KR20080109612A - Abnormality detection system and method for coaxial cable, and processing apparatus equipped with said system - Google Patents

Abstract

An abnormal detection system of coaxial cable capable of continuously detecting, method thereof, and processing apparatus including the same are provided to reduce a defect of the coaxial cable by detecting a crack and a buckling. An abnormal detection system of coaxial cable capable of continuously detecting comprises a coaxial cable(3), a first reflected wave detection unit, a second reflected wave detection unit, and a detector(6). One end of the coaxial cable is connected to an output of a RF(Radio Frequency) generator(1). The other end of the coaxial cable is connected to an input of a matching unit(4). The first reflected wave detection unit detects a reflected wave R in the output of the RF generator of the coaxial cable. The second reflected wave detection unit detects a reflected wave r in the input of the matching unit of the coaxial cable. A relation of the reflected wave r and the reflected wave R is R>r. The detector detects a defect of the coaxial cable when a difference of the reflected wave r and the reflected wave R exceeds a definition value.

Description

FIELD OF THE INVENTION PROCESSING APPARATUS EQUIPPED WITH SAID SYSTEM}

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

In the manufacture of flat panel displays and semiconductor devices, there are steps using a processing device that uses high frequency power, such as a plasma etching process or a CVD film forming process. The high frequency power is generated by the RF generator, and the generated high frequency power is input to the coaxial cable as a feed line, passes through a matcher for matching the impedance of the coaxial cable with the impedance of the processing apparatus, and then is supplied to the processing apparatus.

The processing apparatus used for manufacturing a flat panel display or a semiconductor device is large, and the distance from the matching unit provided in the processing apparatus main body to the RF generator may be too long. In particular, the length of the coaxial cable of the processing apparatus used for the manufacture of flat panel displays often ranges from 20 m to 30 m. If the length of the coaxial cable becomes long, the coaxial cable may be unintentionally bent at the time of installation of the equipment in the factory or when the coaxial cable is moved, and the internal conductor in the coaxial cable may be disconnected. When the internal conductor is disconnected, high frequency power cannot be supplied to the processing apparatus, and plasma is not generated in the processing apparatus.

In the coaxial cable in which the inner conductor is disconnected, a characteristic impedance shift occurs at the disconnected portion. By using this phenomenon, if the characteristic impedance of the coaxial cable is measured using an external measuring device such as a network analyzer, the presence or absence of disconnection can be detected and the disconnected portion can be detected.

In this measurement and detection, the coaxial cable is separated from the RF generator and matching device, one end of the coaxial cable is connected to the network analyzer, and the other end is grounded through a termination resistor. If the characteristic impedance of the coaxial cable is 50Ω, the characteristic impedance of the coaxial cable is measured with the termination resistance set to 50Ω. At this time, a part where the characteristic impedance greatly changes in 50? Such a coaxial cable causes the internal conductor to be disconnected, and is a part where the characteristic impedance is greatly changed.

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

The bending of the coaxial cable may cause buckling and cracks that do not lead to a state in which the inner conductor is completely abnormal. Coaxial cables, which have buckled or cracked internal conductors, can provide high frequency power to the processing device, just like normal coaxial cables, unlike coaxial cables that have caused complete anomalies. That is, in the processing apparatus, plasma is generated normally. For this reason, a coaxial cable in which buckling or cracking occurs in the inner conductor is indistinguishable from a normal coaxial cable.

Buckling and cracking may be a bit of anomalies, but buckling and cracking must be the singularity of coaxial cables. If the coaxial cable having a singular point is used continuously, there is a possibility that the coaxial cable will eventually be defective.

However, buckling and cracking do not significantly change the characteristic impedance of the coaxial cable. For this reason, buckling and cracking are difficult to detect with a network analyzer. Furthermore, measurements and detection using external measurement devices such as network analyzers require that the coaxial cable be disconnected from the RF generator and matcher and then connected to the external measurement device. For this reason, the processing apparatus is forced to stop.

The present invention can detect a slight abnormality such as buckling or cracking, and can detect a slight abnormality without stopping the processing apparatus, the abnormality detecting system of the coaxial cable, and the abnormality detecting method, and the abnormality detecting method. It is an object to provide a processing apparatus having a system.

