shower plate

Abstract

This shower plate comprises a substrate and an electrode. The substrate comprises a ceramic and includes a plurality of gas holes from which a heated gas is ejected. The electrode is positioned in the interior of the substrate and has a plurality of through holes corresponding to each of the positions of the plurality of gas holes. The electrode has one or more slits on which part of the substrate is positioned.

Description

[Technical Field]

[0001] The disclosed embodiments relate to a shower plate. [Background technology]

[0002] Conventionally, shower plates that spray heated gas onto a substrate such as a semiconductor wafer in a semiconductor manufacturing process have been known. The shower plate also functions as an RF electrode that can apply RF (radio frequency) power to generate gas plasma. For example, one such shower plate is known to be made of ceramics and has a base body formed with multiple gas holes that spray heated gas, and an electrode embedded in the base body (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3904886 Summary of the Invention

[0004] A shower plate according to one aspect of the embodiment includes a base and an electrode. The base is made of ceramic and has a plurality of gas holes for ejecting heated gas. The electrode is located inside the base and has a plurality of through holes corresponding to the positions of the plurality of gas holes. The electrode has one or more slits in which a portion of the base is positioned. [Brief explanation of the drawings]

[0005] [Figure 1] FIG. 1 is a plan view showing an outline of a shower plate according to the first embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II of FIG. [Figure 3] FIG. 3 is a plan cross-sectional view of the periphery of the electrodes in the shower plate according to the first embodiment. [Figure 4]FIG. 4 is a schematic enlarged view of part E shown in FIG. [Figure 5] FIG. 5 is a plan cross-sectional view of the periphery of an electrode in a shower plate according to Modification 1 of the first embodiment. [Figure 6] FIG. 6 is a plan cross-sectional view of the periphery of an electrode in a shower plate according to Modification 2 of the first embodiment. [Figure 7] FIG. 7 is a plan cross-sectional view of the periphery of an electrode in a shower plate according to a third modification of the first embodiment. [Figure 8] FIG. 8 is a plan cross-sectional view of the periphery of an electrode in a shower plate according to the fourth modification of the first embodiment. [Figure 9] FIG. 9 is a plan cross-sectional view of the periphery of an electrode in a shower plate according to a fifth modification of the first embodiment. [Figure 10] FIG. 10 is an enlarged plan cross-sectional view of the periphery of a slit in a shower plate according to a sixth modification of the first embodiment. [Figure 11] FIG. 11 is an enlarged plan cross-sectional view of the periphery of a slit in a shower plate according to a seventh modification of the first embodiment. [Figure 12] FIG. 12 is a side cross-sectional view showing an outline of a shower plate according to the second embodiment. [Figure 13] FIG. 13 is a plan cross-sectional view of the periphery of an electrode in a shower plate according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0006] Hereinafter, embodiments of the shower plate disclosed in the present application will be described with reference to the accompanying drawings. Note that the present disclosure is not limited to the embodiments shown below. It should be noted that the drawings are schematic, and the dimensional relationships and ratios of the elements may differ from reality. Furthermore, the dimensional relationships and ratios may differ between the drawings.

[0007] Furthermore, the embodiments can be combined as appropriate within the scope of not causing any contradiction in the processing content. Furthermore, the same components in the following embodiments are denoted by the same reference numerals, and redundant explanations will be omitted.

[0008] [First embodiment] Fig. 1 is a plan view showing an outline of a shower plate 1 according to a first embodiment. Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1.

[0009] 1 ejects heated gas onto a substrate such as a semiconductor wafer in a semiconductor manufacturing process, for example. The shower plate 1 is mounted on a substrate processing apparatus that performs plasma processing or the like on the substrate.

[0010] As shown in FIG. 1, the shower plate 1 has a base 10 and an electrode 20 .

[0011] The base 10 has a disk shape including circular upper and lower surfaces in a plan view.

