JP2002299322A - Plasma processing apparatus and plasma processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily detect the end point of etching in an RIE apparatus. SOLUTION: The processing method comprises applying powers, having two different frequencies from high-frequency power sources 6, 9 to a cathode 3 with a substrate 2 mounted thereon, monitoring the two frequencies concerning a voltage in a vacuum reaction chamber 1 during etching, using impedance probes 4, 7 and taking the time point as an etching end point, when the voltage time change ratio of the two frequencies is changed greatly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a plasma processing apparatus and a plasma processing method using a plasma such as ion etching.

[0002]

2. Description of the Related Art In the field of semiconductor manufacturing, one of processing apparatuses utilizing plasma (plasma processing apparatus) is R.
An IE (Reactive Ion Etching) device is known. R
The IE device applies a negative potential to the wafer, discharges a reactive gas using a high-frequency power source, generates plasma, and pulls ions in the plasma vertically to the wafer surface, thereby performing physical and chemical etching. Is what you do.

[0003] Problems in the etching process using the RIE apparatus include the following. First, the necessity of detecting the etching end point will be described using contact hole etching as an example. FIG. 11 shows a cross-sectional structure of the substrate to be processed in the contact hole etching step. FIG.
(A) shows a cross-sectional structure before etching. In the figure, 101 indicates a mask material such as a resist, 102 indicates an interlayer insulating film such as TEOS, and 103 indicates a semiconductor substrate such as a Si substrate.

In the contact hole etching, the interlayer insulating film 102 is etched using the mask material 101 as a mask, and the etching is stopped in the semiconductor substrate 103. FIG.
(B) shows a cross-sectional structure of the substrate after etching.

If the etching is not stopped on the surface of the semiconductor substrate 103, the semiconductor substrate 103 is dug, causing problems such as an increase in contact resistance and a junction leak. Therefore, it is necessary to control the etching time.

As a means for controlling the etching time, there is detection of the end point of etching, and the end point detection by emission spectroscopy is most common. However, there are problems that the method can be applied only to a specific etching gas and a material to be etched, and that the luminescence intensity decreases with time due to an etching product or the like adhering to a luminescence extraction window.

A plasma impedance monitor has attracted attention as a method of detecting an end point of etching instead of emission spectroscopy. FIG. 12 shows R with a plasma impedance monitor.
1 shows an example of an IE device. In the figure, 111 is a vacuum reaction chamber, 112 is a cathode, 113 is an anode, 114 is a high frequency power supply, 115 is an impedance matching device (matcher), 116 is a gas inlet, 117 is a substrate to be processed, 11
Reference numeral 8 denotes each of the impedance probes.

The etching is performed as follows. That is, while the etching gas is introduced into the vacuum reaction chamber 111 from the gas introduction port 116, high-frequency power is applied to the cathode 112 by the high-frequency power supply 114, and the impedance matching device 115 controls the impedance between the output of the high-frequency power supply 114 and the load side. Is generated, a plasma is generated in the vacuum reaction chamber 111, and the target substrate 117 supported on the cathode 112 is etched using a self-bias generated on the cathode 112.

At this time, the vacuum reaction chamber 11 including the plasma, the cathode 112, the anode 113, and the substrate 117 to be processed is provided by the impedance probe 118 inserted between the cathode 112 and the impedance matching device 115.
The impedance, voltage, current, phase,
Physical quantities such as power can be measured.

Before and after the end point of the etching, the amounts of the etching species, reactive products, and the like in the plasma are different, so that impedance, voltage, current, phase, and power also change. By detecting this change using the impedance probe 118, the end point of the etching can be detected.

Also, unlike the method of monitoring the emission spectrum of plasma, there are limitations on the etching gas and the material to be etched,
It is less susceptible to the deterioration of accuracy over time due to adhesion of etching products and the like to the light receiving window.

However, even when the above method is used, in the process of etching contact holes and via holes, the ratio of the area of the region to be etched (opening ratio) is small, so that impedance, voltage, current, phase, power, etc. The amount of change before and after the etching end point is small (the sensitivity is low), and it is becoming difficult to detect the end point.

Further, there is a problem that radical species generated by plasma and reactive products generated by etching adhere to the inner wall of the vacuum reaction chamber 111, and the characteristics of the RIE apparatus change with time.

