Sintered body, component for semiconductor manufacturing equipment, and method for manufacturing a sintered body

Abstract

The present invention provides a sintered body of yttrium-containing oxide, a component for semiconductor manufacturing equipment, and a method for manufacturing the sintered body, which generates submicron-sized particles but suppresses particle adhesion to the workpiece by ensuring that the detached and falling particles are of a size that does not float on the gas flow. [Solution] In a sintered body of yttrium-containing oxide, a processed surface is formed having a surface layer and a fractured layer located directly beneath the surface layer. The surface layer has a surface roughness below a specific value, and the fractured layer has specific cracks and a thickness within a specific range.

Description

[Technical Field]

[0001] The present invention relates to a sintered body, a component for semiconductor manufacturing equipment, and a method for manufacturing a sintered body. [Background technology]

[0002] Some semiconductor manufacturing equipment uses halogen-based corrosive gases or plasma containing these corrosive gases. In environments where halogen-based corrosive gases or plasma containing them are used, the components that make up the semiconductor manufacturing equipment are corroded by these corrosive gases or plasma, and fine particles are peeled off from the surface of the components.

[0003] The size and type of particles generated under the above conditions vary. For example, in semiconductor manufacturing equipment, the material constituting a component may peel off and detach from its surface. In thin-film deposition equipment, a reaction film formed by the reaction of a component constituting the reaction chamber with a corrosive gas may adhere to the component, grow, and then peel off.

[0004] Furthermore, when particles generated on the surface of the semiconductor wafer being processed adhere to it, it results in product defects and causes a decrease in yield.

[0005] For this reason, sintered bodies of yttrium-containing oxides (e.g., yttrium oxide (Y2O3)), which have excellent corrosion resistance to halogen-based corrosive gases and plasmas containing such corrosive gases, are used as components for semiconductor manufacturing equipment, particularly for components used in plasma environments (see Patent Document 1).

[0006] Patent Document 1 proposes a ceramic gas nozzle made of a Y2O3 sintered body, in which the inner surface of the nozzle through which halogen-based corrosive gas flows is left as-fired, and the outer surface of the nozzle exposed to halogen-based corrosive gas or plasma containing halogen-based corrosive gas is roughened (see Patent Document 1).

[0007] The ceramic gas nozzle described in Patent Document 1 has an inner surface through which the gas passes that is in the as-fired state, and therefore does not undergo grinding and does not have a fractured layer due to processing. As a result, it is possible to avoid the generation of particles from the nozzle material that peel off and detach from the nozzle surface with the flow of gas. Consequently, the initial inner diameter dimension of the nozzle can be maintained over a long period of time.

[0008] Furthermore, the ceramic gas nozzle described in Patent Document 1 has a roughened outer surface, resulting in high adhesion between the reaction film formed by the reaction of Y2O3 and corrosive gas that adheres to the outer surface of the nozzle and the nozzle substrate. Therefore, it is possible to prevent the reactive film attached to the outer surface of the nozzle from easily peeling off and to suppress the generation of particles.

[0009] Therefore, the ceramic gas nozzle made of a Y2O3 sintered body described in Patent Document 1 has a surface without a fractured layer due to processing and a roughened surface, thereby providing the effect of suppressing different types of particles. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] Japanese Patent Publication No. 2007-63595 [Overview of the Initiative] [Problems that the invention aims to solve]

[0011] Incidentally, the size of the generated particles varies greatly, and the mechanisms by which they are generated also differ. Furthermore, it was not yet possible to completely suppress the generation of particles of all sizes.

[0012] For example, if the generated particles are about 1 micron in size, they will move through the reaction chamber of the semiconductor manufacturing equipment on the gas flow, such as etching gas, and adhere to the surface of the semiconductor wafer being processed. Furthermore, if the generated particles are 5 microns or larger, a higher proportion will fall to the bottom of the reaction chamber rather than floating within it. Thus, various behavioral patterns for particles are conceivable, and conventional technology has made it difficult to provide components optimized for each individual pattern.

