Member for semiconductor manufacturing apparatus

Abstract

This member for a semiconductor manufacturing apparatus includes: a ceramic plate having an object placement surface on an upper surface; a plug arrangement hole penetrating the ceramic plate in a vertical direction; a plug arranged in the plug arrangement hole; a gas flow path provided inside the plug and extending from a lower surface of the plug to an outer peripheral surface without reaching an upper surface; and a gas discharge part formed at a contact interface between an outer peripheral surface of the plug arrangement hole and an inner peripheral surface of the plug and allowing gas to be discharged from the gas flow path to the object placement surface.

Description

Member for semiconductor manufacturing apparatus

[0001] The present invention relates to a member for a semiconductor manufacturing apparatus.

[0002] Conventionally, as a member for a semiconductor manufacturing apparatus, a member including a ceramic plate having a wafer mounting portion on the upper surface and a plug disposed in a plug arrangement hole penetrating the ceramic plate in the vertical direction is known. For example, in Patent Document 1, in such a member for a semiconductor manufacturing apparatus, a female screw is provided on the inner peripheral surface of the plug arrangement hole, a male screw is provided on the outer peripheral surface of the dense plug, and a gas passage communicating from the lower surface to the upper surface of the ceramic plate is provided between the female screw of the plug arrangement hole and the male screw of the dense plug. In Patent Document 1, since the gas passage is a spiral passage formed along the screw, the creepage distance from the wafer mounting surface to the base plate can be increased, whereby arc discharge occurring through the gas flow path when processing a wafer with plasma can be suppressed. Further, for example, Patent Document 2 discloses a plug used for a member for a semiconductor manufacturing apparatus, which includes a spiral gas flow path extending from the lower surface to the upper surface of the plug main body inside the plug main body, and a branch path branching in the middle of the spiral gas flow path and opening to the outer peripheral surface of the plug main body. In Patent Document 2, a molding die used for manufacturing the plug is provided with a spiral core corresponding to the spiral gas flow path, and the spiral core is held on the inner peripheral surface of the molding die via a holding core corresponding to the branch path, so that damage to the spiral core can be prevented, and the plug can be manufactured with high yield.

[0003] International Publication No. 2024 / 116412 Pamphlet, Japanese Unexamined Patent Publication No. 2024-088883

[0004] However, in Patent Document 1 and Patent Document 2, although the occurrence of discharge through the gas passage is suppressed due to the spiral shape of the gas flow path or the like, the suppression may still be insufficient in some cases.

[0005] The present invention has been made to solve such a problem, and a main object of the present invention is to suppress the occurrence of discharge through a gas passage.

[0006] [1] The semiconductor manufacturing apparatus component of the present invention comprises: a ceramic plate having an object placement surface on its upper surface; a plug placement hole penetrating the ceramic plate in the vertical direction; a plug placed in the plug placement hole; a gas passage provided inside the plug, extending from the lower surface of the plug to the outer peripheral surface without reaching the upper surface; and a gas discharge section configured at the contact interface between the inner peripheral surface of the plug placement hole and the outer peripheral surface of the plug, which discharges gas from the gas passage to the object placement surface.

[0007] In this semiconductor manufacturing equipment component, the gas flow path inside the plug opens to the outer surface of the plug, not the top surface. As a result, the orientation of the gas flow path space and the orientation of the electric field during plasma generation are approximately perpendicular (see Figure 6C), suppressing the acceleration of charged particles (such as electrons generated by the ionization of gas molecules). This suppresses discharges caused by accelerated charged particles colliding with other gas molecules. Furthermore, gas is released onto the object placement surface from a gas release section formed at the contact interface between the inner surface of the plug placement hole and the outer surface of the plug. In the gas release section, the gas passage is composed of minute gaps caused by the surface roughness of the plug placement hole and the plug itself, thus suppressing the acceleration of charged particles and preventing discharges.

[0008] In this specification, the present invention may be described using terms such as up and down, left and right, front and back, but up and down, left and right, and front and back are merely relative positional relationships. Therefore, when the orientation of a semiconductor manufacturing equipment component is changed, up and down may become left and right, or left and right may become up and down, but such cases are also included within the technical scope of the present invention.

[0009] [2] In the semiconductor manufacturing apparatus component of the present invention (the semiconductor manufacturing apparatus component described in [1] above), the gas discharge portion may be configured such that the inner circumferential surface of the plug placement hole and the outer circumferential surface of the plug are in contact, each having a maximum height roughness Rz of 3 μm or more and 10 μm or less. If the maximum height roughness Rz is 3 μm or more, gas can be supplied more smoothly to the object placement surface. Also, if the maximum height roughness Rz is 10 μm or less, discharge can be further suppressed.

[0010] [3] In the semiconductor manufacturing apparatus component of the present invention (the semiconductor manufacturing apparatus component described in [1] or [2] above), the outer peripheral end of the gas flow path may be provided such that the vertical inclination with respect to the direction perpendicular to the central axis of the plug is within ±30°. In this way, the orientation of the space of the gas flow path and the direction of the electric field during plasma processing become substantially perpendicular around the outer peripheral end of the gas flow path, and the acceleration of charged particles is further suppressed, thereby further suppressing discharge.

