Temperature measuring mechanism, temperature measuring method, and stage device

A temperature measuring device that measures a temperature of a rotatable stage that holds a substrate, includes: a contact portion provided at a position that does not hinder placing of the substrate on the stage, and a temperature detector having a temperature sensor, and provided at a position separated from the temperature detection contact portion except when measuring a temperature. When measuring the temperature of the stage, the temperature detection contact portion and the temperature detector are relatively moved and brought into contact with each other in a state where the stage is not rotating to detect the temperature of the stage.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority from Japanese Patent Application No. 2019-050482 filed on Mar. 18, 2019 with the Japan Patent Office, the disclosure of which is incorporated herein in its entirety by reference.

TECHNICAL FIELD

The present disclosure relates to a temperature measuring mechanism, a temperature measuring method, and a stage device.

BACKGROUND

A processing apparatus may include a rotating stage on which a substrate such as a semiconductor wafer is placed and rotated. As a technique for measuring the temperature of the rotating stage, a technique in which a temperature sensor is embedded in a rotating stage, the output of the temperature sensor is guided to a room temperature portion through the inside of a rotation shaft, a sliding unit is provided near the center of the shaft at which the rotating peripheral speed is reduced, and the output of the sensor is transmitted to a fixed system by the sliding is disclosed in Japanese Patent Laid-Open Publication No. 01-164037.

SUMMARY

A temperature measuring mechanism according to an aspect of the present disclosure is a temperature measuring mechanism that measures a temperature of a rotatable stage on which a substrate is placed, including a temperature detection contact portion provided at a position where does not hinder placing of the substrate on the stage, and a temperature detector including a temperature sensor and provided at a position separated from the temperature detection contact portion except when measuring a temperature. When measuring the temperature of the stage, the temperature detection contact portion and the temperature detector are brought into contact with each other in a state where the stage is not rotating.

DETAILED DESCRIPTION

First, an example of a processing apparatus to which a stage device including a temperature measuring mechanism according to an embodiment is applied will be described.FIG.1is a schematic cross-sectional view illustrating an example of the processing apparatus.

As illustrated inFIG.1, the processing apparatus1includes a processing container10capable of being maintained in a vacuum, a target30, and a stage device50. The processing apparatus1is configured as a film forming apparatus capable of forming a magnetic film by sputtering on a semiconductor wafer (hereinafter, simply referred to as a “wafer”) W serving as a substrate in an ultra-high vacuum and an extremely low temperature environment in the processing container10. The magnetic film is used for, for example, a tunneling magneto resistance (TMR) element.

The processing container10is a processing container configured to process the wafer W serving as a substrate. The processing container10is connected with an exhaust unit (not illustrated) such as a vacuum pump capable of depressurizing at an ultra-high vacuum, and is configured to be able to depressurize the inside thereof to an ultra-high vacuum (e.g., 10−5Pa or less). The processing container10is connected with a gas supply pipe (not illustrated) from the outside, and a sputtering gas (e.g., a rare gas such as an argon Ar gas, a krypton Kr gas, or a neon Ne gas, or a nitrogen gas) necessary for sputtering film formation is supplied from the gas supply pipe. Further, a carry-in/out port (not illustrated) for the wafer W is formed on a side wall of the processing container10, and the carry-in/out port may be open/close by a gate valve (not illustrated).

The target30is provided to face above the wafer W held by the stage device50, in an upper portion of the processing container10. An AC voltage is applied to the target30from a plasma generation power source (not illustrated). When an AC voltage is applied to the target30from the plasma generation power source in a state where a sputtering gas is introduced into the processing container10, plasma of the sputtering gas is generated in the processing container10, and the target30is sputtered by ions in the plasma. Atoms or molecules of the sputtered target material are deposited on the surface of the wafer W held by the stage device50. The number of targets30is not particularly limited, but the number of targets30may be plural from the viewpoint that a film of different materials may be formed by one processing apparatus1. For example, when depositing the magnetic film (a film containing a ferromagnetic material such as Ni, Fe, or Co), for example, CoFe, FeNi, or NiFeCo may be used as a material of the target30. Further, a material to which other elements are added to these materials may be used as the material of the target30.

As will be described later, the stage device50is configured to hold the wafer W on a stage56, rotates the stage56together with the wafer W, and cools the wafer W to an extremely low temperature through the stage56. Further, as will be described later, the stage device50includes a lifting mechanism74that moves the stage56up and down and a temperature measuring mechanism90that measures the temperature of the stage.

Subsequently, the stage device50will be described in detail.

