JPH0331481A - Ecr plasma cvd device - Google Patents

Abstract

PURPOSE:To prevent a film from being built-up in a microwave introducing window without causing etching in this window by arranging a magnetic field generating means to the outside of a plasma forming chamber and making this magnetic field generating means movable, etching and removing the unnecessary deposit built-up in the microwave introducing window. CONSTITUTION:The exciting coil 10 of a magnetic field generating means is provided freely slidingly and vertically to the outside of a plasma forming chamber 2. During film formation, the exciting coil 10 is positioned to the lower part of the chamber 2, namely to the part nearest to a reaction chamber 1. When a film is built-up in a microwave introducing window 7 by repeating film formation, etching gas is introduced through an introduction pipe 9 in a state wherein a wafer 3 is not placed on a susceptor 4. Together therewith, the exciting coil 10 is positioned to the upper part of the plasma forming chamber 2, namely to the part nearest to a microwave waveguide 8. The film built-up in the microwave introducing window 7 is etched. The etched film is made reactive gas and it is discharged.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to a plasma CVD apparatus for growing thin films in the vapor phase through plasma excitation and surface reactions, and in particular utilizes the ECR (electron cyclotron resonance) phenomenon as a plasma generation source. The present invention relates to an ECR plasma CVD apparatus.

[Summary of the invention]

The present invention introduces a gas into a plasma generation chamber through a gas introduction means, generates plasma by guiding microwaves through a microwave introduction window, activates molecules in the plasma, and forms a film. In an ECR plasma CVD apparatus for depositing a thin film by reaction on a substrate to be treated, a magnetic field generating means disposed outside the plasma generation chamber having the microwave introduction window is movable to deposit a thin film on the microwave introduction window. By configuring the device to remove unnecessary deposits by etching, the deposition of unnecessary deposits on the microwave introduction window is prevented, and the reliability of the film forming process and the apparatus itself, as well as the efficiency of the film forming process are improved. This is what I did.

Further, in the ECR plasma CVD apparatus, the present invention provides two magnetic field generating means on the outside of the plasma generation chamber having the microwave introduction window, and the magnetic field generated by one of the magnetic field generating means is diverged toward the microwave introduction window. By etching and removing unnecessary deposits deposited on the microwave introduction window, the deposition of unnecessary deposits on the microwave introduction window is prevented, thereby improving the reliability of the film forming process and the device itself. This is intended to improve the efficiency of the membrane treatment process.

[Conventional technology]

Generally, charged particles in a static magnetic field perform circular motion (cyclotron motion) due to Lorentz force.

The angular frequency of this movement and the frequency of the high frequency electric field is 2.45GH
When z is matched, resonance absorption occurs and electric field energy is efficiently absorbed by the charged particles. This phenomenon can be used to efficiently decompose and activate reaction gases, such as 10-'To
The ECR plasma CVD method is a method for forming a film in a high vacuum of about rr.

This ECR plasma CVD method is attracting attention as a film forming technology for future ultra-highly integrated circuits. The reason for this is that it is not only possible to perform discharge (ionization) at low pressure and form a high-density plasma film even at low pressure, but also to be able to separate the plasma generation region and film growth region, and to support the wafer. By applying a high frequency voltage (RF bias) to the sample stage, it is possible to form a flattened film on the uneven surface of the wafer, and in addition, damage to the substrate and generation of foreign matter due to high frequency can be reduced. It is possible to form high-quality thin films at low temperatures.

Now, taking full advantage of the above features, ECR Plasma C
Metal film with good film quality (e.g. tungsten film) by VD method
There is an attempt to form a

[Problem to be solved by the invention]

However, when forming a metal film using the ECR plasma CVD method, the temperature of the quartz microwave introduction window rises due to heat generation when microwaves are introduced, and the microwaves are guided and the raw material gas is diffused. Below, the thermal energy of the microwave introduction window increases the rate at which molecules in the source gas attach to the microwave introduction window, and film deposition (deposition of unnecessary deposits) also occurs on the microwave introduction window. Therefore, as film deposition on the microwave introduction window progresses, microwaves no longer enter the plasma generation source (plasma generation chamber), resulting in a disadvantage that film growth on the wafer becomes impossible.

In order to solve this problem, the current voltage (t
A method has been reported in which the film deposited on the microwave introduction window is etched while the film is grown on the wafer by applying a There was an inconvenience in that it caused fogging on the window, which inhibited film growth on the wafer.
-See ZF-1).