[0011] [4] In the semiconductor manufacturing apparatus component of the present invention (the semiconductor manufacturing apparatus component described in any of [1] to [3] above), the gas flow path may have a spiral flow path provided spirally inside the plug and a branch path that branches off from the spiral flow path and reaches the outer surface of the plug. By having a spiral flow path and a branch path, the creepage distance of the gas flow path can be made longer, and discharge can be suppressed further.

[0012] [5] In the semiconductor manufacturing apparatus component of the present invention (the semiconductor manufacturing apparatus component described in [4] above), the branching path may branch off at multiple points along the spiral flow path and be provided at equal angular intervals along the concentric circles of the plug when viewed from above. This allows for smoother supply of gas to the object placement surface.

[0013] [6] In the semiconductor manufacturing apparatus component of the present invention (the semiconductor manufacturing apparatus component described in any of [1] to [5] above), the outer circumferential surface of the plug may be inclined with respect to the axial direction of the plug such that the lower surface of the plug is closer to the central axis of the plug. This makes it possible to increase the creepage distance between the inner circumferential surface of the plug placement hole and the outer circumferential surface of the plug, thereby further suppressing discharge. In addition, the plug can be easily press-fitted and fixed into the plug placement hole.

[0014] [7] In the semiconductor manufacturing apparatus component of the present invention (the semiconductor manufacturing apparatus component described in any of [1] to [6] above), the maximum vertical length Hmax in the gas flow path may be 0.5 mm or less. This suppresses the acceleration of charged particles in the gas flow path and further suppresses the occurrence of discharge in the gas flow path.

[0015] [8] The semiconductor manufacturing apparatus component of the present invention (the semiconductor manufacturing apparatus component described in any of [1] to [7] above) may further include a conductive substrate bonded to the lower surface of the ceramic plate and provided with a gas supply passage communicating with the plug placement hole.

[0016] A longitudinal cross-sectional view of semiconductor manufacturing equipment component 10. A plan view of ceramic plate 20. A perspective view of plug 50. A plan view of plug 50. A partial enlarged view of Figure 1. An explanatory diagram illustrating the relationship between the direction of the electric field and the direction of space. A perspective view of plug 150.

[0017] Preferred embodiments of the present invention will be described with reference to the drawings. Figure 1 is a longitudinal cross-sectional view of a wafer mounting stage 10, which is an example of a semiconductor manufacturing apparatus component of the present invention; Figure 2 is a plan view of a ceramic plate 20; Figure 3 is a perspective view of a plug 50; Figure 4 is a plan view of a plug 50; and Figure 5 is a partially enlarged view of Figure 1 (a longitudinal cross-sectional view of the peripheral portion of the plug 50).

[0018] The wafer mounting stage 10 comprises a ceramic plate 20, a base plate 30, and a metal bonding layer 40. The ceramic plate 20 is provided with plug placement holes 24 and plug placement holes 28, with plugs 50 placed in plug placement hole 24 and plugs 55 placed in plug placement hole 28.

[0019] The ceramic plate 20 is a ceramic disc (for example, 300 mm in diameter) made of an alumina sintered body or an aluminum nitride sintered body. The thickness of the ceramic plate 20 is, for example, 1 mm to 5 mm. The ceramic plate 20 has a wafer mounting surface 21 and a focus ring (FR) mounting surface 26 on its upper surface. The wafer mounting surface 21 is a circular surface on which the wafer W is placed. As shown in Figure 2, a seal band 21a is formed along the outer edge of the wafer mounting surface 21, and a plurality of small circular protrusions 21b are formed on the entire surface. The seal band 21a and the small circular protrusions 21b are of the same height, for example, several μm to several tens of μm. The part of the wafer mounting surface 21 that does not have the seal band 21a or the small circular protrusions 21b is called the reference surface 21c. The FR mounting surface 26 is an annular surface provided around the wafer mounting surface 21. The height of the FR mounting surface 26 is one step lower than the height of the wafer mounting surface 21. As shown in Figure 2, the FR mounting surface 26 has an FR support surface 26a and an annular recess 26b. The bottom surface of the recess 26b is one step lower than the FR support surface 26a. An annular focus ring 60 is placed on the FR mounting surface 26 in contact with the FR support surface 26a. The focus ring 60 is made of, for example, Si. A circumferential groove 62 is provided above the inner surface of the focus ring 60 so as not to come into contact with the wafer W. The outer diameter of the focus ring 60 is larger than the outer diameter of the ceramic plate 20. Therefore, the focus ring 60 is placed on the FR mounting surface 26 in an overhanging state, extending beyond the outside of the wafer mounting base 10. The ceramic plate 20 has electrodes 22 built in. The electrodes 22 are planar mesh electrodes used as electrostatic electrodes, and a DC voltage can be applied to them. When a DC voltage is applied to the electrode 22, the wafer W is attracted and fixed to the wafer mounting surface 21 (specifically, the upper surface of the seal band 21a and the upper surface of the circular small protrusion 21b) by electrostatic attraction force, and when the application of the DC voltage is removed, the attraction and fixation of the wafer W to the wafer mounting surface 21 is released. Note that the wafer W is an example of an object of the present invention, the wafer mounting surface 21 is an example of an object mounting surface of the present invention, and the top surface of the seal band 21a and the top surface of the circular small protrusion 21b on the wafer mounting surface 21 are examples of object support surfaces of the present invention.Furthermore, the focus ring 60 is an example of an object of the present invention, the FR mounting surface 26 is an example of an object mounting surface of the present invention, and the FR support surface 26a of the FR mounting surface 26 is an example of an object support surface of the present invention. The ceramic plate 20 may be made, for example, by creating a molded body of ceramic powder containing electrodes 22 and then hot-press firing the molded body. The molded body in this case may be made by stacking multiple tape molded bodies, by a mold-casting method, or by compressing ceramic powder.

