JP2012028428A - Mounting table structure and processing apparatus - Google Patents

Abstract

Provided is a mounting table structure capable of suppressing a temperature rise at a lower end portion of a support structure by blocking radiant heat from the mounting table.
In a mounting table structure 54 for mounting a target object W to be processed, which is provided in a processing container 22 which can be evacuated, the target object is mounted and supported and the target object is processed. A mounting table 58 provided with a heating means 74 for heating the body, a column structure 60 provided upright from the bottom side of the processing container and having an upper end connected to the lower surface of the table, and a lower end of the column structure The fixing part 62 fixed to the bottom part of a processing container, and the heat insulation structure 66 which has the some heat insulation board 64 disperse | distributed and provided along the height direction outside the support | pillar structure are provided. Thereby, the radiant heat from a mounting base is interrupted | blocked.
[Selection] Figure 1

Description

  The present invention relates to a processing apparatus for a target object such as a semiconductor wafer and a mounting table structure.

  In general, in order to manufacture a semiconductor integrated circuit, it is desired to repeatedly perform various single wafer processes such as a film forming process, an etching process, a heat treatment, a modification process, and a crystallization process on a target object such as a semiconductor wafer. An integrated circuit is formed. For example, in the case of a single wafer processing apparatus that performs heat treatment on each semiconductor wafer, for example, a mounting table with a built-in resistance heater is installed in a processing container that can be evacuated. A semiconductor wafer is placed on the upper surface, and a predetermined processing gas is flowed in a state heated at a predetermined temperature (for example, 100 ° C. to 1000 ° C.), and various heat treatments are performed on the semiconductor wafer under predetermined process conditions. (Patent Documents 1 to 4).

  Here, an example of a conventional mounting table structure will be described. FIG. 10 is a sectional view showing an example of a conventional mounting table structure. This mounting table structure is provided in a processing vessel that can be evacuated. As shown in FIG. 10, this mounting table structure has a disk-shaped mounting table 2 made of a ceramic material such as AlN. is doing. A cylindrical column 4 made of a ceramic material such as AlN is connected to the center of the lower surface of the mounting table 2 to support the mounting table 2.

  The size of the mounting table 2 is, for example, about 350 mm in diameter when the semiconductor wafer size is 300 mm, and the diameter of the column 4 is about 56 mm. A heating means 6 such as a heater is provided in the mounting table 2 to heat the semiconductor wafer W as the object to be processed on the mounting table 2.

  The lower end portion of the support column 4 is in an upright state by being fixed to the container bottom portion 8 by the fixing portion 10. In the fixed portion 10, an O-ring 12 is provided as a seal member interposed between the lower end portion of the support column 4 and the container bottom portion 8, and the airtightness in the support column 4 and the processing container is maintained. ing. In the cylindrical column 4, a power supply rod 14 having an upper end connected to the heating means 6 is provided, and the lower end side of the power supply rod 14 is connected to the bottom 8 of the container via an insulating member 16. Is drawn out to the outside. As a result, it is possible to prevent the process gas and the like from entering the support column 4 and prevent the feeding rod 14 and the like from being corroded by the corrosive process gas.

  Further, as another mounting table structure, a mounting table structure in which a plurality of small pipe-shaped support pipes made of ceramic material or quartz are provided in place of the support columns 4 and the power supply rod 14 or the like is inserted into the support pipe. Has also been proposed (for example, Patent Document 4). Also in this case, a seal member such as an O-ring is provided on the lower end side of each support tube in order to maintain the airtightness inside the processing container or the like.

JP 2004-356624 A JP 2006-295138 A JP 2009-231401 A Japanese Patent No. 4450106

  By the way, during the heat treatment of the semiconductor wafer, the mounting table 2 becomes high temperature, so that the lower end portion of the column 4 is also heated by this temperature conducting the column 4 or by radiation from the mounting table 2. become. In this case, there is no problem if the process temperature is not so high, but when the process temperature is high, for example, when the temperature is 800 ° C. or higher, the lower end of the support column 4 is also exposed to a high temperature depending on the process time. As a result, there is a problem that the lower end portion of the support column 4 becomes a heat resistant temperature of the O-ring which is the seal member 12, for example, 260 ° C. or more, and the sealing performance is deteriorated.

