorine-based gases in the chamber occurs, which increases the Seasoning Time of the etching process, and the surface of the Y2O3 reacts with the plasma gas to form contaminant particles containing fluorine, and when the Y2O3 undergoes a thermal cycle, stress is generated due to the difference in thermal expansion coefficient between the contaminant particles and the Y2O3, and there is a problem that the contaminant particles fall off. To solve this problem, YF3, which has excellent corrosion resistance, was introduced, but the YF3 has a problem in that it melts in the ultra-high temperature plasma during the atmospheric plasma spraying (APS) process, and some of the fluoride is oxidized, forming a coating layer partially mixed with fluoride and oxide, and in addition, compared to the Y2O3 sprayed coating layer, cracks in the coating layer and the generation of particles in the etching chamber can cause many problems. To solve these problems of Y2O3 and YF3, a YOF coating layer having intermediate properties of Y2O3 and YF3 has been introduced.

[0006] Meanwhile, the plasma resistance characteristics of a plasma-resistant member depend on the size of the crystal grains. When the crystal grain size is large, the change in roughness after plasma etching is large, resulting in a decrease in the plasma resistance characteristics. In addition, when the crystal grain size is large, the size of the particles generated by plasma etching becomes large, and these cannot escape out of the chamber by the fluid flow and are adsorbed on the wafer, causing problems such as device malfunction and lowering the yield. Therefore, there is a need for a Y2O3 compound spray coating having a small particle size.

[0007] On the other hand, the hardness of plasma-sprayed coatings affects the yield of semiconductor processes. Low hardness coatings can generate particles due to plasma impact or high temperatures. Therefore, there is a need for high-hardness Y2O3 compound sprayed coatings.

[0008] In order to achieve the above technical task, the present invention aims to provide a plasma sprayed coating comprising a Y2O3 complex having a low average particle size.

[0009] In addition, the present invention aims to provide a plasma sprayed coating comprising a Y2O3 complex having high hardness.

[0010] In addition, the present invention aims to provide a method for manufacturing the above-described plasma spray film.

[0011] In order to achieve the above technical task, the present invention provides a plasma sprayed coating comprising a complex of a magnesium compound and an yttrium compound, wherein the complex comprises monoclinic yttrium oxide.

[0012] In the present invention, it is preferable that the monoclinic yttrium oxide is a main phase of crystalline yttrium oxide.

[0013] In the present invention, the yttrium compound may further include cubic yttrium oxide.

[0014] In the present invention, the composite may include crystal grains having an EBSD particle size of 250 nm or less. In addition, the composite may include crystal grains having an EBSD particle size of 100 nm or less.

[0015] In the present invention, it is preferable that the weight ratio of the yttria compound to the magnesium compound in the complex is 1:9 to 9:1.

[0016] In the present invention, the complex may have a maximum frequency peak in the EBSD particle size distribution at 200 nm or less.

[0017] In the present invention, the complex may have a maximum frequency peak in the EBSD particle size distribution at 100 nm or less.

[0018] In the present invention, the complex may further include Al2O3.

[0019] Additionally, the yttrium compound may include YF3 or YOF.

[0020] In order to achieve the above other technical tasks, the present invention provides a method for manufacturing a plasma sprayed coating, comprising the steps of: (a) introducing raw material powder containing yttrium and magnesium sources into a plasma stream and melting at least a portion of the raw material powder; and (b) exposing a base material to an atmospheric plasma stream containing the yttrium and magnesium sources to form a plasma sprayed coating containing a complex of a magnesium compound and an yttrium compound.

[0021] In the step (a) of the present invention, the yttrium and magnesium source may be a mixture of yttrium oxide and magnesium oxide.

[0022] In addition, it is preferable that the weight ratio of the magnesium and yttrium in the magnesium and yttrium source converted to MgO and Y2O3 is 1:9 to 9:1.

[0023] Additionally, in the present invention, the yttrium and magnesium source may include cubic yttria.

