Classifications

• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P72/00—Handling or holding of wafers, substrates or devices during manufacture or treatment thereof
  • H10P72/70—Handling or holding of wafers, substrates or devices during manufacture or treatment thereof for supporting or gripping
  • H10P72/72—Handling or holding of wafers, substrates or devices during manufacture or treatment thereof for supporting or gripping using electrostatic chucks
  • H10P72/722—Details of electrostatic chucks
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
  • H01J37/32—Gas-filled discharge tubes
  • H01J37/32431—Constructional details of the reactor
  • H01J37/32532—Electrodes
  • H01J37/32568—Relative arrangement or disposition of electrodes; moving means
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
  • H01J37/32—Gas-filled discharge tubes
  • H01J37/32431—Constructional details of the reactor
  • H01J37/32715—Workpiece holder
  • H01J37/32724—Temperature
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P72/00—Handling or holding of wafers, substrates or devices during manufacture or treatment thereof
  • H10P72/04—Apparatus for manufacture or treatment
  • H10P72/0431—Apparatus for thermal treatment
  • H10P72/0434—Apparatus for thermal treatment mainly by convection
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P72/00—Handling or holding of wafers, substrates or devices during manufacture or treatment thereof
  • H10P72/70—Handling or holding of wafers, substrates or devices during manufacture or treatment thereof for supporting or gripping
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P72/00—Handling or holding of wafers, substrates or devices during manufacture or treatment thereof
  • H10P72/70—Handling or holding of wafers, substrates or devices during manufacture or treatment thereof for supporting or gripping
  • H10P72/76—Handling or holding of wafers, substrates or devices during manufacture or treatment thereof for supporting or gripping using mechanical means, e.g. clamps or pinches
  • H10P72/7604—Handling or holding of wafers, substrates or devices during manufacture or treatment thereof for supporting or gripping using mechanical means, e.g. clamps or pinches the wafers being placed on a susceptor, stage or support
  • H10P72/7624—Handling or holding of wafers, substrates or devices during manufacture or treatment thereof for supporting or gripping using mechanical means, e.g. clamps or pinches the wafers being placed on a susceptor, stage or support characterised by the mechanical construction of the susceptor, stage or support

