WO2011099481A1 - Mounting table structure, and processing device - Google Patents

Abstract

Disclosed is a mounting table structure for mounting an object to be processed that is disposed in a processing container capable of discharging gas. The mounting table structure is provided with: a mounting table for mounting the aforementioned object to be processed, which is configured from a dielectric body provided with at least a heating means; and a support column which is disposed up right from the bottom side of the aforementioned processing container for the purpose of supporting the mounting table, has an upper edge that is connected to the bottom surface of the mounting table, and is configured from a dielectric body having a plurality of through holes formed along the lengthwise direction in the inside of the support column.

Description

Mounting table structure and processing apparatus

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, for example, a film forming gas or a halogen gas in the case of a film forming process, or a gas or a halogen gas in the case of a reforming process, corresponding to the type of the process. In the case of crystallization treatment, ozone gas or the like, and an inert gas such as N ₂ gas or O ₂ gas are 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. (Japanese Patent Laid-Open Nos. 07-077866, Japanese Patent Laid-Open Nos. 03-220718, 2004-356624, 2002-313900). 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, regarding the mounting table structure on which the semiconductor wafer is mounted, in general, it is necessary to provide heat resistance and corrosion resistance and to prevent metal contamination such as metal contamination. For example, a ceramic such as aluminum nitride (AlN) is used. A resistance heater is embedded in the material as a heating element, and is integrally fired at a high temperature to form a mounting table. In a separate process, a ceramic material or the like is also fired to form a support column. Are mounted and integrated by, for example, thermal diffusion bonding to manufacture a mounting table structure. The mounting table structure integrally formed in this way is provided upright at the bottom of the processing container. In place 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 cross-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, and has a disk-shaped mounting table 2 made of a ceramic material such as aluminum nitride (AlN), as shown in FIG. ing. A cylindrical column 4 made of a ceramic material such as aluminum nitride (AlN), for example, is joined and integrated at the center of the lower surface of the mounting table 2 by thermal diffusion bonding.

That is, both are airtightly joined by the thermal diffusion joining portion 6. Here, the size of the mounting table 2 is, for example, about 350 mm in diameter when the wafer size is 300 mm, and the diameter of the support column 4 is about 56 mm. In the mounting table 2, for example, a heating unit 8 made of a heater or the like is provided to heat the semiconductor wafer W as a target object on the mounting table 2.

The lower end of the support column 4 is in an upright state by being fixed to the container bottom 9 by a fixing block 10. In the cylindrical support column 4, a power supply rod 14 whose upper end is connected to the heating means 8 via the connection terminal 12 is provided. The lower end portion side of the power feeding rod 14 penetrates the container bottom portion downward via the insulating member 16 and is drawn to the outside. With such a configuration, it is possible to prevent the process gas and the like from entering the support column 4 and to prevent the feeding rod 14 and the connection terminal 12 and the like from being corroded by the corrosive process gas. Yes. In Japanese Patent Application Laid-Open No. 2002-313900, the mounting table is supported by a plurality of cylindrical support members arranged in the periphery thereof, and the push-up pins are accommodated in these cylindrical support members so as to be movable up and down. A mounting table structure is disclosed.

By the way, when the processing apparatus itself needs to be moved or transported at the time of maintenance of the processing apparatus or the like, the mounting table structure as described above is still incorporated in the processing apparatus in order to perform work quickly. There is a need to move or transport the processing equipment. In such a case, in the configuration in which the upper end of the cylindrical column 4 described above is simply joined to the lower surface of the mounting table 2 and both are fixed, the strength of the joined portion is insufficient, and a crack or the like occurs in this portion. There was a fear. In addition, since the support column 4 itself has a relatively thin structure, the support column 4 itself may be damaged.

In addition, there was a risk that the mounting table itself could become pregnant and cause damage due to a large vibration such as an earthquake. Such a concern also exists in the mounting table structure in which the mounting table is supported by a plurality of support members disclosed in Japanese Patent Application Laid-Open No. 2002-313900. In particular, since the diameter of the wafer W tends to be further increased from about 300 mm, the diameter of the mounting table 2 itself is expected to be further increased and further weighted. A solution is desired.

