Semiconductor manufacturing equipment parts

Abstract

To provide an inexpensive member for a semiconductor manufacturing device with a porous plug that allows gas flow.SOLUTION: A member 10 for a semiconductor manufacturing device includes a ceramic plate 20 having a wafer mounting surface 21 on its upper surface, and a resin porous plug 50 having an upper surface 50a exposed to a wafer mounting surface 21. The resin porous plug 50 is press-fitted and fixed in a plug insertion hole 54 vertically penetrating the ceramic plate 20 to allow gas flow.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a member for a semiconductor manufacturing device. [Background technology]

[0002] Conventionally, a semiconductor manufacturing device member is known that includes an electrostatic chuck having a wafer mounting surface on the upper surface. For example, Patent Document 1 discloses an electrostatic chuck that includes a ceramic plate that attracts and holds a wafer, a through hole formed in the ceramic plate, and a porous plug disposed in the through hole. To manufacture such an electrostatic chuck, a ceramic plate is first prepared by firing a green sheet that includes an electrostatic electrode, and a through hole is formed in the ceramic plate. Next, a paste-like ceramic mixture containing ceramic particles and burned-out particles is filled in the through hole, and then the paste is heated to a predetermined temperature to burn the ceramic particles in the mixture and to burn out the burned-out particles. This forms a porous plug in the through hole, and the electrostatic chuck described above is obtained. In such an electrostatic chuck, helium gas is introduced from the outside into the porous plug while the wafer is electrostatically attracted to the wafer mounting surface. Then, the helium gas is supplied to the back side of the wafer to improve the thermal conduction between the wafer and the ceramic plate. At this time, the helium gas passes through the pores of the porous plug, and therefore arc discharge on the back side of the wafer can be suppressed compared to when the helium gas passes through a through hole in which no porous plug exists. Without the porous plug, electrons generated by the ionization of helium would accelerate and collide with other helium particles, causing arcing, but with the porous plug, the electrons strike the porous plug before colliding with other helium particles, suppressing arcing. Arcing on the backside of the wafer is undesirable because it alters the quality of the wafer and makes it unusable as a device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-29384 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the electrostatic chuck described above requires two firing steps, one for making the ceramic plate and one for making the porous plug, resulting in high manufacturing costs.

[0005] The present invention has been made to solve these problems, and a main object of the present invention is to provide an inexpensive semiconductor manufacturing equipment member having a porous plug that allows gas to flow. [Means for solving the problem]

[0006] The semiconductor manufacturing equipment member of the present invention comprises: a ceramic plate having a wafer mounting surface on an upper surface thereof; a resin porous plug, the upper surface of which is exposed on the wafer mounting surface, the resin porous plug being press-fitted into a plug insertion hole that vertically penetrates the ceramic plate and allows gas to pass through; It is equipped with the following:

[0007] In this semiconductor manufacturing equipment component, a resin porous plug that allows gas to flow is press-fitted and fixed into a plug insertion hole that penetrates the ceramic plate in the vertical direction. Therefore, there is no need to sinter the resin porous plug to fix it in the plug insertion hole. Furthermore, even if the resin porous plug deteriorates with use, the deteriorated resin porous plug can be easily replaced with a new resin porous plug. Therefore, a semiconductor manufacturing equipment component equipped with a porous plug can be provided at low cost.

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

[0009] In the semiconductor manufacturing equipment member of the present invention, the ceramic plate may have a conductive substrate on its lower surface, and the resin porous plug may be in contact with the conductive substrate. When the resin porous plug is not in contact with the conductive substrate, arc discharge may occur between the porous plug and the conductive substrate. However, when the resin porous plug is in contact with the conductive substrate, the occurrence of such arc discharge can be suppressed.

[0010] In the semiconductor manufacturing equipment member of the present invention, the resin porous plug may incorporate a dense cylindrical member having a smaller diameter than the resin porous plug, whereby the dense cylindrical member serves as a core material, making it easier to press the resin porous plug into the plug insertion hole and enabling the height of the upper surface of the resin porous plug to be accurately positioned.

