JPH06181186A - Joint - Google Patents

Abstract

PURPOSE:To provide a joint excellent in dielectric strength, mechanical strength, and thermal insulation properties. CONSTITUTION:In a joint for coupling an external refrigerant passage with a refrigerant containing section, a thermal insulation intermediate section 90 made of a highly dielectric material having low thermal conductivity is interposed between a coupling section 88 to be mounted on the containing section and a coupling section 92 to be coupled with the refrigerant passage. This structure enhances electrical and thermal insulation between the refrigerant containing section side and the refrigerant passage side.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a joint device.

[0002]

2. Description of the Related Art Generally, in a semiconductor manufacturing process, an object to be processed, for example, a semiconductor wafer is repeatedly subjected to a plasma process such as a sputtering process or an etching process in various processing apparatuses. For example, in the plasma etching process, a plasma is generated by applying a high frequency between the electrodes in a state where a process gas is introduced into the processing container, and the reactive ions generated at this time cause the surface of the semiconductor wafer placed on the lower electrode to be removed. It is performed by etching.

When plasma processing is performed on a wafer in accordance with miniaturization and high integration of semiconductor integrated circuits, for example, liquid nitrogen as a coolant is circulated to a mounting table to keep the wafer temperature relatively low. In some cases, so-called low temperature etching is performed. For the purpose of improving the efficiency of plasma processing, a high frequency power source may be applied to the lower electrode, that is, the wafer mounting table side to be the cathode side, and the upper electrode side may be the ground side to make the distance between the upper and lower electrodes very close. Has been done.

By the way, as described above, in order to apply a high frequency to the lower electrode side to make it the cathode side and to supply a cooling medium such as liquid nitrogen to this portion, the cooling means of the mounting table which is the lower electrode and the liquid means The joint portion with the supply path for supplying the refrigerant must have a structure that can withstand low temperature while maintaining insulation between the mounting table and the processing container or the pipe. Therefore, in the related art, a pipe made of an insulator such as Teflon is used in the joint portion, and a Teflon tape is wound around the pipe for insulation.

[0005]

However, when the joint portion is formed by using this kind of Teflon, the insulating property can be maintained, but since the Teflon itself is a polymer, it is used for this Teflon and the joint portion. There is an improvement in that the cooling medium leaks due to the difference in heat shrinkage between the metal such as stainless steel and the like. In particular,
This heat shrinkage difference does not cause a problem in the normal operating temperature range, but cannot be ignored because the joint portion is exposed to extremely low temperature such as liquid nitrogen.

It is also conceivable to use a vacuum double tube formed of a metal material such as stainless steel as another joint structure. In this case, the heat insulating property is relatively excellent, but as described above, When applying a high frequency to the electrode and using this as the cathode side, it was not realistic because a separate insulating measure had to be taken. Therefore, in the previous application (Japanese Patent Application No. 4-220624), the present applicant has proposed a joint device in which a vacuum double pipe joint is formed by using a material having low thermal conductivity and an electrical insulating material, for example, a ceramic material. And obtained relatively good results.

However, in this joint device, it is necessary to perform vacuum brazing by joining dissimilar materials, for example, pipe-shaped ceramic material and stainless steel, but joining of end portions of the pipe-shaped ceramic material is required. It is very difficult, and stress may be repeatedly applied to this portion due to the difference in linear expansion coefficient between different materials, and it may be difficult to maintain the connection. Further, since the ceramic material itself is a brittle material compared to the metal material, there is also an improvement point such that the pipe made of the ceramic material is excessively shocked during processing or mounting and is damaged. . The present invention has been made to pay attention to the above problems and to solve them effectively. An object of the present invention is to provide a joint device excellent in electrical insulation, heat insulation and strength.

[0008]

In order to solve the above problems, the present invention provides a joint device for connecting an external refrigerant passage to a refrigerant accommodating portion formed on a mounting table to which a voltage is applied. And a housing portion side coupling portion that is mounted in the housing portion, and a housing portion side coupling portion that is made of a material having low thermal conductivity and high electrical insulation and has a channel in the center. And an insulating heat insulating intermediate portion connected to the portion, and a refrigerant passage side coupling portion that has a flow path in the center and is connected to the insulating heat insulating intermediate portion and that couples the refrigerant passages.