Summary of the Invention

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 the present invention, in a mounting table structure for mounting a target object to be processed, which is provided in a processing container that can be evacuated, at least a heating unit is provided for mounting the target target object. In addition, a support table made of a dielectric material and a support table that is erected from the bottom side of the processing vessel in order to support the test table, and an upper end portion is connected to the lower surface of the test table, and along the length direction. And a support post made of a dielectric having a plurality of through holes formed in this manner.

According to the present invention, the area of the connecting portion between the mounting table and the column can be increased, and as a result, the strength of the connecting portion between the mounting table and the column and further the strength of the column itself can be improved. Is possible. Therefore, there is no problem in moving or transporting the processing apparatus with the mounting table structure incorporated, and the earthquake resistance can be improved.

Alternatively, the present invention provides a processing container for performing processing on a target object, a processing container that can be evacuated, and a mounting table structure having the above-mentioned characteristics for mounting the target object, And a gas supply means for supplying a gas into the processing container.

According to the present invention, the area of the connecting portion between the mounting table and the column can be increased, and as a result, the strength of the connecting portion between the mounting table and the column and further the strength of the column itself can be improved. Is possible. Therefore, there is no problem in moving or transporting the processing apparatus with the mounting table structure incorporated, and the earthquake resistance can be improved.

It is a section lineblock diagram showing a processing device which has a mounting base structure concerning one embodiment of the present invention. It is a top view which shows an example of the heating means provided in the mounting base. FIG. 2 is a cross-sectional view taken along line AA in FIG. FIG. 2 is a partially enlarged sectional view representatively showing a part of a part of the through hole of the mounting table structure of FIG. 1. It is explanatory drawing for demonstrating the assembly state of the mounting base structure of 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 cross-sectional configuration diagram showing a processing apparatus having a mounting table structure according to an embodiment of the present invention. FIG. 2 is a plan view showing an example of heating means provided on the mounting table. 3 is a cross-sectional view taken along line AA in FIG. 4 is a partial enlarged cross-sectional view representatively showing a part of a part of the through hole of the mounting table structure of FIG. FIG. 5 is an explanatory diagram for explaining an assembled state of the mounting table structure of FIG. 4. Here, a case where film formation processing is performed using plasma will be described as an example. The “functional rod” described below is not only a single metal rod but also a flexible wire or a plurality of wires covered with an insulating material and combined into one to form a rod. It is also assumed to include such a member.

As shown in the figure, this processing apparatus 20 has a processing container 22 made of aluminum or aluminum alloy, for example, whose cross section is substantially circular. On the ceiling of the processing vessel 22, a shower head unit 24 serving as a gas supply unit is provided via an insulating layer 26 in order to introduce a necessary processing gas, for example, a film forming gas. The processing gas is jetted toward the processing space S from a number of gas jetting holes 32A and 32B provided on the gas jetting surface 28 on the lower surface. The shower head unit 24 also serves as an upper electrode during plasma processing.

In the shower head part 24, gas diffusion chambers 30A and 30B divided into two hollow shapes are formed. After the processing gas introduced into the gas diffusion chambers 30A and 30B diffuses in the plane direction, The gas is injected from the gas injection holes 32A and 32B respectively connected to the gas diffusion chambers 30A and 30B. Here, 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, for example. In addition, as the shower head part 24, the structure with one gas diffusion chamber may be employ | adopted.

A sealing member 34 made of, for example, an O-ring or the like 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 so as to maintain the airtightness in the processing container 22. It has become. 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 13.56 MHz.

Further, on the side wall of the processing container 22, a loading / unloading port 40 for loading and unloading the semiconductor wafer W as the object to be processed into the processing container 22 is provided. The carry-in / out port 40 is provided with a gate valve 42 that can be opened and closed in an airtight manner.

Further, an exhaust port 46 is provided on the side portion 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 container 22 is desired. The pressure to be maintained 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.

And the mounting part structure 54 which is the characteristic of this invention is provided in the bottom part 44 in the processing container 22 so that it may stand up from this. Specifically, the mounting table structure 54 is mainly configured by a mounting table 58 for mounting an object to be processed on an upper surface and a column 63 connected to the mounting table 58. The support column 63 supports the mounting table 58 so as to stand up from the bottom of the processing container 22, and has a plurality of through holes 60 formed along the length direction therein. A functional bar 62 is inserted into each through hole 60. The support | pillar 63 is manufactured by forming the several through-hole 60 by perforation, for example in a column-shaped support | pillar material.