As illustrated inFIG.1, the stage device50includes the stage56, the lifting mechanism74, and the temperature measuring mechanism90. Further, the stage device50includes a refrigerator52, a refrigeration heat transfer body54, a stage support58, a seal rotating mechanism62, and a driving mechanism68as well.

The lifting mechanism74is configured to be capable of moving the stage56among a transfer position when the wafer W is placed on the stage56, a processing position when forming a film on the wafer W placed on the stage56, and a temperature measuring position at which the temperature of the stage is measured. The transfer position is set to a position lower than the processing position, and the temperature measuring position is set to a position lower than the transfer position. Further, it is possible to control a distance between the target30and the wafer W by the lifting mechanism74.

The temperature measuring mechanism90includes a temperature detection contact portion91provided at a position where does not hinder the placing of the wafer W on the stage56, and a temperature detector92provided below the stage56. Details of the temperature measuring mechanism90will be described later.

The refrigerator52holds the refrigeration heat transfer body54, and cools an upper surface of the refrigeration heat transfer body54to an extremely low temperature (e.g., −20□ or less). The refrigerator52has a cold head52aat an upper portion, and cold heat is transferred from the cold head52ato the refrigeration heat transfer body54. The refrigerator52may be a type using a Gifford-McMahon (GM) cycle from the viewpoint of the cooling capability. When forming a magnetic film used for a TMR element, the cooling temperature of the refrigeration heat transfer body54by the refrigerator52may be in a range of −23□ to −223□ (250 K to 50 K).

The refrigeration heat transfer body54is fixedly disposed on the refrigerator52and forms a substantially columnar shape, and is made of a material having a high thermal conductivity such as pure copper (Cu). An upper portion of the refrigeration heat transfer body54is disposed in the processing container10.

The refrigeration heat transfer body54is disposed below the stage56such that the center axis thereof coincides with the center axis C of the stage56. A first cooling gas supply passage54athrough which a first cooling gas may flow is formed along the center axis C inside the refrigeration heat transfer body54, and the first cooling gas is supplied from a gas supply source (not illustrated) to the first cooling gas supply passage54a. A helium He gas having a high thermal conductivity may be used as the first cooling gas.

The stage56is disposed to have a gap G (e.g., 2 mm or less) formed between the stage56and the upper surface of the refrigeration heat transfer body54. The stage56is made of a material having a high thermal conductivity such as pure copper (Cu). The gap G communicates with the first cooling gas supply passage54aformed inside the refrigeration heat transfer body54. Therefore, the first cooling gas at an extremely low temperature cooled by the refrigeration heat transfer body54is supplied to the gap G from the first cooling gas supply passage54a. As a result, the cold heat of the refrigerator52is transferred to the stage56via the refrigeration heat transfer body54and the first cooling gas supplied to the gap G, and the stage56is cooled to an extremely low temperature (e.g., −20□ or less). A cooling medium is not limited to the first cooling gas, but other fluids having a good thermal conductivity, for example, thermal conductive grease having a good thermal conductivity may be filled in the gap G In this case, since it is not necessary to provide the first cooling gas supply passage54a, the structure of the refrigeration heat transfer body54may be simplified.

The stage56includes an electrostatic chuck56a. The electrostatic chuck56ais made of a dielectric film, and has a chuck electrode56bembedded therein. A predetermined DC voltage is applied to the chuck electrode56bvia a wiring L. As a result, the wafer W may be attracted and fixed by the electrostatic attraction force.

The stage56has a first heat transfer portion56cbelow the electrostatic chuck56a, and a convex portion56dprotruding toward the refrigeration heat transfer body54is formed on a lower surface of the first heat transfer portion56c. In the illustrated example, the convex portion56dis constituted by two annular portions surrounding the center axis C of the stage56. The height of the convex portion56dmay be, for example, 40 mm to 50 mm. The width of the convex portion56dmay be, for example, 6 mm to 7 mm. The shape and the number of convex portions56dare not particularly limited, but the shape and the number of convex portions may be set to have a surface area sufficient for heat exchange, from the viewpoint of increasing the efficiency of the heat transfer with the refrigeration heat transfer body54.

The refrigeration heat transfer body54has a second heat transfer portion54bon the upper surface of the body, that is, a surface facing the first heat transfer portion56c. A concave portion54chaving a gap G with respect to the convex portion56dand fitted with the convex portion is formed in the second heat transfer portion54b. In the illustrated example, the concave portion54cis constituted by two annular portions surrounding the center axis C of the stage56. The height of the concave portion54cmay be the same as that of the convex portion54d, and may be, for example, 40 mm to 50 mm. The width of the concave portion54cmay be, for example, a width slightly wider than that of the convex portion56d, and may be, for example, 7 mm to 9 mm. The shape and the number of concave portions54care determined to correspond to the shape and the number of convex portions56d.