In order to solve the said subject, the coaxial cable abnormality detection system which concerns on Example 1 of this invention is a coaxial cable which connected one end to the output of an RF generator, and the other end to the input of a matcher, and the said coaxial. First reflected wave detection means for detecting reflected wave R at the output of said RF generator of the cable, second reflected wave detecting means for detecting reflected wave r at the input of said matcher of said coaxial cable, and said reflected wave R; The reflection wave r is compared with each other, and a detector is provided for detecting an abnormality in the coaxial cable when the relationship between the reflection wave R and the reflection wave r is R> r and the difference between the reflection wave R and the reflection wave r exceeds a prescribed value. .

Moreover, the abnormality detection method of the coaxial cable which concerns on Example 2 of this invention connects one end of a coaxial cable to the output of an RF generator, and connects the other end of the coaxial cable to the input of a matcher, and said coaxial cable Detects the reflected wave R at the output of the RF generator, detects the reflected wave r at the input of the matcher of the coaxial cable, compares the reflected wave R with the reflected wave r, and compares the reflected wave R with the reflected wave When the relationship of r is R> r and the difference between the reflected wave R and the reflected wave r exceeds a prescribed value, abnormality occurrence in the coaxial cable is detected.

Moreover, the processing apparatus provided with the abnormality detection system of the coaxial cable which concerns on Example 3 of this invention is an RF generator which generate | occur | produces a high frequency electric power, the processing apparatus which processes a to-be-processed body, and the output of the said RF generator. The coaxial cable serving as a feeder for feeding the high frequency power from the RF generator to the processing apparatus, and the coaxial cable connecting the input to the other end of the coaxial cable and connecting the output to the processing apparatus. A matcher for matching an impedance with an impedance of the processing apparatus, a controller for controlling the matcher, first reflected wave detection means for detecting reflected wave R at an output of the RF generator of the coaxial cable, and the coaxial cable Second reflected wave detecting means for detecting reflected wave r at the input of the matching unit; Comparing the reflected wave R with the reflected wave r and detecting an abnormality in the coaxial cable 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 prescribed value. A detector is provided.

According to the present invention, a slight abnormality such as buckling or cracking can be detected and a slight abnormality can be detected without stopping the processing apparatus, a coaxial cable abnormality detection system, the abnormality detection method, and the abnormality detection system. The processing apparatus provided with this can be provided.

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

BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram which shows an example of the processing apparatus provided with the abnormality detection system of the coaxial cable which concerns on one Embodiment of this invention.

As shown in FIG. 1, a processing apparatus including an abnormality detection system for a coaxial cable according to an embodiment includes an RF generator 1 for generating high frequency power, a processing apparatus 2 for processing a gas to be processed, and , A coaxial cable 3 serving as a feed line for feeding high frequency power from the RF generator 1 to the processing device 2, and a matching device 4 for matching the impedance of the coaxial cable 3 with the impedance of the processing device 2. ), A controller 5 for controlling the matching device 4, and a detector 6 for detecting an abnormal occurrence in the coaxial cable.

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

The coaxial cable 3 connects one end to the output 11 of the RF generator 1 and the other end to the input 41 of the matcher 4. The output 42 of the matcher 4 is connected to the processing apparatus 2.

The detector 6 is similar to the reflected wave R at the output 11 of the RF generator 1 of the coaxial cable 3 and the reflected wave r at the input 41 of the matcher 4 of the coaxial cable 3. Compare The detector 6 detects that an abnormality has occurred 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 prescribed value.

Although the reflected wave R and the reflected wave r may be separately detected by using the reflection means which separately provided the reflection wave detection means which detects these, and in this example, the standing wave ratio detection board | substrate with which the RF generator 1 and the matching device 4 were equipped. The reflected wave detected by the VSWR (Voltage Standing Wave Ratio) substrate is used. That is, in the present example, the reflected wave R uses the reflected wave R detected by the standing wave ratio detecting substrate (VSWR substrate) 12 included in the RF generator 1, and the reflected wave r is detected by the standing wave ratio provided in the matching unit 4. The reflected wave r detected by the substrate (VSWR substrate) 43 is used.

In addition, an example of a prescribed value is as follows.

