JP2011165891A - Mounting stand structure, and processing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mounting stand structure improving strength of a connection part between a mounting table and a support post and strength of the support post itself. <P>SOLUTION: The mounting stand structure 54 arranged in a processing vessel 22 allowed to exhaust air for mounting a processing object W to be processed thereon includes: a mounting stand 58 provided with at least a heating means 64 and formed of a dielectric material for mounting a processing object thereon; and a support post 63 arranged by being erected from the bottom side of the processing vessel to support the mounting stand, having an upper end connected to the undersurface of the mounting table, having a plurality of through-holes 60 formed along the longitudinal direction in the inside, and formed of a dielectric material. Thus, the strength of the connection part between the mounting stand and the support post and the strength of the support post itself are improved. <P>COPYRIGHT: (C)2011,JPO&INPIT

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. When performing various processes as described above, a necessary processing gas corresponding to the type of the process, for example, a film forming gas or a halogen gas in the case of a film forming process, and an ozone gas in the case of a reforming process. In the case of crystallization treatment, an inert gas such as N ₂ gas or O ₂ gas is introduced into the treatment container.

  For example, in the case of a single wafer processing apparatus for performing heat treatment on a semiconductor wafer one by one, a mounting table having a built-in resistance heater, for example, is installed in a processing container that can be evacuated. A semiconductor wafer is placed on the wafer, and a predetermined processing gas is flowed in a state heated at a predetermined temperature (for example, 100 ° C. to 1000 ° C.), and the wafer is subjected to various heat treatments under predetermined process conditions. (Patent Documents 1 to 4). For this reason, the members in the processing container are required to have heat resistance against such heating and corrosion resistance that does not corrode even when exposed to the processing gas.

  By the way, with respect to the mounting table structure on which the semiconductor wafer is mounted, it is generally necessary to provide heat resistance and corrosion resistance and to prevent metal contamination such as metal contamination. Embedded in a resistance heater and integrally fired at a high temperature to form a mounting table, and in a separate process, a ceramic material or the like is fired to form a support column. The mounting table structure is manufactured by welding and integration by thermal diffusion bonding. The mounting table structure integrally formed in this way is provided upright at the bottom of the processing container. Instead of the ceramic material, quartz glass having heat and corrosion resistance and less thermal expansion and contraction may be used.

  Here, an example of a conventional mounting table structure will be described. FIG. 8 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. 8, 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 joined and integrated at the center of the lower surface of the mounting table 2 by, for example, thermal diffusion bonding.

  Therefore, both are airtightly joined by the thermal diffusion joining portion 6. Here, the size of the mounting table 2 is about 350 mm in diameter when the wafer size is 300 mm, for example, and the diameter of the column 4 is about 56 mm. A heating means 8 such as a heater is provided in the mounting table 2 to heat the semiconductor wafer W as a target object 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 9 by a fixing block 10. The cylindrical support column 4 is provided with a power supply rod 14 whose upper end is connected to the heating means 8 via a connection terminal 12. The lower end portion of the power supply rod 14 is provided with an insulating member 16. Through the bottom of the container, it passes through the bottom of the container and is drawn out. 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 connection terminal 12 from being corroded by the corrosive process gas. Further, in Patent Document 7, a mounting table structure in which the mounting table is supported by a plurality of cylindrical support members disposed in the peripheral portion, and a push-up pin is accommodated in the cylindrical support member so as to be movable up and down. Is disclosed.

JP 07-077866 A Japanese Patent Laid-Open No. 03-220718 JP 2004-356624 A JP 2002-313900 A

  By the way, when the processing apparatus itself needs to be moved or transported during maintenance of the processing apparatus, the mounting table structure as described above is incorporated in the processing apparatus in order to perform work quickly. In this state, it is necessary to move or transport it. In such a case, as described above, simply joining the upper end of the cylindrical support column 4 to the lower surface of the mounting table 2 and fixing them may cause the strength of the joined portion to be insufficient and cause cracks or the like in this portion. It was. Further, since the support column 4 itself has a relatively thin structure, the support column 4 itself may be damaged.

  In addition, due to large vibrations such as earthquakes, the mounting table itself could co-pregnant and cause this damage. Such fear also exists in the mounting table structure in which the mounting table is supported by a plurality of support members as shown in Patent Document 4. In particular, since the diameter of the wafer W tends to become larger from about 300 mm, the diameter of the mounting table 2 itself is further increased and the weight is further increased. It is rare.

  The present invention has been devised to pay attention to the above problems and to effectively solve them. The present invention provides a mounting table structure and a processing apparatus capable of improving the strength of the connecting portion between the mounting table and the column and the strength of the column itself.

  According to a first aspect of the present invention, there is provided a mounting table structure for mounting an object to be processed which is provided in a processing container made evacuable, and at least a heating means for mounting the object to be processed. And a support table made of a dielectric material provided with an upper end portion connected to the lower surface of the mounting table to support the mounting table. A mounting table structure comprising: a support post made of a dielectric having a plurality of through holes formed along a vertical direction.

