JP2001023969A - Plasma system having exhaust gas monitor and method of operating the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a plasma system and a method of operating the same, where PFC(perfluoro compounds) contained in an exhaust gas can be monitored on a real-time basis. SOLUTION: This plasma system performs chemical processing using a plasma of a gas containing molecules, having affinity with electrons, and includes a reaction chamber 1 for performing the processing, a pump 5 for discharging a gas within the chamber 1, a contaminant-removing unit 6 for dissolving or adsorbing the gas discharged from the chamber 1, a mass analyzer 8 for sampling a part of the gas discharged from the unit 6 for measuring the quantity of PFC contained in the exhaust gas, and a control section for controlling the operation of the unit 6, based on the result of the measurements made by the analyzer 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a plasma apparatus suitable for manufacturing a semiconductor device and a method of operating the same.
In particular, the present invention relates to a plasma apparatus capable of detecting an amount of a specific type of gas formed in plasma remaining in exhaust gas and a method of operating the same.

[0002]

2. Description of the Related Art In recent years, when manufacturing semiconductor devices, it has become a major issue to take care not to pollute the global environment. In the semiconductor device manufacturing process, C
Many kinds of perfluoro compound (PFC) gases are used, starting with F ₄ gas. These PFC gases (for example, CF ₄ , C ₂ F ₆ , C ₄ F ₈ , CHF ₃ , NF ₃ ,
Since such SF ₆₎ has a larger global warming potential GWP, when released into the atmosphere air temperature rises due to the greenhouse effect, leading to the destruction of the natural environment. For this reason, the semiconductor device manufacturing industry is seriously considering measures against global warming.
There is aggressive study of gas alternatives to FC. Alternatively the gas, for example, small C ₅ F ₈ process or the like using the gas (unregulated) global warming potential GWP has been proposed.

[0003] However, it has become clear that PFC is generated by a chemical reaction in plasma even when such an alternative gas is used. Therefore, even if an alternative gas is employed, it is not possible to prevent pollution of the global environment unless the emission of PFC generated in plasma is restricted.
In order to suppress the emission of PFC generated in the plasma,
It has been proposed to add a PFC abatement device to a dry etching device. Hereinafter, the configuration and operation of such a PFC abatement apparatus will be described.

FIG. 9 is a schematic diagram of a dry etching apparatus using inductively coupled plasma. The illustrated apparatus is an etching apparatus having a reaction chamber 1, which performs etching on a surface of a semiconductor substrate disposed on a substrate holder in the reaction chamber 1. An induction coil 2 is provided on the outer periphery of the reaction chamber 1, and the induction coil 2 is connected to a high-frequency power supply 19. Plasma is formed in the reaction chamber 1 by the high-frequency power applied to the induction coil 2. The substrate holder in the reaction chamber 1 has another high-frequency power source 1
Power for substrate bias is supplied from 7. In the reaction chamber 1, the gas (C ₅ F ₈ , O
_The reaction chamber 1 is connected to an exhaust pump 5 through a pipe 3. A pressure control valve 4 is inserted between the reaction chamber 1 and the exhaust pump 5.
An abatement device 6 for decomposing or adsorbing gas exhausted from the exhaust pump 5 is provided. The gas in the reaction chamber 1 is exhausted to the outside via the abatement device 6.

[0005] An induction coil 7 connected to a high frequency power supply 15 is also provided on the outer periphery of the abatement apparatus 6. Removal equipment 6
, A gas such as oxygen is supplied from a gas cylinder 11 through a flow control device 12, and is turned into plasma by high-frequency power supplied to the induction coil 7. This plasma decomposes PFC gas and the like in the exhaust gas.

Although the apparatus shown in FIG. 9 employs a plasma type abatement apparatus, a catalytic combustion apparatus as shown in FIG. 10 may be used. The abatement apparatus shown in FIG. 10 includes a preheating chamber 143 having a heater 144 and a catalyst layer 145 in order to decompose exhaust gas emitted from a plasma device (not shown) by a catalyst. In addition, the abatement apparatus includes a filling chamber 141 for receiving exhaust gas emitted from the plasma device, a water spray chamber 142 for removing water-soluble gas and fine particles contained in the exhaust gas, and a catalyst layer 145. A cooling chamber 146 for cooling the permeated gas and a scrubber 147 are provided.
Electric power supplied to the heater 144 is supplied from a power supply 149, and the output of the power supply 149 is maintained at a predetermined temperature by a temperature control device 148. The temperature control device 148 includes the heater 1
The output of the power supply 149 is controlled based on the output of the temperature sensor 150 that detects the temperature of the power supply 44.