For example, when etching an insulating film such as a silicon oxide film, it is general to perform etching using a fluorocarbon-based gas.
When the above-described radical species and reactive products (hereinafter referred to as “adhered matter”) adhere to the inner wall of the eleventh, the radical composition in the plasma changes due to the reaction between the adhering matter and the plasma, and consequently the etching performance is changed. It is known. That is, as the number of substrates to be processed increases, the amount of deposits on the inner wall of the vacuum processing chamber 111 increases, and the etching performance changes with time.

As an example of such a change in etching performance, when the etching rate is reduced, a contact hole is not opened, and the production yield of the substrate to be processed is remarkably reduced.

When the amount of deposits increases, a part of the deposits peels off from the inner wall of the vacuum processing chamber 111,
When the dust is deposited on the substrate 117 to be processed, a short circuit or an open occurs in the wiring, which causes a problem that the yield of semiconductor device manufacturing is reduced.

At present, in order to avoid such a decrease in yield, cleaning of the vacuum processing chamber 111 is generally performed. When cleaning the vacuum processing chamber 111, the production efficiency is remarkably reduced by opening to the atmosphere and the like, so that the cycle needs to be lengthened as much as possible. Vacuum processing chamber 11
Since the state management of the inner wall of No. 1 is directly difficult in structure, the cleaning cycle is determined by time management. However, it is questionable whether an optimal cleaning time has been realized in this method.

By monitoring the impedance, voltage, current, phase, power, etc. of the system in the vacuum processing chamber 111 including the plasma, the cathode 112, the anode 113, and the substrate 117 by the above-described impedance monitor, a vacuum reaction is performed. A temporal change in the state of the chamber 11 can be detected. This is because when radical species in the plasma change due to the deposits on the inner wall of the vacuum reaction chamber 111, the impedance of the plasma naturally changes.

Therefore, a change in etching performance and an increase in dust in advance, and impedance, voltage, current, phase, power, etc. relating to the system in the vacuum processing chamber 111 including the plasma, the cathode 112, the anode 113, and the substrate 117 to be processed. By grasping the correspondence with the change of the temperature, an appropriate chamber cleaning cycle can be determined.

However, in practice, physical quantities such as impedance, voltage, current, phase, and power measured by an impedance monitor have a small amount of change with time (low sensitivity), and it is difficult to detect a cleaning time. .

[0021]

As described above, the conventional R
In the IE apparatus, the end point of the etching of the contact hole and the like and the cleaning time of the vacuum reaction chamber are detected by the impedance monitor. However, since this type of monitor has low sensitivity, the etching end point and the cleaning time of the cleaning time are not detected. There was a problem that detection was difficult.

The present invention has been made in view of the above circumstances, and has as its object to provide a plasma processing apparatus and a plasma processing apparatus capable of easily detecting whether or not the inside of a processing vessel in which plasma processing is performed is in a predetermined state. It is to provide a plasma processing method.

[0023]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, typical ones are briefly described as follows. That is, in order to achieve the above object, the plasma processing apparatus according to the present invention is provided with a processing container for performing plasma processing, and provided in the processing container,
An electrode on which a substrate to be processed to be subjected to plasma processing is mounted and to which power having two or more frequencies is applied; gas introduction means for introducing a gas to be plasma into the processing container; Power generating means for generating power having the above-described frequency, and monitoring means for monitoring whether or not the inside of the processing container is in a predetermined state, including a plasma generated in the processing container and the electrode A monitor means including a measuring means for simultaneously measuring at least one physical quantity of impedance, voltage, current and phase with respect to the system in the processing container for the two or more frequencies is provided.

Further, the plasma processing method according to the present invention comprises:
While placing the substrate to be processed on the electrode in the processing vessel,
Introducing a gas into the processing container, applying power having two or more frequencies to the electrodes, generating a plasma of the gas, and performing a plasma process on the substrate to be processed by the plasma; A monitoring step of monitoring whether or not the inside of the processing container is in a predetermined state, wherein at least one of impedance, voltage, current, and phase related to a system in the processing container including the plasma generated in the processing container and the electrode. And a monitoring step including a step of continuously measuring the physical quantity for the two or more frequencies at the same time.