  The present invention has been devised to pay attention to the above problems and to effectively solve them. The present invention is a mounting table structure and a processing apparatus capable of suppressing a temperature rise at a lower end portion of a support structure by blocking radiant heat from the mounting table.

  According to a first aspect of the present invention, there is provided a mounting table structure for mounting a target object to be processed which is provided in a processing container which can be evacuated, and supports and supports the target object. A mounting table provided with heating means for heating the object to be processed; a column structure that is provided upright from the bottom side of the processing container and whose upper end is connected to the lower surface of the table; and A fixing portion that fixes the lower end portion to the bottom of the processing vessel, and a heat insulating structure having a plurality of heat insulating plates provided on the outside of the support structure and distributed along the height direction thereof. This is a mounting table structure.

  Thus, on the outside of the support structure, provided with a heat shield structure having a plurality of heat shield plates distributed along the height direction, it is possible to block the radiant heat from the mounting table, Temperature rise at the lower end of the support structure can be suppressed. As a result, it is possible to prevent deterioration due to heat of the sealing member used for the fixing portion for fixing the lower end portion of the support structure, and to maintain the sealing performance of this portion.

  According to an eleventh aspect of the present invention, there is provided a processing apparatus for performing processing on an object to be processed, wherein the processing container is configured to be evacuated and provided in the processing container for mounting the object to be processed. A processing apparatus comprising: the mounting table structure according to any one of claims 1 to 10; and gas introduction means for supplying gas in the processing container.

According to the mounting table structure and the processing apparatus according to the present invention, the following excellent operational effects can be exhibited.
Since the heat shield structure having a plurality of heat shield plates distributed along the height direction is provided outside the support structure, the radiant heat from the mounting table can be blocked, and the lower end of the support structure. The temperature rise of the part can be suppressed. As a result, it is possible to prevent deterioration due to heat of the seal member used for the fixing portion for fixing the lower end portion of the support structure, and to maintain the sealing performance of this portion.

It is a section lineblock diagram showing a processing device which has a mounting base structure concerning the present invention. It is a partial expanded sectional view which shows the mounting base structure of the state except the heat shield structure. It is a figure which shows the arrangement | positioning relationship between a support | pillar structure and a heat shield structure. It is a perspective view which shows a heat insulation structure. It is an expanded sectional view showing a part of heat insulation structure. It is sectional drawing which shows the cross section of the part of a thermal-insulation structure. It is a schematic diagram which shows the support | pillar structure when conducting an evaluation experiment. It is a figure which shows the 1st modification of a support | pillar structure. It is a figure which shows the 2nd modification of a support | pillar structure. It is sectional drawing which shows an example of the conventional mounting base structure.

  Hereinafter, a preferred embodiment of a mounting table structure and a processing apparatus according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a cross-sectional configuration diagram showing a processing apparatus having a mounting table structure according to the present invention, FIG. 2 is a partially enlarged sectional view showing the mounting table structure in a state excluding the heat shielding structure, and FIG. 3 is a column structure and a heat shielding structure. 4 is a perspective view showing the heat shield structure, FIG. 5 is an enlarged cross-sectional view showing a part of the heat shield structure, and FIG. 6 is a cross-sectional view showing a cross section of the portion of the heat shield structure. . Here, a case where film formation is performed using thermal CVD will be described as an example.

  As shown in the figure, the processing apparatus 20 includes a processing vessel 22 made of aluminum (including an aluminum alloy) having a substantially circular cross section. A shower head portion 24 serving as a gas introduction means is provided on the ceiling portion in the processing container 22 to introduce a necessary processing gas, for example, a film forming gas. The processing gas is injected toward the processing space S from the gas injection holes 32A and 32B.

  In the shower head portion 24, two hollow gas diffusion chambers 30A and 30B are formed. After the processing gas introduced therein is diffused in the plane direction, each gas diffusion chamber 30A is formed. , 30B are respectively injected from the gas injection holes 32A, 32B communicated with each other. That is, the gas injection holes 32A and 32B are arranged in a matrix. The entire shower head portion 24 is formed of nickel alloy such as nickel or Hastelloy (registered trademark), aluminum, or aluminum alloy. Depending on the gas type used as the shower head 24, there may be one gas diffusion chamber or three or more gas diffusion chambers.