[0020] The plug placement holes 24 are holes that penetrate the ceramic plate 20 in the vertical direction, and are through holes that extend from the lower surface of the ceramic plate 20 to the reference surface 21c of the wafer mounting surface 21. The plug placement holes 24 are opposite the gas holes (gas supply passages) 34 of the base plate 30. The plug placement holes 24 penetrate the electrodes 22 in the vertical direction, but the electrodes 22 are not exposed on the inner circumferential surface of the plug placement holes 24. The plug placement holes 24 are tapered holes with a frustoconical space that tapers towards the bottom. As shown in Figure 2, the plug placement holes 24 are provided at multiple locations (for example, at multiple locations provided at equal intervals along the circumferential direction) so as to open to the reference surface 21c of the wafer mounting surface 21 of the ceramic plate 20.

[0021] The plug placement holes 28 are holes that penetrate the ceramic plate 20 in the vertical direction, and are through holes that extend from the lower surface of the ceramic plate 20 to the bottom surface of the recess 26b of the FR mounting surface 26. The plug placement holes 28 are opposite the gas holes 34 of the base plate 30. The plug placement holes 28 are tapered holes with a frustoconical space that tapers towards the bottom. As shown in Figure 2, the plug placement holes 28 are provided at multiple locations (for example, at multiple locations that are equally spaced along the circumferential direction) so as to open to the bottom surface of the recess 26b of the FR mounting surface 26 of the ceramic plate 20.

[0022] The base plate 30 is an example of a conductive substrate, and is a conductive disc with good thermal conductivity (a disc with the same diameter as or larger than the ceramic plate 20). Inside the base plate 30, a refrigerant channel 32 through which a refrigerant (for example, an electrically insulating liquid such as a fluorine-based inert liquid) circulates and gas holes 34 for supplying gas to plugs 50 and 55 are formed. The gas holes 34 are provided to penetrate the base plate 30 in the vertical direction and have a large-diameter portion 34a at the top. In a plan view, the large-diameter portion 34a encompasses the lower opening of the plug placement hole 24. In a plan view, the refrigerant channel 32 is formed in a continuous line from the inlet to the outlet across the entire surface of the base plate 30. Examples of materials for the base plate 30 include metals and composite materials. Examples of metals include Mo. Examples of composite materials include composite materials of metal and ceramic. Examples of composite materials of metals and ceramics include metal matrix composites (MMCs) and ceramic matrix composites (CMCs). Specific examples of such composite materials include materials containing Si, SiC, and Ti, and materials in which Al and / or Si are impregnated into a porous SiC body. Materials containing Si, SiC, and Ti are called SiSiCTi, materials in which Al is impregnated into a porous SiC body are called AlSiC, and materials in which Si is impregnated into a porous SiC body are called SiSiC. It is preferable to select a base plate 30 material with a thermal expansion coefficient similar to that of the ceramic plate 20. The base plate 30 is also used as an RF electrode. Specifically, an upper electrode (not shown) is placed above the wafer mounting surface 21, and plasma is generated when high-frequency power is applied between the upper electrode and the base plate 30, which are parallel plate electrodes.

[0023] The metal bonding layer 40 joins the lower surface of the ceramic plate 20 to the upper surface of the base plate 30. The metal bonding layer 40 is formed, for example, by TCB (Thermal Compression Bonding). TCB is a known method in which a metal bonding material is sandwiched between two members to be joined, and the two members are pressurized and joined while heated to a temperature below the solidus temperature of the metal bonding material. The metal bonding layer 40 may also be a layer formed of solder or metal brazing material. The metal bonding layer 40 has through holes 42. The through holes 42 are provided at a position opposite the large diameter portion 34a of the gas hole 34. The through holes 42 are provided coaxially with the large diameter portion 34a, and the diameter of the through holes 42 is the same as the diameter of the large diameter portion 34a. In this specification, "coaxial" includes not only cases where they are perfectly coaxial, but also cases where they are substantially coaxial (for example, when they are within tolerance) (the same applies hereinafter). Furthermore, in this specification, "identical" includes not only exact agreement but also substantial agreement (for example, falling within the tolerance range) (the same applies hereafter).