The present invention has been made in view of these points, and its purpose is to prevent film deposition on the microwave introduction window without allowing etching to occur on the microwave introduction window itself, and to prevent film deposition on the microwave introduction window. The purpose of the present invention is to provide an ECR plasma CVD apparatus that can increase the reliability of the film growth and the apparatus itself, and improve the efficiency of the film forming process.

[Means to solve the problem]

The ECR plasma CVD apparatus of the present invention introduces gas into the plasma generation chamber (2) through the gas introduction means (9), and guides microwaves through the microwave introduction window (7) to generate plasma. In an ECR plasma CVD apparatus that generates a microwave, activates molecules in the plasma, and causes a reaction to deposit a thin film on a substrate (wafer) (3) on which a film is to be formed, a plasma generation system having a microwave introduction window (7) is used. Room (
2) is arranged so that the magnetic field generating means (10) disposed outside is movable to etch away unnecessary deposits deposited on the microwave introduction window (7).

Further, the present invention provides the above ECR plasma CVD apparatus, in which a plasma generation chamber (2) having a microwave introduction window (7) is provided.
) are provided on the outside of the microwave introduction window (7), and the magnetic field generated by one of the magnetic field generation means (22) is diverged toward the microwave introduction window (7).
) is configured to remove unnecessary deposits deposited thereon by etching.

[Effect]

According to the configuration of the first invention described above, the plasma generation chamber (
Since the magnetic field generating means (10) disposed outside the wafer (2) is made movable, the magnetic field generating means (10) is placed on the film growth region side, that is, on the reaction chamber (1) side during the film forming process on the wafer (3). By locating it at , film formation can be performed on the wafer (3). On the other hand, the microwave introduction window (7)
When removing the film deposited on the magnetic field generating means (10)
The microwave is It becomes possible to remove the film deposited on the microwave introduction window (7) without etching the introduction window (7) itself (because of the low ion energy).

At this time, the resonance point r of the ECR is at the microwave introduction window (7)
, the microwave introduction window (7) can be efficiently cleaned. In addition, since the film removed by etching becomes a gas, the microwave introduction window (7)
It is possible to suppress the generation of dust due to etching of the film deposited on the surface.

Further, according to the configuration of the second present invention, the plasma generation chamber (
2) two magnetic field generating means (21) and (
22), the magnetic field generated by one of the magnetic field generating means (22) is diverged toward the microwave introducing window (7), so that by introducing the etching gas, the plasma of the etching gas is exposed to the microwave by the magnetic field. Introduction window (7
) side, microwave introduction window (7)
The film (unnecessary deposit) deposited on the surface can be removed by etching. Since this etching uses low ion energy, the microwave introduction window (7) is hardly etched. Further, since the film removed by etching becomes a gas, it is possible to suppress the generation of dust due to etching of the film deposited on the microwave introduction window (7).

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to FIGS. 1 to 8.

FIGS. 1A and 1B show ECR plasma C according to the first embodiment.
FIG. 2 is a configuration diagram showing a VD device. In this figure, (1)
2 shows a reaction chamber in which a film is formed on a wafer (3), and (2) a plasma generation chamber.

The reaction chamber (υ) has a susceptor (4) on which the wafer (3) is placed, and a gas introduction pipe (5) on the side wall.The reaction chamber (1) also has a valve, It is connected to an exhaust system consisting of a pump, etc.A plasma generation chamber (2) is provided in the upper part of this reaction chamber (1) via a plasma extraction window (6); A microwave waveguide (8) is provided through a microwave introduction window (7) made of quartz.A gas introduction pipe (9) is also provided above the plasma generation chamber (2).

In this example, the excitation coil (10) is connected to a vertical sliding mechanism (not shown) on the outside of the plasma generation chamber (2), and can freely slide up and down on the outside of the plasma generation chamber (2). It consists of In addition, the pressure inside the plasma generation chamber (2) and the reaction chamber (1) is maintained at 5 by the exhaust system.
It is maintained at a high vacuum of Xl0-3 Torr.

The ECR plasma CVD apparatus then forms a film on the wafer (3) in the following manner.