  A sealing member 34 made of, for example, an O-ring or the like is interposed at the joint between the shower head portion 24 and the upper end opening of the processing container 22 so as to maintain the airtightness in the processing container 22. ing.

  In addition, a loading / unloading port 40 for loading / unloading a semiconductor wafer W as an object to / from the processing container 22 is provided on the side wall of the processing container 22, and the loading / unloading port 40 can be opened and closed in an airtight manner. A gate valve 42 is provided.

  An exhaust port 46 is provided on the side of the bottom 44 of the processing container 22. An exhaust system 48 for exhausting, for example, evacuating the inside of the processing container 22 is connected to the exhaust port 46. The exhaust system 48 has an exhaust passage 49 connected to the exhaust port 46, and a pressure regulating valve 50 and a vacuum pump 52 are sequentially provided in the exhaust passage 49, and the processing vessel 22 is connected to the exhaust passage 49. The desired pressure can be maintained. Depending on the processing mode, the inside of the processing container 22 may be set to a pressure close to atmospheric pressure.

  A mounting table structure 54 is provided at the bottom 44 in the processing container 22 so as to stand up. Specifically, the mounting table structure 54 is connected to a mounting table 58 for mounting and supporting the object to be processed on the upper surface, and a lower surface of the mounting table 58, and the upper mounting table 58 is connected to the upper table 58. A support structure 60 for standing and supporting from the bottom 44 side of the processing container 22, a fixing part 62 for fixing the lower end portion of the support structure 60 to the bottom 44 of the processing container 22, and an outer side of the support structure 60. And a heat shield structure 66 having a plurality of heat shield plates 64, which is a feature of the present invention and is distributed along the height direction.

  Here, the support structure 60 is formed by a plurality of support pipes 68 assembled at the center of the mounting table 58. As shown in FIG. 4, five support pipes 68 are provided (only three are shown as representative in FIG. 2). Of course, the number of support pipes 68 is not limited to five, and can be increased or decreased as necessary.

  Specifically, the mounting table 58 is entirely made of a dielectric. Here, the mounting table 58 is provided on a mounting table main body 70 made of thick and transparent quartz and on the upper surface side of the mounting table main body 70. It is composed of an opaque dielectric material different from the mounting table main body 70, for example, a heat diffusion plate 72 made of a ceramic material such as aluminum nitride (AlN) which is a heat resistant material. The heat diffusion plate 72 may be formed of opaque quartz containing a large number of bubbles.

  And the heating means 74 is provided so that it may embed in the said mounting base main body 70, for example. The semiconductor wafer W is placed on the upper surface of the heat diffusion plate 72 and the semiconductor wafer W is heated via the heat diffusion plate 72 by radiant heat from the heating means 74. The heating means 74 includes a heater wire 75 made of, for example, a carbon wire, and is provided in a predetermined pattern shape over substantially the entire surface of the mounting table main body 70.

  Specifically, the mounting table main body 70 is divided into two divided bodies 70A and 70B, for example, up and down, and accommodated on one of the divided bodies, for example, on the surface of the divided body 70A as shown in FIG. A groove 76 is formed over the entire surface in a single stroke, and the heater element wire 75 is disposed along the housing groove 76. Thereafter, the divided bodies 70A and 70B are welded or fusion bonded. The heating means 74 is concentrically divided into, for example, two heating zones, and the starting point and the ending point of the heater wire 75 in each heating zone are gathered at the center (center) of the mounting table 58.

  The mounting table 58 is formed with a plurality of, for example, three pin insertion holes 78 penetrating in the vertical direction (only two are shown in FIG. 1). A push-up pin 80 that is movably inserted in a loosely fitted state is disposed. An arc-shaped ceramic push-up ring 82 such as alumina is disposed at the lower end of the push-up pin 80, and the lower end of each push-up pin 80 is fixed to the push-up ring 82. The arm portion 84 extending from the push-up ring 82 is connected to an elevating rod 88 provided through the bottom 44 of the processing container 22, and the elevating rod 88 can be moved up and down by an actuator 90.