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

In the mounting table main body 59, for example, a heating means 64 is provided so as to be embedded. A dual-purpose electrode 66 is embedded in the heat diffusion plate 61. Thus, when the wafer W is placed on the upper surface of the heat diffusing plate 61, the wafer W can be 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 is provided in a predetermined pattern shape over substantially the entire surface of the mounting table 58. 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 on the outer side. The connection terminals of the zone heating elements 68A and 68B 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 made 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.

Further, a power bar for feeding power to the heating element 68 and the dual-purpose electrode 66 and a functional bar 62 as a conductive bar for a thermocouple for measuring temperature are provided. Specifically, each of these functional rods 62 is inserted into the thin through hole 60. The support 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. A plurality of the support posts 63 are drilled by drilling along the length direction of the support 63, for example. In the illustrated example, six through holes 60 are formed.

As the material of the support 63, a dielectric material other than quartz, for example, a ceramic material such as aluminum nitride (AlN), alumina (Al ₂ O ₃ ), silicon carbide (SiC), or the like can be used. The support | pillar 63 is joined to the lower surface of the mounting base main body 59 so that it may become airtightly integrated by welding, for example. In this case, as 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. It should be as wide as possible. Therefore, preferably, the entire upper end surface of the column 63 is joined to the lower surface of the mounting table main body 59.

As a result, a heat-welded joint 63A (see FIG. 4) is formed at the connecting portion at the upper end of the support 63, whereby the mounting table 58 and the support 63 are firmly joined. On the other hand, a 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. In one of these through holes 60, two function rods 62 are accommodated as will be described later.

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

In addition, heater power feed rods 74 and 76 are individually inserted into the through holes 60 as two function rods 62 for power-in and power-out for the outer peripheral zone heating element 68B. The upper ends of the heater power supply 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.

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

Further, two thermocouples 80 and 81 are inserted into the remaining one through hole 60 as the functional rod body 62 in order to measure the temperature of the mounting table 58. The temperature measuring contacts 80A and 81A of the thermocouples 80 and 81 are positioned on the lower surfaces of the inner and outer peripheral zones of the heat diffusion plate 61, respectively, so that the temperature of each zone can be detected. As the thermocouples 80 and 81, for example, a sheath type thermocouple can be used. This sheath type thermocouple is formed by inserting a thermocouple wire into a metal protective tube (sheath) and sealingly filling it with a powder of an inorganic insulator such as high-purity magnesium oxide. As a result, it has excellent insulating properties, airtightness, and responsiveness, and exhibits outstanding 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 portions of the mounting table main body 59 through which the connection terminals 78 </ b> A and the thermocouples 80 and 81 pass, respectively, and on the upper surface of the mounting table main body 59. Are communicated with the respective communication holes 84 and 86, and a groove portion 88 is formed for disposing one of the thermocouples 81 toward the outer peripheral zone. In FIG. 4, a heater power supply rod 70, a dual-purpose power supply rod 78, and two thermocouples 80 and 81 are representatively shown 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 an inner side of the conductor outlet 90 has, for example, A mounting base 92 made of stainless steel or the like is hermetically attached and fixed via a seal member 94 such as an O-ring.

And, on this mounting base 92, a fixing base 96 for fixing the column 63 is provided. The fixed base 96 is made of the same material as that of the support 63, that is, here, quartz, and communication holes 98 corresponding to the respective through holes 60 are formed. And the lower end part side of the support | pillar 63 is connected and fixed to the upper surface side of the fixing stand 96 by welding similar to the upper end part of the support | pillar 63. That is, the heat welding joint 63B is formed. In this case, as the above 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. Should be as wide as possible. Therefore, it is preferable to join the entire lower end surface of the column 63 to the upper surface of the fixed base 96.

A fixing member 100 made of, for example, stainless steel is provided around the periphery of the fixing base 96 to which the lower end portion of the column 63 is connected and fixed. The fixing member 100 is fixed to the mounting base 92 side by bolts 102.

Further, the mounting base 92 is formed with communication holes 104 corresponding to the respective communication holes 98 of the fixed base 96, and the functional 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 each communication hole 104, and the sealing performance of this portion is improved. I am doing so.

In addition, 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 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 periphery. 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.

