JPH10308385A - Plasma treatment, plasma treater and manufacture of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a uniform plasma treatment of a sample by a method wherein a prescribed magnetic field for controlling the progressing direction of a plasma is formed between the sample and the inner wall of one of vacuum containers and at the same time, the intensity distribution of the magnetic field in the circumferential direction of the sample is adjusted. SOLUTION: Permanent magnets 44 are arranged between a sample 10 and the inner wall of the reaction chamber 14, which is one of vacuum containers 12 and 14, in such a way as to encircle the sample 10 and the magnets 44 are respectively constituted of a plurality of permanent magnet pieces. The positions, which are respectively positioned in the direction parallel to the progressing direction of a plasma, of those magnet pieces are controlled by a magnet position control mechanism 50. Moreover, a plasma treater comprises the connection part of a circular waveguide 16 on the outside of the plasma producing chamber 12, 3-step main coils 22, 24 and 26 are arranged in such a way as to encircle those of the waveguide 16 and the chamber 12 into the form of a concentric circle and subcoils 28 are arranged under the lower parts of those main coils. Thereby, the intensity distribution of a magnetic field in the circumferential direction of the sample 10 is adjusted so that the density distribution of the plasma on the sample 10 is made uniform.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing technique for performing processes such as etching and thin film formation in a process of manufacturing electronic parts and semiconductor elements by using plasma.

[0002]

2. Description of the Related Art In a plasma processing apparatus, microwaves are introduced into a vacuum vessel containing a small amount of reaction gas, and a gas discharge is generated in the vacuum vessel to generate plasma. And
By irradiating the surface of the sample substrate with the plasma, processes such as etching and thin film formation are performed. Such a plasma processing apparatus is being studied as being indispensable for manufacturing a highly integrated semiconductor device. Especially,
Electron cyclotron resonance (ECR: El
An ECR plasma processing apparatus using ectron cyclotron resonance has been put to practical use as an apparatus capable of generating highly active plasma under a low gas pressure region.

In order to improve the processing quality in a plasma processing apparatus, it is important that the plasma has a uniform density over the entire range of the sample. In particular, when the processing area of a sample becomes large, such as a semiconductor wafer having a diameter of 300 mm, which has been developed in recent years, it is more important than ever to maintain a uniform plasma (particularly, ion) intensity distribution on the sample. However, it has been difficult to maintain plasma uniformity on the sample. For example, if the sample is irradiated with plasma generated in a vacuum vessel using a divergent magnetic field in which the strength of the magnetic field weakens with an appropriate gradient toward the sample, the processing surface of the sample is used. The distribution of the magnetic flux density above becomes non-uniform. In addition, the plasma in the vacuum vessel is basically illuminated on the sample while being constrained by the magnetic field (divergent magnetic field) in the vacuum vessel, but the effect of diffusion is remarkable in the outer peripheral portion of the sample in the direction of the inner wall of the vacuum vessel. Therefore, the plasma on the sample is not uniform.

[0004] If the distribution of plasma particles on the sample is not uniform, a high ion density region and a low ion density region are formed on the sample.
Inconveniences such as deterioration of processing speed uniformity or anisotropy occur. In addition, a potential difference may be generated on the sample, a current may flow, and a semiconductor element formed on the sample may be broken. On the other hand, in the CVD process, the thickness of the film formed on the semiconductor substrate becomes uneven, and uniform film formation becomes difficult. If the plasma processing of the semiconductor substrate is not performed uniformly, the performance of the finally manufactured semiconductor device deteriorates.

For this reason, conventionally, Japanese Patent Publication No. 6-4
0542, JP-A-6-210646, JP-A-1-222
As shown by reference numeral 437, a permanent magnet is arranged behind the sample in the direction of plasma transport to make the magnetic flux density distribution on the sample table uniform, thereby improving the uniformity of the plasma.