[0011] In the semiconductor manufacturing equipment member of the present invention, the resin porous plug may incorporate a dense cylindrical member having a smaller diameter than the resin porous plug, inserted from the bottom surface of the resin porous plug without penetrating the top surface of the resin porous plug. In this way, the dense cylindrical member acts as a core material, making it easier to press the resin porous plug into the plug insertion hole and allowing the height of the top surface of the resin porous plug to be accurately positioned. In addition, gas mainly passes through the upper part of the resin porous plug (the part above the dense cylindrical member), thereby reducing gas pressure loss.

[0012] In the semiconductor manufacturing equipment member of the present invention, the resin porous plug may incorporate a porous cylindrical member having a higher porosity than the resin porous plug, whereby the gas mainly passes through the porous cylindrical member, thereby making it possible to reduce the pressure loss of the gas.

[0013] In the semiconductor manufacturing device member of the present invention, the wafer mounting surface may have a number of small protrusions for supporting the wafer, and the upper surface of the resin porous plug may be located lower than the upper surface of the small protrusions. In this way, the wafer is not lifted by the upper surface of the resin porous plug. In this case, the upper surface of the resin porous plug may be at the same height as a reference surface of the wafer mounting surface on which the small protrusions are not provided, or may be located at a position lower than the reference surface by 0.5 mm or less. In this way, the height of the space between the back surface of the wafer and the upper surface of the resin porous plug is kept low, so that it is possible to prevent arc discharge from occurring in this space. The height of the reference surface may be different for each small protrusion. Also, the height of the reference surface may be the same height as the bottom surface of the small protrusion that is located immediately adjacent to the plug insertion hole. [Brief description of the drawings]

[0014] [Figure 1] FIG. 2 is a longitudinal sectional view of a semiconductor manufacturing equipment member 10. [Diagram 2] FIG. [Diagram 3] A partially enlarged view of Figure 1. [Figure 4] 1 is a manufacturing process diagram of a semiconductor manufacturing equipment member 10. [Diagram 5] FIG. 2 is a longitudinal cross-sectional view of a resin porous plug 150. [Figure 6] FIG. 2 is a longitudinal cross-sectional view of a resin porous plug 250. [Figure 7] FIG. 3 is a longitudinal cross-sectional view of a resin porous plug 350. [Figure 8] FIG. 13 is a longitudinal cross-sectional view of another example of a resin porous plug 350. [Figure 9] FIG. 4 is a longitudinal cross-sectional view of a resin porous plug 550. [Figure 10]FIG. 6 is a longitudinal cross-sectional view of a resin porous plug 650. [Figure 11] FIG. 4 is a vertical cross-sectional view of another example of the resin porous plug 50. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Next, preferred embodiments of the present invention will be described with reference to the drawings. Fig. 1 is a vertical cross-sectional view of a semiconductor manufacturing equipment member 10, Fig. 2 is a plan view of a ceramic plate 20, and Fig. 3 is a partially enlarged view of Fig. 1.

[0016] The semiconductor manufacturing equipment member 10 includes a ceramic plate 20, a cooling plate 30, a metal bonding layer 40, and a resin porous plug 50.

[0017] The ceramic plate 20 is a ceramic disk (e.g., 300 mm in diameter and 5 mm in thickness) made of sintered alumina or sintered aluminum nitride. The upper surface of the ceramic plate 20 is a wafer mounting surface 21. The ceramic plate 20 has an electrode 22 built in. As shown in FIG. 2, a seal band 21a is formed along the outer edge of the wafer mounting surface 21 of the ceramic plate 20, and a plurality of small circular protrusions 21b are formed on the entire surface. The seal band 21a and the small circular protrusions 21b have the same height, which is, for example, several μm to several tens of μm. The electrode 22 is a flat mesh electrode used as an electrostatic electrode, and a DC voltage can be applied to it. 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 small circular protrusions 21b) by electrostatic attraction force, and when the application of the DC voltage is stopped, the wafer W is released from the attraction and fixation to the wafer mounting surface 21. The portion of the wafer mounting surface 21 on which the seal band 21a and the small circular protrusions 21b are not provided is referred to as a reference surface 21c.

