JP2007266342A - Mounting stand and vacuum processor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mounting stand capable of improving cooling efficiency of a substrate to be processed such as a wafer W by a refrigerant, and to provide a plasma processor equipped with the mounting stand. <P>SOLUTION: The mounting stand 1 on which the substrate to be processed such as a wafer W is mounted is configured in such a way that a ceramic plate 2 is laminated on a support member 4 (metal member). The ceramic plate 2 includes an electrode (sheet-shaped electrode 22) for electrostatic chuck buried in the vicinity of the surface and a groove part formed in an under surface. The ceramic plate 2 and the support member 4 are joined via an adhesive layer 3 so that a refrigerant flow passage 23 through which the refrigerant flows is formed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a mounting table on which a substrate to be processed is mounted when vacuum processing such as plasma processing is performed on the substrate to be processed, and a vacuum processing apparatus including the mounting table.

  Many semiconductor device manufacturing processes perform substrate processing in a vacuum atmosphere, such as film formation by etching or CVD (Chemical Vapor Deposition). For example, as shown in FIG. 5, a processing apparatus that performs such vacuum processing arranges a mounting table 91 of a semiconductor wafer (hereinafter referred to as a wafer) W that also serves as a lower electrode in a processing container 9. A gas supply chamber 92 serving as an upper electrode is provided on the upper side of the mounting table 91. Then, a high frequency voltage for plasma generation is applied to the mounting table 91 from the high frequency power source 91a to generate plasma between the mounting table 91 and the gas supply chamber 92, and the plasma supplies the plasma into the processing container 9 from the gas supply chamber 92. The introduced processing gas is activated, whereby a predetermined processing is performed on the wafer W placed on the placement table 91.

  The mounting table 91 includes a metal support member 93 (metal member), an electrostatic chuck 94 installed on the upper surface of the support member 93, and a focus ring 96 disposed so as to surround the electrostatic chuck 94. Has been. Here, the electrostatic chuck 94 has a structure in which a sheet-like chuck electrode 94a made of tungsten, for example, is sandwiched between insulating layers 94b made of a dielectric material such as alumina. By applying a DC voltage (chuck voltage) from the DC power source 95 to the chuck electrode 94a, the wafer W can be electrostatically attracted and held by the Coulomb force generated on the surface of the insulating layer 94b. In FIG. 5, reference numeral 97 denotes an exhaust path for exhausting the atmosphere in the processing container 9 to the outside.

  Conventionally, an electrostatic chuck is a thermal spray type having a structure in which, for example, a sheet-like chuck electrode made of tungsten is sandwiched between two insulating layers formed on a lower surface side and an upper surface side formed by spraying alumina or the like. Most of the things.

  However, when the electrostatic chuck produced by the above method is used in a high-temperature processing atmosphere, thermal stress may occur due to a difference in thermal expansion coefficient between the chuck electrode and the insulating layer, and the insulating layer may be broken. Further, when the upper insulating layer is formed by thermal spraying, the thermal sprayed surface has a shape with irregularities, so that film peeling may occur from the front end portion to form particles and adhere to the back side of the wafer.

  For this reason, a ceramic plate made of aluminum nitride or the like that is resistant to thermal stress and can form a flat surface with less unevenness has been used as the insulating layer 94b. The mounting table 91 using the insulating layer 94b made of a ceramic plate has a structure as shown in FIG. 5, for example. That is, the electrostatic chuck 94 includes a ceramic plate that is an insulating layer 94 b and a sheet-like chuck electrode 94 a embedded in the ceramic plate. The electrostatic chuck 94 and the bottom of the processing container 9 are formed. A support member 93 made of, for example, aluminum, which is fixed to the substrate, is bonded via an adhesive layer 98. As the adhesive layer 98, for example, a silicone-based adhesive resin or the like is used.

  Further, the mounting table 91 has a coolant channel 93a formed in the support member 93. By passing the coolant adjusted to a predetermined temperature through the coolant channel 93a, the surface of the support member 93 is provided. Can be adjusted to a predetermined reference temperature. Then, the heat of the wafer W, which becomes high due to heat input from the plasma, is released to the refrigerant flowing through the refrigerant flow path 93a via the electrostatic chuck 94, the adhesive layer 98, and the support member 93, so that the wafer W temperature is increased. It is possible to control the temperature so as to reach a predetermined process temperature.