[0024] Additionally, in the present invention, the complex may include monoclinic yttrium oxide.

[0025] In addition, in the present invention, it is preferable that the monoclinic yttrium oxide is a main phase of crystalline yttrium oxide.

[0026] In the present invention, the yttrium compound may further include cubic yttrium oxide.

[0027] According to the present invention, it is possible to provide a plasma sprayed coating comprising a Y2O3-based composite having a low average particle size. In addition, the present invention can provide a plasma sprayed coating comprising a Y2O3-based composite having a high hardness.

[0028] FIG. 1 is a schematic diagram illustrating a plasma spraying device according to one embodiment of the present invention.

[0029] Figure 2 shows a graph showing the results of X-ray diffraction analysis of a spray coating specimen manufactured according to one embodiment of the present invention.

[0030] Figures 3 (a) and (b) are drawings showing XRD patterns of JCPDS for cubic Y2O3 and monoclinic Y2O3.

[0031] Figures 4 (a) and (b) are photographs showing EBSD maps for a specimen manufactured according to one embodiment of the present invention, where (a) is a photograph showing a crystal structure, and (b) is a photograph showing a crystal orientation.

[0032] FIGS. 5 and 6 are photographs showing EBSD maps for specimens manufactured according to one embodiment of the present invention, wherein FIG. 5 is a photograph showing a crystal structure, and FIG. 6 is a photograph showing a crystal orientation.

[0033] Figures 7 (a) and (b) are photographs showing the crystal grain size distribution calculated from EBSD computational analysis of a specimen manufactured according to one embodiment of the present invention.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In general, the nomenclature used herein is well known and commonly used in the art.

[0035] Whenever it is said throughout this specification that a part "includes" a component, this does not exclude other components, but rather may include other components, unless specifically stated otherwise.

[0036] In the present invention, the yttrium compound includes a Y2O3-based complex. In the present invention, the Y2O3-based complex means a composition that further includes other components in addition to Y2O3, which is an yttrium oxide. The Y2O3-MgO described below is a type of Y2O3-based complex, and the complex may further include two or more additional components. The form of the phase constituting the complex in the present invention is not particularly limited. For example, each compound constituting the complex may exist as a separate phase or may form a solid solution.

[0037] In the present invention, the weight ratio of Y2O3:MgO in the Y2O3-MgO composite may be 9:1 to 1:9, 8:2 to 2:8, 7:3 to 3:7, or 6:4 to 4:6. Preferably, the MgO content is 30 wt% or more based on the total weight of the Y2O3-MgO composite of the present invention.

[0038] In addition, in the specification of the present invention, the yttrium compound may include YF3 or YOF (Yttrium Oxyfluoride) in addition to Y2O3. In the specification of the present invention, the YOF compound is a chemical element Y x O y F zThe YOF compound refers to a ternary compound of Y, O and F represented by the chemical formula, but is not necessarily limited thereto and may include trace amounts of additional elements that can be employed while maintaining the crystal structure. In the present invention, the YOF compound may include at least one compound selected from the group consisting of YOF, Y7O6F9, Y6O5F8, Y5O4F7, and Y4O3F6. In addition, the yttrium compound in the present invention may be configured to include two or more cations. For example, the yttrium compound may include at least one element selected from the group consisting of Al, Zr, Y, Sm, Dy, Er and Hf.

[0039]

[0040] Therefore, in the present invention, the yttrium compound is Y4Al2O9, Y3Al5O 12 It may include yttrium aluminate such as YAlO3, yttria-stabilized zirconia. Meanwhile, the term "magnesium compound" in the present invention is also interpreted similarly. For example, the magnesium compound may include fluorides such as Mg-OF and MgF2 in addition to MgO. In addition, the magnesium compound may include a ternary compound such as MgAl2O4 or a multi-component compound having more than one cation and anion.

[0041]

[0042] Hereinafter, a method for manufacturing a plasma sprayed coating containing a complex of a magnesium compound and an yttrium compound is described.