That is, as shown in FIG. 1A, for example, Narbon-Ar gas (hydrogen H8 gas may also be used) is introduced into the plasma generation chamber (2) from the gas introduction pipe (9), and a microwave waveguide is introduced into the plasma generation chamber (2). (8) and the microwave introduction window (7) into the plasma generation chamber (2).
4507, 800W), and an excitation coil (10
) to generate a downward magnetic field in the plasma generation chamber (2), argon Ar gas plasma is generated in the plasma generation chamber (2), and self-diffusion or the magnetic field causes it to flow downward, that is, in the reaction chamber (1). ), forming a so-called plasma flow (11). At this time, the excitation coil (1O) is positioned at the lower part of the plasma generation chamber (2), that is, at the closest position to the reaction chamber (1) by a vertical sliding mechanism (not shown) (the position indicated by symbol a in FIG. 1). ), along with this, the point where the angular frequency of a charged particle performing cyclotron motion due to the action of a magnetic field and the frequency of the microwave coincide (in terms of magnetic field strength, it is 875G).
Point S), that is, the ECR resonance point r is located at the lower part of the plasma generation chamber (2) far from the microwave introduction window (7).

The reaction gas i/5iHa/Hz introduced into the reaction chamber (1) from the gas introduction pipe (5) is argon in a plasma state, which is diffused through the plasma extraction window (6) together with the plasma flow (11). It is directly dissociated by Ar'' in the excited metastable state of Ar.Reactant gas WF, /Si
In this example, H4/Ht is ridge 6 = 20SCCM,
SiNa=30SCCM, H! =1005CCM. Note that 0t is a carrier gas and a reducing gas.

Wo or -S, which is thus dissociated and becomes an active species,
ix” is integrated with the plasma flow (11) and forms the susceptor (
4) Tungsten (W) is transported onto the wafer (3).
) film (hereinafter simply referred to as a W film) or a tungsten silicide (WSix) film (hereinafter simply referred to as a WSix film) is formed. At this time, the microwave introduction window σ)
However, in this example, since the resonance point r is formed far from the microwave introduction window (7), the W film or the WSix film is deposited on the microwave introduction window (7). 7), there is almost no accumulation. but,
After several cycles of film formation on the wafer (3), a W film or -Six was formed on the microwave introduction window (7).
A film is deposited. Therefore, in this example, as shown in FIG. 1B, after a number of cycles of film formation on the wafer (3), the gas introduction tube is opened without placing the wafer (3) on the susceptor (4). An etching gas such as SF4 is introduced from (9), and the excitation coil (10) is located in the upper part of the plasma generation chamber (2), that is, in the closest position to the microwave waveguide (8) (see Fig. 1). The W film or WSix film deposited on the microwave introduction window (7) is removed by etching.

That is, the SFh gas is plasma-excited to SF- at the resonance point r and diffuses below the magnetic field 12, but due to the positional relationship of the excitation coil (10), the resonance point r is close to the microwave introduction window (7). Because it is formed in the position, sp
,” the aftereffects of the diffusion reach the microwave introduction window (7),
In addition to etching and removing the W film or WSix film deposited on the window (7), the microwave introduction window (7) is efficiently etched as the resonance point r is close to the microwave introduction window (7) as described above. ) Cleaning (W film or -S
ix film is removed by etching). To clean the microwave introduction window (7) more efficiently, set the direction of the magnetic field of the excitation coil (lO) upward, that is, from the reaction chamber (1) to the microwave introduction window (7). Good (indicated by the dashed line in Figure 1B).

Since the above etching uses low ion energy, the etching rate ratio of quartz and tungsten (W) is l:50,
Quartz is rarely etched.

Therefore, the microwave introduction window (7) made of quartz is hardly etched, and the inconvenience of clouding of the microwave introduction window (7) due to etching does not occur.
Furthermore, the etched W film, for example, is W+χF0→-
It becomes a gas through the reaction F×↑ and is finally exhausted by the exhaust system, so it is possible to suppress the generation of dust due to etching.

Next, as in the first embodiment, unnecessary deposits (for example, W film or WSi
A second embodiment in which the deposition of the x film on the microwave introduction window (7) is prevented will be described with reference to FIG.

The configuration of this second embodiment is basically the same as that of the first embodiment, but differs in that two excitation coils are used. Components corresponding to those in the first embodiment are denoted by the same reference numerals, and a detailed explanation of ECR plasma CVD will be omitted.

