JP2003037105A - Plasma treatment apparatus and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form an insulation film which is hard to delaminate in a process vessel in a short time. SOLUTION: The apparatus comprises a process vessel 11 wherein a work piece is placed and a plasma generating means 30 for plasma generation excited by micro wave. Before the work piece is loaded in the vessel 11, plasma is generated to deposit insulation film inside of the vessel 11. Then the work piece is placed in the vessel 11 for processing by generating plasma. The apparatus is also provide with a process control means 50, which controls a process of taking out the work piece from the process vessel 11 and cleaning the work piece by removing an insulating film deposited in the process vessel 11.

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 method, and more particularly to a plasma processing apparatus and method for processing an object to be processed using plasma.

[0002]

2. Description of the Related Art Conventionally, a gate insulating film of a semiconductor element has been formed by a thermal oxidation method. However, it is difficult to control the film thickness by this method, and it is difficult to form a thin gate insulating film on the order of 1 nm required for the next-generation transistors. Therefore, the plasma CVD method that can easily control the film thickness and realize the above film thickness has begun to be used for forming the gate insulating film.

The plasma CVD method is a method in which plasma is generated in a processing container, the gas in the processing container is activated using this plasma, and the reactivity is utilized to form a thin film. As one of the film forming apparatuses by the plasma CVD method, there is a parallel plate type plasma processing apparatus which generates a plasma by causing an electric discharge between parallel plate electrodes. Regarding this parallel plate type plasma processing apparatus, in order to prevent the contaminants detached from the processing container from adhering to the surface of the wafer to be processed, an insulating film is formed on the inner surface of the processing container before wafer processing. Deposition and coating techniques have been proposed. This technique is called pre-deposition.

[0004]

However, in the parallel plate type plasma processing apparatus, since the electron temperature of plasma is high, a dense and uniform insulating film cannot be formed by pre-deposition. Therefore, there is a problem that the insulating film formed on the inner surface of the processing container has poor adhesion and is easily peeled off. In addition, in the parallel plate type plasma processing apparatus, the ion energy of the plasma is low, so
There is a problem that it takes a long time to deposit an insulating film by deposition. The present invention has been made to solve such a problem, and an object of the present invention is to form an insulating film which is hardly peeled off in a processing container by pre-deposition. Another object is to reduce the time required for pre-deposition.

[0005]

In order to achieve such an object, a plasma processing apparatus according to the present invention includes a processing container in which an object to be processed is disposed, and a plasma is generated in the processing container by microwave excitation. And a plasma generating means for generating a plasma in a state where the object to be processed is not loaded into the processing container, depositing an insulating film inside the processing container, and loading the object to be processed into the processing container to generate the plasma Processing the processing body,
And a process control means for controlling a process of carrying out the object to be processed from the processing container and performing a cleaning process for removing the insulating film deposited inside the processing container.
Since microwave-excited plasma has a lower electron temperature than the plasma generated by the parallel plate type plasma processing apparatus, a denser and more uniform insulating film is deposited inside the processing container including the inner surface of the processing container. This insulating film has good adhesion to a processing container or the like and is difficult to peel off. Further, since microwave-excited plasma is generated under a low pressure of, for example, 10 Pa or less, ion energy is higher than that of plasma generated by a parallel plate type plasma processing apparatus. Therefore, the insulating film can be deposited inside the processing container in a shorter time than in the past. Also, if an insulating film is deposited again on the insulating film deposited inside the processing container, the film thickness becomes thicker and peeling easily occurs.However, once the insulating film deposited inside the processing container is removed, the insulating film is re-insulated. By depositing the film, the insulating film can be made difficult to peel off.

Here, the plasma generating means may have a radial line antenna for supplying microwaves into the processing container. Further, the radial line antenna may have a plurality of pairs of two slots that are separated from each other and are orthogonal to each other. By using such a radial line antenna, the electron temperature of plasma can be further lowered.

In the plasma processing apparatus of the present invention, the processing container in which the object to be processed is placed, the plasma generating means for generating plasma by induction excitation in the processing container, and the object to be processed are carried into the processing container. The plasma is generated in the untreated state, the insulating film is deposited inside the processing container, the processed object is loaded into the processing container, the plasma is generated to process the processed object, and the processed object is unloaded from the processing container. And a process control means for controlling a cleaning process for removing the insulating film deposited inside the processing container. The same effect as that of the microwave-excited plasma described above can be obtained by the induction-excited plasma.

Here, a grid fixed in the processing container and having a plurality of holes may be provided. This grid divides the inside of the processing chamber into a plasma generation space and a processing space. The plasma generated in the plasma generation space is
When passing through the plurality of holes in the grid and moving into the processing space, energy is taken by the grid, so that plasma having a low electron temperature is introduced into the processing space.
Further, a Faraday shield for cutting off the capacitive coupling between the plasma generating means and the plasma may be provided. This allows
It is possible to suppress generation of plasma due to capacitive excitation, which has a higher electron temperature than plasma due to induction excitation, and to lower the electron temperature of plasma.

Further, in the above-described plasma processing apparatus, the process control means may start cleaning based on a preset set value. As a criterion for starting cleaning, a function of a physical quantity that is easy to measure, for example, an integrated time of plasma generation, the number of processed objects, a deposition time of an insulating film inside the processing container, and a processed time of the processed objects are combined. You may use total time etc. This makes it possible to control the start of cleaning with a simple configuration.

The set value which is the standard for starting cleaning is that the thickness of the insulating film deposited inside the processing container is 10 μm.
You may decide on the function value used as about m. The insulating film has a thickness of 1
It is empirically known that if the thickness exceeds 0 μm, peeling is likely to occur, so that the effect of preventing the peeling of the insulating film is improved. Alternatively, a film thickness measuring unit that measures the film thickness of the insulating film deposited inside the processing container and outputs the film thickness to the process control unit is further provided, and the process control unit starts cleaning based on the measurement result of the film thickness measurement unit. You may As a result, the cleaning can be reliably started before the insulating film exceeds the film thickness at which it is easily peeled off. Further, the process control means may start the cleaning when the measurement result that the thickness of the insulating film is about 10 μm is obtained.

Further, in the above-described plasma processing apparatus, two processing containers and two plasma generating means are provided, and further, a transfer means for transferring the object to be processed in one processing container to the other processing container is provided. You may
This enables continuous processing in two processing vessels.

