JP2022115831A - Member for semiconductor manufacturing device - Google Patents

Abstract

To provide a member for a semiconductor manufacturing device that is sufficiently blackened, prevents cracks and color irregularities, and reduces the likelihood of peeling of a surface.SOLUTION: A member for a semiconductor manufacturing device according to the present disclosure is a base material having a black area on its surface. The black area has, as a main component, rare earth oxide in which the composition of oxygen is smaller than a stoichiometric composition. A correlation coefficient of a curve obtained by applying log approximation to the relationship between a wavelength of every 10 nm interval in a wavelength region of 360 nm-740 nm and the reflectance R(λ) of the black area (wherein, λ is the wavelength (nm) in the wavelength region) is 0.94 or more.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to members for semiconductor manufacturing equipment.

It is known that when white yttria is exposed to electron beam (EB) irradiation or laser irradiation to cause oxygen deficiency (Y ₂ O _3-x ), the surface turns black (eg, Patent Document 1). Since yttria has excellent resistance to plasma and corrosive gases, yttria members having black regions can be used for position detection and identification of semiconductor wafers, and for reducing reflectance in semiconductor manufacturing equipment and the like.

JP 2005-256098 A

If EB irradiation or laser irradiation is insufficient for rare earth oxides such as yttria, blackening will be insufficient. On the other hand, excessive irradiation reduces the crystallinity, making cracks more likely to occur and the blackened surface to peel off more easily. Furthermore, color unevenness occurs on the surface depending on the irradiation conditions of EB irradiation and laser irradiation.

An object of the present disclosure is to provide a member for a semiconductor manufacturing apparatus that is sufficiently blackened, has suppressed cracks and color unevenness, and has a surface that is resistant to peeling.

A member for a semiconductor manufacturing apparatus according to the present disclosure is a base material having a black region on the surface, and the black region is mainly composed of a rare earth oxide having an oxygen composition smaller than the stoichiometric composition, and has a wavelength range of 360 nm to 740 nm. The correlation coefficient of the curve obtained by logarithmically approximating the relationship between the wavelength at intervals of 10 nm and the reflectance R (λ) of the black region (where λ is the wavelength (nm) in the wavelength range) is 0 .94 or higher.

As described above, the member for a semiconductor manufacturing apparatus according to the present disclosure is a base material having a black region on its surface, and the black region is mainly composed of a rare earth oxide having an oxygen composition smaller than the stoichiometric composition, Correlation of a curve obtained by logarithmically approximating the relationship between the wavelength in the wavelength range of 360 nm to 740 nm at intervals of 10 nm and the reflectance R (λ) of the black region (where λ is the wavelength (nm) in the wavelength range) The correlation coefficient is 0.94 or more. Therefore, the member for a semiconductor manufacturing apparatus according to the present disclosure has a black surface in which color unevenness is suppressed, cracks are also suppressed, and the surface is difficult to peel off.

1 is a photograph showing a state after irradiating a substrate containing yttria as a main component with an electron beam. FIG. 2 is a graph showing measurement results of reflectance for visible light with a wavelength of 360 nm or more and 740 nm or less in the substrate shown in FIG. 1. FIG.

A member for a semiconductor manufacturing apparatus according to an embodiment of the present disclosure is a base material having a black region on its surface. This base material is, for example, yttria (yttrium oxide (Y ₂ O ₃ )), erbia (erbium oxide (Er ₂ O ₃ ), ceria (cerium oxide (CeO ₂ ), composite oxide containing yttrium (yttrium-aluminum- Garnet (Y ₃ Al ₅ O ₁₂ ), yttrium aluminum monoclinic (Y ₄ Al ₂ O ₉ ), yttrium aluminum perovskite (YAlO ₃ ), etc.), composite oxides containing erbium (erbium aluminum garnet (Er ₃ Al ₅ O ₁₂ ), erbium aluminum monoclinic _{( Er4Al2O9} ), erbium aluminum perovskite ( _ErAlO3 ) _, etc.), composite oxides containing cerium (cerium aluminum garnet _{( Ce3Al5O12} ), cerium aluminum _monoclinic (Ce ₄ Al ₂ O ₉ ), cerium aluminum perovskite (CeAlO ₃ ) and other rare earth oxides as main components or single crystals.The main component of ceramics is a total of 100% by mass of the components constituting the ceramics. The main component of the single crystal means the component of 80% by mass or more in the total 100% by mass of the components constituting the single crystal. It is preferable that the total amount of the components constituting the is 90% by mass or more, and that the main component is 99.9% by mass or more.

