TW201735089A - Monitoring method and apparatus of plasma arc by comparing the electrical signal with the first threshold value to obtain the first comparison waveform, and comparing the electrical signal with the second threshold value to obtain the second comparison waveform - Google Patents

Abstract

The present invention provides a monitoring method of plasma arc. When an electrical signal of electrostatic sucking disc is applied for monitoring the arc, compare the electrical signal with a first threshold value to obtain a first comparison waveform. Compare the electrical signal with a second threshold value to obtain a second comparison waveform. Since the first threshold value is smaller, the pulse of first comparison waveform has a longer lasting time, which is convenient for obtaining the relatively wider lasting time of the electrical signal that varies faster. The second waveform is obtained by comparing with a larger threshold value, which means the pulse of second waveform stands for the situation that the amplitude satisfies the demand. By determining both of them, the interference signals such as minute fluctuation or temporary fluctuation, etc. are removed, thereby effectively determining precise occurrence situations of arc , and achieving the purpose of monitoring occurrence of plasma arc reliably.

Description

Plasma arc monitoring method and device

The invention relates to the field of semiconductor etching technology, and in particular to a plasma arc detecting method.

A plasma device is a commonly used device in a semiconductor device processing process. It ionizes a gas to produce a plasma, and the surface of the substrate is processed by plasma, such as cleaning, etching, or substrate.

When the plasma equipment uses plasma to surface-treat the substrate, if a plasma arc is generated in the reaction chamber, the surface of the substrate may be damaged or may not work properly, and sometimes the reaction chamber of the plasma device may be used. The room caused adverse effects. If the occurrence of the arc can be detected when an arc occurs, subsequent damage to the substrate or even the chamber can be avoided.

At present, a plasma arc monitoring method is to monitor a high-voltage DC power source of a sputtering target, and the arc phenomenon is reflected by a transient voltage or current generated when an arc occurs. However, this method can only monitor the proximity. The arc in the target area cannot reliably monitor the arc of the plasma.

In view of the above, an object of the present invention is to provide a plasma arc detecting method and apparatus for effectively monitoring the occurrence of a plasma arc.

In order to achieve the above object, the present invention has the following technical means:

A plasma arc monitoring method, comprising:

Monitoring the occurrence of a plasma arc by using a change in the electrical signal of the electrostatic chuck power supply, the electrical signal including a voltage signal or a current signal;

The steps of monitoring the occurrence of a plasma arc using changes in the electrical signal of the electrostatic chuck power supply include:

Comparing the electrical signal with the first threshold to obtain a first comparison waveform;

Comparing the electrical signal with the second threshold to obtain a second comparison waveform, wherein the second threshold is greater than the first threshold;

Determining whether the duration of the pulse in the first comparison waveform is within a preset duration, to output a third waveform, wherein the pulse in the third waveform corresponds to a pulse in the first comparison waveform whose pulse duration is within a preset duration And determining whether there is also a pulse in the second comparison waveform during the pulse duration of the third waveform, and if so, it is considered that a plasma arc occurs.

Preferably, the step of monitoring the occurrence of the plasma arc by using a change in the electrical signal of the electrostatic chuck power supply comprises:

Comparing the electrical signal with the first threshold to obtain a first comparison waveform;

Comparing the electrical signal with the second threshold to obtain a second comparison waveform, wherein the second threshold is greater than the first threshold;

Determining whether the duration of the pulse in the first comparison waveform is within a preset duration, to output a third waveform, wherein the pulse in the third waveform corresponds to a pulse in the first comparison waveform whose pulse duration is within a preset duration It is determined whether there is a pulse in the second comparison waveform during the pulse duration of the third waveform, and if so, it is considered that a plasma arc occurs.

Preferably, after a plasma arc is considered to occur, the method further comprises:

A pulse waveform of a preset period is output for identification of the arc.

Preferably, the electrical signal of the electrostatic chuck power source is derived from the current detection of the electrostatic chuck high voltage DC converter.

Preferably, the method for determining whether a pulse is also present in the second comparison waveform during the pulse duration of the third waveform comprises:

And delaying the pulse in the second comparison waveform, the time of ending the delay is within a predetermined time after the pulse of the third waveform is inverted to output the fourth waveform;

The third waveform and the fourth waveform are logically operated to output a fifth waveform, and the pulse in the fifth waveform is considered to correspond to a signal generated by the plasma arc.

