JP2011187576A - Crack detector, processing equipment, and crack detecting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a crack detector which can rapidly and easily detect a crack such as a fissure or a crack of a thermal diffusion plate without lowering the productivity of a product. <P>SOLUTION: The crack detector detects a crack in mounting stand structure in which a mounting stand 58 having the thermal diffusion plate 61 for mounting a treated object W to be treated is erected from a bottom of a treatment container 22 through a column 60. The crack detector includes a vibration detecting means 202 provided outside the treatment container and a crack detecting means 204 detecting a crack vibration signal, which is a frequency signal generated in accordance with state of the crack of the thermal diffusion plate, from signals obtained by the vibration detecting means. Thus, the crack such as the fissure or the crack of the thermal diffusion plate is rapidly and easily detected without lowering the productivity of the product. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a processing apparatus for an object to be processed such as a semiconductor wafer, a crack detection apparatus and a crack detection method for detecting a crack in a mounting table structure used therefor.

  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, in the case of a film forming process, a film forming gas or a halogen gas is introduced into the processing container and heated. Film formation is performed by CVD (Chemical Vapor Deposition), plasma CVD, or the like.

  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 3).

  By the way, with respect to a mounting table structure for mounting a semiconductor wafer, it is generally necessary to provide heat resistance and corrosion resistance and prevent metal contamination such as metal contamination in a dielectric material such as quartz. A resistance heater is embedded as a heating element and integrally baked at a high temperature to form a mounting table, and quartz or the like is similarly baked in a separate process to form a support column. For example, 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.

  On the upper surface side of this mounting table, for example, a thin heat diffusion plate that is disk-shaped from a ceramic material such as AlN is provided, and a semiconductor wafer is directly mounted on this heat diffusion plate to perform a film forming process or the like. To do. When plasma processing is performed here, an electrode for forming a lower electrode is embedded in the thermal diffusion plate, and the lower electrode is grounded or a high-frequency voltage is applied depending on the processing mode.

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

  By the way, although the thermal diffusion plate is formed of a very thin and hard ceramic material having a thickness of about 5 mm, for example, cracks such as cracks may occur due to thermal expansion and contraction due to repeated use. When this crack occurs, the uniformity of the in-plane temperature of the semiconductor wafer placed thereon is adversely affected, particles or the like are generated, and further, the heater is adversely affected by corrosive gas entering the crack. Therefore, the quality confirmation wafer is processed periodically to confirm the film formation quality, or visual inspection or the like is performed to confirm the presence or absence of cracks.

  However, in the case of using the quality confirmation wafer in the inspection as described above, if the period for performing the periodic confirmation inspection is too long, a large number of defective wafers with reduced quality are produced during that period. There is a risk that. Therefore, it is conceivable to shorten the inspection period. In this case, however, not only the productivity of the product wafer is lowered, but also in this case, it is unavoidable that a defective product is generated.

  Further, in the case of visual inspection, for example, the inspection is performed from a viewing window provided on the side wall of the processing container. However, there is a problem that a crack may be overlooked at this time. In this case, as disclosed in Japanese Patent Application Laid-Open No. 2000-323260, a crack detection structure for a ceramic heater has been proposed, but this detects a break in the conductive pattern, and cracks in the ceramic part itself are detected. It does not detect and does not solve the above problems.

  The present invention has been devised to pay attention to the above problems and to effectively solve them. The present invention is a crack detection device, a processing device, and a crack detection method capable of quickly and easily detecting cracks such as cracks and cracks in a thermal diffusion plate without reducing product productivity.

  The invention according to claim 1 is a method for detecting a crack in a mounting table structure in which a mounting table having a heat diffusion plate for mounting a workpiece to be processed is provided upright from a bottom of a processing container by a column. In the detection device, vibration detection means provided outside the processing vessel and a crack vibration signal that is a signal of a frequency generated according to a cracking state of the heat diffusion plate is detected from signals obtained by the vibration detection means. And a crack detecting means.

  In this way, in the crack detection device for detecting a crack in the mounting table structure in which the mounting table having the heat diffusion plate for mounting the object to be processed is provided upright from the bottom of the processing container by the support column, A vibration detecting means is provided outside the processing vessel, and a crack detecting means for detecting a crack vibration signal, which is a frequency signal generated according to the cracking mode of the thermal diffusion plate, is provided from the signal obtained by the vibration detecting means. As a result, it is possible to quickly and easily detect cracks such as cracks and cracks in the heat diffusion plate without reducing the productivity of the product.

  According to a thirteenth aspect of the present invention, there is provided a heat diffusion plate on which an object to be processed is placed with electrodes embedded therein, and a mounting table that supports the heat diffusion plate and has a heater embedded therein as a heating means. In a crack detection device for detecting a crack in a mounting table structure in which a mounting table having a main body is erected from a bottom portion of the processing vessel by a support column, a signal voltage is applied to a stray capacitance formed between the electrode and the heater. A signal voltage source for applying a voltage, a characteristic detection unit for detecting an electrical characteristic due to the stray capacitance, and a detection result of the characteristic detection unit and a predetermined reference value are compared to determine the presence or absence of a crack A crack detection device characterized by comprising a crack determination unit.

  In this way, a mounting having a heat diffusion plate on which an object to be processed is placed with electrodes embedded therein, and a mounting table body that supports the heat diffusion plate and in which a heater is embedded as a heating means. In a crack detection device for detecting a crack in a mounting table structure in which a mounting table is erected from a bottom of the processing vessel by a support column, a signal voltage source that applies a signal voltage to a stray capacitance formed between an electrode and a heater is provided. Provided is a characteristic detection unit that detects electrical characteristics caused by stray capacitance, and a crack determination unit that determines the presence or absence of a crack by comparing the detection result of the characteristic detection unit with a predetermined reference value. Therefore, cracks such as cracks and cracks in the heat diffusion plate can be detected quickly and easily without reducing the productivity of the product.