[0018] The cooling plate 30 is a disk with good thermal conductivity (a disk with the same diameter as or larger than the ceramic plate 20). Inside the cooling plate 30, a refrigerant flow path 32 through which the refrigerant circulates and a gas hole 34 through which gas is supplied to the resin porous plug 50 are formed. The refrigerant flow path 32 is formed in a single stroke from the inlet to the outlet over the entire surface of the cooling plate 30 in a plan view. The gas hole 34 is a stepped hole, and has a step portion 34c at the upper opening edge. The material of the cooling plate 30 may be, for example, a metal material or a metal matrix composite material (MMC). Examples of the metal material include Al, Ti, Mo, or an alloy thereof. Examples of the MMC include a material containing Si, SiC, and Ti (also called SiSiCTi) and a material in which a SiC porous body is impregnated with Al and / or Si. It is preferable to select a material for the cooling plate 30 that has a thermal expansion coefficient close to that of the material of the ceramic plate 20. The cooling plate 30 is also used as an RF electrode. Specifically, an upper electrode (not shown) is disposed above the wafer mounting surface 21, and when high-frequency power is applied between parallel plate electrodes consisting of the upper electrode and the cooling plate 30, plasma is generated.

[0019] The metal bonding layer 40 bonds the lower surface of the ceramic plate 20 and the upper surface of the cooling plate 30. The metal bonding layer 40 is formed, for example, by TCB (thermal compression bonding). TCB refers to a known method in which a metal bonding material is sandwiched between two members to be bonded, and the two members are pressurized and bonded while being heated to a temperature equal to or lower than the solidus temperature of the metal bonding material. The metal bonding layer 40 and the cooling plate 30 of this embodiment correspond to the conductive substrate of the present invention.

[0020] The resin porous plug 50 is press-fitted and fixed in the plug insertion hole 54. The plug insertion hole 54 is a cylindrical hole that penetrates the ceramic plate 20 and the metal bonding layer 40 in the vertical direction and reaches the annular step portion 34c provided at the upper opening edge of the gas hole 34 of the cooling plate 30. The plug insertion holes 54 are provided at multiple locations (e.g., multiple locations provided at equal intervals along the circumferential direction) of the ceramic plate 20. The resin porous plug 50 is an electrically insulating resin porous cylindrical member that allows gas to flow in the vertical direction. As the resin porous plug 50, for example, a commercially available resin porous body such as PTFE, PPS, PEEK, or PEKK can be used. The upper surface 50a of the resin porous plug 50 is exposed to the upper opening of the plug insertion hole 54 and is flush with the reference surface 21c. Note that "same" includes not only completely same cases, but also substantially same cases (for example, within the range of tolerance) (the same applies below). The resin porous plug 50 is press-fitted into the upper opening of the plug insertion hole 54 until the lower surface 50b abuts against the annular stepped portion 34c forming the lower surface of the plug insertion hole 54, and is fixed therein.

[0021] Next, an example of use of the semiconductor manufacturing equipment member 10 thus configured will be described. First, the semiconductor manufacturing equipment member 10 is installed in a chamber (not shown), and the wafer W is placed on the wafer placement surface 21. Then, the chamber is depressurized by a vacuum pump to adjust the chamber to a predetermined vacuum level, and a DC voltage is applied to the electrode 22 of the ceramic plate 20 to generate an electrostatic adsorption force, and the wafer W is adsorbed and fixed to the wafer placement surface 21 (specifically, the upper surface of the seal band 21a or the upper surface of the circular small protrusion 21b). Next, the chamber is made into a reactive 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 part of the chamber and the cooling plate 30 of the semiconductor manufacturing equipment member 10 to generate plasma. The surface of the wafer W is treated by the generated plasma. A coolant is circulated through the coolant flow path 32 of the cooling plate 30. A backside gas is introduced into the gas hole 34 from a gas cylinder (not shown). A thermally conductive gas (for example, helium, etc.) is used as the backside gas. The backside gas is supplied and sealed in the space between the back surface of the wafer W and the reference surface 21c of the wafer mounting surface 21 through the gas holes 34 and the resin porous plug 50. The presence of this backside gas allows efficient thermal conduction between the wafer W and the ceramic plate 20.

