JPH11121198A - Plasma generating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate high-density plasma even in the central part of a plasma generating field. SOLUTION: The plasma generating device is provided with a vacuum vessel 11; a gas introducing part 12; an exhaust part 13; a cylindrical discharge electrode 14; high-frequency oscillators 19, 21; ring-shaped permanent magnets 15, 16; and a pair of discoid walls 17, 18. The discharge electrode 14 is arranged so as to surround a plasma generating field 41. The permanent magnets 15, 16 form prescribed lines of magnetic force. The lines of magnetic force have parts approximately parallel to a center axis 42 of the discharge electrode 14, and length of the parallel parts of the lines of magnetic force gets longer as they approach the center axis 42. The pair of walls 17, 18 define the region of the plasma generating field 41 in the direction of the center axis 42 of the discharge electrode 14. The pair of walls 17, 18 are arranged so as to sandwich the plasma generating field 41 from the direction of the center axis 42. The plasma generating device is constituted so that it has a shape that lines 43 of magnetic force passing through the central part of the plasma generating field 41 do not cross the pair of walls 17, 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a modified magnetron high-frequency discharge type plasma generation apparatus.

[0002]

2. Description of the Related Art Generally, in order to manufacture a solid-state device, a surface treatment apparatus for performing a predetermined treatment on a surface of a substrate of the solid-state device is required. Here, the solid-state device refers to, for example, a device such as a semiconductor device or a liquid crystal display device. The substrate of a solid-state device refers to a substrate such as a wafer of a semiconductor device or a glass substrate of a liquid crystal display device.

As the surface treatment apparatus, there are a dry etching apparatus, a CVD (Chemical Vapor Deposition) apparatus, and the like. Here, the dry etching apparatus is an apparatus that dry-etches the surface of the substrate. The CVD apparatus is an apparatus for forming a predetermined thin film on the surface of a substrate by using a chemical reaction.

[0004] These surface treatment apparatuses are plasma surface treatment apparatuses that perform predetermined processing on the surface of a substrate using plasma. In order to realize this plasma surface treatment apparatus, a plasma generation apparatus that generates plasma is required.

[0005] In recent years, as this plasma generation apparatus, an apparatus capable of generating plasma in a state where the pressure of the discharge gas is low has been desired. This is because miniaturization of solid-state devices has been advanced in recent years.

That is, as the solid-state device is miniaturized, it is required to increase the precision of the direction of incidence of ions on the substrate. The accuracy of the incident direction depends on the pressure of the discharge gas. That is, when the gas pressure is low, the accuracy of the incident direction increases, and when the gas pressure is high, the accuracy decreases. This is because, when the gas pressure is high, ions in the plasma collide with the neutral gas on the way when entering the substrate while being accelerated by the sheath voltage on the front surface of the substrate. Therefore, in order to cope with miniaturization of solid-state devices, it is necessary to generate plasma at a low gas pressure.

The low gas pressure depends on the type of surface treatment, but is generally considered to be 30 mTorr or less. Incidentally, when dry etching a semiconductor device wafer, it is desired to generate plasma at a gas pressure of about 10 mTorr.

As a plasma generator capable of generating plasma at a low gas pressure, a magnetron high-frequency discharge type plasma generator has been conventionally known. This device generates plasma by magnetron discharge using a high-frequency electric field.

As this plasma generating apparatus, for example,
There are devices described in the following documents. Reference: JP-A-7-201831

The plasma generator described in this document generates a plasma by generating a magnetron discharge by a high-frequency electric field formed by a cylindrical discharge electrode and a magnetic field formed by a ring-shaped permanent magnet. It is supposed to.

[0011]

However, the plasma generating apparatus described in the above document has a problem that high-density plasma cannot be generated at the center of the plasma generating region. This is because the plasma is generated mainly on the surface of the discharge electrode in this plasma generation device. Here, the center of the plasma generation region refers to the center in the radial direction of the discharge electrode (hereinafter, referred to as the center).
Similar).

Thus, in this plasma generating apparatus,
When realizing a plasma surface treatment apparatus, there is a problem that surface treatment cannot be performed under the condition of uniform plasma density.

In order to solve this problem, the susceptor may be installed at a location far away from the discharge electrode in the axial direction. Here, the susceptor is a substrate mounting body on which a substrate to be processed is mounted.

However, in such a configuration, although the surface treatment can be performed under the condition of uniform plasma density, there is a new problem that the surface treatment cannot be performed under the condition of high plasma density. This is because, in the above-described plasma generating apparatus, as the distance from the discharge electrode in the axial direction increases, the plasma density decreases due to plasma diffusion loss. As a result, in such a configuration, the processing speed of the surface treatment is reduced.