  In this way, in the mounting table structure for mounting the object to be processed that is provided in the processing container that can be evacuated, at least a heating means is provided for mounting the object to be processed. A mounting table made of a body, and provided to stand upright from the bottom side of the processing container to support the mounting table, and an upper end portion is connected to the lower surface of the mounting table, and is formed along the length direction inside. Since the support column made of a dielectric having a plurality of through holes is provided, the area of the connection portion between the mounting table and the support column increases. As a result, the strength of the connection portion between the mounting table and the support column and the support column itself are increased. Strength can be improved.

  According to a seventeenth aspect of the present invention, there is provided a processing apparatus for performing a process on an object to be processed, wherein a processing container that can be evacuated and the object to be processed are placed on the processing container. A processing apparatus comprising: the mounting table structure according to claim 1; and gas supply means for supplying gas into 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.
In a mounting table structure for mounting a target object to be processed which is provided in a processing container made evacuable, a mounting made of a dielectric provided with at least a heating means for mounting the target object. A plurality of through holes formed along the length direction inside the mounting table and provided to stand from the bottom side of the processing container to support the mounting table, and whose upper end is connected to the lower surface of the mounting table Since the support column made of a dielectric material having the structure is provided, the area of the connection portion between the mounting table and the support column is increased. As a result, the strength of the connection portion between the mounting table and the support column and the strength of the support column itself are improved. be able to.
Therefore, not only can the processing apparatus be moved and transported in a state in which the mounting table structure is incorporated, but also the earthquake resistance can be improved.

It is a cross-sectional block diagram which shows the processing apparatus which has the mounting base structure which concerns on this invention. It is a top view which shows an example of the heating means provided in the mounting base. It is arrow sectional drawing along the AA in FIG. FIG. 2 is a partial enlarged cross-sectional view representatively showing a part of a part of the through hole of the mounting table structure in FIG. 1. It is explanatory drawing for demonstrating the assembly state of the mounting base structure in FIG. It is the elements on larger scale which show the 1st modification of this invention. It is the elements on larger scale which show the part of the support | pillar of the 2nd modification of this invention. 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 sectional view showing a processing apparatus having a mounting table structure according to the present invention, FIG. 2 is a plan view showing an example of heating means provided on the mounting table, and FIG. 3 is taken along the line AA in FIG. 4 is a partially enlarged sectional view representatively showing a part of a part of the through hole of the mounting table structure in FIG. 1, and FIG. 5 is an assembled state of the mounting table structure in FIG. It is explanatory drawing for demonstrating. Here, a case where film formation is performed using plasma will be described as an example. In addition, the “functional rod” described below is not only a single metal rod but also a flexible wire, and a plurality of wires are covered with an insulating material and joined to one to form a rod. Including members and the like.

  As shown in the figure, the processing apparatus 20 includes a processing vessel 22 made of aluminum or aluminum alloy having a substantially circular cross section, for example. A shower head portion 24 serving as a gas supply means for introducing a necessary processing gas, for example, a film forming gas, is provided on the ceiling portion in the processing container 22 via an insulating layer 26. A processing gas is jetted toward the processing space S from a large number of gas injection holes 32 </ b> A and 32 </ b> B provided on the surface 28. The shower head 24 also serves as an upper electrode during plasma processing.

  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. The shower head unit 24 may have one gas diffusion chamber.

  A sealing member 34 made of, for example, an O-ring is interposed at the joint between the shower head 24 and the insulating layer 26 at the upper end opening of the processing container 22 to maintain the airtightness in the processing container 22. It is supposed to be. The shower head unit 24 is connected to a high frequency power source 38 for plasma of, for example, 13.56 MHz through a matching circuit 36 so that plasma can be generated when necessary. This frequency is not limited to the above 13.56 MHz.

  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.

  The bottom 44 in the processing container 22 is provided with a mounting table structure 54 that is characterized by the present invention. Specifically, the mounting table structure 54 is mainly configured by a mounting table 58 for mounting the object to be processed on the upper surface and a column 63 connected to the mounting table 58. The column 63 supports the mounting table 58 upright from the bottom of the processing container 22 and has a plurality of through holes 60 formed along the length direction inside. A functional rod 62 is inserted into each through hole 60. The column 63 is manufactured, for example, by forming a plurality of through holes 60 by drilling a columnar column material.

  In FIG. 1, in order to facilitate understanding of the invention, the respective through holes 60 are arranged in the horizontal direction. The mounting table 58 is entirely made of a dielectric. Here, the mounting table 58 is provided on a mounting table main body 59 made of thick and transparent quartz, and on the upper surface side of the mounting table main body 59. The heat diffusion plate 61 is made of an opaque dielectric material different from 59, for example, a ceramic material such as aluminum nitride (AlN) which is a heat resistant material.

  In the mounting table main body 59, a heating means 64 is provided so as to be embedded, for example, and a dual-purpose electrode 66 is provided so as to be embedded in the heat diffusion plate 61. The wafer W is placed on the upper surface of the heat diffusing plate 61 and the wafer W is heated via the heat diffusing plate 61 by radiant heat from the heating means 64.

