Fluorination method for fluoridation object and fluoridation component by the method

Abstract

The present invention relates to a fluorination processing method for a fluorinated object and a component fluorinated by the method, which can achieve high density and high strength of various components in semiconductor processes through a fluoride coating based on atmospheric pressure high-frequency plasma while significantly improving productivity, and is particularly suitable for normal etching rates of large-area semiconductor equipment.

Description

Technical Field

[0001] The present invention relates to a fluorination processing method for a fluorided object and a component fluorided by the method, and more particularly, to a fluorination processing method for a fluorided object and a component fluorided by the method, which can achieve high density and high strength for various components in semiconductor processes by coating with fluorides based on atmospheric pressure high-frequency plasma, and significantly improve productivity by shortening aging in the debugging step, and is particularly suitable for the normal etching rate of large-area semiconductor equipment. Background Art

[0002] After semiconductor dry etching equipment is shut down for periodic equipment inspection or component replacement (maintenance), when the equipment is restarted, a debugging (backup) process is required to operate the semiconductor manufacturing equipment normally.

[0003] In semiconductor dry etching equipment, the debugging (Back up) process is carried out through the following steps, namely, the step of removing gas pollution such as moisture in the equipment (Out-gasing); the step of reducing the pollution factors (particles) in the equipment; the step of aging (Aging) in the fluorination equipment; and the step of using mass-produced wafers (Wafer) to conduct sample (Sample) quality inspection (factory database In Fab.Data).

[0004] Among them, an aging process will be accompanied to form a fluorinated atmosphere inside the semiconductor dry etching equipment that can achieve a normal etching rate. This aging process allows a specified level of corrosive gas to adhere to the surface of a plasma-resistant coating (Al2O3, Y2O3, YAG, etc.) installed inside the equipment, thereby arbitrarily forming a fluorinated layer with a yttrium oxyfluoride (YOF) component of several nm to several hundred nm on the surface.

[0005] If a fluorinated atmosphere is not sufficiently formed inside the semiconductor dry etching equipment, the operation time of the semiconductor equipment is greatly reduced as the time of repeated aging processes increases, which may lead to a decrease in the productivity of the semiconductor equipment and an increase in manufacturing costs.

[0006] On the other hand, as an existing example of a method for forming a fluorinated layer, there is a well-known method in which a component to be fluorinated is placed in a vacuum tank and a low-pressure vacuum plasma containing fluorine-containing gases such as CF4, SF6, and NF3 is generated, thereby fluorinating the surface through fluorine-containing free radicals ("Fabrication, characterization, and fluorine-plasma exposure behavior of dense yttrium oxyfluoride ceramic", T Tsunoura et al, Japanese Journal of Applied Physics 56, 06HC02 (2017), "Fluorination mechanisms of Al2O3 and Y2O3 surfaces irradiated by high-density CF4 / O2 and SF6 / O2 plasmas", K Miwa et al, J Vac Sci Technol A 27(4), Jul / Aug 2009).

[0007] However, this method has the following disadvantages. That is, since a vacuum tank and a vacuum device need to be built, it is not conducive to mass production and has low economic efficiency. Moreover, since a low-pressure plasma process is used, the density of fluorine-containing free radicals is low, resulting in a slow fluorination rate, thereby reducing productivity.

[0008] As another example, there is a known method of fluorinating the surface of a part to be fluorinated by immersing it in a solution of HF, SF4, CHF3, etc. and then raising the temperature to ~250°C ("Preparation of Fluorinated-Alumina", EKemnitz et al, "Efficient Preparations of Fluorine Compounds", Edited by H WRoesky, 2013, 442).

[0009] However, this method has the disadvantage that it is disadvantageous in terms of process safety because hazardous solutions are used during operation and handling.

[0010] As another example, US Pat. No. 8,206,829 and / or US Patent Publication No. 2017 / 0114440 are known. The above documents disclose a method of coating a powder material such as AlF3, YF3, AlOF, YOF, etc. on a component surface by plasma spraying or the like.

[0011] However, the raw material prices of AlF3 or YF3, which are used to coat ceramic protective films such as alumina (Al2O3) or yttrium trioxide (Y2O3), are very high, and the limited number of raw material suppliers leads to poor supply, so there is a problem of low economic efficiency. Summary of the invention

[0012] Technical issues

[0013] Therefore, the purpose of the present invention for solving the above-mentioned problems is to provide a fluorination processing method for a fluorinated object and a component fluorinated by this method, namely, it is possible to achieve high density and high strength for various components in semiconductor processes by coating with fluorides based on an atmospheric pressure high-frequency plasma source, and at the same time significantly improve productivity by shortening the aging step performed in the debugging step, which is particularly suitable for the normal etching rate of large-area semiconductor equipment.

[0014] The technical problems of the present invention are not limited to the above-mentioned contents, and a person skilled in the art can clearly understand other technical problems not mentioned from the following description.