[0009]

Since the present invention is configured as described above, since the insulating and heat insulating intermediate portion having a low thermal conductivity and made of an electrically insulating material is formed in the middle of the joint device, the accommodating portion side coupling portion is formed. The refrigerant passage side coupling portion is thermally and electrically insulated from each other, and the strength is not deteriorated.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a joint device according to the present invention will be described in detail below with reference to the accompanying drawings. 1 is a cross-sectional view showing an embodiment of a joint device according to the present invention, FIG. 2 is a cross-sectional view showing a plasma processing device to which the joint device of the present invention is applied, and FIG. 3 is a joint showing a state of attachment to the plasma processing device. FIG. 4 is a sectional view of the apparatus, and FIG. 4 is a schematic exploded view showing a mounting table of the plasma processing apparatus. In this embodiment, a case where a joint device is applied to a plasma etching device will be described. First, this plasma etching apparatus will be described prior to the description of the joint apparatus of the present invention.

As shown in the figure, the etching apparatus 2 is
The processing container 4 has a cylindrical or rectangular shape and is made of a conductive material such as aluminum.
A substantially column-shaped mounting table 8 for accommodating an object to be processed, for example, a semiconductor wafer W, is housed in the inner bottom portion thereof while being insulated from the bottom portion 6 of the processing container 4. The mounting table 8 includes a susceptor supporting table 10 formed of aluminum or the like in a cylindrical shape.
And a susceptor 14 made of aluminum or the like, which is detachably provided by means of a bolt 12 thereon.

The susceptor support 10 has a coolant accommodating portion, for example, a cooling jacket 1 in which the coolant is stored and circulated.
6, a coolant such as liquid nitrogen is introduced into the jacket 16 through a coolant supply passage 18 serving as a coolant passage to circulate in the jacket, and a coolant discharge passage 20 serving as a coolant passage is also provided. Are discharged outside the container.

The susceptor 14 is formed in a disk shape having a protrusion in the center, and an electrostatic chuck 22 is formed in a wafer mounting portion at the center of the susceptor 14 with an area substantially the same as the wafer area. The electrostatic chuck 22 is formed, for example, by sandwiching a conductive film 24 such as a copper foil in an insulating state between two polymer polyimide films. The conductive film 24 is a filter that cuts a high frequency on the way by a voltage supply lead 26. Two
It is connected to the DC high voltage source 28 via 7. Therefore, by applying a high voltage to the conductive film 24, the wafer W can be sucked and held on the upper surface of the chuck 22 by Coulomb force. And the susceptor support 1
0 and the susceptor 14 are provided with a gas passage 30 for supplying a heat transfer gas such as He to the back surface of the wafer W. The electrostatic chuck 22 also has a large number of vent holes (not shown) through which the heat transfer gas passes.

An annular focus ring 32 is arranged on the upper peripheral edge of the susceptor 14 so as to surround the wafer W. The focus ring 32 is made of an insulating material that does not attract the reactive ions, and allows the reactive ions to effectively enter only the semiconductor wafer W inside. The susceptor 14 is provided with a pipe lead 34 made of a hollow conductor that penetrates the susceptor support 10. The pipe lead 34 has a wiring 36.
Is connected to a high frequency power source 38 for generating plasma of 380 KHz, for example. Therefore, the susceptor 14
Will be configured as the lower electrode. A filter 40 for noise cutting and a capacitor 42 for matching are sequentially provided on the wiring 36.

Above the susceptor 14, the upper electrode 4 is grounded at a distance of about 15 to 20 mm.
4 are provided, a process gas, for example, an etching gas such as CF ₄ is supplied to the upper electrode 44 through a gas supply pipe 46, and a large number of small holes 48 formed on the electrode surface of the upper electrode 44. The etching gas is blown out into the processing space below. An exhaust pipe 50 is connected to the lower side wall of the processing container 4 so that the atmosphere inside the processing container 4 can be exhausted by an exhaust pump (not shown).

