JP6462449B2 - High-frequency window member, semiconductor manufacturing device member, and flat panel display (FPD) manufacturing device member - Google Patents

Description

  The present invention relates to a high-frequency window member, a semiconductor manufacturing apparatus member, and a flat panel display (FPD) manufacturing apparatus member.

  Conventionally, high-frequency window members having flow paths have been used in semiconductor manufacturing apparatuses and FPD manufacturing apparatuses. Patent Document 1 describes, as an example of a high-frequency window member, a high-frequency window member for a plasma processing apparatus having a flow path for flowing a refrigerant or a heating medium. In order to form a flow path inside the high-frequency window member of Patent Document 1, a first dielectric plate and a second dielectric plate, each of which has a recess serving as a flow path, are formed by using a silicon-based adhesive or the like. The high-frequency window member is configured by joining them. Patent Document 1 exemplifies quartz glass, various ceramic sintered bodies, single crystal bodies such as sapphire, and the like as materials constituting the first dielectric plate and the second dielectric plate. Among them, the alumina sintered body has advantages such as relatively easy formation of a large member, relatively low price, and high corrosion resistance against plasma and the like, and is being used.

  In recent years, the technical issues required for semiconductor manufacturing equipment and FPD manufacturing equipment are high, such as the need to cope with the increase in size and the reduction in circuit wiring due to higher integration and miniaturization of semiconductor devices. It has become. In order to miniaturize circuit wiring, it is necessary to increase the stability of plasma generated in a plasma processing apparatus which is a part of a semiconductor manufacturing apparatus or an FPD manufacturing apparatus. In order to stabilize the plasma, it is necessary that the high-frequency window member has high permeability of high-frequency electromagnetic waves (hereinafter also simply referred to as high frequency), and for this purpose, the dielectric loss tangent (tan δ) of the high-frequency window member is low. It is demanded. For example, Patent Documents 2 and 3 list an example of an alumina sintered body having a low dielectric loss tangent (tan δ). As an alumina sintered body used for a high-frequency window member, use of an alumina sintered body having a low dielectric loss tangent (tan δ) as described in Patent Documents 2 and 3 has been studied.

JP 2003-309109 A JP-A-8-143358 JP-A-5-217946

  However, in the high-frequency window member with a flow path described in Patent Document 1, since the first dielectric plate and the second dielectric plate are joined using a silicon-based adhesive or the like, the dielectric loss tangent (tan δ) Even if an alumina sintered body having a low) is used, this adhesive layer deteriorates the dielectric loss tangent (tan δ), and the dielectric tangent (tan δ) as a whole is not sufficiently lowered. In addition, in the alumina sintered bodies described in Patent Documents 2 and 3, the dielectric loss tangent is lowered by reducing the content of Na oxide, but Na oxide is unavoidable in the alumina raw material. Since it is included, a large cost is required for the removal process. For this reason, when the alumina sintered body having a low dielectric loss tangent (tan δ) as described in Patent Documents 2 and 3 is used, there is a problem that the high-frequency window member becomes expensive. The present application aims to solve such problems.

  In order to solve the above problems, a first substrate having a first main surface, a second substrate having a second main surface, the first main surface and the second main surface are joined, and the first substrate and A high-frequency window member that is located between the second substrates and includes a flow path that extends in a direction parallel to the first main surface and the second main surface, the first main surface and the A bonding member for bonding the second main surface, and each of the first substrate, the second substrate, and the bonding member is made of an alumina sintered body, and in the grain boundary phase of the alumina sintered body; The high frequency window member is characterized in that the inner region other than the boundary region contains more Na oxide than the boundary region with the alumina crystal.

  Moreover, the member for semiconductor manufacturing apparatuses comprised including the above-mentioned high frequency window member, and the member for flat panel display (FPD) manufacturing apparatuses comprised including the above-mentioned high frequency window member are provided together.

  The high-frequency window member of the present invention has a relatively high high-frequency permeability while being relatively inexpensive. Since the semiconductor manufacturing apparatus member and the FPD manufacturing apparatus member of the present invention stably generate high-output plasma with less energy, various processing accuracy is high.

It is sectional drawing along the thickness direction of the plasma processing apparatus using the window member for high frequency in one Embodiment of this invention. (A) is a perspective view of the high-frequency window member shown in FIG. 1, and (b) is a plan view of the high-frequency window member shown in FIG. 2 (a). (A) is a figure which shows an example of the cross section in the AA line of the window member for high frequency shown in FIG.2 (b), (b) is an enlarged view of R1 part of Fig.3 (a). (A) is a figure which shows the other example of the cross section in the AA line of the window member for high frequency shown in FIG.2 (b), (b) is an enlarged view of R1 part of Fig.4 (a), (C) is an enlarged view of R2 part of FIG.4 (b). (A) is a figure which shows an example of the cross section in the AA line of the high frequency window member shown to Fig.4 (a), (b) is an enlarged view of R3 part of Fig.5 (a).

  Hereinafter, a high-frequency window member according to an embodiment of the present invention will be described with reference to the drawings. The high-frequency window member 1 of the present embodiment is used as a window member that transmits a high frequency for generating plasma in a chamber, for example, in a semiconductor manufacturing apparatus, an FPD manufacturing apparatus, or the like. Moreover, the high frequency window member 1 has a flow path therein, and also functions as a heat exchange device for cooling or heating itself.

  A semiconductor manufacturing apparatus is an apparatus for manufacturing a semiconductor device by performing various processes on a semiconductor wafer. The FPD manufacturing apparatus is an apparatus that manufactures FPD by performing various processes on a glass substrate. In the present embodiment, a plasma processing apparatus 2 for performing an etching process or a film forming process on a semiconductor wafer or a glass substrate will be described as an example of a semiconductor manufacturing apparatus and an FPD manufacturing apparatus.