  According to the nineteenth aspect of the present invention, there is provided a processing container capable of being evacuated, a gas supply means for supplying a necessary gas into the processing container, and a mounting for mounting an object to be processed in the processing container. A processing apparatus comprising: a mounting structure; and the crack detection device according to any one of claims 1 to 18.

  According to a twenty-first aspect of the present invention, there is provided a detection for detecting a crack in a mounting table structure in which a mounting table having a heat diffusion plate for mounting a workpiece to be processed is provided upright from a bottom of a processing container by a support column. In the method, the vibration detecting step for detecting the vibration generated in the mounting table structure, and the heat based on information predetermined in accordance with a cracking state of the heat diffusion plate from the vibration obtained in the vibration detecting step. And a crack detection step of detecting vibration generated when the diffusion plate is cracked as a crack vibration signal.

  According to a twenty-third aspect of the present invention, there is provided a thermal diffusion plate on which an object to be processed is placed with electrodes embedded therein, and a mounting table that supports the thermal diffusion plate and has a heater embedded therein as a heating means. In a crack detection method for detecting a crack in a mounting table structure in which a mounting table having a main body is erected from a bottom portion of the processing vessel by a support column, a signal voltage is applied to a stray capacitance formed between the electrode and the heater. A signal voltage applying step for blocking, a characteristic detecting step for detecting an electric characteristic due to the stray capacitance when the signal voltage is applied or cut off, and an electric characteristic obtained in the characteristic detecting step It is a crack detection method characterized by having a crack judgment process of judging the presence or absence of a crack of the thermal diffusion plate by comparing with a predetermined reference value.

According to the crack detection device, the processing device, and the crack detection method of the present invention, the following excellent operational effects can be exhibited.
According to the present invention, it is possible to quickly and easily detect cracks such as cracks and cracks in the thermal diffusion plate without reducing the productivity of the product.

It is a section lineblock diagram showing a processing device which has a crack detection device concerning the present invention. It is a top view which shows an example of the heating means provided in the mounting base of a mounting base structure. It is arrow sectional drawing along the AA in FIG. It is a partial expanded sectional view which shows the crack detection apparatus attached to the mounting base structure in FIG. It is an enlarged block diagram which shows a crack detection apparatus. It is a figure which shows an example of the aspect of a crack of a thermal-diffusion board. It is a flowchart which shows each process of 1st Example of this invention method. It is a block block diagram which shows 2nd Example of the crack detection apparatus of this invention. It is a figure for demonstrating the impedance change when a thin film is formed in the clearance gap between the cracks which entered the thermal diffusion board. It is a figure which shows an example of the electric potential of the stray capacity when applying a signal voltage between an electrode and a heater. It is a flowchart which shows each process of 2nd Example of this invention method. It is a figure which shows an example of the change of the frequency characteristic of an impedance.

  Hereinafter, a preferred embodiment of a crack detection device, a processing device, and a crack detection method according to the present invention will be described in detail with reference to the accompanying drawings. 1 is a cross-sectional configuration diagram showing a processing apparatus having a crack detection apparatus according to the present invention, FIG. 2 is a plan view showing an example of a heating means provided on a mounting table of the mounting table structure, and FIG. 3 is an A- in FIG. FIG. 4 is a partially enlarged sectional view showing a crack detecting device attached to the mounting table structure in FIG. 1, FIG. 5 is an enlarged block diagram showing the crack detecting device, and FIG. 6 is a thermal diffusion. It is a figure which shows an example of the aspect of a crack of a board. 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 an aluminum processing container 22 having, for example, a substantially circular cross section. 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. 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. A plasma generating means 39 is formed by the shower head portion 24, the matching circuit 36, the high frequency power source 38 and the lower electrode which will be described later.

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

  A mounting table structure 54 is provided at the bottom 44 in the processing container 22 so as to stand up. Specifically, the mounting table structure 54 is connected to the mounting table 58 for mounting the object to be processed on the upper surface and the mounting table 58, and the upper mounting table 58 is connected to the bottom of the processing container 22. It is mainly comprised by the several thin tubular support | pillar 60 for standing up and supporting from, and the functional rod body 62 penetrated in these support | pillars 60. FIG.

  In FIG. 1, in order to facilitate understanding of the invention, the columns 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 an electrode 66 forming a lower electrode is provided in the heat diffusion plate 61 so as to be embedded. 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 heater 68 made of, for example, a carbon wire heater or a molybdenum wire heater. The heater 68 has a predetermined pattern shape over substantially the entire surface of the mounting table 58. Is provided. Here, the heater 68 is electrically separated into two zones of 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 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 electrode 66 is provided in the opaque heat diffusion plate 61 as described above. The electrode 66 is made of, for example, a conductor wire formed in a mesh shape, and the connection terminal of the electrode 66 is located at the center of the mounting table 58. Here, the electrode 66 is grounded as described later. In some cases, a DC voltage for electrostatic chucking or high-frequency power for biasing is applied to this electrode.

  Then, the power supply rod for supplying power to the heater 68, the conductive rod of the electrode 66, and the functional rod 62 as a thermocouple for measuring temperature are provided, and each of these functional rods 62 is thin. It will be inserted into the column 60.

  First, as shown in FIGS. 1 and 3, here, six support columns 60 are provided in a central portion of the mounting table 58. Each support column 60 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. Each support column 60 is air-tightly bonded to the lower surface of the mounting table main body 59, for example, by heat welding. Are joined together. The function bar 62 is inserted into each column 60. In FIG. 4, as described above, some of the support columns 60 are shown as representatives, and in one of the support columns 60, two function rod bodies 62 are accommodated as described later.

  That is, with respect to the inner peripheral zone heating element 68A, the power feeding rods 70 and 72 for the heater are individually inserted through the support column 60 as the two function rods 62 for power-in and power-out. 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, power supply rods 74 and 76 for heaters are individually inserted into the support column 60 as two functional rods 62 for power-in and power-out with respect to the outer peripheral zone heating element 68B. The upper ends of the power feeding rods 74 and 76 are electrically connected to the outer peripheral zone heating element 68B (see FIG. 1). The power supply rods 70 to 76 for the heaters are made of, for example, a nickel alloy.