A temperature adjusting heater 52 is provided between the electrostatic chuck 22 and the coolant accommodating portion 16. Specifically, the heater 52 is a plate-shaped ceramics heater having a thickness of about several mm.
2 is completely housed in a heater housing groove 56 formed in an upper portion of a heater fixing base 54 provided on the upper surface of the susceptor support base 10 with its upper surface at the same level. The heater fixing base 54 is made of a material having a good heat transfer property, such as aluminum. The size of the heater 52 is preferably set to be substantially the same as the wafer area, and the cooling heat from the cooling jacket 16 located below this is controlled to transfer to the wafer W. The temperature of W can be adjusted.

A through hole (not shown) through which a pusher pin or the like penetrates through the temperature adjusting heater 52 and the heater fixing base 54.
Etc. are formed. An appropriate number of bolt holes 58 are formed in the peripheral portion of the heater fixing base 54, and the fixing base 54 is detachably attached to the susceptor support base 10 side with bolts 60. Further, on the lower surface of the susceptor 14, an accommodation recess 62 for accommodating the entire heater fixing base 54 is provided.
The heater fixing base 54 is connected to the gas passage 30 in order to supply a heat transfer medium such as He to the boundary between the upper surface of the heater 52 and the lower surface of the accommodation recess 62 of the susceptor 14. The divided branch path 64 (see FIG. 2) is formed. The power supply lead 6 is connected to the heater 52.
6 is connected, and the filter 6 is connected to the lead 66.
A power source 68 is connected via 7 to supply a predetermined power to the heater 52.

Further, the electrostatic chuck 22 is provided with a thermometer for detecting the wafer temperature, for example, a temperature detector 70 composed of a Luxtron, a thermocouple or the like. The temperature detector 70 is connected with a temperature detection lead 72 that transmits a detected value. This temperature detection lead 72
Is composed of an optical fiber when a Luxtron is used as the temperature detector 70, but an ordinary conductor is used when a thermocouple is used. In this case, a filter 74 for removing high frequency noise is used. A control unit 7 including, for example, a computer or the like, which is provided on the way and controls the entire apparatus.
6 is input. The control unit 76 controls the entire apparatus by a predetermined program as described above, and for example, the high frequency power source 38, the power source 68 to the heater 52,
The distribution of the DC high voltage source 28 to the electrostatic chuck 22 is controlled.

In particular, in the present embodiment, various wirings which are susceptible to high frequency for plasma generation, for example, power supply lead 66 connected to the heater, voltage supply lead 26 connected to the electrostatic chuck 22, All the temperature detection leads 72 connected to the temperature detector 70 are housed in the pipe lead 34 that supplies a high frequency for plasma, so that the high frequency noise does not affect the outside. Then, as described above, each of the leads 66, 26, 7
2 is a filter 67 for cutting high frequency noise,
27 and 74 are connected. Further, an insulator 78 is provided in a penetrating portion of the bottom of the processing container of the pipe lead 34 to electrically insulate it from the container side.

As shown in FIG. 1, the present invention is provided between the coolant supply port 80 and the coolant supply passage 18 of the cooling jacket 16 and between the coolant discharge port 82 and the coolant discharge passage 20. The joint devices 84 and 86 are connected to each other to electrically insulate the susceptor support 10 from the processing container bottom 6 and the refrigerant passages 18 and 20 and to prevent cold heat from leaking to the processing container bottom 6 side. ing.

The joint devices 84 and 86 provided at the coolant supply port 80 and the coolant discharge port 82 are formed and provided in the same manner except for the flow passage area. The attachment state of only the joint device 84 is shown. The joint device 84 has a passage in the center and is attached to the refrigerant accommodating portion on the accommodating portion side coupling portion 8.
8 and a material having low thermal conductivity and high electrical insulation, for example, ceramics obtained by firing alumina or the like,
An insulating and heat insulating intermediate portion 90 having a flow passage in the center and connected to the accommodation portion side coupling portion 90, and an insulating heat insulating intermediate portion 90 having a flow passage in the center and being connected to the insulating heat insulating intermediate portion 90 and the refrigerant supply passage 1
8 and a refrigerant passage side coupling portion 92 connected to the main unit 8.