A simple combustion type abatement apparatus is shown in FIG.
Has a configuration in which the catalyst layer 145 is removed from the abatement apparatus.

[0008]

The conventional plasma apparatus does not include a device for monitoring how much PFC contained in the exhaust gas is removed. Therefore, there is a problem that even if sufficient detoxification is achieved under certain plasma processing conditions, if the processing conditions are changed or fluctuated, the detoxification becomes insufficient. If the abatement apparatus is operated excessively in order to avoid such a problem, energy consumption by the abatement apparatus increases, and the life of the abatement apparatus becomes shorter.

The present invention has been made in view of the above points, and a main object of the present invention is to provide a PFC contained in exhaust gas.
It is an object of the present invention to provide a plasma apparatus capable of monitoring the amount of the plasma in real time and an operation method thereof.

[0010]

SUMMARY OF THE INVENTION A plasma apparatus according to the present invention is a plasma apparatus for performing a chemical treatment using plasma, and comprises a reaction chamber for performing the treatment, and exhausting gas in the reaction chamber. A pump, an abatement unit that decomposes or adsorbs the gas exhausted from the reaction chamber, and a part of the gas exhausted from the abatement unit, and a gas composed of molecules having electron affinity in the exhaust gas. A mass spectrometer for measuring the amount of the gas, and a controller for controlling the operation of the abatement unit based on the measurement result of the mass spectrometer.

[0011] It is preferable that the mass spectrometer attaches an electron to the molecule to generate a negative ion, and measures the amount of the specific gas by detecting the amount of the negative ion.

[0012] It is preferable that the apparatus further comprises a pipe for guiding the gas exhausted from the mass spectrometry section to the pump.

A control unit configured to calculate an amount of the specific gas from a result of mass spectrometry in the abatement unit;
The apparatus may further include a second operation unit that compares a preset reference value with a calculation result of the first operation unit and adjusts an operation of the abatement unit.

The abatement unit may be of a type that decomposes a gas using plasma, or may be of a catalytic type.

The operation method of the plasma device according to the present invention is as follows.
The method for operating a plasma apparatus according to any one of the above, wherein the mass spectrometry unit generates negative ions by adsorbing electrons to the molecules while changing electron energy in a range of 0 to 10 eV; Separating a peak of a signal waveform indicating a result by a Gaussian function; storing a peak value of a specific energy peak in the signal waveform in a memory; and displaying the peak value stored in the memory in a display unit. And outputting to the

The method may further include calculating an area intensity of the specific energy peak and storing the area intensity in a memory, and outputting the peak intensity and the area intensity to the display unit. .

Comparing the peak value of the specific energy peak with a previously input peak reference value, and stopping the chemical treatment when the peak value of the specific energy peak is equal to or greater than the peak reference value. And a step.

Comparing the peak value of the specific energy peak with a previously input peak reference value; and removing the harmful substance by the abatement unit when the peak value of the specific energy peak is equal to or greater than the peak reference value. And a step of increasing efficiency.

[0019] The step of increasing the harm removal efficiency in the harm removal section may include a step of increasing high frequency power used for forming plasma in the harm removal section.

It is preferable to use fluorine ions as the negative ions.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a plasma device according to the present invention and an operation method thereof will be described with reference to the drawings.

(Embodiment 1) FIG. 1 is a configuration diagram showing a first embodiment of a plasma apparatus according to the present invention.

The illustrated apparatus is a plasma apparatus provided with a reaction chamber 1 for performing a chemical treatment such as etching or thin film deposition, and performs a plasma treatment on a surface of a semiconductor substrate placed on a substrate holder in the reaction chamber. Then, various chemical treatments (for example, etching) are performed. In the present embodiment, a C ₅ F ₈ gas having a small global warming potential GWP is used as the gas to be turned into plasma in the reaction chamber 1. Note that C ₄ F ₆ , C ₆ F ₆ , C ₃ F ₆ or the like may be used as the gas having a small global warming coefficient GWP.