  As shown in FIG. 2, the heating means 64 includes a heating element 68 made of, for example, a carbon wire heater or a molybdenum wire heater. The heating element 68 has a predetermined pattern shape over substantially the entire surface of the mounting table 58. Is provided. Here, the heating element 68 is electrically separated into two zones, an inner peripheral zone heating element 68A on the center side of the mounting table 58 and an outer peripheral zone heating element 68B. The connection terminals 68 </ b> A and 68 </ b> B are gathered on the center side of the mounting table 58. The number of zones may be set to 1 or 3 or more.

  The dual-purpose electrode 66 is provided in the opaque heat diffusion plate 61 as described above. The dual-purpose electrode 66 is formed of a conductor wire formed in a mesh shape, for example, and the connection terminal of the dual-purpose electrode 66 is located at the center of the mounting table 58. Here, the dual-purpose electrode 66 serves as a chuck electrode for an electrostatic chuck and a high-frequency electrode serving as a lower electrode for applying high-frequency power.

  Then, the function bar 62 serving as a power supply rod for supplying power to the heating element 68 and the dual-purpose electrode 66 and a conductive bar of a thermocouple for measuring temperature is provided. The thin through hole 60 is inserted. The column 63 is made of a dielectric material, specifically made of, for example, quartz, which is the same dielectric material as the mounting table main body 59, and is drilled along the length direction of the column 63 with, for example, a drill. A plurality, six in the illustrated example, are formed.

  As the material of the support 63, a dielectric other than quartz, for example, a ceramic material such as AlN can be used. The column 63 is joined to the lower surface of the mounting table main body 59 so as to be integrated in an airtight manner, for example, by welding. In this case, as the welding, both base materials may be melted and joined, or may be joined by a filler material having a melting point lower than that of the base material, and the joining area is made as wide as possible in order to improve joining strength. It is good to do. Therefore, it is preferable to join the entire upper end surface of the column 63 to the lower surface of the mounting table main body 59.

  As a result, a heat welding joint 63A (see FIG. 4) is formed at the connection portion at the upper end of the support 63, and the mounting table 58 and the support 63 are firmly joined. The functional rod 62 is inserted into each through hole 60. In FIG. 4, as described above, some of the through holes 60 are representatively shown, and two functional rod bodies 62 are accommodated in one of the through holes 60 as described later. .

  That is, heater feed rods 70 and 72 are individually inserted into the through holes 60 as two functional rods 62 for power in and power out for the inner peripheral zone heating element 68A. The upper ends of the power feeding rods 70 and 72 are electrically connected to the inner peripheral zone heating element 68A.

  In addition, heater feed rods 74 and 76 are inserted through the through holes 60 as two functional rods 62 for power-in and power-out, respectively, to the outer peripheral zone heating element 68B. The upper ends of the rods 74 and 76 are electrically connected to the outer peripheral zone heating element 68B (see FIG. 1). Each of the heater power supply rods 70 to 76 is made of, for example, a nickel alloy.

  A dual-purpose power supply rod 78 is inserted into the through-hole 60 as a functional rod 62 with respect to the dual-purpose electrode 66, and the upper end of the dual-purpose power supply rod 78 is connected to the dual-purpose electrode 66 via a connection terminal 78A (see FIG. 4). Is electrically connected. The dual-purpose power supply rod 78 is made of, for example, a nickel alloy, a tungsten alloy, a molybdenum alloy, or the like.

  Further, in order to measure the temperature of the mounting table 58, two thermocouples 80 and 81 are inserted into the remaining one through hole 60 as the functional rod body 62, and the thermocouples 80 and 81 The temperature measuring contacts 80A and 81A are respectively positioned on the lower surfaces of the inner and outer peripheral zones of the heat diffusing plate 61 so as to detect the temperature of each zone. As the thermocouples 80 and 81, for example, a sheath type thermocouple can be used. This sheath type thermocouple is hermetically sealed with a powder of an inorganic insulator such as high-purity magnesium oxide by inserting a thermocouple wire inside a metal protective tube (sheath). Excellent responsiveness and excellent durability even for long-term continuous use in high temperature environments and various malignant atmospheres.

  In this case, as shown in FIG. 4, communication holes 84 and 86 are formed in the portion of the mounting table main body 59 through which the connection terminal 78A and the thermocouples 80 and 81 pass, respectively, and the upper surface of the mounting table main body 59 is formed above. Is formed with a groove 88 for communicating with each of the communication holes 84 and 86 and for disposing one of the thermocouples 81 toward the outer peripheral zone. In FIG. 4, the heater power supply rod 70, the dual-purpose power supply rod 78, and the two thermocouples 80 and 81 are representatively described as the functional rod body 62.

  Further, the bottom 44 of the processing container 22 is made of, for example, stainless steel, and as shown in FIG. 4, a conductor outlet 90 is formed at the center, and for example, stainless steel is formed inside the conductor outlet 90. A mounting base 92 made of steel or the like is hermetically attached and fixed via a seal member 94 such as an O-ring.