[0043] In the present invention, the sprayed coating can preferably be implemented by plasma spraying. Hereinafter, atmospheric pressure plasma spraying is described as the sprayed coating forming method of the present invention, but the present invention is not limited thereto, and other spraying methods such as low-pressure plasma spraying or suspension plasma spraying may be used.

[0044] Atmospheric Plasma Spray (APS) is a thermal spray technology that forms a layered film by rapidly cooling and solidifying powder or linear materials by converting them into a molten liquid using a high-temperature heat source and colliding them with a base material at high speed. More specifically, APS is a film-forming technology that converts gases such as Ar, He, and N2 in the atmosphere into plasma using an arc, and discharges this through a nozzle to produce an ultra-high-temperature, high-speed plasma jet as a heat source. This has the advantage of being able to produce a film with high adhesion strength and high density because the sprayed material collides with the base material to be treated at high speed.

[0045] FIG. 1 is a schematic diagram illustrating a plasma spraying device according to one embodiment of the present invention.

[0046] Referring to FIG. 1, a plasma spraying device (100) includes a plasma torch (110) or plasma gun and a raw material powder injector (120). In addition, the device may be equipped with a stage (140) for placing a base material (12) for film formation.

[0047] In the present invention, the above-mentioned parent material (120) may be any material. For example, materials such as aluminum, Al2O3, quartz, stainless steel, AlN, Y2O3, etc. may be used.

[0048] In the present invention, the above-mentioned base material (12) may be, for example, a base material used in components for semiconductor processes such as plasma etching, for example, a nozzle, an injector, a focus ring, an edge ring, a cover ring, an electrostatic chuck, a heater, a liner, etc.

[0049] In the present invention, the distance between the plasma torch and the base material can be appropriately set. In the present invention, the distance refers to the distance from the nozzle (112) of the plasma torch to the surface of the base material (12), and is preferably maintained in the range of 130 to 180 mm to provide molten powder droplets without loss and thereby improve yield.

[0050] A plasma torch (110) injects plasma in a jet state by generating an arc discharge between a cathode and an anode while flowing a large amount of gas. The plasma injected from the plasma torch forms a plasma stream toward the base material. When raw material powder is injected into the plasma stream, the raw material powder can be melted in a short period of time.

[0051] In the present invention, the powder injector (120) supplies raw material powder as a material for a thermal spray coating. The present invention includes an yttrium and magnesium source as the raw material powder of the injector. In the present invention, the yttrium and magnesium source may be an yttrium salt and a magnesium salt or an yttrium magnesium salt. Preferably, the yttrium and magnesium source may be in the form of an oxide, but is not limited thereto, and an appropriate source capable of forming a compound of yttrium and magnesium after thermal spraying may be used. In addition, the source may be composed of yttrium oxide and magnesium oxide, or may include yttrium magnesium oxide.

[0052] In the present invention, the raw material powder may be a powder formed into granules. The raw material powder may be, for example, a molded body obtained by spray drying yttrium oxide and magnesium oxide powder. In addition, the raw material powder may be manufactured by heat-treating or plasma-treating a spray-dried molded body and melting a portion of it.

[0053]

[0054] The present invention provides a plasma sprayed coating comprising a composite of a magnesium compound and an yttrium compound. In the present invention, the composite of the coating may comprise monoclinic yttrium oxide.

[0055] As described below, yttrium oxide is a compound having a cubic crystal structure in a stable state. The composite film of the present invention comprises monoclinic yttrium oxide, and preferably comprises monoclinic yttrium oxide as a main phase among the crystalline yttrium oxide. In the present invention, the 'main phase' means a phase having a weight fraction of 50% or more among the phases constituting a specific compound. According to one embodiment of the present invention, monoclinic yttrium oxide may be included in an amount of 60 wt% or more, 70 wt% or more, 80 wt% or more, 90 wt% or more, or 95 wt% or more of the crystalline yttrium oxide. In an extreme case, yttrium oxide having a crystal structure other than monoclinic may not be substantially detected among the yttrium oxide.