The convex portion56dof the first heat transfer portion56cand the concave portion54cof the second heat transfer portion54bare fitted with each other via the gap G and constitute a comb tooth portion. Since the gap G is bent by providing the comb tooth portions in this manner, it is possible to increase the efficiency of the heat transfer by the first cooling gas between the first heat transfer portion56cof the stage56and the second heat transfer portion54bof the refrigeration heat transfer body54.

As illustrated inFIG.2, the convex portion56dand the concave portion54cmay have a shape forming a waveform corresponding with each other, respectively. Further, the surface of the convex portion56dand the concave portion54cmay have been subjected to an uneven processing by, for example, blasting. As a result, the surface area for heat transfer may be increased, and thus, the heat transfer efficiency may be further increased.

A concave portion may be provided in the first heat transfer portion56c, and a convex portion corresponding to the concave portion may be provided in the second heat transfer portion54b.

The electrostatic chuck56aand the first heat transfer portion56cof the stage56may be integrally formed, or may be separately formed and then bonded together. The body of the refrigeration heat transfer body54and the second heat transfer portion54bmay be integrally formed, or may be separately formed and then bonded together.

The stage56has a through hole56ethat penetrates vertically. The through hole56eis connected with a second cooling gas supply passage57, and a second cooling gas for transferring heat is supplied to the back surface of the wafer W through the through hole56efrom the second cooling gas supply passage57. A helium He gas having a high thermal conductivity may be used as the second cooling gas, similarly to the first cooling gas. By supplying the second cooling gas to the back surface of the wafer W, that is, between the wafer W and the electrostatic chuck56ain this manner, the cold heat of the stage56may be efficiently transferred to the wafer W via the second cooling gas. One through hole56emay be provided, but a plurality of through holes may be provided, from viewpoint of transferring the cold heat of the refrigeration heat transfer body54to the wafer W particularly efficiently.

By separating the flowing passage of the second cooling gas supplied to the back surface of the wafer W from the flowing passage of the first cooling gas supplied to the gap G, it is possible to supply the cooling gas with a desired pressure and flow rate to the back surface of the wafer W, regardless of the supply of the first cooling gas. At the same time, it is possible to continuously supply the cooling gas in a high-pressure⋅extremely low temperature state to the gap G of the wafer W without being limited by the pressure, flow rate, and supply timing of the gas supplied to the back surface.

A portion of the first cooling gas may be supplied to the back surface of the wafer W as a cooling gas, by providing a through hole connected with the gap G in the stage56.

The stage support58is disposed outside the refrigeration heat transfer body54, and rotatably supports the stage56. The stage support58includes a body58ahaving a substantially cylindrical shape, and a flange58bextending outward at the lower surface of the body58a. The body58ais disposed so as to cover the gap G and the outer peripheral surface of the upper portion of the refrigeration heat transfer body54. As a result, the stage support58also has a function of blocking the gap G serving as a connecting portion of the refrigeration heat transfer body54and the stage56.

The seal rotating mechanism62is provided below an insulating member60. The seal rotating mechanism62has a rotating portion62a, an inner fixed portion62b, an outer fixed portion62c, and a heater62d.

The rotating portion62ahas a substantially cylindrical shape extending downward coaxially with the insulating member60, and is rotated by the driving mechanism68in a state of being hermetically sealed by a magnetic fluid with respect to the inner fixed portion62band the outer fixed portion62c. Since the rotating portion62ais connected to the stage support58through the insulating member60, the transfer of the cold heat from the stage support58to the rotating portion62ais blocked by the insulating member60. As a result, it is possible to suppress a decrease in the sealing performance or the occurrence of dew condensation due to a decrease in the temperature of the magnetic fluid of the seal rotating mechanism62.

The inner fixed portion62bhas a substantially cylindrical shape having an inner diameter larger than the outer diameter of the refrigeration heat transfer body54, and an outer diameter smaller than the inner diameter of the rotating portion62a, and is provided between the refrigeration heat transfer body54and the rotating portion62avia the magnetic fluid.

The outer fixed portion62chas a substantially cylindrical shape having an inner diameter larger than the outer diameter of the rotating portion62a, and is provided outside the rotating portion62avia the magnetic fluid.

The heater62dis embedded in the inner fixed portion62b, and heats the entire seal rotating mechanism62. As a result, it is possible to suppress a decrease in the temperature of the fluid magnetic, and a decrease in the sealing performance or the occurrence of dew condensation.