[0024] The plug 50 is positioned in the plug placement hole 24. The plug 50 may be fitted into the plug placement hole 24 by a method such as press-fitting. The plug 50 has a plug body 51 and a gas passage 52 formed inside the plug body 51. The plug body 51 is an electrically insulating dense material, and is made of the same material as the ceramic plate 20 (such as alumina or aluminum nitride). The plug body 51 is a frustoconical member that tapers to the bottom. The dense material may have a porosity of 5% or less (preferably 3% or less, more preferably 1% or less). The upper surface 51b of the plug body 51 is positioned below the lower surface of the wafer W (for example, on the same plane as the reference surface 21c). The lower surface of the wafer W coincides with the wafer support surface (top surface) of the seal band 21a and the circular small protrusion 21b. The plug 50 may be manufactured, for example, in accordance with the above-mentioned Patent Document 2, or it may be manufactured, for example, by firing a molded body obtained by mold casting. The same applies to plug 55.

[0025] The gas passage 52 is a passage that allows gas to flow, and as shown in Figure 3, it is formed so that the gas flows from an inlet 52a provided on the lower surface 51a of the plug body 51 to an outlet 52c provided on the outer circumferential surface 51c of the plug body 51, without going to the upper surface 51b of the plug body 51. The gas passage 52 is formed in a spiral shape here. The gas passage 52 has a spiral passage 53 provided inside the plug body 51 and a branch passage 54 that branches off from the spiral passage 53 and goes to the outer circumferential surface 51c of the plug body 51. The spiral passage 53 is provided so that it goes from the lower surface 51a of the plug body 51 to a virtual plane 51d that is lower than the upper surface 51b. The portion of the spiral passage 53 that opens to the lower surface 51b of the plug body 51 becomes the inlet 52a of the gas passage 52. The upper end 52d of the spiral channel 53 is sealed off by the portion of the plug body 51 above the virtual plane 51d and does not open to the upper surface 51b of the plug body 51. The branching passages 54 are provided so as to branch off at multiple points along the spiral channel 53 and are provided so as to reach the outer circumferential surface 51c of the plug body 51. The branching passages 54 are provided horizontally in the left-right direction. When the plug 50 is viewed from above, the multiple branching passages 54 are provided at equal angular intervals (180° intervals in Figure 4) along the concentric circles of the plug body 51. The portion of the branching passages 54 that opens to the outer circumferential surface 51c of the plug body 51 becomes the outlet 52c of the gas channel 52.

[0026] A gas release section 70 is provided at the contact interface between the inner circumferential surface 24c of the plug placement hole 24 and the outer circumferential surface 51c of the plug 50 (plug body 51), which releases gas from the gas flow path 52 to the wafer mounting surface 21. As shown in Figure 5, for example, a small gap is created at the interface between the plug placement hole 24 and the plug 50 due to the surface roughness of the inner circumferential surface 24c of the plug placement hole 24 and the outer circumferential surface 51c of the plug 50. This gap is used as the gas release section 70 to release gas from the outlet 52c of the gas flow path 52 to the wafer mounting surface 21. The maximum height roughness Rz of the inner circumferential surface 24c of the plug placement hole 24 is, for example, 3 μm or more and 10 μm or less. The maximum height roughness Rz of the outer circumferential surface 51c of the plug 50 is, for example, 3 μm or more and 10 μm or less. The inner circumferential surface 24c of the plug placement hole 24 and the outer circumferential surface 51c of the plug 50 may be left as is after firing, or they may be machined.

[0027] The plug 55 is positioned in the plug placement hole 28. The plug 55 may be fitted into the plug placement hole 28 by a method such as press-fitting. The plug 55 has a plug body 56 and a gas passage 57 formed inside the plug body 56. The plug body 56 and the gas passage 57 are generally the same as the plug body 51 and the gas passage 52, so the differences will be described below. The upper surface of the plug body 56 is positioned below the lower surface of the focus ring 60 (for example, on the same plane as the bottom surface of the recess 26b). The lower surface of the focus ring 60 coincides with the FR support surface 26a. The gas passage 57, like the gas passage 52, is formed so that the gas flows from an inlet provided on the lower surface of the plug body 56 to an outlet provided on the outer circumferential surface of the plug body 56 without going to the upper surface of the plug body 56.

[0028] A gas discharge section 75 is provided at the contact interface between the inner circumferential surface of the plug placement hole 28 and the outer circumferential surface of the plug 55 (plug body 56), which releases gas from the gas passage 57 to the FR mounting surface 26. Similar to the interface between the plug placement hole 24 and the plug 50, a small gap is created at the interface between the plug placement hole 28 and the plug 55 due to the surface roughness of the inner circumferential surface of the plug placement hole 28 and the outer circumferential surface of the plug 55. This gap is used as the gas discharge section 75 to release gas from the outlet of the gas passage 57 to the FR mounting surface 26. The maximum height roughness Rz of the inner circumferential surface of the plug placement hole 28 is, for example, 3 μm or more and 10 μm or less. Similarly, the maximum height roughness Rz of the outer circumferential surface of the plug 55 is, for example, 3 μm or more and 10 μm or less. The inner circumferential surface of the plug placement hole 28 and the outer circumferential surface of the plug 55 may be left as they are after firing, or they may be machined.

