JP2008309492A - System and apparatus for detecting anomaly of coaxial cable and processing apparatus provided with the system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coaxial cable anomaly detection system which detects slight anomalies such as buckling and cracks, and also detects the slight anomalies without stopping a processing apparatus. <P>SOLUTION: The coaxial cable anomaly detection system is provided with: a coaxial cable 3 having one end connected to an output 11 of an RF generator 1 and the other end connected to an input 41 of a matching device 4; a first reflected wave detection means 12 for detecting reflected waves R of the coaxial cable 3 in the output 11 of the RF generator 1; a second reflected wave detection means 43 for detecting reflected waves r of the coaxial cable 3 in the input of the matcher 4; and a detector 6 for comparing the reflected waves R with the reflected waves r and detecting the occurrence of anomalies in the coaxial cable 3 when the relation between the reflected waves R and the reflected waves r is R>r, and when the difference between the reflected waves R and the reflected waves r exceeds a prescribed value. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a coaxial cable abnormality detection system and an abnormality detection method for detecting abnormality of a coaxial cable, and a processing apparatus including the abnormality detection system.

  In the manufacture of flat panel displays and semiconductor devices, there are processes using processing equipment that uses high-frequency power, such as plasma etching and CVD film formation. The high-frequency power is generated by an RF generator, and the generated high-frequency power is input to a coaxial cable as a feed line, and is supplied to the processing device via a matching unit that matches the impedance of the coaxial cable and the impedance of the processing device. Is done.

  Processing apparatuses used for manufacturing flat panel displays and semiconductor devices are large, and the distance from the matching unit installed in the processing apparatus body to the RF generator may be long. In particular, the length of a coaxial cable of a processing apparatus used for manufacturing a flat panel display often ranges from 20 m to 30 m. If the length of the coaxial cable is increased, the coaxial cable may be bent inadvertently when the equipment is installed in the factory or when the coaxial cable is moved, and the internal conductor in the coaxial cable may be disconnected. is there. If the internal conductor is disconnected, high-frequency power cannot be supplied to the processing apparatus, and plasma is not generated in the processing apparatus.

  A coaxial cable whose internal conductor is disconnected has a phenomenon that the characteristic impedance is shifted at the disconnected position. By utilizing this phenomenon and measuring the characteristic impedance of the coaxial cable using an external measuring device, for example, a network analyzer, it is possible to detect the occurrence of disconnection and the location of the disconnection.

  In this measurement and detection, the coaxial cable is removed from the RF generator and the matching unit, one end of the coaxial cable is connected to a network analyzer, and the other end is grounded via a termination resistor. If the characteristic impedance of the coaxial cable is 50Ω, the characteristic impedance of the coaxial cable is measured with a termination resistance of 50Ω. At this time, there may be a portion where the characteristic impedance changes greatly from 50Ω. In such a coaxial cable, the internal conductor is disconnected, and the portion where the characteristic impedance is greatly changed is the disconnected portion.

  In the measurement and detection using a network analyzer, the abnormality cannot be detected unless the state is completely abnormal, such as the internal conductor of the coaxial cable is disconnected.

  The bending of the coaxial cable may cause buckling or cracking that prevents the inner conductor from being completely abnormal. A coaxial cable having a buckled or cracked inner conductor can supply high-frequency power to a processing apparatus in the same manner as a normal coaxial cable, unlike a coaxial cable that has caused a complete abnormality. That is, plasma is normally generated in the processing apparatus. For this reason, a coaxial cable having a buckled or cracked inner conductor cannot be distinguished from a normal coaxial cable.

  Buckling and cracking may be a slight anomaly, but buckling and cracking must be unique for coaxial cables. If a coaxial cable having a singular point is continuously used, there is a possibility that a problem will occur in the coaxial cable.

  However, buckling and cracks do not greatly change the characteristic impedance of the coaxial cable. For this reason, buckling and cracks are difficult to detect with a network analyzer. In addition, in measurement and detection using an external measurement device such as a network analyzer, the coaxial cable must be removed from the RF generator and the matching unit and reconnected to the external measurement device. For this reason, the processing apparatus must be stopped.