Definitions

• the present invention relates to a wafer mounting table.
• the wafer mounting table disclosed in Patent Document 1 includes a ceramic plate having a wafer mounting surface on its upper surface, a gas passageway through which gas can pass vertically through the ceramic plate, a conductive base plate bonded to the underside of the ceramic plate, and a gas supply passageway provided within the base plate.
• the gas passageway is composed of a porous plug disposed in a through-hole formed in the ceramic plate.
• a high-frequency voltage is applied between the base plate and an upper electrode provided above the wafer to generate plasma above the wafer, and the wafer is processed using this plasma.
• helium gas is introduced from the outside into the gas supply passageway.
• the helium gas is then supplied from the gas supply passageway through the gas passageway to the underside of the wafer, improving thermal conduction between the wafer and the ceramic plate. Because the helium gas passes through the pores of the porous plug, arc discharge on the underside of the wafer is suppressed compared to when the porous plug is not present. Without the porous plug, arcing would occur when electrons generated by ionization of helium accelerate and collide with other helium particles. However, with the porous plug, arcing is suppressed because the electrons strike the porous plug before colliding with other helium particles. Arcing on the underside of the wafer is undesirable because it alters the wafer, making it unusable as a device.
• the present invention was made to solve the above-mentioned problems, and its main objective is to provide a new structure that suppresses discharge within the gas passage.
• the wafer mounting table of the present invention comprises: a ceramic plate having a wafer mounting surface on its upper surface; a gas passage through which gas can pass in the vertical direction of the ceramic plate; a conductive base plate bonded to the lower surface of the ceramic plate and used as a plasma generating electrode; a gas supply passage provided inside the base plate and communicating with the gas passage; a shield member provided to surround the gas passage and electrically connected to the base plate; It is equipped with the following.
• This wafer mounting table is equipped with a shielding member electrically connected to the conductive base plate, which prevents equipotential lines from entering the lower part of the gas passage when plasma is generated. This makes it easier to prevent discharge within the gas passage than if there were no shielding member.
• the shielding member may be provided at a position at least close to the wafer mounting surface. This makes it easier to suppress discharge within the gas passage. Note that "a position close to the wafer mounting surface” refers to a position above half the thickness of the ceramic plate from the wafer mounting surface.
• the ceramic plate may have at least one electrode
• the gas passage may be provided to pass through an electrode through-hole provided in each of the at least one electrode so that each of the at least one electrode is not exposed to the inner surface of the gas passage
• the shielding member may be provided corresponding to each of the at least one electrode and electrically insulated from each of the at least one electrode. This can also prevent equipotential lines generated by the electrodes in the ceramic plate from entering the gas passage.
• the ceramic plate may have a ceramic plate through-hole that passes through the ceramic plate in the vertical direction, and the gas passage may be provided in a plug disposed in the ceramic plate through-hole. This may make it easier to form the gas passage compared to providing the gas passage directly in the ceramic plate itself.
• the shielding member may be embedded in the plug. This allows the shielding member to be built in when the plug is manufactured.
• the shielding member may be embedded in the ceramic plate. This allows the shielding member to be built into the ceramic plate when it is manufactured.
• the gas passage may have a porous body at least in the upper part of the gas passage, through which gas can pass in the vertical direction. Because equipotential lines penetrate the upper part of the gas passage, providing a porous body at least in the upper part of the gas passage can suppress the occurrence of discharge in the upper part of the gas passage.
• the porous body may be provided only in the upper part of the gas passage (the part of the gas passage where equipotential lines penetrate), or it may be provided throughout the entire gas passage. In the former case, the gas flow rate can be increased compared to the latter case.
• the gas passage may have a spiral or zigzag portion at least in the upper portion of the gas passage. Because equipotential lines penetrate the upper portion of the gas passage, providing a spiral or zigzag portion at least in the upper portion of the gas passage can suppress the occurrence of discharge in the upper portion of the gas passage.
• the spiral or zigzag portion may be provided only in the upper portion of the gas passage (the portion of the gas passage where equipotential lines penetrate), or it may be provided throughout the entire gas passage. In the former case, the gas flow rate can be increased compared to the latter case.