  As shown in FIG. 1, the plasma processing apparatus 2 of the present embodiment includes a chamber 5 in which a reaction chamber 4 that accommodates an object 3 such as a semiconductor wafer or a glass substrate is formed, and an object in the reaction chamber 4. 3, a chuck 6 such as an electrostatic chuck that adsorbs 3, a supply port 7 for supplying a gas to the reaction chamber 4, an exhaust port 8 for exhausting the gas from the reaction chamber 4, and a position located on the chamber 5 and in the reaction chamber 4 Are provided with a coil 9 for applying a high-frequency voltage and a power source 10 for applying a high-frequency voltage to the coil 9.

  In this plasma processing apparatus 2, after supplying gas from the supply port 7 into the reaction chamber 4, the coil 9 generates an electric field in the reaction chamber 4, thereby generating plasma in the reaction chamber 4. Etching or film formation is performed on the object 3 by this plasma.

  The chamber 5 of the plasma processing apparatus 2 has a high-frequency window member 1 that is located above the object 3 and supports the coil 9. The high frequency window member 1 functions as a window member through which the high frequency voltage generated by the coil 9 is transmitted.

  When the plasma processing apparatus 2 generates plasma, a high frequency voltage is applied to the coil 9. At this time, the high frequency window member 1 is induction heated by the high frequency voltage. The intensity of the high-frequency voltage passing through the high-frequency window member 1 is spatially non-uniform according to the shape of the coil 9, and the degree of heating of the high-frequency window member 1 is also due to the variation in the intensity of the high-frequency voltage. Accordingly, it tends to vary partially. When the temperature in each part of the high-frequency window member 1 becomes non-uniform due to partial variations in the degree of heating of the high-frequency window member 1, the plasma intensity in the reaction chamber 4 tends to be spatially non-uniform. In the present embodiment, as the dielectric window member, by using the high frequency window member 1 provided therein with a flow path 16 through which a fluid such as water or oil or a fluid such as a heating medium passes, the temperature of the high frequency window member 1 is determined. By reducing the distribution, the uniformity of the plasma intensity in the reaction chamber 4 is made relatively high.

  In the high-frequency window member 1 of the present embodiment, the first substrate 12 having the first main surface 11, the second substrate 14 having the second main surface 13, and the first main surface 11 and the second main surface 13 are joined. And a flow path 16 located between the first substrate 12 and the second substrate 14 and extending in a direction parallel to the first main surface 11 and the second main surface 13. A joining member 15 for joining the second main surface 12 is provided, and the first substrate 12, the second substrate 14, and the joining member 15 are all made of an alumina sintered body, and a grain boundary phase in the alumina sintered body. In the inner region, the inner region other than the boundary region has more oxide of Na than the boundary region with the alumina crystal.

  The first substrate 12, the second substrate 14, and the joining member 15 made of such an alumina sintered body contain Na unavoidably contained in the alumina raw material, and require a cost for removing Na or the like. Therefore, the first substrate 12 and the second substrate 14 are relatively inexpensive, and the high-frequency window member 1 including the first substrate 12, the second substrate 14, and the bonding member 15 can be configured relatively inexpensively. it can. Further, since the first substrate 12, the second substrate 14, and the bonding member 15 for bonding the first substrate 12 and the second substrate 14 are made of the same material, the first substrate 12, the second substrate 14 and the bonding member 15 are close to each other, and even if heating and cooling are repeated, the thermal stress acting between the first substrate 12 and the second substrate 14 is suppressed. Separation from the second substrate 14 can be reduced. The first substrate 12, the second substrate 14, and the bonding member 15 all have a relatively low value of dielectric loss tangent, compared to the conventional case where, for example, a silicon-based adhesive layer or the like is used as the bonding member, The high frequency window member 1 as a whole has high high frequency permeability. Moreover, the flow path which can flow the fluid which can adjust the temperature of the high frequency window member 1 is provided, the fluctuation | variation of the temperature of the high frequency window member 1 is suppressed, and the high frequency which permeate | transmits the high frequency window member 1 is transmitted. It is possible to suppress the intensity distribution of the plasma generated in the above. Such a high-frequency window member 1 is relatively inexpensive, but has a relatively high high-frequency permeability. In addition, the plasma processing apparatus 2 including the high-frequency window member 1 can stably generate high-power plasma with less energy, and thus has high accuracy in various processes.

  The boundary region with the alumina crystal in the grain boundary phase means within a range up to a position 5 nm away from the surface of the alumina crystal. The content of Na oxide in the first substrate 12, the second substrate 14, and the bonding member 15 can be confirmed by the following method.

  First, a part of the alumina sintered body is etched using a processing apparatus such as an ion thinning apparatus to obtain a measurement surface. Next, using a transmission electron microscope (JEM-2010F, manufactured by TEM JEOL), the grain boundary phase is observed at a magnification of 10,000 to 100,000 times with a specific visual field on the measurement surface with an acceleration voltage of 200 kV. In order to confirm the content of the oxide of Na depending on the position, it is preferable to observe the triple point.

  And at the 3 points, the part corresponding to the boundary region and the part corresponding to the inner region (region other than the boundary region) are measured by energy dispersive X-ray analysis (EDS), and the content of Na is confirmed. The content of the oxide of Na at the position of the grain boundary phase can be confirmed.

  The value of the dielectric loss tangent increases when the oxide of Na is dissolved in the alumina crystal. In the grain boundary phase in the alumina sintered body, the amount of Na oxide in the inner region other than this boundary region is larger than that in the boundary region with the alumina crystal. This means that the oxide is retained and solid solution of the Na oxide in the alumina crystal is suppressed, and the value of the dielectric loss tangent is kept low.