Preferably, the step of delaying the pulse in the second comparison waveform, the time at which the delay ends is within a predetermined time after the pulse of the third waveform is inverted, to output the fourth waveform includes:

The pulse of the second comparison waveform is delayed by the capacitance delay circuit, and the time delay end is determined by the delay circuit, and the time of the end of the delay is a predetermined time after the pulse of the third waveform is inverted to output the fourth waveform.

Preferably, the step of delaying the pulse in the second comparison waveform, the time at which the delay ends is within a predetermined time after the pulse of the third waveform is inverted, to output the fourth waveform includes:

Delaying the pulse of the second comparison waveform for a period of time, determining the end time of the delay by the falling edge of the pulse of the third waveform, and the time of ending the delay is within a predetermined time after the pulse of the third waveform is inverted to output the fourth waveform .

Preferably, before detecting the occurrence of the plasma arc by using the change of the electrical signal, the method further comprises: filtering the electrical signal.

In addition, the present invention also provides a plasma arc monitoring device for monitoring the occurrence of a plasma arc by using a change in the electrical signal of the electrostatic chuck power source, the electrical signal including a voltage signal or a current signal, including:

a first comparator, configured to compare the electrical signal with the first threshold to obtain a first comparison waveform;

The second comparator compares the electrical signal with the second threshold to obtain a second comparison waveform, wherein the second threshold is greater than the first threshold;

The first determining unit determines whether the duration of the pulse in the first comparison waveform is within a preset duration, to output a third waveform, wherein the pulse in the third waveform corresponds to a pulse duration in the first comparison waveform at a preset time a pulse within a long range;

The second determining unit is configured to determine whether a pulse is also present in the second comparison waveform during the pulse duration of the third waveform, and if so, it is considered that a plasma arc occurs.

Preferably, it also includes:

A pulse output unit for outputting a pulse waveform of a preset period for identification of an arc.

Preferably, the electrical signal of the electrostatic chuck power source is derived from the current detection of the electrostatic chuck high voltage DC converter.

Preferably, it also includes:

A filtering unit for filtering the electrical signal.

Preferably, the second determining unit comprises: a delay unit, configured to delay the pulse in the second comparison waveform, and the time of ending the delay is within a predetermined time after the pulse of the third waveform is inverted to output the fourth waveform;

And a circuit unit for performing a logical operation on the third waveform and the fourth waveform to output a fifth waveform, and considering that the pulse in the fifth waveform corresponds to a signal generated by the plasma arc.

Preferably, in the delay unit, the pulse of the second comparison waveform is delayed by the capacitor delay circuit, and the time delay end is determined by the delay circuit, and the delay end time is within a predetermined time after the pulse of the third waveform is inverted. To output the fourth waveform.

Preferably, in the delay unit, the pulse of the second comparison waveform is delayed for a period of time, the time of the end of the delay is determined by the falling edge of the pulse of the third waveform, and the time of the end of the delay is predetermined after the pulse of the third waveform is inverted. Time to output the fourth waveform.

The plasma arc monitoring method and device provided by the embodiment of the invention obtains a first comparison waveform by comparing the electrical signal with the first threshold when the arc is monitored by the electrical signal of the pair of electrostatic chucks, The electrical signal is compared with the second threshold to obtain a second comparison waveform. Since the first threshold is small, the pulse of the first comparison waveform has a longer duration, which facilitates obtaining a relatively wider duration of the faster changing electrical signal. And the second waveform is obtained by comparing the waveform with a larger threshold, that is, the pulse in the second waveform represents a situation in which the amplitude satisfies the requirement, and by judging the two, the small signal can be removed. Interference signals such as fluctuations or short-term fluctuations can effectively judge the occurrence of accurate arcing and achieve the purpose of reliably monitoring the occurrence of plasma arc.