As described above, in the modified magnetron high-frequency discharge type plasma generation apparatus, an apparatus capable of generating high-density plasma at the center of the discharge electrode as well as at the periphery thereof is desired. Here, the peripheral portion of the plasma generation region refers to the peripheral portion in the radial direction of the discharge electrode (the same applies hereinafter).

Accordingly, an object of the present invention is to provide a modified magnetron high-frequency discharge type plasma generation apparatus capable of generating high-density plasma at the center of the plasma generation region as well as at the periphery. .

[0017]

According to a first aspect of the present invention, there is provided a plasma generating apparatus, comprising: a vacuum vessel, a gas introducing means, an exhaust means, a discharge electrode, and a first high-frequency power application. Means, a magnetic field line forming means, and a pair of walls.

Here, the vacuum vessel is a vessel in which a plasma generation region is set. The gas introduction means is a means for introducing a discharge gas into the inside of the vacuum vessel. The exhaust means is a means for exhausting the atmosphere inside the vacuum vessel.
The discharge electrode is an electrode provided so as to surround the plasma generation region. This electrode is formed in a cylindrical shape.

The first high-frequency power applying means is means for applying high-frequency power to the discharge electrode. The magnetic force line forming means is means for forming a predetermined magnetic force line. The line of magnetic force has a portion substantially parallel to the center axis of the discharge electrode, and the length of the parallel portion becomes longer as approaching the center axis. The pair of walls are walls that define the range of the plasma generation region in the direction of the central axis of the discharge electrode. The pair of walls are provided so as to sandwich the plasma generation region from the center axis direction of the discharge electrode.

Further, the plasma generating apparatus according to the present invention is characterized in that the lines of magnetic force passing through the central portion of the plasma generating region have a shape such that they do not intersect with the pair of walls.

Such magnetic lines of force are formed, for example, by appropriately setting the size of the vacuum container, the position and configuration of the magnetic line forming means, the positions and intervals of the pair of walls, and the like.

In the plasma generating apparatus according to the first aspect, when plasma is generated, a discharge gas is introduced into the vacuum vessel by a gas introducing means. In this case, the atmosphere inside the vacuum container is exhausted by the exhaust means. Thereby, the inside of the vacuum vessel is set in a reduced pressure state. Further, in this case, high-frequency power is applied to the discharge electrode. As a result, a high-frequency electric field component is formed in the radial direction of the discharge electrode. Furthermore, in this case, the magnetic force line forming means forms a magnetic force line having a portion substantially parallel to the central axis of the discharge electrode. Thereby, a high-frequency electric field and a magnetic field orthogonal to each other are formed in the plasma generation region. As a result, the electrons emitted from the discharge electrode perform magnetron motion. This magnetron movement generates a magnetron discharge. Plasma is generated by this magnetron discharge.

In this case, the apparatus is set so that the lines of magnetic force passing through the center of the plasma generation region do not intersect with the pair of walls. Thereby, the outflow of high-energy electrons is suppressed at the center of the plasma generation region.

Here, the outflow of high-energy electrons means that the high-energy electrons trapped by the lines of magnetic force flow out through a pair of walls. This outflow occurs regardless of the constituent materials of the pair of walls. In this case, the outflow amount is determined by the difference between the surface potential of the pair of walls and the plasma space potential, and the positional relationship between the lines of magnetic force formed in the plasma generation region and the pair of walls.

Due to this suppression, the efficiency of magnetron discharge generation is increased in the center of the plasma generation region as in the peripheral portion. Thus, the plasma generation efficiency can be increased in the central portion of the plasma generation region as in the peripheral portion. As a result, high-density plasma is generated at the center of the plasma generation region as well as at the periphery.

According to a second aspect of the present invention, there is provided the plasma generating apparatus according to the first aspect, wherein the pair of walls are formed of a conductive material.

In the plasma generating apparatus according to the second aspect, the pair of walls are formed of a material having conductivity.
This makes it possible to electrically control the plasma density using this wall.

According to a third aspect of the present invention, there is provided the plasma generating apparatus according to the second aspect, further comprising second high frequency power applying means for applying high frequency power to one of the pair of walls.

In the plasma generating apparatus according to the third aspect, high-frequency power is applied to one of the pair of walls by the second high-frequency power applying means. As a result, a high-frequency electric field directed toward the central axis of the discharge electrode is formed. as a result,
High-energy electrons trapped by the lines of magnetic force vibrate at high frequencies in the direction of the central axis of the discharge electrode. Due to this high frequency vibration, a discharge different from the magnetron discharge (hereinafter referred to as “high frequency vibration discharge”) is generated. As a result, the plasma generation efficiency is improved.