An induction coil 2 is provided on the outer periphery of the reaction chamber 1, and the induction coil 2 is connected to a high frequency power supply 19. Plasma is formed in the reaction chamber 1 by the high-frequency power applied to the induction coil 2. Power for substrate bias is supplied to the substrate holder in the reaction chamber 1 from another high frequency power supply 17. The gas stored in the gas cylinder 16 is introduced into the reaction chamber 1 via the flow control device 18. Although a single gas cylinder 11 is illustrated in FIG. 1, a predetermined gas can be actually introduced into the reaction chamber 1 at a predetermined flow rate from each of the plurality of gas cylinders.

The reaction chamber 1 is connected to an exhaust pump 5 through a pipe 3. A pressure control valve 4 is inserted between the reaction chamber 1 and the exhaust pump 5.
At the subsequent stage, an abatement apparatus 6 for decomposing or adsorbing gas exhausted from the exhaust pump 5 is provided. The gas in the reaction chamber 1 is exhausted to the outside through the abatement device 6,
A part of the exhausted gas is collected by the mass spectrometer 8 and is subjected to mass analysis. The diameter of the sampling orifice of the mass spectrometer 8 is preferably changed according to the operating pressure of the abatement apparatus. For example, operating pressures up to 50
In the case of 0 mTorr, the diameter of the sampling orifice is selected to be about 500 μm.

An induction coil 7 connected to a high-frequency power supply 15 is also provided on the outer periphery of the abatement apparatus 6. The abatement apparatus 6 of the present embodiment is of a type that decomposes exhaust gas by plasma. As such an abatement apparatus 6,
What is necessary is just to use the abatement apparatus which has a well-known structure. A gas such as oxygen is supplied from the gas cylinder 11 to the abatement apparatus 6 through the flow rate control device 12, and is turned into plasma by high-frequency power (for example, frequency: 13.56 MHz, power: 1000 to 1200 W) supplied to the induction coil 7. Is done. In the present embodiment, oxygen or a mixed gas of oxygen and water is supplied to the abatement apparatus 6, and plasma of the gas decomposes PFC gas and the like in the exhaust gas.

In the plasma apparatus having the above-described structure, a part of the gas introduced into the reaction chamber 1 is changed into a reaction gas by the plasma, but some of the gases remain undissociated. Further, PF is used as a gas introduced into the reaction chamber 1.
Even when a gas containing no C is used, a PFC gas is formed by the chemical reaction in the plasma as described above. All of the gas in the reaction chamber 1 is sent to the abatement device 6, and most of the exhaust gas is decomposed or adsorbed by the abatement device 6. However, if the operation of the abatement apparatus 6 becomes unstable or the conditions of the chemical treatment performed in the plasma apparatus main body change, the abatement apparatus 6 can sufficiently achieve the decomposition or adsorption of the PFC gas. It may not be possible.

The operations of the pressure control valve 4, the flow controllers 12 and 18, and the high-frequency power supplies 15, 17 and 19 are controlled by the arithmetic unit 14. Arithmetic unit 1
4 is connected to another arithmetic unit 10 via an electric circuit 13. The arithmetic devices 10 and 14 are, for example,
It is constituted by a microcomputer having a CPU and a memory. The computing device 10 and the computing device 14 may be independent computers, respectively, or one computer may serve as both computing devices. In the example of FIG. 1, a computing device 10 is added for controlling the abatement device 6 in addition to the computing device 14 used for controlling the plasma device main body.

The mass spectrometer 8 can detect the amount of PFC gas in the exhaust gas by the electron attachment mass spectrometry described later. The mass spectrometer 8 has a filament electrode for generating attached electrons. A preferred material for the filament is a tricoat iridium filament. In this embodiment, a relatively large current flows through the filament because low-energy electrons whose generation efficiency is not high are used.

In this embodiment, the exhaust gas collected by the mass spectrometer 8 is exhausted to the outside by the second exhaust pump 9.

The result of mass analysis by the mass spectrometer 8 is subjected to various arithmetic processing by the arithmetic unit 10. A signal based on the result of the data processing is transmitted to the arithmetic unit 14 via the electric circuit 13 described above.