[0012] The base 10 is made of, for example, ceramics and has insulating properties. The ceramics that make up the base 10 are sintered bodies whose main component is, for example, aluminum nitride (AlN), aluminum oxide (Al2O3, alumina), silicon carbide (SiC), silicon nitride (Si3N4), or the like. The main component is a material that accounts for, for example, 50% by mass or more or 80% by mass or more of the material. When the main component of the base 10 is aluminum nitride, the base 10 may contain an yttrium (Y) compound. Examples of Y compounds include YAG (Y3Al5O 12 ) and Y2O3.

[0013] The base 10 has a plurality of gas holes 11 that penetrate the base 10 in the thickness direction and eject heated gas. The gas ejected from the plurality of gas holes 11 is heated, for example, by a resistance heating element (not shown) located inside the base 10.

[0014] The shape of the base 10 is arbitrary. For example, in the first embodiment, the shape of the base 10 is circular in plan view, but is not limited to this, and may be elliptical, rectangular, trapezoidal, etc. in plan view.

[0015] As shown in Fig. 2, the electrode 20 is located inside the substrate 10. The electrode 20 may be a solid structure. For example, the electrode 20 has a disk shape with a smaller diameter than the substrate 10 in a plan view. The electrode 20 is made of, for example, a metal such as Ni, W, Mo, or Pt, or an alloy containing at least one of the above metals.

[0016] The electrode 20 has a plurality of through holes 21 corresponding to the positions of the plurality of gas holes 11 of the base 10. Each of the plurality of through holes 21 has a larger diameter than each of the plurality of gas holes 11.

[0017] 1, the electrode 20 has one or more slits 22 in which a part of the substrate 10 is located. Although Fig. 1 shows an example in which the electrode 20 has four slits 22, the number of slits 22 is not limited to four. The number of slits 22 may be one, or may be five or more.

[0018] The electrode 20 may be, for example, an RF electrode to which RF (radio frequency) power can be applied to generate gas plasma. The substrate processing apparatus equipped with the shower plate 1 can generate gas plasma in the chamber by applying RF power to the electrode 20 while heated gas is being ejected into the chamber from the multiple gas holes 11 in the substrate 10.

[0019] Incidentally, in the shower plate 1, there is a difference in the thermal expansion coefficient between the base 10 and the electrode 20. For this reason, when expansion and contraction are repeated due to the thermal cycle for generating plasma, for example, stress may concentrate on the portion of the base 10 that contacts the outer periphery of the electrode 20, and cracks may occur in the base 10.

[0020] In contrast, the shower plate 1 according to the first embodiment has one or more slits 22 in the electrode 20. A portion of the base 10 is located in the slit 22. When expansion and contraction due to thermal cycles are repeated, the portion of the base 10 located in the slit 22 comes into contact with the inner wall surface of the slit 22. Therefore, when expansion and contraction due to thermal cycles are repeated, stress from the electrode 20 is dispersed to the portion of the base 10 within the slit 22, and stress concentration in the portion of the base 10 that contacts the outer periphery of the electrode 20 is reduced. As a result, the shower plate 1 according to the first embodiment can suppress the occurrence of cracks in the base 10, thereby improving reliability against thermal cycles.

[0021] Here, the configuration of the slits 22 will be described in more detail with reference to Figures 3 and 4. Figure 3 is a plan cross-sectional view of the periphery of the electrode 20 in the shower plate 1 according to the first embodiment. Note that Figure 3 shows a cross-sectional view taken along line III-III in Figure 2. As described above, the electrode 20 has one or more slits 22 in which a part of the base 10 is located.

[0022] The electrode 20 may have a central portion 20a that does not have multiple through-holes 21 and an annular peripheral portion 20b that surrounds the central portion 20a and has multiple through-holes 21. One or more slits 22 may be located in the peripheral portion 20b of the electrode 20. In other words, the central portion 20a of the electrode 20 does not need to have multiple through-holes 21 and one or more slits 22. By providing the slits 22 in the peripheral portion 20b rather than the central portion 20a of the electrode 20, the strength of the central portion 20a can be maintained, thereby preventing damage to the electrode 20 even when an external force is applied to the electrode 20 through the base 10. Furthermore, by providing the slits 22 in the peripheral portion 20b, it is possible to prevent the slits 22 from interfering with the flow of current between the central portion 20a and the peripheral portion 20b, for example, when RF power is applied to the electrode 20.