Further, an inert gas passage 122 communicating with each communication hole 104 is formed in the mounting base 92 and the bottom 44 of the processing container 22 in contact with the mounting base 92, and is directed into each through hole 60 through which each functional rod 62 passes. Thus, an inert gas such as N ₂ can be supplied. 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-purpose power supply rod 78 is inserted and the through holes through which the two thermocouples 80 and 81 are inserted. The inert gas may be supplied through the inert gas path 122 into only one of the through holes 60.

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, and about 230 mm and 400 mm for a 200 mm (8 inch) wafer. In the case of 16 inches) 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.

Here, returning to FIG. 1, the thermocouples 80 and 81 are connected to a heater power supply control unit 134 having, for example, a computer or the like. 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 measured by the thermocouples 80, 81. Based on the set temperature, the inner zone heating element 68A and the outer zone heating element 68B can be individually controlled 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. In addition to electrostatically adsorbing W, high frequency power as a bias is applied 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 also be used, that is, there is no particular limitation.

In addition, a plurality of, for example, three pin insertion holes 150 penetrating in the vertical direction are formed in the mounting table 58 (only two are shown in FIG. 1). Each pin insertion hole 150 is provided with a push-up pin 152 that is inserted in a loosely-fitted state so as to be vertically movable. At the lower ends of these push-up pins 152, arc-shaped ceramic push-up rings 154 such as alumina (Al ₂ O ₃ ) are arranged, and the lower ends of the push-up pins 152 ride on the push-up rings 154. Yes. 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.

With this configuration, each push-up pin 152 can be projected and retracted upward from the upper end of each pin insertion hole 150 when the wafer W is transferred. In addition, an extendable bellows 162 is interposed in the penetrating portion of the retracting rod 158 provided at the bottom 44 of the processing container 22, and the retracting rod 158 moves up and down while maintaining the airtightness in the processing container 22. It can be done.

Here, as shown in FIGS. 4 and 5, the pin insertion hole 150 is formed along the length direction of the 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 bolts 170 in which the pin insertion holes 150 are formed in the bolt holes 174 and 176. Is inserted and tightened with a nut 178 to couple the mounting table main body 59 and the heat diffusion plate 61. These bolts 170 and nuts 178 are formed of a ceramic material such as aluminum nitride (AlN) or alumina (Al ₂ O ₃ ).

The entire operation of the processing apparatus 20, for example, control of the process pressure, temperature control of the mounting table 58, supply or stop of supply of the processing gas, and the like are performed by an apparatus control unit 180 formed of, for example, a computer. The device control unit 180 generally has a storage medium 182 that stores a computer program necessary for the above-described operation. The storage medium 182 includes, for example, a flexible disk, a CD (Compact や 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, an unprocessed semiconductor wafer W is held by a transfer arm (not shown) and is loaded into the processing container 22 through the gate valve 42 and the loading / unloading port 40 opened. The wafer W is transferred to the raised push-up pins 152, and then the push-up pins 152 are lowered to place the wafer W on the upper surface of the heat diffusion plate 61 of the placement table 58 supported by the support 63 of the placement table structure 54. Placed and supported. At this time, 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, the electrostatic chuck functions and the wafer W is attracted and held on the mounting table 58. Is done. 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 being controlled in flow rate, 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 by adjusting the valve opening degree of the pressure regulating valve 50, the atmosphere of the processing space S is changed. Maintained at a predetermined process pressure. At this time, the temperature of the wafer W is maintained at a predetermined process temperature. That is, by applying a voltage from the heater power supply control unit 134 to the inner zone heating element 68A and the outer zone heating element 68B constituting the heating means 64 of the mounting table 58, the heating means 64 (each zone heating element 68A, 68B). ) Is controlled as desired.

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 wafers (mounting table) temperatures in the inner peripheral zone and the outer peripheral zone are respectively measured by thermocouples 80 and 81 provided at the lower surface central portion and the peripheral portion of the heat diffusion plate 61, and based on these measured values. The heater power supply control unit 134 performs feedback temperature control for each zone. For this reason, the temperature of the wafer W can be constantly 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 about 700 ° C., for example.

Further, when plasma processing is performed, a high frequency power is applied between the shower head unit 24 as the upper electrode and the mounting table 58 as the lower electrode by driving the high frequency power supply 38. Thereby, plasma is generated in the processing space S and predetermined plasma processing can be performed. At this time, plasma ions can be attracted by applying high-frequency power from a high-frequency power source 148 for bias to the dual-purpose electrode 66 provided on the heat diffusion plate 61 of the mounting table 58.