A feature of this embodiment is that a mass spectrometer 8 for performing electron attachment mass spectrometry is added to the abatement apparatus 6 as an exhaust gas monitor. An output signal obtained by the mass spectrometer 8 is transmitted to an arithmetic circuit of the plasma device main body via an electric circuit, whereby the operations of the plasma device main body and the abatement apparatus can be adjusted. As a result, it is possible to prevent a problem that a predetermined high-frequency power is not output in the abatement apparatus 6 and a problem that oxygen or a mixed gas of oxygen and water is not introduced at a predetermined flow rate.

It is not necessary to keep the mass spectrometer 8 operating at all times. When performing a process such as etching or thin film deposition in a reaction chamber, it is sufficient to perform mass spectrometry once for each process. By doing so, the filament of the mass spectrometer 8 is prevented from deteriorating, and can be used for a long time.

The reason why the exhaust gas is monitored by electron attachment mass spectrometry is as follows.

Many gases used for manufacturing semiconductor devices, such as etching of oxide films, have an electron affinity, and these gases are easily ionized. For example, CF ₄ , C ₂ F
₆ , CHF ₃ , NF ₃ , SF ₆ , C ₃ F ₈ , C ₄ F ₈ , and C
PFC gases such as ₅ F ₈ are all with electron affinity. For this reason, the low-energy electrons are likely to resonately attach to the PFC molecules due to the interaction with the Coulomb field of the PFC molecules and generate negative ions. According to the electron attachment mass spectrometry, since such characteristics of the PFC gas can be used, PFC can be quantitatively measured.

The graph of FIG. 2 shows a signal waveform obtained by electron attachment mass spectrometry for fluorine negative ions in plasma. Fitting to the measured data is performed using an arithmetic unit, and the peak values are separated as shown in the graph of FIG. The fitting is preferably performed using, for example, a Gaussian function. From FIG. 2, it can be seen that the curve (signal waveform) indicated by the data points of the black circles is a superposition of seven peak signals (S1 to S7).

From the graph of FIG. 2, the negative ions of fluorine were
Analysis reveals what molecules are contained in the plasma.
Call In this example, peak P6 is CF_Four, Peak P3
C_TwoF ₆, Peak P2 is C_ThreeF₈From the signal. to this
On the other hand, peak P7 is C_FiveF₈, Peak P5 is C_FiveF₈,
Peak P4 is undetermined gas, peak P1 is C_FiveF₈Faith from
No. The area of the peak Pi (i is a natural number) is represented by Si.
To show, for example, CF _FourIs the share of the entire exhaust gas
Is S6 / (S1 + S2 + S3 + S4 + S5 + S6 + S
7 ...). In this specification,
It may be referred to as “the occupancy of fragment 6”.

In this way, the P present in the exhaust gas
The amount of FC gas can be grasped quantitatively. If the operations of the plasma device main body and the abatement apparatus are adjusted based on the measured value of the PFC gas amount thus obtained, the PFC gas amount in the exhaust gas can be reduced.

(Embodiment 2) Next, another embodiment of the plasma apparatus according to the present invention will be described with reference to FIG.

In the first embodiment described above, a dedicated pump is used as the exhaust pump 9 for the mass spectrometer 8, but in the present embodiment, the exhaust pump of the mass spectrometer 8 is replaced with the exhaust pump of the plasma device body. 5 doubles. That is, the exhaust gas taken into the mass spectrometer 8 is sent to the exhaust pump 5 through the pipe 20 connecting the ionization chamber of the mass spectrometer 8 and the exhaust pump 5.

By adopting such a configuration,
The total number of exhaust pumps can be reduced, and the cost of the apparatus can be reduced. In addition, since the gas collected by the mass spectrometer 8 is exhausted again through the abatement device 6,
A more complete closed gas system can be constructed. With such a configuration, even when a harmful gas such as chlorine or carbon monoxide is used as the process gas,
Higher safety can be ensured.

Although the plasma apparatus shown in FIGS. 1 and 3 uses a type in which gas is decomposed by plasma as the abatement apparatus 6, a catalytic abatement apparatus may be used. FIG.
Shows the configuration of a catalytic abatement device.