  As a result, the push-up pins 80 are projected and retracted upward from the upper ends of the pin insertion holes 78 when the semiconductor wafer W is transferred. In addition, an extendable bellows 92 is interposed in a penetrating portion of the lifting rod 88 with respect to the bottom 44 of the processing container 22 so that the lifting rod 88 can be lifted and lowered while maintaining the airtightness in the processing container 22. It has become.

  As described above, here, the five support pipes 68 are provided in the central portion of the mounting table 58 as shown in FIGS. 4 and 6. Each column tube 68 is made of a dielectric material, specifically made of, for example, quartz, which is the same dielectric material as the mounting table main body 70. Each column tube 68 is, for example, thermally welded to the lower surface of the mounting table main body 70. So as to be airtight and integrated.

  Here, of the five strut pipes 68, the heater power supply rods 94 are loosely fitted into the four strut pipes 68A, 68B, 68C, 68D with respect to the heater wires 75 divided into two heating zones. The thermocouple 96 for temperature measurement is inserted in a loosely fitted state in the remaining one column pipe 68E. That is, for each heater wire 75 for the two heating zones, a total of four heater power supply rods 94 for power-in and power-out are individually inserted into the column pipes 68, respectively. The upper end 94 of each heater is electrically connected to both ends of each heater wire 75. Each heater power supply rod 94 is made of, for example, carbon, nickel alloy, tungsten alloy, molybdenum alloy or the like. These heater power supply rods 94 are connected to a heater power supply unit 95 that supplies heater power.

  Further, the bottom 44 of the processing container 22 is made of, for example, stainless steel, and as shown in FIGS. 1 and 2, a conductor outlet 98 is formed at the center, and the conductor outlet 98 has the above-described portion. The lower end portion of the column structure 60 is fixed by the fixing member 62. Specifically, the fixing member 62 has a mounting base 100 made of, for example, stainless steel, and the mounting base 100 is hermetically sealed via a sealing member 102 such as an O-ring inside the conductor outlet 98. It is fixed and attached to.

  On the mounting base 100, a pipe fixing base 104 for fixing the column pipes 68 is provided. The tube fixing base 104 is made of the same material as each of the column tubes 68, that is, here, quartz. A through hole 106 is formed so as to penetrate the tube fixing base 104 and the mounting base 100 in correspondence with the column pipe 68E through which the thermocouple 96 is inserted. And the lower end part of the said support pipe 68E and the upper surface of the said pipe | tube fixing stand 104 are joined and fixed by thermal welding etc.

  The lower ends of the other column pipes 68 </ b> A to 68 </ b> D extend through the tube fixing base 104 to the middle of the mounting base 100, and the lower ends of the column pipes 68 </ b> A to 68 </ b> D are the upper surfaces of the pipe fixing base 104. These parts are joined and fixed by heat welding or the like.

  A seal member 108 made of an O-ring or the like is interposed between the tube fixing base 104 and the mounting base 100 so as to surround the through hole 106 and the support pipes 68A to 68D. Further, the lower end portion of each heater power supply rod 94 is inserted into the insulating material 110, and a seal member 112 made of an O-ring or the like is also provided between the periphery of the insulating material 110 and the inner wall of the through hole of the mounting base 100. It is interposed and maintains the airtightness in the support pipes 68A to 68D. Furthermore, a seal member 112 made of an O-ring or the like is also provided in a through portion of the thermocouple 96 with respect to the mounting base 100 so as to maintain the airtightness in the column pipe 68E.

  The heat shield structure 66, which is a feature of the present invention, is provided on the support structure 60 configured as described above. As described above, the heat shield structure 66 has a plurality of heat shield plates 64 provided on the outside of the support structure 60 so as to be distributed along the height direction thereof. Specifically, as shown in FIGS. 3 to 6, a plurality of upright pins 120 are provided in the peripheral portion on the upper surface side of the fixing portion 62 that fixes the lower end portion of the support structure 66. A circular ring-shaped mounting plate 122 is provided at the upper end of the pin 120 so as to surround the periphery of the support structure 66. The mounting plate 122 is made of, for example, a nickel alloy.

  A plurality of support bars 124 are provided upright from the circular ring-shaped mounting plate 122 so as to surround the support structure 60. In the illustrated example, five support rods 124 are provided so as to be arranged substantially evenly along the circumferential direction of the mounting plate 122. The heat shield plate 64 is attached to the support rod 124 in a vertically dispersed manner.