[0023] The one or more slits 22 may extend in the radial direction of the peripheral portion 20b of the electrode 20. Specifically, the one or more slits 22 may extend along the radial direction of the peripheral portion 20b from the outer peripheral edge of the electrode 20 to a position close to the central portion 20a. By having the one or more slits 22 extend in the radial direction of the peripheral portion 20b, thermal expansion of the electrode 20 along the circumferential direction of the peripheral portion 20b is alleviated, thereby further reducing stress concentration in the portion of the base 10 that contacts the outer peripheral edge of the electrode 20.

[0024] The length of each of the one or more slits 22 may be greater than the diameter of each of the plurality of through holes 21. This increases the contact area between the inner wall surface of the slit 22 and the part of the base 10 located inside the slit 22 when expansion and contraction due to thermal cycles are repeated, thereby allowing the stress from the electrode 20 to be efficiently dispersed to the part of the base 10.

[0025] Fig. 4 is a schematic enlarged view of part E shown in Fig. 3. As shown in Fig. 4, the ends 22a of one or more slits 22 may be rounded. By rounding the ends 22a of one or more slits 22, even if the vicinity of the slit 22 of the electrode 20 thermally expands due to thermal cycling, the stress applied from the expanded electrode 20 to a part of the base 10 located inside the slit 22 can be dispersed.

[0026] The configuration of the slits 22 according to the first embodiment is not limited to the examples shown in Fig. 3 and Fig. 4. Fig. 5 is a plan cross-sectional view of the periphery of the electrode 20 in the shower plate 1 according to the first modification of the first embodiment. Fig. 5 shows a plan cross-sectional view corresponding to the cross-sectional view taken along the line III-III in Fig. 2.

[0027] 5, one or more slits 22A according to Modification 1 may extend in the circumferential direction of the peripheral portion 20b of the electrode 20. Specifically, one or more slits 22A may extend in an arc shape of a predetermined length along the circumferential direction of the peripheral portion 20b. By having one or more slits 22A extend in the circumferential direction of the peripheral portion 20b, thermal expansion of the electrode 20 along the radial direction of the peripheral portion 20b is alleviated, thereby further reducing stress concentration in the portion of the base 10 that contacts the outer periphery of the electrode 20.

[0028] Here, the "circumferential direction of the peripheral portion 20b" refers to a direction perpendicular to the radial direction of the peripheral portion 20b. Therefore, the one or more slits 22A do not necessarily need to extend in an arc shape along the circumferential direction of the peripheral portion 20b. For example, the one or more slits 22A may extend linearly along the circumferential direction of the peripheral portion 20b (i.e., a direction perpendicular to the radial direction of the peripheral portion 20b).

[0029] 6 is a plan cross-sectional view of the periphery of the electrode 20 in the shower plate 1 according to the second modification of the first embodiment. Note that Fig. 6 shows a plan cross-sectional view corresponding to the cross-sectional view taken along the line III-III in Fig. 2.

[0030] 6, the one or more slits 22B according to Modification 2 extend in the circumferential direction of the peripheral portion 20b of the electrode 20, similar to the slits 22A according to Modification 1. The one or more slits 22B are arranged along the radial direction of the peripheral portion 20b of the electrode 20. Of the one or more slits 22B, the slit 22B located outermost in the radial direction of the peripheral portion 20b is located further outward than the multiple through-holes 21 in the radial direction of the peripheral portion 20b.

[0031] In this way, by positioning the slits 22B radially outward of the plurality of through holes 21 in the peripheral portion 20b, the part of the base 10 located within the slits 22B can be brought closer to the outer periphery of the electrode 20. This allows the part of the base 10 located within the slits 22B to block heat transfer from the outer periphery of the electrode 20, thereby improving the thermal uniformity of the shower plate 1.