  Further, a conductive rod 78 is inserted into the support column 60 as a functional rod 62 with respect to the electrode 66, and the upper end of the conductive rod 78 is electrically connected to the electrode 66 via a connection terminal 78A (see FIG. 4). Has been. The conductive 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 as function rods 62 into the remaining one column 60, and each of the thermocouples 80 and 81 is inserted. The temperature measuring contacts 80A and 81A are positioned on the lower surfaces of the inner and outer peripheral zones of the thermal diffusion plate 61, respectively, and 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 FIG. 4, the power supply rod 70 for heater, the conductive rod 78 and the 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 for example, stainless steel is formed inside the conductor outlet 90. A column fixing base 92 made of steel or the like is hermetically attached and fixed via a seal member 94 such as an O-ring.

  A tube fixing table 96 for fixing each column 60 is provided on the column fixing table 92. The tube fixing base 96 is made of the same material as each of the columns 60, that is, here, quartz, and a through hole is formed corresponding to each column 60. And the lower end part side of each said support | pillar 60 is connected and fixed to the upper surface side of the said tube fixing stand 96 by heat welding etc. As shown in FIG.

In this case, each support column 60 through which the power supply rods 70, 72, 74, 76 for heaters are inserted is passed through a through-hole formed in the tube fixing base 96, and its lower end is sealed. An inert gas such as N ₂ or Ar is enclosed in a reduced pressure atmosphere. 4 shows only one heater power supply rod 70, the other heater power supply rods 72 to 76 have the same configuration.

  As described above, a fixing member 100 made of, for example, stainless steel is provided around the pipe fixing base 96 that fixes the lower end portion of each column 60 so as to surround the fixing base 100. It is fixed to the column fixing base 92 side. Thereby, the lower end part of each support | pillar 60 is firmly fixed to the support | pillar fixing stand 92 side.

  In addition, a similar through hole is formed in the column fixing base 92 so as to correspond to each through hole of the tube fixing base 96, and the functional rod body 62 is inserted downward. A sealing member 106 such as an O-ring is provided on the joint surface between the lower surface of the tube fixing table 96 and the upper surface of the column fixing table 92 so as to surround each of the through holes. I try to increase the sex.

  A sealing plate 112 is attached by bolts 116 to the lower ends of the through holes through which the conductive rod 78 and the two thermocouples 80 and 81 are inserted through seal members 108 made of O-rings or the like. It is fixed. The conductive bars 78 and the thermocouples 80 and 81 are provided so as to penetrate the sealing plate 112 in an airtight manner. These sealing plates 112 are made of, for example, stainless steel, and an insulating member 120 is provided around the conductive rods 78 so as to correspond to the through portions of the conductive rods 78 with respect to the sealing plates 112.

In addition, an inert gas path 122 is formed in the column fixing base 92 and the bottom 44 of the processing vessel 22 in contact with the column to communicate with a through-hole through which the conductive rod 78 is inserted. An inert gas such as N ₂ can be supplied toward the support column 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, 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. Each strut 60 has a diameter of about 8 to 16 mm, and each functional rod 62 has a diameter of about 4 to 6 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 thermocouple 80 is connected. , 81 based on the temperature measured at 81, the inner zone heating element 68A and the outer zone heating element 68B are individually controlled to maintain a desired temperature. The wiring 144 connected to the conductive rod 78 is grounded, and therefore the electrode 66 constituting the lower electrode is a ground electrode.

  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 push-out ring 154 has a retractable rod provided through the bottom 44 of the processing vessel 22. 158, 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 bottom 44 of the processing container 22 of the retracting rod 158 so that the retracting rod 158 can move up and down while maintaining the airtightness in the processing container 22. It has become.

  Here, as shown in FIG. 4, the pin insertion hole 150 is formed along the length direction of the bolt 170 which is a fastener for connecting the mounting table main body 59 and the heat diffusion plate 61. A through 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.

  And the crack detection apparatus 200 which concerns on this invention is provided in the processing apparatus comprised in this way, The crack of the thermal diffusion plate 61 which is a part of the mounting base structure 54 is detected. 4 and 5 show a first embodiment of the crack detection device 200. FIG.

  When cracks such as cracks and cracks enter the thermal diffusion plate 61, slight vibrations are generated, and here, the occurrence of cracks is detected by detecting the vibrations. Specifically, in the first embodiment of the crack detection device 200, the vibration detection means 202 provided outside the processing container 22 and a crack for detecting a crack vibration signal from the signal obtained from the vibration detection means 202. It mainly comprises a detection means 204, and also has a crack detection device control unit 206 made of, for example, a computer for controlling the entire device.

  Specifically, as the vibration detection means 202, for example, a mechanical electrical conversion such as a piezoelectric element or an acceleration sensor can be used, and the vibration detection means 202 is provided outside the processing container 22 as described above. . Here, the vibration detection means 202 is provided on the lower side of the support column 60 where the vibration when the thermal diffusion plate 61 is broken is most easily transmitted, and at the portion where the lower end of the support column 60 is fixed. Specifically, the vibration detecting means 202 is directly attached to the lower end portion of the conductive rod 78 connected to the electrode 66 and located outside the processing container 22, and is attached to the heat diffusion plate 61. The vibration when a crack occurs is captured with high accuracy. Since the upper end of the conductive rod 78 is directly connected to the heat diffusion plate 61 via the connection terminal 78A, the conductive rod 78 is generated at this time when the heat diffusion plate 61 is cracked. Fine vibrations are transmitted most effectively. Therefore, by attaching the vibration detecting means 202 to such a conductive rod 78, vibration can be captured effectively.