Ceramics and single crystals forming the substrate may contain, for example, silicon, iron and AE (AE is an element of Group 2 of the periodic table) in addition to rare earth oxides. From the viewpoint of further improving the resistance to plasma and corrosive gases, silicon contained in the ceramics and single crystals constituting the base material is ₃₀₀ mass ppm or less in terms of _SiO2 , and iron is 50 mass ppm in terms of _Fe2O3 . ppm or less, and AE may be 350 mass ppm or less in terms of AEO. Components constituting ceramics and single crystals can be identified by an X-ray diffraction apparatus using CuKα rays. The content of each component can be determined by, for example, an ICP (Inductively Coupled Plasma) emission spectrometer or a fluorescent X-ray spectrometer.

The black region has oxygen deficiency and is a region mainly composed of a rare earth oxide having an oxygen composition smaller than the stoichiometric composition. The rare earth oxides forming the black regions have, for example, composition formulas of Y ₂ O _3-x , Er ₂ O _3-x , CeO _2-x , Y ₃ Al ₅ O _12-x , Y ₄ Al ₂ O _{9- x} , YAlO3 _{- x} , _{Er3Al5O12 - x} , _{Er4Al2O9 -} x, ErAlO3 _- x, _{Ce3Al5O12 - x} , _{Ce4Al2O9 - x} , _{CeAlO3 −x} , where x ranges from 0<x≦1.5. The presence or absence of oxygen deficiency can be confirmed by electron energy-loss spectroscopy (EELS), and the value of x can be determined by X-ray photoelectron spectroscopy.

In the member for a semiconductor manufacturing apparatus according to one embodiment, the black region includes wavelengths at intervals of 10 nm in the wavelength range of 360 nm to 740 nm, and reflectance R (λ) of the black region (where λ is the wavelength in the previous wavelength range ( nm)) is 0.94 or more.

A wavelength range of 360 nm to 740 nm is the visible light range. This reflectance R (λ) is measured using, for example, a spectrophotometer (CM-2600d manufactured by Konica Minolta Co., Ltd. or its successor model), and the measurement conditions are CIE standard light source D65 and a viewing angle of 2°. is obtained by setting When calculating the correlation coefficient, the number of samples of wavelengths, which are independent variables, is 39, and the degree of freedom is 38. A natural logarithm is used to logarithmically approximate the relationship between the reflectance R(λ) and the wavelength at intervals of 10 nm in the wavelength range of 360 nm to 740 nm.

If the correlation coefficient of the curve obtained by logarithmic approximation is 0.94 or more, it is significant when tested at the significance level of 0.1%, and the positive correlation is extremely high, and the reflectance R (λ ) increases almost upward to the right as the wavelength increases, and the increase slows down near the wavelength of 740 nm. Due to such characteristics, the black region of the member for a semiconductor manufacturing apparatus according to one embodiment presents a black color with suppressed color unevenness. As a result, cracks are suppressed in the member for the semiconductor manufacturing apparatus, and the surface is less likely to peel off. In particular, the correlation coefficient is preferably 0.976 or more.

In the case of logarithmic approximation with natural logarithms, the slope of the regression equation is preferably 9 or less, for example. If the slope is 9 or less, even if the wavelength increases, the increase in the reflectance R(λ) becomes more moderate, so that color unevenness can be suppressed.

The black region satisfies the relationship R(740)>R(550)>R(360), and R(λ+10)−R(λ) is −0.1% or more. In this case, the difference between the reflectance R (370) at a wavelength of 370 nm and the reflectance R (360) at a wavelength of 360 nm (R (370) - R (360)) is -0.1% or more, and the reflectance R at a wavelength of 380 nm (380) and the reflectance R (370) at a wavelength of 370 nm (R (380) - R (370)) is -0.1% or more, so that the reflectance R (λ) measured at intervals of 10 nm , the 10 nm longer reflectance R(λ) is not less than 0.1% compared to the 10 nm shorter reflectance R(λ).