Next, according to the plasma processing method of the present invention, a first step of generating plasma by microwave excitation in the processing container to deposit an insulating film inside the processing container, and an object to be processed in the processing container. The second step of carrying in and generating plasma by microwave excitation into the processing container to perform processing on the object to be processed, and carrying out the object to be processed from the processing container and removing the insulating film deposited inside the processing container And a third step of performing cleaning. Further, the plasma processing method of the present invention includes a first step of generating plasma in the processing container by induction excitation and depositing an insulating film inside the processing container; Second step of generating plasma by induction excitation to process the object to be processed, and third step of carrying out the object to be processed from the processing container and removing the insulating film deposited inside the processing container And a process.

In the plasma processing method using microwave-excited plasma, the insulating film deposited in the first step is
It may be a silicon oxide film. In this case, in the first step, the flow rate of TEOS (tetraethoxysilane) gas supplied into the processing container is 1 to 100 sccm, the flow rate of O ₂ gas supplied into the processing container is 100 to 2000 sccm,
A silicon oxide film may be deposited inside the processing container by setting the pressure in the processing container to 1 to 133 Pa and the microwave power supplied to the processing container to 1 to 5 kW. TEOS
The use of gas enables safer processing than the case of using SH ₄ . Alternatively, the insulating film deposited in the first step may be a silicon nitride film.

In the plasma processing method using microwave-excited plasma, the second step has a fourth step of oxidizing the surface of the silicon wafer which is the object to be processed to form a silicon oxide film. Good. In this case, in the fourth step, the flow rate of Ar gas supplied into the processing container is 200 to 2000 sccm, the flow rate of O ₂ gas supplied into the processing container is 1 to 50 sccm, and the pressure inside the processing container is 13 to 400 Pa. The silicon oxide film may be formed by setting the microwave power supplied into the processing container to 1 to 5 kW. When a silicon wafer with a diameter of 8 inches is used, by continuing this treatment for about 15 seconds,
A silicon oxide film of about 1.5 nm can be formed.

In the fourth step, the flow rate of Ar gas supplied into the processing container is 300 to 3000 sccm, and the flow rate of O ₂ gas supplied into the processing container is 1.5 to 75 sccc.
m, the pressure in the processing container is 13 to 400 Pa, and the microwave power supplied into the processing container is 1.5 to 7.5 kW, and the silicon oxide film may be formed. Diameter is 12i
If nch silicon wafer is used, this process is 1
By continuing for about 5 seconds, a silicon oxide film of about 1.5 nm can be formed.

In the plasma processing method using microwave-excited plasma, the second step may include a fifth step of nitriding the surface of the silicon oxide film formed on the object to be processed. Thereby, the film thickness of the insulating film made of the silicon oxide film can be easily made uniform. In this case, in the fifth step, the flow rate of Ar gas supplied into the processing container is 500 to 2000 sccm, and the flow rate of N ₂ gas supplied into the processing container is 10 to 200 sccm.
The surface of the silicon oxide film may be nitrided by setting the pressure in the processing container to 67 to 400 Pa and the microwave power supplied to the processing container to 1 to 5 kW. If a wafer with a diameter of 8 inches is used as the object to be processed, this processing is performed 20 times.
By continuing for about 2 seconds, 1
A silicon nitride film of about 5 nm can be formed.

In the fifth step, the flow rate of Ar gas supplied into the processing container is 750 to 3000 sccm, and the flow rate of N ₂ gas supplied into the processing container is 15 to 300 sccc.
m, the pressure in the processing container is 67 to 400 Pa, and the microwave power supplied into the processing container is 1.5 to 7.5 kW, and the surface of the silicon oxide film may be nitrided. When a wafer with a diameter of 12 inches is used as the object to be processed,
By continuing this treatment for about 20 seconds, a silicon nitride film of about 1 to 5 nm can be formed on the surface of the silicon oxide film.

Further, in the above-mentioned plasma processing method, the second to third steps are performed based on preset values.
You may make it transfer to the process of. Alternatively, the thickness of the insulating film deposited inside the processing container may be measured, and the second step to the third step may be performed based on the measurement result.

In the plasma processing method using microwave-excited plasma, in the third step, the flow rate of NF ₃ gas supplied into the processing container is 500 sccm, and the flow rate of N ₂ gas supplied into the processing container is 500 sccm. The inside of the processing container may be cleaned by setting the pressure in the processing container to 67 Pa and the power of the microwave supplied to the processing container to 2 kW. In addition, in the above-described plasma processing method, the first step and the second step may be repeated a plurality of times before shifting to the third step. As a result, the number of times cleaning is performed can be reduced. Further, in the above-described plasma processing method, two processing containers may be provided and the object to be processed in one processing container may be transported to the other processing container.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the drawings.

(First Embodiment) FIG. 1 is a diagram showing a main configuration of a microwave plasma processing apparatus according to a first embodiment of the present invention. In this figure, a sectional structure is partially shown. FIG. 2 is a plan view of the radial line antenna included in this plasma processing apparatus as seen from the direction of the line II-II ′, showing the slot arrangement of the radial line antenna. The microwave plasma processing apparatus shown in FIG. 1 has a bottomed cylindrical processing container 11 with an open top.
have. The processing container 11 is formed of a metal such as Al (aluminum). A mounting table 22 is fixed to the center of the bottom surface of the processing container 11 via an insulating plate 21, and a wafer (not shown), which is an object to be processed, is mounted on the upper surface of the mounting table 22. The mounting table 22 contains a heater (not shown) for heating the wafer to a predetermined temperature. A gate valve 20 that opens and closes when loading and unloading a wafer is provided on the side wall of the processing container 11.

An exhaust port 12 connected to a vacuum pump 13 as an exhaust means is provided on the outer peripheral portion of the bottom surface of the processing container 11, so that the inside of the processing container 11 can be exhausted to a desired degree of vacuum. A nozzle 14 is provided on the upper side wall of the processing container 11, and the nozzle 14 has a mass flow controller 15A, 15B, 15C, 15D, 15E and an on-off valve 1.
Gas sources 17A, 17B, 17C, 17D and 17E are connected via 6A, 16B, 16C, 16D and 16E. Here, the gas sources 17A, 17B, 17C, 17
D and 17E are TEOS, O ₂ , Ar, NF ₃ ,
It is used as a gas source of N ₂ . The nozzle 14, the mass flow controllers 15A to 15E, the open / close valves 16A to 16E, and the gas sources 17A to 17E form a gas supply unit that supplies gas into the processing container 11. The upper opening of the processing container 11 is closed with a dielectric plate 18 made of quartz glass or ceramics (for example, Al ₂ O ₃ , AlN) or the like so that plasma generated in the processing container 11 does not leak to the outside. There is.