For example, each of the first substrate 12, the second substrate 14, and the bonding member 15 has a content of Na in terms of Na ₂ O in a component of 100% by mass constituting 30 ppm or more and 500 ppm or less, and Al. The content in terms of Al ₂ O ₃ is 99.4% by mass or more. When the content of Al in terms of Al ₂ O ₃ is 99.4% by mass or more, the plasma resistance of the high-frequency window member 1 is relatively high. Further, if the content of Na converted to Na ₂ O is 30 ppm or more and 500 ppm or less, there is no special treatment for removing Na from the alumina raw material powder, so the manufacturing cost of the high-frequency window member 1 is low, and The value of dielectric loss tangent can be made relatively low.

For example, the value of the dielectric loss tangent at 8.5 GHz of the first substrate 12 and the second substrate 14 is 2.5 × 10 ⁻⁴ or less when the content of Na converted to Na ₂ O is 500 ppm, and 0 at 30 ppm. .15 × 10 ⁻⁴ or less, which is lower than in the case of using conventionally proposed alumina sintered bodies (for example, the alumina sintered bodies described in Patent Document 2 and Patent Document 3). Yes.

  For the dielectric loss tangent of the first substrate 12 and the second substrate 14, for example, a disk-shaped sample having a diameter of 50 mm and a thickness of 1 mm is prepared, and the value of the dielectric loss tangent at a frequency of 8.5 GHz is set to a capacitance meter (HP-4278A). ), Impedance analyzer (HP-4291A) and cavity resonator (network analyzer 8722ES).

As for the content of Na in component 100 mass% constituting the respective members and the content and Al were terms of Na 2 _O Al ₂ O ₃ in terms grinding a portion of the alumina sintered body, resulting after dissolving the powder in a solution such as hydrochloric acid, ICP (Inductively Coupled Plasma) emission spectrometer (e.g., Shimadzu: ICPS-8100) was used to measure the content of Na and Al, _Na 2 O And Al ₂ O ₃ may be converted.

The position of the joining member 15 can be confirmed as follows, for example. First, the high-frequency window member 1 is parallel to the thickness direction (z direction shown in FIG. 3) of the first substrate 12 and the second substrate 14 and perpendicular to the length direction of the flow path 16 (fluid flow direction). And the cross section (the cross section shown in FIG. 3) is polished into a mirror surface. Next, this mirror surface is observed using, for example, a digital microscope manufactured by Keyence Corporation. In this observation, the first substrate 12, the bonding member 15, and the second substrate 14 are placed in the same field of view. By this observation, the regions corresponding to the first substrate 12 and the second substrate 14 with relatively few pores 30, and the first substrate 12 and the second substrate 14 are shown.
It is possible to observe a region having a relatively large number of pores 30 sandwiched between regions corresponding to. A region having a relatively large number of pores 30 is a region corresponding to the joining member 15. In addition, even when the pores 30 cannot be significantly distinguished by the above-described digital microscope, the position of the joining member 15 can be confirmed by analyzing the crystal state and the contained components using an electron microscope or other analysis techniques. That is, since the boundary portion between the first substrate 12 and the second substrate 14 can be estimated from the shape of the flow path 16, the vicinity of the boundary portion is observed, and the first substrate 12 and the second substrate 14 and pores and grain boundaries are observed. The position of the joining member 15 can be confirmed by measuring the state, the content rate of the contained components, and the like, and confirming a region significantly different from the first substrate 12 and the second substrate 14.

The first substrate 12, the second substrate 14, and the bonding member 15 preferably contain Mg, and the MgO equivalent content is preferably 200 ppm or more and 1500 ppm or less. By satisfying such a configuration, there is little risk of generating spinel (MgAl ₂ O ₄ ) crystals that tend to increase the dielectric loss tangent, and sintering can be promoted. The mechanical strength of the body can be improved.

Moreover, the 1st board | substrate 12, the 2nd board | substrate 14, and the joining member 15 contain at least Si and Ca as components other than Al and Na. Then, Si and Ca are content that content and as CaO that each SiO ₂ in terms, of the component 100 mass% constituting each member, respectively, it is preferable that both at 200ppm or more. In addition, any of Ba and Sr may be included. Na, Si, Ca, Ba, and Sr are present as a crystal phase or an amorphous phase made of an oxide in a grain boundary phase between alumina crystals that are main crystals. When Mg is included, Mg is also present in the grain boundary phase. In some cases, Al is present in the grain boundary phase. And in the following description, components other than Na are described as other components as components constituting the grain boundary phase.

The first substrate 12, the second substrate 14, and the bonding member 15 each oxidize other components other than Na in a grain boundary phase between alumina crystals, where Na is converted to Na ₂ O. When the total content converted to a product is B, the ratio A / B is preferably 0.11 or less.

Thus, in the grain boundary phase between alumina crystals, when the content of Na converted to Na ₂ O is A and the total content of other components converted to oxides is B, the ratio A / When B is 0.11 or less, the dielectric loss tangent can be further reduced.

The ratio A / B between the content A in which Na in the grain boundary phase between alumina crystals is converted to Na ₂ O and the total content B in which components other than Na are converted into oxides is as follows: Can be obtained.

First, a measurement surface obtained by etching a part of an alumina sintered body using a processing device such as an ion thinning device is measured with a TEM, and a specific field of view on the measurement surface is set at a magnification of 10,000 to 100,000 times under an acceleration voltage of 200 kV. The EDS measurement of the grain boundary phase was performed, the content of each component obtained was determined, converted into oxides, the content of Na converted into Na ₂ O as A, and the other components as What is necessary is just to calculate ratio A / B by making the sum total of the content converted into the oxide into B. In one grain boundary phase, it is preferable to perform EDS measurement at a plurality of places, for example, three places, and calculate the ratio A / B using an average value, and round off to the third decimal place.

  In addition, when Al is not contained in the grain boundary phase, after crushing a part of the alumina sintered body and dissolving the obtained powder in a solution such as hydrochloric acid, using an ICP emission spectroscopic analyzer The content of other components other than Na and Na may be measured, and the ratio (A / B) may be calculated using the values converted into oxides.