[0029] Next, an example of using the wafer mounting stand 10 configured in this way will be described. First, with the wafer mounting stand 10 installed in a chamber (not shown), the focus ring 60 is placed on the FR mounting surface 26, and the wafer W is placed on the wafer mounting surface 21. Then, the pressure inside the chamber is reduced using a vacuum pump to adjust to a predetermined vacuum level, and a DC voltage is applied to the electrode 22 of the ceramic plate 20 to generate electrostatic adsorption force, thereby adsorbing and fixing the wafer W to the wafer mounting surface 21 (specifically, the upper surface of the seal band 21a and the upper surface of the circular protrusion 21b). Next, the inside of the chamber is made into a reaction gas atmosphere with a predetermined pressure (for example, several tens to several hundreds of Pa), and in this state, a high-frequency voltage is applied between an upper electrode (not shown) provided on the ceiling of the chamber and the base plate 30 of the wafer mounting stand 10 to generate plasma. The surface of the wafer W is treated by the generated plasma. A refrigerant is circulated in the refrigerant flow path 32 of the base plate 30. Backside gas is introduced from a gas cylinder (not shown) into the gas hole 34. A thermal conductive gas (such as helium) is used as the backside gas. The backside gas is supplied and sealed into the space between the back surface of the wafer W and the reference surface 21c of the wafer mounting surface 21 through the gas hole 34, the through hole 42, and the plug 50. The backside gas is also supplied and sealed into the space between the back surface of the focus ring 60 and the recess 26b of the FR mounting surface 26 through the gas hole 34, the through hole 42, and the plug 55. The presence of this backside gas allows for efficient heat conduction between the wafer W, the focus ring 60, and the ceramic plate 20. Furthermore, the presence of electrically insulating plugs 50 and 55 placed in the plug placement holes 24 and 28 increases the creepage distance between the wafer W, the focus ring 60, and the base plate 30, thereby suppressing discharge within the plug placement holes 24 and 28.

[0030] Incidentally, when plasma is generated, a roughly upward electric field is created between the object, such as a wafer, and the base plate, as shown by the arrow in Figure 6A, due to the DC voltage applied to the electrostatic electrode and the high-frequency voltage applied between the upper electrode and the base plate. Here, if the gas flow path is provided to open on the upper surface of the plug, as in the conventional technology, the direction of the gas flow path space and the direction of the electric field become roughly parallel, as shown in Figure 6B, for example. As a result, charged particles (such as electrons generated by the ionization of gas molecules) may be accelerated and collide with other gas molecules, causing a discharge to occur in the gas flow path. In contrast, if the gas flow path is provided to open on the outer surface of the plug, as in the present invention, the direction of the gas flow path space and the direction of the electric field become roughly perpendicular, as shown in Figure 6C, for example. As a result, the acceleration of charged particles is suppressed, and the discharge in the gas flow path is suppressed. Furthermore, in the present invention, gas is released from the interface between the plug and the ceramic plate, but since the gas passage is composed of minute gaps caused by the surface roughness of the outer surface of the plug and the surface roughness of the inner surface of the plug placement hole, the acceleration of charged particles is suppressed, and the occurrence of discharge is suppressed.

[0031] In the wafer mounting table 10 described in detail above, the gas passage 52 provided inside the plug 50 opens to the outer peripheral surface 51c of the plug 50 rather than the upper surface 51b of the plug 50, thus suppressing discharge. The same applies to the plug 55. Furthermore, gas is released to the wafer mounting surface 21 from the gas release section 70, which is configured at the contact interface between the inner peripheral surface 24c of the plug placement hole 24 and the outer peripheral surface 51c of the plug 50, thus suppressing the occurrence of discharge. The same applies to the gas release section 75. In this way, the wafer mounting table 10 can suppress the occurrence of discharge through the gas passages.

[0032] Furthermore, the gas discharge section 70 may be configured such that the inner circumferential surface 24c of the plug placement hole 24 and the outer circumferential surface 51c of the plug 50 are in contact, with each having a maximum height roughness Rz of 3 μm or more and 10 μm or less. If the maximum height roughness Rz is 3 μm or more, gas can be supplied to the wafer mounting surface 21 more smoothly. Also, if the maximum height roughness Rz is 10 μm or less, discharge can be further suppressed. The same applies to the gas discharge section 75.

[0033] Furthermore, the outer peripheral end of the gas flow path 52 (the flow path near the outlet 52c, preferably the entire branch path 54) may be provided such that its vertical inclination with respect to the direction perpendicular to the central axis of the plug 50 is within ±30°. In this way, the orientation of the space of the gas flow path 52 and the direction of the electric field during plasma processing become approximately perpendicular around the outer peripheral end of the gas flow path 52, further suppressing the acceleration of charged particles and thus further suppressing discharge. The same applies to the gas flow path 57.