  However, in the ceramic plate type electrostatic chuck 94 described above, the heat of the wafer W is supported because the thermal conductivity of the adhesive layer 98 (silicone adhesive resin) that joins the electrostatic chuck 94 and the support member 93 is low. Difficult to reach to member 93. On the other hand, the surface temperature of the mounting table 91 is determined by the balance between the heat input from the plasma and the heat radiation to the refrigerant flow path. The first few wafers W are in an unstable temperature state. Accordingly, if the time until the above-mentioned balance is taken is difficult for the heat of the wafer W to be transferred to the refrigerant, it takes a long time for the surface temperature of the mounting table 91 to be stabilized in the lot, so that the temperature is unstable. There is a problem that the number of wafers W to be processed increases, which causes a decrease in yield.

  Further, a focus ring 96 is disposed around the side peripheral surface of the adhesive layer 98. However, since there is a slight gap between the adhesive layer 98 and the focus ring 96, the adhesive layer 98 is processed during processing of the wafer W. Are exposed to active species in the plasma. Here, the silicone-based adhesive resin constituting the adhesive layer 98 has particularly low resistance to fluorine (F) radicals. For this reason, in the process which produces | generates a fluorine radical, for example, the etching which uses the process gas containing a fluorine, the side peripheral surface of a silicone type adhesive resin will be eroded by a fluorine radical. Since the thermal conductivity of the side peripheral portion of the eroded adhesive layer 98 is deteriorated, the heat input from the plasma to the wafer W is difficult to escape to the support member 93 via the side peripheral surface of the adhesive layer 98. For this reason, the temperature of the outer peripheral portion of the wafer W increases with the erosion of the adhesive layer 98. As a result, the processing uniformity, for example, the in-plane uniformity of the etching rate deteriorates, and the electrostatic chuck 94 can be replaced early. There is a problem that it becomes necessary. In addition, in order to perform uniform processing between the wafers W, it is necessary to stabilize the temperature of the focus ring as soon as possible immediately after the start of operation of the apparatus, as with the surface temperature of the mounting table 91.

  In order to cope with problems such as low thermal conductivity of the adhesive layer and poor controllability of the wafer temperature due to erosion of the adhesive layer side peripheral surface, for example, Patent Document 1 discloses a refrigerant on the ceramic plate side constituting the electrostatic chuck. A mounting table in which a channel is formed is described. Specifically, the thickness of the ceramic plate is made thicker than that of the conventional one, a groove is formed on the lower surface thereof, and the ceramic plate is fixed on a support member having a flat upper surface by a clamp. Thereby, the area | region enclosed by the groove part of a ceramic plate and a supporting member upper surface becomes a refrigerant | coolant flow path. In such a mounting table, the ceramic plate on which the wafer is mounted and the coolant are in contact with each other, and since the thermal resistance from the wafer to the coolant is small, the time until the surface temperature of the mounting table 91 is stabilized is shortened. can do. Further, since the ceramic plate is fixed to the support member using the clamp, the adhesive layer is not eroded.

By the way, in order to maintain the in-plane uniformity of the wafer temperature, it is necessary to form a flow path not only in the outer peripheral portion of the ceramic plate but also in the central portion. However, the clamp usually has a structure in which the ceramic plate is fixed at the outer peripheral portion, so that the force for pressing the ceramic plate against the support member is weak at the central portion. Therefore, in the mounting table disclosed in Patent Document 1, there is a bypass in which a part of the refrigerant leaks from the refrigerant flow path formed in such a weakly pressing part and leaks into, for example, the adjacent flow path. In some cases, the cooling function is not obtained. In addition, as the ceramic plate becomes thicker, the distance between the support member and the wafer increases, so the ratio of the power used for generating plasma to the high-frequency electricity applied to the support member decreases, and the power consumption increases. There is also the problem of becoming.
JP-A-2003-77996: page 3, paragraph 22 to page 4, paragraph 24

  The present invention has been made based on such circumstances, and an object of the present invention is to place a substrate to be processed on which a ceramic plate in which an electrode for an electrostatic chuck is embedded is laminated on a metal member. An object of the present invention is to provide a mounting table capable of improving the cooling efficiency by the refrigerant. Another object is to provide a vacuum processing apparatus provided with this mounting table.