[0006]

However, in the above-described conventional method, the magnetic field formed in the vacuum chamber by the coil for plasma generation is forcibly controlled on the sample, and therefore various problems are caused. A point has occurred. For example, when a magnet is arranged below (rearward) the outer peripheral portion of the sample, the divergence of the plasma becomes larger in the central portion of the sample than in the outer peripheral portion of the sample. As a result, the charged particles are accelerated at the center of the sample, causing damage to the sample. Also,
Since the magnetic flux toward the sample surface is locally bent, the magnetic flux density, that is, the plasma density becomes non-uniform. Further, when a high-frequency bias (RF bias) is applied to the sample (sample stage), the impedance of the plasma becomes spatially non-uniform, and the RF bias applied to the sample becomes non-uniform. These various problems have hindered uniform processing of the sample.

Further, the electric field intensity distribution of the microwave introduced into the vacuum vessel is, for example, a circular TE which is a fundamental mode.
If you have a distribution that is not axisymmetric like ₁₁ modes,
The distribution of the plasma generated by the microwave is not axially symmetric. As a result, the distribution of the processing speed of the sample also differs in the X and Y directions. Such a situation can be avoided by changing the mode of the microwave before the microwave is introduced into the vacuum vessel, but the configuration and the size of the plasma processing apparatus are complicated.

[0008] The present invention has been made in view of the above situation, and while minimizing damage to a sample,
A first object is to provide a plasma processing method capable of realizing uniform plasma processing by a simple method.

It is a second object of the present invention to provide a plasma processing apparatus capable of realizing uniform plasma processing with a simple configuration while minimizing damage to a sample.

Further, it is an object of the present invention to provide a method of manufacturing a semiconductor device which contributes to manufacture of a high quality semiconductor device by realizing uniform plasma processing by a simple method while minimizing damage to a semiconductor substrate. Is a third object of the present invention.

[0011]

Means for Solving the Problems In order to solve the above problems, in the plasma processing method according to the first aspect of the present invention, there is provided a method in which a sample (10) and an inner wall of a vacuum vessel (12, 14) are provided. A predetermined magnetic field that regulates the direction of the plasma is formed. Further, the intensity distribution of the magnetic field in the circumferential direction of the sample (10) is adjusted so that the plasma density distribution on the sample (10) becomes uniform.

According to a second aspect of the present invention, there is provided a plasma processing apparatus, comprising: a magnetic field forming means for forming a magnetic field for regulating a traveling direction of plasma between a sample (10) and inner walls of vacuum vessels (12, 14). (44) is provided. Further, a predetermined adjustment is made to the magnetic field forming means (44) in order to control the intensity distribution of the magnetic field in the circumferential direction of the sample (10). Here, as the magnetic field forming means, the sample (1) is placed between the sample (10) and the inner wall of the vacuum vessel (12, 14).
A permanent magnet (44) arranged to surround 0) can be used. Further, the permanent magnet (44) is composed of a plurality of permanent magnet pieces (44a), and the position of each permanent magnet piece (44a) in the direction parallel to the plasma traveling direction is adjusted by the magnet position adjusting mechanism (50). Can be configured. Alternatively, the height of the permanent magnet (56) in the direction parallel to the direction in which the plasma travels is controlled by using a ring-shaped integral permanent magnet (56) to control the intensity distribution of the magnetic field in the circumferential direction of the sample (10). May be adjusted in advance.

In the method of manufacturing a semiconductor device according to a third aspect of the present invention, a predetermined magnetic field is formed between the semiconductor substrate (10) and the inner walls of the vacuum vessels (12, 14).
Plasma that diffuses to the inner wall side of the vacuum vessels (12, 14) is trapped. Further, the semiconductor substrate (1) is controlled so that the plasma density distribution on the semiconductor substrate (10) becomes uniform.
0) The intensity distribution of the magnetic field in the circumferential direction is adjusted.

[0014]