[0015] Technical Solution

[0016] According to one aspect of the present invention for achieving the above-mentioned purpose and other features of the present invention, there is provided a fluorination processing method for a fluoridation object, which is used for fluoriding the surface of the fluoridation object, and comprises: a first step of placing the fluoridation object in a processing chamber having a plasma reaction space; a second step of introducing a working gas into the processing chamber, wherein the working gas is a discharge gas selected from He, Ne, Ar, Kr, and Xe, a non-fluorine reaction gas selected from O2, N2, and air (air), and a mixed gas of a fluorine-containing fluorocarbon gas selected from CF4, C2F6, C4F8, or a fluorine-containing reaction gas selected from nitrogen trifluoride (NF3) gas, that is, introducing the mixed gas into the processing chamber; a third step of introducing the mixed gas introduced into the processing chamber into the plasma reaction space; and a fourth step of generating plasma in the plasma reaction space by applying high-frequency power to the processing chamber, and fluoriding the surface of the fluoridation object with the generated fluorine-containing free radical gas and plasma, wherein the atmosphere in the processing chamber is formed into an atmospheric pressure atmosphere in the first to fourth steps.

[0017] According to one aspect of the present invention, the fluorination processing method of the fluorinated object is characterized in that in the above-mentioned mixed gas introduction step, a mixed gas of argon gas as a discharge gas, oxygen as a non-fluorine reaction gas and carbon tetrafluoride as a fluorine-containing reaction gas is introduced as the used gas, and the flow ratio of Ar, O2 and CF4 is Ar:O2:CF4 is 0.1~60:0.1~10:0.1~10.

[0018] According to one aspect of the present invention, the fluorination processing method of the fluorinated object is characterized in that in the above-mentioned fluorination step, the frequency of the high-frequency power supply is 1Hz~100MHz, and the high-frequency power is 300W~400W.

[0019] According to one aspect of the present invention, the fluorination processing method for a fluorinated object is characterized in that the temperature in the processing chamber is below 400° C. at room temperature.

[0020] According to one aspect of the present invention, the fluorination processing method of the fluorinated object is characterized by repeatedly performing the third step and the fourth step.

[0021] According to one aspect of the present invention, the fluorination processing method of the fluorination object is characterized in that the distance between the fluorination object and the plasma is greater than or equal to 2 mm and less than or equal to 5 mm.

[0022] According to one aspect of the present invention, the fluorination processing method of the fluoridation object is characterized in that the thickness of the fluoridation coating formed on the fluoridation object is 150 μm to 200 μm.

[0023] Effects of the Invention

[0024] The fluorination method of a fluorinated object and the part fluorinated by the method of the present invention provide the following effects.

[0025] First, the effect of the present invention is to provide a new concept component fluorination technology, that is, taking the plasma-resistant coating installed in the semiconductor dry etching equipment as the object, the processed parts can be fluorinated by high-frequency plasma with specific process factors under normal temperature and atmospheric pressure.

[0026] Second, the present invention has an effect that productivity can be improved by shortening the aging step which is one of the debugging processes performed in semiconductor dry etching equipment.

[0027] Thirdly, the present invention has the effect that it can be applied to high-density, high-strength, large-area objects while relatively reducing costs, and can increase productivity by increasing the speed of fluorination (process) performed in the aging step.

[0028] The effects of the present invention are not limited to the above-mentioned contents, and a person skilled in the art can clearly understand other technical problems not mentioned from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a flow chart showing the fluorination method of the fluorination object of the present invention.

[0030] Figure 2 The present invention provides a graph showing experimental results related to the flow ratio of Ar, O2, and CF4 (Ar:O2:CF4) used as gases in the fluorination processing method of the fluorination object of the present invention, including a graph showing a scanning electron microscope image (a) of the surface layer of the fluorination object with respect to the flow ratio of Ar and a bar graph (b) showing the contents of F and Al components.

[0031] Figure 3 The present invention provides a graph showing experimental results related to the flow ratio of Ar, O2, and CF4 (Ar:O2:CF4) used as gases in the fluorination processing method of the fluorination object of the present invention, including a graph showing a scanning electron microscope image (a) of the surface layer of the fluorination object with respect to the flow ratio of O2 and a bar graph (b) showing the contents of F and Al components.

[0032] Figure 4 The present invention provides a graph showing experimental results related to the flow ratio of Ar, O2, and CF4 (Ar:O2:CF4) used as gases in the fluorination processing method of the fluorination object of the present invention, including a graph showing a scanning electron microscope image (a) of the surface layer of the fluorination object with respect to the flow ratio of CF4 and a bar graph (b) showing the contents of F and Al components.

[0033] Figure 5 The figures show the experimental results related to the high-frequency power in the fluorination processing method of the fluorination object of the present invention, which are figures showing the surface layer scanning electron microscope image of the fluorination object related to the plasma power (a) and the content bar graph of F and Al components (b).