For example, when the relationship R(740)>R(550)>R(360) is satisfied and R(λ+10)−R(λ) is 0% or more, the reflectance R(λ) “always” rises to the right. becomes. When R(λ+10)−R(λ) is −0.1% or more, the reflectance R(λ) “almost” rises to the right. If the reflectance R(λ) "almost" rises to the right, color unevenness is less likely to occur, making it easier to detect and identify objects to be detected such as semiconductor wafers. In particular, visual detection and identification (visual recognition) are facilitated.

R(360) is, for example, 15% or less, preferably 12% or less. R(550) is, for example, 18% or less, preferably 15% or less. R(740) is, for example, 22% or less, preferably 18% or less.

R(λ+10)−R(λ) is not limited as long as it is −0.1% or more, but R(λ+10)−R(λ) is preferably −0.05% or more. Furthermore, it is preferable that the reflectance R(λ) gradually increases from the wavelength of 360 nm to the wavelength of 740 nm.

Color unevenness is less likely to occur when the reflectance R(λ) increases gradually, that is, when it increases relatively monotonously, rather than when it increases upward to the right. R(λ+10)-R(λ) may be 0.33% or less. Color unevenness can be represented by the color difference (ΔE*ab) shown by the following formula (A).
ΔE*ab=((ΔL*) ² +(Δa*) ² +(Δb*) ² )) ^1/2 (A)
(ΔL*: the difference in the lightness index L* of the comparison measurement point with respect to the reference measurement point,
Δa*: the difference in the chromaticness index a* of the comparative measurement point with respect to the reference measurement point;
Δb*: Difference in chromaticness index b* of comparative measurement point from reference measurement point)

In the present embodiment, the state of no color unevenness means a state in which the color difference ΔE*ab is 7 or less, and when this value is exceeded, the color unevenness is easily recognized by human eyes. The color difference (ΔE*ab) in the black region is preferably 3 or less. When the color difference (ΔE*ab) in the black region is within this range, the color unevenness is reduced, so the commercial value is improved. In particular, the color difference (ΔE*ab) in the black region is preferably 1.7 or less.

For example, when a chamber mark for indicating a reference position of the chamber is provided on the inner bottom surface of a chamber used in a plasma processing apparatus, a plurality of semiconductor wafers W can be placed and rotated with reference to the chamber mark. The position of each semiconductor wafer W placed on the table can be detected. Specifically, a susceptor mark for detecting the position of the semiconductor wafer W is provided in the vicinity of a recess provided on the surface of the table 2 so as to surround the semiconductor wafer W, and the chamber mark is the absolute reference. , the position of the semiconductor wafer W can be detected by detecting the relative position of the susceptor mark with respect to the chamber mark. The member for a semiconductor manufacturing apparatus may be used as such a susceptor mark.

Generally, when the irradiation amount of electron beams or laser beams is increased, the brightness of the black region is decreased, while the stress caused by the irradiation is increased, making peeling more likely to occur. The human eye and various light-receiving sensors have wavelength dependence in light-receiving sensitivity. If there is an amplitude in the visible light region that indicates peaks and troughs of the reflectance R(λ) that deviates from the “almost rising to the right” (wavelength region in which the reflectance has a large wavelength dependence), a slight variation in irradiation conditions will cause , colors (brightness and saturation) change easily. As a result, the color unevenness is easily recognized by the human eye.

The amplitude of such reflectance R(λ) varies with the bandgap level and density of oxygen vacancies and other crystal defects formed in the black region. The level of oxygen vacancies changes, for example, depending on the charge state of the oxygen vacancies. The level of oxygen vacancies changes depending on the irradiation conditions during the formation of the black region and the conditions of subsequent processing (for example, heat treatment). For example, a black region formed by electron beam irradiation is further heat-treated to change the level of oxygen vacancies in the black region, or to adjust the distribution and density of crystal defects to improve color unevenness. You may

A method for manufacturing a member for a semiconductor manufacturing apparatus according to one embodiment is not limited, and the member is manufactured by, for example, the following method.