[0032] 7 is a plan cross-sectional view of the periphery of the electrode 20 in the shower plate 1 according to the third modification of the first embodiment. Note that Fig. 7 shows a plan cross-sectional view corresponding to the cross-sectional view taken along the line III-III in Fig. 2.

[0033] As shown in FIG. 7 , one or more slits 22C according to Modification 3 may extend in the circumferential direction of the peripheral portion 20b of the electrode 20, similar to the slits 22A according to Modification 1. The one or more slits 22C may be arranged along the radial direction of the peripheral portion 20b of the electrode 20. Of the one or more slits 22C, the width of the slits 22C relatively closer to the central portion 20a of the electrode 20 may be greater than the width of the slits 22C relatively farther from the central portion 20a. The central portion 20a of the electrode 20 is more susceptible to thermal stress than other portions due to repeated expansion and contraction caused by thermal cycles. Increasing the width of the slits 22C near the central portion 20a increases the strength of the portion of the substrate 10 located within the slits 22C near the central portion 20a, thereby improving durability against thermal stress.

[0034] 8 is a plan cross-sectional view of the periphery of the electrode 20 in the shower plate 1 according to the fourth modification of the first embodiment. Note that Fig. 8 shows a plan cross-sectional view corresponding to the cross-sectional view taken along the line III-III in Fig. 2.

[0035] 8, one or more slits 22D according to Modification 4 may include a first slit 22-1 and a second slit 22-2. The first slit 22-1 extends in the radial direction of the peripheral portion 20b of the electrode 20. The second slit 22-2 extends in the circumferential direction of the peripheral portion 20b of the electrode 20 and may intersect with the first slit 22-1.

[0036] In this way, one or more slits 22D have first slits 22-1 and second slits 22-2 that extend in the radial and circumferential directions of the peripheral portion 20b and intersect with each other, thereby mitigating thermal expansion of the electrode 20 along the radial and circumferential directions of the peripheral portion 20b, thereby further reducing stress concentration in the portion of the base 10 that contacts the outer periphery of the electrode 20.

[0037] 9 is a plan cross-sectional view of the periphery of the electrode 20 in the shower plate 1 according to the fifth modified example of the first embodiment. Note that Fig. 9 shows a plan cross-sectional view corresponding to the cross-sectional view taken along the line III-III in Fig. 2.

[0038] 9, one or more slits 22E according to Modification 5 may be divided into a plurality of individual slits aligned in the longitudinal direction. This increases the contact area between the inner wall surface of each individual slit and a portion of base 10 located within each individual slit when expansion and contraction due to thermal cycling is repeated, and allows stress from electrode 20 to be efficiently distributed to the portion of base 10.

[0039] FIG. 10 is an enlarged plan cross-sectional view of the periphery of slit 22F in shower plate 1 according to modified example 6 of the first embodiment.

[0040] 10, one or more slits 22F according to Modification 6 have recesses 22b recessed in the width direction of the one or more slits 22F on their inner wall surfaces. Specifically, the one or more slits 22F are positioned so as to overlap, in plan view, with a portion of at least one through hole 21 (three in the example of FIG. 10). The inner wall surface of the recesses 22b is formed by the inner wall surface of at least one through hole 21 that partially overlaps with the one or more slits 22F.

[0041] In this way, by providing recesses 22b on the inner wall surface of one or more slits 22F, it is possible to increase the area of ​​contact between the inner wall surface of slit 22F and a part of base 10 located inside slit 22F when expansion and contraction due to thermal cycles are repeated, thereby making it possible to efficiently distribute stress from electrode 20 to a part of base 10 when expansion and contraction due to thermal cycles are repeated.

[0042] FIG. 11 is an enlarged plan cross-sectional view of the periphery of a slit 22G in a shower plate 1 according to a seventh modification of the first embodiment.