[0034] Figure 6 The figures show experimental results related to the temperature of the fluoriding object in the fluoriding method of the fluoriding object of the present invention, and are figures showing a scanning electron microscope image of the surface layer with respect to temperature (a) and a bar graph of the contents of F and Al components (b).

[0035] Figure 7 The present invention provides a diagram showing experimental results related to the step of introducing a mixed gas and the number of repetitions of the fluorination step in the fluorination processing method of a fluorination object of the present invention, and includes a scanning electron microscope image (a) of the surface layer of the fluorination object and a bar graph (b) showing the content of F and Al components with respect to the number of repetitions.

[0036] Figure 8 The present invention provides a diagram showing experimental results related to the distance between a fluoridation object (base material) and plasma in the fluoridation processing method of a fluoridation object of the present invention, including a scanning electron microscope image (a) of the surface layer of the fluoridation object and a bar graph (b) showing the contents of F and Al components relative to the distance.

[0037] Fig. 9 This is a table showing a cross-sectional image and component analysis of a fluoridation object related to the temperature factor in the fluoridation method of the fluoridation object of the present invention.

[0038] Fig.10 This is a table showing the cross-sectional image and component analysis of the fluoridation object related to the factor of the number of repetitions in the fluoridation method of the fluoridation object of the present invention.

[0039] Fig.11 This is a table showing a cross-sectional image and component analysis of a fluoridation object related to the power factor in the fluoridation method of the fluoridation object of the present invention.

[0040] Fig.12 This is a table showing the X-ray photoelectron spectroscopy analysis of the fluoridation object related to the content of the F component in the fluoridation method of the fluoridation object of the present invention.

[0041] Fig.13 This is a table showing transmission electron microscope images and component analysis of a fluoridation object related to the content of the F component in the fluoridation method of the fluoridation object of the present invention.

[0042] Fig.14 This is a bar graph showing the hardness analysis of the fluoridation object in relation to the content of the F component in the fluoridation method of the fluoridation object of the present invention.

[0043] Fig.15 This is a photograph showing the evaluation of the chemical resistance of a fluorinated object in a hydrogen chloride (HCl) solution in relation to the content of the F component in the fluorination method of the fluorinated object of the present invention.

[0044] Description of Reference Numerals

[0045] S100: Fluoridation object placement step

[0046] S200: Mixed gas introduction step

[0047] S300: Mixed gas introduction step

[0048] S400: Fluorination step DETAILED DESCRIPTION

[0049] Other objects, features and advantages of the present invention will be more clearly understood from the following detailed description and accompanying drawings.

[0050] Hereinafter, a component fluorination processing method according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0051] Figure 1 This is a flow chart showing the fluorination method of the fluorination object of the present invention.

[0052] like Figure 1 As shown, the fluorination processing method of the fluorination object of the present invention belongs to a processing method for fluoriding the surface of a fluorination object including components used in semiconductor processes, and generally includes a fluorination object placement step S100, a mixed gas introduction step S200, a mixed gas introduction step S300 and a fluorination step S400.

[0053] Specifically, Figure 1 As shown, the fluorination processing method of the fluorination object of the present invention is used to fluorinate the surface of the fluorination object including parts used in semiconductor processes, and comprises: a first step S100 as a fluorination object placement step, in a processing chamber of a fluorination processing device having a plasma jet outlet and a plasma reaction space, placing the fluorination object facing the above-mentioned plasma jet outlet; a second step S200 as a mixed gas introduction step, introducing a working gas into the above-mentioned processing chamber, wherein the working gas is a discharge gas selected from He, Ne, Ar, Kr, and Xe, a non-fluorine reaction gas selected from O2, N2, and air, a fluorine-containing fluorocarbon gas selected from CF4, C2F6, C4F8, or a fluorine-containing reaction gas in nitrogen trifluoride (NF3) gas. a mixed gas, introducing the mixed gas into the processing chamber; a third step S300 as a mixed gas introducing step, introducing the mixed gas introduced into the processing chamber into the plasma reaction space; and a fourth step S400 as a fluorination step, generating plasma in the plasma reaction space by applying high-frequency power to the metal electrode rod in the processing chamber, and injecting the generated fluorine-containing free radical gas and plasma toward the fluorination object through the plasma injection outlet to fluorinate the surface of the fluorination object. In the first step S100 to the fourth step S400, the atmosphere in the processing chamber is formed into an atmospheric pressure atmosphere, and the third step S300 and the fourth step S400 are performed more than once and less than 10 times.

[0054] The fluorination object placement step S100 as the first step is a process of placing the fluorination object in a processing chamber having a plasma jet outlet and a plasma reaction space facing the plasma jet outlet, and placing the fluorination object to be fluorinated on the upper part of a bracket (a bracket having a heater) located inside the processing chamber, and isolating the inside from the outside by closing the door of the processing chamber.