The technical means in the embodiments of the present invention are clearly and completely described in the following with reference to the drawings in the embodiments of the present invention. It is a partial embodiment of the invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

As described in the prior art, in the prior art, the occurrence of a plasma arc is monitored by monitoring the high voltage DC power source of the sputtering target in the plasma apparatus, however, this method can only monitor the arc near the target area. It is impossible to reliably monitor the arc of the plasma.

To this end, the present invention proposes a plasma arc monitoring method for the purpose of reliably monitoring the arc of the plasma. In repeated implementations, the Applicant has found that the occurrence of a plasma arc can be reliably monitored by the change in the electrical signal using the electrostatic chuck power supply. Referring to FIG. 1 , which is a schematic structural view of an upper electrode and an electrostatic chuck in a plasma device, it can be seen that an electrostatic chuck (ESC, Electrostatic Chuck) is located between the upper and lower electrodes 10 and 12 that generate plasma, and is disposed under Above the electrode 12, the RF power delivered to the lower electrode can be coupled to the electrode 12 in the electrostatic chuck. When the plasma 14 has an arc 16, the arc 16 will affect the electrostatic chuck, and this effect will be reflected in the ESC. On the electrical signal, especially the voltage signal V (IESC) and the current signal IESC.

The electrostatic chuck is a device for fixing a substrate to be processed by electrostatic charge attraction. The electrostatic chuck is usually connected with a high voltage direct current converter (HV DC/DC converter) 18 to provide a high voltage DC power supply for the electrostatic chuck, as shown in FIG. To monitor the waveform obtained by the electrical signal of the electrostatic chuck in the plasma equipment, it can be seen that when a plasma arc occurs, the electrical signal of the electrostatic chuck suddenly increases, and when the arc disappears, the electrical signal gradually decreases. To normal value. Based on this, the present invention provides a plasma arc monitoring method, as shown in FIG. 3, comprising: S101, monitoring the occurrence of a plasma arc by using a change of an electrical signal of an electrostatic chuck power source, the electrical signal including a voltage signal or a current signal; The change of the electrical signal of the electrostatic chuck power supply to monitor the occurrence of the plasma arc includes: comparing the electrical signal with the first threshold to obtain a first comparison waveform; comparing the electrical signal with the second threshold to obtain a second comparison waveform, The second threshold is greater than the first threshold; determining whether the duration of the pulse in the first comparison waveform is within a preset duration to output a third waveform, and the pulse in the third waveform corresponds to the pulse duration in the first comparison waveform A pulse having a time within a preset duration and determining whether a pulse is also present in the second comparison waveform during the pulse duration of the third waveform, and if so, it is considered that a plasma arc occurs. By monitoring the electrical signal of the electrostatic chuck, the purpose of effectively monitoring the occurrence of the plasma arc is achieved.

In order to facilitate the acquisition of the electrical signal of the electrostatic chuck power supply, in the embodiment of the present invention, referring to FIG. 1, the electrical signal of the electrostatic chuck power supply is the current detecting voltage or the voltage signal V of the high voltage direct current converter 18 of the electrostatic chuck (IESC). The current output of the current detecting port is proportional to the current of the electrostatic chuck power supply, and can reflect the change of the current. The current detects the electrical signal of the voltage or current signal provided by the current, and monitors the plasma by monitoring the change of the electrical signal. The occurrence of an electric arc.

For a better understanding of the technical means and technical effects of the present invention, the specific embodiments will be described in detail below with reference to the flowchart.

In step S101, the electrical signal is compared with the first threshold to obtain a first comparison waveform.

In the embodiment of the present invention, the first threshold has a smaller value than the second threshold. When the electrical signal is a current signal, the electrical signal is compared with the first threshold, that is, if the value of the electrical signal is greater than the first threshold, then the comparison is compared. After the first value is output, the first value is, for example, 1. If the value of the electrical signal is less than the first threshold, the second value is output after comparison. The second value is, for example, 0. The first value and the second value constitute a time-varying component. A comparison waveform, wherein the first value represents a value when the electrical signal is abnormal, and is a pulse in the first comparative waveform.

In step S102, the electrical signal is compared with the second threshold to obtain a second comparison waveform, wherein the second threshold is greater than the first threshold.

In this step, the electrical signal is compared with a threshold, a second threshold, and the second threshold is greater than the first threshold. In a specific embodiment, for example, the first threshold may be 10 uA, and the second threshold may be 20uA.