In the normal state of the coaxial cable 3, 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 with the length of the coaxial cable 3 or the magnitude of the high frequency power, but is less than approximately 100 W.

On the other hand, in the state where the internal conductor of the coaxial cable 3 has an abnormality, the relationship between the reflected wave R and the reflected wave r becomes "R> r". In addition, although the difference between the reflected wave R and the reflected wave r changes to the length of the coaxial cable 3 and the magnitude | size of a high frequency power, it extends to about 100W or more and about 200W. Therefore, the prescribed value is 100W or more and 200W or less. For example, when the prescribed value is set to 101 W, the detector 6 has a relationship R> r between the reflected wave R and the reflected wave r, and when the difference between the reflected wave R and the reflected wave r exceeds 101 W or exceeds 101 W, the coaxial cable 3 ) Is detected.

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 one of the reasons why the difference between the reflected wave R and the reflected wave r extends to 100 W or more is shown below. .

FIG. 2 (a) shows the relationship between the reflected wave R and the reflected wave r when the coaxial cable 3 is in a normal state, and FIG. 2 (b) shows the reflected wave when the inner conductor of the coaxial cable 3 is abnormal. It is a figure which shows the relationship between R and the reflected wave r.

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 input to the input 41 of the matching unit 4 as it is. At this time, although the reflected wave r is generated in the input 41 portion, the reflected wave r also reaches the output 11 of the RF generator 1 as it is. For this reason, the reflected wave R in the output 11 of the RF generator 1 and the reflected wave r in the input of the matcher 4 become substantially the same. 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 matcher 4 side is " R ≒ r ".

On the other hand, when there is an abnormality in the inner conductor of the coaxial cable 3, a part of the high frequency power from the RF generator 1 is reflected by the abnormal part 7, as shown in FIG. For this reason, the high frequency electric power input to the input 41 of the matcher 4 reduces compared with the case where it is a normal state. As a result, the reflected wave r also decreases as compared with the case of the normal state.

In addition to the reflected wave r, the output wave 11 of the RF generator 1 arrives at the reflected wave r 'reflected by the abnormal portion 7. As a result, the reflected wave R at the output 11 of the RF generator 1 becomes larger than the reflected wave r. Therefore, 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 matcher 4 side is " R> r ", and the difference between the reflected wave R and the reflected wave r is also expanded to, for example, 100 W or more.

As described above, in the present embodiment, whether or not an abnormality has occurred in the inner conductor of the coaxial cable 3 is detected using the relationship shown in Figs. 2 (a) and 2 (b).

In addition, since the reflection phenomenon in the abnormal part 7 shown in FIG.2 (b) also appears as a slight abnormality which generate | occur | produced in an internal conductor, for example, buckling and a crack, even slight abnormality, such as buckling and a crack, can be detected. .

When abnormality is detected by the detector 4, for example, the RF generator 1 and the processing apparatus 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, on the display 81 of the operating device 8 that operates the processing device 2, the " Occurrence "or the alarm 10 is sounded to notify the" error occurrence "so that the operator is informed of the" error occurrence "and the operator himself stops the RF generator 1 and the processing device 2. You may do so.

The display of the above abnormal occurrence and the notification of the above abnormal occurrence may be employed as necessary. In the case of employing, only one or both may be employed.

In addition, although the detector 6 of this example added the function of the detector 6 to the controller 5 which controls the matcher 4, and built-in the detector 6 in the controller 5, the detector 6 ) May be, for example, an external attachment device of the controller 5.

In the apparatus shown in FIG. 1, the portion functioning as the abnormality detection system 100 of the coaxial cable detects the reflected wave R at the output 11 of the coaxial cable 3 and the RF generator 1 of the coaxial cable 3. 1st reflected wave detection means (in this example, standing wave ratio detection board | substrate (VSWR board | substrate) 12) and the 2nd reflected wave which detects the reflected wave r in the input 41 of the matcher 4 of the coaxial cable 3 The detection means (standing wave ratio detection substrate (VSWR substrate) 43) and the reflected wave R and the reflected wave r are compared, and 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 It is a part of the detector 6 which detects an abnormal occurrence in the coaxial cable 3 when the prescribed value is exceeded.