The mounting table according to the present invention is a mounting table in which a substrate to be processed is mounted and a ceramic plate in which an electrode for an electrostatic chuck is embedded is laminated on a metal member.
A groove for forming a coolant flow path is processed in at least one of the lower surface of the ceramic plate and the upper surface of the metal member, and the ceramic plate and the metal member are bonded to each other through an adhesive layer.

  At this time, it is preferable that the groove is not formed on the metal member side but formed on the ceramic plate side. Further, an adhesive layer is preferably formed on the surface of the metal member facing the groove, and the electrostatic chuck electrode electrostatically attaches a focus ring arranged so as to surround the substrate to be processed. It is good to be provided so that adsorption | suction is possible.

  In the ceramic plate, an electrode for plasma generation may be provided above the refrigerant flow path. At this time, it is preferable that the electrode for generating plasma also serves as the electrode for electrostatic chuck.

Furthermore, a processing container in which vacuum processing is performed on the substrate to be processed;
A processing gas introduction section for introducing a processing gas into the processing container;
The mounting table having the above-described characteristics may be applied to a vacuum processing apparatus including means for evacuating the inside of the processing container.

  According to the present invention, the refrigerant flow path through which the refrigerant for cooling the wafer flows is formed between the lower surface of the ceramic plate for electrostatically adsorbing the substrate to be processed such as a wafer and the metal member. These members are bonded via an adhesive layer. For this reason, high cooling efficiency is obtained, and the surface temperature of the ceramic plate is quickly stabilized, so that variations in process temperature among the substrates to be processed can be suppressed. Also, compared to the case where the ceramic plate and the metal member are mechanically fixed by a clamp or the like, a part of the refrigerant does not leak from the refrigerant flow path, and the planned cooling function can be reliably obtained. It is done.

  Hereinafter, based on FIGS. 1-3, embodiment of the mounting base based on this invention is described. In the following embodiments, a description will be given by taking as an example a mounting table applied to a vacuum processing apparatus that performs vacuum processing on a wafer that is a substrate to be processed, for example, a plasma processing apparatus that performs etching using plasma. FIG. 1 is a longitudinal side view of a mounting table 1 according to the present embodiment.

  The mounting table 1 is formed in a columnar shape, for example, and has a structure in which a ceramic plate 2 is laminated on the upper surface of a conductive support member 4 (metal member) made of aluminum or the like. The support member 4 serves to position the installation position of the ceramic plate 2 so that the wafer W is placed at an appropriate position in the plasma processing apparatus. The support member 4 is fixed on the bottom plate of the processing container 61 of the plasma processing apparatus in which the mounting table 1 is incorporated. A through hole 40a is formed in a substantially central portion of the columnar support member 4 in the vertical direction, and the upper end portion of the through hole 40a is formed as an enlarged diameter portion 40b by expanding the diameter. For example, a first electrode rod 41 made of a conductive material such as aluminum is inserted into the through hole 40a in a state of being fitted in an insulating sleeve 42. A female thread is formed at the upper end of the first electrode rod 41, and is screwed into the lower end of the second electrode rod, which will be described later.

  Next, the ceramic plate 2 and the sheet-like electrode 22 embedded in the ceramic plate 2 will be described. In the present embodiment, the ceramic plate 2 functions as an electrostatic chuck that holds the wafer W to be processed and a focus ring 5 (described later) while being electrostatically attracted, and serves as a lower electrode of the plasma processing apparatus. It also has functions. The ceramic plate 2 is made of a dielectric material such as aluminum nitride having a relatively high thermal conductivity among the ceramics. As shown in FIGS. 1 and 3, the outer edge of the upper surface of the flat cylindrical body is cut into a ring shape. The shape in which the cut portion is formed, that is, the disc-like lower surface plate portion 21b having substantially the same diameter as the support member 4 and the disc-like upper surface plate portion 21a having a slightly smaller diameter than the wafer W are overlapped on a concentric circle. It has a shape. Further, as shown in FIG. 1, a convex portion having a shape that fits into the enlarged diameter portion 40b of the support member 4 is formed at a substantially central portion of the lower surface of the ceramic plate 2, and the ceramic plate 2 is not displaced. Can be fixed to the support member 4.