• the vertical length of the interior of the spiral or zigzag portion is preferably set to a predetermined length (e.g., 0.5 mm, preferably 0.2 mm) or less to suppress discharge therein.
• the shielding member may be a ring-shaped member whose central axis is perpendicular to the wafer mounting surface. This allows the shielding member to more easily exert its shielding effect.
• the central axis is perpendicular to the wafer mounting surface includes not only cases where the central axis is completely perpendicular to the wafer mounting surface, but also cases where the central axis is nearly perpendicular to the wafer mounting surface (for example, when perpendicular within an allowable range such as a tolerance) (the same applies below).
• the shielding member may be a cylindrical member whose central axis is perpendicular to the wafer mounting surface. This makes it easier for the shielding member to exert its shielding effect.
• a flange portion may be provided at the upper end of the cylindrical member. This prevents the electric field strength at the upper end of the cylindrical member from becoming too strong.
• FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1;
• FIG. 3 is a partially enlarged view of FIG. 2 .
• FIG. 4 is a manufacturing process diagram of the ceramic plate 20.
• Figure 1 is a plan view of the wafer mounting table 10
• Figure 2 is a cross-sectional view taken along line A-A in Figure 1
• Figure 3 is an enlarged view of a portion of Figure 2.
• seal band 21a, small circular protrusion 21b, and reference surface 21c on the wafer mounting surface 21 have been omitted from Figures 2 and 3.
• the wafer mounting table 10 includes a ceramic plate 20, a gas passage 52, a base plate 30, a metal bonding layer 40, and first and second shield members 61, 62.
• the ceramic plate 20 is a circular ceramic plate (e.g., 300 mm in diameter, 5 mm in thickness) made of alumina sintered body, aluminum nitride sintered body, or the like.
• the upper surface of the ceramic plate 20 forms the wafer mounting surface 21.
• the ceramic plate 20 incorporates an electrostatic electrode 22 and a bias electrode 23.
• the electrostatic electrode 22 is located close to the wafer mounting surface 21 (e.g., 0.3 to 0.6 mm from the wafer mounting surface 21), while the bias electrode 23 is located far from the wafer mounting surface 21.
• the wafer mounting surface 21 of the ceramic plate 20 has a seal band 21a formed along its outer edge, and multiple small circular protrusions 21b formed all over its surface.
• the seal band 21a and the small circular protrusions 21b have the same height, e.g., several ⁇ m to several tens of ⁇ m.
• the electrostatic electrode 22 is, for example, a planar mesh electrode, to which a DC voltage can be applied.
• a DC voltage is applied to the electrostatic 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 surfaces of the small circular protrusions 21b) by electrostatic attraction; when the application of the DC voltage is released, the wafer W is released from the wafer mounting surface 21.
• the bias electrode 23 is, for example, a planar mesh electrode, and a high-frequency bias voltage is applied to attract ions to the wafer W.
• the bias electrode 23 is a type of plasma generating electrode (RF electrode).
• the gas passage 52 is a passage through which gas can pass in the vertical direction of the ceramic plate 20.
• the gas passage 52 is provided inside the plug 50 fixed to the plug arrangement hole 24.
• the plug arrangement hole 24 penetrates the ceramic plate 20 in the vertical direction and is provided so as to communicate with the gas supply path 34 of the base plate 30.
• the plug arrangement hole 24 penetrates the electrostatic electrode 22 and bias electrode 23 in the vertical direction, but the electrostatic electrode 22 and bias electrode 23 are not exposed on the inner surface of the plug arrangement hole 24.
• the plug arrangement hole 24 is a tapered hole having an inverted truncated cone space in which the area of the upper opening is larger than the area of the lower opening.
• the plug arrangement hole 24 is provided at multiple locations on the ceramic plate 20 in a planar view (e.g., multiple locations equally spaced around the circumference).
• the plug 50 is a dense ceramic inverted truncated cone (e.g., made of the same material as the ceramic plate 20) placed in the plug arrangement hole 24.
• the plug 50 is provided with a gas passage 52 extending from the lower surface to the upper surface of the plug 50.
• the gas passage 52 has a linear portion 52a extending in the vertical direction at the bottom of the gas passage 52 and a spiral portion 52b at the top of the gas passage 52.
• the spiral portion 52b extends from the upper end of the gas passage 52 to at least the position where the equipotential lines EL (see FIG. 3) enter.
• the vertical length L (see FIG. 3) of the spiral portion 52b is preferably set to 0.5 mm or less, more preferably 0.2 mm or less.
• Arc discharge occurs when electrons generated as a result of ionization of a gas (e.g., helium gas) in the gas passage 52 accelerate in the direction of the electric field lines (a direction perpendicular to the equipotential lines EL) and collide with other helium gas.