In the same step S101, the electrical signal is compared with the second threshold. If the electrical signal is greater than the second threshold, the third value is output after comparison. The third value is, for example, 1. If the electrical signal is less than the second threshold, the output is compared. The fourth value, the fourth value is, for example, 1, the third value and the fourth value constitute a first comparison waveform that changes with time, wherein the third value represents a value when the electrical signal is abnormal, and is a pulse in the second comparative waveform.

For the above-mentioned electrical signal, it may be an electrical signal directly from the electrostatic chuck power supply, such as a current detecting 埠 electrical signal from the electrostatic chuck high voltage direct current converter. More preferably, the electrical signal is a filtered electrical signal, such as after a low Through-filter and high-pass filtered electrical signals.

In step S103, it is determined whether the duration of the pulse in the first comparison waveform is within a preset duration, to output a third waveform, and the pulse in the third waveform corresponds to a pulse duration in the first comparison waveform at a preset duration A pulse within the range is determined whether a pulse is also present in the second comparison waveform during the pulse duration of the third waveform, and if so, a plasma arc is considered to have occurred.

For the first comparison waveform, it is determined whether the duration of the pulse is within a preset duration, and the preset duration may be, for example, 25-330 us. For the pulse within the preset duration, it is considered that An arc occurs, that is, an abnormal condition of a longer or shorter duration in the first comparison waveform is excluded, a short abnormality is usually a disturbance condition, and an excessively long abnormality is usually a failure condition, and these are not It is the case where an arc occurs.

For the case where the duration meets the condition, it may still be an interference signal. In actual production, it cannot be considered that an arc occurs. Therefore, in the embodiment of the present invention, it is further determined whether there is a pulse in the second comparison waveform in the duration period, and if so, the secondary pulse is considered to correspond to the occurrence of a plasma arc. That is to say, after the abnormal duration satisfies the condition, if there is a pulse in the second comparison waveform during the duration period, it indicates that the abnormality causes a large fluctuation of the electrical signal, and is not an interference signal, and the The secondary pulse is a sudden change in the electrical signal caused by the occurrence of a plasma arc.

In the preferred embodiment, when the arc is monitored by the electrical signals of the pair of electrostatic chucks, the first comparison waveform is obtained by comparing the electrical signal with the first threshold by using the electrical signal and the second threshold. Comparing, obtaining a second comparison waveform, since the first threshold is smaller, the pulse of the first comparison waveform has a longer duration, which is convenient for obtaining a relatively wider duration of the faster changing electrical signal, and the second waveform is By obtaining a waveform after comparing with a larger threshold, that is, the pulse in the second waveform represents a situation in which the amplitude satisfies the requirement, by judging the two, the interference of small fluctuations or short-term fluctuations of the electrical signal can be removed. The signal effectively judges the occurrence of an accurate arc and achieves the purpose of reliably monitoring the occurrence of the plasma arc.

In a specific embodiment, the method for determining whether a pulse is also present in the second comparison waveform during the pulse duration of the third waveform includes:

And delaying the pulse in the second comparison waveform, the time of ending the delay is within a predetermined time after the pulse of the third waveform is inverted to output the fourth waveform;

The third waveform and the fourth waveform are logically operated to output a fifth waveform, and the pulse in the fifth waveform is considered to correspond to a signal generated by the plasma arc.

In order to better illustrate the method for obtaining the signal generated by the plasma arc in this embodiment, a specific embodiment will be described in conjunction with the waveform variation diagram. Referring to FIG. 4, it can be seen that the electrical signal A of the electrostatic chuck power supply is After comparing with the first threshold, outputting a first comparison waveform (not shown), the pulse duration in the first comparison waveform is within a preset duration, and therefore, outputting the third waveform B, the telecommunication of the electrostatic chuck power supply After comparing with the second threshold, the number A outputs a second comparison waveform C, and delays the pulse in the second comparison waveform C. The time after the delay ends is within a predetermined time after the pulse of the third waveform B is inverted. In the example shown in Figure 4, the delay ends after a certain time after the falling edge of the third waveform comes E, so that after the E signal, the delayed waveform of the second comparative waveform is inverted, thereby outputting the fourth waveform D, which will be the fourth The waveform D and the third waveform B are logically operated, so that a fifth waveform for confirming the occurrence of the plasma arc can be obtained, and the pulse in the waveform corresponds to the plasma arc. Signal.