  The present invention provides a coaxial cable abnormality detection system and an abnormality detection method capable of detecting a slight abnormality such as a buckling or a crack and detecting a slight abnormality without stopping the processing device. And it aims at providing the processing apparatus provided with this abnormality detection system.

  In order to solve the above-mentioned problems, a coaxial cable abnormality detection system according to a first aspect of the present invention includes a coaxial cable having one end connected to an output of an RF generator and the other end connected to an input of a matching unit, and the coaxial cable. A first reflected wave detecting means for detecting a reflected wave R at the output of the RF generator of the cable; a second reflected wave detecting means for detecting a reflected wave r at the input of the matching unit of the coaxial cable; When the wave R and the reflected wave r are compared, the relationship between the reflected wave R and the reflected wave r is R> r, and the difference between the reflected wave R and the reflected wave r exceeds a specified value And a detector for detecting occurrence of an abnormality in the coaxial cable.

  In addition, in the coaxial cable abnormality detection method according to the second aspect of the present invention, one end of the coaxial cable is connected to the output of the RF generator, the other end of the coaxial cable is connected to the input of the matching unit, The reflected wave R at the output of the RF generator is detected, the reflected wave r at the input of the matching unit of the coaxial cable is detected, the reflected wave R and the reflected wave r are compared, and the reflected wave R and the When the relationship with the reflected wave r is R> r and the difference between the reflected wave R and the reflected wave r exceeds a specified value, the occurrence of an abnormality in the coaxial cable is detected.

  According to a third aspect of the present invention, there is provided a processing apparatus including the coaxial cable abnormality detection system, an RF generator for generating high-frequency power, a processing apparatus for processing a substrate to be processed, and an output of the RF generator. A coaxial cable as a feed line for feeding high-frequency power from the RF generator to the processing device, an input connected to the other end of the coaxial cable, and an output connected to the processing device. A matching unit that matches the impedance of the processing device with the impedance of the processing device, a controller that controls the matching unit, a first reflected wave detection unit that detects a reflected wave R at the output of the RF generator of the coaxial cable, Second reflected wave detection means for detecting a reflected wave r at the input of the matching unit of the coaxial cable; and the reflected wave And the reflected wave r, the relationship between the reflected wave R and the reflected wave r is R> r, and the difference between the reflected wave R and the reflected wave r exceeds the specified value. And a detector for detecting occurrence of abnormality in the coaxial cable.

  According to the present invention, a coaxial cable abnormality detection system capable of detecting a slight abnormality such as buckling or crack and detecting a slight abnormality without stopping the processing apparatus, and the abnormality detection. A method and a processing apparatus including the abnormality detection system can be provided.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a configuration diagram showing an example of a processing apparatus including a coaxial cable abnormality detection system according to an embodiment of the present invention.

  As shown in FIG. 1, a processing apparatus including a coaxial cable abnormality detection system according to an embodiment includes an RF generator 1 that generates high-frequency power, a processing apparatus 2 that processes a substrate to be processed, and an RF generator 1. A coaxial cable 3 as a feed line for feeding high-frequency power from the processing device 2, a matching unit 4 for matching the impedance of the coaxial cable 3 and the impedance of the processing device 2, and a controller 5 for controlling the matching unit 4, And a detector 6 for detecting the occurrence of abnormality in the coaxial cable.

  Examples of the processing apparatus 2 include a plasma dry etching apparatus and a plasma CVD apparatus used for manufacturing a flat panel display and a semiconductor device. FIG. 1 shows a flat panel display (FPD) plasma dry etching apparatus as an example. The FPD plasma dry etching apparatus is used, for example, in a process of removing a thin film on a glass substrate that is a substrate to be processed 21 and forming a circuit pattern by etching. The high frequency power is supplied to the substrate 21 to be processed, in this example, the mounting table 22 on which a glass substrate is mounted. The etching gas is supplied into the chamber 24 from a shower head 23 provided above the substrate 21 to be processed. The shower head 23 is grounded and functions as a counter electrode of the mounting table 22.