[0022] Next, a manufacturing example of the semiconductor manufacturing equipment member 10 will be described with reference to FIG. 4. FIG. 4 is a manufacturing process diagram of the semiconductor manufacturing equipment member 10. First, a ceramic plate 20, a cooling plate 30, and a metal bonding material 90 are prepared (FIG. 4A). The ceramic plate 20 has an electrode 22 built in and a through hole 24 that constitutes a part of the plug insertion hole 54. The cooling plate 30 has a refrigerant flow path 32 built in and a gas hole 34 that penetrates in the vertical direction. The gas hole 34 has a large-diameter upper hole portion 34a, a small-diameter lower hole portion 34b, and a step portion 34c that forms the boundary between the hole upper portion 34a and the hole lower portion 34b. The metal bonding material 90 has a through hole 92 that will eventually constitute a part of the plug insertion hole 54.

[0023] Then, the lower surface of the ceramic plate 20 and the upper surface of the cooling plate 30 are bonded together by TCB to obtain a bonded body 94 (see FIG. 4 B). The TCB is performed, for example, as follows. First, a metal bonding material 90 is sandwiched between the lower surface of the ceramic plate 20 and the upper surface of the cooling plate 30 (FIG. 4 A) is formed into a laminate. At this time, the through hole 24 of the ceramic plate 20, the through hole 92 of the metal bonding material 90, and the gas hole 34 of the cooling plate 30 are laminated so as to be coaxial with each other. Then, the laminate is pressed and bonded at a temperature equal to or lower than the solidus temperature of the metal bonding material 90 (for example, a temperature equal to or higher than the solidus temperature minus 20°C and equal to or lower than the solidus temperature), and then returned to room temperature. As a result, the metal bonding material 90 becomes the metal bonding layer 40, and the through holes 24, 92 and the hole upper portion 34a of the gas hole 34 become the plug insertion hole 54, and a bonded body 94 in which the ceramic plate 20 and the cooling plate 30 are bonded with the metal bonding layer 40 is obtained. As the metal bonding material at this time, an Al-Mg-based bonding material or an Al-Si-Mg-based bonding material can be used. For example, when TCB is performed using an Al-Si-Mg-based bonding material, the laminate is pressed in a heated state under a vacuum atmosphere. It is preferable to use the metal bonding material 90 having a thickness of about 100 μm.

[0024] Next, a resin porous plug 50 is prepared. The diameter of the resin porous plug 50 is slightly larger than the diameter of the plug insertion hole 54. This resin porous plug 50 is pressed into and fixed in place from the upper opening of the plug insertion hole 54 until the lower surface 50b abuts against the annular step portion 34c that forms the lower surface of the plug insertion hole 54. The resin porous plug 50 can be pressed into and fixed in place because it has a higher elasticity than ceramic materials. The resin porous plug 50 is designed so that when the lower surface 50b abuts against the step portion 34c, the upper surface 50a is flush with the reference surface 21c (see FIG. 3) of the wafer mounting surface 21. In this manner, a semiconductor manufacturing equipment member 10 is obtained (FIG. 4 C).

[0025] In the semiconductor manufacturing equipment component 10 described above in detail, the resin porous plug 50, which allows gas to flow, is press-fitted and fixed into the plug insertion hole 54 that vertically penetrates the ceramic plate 20. Therefore, there is no need to sinter the resin porous plug 50 to fix it in the plug insertion hole 54. Furthermore, even if the resin porous plug 50 deteriorates with use, the deteriorated resin porous plug 50 can be easily replaced with a new resin porous plug 50. Therefore, the semiconductor manufacturing equipment component 10 equipped with a porous plug can be provided at low cost.

[0026] Furthermore, in the case where the resin porous plug 50 is pressed and fixed last in the manufacturing process, the subsequent step of washing the resin porous plug 50 can be omitted.