[0056] In addition, the composite film of the present invention contains sub-micron or nano-sized crystal particles. In the specification of the present invention, nano-size means having a particle size of 100 nm or less. In the specification of the present invention, 'particle size' means a particle size converted from the volume, surface area, or cross-sectional area of ​​the particle, and may mean, for example, a diameter when converted into a three-dimensional sphere having the same volume or surface area as the particle volume or surface area, or a two-dimensional circle having the same area as the particle cross-sectional area.

[0057] In addition, in the present invention, the grain size of the crystal grains can be obtained by computer analysis of the diffraction pattern obtained by electron backscatter diffraction analysis (EBSD). Hereinafter, the grain size obtained thereby is referred to as the EBSD grain size in the present specification. EBSD refers to an experimental technique that analyzes the crystal structure and crystal orientation of a specimen by shooting electrons at the specimen and measuring the electrons (backscattered electrons) reflected at a specific angle.

[0058] The Y2O3-based composite of the present invention exhibits a maximum frequency peak at 200 nm or less, more preferably 100 nm or less, in the EBSD particle size distribution.

[0059] Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited by the examples.

[0060]

[0061] A. Example of manufacturing raw material powder for warriors

[0062] Each granular powder sample was manufactured by varying the mixing ratio of cubic Y2O3 powder with a particle size of 3–5 μm and cubic MgO powder with a particle size of 0.1–1.0 μm. The contents of Y2O3 powder and MgO powder and the particle size of the granules in the manufactured granular powder sample are shown in Table 1.

[0063]

[0064] The composition ratio of Y2O3 and MgO and the granule particle size in the manufactured raw material powder are shown in Table 1 below.

[0065] Classification Y2O3 (wt%) MgO (wt%) Granule average particle size (㎛, D50) Manufacturing example 1100-35 Manufacturing example 2109035 Manufacturing example 3703035

[0066] B. Manufacturing of plasma sprayed coatings Using the raw material powders of Examples 1 to 3, a sprayed coating was manufactured by atmospheric plasma spraying (APS). At this time, Al 6061 (20 mm*20 mm*3 mm(t)) was used as the base material substrate.

[0067] The plasma spraying conditions for manufacturing the solder film are summarized in Table 2 below.

[0068] Classification Voltage (V) Current (A) Power (kW) Powder transfer rate (g / min) Base material separation distance (mm) Manufacturing example 160~80400~7003510130~180 Manufacturing example 28.2130~180 Manufacturing example 39.1130~180

[0069] EDS component analysis of the manufactured thermal spray coating was performed. EDS analysis was performed using JEOL's JSM-IT700HR model at a magnification of 10,000x and an electron beam output of 15 kV. The thermal spray coating specimens were mounted, polished, and plated with Au before EDS analysis. The EDS analysis results are shown in Table 3.

[0070] Classification Y(at%)Mg(at%)O(at%)#1 (Manufacturing Example 1)40-60#2 (Manufacturing Example 2)233443#3 (Manufacturing Example 3)75043

[0071] The manufactured thermal spray coating was subjected to XRD analysis. The analysis was performed using an XRD (model name: Empyrean) from Marvern Panalytical. Cu Ka was used as an X-ray source, and the voltage was 40 kV and the current was 30 mA. Graphs showing the X-ray diffraction analysis results for specimens #1 to #3 are shown in (a) to (c) of Fig. 2. For reference, (a) and (b) of Fig. 3 are drawings showing the XRD patterns of JCPDS for cubic Y2O3 and monoclinic Y2O3. The phase fraction was quantified from the XRD diffraction analysis results. The phase fraction was calculated by the RIR (Reference Intensity Ratio) method. Table 4 shows the results of calculating the phase fraction. In Table 4, the base is the intensity of the baseline expressed as a fourth-order polynomial of the measured intensity, and is a value calculated using pybaselines, a library of the programming language Python, and the absolute intensity is the value obtained by subtracting the base from the measured intensity at the same angle.