  The coaxial cable 3 has one end connected to the output 11 of the RF generator 1 and the other end connected to the input 41 of the matching unit 4. The output 42 of the matching unit 4 is connected to the processing device 2.

  The detector 6 compares the reflected wave R at the output 11 of the RF generator 1 of the coaxial cable 3 with the reflected wave r at the input 41 of the matching device 4 of the coaxial cable 3. The detector 6 has an abnormality in the coaxial cable 3 when the relationship between the reflected wave R and the reflected wave r is R> r and the difference between the reflected wave R and the reflected wave r exceeds a specified value. Detect what happened.

The reflected wave R and the reflected wave r may be detected by separately providing a reflected wave detection means for detecting them, and may be detected by using a separately provided detection means. In this example, the RF wave generator 1 and the matching unit 4 are provided. Standing wave ratio detection board (VSWR (Voltage
The reflected wave detected by the Standing Wave Ratio substrate) is used. That is, in this example, the reflected wave R uses the reflected wave R detected by the standing wave ratio detection board (VSWR board) 12 provided in the RF generator 1, and the reflected wave r is the constant wave provided in the matching unit 4. The reflected wave r detected by the standing wave ratio detection substrate (VSWR substrate) 43 is used.

  An example of the specified value is as follows.

  When the coaxial cable 3 is in a normal state, the relationship between the reflected wave R and the reflected wave r is “R≈r”. The difference between the reflected wave R and the reflected wave r varies depending on the length of the coaxial cable 3 and the strength of the high-frequency power, but is approximately less than 100 W.

  On the other hand, in a state where the inner conductor of the coaxial cable 3 is abnormal, the relationship between the reflected wave R and the reflected wave r is “R> r”. Furthermore, the difference between the reflected wave R and the reflected wave r varies depending on the length of the coaxial cable 3 and the strength of the high-frequency power, but increases to approximately 100 W to 200 W. Therefore, the specified value is 100 W or more and 200 W or less. For example, when the specified value is set to 101 W, the detector 6 has a relationship of R> r between the reflected wave R and the reflected wave r, and the difference between the reflected wave R and the reflected wave r is 101 W or more, or 101 W. Is detected, an abnormality has occurred in the coaxial cable 3.

  If there is an abnormality in the inner conductor of the coaxial cable 3, the relationship between the reflected wave R and the reflected wave r becomes “R> r” and the difference between the reflected wave R and the reflected wave r increases to 100 W or more. One is shown below.

  FIG. 2A is a diagram showing the relationship between the reflected wave R and the reflected wave r when the coaxial cable 3 is in a normal state, and FIG. 2B is the reflected wave R and the reflected wave r when the internal conductor of the coaxial cable 3 is abnormal. It is a figure which shows the relationship.

  As shown in FIG. 2A, when the coaxial cable 3 is in a normal state, the high-frequency power from the RF generator 1 is almost directly input to the input 41 of the matching unit 4. At this time, a reflected wave r is generated at the input 41, and this reflected wave r reaches the output 11 of the RF generator 1 almost as it is. For this reason, the reflected wave R at the output 11 of the RF generator 1 and the reflected wave r at the input of the matching unit 4 are substantially equal. That is, the relationship between the reflected wave R detected by the standing wave ratio detection substrate (VSWR substrate) 12 on the RF generator 1 side and the reflected wave r detected by the standing wave ratio detection substrate 43 on the matching unit 4 side is “R ≈r ″.

  On the other hand, when the internal conductor of the coaxial cable 3 is abnormal, a part of the high-frequency power from the RF generator 1 is reflected at the abnormal portion 7 as shown in FIG. 2B. For this reason, the high frequency electric power input into the input 41 of the matching device 4 decreases compared with the case of a normal state. As a result, the reflected wave r also decreases compared to the normal state.

  Furthermore, in addition to the reflected wave r, the reflected wave r ′ reflected at the abnormal location 7 reaches the output 11 of the RF generator 1. As a result, the reflected wave R at the output 11 of the RF generator 1 is larger than the reflected wave r. Therefore, the relationship between the reflected wave R detected by the standing wave ratio detection board (VSWR board) 12 on the RF generator 1 side and the reflected wave r detected by the standing wave ratio detection board 43 on the matching unit 4 side is “R > R ″, and the difference between the reflected wave R and the reflected wave r is also increased to, for example, 100 W or more.