With such a configuration, the seal rotating mechanism62may rotate the stage support58in a state where a region communicating with the processing container10is hermetically sealed with the magnetic fluid and maintained in a vacuum.

A bellows64is provided between the upper surface of the outer fixed portion62cand the lower surface of the processing container10. The bellows64is a corrugated box structure made of metal that is expandable and contractible in the vertical direction. The bellows64surrounds the refrigeration heat transfer body54, the stage support58, and the insulating member60, and separates the space in the processing container10and the space maintained in a vacuum and a space in the atmosphere, communicating with the space.

A slip ring66is provided below the seal rotating mechanism62. The slip ring66includes a rotating body66ahaving a metal ring, and a fixed body66bhaving a brush. The rotating body66ais fixed to the lower surface of the rotating portion62aof the seal rotating mechanism62, and has a substantially cylindrical shape extending downward coaxially with the rotating portion62a. The fixed body66bhas a substantially cylindrical shape having an inner diameter slightly larger than the outer diameter of the rotating body66a.

The slip ring66is electrically connected to a DC power source (not illustrated), and transfers a voltage supplied from the DC power source to the wiring L via the brush of the fixed body66band the metal ring of the rotating body66a. As a result, it is possible to apply a voltage from the DC power source to the chuck electrode without causing a twist on the wiring L. The rotating body66aof the slip ring66is configured to be rotated by the driving mechanism68.

The driving mechanism68is a direct drive motor having a rotor68aand a stator68b. The rotor68ahas a substantially cylindrical shape extending coaxially with the rotating body66aof the slip ring66, and is fixed to the rotating body66a. The stator68bhas a substantially cylindrical shape having an inner diameter larger than the outer diameter of the rotor68a. When driving the driving mechanism68, the rotor68ais rotated, and the rotation of the rotor68ais transferred to the stage56via the rotating body66a, the rotating portion62a, and the stage support58, and the stage56and the wafer W on this stage are rotated with respect to the refrigeration heat transfer body54. InFIG.1, for convenience, rotating members are illustrated with dots.

A direct drive motor is illustrated as an example of the driving mechanism68, the driving mechanism68may be driven via, for example, a belt.

A first insulating structure70forming a cylindrical shape having a double tube structure so as to cover the cold head52aof the refrigerator52and the lower portion of the refrigeration heat transfer body54, and forming a vacuum insulating structure (a vacuum double tube structure) in which the inside is in a vacuum is provided. With the first insulating structure70, it is possible to suppress a decrease in the cooling performance due to the heat from the outside such as the driving mechanism68that is entered to the cold head refrigerator52and the lower portion of the refrigeration heat transfer body54, which are important for cooling the stage56or the wafer W.

Further, a second insulating structure71forming a cylindrical shape having a vacuum double tube structure in which the inside is in a vacuum so as to cover the substantially entire of the refrigeration heat transfer body54, and to overlap the inside of the first insulating structure70. With the second insulating structure71, it is possible to suppress a decrease in the cooling performance due to the heat from the outside such as the first cooling gas leaking into the magnetic fluid seal or the space S that is entered to the refrigeration heat transfer body54. By overlapping the first insulating structure70and the second insulating structure71with each other in the lower portion of the refrigeration heat transfer body54, it is possible to eliminate the uninsulated portion of the refrigeration heat transfer body54, and to enhance the insulation in the cold head52aand in the vicinity of the cold head.

Further, with the first insulating structure70and the second insulating structure71, it is possible to suppress the cold heat of the refrigerator52and the refrigeration heat transfer body54from being transferred to the outside.

A seal member81is provided between the body58aof the stage support58and the second insulating structure71. The space S sealed with the seal member81is formed by the body58aof the stage support58, the second heat transfer portion54bof the refrigeration heat transfer body54, and the upper portion of the second insulating structure71. The first cooling gas leaked from the gap G flows into the space S. A gas flowing passage72is connected to the space S through the seal member81. The gas flowing passage72extends downward from the space S. A space between the upper surface of the second insulating structure71and the second heat transfer portion54bof the refrigeration heat transfer body54is sealed by a seal member82. The first cooling gas leaking to the space S is suppressed from being supplied to the body of the refrigeration heat transfer body54by the seal member82.