[0034] Furthermore, the gas flow path 52 includes a spiral flow path 53 provided spirally inside the plug 50, and a branch path 54 that branches off from the spiral flow path 53 and reaches the outer surface 51c of the plug 50. By having a spiral flow path 53 and a branch path 54, the creepage distance of the gas flow path can be made longer, and discharge can be further suppressed. The same applies to the gas flow path 57.

[0035] The branching paths 54 branch off at multiple points along the spiral flow path 53 and are arranged so as to be at equal angular intervals along the concentric circles of the plug 50 when viewed from above. This allows for a smoother supply of gas to the wafer mounting surface 21. The same applies to the branching paths of the gas flow path 57.

[0036] Furthermore, the outer circumferential surface 51c of the plug 50 is inclined with respect to the axial direction of the plug 50 such that the lower surface 51b side of the plug 50 is closer to the central axis of the plug. As a result, the creepage distance between the inner circumferential surface 24c of the plug placement hole 24 and the outer circumferential surface 51c of the plug 50 can be made longer, and discharge can be further suppressed. In addition, the plug can be easily press-fitted and fixed into the plug placement hole 24. The same applies to the plug 55.

[0037] Furthermore, the maximum vertical length Hmax (see Figure 5) in the gas flow path 52 (spiral flow path 53 and branch path 54) may be 0.5 mm or less. This suppresses the acceleration of charged particles within the gas flow path 52, further suppressing the occurrence of discharges within the gas flow path 52. If it is desirable to further suppress the occurrence of discharges within the gas flow path 52, it is preferable to set the maximum length Hmax to 0.3 mm or less. The diameter of the gas flow path 52 is preferably 0.5 mm or less, and more preferably 0.3 mm or less. The same applies to the gas flow path 57.

[0038] Furthermore, the wafer mounting stage 10 also has a base plate 30 (conductive substrate) which is used as a plasma generation electrode. When the wafer W is processed with plasma, a high voltage is applied between the wafer W and the base plate 30, creating conditions that facilitate discharge around the outlets of the gas flow paths 52 and 57 of the plugs 50 and 55. Therefore, there is great significance in applying the present invention.

[0039] It goes without saying that the present invention is not limited in any way to the embodiments described above, and can be implemented in various forms as long as they fall within the technical scope of the present invention.

[0040] For example, in the embodiment described above, the cross-section of the gas passage 52 (spiral passage 53 and branch passage 54) of the plug 50 is circular, but it is not limited to this, and for example, the cross-section of the gas passage 52 may be rectangular or elliptical. The same applies to the plug 55.

[0041] In the embodiment described above, one gas passage 52 is formed in the plug body 51, but the invention is not limited to this, and multiple gas passages 52 may be formed in the plug body 51. This would increase the amount of gas that can be supplied. The same applies to the plug 55.

[0042] In the embodiment described above, the branch path 54 was provided in a straight line in the horizontal direction, but the invention is not limited to this. For example, the branch path 54 may be provided in a straight line diagonally upward (or diagonally downward), or the branch path 54 may be provided in a curved manner rather than in a straight line. The same applies to the branch path of the plug 55.

[0043] In the above-described embodiment, the branch passages 54 are provided so as to branch at a plurality of locations in the middle of the spiral flow passage 53, but the present invention is not particularly limited thereto. For example, although the branch passages 54 are provided on both left and right sides of the spiral flow passage 53 in FIG. 4, they may be provided on either one of the left and right sides. Alternatively, the branch passage 54 may be provided at one location in the middle of the spiral flow passage 53. The branch passage 54 may be provided, for example, so as to branch from the upper half or the upper 1 / 4 portion of the spiral flow passage 53. This also applies to the branch passages of the plug 55.

[0044] In the above-described embodiment, the branch passages 54 are provided at 180° intervals along the concentric circles of the plug main body 51 when viewed in plan, but the present invention is not particularly limited thereto. For example, the angle may be set to 120°, 90°, or 60° instead of 180°. Further, the branch passages 54 may be provided at random intervals instead of equal angular intervals. This also applies to the branch passages of the plug 55.

[0045] In the above-described embodiment, the gas flow passage 52 has the spiral flow passage 53, but the present invention is not particularly limited thereto, and for example, a zigzag flow passage may be provided instead of the spiral flow passage 53. This also applies to the gas flow passage 57.

[0046] In the above-described embodiment, the upper surface of the plug 50 is flush with the reference surface 21c of the wafer mounting surface 21, but the present invention is not limited thereto, and it suffices that the upper surface is at a position lower than the wafer supporting surfaces (the top surfaces of the seal band 21a and the small circular protrusions 21b). Further, although the upper surface of the plug 55 is flush with the bottom surface of the recess 26b of the FR mounting surface 26, the present invention is not limited thereto, and it suffices that the upper surface is at a position lower than the FR supporting surface 26a.

[0047] In the above-described embodiment, the plug 50 and the plug 55 are each in the shape of a truncated cone tapered toward the lower side, but the present invention is not limited thereto, and for example, they may be in a cylindrical shape or in the shape of a truncated cone tapered toward the upper side.