  The sheet-like electrode 22 is made of, for example, molybdenum or tungsten and has a sheet-like shape. The sheet-like electrode 22 covers substantially the entire region of the ceramic plate 2 shown in FIG. 3, and is embedded in the vicinity of the surface of the ceramic plate 2 as shown in FIG. The sheet-like electrode 22 is connected to the upper end of the second electrode rod 25 that forms a conductive path for electric power supplied to the electrode. The second electrode rod 25 is made of a conductive material such as aluminum, and has a male screw formed at the lower end thereof. The second electrode rod 25 is screwed with the first electrode rod 41 to form a conductive path that penetrates the entire mounting table 1, and power can be supplied to the sheet-like electrode 22 from an external power source. It becomes possible.

  Here, a high frequency power source 71 is connected to the first electrode rod 41 via a matching unit 72, and high frequency power can be supplied to the sheet electrode 22. In the present embodiment, the high frequency power supply 71 is provided for bias power for drawing ions in plasma, but a high frequency power supply for supplying high frequency power for plasma generation to the sheet-like electrode 22 is provided. Further, it may be connected. In this case, the high frequency power source is connected to the first electrode rod 41 via a rectifier corresponding to the high frequency power source. Further, a DC power source 73 is connected to the first electrode rod 41 via a switch 75 and a resistor 74, and DC power can be supplied to the sheet electrode 22.

  On the other hand, on the lower surface of the ceramic plate 2, as shown in FIGS. 1 and 3, grooves that meander in the ceramic plate 2 are formed. By fixing the ceramic plate 2 on the support member 4, a space formed by the groove portion of the ceramic plate 2 and the flat upper surface of the support member 4 becomes the refrigerant flow path 23. In the figure, 23a is a refrigerant supply path, and 23b is a refrigerant discharge path. A refrigerant such as Galden (registered trademark) adjusted to a predetermined temperature by a temperature control unit (not shown) is passed through the refrigerant channel 23 via a refrigerant supply means (not shown). A temperature sensor (not shown) is mounted near the surface of the ceramic plate 2, and the temperature of the surface of the ceramic plate 2 is constantly monitored by this temperature sensor. And it becomes possible to control the surface temperature of the ceramic plate 2 to predetermined | prescribed temperature, for example, about 10 to 60 degreeC, by adjusting the temperature of a refrigerant | coolant in a temperature control part based on this monitoring result.

  Here, the ceramic plate 2 and the support member 4 are bonded to each other through an adhesive layer 3 made of, for example, a silicone-based adhesive resin. In this case, for example, the adhesive resin is applied to the entire upper surface of the support member 4. As a result, in addition to the joint surface between the ceramic plate 2 and the support member 4, the surface on the support member 4 side that forms the coolant channel 23 is also covered with the adhesive layer 3. Since the silicone-based adhesive resin has a lower thermal conductivity than a metal such as aluminum, it is difficult for the refrigerant flowing through the refrigerant flow path 23 to take heat away from the support member 4 that is not subject to temperature control. It will also function as a heat insulator. That is, the adhesive layer 3 plays two roles, that is, a role of adhering and fixing the ceramic plate 2 to the support member 4 and a role as a heat insulating material for the support member 4.

  1 and FIG. 2 indicate the backside gas of heat conductivity such as helium (He) gas supplied to enhance the heat transfer between the front surface of the ceramic plate 2 and the back surface of the wafer W. A gas supply hole 24a is a gas supply pipe. A large number of thin disk-like convex portions called dots 26 are formed on the upper surface of the upper surface plate portion 21a. The dots 26 reduce the contact area between the wafer W and the ceramic plate 2 so as to ensure that these portions are in contact with each other, thereby ensuring the electrostatic adsorption of the wafer W to the ceramic plate 2 and the wafer W. It has a role of suppressing adhesion of particles to the back surface. Further, since a gap can be formed between the back surface of the wafer W and the front surface of the ceramic plate 2, the backside gas supplied from the gas supply hole 24 can be easily flown so that the wafer W and the ceramic plate 2 can flow. It also has the role of improving heat transfer. In the drawings other than FIG. 2, the illustration of the dots 26 is omitted.

  In FIG. 1 and FIG. 2, reference numeral 5 denotes a role of adjusting the plasma state in the outer region of the periphery of the wafer W when the wafer W is processed by plasma, for example, wider than the wafer W, The focus ring plays a role of improving the uniformity of the etching rate. In the present embodiment, the focus ring 5 is made of, for example, a conductor such as silicon, and is configured as an annular member having a step portion that is one step lower inward as shown in FIG.