The gas flowing passage72may discharge a gas in the space S, or may supply the cooling gas to the space S. In both cases where the gas flowing passage72discharges the gas and where the gas flowing passage supplies the cooling gas, it is possible to prevent a decrease in the seal performance due to penetration of the first cooling gas into the seal rotating mechanism62, and thus a decrease in the temperature of the magnetic fluid. When the gas flowing passage72has a cooling gas supply function, a third cooling gas is supplied to function as a counter flow with respect to the first cooling gas leaked from the gap G From the viewpoint of enhancing the function as the counter flow, the supply pressure of the third cooling gas may be substantially the same as or slightly higher than the supply pressure of the first cooling gas. Due condensation may be prevented by using a gas having a thermal conductivity lower than that of the first cooling gas, such as an argon Ar gas or a neon Ne gas as the third cooling gas.

Subsequently, the temperature measuring mechanism90will be described in detail.

As described above, the temperature measuring mechanism90includes a portion of the stage56that is a temperature measurement target other than the placing surface for the wafer W, in the present example, the temperature detection contact portion91provided on the outer peripheral portion of the stage56, and the temperature detector92provided below the stage56. The temperature detector92has a temperature sensor, and provided at a position separated from the temperature detection contact portion91except when measuring the temperature. In the present example, the temperature detector92is attached to the bottom of the processing container10. The temperature of the stage56may be measured by bringing the temperature detector92into contact with the temperature detection contact portion91. The temperature detection contact portion91is configured to be connectable to and separable from the temperature detector92by moving the stage56up and down by the lifting mechanism74. Then, as illustrated inFIG.3, the temperature detection contact portion91and the temperature detector92are corresponded with each other by rotating the stage56, and the temperature detection contact portion91is brought into contact with the temperature detector92by moving down the stage56to the temperature measuring position. In this stage, the temperature of the stage56is measured.

The stage56is rotated in a state of being moved up to the processing position above the temperature measuring position, and the film forming processing is performed. At this time, since the temperature detector92is separated from the temperature detection contact portion91, the temperature is not measured.

Subsequently, the temperature detection contact portion91will be described in detail.

FIG.4is a cross-sectional view illustrating the temperature detection contact portion91, andFIG.5is a side view of the temperature detection contact portion91inFIG.4as viewed from an arrow A.

The temperature detection contact portion91includes a bracket (connecting member)101, an indium sheet102, a heat transfer member103, a coil spring (spring member)104, and a leaf spring105.

The bracket101is made of a material having a high thermal conductivity similarly to the stage56, for example, pure copper (Cu), and is connected to the lower surface of the outer peripheral portion of the stage56by screws107via the indium sheet102. The bracket101has a vertical portion101aextending downward from the stage56, and a horizontal portion101bextending outward horizontally with respect to the stage56at the lower end of the vertical portion101a. Since the indium sheet102is soft and has a high thermal conductivity, the heat transfer capability from the stage56to the bracket101may be improved, and a temperature measurement error may be extremely reduced.

The heat transfer member103is configured to transfer the cold heat of the stage56transferred via the bracket101to the temperature detector92, and is made of a material having a high thermal conductivity, for example, pure copper (Cu). The heat transfer member103has a body103athat has a rod shape and is vertically inserted into a hole101cprovided in the horizontal portion of the bracket101. Further, the heat transfer member103has a head103bthat is attached to a portion of the body103aextending upward from the horizontal portion101bof the bracket101. An engaging portion103cconfigured to engage the coil spring104is formed at the lower end of the body103a. A bottom surface103dof the heat transfer member103is serving as a pressing surface that presses the upper surface of the temperature detector92.

The coil spring104is provided between the lower surface of the horizontal portion101bof the bracket101and the engaging portion103aof the heat transfer member103, and bias the heat transfer member103downward. The coil spring104is formed of a material that is usable at an extremely low temperature, for example, a nickel-based alloy such as Inconel or Elgiloy. When measuring the temperature, the heat transfer member103is moved down together with the stage56, and the bottom surface103dis pressed against the temperature detector92against the biasing force of the coil spring104.

When not measuring the temperature, the lower surface of the head103bis in contact with the horizontal portion101bof the bracket101by the biasing force of the coil spring104. As a result, the heat of the stage56is transferred to the heat transfer member103via the indium sheet102and the bracket101. The head103bmay be integrally formed with the body103a.

From the viewpoint of measuring more accurate temperature at an extremely low temperature, all of the stage56, the bracket101, and the heat transfer member103may be made of pure copper (Cu) having an extremely good thermal conductivity at an extremely low temperature.

Meanwhile, when measuring the temperature, the heat transfer member103is moved down together with the stage56, and the bottom surface103dof the heat transfer member103is pressed against the temperature detector92against the biasing force of the coil spring104. At this time, the head103band the horizontal portion101bof the bracket101are separated from each other.

The leaf spring105is fixed to the upper end of the head103band the lower end of the horizontal portion101bof the bracket101by screws108, and has a function of preventing the heat transfer member103from being loosed.