As described above, the abnormality detection system 100 can be attached with a display 81 for displaying "problems of abnormality" and an alarm 10 for notifying of "problems of abnormality" as necessary.

Next, an example of the operation procedure of the abnormality detection system 100 is demonstrated.

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

First, the delay time from the ON of the RF generator 1 is set (ST. 1).

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

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

As described above, the prescribed value varies depending on the length of the coaxial cable 3 and the magnitude of the high frequency power, but is, for example, 100 W or more and 200 W or less.

Next, the detection time is set (ST. 3).

The detection time is a time for comparing the reflected wave R with the reflected wave r, and monitoring whether 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 prescribed value. This detection time also varies depending on the length of the coaxial cable 3 and the magnitude of the high frequency power, but is, for example, about 5 seconds or more and 10 seconds or less.

This order ST. 1 to ST. Step 3 is set in the abnormality detection system 100 to detect the delay time, the specified value, and the detection data of the detection time. These data are input from the input means (for example, keyboard) 82 of the operation apparatus 8 shown in FIG. 1, for example, and are set in the detector 6 of the abnormality detection system 100. As shown in FIG.

In addition, the setting order of detection data is not limited to the procedure shown in FIG. 3, and may be arbitrary.

Also, by storing the set detection data in the controller 5 or the scanning device 8, as long as there is no change in the data, the procedure ST. 1 to ST. 3 is good for one implementation.

After the detection data is set, the RF generator 1 is turned on (ST. 4), the high frequency power is supplied to the processing apparatus 2, and the processing on the target gas body 21 is started (ST. 5). . In addition, after the RF generator 1 is turned on, after the delay time has elapsed, abnormality detection with respect to 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 gas to be processed 21.

As described above, since the abnormality detection system 100 according to the present embodiment can perform the abnormality detection for the coaxial cable 3 in parallel with the processing of the gas to be processed 21, slight abnormality such as buckling or cracking. Not only can it be detected, but this slight abnormality can be detected without stopping the processing apparatus 2. Moreover, since the abnormality detection with respect to the coaxial cable 3 is performed in parallel with the process with respect to the to-be-processed body 21, the throughput of the processing apparatus 2 is also not disturbed.

In addition, the abnormality detection system 100 may be operated at all times while repeating detection between the processing to the to-be-processed gas 21, and may be operated intermittently, for example, between several minutes.

Next, an example of the coaxial cable 3 is demonstrated.

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

One of the coaxial cables 3 used in the plasma dry etching apparatus and the plasma CVD apparatus used for the manufacture of a flat panel display or a semiconductor device, and for reducing the weight, the coaxial cable having the inner conductor 31 in a hollow shape. (3 '). An example of this 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 'with the inner conductor 31 as the hollow conductor is extremely bent as shown in Fig. 5 (a), the coaxial cable 3' is bent at the bent part as shown in Fig. 5 (b). Buckling 32 tends to occur. When the buckling 32 occurs, it is almost unthinkable to return to the original state, and thus remains almost permanently as a singularity in the coaxial cable 3 '.

Also in the coaxial cable 3 'which such an internal conductor 31 is easy to buckle, when the abnormality detection system 100 which concerns on a present Example is used, whether the buckling 32 has arisen can be detected easily, Even coaxial cable (3) 'which is easy to buckling can be used safely.

As mentioned above, although one Example demonstrated this invention, this invention is not limited to the said Example, A various deformation | transformation is possible. In addition, the embodiment of the present invention is not the only embodiment described above.

For example, in the above embodiment, the plasma dry etching apparatus and the plasma CVD apparatus used for the manufacture of the flat panel display and the semiconductor apparatus are described as the processing apparatus 2, but the processing apparatus using high frequency power is limited to the apparatus. It is not.

In addition, the above embodiment can be modified in various ways without departing from the spirit of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The block diagram which shows an example of the processing apparatus provided with the abnormality detection system of the coaxial cable which concerns on one Embodiment of this invention.

FIG. 2 (a) shows the relationship between the reflected wave R and the reflected wave r when the coaxial cable 3 is in a normal state, and FIG. 2 (b) shows the reflected wave when the inner conductor of the coaxial cable 3 is abnormal. A diagram showing a relationship between R and a reflected wave r,

3 is a flowchart showing an example of an operation procedure of the abnormality detection system 100;

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

Fig. 5A is a cross-sectional view showing a state where the coaxial cable 3 'is bent, and Fig. 5B is a cross-sectional view showing a state where the buckling 32 is generated in the bent coaxial cable 3'.