That is, in this second embodiment, as shown in FIG. 2, an excitation coil (21) for generating a downward magnetic field is provided outside the plasma generation chamber (2), and an excitation coil (21) is provided outside the reaction chamber (1). is an excitation coil (22) that generates an upward magnetic field.
It consists of

When forming a W film or a 5ixlla on the wafer (3) on the susceptor (4) as in the first embodiment, the excitation coil (21) is turned on (as shown in FIG. 2A). At this time, the excitation coil (22) is turned off), argon Ar gas is introduced into the plasma generation chamber (2) from the gas introduction pipe (9), and the microwave waveguide (8) and microwave introduction Microwaves are guided into the plasma generation chamber (2) through the window (7), and a plasma flow (11) of Ar'' is directed downward into the plasma generation chamber (2).
), and further a reaction gas WFi is formed from the gas introduction pipe (5).
/SiH4/Hz is introduced into the reaction chamber (1) and the wafer (
3) Form a W film or a -Six film thereon.

On the other hand, when etching away the W film or -Six film deposited on the microwave introduction window (7), as shown in FIG. 2B, turn off the excitation coil (21) and
Turn on the excitation coil (22), and then turn on the etching gas.
For example, SF is introduced into the reaction chamber (1) from the gas introduction pipe (5), and from above, that is, from the reaction chamber (1) to the plasma generation chamber (
By forming a plasma flow (23) of SF- directed toward
(removal of film by etching).

In order to further improve efficiency (to clean the microwave introduction window (7)), a microwave waveguide may also be provided on the reaction chamber (1) side, as shown in FIG.

That is, the susceptor (4) is formed hollow, and a transparent quartz plate (24) is fitted to the upper end of the susceptor (4) so that the susceptor (4) also functions as a kind of optical waveguide. A microwave waveguide (25) is connected to the lower part of the waveguide. Then, when cleaning the microwave introduction window (7), the microwave guide from the microwave waveguide (8) is stopped, and then the microwave is transmitted from the microwave waveguide (25) provided at the bottom of the susceptor (4). waveguide, and the rest is carried out in the same manner as described above. In this way, the direction in which the microwaves travel and the direction of the magnetic field from the excitation coil (22) match, so that the SF- plasma flow (23) efficiently flows toward the microwave introduction window (7). The W film or 1s deposited on the microwave introduction window (7) according to the second embodiment
Since the etching of the ix film is performed using low ion energy as in the first embodiment, the microwave introduction window (7) made of quartz is hardly etched;
) no clouding occurs. Further, since the etched WS or WSix film becomes a gas, generation of dust due to etching can be suppressed.

As described above, according to the first and second embodiments, the excitation coil (
10), (21) and (22), and also introduced an etching gas (for example, SF4), so that unnecessary deposits deposited on the microwave introduction window (7) due to repeated film-forming processing cycles can be removed. Place the object in the window (7)
The film can be removed without being etched, and the reliability of film formation on the wafer (3) as well as the reliability of the apparatus itself can be improved. In particular, according to the first embodiment, the film can be removed without etching. When forming the film, the position of the resonance point r is far from the microwave introduction window (7), so the microwave introduction window (7)
There is almost no accumulation of unnecessary deposits on the microwave introduction window (7), and the number of times the microwave introduction window (7) is cleaned (etching and removing accumulated unnecessary deposits) can be significantly reduced. Efficiency can be improved.

Next, Fig. 4 shows some examples of preventing unnecessary deposits (for example, W film or -Six film) from being deposited on the microwave introduction window (7) without using the action of the magnetic field from the excitation coil. 〜Explained based on FIG. 7.

Since the examples shown in FIGS. 4 to 7 basically have the same configuration as the first embodiment, the same reference numerals are given to the parts corresponding to those in the first embodiment, and in particular, FIGS. In FIGS. 6 and 7, only the main parts are shown, with the negative part omitted. In addition, the excitation coil (lO
) is a fixed type, not a movable type.

First, the third embodiment shown in FIG.
) to remove unnecessary deposits deposited on the microwave introduction window (7) by photo-etching.

That is, from the plasma generation chamber (2) to the microwave introduction window (7
), the microwave waveguide (8) is bent in the middle to form an almost L-shape, and a light transmitting window (31) made of quartz is provided at a position facing the microwave introduction window (7).
It consists of

Then, the microwave introduction window (
7) Unnecessary deposits (e.g. W film or -Six film)
When chlorine C is deposited, for example, chlorine C is
L gas is introduced into the plasma generation chamber (2), and light (33) is irradiated from a light source (for example, a Xe-Hg lamp, etc.) (32) toward the light transmission window (31). It goes without saying that the light transmission window (31) and the microwave introduction window (7) are both made of quartz, and of the light emitted from the light source (32), light with a wavelength of 313n+i that dissociates C1t is transmitted.