Subsequently, the temperature detector92will be described in detail.

FIG.6is a perspective view illustrating the temperature detector92,FIG.7is a cross-sectional view taken along a plane corresponding to line VII-VII inFIG.6,FIG.8is an exploded perspective view of the temperature detector92, andFIG.9is a plan view illustrating an attached state of a sheath thermocouple125of the temperature detector92.

The temperature detector92includes a base member120constituted by a metal member121such as aluminum, and a resin member122provided on the metal member, and made of a resin material such as PTFE, and the sheath thermocouple125serving as a temperature sensor. The resin member122functions as an insulating member, and the sheath thermocouple125is disposed on the upper surface of the resin member. The metal member121is fixed to the bottom of the processing container10by screws128. The base member120may have only a resin member. Further, the temperature detector92further includes a heat collecting plate123and an indium sheet124.

The indium sheet124is disposed on the upper surface of the resin member122where the sheath thermocouple125is disposed so as to cover the sheath thermocouple125. The indium sheet124has a thin plate shape with a thickness of, for example, 0.3 mm, and has a function of improving thermal responsiveness.

The heat collecting plate123is disposed on the upper surface of the indium sheet124in a region where the sheath thermocouple125is disposed. The heat collecting plate123is made of a material having a good thermal conductivity, and for example, at least the body thereof is made of pure copper (Cu). A high thermal conductivity in an extremely low temperature region is obtained by forming the heat collecting plate123with Cu, and additionally, the heat capacity may be reduced by forming the heat collecting plate as a thin plate shape. Further, it is possible to suppress the fluctuation when measuring the temperature by the sheath thermocouple125, by providing the heat collecting plate123. The heat collecting plate123has a thin plate shape having a thickness of, for example, 0.1 mm From the viewpoint of preventing corrosion of the heat collecting plate123, a corrosion-resistant coating, for example, nickel Ni plating with a thickness of about 5 μm may be applied to the body made of pure copper (Cu). At this time, from the viewpoint of the responsiveness of the temperature measurement, the contact portion of the sheath thermocouple125may expose pure copper without being plated.

When measuring the temperature, the heat transfer member103(the bottom surface103d) of the temperature detection contact portion91is pressed against the region where the sheath thermocouple125is disposed, and the temperature is measured.

Holding members126that hold the heat collecting plate123are disposed on the upper surface of both ends of the heat collecting plate123, and the holding members126and the resin member122are screwed to the metal member121by screws127that penetrate these members. The heat collecting plate123and the indium sheet124are pressed against each other by the holding members126, by screwing by the screws127. As a result, as illustrated inFIG.10, the sheath thermocouple125is embedded in the indium sheet124that is soft and has a high thermal conductivity, and thus, the temperature detection by the sheath thermocouple125may be performed with high accuracy.

A groove121ais provided at the lower portion of the metal member121, and a cylindrical hollow121bthat penetrates vertically is provided at the central portion of the metal member. Further, the resin member122is also provided with a hollow122athat penetrates vertically. As a result, in addition to insulate the heat from the processing container10by the resin member122, it is possible to reduce the heat capacity by the vacuum insulating by the groove121aand the hollows121band122a.

The sheath thermocouple125has a structure in which a thermocouple, for example, a k-type thermocouple (aluminum chromel) is covered with a metal tube via an insulating member. It is advantageous when the sheath thermocouple125is thinner from the viewpoint of improving the responsiveness and shortening the temperature measuring time, and for example, the diameter thereof may be 0.3 mm to 1.0 mm A wiring125aof the sheath thermocouple125extends from a measurement unit outside the processing container10, is inserted into the processing container10via an introducing port, and is guided by a plurality of insulating tubes and is drawn to the temperature detector92at the bottom of the processing container. It is possible to minimize the influence of heat by being guided by the insulating tubes. A hermetic seal may be used for the introduction port.

Further, the temperature detector92further includes a wiring relay panel129attached to the metal member121by screws130. The wiring relay panel129is configured to relay the wiring125aof the sheath thermocouple125, and the wiring125areaches the upper surface of the resin member122through the wiring relay panel129and is connected to the thermocouple125.

[Operation of Processing Apparatus and Temperature Measuring Method by Temperature Measuring Mechanism]

In the processing apparatus1, the inside of the processing container10becomes a vacuum, and the refrigerator52of the stage device50is operated. Further, the first cooling gas is supplied to the gap G through the first cooling gas flowing passage54a. As a result, the cold heat transferred from the refrigerator52maintained at an extremely low temperature to the refrigeration heat transfer body is transferred to the stage56via the first cooling gas supplied to the gap G, and the state56provided rotatably is maintained at an extremely low temperature of −20□ or less.