  As described above, in the present embodiment, it is detected whether an abnormality has occurred in the inner conductor of the coaxial cable 3 using the relationship shown in FIGS. 2A and 2B.

  Further, since the reflection phenomenon at the abnormal portion 7 shown in FIG. 2B occurs even in a slight abnormality occurring in the inner conductor, for example, a buckling or a crack, even a slight abnormality such as a buckling or a crack can be detected. .

  When an abnormality is detected by the detector 4, for example, the RF generator 1 and the processing device 2 are stopped and the coaxial cable 3 is replaced. The RF generator 1 and the processing device 2 may be stopped by a direct command from the detector 6. For example, “abnormality occurrence” is displayed on the display 81 of the operating device 8 that operates the processing device 2. Or, the alarm device 10 may be sounded to notify the “abnormality occurrence” to notify the operator of the “abnormality occurrence” and stop the RF generator 1 and the processing device 2 by the operator himself / herself. good.

  The display of the “occurrence of abnormality” and the notification of the “occurrence of abnormality” may be employed as necessary, and when employed, only one or both may be employed. .

  In addition, the detector 6 of this example adds the function of the detector 6 to the controller 5 that controls the matching device 4 and incorporates the detector 6 in the controller 5. An external device of the controller 5 may be used.

  In the apparatus shown in FIG. 1, the portion functioning as the coaxial cable abnormality detection system 100 is a first reflected wave detecting means (a first reflected wave detecting means for detecting a reflected wave R at the output 11 of the coaxial cable 3 and the RF generator 1 of the coaxial cable 3). In this example, a standing wave ratio detection board (VSWR board) 12) and second reflected wave detection means for detecting the reflected wave r at the input 41 of the matching unit 4 of the coaxial cable 3 (standing wave ratio detection board in this example). (VSWR substrate) 43) and the reflected wave R and the reflected wave r are compared, the relationship between the reflected wave R and the reflected wave r is R> r, and the difference between the reflected wave R and the reflected wave r is a specified value. This is the part of the detector 6 that detects the occurrence of an abnormality in the coaxial cable 3 when the value exceeds.

  As described above, such an abnormality detection system 100 can be equipped with the display 81 that displays “occurrence of abnormality” and the alarm device 10 that notifies “occurrence of abnormality” as necessary.

  Next, an example of an operation procedure of the abnormality detection system 100 will be described.

  FIG. 3 is a flowchart illustrating an example of an operation procedure of the abnormality detection system 100.

  First, a delay time from turning on the RF generator 1 is set (ST. 1).

  This delay time is a waiting time until the RF generator 1 is turned on and high-frequency power is stably supplied to the matching unit 4. The delay time varies depending on the length of the coaxial cable 3 and the strength of the high-frequency power, but is 10 seconds as an example.

  Next, a difference between the reflected wave R and the reflected wave r, that is, a specified value is set (ST. 2).

  The specified value varies depending on the length of the coaxial cable 3 and the strength of the high-frequency power as described above, but is 100 W or more and 200 W or less as an example.

Next, the detection time is set (ST.3).
The detection time is a comparison between the reflected wave R and the reflected wave r, the relationship between the reflected wave R and the reflected wave r is R> r, and whether or not the difference between the reflected wave R and the reflected wave r exceeds a specified value. It is time to monitor. This detection time also varies depending on the length of the coaxial cable 3 and the strength of the high-frequency power, but for example, it is approximately 5 seconds to 10 seconds.

  Such a procedure ST. 1-ST. By stepping 3, the detection data of the delay time, the specified value, and the detection time is set in the abnormality detection system 100. These data are input from, for example, the input means (for example, keyboard) 82 of the operation device 8 shown in FIG. 1 and set in the detector 6 of the abnormality detection system 100.

  Note that the detection data setting order is not limited to the order shown in FIG.