As described above, in the present invention, the sample (1
0) and the inner wall of the vacuum vessel (12, 14), a predetermined magnetic field is formed, so that the diffusion of plasma to the inner wall side of the vacuum vessel (12, 14) is suppressed, and the vacuum vessel (12, 14) 1
4) The plasma density gradient decreasing toward the side can be moderated, which can contribute to the improvement of the uniformity of the plasma density on the sample (10). Such a method improves the uniformity in the radial direction from the center of the sample (10) toward the inner wall of the vacuum vessel (12, 14), and the plasma density in the circumferential direction on the sample (10) is reduced. The effect is great when uniform. However, the vacuum container (12, 1
In the case where nonuniform plasma is generated in the circumferential direction of the sample (10) due to the influence of the magnetic field intensity distribution of the microwave introduced into 4), the uniformity of the plasma on the sample (10) is sufficiently improved. It is difficult to secure. Therefore, in the present invention, the intensity distribution of the magnetic field in the circumferential direction of the sample (10) is adjusted so that the plasma density distribution on the sample (10) becomes uniform. That is, the strength of the magnetic field formed between the sample (10) and the inner wall of the vacuum vessel (12, 14) is adjusted independently (non-uniformly) in the circumferential direction of the sample (10). For example, the height of the plurality of permanent magnet pieces (44a) surrounding the sample (10) can be individually adjusted. Alternatively, the height of the permanent magnet (56) in the direction parallel to the direction in which the plasma travels is controlled by using a ring-shaped integral permanent magnet (56) to control the intensity distribution of the magnetic field in the circumferential direction of the sample (10). Can be adjusted in advance. As a result, even when a non-uniform plasma is generated in the circumferential direction of the sample (10) due to the influence of the magnetic field intensity distribution of the microwave or the like, the uniformity of the plasma on the sample (10) is sufficiently ensured. can do.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to examples. In each of the embodiments described below, the technical idea of the present invention is applied to plasma processing of a silicon wafer, which is a part of a manufacturing process of a semiconductor device.

[0016]

FIG. 1 shows a configuration of a plasma processing apparatus according to a first embodiment of the present invention. The plasma processing apparatus of the present embodiment performs a predetermined plasma processing such as etching on a silicon wafer 10 having a diameter of 300 mm, and includes a hollow cylindrical plasma generation chamber 12 for generating plasma;
And a reaction chamber 14 communicating with the plasma generation chamber 12. The sample processed by this device has a diameter of 300 mm
In addition to the silicon wafer 10 described above, various samples requiring uniform plasma processing, such as a wafer having a diameter of 200 m and a glass substrate for LCD, can be used. A circular waveguide 16 connected to a microwave oscillator (not shown) such as a magnetron is connected to the upper part of the plasma generation chamber 12, and the microwave (2.45 GHz) is transmitted to the circular waveguide 16.
Through to the plasma generation chamber 12.

A microwave introduction window 20 is arranged between the circular waveguide 16 and the plasma generation chamber 12. The microwave introduction window 20 is made of a microwave transmitting material such as quartz glass, and is designed to hermetically seal the plasma generation chamber 12. Outside the plasma generation chamber 12, three-stage main coils 22, 24, and 26 are arranged so as to include a connection part of the circular waveguide 16 and concentrically surround the connection part. Below the main coils 22, 24, 26, a one-stage sub coil 28 is arranged. These main coils 22, 24, 26 and sub-coil 28 apply a magnetic field in the direction of introduction of the micro-
Magnetic flux density satisfying R condition 875gauss area (100)
To form The main coils 22, 24, 26 and the sub coil 28 are supplied with necessary current from a current supply unit 40. In the reaction chamber 14 connected to the plasma generation chamber 12, a sample table 32 for holding the silicon wafer 10 by a fixing means such as electrostatic suction is provided.

Around the sample stage 32, a silicon wafer 1
A permanent magnet 44 is provided so as to be concentric with zero. The permanent magnet 44 is composed of a plurality of magnet pieces 44a, as will be described in detail later. Each of the magnet pieces 44a can be moved up and down by the elevating mechanism 50, that is, in a direction parallel to the traveling direction of the plasma. Has become.

On the side wall of the reaction chamber 14, the plasma generation chamber 1
An exhaust pipe 34 for exhausting the gas in the reaction chamber 14 and the reaction chamber 14 is provided, and the plasma generation chamber 12 and the reaction chamber 14 are maintained in a high vacuum state by evacuation from the exhaust pipe 34. The reaction chamber 14 is provided with a gas supply pipe 36 for supplying a reaction gas required for plasma generation. Although not shown, a coolant path is formed around the plasma generation chamber 12, and the plasma generation chamber 12 is cooled by cooling water (coolant) circulating through the coolant path.

In the apparatus shown in FIG. 1, a high-frequency power supply 48 having one end grounded is connected to the sample table 32,
By applying RF power to the sample stage 32, a chemical reaction occurring near the surface of the silicon wafer 10 can be promoted. This makes it possible to improve the efficiency of the plasma processing, such as the improvement of the thin film deposition rate and the etching rate.