Here, functions in the mounting table 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 to the outer peripheral zone heating element 68B via the heater power supply rods 74 and 76. Power is supplied.

Also, the temperature at the center of the mounting table 58 is transmitted to the heater power supply control unit 134 via the thermocouple 80 arranged so that the temperature measuring contact 80A is in contact with the center of the lower surface 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 81 </ b> A, and the measured value is transmitted to the heater power supply control unit 134. As described above, the power supplied to the inner peripheral zone heating element 68A and the outer peripheral zone heating element 68B is supplied based on the 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 function rods 62, are airtightly welded to the lower surface of the mounting table main body 59 of the mounting table 58. The thermocouples 80 and 81 are individually inserted into the plurality of through holes 60 formed in each of the two through holes 60 in common.

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 combined power supply rods 78 are inserted are inert through an inert gas passage 122. For example, N ₂ gas is supplied as a gas, 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 N ₂ gas is heated with the mounting table main body 59. It is also supplied to the joint surface with the diffusion plate 61. As a result, the inert gas is discharged radially from the periphery of the mounting table 58 through a slight gap between the joint surfaces. As a result, it is possible to prevent the deposition gas, the cleaning gas, and the like in the processing space S from entering the gap.

Further, it is possible to prevent corrosive gases such as a film forming gas and a cleaning gas from entering the inside through the gap. In addition, since the heater power supply rods 70 to 76 and the dual-purpose power supply rod 78 are covered with N ₂ gas, these power supply rods are corroded by corrosive gas or oxidized by oxidizing gas. , Can be prevented.

In addition, as described above, the inert gas leaks 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, so that the film forming gas or the like flows on the mounting table 58. Although it is prevented from entering the inside, each through hole 60 for purging with an inert gas may be sized so that each functional rod 62 can be inserted, so that the conventional support 4 (see FIG. 8) The volume is very small compared to Therefore, the amount of leaking 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 in-plane temperature of the wafer W is connected to the central portion of the lower surface of the mounting table 58. Unnecessary films that cause non-uniformity are not attached. As a result, the uniformity of the in-plane temperature 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 column 63, that is, an insulator made of quartz in this case. Abnormal discharge can be prevented.

In such a situation, for example, when a large vibration occurs due to an earthquake or the like, the connecting portion between the mounting table 58 and the column 63, which is a heavy object, is cracked or damaged, or the column 63 itself is cracked. Assess the possibility (risk) of the occurrence of

In the present embodiment, 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 are formed in the column, 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, the bonding area of the heat-welded joint 63A formed between the upper end surface of the column 63 and the lower surface of the mounting table 58 is sufficiently large, and in particular, the bonding strength between the mounting table 58 and the column 63 is increased. Can be improved.

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, as described above, since the strength of the mounting table structure 54 against vibration can be improved, there is no problem in moving or transporting the processing apparatus with the mounting table structure 54 incorporated.

As described above, according to the present embodiment, 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 that can be evacuated, the processing target is A mounting table 58 made of a dielectric is provided with at least a heating means 64 for mounting, and is provided upright from the bottom side of the processing container 22 to support the mounting table. And a support column 63 made of a dielectric material having a plurality of through holes 60 formed along the length direction and connected to the lower surface, thereby providing an area of a connection portion between the mounting table 58 and the support column 63. Therefore, as a result, it is possible to improve the strength of the connecting portion between the mounting table 58 and the column 63 and further the strength of the column itself. Therefore, there is no problem in moving or transporting the processing apparatus with the mounting table structure incorporated, and 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 such a first modified embodiment of the present invention. 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 the 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 a material of the connecting member 202, a ceramic material such as aluminum nitride (AlN) or a metal with a low possibility 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. Accordingly, it is possible to prevent the deposition gas, the cleaning gas, or the like from entering the gap or the through-hole 60, and it is possible to prevent an unnecessary film from adhering to this portion or corrosion of each functional rod 62. .

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 both are welded, but the strength of the column 63 itself is maintained high as in the previous embodiment. And the same effects as those of the previous embodiment can be exhibited.