The accommodation portion-side coupling portion 88 has a distal end made of a conductive member such as aluminum whose upper supply port 94 is inserted into the cooling jacket 16 and is wholly liquid-tightly attached and fixed to the partition wall of the jacket 16. A member 96, a ring-shaped ring member 98 made of, for example, stainless steel connected to the member 96, and a linear expansion coefficient alleviating member 100 made of, for example, Kovar connected to the ring member 98 are sequentially connected in a three-layer structure. Is configured. And
The insulating and insulating intermediate portion 90 formed in a ring shape is connected to the relaxing member 100, and the intermediate portion 90 serves to insulate high frequencies and insulate liquid nitrogen.

As for the method of connecting the tip member 96 and the ring member 98, since the materials are aluminum and stainless, for example, they are connected by a friction welding method, and the ring member 98 and the relaxing member 100 are connected. As the connection method with, for example, electron beam welding is used because the respective materials are stainless steel and Kovar. Then, as a connection method between the relaxing member 100 and the insulating and heat insulating intermediate portion 90, for example, a vacuum brazing method using a brazing material made of silver and copper is adopted. In this case, at the time of brazing, wettability is improved by applying a metal paste or the like to the joint surface of alumina, which is a typical material of the intermediate portion 90, to improve the wettability, and the joint property with the relaxation member 100 made of Kovar is good. To

A ring-shaped upper guide concave portion 102 is formed on the upper edge of the insulating and heat insulating intermediate section 90, and a ring-shaped upper guide convex portion formed on the lower edge of the relaxing member 100 is formed on this portion. The portion 104 is fitted, and is configured so as to be able to guide the shaft so as not to cause a shaft shift when these are joined. Further, the linear expansion coefficient relaxing member 10
As the material of 0, the material of the accommodating portion side coupling portion 88, for example, the material of the linear expansion coefficient of stainless steel and the insulating and heat insulating intermediate portion 90
For example, by using a material having a linear expansion coefficient intermediate to that of ceramics, for example, Kovar, it is possible to reduce the difference in the linear expansion amount between these members.

In this embodiment, the diameter of the entire apparatus, that is, each member is set to about 30 mm, the diameter of the central flow passage is set to about 6 mm, and the thickness of the insulating and heat insulating intermediate portion 88 is set to about 10 mm. It is set to a degree. As a result, the normal supply pressure of liquid nitrogen is 3 kg / mm ² , whereas 9.1 at the connection portion by the friction welding.
kg / mm ² or more, in the brazed connection according Kovar and alumina can be obtained 9.0 kg / mm ² or more tensile strength, show good properties.

The refrigerant passage side joint portion 92 connected to the insulating heat insulating intermediate portion 90 has a vacuum double tube structure made of, for example, stainless steel, and is connected to the upper end portion thereof by, for example, butt welding. Further, a linear expansion coefficient relaxing member 106 made of, for example, Kovar is provided. Then, the relaxing member 106 is brazed and joined in the same manner as described above,
It is connected to the insulating and heat insulating intermediate portion 90 made of ceramics, and as described above, achieves electrical insulation and heat insulation between the refrigerant passage side joint portion 92 and the accommodation portion side joint portion 88. A ring-shaped lower guide recess 108 is formed at the lower end peripheral portion of the heat insulating intermediate portion 90, and a ring-shaped lower guide recess formed at the upper end peripheral portion of the lower relaxing member 106 is provided at this portion. The convex portion 110 is fitted so that axial misalignment does not occur at the time of joining them.

An auxiliary insulating heat insulating member 112 made of, for example, ceramics such as alumina or Teflon is fitted in the lower peripheral edge of the lower relaxing member 106.
The double pipe structure has an inner pipe 114 made of, for example, stainless steel, and an outer pipe 116 made of, for example, stainless steel and arranged concentrically on the outer side of the inner pipe 114 with a predetermined distance therebetween.