A radial line antenna 30 is arranged on the dielectric plate 18. The radial line antenna 30 is isolated from the inside of the processing container 11 by the dielectric plate 18, and is protected from the plasma generated in the processing container 11. Radial line antenna 30
A microwave generator 45 for generating a microwave of a predetermined frequency within the range of 1 GHz to a few tens of GHz via the coaxial waveguide 41, the rectangular / coaxial converter 42, the rectangular waveguide 43, and the matching circuit 44. Are connected. The radial line antenna 30, the coaxial waveguide 41, the rectangular / coaxial converter 42, the rectangular waveguide 43, the matching circuit 44, and the microwave generator 45 constitute a plasma generating means. The outer peripheries of the dielectric plate 18 and the radial line antenna 30 are covered with an annular shield material 19 arranged on the side wall of the processing container 11, so that microwaves do not leak outside.

The configuration of the radial line antenna 30 will be further described. The radial line antenna 30 is composed of two circular conductor plates 31 and 32 which are parallel to each other and which form a radial waveguide 33, and a conductor ring 34 which connects and shields the outer peripheral portions of these conductor plates 31 and 32. ing. The conductor plates 31, 32 and the conductor ring 34 are formed of a metal such as Al.

Here, a microwave introduction port 35 for introducing microwaves into the radial waveguide 33 is formed in the central portion of the conductor plate 32, which is the upper surface of the radial waveguide 33, and serves as the lower surface of the radial waveguide 33. The conductor plate 31 is provided with a plurality of slots 36 for supplying the microwave propagating in the radial waveguide 33 into the processing container 11. For example, as shown in FIG.
A plurality of pairs of one slot 36A and 38B are arranged. Further, as shown in FIG. 1, a dielectric plate 37 made of Al ₂ O ₃ , AlN or the like is arranged in the radial waveguide 33. With this dielectric plate 37, the radial waveguide 3
Since the wavelength of the microwave propagating inside 3 is shortened, the number of slots 36 can be increased to improve the microwave supply efficiency.

Further, the microwave plasma processing apparatus shown in FIG. 1 has a process control device 5 for controlling the process.
Has 0. The process control device 50 is electrically connected to the vacuum pump 13, the mass flow controllers 15A to 15E and the open / close valves 16A to 16E, and the microwave generator 45, and controls the operations thereof, so that the process will be described below. Realize the process of doing. FIG. 3 shows FIG.
3 is a flowchart showing a process flow of the microwave plasma processing apparatus shown in FIG. The process of this plasma processing apparatus includes a pre-deposition step S1 of depositing an insulating film inside the processing container 11, a film forming step S2 of forming an insulating film on the surface of a wafer to be processed, and a processing step S2. The cleaning step S3 removes the insulating film deposited inside the container 11.

The pre-deposition process S1 will be described.
It FIG. 4 shows the microwave plasma in this step S1.
It is a figure which shows the cross-sectional structure of a processing apparatus. In step S1,
No wafer is placed on the upper surface of the mounting table 22.
In this state, the inside of the processing container 11 is evacuated by the vacuum pump 13.
The pressure is set to 13.3 Pa (100 mTorr). this
While maintaining the pressure, TEOS and O from the nozzle 14₂With
The mixed gas is introduced into the processing container 11. TEOS flow rate
100 sccm, O ₂Flow rate of 1000 sccm
It Here, the microwave generator 45 is driven and the frequency
Radiating a microwave MW of 2.45 GHz and power of 3 kW
Processing from the Alline antenna 30 via the dielectric plate 18
When introduced into the container 11, O is excited by microwaves.₂But
Plasma P containing O radicals is generated by dissociation.
O radicals are inside the processing container 11, that is, the processing container 1.
1, the inner surface of the dielectric plate 18 and the surface of the mounting table 22.
TEOS that adheres to the substrate and later arrives is decomposed and reacts with S
iO ₂Becomes By continuing this process for 60 seconds,
As shown in FIG. 4, a uniform Si film having a thickness of 2 μm is used as an insulating film.
O₂The film 51 can be formed.

Here, the generation of plasma P is 2.45 GH.
Since the microwave MW having a high frequency of z is used, it is possible to generate the plasma P having an electron temperature lower than that of the parallel plate type plasma processing apparatus. Further, by arranging the slots of the radial line antenna 30 as shown in FIG. 2, the electron temperature can be further reduced. Therefore, a denser and more uniform SiO ₂ film 51 than before can be formed inside the processing container 11. The dense and uniform SiO ₂ film 51 has a good adhesiveness to the processing container 11, and thus is inherently difficult to peel off. Further, since a sufficient coating action can be obtained even if the film thickness is made thinner than in the conventional case, the peeling caused by the difference in the linear thermal expansion coefficient with the processing container 11 which occurs when the film thickness of the SiO ₂ film is 10 μm or more is suppressed. You can also do it. Also, 13.3
Since the plasma P is generated under a low pressure of Pa, the mean free path of electrons is longer and the ion energy is higher than in the parallel plate plasma processing apparatus. For this reason, the deposition rate of SiO ₂ is faster than in the past, and the time required for pre-deposition can be shortened.

The above-mentioned pre-deposition processing conditions are merely examples, and a good SiO ₂ film can be formed inside the processing container 11 if the processing is performed within the following range. TEOS gas flow rate: 1 to 100 sccm, O ₂ gas flow rate: 100 to 2000 sccm, pressure inside the processing container 11: 1 to 133 Pa (7.5 to 10 Pa)
00 mTorr), frequency of microwave MW: 2.45 GHz, power: 1
~ 5kW, processing time: 10-360 seconds

When the pre-deposition step S1 is completed, the process proceeds to the film forming step S2 as shown in FIG. FIG. 5 is an explanatory diagram of this step S2. In this figure,
(A) is a figure which shows the cross-sectional structure of the microwave plasma processing apparatus at the time of carrying in a silicon wafer, (b) is a partial expanded sectional view of the silicon wafer at the time of processing completion. In step S2, a silicon wafer 23 having a diameter of 8 inches is loaded into the processing container 11 via the gate valve 20,
As shown in (a), it is mounted on the upper surface of the mounting table 22. Then, the surface of the wafer 23 is oxidized under the following processing conditions. The allowable range is shown in parentheses together with the representative value.

Flow rate of Ar gas: 1000 sccm (20
0 to 2000 sccm), O ₂ gas flow rate: 20 sccm (1 to 50 sccm), pressure inside the processing container 11: 67 Pa (13 to 400 Pa)
(500mTorr (100 ~ 3000mTorr
r)), the frequency of the microwave MW: 2.45 GHz, the power of the microwave MW: 2 kW (1 to 5 kW), and the processing is continued for 15 seconds under this condition (representative value), as shown in FIG. Thus, the SiO ₂ film 24 having a film thickness of 1.5 nm can be formed on the surface of the wafer 23.