  As shown in FIGS. 3 to 5, six heat shield plates 64 are provided here. As shown in FIG. 6 (A), in each heat shield plate 64, the five first through holes 126 for allowing the support tubes 68 to be inserted in a loosely fitted state and the support rods 124 are loosely fitted. Five second through-holes 128 are formed for insertion. In this case, in order to facilitate the mounting operation of the heat shield plate 64, the heat shield plate 64 itself may be divided into two as shown in FIG. You may make it do.

  As a method of attaching each heat shield plate 64 to the support rod 124, for example, as shown in FIG. 5, a cylindrical spacer member 130 having an inner diameter larger than the diameter of the second through hole 128 is prepared. The support rod 124 is stacked by alternately inserting the spacer member 130 and the second through hole 128 of the heat shield plate 64. The upper and lower ends of the support rod 124 are fastened and fixed by bolts 132, respectively. As a result, the heat shield plates 64 adjacent in the vertical direction are spaced apart by the length of the spacer member 130 and arranged at equal intervals, for example.

  Thus, the radiant heat from the mounting table 58 is reflected by the heat shield plates 64 to suppress an excessive temperature rise of the fixing portion 62. The important point here is that the mounting position of the heat shield plate 64 includes the middle stage when the height direction of the support structure 60 is equally divided into three, and the upper stage, middle stage, and lower stage are included. Provide at least below. If this heat shield plate 64 is concentrated only on the upper side, the effect of blocking radiant heat is reduced. In the case of FIG. 3, the heat shield plate 64 is provided up to the entire middle part and a part of the lower part.

  The heat shield plate 64 is formed of a metal plate and has a high reflectance with respect to heat rays. This reflectance is, for example, 68% or more. The metal plate can be formed of nickel, a nickel alloy, such as Hastelloy (registered trademark), which has strong corrosion resistance and is less susceptible to metal contamination. The thickness of the heat shield plate 64 is preferably in the range of 0.2 to 5 mm, and it is preferable to set the heat capacity as small as possible while maintaining the mechanical strength.

  In addition, the distance L1 between the heat shield plates 64 (see FIGS. 3 and 5) is 18 mm or more. If the distance between the heat shield plates 64 is narrower than this, heat is accumulated between the heat shield plates 64 and the heat retaining effect. Will occur, and the temperature rise suppression effect of the fixing portion 62 will decrease. In addition, the diameter of the heat shield plate 64 is set to a diameter that can completely cover at least the portion directly above each seal member provided in the fixing portion 62, and is preferably set to be larger than the diameter of the fixing portion 62. It is good to do. Here, the diameter of the heat shield plate 64 is set to 90 to 100 mm.

  The support rod 124 is preferably made of nickel or a nickel alloy made of the same material as the heat shield plate 64. Furthermore, the spacer member 130 can be made of a material having low thermal conductivity, for example, a ceramic material such as alumina or stainless steel, and the above nickel or nickel alloy can also be used. Although each heat shield plate 64 is supported by the support rod 124 here, the present invention is not limited to this, and each heat shield plate 64 may be directly attached to and supported by each column pipe 68. .

  Returning to FIG. 1, the overall operation of the processing device 20 is controlled by a device control unit 140 formed of, for example, a computer. A computer program for performing this operation is stored in the storage medium 142. Yes. The storage medium 142 includes, for example, a flexible disk, a CD (Compact Disc), a hard disk, a flash memory, or a DVD. Specifically, in response to a command from the apparatus control unit 140, supply of each gas is started, stopped, flow rate is controlled, process temperature and process pressure are controlled, and the like.

  Next, the operation of the processing apparatus 20 configured as described above will be described. First, the unprocessed semiconductor wafer W is loaded into the processing container 22 through the gate valve 42 and the loading / unloading port 40 which are opened by being held by a transfer arm (not shown), and the semiconductor wafer W is raised. After being transferred to the push-up pins 80, the push-up pins 80 are lowered to place the semiconductor wafer W on the upper surface of the heat diffusion plate 72 of the placement table 58 supported by each column tube 68 of the placement table structure 54. And support this. The semiconductor wafer W is fixed by a clamp mechanism (not shown) that holds the periphery of the semiconductor wafer W.