Then, the stage device50is moved (moved down) by the lifting mechanism74such that the stage56is at the transfer position, and the wafer W is transferred from the vacuum transfer chamber by the transfer device (neither is illustrated), into the processing container10, and is placed on the stage56. Subsequently, a DC voltage is applied to the chuck electrode56b, and the wafer W is electrostatically attracted by the electrostatic chuck56a. Then, the second cooling gas is supplied to the back surface of the wafer W, and the wafer W is also maintained at an extremely low temperature of −20□ similarly to the stage56.

After that, the stage56is moved up to the processing position, and the film forming processing is performed while rotating the stage56maintained at an extremely low temperature. However, in the present embodiment, prior to the film forming processing, the temperature of the stage56is measured before rotating the stage56.

When measuring the temperature of the stage56, the stage56is positioned at the temperature measuring position lower than the transfer position by the lifting mechanism74. In this state, the stage56is positioned such that the height position of the temperature detection contact portion91and the height position of the temperature detector92are separated from each other by about several mm, and as illustrated inFIG.11, the stage56is rotated in this state to adjust the position of the temperature detection contact portion91to the position of the temperature detector92.

After finishing the positioning of the temperature detection contact portion91and the temperature detector92, the stage56is moved down by several mm from the temperature measuring position, and as illustrated inFIG.12, the lower end of the temperature detection contact portion91, that is, the bottom surface103dof the heat transfer member103is brought into contact with the upper surface (i.e., heat collecting plate123) of the temperature detector92. Then, by further moving the stage56down by several mm, as illustrated inFIG.13, the bottom surface103dof the heat transfer member103presses the upper surface (i.e., heat collecting plate123) of the temperature detector92. In this stage, although depending on the attained temperature, the temperature of the stage56is measured by the sheath thermocouple125, by holding for about 1 sec to 30 sec (detecting time). The detecting time at this time depends on the responsiveness (sensitivity) of the sheath thermocouple125, and the smaller the diameter of the sheath thermocouple125, the higher the responsiveness (sensitivity), and thus, the detecting time may be shortened. When the diameter of the sheath thermocouple125is 0.3 mm, the temperature may be detected almost accurately by holding the sheath thermocouple for about 2 sec.

In the related art, temperature measurement of a rotating stage is performed by measuring the temperature via a sliding member while the stage is rotating as disclosed in Japanese Patent Laid-Open Publication No. 01-164037. However, in this temperature measuring, a measurement error increases due to the measurement via the sliding member, and it is difficult to measure stably due to, for example, wear or the sliding member.

With respect to the above, in the present embodiment, the temperature detector92is provided separately from the stage56, and the temperature is measured by bringing the temperature detection contact portion91provided in the stage56into contact with the temperature detector92while the stage56is rotated. As a result, since the temperature is measured without using a sliding member, it is possible to measure the temperature stably and with high accuracy, without causing a temperature error or instability of the temperature measurement. Further, it is possible to measure the temperature of the stage56at an arbitrary timing at which the stage56is not rotated by moving the stage56up and down, and when performing the measurement immediately before the film forming processing in which the stage56is rotated, the temperature substantially the same as when the stage is rotating may be detected.

Further, when the temperature detector is in contact with the stage via a sliding member as in the related art, in the temperature measurement of the stage in an extremely low temperature as in the present embodiment, it may be difficult to maintain the stage at an extremely low temperature due to the heat entered from the temperature detector.

With respect to the above, in the present embodiment, the temperature detection contact portion91and the temperature detector92are brought into contact with each other only when measuring the temperature, and thus, the heat entered to the stage56is essentially small. Further, even during the temperature measurement, it is possible to prevent the heat from entering to the stage56extremely effectively and to measure the temperature with extremely high accuracy.

Hereinafter, descriptions will be made in detail with respect to this aspect.