When R is a positive number, the diameter is R (in
When the same process is performed on the silicon wafer of ch), the gas flow rate and the microwave power may be set to about R / 8 times the process conditions. Therefore, the diameter is 12 inches
The processing conditions for the ch silicon wafer are as follows. Ar gas flow rate: 1500 sccm (300 to 3000)
sccm), O ₂ gas flow rate: 30 sccm (1.5 to 75 scc)
m), pressure in the processing container 11: 67 Pa (13 to 400 Pa)
(500mTorr (100 ~ 3000mTorr
r)), microwave MW frequency: 2.45 GHz, microwave MW power: 3 kW (1.5 to 7.5 k)
W), by continuing the treatment for 15 seconds under these conditions (representative value), a Si film having a film thickness of 1.5 nm is formed on the surface of the 12-inch wafer.
An O ₂ film can be formed.

After forming the SiO ₂ film 24, the wafer 23 is unloaded from the processing container 11 through the gate valve 20. After that, the same film forming process is repeatedly performed on a plurality of different wafers 23. However, the SiO ₂ film 51 deposited inside the processing container 11 in the pre-deposition step S1 is partially peeled off while the film forming process is repeated, and the structure of the processing container 11 and the like is formed therefrom. There is a possibility that the metal may be separated and the inside of the processing container 11 may be contaminated. Therefore, Si
Before the O ₂ film 51 is peeled off, it is necessary to perform pre-deposition again to recoat the inside of the processing container 11. At this time, the process of newly depositing the SiO ₂ film on the SiO ₂ film 51 is repeatedly performed, and when the total thickness of the SiO ₂ film exceeds 10 μm, the SiO ₂ film will be stored in the processing container 11 as described above. It is easy to peel from the wall surface. Therefore, the film forming step S2 is terminated when the film forming process is performed on a predetermined number of wafers 23, and the process proceeds to the cleaning step S3 as shown in FIG.

In step S3, with the wafer not placed on the upper surface of the mounting table 22, the SiO ₂ film 51 deposited inside the processing container 11 under the following processing conditions.
Is completely removed. NF ₃ gas flow rate: 500 sccm, N ₂ gas flow rate: 500 sccm, pressure inside the processing container 11: 67 Pa (500 mTorr)
r), microwave MW frequency: 2.45 GHz, power: 2
kW, processing time: 300 seconds, when the cleaning step S3 is completed, the process proceeds to the pre-deposition step S1 again as shown in FIG. 3, and steps 1 to 3 are repeated thereafter.

The above process is merely an example.
For example, in the step S1 of pre-deposition, Si
A mixed gas of H ₄ and O ₂ may be used to deposit the SiO ₂ film 51 as an insulating film inside the processing container 11. In this case, the gas source 17A shown in FIG. 1 is used as the SiH ₄ gas source, and the process is performed under the following conditions, for example. SiH ₄ gas flow rate: 100 sccm, O ₂ gas flow rate: 500 sccm, pressure inside the processing container 11: 6.7 Pa (50 mTorr)
r), frequency of microwave MW: 2.45 GHz, power:
0.2 kW, processing time: 120 seconds,

In the step S1 of pre-deposition,
A SiN _x film may be deposited as an insulating film inside the processing container 11. When depositing a SiN _x film using a mixed gas of SiH ₄ and N ₂ , these gas sources are prepared and the treatment is performed, for example, under the following conditions. SiH ₄ gas flow rate: 10 sccm, N ₂ gas flow rate: 100 sccm, pressure inside the processing container 11: 7 Pa (50 mTorr), microwave MW frequency: 2.45 GHz, power: 3
kW, processing time: 60 seconds

S using a mixed gas of SiH ₄ and NH ₃
When depositing the iN _x film, these gas sources are prepared and the treatment is performed, for example, under the following conditions. SiH ₄ gas flow rate: 10 sccm, NH ₃ gas flow rate: 100 sccm, pressure inside the processing chamber 11: 7 Pa (50 mTorr), microwave MW frequency: 2.45 GHz, power: 3
kW, processing time: 60 seconds

Further, in the film forming step S2, a treatment of nitriding the SiO ₂ surface of the object to be treated can be performed. This treatment is performed for the purpose of making the thickness of the insulating film made of SiO ₂ uniform. As the object to be processed, the silicon wafer 23 having the SiO ₂ film 24 formed on the surface by the above-described method may be used, or the silicon wafer having the SiO ₂ film formed on the surface by the thermal oxidation method may be used.

The diameter of the silicon wafer 23 is 8 inches
In this case, for example, under the following processing conditions, the SiO ₂ film 2
4. Surface 4 is nitrided. The allowable range is shown in parentheses together with the representative value. Ar gas flow rate: 1000 sccm (500 to 2000)
sccm), N ₂ gas flow rate: 20 sccm (10 to 200 scc)
m), pressure inside the processing container 11: 67 Pa (67 to 400 Pa)
(500mTorr (500 ~ 3000mTorr
r)), microwave MW frequency: 2.45 GHz, microwave MW power: 2 kW (1 to 5 kW), by continuing the treatment for 20 seconds under these conditions (representative value), as shown in FIG. ₂ Film thickness 2n on the surface of film 24
The SiN _x film 25 of m can be formed.

When R is a positive number, the diameter is R (inch)
When the same treatment is applied to the silicon wafer of, the gas flow rate and the microwave power are set to about R / 8 of the above treatment conditions.
You can double it. Therefore, the processing conditions for a silicon wafer having a diameter of 12 inches are as follows. Ar gas flow rate: 1500 sccm (750-3000)
sccm), N ₂ gas flow rate: 30 sccm (15 to 300 scc)
m), pressure inside the processing container 11: 67 Pa (67 to 400 Pa)
(500mTorr (500 ~ 3000mTorr
r)), microwave MW frequency: 2.45 GHz, microwave MW power: 3 kW (1.5 to 7.5 k)
W), by continuing the treatment for 20 seconds under these conditions (representative value), a Si film having a thickness of 1.5 nm is formed on the surface of the 12-inch wafer.
An N _x film can be formed. Needless to say, when performing this treatment, it is necessary to provide the gas supply means with a gas source of Ar and N ₂ .

In the cleaning step S3,
The insulating film deposited inside the processing container 11 may be removed using ClF ₃ gas. The process of the microwave plasma processing apparatus shown in FIG. 1 can be configured by combining the processes in steps S1 to S3 described here. For example, in the pre-deposition step S1, the SiO ₂ film 51 may be deposited inside the processing container 11, while in the film forming step S2, a process of nitriding the SiO ₂ surface of the object may be performed. In addition, while the SiN _x film is deposited inside the processing container 11 in step S1, the surface of the object to be processed may be oxidized in step S2.