[0055] For example, the fluorination processing device with a processing chamber used in the above-mentioned fluorination object placement step S100 may include: a metal electrode rod, the surface of which is insulated by an insulator; a non-conductive ceramic tube, which is coaxially arranged with the above-mentioned metal electrode rod and extends to form a gap with the above-mentioned metal electrode rod; a grounding conduit, which is a grounding conduit that extends around the outer circumference of the above-mentioned non-conductive ceramic tube and is electrically grounded, and the inner circumference of the above-mentioned grounding conduit is in contact with the above-mentioned non-conductive ceramic tube as a whole; and a plasma injection head module, which forms an annular space portion between the outer circumference of the above-mentioned metal electrode rod and the inner circumference of the above-mentioned non-conductive ceramic tube, and extends along the length direction, and the open part at the lower end of the above-mentioned annular space portion becomes a plasma reaction space with a plasma injection outlet.

[0056] Furthermore, the processing chamber may include: a high-frequency power supply device, which applies high-frequency power to the metal electrode rod and is connected to the metal electrode rod via a high-frequency matcher for impedance matching; a gas supply unit, which supplies a working gas including a fluorine-containing reaction gas to the plasma reaction space; and a sample holder, which is arranged at the lower end of the plasma jet outlet and places the sample.

[0057] The upper part of the plasma injection head module is fixed on the upper part of the processing chamber. The metal electrode rod is formed in the form of penetrating the gas introduction chamber and extending vertically downward. The upper end is connected to the high-frequency matcher. The upper end of the non-conductive ceramic tube is located in the gas introduction chamber and extends downward along the length direction to introduce the used gas from the gas introduction chamber into the plasma reaction space.

[0058] Then, the mixed gas introduction step S200 as the second step is a process of introducing the working gas into the processing chamber, wherein the working gas is a discharge gas selected from He, Ne, Ar, Kr, and Xe, a non-fluorine reaction gas selected from O2, N2, and air, a mixed gas of a fluorine-containing fluorocarbon gas selected from CF4, C2F6, C4F8, or a fluorine-containing reaction gas in nitrogen trifluoride (NF3) gas, that is, a process of introducing the mixed gas into the processing chamber.

[0059] In the mixed gas introduction step S200, argon (Ar) gas as a discharge gas, oxygen (O2) as a non-fluorine reaction gas, and carbon tetrafluoride (CF4) as a fluorine-containing reaction gas are used as working gases to be introduced into the processing chamber from each gas tank of the gas supply unit.

[0060] In this case, the introduced gas is introduced into the processing chamber by adjusting the flow ratio of the mixed gas through a gas flow regulator, and the mixed gas is introduced into the plasma reaction space through the mixed gas introduction step S300 as the third step.

[0061] Among them, in addition to Ar gas, the discharge gas can also use inert gases such as He, Ne, Ar, Kr, and Xe. In addition, in addition to oxygen (O2) gas, the non-fluorine reaction gas can use nitrogen (N2), air, etc. In addition, in addition to CF4 gas, the fluorine-containing reaction gas can use fluorine-containing fluorocarbon gas gases such as C2F6 and C4F8 or nitrogen trifluoride (NF3) gas, etc., but in the present invention, preferably, the discharge gas is argon (Ar) gas, the non-fluorine reaction gas is oxygen (O2), and the fluorine-containing reaction gas is carbon tetrafluoride (CF4).

[0062] Furthermore, in the mixed gas introduction step S200, the flow ratio of Ar, O2, and CF4 (Ar:O2:CF4) used as the working gas is 0.1-60:0.1-10:0.1-10, preferably 25-40:0.1-0.4:0.3-1.0.

[0063] The inventors of the present invention have confirmed through experiments that the above flow ratio of Ar, O 2 , and CF 4 (Ar:O 2 :CF 4 ) used as the working gas is the optimal ratio.

[0064] Figures 2 to 4 This is a diagram showing experimental results related to the flow ratio (Ar:O2:CF4) of Ar, O2, and CF4 used as gases in the fluorination processing method of the fluorination object of the present invention. Figure 2 : is a diagram showing a scanning electron microscope image (a) of the surface layer of the fluorinated object and a bar graph (b) of the contents of F and Al components in relation to the Ar flow rate ratio. Figure 3 The figure shows a scanning electron microscope image (a) of the surface layer of the fluorinated object and a bar graph (b) of the content of F and Al components in relation to the flow rate ratio of O2. Figure 4 The figures are a scanning electron microscope image (a) of the surface layer of the fluorinated object and a bar graph (b) showing the contents of F and Al components in relation to the flow rate ratio of CF4.

[0065] like Figure 2 As shown, the inventors of the present invention have confirmed the existence of the following problems: when the Ar flow ratio is greater than 40, a small amount of particles (P / C: particle) are generated, and especially when it is greater than 60, particles are significantly generated, and when the Ar flow ratio is less than 0.1, the plasma is unstable and unsuitable. In particular, when the Ar flow ratio is within 25, the plasma is stable, and based on this, the best fluorination processing can be performed on the fluorination object.