For the determination of the time of the end of the delay, different manners may be used. In some embodiments, the pulse of the second comparison waveform may be delayed by the capacitor delay circuit, and the end time of the delay is also determined by the circuit delay circuit, by the capacitor delay. The capacitive characteristic of the circuit is designed to delay the second comparison waveform for a specific period of time such that the time at which the delay ends occurs within a predetermined time after the pulse of the third waveform is inverted.

In other embodiments, by determining the end of the delay by the falling edge of the pulse of the third waveform, the flipping of the delayed waveform of the second comparison waveform may be directly triggered by the falling edge of the pulse of the third waveform, or by The falling edge of the pulse of the third waveform delays the flipping of the delayed waveform of the second comparative waveform after a certain time, so that the time of the end of the delay occurs within a predetermined time after the pulse of the third waveform is inverted.

After determining that a plasma arc has occurred, an appropriate signal can be output to indicate the occurrence of the arc. For example, a sixth waveform can be output, the pulse in the sixth waveform represents an arc, and other signals can be provided for further application. Such as alarms or statistics, so that the staff can carry out further operations based on this information.

It is also possible to include a step S104 of outputting a pulse waveform of a preset period for identification of the arc.

In an actual plasma equipment, a PLC (programmable controller) is usually used as a signal processing and control device. The PLC device cannot capture a pulse signal whose duration is too short. For example, a pulse with a duration of less than 150 ms cannot be used. The time that the arc is captured and the arc occurs is microsecond. Even if the signal of the arc is effectively recognized, it cannot be obtained and further applied by the PLC. Based on this, in a preferred embodiment, after the occurrence of the plasma arc is confirmed, a pulse waveform of a period length which can be further recognized is output, for example, a pulse waveform of 150 ms is output, which is expressed as having a plasma. An electric arc occurs. The pulse waveform of the preset period will be sent to the signal processing and control device for identification and further application of the arc signal.

The plasma arc monitoring method of the embodiment of the present invention has been described in detail above. In addition, the present invention also provides a plasma arc monitoring device 300 corresponding to the above method for monitoring the plasma by using the change of the electrical signal of the electrostatic chuck power supply. For the occurrence of an electric arc, the electrical signal includes a voltage signal or a current signal, as shown in FIG. 5, including:

The first comparator 320 is configured to compare the electrical signal with the first threshold Vref1 to obtain a first comparison waveform;

The second comparator 330 compares the electrical signal with the second threshold Vref2 to obtain a second comparison waveform, wherein the second threshold is greater than the first threshold;

The first determining unit 340 determines whether the duration of the pulse in the first comparison waveform is within a preset duration, to output a third waveform, and the pulse in the third waveform corresponds to the pulse duration in the first comparison waveform is preset a pulse within the duration;

The second determining unit 350 is configured to determine whether a pulse is also present in the second comparison waveform during the pulse duration of the third waveform, and if so, it is considered that a plasma arc occurs. Further, a pulse output unit 360 is further included for outputting a pulse waveform of a preset period, for example, a pulse waveform with a period of 150 ms for identification of the arc.

Further, the electrical signal of the electrostatic chuck power source is derived from the current detection of the electrostatic chuck high voltage DC converter.

Further, the method further includes: a filtering unit 310, configured to filter the electrical signal.

Referring to FIG. 6 and FIG. 7, the second determining unit includes: a delay unit 3501/3503 for delaying a pulse in the second comparison waveform, and the time of ending the delay is within a predetermined time after the pulse of the third waveform is inverted. To output a fourth waveform;

The AND circuit unit 3502 is configured to perform a logical operation on the third waveform and the fourth waveform to output a fifth waveform, and consider that the pulse in the fifth waveform corresponds to a signal generated by the plasma arc.