According to the present invention, by applying power having two or more frequencies to an electrode (anode) and performing impedance monitoring of a physical quantity to be measured for two or more frequencies, a physical quantity of one frequency can be monitored. A measurement result including more information about the physical quantity to be measured can be obtained as compared with the related art in which only measurement is performed. Thereby, the sensitivity can be improved, and as a result, it is possible to easily detect whether or not the inside of the processing container is in a predetermined state.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0027]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 shows a first embodiment of the present invention.
It is a schematic diagram which shows the RIE apparatus with an impedance monitor which concerns on embodiment. In the figure, reference numeral 1 denotes a vacuum reaction chamber, in which a substrate 2 to be processed is mounted and a cathode 3 to which high-frequency power is applied is installed in a lower part of the vacuum reaction chamber 1.

The cathode 3 is connected to a first impedance probe 4 provided outside the vacuum reaction chamber 1, and the first impedance probe 4 is connected to a first impedance matching device (matcher) 5, and The impedance matching device 5 is connected to a first high-frequency power supply 6. That is, the cathode 3 is connected to the high frequency power supply 6 via the impedance probe 4 and the impedance matching device 5. Further, the cathode 3 is connected to a second high-frequency power supply 9 via a second impedance probe 7 and a second impedance matching device 8.

First high frequency power supply 6 and second high frequency power supply 9
Are different from each other, so that two high-frequency powers having different frequencies can be simultaneously applied to the cathode 3. The vacuum reaction chamber 1 above the cathode 3 is used as an anode 10 and is grounded. Reactive gas (etching gas) is in the upper part of the vacuum reaction chamber 1
A gas inlet 11 for introducing a gas or the like is provided.

The etching using the RIE apparatus having the above structure is performed as follows. That is, high-frequency power is applied to the cathode 3 by the first high-frequency power supply 6 and the second high-frequency power supply 9 in a state where the reactive gas is introduced into the vacuum reaction chamber 1 from the gas inlet 11, and the first impedance matching device 5, the output of the first high-frequency power supply 6 and the output of the second high-frequency power supply 9 are matched with the load side by the second impedance matching device 8 to discharge the reactive gas in the vacuum reaction chamber 1. Then, a plasma of a reactive gas is generated, and the substrate 2 supported on the cathode 3 is physically and chemically etched using the self-bias generated on the cathode 3.

At this time, the first impedance matching device 5
The first impedance probe 4 inserted between the cathode 3 and the first impedance probe 4 and the second impedance probe 7 inserted between the second impedance matching device 8 and the cathode 3 generate in the vacuum reaction chamber 1. The physical quantities such as the impedance, voltage, current, phase, and power of the plasma, the cathode 3, the anode 10, and the system in the vacuum reaction chamber 1 including the substrate 2 to be processed are measured by the frequency of the first high-frequency power supply 6, the second It is possible to simultaneously measure the frequency of the high frequency power supply 9. Since the power can be obtained by calculation from the voltage and the current, it is not always necessary to measure it. However, if there is a high-precision power measuring device, it may be obtained by measurement.

The frequency of the first high frequency power supply 6 is 3.2
MHz and 27.12 as the frequency of the second high-frequency power supply 9.
A description will be given of an impedance monitor when the target substrate 2 is actually etched using MHz.

FIG. 2 shows a sectional view of the substrate 2 to be processed used in the etching process. The substrate to be processed 2 was prepared as follows. That is, a thermal oxide film 22 is formed on a silicon substrate 21 using an oxidation technique, a polysilicon film 23 is deposited on the thermal oxide film 22 using a CVD technique, and then a polysilicon film 23 is deposited using a CVD technique. A TEOS film 24 was deposited thereon, and then a wiring pattern was transferred to the TEOS film 24 using a lithography technique, a dry etching technique, and an ashing technique. Here, it is assumed that the gate wiring of the polysilicon film 23 is processed by RIE using the TEOS film 24 as a mask material.

Next, the etching (plasma processing) of the substrate 2 shown in FIG. 2 by the RIE apparatus of this embodiment will be described.