[0066] And, if Figure 3As shown in FIG. 1 , it was confirmed that there was a problem that when the flow rate ratio of O2 was greater than 0.4, a small amount of particles (P / C: particle) were generated, and in particular, when the flow rate ratio was greater than 10, particles were significantly generated, and as shown in FIG. Figure 4 As shown, when the flow rate ratio of CF4 is greater than 1.0, a small amount of particles are generated, and particularly when it is greater than 10, particles are significantly generated, so it is not suitable.

[0067] Then, the fluorination step S400 is a process of applying high-frequency power to the metal electrode rod arranged in the processing chamber to generate plasma in the plasma reaction space, and spraying the generated fluorine-containing free radical gas and plasma toward the fluorination object through the plasma jet outlet to fluorinate the surface of the fluorination object.

[0068] In the fluorination step S400 of the present invention, the frequency of the high-frequency power applied by the high-frequency power supply device is preferably 1 MHz to 100 MHz, and the high-frequency power is 300 W to 400 W.

[0069] Figure 5 The figures show the experimental results related to the high-frequency power in the fluorination processing method of the fluorination object of the present invention. Part (a) is a figure showing a scanning electron microscope image of the surface layer of the fluorination object, and part (b) is a figure showing a bar chart of the content of F and Al components.

[0070] like Figure 5 As shown, it was confirmed that there was a problem that in the above-mentioned fluorination step S400, when the power of the applied high-frequency power source was less than 100 W or greater than 1000 W, particles were generated and the plasma was unstable, so it was not suitable.

[0071] On the other hand, in the fluorination method of the fluorination object of the present invention, the temperature in the processing chamber, that is, the temperature at which the fluorination object is heated, is preferably 400° C. or lower at room temperature. Figure 6 The figures show experimental results related to the temperature of the fluoriding object in the fluoriding processing method of the fluoriding object of the present invention. Part (a) is a figure showing a scanning electron microscope image of the surface layer of the fluoriding object, and part (b) is a figure showing a bar chart of the contents of F and Al components.

[0072] It was confirmed that the method for fluoriding a fluorided object of the present invention is not suitable because the coating peels off or separates from the fluorided object when the temperature at which the fluorided object is heated exceeds 400°C.

[0073] Furthermore, in the fluorination method of the fluorination object of the present invention, the mixed gas introducing step S300 and the fluorination step S400 are preferably repeated one or more times.

[0074] Figure 7 The figures are figures showing experimental results related to the introduction step of the mixed gas and the number of repetitions of the fluorination step in the fluorination processing method of the fluorination object of the present invention. Part (a) is a figure showing a scanning electron microscope image of the surface layer of the fluorination object, and part (b) is a figure showing a bar chart of the content of F and Al components.

[0075] Among them, when the mixed gas introduction step and the fluorination step performed when the number of repetitions is one or more is regarded as one cycle, it is preferred that the interruption time between cycles is 60 seconds to 10 minutes.

[0076] On the other hand, the inventors of the present invention have confirmed that in the fluorination processing method of the fluorination object of the present invention, the distance between the fluorination object and the plasma in the processing chamber is an important process factor. The distance between the fluorination object and the plasma is the distance from the surface of the fluorination object to the entrance of the plasma injection port.

[0077] Figure 8 The figures show the experimental results related to the distance between the fluoridation object (base material) and plasma in the fluoridation processing method of the fluoridation object of the present invention. Part (a) is a figure showing a scanning electron microscope image of the surface layer of the fluoridation object, and part (b) is a figure showing a bar chart of the content of F and Al components.

[0078] In the fluorination method of the fluoridation object of the present invention, the distance between the fluoridation object and the plasma is preferably 1 mm or more and 50 mm or less.

[0079] The inventors of the present invention have confirmed that the following problems exist: when the distance between the fluoridation object and the plasma is less than 1 mm, particles are generated and discharge is difficult, and when it is greater than 50 mm, a large-capacity high-frequency power supply device is required to increase the discharge voltage, but this leads to increased costs and is therefore not suitable.

[0080] In the fluorination method of the fluoridation object of the present invention, the thickness of the fluoridation coating of the fluoridation object is preferably 0.001 μm to 10 μm.

[0081] On the other hand, the inventors of the present invention evaluated the process factors (power, temperature, number of repetitions) that can form a fluorinated layer by reacting a Y2O3 coating prepared by atmospheric plasma spraying with F as a corrosive gas.

[0082] The surface of the Y2O3 coating prepared by atmospheric plasma spraying uses particle powder of several tens of μm as raw material, and therefore has a surface roughness of several μm. In order to correctly confirm the surface fine structure and composition changes caused by the fluorination reaction layer after fluorination modification, the surface is mirror polished to 0.1 μm, and the fluorination processing method of the present invention (new process for fluorination modification of coating) is applied.