The abatement apparatus includes a preheating chamber 43 having a heater 44 and a catalyst layer 45 for decomposing exhaust gas discharged from the plasma apparatus by a catalyst. Further, the abatement apparatus includes a filling chamber 41 for receiving exhaust gas emitted from a plasma apparatus such as an etching apparatus, a water spray chamber 42 for removing water-soluble gas and fine particles contained in the exhaust gas, and a catalyst layer. A cooling chamber 46 for cooling the gas that has passed through 45 and a scrubber 47 are provided. Electric power supplied to the heater 44 is supplied from a power supply 49, and the output of the power supply 49 is adjusted by a temperature control device 48. The temperature control device 48 includes a temperature sensor 50 for detecting the temperature of the heater 44.
The output of the power supply 49 is controlled based on the output of.

According to such an abatement apparatus, CO, SiF ₄ , solid content, acid gas, and CF ₄ which is difficult to decompose among PFCs can be collectively processed while having a simple structure.

In this embodiment, the mass spectrometer 8 collects a part of the gas exhausted from the scrubber 47 and performs the above-described mass analysis on the gas. The analysis result is the arithmetic unit 10
And the PFC in the exhaust gas is quantitatively grasped. If the PFC in the exhaust gas is larger than a preset reference value, the arithmetic unit 14 sends a signal to the temperature control unit 48 through the electric circuit 13, thereby increasing, for example, the heater temperature and decomposing the PFC by the catalyst. It works to promote and increase the abatement efficiency. (Embodiment 3) An embodiment of a plasma device operating method according to the present invention will be described with reference to FIG.

First, processes such as etching in the reaction chamber
Before performing the above, in step S1, the height of the abatement apparatus is increased.
When the calibration gas is
To supply oxygen gas to the abatement system. Next, step S
In part 2, a part of the exhaust gas (oxygen gas) of the abatement system is
Energy axis of mass spectrometry
Perform calibration for. Calibration of energy axis is mass
This is performed to compensate for measurement variations of the analyzer. Carry
As the brazing gas, other than oxygen, SF ₆, C
l_Two, CO, and C_TwoF₆Known cross-section data
Gas can be used. Filament in mass spectrometer
F gas may be released from the
It is preferable to calibrate while grasping the background amount.
After the calibration is completed, the end signal (Pro
Process start command), and the arithmetic unit of the plasma device body
(Step S3).

In step S4, high frequency power is applied to the abatement apparatus to operate the abatement apparatus. In step S5, after a process such as etching is started in the plasma device main body, electron attachment mass spectrometry is performed on a part of the exhaust gas discharged from the abatement apparatus, and the signal intensity of fluorine negative ions in the exhaust gas is measured. (Step S6). In step S7, fitting is performed on the measured data using an arithmetic unit, and peak values are separated as shown in the graph of FIG. The fitting is preferably performed using, for example, a Gaussian function.

In step S8, these peak values are stored in the storage device in association with the process time. The storage device may be provided in either the mass spectrometer or the plasma device.

In step S9, the peak value stored in the storage device may be output on the display device of the plasma device and / or the mass spectrometer. By doing so, the operator of the plasma apparatus can monitor the PFC removal status almost in real time.

Note that the mass spectrometer does not need to be constantly operating. It is often sufficient to perform exhaust gas monitoring once during one process step, such as etching or thin film deposition.

(Embodiment 4) Another embodiment of the plasma device operating method according to the present invention will be described with reference to FIG. The monitoring method of the present embodiment is executed in the same manner as the monitoring method of the third embodiment until the start of the process (Step S
11 to S15).

After starting a process such as etching in step S15, electron attachment mass spectrometry is performed on a part of the exhaust gas of the abatement apparatus, and the signal intensity of fluorine negative ions in the exhaust gas is measured (steps S16 to S16). S17). In the present embodiment, after performing peak value separation as shown in the graph of FIG. 2, fragments of each gas are further separated,
The area intensity is calculated by integrating the area of the fragment (step S18).

By calculating the ratio of the area intensity of each gas to the total area intensity, the occupancy of each gas (fragment) in the exhaust gas can be calculated (step S19). In step S20, values such as the area intensity and the occupancy may be stored in the storage device of the mass spectrometer and / or the plasma device, and in step S21, may be output to, for example, a display device of the plasma device.

(Embodiment 5) Still another embodiment of the plasma device operating method according to the present invention will be described with reference to FIG.