  Next, various processing gases are supplied to the shower head unit 24 while controlling the flow rate, and the gases are injected from the gas injection holes 32A and 32B and introduced into the processing space S. Then, by continuing to drive the vacuum pump 52 of the exhaust system 48, the atmosphere in the processing container 22 is evacuated, and the valve opening degree of the pressure adjusting valve 50 is adjusted to change the atmosphere of the processing space S to a predetermined level. Maintain at process pressure. At this time, the temperature of the semiconductor wafer W is maintained at a predetermined process temperature. That is, heat is generated by applying a voltage from the heater power supply unit 95 to the heater wire 75 constituting the heating means 74 of the mounting table 58.

  As a result, the semiconductor wafer W is heated and heated by the heat from the heater wire 75. In this case, the temperature is individually controlled for each heating zone based on the temperature detection value of the thermocouple 96. That is, the temperature is measured by the thermocouple 96 provided on the heat diffusion plate 72, and the heater power supply unit 95 controls the temperature by feedback based on the measured value. For this reason, the temperature of the semiconductor wafer W can always be controlled in a state where the in-plane uniformity is high. In this case, although depending on the type of process, the temperature of the mounting table 58 reaches, for example, about 850 ° C. As a result, the processing gas reacts and a film forming process is performed on the semiconductor wafer W by, for example, thermal CVD.

  Now, during the film forming process, the mounting table 58 is in a high temperature state substantially equal to the process temperature due to heat generated by the heating means 74. Radiation heat is emitted from the mounting table 58 in the high temperature state, and heat is transmitted downward by heat conduction to the plurality of column pipes 68 of the column structure 60, and the fixing portion 62 that fixes the column structure 60 is heated together with the radiation heat. The temperature will rise. In this case, the cause of heating of the fixed portion 62 is greater in radiant heat than in heat conduction.

  Under such circumstances, in the case of the conventional mounting table structure, there is a concern that the fixing portion 62 is excessively heated and the seal member used here is deteriorated. Since the radiant heat of the mounting table 58 is blocked by the plurality of heat shield plates 64 of the heat shield structure 66, it is possible to prevent the temperature of the fixing portion 62 from rising excessively.

  That is, although a large amount of radiant heat is released downward from the mounting table 58, a plurality of heat shield plates 64 are separated from each other by a distance equal to or greater than a predetermined distance almost directly above the fixed portion 62. Therefore, the downward radiant heat is blocked by the heat shield plate 64. As a result, an excessive temperature rise of the fixing portion 62 can be suppressed, and the heat resistance temperature of the O-ring constituting the seal members 102, 108, 112, for example, 260 ° C. or less can be maintained. It is possible to prevent the deterioration of 108 and 112.

  In this case, the radiant heat from the peripheral portion of the mounting table 58 is directly irradiated to the fixed portion 62 without being blocked by the heat shield plate 64, but from the peripheral portion of the mounting table 58 to the fixed portion 62. Since the distance is longer than the distance to the mounting table 58 just above, the radiant heat is reduced correspondingly, and the fixing portion 62 is not excessively heated. Furthermore, since the distance between the heat shield plates 64 positioned in the vertical direction as described above is a predetermined distance, for example, 18 mm or more, heat is accumulated between the heat shield plates 64 and a heat retaining effect is produced. However, as described above, it is possible to prevent the fixing portion 62 from being heated excessively.

  As described above, according to the present invention, since the heat shield structure 66 having the plurality of heat shield plates 64 provided to be distributed along the height direction is provided outside the support structure 60, the mounting table 58 is provided. The radiation heat from can be cut off, and the temperature rise at the lower end of the column structure 60 can be suppressed. As a result, it is possible to prevent deterioration of the seal member 102 used for the fixing portion 62 that fixes the lower end portion of the support structure 60 due to heat, and to maintain the sealing performance of this portion.