Although the number of wafers 23 to be processed has been taken as an example of the standard for shifting from the film forming step S2 to the cleaning step S3, other than this, for example, the cumulative time of plasma generation and the inside of the processing container 11 are used. The total time of the deposition time of the insulating film and the processing time of the wafer 23 may be used as a reference. Since both are functions of physical quantities that can be easily measured, cleaning start control can be performed with an extremely simple configuration.

(Second Embodiment) In the process of the microwave plasma processing apparatus shown in FIG. 3, the pre-deposition step S1 is performed once, and then the cleaning step S3 is performed once. The pre-deposition process may be performed a plurality of times and then the cleaning process may be performed once. This process will be described as the second embodiment of the present invention. FIG. 7 is a flowchart showing another process flow of the microwave plasma processing apparatus shown in FIG. This process is also realized by the control of the process control device 50 shown in FIG.

In this process, first, step S1
In 1, the number n of pre-depositions is 0
Set to (zero). Then, the process proceeds to step S12, in which SiO _{2 having a} film thickness of 2 μm is formed as an insulating film inside the processing container 11.
Perform pre-deposition to deposit the film. This step S
The process in 12 is the same as the process S1 shown in FIG. Next, the process proceeds to step S13, and 1 is added to the number n of times of pre-deposition. As a result, n becomes 1. Next, in step S14, a film formation process is performed on a predetermined number of silicon wafers 23. The process in this step S14 is the same as the process S2 shown in FIG.

Next, in step S15, it is determined whether n = 5, that is, whether pre-deposition has been performed 5 times. Since n = 1 now, NO is selected, the process proceeds to step S12, and pre-deposition is performed again. Here, on the SiO ₂ film previously deposited inside the processing container 11,
Since the SiO ₂ film having a film thickness of 2 μm is deposited again, the total film thickness of the SiO ₂ film deposited inside the processing container 11 becomes 4 μm. By repeating such processing and performing pre-deposition 5 times and n = 5,
YES is selected in step S15 and the process proceeds to step S16. In step S16, cleaning is performed to remove the SiO ₂ film deposited inside the processing container 11. The processing conditions are based on the step S3 shown in FIG. 3, but the processing time is lengthened because the total thickness of the SiO ₂ film is 10 μm. When a mixed gas of NF ₃ and N ₂ is used, the treatment time may be about 60 seconds.

When the SiO ₂ film deposited inside the processing container 11 is completely removed in step S16, the process proceeds to step S11 and the number n of pre-deposition is reset to 0 (zero), and thereafter the same. Repeat the process.
By performing pre-deposition a plurality of times and then performing the cleaning once as in this process, the number of times of cleaning is reduced and the cleaning is required as compared with the process shown in FIG. 3 in which cleaning is performed every time. Time and cost can be reduced. The SiO ₂ film deposited inside the processing container 11 has a film thickness of 10
Since it may easily peeled exceeds μm known empirically, by a cleaning pre-deposition to deposit an SiO ₂ film having a thickness of 2μm at 5 times conducted timing, SiO ₂ film Contamination inside the processing container 11 due to peeling can be prevented.

In this process, since cleaning may be performed before the total thickness of the SiO ₂ films deposited inside the processing container 11 exceeds 10 μm, the SiO deposited per pre-deposition may be increased. _The timing of cleaning may be changed according to the film thickness of the _two films. In addition, SiO that is a standard for performing cleaning
_The film thickness “10 μm” of the _two films is not an absolute value and may vary depending on the device configuration or processing conditions.

(Third Embodiment) FIG. 8 is a sectional view showing a main structure of a microwave plasma processing apparatus according to a third embodiment of the present invention. In this drawing, the sectional structure is partially shown, and the same or corresponding portions as in FIG. 1 are designated by the same reference numerals. The microwave plasma apparatus shown in FIG. 8 has a film thickness measuring device 60 for measuring the film thickness of the SiO ₂ film deposited inside the processing container 11. Figure 9
It is a block diagram showing a configuration of the film thickness measuring device 60. The film thickness measuring device 60 includes, for example, a vibrator 61 such as a tuning fork, an amplifier circuit 62 that constitutes an oscillator together with the vibrator 61, and a frequency counter 63 that detects the frequency of the oscillator composed of the vibrator 61 and the amplifier circuit 62. It is configured. As shown in FIG. 8, the vibrator 61 is fixed to the inner wall surface of the processing container 11, and the circuit section 64 including the amplification circuit 62 and the frequency counter 63 is provided outside the processing container 11. The output terminal of the frequency counter 63 is electrically connected to the input terminal of the process control device 50.

In the plasma processing apparatus shown in FIG.
The SiO inside the processing container 11 by pre-deposition
_{When the two} films are deposited, the SiO ₂ film is also deposited on the oscillator 61, and the frequency of the oscillator including the oscillator 61 decreases. S
Since the thickness of the iO ₂ film and the amount of decrease in frequency are uniquely determined, the thickness of the SiO ₂ film deposited inside the processing container 11 can be known from the detection result of the frequency of the oscillator by the frequency counter 63. Since the detection result of the frequency counter 63 is output to the process control device 50, the process control device 50 can control the start of cleaning based on the measurement result of the film thickness of the SiO ₂ film. For example, as in the process shown in FIG. 7, the pre-deposition process S1
When the cleaning step S16 is performed once after performing step 2 several times, in step S15, "whether or not the measurement result of the film thickness of the SiO ₂ film deposited inside the processing container 11 is 10 μm" is determined. You should make a judgment.

By using the measurement result of the film thickness of the SiO ₂ film deposited inside the processing container 11 as the reference for starting cleaning, before the SiO ₂ film exceeds the film thickness at which it is easily peeled off,
The cleaning can be surely started. SiO ₂
The method in which the measurement result of the film thickness is used as a reference for starting cleaning is more effective than the case where an insulating film is formed by oxidizing the surface of the silicon wafer 23 in the film forming process on the object to be processed. A remarkable effect is obtained when the insulating film is formed by deposition.

(Fourth Embodiment) In the above description, the microwave plasma processing apparatus for generating plasma by microwave excitation is used, but an inductively coupled plasma processing apparatus for generating plasma by inductive excitation is used. You can also FIG. 10 is a diagram showing a main configuration of an inductively coupled plasma processing apparatus which is the fourth embodiment of the present invention. In this figure, the same or corresponding portions as those in FIG. 1 are indicated by the same reference numerals, and the description thereof will be omitted as appropriate. Note that the cross-sectional structure is partially shown in this figure.