[0027] Furthermore, the resin porous plug 50 abuts against the conductive base material (the metal bonding layer 40 and the cooling plate 30). When the resin porous plug 50 is not in contact with the conductive base material, arc discharge may occur between the resin porous plug 50 and the conductive base material, whereas when the resin porous plug 50 abuts against the conductive base material, the occurrence of such arc discharge can be suppressed.

[0028] Furthermore, the upper surface 50a of the resin porous plug 50 is located lower than the upper surfaces of the seal bands 21a and the small circular protrusions 21b. Therefore, the upper surface 50a of the resin porous plug 50 does not lift up the wafer W.

[0029] The upper surface 50a of the resin porous plug 50 is at the same height as the reference surface 21c of the wafer mounting surface 21. Therefore, the height of the space between the lower surface of the wafer W and the upper surface 50a of the resin porous plug 50 is kept low. Therefore, it is possible to prevent arc discharge from occurring in this space.

[0030] It goes without saying that the present invention is not limited to the above-described embodiment, and can be embodied in various forms within the technical scope of the present invention.

[0031] Instead of the resin porous plug 50 of the above-described embodiment, resin porous plugs 150 to 350 shown in Figs. 5 to 8 may be used.

[0032] The resin porous plug 150 in FIG. 5 incorporates a dense columnar member 152 having a smaller diameter than the resin porous plug 150. The dense columnar member 152 is coaxial with the resin porous plug 150 and penetrates the resin porous plug 150 from the upper surface 150a to the lower surface 150b. In this case, the dense columnar member 152 serves as a core material, making it easier to press the resin porous plug 150 into the plug insertion hole and allowing the height of the upper surface of the resin porous plug 150 to be positioned with high accuracy. The dense columnar member 152 may be incorporated in the resin porous plug 150 without penetrating it in the vertical direction. The material of the dense columnar member 152 is not particularly limited as long as it is dense, and may be, for example, ceramic or resin (for example, hard resin).

[0033] The resin porous plug 250 in FIG. 6 incorporates a dense cylindrical member 252 having a smaller diameter than the resin porous plug 250, inserted from a lower surface 250b of the resin porous plug 250 without penetrating an upper surface 250a of the resin porous plug 250. The dense cylindrical member 252 is coaxial with the resin porous plug 250. In this case, the dense cylindrical member 252 plays the role of a core material, so that the resin porous plug 250 can be easily press-fitted into the plug insertion hole, and the height of the upper surface of the resin porous plug 250 can be accurately positioned. In addition, the gas mainly passes through the upper part of the resin porous plug 250 (the part above the dense cylindrical member 252), so that the pressure loss of the gas can be reduced. The material of the dense cylindrical member 252 is not particularly limited as long as it is dense, and may be, for example, ceramic or resin (for example, hard resin).

[0034] The resin porous plug 350 in FIG. 7 incorporates a porous columnar member 352 having a higher porosity than the resin porous plug 350. The porous columnar member 352 is coaxial with the resin porous plug 350 and penetrates the resin porous plug 350 from the upper surface 350a to the lower surface 350b. In this case, the gas mainly passes through the porous columnar member 352, so that the pressure loss of the gas can be reduced. As shown in FIG. 8, the porous columnar member 352 may be incorporated in a state in which it does not penetrate the resin porous plug 350 in the vertical direction, in this case, it is inserted from the lower surface 350b and does not penetrate the upper surface 350a. The material of the porous columnar member 352 is not particularly limited as long as it is porous, and may be, for example, ceramic or resin.

[0035] In the above-described embodiment, the cylindrical resin porous plug 50 is used, but instead, resin porous plugs 550, 650 having the shapes shown in Figs. 9 and 10 may be used.

[0036] 9 is a plug having an inverted truncated cone shape in which the area of ​​the lower surface 550b is smaller than the area of ​​the upper surface 550a. When using this resin porous plug 550, the plug insertion hole is also changed to a shape suitable for it.

[0037] 10 is a plug that is cylindrical from the lower surface 650b to the intermediate position 650c (a predetermined height) and has an inverted truncated cone shape from the intermediate position 650c to the upper surface 650a. When using this resin porous plug 650, the plug insertion hole is also changed to a shape that matches it.