First, a substrate containing a rare earth oxide as a main component is prepared. Such substrates are manufactured by known methods. The shape and size of the substrate are not limited, and are appropriately set according to the shape and size of the finally obtained member for semiconductor manufacturing equipment. The semiconductor manufacturing apparatus member may be plate-shaped, for example, having a circular shape, an elliptical shape, or a polygonal shape (triangular, quadrangular, pentagonal, hexagonal, etc.) when viewed from above. The shape of the member for a semiconductor manufacturing apparatus may be a bulk shape, or may be formed as a film on another member.

Then, the surface of the substrate is irradiated with an electron beam or a laser beam under a reduced pressure atmosphere or a reducing atmosphere. When using a laser beam, the portion to be blackened may be pinpointed, or the area to be blackened may be scanned with the laser beam. On the other hand, when an electron beam is used, the area to be blackened is covered with a mask having openings, and the electron beam is irradiated. Since the electron beam is irradiated on the plane, a desired region can be partially blackened by using a mask.

Masks used for electron beam irradiation include masks made of oxide. The oxide forming the mask is not limited, and examples thereof include insulating oxide ceramics such as alumina. The thickness of the mask is not limited, and is, for example, 1 mm or more and 5 mm or less.

The black region of the member for a semiconductor manufacturing apparatus according to one embodiment thus obtained may have an arithmetic mean roughness Ra of 0.2 μm or more and 0.5 μm or less, or 1 μm or more and 3 μm or less. may have a maximum height Ry of Generally, the reflectance tends to decrease as the surface roughness increases, but particles are more likely to occur and adhere. When electron beams or laser beams are irradiated, a dense surface with fewer pores than before irradiation is formed due to grain growth due to promotion of sintering and re-solidification after once melting. As a result, even with such a relatively large surface roughness, the reflectance is low, and particles are less likely to be generated and attached.

As a result, such a member for a semiconductor manufacturing apparatus can be suitably used in applications that require plasma resistance that dislikes particles. Arithmetic mean roughness Ra and maximum height Ry can be measured with a contact or non-contact surface roughness measuring device in accordance with JIS B 0601 (1994).

For example, using a surface roughness/contour measuring machine (SEF680) manufactured by Kosaka Laboratory Co., Ltd., the measurement conditions are, for example, the radius of the stylus is 5 μm, the material of the stylus is diamond, and the measurement length is 2. 0.5 mm or more, the cut-off value is set to 0.8 mm, and the scanning speed of the stylus is set to 0.5 mm/sec. Then, the arithmetic average roughness Ra and the maximum height Ry are measured at least five points on the surface to be measured, and the average value thereof is obtained. This average value is the object of each of the above ranges of the arithmetic mean roughness Ra and the maximum height Ry.

The average grain size of the crystals forming the black region is preferably larger than the average grain size of the crystals forming the substrate. If the average grain size of the crystal is large, the area occupied by the grain boundary phase per unit area is small, so when exposed to plasma, grain shedding from the grain boundary phase is suppressed. On the other hand, since the base material contains a large number of crystals having a relatively small grain size, mechanical properties such as mechanical strength and rigidity are maintained.

The average grain size of the crystals forming the base material is measured for the base material excluding the black region. For example, the average grain size of crystals forming the black region is 15 μm or more and 30 μm or less, and the average grain size of crystals forming the substrate is 2 μm or more and 4 μm or less. In particular, the average grain size of the crystals forming the black region is preferably 5 times or more, more preferably 6.7 times or more, that of the crystals forming the substrate.

The average grain size of crystals can be determined as follows. First, a fractured surface of a member for semiconductor manufacturing equipment is polished with a copper disk using diamond abrasive grains having an average particle diameter _D50 of 3 μm. After that, it is polished with a tin plate using diamond abrasive grains having an average particle diameter _D50 of 0.5 μm. The polished surface obtained by these polishing processes is etched at a temperature of 1600° C. until the crystal grains and the grain boundary layer can be distinguished to obtain an observation surface. With a scanning electron microscope, straight lines of the same length, for example, 6 straight lines of 100 μm are drawn in a range of 60 μm×45 μm in which the observation surface is magnified 2000 times. By dividing the number of crystals existing on these six straight lines by each of these straight lines, the average grain size of crystals can be obtained.