  The focus ring 5 is placed on the lower plate portion 21b side of the ceramic plate 2, that is, on the ring-shaped surface shown in FIG. In a state where the focus ring 5 is placed, as shown in FIGS. 1 and 2, the step inside the focus ring 5 has a positional relationship surrounding the side peripheral surface of the upper surface plate portion 21a with a slight gap. . The upper surface of the stepped portion inside the focus ring 5 is set to be slightly lower than the dots 26 on which the wafer W is placed. Further, since the diameter of the upper surface plate portion 21a is slightly smaller than the diameter of the wafer W, the outer peripheral portion of the wafer W mounted on the mounting table 1 is slightly from the upper surface of the step portion of the focus ring 5 as shown in FIG. It floats through the gap.

  Next, an example of the plasma processing apparatus 6 provided with the mounting table 1 according to the present embodiment will be described with reference to FIG. The plasma processing apparatus 6 shown in FIG. 4 includes, for example, a processing container 61 composed of a vacuum chamber whose inside is a sealed space, and a mounting table 1 according to the present embodiment fixed to the center of the bottom plate in the processing container 61. And an upper electrode 62 provided so as to face the mounting table 1 above the mounting table 1. In addition, description of the 1st, 2nd electrode rod 41, 25 etc. which comprise the conductive path in the mounting base 1 was abbreviate | omitted.

  The processing container 61 is electrically grounded, and an exhaust device 81 such as a vacuum pump is connected to an exhaust port 63 on the bottom plate of the processing container 61 via an exhaust pipe 81a. A transfer port 61a for the wafer W is provided on the side surface of the processing container 61, and the transfer port 61a can be opened and closed by a gate valve 61b.

  The sheet electrode 22 embedded in the ceramic plate 2 of the mounting table 1 is grounded via a high pass filter (HPF) 76. Further, a high frequency power of, for example, 13.56 MHz is supplied from a high frequency power source 71 (first high frequency power source) connected to the sheet-like electrode 22.

  On the other hand, the upper electrode 62 is formed in a hollow shape, and a plurality of processing gas supply holes 62a for distributing and supplying the processing gas into the processing vessel 61 are formed on the lower surface thereof, for example, by uniformly distributing the gas. It constitutes a shower head. A processing gas supply pipe 82a is provided at the center of the upper surface of the upper electrode 62, and the processing gas supply pipe 82a penetrates the center of the upper surface of the processing container 61 through an insulating member 61c. A processing gas supply unit 82 is connected upstream of the processing gas supply pipe 82a, and a processing gas flow rate and its supply / disconnection can be controlled by a valve and a flow rate control unit (not shown).

  The upper electrode 62 is grounded via a low pass filter (LPF) 77, and a high frequency power source 79 having a frequency higher than that of the first high frequency power source 71, for example, 60 MHz, is provided on the upper electrode 62 as a second high frequency power source. They are connected via a matching unit 78. The high-frequency power from the second high-frequency power source 79 is for converting the processing gas into plasma, and the high-frequency power from the first high-frequency power source 71 is ion in the plasma by applying bias power to the wafer W. Into the surface of the wafer W. The high-frequency power sources 79 and 71 are connected to a control unit (not shown), and power supply to the upper electrode 62 and the sheet-like electrode 22 is controlled according to a control signal from the control unit.

  Next, the operation of this embodiment will be described. First, the gate valve 61b is opened, and the wafer W is placed on the surface of the ceramic plate 2 in the processing container 61 by a transfer arm (not shown) through the transfer port 61a. After the transfer arm is retracted and the gate valve 61 b is closed, the processing chamber 61 is evacuated through the exhaust port 63. At this time, a DC voltage is applied from the DC power source 73 to the sheet-like electrode 22 as an electrostatic chuck electrode, and the wafer W is electrostatically attracted to the surface of the ceramic plate 2 by the Coulomb force. In addition, since a Coulomb force is generated on the mounting surface of the focus ring 5 by applying a DC voltage to the sheet-like electrode 22, the bottom surface of the focus ring 5 is also electrostatically attracted to the surface of the ceramic plate 2.