FIG. 2 shows the structure of the permanent magnet 44 arranged around the sample table 32. 3A and 3B show the arrangement of the magnet pieces 44a constituting the permanent magnet 44. FIG. 3A is a view from above, and FIG. 3B is a view from the front. The permanent magnet 44 is composed of 16 magnet pieces 44 a arranged at equal intervals so as to surround the sample table 32. The sixteen magnet pieces 44a have the same strength (magnetic force), and are configured to be movable in the vertical direction by separate lifting mechanisms 50a, respectively, and have a high strength according to the plasma density distribution on the silicon wafer 10. H has been adjusted. The height h in the present embodiment is set as a distance from the upper surface of the magnet piece 44a to the processing surface of the silicon wafer 10.
It is needless to say that the number of the magnet pieces 44a is not limited to 16 and can be increased or decreased as needed.

FIG. 4 shows the height h of each magnet piece 44a as a value with respect to the angle θ with respect to the center of the silicon wafer 10 as a white circle. That is, in the present embodiment, the height h of the magnet piece 44a at the position where θ is 90 degrees and 270 degrees is maximum, and the height h of the magnet piece 44a at the position where θ is 0 degrees (360 degrees) and 180 degrees. H is set to be minimum. The lifting mechanism 50a may be configured to be driven up and down manually, or may be configured to be automatically driven by a predetermined driving mechanism (such as a motor).

FIG. 5 shows an electric field intensity distribution of a microwave (circular TE ₁₁ mode) transmitted through the microwave introduction window 20 and introduced into the plasma chamber 12. As can be seen from the figure, the microwave electric field strength distribution in such a mode is X
The direction differs from the Y direction. Due to the microwave electric field intensity distribution as shown in the figure, the plasma density distribution in the circumferential direction on the silicon wafer 10 becomes non-uniform. The method and apparatus of the present invention correct such non-uniformity of the plasma density distribution.

Next, the overall operation of this embodiment will be described. When etching the polysilicon film formed on the silicon wafer 10 using the apparatus of the present embodiment, first, the silicon wafer 10 to be processed is fixed on the sample stage 32, By evacuation, the internal pressures of the plasma generation chamber 12 and the reaction chamber 14 are reduced to a predetermined pressure. Next, the plasma generation chamber 1 is connected to the gas supply pipe 36.
2 and a reaction gas (Cl ₂ ) are introduced into the reaction chamber 14, and the internal pressure of the plasma generation chamber 12 and the reaction chamber 14 is reduced to 1 × 10 ⁻³ To
rr Keep around.

Thereafter, a magnetic field is formed inside the plasma generation chamber 12 by energizing the main coils 22, 24, 26 and the sub-coil 28, and the magnetic field is generated from the circular waveguide 16 through the microwave introduction window 20 into the plasma generation chamber 12. Introduce microwave. This microwave has a frequency f = 2.45.
GHz (wavelength λ = about 12.2 cm), power 1000W
Is set to

When a microwave is introduced into the plasma generation chamber 12, the reaction gas is resonantly excited on the ECR surface 100 to generate plasma. Main coil 22, 24, 2
The magnetic field formed by the sub-coil 6 and the sub-coil 28 is a divergent magnetic field whose magnetic flux density decreases toward the reaction chamber 14 side, and the plasma generated in the plasma generation chamber 12 is drawn into the reaction chamber 14 by the action of the divergent magnetic field. Then, the surface of the silicon wafer 10 on the sample stage 32 is irradiated and etched.

As described above, the main coils 22, 2
The plasma radiated along the divergent magnetic field generated by the sub-coils 4 and 26 and the sub-coil 28 is trapped by the magnetic field of the permanent magnet 44, so that the
Can be greatly reduced toward the inner wall. In addition, no abrupt change in the magnetic field occurs on the silicon wafer 10, and no local change in the plasma density on the silicon wafer 10 occurs.
Further, the height h of each magnet piece 44a is increased by the lifting mechanism 50a.
Is adjusted in advance, for example, the microwave introduction window 2
In the case where the electric field intensity distribution of the microwave (circular TE ₁₁ mode) transmitted through the plasma chamber 12 through the zero is different between the X direction and the Y direction and the plasma density distribution in the circumferential direction of the silicon wafer 10 is not uniform Also, silicon wafer 1
It is possible to correct the plasma density distribution on zero.