[0013] The present invention has been made in view of the above, and aims to provide a sintered body of yttrium-containing oxide, a component for semiconductor manufacturing equipment, and a method for manufacturing a sintered body, which generates submicron-sized particles but suppresses particle adhesion to the workpiece by ensuring that the particles that peel off and fall off are of a size that does not float on the gas flow. [Means for solving the problem]

[0014] The inventors diligently conducted research to achieve the above objectives. Focusing on the mechanism by which the reaction film generated during semiconductor manufacturing peels off and becomes particles, they discovered that the above problems can be solved by forming a processed surface in a sintered body of yttrium-containing oxide having a surface layer and a fractured layer located directly beneath the surface layer, with the surface layer having a surface roughness below a specific value, and the fractured layer having specific cracks and a thickness within a specific range. This led to the completion of the present invention.

[0015] In other words, the present invention includes the following embodiments.

[0016] The sintered body of the present invention is a sintered body of yttrium-containing oxide, comprising a processed surface having a surface layer and a fractured layer located directly beneath the surface layer, wherein the surface layer has a surface roughness Ra of 0.1 μm or less, the fractured layer has a thickness of 5 μm or more and 20 μm or less, and has cracks extending in the thickness direction of the sintered body, the length of which is 5 μm or more and 20 μm or less.

[0017] When such a sintered body is used as a member for a semiconductor manufacturing apparatus, it generates particles of submicron size, but can generate particles of a size that do not float on the gas flow. Specifically, after the formed reaction film has grown to a certain extent, particles of a size larger than 10 microns are generated.

[0018] The sintered body of the present invention has a processed surface having a surface layer with a small surface roughness and a crushed layer existing immediately below the surface layer, so that only submicron-order minute particles are generated from the surface layer, and from the crushed layer existing immediately below the surface layer, a reaction film generated by reaction with a corrosive gas is peeled off at a size larger than 10 microns.

[0019] The processed surface is preferably a surface exposed to a corrosive gas or a plasma containing the corrosive gas.

[0020] The processed surface may be the entire surface of the sintered body. However, when the sintered body of the present invention is used as a member for a semiconductor manufacturing apparatus, as long as at least the surface exposed to a corrosive gas or a plasma containing the corrosive gas is the processed surface, the effects of the present invention can be enjoyed.

[0021] Another aspect of the present invention is a member for a semiconductor manufacturing apparatus comprising the sintered body of the present invention described above.

[0022] The sintered body of the present invention can be applied to various uses, but by using it as a member for a semiconductor manufacturing apparatus, the effects of the present invention can be fully exhibited.

[0023] The member for a semiconductor manufacturing apparatus is preferably a member used in a part exposed to a corrosive gas or a plasma containing the corrosive gas in a reaction chamber of the semiconductor manufacturing apparatus.

[0024] The semiconductor manufacturing apparatus component of the present invention, which is made of a sintered body of the present invention, can be used as a component in a part exposed to corrosive gas or plasma containing said corrosive gas, thereby fully demonstrating the effects of the present invention.

[0025] The semiconductor manufacturing apparatus component is preferably located downstream of the position where the workpiece is placed in the flow of corrosive gas or plasma containing the corrosive gas in the reaction chamber of the semiconductor manufacturing apparatus.

[0026] When semiconductor manufacturing is carried out using the semiconductor manufacturing apparatus component of the present invention, the particles generated by the peeling of the reaction-generated film are of a size that prevents them from floating in the reaction chamber. Therefore, by using the semiconductor manufacturing apparatus component of the present invention as a component located downstream of the position where the workpiece is placed in the flow of corrosive gas or plasma containing corrosive gas in the reaction chamber of the semiconductor manufacturing apparatus, the detached particles can be made to fall to the bottom of the reaction chamber, thereby preventing contamination of the workpiece by the detached particles.

[0027] The semiconductor manufacturing apparatus component is preferably the lower inner wall of the reaction chamber or a plate on which the workpiece is placed in the semiconductor manufacturing apparatus.

[0028] For example, when constructing the reaction chamber of an etcher, if conventional sintered bodies are used for the gas nozzle and top plate, and the inner wall of the lower part of the reaction chamber and the plate on which the workpiece is placed are constructed using the semiconductor manufacturing equipment components of the present invention, it becomes possible to realize a semiconductor manufacturing equipment with a low overall particle adhesion amount.

[0029] Another aspect of the present invention is a method for manufacturing a sintered body of yttrium-containing oxide, comprising the steps of: preparing a sintered body mainly composed of yttrium; grinding a predetermined surface of the sintered body to form a fractured layer; and polishing the ground surface to form a surface layer.