Then, the flow of the refrigerant into the refrigerant flow path 23 is started and the backside gas is supplied from the gas supply hole 24. Next, a processing gas such as C ₄ F ₈ gas is supplied toward the wafer W, a high frequency voltage is applied to the upper electrode 62 from a high frequency power source 79 to generate plasma, and a high frequency power source is applied to the sheet-like electrode 22 as the lower electrode. For example, a silicon oxide film on the surface of the wafer W is etched by applying a high frequency voltage from 71.

  Since the sheet electrode 22 as a high frequency electrode is embedded in the vicinity of the surface of the ceramic plate 2, the power loss associated with the increase in the thickness of the ceramic plate 2 due to the provision of the refrigerant flow path 23 can be reduced. Further, when a high-frequency voltage is applied to the sheet-like electrode 22, an electric field is generated in the vicinity of the surface of the ceramic plate 2, so that it is possible to repel particles existing in the processing container 61 and make it difficult for the particles to adhere to the wafer W. Conceivable.

  The wafer W becomes high temperature by being exposed to plasma, but the surface of the ceramic plate 2 is controlled to a reference temperature of, for example, 60 ° C. by the refrigerant flowing through the refrigerant flow path 23. For this reason, the heat of the wafer W moves directly to the refrigerant flowing through the refrigerant flow path 23 formed in the ceramic plate 2 without passing through other members except for the thin sheet-like electrode 22, and is being processed. The temperature of the wafer W can be adjusted to a predetermined process temperature.

Here, since the surface of the coolant channel 23 on the support member 4 side is covered with the adhesive layer 3 that bonds the support member 4 and the ceramic plate 2, the heat from the support member 4 is not easily transmitted to the coolant. It has become. For this reason, the refrigerant flowing through the refrigerant flow path 23 can efficiently absorb mainly the heat transferred from the wafer W. Further, since the bottom surface of the focus ring 5 is electrostatically attracted to the surface of the ceramic plate 2, the contact area between these members is increased and the slit is reduced, so that the heat of the focus ring 5 is applied to the ceramic plate 2. Easier to escape. As a result, the temperature of the focus ring 5 can be kept low. Further, as can be seen from a comparison between FIG. 1 and FIG. 5, the ceramic plate 2 according to the present embodiment increases the thickness of the ceramic plate 2 in order to form the groove of the refrigerant flow channel 23 therein. The position of the adhesive surface between the support member 4 and the support member 4 has moved downward from the conventional one. For this reason, it is difficult for plasma to reach the above-described adhesion surface, and the side peripheral surface of the adhesion layer 3 is less likely to be eroded by fluorine radicals or the like generated from C ₄ F ₈ gas or the like. Even if a part of the fluorine radicals reach the adhesive layer 3 and erode the side peripheral surface thereof, the position of the adhesive layer 3 is far from the wafer W as compared with the conventional one. It is considered that there is almost no influence on the control of the wafer W temperature due to the erosion of the side peripheral surface.

  After the wafer W is etched through the above operation, the wafer W is unloaded from the processing container 61 in the reverse order of loading.

  In the embodiment, the example in which the mounting table 1 is incorporated in the plasma processing apparatus 6 has been described. However, the vacuum processing apparatus that can use the mounting table 1 according to the present invention is not limited thereto. For example, the mounting table 1 according to the present invention can be applied to a CVD apparatus or the like that performs a film forming process on a wafer or the like.

  In addition, the present invention is not limited to the so-called upper and lower two-frequency type exemplified in the embodiment, but for example, a lower two-frequency type in which both the first and second high-frequency power sources are connected to the sheet-like electrode 22. Can also be applied.

  Further, in the present embodiment, the case where the sheet-like electrode 22 is integrally formed to serve as both the chuck electrode and the lower electrode (high-frequency electrode) related to the plasma processing has been described. It may be configured and embedded in the ceramic plate 2. Further, the sheet-like electrode 22 as the chuck electrode may be embedded in the ceramic plate 2 by separately configuring a chuck electrode for electrostatically attracting the wafer W and a chuck electrode for electrostatically attracting the focus ring 5. Good.

  According to the mounting table 1 according to the present embodiment, a coolant for cooling the wafer W flows between the lower surface of the ceramic plate 2 that electrostatically attracts the wafer W, which is the substrate to be processed, and the support member 4. A refrigerant flow path 23 is formed, and these members 2 and 4 are bonded via an adhesive layer. For this reason, high cooling efficiency is obtained, and the surface temperature of the ceramic plate 2 is quickly stabilized, so that variations in process temperature among the wafers W can be suppressed. Further, compared to the case where the ceramic plate 2 and the support member 4 are mechanically fixed by a clamp or the like, a part of the refrigerant does not leak from the refrigerant flow path 23, and the planned cooling function is achieved. It is definitely obtained.