The method of adjusting the strength of the magnetic field formed between the silicon wafer 10 and the inner wall of the reaction chamber 14 is as follows.
The strength of the plurality of permanent magnets surrounding the silicon wafer 10 can be adjusted (changed) in advance. However, in this method, fine adjustment of the magnetic field intensity distribution cannot be performed after the magnet is installed. In addition, there is an inconvenience that it costs a lot to manufacture a large number of magnets having different strengths. Therefore, as in the above-described embodiment, the above-mentioned disadvantage is solved by adjusting the magnetic field intensity distribution between the silicon wafer 10 and the reaction chamber 14 by adjusting the height h of each magnet piece 44a while keeping the strength of each magnet piece 44a constant. can do. In other words, it is possible to easily perform fine adjustment after installation, at low cost.

Next, when a thin film is formed on the silicon wafer 10 using the apparatus of this embodiment, in addition to the above procedures, a predetermined source gas is introduced through a gas supply pipe 36.
The plasma generated by the gas is applied to the silicon wafer 1
Irradiate to zero. As a result, a thin film of a substance generated by the reaction of the source gas is formed on the surface of the silicon wafer 10. Also in such thin film formation, plasma having a uniform density is generated, and the film thickness distribution of the thin film formed on the surface of the silicon wafer 10 is equalized. As a result, the quality and performance of the finally manufactured semiconductor device are improved. Here, the semiconductor device includes a semiconductor element itself such as a transistor, a completed semiconductor device such as a RAM, and the like.

FIGS. 6A and 6B show a configuration of a permanent magnet 56 according to another embodiment of the present invention, wherein FIG. 6A is a plan view and FIG. 6B is a front view. The permanent magnet 56 of this embodiment is used in place of the permanent magnet 44 (44a) of the above-described embodiment, and is integrally formed in a ring shape. Also in this embodiment, the distance (height) from the upper surface of the silicon wafer 10 to the upper surface of the permanent magnet 56 is defined as h, and the height h is adjusted for deformation. 4, the height h of the permanent magnet 56 is shown in FIG.
Is shown by a continuous line as a value with respect to the angle θ with respect to the center of the silicon wafer 10. That is, also in this embodiment, the permanent magnets 56 at the positions where θ is 90 degrees and 270 degrees are used.
Is the maximum, and θ is 0 degree (360 degrees) and 180 degrees.
The height h of the permanent magnet 56 at the position of the degree is set to be minimum. By adopting such a configuration,
The same operation and effect as those of the above-described embodiment can be obtained.

FIG. 7 shows the distribution of ion current density on the silicon wafer 10 when the permanent magnet 56 of the embodiment of FIG. 6 is used. The data shown in FIG.
Using a microwave of W, the pressure in the plasma generation chamber 12 and the reaction chamber 14 was maintained at 2 × 10 ⁻³ Torr, and
This is a result of a test performed using l ₂ gas. FIG. 8 shows the distribution of ion current density on the silicon wafer 10 when a permanent magnet having a fixed height is used without adjusting the height. As can be seen from FIGS. 7 and 8, the uniformity of the ion current density on the silicon wafer 10 is superior when the permanent magnet 56 of the present embodiment is used. Furthermore, according to the present embodiment, not only the uniformity of the ion current but also the absolute value of the ion current on the silicon wafer 10 (sample) is high, and it is expected that the processing speed is increased in addition to the uniform processing. it can.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and does not depart from the gist of the technical idea of the present invention shown in the claims. Various changes are possible within the scope.