<Evaluation of the present invention>
Next, since an evaluation experiment was performed on the support structure of the present invention, the experimental result will be described. The support structure used in this experiment will be described with reference to FIG. FIG. 7 shows a schematic diagram of a support structure when an evaluation experiment is performed. FIG. 7 (A) shows Comparative Example 1, which corresponds to a conventional support structure without a heat shield. FIG. 7B shows a comparative example 2, which is provided with a heat shield plate 64 in the lower stage. FIG. 7C corresponds to the support structure of the present invention described above.

  As shown in each drawing, the mounting table 58 is supported by five support pipes 68 </ b> A to 68 </ b> E, and the lower end portion thereof is fixed by a fixing portion 62. In the case of FIG. 7B, a case is shown in which five heat shield plates 64 having a thickness of 2 mm are provided densely at intervals of 3 mm in the lower portion of the column pipes 68A to 68E. In the case of the present invention shown in FIG. 7C, a case is shown in which five heat shield plates 64 having a thickness of 2 mm are dispersed and arranged at intervals of 18 mm in the middle portion of the column pipes 68A to 68E. . The structure shown in FIG. 7C is a structure in which one heat shield structure located on the uppermost stage is removed from the six heat shield plates of the heat shield structure described above with reference to FIGS. It is. Here, a nickel alloy is used as the heat shield plate 64.

  At this time, the mounting table 58 has a diameter of 340 mm, the support pipes 68A to 68E have a length of 256 mm, and the heat shield plate 64 has a diameter of 94 mm. When the mounting table 58 is heated and the temperature of the mounting table 58 is set to 650 ° C., the temperature of the fixing unit 62 is 330 ° C. in the case of Comparative Example 1 shown in FIG. In the case of Comparative Example 2 shown in FIG. 7, the temperature was 300 ° C., whereas in the case of the present invention shown in FIG.

  Thus, in the conventional support | pillar structure shown to FIG. 7 (A), since the heat shield plate 64 is not provided, the fixing | fixed part 62 is heated too much by the effect | action of a radiant heat. In addition, as shown in FIG. 7B, when the heat shield plates 64 are densely provided with a small distance from each other, heat is trapped between the heat shield plates 64 to produce a heat retaining effect. As a result, even if the radiant heat was cut off, the temperature of the fixed portion 62 could not be lowered sufficiently.

  On the other hand, in the case of the present invention, the radiant heat can be blocked by the heat shield plate 64 without producing a heat retaining effect, and the temperature of the fixing portion 62 is set to the heat resistance of the O-ring which is a seal member provided here. It has been found that the temperature can be lower than, for example, 260 ° C. Further, in the column structure shown in FIG. 7C, the temperature of the mounting table 58 was raised to 750 ° C. and 850 ° C., respectively, and the temperature of the fixing portion 62 was 215 ° C. and 230 ° C., respectively. Thus, even if the temperature of the fixing portion 62 is increased to 215 degrees and 230 ° C., the heat resistance temperature of the O-ring is lower than, for example, 260 ° C., and the effectiveness of the column structure of the present invention can be confirmed. It was. 7A and 7B, the temperature data could not be acquired because it exceeded the heat resistance temperature of the member used for the fixing portion.

  Further, in the heat shield structure shown in FIG. 7C, another heat shield plate is provided on the uppermost stage to make a total of six heat shield structures that are the same as the heat shield structure shown in FIGS. As a result, when the temperature of the mounting table 58 is set to 650 ° C., 750 ° C., and 850 ° C., the temperatures of the fixing unit 62 are 165 ° C., 195 ° C., and 210 ° C., respectively. It was confirmed that the temperature can be further reduced as compared with the case where the heat shield plate is provided.

  In the above embodiment, the case where the heat shield plate 64 is provided on the entire middle part and part of the lower part of the column structure 60 has been described as an example, but the present invention is not limited to this. 64 may be provided at equal intervals over the entire middle portion and lower portion of the column structure 60 as in the first modified example of the column structure shown in FIG. In FIG. 8, the same reference numerals are assigned to the components shown in FIGS. In this case as well, the distance between the heat shield plates 64 is preferably set to 18 mm or more in order to prevent the above-described heat retention effect.