  Moreover, it is suitable for the 1st board | substrate 12, the 2nd board | substrate 14, and the joining member 15 that the content which converted Ni into NiO is 4 ppm or less.

  When Ni is oxidized, the color tone is likely to vary depending on the degree of oxidation, and the commercial value is likely to be impaired. By setting the content of Ni converted to NiO within the above range, the variation in the color tone is suppressed, and the commercial value is reduced. Will improve.

  The first substrate 12, the second substrate 14, and the bonding member 15 preferably have an average crystal grain size of 1 to 3 μm in alumina crystals.

  When the average crystal grain size of the alumina crystal is in the above range, the distribution of the size of the alumina crystal is narrowed, so that the mechanical strength of each member can be increased.

  In order to obtain the average crystal grain size of the alumina crystal, first, each of the above members is polished with diamond abrasive grains to obtain a mirror surface having an arithmetic average roughness Ra of 0.1 μm or less. And the same length in the range of 86-110 μm × 65-92 μm obtained by enlarging the surface obtained by thermal etching of this mirror surface at 1450 ° C. for 1 hour in the air atmosphere by 1000 times to 3000 times with a scanning electron microscope. Is obtained by dividing the number of crystals existing on the eight straight lines by the total length of these straight lines.

  When the magnification is 100 times, the length per straight line is 80 μm, and when the magnification is 3000 times, the length per straight line is 27 μm.

  Further, in the high-frequency window member 1 of the present embodiment, when the joining member 15 has a plurality of pores 30, it is preferable that the average value of the equivalent circle diameters of the pores 30 in the joining member 15 is 5 μm or less. In the high-frequency window member 1 of the present embodiment, it is preferable that the maximum value of the equivalent circle diameter of the pores 30 in the joining member 15 is 14 μm or less. Further, in the high frequency window member 1 of the present embodiment, the area ratio of the pores 30 in the joining member 15 is preferably 4.5% or less. When the joining member 15 has a plurality of pores, satisfying any of the above-described structures makes it difficult for a conductive component such as metal or water to enter the pores, so that current leakage on the surface of the high-frequency window member 1 or the like Can be suppressed, and the insulating property of the high-frequency window member 1 can be maintained high.

In order to obtain the average value, the maximum value, and the area ratio of the equivalent circle diameter of the pores 30 in the bonding member 15, a mirror surface obtained by polishing the bonding member 15 with diamond abrasive grains with a magnification of 270 times using an optical microscope. Is targeted. From this mirror surface, a portion where the pore size and distribution are observed on average is selected, and the area is 3.54 × 10 ⁵ μm ² (for example, the horizontal length is 708 μm and the vertical length is 500 μm). The image analysis software “A Image-kun” (registered trademark, manufactured by Asahi Kasei Engineering Co., Ltd.) is used as an object to be observed. The setting conditions for particle analysis are the brightness of the particles, the binarization method, and the small figure removal area, which are dark, automatic, and 3 μm, respectively.

  The high-frequency window member of the present embodiment can be suitably used as a large and thick member (a member for a semiconductor manufacturing apparatus, a member for an FPD manufacturing apparatus) used in a semiconductor manufacturing apparatus or an FPD manufacturing apparatus. When the member is made of the high-frequency window member of the present embodiment, it has high corrosion resistance, has little energy loss, and can improve various processing accuracy.

Next, the shape and the like of the high frequency window member 1 will be described in detail. FIG. 3 shows one embodiment of the high-frequency window member 1. In the embodiment of the high-frequency window member 1 shown in FIG. 3, a first main surface 11, a second main surface 13, and a joining member 15 that joins the first main surface 11 and the second main surface 13 are provided.
The first substrate 12 and the second substrate 14 have, for example, a disk shape in plan view. The width (diameter) of the first substrate 12 and the second substrate 14 is, for example, not less than 100 mm and not more than 1000 mm. The thickness of the joining member 15 between the 1st main surface 11 and the 2nd main surface 13 is 50 micrometers or more and 65 micrometers or less, for example. The first portion 21 that is an end portion in the radial direction of the flow path 16 includes a first groove portion 18 provided in the thickness direction (z direction) from the second main surface 13 of the second substrate 14. The second portion 22, which is the central portion in the radial direction of the flow path 16, includes the second groove portion 19 that is adjacent to the first groove portion 18 and shallower than the first groove portion 18. In the high frequency window member 1, a region (second portion 22) sandwiched between the second bottom surface 31 of the second groove portion 19 of the second substrate 14 and the first main surface 11 of the first substrate 12, and the second substrate 14. The first groove portion 18 has a region (first portion 21) sandwiched between the inner surface of the first groove portion 18 and the first main surface 11 of the first substrate 12. The second groove portion 19 is not always necessary, but it is preferable to provide the second groove portion 19 in order to increase the flow rate of the fluid flowing through the flow path 16. The flow channel 16 has a second portion 22 and two first portions 21 arranged with the second portion 22 interposed therebetween.

  The height H1 of the first portion 21 is greater than the height H2 of the second portion 22. The height H2 of the first portion 21H1 and the second portion 22 is the height along the thickness direction (z direction in the drawing) of the first substrate 12 and the second substrate 14. The height H1 of the first portion 21 is, for example, not less than 2 mm and not more than 30 mm. The height H2 of the second portion 22 is, for example, not less than 0.1 mm and not more than 2 mm. The width W1 of the first portion 21 is, for example, not less than 1 mm and not more than 10 mm. The width W2 of the second portion 22 is, for example, not less than 5 mm and not more than 100 mm.

In the channel 16, the width W <b> 2 of the second portion 22 is larger than the width W <b> 1 of the first portion 21. The width W1 of the first portion 21 and the width W2 of the second portion 22 are the lengths in the direction perpendicular to the thickness direction of the first substrate 12 and the second substrate 14 and the length direction of the flow path 16 (the x direction in FIG. 3). That's it. By increasing the width W2 of the second portion 22 that substantially functions as a flow path, the degree of heat exchange in the second portion 22 can be increased. Thereby, the temperature of the high frequency window member 1 can be stably adjusted by the fluid flowing stably in the second portion 22.