First, the substrate 2 shown in FIG. 2 is set on the cathode 3, and HBr gas is supplied through the gas inlet 11 at 150 sc.
While controlling the pressure in the vacuum reaction chamber 1 to 75 mTorr by an exhaust means (not shown) in a state where the flow rate of cm is introduced,
Power of 100 W from the high-frequency power supply 6 of 3.2 MHz;
A 100 W power is superimposed and applied to the cathode 3 from the 7.12 MHz high frequency power supply 9, and the outputs of the first high frequency power supply 6 and the second high frequency power supply 9 are applied by the first impedance matching device 5 and the second impedance matching device 8. By matching the impedance between the load side and the load side, H
A plasma of the Br gas is generated, and the polysilicon film 23 of the substrate 2 to be processed shown in FIG.
E) Yes.

The end point is where the polysilicon film 23 is etched and the surface of the thermal oxide film 22 is exposed. At this time, 3.2 M
The voltage of the system in the vacuum reaction chamber 1 including the plasma, the cathode 3, the anode 10, and the substrate 2 to be processed is measured at 27.12 Hz by the second impedance probe 8.
The voltage for the sibling at MHz was kept measured simultaneously. That is, the voltage was monitored.

FIG. 3 schematically shows the above measurement results. FIG.
FIG. 3A shows a time change of a 3.2 MHz voltage with respect to a system in the vacuum reaction chamber 1 including the plasma at the time of etching, the cathode 3, the anode 10, and the substrate 2 to be processed, and FIG. 4 schematically shows a time change of a voltage. The time is the etching time. From FIG. 3, at the end point of the etching, the voltage of 3.2 MHz decreases,
It was found that the voltage at 27.12 MHz increased.

Considering the end point detection, the time change of the 3.2 M voltage in FIG.
By taking, for example, the ratio of the time change of the voltage of 7.12 MHz and setting the time when the ratio largely changes as the end point of etching, only 3.2 MHz in FIG. 3A or 27.27 in FIG. 3B. It can be seen that the sensitivity can be increased as compared with the measurement of the voltage of only 12 MHz, and the end point of the etching can be easily detected with high accuracy. A series of processes for obtaining the ratio, obtaining the time change thereof, and detecting the end point are performed by, for example, a dedicated or general-purpose computer (not shown). Measurement results of the impedance probes 4 and 8 are input to this computer as needed.

The difference in the voltage behavior depending on the frequency at the end point of the etching is due to the difference in the appearance of the voltage regarding the system in the vacuum reaction chamber 1 including the plasma, the cathode 3, the anode 10, and the substrate 2 depending on the frequency. it seems to do.

Using a voltage having the same frequency, changes in current, phase, impedance, and power over time were also examined. The results are schematically shown in FIGS. Each figure (a)
Shows the measurement result at a frequency of 3.2 MHz, and each figure (b) shows the measurement result at a frequency of 27.12 MHz.

From FIG. 4 to FIG. 7, the time change of the current and the impedance is the same as that of the voltage, and the frequency is 3.2.
In MHz, it decreases at the end of etching, and the frequency is 27.1.
On the other hand, it increases at 2 MHz, and conversely, the time change of the phase and power increases at the frequency of 3.2 MHz and the frequency is 27.12 MH.
At z, it was found to decrease. Therefore, even when the current, phase, impedance, and power are measured, the end point of etching can be easily detected with high accuracy, as in the case of voltage.

As described above, plasma is generated by superimposing high-frequency powers of two different frequencies, and physical quantities such as impedance, voltage, current, phase, and power at two or more frequencies are measured, so that etching can be performed. End point detection can be performed with high sensitivity and high accuracy. In order to further enhance sensitivity and high accuracy, it is desirable to measure a plurality of physical quantities at the same time. However, for simplicity, it is necessary to simultaneously measure only one physical quantity such as a voltage at two frequencies. Is desirable.

In the above example, an example of gate wiring processing has been described. However, the present method is also useful in other etching steps in the manufacture of a semiconductor device such as contact hole etching and via hole etching.

Next, a method for detecting a temporal change in the state in the RIE apparatus (cleaning time) using the above principle of detecting the end point of the etching will be described below.

In the RIE apparatus, radical species generated by plasma, reaction products generated by etching, and the like adhere to the inner wall of the vacuum reaction chamber 1, and the characteristics of the apparatus change with time. As a result, inconveniences such as unopened contact holes and a reduction in the yield at the time of manufacturing a semiconductor device due to generation of dust occur.