  The crack detecting means 204 has a Fourier transform frequency decomposing unit 207 for frequency-decomposing the vibration detected by the vibration detecting unit 202 by Fourier transform (FFT), and a digital filter unit 208 for selecting the frequency-decomposed waveform. is doing. The digital filter unit 208 allows only vibrations in a plurality of specific frequency bands determined according to the shape and cracking state of the heat diffusion plate 61 to pass. Here, two filters 208A and 208B corresponding to the specific frequency are provided. The number of filters is not limited to two, and a larger number of filters may be provided. Although not shown, an amplifier and an A / D converter are set before the Fourier transform frequency decomposition unit 207. Each frequency band of the filters 208A and 208B is controlled by the filter control unit 210.

  It is known that the heat diffusion plate 61 has a plurality of natural frequencies. When this cracks, it is expected that the frequencies generated will also be a plurality of frequencies. Further, when the heat diffusion plate 61 is cracked, there are various empirically presents, and FIG. 6 shows a typical example of the crack. As shown in FIG. 6, the thermal diffusion plate 61 is often cracked starting from a bolt hole 176 formed at the peripheral edge, and the thermal diffusion plate 61 of FIG. A case where a crack 212A enters through 176 and the whole is divided into two parts is shown.

  In addition, the heat diffusion plate 61 in FIG. 6B shows a case where a crack 212B is formed between the two bolt holes 176. Comparing the cases of cracking in FIGS. 6A and 6B, the former has a lower frequency and a larger amplitude than the latter. Actually, there may be a crack that does not pass through the bolt hole 176, and the description thereof is omitted here.

  And the frequency band of the said filters 208A-208B is set corresponding to the vibration frequency which is the vibration information generated according to each crack aspect of the said FIG. 6 (A)-FIG. 6 (B). For example, the 1st filter 208A respond | corresponds to the crack aspect of FIG. 6 (A), and has set the frequency band in the range of 400-600 Hz, for example. Moreover, the 2nd filter 208B respond | corresponds to the crack aspect of FIG. 6 (B), and has set the frequency band in the range of 1300-1400 Hz, for example.

  Each vibration frequency when the above-described cracking state of the heat diffusing plate 61 is generated is obtained empirically in advance, and this information is determined in advance and stored in the crack detection device controller 206. . Based on this information, the digital filter sections 208A to 208B are controlled via the filter control section 210.

  Here, in order to facilitate the understanding of the invention, as described above, two types of representative cracking modes are shown as an example, but actually, there are more cracking modes and corresponding to these. A number of filters and the like are provided.

  A plurality of, that is, two comparators 214A to 214B are provided in a subsequent stage of the crack detection means 204 in correspondence with the filters 208A to 208B. The threshold value is compared with a predetermined threshold value here. When the above signal is received, it is directed to the crack detection device controller and output as a crack vibration signal. The threshold values of the comparators 214A to 214B are controlled by the comparator control unit 211. FIG. 5 also shows an example of the waveform in each of the above-described components, and schematically shows the function of each component.

  The crack detection device control unit 206 is connected to an alarm generation unit 216 for issuing an alarm to the operator. The alarm generation unit 216 includes, for example, an alarm lamp 216A that lights to indicate that a crack has occurred, and a display 216B that indicates the occurrence of the crack with a message. At the same time, a signal indicating that a crack has occurred is also transmitted to the apparatus control unit 180, and after processing the wafer currently being processed, processing of the next wafer is stopped. .

  Next, the operation of the processing apparatus 20 using the plasma configured as described above will be described with reference to FIG. FIG. 7 is a flowchart showing each step of the first embodiment of the method of the present invention. 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 each column 60 of the mounting table structure 54. Support.

  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 unit 24 as the upper electrode and the mounting table 58 as the lower electrode (ground electrode), and plasma is generated in the processing space S. And a predetermined plasma treatment is performed. Thereby, for example, a metal film such as a Ti film or a metal nitride film such as a TiN film is formed.

  Here, the function of the mounting table structure 54 will be described. First, electric power is supplied to the inner zone heating element 68A of the heating means via heater power supply rods 70 and 72, which are functional rods 62, and to the outer zone heating element 68B, heater power supply rods 74 and 76. Power is supplied via 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. Further, the thermocouple 81 arranged on the outer periphery measures the temperature of the outer peripheral zone, 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.

  The power supply rods 70, 72, 74, 76, the thermocouples 80, 81, and the conductive rod 78 for the heaters, which are the functional rods 62, are airtightly heated on the lower surface of the mounting table main body 59 of the mounting table 58. The welded thin columns 60 are individually inserted (thermocouples 80 and 81 are one column). At the same time, these support columns 60 stand and support the mounting table 58 itself.

Further, the inside of each support column 60 through which the power supply rods 70 to 76 for heaters are inserted is sealed in a depressurized state with an inert gas, for example, N ₂ gas, and oxidation of the power supply rods 70 to 76 for heaters is prevented. Has been. Further, for example, N ₂ gas is supplied as an inert gas into the support column 60 through which the conductive rod 78 is inserted through the inert gas path 122, and this N ₂ gas is supplied to the upper surface of the mounting table main body 59. It is also supplied into the support column 60 through which the thermocouples 80 and 81 are inserted through the formed groove 88 (see FIG. 4), and further supplied to the joint surface between the mounting table main body 59 and the heat diffusion plate 61. Therefore, since the inert gas is released radially from the peripheral portion of the mounting table 58 through a slight gap in the joining surface, it is possible to prevent the deposition gas or the like in the processing space S from entering the inside. it can.

  In such a situation, when the process on the wafer W is repeatedly performed, the temperature of the mounting table 58 is repeatedly raised and lowered. As a result, cracks such as cracks and cracks may occur in the heat diffusion plate 61 due to repeated thermal expansion and contraction of the thin heat diffusion plate 61 made of, for example, aluminum nitride. And the presence or absence of the generation | occurrence | production of this crack is detected by the crack detection apparatus 200 based on this invention. That is, when a crack occurs in the heat diffusing plate 61, minute vibrations with different frequencies are generated according to the cracking state as shown in FIG. 6 when the crack occurs.