  In addition, since the surface of the coolant channel 23 on the support member 4 side is covered with the adhesive layer 3, heat is generated between the support member 4 and the coolant due to the heat insulating effect of the silicone-based adhesive resin constituting the adhesive layer 3. Is less likely to be transferred, and the cooling efficiency of the wafer W is further improved. The adhesive layer 3 may be formed only on the joint surface between the ceramic plate 2 and the support member 4 without being formed on the surface of the support member 4 facing the refrigerant flow path 23.

  In the present embodiment, the case where a groove serving as the refrigerant flow path 23 is formed on the ceramic plate 2 side is illustrated, but the groove is formed only on both the ceramic plate 2 and the support member 4 or on the support member 4 side. May be formed. In these cases, if a layer (adhesive layer) made of an adhesive resin or the like is formed not only in the joint surface between the ceramic plate 2 and the support member 4 but also in the groove portion, the heat insulating effect of the adhesive resin or the like can cause As described above, the cooling efficiency of the wafer W can be increased.

It is a vertical side view which shows an example of the mounting base which is embodiment of this invention. It is a perspective view which shows said embodiment. It is a top view which shows the ceramic plate which comprises said embodiment. It is a vertical side view which shows an example of the plasma processing apparatus to which the mounting base which concerns on said embodiment is applied. It is a vertical side view which shows an example of the plasma processing apparatus provided with the conventional mounting base.

Explanation of symbols

W Wafer 1 Mounting table 2 Ceramic plate 3 Adhesive layer 4 Support member 5 Focus ring 6 Plasma processing apparatus 9 Processing vessel 21a Upper surface plate portion 21b Lower surface plate portion 22 Sheet electrode 23 Refrigerant flow path 23a Refrigerant supply path 23b Refrigerant discharge path 24 Gas Supply hole 24a Gas supply pipe 25 Second electrode rod 26 Dot 40a Through hole 40b Expanded portion 41 First electrode rod 42 Sleeve 61 Processing vessel 61a Transfer port 61b Gate valve 61c Insulating member 62 Upper electrode 62a Processing gas supply hole 63 Exhaust port 71 High frequency power supply (first high frequency power supply)
72 Matching Unit 73 DC Power Supply 74 Resistance 75 Switch 76 High Pass Filter (HPF)
77 Low Bass Filter (LPH)
78 Matching device 79 High frequency power supply (second high frequency power supply)
81 Exhaust device 81a Exhaust pipe 82 Processing gas supply part 82a Processing gas supply pipe 91 Mounting table 91a High frequency power supply 92 Gas supply chamber 93 Support member 93a Refrigerant flow path 94 Electrostatic chuck 94a Chuck electrode 94b Insulating layer 95 DC power supply 96 Focus ring 97 Exhaust path 98 Adhesive layer

Claims (7)

In a mounting table on which a substrate to be processed is mounted and a ceramic plate in which an electrode for an electrostatic chuck is embedded is laminated on a metal member,
A groove for forming a refrigerant flow path is processed in at least one of the lower surface of the ceramic plate and the upper surface of the metal member, and the ceramic plate and the metal member are bonded to each other through an adhesive layer. Stand.   The mounting table according to claim 1, wherein the groove is not formed on the metal member side but formed on the ceramic plate side.   The mounting table according to claim 1, wherein an adhesive layer is formed on a surface of the metal member facing the groove.   4. The electrostatic chuck electrode according to claim 1, wherein a focus ring disposed so as to surround the substrate to be processed can be electrostatically attracted. The mounting table described.   The mounting table according to any one of claims 1 to 4, wherein an electrode for plasma generation is provided above the refrigerant flow path in the ceramic plate.   6. The mounting table according to claim 5, wherein the electrode for generating plasma also serves as an electrode for electrostatic chuck. A processing container in which vacuum processing is performed on a substrate to be processed;
A processing gas introduction section for introducing a processing gas into the processing container;
The mounting table according to any one of claims 1 to 6 provided in the processing container;
Means for evacuating the inside of the processing vessel.

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