[0072]

[0073] Distinctive composition determination structure peak position (°) measurement intensity (Count, x10 3 )Base (Count, x10 3 )Absolute Strength (Count, x10) 3 ) Fraction (wt%)#1Y2O3Cubic29.276.380.016.37100#2Y2O3Monoclinic28.913.041.621.42830.723.511.581.93MgOCubic42.9621.371.3 720.0092#3Y2O3Cubic29.238.383.654.739Monoclinic28.868.063.674.392730.777.953.654.30MgOCubic42.8913.713.3510.3664

[0074] From Table 3, it can be seen that for specimen #1, the Y2O3 grains have a cubic crystal structure with peaks around 2θ=29.3°. However, for specimen #2, it can be seen that the Y2O3 grains have a monoclinic crystal structure with peaks around 2θ=28.9° and 30.7°. For specimen #3, it can be seen that monoclinic Y2O3 with peaks at similar locations forms the main phase.

[0075]

[0076] The crystal structure and grain size of the sprayed coating were analyzed by EBSD of the manufactured coating. EBSD was analyzed using an e-Flash FS model from Bruker Optik GmbH. The magnification was measured at 10,000x, and the measurement area was 20.76 x 15.52 ㎛. 2 , the resolution was set to 500 x 375 pixels.

[0077] Figures 4(a) and (b) are photographs showing EBSD maps for specimen #1, where (a) shows the crystal structure, and (b) shows the crystal orientation. In each photograph, the black background indicates an unmeasurable area.

[0078] Referring to Fig. 4(a), it can be seen that the #1 specimen is composed of cubic yttria. In addition, Fig. 4(b) shades the crystal orientations of the crystals within the region of Fig. 4(a), and it can be seen that the portion that appears to be a single large region in Fig. 4(a) is actually composed of fine crystal particles with different crystal orientations, such as (100), (111), and (001).

[0079] Figures 5 and 6 are photographs showing EBSD maps for specimen #3, respectively. Figure 5 shows the crystal structure, and Figure 6 shows the crystal orientation. The black background in Figures 5 and 6 indicates an unmeasurable area.

[0080] As shown in Fig. 5, the Y2O3 phase in specimen #3 was composed of a monoclinic crystal structure and a cubic crystal structure, and the crystals of the monoclinic crystal structure occupied a larger area than the crystals of the cubic crystal structure. Meanwhile, similar to Fig. 4 (b), Fig. 6 shades the directions of the crystals forming each crystal structure, and it was found that the monoclinic and cubic crystals were actually composed of fine-sized crystal particles with different orientations.

[0081] Table 5 below is a table that summarizes the crystal structure fractions in the EBSD map described above.

[0082] Distinctive SubstanceCrystal StructureOverall Distribution (%)Fraction within Crystal Area (%)#1Y2O3Cubic68.5100.0Unmeasurable Area-31.5-#3Y2O3Cubic0.216.2Monoclinic0.437.6MgOCubic0.646.2Unmeasurable Area-98.8-

[0083] The Vickers hardness of the manufactured thermal spray coating was measured. The measurement specimen was a hexahedral aluminum specimen measuring 20 mm x 20 mm x 3 mm (t) with a 150 ㎛ thick coating formed on it, and then mounted and polished so that the cross-section could be measured. The Vickers hardness was measured using a Vickers hardness tester (model name: HM) from Mitutoyo, and was defined as the Vickers hardness (Hv0.05) obtained when a test force of 0.05 kgf was applied using a diamond indenter with a facing angle of 136°. The measurement was performed at the center of the cross-section of the coating, the number of measurements was 30, and the median value was set as the representative value. The measurement results are shown in Table 6 below.