Examples of the present disclosure will be specifically described below, but the present disclosure is not limited to these examples.

In the following, an example of forming a black region on the surface of a substrate using electron beam irradiation will be described in detail.

First, a disk-shaped base material made of white ceramics containing yttria as a main component was prepared, and the regions indicated by numbers 1 and 2 shown in FIG. ) were covered with an alumina mask.

Then, a cathode electrode having a predetermined cross-sectional area and a substrate partially covered with a mask were placed at a predetermined distance in a chamber of an electron beam irradiation apparatus. An annular anode electrode is provided between the cathode electrode and the substrate for converting argon gas into plasma.

A solenoid is provided outside the chamber to create magnetic lines of force parallel to the direction in which the electron beam is irradiated. After the chamber was sealed, the pressure in the chamber was reduced to a substantially vacuum state, and argon gas was supplied into the chamber. Next, the solenoid was energized to generate magnetic lines of force, and the pressure of the argon gas was maintained at a predetermined pressure. In this state, a voltage of 25 kV was applied to the cathode electrode, and a voltage of 1 kV or more was applied to the solenoid, and the electron beam was irradiated to each of the regions 1, 2, and 3 four times to obtain a black region (irradiation time was 20 minutes). ).

The area below area 4 shown in FIG. 1 was then covered with an alumina mask, and the substrate was placed in the chamber as described above. Then, a voltage was applied to the cathode electrode and the solenoid in the same procedure as described above. The irradiation conditions were such that a voltage of 30 kV was applied to the cathode electrode and a voltage of 1 kV or more was applied to the solenoid, and the electron beam was irradiated to the region 4 four times to obtain a black region (irradiation time: 20 minutes).

Furthermore, areas other than the region 5 shown in FIG. 1 were covered with an alumina mask, and the substrate was placed in the chamber as described above. Then, a voltage was applied to the cathode electrode and the solenoid in the same procedure as described above. The irradiation conditions were such that a voltage of 20 kV was applied to the cathode electrode and a voltage of 1 kV or more was applied to the solenoid, and the electron beam was irradiated to the region 5 four times (irradiation time: 20 minutes). After that, a voltage of 25 kV was applied to the cathode electrode and a voltage of 1 kV or more was applied to the solenoid, and the electron beam was irradiated to the region 5 four times to obtain a black region (irradiation time: 20 minutes).

When the cross section of the substrate shown in FIG. 1 after electron beam irradiation was observed with a scanning electron microscope (SEM), the thickness of the black region was about 0.8 μm.

The reflectance R(λ) was measured for wavelengths at intervals of 10 nm in the wavelength range of 360 nm to 740 nm in regions 1 to 5 shown in FIG. The number of samples of wavelengths, which are independent variables, was 39, and the degree of freedom was 38.

The reflectance R(λ) was measured using a spectrophotometer (CM-2600d, manufactured by Konica Minolta, Inc.) under the measurement conditions of a CIE standard light source D65 and a viewing angle of 2°. The measurement results are shown in FIG. As shown in FIG. 2, it can be seen that the reflectance R(740) is greater than the reflectance R(360) in all of regions 1-5.

The slope of the curve obtained by logarithmic approximation of the relationship between the wavelength at intervals of 10 nm in the wavelength range of 360 nm or more and 740 nm or less in each region and the reflectance R (λ), the correlation coefficient, and the test by the significance level of 0.1% Table 1 shows the results and the minimum value of R(λ+10)-R(λ).

Furthermore, the lightness index L*, the chromaticness index a*, and the chromaticness index b* were measured for each of the regions 1 to 5. For regions 2 and 33, the color difference (ΔE*ab) relative to region 1 was calculated. The measurement was performed according to JIS Z 8722:2009. Specifically, a spectrophotometer (CM-2600d, manufactured by Konica Minolta, Inc.) was used, and the measurement conditions were a CIE standard light source D65 and a viewing angle of 2°. The closer the lightness index L* is to 0, the more black it is, and the closer it is to 100, the more white it is.

The chromaticness index a* and the chromaticness index b* indicate saturation, and 0 indicates achromatic color. Table 1 shows the results. The white portion shown in Table 1 is the result of measuring two arbitrary points on the substrate before electron beam irradiation.