  In addition, by storing the set detection data in the controller 5 or the scanning device 8, the procedure ST. 1-ST. Step 3 may be performed once.

  After the detection data is set, the RF generator 1 is turned on (ST. 4), high frequency power is supplied to the processing apparatus 2, and the processing for the substrate 21 is started (ST. 5). After turning on, after the delay time has elapsed, abnormality detection for the coaxial cable 3 is started (ST. 6). In the present embodiment, the abnormality detection for the coaxial cable 3 is executed in parallel with the processing for the substrate 21 to be processed.

  As described above, the abnormality detection system 100 according to the present embodiment can execute the abnormality detection for the coaxial cable 3 in parallel with the processing of the substrate to be processed 21, so that there is a slight amount such as buckling or cracking. Not only can the abnormality be detected, but this slight abnormality can be detected without stopping the processing device 2. In addition, since the abnormality detection for the coaxial cable 3 is executed in parallel with the processing for the substrate 21 to be processed, the throughput of the processing apparatus 2 is not hindered.

  In addition, the abnormality detection system 100 may be operated constantly while repeating detection during the processing on the substrate 21 to be processed, or may be operated intermittently, for example, every few minutes.

  Next, an example of the coaxial cable 3 will be described.

  FIG. 4 is a perspective view showing an example of the coaxial cable 3.

  As one of coaxial cables 3 used in plasma dry etching apparatuses and plasma CVD apparatuses used in the manufacture of flat panel displays and semiconductor devices, there is a coaxial cable 3 'having a hollow inner conductor 31 for weight reduction. . An example of the coaxial cable 3 ′ is shown in FIG. As the hollow conductor, a copper pipe, an aluminum pipe or the like is used.

  However, if the coaxial cable 3 ′ in which the inner conductor 31 is a hollow conductor is extremely bent as shown in FIG. 5A, it tends to buckle 32 at the bent portion as shown in FIG. 5B. When the buckling 32 occurs, it is almost impossible to return to the original state, so that it remains almost permanently as a singular point in the coaxial cable 3 ′.

  Even in such a coaxial cable 3 ′ in which the inner conductor 31 is likely to buckle, if the abnormality detection system 100 according to the present embodiment is used, it can be easily detected whether or not the buckling 32 has occurred. Even the coaxial cable 3 ′ that easily buckles can be used safely.

  As mentioned above, although this invention was demonstrated by one Embodiment, this invention can be variously deformed, without being limited to the said one Embodiment. In the embodiment of the present invention, the above-described embodiment is not the only embodiment.

  For example, in the above embodiment, a plasma dry etching apparatus or a plasma CVD apparatus used for manufacturing a flat panel display or a semiconductor device has been described as the processing apparatus 2. It is not limited to a device.

  In addition, the one embodiment described above can be variously modified without departing from the gist of the present invention.

FIG. 1 is a block diagram showing an example of a processing apparatus equipped with a coaxial cable abnormality detection system according to an embodiment of the present invention. FIG. 2A is a diagram showing the relationship between the reflected wave R and the reflected wave r when the coaxial cable 3 is in a normal state, and FIG. 2B is the reflected wave R and the reflected wave r when the internal conductor of the coaxial cable 3 is abnormal. Diagram showing the relationship FIG. 3 is a flowchart showing an example of an operation procedure of the abnormality detection system 100. FIG. 4 is a perspective view showing an example of the coaxial cable 3. 5A is a cross-sectional view showing a state in which the coaxial cable 3 ′ is bent, and FIG. 5B is a cross-sectional view showing a state in which the buckling 32 is generated in the bent coaxial cable 3 ′.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... RF generator, 2 ... Processing apparatus 3, 3 '... Coaxial cable, 4 ... Matching device, 5 ... Controller, 6 ... Detector, 8 ... Operating device, 10 ... Alarm, 11 ... Output of RF generator, 12 ... Standing wave ratio detection board, 31 ... Inner conductor, 32 ... Buckled part, 41 ... Input of matching unit, 42 ... Output of matching unit, 43 ... Standing wave ratio detection board

Claims (13)