In this inductively coupled plasma processing apparatus, a coil 131 having a spiral shape in plan view, which constitutes an antenna, is provided on a dielectric plate 118 that closes the upper opening of the processing container 11. A high frequency power supply 145 that outputs high frequency power of 13.56 MHz, 1 kW, for example, is connected via a matching circuit 144 between the outer terminal and the inner terminal of the coil 131. The coil 131, the matching circuit 144, and the high-frequency power source 145 form a plasma generation unit. A grid 181 is fixed in the processing container 11 between the dielectric plate 118 and the mounting table 22. As the grid 181, a conductive plate made of Al or the like having a plurality of substantially circular through holes formed therein, or a mesh material having conductivity is used. Grid 18
1 is fixed to the side wall of the processing container 11,
Grounded through. With this grid 181,
A plasma generation space C1 and a processing space C2 are provided in the processing container 11.
Is divided into and

When high frequency power is supplied to the coil 131 from the high frequency power supply 145, plasma is generated in the plasma generating space C1 by induction excitation. When this plasma moves from the plasma generation space C1 through the through holes of the grid 181 to the processing space C2, energy is taken away by the grid 181. Therefore, plasma with a low electron temperature is introduced into the processing space C2. Become. By performing pre-deposition using this low electron temperature plasma,
Similar to the microwave plasma processing apparatus shown in FIG.
An insulating film that is difficult to peel off can be deposited inside the processing container 11. In addition, since this inductively coupled plasma processing apparatus also generates the plasma P under a low pressure of 7 Pa, the time required for pre-deposition can be shortened as in the microwave plasma processing apparatus shown in FIG. it can.

(Fifth Embodiment) FIG. 11 is a diagram showing a main configuration of an inductively coupled plasma processing apparatus according to a fifth embodiment of the present invention. In this figure, the same or corresponding portions as those in FIGS. 1 and 10 are indicated by the same reference numerals, and the description thereof will be appropriately omitted. Note that the cross-sectional structure is partially shown in this figure. FIG. 12 is a plan view of a Faraday shield included in this inductively coupled plasma processing apparatus. The dielectric plate 190 of the inductively coupled plasma processing apparatus shown in FIG. 11 has an upper dielectric layer 191 and a lower dielectric layer 192.
Of the upper dielectric layer 191 and the lower dielectric layer 1
A Faraday shield 193 is sandwiched between the Faraday shield 192 and the frame 92. As shown in FIG. 12, the Faraday shield 193 has a circular metal film 193A made of Cu (copper) or the like,
The plurality of slots 193B are formed at equal angular intervals and are grounded via the processing container 11.

Generally, in the inductively coupled plasma processing apparatus, not only the antenna formed of the coil 131 and the plasma are inductively coupled but also capacitively coupled. Faraday shield 1
93 cuts off this capacitive coupling and suppresses the generation of plasma by capacitive excitation, which has a higher electron temperature than plasma by inductive excitation. Therefore, Faraday Shield 193
Is used to reduce the electron temperature of the plasma, and like the induction excitation plasma processing apparatus shown in FIG.
An insulating film that is difficult to peel off can be deposited inside the processing container 11. Also, the time required for pre-deposition can be shortened. The grid 181 shown in FIG. 10 may be used in combination with the Faraday shield 193.

(Sixth Embodiment) The microwave plasma processing apparatus or the inductively coupled plasma processing apparatus described above may be applied to a cluster tool apparatus capable of continuous processing.
FIG. 13 is a schematic diagram showing a planar configuration of a cluster tool device to which the plasma processing device described above is applied. In this cluster tool device, a first cassette chamber 272, a preheating chamber 273, a first and a second film formation processing chambers are provided around a common transfer chamber 271 formed of Al or the like in a hexagonal container shape in plan view. 274 and 275 and the second cassette chamber 276,
It is arranged in this order. Common transfer room 27
1 and the respective chambers 272 to 276 around it are connected via openable and closable gate valves 20 _{2 to} 20 ₆ .

In the common transfer chamber 271, there is arranged a transfer arm 271A which is configured to be expandable / contractible and rotatable while holding the silicon wafer 23. The transfer arm 271A moves the wafer 23 between the chambers. It can be carried in and out. Further, the common transfer chamber 271 can be evacuated. A gate door 272 that can be freely opened and closed is provided in the first and second cassette chambers 272 and 276.
A, 276A are provided, and the gate door 272A,
A cassette 272B capable of accommodating, for example, 25 wafers 23 in the cassette chambers 272, 276 via the 276A,
276B can be loaded and unloaded. The cassette chambers 272 and 276 can also be evacuated.

The preheating chamber 273 is a processing chamber for heating the wafer 23 in advance before the film forming process for the wafer 23 in the first film forming process chamber 274 described later. The preheating chamber 273 can also be evacuated. The first and second film forming processing chambers 274 and 275 are obtained by applying the plasma processing apparatus shown in FIG. 1, FIG. 8, FIG. 10 or FIG. 11, and particularly the first film forming processing apparatus 274.
Is set for forming an oxide film on the surface of the wafer 23, and the second film forming apparatus 275 is set for forming a nitride film on the surface of the oxide film.

Next, the flow of processing by the cluster tool device shown in FIG. 13 will be described. A cassette 272 containing, for example, 25 unprocessed silicon wafers 23
After B is loaded into the first cassette chamber 272 from the outside through the gate door 272A, the cassette chamber 272 is sealed and the inside is evacuated to the base pressure. The base pressure is the lowest pressure that can be evacuated in this state. When the inside of the cassette chamber 272 reaches the base pressure, the gate valve 20 ₂ between the cassette chamber 272 and the common transfer chamber 271, which is maintained at the base pressure in advance, is opened. Then, one unprocessed wafer 23 is taken out from the cassette 272B using the transfer arm 271A, and is transferred via the gate valve 20 ₃ .
It is carried into the preheating chamber 273 adjusted to the base pressure.
In the preheating chamber 273, the loaded wafer 23 is heated to 400 ° C., for example.