[0030] By forming a crushed layer by grinding the surface, and then polishing the formed crushed layer to create a surface layer, the sintered body having both a crushed layer and a surface layer generates submicron-sized particles when used as a component for semiconductor manufacturing equipment, but also generates larger particles that do not float on the gas flow.

[0031] Preferably, the grinding step involves forming the fractured layer, which has a thickness of 5 μm or more and 20 μm or less, has cracks extending in the thickness direction of the sintered body, and the length of the cracks is 5 μm or more and 20 μm or less.

[0032] The polishing step is preferably used to form the surface layer having a surface roughness Ra of 0.1 μm or less. [Effects of the Invention]

[0033] When the yttrium-containing oxide sintered body of the present invention is used as a component for semiconductor manufacturing equipment, it generates submicron-sized particles, but does not generate particles that are large enough to float on the gas flow. After the reaction film has grown to a certain extent, it generates larger particles exceeding 10 microns in size.

[0034] As a result, when the sintered body of the present invention is used as a component for semiconductor manufacturing equipment, the generated particles can be prevented from floating in the reaction chamber, moving on gas flows such as etching gas, and adhering to the surface of the semiconductor wafer being processed. Consequently, the defect rate of semiconductor products can be reduced, and productivity can be improved.

[0035] Furthermore, when the sintered body of the present invention is used as a component for semiconductor manufacturing equipment, the reaction film formed by the reaction with corrosive gas is difficult to peel off until it grows to a certain size. Therefore, the lifespan of the generated reaction film before peeling can be extended.

[0036] Furthermore, by using the sintered body of the present invention as a component located downstream of the position where the workpiece is placed in the flow of corrosive gas or plasma containing corrosive gas in the reaction chamber of a semiconductor manufacturing apparatus, it is possible to further reduce the amount of detached particles adhering to the workpiece.

[0037] Furthermore, for example, when constructing the reaction chamber of an etcher, if conventional sintered bodies are used for the gas nozzles and top plate, and the sintered bodies of the present invention are applied as components for forming the lower walls and stage of the reaction chamber, it becomes possible to construct a semiconductor manufacturing apparatus with a low overall particle adhesion amount. [Brief explanation of the drawing]

[0038] [Figure 1] This is a schematic diagram showing a sintered body of the present invention according to one embodiment, viewed from an arbitrary cross-sectional direction. [Modes for carrying out the invention]

[0039] ≪Sintered body of yttrium-containing oxide≫ The sintered body of the yttrium-containing oxide of the present invention will be described below with reference to Figure 1. Figure 1 is a schematic diagram of the sintered body of the yttrium-containing oxide of the present invention as viewed from an arbitrary cross-sectional direction. That is, the sintered body 1 has a processed surface 2 having a surface layer 3 and a crushed layer 4 located directly beneath the surface layer 3. The sintered body 1 of the present invention has a surface roughness of the surface layer 3 that is below a specific value, a thickness 6 of the crushed layer 4 that is within a specific range, and the crushed layer 4 has cracks 5 in the thickness direction with a length within a specific range.

[0040] <Yttrium-containing oxides> The yttrium-containing oxide that serves as the material of the sintered body 1 of the present invention is not particularly limited as long as it is an oxide containing yttrium (Y) as a main component. Here, the main component means that yttrium is 70 wt% or more. As elements other than yttrium, rare earth metal elements such as tantalum, zirconium, and erbium may be included. Further, in addition to yttrium and other rare earth metal elements, aluminum may be included.

[0041] Examples of the yttrium-containing oxide include, for example, Y x Zr y O z , YZr x Al y O z , Y x Al y O z , or Y x Er y O z and the like. Further, the yttrium-containing oxide may be yttria (Y2O3) having a cubic structure of yttria stone. Furthermore, as the yttrium-containing oxide, for example, those containing fluorine such as Y5O4F7 and YOF may be used. The yttrium-containing oxide may have a single composition, or may contain a plurality of the above-described yttrium-containing oxides.

[0042] As the yttrium-containing oxide that serves as the material of the sintered body 1 of the present invention, when formed into a sintered body, it has excellent plasma resistance and can reduce contamination by particles and impurities. Therefore, it is preferably yttria (Y2O3).

[0043] <Sintered body 1> The sintered body 1 of the present invention is a sintered body of the above-described yttrium-containing oxide.

[0044] As described above, the sintered body 1 of the present invention is preferably a sintered body containing yttria (Y2O3) as a main component among yttrium-containing oxides. Further, it is desirable that the sintered body 1 of the present invention contains 95% by mass or more of yttria (Y2O3).