Now, the unnecessary deposits deposited on the microwave introduction window (7) are removed by light transmission from the etching gas (Cj!z) and the light source (32), resulting in C1t-+(/!" (dissociation by light) W ( WSix) 10xCl” −+WClx
It is etched away in the form ↑ (or WOCl x ↑). The microwave introduction window (made of quartz) (7) is not etched in C1''.

As described above, according to the third embodiment, like the first and second embodiments, unnecessary deposits accumulated on the microwave introduction window (7) due to repeated film-forming processing cycles are removed from the window (7). 7) can be removed without etching, and the reliability of film formation on the wafer and the reliability of the apparatus itself can be improved.

Next, the fourth embodiment shown in FIG. 5 has a microwave introduction window (
The microwave introduction window (7) is designed so that the force is separated from the plasma generation chamber (2), and the microwave is reflected by a reflector (reflector (41)) and introduced into the plasma generation chamber (2). This prevents unnecessary deposits from accumulating on the surface.

That is, the microwave waveguide (8) extending upward from the plasma generation chamber (2) is bent in the middle to form an almost inverted V-shape, and the microwave introduction window (7) is connected to the plasma generation chamber (2). ), that is, one wing part (8a) of the microwave waveguide (8) having an inverted V shape in this example.
Furthermore, a reflector (41) is provided in the microwave introduction window (7) at the apex portion of the microwave waveguide (8).
It is arranged so that it is parallel to the

When forming a film on the wafer (3) on the susceptor (4), for example, argon A is used from the gas introduction pipe (9).
At the same time, r gas is introduced into the plasma generation chamber (2), and microwaves are made incident through the microwave waveguide (8) and the microwave introduction window (7), and are reflected by the dust flafter (41) to generate the plasma generation chamber. (2) to form a plasma flow (11) of Ar'' flowing from the plasma generation chamber (2) to the reaction chamber (1), and further from the gas introduction pipe (5) to the ridge i/5iHa/ Hz into the reaction chamber (1) to form a W film or -S on the wafer (3).
ix film is formed. At this time, the reaction gas and plasma flow (
11) WI′ or -Six” produced by the reaction with
diffuses to the upper part of the plasma generation chamber (2), but
The microwave introduction window (7) is separated from the upper part of the plasma generation chamber (2) and is located in a position that does not directly face the inside of the plasma generation chamber (2).
Or -Six'' is not reached and no W film or WSix film is deposited.

Next, the fifth embodiment shown in FIG. 6 has a microwave introduction window (
A fan (51) made of a material that transmits microwaves is provided on the outside of 7), that is, on the plasma generation chamber (2) side,
The rotation of the fan (51) causes the microwave introduction window (7
) is designed to forcibly suppress the accumulation of unnecessary deposits. In the illustrated example, a quartz fan (51) is provided near the outside of the microwave introduction window (7), and a motor (52) is provided near the outside of the microwave introduction window (7).
) at a speed of, for example, 60 revolutions per minute.
) to forcefully direct the gas flow downward by the downward airflow generated by the rotation of the fan (51), thereby preventing unnecessary deposits from accumulating on the microwave introduction window (7). It was designed to do so.

Next, in the sixth embodiment shown in FIG. 7, the microwave introduction window (7) is heated by plasma excitation, and the thermal energy of the microwave introduction window (7) causes molecules in the reaction gas to be heated through the microwave introduction window (7). This was done by focusing on the fact that the deposition rate on the microwave introduction window (7) increases, causing unnecessary deposits to accumulate on the microwave introduction window (7).
By providing a cooling means around the periphery of the window (7) to cool the window (7), deposition of unnecessary deposits on the microwave introduction window (7) is suppressed. In other words, the amount of unwanted deposits attached to the microwave introduction window (7) has a temperature dependence, as shown in the characteristic diagram of Fig. 8. In low temperature regions, the amount of deposits due to adsorption increases, and in high temperature regions, it increases. In both cases, the amount of unnecessary deposits adhering to the microwave introduction window (7) increases rapidly. For this reason, the cooling temperature varies depending on the type of raw material gas, but
By maintaining the temperature in the intermediate temperature range, attachment of unnecessary deposits can be suppressed. In the illustrated example, a coiled conduit (61) is provided around the microwave introduction window (7), and a refrigerant is flowed through the conduit (61) to cool the microwave introduction window (7). , maintenance of the intermediate temperature range shown in FIG. 8, that is, temperature control, can be achieved by controlling the flow rate of the refrigerant. Although the sixth embodiment uses a refrigerant as a means for cooling the microwave introduction window (7), the method is not limited to this, and other cooling means may also be used. good.