First, in step S31, the upper limit (for example, 20 ppm) of the amount of PFC released from the exhaust gas is input to the arithmetic unit of the plasma apparatus. In step S32, oxygen is supplied to the abatement apparatus before the execution of the treatment process. Step S3
At 3, a part of the flowed oxygen is taken into the mass spectrometer and the energy axis of the mass spectrometer is calibrated. After the calibration is completed, in step S34, a command to start the process is transmitted from the mass spectrometer to the arithmetic unit of the plasma device.

After the arithmetic unit of the plasma apparatus transmits and receives this command, high frequency power is supplied to the abatement apparatus in step S35, and a process such as etching is started in step S36. When the process starts, exhaust gas flows from the exhaust pump to the abatement device, and a part of the exhaust gas is taken into the mass spectrometer. In step S37, the signal intensity of the fluorine negative ion is measured by the electron attachment mass spectrometry.

In step S38, the fitting of the measured data in the arithmetic unit of the mass spectrometer or the plasma device is performed, and the peak value is separated. The peak value is stored in a storage device in the arithmetic unit. In step S39, the area of each gas fragment is further integrated to calculate the area intensity. The area intensity of each gas is divided by the sum of the area intensity of each gas, and the occupancy of each gas in the exhaust gas is calculated (step S40). This value is also stored in a storage device different from the storage device of the mass spectrometer and the plasma device (step S41).

In step S42, the peak value or the area intensity value stored in the storage device is compared with the upper limit of the PFC emission amount input before the start of the process. As a result of the comparison, if the value exceeds the upper limit, the process is stopped (step S43).

(Embodiment 6) Still another embodiment of the plasma device operating method according to the present invention will be described with reference to FIG.

First, in step S51, the upper limit of the amount of PFC released from exhaust gas is input to the arithmetic unit of the plasma apparatus. In step S52, oxygen is supplied to the abatement apparatus before the process is performed. In step S53, a part of the flowed oxygen is taken into the mass spectrometer and the energy axis of the mass spectrometer is calibrated. After the calibration is completed, step S54
Then, a command to start the process is transmitted from the mass spectrometer to the arithmetic unit of the plasma device.

After the arithmetic unit of the plasma apparatus transmits and receives this command, high frequency power is applied to the abatement apparatus in step S55, and a process such as etching is started in step S56. When the process starts, exhaust gas flows from the exhaust pump to the abatement device, and a part of the exhaust gas is taken into the mass spectrometer. In step S57, the signal intensity of fluorine negative ions is measured by electron attachment mass spectrometry.

In step S58, the fitting of the measurement data in the arithmetic unit of the mass spectrometer or the plasma device is performed, and the peak value is separated. The peak value is stored in a storage device in the arithmetic unit. In step S59, the area of each gas fragment is further integrated to calculate the area intensity. The area intensity of each gas is divided by adding the area intensity of each gas, and the occupancy of each gas in the exhaust gas is calculated (step S60). This value is also stored in a storage device other than the storage devices of the mass spectrometer and the plasma device (step S61).

In step S62, the peak value or the area intensity value stored in the storage device is compared with the upper limit of the PFC emission amount input before the start of the process. As a result of the comparison, if the upper limit value is exceeded, a command to increase the high-frequency power of the abatement apparatus is output from the arithmetic unit of the plasma apparatus or the mass spectrometer (step S63). After increasing the high-frequency power, the PFC is again processed through the same process as described above.
Measure the amount of release and give feedback. By doing so, the emission of PFC can be suppressed to a certain value or less.

The "plasma apparatus" in the present specification includes an etching apparatus and a thin film deposition apparatus. Also,
In each of the above embodiments, the abatement is performed using the plasma, but the abatement may be performed using a catalytic method or a combustion method.

[0065]

According to the present invention, the amount of PFC contained in exhaust gas is measured using the mass spectrometer, so that the status of the abatement operation can be fed back to the abatement apparatus or the plasma apparatus. Therefore, it is possible to prevent more PFC from being released into the atmosphere than the preset amount.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of a plasma device according to the present invention.

FIG. 2 is a graph showing data measured by electron attachment mass spectrometry.

FIG. 3 is a configuration diagram showing another embodiment of the plasma device according to the present invention.

FIG. 4 is a configuration diagram of a plasma apparatus to which a catalytic exhaust gas monitor is added.

FIG. 5 is a flowchart illustrating process steps in an embodiment of a plasma device operating method according to the present invention.