[0045] The yttrium-containing oxide sintered body 1 of the present invention may contain other components in addition to the yttrium-containing oxide. These other components are not limited to those mentioned above, but examples include unavoidable impurities and metal elements that function as sintering accelerators.

[0046] <Processed surface 3> The sintered body 1 of the present invention comprises a processed surface 2 having a surface layer 3 and a crushed layer 4 located directly beneath the surface layer 3. The entire surface of the sintered body 1 of the present invention may be the processed surface 2, or, when the sintered body 1 of the present invention is used as a component for semiconductor manufacturing equipment, at least the surface exposed to corrosive gas or plasma containing corrosive gas should be the processed surface 2.

[0047] The processed surface 2 in the sintered body 1 of the present invention is obtained by grinding and polishing a predetermined surface of the sintered body 1. Therefore, the material of the surface layer 3 and the crushed layer 4 constituting the processed surface 2 is the same as that obtained by sintering the yttrium-containing oxide described above.

[0048] [Surface layer 3] The surface layer 3 on the processed surface 2 of the sintered body 1 of the present invention is the outermost layer on the processed surface 2 of the sintered body 1. In other words, as shown in Figure 1, in the sintered body 1, the surface layer 3 is directly above the crushed layer 4 and corresponds to the outermost layer of the sintered body 1.

[0049] In the sintered body 1 of the present invention, the surface roughness Ra of the surface layer 2 is 0.1 μm or less. That is, in the sintered body 1 of the present invention, the surface layer 3 of the processed surface 2 is a so-called mirror surface.

[0050] When the sintered body 1 of the present invention is exposed to a corrosive gas or plasma containing a corrosive gas for processing semiconductors, a reaction film is formed on the surface of the surface layer 3. The grown reaction film then peels off from the peaks or valleys of the irregularities on the surface of the surface layer 3, and detaches as particles.

[0051] In this case, if the surface roughness Ra of the surface layer 3 is greater than 0.1 μm, the size of the particles generated by peeling will be relatively large due to the large irregularities, and it will become a dust source in the early stages after the semiconductor manufacturing equipment starts up.

[0052] However, in the sintered body 1 of the present invention, the surface roughness Ra of the surface layer 3 of the processed surface 2 is 0.1 μm or less, so the particles generated by the peeling of the formed reaction film are submicron in size and extremely small. It should be noted that submicron-sized particles are also generated in sintered bodies of the conventional technology, and the properties are not significantly impaired compared to the conventional technology.

[0053] In the sintered body 1 of the present invention, the surface roughness Ra of the surface layer 3 is preferably 0.08 μm or less, more preferably 0.05 μm or less, and particularly preferably 0.01 μm or less. It should be noted that the surface layer 3 of the present invention is formed by processing and polishing the surface of the sintered body, unlike a film formed later by methods such as PVD. Therefore, strictly defining the thickness as in a film is not necessarily appropriate, but if we were to mention it, the thickness of the surface layer 3 can be said to correspond to the maximum depth of the surface roughness Ra, and is preferably, for example, 0.01 μm or less.

[0054] [Fractured layer 4] The crushed layer 4 on the processed surface 2 of the sintered body 1 of the present invention is a layer located directly beneath the surface layer 3 described above. The crushed layer 4 in the sintered body 1 of the present invention is produced by grinding a predetermined surface of the sintered body 1.

[0055] (Crack 5) The fractured layer 4 in the sintered body 1 of the present invention has cracks 5 that are formed when the sintered body 1 is fractured by grinding.

[0056] The cracks 5 in the fractured layer 4 of the sintered body 1 of the present invention extend in the thickness direction of the sintered body 1. Here, the cracks 5 extending in the thickness direction of the sintered body are crack-like structures with an angle ranging from 5° to 90° (perpendicular) with respect to the surface layer 3 of the sintered body 1. This angle is within the range that can be visually observed in the fractured layer 3 described later, and the lower limit is not required to be strictly 5°, but since such shallow cracks are peeled off or removed along with the crack during the grinding process, the angle is defined as 5° or more, taking into consideration that the sintered body 1 is a brittle material.