  A fixing base 96 for fixing the support 63 is provided on the mounting base 92. The fixing base 96 is made of the same material as that of the support 63, that is, here, quartz, and communication holes 98 are formed corresponding to the through holes 60. And the lower end part side of the said support | pillar 63 is connected and fixed to the upper surface side of the said fixing stand 96 by the welding similar to the upper end part of the support | pillar 63. Accordingly, the heat welding joint 63B is formed here. In this case, as the welding, both base materials may be melted and joined, or may be joined by a filler material having a melting point lower than that of the base material, and the joining area is made as wide as possible in order to improve joining strength. It is good to do. Therefore, it is preferable to join the entire lower end surface of the column 63 to the upper surface of the fixed base 96.

  As described above, the fixing member 100 made of, for example, stainless steel is provided around the fixing base 96 that fixes the lower end portion of the column 63 so as to surround the fixing base 96. The fixing member 100 is attached to the mounting base by the bolts 102. It is fixed to the 92 side.

  In addition, similar mounting holes 104 are formed in the mounting base 92 so as to correspond to the respective communication holes 98 of the fixed base 96, and the function rods 62 are respectively inserted downward. A sealing member 106 such as an O-ring is provided on the joint surface between the lower surface of the fixed base 96 and the upper surface of the mounting base 92 so as to surround the communication holes 104. To increase.

  Further, seal members 108, 110, and 111 made of O-rings or the like are provided at the lower ends of the communication holes 104 through which the dual-purpose power supply rod 78, the two thermocouples 80 and 81, and the heater power supply rod 70 are inserted. The sealing plates 112 and 114 are attached and fixed by bolts 116 and 118. The dual-purpose power supply rod 78, the thermocouples 80 and 81, and the heater power supply rod 70 are provided so as to penetrate the sealing plates 112 and 114 in an airtight manner. These sealing plates 112, 114 are made of, for example, stainless steel, and the dual-purpose power supply rod 78 and the heater power supply rod 70 correspond to the penetrating portions of the dual-purpose power supply rod 78 and the heater power supply rod 70 with respect to the sealing plate 112. An insulating member 120 is provided around the. In FIG. 4, only one heater power supply rod 70 is shown, but the other heater power supply rods 72 to 76 are similarly configured.

In addition, an inert gas passage 122 is formed in the mounting base 92 and the bottom 44 of the processing container 22 in contact with the communication hole 104, and the through holes 60 through which the functional rods 62 pass. An inert gas such as N ₂ can be supplied inward. That is, the inert gas can be made to flow in all the through holes 60 here. Since the communication hole 84 and the communication hole 86 communicate with each other through the groove portion 88 of the mounting table main body 59, the through hole 60 through which the dual power feeding rod 78 is inserted and the two thermocouples 80 and 81 are inserted. An inert gas may be supplied into any one of the through-holes 60 through the inert gas passage 122.

  Here, an example of the dimensions of each part will be described. The diameter of the mounting table 58 is about 340 mm for a 300 mm (12 inch) wafer, about 230 mm for a 200 mm (8 inch) wafer, and 400 mm (16 mm). In the case of supporting an inch) wafer, it is about 460 mm. The inner diameter of each through hole 60 is about 5 to 16 mm, the diameter of each functional rod 62 is about 4 to 6 mm, and the diameter of the column 63 is about 60 to 90 mm.

  Returning to FIG. 1, the thermocouples 80 and 81 are connected to a heater power supply control unit 134 having, for example, a computer. Further, the wires 136, 138, 140, 142 connected to the heater power supply rods 70, 72, 74, 76 of the heating means 64 are also connected to the heater power supply control unit 134, and the thermocouples 80, 81 are connected. The inner zone heating element 68A and the outer zone heating element 68B are individually controlled on the basis of the temperature measured by the above to maintain a desired temperature.

  The wiring 144 connected to the dual-purpose power supply rod 78 is connected to a DC power source 146 for electrostatic chuck and a high frequency power source 148 for applying high frequency power for bias, respectively. The wafer W can be electrostatically attracted and high-frequency power can be applied as a bias to the mounting table 58 serving as a lower electrode during the process. As the frequency of the high-frequency power, 13.56 MHz can be used, but 400 kHz or the like can be used in addition, and is not limited to this frequency.

  In addition, a plurality of, for example, three pin insertion holes 150 are formed in the mounting table 58 so as to penetrate in the vertical direction (only two are shown in FIG. 1). A push-up pin 152 that is movably inserted in a loosely fitted state is disposed. An arc-shaped ceramic push-up ring 154 such as alumina is disposed at the lower end of the push-up pin 152, and the lower end of each push-up pin 152 is on the push-up ring 154. The arm portion 156 extending from the push-up ring 154 is connected to a retracting rod 158 provided through the bottom 44 of the processing container 22, and the retracting rod 158 can be moved up and down by an actuator 160.

  As a result, the push-up pins 152 are projected and retracted upward from the upper ends of the pin insertion holes 150 when the wafer W is transferred. In addition, an extendable bellows 162 is interposed in the penetrating portion of the in / out rod 158 provided in the bottom 44 of the processing container 22, and the in / out rod 158 maintains airtightness in the processing container 22. It can be moved up and down.