[0043] As shown in FIG. 11 , one or more slits 22G according to Modification 7 have recesses 22b on their inner wall surfaces, similar to one or more slits 22F according to Modification 6. The boundary portions 22ba where the recesses 22b intersect with the inner wall surfaces of one or more slits 22G are rounded. The boundary portions 22ba of the recesses 22b are more likely to generate thermal stress than other portions when repeated expansion and contraction occurs due to thermal cycling. Because the boundary portions 22ba of the recesses 22b are rounded, even if the vicinity of the slits 22G of the electrode 20 thermally expands due to thermal cycling, the stress applied from the expanded electrode 20 to the portion of the base 10 located within the slits 22G can be dispersed.

[0044] A gap may be formed between boundary portion 22ba of recess 22b and a portion of base 10 located within one or more slits 22G. By positioning boundary portion 22ba of recess 22b with a gap between it and a portion of base 10, the portion of base 10 is less likely to receive stress from boundary portion 22ba even if the vicinity of slit 22G of electrode 20 thermally expands due to thermal cycling, for example. This makes it possible to suppress damage to the portion of base 10 located within slit 22G.

[0045] Although a gap is formed between the boundary portion 22ba of the recess 22b and a portion of the base 10 in this example, a gap may also be formed between a portion of the inner wall surface of one or more slits 22G other than the recess 22b and a portion of the base 10. In other words, it is sufficient that a gap is formed between at least a portion of the inner wall surface of one or more slits 22G and a portion of the base 10 located within the one or more slits 22G. By positioning at least a portion of the inner wall surface of one or more slits 22G with a gap between it and a portion of the base 10, even if the vicinity of the slit 22G of the electrode 20 thermally expands due to, for example, a thermal cycle, the portion of the base 10 is less likely to be subjected to stress from the inner wall surface of the slit 22G. This makes it possible to suppress damage to the portion of the base 10 located within the slit 22G.

[0046] [Second embodiment] Fig. 12 is a side cross-sectional view showing an outline of a shower plate 1A according to the second embodiment. Fig. 13 is a plan cross-sectional view of the periphery of electrode 20 in shower plate 1A according to the second embodiment. Fig. 13 shows a cross-sectional view taken along line XIII-XIII in Fig. 12.

[0047] As shown in FIG. 12, a shower plate 1A according to the second embodiment has a base 10A, an electrode 20, a resistance heating element 30, and a shaft .

[0048] The substrate 10A has a plurality of gas holes 11A, a flow path 12, and an inlet 13.

[0049] The gas holes 11A eject gas heated by a resistance heating element 30, which will be described later.

[0050] The flow path 12 supplies heated gas to the plurality of gas holes 11A. The flow path 12 may be provided with a plurality of supports 12a extending in the thickness direction of the base 10A to support the flow path 12. By appropriately supporting the flow path 12 with the plurality of supports 12a, defects due to deformation of the base 10A can be reduced, for example, even when the base 10A is subjected to an external force in the thickness direction.

[0051] The inlet 13 introduces heated gas into the flow path 12. The gas introduced into the flow path 12 from the inlet 13 is diffused in the flow path 12 while being heated by the resistance heating element 30, and then ejected to the outside from the plurality of gas holes 11A.

[0052] As shown in FIG. 13 , the inlet 13 may be positioned so as to overlap the central portion 20a of the electrode 20 in a plan view. In FIG. 13 , the position of the inlet 13 is indicated by a two-dot chain line. By positioning the inlet 13 so as to overlap the central portion 20a of the electrode 20 in a plan view, gas introduced from the inlet 13 into the flow path 12 can be made to collide with the central portion 20a of the electrode 20. The heat of the gas colliding with the central portion 20a is easily transferred to the peripheral portion 20b surrounding the central portion 20a. This maintains the uniform temperature of the electrode 20. Therefore, the shower plate 1A according to the second embodiment can eject heated gas while maintaining the uniform temperature of the electrode 20. The electrode 20 may be integral and not divided in areas other than the through-holes 21 and the slits 22. This configuration may be referred to as solid.