<Second Modification>
Next, a second modified embodiment of the present invention will be described. In the embodiment shown in FIG. 4, the upper end and the lower end 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 recessed. You may make it form a shaving part. FIG. 7 is a partial enlarged view showing a portion of a column of such a second modified example of the present invention. 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, in this second modified embodiment, the shaving portions 206A and 206B formed by shaving the upper and lower ends of the support 63 into a concave shape while leaving the peripheral portions in a ring shape. Are provided respectively. Note that only one of the two cutting portions 206A and 206B may be provided. The thickness L1 of the peripheral portion of the column 63 in the portions of the shaving portions 206A and 206B is, for example, about 2 to 5 mm, which corresponds to about 2 to 9% of the thickness of the mounting table main body 59.

And the upper end part of the support | pillar 63 is welded to the lower surface of the mounting base main body 59, and the support | pillar 63 and the mounting base 58 are joined. Further, the support 63 and the fixing table 96 are joined by welding the lower end of the support 63 to the upper surface of the fixing table 96. When performing these thermal weldings, it is necessary to heat both base materials to be welded to a high temperature. However, as described above, since the recesses 206A and 206B are formed, the thickness is reduced. Since the ring-shaped peripheral portion can be heated quickly in the same manner as the central portion of the lower surface of the mounting table main body 59 to be welded or the upper surface of the fixing table 96, both can be easily and quickly joined.

On the other hand, 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 bonding area between the mounting table main body 59 and the fixing table 96 is sufficiently large. Therefore, the bonding strength between the mounting table main body 59 and the fixing table 96 can be maintained high. That is, also in the case of the second modified example, 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 thereto, and the material of the support 63 is opaque by including, for example, bubbles. It is possible to use non-transparent quartz or opaque ceramic material such as aluminum nitride (AlN). According to these, 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, and to prevent thermal deterioration of the seal member 106. 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 when the mounting table main body 59 is formed of quartz or the like, the quartz is an etching gas. There is a risk of corrosion. Therefore, a protective cover made of a material excellent in corrosion resistance against the etching gas, for example, a ceramic material such as aluminum nitride (AlN) or alumina (Al ₂ O ₃ ) is provided on the side surface and the lower surface of the mounting table 58. It may be.

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 the two are integrally joined by an adhesive or welding.

In each of the above embodiments, the case where aluminum nitride (AlN) is mainly used as a ceramic material has been described as an example. However, the present invention is not limited to this, and alumina (Al ₂ O ₃ ), silicon carbide (SiC), etc. Other ceramic materials 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, in the case where opaque quartz containing bubbles or the like is used as the material of the mounting table 58, the above-mentioned soaking plate is not necessary. Here, the case where N ₂ gas is mainly used as an inert gas has been described as an example, but the present invention is not limited to this, and a rare gas such as He or Ar may be used.

In each of the above-described embodiments, the dual-purpose electrode 66 is provided on the mounting table 58, and the DC voltage for the electrostatic chuck and the high-frequency power for the bias are applied thereto via the dual-purpose power supply rod 78. 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 points where 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.

Alternatively, a ground electrode having the same structure as that of the dual-purpose electrode 66 may be provided, and the lower end of the functional bar 62 connected to the ground electrode may be grounded and used as a conductive bar, thereby grounding the ground electrode. 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 each of the above embodiments, the processing apparatus using plasma has been described as an example. However, the present invention is not limited to this, and all processing apparatuses using a mounting table structure in which the heating unit 64 is embedded in the mounting table 58, for example, The present invention can also be applied to a film forming apparatus using plasma CVD using plasma, a film forming apparatus using thermal CVD not using plasma, an etching apparatus, a thermal diffusion apparatus, a diffusion apparatus, a reforming apparatus, and the like. 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.

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

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 processing container is erected from the bottom side, and the upper end is connected to the lower surface of the mounting table, and has a plurality of through holes 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. The mounting table is provided with a chuck electrode for an electrostatic chuck,
6. The mounting table structure according to claim 5, wherein the functional bar is a chuck feeding bar electrically connected to the chuck electrode. The mounting table is provided with a high-frequency electrode for applying high-frequency power,
6. The mounting table structure according to claim 5, wherein the functional bar is a high-frequency power feeding bar electrically connected to the high-frequency electrode. 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,
6. The mounting table structure according to claim 5, wherein the functional bar is a dual-purpose power feed rod that is electrically connected to the dual-purpose electrode. 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 means, 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, and The mounting table structure according to any one of claims 1 to 11, wherein 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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