[0057] The length of the cracks 5 in the fractured layer 4 of the sintered body 1 of the present invention is 5 μm or more and 20 μm or less. The length of these cracks 5 can be obtained using various microscopes as follows: Specifically, an image of the cross-section obtained by polishing an arbitrary cross-section of the sintered body 1 is acquired. Then, a reference line parallel to the surface layer 3 is drawn on the acquired cross-sectional image, and a region of 1 mm in length is selected on that reference line. The length of the cracks (from the surface layer 3 to the tip of the crack) that exist in the thickness direction of the sintered body 1 from the surface layer 3 within that region is obtained by calculation or actual measurement. If multiple cracks exist, the longest one is selected.

[0058] If the length of crack 5 is too short, the size of the detached particles will be too small, making it difficult to obtain the effect of the present invention, which suppresses the particles from floating and adhering to the workpiece. On the other hand, if the length of crack 5 is too long, large detached particles are likely to be generated, and there is a concern that they will easily detach before being exposed to etching gas or the like. Taking these factors into consideration, the length of the crack is 5 μm or more and 20 μm or less, and more preferably 8 μm or more and 15 μm or less.

[0059] The sintered body 1 of the present invention is provided with a fractured layer 4 having cracks 5 of the above-described length extending in the thickness direction of the sintered body 1, thereby mitigating the compressive stress caused by the growth (volume expansion) of the reaction film formed by the reaction of yttrium-containing oxide and corrosive gas. As a result, the sintered body 1 of the present invention can extend the time until peeling occurs in the reaction film formed by the reaction with corrosive gas, thereby extending the life of the sintered body 1 (the period until the amount of particles generated becomes excessive and it can no longer be used as a component).

[0060] Here, the reaction film formed and adhering to the sintered body 1 of the present invention is stress-relieved by the cracks 5 in the fractured layer 4. As a result, it grows on the surface of the sintered body 1 to a certain volume, approximately proportional to the length of the cracks 5, especially the length of the cracks 5 extending in the thickness direction of the sintered body 1, and is maintained in an adhering state to the sintered body 1.

[0061] Therefore, the particles that peel off from the sintered body 1 of the present invention are coarse particles on the order of 10 microns in size, and because the generated particles are heavy, they do not float around in the reaction chamber. As a result, the component for semiconductor manufacturing equipment made of the sintered body 1 of the present invention can suppress the generation of particles from moving on the gas flow, such as etching gas, and adhering to the surface of the semiconductor wafer, which is the workpiece.

[0062] (Thickness of crushed layer 4) The thickness 6 of the fractured layer 4 in the sintered body 1 of the present invention is defined by the depth at which the tip of a crack 5 extending in the thickness direction of the sintered body 1 is located. Specifically, the cross-section of the sintered body 1 of the present invention is observed using the same method as the method for determining the length of the crack 5 described above, and within the measurement area, the crack 5 extending from the surface layer 3 in the thickness direction of the sintered body 1 whose tip is furthest from the surface layer 3 (the longest distance perpendicular to the surface layer 3) is selected, and the distance from the surface layer 3 to the depth at which the tip is located is defined as the thickness of the fractured layer 4.

[0063] Therefore, the length of crack 5 and the thickness of the fractured layer 4 are not necessarily proportional, and the longest crack 5 does not determine the thickness of the fractured layer 4.

[0064] In the sintered body 1 of the present invention, the thickness 6 of the crushed layer 4 is 5 μm or more and 20 μm or less.

[0065] If the thickness 6 of the crushed layer 4 is less than 5 μm, the particles generated when the reaction film is peeled off are small and float in the reaction chamber, making it difficult to obtain the effects of the present invention. On the other hand, if the thickness 6 of the crushed layer 4 exceeds 20 μm, the size of the cracks 5 is too large, causing the reaction film to break into small pieces before it can peel off and detach, resulting in particles that float in the reaction chamber, which is undesirable. More preferably, the thickness 6 of the crushed layer 4 is 8 μm or more and 15 μm or less, similar to the cracks 5.

[0066] Furthermore, the size of the reaction film that peels off from the sintered body 1 can be controlled by adjusting the thickness 6 of the crushed layer 4 in the sintered body 1 of the present invention. The thickness 6 of the crushed layer 4 can be controlled by appropriately adjusting the grit size of the grinding wheel, the grinding time, etc.

[0067] <Applications of Sintered Body 1> The applications of the sintered body 1 of the present invention are not particularly limited, but it may be used as a component for semiconductor manufacturing equipment. Since the sintered body 1 of the present invention is a yttrium-containing oxide, it has plasma resistance.