  Here, as shown in FIGS. 4 and 5, the pin insertion hole 150 is provided along a length direction of a bolt 170 that is a fastener for connecting the mounting table main body 59 and the heat diffusion plate 61. The communication hole 172 is formed. Specifically, bolt holes 174 and 176 through which the bolts 170 are passed are formed in the mounting table main body 59 and the heat diffusion plate 61, and the pin insertion holes 150 are formed in the bolt holes 174 and 176. The mounting base body 59 and the heat diffusing plate 61 are coupled by inserting the bolt 170 and tightening the bolt 170 with the nut 178. These bolts 170 and nuts 178 are formed of a ceramic material such as aluminum nitride or alumina.

  The overall operation of the processing apparatus 20, for example, control of the process pressure, temperature control of the mounting table 58, supply and stop of supply of the processing gas, and the like are performed by the apparatus control unit 180 including, for example, a computer. The apparatus control unit 180 includes a storage medium 182 that stores a computer program necessary for the above operation. The storage medium 182 includes a flexible disk, a CD (Compact Disc), a hard disk, a flash memory, or the like.

Next, the operation of the processing apparatus 20 using the plasma 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 held by a transfer arm (not shown) and opened, and the wafer W is lifted up. After being transferred to the pins 152, the push-up pins 152 are lowered to place the wafer W on the upper surface of the heat diffusion plate 61 of the mounting table 58 supported by the column 63 of the mounting table structure 54. To support. At this time, the electrostatic chuck functions by applying a DC voltage from the DC power source 146 to the dual-purpose electrode 66 provided on the heat diffusion plate 61 of the mounting table 58, and the wafer W is attracted and held on the mounting table 58. In some cases, a clamp mechanism that holds the periphery of the wafer W is used instead of the electrostatic chuck.

  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 wafer W is maintained at a predetermined process temperature. That is, heat is generated by applying a voltage to the inner zone heating element 68A and the outer zone heating element 68B constituting the heating means 64 of the mounting table 58 from the heater power supply control unit 134, respectively.

  As a result, the wafer W is heated and heated by the heat from the zone heating elements 68A and 68B. At this time, the thermocouples 80 and 81 provided at the center and the periphery of the lower surface of the heat diffusing plate 61 respectively measure the wafer (mounting table) temperatures in the inner and outer zones, and based on the measured values, the heaters The power controller 134 controls the temperature by feedback for each zone. For this reason, the temperature of the wafer W can be controlled in a state where the in-plane uniformity is always high. In this case, although depending on the type of process, the temperature of the mounting table 58 reaches about 700 ° C., for example.

  When plasma processing is performed, a high frequency power source 38 is driven to apply a high frequency between the shower head portion 24 as the upper electrode and the mounting table 58 as the lower electrode, and plasma is generated in the processing space S to be predetermined. The plasma treatment is performed. At this time, plasma ions can be attracted by applying high-frequency power from the biasing high-frequency power source 148 to the dual-purpose electrode 66 provided on the heat diffusion plate 61 of the mounting table 58.

  Here, the function in the mounting structure 54 will be described in detail. First, electric power is supplied to the inner peripheral zone heating element 68A of the heating means via the heater power supply rods 70 and 72 as the functional rod 62, and power is supplied to the outer peripheral zone heating element 68B via the heater power supply rods 74 and 76. Is supplied. The temperature at the center of the mounting table 58 is transmitted to the heater power supply control unit 134 via a thermocouple 80 arranged so that the temperature measuring contact 80A is in contact with the lower surface center of the mounting table 58.

  In this case, the temperature measuring contact 80A measures the temperature of the inner peripheral zone. The thermocouple 81 arranged on the outer periphery of the mounting table 58 measures the temperature of the outer peripheral zone at the temperature measuring contact 81A, and the measured value is transmitted to the heater power supply control unit 134. Thus, the power supplied to the inner zone heating element 68A and the outer zone heating element 68B is supplied based on feedback control.

  Furthermore, a DC voltage for electrostatic chuck and a high-frequency power for bias are applied to the dual-purpose electrode 66 via the dual-purpose power supply rod 78. The heater power supply rods 70, 72, 74, 76, the thermocouples 80, 81, and the dual-purpose power supply rod 78, which are functional rod bodies 62, are hermetically welded to the lower surface of the mounting table main body 59 of the mounting table 58. Each of the plurality of through holes 60 formed in the support column 63 is individually inserted (the thermocouples 80 and 81 are inserted into one through hole).

Further, the through holes 60 through which the heater power supply rods 70 to 76 are inserted, the thermocouples 80 and 81, and the through holes 60 through which the dual-purpose power supply rods 78 are inserted as an inert gas through the inert gas passage 122. For example, N ₂ gas is supplied, and this N ₂ gas diffuses through a groove portion 88 (see FIG. 4) formed on the upper surface of the mounting table main body 59, and further, the mounting table main body 59 and the thermal diffusion. Since the gas is also supplied to the joint surface with the plate 61, the inert gas is discharged radially from the peripheral portion of the mounting table 58 through a slight gap generated on the joint surface. It is possible to prevent the deposition gas, the cleaning gas, and the like in the processing space S from entering the interior of the chamber.