[0060] Then, the wafer 23 which has been heated by the preheating chamber 273, through a gate valve 20 ₄ is carried into the first film forming process chamber 274 is adjusted to base pressure. In the film forming processing chamber 274, the surface of the loaded wafer 23 is oxidized and the SiO ₂ film 2 as shown in FIG.
4 is deposited. The details of this processing are as described above.
However, since the wafer 23 is loaded while being heated to a temperature of 400 ° C. that is suitable for this deposition process, the deposition process can be started immediately after loading. After the film forming process is completed, the gas remaining in the film forming process chamber 274 is exhausted, and then the base pressure is set, and then the gate valve 20 ₄ is opened. Then, the wafer 23 having the SiO ₂ film 24 formed thereon is taken out by using the transfer arm 271A and carried into the second film formation processing chamber 275 adjusted to the base pressure via the gate valve 20 ₅ . In the film forming processing chamber 275, the SiO ₂ surface of the loaded wafer 23 is nitrided to form the SiN _x film 25 as shown in FIG. The details of this processing are as described above.

After the film forming process is completed, the gas remaining in the film forming process chamber 275 is exhausted, and then the base pressure is set, and then the gate valve 20 ₅ is opened. Then, the wafer 23 on which SiN _x 25 is deposited is taken out by using the transfer arm 271A, and is housed in the cassette 276B in the second cassette chamber 276 whose base pressure is adjusted via the gate valve 20 _6, and Ends the process. As described above, by using the cluster tool shown in FIG. 13, the oxidation treatment and the nitridation treatment on the silicon wafer 23 are continuously performed, and the SiO ₂ film 24 and the SiN _x film 2 as shown in FIG.
It is possible to form an insulating film having a two-layer structure composed of 5 and 5 in a short time.

Although specific examples of the processing conditions and the like have been shown above, it goes without saying that the present invention is not limited to these. Further, although the example in which the plasma processing apparatus of the present invention is applied to the film forming apparatus is shown, the plasma processing apparatus is also applicable to an etching apparatus, an ashing apparatus and the like.

[0063]

As described above, in the present invention, plasma is generated by microwave excitation or induction excitation in a state where the object to be processed is not loaded into the processing container, and an insulating film is formed inside the processing container. Perform pre-deposition to deposit. Since this plasma has a low electron temperature, it is possible to form a denser and more uniform insulating film than in the past and to make it difficult to peel off. Also, since the ion energy of the plasma is high,
The deposition rate of the insulating film inside the processing container can be increased, and the time required for pre-deposition can be shortened. Further, in the present invention, cleaning is performed to remove the insulating film deposited inside the processing container while the object to be processed is carried out from the processing container. As a result, it is possible to avoid an increase in film thickness when the insulating film is deposited again on the insulating film, and it is possible to make the insulating film difficult to peel off.

Further, when plasma is generated by microwave excitation, a radial line antenna having a plurality of pairs of two slots separated from each other and orthogonal to each other is used to further lower the electron temperature of plasma, An insulating film that is more difficult to peel can be formed.
Further, when plasma is generated by induction excitation, by using at least one of a grid and a Faraday shield provided in the processing container, the electron temperature of the plasma is further lowered, and an insulating film that is more difficult to peel off is formed. You can

Further, by starting the cleaning on the basis of a predetermined set value, it is possible to control the cleaning start with a simple structure. Alternatively, measure the thickness of the insulating film deposited inside the processing container,
By starting the cleaning based on the measurement result, the cleaning can be surely started before the thickness of the insulating film exceeds the thickness at which the insulating film is easily peeled, and the contamination of the processing container due to the peeling of the insulating film can be prevented. Further, by providing a transfer means for transferring the target object processed in one processing container to the other processing container, continuous processing in two processing containers becomes possible.

[Brief description of drawings]

FIG. 1 is a diagram showing a main configuration of a microwave plasma processing apparatus according to a first embodiment of the present invention.

FIG. 2 is a plan view showing a slot arrangement of a radial line antenna.

FIG. 3 is a flowchart showing a process flow of the microwave plasma processing apparatus shown in FIG.

FIG. 4 is a diagram showing a sectional configuration of a microwave plasma processing apparatus in a pre-deposition step.

FIG. 5 is an explanatory diagram of a film forming step S2.

FIG. 6 is a partially enlarged cross-sectional view at the end of the nitriding treatment on the oxide film surface of the silicon wafer.

7 is a flowchart showing another process flow of the microwave plasma processing apparatus shown in FIG.

FIG. 8 is a cross-sectional view showing a main-part configuration of a microwave plasma processing apparatus according to a third embodiment of the present invention.

FIG. 9 is a block diagram showing a configuration of a film thickness measuring instrument.

FIG. 10 is a diagram showing a main configuration of an inductively coupled plasma processing apparatus according to a fourth embodiment of the present invention.

FIG. 11 is a diagram showing a main configuration of an inductively coupled plasma processing apparatus which is a fifth embodiment of the present invention.

FIG. 12 is a plan view of a Faraday shield.

FIG. 13 is a schematic diagram showing a planar configuration of a cluster tool device.

[Explanation of Codes] 11 ... Processing container, 12 ... Exhaust port, 13 ... Vacuum pump, 1
4 ... Nozzle, 15A to 15E ... Mass flow controller, 16A to 16E ... Open / close valve, 17A to 17E ... Gas source, 18, 118, 190 ... Dielectric plate, 19 ... Shielding material, 20, 20 _{2 to} 20 ₆ ... Gate valve , 21 ... Insulating plate, 22 ... Mounting table, 23 ... Silicon wafer (object to be processed), 24 ... SiO ₂ film (silicon oxide film), 25 ... S
iN _x film (silicon nitride film), 30 ... Radial line antenna 31, 31, 32 ... Conductor plate, 33 ... Radial waveguide,
34 ... Conductor ring, 35 ... Microwave inlet, 36, 3
6A, 36B, 193B ... Slot, 41 ... Coaxial waveguide, 42 ... Rectangular / coaxial converter, 43 ... Rectangular waveguide, 4
4, 144 ... Matching circuit, 45 ... Microwave generator, 50 ... Process control device, 51 ... SiO ₂ film (insulating film), 60 ... Film thickness measuring device, 61 ... Transducer, 62 ... Amplifying circuit, 63 ... Frequency Counter, 64 ... Circuit part, 131 ...
Coil, 145 ... High frequency power supply, 181, ... Grid, 19
DESCRIPTION OF SYMBOLS 1 ... Upper dielectric layer, 192 ... Lower dielectric layer, 193 ... Faraday shield, 193A ... Metal film, 271 ... Common transfer chamber, 271A ... Transfer arm, 272, 276 ... Cassette chamber, 272A, 276A ... Gate door, 272B, Two
76B ... Cassette, 273 ... Preheating chamber, 274, 27
5 ... Film formation processing chamber, C1 ... Plasma generation space, C2 ... Processing space, MW ... Microwave, P ... Plasma, S1, S12
... Pre-deposition process (first process), S2, S
14 ... Film forming step (second step), S3, S16 ... Cleaning step (third step).