[0068] Therefore, when using the sintered body 1 of the present invention as a component for semiconductor manufacturing equipment, it is preferable to use it as a component in a part of the reaction chamber of the semiconductor manufacturing equipment that is exposed to corrosive gas or plasma containing corrosive gas.

[0069] Furthermore, when using the sintered body 1 of the present invention as a component for semiconductor manufacturing equipment, it is preferable to arrange the processed surface of the sintered body so that it is exposed to corrosive gas or plasma containing corrosive gas.

[0070] Examples of semiconductor manufacturing equipment components exposed to corrosive gases or plasma containing corrosive gases include chambers, bell jars, susceptors, clamp rings, focus rings, shadow rings, insulating rings, dummy wafers, tubes for generating plasma, domes for generating plasma, high-frequency transmission windows, infrared transmission windows, monitoring windows, lift pins for supporting workpieces such as semiconductor wafers, shower plates, baffle plates, bellows covers, upper electrodes, lower electrodes, and the like.

[0071] Furthermore, when the sintered body 1 of the present invention is used as a component for semiconductor manufacturing equipment, it is preferable that the component be located downstream of the position where the workpiece is placed in the flow of corrosive gas or plasma containing corrosive gas in the reaction chamber of the semiconductor manufacturing equipment.

[0072] By positioning the component downstream of the location where the object to be processed is placed, the effects of the present invention can be achieved at a higher level. In other words, since the particles generated when the reaction-generated film peels off are of a size that does not float within the reaction chamber, the detached particles fall and accumulate at the bottom of the reaction chamber, reducing the likelihood of contamination of the object to be processed.

[0073] Among the components for semiconductor manufacturing equipment, examples of components located downstream of the position where the workpiece is placed in a flow of corrosive gas or plasma containing corrosive gas include the lower inner wall of the reaction chamber or the plate on which the workpiece is placed.

[0074] (Corrosive gas or plasma containing corrosive gas) When the sintered body 1 of the present invention is used as a component for semiconductor manufacturing equipment, the corrosive gas or plasma containing the corrosive gas used in the semiconductor manufacturing equipment is not particularly limited and may be any known gas or plasma. Examples include halogen-based gases such as fluorine-based or chlorine-based gases.

[0075] Method for manufacturing sintered body 1 The method for manufacturing the sintered body 1 of the present invention is not particularly limited. For example, the sintered body can be manufactured by a method that includes the steps of preparing a sintered body mainly composed of yttrium, grinding a predetermined surface of the sintered body, and polishing the ground surface.

[0076] In the manufacturing method of the sintered body 1 of the present invention, both grinding and polishing are performed. Here, grinding means obtaining a surface with a roughness of approximately 10 μm, and polishing is performed on the polished surface to obtain a surface with an even finer roughness (approximately 1 μm or less).

[0077] <Steps for preparing a sintered body 1 mainly composed of yttrium> In the process of preparing a sintered body 1 mainly composed of yttrium, the above-mentioned yttrium-based material is prepared, and the sintered body 1 is produced by sintering the said material.

[0078] The method for producing the sintered body 1 from a material mainly composed of yttrium is not particularly limited, and known methods can be applied.

[0079] For example, first, the yttria powder to be used as the raw material is weighed, put into a ball mill or the like for grinding, and then undergoes a granulation process to obtain granulated powder. This granulated powder is dried by various known methods (such as spray drying). Then, the dried powder is sieved by methods such as passing it through a sieve, and subsequently, a slurry is prepared by adding ion-exchanged water, a dispersant, etc.

[0080] Next, the obtained slurry is used to create a molded body. Then, by firing this molded body, a sintered body 1 can be obtained.

[0081] In addition, commercially available sintered bodies can be used as is in this invention.

[0082] <Grinding process for grinding a predetermined surface of the sintered body 1> In the grinding step for grinding a predetermined surface of the sintered body, grinding is performed on the predetermined surface of the sintered body 1 prepared in the above step to form a crushed layer 4.

[0083] The fractured layer 4 formed by the grinding process has cracks 5 extending in the thickness direction of the sintered body 1, with the length of the cracks 5 being 5 μm or more and 20 μm or less, and the thickness 6 being 5 μm or more and 20 μm or less.

[0084] The definition of cracks 5 extending in the thickness direction, the definition of the thickness of the fractured layer 4, the preferred length of cracks 5, and the preferred thickness 6 of the fractured layer 4 are as described above.