• a gas e.g., helium gas
• such arc discharge can be suppressed by setting the vertical length of the gas passage 52 to 0.5 mm or less (more preferably 0.2 mm or less).
• the vertical length within the spiral portion 52b be as long as possible without causing arc discharge (for example, 0.1 mm or more).
• the base plate 30 is a conductive circular plate (a circular plate with the same or larger diameter as the ceramic plate 20) with good thermal conductivity.
• a refrigerant e.g., an electrically insulating liquid such as a fluorine-based inert liquid
• a gas supply path 34 through which gas is supplied to the gas passage 52.
• the refrigerant flow path 32 is formed in a single line from inlet to outlet across the entire surface of the base plate 30 in a plan view.
• 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.
• composite materials of metal and ceramic include metal matrix composites (MMCs) and ceramic matrix composites (CMCs).
• MMCs metal matrix composites
• CMCs ceramic matrix composites
• Specific examples of such composite materials include materials containing Si, SiC, and Ti, and materials in which porous SiC is impregnated with Al and/or Si.
• a material containing Si, SiC, and Ti is called SiSiCTi
• AlSiC a material in which porous SiC is impregnated with Al
• SiSiC a material in which porous SiC is impregnated with Si. It is preferable to select a material for the base plate 30 that has a thermal expansion coefficient close to that of the material for the ceramic plate 20.
• the base plate 30 is used as a source electrode (a type of plasma generating electrode (RF electrode)) to which a source high frequency is applied to generate plasma.
• a source electrode a type of plasma generating electrode (RF electrode)
• the bias high frequency is several hundred kHz
• the source high frequency is several tens to several hundred MHz.
• the gas supply path 34 includes a ring portion 34b that is concentric with the base plate 30 in a plan view, and an inlet portion 34a that introduces gas into the ring portion 34b from the underside of the base plate 30.
• the ring portion 34b is connected to the gas passages 52 via through holes 42 in the metal bonding layer 40. There may be, for example, only one inlet portion 34a.
• the gas introduced into the inlet portion 34a passes through the ring portion 34b and is distributed to each gas passage 52.
• the metal bonding layer 40 bonds 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 well-known method in which a metal bonding material is sandwiched between two components to be joined, and the two components are pressure-bonded while heated to a temperature below the solidus temperature of the metal bonding material.
• the metal bonding layer 40 may be a layer formed from solder or a metal brazing material.
• the metal bonding layer 40 has a through-hole 42. The through-hole 42 is located at a position that connects the gas passage 52 and the gas supply path 34.
• the first and second shield members 61, 62 are ring-shaped members whose central axes are perpendicular to the wafer mounting surface 21 and are arranged to surround the gas passage 52 (here, to surround the plug 50).
• the width W ( Figure 3) of the ring shape is larger than the diameter of the first and second vias 61a, 62a.
• the first shield member 61 is arranged to correspond to the electrostatic electrode 22 and be at the same height as the electrostatic electrode 22.
• the second shield member 62 is arranged to correspond to the bias electrode 23 and be at the same height as the bias electrode 23.
• the first shield member 61 is arranged close to the wafer mounting surface 21, and the second shield member 62 is arranged in a portion of the area between the position of the first shield member 61 (close to the wafer mounting surface 21) and the underside of the ceramic plate 20.
• the electrostatic electrode 22 has an electrostatic electrode through-hole 22a facing the plug 50.
• the bias electrode 23 has a bias electrode through-hole 23a facing the plug 50.
• the first shield member 61 is embedded in the ceramic plate 20 inside the electrostatic electrode through-hole 22a while being electrically insulated from the electrostatic electrode 22.
• the second shield member 62 is embedded in the ceramic plate 20 inside the bias electrode through-hole 23a while being electrically insulated from the bias electrode 23.
• the first shield member 61 and the second shield member 62 are electrically connected by a first via 61a extending in the vertical direction, and the second shield member 62 and the metal bonding layer 40 are electrically connected by a second via 62a extending in the vertical direction. At least one first via 61a is required, and at least one second via 62a is also required. Because the metal bonding layer 40 is electrically connected to the base plate 30, the first and second shield members 61 and 62 are also electrically connected to the base plate 30. Therefore, the first and second shield members 61 and 62 are at the same potential as the base plate 30.
• a wafer W is placed on the wafer mounting surface 21.