[0053] Returning to the description of Fig. 12, the electrode 20 and the resistance heating element 30 are located inside the base 10A. Specifically, the electrode 20 is located downstream of the flow path 12 of the base 10A in the gas flow direction, and the resistance heating element 30 is located upstream of the flow path 12 of the base 10A in the gas flow direction. The position of the resistance heating element 30 is not limited to the position shown in Fig. 12, and it may also be located downstream of the flow path 12 of the base 10A in the gas flow direction. The configuration of the electrode 20 is similar to that of the electrode 20 in the first embodiment.

[0054] The resistance heating element 30 is laid out in a predetermined pattern, such as a spiral or meandering pattern, so that its outer shape in plan view is circular.

[0055] The resistance heating element 30 generates heat by Joule heat generated by power supplied from a power supply unit (not shown), thereby enabling the resistance heating element 30 to heat the gas ejected from the plurality of gas holes 11A.

[0056] The shaft 40 may have a cylindrical shape with both ends open. The shaft 40 may be connected to the inlet 13 of the base 10A. In one embodiment, the shaft 40 is connected to the inlet 13 by being bonded (adhered) to the surface of the base 10A with an adhesive. In another embodiment, the shaft 40 may be bonded to the surface of the base 10A by solid-state welding. The shaft 40 supplies gas supplied from a gas supply source (not shown) to the inlet 13.

[0057] The shape of the shaft 40 is arbitrary. In one embodiment, the shape of the shaft 40 is cylindrical. In another embodiment, the shape of the shaft 40 may be, for example, a square tube.

[0058] The material of the shaft 40 is arbitrary. In one embodiment, the material of the shaft 40 is insulating ceramics. In another embodiment, the material of the shaft 40 may be, for example, a conductive material (metal). The ceramic that constitutes the shaft 40 is a sintered body whose main component is, for example, aluminum nitride (AlN), aluminum oxide (Al2O3, alumina), silicon carbide (SiC), silicon nitride (Si3N4), or the like.

[0059] [others] In each of the above-described embodiments, the slits 22, 22A to 22G may be bottomed slits that do not penetrate the electrode 20 in the thickness direction. Even in this case, a part of the base 10 is located in the slits 22, 22A to 22G. By providing the electrode 20 with the slits 22, 22A to 22G that are bottomed slits, it is possible to suppress the occurrence of cracks in the base 10 while maintaining the strength of the electrode 20.

[0060] [Shower plate manufacturing method] Next, a method for manufacturing a shower plate according to the present disclosure will be described. Here, as an example, a method for manufacturing the shower plate 1 according to the first embodiment will be described.

[0061] First, a base is formed by stacking multiple ceramic green sheets. Specifically, ceramic green sheets that form the base and metal sheets that form the electrodes are prepared. Here, to form multiple gas holes and multiple through holes, multiple first holes with relatively small diameters are pre-formed in the multiple ceramic green sheets, and multiple second holes with relatively large diameters are pre-formed in the metal sheets. In addition, one or more slits are pre-formed in the metal sheets. Then, the prepared sheets are stacked so that each first hole corresponds to each second hole. Note that, instead of stacking metal sheets, electrodes may be formed by printing using a metal paste.

[0062] Next, the laminate of the ceramic green sheets and the metal sheets is degreased and fired. The firing temperature is, for example, 1700°C or higher and 1850°C or lower. This results in a shower plate according to the present disclosure. During firing of the laminate, warping of the laminate may occur due to the difference in thermal expansion coefficient between the ceramic green sheets and the metal sheets. Here, by forming one or more slits in advance in the metal sheets of the laminate, deformation of the metal sheets is suppressed. As a result, warping of the laminate after firing can be reduced.