Explanation of symbols for the main parts of the drawings

1: RF Generator 2: Processing Unit

3,3 ': coaxial cable 4: matcher

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 portion

41: input of matcher 42: output of matcher

43: standing wave ratio detection substrate

Claims (13)

A coaxial cable connecting one end to the output of the RF generator and the other end to the input of the matcher, First reflected wave detecting means for detecting reflected wave R at an output of said RF generator of said coaxial cable; Second reflected wave detection means for detecting a reflected wave r at an input of the matcher of the coaxial cable; The reflection wave R and the reflection wave r are compared to detect an abnormality in the coaxial cable when the relationship between the reflection wave R and the reflection wave r is R> r and the difference between the reflection wave R and the reflection wave r exceeds a prescribed value. Detector Abnormality detection system of the coaxial cable comprising a. The method of claim 1, The first reflected wave detection means is a standing wave ratio detection substrate provided in the RF generator, The second reflected wave detection means is a standing wave ratio detection substrate provided in the matching unit, The reflected wave R uses the reflected wave detected by the standing wave ratio detection substrate provided in the RF generator, The reflected wave r uses the reflected wave detected by the standing wave ratio detection substrate provided in the matching unit. The abnormality detection system of the coaxial cable characterized by the above-mentioned. The method according to claim 1 or 2, When the detector detects an abnormal occurrence in the coaxial cable, at least one of a display for indicating the abnormal occurrence and an alarm for notifying the abnormal occurrence includes an abnormality detecting system for the coaxial cable. The method according to claim 1 or 2, The abnormality detection system of the coaxial cable, characterized in that the specified value is 100W or more and 200W or less. The method according to claim 1 or 2, The coaxial cable has an abnormality detection system for a coaxial cable, wherein a hollow conductor is used as an inner conductor. The method according to claim 1 or 2, The abnormality detecting system of the coaxial cable is executed in parallel with the processing to the target gas by the processing apparatus using the high frequency power from the RF generator. 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, Detects the reflected wave R at the output of the RF generator of the coaxial cable, Detects a reflected wave r at the input of the matcher of the coaxial cable, Comparing the reflected wave R and the reflected wave r, the occurrence of an abnormality in the coaxial cable is detected 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 prescribed value. that The abnormality detection method of the coaxial cable characterized by the above-mentioned. The method of claim 7, wherein Said prescribed value is 100W or more and 200W or less, The phase-detection method of the coaxial cable characterized by the above-mentioned. The method according to claim 7 or 8, The abnormality detecting method of the coaxial cable is carried out in parallel with the processing to the processing target body by the processing apparatus using the high frequency power from the RF generator. RF generator which generates high frequency power, A processing apparatus for processing the gas to be processed, A coaxial cable as a feed line for connecting one end to an output of the RF generator and feeding high frequency power from the RF generator to the processing apparatus; A matching device connecting an input to the other end of the coaxial cable and an output to the processing device to match the impedance of the coaxial cable with the impedance of the processing device; A controller for controlling the matcher; First reflected wave detecting means for detecting reflected wave R at an output of said RF generator of said coaxial cable; Second reflected wave detection means for detecting a reflected wave r at an input of the matcher of the coaxial cable; Comparing the reflected wave R and the reflected wave r, the occurrence of an abnormality in the coaxial cable is detected 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 prescribed value. Probe The processing apparatus provided with the abnormality detection system of the coaxial cable characterized by the above-mentioned. The method of claim 10, The said prescribed value is 100W or more and 200W or less, The processing apparatus provided with the abnormality detection system of the coaxial cable. The method of claim 10 or 11, The abnormality detection of the coaxial cable is performed in parallel with the processing to the to-be-processed body by the processing apparatus using the high frequency power from the RF generator, wherein the abnormality detection system of the coaxial cable is provided. The method of claim 10 or 11, The processing apparatus includes a coaxial cable abnormality detection system, wherein the processing apparatus is a plasma dry etching apparatus or a plasma CVD apparatus.

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