• the chamber is then depressurized using a vacuum pump to adjust the pressure to a predetermined level, and a DC voltage is applied to the electrostatic electrode 22 of the ceramic plate 20 to generate an electrostatic adsorption force, adsorbing and fixing the wafer W to the wafer mounting surface 21 (specifically, the upper surface of the seal band 21a or the upper surface of the small circular protrusions 21b).
• a reactive gas atmosphere of a predetermined pressure e.g., several tens to several hundreds of Pa
• a source high-frequency voltage is applied between an upper electrode (not shown) installed on the ceiling of the chamber and the base plate 30, and a bias high-frequency voltage is applied between the upper electrode and the bias electrode 23, generating plasma.
• the surface of the wafer W is then processed by the generated plasma.
• a coolant circulates through the coolant flow path 32 of the base plate 30.
• Backside gas is introduced into the gas supply path 34 from a gas cylinder (not shown).
• a thermally conductive gas e.g., helium
• 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 supply path 34, through-hole 42, and gas passage 52. The presence of this backside gas ensures efficient thermal conduction between the wafer W and the ceramic plate 20.
• the wafer mounting table 10 includes first and second shield members 61, 62 electrically connected to the conductive base plate 30, which can prevent the equipotential lines EL from penetrating into the lower part of the gas passage 52 (a position farther from the wafer mounting surface 21) during plasma generation. Therefore, discharge within the gas passage 52 is more easily prevented than when the first and second shield members 61, 62 are not present.
• An example of the equipotential lines EL in this embodiment is shown in FIG. 3, and an example of the equipotential lines EL when the first and second shield members 61, 62 are not present (comparative embodiment) is shown in FIG. 4.
• FIG. 4 In the comparative embodiment, as shown in FIG. 4, horizontal equipotential lines EL exist throughout the entire vertical length of the gas passage 52.
• FIG. 5 is a manufacturing process diagram of the ceramic plate 20.
• three ceramic green sheets 81, 82, and 83 are prepared, each of which roughly matches the shape of the ceramic plate 20 cut horizontally at the surface of the electrostatic electrode 22 and the surface of the bias electrode 23 ( Figure 5A).
• a hole 81a penetrating vertically is formed in the first ceramic green sheet 81 at the position of the second via 62a, and a hole 82a penetrating vertically is formed in the second ceramic green sheet 82 at the position of the first via 61a ( Figure 5B).
• a pattern of the same shape as the electrostatic electrode 22 and first shield member 61 is printed on the top surface of the first ceramic green sheet 81 using conductive paste, and the hole 81a is filled with conductive paste.
• a conductive paste pattern identical to the bias electrode 23 and second shield member 62 is printed on the top surface of the second ceramic green sheet 82, and the holes 82a are filled with the conductive paste (FIG. 5C).
• the second ceramic green sheet 82 is then stacked on top of the first ceramic green sheet 81, and a third ceramic green sheet 83 is then stacked on top of that.
• the resulting stack is then hot-press fired to obtain a fired ceramic body 90 (FIG. 5D).
• the fired ceramic body 90 also contains first and second shield members 61 and 62 and first and second vias 61a and 62b.
• a plug placement hole 24 is then formed in the fired ceramic body 90 (FIG. 5E).
• a separately fabricated plug 50 is then placed in the plug placement hole 24 and secured with adhesive to obtain a ceramic plate 20 (FIG. 5F).
• the wafer mounting table 10 described above is provided with first and second shield members 61, 62 electrically connected to the conductive base plate 30, thereby preventing equipotential lines EL from entering the lower part of the gas passage 52 (a position far from the wafer mounting surface 21) when plasma is generated. Therefore, discharge within the gas passage 52 is more easily suppressed than when the first and second shield members 61, 62 are not present. As a result, the design freedom for the lower part of the gas passage 52 is increased. For example, as with the wafer mounting table 10 described above, it is possible to omit providing discharge countermeasures (such as making the lower part of the gas passage 52 spiral) and instead use a straight section 52a.
• the ceramic plate 20 also has an electrostatic electrode 22 and a bias electrode 23.
• the gas passage 52 passes through an electrostatic electrode through-hole 22a so that the electrostatic electrode 22 is not exposed to the inner surface of the gas passage 52, and the bias electrode 23 passes through a bias electrode through-hole 23a so that the bias electrode 23 is not exposed to the inner surface of the gas passage 52.
• a first shield member 61 is provided corresponding to the electrostatic electrode 22 and is electrically insulated from the electrostatic electrode 22, and a second shield member 62 is provided corresponding to the bias electrode 23 and is electrically insulated from the bias electrode 23. This prevents equipotential lines generated by the electrostatic electrode 22 and bias electrode 23 in the ceramic plate 20 from entering the gas passage 52.