For the delay unit, a different manner of delay circuit can be used. In some embodiments, referring to FIG. 6, the delay unit is a capacitor delay circuit 3501, and the pulse of the second comparison waveform C is delayed by the capacitor delay circuit 3501, and The time at which the delay ends is determined by the delay circuit 3501, and the time at which the delay ends is within a predetermined time after the pulse of the third waveform B is inverted to output the fourth waveform D. The second comparison waveform can be delayed by a specific time by the design of the capacitance characteristic of the capacitor delay circuit.

In other embodiments, referring to FIG. 7, the delay unit is a delay trigger circuit 3503 for delaying the pulse of the second comparison waveform C for a period of time, and triggering the end of the delay by the falling edge of the pulse of the third waveform B. And the time at which the delay ends is within a predetermined time after the pulse of the third waveform is inverted to output the fourth waveform D. In the illustrated embodiment, the trigger signal end of the delay trigger circuit 3503 is connected to the output terminal D of the delay terminal trigger circuit and the output terminal E of the third waveform B, and thus, by the pulse of the third waveform. The falling edge delays the flipping of the delayed waveform of the second comparison waveform after a certain time delay.

The various embodiments in the specification are described in a progressive manner, and the same or similar parts between the various embodiments may be referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the description of the method embodiment. The system embodiments described above are merely illustrative, wherein the modules or units described as separate components may or may not be physically separate, and the components displayed as modules or units may or may not be Physical units can be located in one place or distributed to multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the embodiment. Those of ordinary skill in the art can understand and implement without any creative effort.

The above is only a preferred embodiment of the present invention, and although the present invention has been disclosed in the above preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make many possible changes and modifications to the technical means of the present invention by using the methods and technical contents disclosed above, or modify the equivalent of equivalent changes without departing from the scope of the technical means of the present invention. Example. Therefore, any simple modifications, equivalent changes, and modifications of the above-described embodiments in accordance with the technical spirit of the present invention are still within the scope of the technical means of the present invention.

10, 12‧‧‧ electrodes
14‧‧‧ Plasma
16‧‧‧Arc
18‧‧‧HVDC converter
300‧‧‧plasma arc monitoring device
310‧‧‧Filter unit
320‧‧‧First comparator
330‧‧‧Second comparator
340‧‧‧First Judgment Unit
350‧‧‧Second Judging Unit
360‧‧‧pulse output unit
3501, 3503‧‧‧ delay unit
3502‧‧‧ circuit unit
A‧‧‧Electric signal for electrostatic chuck power supply
B‧‧‧ Third Waveform
C‧‧‧Second comparison waveform
D‧‧‧ fourth waveform
E‧‧‧ output
S101, S102, S103‧‧‧ steps
V (IESC) ‧ ‧ voltage signal
Vref1‧‧‧ first threshold
Vref2‧‧‧ second threshold
IESC‧‧‧current signal

In order to more clearly illustrate the embodiments of the present invention or the technical means in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description are the present invention. Some embodiments of the present invention can also obtain other drawings based on these drawings without departing from the prior art.

1 is a schematic structural view of an upper electrode and an electrostatic chuck in a plasma device;

2 is a schematic diagram showing the electrical signal waveform of the electrostatic chuck when a plasma arc occurs in the plasma device of FIG. 1;

3 is a schematic flow chart of a plasma arc monitoring method according to an embodiment of the present invention;

4 is a schematic waveform diagram of a signal for obtaining a plasma arc in a monitoring method according to an embodiment of the present invention;

FIG. 5 is a schematic structural view of a plasma arc monitoring device according to an embodiment of the present invention; FIG.

6 is a schematic circuit diagram of a plasma arc monitoring device according to an embodiment of the invention;

FIG. 7 is a schematic diagram showing the circuit structure of a plasma arc monitoring device according to another embodiment of the present invention.