The upper portion of the outer pipe 116 is connected to a joining member 118 made of, for example, stainless steel, and the joining member 118 has an inner pipe 114 and an outer pipe 1.
16 and an annular chamber formed between the vacuum chamber 12 and
A communication path 122 is formed to connect 0 to the outside, and the vacuum chamber 120 is connected to the inside of the processing container 4. Therefore, by vacuuming the inside of the processing container 4 at the time of processing, the inside of the vacuum chamber 120 can be made into a vacuum state to prevent the transfer of cold heat to the outside. At the lower ends of the inner and outer pipes 114 and 116, there is provided a lower joining member 126 made of, for example, stainless steel, in which a flow path 124 is formed in the central portion, and these pipes are fixed to each other.

The lower portion of the joint device constructed as described above is accommodated in a recessed penetrating auxiliary member 128 fixed by bolts or the like in a stepped through hole formed in the container bottom 6 in a loosely fitted state. Between the inner peripheral surface of the auxiliary member 128 and the outer peripheral surface of the joint device, the inside of the processing container and the communication passage 1
A ring-shaped flow path 130 communicating with 22 is formed. Then, the container bottom 6 and the joining member 11
Sealing members 132 and 134 for blocking ventilation from the outside are provided at a portion in contact with 8 and a portion in contact with the recess-shaped penetration assisting member 128 and the joining member 118, respectively.

On the other hand, the coolant supply passage 18 has a double pipe structure made of, for example, a stainless pipe, and the upper end of the inner stainless pipe 18A through which liquid nitrogen as a coolant passes, for example, is the lower end of the flow path 124 of the lower joining member 126. And is configured to be able to supply the refrigerant into the inner pipe 114. And the inner stainless pipe 18
An inner auxiliary stainless pipe 18C is provided at the upper end of A so as to surround the outer pipe 116 via an auxiliary member 136. This inner auxiliary stainless pipe 18C is provided.
The upper end of the outer stainless pipe 18B is connected to the lower surface of the container bottom via a flange 138 made of, for example, stainless steel. Incidentally, 140 is a ring-shaped Teflon seal provided below the lower joining member 126.

Next, the operation of this embodiment configured as described above will be described. First, the wafer W is placed on the upper portion of the susceptor 14 of the processing container 4 which is depressurized to a predetermined pressure from a load lock chamber (not shown), for example, about 1 × 10 ⁻⁴ to several Torr, and the wafer W is placed by the electrostatic chuck 22. Adsorbed and held on the susceptor 14 side by Coulomb force. Then, a high frequency is applied between the upper electrode 44 and the lower electrode (susceptor) 14 through the pipe lead 34 to generate plasma, and at the same time, a process gas is caused to flow from the upper electrode 44 side into the processing space to perform etching treatment. I do.

Further, since the wafer is excessively heated above a predetermined set temperature by the heat of the plasma, a coolant, for example, liquid nitrogen, is circulated through the cooling jacket 16 of the susceptor support 10 to cool the wafer. The predetermined temperature,
For example, the temperature is maintained at −196 ° C., and the cold heat from this is supplied to the wafer W via the susceptor 14 on the upper side to cool it.

A temperature adjusting heater 52 is provided between the cooling jacket 16 and the wafer W to adjust the amount of heat generated at this portion to adjust the cold heat transferred to the wafer W, thereby keeping the wafer W at a predetermined temperature. The temperature is maintained at, for example, about -150 ° C. In the conventional device, the temperature of the wafer is controlled by controlling the temperature of the cooling medium itself. Further, the distance between the cooling jacket and the wafer is long, and there are many interfaces for joining members, so that the thermal response is high. It was very bad. On the other hand, in this embodiment, as described above, the cooling jacket 16 is fixed at a constant low temperature, for example, −196 ° C., whereas the heater 52 is mounted on the wafer W by, for example, 15 to 15.
Since it is installed close to a distance of up to 20 mm,
This change in the amount of heat generated by the heater 52 promptly appears as a change in the temperature of the wafer W. Therefore, the thermal responsiveness is good and the wafer temperature can be quickly controlled. Therefore, the heater 5
Wafer cooling temperature only by liquid nitrogen when 2 is turned off, for example, -160 ° C (temperature difference between liquid nitrogen (-196 ° C) and liquid nitrogen (-196 ° C, for example, 36 ° C is loss due to susceptor)) is set as the minimum temperature value, and room temperature is exceeded. It is possible to control the wafer temperature quickly and linearly within the temperature range up to.
The temperature control may be performed only by the heater 52 with the supply of liquid nitrogen cut off.