As is clear from the results shown in Table 1, since the reflectances R(λ) of the regions 1 to 4 fluctuate little, the correlation coefficients are as high as 0.94 or more. As a result, color unevenness is suppressed more than in the region 5 where the reflectance R(λ) fluctuates greatly. R(λ+10)-R(λ) in regions 1 to 4 is also -0.1% or more. Therefore, it is better than region 5 where R(λ+10)−R(λ) is small.

Furthermore, as shown in Table 1, the regions 2 and 3 have a small color difference (ΔE*ab) with respect to the region 1, which is 3 or less. Therefore, it can be seen that the color unevenness is suppressed and the commercial value is improved.

Separately, disc-shaped substrates made of white ceramics containing Er ₂ O ₃ , CeO ₂ , Er ₃ Al ₅ O ₁₂ (EAG) and Ce ₃ Al ₅ O ₁₂ (CAG) as main components were prepared. Areas 1 to 5 were irradiated with an electron beam in the same manner as described above to obtain black areas.

The correlation coefficient R of the curve obtained by logarithmically approximating the relationship between the wavelengths at intervals of 10 nm in the wavelength range of 360 nm to 740 nm and the reflectance R (λ) of the black region corresponding to the regions 1 to 4 It was 0.94 or more, satisfying the relationship of R(740)>R(550)>R(360). R(λ+10)−R(λ) of black regions corresponding to regions 1 to 4 was 0.1% or more.

A member for a semiconductor manufacturing apparatus according to one embodiment has a reflectance R (λ) that is substantially upward to the right in the visible light region, and has a black region that is highly visible and difficult to peel off. black parts and markers (for example, susceptor marks).

Claims (11)

A substrate having a black region on the surface,
The black region is mainly composed of a rare earth oxide having an oxygen composition smaller than the stoichiometric composition,
A curve obtained by logarithmically approximating the relationship between the wavelength at intervals of 10 nm in the wavelength range of 360 nm to 740 nm and the reflectance R (λ) of the black region (where λ is the wavelength (nm) in the wavelength range). The correlation coefficient of is 0.94 or more,
Components for semiconductor manufacturing equipment. 2. The member for semiconductor manufacturing equipment according to claim 1, wherein R(λ+10)−R(λ) is −0.1% or more. A base material having a black region on the surface, the black region mainly comprising a rare earth oxide having an oxygen composition smaller than the stoichiometric composition, and reflecting the black region at intervals of 10 nm in a wavelength range of 360 nm to 740 nm. When the ratio is R (λ) (where λ is the wavelength (nm) in the wavelength range), the relationship R (740)>R (550)>R (360) is satisfied, and R (λ+10)- R (λ) is -0.1% or more,
Components for semiconductor manufacturing equipment. 4. The member for semiconductor manufacturing equipment according to claim 1, wherein said reflectance R(λ) gradually increases from a wavelength of 360 nm to a wavelength of 740 nm. 5. The member for semiconductor manufacturing equipment according to claim 1, wherein said base material is made of ceramics containing a rare earth oxide as a main component. 6. The member for semiconductor manufacturing equipment according to claim 1, wherein said black region has an arithmetic mean roughness Ra of 0.2 μm or more and 0.5 μm or less. 7. The member for a semiconductor manufacturing apparatus according to claim 1, wherein said black region has a maximum height Ry of 1 μm or more and 3 μm or less. 8. The member for semiconductor manufacturing equipment according to claim 1, wherein an average grain size of crystals forming said black region is larger than an average grain size of crystals forming said base material. 9. The member for a semiconductor manufacturing apparatus according to claim 1, wherein an average grain size of crystals forming said black region is at least five times as large as an average grain size of crystals forming said base material. 10. The member for semiconductor manufacturing equipment according to claim 1, wherein said black region has a color difference (ΔE*ab) of 3 or less. A method for manufacturing a member for a semiconductor manufacturing apparatus according to any one of claims 1 to 10,
irradiating the surface of the base material with an electron beam or a laser beam in a reduced pressure atmosphere or a reducing atmosphere to form the black region;
A method for manufacturing a member for semiconductor manufacturing equipment.

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