Further, the corrosive gas such as the film forming gas and the cleaning gas can be prevented from entering the inside through the gap, and the heater power supply rods 70 to 76 and the combined power supply rod 78 are covered with the N ₂ gas. The power supply rods can be prevented from being corroded by a corrosive gas, for example, being oxidized.

  Further, as described above, the inert gas penetrates into the processing vessel 22 so as to leak into the processing container 22 through a slight gap at the joint between the mounting table main body 59 and the heat diffusion plate 61. However, each through hole 60 that is purged with an inert gas may be sized so that each functional rod 62 can be inserted therethrough, compared to the conventional support column 4 (see FIG. 8). Since the volume is very small, the amount of gas can be reduced as compared with the conventional mounting table structure, and the consumption of the inert gas can be reduced accordingly, so that the running cost can be reduced.

  Further, as described above, since the upper end portion of the support column 63 is joined to the center portion of the lower surface (back surface) of the mounting table 58, the center portion of the lower surface of the mounting table 58 is in the plane of the wafer W. Unnecessary films that cause temperature non-uniformity are not attached, and as a result, the in-plane temperature uniformity of the wafer W can be maintained high. Further, each of the heater power supply rods 72 to 76 and the dual-purpose power supply rod 78 are individually separated by the material forming the support 63, that is, here, an insulator made of quartz. It is possible to prevent abnormal discharge from occurring.

  In such a situation, for example, when a large vibration occurs due to an earthquake or the like, the mounting table 58 that is a heavy object is broken due to a crack or the like from the connecting portion with the column 63, or the column 63 itself is cracked. There is a fear.

  However, in the present invention, the column 63 itself is formed into a columnar shape, and a plurality of through holes 60 for inserting a functional rod or the like into the column are formed, and the upper end of the column 63 is formed. Since the portion is connected to the lower surface of the mounting table 58, the strength of the column 63 itself can be greatly improved, and the strength of the connecting portion between the mounting table 58 and the column 63 can also be improved. In this case, since the bonding area in the heat welding joint 63A formed between the upper end surface of the column 63 and the lower surface of the mounting table 58 is sufficiently large, the bonding strength between the mounting table 58 and the column 63 is particularly improved. Can be made.

  Therefore, even if a large vibration such as an earthquake occurs, the mounting table structure 54 itself can be prevented from being damaged or destroyed. Further, since the strength of the mounting table structure 54 itself against vibration can be improved as described above, the processing apparatus can be moved or transported in a state where the mounting table structure 54 is incorporated.

  As described above, according to the present invention, in the mounting table structure for mounting, for example, a semiconductor wafer as a processing target to be processed which is provided in the processing container 22 which can be evacuated, the processing target is mounted. In order to do so, a mounting table 58 made of a dielectric provided with at least a heating means 64, and a stand placed on the bottom side of the processing container 22 to support the mounting table, and an upper end portion on the lower surface of the mounting table 58 are provided. Since the support column 63 made of a dielectric having a plurality of through-holes 60 formed therein along the length direction is provided, the area of the connection portion between the mounting table 58 and the support column 63 is increased. As a result, the strength of the connecting portion between the mounting table 58 and the column 63 and the strength of the column itself can be improved. Therefore, not only can the processing apparatus be moved and transported in a state in which the mounting table structure is incorporated, but also the earthquake resistance can be improved.

<First Modification>
Next, a first modified embodiment of the present invention will be described. In the previous embodiment, the mounting table 58 and the support column 63 are connected by welding. FIG. 6 is a partially enlarged view showing the first modified embodiment of the present invention as described above. 4 that are the same as those shown in FIG. 4 are given the same reference numerals, and descriptions thereof are omitted.

  As shown in FIG. 6, in the first modified embodiment, a flange portion 200 is provided around the upper end portion of the column 63. And the support | pillar 63 and the mounting base 58 are connected by fixing this flange part 200 to the lower surface side of the mounting base 58 by the some connection member 202. FIG. As the connecting member 202, a bolt, a screw, or the like can be used. As the material of the connecting member 202, a ceramic material such as aluminum nitride, or a metal with less fear of contamination such as stainless steel can be used.

In the case of this embodiment, unlike the case of joining by welding, a slight gap is generated at the connecting portion between the lower surface of the mounting table 58 and the upper end surface of the column 63. However, as described above, as shown in the arrow 204 through the gap (not shown), for example, N ₂ gas is supplied as an inert gas into all the through holes 60 formed in the column 63. Thus, the N ₂ gas is released almost radially into the processing container. Therefore, the film forming gas, the cleaning gas, and the like are prevented from entering the gap and the through hole 60, and an unnecessary film is prevented from adhering to this portion and the function rods 62 are not corroded. be able to.

  In this case, the connection strength between the mounting table 58 and the column 63 is slightly inferior to that in the previous embodiment in which the two are welded together, but the strength of the column 63 itself is as high as in the previous embodiment. It is possible to maintain the same effect as in the previous embodiment.