  The vibration generated along with the crack is transmitted to the entire mounting table structure 54, and particularly strongly transmitted to the conductive rod 78 directly connected to the heat diffusion plate 61. The specific vibration transmitted to the conductive rod 78 is detected by the vibration detecting means 202 of the crack detecting device 200 attached to the lower end of the conductive rod 78 (S1 in FIG. 7). Actually, in the processing apparatus 20, various vibrations such as vibrations associated with the transfer of the wafer W, vibrations associated with the control of various valves and vibrations associated with the driving of the pump are generated along with the vibrations generated as a result of the cracks. It is detected by the vibration detection means 202. The vibration obtained by the vibration detection means 202 is converted into an electric signal and transmitted to the crack detection means 204 as a crack vibration signal.

  In the Fourier transform frequency decomposition unit 207 of the crack detection means 204, the crack vibration signal is subjected to frequency decomposition by Fourier transform and output to the digital filter unit 208 at the subsequent stage. In the digital filter unit 208, as described above, a plurality of filters 208A to 208B corresponding to the natural frequencies generated according to the cracking mode are provided. Therefore, only the vibration signal suitable for the frequency band set for each of the filters 208A to 208B passes through the digital filter unit 208 and is transmitted to the subsequent stage. As a result, only the vibration signal corresponding to the cracking state of the thermal diffusion plate 61 is transmitted to the comparison unit 214 side in the subsequent stage (S2 in FIG. 7).

  Since the vibration signal transmitted to the comparison unit 214 may include a very weak signal as a noise component even in the vibration component of the frequency band that has passed through the digital filter unit 208 in the previous stage, the comparators 214A to 214A provided here are included. A weak signal component equal to or lower than a preset threshold is blocked by 214B. Therefore, the comparison unit 214 outputs a signal having a specific frequency corresponding to the cracking mode of the heat diffusion plate 61 toward the crack detection device control unit 206 as a crack vibration signal. For example, when a crack 212 </ b> A as shown in FIG. 6A has occurred, a frequency signal generated at this time is output to the crack detection device controller 206 as a crack vibration signal.

  Upon receiving this crack vibration signal, the crack detection device control unit 206 notifies the operator to that effect by turning on the alarm lamp 216A of the alarm generation unit 216, and a crack in a specific crack mode has occurred on the display 216B. And inform the operator to that effect. The fact that the crack has occurred is also transmitted to the apparatus control unit 180 that performs the entire operation of the processing apparatus 20, and performs a predetermined control operation. For example, after the processing of the wafer W currently being processed is completed, control is performed so that the processing of the wafer W is stopped next.

  Thus, when a crack occurs in the thermal diffusion plate 61 during processing, the occurrence of the crack can be detected quickly and easily in real time. Therefore, even if a crack is generated in the thermal diffusion plate 61, it is possible to prevent the defective product wafer from being generated by suppressing the film forming process without recognizing the crack, thereby preventing the product yield from being lowered. be able to. In addition, it is possible not only to suppress the number of times of processing a quality confirmation wafer, which has been conventionally performed, but also to eliminate the quality confirmation wafer processing itself.

  In the above-described embodiment, a plurality of filters 208A to 208B are provided in the digital filter unit 208 of the crack detection means 204. However, the present invention is not limited to this. A plurality of specific frequency bands may be scanned by the filter control unit 210 at high speed.

  Moreover, in the said Example, although the vibration detection means 202 was attached to the lower end part of the electrically-conductive rod 78, it is not limited to this. For example, as a part where crack vibration of the heat diffusing plate 61 is transmitted, the lower end portion of the support rod base 92 shown at point P1 shown in FIG. 4 and the power supply rod 70 (72 to 76) shown at point P2 and the thermocouple 80 shown at point P3 ( 81) or the vibration detecting means 202 may be attached to the bottom 44 of the processing container 22 indicated by the point P4. Furthermore, the vibration detection means 202 may be provided inside the support column 60. Further, here, the mounting table 58 in which the electrode 66 is embedded in the heat diffusion plate 61 has been described as an example, but the present invention can also be applied to the mounting table 58 having a heat diffusion plate in which the electrode 66 is not provided.

  Thus, according to the present invention, a mounting table structure in which the mounting table 58 having the heat diffusion plate 61 for mounting the workpiece W to be processed is provided upright from the bottom of the processing container 22 by the support column. In the crack detection device for detecting cracks in the process, a vibration detection unit 202 is provided outside the processing container 22, and a signal of a frequency generated according to a cracking mode of the thermal diffusion plate 61 from signals obtained by the vibration detection unit 202 is used. Since the crack detecting means 204 for detecting a certain crack vibration signal is provided, cracks such as cracks and cracks in the heat diffusion plate 61 can be detected quickly and easily without reducing the productivity of the product.

<Second embodiment>
Next, a second embodiment of the crack detection apparatus 200 of the present invention will be described. In the first embodiment, the inherent vibration generated when the thermal diffusion plate 61 is broken is detected. However, the present invention is not limited to this, and a thin film is deposited in the gap generated when the thermal diffusion plate 61 is broken. The crack of the thermal diffusion plate 61 may be detected by detecting a change in stray capacitance or impedance caused by the above.

  FIG. 8 is a block diagram showing such a second embodiment of the crack detection apparatus 200 of the present invention, and FIG. 9 is a diagram for explaining the impedance change when a thin film is formed in the crack gap in the thermal diffusion plate. FIG. 10 is a diagram showing an example of the potential of the stray capacitance when a signal voltage is applied between the electrode and the heater, FIG. 11 is a flowchart showing each step of the second embodiment of the method of the present invention, and FIG. FIG. 5 is a diagram illustrating an example of a change in frequency characteristics of impedance. The processing apparatus used here is configured in the same manner as described with reference to FIGS. 1 to 4, and FIG. 8 schematically shows only the part necessary for the description of the mounting table 58. In FIG. 8, the same components as those described above are denoted by the same reference numerals.