  The first groove portion 18 has a first bottom surface 26, a side surface 27 connected to the first bottom surface 26, and an inclined surface 28 disposed between the first bottom surface 26 and the side surface 27. In other words, for example, when the shape of the first groove 18 in a cross-sectional view is rectangular, the corners of the rectangle are cut off (corner cut). A region corresponding to the first groove portion 18 in the flow path 16 has a relatively large cross-sectional area, and the flow of fluid tends to be slow. For example, in the case where the first groove 18 does not have the inclined surface 28 and the cross section shown in FIG. 3 is a rectangular shape having a corner, the flow velocity of the fluid is remarkably slowed at the corner and the portion corresponding to the corner. May not be able to fully exchange heat. The high-frequency window member 1 has an inclined surface 28 between the first bottom surface 26 and the side surface 27, and a decrease in the flow velocity at such corners is suppressed. In the high-frequency window member 1 in the example shown in FIG. 3B, the inclined surface 28 is curved, but the inclined surface 28 may be planar. Further, the inclined surface 28 may be formed from a plurality of flat surfaces having different inclinations.

  As shown in FIG. 2, the high-frequency window member 1 includes a through hole 17 that penetrates at least one of the first substrate 12 and the second substrate 14 in the thickness direction (z direction). The through-hole 17 is connected to the flow path 16 and functions as a fluid supply hole to the flow path 16 or a fluid discharge hole from the flow path 16. The opening of the through hole 17 is connected to fluid supply means (not shown) for supplying and discharging fluid. The through hole 17 may penetrate only one of the first substrate 12 and the second substrate 14, or may penetrate both the first substrate 12 and the second substrate 14 in the thickness direction. .

FIG. 4 is a cross-sectional view of another embodiment of the high-frequency window member 1. The high-frequency window member 1 shown in FIG. 4 also includes a joining member 15 that joins the first main surface 11 and the second main surface 13.
The thickness of the bonding member 15 between the main surface 11 and the second main surface 13 is, for example, 50 μm or more and 65 μm or less. As shown in FIG. 4, the bonding member 15 has a protruding portion 20 that protrudes from between the first main surface 11 and the second main surface 13 toward the inside of the flow path 16. In the case of such a configuration, the flow path 16 includes the first portion 21 in which the protruding portion 20 is disposed inside, and the first portion 21 on the opposite side of the first portion 21 on which the protruding portion 20 is disposed. And a second portion 22 connected thereto.

  By providing the bonding member 15 so that it protrudes until the protruding portion 20 is disposed in the flow path 16, the bonding strength is increased, and the intrusion of fluid between the first substrate 12 and the second substrate 14 is prevented. Suppression by the bonding member 15 can suppress separation of the first substrate 12 and the second substrate 14.

  In the high-frequency window member 1, it is preferable that the thickness Tp of the protruding portion 20 along the thickness direction of the first substrate 12 and the second substrate 14 is larger than the height H <b> 2 of the second portion 22. By doing so, the fluid flowing at a relatively high flow rate in the second portion 22 is prevented from directly contacting the boundary portion between the first substrate 12 and the second substrate 14, and the first substrate 12 and the second substrate 22 are prevented from contacting each other. Separation from the substrate 14 is more reliably suppressed.

  Moreover, the thickness Tp of the protrusion part 20 is about 0.1 mm or more and 11 mm or less, for example. The width Wp of the protruding portion 20 is smaller than the width W1 of the first portion 21 and is, for example, about 0.5 mm to 10 mm.

  Further, in the high frequency window member 1 shown in FIG. 4, the height H1 of the first portion 21 where the protruding portion 20 of the joining member 15 is arranged is set to the height H2 of the second portion 22 connected to the first portion 21. It is preferable to make it larger than. While the flow velocity of the fluid around the protrusion 20 is relatively small, the turbulent flow caused by the protrusion 20 is likely to stay in the first portion 21. That is, by making the height H1 of the first portion 21 where the protruding portion 20 is disposed relatively large, the cross-sectional area of the flow path 16 around the protruding portion 20 that tends to be reduced by the protruding portion 20 becomes relatively large, and the protruding portion 20 The flow velocity of the fluid is prevented from becoming too high in the vicinity of the portion 20. As a result, the degree of turbulence caused by the protrusion 20 is suppressed to a low level. In addition, by increasing the cross-sectional area of the flow path 16 in the vicinity of the protrusion 20, the influence of the turbulent flow generated in the first portion 21 is hardly transmitted to the second portion 22. For this reason, in the window member 1 for high frequency, the flow velocity of the fluid in the second portion 22 can be relatively large, and the turbulent flow in the second portion 22 can be reduced. As a result, the fluid can flow through the second portion 22 of the flow channel 16 in a relatively fast and relatively stable state. That is, the second portion 22 is mainly provided with a function as a flow path, and thus the high frequency window member 1 can easily adjust the temperature of the high frequency window member 1 itself to a desired temperature.

  As shown in FIG. 5, the projecting portion 20 includes a convex portion 29 that is convex toward the flow path 16 (second portion 22) and a concave portion 32 that is concave on the surface portion facing the second portion 22. It is preferable to have the uneven region 33 in which the concave portions 32 and the convex portions 29 are alternately arranged along the length direction of the flow path 16. In the example shown in FIG. 5, the high-frequency window member 1 has a plurality of annular flow paths 16 arranged concentrically, and the uneven region 33 of the flow path 16 is continuous in an annular shape. Each channel 16 is disposed on the entire surface portion on the side facing the second portion 22. By arranging such an uneven region 33, it is possible to generate a stable turbulent flow in the first portion 21 in which the protruding portion 20 is disposed in the entire flow path 16. As a result, the temperature distribution of the high-frequency window member 1 due to local turbulence of the degree of heat exchange due to the occurrence of local turbulence, and the first substrate 12 and the second substrate due to local turbulence. Local peeling from the substrate 14 is suppressed.