The generation efficiency of the high-frequency oscillation discharge is higher at the center than at the periphery of the plasma generation region. This is because, in the line of magnetic force, the length of a portion parallel to the central axis of the discharge electrode becomes longer as approaching the central axis. As a result, the efficiency of plasma generation at the center of the plasma generation region is increased.

According to a fourth aspect of the present invention, in the plasma generating apparatus according to the third aspect, the other of the pair of walls is connected to a reference potential point.

In the plasma generating apparatus according to the fourth aspect, the other of the pair of walls is connected to the reference potential point. Thereby, the plasma space average potential can be reduced. As a result, metal contamination from the surface of another electrode connected to the reference potential point can be reduced.

According to a fifth aspect of the present invention, in the plasma generating apparatus according to the third aspect, the other of the pair of walls is set in an electrically floating state.

In the plasma generating apparatus according to the fifth aspect, the other of the pair of walls is set in an electrically floating state. Thereby, damage to the other of the pair of walls due to the sheath voltage can be reduced.

According to a sixth aspect of the present invention, in the plasma generating apparatus according to the fourth or fifth aspect, the other of the pair of walls includes:
In the case where predetermined processing is performed on an object to be processed using plasma, the object is used as a holding unit that holds the object to be processed.

In the plasma generating apparatus according to the sixth aspect, the sheath voltage on the surface of the workpiece held on the other of the pair of walls can be reduced. as a result,
Damage to the object by the sheath voltage can be reduced.

According to a seventh aspect of the present invention, in the plasma generating apparatus according to the third aspect, the first high frequency power applying means includes a first high frequency power supply for outputting a high frequency power applied to the discharge electrode. Features. Further, the present apparatus is characterized in that the second high-frequency power applying means includes a second high-frequency power supply for outputting high-frequency power applied to one of the pair of walls.

In the plasma generating apparatus according to the seventh aspect, the high-frequency power applied to the discharge electrode is output from the first high-frequency power supply. On the other hand, the high-frequency power applied to one of the pair of walls is output from the second high-frequency power supply. Thus, the magnitude of the high-frequency power applied to the discharge electrode and the magnitude of the high-frequency power applied to one of the pair of walls can be set independently. As a result, the density of the plasma generated by the magnetron discharge and the density of the plasma generated by the high frequency oscillation discharge can be set independently. Thus, a uniform density distribution can be set as the plasma density distribution in the radial direction of the discharge electrode.

According to an eighth aspect of the present invention, in the plasma generating apparatus according to the third aspect, the first high frequency power applying means includes a high frequency power supply for outputting a high frequency power applied to the discharge electrode. I do. Further, the present apparatus is characterized in that the second high-frequency power applying means includes a high-frequency resonance circuit that resonates with high-frequency power output from the high-frequency power supply.

In the plasma generating apparatus according to the eighth aspect, the high-frequency power applied to the discharge electrode is supplied from a high-frequency power supply. On the other hand, high-frequency power applied to one of the pair of walls is provided from a high-frequency power supply via a high-frequency resonance circuit. Thereby, the number of high frequency power supplies can be reduced to one. As a result, the circuit configuration of the device can be simplified, and the manufacturing cost can be reduced.

According to a ninth aspect of the present invention, in the plasma generating apparatus according to the second aspect, each of the pair of walls is connected to a reference potential point.

In the plasma generating apparatus according to the ninth aspect, both the pair of walls are connected to the reference potential point.
As a result, the plasma space average potential can be further reduced. As a result, metal contamination from the surface of the electrode connected to the reference potential point can be extremely suppressed.

According to a tenth aspect of the present invention, there is provided the plasma generating apparatus according to the first aspect, further comprising control means for controlling the magnitude of the high frequency power applied to the discharge electrode from the first high frequency power application means. Features.

In the plasma generating apparatus according to the tenth aspect, the magnitude of the high-frequency power applied to the discharge electrode is controlled by the control means. Thereby, the density of the plasma generated by the magnetron discharge can be controlled.

An eleventh aspect of the present invention is the plasma generating apparatus according to the seventh aspect, further comprising control means for controlling high frequency power output from the first and second high frequency power supplies.