  As shown in FIG. 8, in the second embodiment of the crack detection device 200, an electrode 66 provided on the heat diffusion plate 61 of the mounting table 58 and a heater 68 which is a heating means 64 provided on the mounting table main body 59. A signal voltage source 218 that applies a signal voltage to the stray capacitance formed therebetween, a characteristic detector 220 that detects electrical characteristics due to the stray capacitance, and a detection result in the characteristic detector 220 are predetermined. It is mainly comprised by the crack judgment part 222 which judges the presence or absence of a crack by comparing with the reference value which exists. In order to control the operation of the entire apparatus, a crack detection apparatus control unit 224 made of, for example, a computer is provided. Further, the same alarm generation unit 216 as that described in the first embodiment is connected to the crack detection device control unit 224.

  Specifically, the lead wire 226 is drawn from the wiring 144 connected to the conductive rod 78 of the electrode 66 provided on the heat diffusion plate 61. In addition, a lead wire 228 is drawn from the wiring 140 connected to the heater power supply rod 74 for the outer peripheral zone among the power supply rods for the heater. Note that the lead wire 228 may be drawn from the wiring 142 connected to the power supply rod 76 for the other heater. As described above, the reason why the heater feeding rods 74 and 76 for the outer peripheral zone are used is that cracks are likely to occur in the peripheral portion of the heat diffusion plate 61 in which the bolt holes 176 (see FIG. 4) are formed. Because.

  The signal voltage source 218 is connected to one lead line, for example, the lead line 228. As this signal voltage, for example, a pulse wave having a constant period can be used. Here, since the electrode 66 and the heater 68 are disposed with a dielectric material constituting the heat diffusion plate 61 and the mounting table main body 59 interposed therebetween, stray capacitance is generated between the electrodes 66 and the heater 68. The charge is accumulated by charging the stray capacitance.

  The characteristic detector 220 has a capacitance measuring resistor 220A, and the lead lines 226 and 228 are connected to the capacitance measuring resistor 220A. Thus, the electrical characteristics are detected based on the voltage applied to the capacitance measuring resistor 220A when the signal voltage is applied to the stray capacitance and the current flowing therethrough. The electrical characteristics correspond to the size of the stray capacitance, the ultimate potential at the time of applying the signal voltage, and the time constant at the time of charge / discharge accompanying the application or interruption of the signal voltage.

  The crack determination unit 222 compares the detection result obtained by the characteristic detection unit 220 with a reference value set in advance here. As the reference value, the electrical characteristics as described above when the film forming process is performed in a state where the thermal diffusion plate 61 is not cracked are used. The electrical characteristics are obtained in advance, and are stored in the crack determination unit 222 and the crack detection device control unit 224.

  Further, when a signal voltage is applied between the electrode 66 and the heater 68, it is necessary to temporarily bring the electrode 66 and the heater 68 into an electrically floating state, and switching for this purpose. It has the switch means 230 which performs. Specifically, the switch means 230 includes an open / close switch 230A provided in the middle of the wiring 144 of the conductive rod 78, and an open / close switch provided in the middle of the wires 140 and 142 of the heater power supply rods 74 and 76. 230B and 230C, and open / close switches 230D and 230E provided in the middle of both lead lines 226 and 228, and the opening / closing is controlled by the crack detection device controller 224.

  The three switches 230A to 230C and the two switches 230D and 230E are opened and closed so as to be opposite to each other. For example, when the switches 230D and 230E are closed to check for cracks, the other three switches 230A to 230C On the contrary, when the crack is not inspected, the switches 230D and 230E are opened, and the other three switches 230A to 230C are closed on the contrary.

  Next, the operation of the second embodiment of the crack detection apparatus will be described with reference to FIG. FIG. 11 is a flowchart showing each process of the second embodiment of the method of the present invention. Here, the case where the presence or absence of a crack is determined using the magnitude of the stray capacitance will be described as an example of the electrical characteristics.

  First, the film forming process on the semiconductor wafer W is performed in the same manner as described above with reference to the first embodiment. When the film forming process is repeatedly performed in a state where there is no crack or the like in the heat diffusion plate 61, an unnecessary thin film 232 is deposited little by little on the upper surface or side surface of the mounting table 58 as shown in FIG. is there. However, as shown in FIG. 9B, when the film forming process is repeated with the thermal diffusion plate 61 cracked, such as a crack 212, the film forming gas enters the inside through a slight gap in the crack 212. An unnecessary thin film 234 is deposited along the interface portion between the heat diffusion plate 61 and the mounting table main body 59 and the gap between the cracks 212. This unnecessary thin film 234 acts to change the stray capacitance and impedance in this portion. For this reason, this change is measured by the signal voltage from the signal voltage source 218.

  In FIG. 9, the right diagram shows an equivalent circuit of the left diagram. In FIG. 9A, the existing stray capacitance C1 and resistor R1 are shown. On the other hand, when the heat diffusion plate 61 is cracked and a metal film such as a Ti film or a TiN film or a metal-containing film is deposited as an unnecessary thin film 234, the equivalent circuit changes in parallel with the stray capacitance C1. Thus, the stray capacitance C2, the resistance R2, and the inductance L1 are connected. The values of “C1” and “R1” are stored in advance in the crack detection device controller 224 and used as reference values.

  Then, a pulsed signal voltage having a cycle of “T”, a pulse width of “T / 2”, and a pulse height of “E” as shown in FIG. When applied between the two, a potential as shown in FIG. 10B is generated in the capacitance measuring resistor 220A due to the stray capacitances C1 and C2.

  In this case, in the case of a normal heat diffusion plate 61 in which the heat diffusion plate 61 is not cracked (see FIG. 9A), the peak voltage during charging is “Ea”, and time “ta” is required. To zero potential. On the other hand, if the thermal diffusion plate 61 is cracked and an unnecessary thin film 234 is deposited on the crack 212 or the interface to form an abnormal thermal diffusion plate 61 (see FIG. 9B), charging is performed. The peak voltage at that time is “Eb”, which is lower than the above “Ea”, and takes a time “tb” shorter than the time “ta”, and becomes zero potential. Further, the direction of the potential is reversed at the time of discharging, and the same state as described above is obtained. When the electrostatic capacity (Q = CV) obtained at this time reaches a predetermined level, it is determined that a crack has occurred.