In order to avoid such inconvenience, it is necessary to clean the vacuum reaction chamber 1 at regular intervals. However, the determination of this type of cleaning cycle largely depends on experience, and it is difficult to determine the optimum cleaning cycle.

As in the case of the above-described detection of the end point of etching, plasma is generated by superimposing high-frequency powers of two different frequencies, and impedance, voltage, current, phase, power, etc. at the two frequencies are measured and obtained. The correlation between the measured value and the etching rate and the number of dusts for each substrate to be processed or each lot of the substrate to be processed is checked in advance.

By comparing this correlation with the measured values of the impedance probes 4 and 7 during the actual etching of the substrate 2 to be processed, a change in the state of the vacuum reaction chamber 1 can be detected, and the cleaning cycle can be determined. Become like A series of processing for comparing the correlation with the measured value and detecting the cleaning cycle is performed by, for example, a dedicated or general-purpose computer (not shown). The above-described correlation is input to this computer in advance, and the measurement results of the impedance probes 4 and 8 are input as needed.

By using this method, it is possible to determine the cleaning cycle of the vacuum reaction chamber from more information than to monitor using a single frequency. For an RIE apparatus for which it was difficult to determine the cleaning cycle, it is possible to detect the cleaning cycle with higher sensitivity.

The frequencies and power settings of the two high-frequency power supplies 4 and 9 are arbitrary. For example, 13.56 MHz is used as the frequency of the first high-frequency power supply 6 and 100 to 200
The plasma is generated by applying a power of about 0 W,
40 MHz as the frequency of the high-frequency power supply 9 of 10
Even when a power of about 0 W or less that does not significantly affect the generation of plasma is applied, the same end point detection characteristics and cleaning cycle monitoring characteristics as those of the above values can be obtained.

(Second Embodiment) FIG. 8 shows a second embodiment of the present invention.
It is a schematic diagram which shows the RIE apparatus with an impedance monitor which concerns on embodiment. The parts corresponding to the above-mentioned drawings are denoted by the same reference numerals as those in the above-mentioned drawings, and detailed description will be omitted.

This embodiment is different from the first embodiment in that impedance probes 4, 7 are provided as shown in FIG.
Are connected in series, and the impedance matching devices 5 and 8 are connected to the impedance probe 7. Even with such a configuration, the same etching end point detection characteristics and cleaning cycle monitoring characteristics as those of the first embodiment can be obtained.

(Third Embodiment) FIG. 9 shows a third embodiment of the present invention.
It is a schematic diagram which shows the RIE apparatus with an impedance monitor which concerns on embodiment.

This embodiment differs from the first embodiment in that a second impedance probe 7 is provided on the anode side as shown in FIG. In this case, the anode 10 is connected to the second high frequency power supply 9 via the second impedance monitor 7 and the second impedance matching device 8.

In general, in an RIE apparatus in which a high frequency is applied from both sides of the anode and the cathode, a high frequency power supply having a low frequency of, for example, 3.2 MHz for attracting ions is provided on the cathode side, and a plasma density is provided on the anode side. A high frequency power supply having a high frequency, for example, 40 MHz, to be controlled is used.

Therefore, in the case of the present embodiment, the frequency of the first high frequency power supply 6 is set lower than the frequency of the second high frequency power supply 9. Thus, even when the arrangement of the high-frequency power supplies 6, 9 and the impedance probes 4, 7 is different from that of the first embodiment, it is possible to obtain the same etching end point detection characteristics and cleaning cycle monitoring characteristics as those of the first embodiment. Can be.

(Fourth Embodiment) FIG. 10 is a schematic view showing an RIE apparatus with an impedance monitor according to a fourth embodiment of the present invention. In this embodiment, the inductively coupled R
This is an example in which the present invention is applied to an IE device.

In the drawing, reference numeral 12 denotes an antenna provided above the vacuum reaction chamber 1, and this antenna 12 is connected to a third impedance matching device (matcher) 13 through a third impedance matching device (matcher) 13.
Is connected to the high-frequency power supply 14 of FIG. Other configurations are
This is the same as the first embodiment except that the anode 10 is not provided because of the inductive coupling type.