  In each of the above embodiments, the case where the heat shield plates 64 are provided at equal intervals has been described as an example. However, the distance between the heat shield plates 64 may be set to be different intervals instead of equal intervals. Good. Further, as shown in FIG. 6, the heat shield plate 64 is formed with a wide area so as to block portions other than the cross sections of the column pipe 68 and the support rod 124. However, the present invention is not limited to this, and the heat shield plate 64 is mounted. In order to facilitate this, a large through hole may be formed by connecting a plurality of first through holes 126 through which the support pipe 68 is inserted.

  Further, in each of the above-described embodiments, the case where a plurality of support pipes 68 are assembled as the support structure 60 has been described as an example. However, the support structure 60 is not limited thereto, and the support structure 60 shown in FIG. As in the second modified example of the structure, it may be configured by one cylindrical column 150 having a large inner diameter. 9, the same components as those shown in FIGS. 1 to 8 are denoted by the same reference numerals.

  In this case, the column 150 is made of quartz or ceramic material, and since the column 150 itself has high strength, each heat shield plate 64 constituting the heat shield structure 66 is directly attached to and supported by the column 150 itself. Alternatively, as described in the previous embodiment, a plurality of support bars 124 and the spacer member 130 may be used for support. Also in this case, the same effect as the previous embodiment can be exhibited.

  Moreover, although each said Example demonstrated taking the case of the mounting base structure which provided only the heating means 74 in the mounting base 58, this invention also applies to the mounting base structure which provided the electrostatic chuck, the ground electrode, and the high frequency electrode. In this case, plasma processing means using high-frequency power or the like is provided in the processing apparatus. Further, although the film forming process is described as an example of the heat treatment in the above embodiment, the present invention is not limited to this, and the present invention can be applied to other heat treatments such as an annealing process and a reforming process.

  Although the semiconductor wafer is described as an example of the object to be processed here, the semiconductor wafer includes a silicon substrate and a compound semiconductor substrate such as GaAs, SiC, GaN, and the like, and is not limited to these substrates. The present invention can also be applied to glass substrates, ceramic substrates, and the like used in display devices.

20 treatment apparatus 22 treatment container 24 shower head part (gas introduction means)
48 exhaust system 54 mounting table structure 58 mounting table 60 column structure 62 fixed part 64 heat shield plate 66 heat shield structure 68, 68A to 68E column tube 70 mounting table body 72 heat diffusion plate 74 heating means 100 mounting table 102, 108, 112 Seal member 104 Tube fixing base W Semiconductor wafer (object to be processed)

Claims (11)

In a mounting table structure for mounting an object to be processed that is provided in a processing container that can be evacuated,
A mounting table provided with heating means for mounting and supporting the object to be processed and heating the object to be processed;
A column structure that is provided upright from the bottom side of the processing vessel and whose upper end is connected to the lower surface of the mounting table,
A fixing portion for fixing a lower end portion of the support structure to a bottom portion of the processing container;
A heat-insulating structure having a plurality of heat-shielding plates provided on the outside of the support structure and distributed along the height direction;
A mounting table structure characterized by comprising: 2. The mounting table structure according to claim 1, wherein the support structure is composed of a plurality of support tubes assembled at a central portion of the mounting table. The mounting table structure according to claim 1, wherein the plurality of heat shield plates are provided below a middle stage in the height direction of the support structure. The mounting table structure according to any one of claims 1 to 3, wherein the heat shield plate is made of a metal plate. The mounting table structure according to claim 1, wherein a reflectance of the heat shield plate is 68% or more. The mounting table structure according to any one of claims 1 to 5, wherein a thickness of the heat shield plate is in a range of 0.2 to 5 mm. The mounting table structure according to any one of claims 1 to 6, wherein a distance between the heat shield plates is set to 18 mm or more. The mounting table structure according to claim 1, wherein the heat shield plate is divided into a plurality of pieces. 9. The heat shield structure according to claim 1, wherein the heat shield structure includes a plurality of support bars provided upright outside the support structure, and the heat shield plate is attached to the support bars. The mounting table structure according to any one of claims. The mounting table structure according to claim 9, wherein a cylindrical spacer member into which the support bar is inserted is interposed between the heat shield plates. In a processing apparatus for performing processing on an object to be processed,
A processing vessel that can be evacuated;
The mounting table structure according to any one of claims 1 to 10, provided in the processing container for mounting the object to be processed,
Gas introduction means for supplying gas in the processing container;
A processing apparatus comprising:

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