[0085] Grinding can be performed using known methods. By appropriately setting conditions such as the grit size of the grinding wheel and the grinding time depending on the type of sintered body prepared, a fractured layer 4 with the desired physical properties can be produced.

[0086] <Polishing process to polish the ground surface> In the polishing process for polishing the ground surface, the surface of the crushed layer 4 produced in the above process is polished to form the surface layer 3. That is, a surface layer 3 with a surface roughness Ra of 0.1 μm or less is produced by a known polishing method.

[0087] The surface layer 3 formed by the polishing process has a surface roughness Ra of 0.1 μm or less. The preferred surface roughness Ra is the same as described above for the sintered body 1 of the present invention.

[0088] As mentioned above, known polishing methods applicable to the processing of sintered bodies can be used as appropriate. By appropriately setting conditions such as the grit size of the polishing wheel and the polishing time, a surface layer 3 with the desired physical properties can be produced. [Examples]

[0089] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0090] <Fabrication of sintered bodies> A slurry was formed by adding ion-exchanged water and a binder to a 99.9% pure Y2O3 raw material, and then granulated using a spray dryer to obtain granulated powder. The obtained granulated powder was subjected to a 1500 kgf / cm³ treatment. 2 The material was molded under pressure to form a 50 x 50 x 5 mm plate, which served as the base material. The base material was pre-fired at 900°C for 3 hours to remove the binder, and then fired at 1800°C in a hydrogen atmosphere for 10 hours to obtain a sintered body.

[0091] <Example 1> One surface of the obtained sintered body was ground with an #800 grit grinding wheel. Subsequently, polishing was performed using 3 μm and 1 μm diamond slurries to achieve a mirror surface with an Ra of 0.008 μm. Here, the length of crack 5 was 8 μm, and the thickness 6 of the fractured layer 4 was 8 μm.

[0092] <Comparative Example 1> The sintered body obtained was used as Comparative Example 1, without any surface processing being applied to its surface, leaving it in its as-fired state.

[0093] <Comparative Example 2> A sintered body obtained by grinding one surface of the resulting sintered body with an 800 grit grinding wheel was used as Comparative Example 2.

[0094] <Comparative Example 3> One surface of the obtained sintered body was ground with an #800 grit grinding wheel, and then a 10 μm thick yttria (Y2O3) film was deposited by thermal spraying. This was used as Comparative Example 3.

[0095] <Rating> Each sample from Example 1 and Comparative Examples 1-3 was subjected to etching for 10 hours in a reaction apparatus using a CF-based etching gas. The size and number of reaction products (Y2O3, YF3, etc.) scattered around each sample were counted before and after the etching process.

[0096] As a result, in Example 1, in addition to particles smaller than 1 μm, a large number (over 1000) of particles larger than 10 μm were observed. On the other hand, in Comparative Example 1, particles smaller than 1 μm and medium-sized particles (several microns) were observed. In Comparative Example 2, in addition to particles smaller than 1 μm and medium-sized particles (several microns), it was observed that there were more particles around 30 μm in size than in Example 1. In Comparative Example 3, only particles smaller than 1 μm were observed.

[0097] [Consideration] The experimental results showed that in Example 1, most of the generated reaction products were detached in clumps of 10 μm or larger, confirming that the effects of the present invention as described above were obtained.

[0098] On the other hand, in the sintered body sample of Comparative Example 1, which was left as is (unprocessed), when exposed to corrosive gas, a reaction film was formed. Initially, only minute-sized reaction film peeling occurred, but after a certain amount of time, medium-sized (5 microns) peeling occurred. Since medium-sized (several microns) particles float in the reaction chamber, they adhered more to the workpiece itself compared to Example 1.

[0099] Furthermore, in the sample of Comparative Example 2, which was subjected to grinding only, a large number of particles (over 1000) with a size of 10 μm were observed, in addition to particles with a size of less than 1 μm, similar to Example 1. However, because the sample of Comparative Example 2 was processed by grinding only, the cracks in the fractured layer were large, with a crack length of approximately 30 μm. As a result, a large number of particles with a size of about 30 μm were generated when the detached material was removed, and these clumps subsequently broke down into even smaller particles, generating a large number of even smaller particles. Therefore, the sample of Comparative Example 2 had a large number of particles of all sizes compared to the sample of Example 1, and can hardly be considered a desirable embodiment.