[0083] In order to confirm the cross-sectional fine structure changes, reaction depth and distribution of the fluorination layer of the Y2O3 coating prepared by the atmospheric plasma spraying method applying the fluorination processing method of the present invention, the coating was processed with a focused ion beam, observed with a scanning electron microscope, and the content of the F component was analyzed by energy dispersive spectroscopy.

[0084] Furthermore, high-resolution X-ray diffraction analysis was performed to confirm the crystal phase change caused by the reaction of the Y2O3 coating prepared by atmospheric plasma spraying with the F component as a corrosive gas.

[0085] Fig. 9 This is a table showing a cross-sectional image and component analysis of a fluoridation object related to the temperature factor in the fluoridation method of the fluoridation object of the present invention.

[0086] First, the fine structure of the cross-section of the Y2O3 coating prepared by atmospheric plasma spraying and subjected to surface mirror polishing was analyzed. It was confirmed that almost no micropores were observed on the surface, but there were some scratches caused by mirror polishing, and Y, O, and C components were detected. The contents of Y, O, and C components were 27 atomic percent (at%), 58 atomic percent, and 15 atomic percent, respectively.

[0087] In addition, the results of observing the fine structure inside the processed coating using a focused ion beam showed that there were some vertical cracks caused by the typical volume shrinkage formed in atmospheric plasma spray coating, but the results of confirming the component distribution inside the coating through energy dispersion spectroscopy analysis mapping confirmed that the Y and O components were uniformly distributed as a whole.

[0088] On the other hand, in the fluorination processing method of the fluorination object of the present invention, in order to confirm the fluorination layer generation trend of the fluorination object with respect to the temperature factor, the temperature is changed to 100°C, 250°C, and 350°C to carry out the fluorination processing method of the present invention on the Y2O3 coating prepared by atmospheric plasma spraying, thereby forming a fluorination layer.

[0089] The results of observing the surface fine structure of the coating after applying the fluorination processing method of the present invention confirmed that it showed the same fine structure as the Y2O3 coating prepared by atmospheric plasma spraying before the application of the fluorination processing method. Therefore, there was no change in the fine structure caused by fluorination modification. On the contrary, it can be confirmed that the coating composition also contains an additional F component in addition to Y, O, and C components. This component increases in direct proportion to the increase in temperature and exists in a distribution of 3 atomic percent to 7 atomic percent. Therefore, a YOF fluorination layer is effectively formed on the coating surface.

[0090] Furthermore, as a result of observing the fine structure inside the processed coating using a focused ion beam, no YOF fluoride layer was clearly confirmed near the surface of the coating, but the results of mapping using energy dispersion spectroscopy confirmed the presence of a color equivalent to the F component inside the coating, and that as the temperature increased, the color near the surface became brighter than the inside, which is consistent with the trend, as described above, that the F component content on the coating surface increases to 3 atomic percent, 5 atomic percent, and 7 atomic percent as the temperature increases.

[0091] Fig.10 This is a table showing the cross-sectional image and component analysis of the fluoridation object related to the factor of the number of repetitions in the fluoridation method of the fluoridation object of the present invention.

[0092] Then, in order to confirm the trend of fluorination layer formation of the fluorination object with respect to the number of repetitions, the temperature factor was fixed at 350°C, and the number of repetitions was changed to 1, 5, and 10 times to carry out the fluorination processing method of the present invention (new process for fluorination modification of coating) on ​​the Y2O3 spray coating prepared by atmospheric plasma spraying, thereby forming a fluorination layer.

[0093] The results of observing the fine structure inside the processed coating using a focused ion beam showed that, similar to the previous evaluation of the temperature factor, the YOF fluorination layer of the fluorinated object was not clearly confirmed, but the mapping performed by energy dispersion spectroscopy analysis showed the presence of a color equivalent to the F component inside the coating, and as the number of repetitions increased, the color brightness was more clearly distinguished on the surface, and the reaction of the F component was more active, with the content increasing to a maximum of 12 atomic percent.

[0094] This is because, as the number of repetitions increases, the amount of F component diffused on the coating surface also increases as the coating surface is exposed to dissociated F ions for an increased time, thereby increasing the F content.

[0095] Fig.11 This is a table showing a cross-sectional image and component analysis of a fluoridation object related to the power factor in the fluoridation method of the fluoridation object of the present invention.

[0096] The temperature is fixed at 350°C and the number of repetitions is fixed at 10 times, and the power factor is increased to 300W to 400W to perform the fluorination processing method of the present invention (new process for fluorination modification of coating) on ​​the atmospheric plasma Y2O3 spray coating, thereby forming a fluorinated layer.

[0097] As the power increases, the F content increases to a maximum of 15 atomic percent. However, similar to the evaluation of temperature and repetition times, the YOF fluorination layer of the fluorinated object is not clearly confirmed. However, the color equivalent to the F component exists inside the coating mapped by energy dispersion spectroscopy analysis, and the color brightness is clearly distinguished on the surface as the power increases.