[0038] The resin porous plugs 550, 650 having the shapes shown in FIG. 9 and FIG. 10 may be modified as shown in FIGS.

[0039] In the above-mentioned embodiment, the upper surface 50a of the resin porous plug 50 is set to the same height as the reference surface 21c of the wafer mounting surface 21, but is not particularly limited thereto. For example, as shown in FIG. 11, the difference Δh obtained by subtracting the height of the upper surface 50a of the resin porous plug 50 from the height of the reference surface 21c of the wafer mounting surface 21 may be set to a range of 0.5 mm or less (preferably 0.2 mm or less, more preferably 0.1 mm or less). In other words, the upper surface 50a of the resin porous plug 50 may be disposed at a position lower than the reference surface 21c of the wafer mounting surface 21 by a range of 0.5 mm or less (preferably 0.2 mm or less, more preferably 0.1 mm or less). Even in this way, the height of the space between the lower surface of the wafer W and the upper surface 50a of the resin porous plug 50 is kept relatively low. Therefore, it is possible to prevent arc discharge from occurring in this space.

[0040] In the above-described embodiment, an electrostatic electrode has been exemplified as the electrode 22 built into the ceramic plate 20, but this is not particularly limited. For example, instead of or in addition to the electrode 22, a heater electrode (resistance heating element) or an RF electrode may be built into the ceramic plate 20.

[0041] In the above-described embodiment, the ceramic plate 20 and the cooling plate 30 are joined by the metal joining layer 40, but a resin adhesive layer may be used instead of the metal joining layer 40. In that case, the cooling plate 30 corresponds to the conductive substrate of the present invention. [Explanation of symbols]

[0042] 10 Semiconductor manufacturing equipment member, 20 Ceramic plate, 21 Wafer mounting surface, 21a Seal band, 21b Circular small protrusion, 21c Reference surface, 22 Electrode, 24 Through hole, 30 Cooling plate, 32 Coolant flow path, 34 Gas hole, 34a Hole upper part, 34b Hole lower part, 34c Step part, 40 Metal bonding layer, 50 Resin porous plug, 50a Upper surface, 50b Lower surface, 54 Plug insertion hole, 90 Metal bonding material, 92 Through hole, 94 Bonded body, 150, 250, 350, 550, 650 Resin porous plug, 150a, 250a, 350a, 550a, 650a Upper surface, 150b, 250b, 350b, 550b, 650b Lower surface, 152 Dense cylindrical member, 252 Dense cylindrical member, 352 Porous cylindrical member, 650c intermediate position.

Claims

1. a ceramic plate having a wafer mounting surface on an upper surface thereof; a resin porous plug, the upper surface of which is exposed on the wafer mounting surface, the resin porous plug being press-fitted into a plug insertion hole that vertically penetrates the ceramic plate and allows gas to pass through; Equipped with The ceramic plate has a conductive substrate on a lower surface thereof, The resin porous plug is in contact with the conductive substrate. Components for semiconductor manufacturing equipment.

2. The resin porous plug has a dense cylindrical member with a smaller diameter than the resin porous plug built in. The semiconductor manufacturing equipment member according to claim 1 .

3. The resin porous plug has a dense cylindrical member having a smaller diameter than the resin porous plug, the dense cylindrical member being inserted from the bottom surface of the resin porous plug so as not to penetrate the top surface of the resin porous plug. The semiconductor manufacturing equipment member according to claim 1 .

4. The resin porous plug has a porous cylindrical member with a higher porosity than the resin porous plug built therein. The semiconductor manufacturing equipment member according to claim 1 .

5. The wafer mounting surface has a number of small protrusions for supporting a wafer, The upper surface of the resin porous plug is located lower than the upper surface of the small protrusion. The member for semiconductor manufacturing equipment according to any one of claims 1 to 4.

6. the upper surface of the resin porous plug is at the same height as a reference surface of the wafer mounting surface on which the small protrusions are not provided, or is at a position lower than the reference surface by a range of 0.5 mm or less; The semiconductor manufacturing equipment member according to claim 5 .

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