[0100] In Comparative Example 3, a protective film formed by thermal spraying was created on the fractured layer. Due to the presence of the protective film, the entry of corrosive gases into the cracks of the fractured layer was suppressed, resulting in the generation of no particles larger than 10 μm, and only particles smaller than 1 μm. However, the present invention (Example 1) is relatively superior in that it incurs the cost of forming the protective film and carries the risk of the protective film itself peeling off. [Industrial applicability]

[0101] The yttrium-containing oxide sintered body of the present invention, when used as a component for semiconductor manufacturing equipment, generates submicron-sized particles, but does not generate particles that are large enough to float on the gas flow; instead, it generates particles of a certain size. Therefore, it is possible to suppress the movement of the generated particles on the gas flow, such as etching gas, and their adhesion to the surface of the semiconductor wafer being processed. As a result, the defect rate of semiconductor products can be reduced, and productivity can be improved.

[0102] Furthermore, when the sintered body of the present invention is used as a component for semiconductor manufacturing equipment, the reaction film formed by the reaction with corrosive gas is difficult to peel off until it grows to a certain size. Therefore, the lifespan of the generated reaction film before peeling occurs can be extended.

[0103] Furthermore, by using the sintered body of the present invention as a component located downstream of the position where the workpiece is placed in the flow of corrosive gas or plasma containing corrosive gas in the reaction chamber of a semiconductor manufacturing apparatus, it is possible to further reduce the amount of detached reaction products adhering to the workpiece.

[0104] Furthermore, for example, when constructing the reaction chamber of an etcher, if conventional sintered bodies are used for the gas nozzle and top plate, and semiconductor manufacturing equipment components made of the sintered body of the present invention are used for the inner wall of the lower part of the reaction chamber and the plate on which the workpiece is placed, it becomes possible to realize a semiconductor manufacturing equipment with a low overall particle adhesion amount, which can contribute to the productivity of semiconductor wafers. [Explanation of Symbols]

[0105] 1. Sintered body 2 Processed surface 3 Surface layer 4. Fractured layer 5 Cracks 6. Thickness of the crushed layer

Claims

1. A sintered body of yttrium-containing oxide, The processed surface comprises a surface layer and a crushed layer located directly beneath the surface layer, The aforementioned surface layer has a surface roughness Ra of 0.1 μm or less. The fractured layer has a thickness of 5 μm or more and 20 μm or less. The sintered body has a crack that extends in the thickness direction, The length of the crack is between 5 μm and 20 μm. Sintered body.

2. The aforementioned yttrium-containing oxide is Y ２ O ３ The sintered body according to claim 1.

3. The sintered body according to claim 1, wherein the processed surface is a surface exposed to a corrosive gas or a plasma containing the corrosive gas.

4. A component for semiconductor manufacturing equipment, comprising a sintered body according to any one of claims 1 to 3.

5. The semiconductor manufacturing apparatus component according to claim 4, wherein the semiconductor manufacturing apparatus component is a component used in a part of the reaction chamber of the semiconductor manufacturing apparatus that is exposed to a corrosive gas or a plasma containing the corrosive gas.

6. The semiconductor manufacturing apparatus component according to claim 4, wherein the semiconductor manufacturing apparatus component is located downstream of the position where the workpiece is placed in the flow of corrosive gas or plasma containing the corrosive gas in the reaction chamber of the semiconductor manufacturing apparatus.

7. The semiconductor manufacturing apparatus component according to claim 4, wherein the semiconductor manufacturing apparatus component is the lower inner wall of a reaction chamber or a plate on which a workpiece is placed in a semiconductor manufacturing apparatus.

8. A method for producing a sintered body containing yttrium oxide, A process for preparing a sintered body mainly composed of yttrium, A grinding step of grinding a predetermined surface of the sintered body to form a fractured layer, A method for manufacturing a sintered body, comprising a polishing step of polishing the ground surface to form a surface layer.

9. The aforementioned grinding process is The thickness is 5 μm or more and 20 μm or less. The sintered body has a crack extending in the thickness direction, The length of the crack is 5 μm or more and 20 μm or less. A method for manufacturing a sintered body according to claim 8, which forms the aforementioned crushed layer.

10. The method for manufacturing a sintered body according to claim 8 or 9, wherein the polishing step is to form the surface layer having a surface roughness Ra of 0.1 μm or less.

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