[0063] [effect] As described above, the shower plate according to the embodiment (for example, shower plate 1, 1A) includes a base (for example, base 10, 10A) and an electrode (for example, electrode 20). The base is made of ceramics and has a plurality of gas holes (for example, gas holes 11, 11A) that eject heated gas. The electrode is a solid electrode located inside the base and has a plurality of through holes (for example, through hole 21) that correspond to the positions of the plurality of gas holes. The electrode has one or more slits (for example, slits 22, 22A to 22G) in which a part of the base is located. As a result, the shower plate according to the embodiment can improve reliability against thermal cycles.

[0064] Furthermore, the electrode according to the embodiment may have a central portion (e.g., central portion 20a) that does not have a plurality of through-holes, and a ring-shaped peripheral portion (e.g., peripheral portion 20b) that surrounds the central portion and has a plurality of through-holes. One or more slits may be located in the peripheral portion. As a result, the shower plate according to the embodiment can suppress damage to the electrode even when an external force is applied to the electrode via the base.

[0065] Furthermore, one or more slits according to the embodiment may extend in a radial direction of the peripheral portion. Furthermore, one or more slits may extend in a circumferential direction of the peripheral portion. This makes it possible to further reduce the concentration of stress on the portion of the base that contacts the outer periphery of the electrode.

[0066] Furthermore, the one or more slits according to the embodiment may be arranged along the radial direction of the peripheral portion. Furthermore, of the one or more slits, the slit located at the outermost position in the radial direction of the peripheral portion may be located further outward in the radial direction of the peripheral portion than the plurality of through holes. This allows the shower plate according to the embodiment to improve thermal uniformity.

[0067] Furthermore, the one or more slits according to the embodiment may be arranged along the radial direction of the periphery. Of the one or more slits, the width of a slit relatively closer to the center may be greater than the width of a slit relatively farther from the center. This allows the shower plate according to the embodiment to have improved durability against thermal stress.

[0068] Furthermore, the one or more slits according to the embodiment may include a first slit (e.g., first slit 22-1) extending in the radial direction of the peripheral portion, and a second slit (e.g., second slit 22-2) extending in the circumferential direction of the peripheral portion and intersecting the first slit. This makes it possible to further reduce the concentration of stress on the portion of the shower plate according to the embodiment that contacts the outer periphery of the electrode of the base.

[0069] Furthermore, the length of each of the one or more slits according to the embodiment may be greater than the diameter of each of the plurality of through holes, thereby enabling the shower plate according to the embodiment to efficiently distribute stress from the electrode to a portion of the base.

[0070] Furthermore, the ends of one or more slits according to the embodiment (for example, end 22a) may be rounded. As a result, according to the shower plate according to the embodiment, even if the vicinity of the slit of the electrode thermally expands due to thermal cycling, the stress applied from the expanded electrode to the part of the substrate located inside the slit can be dispersed.

[0071] Furthermore, one or more slits according to the embodiment may have a recess (e.g., recess 22b) recessed in the width direction of one or more slits on the inner wall surface, which allows the shower plate according to the embodiment to efficiently distribute stress from the electrode to a part of the base when expansion and contraction due to thermal cycles are repeated.

[0072] Furthermore, one or more slits according to the embodiment may be positioned so as to overlap a portion of at least one through hole in a plan view. The inner wall surface of the recess may be formed by the inner wall surface of at least one through hole that partially overlaps with one or more slits. As a result, with the shower plate according to the embodiment, stress from the electrode can be efficiently distributed to a portion of the base when expansion and contraction due to thermal cycles are repeated.

[0073] Furthermore, a boundary portion (e.g., boundary portion 22ba) that intersects with the inner wall surface of one or more slits of the recess according to the embodiment may be rounded. As a result, according to the shower plate according to the embodiment, even if the vicinity of the slit of the electrode thermally expands due to thermal cycling, the stress applied from the expanded electrode to the part of the base located inside the slit can be dispersed.

[0074] Furthermore, a gap may be formed between the boundary of the recess according to the embodiment and a portion of the base located in one or more slits, thereby preventing damage to the portion of the base located in the slit according to the shower plate according to the embodiment.