• the ceramic plate 20 has a plug placement hole 24 (ceramic plate through-hole) that passes through the ceramic plate 20 in the vertical direction, and the gas passage 52 is provided in a plug 50 that is placed in the plug placement hole 24. Therefore, it may be easier to form the gas passage 52 than if the gas passage 52 were provided directly in the ceramic plate 20 itself.
• first and second shielding members 61, 62 are embedded in the ceramic plate 20. Therefore, as shown in Figure 5, the first and second shielding members 61, 62 can be built in when manufacturing the ceramic plate 20.
• the gas passage 52 has a straight section 52a at the bottom and a spiral section 52b at the bottom. As shown in Figure 3, the equipotential line EL enters the upper part of the gas passage 52. Therefore, by providing the spiral section 52b at the top of the gas passage 52, it is possible to suppress the occurrence of discharge at the top of the gas passage 52.
• first and second shielding members 61, 62 are ring-shaped members whose central axes are perpendicular to the wafer mounting surface 21. Therefore, the first and second shielding members 61, 62 are more likely to exhibit a shielding effect.
• the gas passage 52 has a straight section 52a at the bottom and a spiral section 52b at the top.
• the gas passage 52 may be replaced with a gas passage 152 shown in FIG. 6.
• the gas passage 152 is a spiral passage extending from the bottom surface of the plug 50 to the top surface. This configuration also achieves the same effects as the above-described embodiment.
• the gas passage 52 has fewer spiral sections than the gas passage 152, allowing gas to flow more easily, thereby increasing the gas flow rate. Therefore, when gas passages 52 are used, the number of gas passages can be reduced compared to when gas passages 152 are used.
• gas passages 52 become temperature singularities for the wafer W, but reducing the number of gas passages reduces the temperature singularities and improves thermal uniformity.
• the spiral section 52b of the gas passage 52 may be replaced with a zigzag section, and the spiral passage of the gas passage 152 may be replaced with a zigzag passage.
• a dense plug 50 having a gas passage 52 therein is used.
• a plug 250 shown in FIG. 7 may be used instead of the plug 50.
• the plug 250 is a plug (porous plug) made of a porous body.
• the plug 250 is provided in the upper part of the plug arrangement hole 24 (for example, the section from the upper end of the plug arrangement hole 24 to the position where the equipotential line EL enters). Gas can pass vertically through the fine pores in the porous body of the plug 250. Therefore, the fine pores in the porous body serve as gas passages. This also achieves the same effects as the above-described embodiment.
• the plug 250 may be provided throughout the entire plug arrangement hole 24. However, providing the plug 250 only in the upper part of the plug arrangement hole 24 allows gas to flow more easily than providing the plug 250 throughout the entire hole. This increases the gas flow rate, and as a result, reduces the number of plugs 250. This reduces manufacturing costs. Additionally, the plugs 250 become temperature singularities on the wafer W, but reducing their number reduces the temperature singularities and improves thermal uniformity.
• the first and second shielding members 61, 62 and the first and second vias 61a, 62b are embedded in the ceramic plate 20, but as shown in FIG. 8, they may also be embedded in the plug 50. In this way, the first and second shielding members 61, 62 and the first and second vias 61a, 62b can be built in when manufacturing the plug 50.
• Such a plug 50 can be manufactured using, for example, a 3D printer.
• the first and second shielding members 61, 62 and the first and second vias 61a, 62b are embedded in the plug 50.
• a shielding member 361 shown in FIG. 9 may be used.
• the shielding member 361 is a cylindrical member whose central axis is perpendicular to the wafer mounting surface 21.
• the lower end of the shielding member 361 is electrically connected to the metal bonding layer 40. Therefore, the shielding member 361 is electrically connected to the base plate 30 via the metal bonding layer 40.
• the upper end of the shielding member 361 is located near the wafer mounting surface 21 (here, the same position as the electrostatic electrode 22).
• the shielding member 361 is located not only near the wafer mounting surface 21, but also over the entire area between that position and the underside of the ceramic plate 20. In this case, the entire shielding member 361 is at the same potential as the base plate 30. Because the shielding member 361 is a cylindrical member, it is easy to achieve a shielding effect. This cylindrical shield member 361 may be embedded in the ceramic plate 20 instead of the plug 50, but it is easier to manufacture if it is embedded in the plug 50.
• the plug 50 in Figure 9 can be manufactured using a 3D printer, for example.
• the cylindrical shielding member 361 is embedded in the plug 50, but as shown in Figure 10, an outward flange portion 361f may be provided at the upper end of the shielding member 361.