In a state where the etching gas is introduced from the gas inlet 6 into the vacuum reaction chamber 1, two high-frequency powers are superimposed and applied from the first high-frequency power supply 6 and the second high-frequency power supply 9 through the cathode 3. High-frequency power is applied from the high-frequency power source 14 through the antenna 12, and the first to third high-frequency power sources 6 and 9 are applied by the first impedance matching device 5, the second impedance matching device 8, and the third impedance matching device 13. , 14 and the load side, a plasma is generated in the vacuum reaction chamber 1, and the substrate 2 supported on the cathode 3 by using a self-bias generated on the cathode 3. Is etched.

In general, in an etching apparatus in which high-frequency power is applied to the cathode 3 and high-frequency power is simultaneously applied to the antenna 12 to generate inductively-coupled plasma, the first high-frequency power supply 6 has a frequency of about several MHz. Using a low frequency and a frequency of about several tens of MHz for the third high-frequency power supply 14, control of ion self-bias and control of plasma density are performed, respectively.

At this time, the second high frequency power supply 9 is connected to the cathode 3.
, A high-frequency power of a high frequency of, for example, about 40 MHz is applied in a power region of about 100 W or less, which does not significantly contribute to plasma generation.
Using the second impedance probe 7, physical quantities such as impedance, voltage, current, phase, and power related to the plasma generated in the vacuum reaction chamber 1, and the system in the vacuum reaction chamber 1 including the cathode 3 and the substrate 2 to be processed. Can be simultaneously measured for the frequency of the first high-frequency power supply 6 and the frequency of the second high-frequency power supply 9.

Therefore, even in the inductively coupled plasma etching apparatus, by newly adding the high frequency power supply 9, the impedance matching unit 8, and the impedance probe 7, the same etching end point detection characteristics and cleaning cycle as those of the first embodiment can be obtained. Monitor characteristics can be obtained.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments. For example, in the above embodiment, the case where the present invention is applied to a plasma etching apparatus has been described, but the present invention can be applied to other plasma processing apparatuses.

Further, in the above embodiment, the case where two powers having different frequencies are applied to the cathode and the physical quantity is simultaneously measured at the two frequencies has been described. However, three or more powers having different frequencies are applied to the cathode. The physical quantity may be simultaneously measured for three or more frequencies by applying the voltage.

Furthermore, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent elements are deleted from all the constituent elements described in the embodiment, if the problem described in the section of the problem to be solved by the invention can be solved, the constituent Can be extracted as an invention. In addition, various modifications can be made without departing from the scope of the present invention.

[0067]

As described in detail above, according to the present invention, it is possible to realize a plasma processing apparatus and a plasma processing method which can easily detect whether or not the inside of a processing vessel where plasma processing is performed is in a predetermined state. .

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an RIE apparatus with an impedance monitor according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a substrate to be processed used in an etching process.

FIG. 3 is a diagram showing a time change of a voltage in a vacuum reaction chamber for two different frequencies.

FIG. 4 is a diagram showing a time change of a current in a vacuum reaction chamber for two different frequencies.

FIG. 5 is a diagram showing a time change of a phase in a vacuum reaction chamber for two different frequencies.

FIG. 6 is a diagram showing a time change of impedance in a vacuum reaction chamber for two different frequencies.

FIG. 7 is a diagram showing a temporal change of power in a vacuum reaction chamber for two different frequencies.

FIG. 8 is a schematic view showing an RIE apparatus with an impedance monitor according to a second embodiment of the present invention.

FIG. 9 is a schematic view showing an RIE apparatus with an impedance monitor according to a third embodiment of the present invention.

FIG. 10 is a schematic view showing an RIE apparatus with an impedance monitor according to a fourth embodiment of the present invention.

FIG. 11 is a diagram showing a cross-sectional structure of a substrate to be processed in a contact hole etching step.