  Next, this detection operation will be specifically described. First, the crack detection device 200 controls the switch means 230 prior to the start of the detection operation by the crack detection device controller 224, and both the open / close switches 230B and 230C of the wires 140 and 142 and the open / close switch 230A of the wire 144 are connected. In the open state, the heater 68B for the outer peripheral zone and the electrode 66 in the heat diffusion plate 61 are both brought into an electrically floating state. Then, the open / close switches 230D and 230E provided on the lead lines 226 and 228 are both closed. Then, the signal voltage source 218 is driven to apply a pulsed signal voltage (see FIG. 10A) to the stray capacitance formed between the electrode 66 and the heater 68 to cut off the signal voltage. A process is performed (S11).

  Changes in current and voltage at this time are monitored by detecting the voltage of the capacitance measuring resistor 220A and the current flowing therethrough in the characteristic detector 220 (see FIG. 10), and the electrical characteristics resulting from the stray capacitance. Is detected (S12). Here, as described above, the characteristics of the graph shown in FIG. 10B are obtained. From the voltage and current measured at this time, the magnitude of the stray capacitance, the reached voltage when the signal voltage is applied, and the signal voltage The time constant at the time of applying or shutting off is obtained. Here, for example, the size of the stray capacitance is obtained.

  Then, the crack determination unit 222 compares the magnitude of the stray capacitance, which is the electrical characteristic obtained by the characteristic detection unit 220, with a reference value (the value shown in FIG. 9A), and this difference is determined in advance. It is determined whether or not the threshold value is exceeded (S13). The reference value and the threshold value can be appropriately changed according to an instruction from the crack detection device control unit 224.

  Then, the result of the comparison determination is transmitted to the crack detection device controller 224, and when a crack occurs and a certain amount of thin film is deposited on the crack portion or the like, a corresponding process is performed. In other words, the crack detection device control unit 224 that has received the crack vibration signal notifies the operator to that effect by turning on the alarm lamp 216A of the alarm generation unit 216, and a crack in a specific crack mode is generated on the display 216B. Is displayed and a message to that effect is sent to the operator. The fact that the crack has occurred is also transmitted to the apparatus control unit 180 that performs the entire operation of the processing apparatus 20, and performs a predetermined control operation. For example, after the processing of the wafer W currently being processed is completed, control is performed so that the processing of the wafer W is stopped next.

  Thus, when a crack occurs in the thermal diffusion plate 61 during processing, the occurrence of the crack can be detected quickly and easily in real time. Therefore, even if a crack is generated in the thermal diffusion plate 61, it is possible to prevent the defective product wafer from being generated by suppressing the film forming process without recognizing the crack, thereby preventing the product yield from being lowered. be able to. In addition, it is possible not only to suppress the number of times of processing a quality confirmation wafer, which has been conventionally performed, but also to eliminate the quality confirmation wafer processing itself.

  Here, the detection operation of the electrical characteristics is performed every time one pulse of the signal voltage is applied. However, the present invention is not limited to this, and the detection operation of the electrical characteristics may be performed every plural pulses. The electrical characteristics used in the crack determination unit 222 may be an average value obtained by measuring a plurality of times. Also, in order not to misjudge the change over time within the normal range as a crack, periodically measure the electrical characteristics and store the measurement results, and save the previous measurement results and the current measurement results. You may make it compare a threshold value with the value of ratio or a difference. In addition, here, the case where the magnitude of the stray capacitance is obtained as an electrical characteristic has been described as an example. However, instead of this, an ultimate voltage or a time constant at the time of applying the signal voltage may be used, of course, Further, a plurality of these electrical characteristics may be used in combination. Further, when the frequency of the pulse wave from the signal voltage source 218 is varied and the impedance of the path at each frequency is measured, the impedance Z is changed according to changes in C2, R2, L1, etc. as shown in FIG. Changes occur from Z0 to Z1. When this amount of change reaches a predetermined level, it is determined that a crack has occurred.

  When the film forming process is performed by the above processing apparatus, in the switch means 230, the open / close switches 230D and 230E of the lead wires 226 and 228 are opened, and the open / close switches 230A, 230B and 230C of the wirings 140 and 142 are set. Of course, both are closed.

  As described above, according to the present invention, the heat diffusion plate 61 on which the electrode is embedded and the object to be processed is placed thereon, the heat diffusion plate 61 is supported, and the heater is embedded as the heating means 64. Floating capacitance formed between an electrode and a heater in a crack detection device for detecting a crack in a mounting table structure in which a mounting table 58 having a mounting table main body 59 is erected from a bottom of a processing vessel by a support column Is provided with a signal voltage source 218 for applying a signal voltage, a characteristic detection unit 220 for detecting an electrical characteristic due to stray capacitance, and comparing a detection result of the characteristic detection unit with a predetermined reference value. Since the crack determination unit 222 for determining whether or not there is a crack is provided, it is possible to quickly and easily detect a crack such as a crack or a crack in the heat diffusion plate without reducing the productivity of the product.

  In the first and second embodiments, the processing apparatus using a plurality of thin tubular struts 60 has been described as an example. However, the present invention is not limited to this, and the processing apparatus using a tubular strut having a large diameter is used. Of course, the present invention can also be applied. In the present embodiment, the processing apparatus using plasma has been described as an example. However, the present invention is not limited to this, and a processing apparatus in which an electrode for an electrostatic chuck is provided as an electrode may be used. Needless to say, the present invention can be applied to a processing apparatus for heat treatment such as thermal CVD in which 66 is not provided.