• the entire shielding member 361, including the flange portion 361f, is at the same potential as the base plate 30. This prevents the electric field strength at the upper end of the cylindrical shielding member 361 from becoming too strong.
• the cylindrical shielding member 361 is electrically connected to the base plate 30 via the metal bonding layer 40.
• the shielding member 361 may be electrically connected to the base plate 30 via a metal spring 370.
• the metal spring 370 is disposed in the gas supply path 34 and the through-hole 42 of the metal bonding layer 40.
• the metal spring 370 is disposed in a compressed state between the lower end of the shielding member 361 and the bottom surface of the gas supply path 34 (ring portion 34b) of the base plate 30.
• FIG. 11 illustrates a metal spring 370, it is not limited to a metal spring 370 as long as it is a conductive elastic member that allows gas to pass through in the vertical direction.
• a metal mesh or a mass of metal fiber that can expand and contract in the vertical direction may also be used. This type of structure is particularly useful when a resin adhesive layer is used instead of the metal bonding layer 40.
• a conductive film 372 may be provided, as shown in FIG. 12, which covers the underside of the plug 50 and also covers part of the underside of the ceramic plate 20 (around the plug placement hole 24).
• the conductive film 372 is formed, for example, by sputtering.
• a through hole 372a is provided in the conductive film 372 at a position facing the gas passage 52. Therefore, the conductive film 372 maintains communication between the gas supply path 34 and the gas passage 52.
• the shield member 361 is electrically connected to the base plate 30 via the conductive film 372 and the metal bonding layer 40.
• the electrostatic electrode 22 and the bias electrode 23 are embedded in the ceramic plate 20.
• at least one of the electrostatic electrode 22, the bias electrode 23, and the heater electrode capable of heating the wafer W may be embedded in the ceramic plate 20.
• these electrodes may not be embedded in the ceramic plate 20.
• the first shield member 61 when only the electrostatic electrode 22 is embedded in the ceramic plate 20, the first shield member 61 may be left and the second shield member 62 may be omitted, as shown in FIG. 13, and the first shield member 61 may be electrically connected to the base plate 30 via the internal via 461a of the ceramic plate 20.
• the first shield member 61 may be left and the second shield member 62 may be omitted, as shown in FIG.
• the first shield member 61 may be electrically connected to the base plate 30 via the internal via 461a of the ceramic plate 20. While at least one shield member is effective in suppressing discharge, the use of multiple shield members can more effectively suppress discharge. Furthermore, the shielding member does not need to be installed at the same height as each electrode (electrostatic electrode 22 and bias electrode 23) and may be installed at a different height.
• the first shield member 61 is provided in a position close to the wafer placement surface 21 (a position above half the thickness of the ceramic plate 20 from the wafer placement surface 21), but this is not particularly limited.
• the first shield member 61 may be provided in any position.
• the ceramic plate 20 and the base plate 30 are joined by a metal joining layer 40, but a resin adhesive layer may be used instead of the metal joining layer 40.
• the electrical connection between the second via 62a and the base plate 30 may be made using the metal spring 370 shown in FIG. 11, or may be made using a conductive wire that passes through the resin adhesive layer in the vertical direction.
• the gas supply path 34 includes an inlet portion 34a and a ring portion 34b, but is not limited to this.
• the gas supply path may be a base plate through-hole that passes through the base plate 30 in the vertical direction and communicates with the gas passage 52.
• the internal space of the plug placement hole 24 is an inverted truncated cone space, but it may also be a cylindrical space. In this case, the plug 50 is also cylindrical.
• a plug 50 is placed in the plug placement hole 24, but it is not necessary to place a plug 50 in the plug placement hole 24. In this case, the plug placement hole 24 becomes a gas passage.
• the present invention can be used for wafer mounting stages used in semiconductor manufacturing equipment, such as ceramic heaters, electrostatic chuck heaters, and electrostatic chucks.

Landscapes

• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Plasma & Fusion (AREA)
• Chemical & Material Sciences (AREA)
• Analytical Chemistry (AREA)
• Container, Conveyance, Adherence, Positioning, Of Wafer (AREA)

Priority Applications (3)

Applications Claiming Priority (1)

Publications (1)

Family

ID=97403145

Family Applications (1)

Country Status (3)

Citations (5)

• 2024
  • 2024-04-15 JP JP2025552164A patent/JP7809252B1/ja active Active
  • 2024-04-15 WO PCT/JP2024/014923 patent/WO2025220060A1/ja active Pending
  • 2024-04-15 KR KR1020267002627A patent/KR20260027328A/ko active Pending

Patent Citations (5)

Also Published As

Similar Documents

Legal Events