FIG. 6 is a flowchart showing process steps in another embodiment of the plasma device operating method according to the present invention.

FIG. 7 is a flowchart showing process steps in still another embodiment of the plasma device operating method according to the present invention.

FIG. 8 is a flowchart showing process steps in still another embodiment of the plasma device operating method according to the present invention.

FIG. 9 is a configuration diagram of a conventional plasma device.

FIG. 10 is a configuration diagram showing a conventional catalytic abatement apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reaction chamber 2 Induction coil 3 Piping 4 Pressure control valve 5 Exhaust pump 6 Absorbing device 7 Induction coil 8 Mass spectrometer 9 Exhaust pump 10 Arithmetic unit 11 Gas cylinder 12 Flow control unit 13 Electric circuit 14 Arithmetic unit 15 High frequency power supply 16 Gas cylinder 17 High frequency power supply 18 Flow control device 19 High frequency power supply 20 Piping

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) H01L 21/205 H05H 1/46 L H05H 1/00 B01D 53/34 ZAB 1/46 134C F-term (Reference) 4D002 AA22 AC10 BA04 BA07 BA12 BA13 BA20 CA01 CA20 EA02 GA02 GA04 GB01 GB02 GB03 GB04 GB20 HA10 4G075 AA22 AA24 AA61 BC06 CA47 DA01 EB01 5F004 AA16 BA20 BB13 BC02 BC08 CA09 CB04 DA00 DA01 DA02 DA03 AC04 DA01 DA26 AC08 EG08 EH11 GB04 GB17

Claims (11)

[Claims] 1. A plasma apparatus for performing chemical treatment using plasma, a reaction chamber for performing the treatment, a pump for exhausting gas in the reaction chamber, and a gas exhausted from the reaction chamber. A detoxifying unit that decomposes or adsorbs, a mass spectrometric unit that collects a part of the gas exhausted from the detoxifying unit and measures the amount of a specific gas composed of molecules having electron affinity in the exhaust gas, A plasma controller comprising: a controller configured to control an operation of the abatement unit based on a measurement result of the mass analyzer. 2. The mass analyzer according to claim 1, wherein an amount of the specific gas is measured by attaching an electron to the molecule to generate a negative ion and detecting the amount of the negative ion.
The plasma device according to item 1. 3. The apparatus according to claim 1, further comprising a pipe for guiding a gas exhausted from the mass spectrometry section to the pump.
The plasma device according to item 1. 4. The control unit, comprising: a first calculation unit that calculates the amount of the specific gas from a result of mass spectrometry in the abatement unit; and a reference value set in advance and a calculation result of the first calculation unit. The plasma device according to any one of claims 1 to 3, further comprising a second calculation unit that compares and adjusts an operation of the abatement unit. 5. The plasma apparatus according to claim 1, wherein the abatement unit decomposes a gas using plasma. 6. The operating method of the plasma device according to claim 1, wherein the mass spectrometry unit sets the electron energy to 0 to 10 e.
Adsorbing electrons on the molecule while changing the range of V to generate negative ions, separating a peak of a signal waveform indicating a result of mass analysis of the negative ions by a Gaussian function, and specifying the signal waveform. About the energy peak of
An operation method including: storing the peak value in a memory; and outputting the peak value stored in the memory to a display unit. 7. The method according to claim 6, further comprising: calculating an area intensity of the specific energy peak and storing the area intensity in a memory; and outputting the peak intensity and the area intensity to the display unit. 4. The method for operating a plasma device according to item 1. 8. A step of comparing a peak value of the specific energy peak with a previously input peak reference value; and performing the chemical treatment when the peak value of the specific energy peak is equal to or more than the peak reference value. 7. The method according to claim 6, further comprising the step of stopping the operation. 9. A step of comparing a peak value of the specific energy peak with a pre-input peak reference value, wherein when the peak value of the specific energy peak is not less than the peak reference value, 7. The method for operating a plasma device according to claim 6, comprising a step of increasing abatement efficiency. 10. The plasma device operating method according to claim 9, wherein the step of increasing the abatement efficiency in the abatement unit includes a step of increasing a high-frequency power used for forming plasma in the abatement unit. . 11. The method according to claim 6, wherein fluorine ions are used as the negative ions.