A coaxial cable with one end connected to the output of the RF generator and the other end connected to the input of the matcher;
First reflected wave detection means for detecting a reflected wave R at the output of the RF generator of the coaxial cable;
Second reflected wave detection means for detecting a reflected wave r at the input of the matching unit of the coaxial cable;
The reflected wave R is compared with the reflected wave r, the relationship between the reflected wave R and the reflected wave r is R> r, and the difference between the reflected wave R and the reflected wave r exceeds a specified value. A detector for detecting the occurrence of abnormality in the coaxial cable when
An abnormality detection system for a coaxial cable, comprising: The first reflected wave detection means is a standing wave ratio detection board provided in the RF generator;
The second reflected wave detection means is a standing wave ratio detection board provided in the matching unit;
The reflected wave R uses a reflected wave detected by a standing wave ratio detection board provided in the RF generator, and the reflected wave r is detected by a standing wave ratio detection board provided in the matching unit. 2. The coaxial cable abnormality detection system according to claim 1, wherein a reflected wave is used.   When the detector detects the occurrence of an abnormality in the coaxial cable, the detector includes at least one of a display for displaying the occurrence of the abnormality and an alarm device for notifying the occurrence of the abnormality. The abnormality detection system for a coaxial cable according to claim 1 or 2.   4. The coaxial cable abnormality detection system according to claim 1, wherein the specified value is not less than 100 W and not more than 200 W. 5.   The coaxial cable abnormality detection system according to any one of claims 1 to 4, wherein a hollow conductor is used as an inner conductor of the coaxial cable.   6. The abnormality detection of the coaxial cable is performed in parallel with the processing of the substrate to be processed by the processing device using the high frequency power from the RF generator. An abnormality detection system for a coaxial cable as described in the paragraph. Connect one end of the coaxial cable to the output of the RF generator,
Connect the other end of the coaxial cable to the input of the matcher,
Detecting a reflected wave R at the output of the RF generator of the coaxial cable;
Detecting a reflected wave r at the input of the matching unit of the coaxial cable;
The reflected wave R is compared with the reflected wave r, the relationship between the reflected wave R and the reflected wave r is R> r, and the difference between the reflected wave R and the reflected wave r exceeds a specified value. An abnormality detection method for a coaxial cable, wherein an abnormality occurrence in the coaxial cable is detected at a time.   The coaxial cable abnormality detection method according to claim 7, wherein the specified value is 100 W or more and 200 W or less.   The abnormality detection of the coaxial cable is executed in parallel with the processing to the substrate to be processed by the processing device using the high frequency power from the RF generator. Coaxial cable abnormality detection method. An RF generator for generating high-frequency power;
A processing apparatus for processing a substrate to be processed;
One end of the RF generator is connected to the output of the RF generator, and a coaxial cable as a power supply line for supplying high-frequency power from the RF generator to the processing device;
A matching unit that connects an input to the other end of the coaxial cable and connects an output to the processing device, and matches the impedance of the coaxial cable and the impedance of the processing device;
A controller for controlling the matching unit;
First reflected wave detection means for detecting a reflected wave R at the output of the RF generator of the coaxial cable;
Second reflected wave detection means for detecting a reflected wave r at the input of the matching unit of the coaxial cable;
The reflected wave R is compared with the reflected wave r, the relationship between the reflected wave R and the reflected wave r is R> r, and the difference between the reflected wave R and the reflected wave r exceeds a specified value. A detector for detecting the occurrence of abnormality in the coaxial cable when
The processing apparatus provided with the abnormality detection system of the coaxial cable characterized by comprising.   11. The processing apparatus having the coaxial cable abnormality detection system according to claim 10, wherein the specified value is 100 W or more and 200 W or less.   The abnormality detection of the coaxial cable is executed in parallel with the processing of the substrate to be processed by the processing apparatus using the high frequency power from the RF generator. Processing equipment equipped with a coaxial cable abnormality detection system.   The said processing apparatus is a plasma dry etching apparatus or a plasma CVD apparatus, The processing apparatus provided with the abnormality detection system of the coaxial cable as described in any one of Claim 10 thru | or 12 characterized by the above-mentioned.

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