<Second Modification>
Next, a second modified embodiment of the present invention will be described. In the embodiment shown in FIG. 4, the upper end portion and the lower end portion of the column 63 are both flat. However, the present invention is not limited to this, and in order to facilitate welding, these portions are cut into recesses. A recessed portion may be formed. FIG. 7 is a partially enlarged view showing the column portion of the second modified embodiment of the present invention as described above. 4 that are the same as those shown in FIG. 4 are given the same reference numerals, and descriptions thereof are omitted.

  As shown in FIG. 7, here, at the upper end portion and the lower end portion of the column 63, cut portions 206A and 206B formed by cutting into a concave shape while leaving the peripheral portion in a ring shape are provided. . Note that only one of the two cutting portions 206A and 206B may be provided. In this case, the thickness L1 of the peripheral portion of the column 63 in the portions of the cut portions 206A and 206B is, for example, about 2 to 5 mm, and is set to a thickness of about 2 to 9% of the thickness of the mounting table main body 59. To do.

  And the support | pillar 63 and the mounting base 58 are joined by welding the upper end part of this support | pillar 63 to the lower surface of the mounting base main body 59. FIG. Further, by welding the lower end portion of the support column 63 to the upper surface of the fixed table 96, the support column 63 and the fixed table 96 are joined. When performing this thermal welding, it is necessary to heat both base materials to be welded to a high temperature, but by forming the recessed portions 206A and 206B as described above, the ring shape has become thin. The peripheral portion can be quickly heated in the same manner as the central portion of the lower surface of the mounting table main body 59 to be welded, and both can be easily and quickly joined.

  Further, if the thickness L1 of the upper and lower ends of the column 63 is set to some extent, for example, 2 mm or more, more preferably 2.5 mm or more, the joining area with the mounting table main body 59 and the fixing table 96 is sufficiently increased. In particular, the bonding strength between the mounting table main body 59 and the column 63 can be kept high. Therefore, also in the case of the second modified embodiment, the same operational effects as those of the embodiment described with reference to FIG. 4 can be exhibited.

  In each of the above embodiments, the case where quartz is mainly used as the dielectric constituting the support 63 has been described as an example. However, the present invention is not limited to this, and the support 63 is made opaque by including, for example, bubbles. It is possible to use a ceramic material such as opaque quartz or opaque aluminum nitride. According to this, the radiant heat irradiated toward the lower end part of the support | pillar 63 from the mounting base 58 can be interrupted | blocked effectively. As a result, it is possible to prevent each seal member 106 (see FIG. 4) made of an O-ring or the like installed at the lower end portion of the support 63 from being excessively heated. Can be prevented.

  Further, in each of the above embodiments, the side surface and the lower surface of the mounting table 58 are exposed in the processing container 22, but particularly when the mounting table body 59 is formed of quartz or the like, the quartz is corroded by the etching gas. There is a fear. Therefore, in this case, a protective cover made of a material excellent in corrosion resistance against the etching gas, for example, a ceramic material such as aluminum nitride or alumina, may be provided on the side surface and the lower surface of the mounting table 58.

  In each of the above-described embodiments, the case where the pin insertion hole 150 is provided in the fastener including the bolt 170 and the nut 178 has been described as an example. However, the present invention is not limited to this, and for example, the mounting table main body 59 and the heat diffusion plate 61. The present invention can also be applied to the case where and are integrally joined by an adhesive, welding, or the like.

  In each of the above embodiments, the case where aluminum nitride is mainly used as the ceramic material has been described as an example. However, the present invention is not limited to this, and other ceramic materials such as alumina and SiC can be used. Although the case where the mounting table 58 has a two-layer structure of the mounting table main body 59 and the heat diffusion plate 61 has been described as an example here, the present invention is not limited to this, and the entire mounting table 58 is made of the same dielectric, for example, A single layer structure may be made of quartz or ceramic material.

In this case, when transparent quartz is used as the quartz, the upper surface of the mounting table 58 is made of, for example, a ceramic material in order to prevent the pattern shape of the heating element from being projected on the back surface of the wafer and generating heat distribution. A hot plate should be provided. Further, when the opaque quartz containing bubbles or the like is used, the above-mentioned soaking plate is not necessary. Although the case where N ₂ gas is mainly used as the inert gas has been described as an example here, the present invention is not limited to this, and a rare gas such as He or Ar may be used.

  Further, in each of the above embodiments, the mounting electrode 58 is provided with the dual-purpose electrode 66, and the electrostatic chuck DC voltage and the bias high-frequency power are applied thereto via the dual-purpose power supply rod 78. These may be provided separately, or only one of them may be provided. For example, when both are provided separately, two electrodes having the same structure as the dual-purpose electrode 66 are provided on the upper and lower sides, one being a chuck electrode and the other being a high-frequency electrode. A chuck power supply rod is electrically connected to the chuck electrode as a functional rod body, and a high frequency power supply rod is electrically connected to the high frequency electrode. The point that the chuck power supply rod and the high frequency power supply rod are inserted into the through hole 60 and the lower structure thereof are exactly the same as the other functional rod bodies 62.