S101, S102, S103‧‧‧ steps

Claims (12)

A plasma arc monitoring method includes: monitoring the occurrence of a plasma arc by using a change of an electrical signal of an electrostatic chuck power source, the electrical signal comprising a voltage signal or a current signal; and the change of the electrical signal using the electrostatic chuck power supply The step of monitoring the occurrence of the plasma arc includes: comparing the electrical signal with a first threshold to obtain a first comparison waveform; comparing the electrical signal with a second threshold to obtain a second comparison waveform, where The second threshold is greater than the first threshold; determining whether the duration of the pulse in the first comparison waveform is within a preset duration to output a third waveform, and the pulse in the third waveform corresponds to the first comparison A pulse in the waveform whose pulse duration is within a preset duration and determines whether a pulse is also present in the second comparison waveform during the pulse duration of the third waveform. If so, it is considered that a plasma arc occurs. The monitoring method of claim 1, wherein after a plasma arc is considered to occur, the method further comprises: outputting a pulse waveform of a preset period for identification of the arc. The monitoring method of claim 1, wherein the method for determining whether a pulse is also present in the second comparison waveform during the pulse duration of the third waveform comprises: pulsing the second comparison waveform Performing a delay, the time of ending the delay is a predetermined time after the pulse of the third waveform is inverted to output a fourth waveform; and the third waveform and the fourth waveform are logically operated to output a fifth waveform. It is considered that the pulse in the fifth waveform corresponds to the signal generated by the plasma arc. The monitoring method of claim 3, wherein the pulse in the second comparison waveform is delayed, and the time at which the delay ends is within a predetermined time after the pulse of the third waveform is inverted to output the fourth The step of waveform includes: delaying the pulse of the second comparison waveform by a capacitance delay circuit, determining a time for ending the delay by the circuit delay circuit, and the time of ending the delay is within a predetermined time after the pulse of the third waveform is inverted To output the fourth waveform. The monitoring method of claim 3, wherein the pulse in the second comparison waveform is delayed, and the time at which the delay ends is within a predetermined time after the pulse of the third waveform is inverted to output the fourth The step of waveforms includes: delaying the pulse of the second comparison waveform for a period of time, determining the end time of the delay by the falling edge of the pulse of the third waveform, and the time of ending the delay is predetermined after the pulse of the third waveform is inverted Time to output the fourth waveform. The monitoring method according to any one of claims 1 to 5, wherein the electrical signal of the electrostatic chuck power source is from a current detecting port of an electrostatic chuck high voltage DC converter. A plasma arc monitoring device for monitoring the occurrence of a plasma arc by using a change of an electrical signal of an electrostatic chuck power supply, the electrical signal comprising a voltage signal or a current signal, comprising: a first comparator for Comparing the electrical signal with a first threshold to obtain a first comparison waveform; a second comparator comparing the electrical signal with a second threshold to obtain a second comparison waveform, wherein the second threshold is greater than a first threshold; a first determining unit, determining whether the duration of the pulse in the first comparison waveform is within a preset duration, to output a third waveform, wherein the pulse in the third waveform corresponds to the first Comparing pulses in the waveform whose pulse duration is within a preset duration; a second determining unit is configured to determine whether a pulse is also present in the second comparison waveform during the pulse duration of the third waveform, and if so, It is believed that there is a plasma arc that occurs. The monitoring device of claim 7, further comprising: a pulse output unit for outputting a pulse waveform of a preset period for identification of the arc. The monitoring device of claim 7, wherein the second determining unit comprises: a delay unit, configured to delay the pulse in the second comparison waveform, and the time delay ends in the pulse of the third waveform a predetermined period of time after the flipping, to output a fourth waveform; and a circuit unit for performing a logical operation on the third waveform and the fourth waveform to output a fifth waveform, and considering the fifth waveform The pulse corresponds to the signal generated by the plasma arc. The monitoring device of claim 9, wherein the delay unit is a capacitor delay circuit, wherein the capacitor delay circuit delays the pulse of the second comparison waveform, and the capacitor delay circuit determines that the delay ends. The time, and the time at which the delay ends, is within a predetermined time after the pulse of the third waveform is inverted to output the fourth waveform. The monitoring device of claim 9, wherein the delay unit is a delay trigger circuit for delaying the pulse of the second comparison waveform for a period of time, and triggering the delay by the falling edge of the pulse of the third waveform Ending, and the time at which the delay ends is within a predetermined time after the pulse of the third waveform is inverted to output the fourth waveform. The monitoring device according to any one of claims 7 to 11, wherein the electrical signal of the electrostatic chuck power source is from a current detecting port of an electrostatic chuck high voltage DC converter.