Further, since the heat transfer gas such as He cooled through the gas passage 30 is introduced into the interface between the heater 52 and the susceptor 14 and the lower surface of the wafer W, the heat transfer efficiency between the upper and lower portions is improved. The thermal response described above can be further improved without deterioration.

The high frequency wave passing through the pipe lead 34 is
Various leads 26, 66, 72 that transmit the peripheral portion of the pipe by the skin effect and that generate induction noise due to the influence of high frequency are housed in the pipe lead 34, and further, for high frequency noise cutting on the outlet side. Since the filters 27, 67, and 74 are installed, the control system is not adversely affected.

When the susceptor, which is a consumable item damaged by plasma, is replaced, the susceptor 14 can be easily removed by loosening the bolt 12 connecting the susceptor 14 and the susceptor support 10. Further, when the heater 52 is damaged due to overcurrent and the heater is deteriorated due to its life, maintenance work such as heater replacement is performed. In this case, the bolts are further removed with the susceptor 14 removed as described above. By removing 60, the heater 52 can be removed from the susceptor support 10 together with the heater fixing base 54, and the replacement work of the heater 52 can be easily performed. In the above embodiment, the case where liquid nitrogen is used as the cooling medium and the ceramic heater is used as the temperature adjusting heater 52 has been described, but the present invention is not limited to this, and liquid helium or the like may be used as the cooling medium. Also, other types of heaters may be used as the heater.

During the plasma processing, liquid nitrogen (-196 ° C.) flows from the refrigerant supply passage 18 to the inner pipe 11 of the joint device 84 according to the present invention as described above.
4 is introduced into the cooling jacket 16 which is a refrigerant accommodating portion, and this refrigerant undergoes heat treatment with the susceptor support 10 in the jacket 16 to be evaporated and vaporized to evaporate into the refrigerant discharge passage 20. The wafer W is cooled by the cold heat. In this case, since the joint device 84 has the insulating and heat insulating intermediate portion 90 made of ceramics having an electrically insulating property interposed in the middle thereof, the cooling jacket 16 that is the cathode side by applying the high frequency power, that is, the lower portion. Not only the electrode side and the coolant supply passage 18 are completely electrically insulated, but also the cold heat on the cooling jacket 16 side can be prevented from being transferred to the container bottom portion 6, and the heat insulation between them can be prevented. It is possible to improve the sex. Particularly, in the present embodiment, the auxiliary insulating heat insulating member 11 is provided in the middle of the refrigerant passage side joint portion 92.
Since 2 is provided, it is possible to further improve the heat insulating property. Further, since the insulating and heat insulating intermediate portion 90 made of ceramics is brazed and joined to the upper and lower Kovars, that is, the linear expansion coefficient relaxing members 100 and 106 on their respective surfaces, the joining strength is high and is not easily dropped. Moreover, since ceramics are not directly bonded to stainless steel or the like and a material having a linear expansion coefficient between those two materials is used to intervene, for example, Kovar, when liquid nitrogen, which is a refrigerant, is circulated. It is possible to reduce the amount of displacement between the linear expansion amounts in the above, and to further improve the bonding strength.

Further, the inner pipe 114 and the outer pipe 11
6 is communicated with the inside of the processing container 4 via the communication passage 122 and the ring-shaped flow path 130, so that this space is maintained in a reduced pressure state like the inside of the processing container 4. As a result, the decompression chamber state is achieved, and therefore, the cold heat transmitted by convection from the inner pipe 114 that is in direct contact with the liquid nitrogen to the outer pipe 116 can be significantly reduced.