[0098] This is also because, with the increase of power, the decomposition of F-based corrosive gases is further accelerated, resulting in an increase in the density of dissociated F radicals, and thus the reactivity of the coating surface increases, resulting in an increase in the F content.

[0099] Next, the inventors of the present invention used the Y2O3 coating prepared by atmospheric plasma spraying, in which the temperature, number of repetitions and power factor were changed by energy dispersion spectroscopy analysis, as a benchmark, and screened out conditions with F content of 5 atomic percent, 9 atomic percent and 15 atomic percent. The YOF fluorination layer of the fluorinated object was analyzed by X-ray photoelectron spectroscopy and transmission electron microscopy to confirm the composition changes and thickness at different depths.

[0100] Fig.12 This is a table showing the X-ray photoelectron spectroscopy analysis of the fluoridation object related to the content of the F component in the fluoridation method of the fluoridation object of the present invention.

[0101] First, the change in F component at different depths from the surface to the inside of the coating is confirmed by X-ray photoelectron spectroscopy, and then the binding state of atoms is confirmed by analyzing the binding energy equivalent to the Y3d orbital function on the surface of the fluorinated object.

[0102] By analyzing the changes in the F content at different depths while sputtering in units of a few nm from the surface, it was confirmed that the Y and O components of the Y2O3 coating prepared by atmospheric plasma spraying before the fluorination processing method were uniformly distributed at 42 atomic percent and 58 atomic percent, respectively.

[0103] On the contrary, in the fluorinated object to which the fluorination processing method of the present invention is applied, F component is detected on all coating surfaces, showing maximum values ​​of 33 atomic percent, 44 atomic percent, and 36 atomic percent, respectively, and shows a trend of a sharp decrease until a depth of 100nm, but slowly decreases after a depth of 100nm, and contents of 5 atomic percent, 9 atomic percent, and 11 atomic percent are confirmed at a depth of about 500nm.

[0104] The reason for the difference in the content of the F component at different depths is that the concentration of F radicals plasma-dissociated on the surface is high, causing a rapid chemical reaction, and then the F radicals diffuse into the coating through micropores and cracks, so the concentration of F radicals is low, causing the chemical reaction rate to slow down.

[0105] As described above, the difference in the content of the F component based on this analysis method is judged to be because the analysis depth of the dispersion spectrum (EDS) is relatively deep, with a minimum range of 1μm, while the analysis depth of the x-ray photoelectron spectroscopy (XPS) is about 1nm, which is used to analyze the components of the local surface. In addition, the results of analyzing the Y3d orbital function of the Y2O3 coating prepared by the atmospheric plasma spraying method show that two peaks corresponding to the YO bond can be confirmed at the binding energies of 158.5eV and 156.7eV. The total binding energy of the Y3d orbital function constitutes a pair of two binding energies caused by Y3d5 and Y3d3, and the ratio of their size (intensity) is 3:2. The difference in binding energy is 2eV, which is consistent with the report.

[0106] In addition, the results of analyzing the atmospheric plasma Y2O3 spray coating that applied the fluorination processing method to form a YOF fluorination layer showed that 4 peaks were confirmed in all Y3d orbital functions. Based on the analysis of the Y, O, and F components confirmed by depth profiling and dispersion spectrum, it was confirmed that the two peaks other than the YO bond were YF bonds, which means that the Y2O3 spray coating reacted with the F component to form a YOF fluorination layer and moved to the YF bond with a higher binding energy than the YO bond.

[0107] Generally, electronegativity refers to a scale of the tendency of an atom to attract electrons to generate anions. It is known that the higher the electronegativity of an element, the greater its binding energy. Since the electronegativity of the F atom is 4, which is higher than the electronegativity of the O atom of 3.5, the binding energy of the YF bond is measured in a higher region compared to the binding energy of the YO bond. Therefore, it can be confirmed that when exposed to the F series corrosive gas plasma, the YO bond is partially decomposed and reacts with the F radical to form a new YF bond, thereby generating a YOF fluorinated layer.

[0108] Fig.13 This is a table showing transmission electron microscope images and component analysis of a fluoridation object related to the content of the F component in the fluoridation method of the fluoridation object of the present invention.

[0109] Then, as a result of analyzing the cross-sectional fine structure by transmission electron microscopy (TEM), a color corresponding to the F component was detected in the coating having a YOF fluoride layer slightly higher than 20 nm on the surface of all coatings, showing a difference in brightness with increasing F component content.

[0110] Fig.14 This is a bar graph showing the hardness analysis of the fluoridation object in relation to the content of the F component in the fluoridation method of the fluoridation object of the present invention.

[0111] The fluorinated object to which the fluorination processing method of the present invention is applied contains a YOF fluorination layer compared to the Y2O3 coating prepared by atmospheric plasma spraying before the fluorination processing method is applied. Therefore, in order to confirm the change in hardness with the change in the content of the F component, the Vickers hardness was measured.