As described above, according to the fourth to sixth embodiments, the first to third embodiments described above
Unlike the case of the embodiment, instead of removing the unnecessary deposits accumulated on the microwave introduction window (7) by etching, it is possible to prevent the unnecessary deposits from accumulating on the microwave introduction window (7) in advance. Therefore, the film forming process can be performed without stopping the film forming process, that is, it can be performed simultaneously with the film forming process, and the efficiency of the film forming process can be further improved.

〔Effect of the invention〕

The ECR plasma CVD apparatus according to the present invention is configured to move a magnetic field generating means disposed outside a plasma generation chamber having a microwave introduction window to etch away unnecessary deposits deposited on the microwave introduction window. Therefore, the deposition of unnecessary deposits on the microwave introduction window can be prevented, and the reliability of the film forming process and the apparatus itself can be improved.

Furthermore, the ECR plasma CVD apparatus according to the present invention is provided with two magnetic field generating means outside the plasma generation chamber having a microwave introduction window, and the magnetic field generated by one of the magnetic field generating means is diverged toward the microwave introduction window. Since it is configured to remove unnecessary deposits accumulated on the microwave introduction window by etching, it is possible to prevent unnecessary deposits from accumulating on the microwave introduction window, thereby improving the reliability of the film forming process and the device itself. In addition, it is possible to improve the efficiency of the film forming process.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an ECR plasma CVD apparatus according to the first embodiment, Fig. 2 is a block diagram showing an ECR plasma CVD apparatus according to the second embodiment, and Fig. 3 is a modification of the second embodiment. A configuration diagram showing an example, FIG. 4 is a configuration diagram partially omitted showing the ECR plasma CVD apparatus according to the third embodiment, and FIG.
A configuration diagram showing an ECR plasma CVD apparatus according to an example,
FIG. 6 is a partially omitted block diagram of an ECR plasma CVD apparatus according to a fifth embodiment, and FIG. 7 is an ECR plasma CVD apparatus according to a sixth embodiment.
FIG. 8 is a block diagram showing the CR plasma CVD apparatus with some parts omitted, and a characteristic diagram showing the temperature dependence of the deposition rate on the microwave introduction window. (1) is a reaction chamber, (2) is a plasma generation chamber, (3) is a wafer, (4) is a susceptor, (5), (9) is a gas introduction tube, (6) is a plasma extraction window, (7) is the microwave introduction window, (8) is the microwave waveguide, (10), (21
) and (22) are exciting coils, (11) are plasma flows,
(25) is a microwave waveguide, (31) is a light transmission window, (
32) is a light source, (41) is a beam flapper, (51) is a fan, and (52) is a motor.

Claims (2)

[Claims] 1. A gas is introduced into the plasma generation chamber through a gas introduction means, and a microwave is guided through a microwave introduction window to generate plasma, and molecules in the plasma are activated, and a film is formed on the substrate on which the film is to be formed. In an ECR plasma CVD apparatus that deposits a thin film by reacting with the microwave, a magnetic field generating means arranged outside the plasma generation chamber having the microwave introduction window is movable to remove unnecessary deposits deposited on the microwave introduction window. An ECR plasma CVD apparatus characterized by etching removal. 2. A gas is introduced into the plasma generation chamber through a gas introduction means, and a microwave is guided through a microwave introduction window to generate plasma, and molecules in the plasma are activated, and a film is formed on the substrate on which the film is to be formed. In an ECR plasma CVD apparatus that deposits a thin film by reacting with the microwave, two magnetic field generation means are provided outside the plasma generation chamber having the microwave introduction window, and the magnetic field from one of the magnetic field generation means is diverged toward the microwave introduction window. . An ECR plasma CVD apparatus, characterized in that unnecessary deposits deposited on the microwave introduction window are removed by etching.