The temperature detection contact portion91has the bracket101and the heat transfer member103which are important components, made of a material having a good thermal conductivity, for example, pure copper (Cu), similarly to the stage56. Further, the indium sheet102that has a good thermal conductivity and is soft is provided between the stage56and the bracket101. As a result, in the state inFIG.11, a good thermal conductivity is maintained between the stage56to the bracket101, and additionally, the presence of the head103ballows that the cold heat from the stage56is sufficiently transferred to the heat transfer member103via the bracket101. In particular, in the case of pure copper (Cu), the heat conductivity at an extremely low temperature is extremely high, and the heat transfer property to the heat transfer member103is extremely high. Therefore, in the heat transfer member103that is in contact with the temperature detector92, the temperature of the bottom surface103dof the heat transfer member103that is in contact with the temperature detector92is substantially the same as the temperature of the stage56. Meanwhile, when the bottom surface103dof the heat transfer member103is in contact with the temperature detector92at the time of temperature measurement, and the heat transfer member103presses the temperature detector92, as illustrated inFIG.13, the head103bis moved up, and thus, the heat from the temperature detector92is blocked between the head103band the bracket101. Since the heat transfer member103and the stage56are maintained substantially the same temperature immediately after being blocked, the temperature may be measured with high accuracy. Additionally, the heat from the temperature detector92to the stage56is blocked, and thus, there is almost no thermal effect on the stage56.

Further, the temperature detector92is fixed to the bottom of the processing container10, the sheath thermocouple125for detecting the temperature is maintained above the resin member122having a high insulating effect. Further, the metal member121and the resin member122are provided with a space such as a hollow to be vacuum insulated. As a result, the heat capacity may be small, and the thermal effect on the sheath thermocouple125may be reduced. The heat collecting plate123made of, for example, pure copper (Cu) is disposed on the sheath thermocouple125via the indium sheet124, and the sheath thermocouple125is buried in the indium sheet124. As a result, when measuring the temperature by bringing the heat transfer member103of the temperature detection contact portion91into contact with the heat collecting plate123, it is possible to perform the temperature detection by the sheath thermocouple125with high accuracy.

After measuring the temperature of the stage56, the stage56is moved (moved up) to the processing position by the lifting mechanism74, and the inside of the processing container10is adjusted to an ultra-high vacuum (e.g., 10−5Pa or less) that is the processing pressure. Then, the rotation of the rotor68ais transferred to the stage56via the rotating body66a, the rotating portion62a, and the stage support58by providing the driving mechanism68, and the stage56and the wafer W on the stage are rotated with respect to the refrigeration heat transfer body54.

At this time, in the stage device50, since the stage56is separated from the refrigeration heat transfer body54fixedly provided, the stage56may be rotated by the driving mechanism68via the stage support58. Further, the cold heat transferred from the refrigerator52maintained at an extremely low temperature to the refrigeration heat transfer body54is transferred to the stage56via the first cooling gas supplied to the narrow gap G of 2 mm or less. Then, the wafer W may be efficiently cooled by the cold heat of the stage56, by attracting the wafer W by the electrostatic chuck56awhile supplying the second cooling gas to the back surface of the wafer W. As a result, the wafer W may be rotated together with the stage56, while maintaining the wafer W at for example, an extremely low temperature of −20□ or less.

In this manner, a voltage is applied to the target30from a plasma generation power source (not illustrated) while introducing a sputtering gas into the processing container10in a state where the wafer W is being rotated. As a result, a plasma of the sputtering gas is generated, and the target30is sputtered by ions in the plasma. Atoms or molecules of the sputtered target material are deposited on the surface of the wafer W held by the stage device50at an extremely low temperature, and a desired film, for example, a magnetic film for a TMR element having a high magneto resistance ratio may be formed.

The temperature measurement timing by the temperature measuring mechanism90is not limited to the timing immediately before performing the film forming processing described above, and the temperature may be measured at an arbitrary timing as long as the stage56is stopped. For example, the temperature of the stage56before the wafer W is placed may be measured, and the temperature of the stage immediately after the film forming processing may be measured.

For example, in the above embodiment, the case in which the stage56is maintained at an extremely low temperature (−20□ or less), and the magnetic film used for a TMR element is applied to the sputtering film formation has been described as an example. However, as long as the processing is performed while rotating the stage, the temperature of the stage or the contents of the processing are not limited thereto.

Further, in the above embodiment, the example in which the temperature detection contact portion is moved up and down together with the stage to connect to and separate from the temperature detector has been described. However, the temperature detector may be moved up and down. The position of the temperature detection contact portion is also not limited to the position in the above embodiment, and may be a position where does not hinder the placing of the substrate on the stage.

In the above embodiment, the temperature measuring mechanism provided with one temperature detection contact portion and one temperature detector is illustrated. However, the present disclosure is not limited thereto, and a plurality of temperature detection contact portions and temperature detectors may be provided. It is possible to measure the temperature of the stage at a plurality of locations, and to grasp the temperature distribution of the stage, by providing a plurality of temperature detection contact portions and temperature detectors.

According to the present disclosure, a temperature measuring mechanism, a temperature measuring method, and a stage device capable of stably measuring the temperature of a rotating stage with high accuracy is provided.