Also, the inner pipe 114 and the outer pipe 11
Lower joint member 12 made of stainless steel for supporting the lower end of 6
Since 6 is in direct contact with the refrigerant, cold heat is generated in the outer pipe 1
16 is transmitted from the lower end to the upper end, but a temperature gradient is generated in the upward direction of the outer pipe 116, and the inner pipe 114 is operated by the vacuum chamber 100.
The convective cold heat supplied from the tank is extremely low, and as a result, the cold heat reaching the upper end portion of the outer pipe 116 is very low, and the cold heat escaping to the processing container bottom 6 side, that is, the outside is significantly reduced. be able to. Therefore, it is possible to significantly improve the heat insulating property as a whole. With such a configuration, the temperature difference between the refrigerant and the bottom portion 6 of the processing container can be maintained at about 100 ° C. or higher.
Further, since the inner and outer pipes 114 and 116 are made of, for example, stainless steel, they are not damaged by an impact at the time of mounting.

The above-mentioned joint apparatus is particularly useful for a plasma processing apparatus for processing a wafer in a low temperature region of -50 ° C. or lower, particularly in a low temperature region of about -150 ° C. Further, in the above embodiment, the joint device 84 on the refrigerant supply side is provided.
However, it is needless to say that the joint device 86 on the refrigerant discharge side operates in exactly the same manner. Further, although the case where the ceramics made of alumina is used as the material of the heat insulating middle portion 90 has been described in the above embodiment, any material may be used as long as it is a material having high insulating properties and heat insulating properties.

In the above embodiment, the cooling mechanism of the plasma etching apparatus has been described as an example, but the present invention is not limited to this, and the present invention is applicable to other plasma CVD apparatus, plasma ashing apparatus, plasma sputtering apparatus and the like. In the case where the cooling mechanism of the plasma processing apparatus or the object to be processed is inspected at a low temperature, for example, it can be applied to the sample mounting table of the electron microscope, the semiconductor material, the cooling mechanism of the sample mounting table for evaluating the element, or the like. Of course.

[0042]

As described above, according to the present invention, the following excellent operational effects can be exhibited. Since a member with excellent electrical insulation and heat insulation properties is placed in the middle of the device, a stable supply of refrigerant can be achieved at low temperatures without sacrificing durability to cooling mechanisms that require electrical insulation. can do.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a joint device according to the present invention.

FIG. 2 is a cross-sectional view showing a plasma processing apparatus to which the joint device of the present invention is applied.

FIG. 3 is a cross-sectional view of a joint device showing a state of attachment to a plasma processing apparatus.

FIG. 4 is a schematic exploded view showing a mounting table of the plasma processing apparatus.

[Explanation of symbols]

 2 Etching device 4 Processing container 16 Cooling jacket (refrigerant accommodating part) 18 Refrigerant supply passage 20 Refrigerant discharge passage 38 High frequency power supply 84,86 Joint device 88 Accommodating portion side coupling part 90 Insulation heat insulation intermediate part 92 Refrigerant passage side coupling part 100, 106 Linear expansion coefficient relaxation member W Semiconductor wafer (processing target)

Claims (3)

[Claims] 1. A joint device for connecting an external refrigerant passage to a refrigerant accommodating portion formed on a mounting table to which a voltage is applied, the accommodating portion side having a flow passage at the center and mounted in the accommodating portion. The coupling portion, the insulating heat insulating intermediate portion made of a material having low thermal conductivity and high electrical insulation and having a flow passage in the center and connected to the accommodation portion side coupling portion, and a flow passage in the center. And a coolant passage side coupling portion that is connected to the insulating and heat insulating intermediate portion and that couples the coolant passages. 2. The joint device according to claim 1, wherein the refrigerant passage side coupling portion has a vacuum double tube structure. 3. At least one of the housing section side joint section and the refrigerant passage side joint section has a difference in linear expansion amount between a portion joined to the insulation heat insulation middle section and the middle section. The joint device according to claim 1 or 2, further comprising a linear expansion coefficient relaxing member for relaxing.