[0048] In the above-described embodiment, the wafer mounting table 10 having the wafer mounting surface 21 and the FR mounting surface 26 has been described as an example of the member for a semiconductor manufacturing apparatus of the present invention, but the wafer mounting table 10 may not have the FR mounting surface 26. Further, the member for a semiconductor manufacturing apparatus of the present invention may be a focus ring mounting table that has the FR mounting surface 26 and does not have a wafer mounting surface.

[0049] In the above-described embodiment, the seal band 21a and the small circular protrusions 21b are formed on the wafer mounting surface 21, but the seal band 21a and the small circular protrusions 21b may not be formed. The wafer mounting surface 21 may be, for example, a flat surface.

[0050] In the above-described embodiment, the annular recess 26b is formed in the FR mounting surface 26, but the recess 26b may not be annular, and may be, for example, a circular recess that is arranged coaxially with the plug arrangement hole 28 and has a larger diameter than the plug arrangement hole 28. Further, the recess 26b may not be formed in the FR mounting surface 26.

[0051] In the above-described embodiment, the electrode 22 is arranged at a position corresponding to the wafer mounting surface 21, but instead of or in addition to this, it may be arranged at a position corresponding to the FR mounting surface 26.

[0052] In the above-described embodiment, an electrostatic electrode is exemplified as the electrode 22 incorporated in the ceramic plate 20, but the present invention is not particularly limited to this. For example, instead of or in addition to the electrode 22, a heater electrode (resistance heating element) may be incorporated in the ceramic plate 20, or an RF electrode may be incorporated therein.

[0053] In the above-described embodiment, the ceramic plate 20 and the base plate 30 are bonded with the metal bonding layer 40, but a resin adhesive layer may be used instead of the metal bonding layer 40.

[0054] In the embodiment described above, multiple gas holes 34 constituting a gas supply passage are provided independently in the base plate 30, but the embodiment is not limited to this. For example, the gas holes 34 may have one or more introduction openings for introducing gas from the back surface of the base plate 30, and may branch off from the introduction openings to open at positions opposite to the plug placement holes 24 and 28. In this way, the number of external gas pipes connected to the lower surface of the base plate 30 can be reduced to the number of plugs 50 and 55.

[0055] In the embodiments described above, plug 150 may be used instead of plug 50 or plug 55. Figure 7 is a reference perspective view of plug 150 (originally, the first to eighth gas passages 151 to 158 should be shown as hidden lines (dotted lines), but for convenience, they are shown as solid lines in this perspective view). Plug 150 is the same as plug 50 except that it has the first to eighth gas passages 151 to 158 instead of gas passage 52. In Figure 7, the same reference numerals are used for components that are the same as those in plug 50.

[0056] The first to eighth gas passages 151 to 158 are passages that allow gas to flow, and are formed so that the gas goes from a lower opening provided on the lower surface 51a of the plug body 51 to an outlet provided on the outer peripheral surface 51c of the plug body without going to the upper surface 51b of the plug body 51. The first, third, fifth, and seventh gas passages 151, 153, 155, and 157 are formed as first, third, fifth, and seventh spiral passages 151a, 153a, 155a, and 157a, which are flat, rectangular, band-shaped passages that rotate clockwise from top to bottom, and the first, third, fifth, and seventh branch passages 151b, 153b, 155b, and 157b that branch off from there and go to the outer peripheral surface of the plug body 51. The first, third, fifth, and seventh branch passages 151b, 153b, 155b, and 157b are flat, rectangular, strip-shaped flow channels that branch off from the first, third, fifth, and seventh spiral flow channels 151a, 153a, 155a, and 157a at multiple points (two points in this case) and reach the outer surface 51c of the plug body 51. The first, third, fifth, and seventh branch passages 151b, 153b, 155b, and 157b are arranged approximately horizontally. When the plug 150 is viewed from above, the multiple first, third, fifth, and seventh branch passages 151b, 153b, 155b, and 157b are arranged along the concentric circles of the plug body 51 at equal angular intervals (180° intervals in Figure 7). The first, third, fifth, and seventh gas channels 151, 153, 155, and 157 are arranged so as to be offset by 90° along the circumferential direction. The second, fourth, sixth, and eighth gas channels 152, 154, 156, and 158 are formed in a spiral shape, with flat, rectangular cross-section strip-shaped channels rotating counterclockwise from top to bottom. The second, fourth, sixth, and eighth gas channels 152, 154, 156, and 158 are arranged so as to be offset by 90° along the circumferential direction. The second, fourth, sixth, and eighth gas channels 152, 154, 156, and 158 are surrounded by the first, third, fifth, and seventh gas channels 151, 153, 155, and 157.

[0057] In plug 150, the sides of two of the first to eighth gas passages 151 to 158 are in point contact with each other and communicate with one another. This point-contact portion (indicated by a dotted circle) is referred to as connection portion B. Connection section B is the portion where the outer side of the first gas passage 151 communicates with the inner side of the second, fourth, sixth, and eighth gas passages 152, 154, 156, and 158; the outer side of the third gas passage 153 communicates with the inner side of the second, fourth, sixth, and eighth gas passages 152, 154, 156, and 158; the outer side of the fifth gas passage 154 communicates with the inner side of the second, fourth, sixth, and eighth gas passages 152, 154, 156, and 158; and the outer side of the seventh gas passage 157 communicates with the inner side of the second, fourth, sixth, and eighth gas passages 152, 154, 156, and 158.