[0075] Furthermore, a gap may be formed between at least a portion of the inner wall surface of one or more slits according to the embodiment and a portion of the substrate located in the one or more slits, thereby preventing damage to the portion of the substrate located in the slit according to the embodiment.

[0076] Furthermore, the substrate according to the embodiment may have a flow path (e.g., flow path 12) for supplying gas to a plurality of gas holes (e.g., gas hole 11A) and an inlet (e.g., inlet 13) for introducing gas into the flow path. The inlet may be positioned so as to overlap with the center portion in a plan view. This allows the shower plate according to the embodiment to eject heated gas while maintaining uniform heating of the electrode.

[0077] Further advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. [Explanation of symbols]

[0078] 1. 1A shower plate 10, 10A base 11, 11A gas hole 12 Flow path 13 Introduction 20 electrodes 20a Central 20b Periphery 21 Through hole 22, 22A~22G Slit 22-1 First slit 22-2 Second slit 22a end 22b Recess 22ba border area

Claims

1. a base made of ceramic and having a plurality of gas holes for ejecting heated gas; at least one or more plate-shaped electrodes located inside the base and having a plurality of through holes respectively corresponding to the positions of the plurality of gas holes; Equipped with the electrode has one or more slits through which a part of the substrate is positioned in an area other than the gas holes; The slit has a width and a length that is greater than the width and extends in any direction; the electrode has a first portion and a second portion positioned on either side of the slit, the electrode has a region where the first portion and the second portion are electrically connected on the same surface, excluding the slit; Shower plate.

2. The electrode is a central portion that does not have the plurality of through holes; an annular peripheral portion surrounding the central portion and having the plurality of through holes; and The shower plate of claim 1 , wherein the one or more slits are located in the periphery.

3. The shower plate according to claim 2 , wherein the one or more slits extend in a radial direction of the periphery.

4. The shower plate according to claim 2 , wherein the one or more slits extend in a circumferential direction of the peripheral portion.

5. When the one or more slits are a plurality of slits, the one or more slits are arranged along a radial direction of the periphery, The shower plate according to claim 4 , wherein the slit located radially outermost of the peripheral portion among the one or more slits is located radially outer than the plurality of through holes of the peripheral portion.

6. When the one or more slits are a plurality of slits, the one or more slits are arranged along a radial direction of the periphery, The shower plate according to claim 4 , wherein a width of the slit relatively closer to the center among the one or more slits is greater than a width of the slit relatively farther from the center.

7. When the one or more slits are a plurality of slits, the one or more slits are a first slit extending in a radial direction of the peripheral portion; a second slit extending in the circumferential direction of the peripheral portion and intersecting the first slit; The shower plate of claim 2 , comprising:

8. The shower plate according to claim 1 , wherein a length of each of the one or more slits is greater than a diameter of each of the plurality of through holes.

9. The shower plate of claim 1 , wherein ends of the one or more slits are rounded.

10. The shower plate according to claim 1 , wherein the one or more slits have a recessed portion on an inner wall surface that is recessed in a width direction of the one or more slits.

11. the one or more slits are positioned so as to overlap with a portion of at least one of the through holes in a plan view, The shower plate according to claim 10 , wherein an inner wall surface of the recess is formed by an inner wall surface of at least one of the through holes that partially overlaps with the one or more slits.

12. The shower plate according to claim 10 , wherein a boundary portion of the recess intersecting with an inner wall surface of the one or more slits is rounded.

13. The shower plate according to claim 12 , wherein a gap is formed between the boundary portion of the recess and a part of the base located within the one or more slits.

14. The shower plate according to claim 1 , wherein a gap is formed between at least a part of an inner wall surface of the one or more slits and a part of the base body located within the one or more slits.

15. The substrate is a flow path for supplying the gas to the plurality of gas holes; an inlet for introducing the gas into the flow path; and The shower plate according to claim 2 , wherein the inlet is positioned so as to overlap the central portion in a plan view.

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