[0033]

As described above, according to the present invention, a magnetic field is formed between the sample (10) and the inner walls of the vacuum vessels (12, 14), and the inner wall side of the vacuum vessels (12, 14) is formed. Since the diffusion of plasma into the sample is suppressed, there is an effect that uniform plasma processing can be performed without damaging the sample. That is, the sample is not damaged by the acceleration of the charged particles due to the unevenness of the divergence of the magnetic field on the sample. Also, the sample (sample stage)
When a high-frequency bias (RF bias) is applied to the sample, the RF bias applied to the sample becomes uniform without impairing the spatial uniformity of the impedance of the plasma. Further, the intensity distribution of the magnetic field in the circumferential direction of the sample (10) is adjusted so that the plasma density distribution on the sample (10) becomes uniform. Even when a non-uniform plasma is generated in the circumferential direction of (10), the sample (10)
The uniformity of the plasma above can be sufficiently ensured. As a result, finally, the quality of the semiconductor device manufactured through the plasma processing method of the present invention is improved.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram illustrating a schematic configuration of a plasma processing apparatus according to an embodiment of the present invention.

FIG. 2 is a front view showing a configuration near a sample stage in the plasma processing apparatus shown in FIG.

3 shows a configuration of a permanent magnet used in the plasma processing apparatus shown in FIG. 1, and FIG. 3 (A) is a plan view,
(B) is a front view.

FIG. 4 is a graph showing a height distribution of the magnet according to the example.

Figure 5 is a graph showing the microwave electric field intensity distribution of the TE ₁₁ mode introduced into the vacuum chamber of the plasma processing apparatus of the embodiment.

6A and 6B show a configuration of a permanent magnet used in a plasma processing apparatus according to another embodiment of the present invention, wherein FIG. 6A is a plan view and FIG. 6B is a front view.

FIG. 7 is a reference diagram (graph) showing experimental data for explaining the effect of the embodiment shown in FIG. 6;

FIG. 8 is a reference diagram (graph) showing experimental data for a comparative example used to explain the effect of the embodiment shown in FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Silicon wafer (sample) 12 ... Plasma generation chamber 14 ... Reaction chamber 22, 24, 26 ... Main coil 28 ... Sub coil 44, 56 ... Permanent magnet 44a ... Magnet Piece 50, 50a ... elevating mechanism

Claims (6)

[Claims] 1. A plasma processing method for performing predetermined processing on a sample placed in a vacuum vessel by irradiating the sample with plasma, wherein a plasma is applied between the sample and an inner wall of the vacuum vessel. Forming a predetermined magnetic field that regulates the direction of travel of the plasma, and adjusting the intensity distribution of the magnetic field in the circumferential direction of the sample so as to control the density distribution of the plasma on the sample. Plasma treatment method. 2. A plasma processing apparatus for performing predetermined processing on a sample placed in a vacuum vessel by irradiating the sample with plasma, wherein a plasma is applied between the sample and an inner wall of the vacuum vessel. Providing a magnetic field forming means for forming a magnetic field that regulates the direction of travel of the plasma, and performing a predetermined adjustment to the magnetic field forming means so as to control an intensity distribution of the magnetic field in a circumferential direction of the sample. A plasma processing apparatus characterized by the above-mentioned. 3. The plasma processing apparatus according to claim 2, wherein said magnetic field forming means is a permanent magnet disposed between said sample and an inner wall of said vacuum vessel so as to surround said sample. apparatus. 4. The permanent magnet is composed of a plurality of permanent magnet pieces, and positions of the plurality of permanent magnet pieces in a direction parallel to a direction in which the plasma travels are controlled to control a magnetic field intensity distribution by the permanent magnet. 4. The plasma processing apparatus according to claim 3, further comprising a magnet position adjusting mechanism for adjusting each of them. 5. The permanent magnet is an integral ring-shaped permanent magnet arranged so as to surround the sample. The permanent magnet is parallel to a traveling direction of the plasma in order to control a magnetic field intensity distribution by the permanent magnet. 4. The plasma processing apparatus according to claim 3, wherein the permanent magnet is formed by adjusting a height of the permanent magnet in a direction in advance. 6. A method for manufacturing a semiconductor device, comprising: a plasma processing step of irradiating a semiconductor substrate disposed in a vacuum container with a plasma to perform a predetermined process on the semiconductor substrate. In the processing step, while forming a predetermined magnetic field that regulates the traveling direction of the plasma between the semiconductor substrate and the inner wall of the vacuum vessel, to control the density distribution of the plasma on the sample, A method of manufacturing a semiconductor device, comprising adjusting an intensity distribution of the magnetic field in a circumferential direction.