  The ground electrode may be grounded by providing a ground electrode having the same structure as the dual-purpose electrode 66 and grounding the lower end of the functional bar 62 connected thereto to use as a conductive bar. Further, when a heater power supply rod of a plurality of zones is provided, if one heater power supply rod is grounded, one heater power supply rod of the heat generator of each zone is commonly used as the grounded heater power supply rod. be able to.

  In the present embodiment, the processing apparatus using plasma has been described as an example. However, the present invention is not limited to this. All processing apparatuses using a mounting table structure in which the heating means 64 is embedded in the mounting table 58, for example, plasma. The present invention can also be applied to a film-forming apparatus using plasma CVD that uses silicon, a film-forming apparatus using thermal CVD that does not use plasma, an etching apparatus, a thermal diffusion apparatus, a diffusion apparatus, and a reforming apparatus. Therefore, the dual-purpose electrode 66 (including the chuck electrode and the high-frequency electrode), the thermocouple 80, and the members attached to them can be omitted.

  Furthermore, the gas supply means is not limited to the shower head unit 24, and the gas supply means may be constituted by, for example, a gas nozzle inserted into the processing container 22. Furthermore, although thermocouples 80 and 81 are used here as temperature measuring means, the present invention is not limited to this, and a radiation thermometer may be used. In this case, the optical fiber that conducts light used in the radiation thermometer becomes a functional rod, and this optical fiber is inserted into the through hole 60. In each of the above embodiments, one or a plurality of functional rods are inserted into all the through holes. However, the present invention is not limited to this, and the purge inert gas is exclusively used without inserting the functional rods. You may make it provide the through-hole for flowing.

  Although the semiconductor wafer is described as an example of the object to be processed here, the present invention is not limited thereto, and the present invention can be applied to a glass substrate, an LCD substrate, a ceramic substrate, and the like.

20 treatment device 22 treatment vessel 24 shower head (gas supply means)
38 High-frequency power supply 48 Exhaust system 54 Mounting table structure 58 Mounting table 59 Mounting table main body 60 Through-hole 61 Heat diffusion plate 62 Functional bar 63 Support column 64 Heating means 66 Dual electrode 68 Heating element 68A Inner peripheral zone heating element 68B Outer peripheral zone heating element 70, 72, 74, 76 Heater feed rod 78 Combined feed rod 80, 81 Thermocouple 146 DC power supply 148 High frequency power supply W Semiconductor wafer (object to be processed)

Claims (17)

In the mounting table structure for mounting the object to be processed which is provided in the processing container made evacuable,
A mounting table made of a dielectric provided with at least a heating means for mounting the object to be processed;
In order to support the mounting table, the plurality of through-holes are provided so as to stand from the bottom side of the processing container, and the upper end portion is connected to the lower surface of the mounting table and is formed along the length direction inside. A post made of a dielectric material having
A mounting table structure characterized by comprising: 2. The mounting table structure according to claim 1, wherein the support column is connected to a central portion of the lower surface of the mounting table. The mounting table structure according to claim 2, wherein the mounting table and the support column are connected by welding. The mounting table structure according to claim 2, wherein the mounting table and the support column are connected by a connecting member. The mounting table structure according to any one of claims 1 to 4, wherein one or a plurality of functional rods are inserted into each through hole. 6. The mounting table structure according to claim 5, wherein the functional bar is a heater power feed bar electrically connected to the heating means side. 6. The chuck according to claim 5, wherein the mounting table is provided with a chuck electrode for an electrostatic chuck, and the functional bar is a chuck feeding bar electrically connected to the chuck electrode. Mounting table structure. The high-frequency electrode for applying high-frequency power to the mounting table is provided, and the functional bar is a high-frequency power feeding rod electrically connected to the high-frequency electrode. Mounting table structure. The mounting table is provided with a dual-purpose electrode that serves both as a chuck electrode for an electrostatic chuck and a high-frequency electrode for applying high-frequency power, and the functional bar is electrically connected to the dual-purpose electrode. 6. The mounting table structure according to claim 5, wherein the mounting table structure is a dual-purpose power feeding rod. 6. The mounting table structure according to claim 5, wherein the functional bar is a thermocouple for measuring the temperature of the mounting table. 6. The mounting table structure according to claim 5, wherein the functional bar is an optical fiber of a radiation thermometer for measuring the temperature of the mounting table. The mounting table includes a mounting table body provided with the heating unit, and a heat diffusion plate made of an opaque dielectric material provided on the upper surface side of the mounting table body and different from the forming material of the mounting table body. The mounting table structure according to any one of claims 1 to 11, wherein the mounting table structure is configured as described above. The mounting table structure according to claim 12, wherein any one of a chuck electrode, a high-frequency electrode, and a dual-purpose electrode is provided in the heat diffusion plate. The mounting table structure according to claim 12 or 13, wherein an inert gas is supplied between the mounting table main body and the heat diffusion plate. The mounting table structure according to any one of claims 1 to 14, wherein an inert gas is supplied to all or a part of the plurality of through holes. The mounting table structure according to any one of claims 1 to 15, wherein a cut-out portion having a concave shape is formed at an upper end portion and / or a lower end portion of the support column. 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 16, for mounting the object to be processed,
Gas supply means for supplying gas into the processing vessel;
A processing apparatus comprising:

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