  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 Post 61 Heat diffusion plate 62 Functional rod body 64 Heating means 66 Electrode 68 Heating element 68A Inner peripheral zone heating element 68B Outer peripheral zone heating element 70, 72, 74, 76 Heating rod for heater 78 Conductive rod 80, 81 Thermocouple 92 Pole fixing base 200 Crack detector 202 Vibration detector 204 Crack detector 206 Crack detector controller 207 Fourier transform frequency resolution unit 208 Digital filter unit 208A- 208B Filter 210 Filter control unit 214 Comparison unit 214A to 214C Comparator 216 Alarm generation unit 218 Signal voltage source 220 Characteristic detection unit 220A Capacitance measurement resistance 222 Crack determination unit 224 Crack detection device control unit 230 Switch means W Semiconductor wafer (processed) body

Claims (24)

In a crack detection device for detecting a crack in a mounting table structure in which a mounting table having a heat diffusion plate for mounting a target object to be processed is provided upright from a bottom of a processing container by a column,
Vibration detecting means provided outside the processing container;
Crack detection means for detecting a crack vibration signal that is a signal of a frequency generated according to a cracking mode of the thermal diffusion plate from signals obtained by the vibration detection means;
A crack detection device comprising: The crack detection apparatus according to claim 1, wherein the vibration detection unit is composed of a mechanical-electric conversion element. The crack detection means includes a Fourier frequency converter that performs Fourier transform on the crack vibration signal to decompose the frequency, a digital filter that selects a signal in a specific frequency band from the frequency converted signal, and the selection should be performed The crack detection apparatus according to claim 1, further comprising a filter control unit that controls a frequency band. The crack detection apparatus according to claim 3, wherein the digital filter section includes a filter corresponding to the number of the crack modes. 5. The crack detection apparatus according to claim 1, further comprising a comparison unit that compares an output of the crack detection unit with a predetermined threshold value. 6. 2. An electrode is embedded in the heat diffusing plate, and the mounting table includes a mounting table body that supports the heat diffusing plate and has a heater embedded therein as a heating unit. The crack detection device according to any one of 5. The crack detection apparatus according to claim 1, wherein the mounting table includes a mounting table body that supports the heat diffusion plate and has a heater embedded therein as a heating unit. The crack detection device according to any one of claims 1 to 6, wherein the vibration detection means is provided on a conductive rod that is inserted into the support column and connected to the electrode. The crack detection device according to any one of claims 1 to 7, wherein the vibration detection unit is provided on a support fixing base that fixes a lower end side of the support to a bottom of the processing container. The crack detection device according to claim 6 or 7, wherein the vibration detecting means is inserted into the support column and provided at an upper end portion of the power supply rod connected to the heater. The crack detection device according to any one of claims 1 to 7, wherein the vibration detection means is provided in a thermocouple that is inserted into the support column and measures the temperature of the mounting table. The crack detection apparatus according to claim 1, wherein the vibration detection unit is provided at a bottom portion of the processing container. A mounting table having a heat diffusion plate on which an object to be processed is mounted with electrodes embedded therein, and a mounting table body that supports the heat diffusion plate and in which a heater is embedded as a heating means. In the crack detection device that detects cracks in the mounting table structure that is erected from the bottom of the processing vessel by a support column,
A signal voltage source for applying a signal voltage to a stray capacitance formed between the electrode and the heater;
A characteristic detector for detecting an electrical characteristic caused by the stray capacitance;
A crack determination unit that determines the presence or absence of a crack by comparing the detection result of the characteristic detection unit with a predetermined reference value;
A crack detection device comprising: The electrode is connected to a conductive rod inserted through the support column, the heater is connected to a power supply rod inserted through the support column, and the signal voltage is applied between the conductive rod and the power supply rod. The crack detection device according to claim 13. 15. The crack detection apparatus according to claim 13, further comprising a switch unit that electrically floats the heater and the electrode when the crack detection apparatus performs a detection operation. The electrical characteristic is any one or more of an ultimate voltage at the time of applying the signal voltage, a time constant at the time of applying or interrupting the signal voltage, a size of the stray capacitance, and a frequency characteristic of impedance. The crack detection device according to any one of claims 13 to 15, wherein The crack detection device according to any one of claims 13 to 16, wherein the signal voltage is applied in a pulse form, and the detection operation is performed for each pulse or for each of a plurality of pulses. The crack detection apparatus according to claim 17, wherein a pulse frequency of the signal voltage is variable. A processing vessel that can be evacuated;
Gas supply means for supplying the necessary gas into the processing vessel;
A mounting table structure for mounting an object to be processed in the processing container;
A crack detection device according to any one of claims 1 to 18,
A processing apparatus comprising: The processing apparatus according to claim 1, further comprising plasma generating means for generating plasma in the processing container. In a detection method for detecting a crack in a mounting table structure in which a mounting table having a heat diffusion plate for mounting a target object to be processed is provided upright from a bottom portion of a processing container by a support column,
A vibration detection step for detecting vibrations generated in the mounting table structure;
A crack detection step of detecting a vibration generated when the thermal diffusion plate is cracked as a crack vibration signal based on information predetermined according to a cracking mode of the thermal diffusion plate from the vibration obtained in the vibration detection step; ,
The crack detection method characterized by having. The crack detection method according to claim 21, wherein the predetermined information is vibration information generated when the thermal diffusion plate is cracked. A mounting table having a heat diffusion plate on which an object to be processed is mounted with electrodes embedded therein, and a mounting table body that supports the heat diffusion plate and in which a heater is embedded as a heating means. In the crack detection method for detecting a crack in the mounting table structure that is erected from the bottom of the processing vessel by a support column,
Applying a signal voltage to the stray capacitance formed between the electrode and the heater to cut off the signal voltage;
A characteristic detection step of detecting an electrical characteristic caused by the stray capacitance when the signal voltage is applied or cut off;
A crack determination step of determining the presence or absence of cracks in the thermal diffusion plate by comparing the electrical characteristics obtained in the characteristic detection step with a predetermined reference value,
The crack detection method characterized by having. The electrical characteristic is any one or more of an ultimate voltage at the time of applying the signal voltage, a time constant at the time of applying or interrupting the signal voltage, a size of the stray capacitance, and a frequency characteristic of impedance. The crack detection method according to claim 23, wherein:

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