[0112] Compared to the hardness value of 475 Hv of the Y2O3 coating prepared by atmospheric plasma spraying before the fluoridation process, all hardness values ​​measured for the fluorided object including the YOF fluoridation layer were within the standard deviation regardless of the content of the F component. As confirmed in the above results, the thickness of the YOF fluoridation layer is very thin, ranging from tens of nm to hundreds of nm, so it is judged that the hardness change based on the different F component content on the surface is very small.

[0113] Fig.15 This is a photograph showing the evaluation of the chemical resistance of a fluorinated object in a hydrogen chloride (HCl) solution in relation to the content of the F component in the fluorination method of the fluorinated object of the present invention.

[0114] In the semiconductor dry etching process, chemical etching occurs by generating highly chemically active free radicals to promote chemical reactions with the coating. The time the coating is corroded by hydrochloric acid is evaluated by directly exposing the coating surface to a 5% hydrochloric acid solution to evaluate the corrosion resistance of the coating. The standard is 3 hours.

[0115] In this evaluation, similarly, fluorinated objects to which the fluorination processing method is applied are prepared at different contents of the F component and evaluated.

[0116] The results of analyzing the changes in chemical resistance showed that in the fluorinated objects, under the conditions where the F content of the YOF fluorination layer was 5 atomic percent and 9 atomic percent, and together with the Y2O3 coating prepared by atmospheric plasma spraying before the fluorination processing method was applied, bubbles began to form after 5 hours of reaction with hydrochloric acid. On the contrary, under the condition where the F content was the highest at 15 atomic percent, bubbles formed after more than 6 hours of reaction with hydrochloric acid.

[0117] Therefore, the reaction time increases by more than 1 hour under the condition where the F component has the highest content, and it can be judged that the resistance to corrosive chemicals increases under the condition where the F component has a specific content or more.

[0118] The advantages of the component fluorination processing method of the present invention as described above and the components fluorinated thereby are that a new concept component fluorination technology is provided, that is, taking the plasma-resistant coating installed on the semiconductor dry etching equipment as the object, the components can be fluorinated by high-frequency plasma at normal temperature and atmospheric pressure and using specific process factors, so that high density and high strength can be achieved, it can be applied to large-area objects while relatively reducing costs, and productivity can be increased by increasing the speed of fluorination (process) carried out in the aging step.

[0119] Furthermore, the advantages of the present invention are that productivity can be improved by shortening the aging step of one of the debugging processes performed in semiconductor dry etching equipment, high density and high strength, can be applied to large-area objects while relatively reducing costs, and productivity can be increased by increasing the speed of fluorination (process) performed in the aging step.

Claims

1. A method for fluoriding a fluoridation object, which is used for fluoridating the surface of the fluoridation object, characterized in that: include: The first step is to place a fluorinated object in a processing chamber having a plasma reaction space; The second step is to introduce a working gas into the processing chamber. The working gas is a mixed gas selected from a discharge gas selected from He, Ne, Ar, Kr, and Xe, a non-fluorine reaction gas selected from O2, N2, and air, and a fluorine-containing reaction gas selected from a fluorine-containing fluorocarbon gas including CF4, C2F6, and C4F8, or a fluorine-containing reaction gas selected from nitrogen trifluoride (NF3) gas, that is, the mixed gas is introduced into the processing chamber; The third step is to introduce the mixed gas introduced into the processing chamber into the plasma reaction space; as well as In the fourth step, high frequency power is applied to the processing chamber to generate plasma in the plasma reaction space, and the surface of the fluorinated object is fluorinated by using the generated fluorine-containing radical gas and plasma. In the first to fourth steps, the atmosphere in the processing chamber is formed into an atmospheric pressure atmosphere. In the above-mentioned mixed gas introduction step, a mixed gas of argon gas as a discharge gas, oxygen as a non-fluorine reaction gas and carbon tetrafluoride as a fluorine-containing reaction gas is introduced as a gas, and the flow ratio of Ar, O2 and CF4 is Ar:O2:CF4 is 25~40:0.1~0.4:0.3~1.

0.

2. The fluorination processing method of a fluorinated object according to claim 1, characterized in that: In the above fluorination step, the frequency of the high-frequency power supply is 1 Hz to 100 MHz, and the high-frequency power is 300 W to 400 W.

3. The fluorination processing method of a fluorinated object according to claim 1, characterized in that: The temperature in the processing chamber is below 400° C. at room temperature.

4. The fluorination method of a fluorinated object according to claim 1, characterized in that: Repeat the third step and the fourth step.

5. The fluorination method of a fluorinated object according to claim 1, characterized in that: The distance between the fluoridation object and the plasma is not less than 2 mm and not more than 5 mm.

6. The method for fluoriding an object to be fluorided according to any one of claims 1 to 5, characterized in that: The fluorinated coating of the fluorinated object is formed to a thickness of 150 μm to 200 μm.

7. A component processed by the fluorination processing method for a fluoridation object according to any one of claims 1 to 5.

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