[0084] Vickers hardness #1400 #2500 #3800

[0085] From Table 6, it can be seen that the Y2O3-based spray coating containing MgO exhibits high hardness. Figures 7 (a) and (b) are photographs showing the results of the crystal grain size distribution calculated from EBSD computational analysis for specimens #1 and #2, respectively.

[0086] Referring to Figure 7, it can be seen that for specimen #1, numerous crystal grains larger than 1 ㎛ as well as sub-micron grains are observed in the EBSD analysis, whereas for specimen #2, only sub-micron-sized crystal grains are observed. In particular, specimen #2 is composed of grains smaller than 0.5 ㎛, and the maximum frequency peak appears at 0.1 ㎛ or less.

[0087]

[0088] Although the present invention has been described above with reference to exemplary embodiments and drawings, these have been provided only to help a more general understanding of the present invention, and the present invention is not limited to the above embodiments, and those skilled in the art to which the present invention pertains will appreciate that various modifications and variations are possible without departing from the essential characteristics of the present invention. Therefore, the spirit of the present invention should not be limited to the described embodiments, and all technical ideas that are equivalent or equivalent to the claims as well as the claims should be interpreted as being included in the scope of the rights of the present invention.

[0089] The present invention is applicable to a semiconductor manufacturing device and a component constituting the semiconductor manufacturing device.

Claims

1. Contains a complex of magnesium compounds and yttrium compounds, The above complex is a plasma sprayed coating comprising monoclinic yttrium oxide.

2. In paragraph 1, The above monoclinic yttrium oxide is a plasma sprayed coating, which is the main phase of crystalline yttrium oxide.

3. In paragraph 1, A plasma sprayed coating, wherein the yttrium compound further comprises cubic yttrium oxide.

4. In paragraph 1, A plasma sprayed coating, wherein the complex comprises grains having an EBSD grain size of 250 nm or less.

5. In paragraph 1, A plasma sprayed coating, wherein the complex comprises grains having an EBSD grain size of 100 nm or less.

6. In paragraph 1, A plasma sprayed film having a weight ratio of yttria compound to magnesium compound in the above complex of 1:9 to 9:

1.

7. In paragraph 1, The above complex is a plasma sprayed coating, wherein the maximum frequency peak in the EBSD particle size distribution appears at 200 nm or less.

8. In paragraph 1, The above complex is a plasma sprayed coating, wherein the maximum frequency peak in the EBSD particle size distribution appears at 100 nm or less.

9. In paragraph 1, The above complex is Al 2 O 3 A plasma spray film further comprising:

10. In paragraph 1, The above yttrium compound is YF 3 A plasma spray film comprising:

11. In paragraph 1, The above yttrium compound is a plasma sprayed film comprising YOF. 12.(a) a step of introducing raw material powder containing yttrium and magnesium sources into a plasma stream and melting at least a portion of the raw material powder; and (b) a method for manufacturing a plasma sprayed coating, comprising the step of exposing a parent material to an atmospheric plasma stream containing the yttrium and magnesium sources to form a plasma sprayed coating comprising a complex of a magnesium compound and an yttrium compound.

13. In paragraph 12, A method for producing a plasma sprayed film, wherein in the step (a), the yttrium and magnesium sources are a mixture of yttrium oxide and magnesium oxide.

14. In paragraph 13, From the above magnesium and yttrium sources, the magnesium and yttrium are added to MgO and Y 2 O 3 Plasma spray film with a weight ratio converted to 1:9 to 9:

1.

15. In paragraph 13, A method for producing a plasma sprayed film, wherein the above yttrium and magnesium sources include cubic yttria.

16. In paragraph 13, A method for producing a plasma sprayed coating, wherein the complex comprises monoclinic yttrium oxide.

17. In paragraph 16, A method for producing a plasma sprayed coating, wherein the above monoclinic yttrium oxide is a main phase of crystalline yttrium oxide.

18. In paragraph 12, A method for producing a plasma sprayed coating, wherein the yttrium compound further comprises cubic yttrium oxide.

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