  Next, an example of a method for manufacturing the high-frequency window member shown in FIG. 4 will be described as an embodiment of the method for manufacturing the high-frequency window member 11.

First, alumina (Al ₂ O ₃ ) A powder having an average particle size of 0.4 to 0.6 μm and alumina B powder having an average particle size of about 1.2 to 1.8 μm are prepared. Further, silicon oxide (SiO ₂ ) powder is prepared as a Si source, and calcium carbonate (CaCO ₃ ) powder is prepared as a Ca source. As the silicon oxide powder, a fine powder having an average particle size of 0.5 μm or less is prepared. Further, magnesium hydroxide powder is used to obtain an alumina sintered body containing Mg. In the following description, powders other than the Alumina A powder and the Alumina B powder are collectively referred to as a first subcomponent powder.

Then, a predetermined amount of each first subcomponent powder is weighed. Next, the alumina A powder and the alumina B powder are mixed so that the mass ratio is 40:60 to 60:40, and among 100 mass% of the components constituting the obtained alumina sintered body, Al is Al. Weighing is performed so that the content in terms of ₂ O ₃ is 99.4% by mass or more to obtain an alumina powder mixture. Further, for the first subcomponent powder, preferably, the amount of Na in the alumina blended powder is first grasped and converted to Na ₂ O from the amount of Na in the case of the alumina sintered body. The components (in this example, Si, Ca, etc.) constituting the subcomponent powder are weighed so that the ratio to the value converted to oxide is 1.1 or less.

  And 1-1.5 mass parts PVA (polyvinyl alcohol) etc. with respect to a total of 100 mass parts of alumina compound powder, 1st subcomponent powder, alumina compound powder, and 1st subcomponent powder A binder, 100 parts by mass of a solvent, and 0.1 to 0.55 parts by mass of a dispersant are placed in a stirring device and mixed and stirred to obtain a slurry.

  Thereafter, the slurry is sprayed and granulated to obtain granules, which are then molded into a predetermined shape by a powder press molding method or an isostatic press molding method (rubber press method), and subjected to cutting as necessary. Through the above steps, a molded body that becomes the first substrate 12 (hereinafter, the molded body that becomes the first substrate 12 is referred to as a first ceramic molded body) and a molded body that becomes the second substrate 14 (hereinafter, the second substrate). 14 is referred to as a second ceramic molded body).

  Next, a predetermined amount of the alumina blended powder, the first sub-component powder in the above-described ratio, and pure water is weighed, placed in a storage container in a stirring device, and mixed and stirred to prepare a paste. In addition, you may adjust the viscosity of a paste by adding a thickener. The filling ratio of the alumina blended powder and the auxiliary component calcined powder in the paste is, for example, 25 volume% or more and 35 volume% or less, and the viscosity of the paste is 4 Pa · s or more and 7 Pa · s or less. Adjust the amount of adhesive. And as stirring conditions, in air | atmosphere, rotation speed shall be 800 rpm or more and 1200 rpm, and rotation time shall be 8 minutes or more and 16 minutes or less.

  Next, after arranging the mesh on the surface (bonding surface) of the second ceramic molded body, the mesh is applied so that the thickness after application is 0.1 mm or more and 2 mm or less in an environment where the humidity is 50% RH or more. Then, paste is applied to the surface (joint surface) of the second ceramic molded body. By applying the paste through the mesh, the paste can be applied uniformly and the thickness of the paste can be adjusted. Further, by setting the humidity to 50% RH or more, rapid drying of the paste can be suppressed and the moisture content of the paste can be maintained.

  Next, the surface of the first ceramic molded body is brought into contact with the surface (bonding surface) of the second ceramic molded body to which the paste is applied. Part of the paste from between the surfaces (joint surfaces) of both shaped bodies is obtained by pressing in the thickness direction at a pressure of 4.9 kPa or more and 98.1 kPa or less for 0.5 hour or more after the contact. Can be protruded into the first groove 18.

Next, the molded body whose surfaces are brought into contact with each other is fired. In the step of firing the composite 50,
The first substrate 12 and the second substrate 14 are bonded via the bonding member 15 formed by baking the paste by baking at, for example, 1500 ° C. or more and 1700 ° C. or less in a state where the paste protrudes into the first groove portion 18. In addition, it is possible to form the high-frequency window member 1 having the flow channel 16 in which the protruding portion 20 is disposed in a region corresponding to the first groove portion 18 of the flow channel 16.

  The bonding member 15 is made of the same material as that of the first substrate 12 and the second substrate 14, and both the first substrate 12 and the second substrate 14 have a low dielectric loss tangent. High permeability. In addition, since the joining member 15 is made of the same material as the first substrate 12 and the second substrate 14, it acts between the first substrate 12 and the second substrate 14 even if heating and cooling are repeated. Thermal stress is suppressed.

  Since the second ceramic molded body includes the first groove portion 18, when the first ceramic molded body and the second ceramic molded body are joined via the paste, the first ceramic molded body and the second ceramic molded body are joined with sufficient force. Even if the ceramic molded body is pressed, the paste that protrudes due to the pressing tends to fit within the relatively large first groove 18, and the cross-sectional shape of the second portion 22 of the high-frequency window member 16 protrudes. It is suppressed that it changes partially by (projection part 20). Further, by providing such a protruding portion in the first groove portion 18, the protruding portion 20 can be disposed in the first portion 21 of the flow path 16 of the high frequency window member 1. The various functions and effects described above can be realized.