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 5F004 AA15 BA20 BB29 BD04 DA17                       DB03 DB07                 5F045 AA09 AA20 AB32 AB33 AC09                       AC11 AC15 AC16 BB14 CA05                       DP04 EB06 EB11 EE12 EH02                 5F058 BA20 BC02 BC08 BE10 BF72                       BF73 BF74 BH20 BJ01

Claims (25)

[Claims] 1. A processing container in which an object to be processed is placed, a plasma generation unit for generating plasma by microwave excitation in the processing container, and a condition in which the object to be processed is not carried into the processing container. Plasma is generated to deposit an insulating film inside the processing container, the target object is loaded into the processing container, plasma is generated to process the target object, and the target object is unloaded from the processing container. And a process control means for controlling a cleaning process for removing the insulating film deposited inside the processing container. 2. The plasma processing apparatus according to claim 1, wherein the plasma generating means has a radial line antenna for supplying microwaves into the processing container. 3. The plasma processing apparatus according to claim 2, wherein the radial line antenna has a plurality of pairs of two slots separated from each other and orthogonal to each other. 4. A processing container in which an object to be processed is placed, a plasma generating unit that generates plasma by induction excitation in the processing container, and a plasma in a state where the object to be processed is not carried into the processing container. To deposit an insulating film inside the processing container, carry in the object to be processed into the processing container, generate plasma to process the object, and carry out the object from the processing container. A plasma processing apparatus comprising: a process control unit that controls a cleaning process for removing an insulating film deposited inside the processing container. 5. The plasma processing apparatus according to claim 4, further comprising a grid fixed in the processing container and having a plurality of holes formed therein. 6. The plasma processing apparatus according to claim 4, further comprising a Faraday shield that cuts off capacitive coupling between the plasma generating means and the plasma. 7. The plasma processing apparatus according to claim 1, wherein the process control means starts the cleaning based on a preset set value. 8. The plasma processing apparatus according to claim 1, further comprising a film thickness measuring unit that measures a film thickness of an insulating film deposited inside the processing container and outputs the film thickness to the process control unit. The plasma processing apparatus, wherein the process control means starts the cleaning based on a measurement result of the film thickness measurement means. 9. The plasma processing apparatus according to claim 1, further comprising two processing containers and two plasma generating means, and the object to be processed processed by one of the processing containers. A plasma processing apparatus comprising: a transporting unit that transports the gas to the other of the processing vessels. 10. A first step in which plasma is generated in a processing container by microwave excitation to deposit an insulating film inside the processing container, and an object to be processed is loaded into the processing container and is then placed in the processing container. A second step of generating plasma by microwave excitation to perform processing on the object to be processed, and cleaning for removing the object to be processed from the processing container and removing an insulating film deposited inside the processing container And a third step for performing the plasma treatment method. 11. A first plasma generating plasma by induction excitation in a processing container to deposit an insulating film inside the processing container.
And a second step of carrying in the object to be processed into the processing container, generating plasma in the processing container by induction excitation to perform processing on the object to be processed, and the object to be processed from the processing container. And a third step of carrying out cleaning for removing the insulating film deposited inside the processing container. 12. The plasma processing method according to claim 10, wherein the insulating film deposited in the first step is a silicon oxide film. 13. The plasma processing method according to claim 12, wherein in the first step, the flow rate of TEOS gas supplied into the processing container is 1 to 1.
00 sccm, the flow rate of O ₂ gas supplied into the processing container is 100 to 2
000 sccm, the pressure in the processing container is 1 to 133 Pa, and the microwave power supplied to the processing container is 1 to 5
The plasma processing method is characterized in that: 14. The plasma processing method according to claim 10, wherein the insulating film deposited in the first step is a silicon nitride film. 15. The plasma processing method according to claim 10, wherein the object to be processed is a silicon wafer, and in the second step, a surface of the silicon wafer is oxidized to form a silicon oxide film. A plasma processing method comprising the steps of: 16. The plasma processing method according to claim 15, wherein in the fourth step, a flow rate of Ar gas supplied into the processing container is 200 to 2
000 sccm, the flow rate of O ₂ gas supplied into the processing container is 1 to 50 s
ccm, the pressure in the processing container is 13 to 400 Pa, and the microwave power supplied to the processing container is 1 to 5
The plasma processing method is characterized in that: 17. The plasma processing method according to claim 15, wherein in the fourth step, the flow rate of Ar gas supplied into the processing container is 300 to 3.
000 sccm, the flow rate of O ₂ gas supplied into the processing container is 1.5 to 7
5 sccm, the pressure in the processing container is 13 to 400 Pa, and the microwave power supplied to the processing container is 1.5.
~ 7.5 kW, the plasma processing method characterized by the following. 18. The plasma processing method according to claim 10, wherein the second step includes a fifth step of nitriding a surface of a silicon oxide film formed on the object to be processed. Plasma treatment method. 19. The plasma processing method according to claim 18, wherein in the fifth step, a flow rate of Ar gas supplied into the processing container is 500 to 2
000 sccm, the flow rate of N ₂ gas supplied into the processing container is 10 to 20
0 sccm, the pressure in the processing container is 67 to 400 Pa, and the microwave power supplied to the processing container is 1 to 5
The plasma processing method is characterized in that: 20. The plasma processing method according to claim 18, wherein in the fifth step, a flow rate of Ar gas supplied into the processing container is 750 to 3.
000 sccm, the flow rate of N ₂ gas supplied into the processing container is 15 to 30
0 sccm, the pressure in the processing container is 67 to 400 Pa, and the microwave power supplied to the processing container is 1.5.
~ 7.5 kW, the plasma processing method characterized by the following. 21. The plasma processing method according to claim 10, wherein the second step is followed by the third step based on a preset set value. 22. The plasma processing method according to claim 10, wherein the film thickness of the insulating film deposited inside the processing container is measured,
A plasma processing method, characterized by shifting from the second step to the third step based on the measurement result. 23. The plasma processing method according to claim 10, wherein in the third step, a flow rate of NF ₃ gas supplied into the processing container is 500 s.
ccm, the flow rate of the N ₂ gas supplied into the processing container is 500 sc
cm, the pressure in the processing container is 67 Pa, the microwave power supplied into the processing container is 2 k
W, The plasma processing method characterized by the following. 24. The plasma processing method according to claim 10 or 11, wherein the first step and the second step are repeated a plurality of times, and then the step is transferred to the third step. 25. The plasma processing method according to claim 10 or 11, further comprising: two processing containers, wherein the object to be processed, which has been processed by one of the processing containers, is transferred to the other of the processing containers. A characteristic plasma processing method.