[0058] Even when using such a plug 150, the first to eighth gas flow paths 151 to 158 provided inside the plug 150 open to the outer circumferential surface 51c of the plug 150, rather than the upper surface 51b of the plug 150. As a result, the orientation of the space of the first to eighth gas flow paths 151 to 158 and the orientation of the electric field during plasma generation become approximately perpendicular, suppressing the acceleration of charged particles, and thus suppressing discharges caused by accelerated charged particles colliding with other gas molecules. Furthermore, since the first to eighth gas flow paths 151 to 158 are rectangular in cross-section, it is easier to increase the flow area compared to gas flow paths with a circular cross-section. In addition, since the connection part B is almost a point contact, the flow rate of gas flowing through the connection part B is small. Therefore, collisions between gases become less likely, and the gas flows more smoothly. The maximum vertical length Hmax in the first to eighth gas flow paths 151 to 158 and the connection path B is preferably 0.5 mm or less. This effectively suppresses the occurrence of arc discharge within the first to eighth gas flow paths 151 to 158 and the connection part B.

[0059] Although the plug 150 is provided to have the first to eighth gas passages 151 to 158, the number is not particularly limited as long as it has one or more of the first, third, fifth, and seventh gas passages 151, 153, 155, and 157. The second, fourth, sixth, and eighth gas passages 152, 154, 156, and 158 may be omitted. Alternatively, the connection part B may be omitted, and the first to eighth gas passages 151 to 158 may be treated as independent gas passages.

[0060] This application is based on the priority claim of Japanese Patent Application No. 2025-068646, filed on 18 April 2025, the entire contents of which are incorporated herein by reference.

[0061] This invention can be used in semiconductor manufacturing equipment.

[0062] 10 Wafer mounting platform, 20 Ceramic plate, 21 Wafer mounting surface, 21a Seal band, 21b Small circular protrusion, 21c Reference surface, 22 Electrode, 24 Plug placement hole, 24c Inner circumferential surface, 26 FR mounting surface, 26a FR support surface, 26b Recess, 28 Plug placement hole, 30 Base plate, 32 Refrigerant flow path, 34 Gas hole, 34a Large diameter section, 40 Metal bonding layer, 42 Through hole, 50 Plug, 51 Plug body, 51a Bottom surface, 51b Top surface, 51c Outer circumferential surface, 51d Virtual plane, 52 Gas flow path, 52a Inlet, 52c Outlet, 52d Upper end, 53 Helical flow path, 54 Branch path, 55 Plug, 56 Plug body, 57 Gas flow path, 60 Focus ring, 62 Circumferential groove, 70 Gas discharge section, 75 Gas discharge section, 150 Plug, 151-158 First to eighth gas flow paths, 151a, 153a, 155a, 157a First, third, fifth, and seventh spiral flow paths, 151b, 153b, 155b, 157b First, third, fifth, and seventh branching paths.

Claims

1. A component for a semiconductor manufacturing apparatus, comprising: a ceramic plate having an object placement surface on its upper surface; a plug placement hole penetrating the ceramic plate in the vertical direction; a plug placed in the plug placement hole; a gas passage provided inside the plug, extending from the lower surface of the plug to the outer peripheral surface without reaching the upper surface; and a gas discharge section configured at the contact interface between the inner peripheral surface of the plug placement hole and the outer peripheral surface of the plug, which discharges gas from the gas passage to the object placement surface.

2. The component for semiconductor manufacturing apparatus according to claim 1, wherein the gas discharge portion is formed by the contact between the inner circumferential surface of the plug placement hole and the outer circumferential surface of the plug, each having a maximum height roughness Rz of 3 μm or more and 10 μm or less.

3. The outer peripheral end of the gas flow path is provided such that its vertical inclination with respect to the direction perpendicular to the central axis of the plug is within ±30°, as described in claim 1 or 2.

4. The semiconductor manufacturing apparatus member according to claim 1 or 2, wherein the gas flow path comprises a spiral flow path provided spirally inside the plug and a branch path that branches off from the spiral flow path and reaches the outer surface of the plug.

5. The semiconductor manufacturing apparatus component according to claim 4, wherein the branching paths branch off at multiple points along the spiral flow path and are arranged at equal angular intervals along the concentric circles of the plug body when viewed from above.

6. The semiconductor manufacturing apparatus member according to claim 1 or 2, wherein the outer circumferential surface of the plug is inclined with respect to the axial direction of the plug such that the lower surface of the plug is closer to the central axis of the plug.

7. The semiconductor manufacturing apparatus component according to claim 1 or 2, wherein the maximum vertical length Hmax in the gas flow path is 0.5 mm or less.

8. A semiconductor manufacturing apparatus component according to claim 1 or 2, further comprising a conductive substrate bonded to the lower surface of the ceramic plate and provided with a gas supply passage communicating with the plug placement hole.

Images