  The reason why the dielectric loss tangent of the alumina sintered body is lowered by using the method described above is not clear, but by using a fine silicon oxide powder of 0.5 μm or less, it is inevitable that it is included in the alumina powder mixture. The oxide of Na, which is an impurity, is in a state where silicon oxide is easily captured, and together with the oxide of the component constituting the other subcomponent powder, oxidation of Na with silicon oxide or the like without being captured by alumina crystals. This is considered to be because an oxide of Na can be present inside the grain boundary phase by covering the object. In addition, it is considered that the use of an alumina preparation powder obtained by mixing alumina A powder and alumina B powder having different average particle diameters at a predetermined ratio also contributes to lowering the dielectric loss tangent.

  In addition, as a paste used for joining the first ceramic molded body and the second ceramic molded body, for example, an alumina mixed powder and a subcomponent calcined powder obtained by the above-described method from the first subcomponent powder in the above-described ratio, Organic solvents (for example, diethylene glycol, dipropylene glycol, triethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, polytetramethylene glycol, polyethylene A predetermined amount of glycol or cyclohexanedimethanol) and a thickener may be weighed, placed in a storage container in a stirrer, mixed and stirred to produce a paste.

Further, instead of the first subcomponent powder, silicon oxide powder as the Si source, calcium carbonate powder as the Ca source, strontium carbonate (SrCO ₃ ) powder or barium carbonate powder (BaCO ₃ ) powder as the Sr source or Ba source, And a second subcomponent powder comprising magnesium hydroxide powder may be used. When preparing the alumina blended powder, the second subcomponent powder is preferably obtained by first grasping the amount of Na in the alumina blended powder, and converting from the Na amount in the case of the alumina sintered body to Na ₂ O. Weighing so that the ratio between the converted value and the value of the component (in this example, Si, Ca, Sr or Ba) constituting the second subcomponent powder is 1.1 or less. Is preferred. The reason why the dielectric loss tangent of the alumina sintered body is low even when the second subcomponent powder is used is not clear, but by calcining the second subcomponent powder, a composite oxide (for example, Si -Oxide containing Ca-Sr or Ba) and by pulverizing it to 1 μm or less, it becomes easy to come into contact with the oxide of Na, which is an inevitable impurity contained in the alumina preparation powder. This is probably because a large amount of Na oxide can be present inside the crystal phase of the composite oxide.

  Regarding the presence of the crystal phase of the composite oxide, the measurement surface obtained by etching a part of the alumina sintered body using a processing device such as an ion thinning device is specified by TEM under the condition of an acceleration voltage of 200 kV. This can be confirmed by observing the visual field at a magnification of 10,000 to 100,000 times and performing limited-field electron diffraction. In addition, in the confirmed crystal phase, it is confirmed whether or not a large amount of oxide of Na is present inside the crystal phase by measuring the outside that is outside the crystal phase and the inside that is near the center by EDS. can do. When the Sr source is used, the crystal phase of the obtained complex oxide contains Si, Ca, Sr and O.

  The present invention is not limited to the above-described embodiments, and various modifications, improvements, combinations, and the like can be made without departing from the scope of the present invention.

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

  Hereinafter, as examples, production examples and evaluation results of the first substrate 12 and the second substrate 14 will be described.

First, alumina A powder having an average particle diameter of 0.4 μm and alumina B having an average particle diameter of 1.6 μm
A powder was prepared. Moreover, silicon oxide powder as a Si source, calcium carbonate powder as a Ca source, and strontium carbonate powder as a Sr source were prepared. As the silicon oxide powder, powders having average particle sizes of 0.5 μm, 3.0 μm, and 5.0 μm were prepared.

Next, alumina A powder and alumina B powder were prepared so that the mass ratio was 50:50. Then, among 100% by mass of the components constituting the alumina sintered body, Al was weighed so that the content in terms of Al ₂ O ₃ was 99.65% by mass or more to obtain an alumina blended powder. Among the components 100 mass% constituting the fabricated alumina sintered body by using the alumina formulated powder, a value obtained by converting the Na to Na 2 _O is made of a 500 ppm.

Next, sample No. No. 1, silicon oxide powder having an average particle size of 0.5 μm and calcium carbonate powder were weighed so as to be 1500 ppm in terms of SiO ₂ and 1500 ppm in terms of CaO.

  And alumina preparation powder, silicon oxide powder and calcium carbonate powder, and 1 part by weight of PVA, 100 parts by weight of solvent, and 0.2 parts by weight of dispersant for a total of 100 parts by weight of these powders Was mixed and stirred to obtain a slurry.

  Thereafter, the slurry was sprayed and granulated to obtain granules, and then a molded body having a predetermined shape was formed by an isostatic pressing method. Then, the obtained molded body was subjected to a cutting process, and was fired by holding it at a maximum temperature of 1600 ° C. for a predetermined time using a firing furnace in an air atmosphere. 1 was obtained.

  Next, Sample No. 4 was used except that silicon oxide powder having an average particle size of 5.0 μm was used. Sample No. 1 by the same method. 2 was produced.

Then, after pulverizing a part of the alumina sintered body and dissolving the obtained powder in hydrochloric acid, the content of Al was measured using an ICP emission spectroscopic analyzer, and converted to Al ₂ O ₃ All were 99.65 mass%. Na was 500 ppm in terms of Na ₂ O. Further, each in terms of SiO ₂ and CaO terms was 1500 ppm.

  Further, a part of the alumina sintered body is etched using a processing apparatus such as an ion thinning apparatus to form a measurement surface, and a specific field of view of the measurement surface is 10,000 times to 10 times under the condition of an acceleration voltage of 200 kV using TEM. The triple point was observed at a magnification of 10,000 times, and at the triple point, the boundary region and the internal region were measured by energy dispersive X-ray analysis (EDS), and the content of Na oxide was confirmed. Further, a sample having a thickness of 1 mm was cut out from the central portion in the thickness direction of the obtained alumina sintered body, the dielectric loss tangent was measured, and the value is shown in Table 1. Here, the dielectric loss tangent tan δ is set to a measurement frequency of 8.5 GHz, 1 MHz, and 12 MHz, respectively, and a capacitance meter (HP-42788A), an impedance analyzer (HP-4291A), a cavity resonator (network Measurement was performed using an analyzer 8722ES).