FIG. 12 shows a conventional R with a plasma impedance monitor.
Schematic diagram showing the IE device

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Vacuum reaction chamber 2 ... Substrate to be processed 3 ... Cathode 4 ... 1st impedance probe 5 ... 1st impedance matching device 6 ... 1st high frequency power supply 7 ... 2nd impedance probe 8 ... 2nd impedance matching device 9: second high-frequency power supply 10: anode 11: gas inlet 12: antenna 13: third impedance matching device 14: third high-frequency power supply 21: silicon substrate 22: thermal oxide film 23: polysilicon film 24: TEOS Oxide film

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kensuke Yamauchi 33, Shinisogocho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture Inside the Toshiba Production Technology Center Co., Ltd. No. 33 F-term in Toshiba Production Technology Center (reference) 4G075 AA24 AA30 AA57 AA61 AA62 AA65 BC06 CA47 DA01 DA11 EA01 EB42 EC21 5F004 AA16 BA09 BA20 CA06 CB05 CB07 DA00 DB02 EB01 EB02

Claims (12)

[Claims] 1. A processing container for performing a plasma processing, and a substrate provided in the processing container and subjected to a plasma processing is mounted thereon, and electric power having two or more frequencies is applied. An electrode, a gas introduction unit that introduces a gas that becomes plasma into the processing container, a power generation unit that generates electric power having the two or more frequencies, and a plasma generated in the processing container and the electrode. A plasma processing apparatus comprising: a measuring means for simultaneously measuring at least one physical quantity of impedance, voltage, current, and phase related to a system in the processing container for two or more frequencies. 2. A processing vessel for performing a plasma processing, and a substrate provided in the processing vessel and subjected to the plasma processing and placed thereon, and electric power having two or more frequencies is applied. An electrode; a gas introducing unit for introducing a gas to be a plasma into the processing container; a power generating unit for generating electric power having two or more frequencies; and monitoring whether or not the inside of the processing container is in a predetermined state. Monitoring means for performing at least one physical quantity of impedance, voltage, current, and phase relating to plasma generated in the processing vessel and a system in the processing vessel including the electrode, for two or more frequencies simultaneously. A plasma processing apparatus comprising: a monitor unit including a measuring unit for measuring. 3. The plasma processing apparatus according to claim 1, wherein said power generation means includes a plurality of power generation sources for generating power having different frequencies. 4. The apparatus according to claim 1, wherein said measuring means is provided between said power generating means and said electrode.
Or the plasma processing apparatus according to 2. 5. The apparatus according to claim 2, wherein the monitor detects a state in the processing container based on the measured values of the physical quantity for two or more frequencies obtained by the measuring means. 3. The plasma processing apparatus according to 1. 6. The monitoring means detects whether or not the inside of the processing container is in a predetermined state, based on a time change of a measured value of the physical quantity at two or more frequencies obtained by the measuring means. 3. The plasma processing apparatus according to claim 2, wherein: 7. The monitor means according to claim 1, wherein said monitor measures the physical quantity for two or more frequencies obtained by said measuring means, and associates the measured value of said physical quantity with a state in said processing container obtained in advance. 3. The plasma processing apparatus according to claim 2, wherein whether the inside of the processing container is in a predetermined state is detected based on the relationship. 8. The plasma processing apparatus according to claim 2, wherein the predetermined state is a state in which plasma processing on the substrate to be processed in the processing container has been completed. . 9. The apparatus according to claim 2, wherein the predetermined state is a state in which it is time to clean the inside of the processing container.
8. The plasma processing apparatus according to any one of items 7 to 7. 10. The plasma processing apparatus according to claim 1, wherein the plasma processing is an etching processing using a plasma. 11. A step of placing a substrate to be processed on an electrode in a processing container and introducing a gas into the processing container; and applying a power having two or more frequencies to the electrode, Generating a plasma of the plasma processing of the substrate to be processed by the plasma; impedance generated by the plasma generated in the processing container and a system in the processing container including the electrode;
Simultaneously measuring at least one physical quantity of current and phase for two or more frequencies. 12. A step of placing a substrate to be processed on an electrode in a processing vessel and introducing a gas into the processing vessel; and applying a power having two or more frequencies to the electrode, Generating a plasma of, and plasma processing the substrate to be processed by the plasma, and a monitoring step of monitoring whether or not the inside of the processing container is in a predetermined state, wherein the plasma generated in the processing container and the A monitoring step including a step of continuously measuring at least one physical quantity of impedance, voltage, current, and phase regarding a system in the processing vessel including electrodes at two or more frequencies.