From the results shown in Table 1, Sample No. For No. 2, even if the position of the grain boundary phase is different, the Na oxide content cannot be confirmed to be more than the error range (no change), and the value of the dielectric loss tangent at 8.5 GHz is Na converted to Na ₂ O. The content was 5.0 × 10 ⁻⁴ , which is one time the content value. On the other hand, sample no. 1 is 2.5 × 10 ⁻⁴ where the value of the dielectric loss tangent at 8.5 GHz is 0.5 times the content value of Na converted to Na ₂ O.

From this result, it can be said that Sample No. 1 of the present invention can form a high-frequency window member having a low dielectric loss tangent. Also, among the components 100 mass% constituting the alumina sintered body, since the amount of content to the Al was _Al 2 _{O 3} in terms is 99.4 mass% or more, with has a high corrosion resistance, oxidation of Na It was found to be an alumina sintered body having a low dielectric loss tangent while containing an object.

  An alumina sintered body containing the amount of Mg shown in Table 2 in terms of MgO is designated as Sample No. 1 was produced by the same method as that produced. And 3 point | piece bending strength was measured based on JISR1601-2008 (ISO17565: 2003 (MOD)).

From the results shown in Table 2, sample No. 4 to 9 contain Mg, and the content in terms of MgO is 20
It was found that the mechanical strength was improved as compared with sample Nos. 3 and 10 outside this range by being 0 ppm or more and 1500 ppm or less. From this result, the sample no. It can be said that 4 to 9 can form a high-frequency window member having a low dielectric loss tangent and high mechanical strength.

As shown in Table 3, alumina-based sintered bodies having different contents of each component were produced, and dielectric loss tangent was measured. The manufacturing method was the same as that of sample No. 1 in Example 1. 1 is the same as the method for manufacturing, and powders having different contents of Na in the alumina A powder and the alumina powder B are used, and each sample has a content in terms of SiO ₂ and CaO of 50:50. In addition, the amount of silicon oxide powder and calcium carbonate powder was adjusted.

And after pulverizing a part of the obtained alumina sintered body and dissolving the obtained powder in a solution such as hydrochloric acid, it was measured using an ICP emission spectroscopic analyzer, the Al ₂ O ₃ content, The Na ₂ O content and other component contents (total of values converted to SiO ₂ and CaO) were calculated. Table 3 shows the ratio A / B calculated from these values and the value of the dielectric loss tangent measured by the same method as that shown in Example 1.

From the results shown in Table 3, when the grain boundary phase between alumina crystals is A, the content of Na converted to Na ₂ O is A, and the total content of components other than Na converted to oxide is B. Sample No. 12 to 15, when the ratio A / B is 0.11 or less, the value of the dielectric loss tangent at 8.5 GHz is 0.16 times or less the content of Na converted to Na ₂ O, and the dielectric loss tangent is further reduced. I found that it can be lowered.

DESCRIPTION OF SYMBOLS 1 High frequency window member 2 Plasma processing apparatus 3 Target object 4 Reaction chamber 5 Chamber 6 Chuck 7 Supply port 8 Exhaust port 9 Coil 10 Power supply 11 1st main surface 12 1st board | substrate 13 2nd main surface 14 2nd board | substrate 15 Joining member 16 Channel 17 Through-hole 18 1st groove part 19 2nd groove part 20 Protruding part 21 1st part 22 2nd part 26 1st bottom face 27 Side face 28 Inclined surface 29 Convex part 30 Pore 31 2nd bottom face 32 Concave area 33 Uneven area

Claims (7)

A first substrate having a first main surface, a second substrate having a second main surface, and the first main surface and the second main surface are bonded together and positioned between the first substrate and the second substrate. And a high-frequency window member comprising a flow path along a direction parallel to the first main surface and the second main surface,
A bonding member for bonding the first main surface and the second main surface;
The first substrate, the second substrate, and the joining member are all made of an alumina sintered body, and the boundary region in the grain boundary phase of the alumina sintered body is larger than the boundary region with the alumina crystal. A high-frequency window member characterized in that the inner region other than the above has more oxide of Na. Said first substrate, said second substrate, and both the joining member, among the components 100 mass% constituting each, or less 500ppm content 30ppm or more and the Na Na ₂ and O terms, the Al Al ₂ It consists of an alumina sintered body having a content converted to O ₃ of 99.4% by mass or more. At least the first substrate and the second substrate have a dielectric loss tangent value at 8.5 GHz, and Na is converted to Na ₂ O. The high-frequency window member according to claim 1, wherein the value is 0.5 times or less of the content value.   3. The high-frequency window member according to claim 1, wherein the first substrate, the second substrate, and the bonding member contain Mg, and the content in terms of MgO is 200 ppm or more and 1500 ppm or less. In the grain boundary phase, the first substrate, the second substrate, and the joining member have a content of Na converted to Na ₂ O as A, and a total content of components other than Na converted to oxides, respectively. The high frequency window member according to any one of claims 1 to 3, wherein the ratio A / B is 0.11 or less, where B is B. The joining member has a protruding portion protruding toward the inside of the flow path from between the first main surface and the second main surface,
The flow path includes a first portion in which the protruding portion is disposed inside, and a second portion connected to the first portion adjacent to the side of the first portion opposite to the side on which the protruding portion is disposed. 5. The high-frequency window member according to claim 1, wherein a height of the first portion is larger than a height of the second portion.   A member for a semiconductor manufacturing apparatus, comprising the high-frequency window member according to claim 1.   A flat panel display (FPD) manufacturing apparatus member comprising the high-frequency window member according to any one of claims 1 to 5.

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