In the plasma generating apparatus according to the eleventh aspect, the magnitude of the high-frequency power applied to the discharge electrode and the magnitude of the high-frequency power applied to one of the pair of walls are controlled by the control means. Thereby, the density of the plasma generated by the magnetron discharge and the density of the plasma generated by the high-frequency oscillation discharge can be controlled. As a result, the plasma density distribution in the radial direction of the discharge electrode can also be controlled.

According to a twelfth aspect of the present invention, in the plasma generating apparatus according to the eleventh aspect, the control means includes a first and a second control means.
When the magnitude of the high-frequency power output from the high-frequency power supply is controlled, the control is performed such that the ratio between the two always becomes a predetermined value.

In the plasma generating apparatus according to the twelfth aspect, the magnitude of the high-frequency power output from the first and second high-frequency power supplies is always controlled such that the ratio between the two becomes a predetermined value. . Thus, when controlling the plasma density, the plasma density distribution in the radial direction of the discharge electrode can be controlled while always maintaining the desired density distribution. Also, by specifying the magnitude of the high frequency power output from one of the first and second high frequency power supplies,
The size of the high frequency power supply automatically output from the other is corrected. Thus, the burden on the operator when controlling the magnitude of the high-frequency power can be reduced.

According to a thirteenth aspect of the present invention, there is provided the plasma generating apparatus according to the eighth aspect, further comprising control means for controlling the magnitude of the high frequency power output from the high frequency power supply.

In the plasma generating apparatus according to the thirteenth aspect, by controlling the magnitude of the high-frequency power output from the high-frequency power supply, the magnitude of the high-frequency power applied to the discharge electrode is controlled. At the same time, the magnitude of the high-frequency power applied to one of the pair of walls is automatically controlled. Thus, the burden on the operator when controlling the magnitude of the high-frequency power can be reduced.

According to a fourteenth aspect of the present invention, there is provided the plasma generating apparatus according to the first aspect, further comprising a position adjusting means for adjusting the position of the pair of walls in the direction of the central axis of the discharge electrode.

In the plasma generating apparatus according to the present invention, the positions of the pair of walls in the direction of the central axis of the discharge electrode can be adjusted. Thereby, after assembling the device, it is possible to form magnetic lines of force that do not cross the pair of walls. As a result, formation of such lines of magnetic force is facilitated.

According to a fifteenth aspect of the present invention, in the plasma generating apparatus according to the first aspect, one of the pair of walls is used as a gas distribution plate for dispersing the discharge gas into the plasma generation region. I do. Further, the present apparatus is characterized in that the other of the pair of walls is used as a holding unit for holding the object when the object is subjected to predetermined processing using plasma.

In the plasma generating apparatus according to the fifteenth aspect, the discharge gas introduced by the gas introducing means is dispersed in the plasma generating region by one of the pair of walls. Thereby, the discharge gas is uniformly supplied to the plasma generation region. Further, in the present apparatus, when a predetermined process is performed on the object using the plasma, the object is held by the other of the pair of walls. Thereby, the plasma processing apparatus can be easily configured from the plasma generating apparatus.

A plasma generating apparatus according to a sixteenth aspect provides a vacuum vessel, a gas introducing means, an exhaust means, a discharge electrode, a first high-frequency power applying means, a magnetic field line forming means,
It is characterized by comprising a pair of walls and second high frequency power applying means.

Here, the vacuum vessel is a vessel in which a plasma generation region is set. The gas introduction means is a means for introducing a discharge gas into the inside of the vacuum vessel. The exhaust means is a means for exhausting the atmosphere inside the vacuum vessel.
The discharge electrode is an electrode provided so as to surround the plasma generation region. This electrode is formed in a cylindrical shape.
The first high-frequency power applying means is means for applying high-frequency power to the discharge electrode. The line of magnetic force forming means is a means for forming a line of magnetic force in the plasma generation region. The pair of walls are walls that define the range of the plasma generation region in the direction of the central axis of the discharge electrode. The pair of walls are formed of a conductive material, and are disposed so as to sandwich the plasma generation region from the center axis direction of the discharge electrode. The second high-frequency power applying means is means for applying high-frequency power to one of the pair of walls.

In the plasma generating apparatus according to the sixteenth aspect, when plasma is generated, a discharge gas is introduced into the vacuum vessel by a gas introducing means. In this case, the atmosphere inside the vacuum container is exhausted by the exhaust means. Thereby, the inside of the vacuum vessel is set in a reduced pressure state. Further, in this case, high-frequency power is applied to the discharge electrode. As a result, a high-frequency electric field directed in the radial direction of the discharge electrode is formed. Furthermore, in this case, the magnetic field lines are formed in the plasma generation region by the magnetic field line forming means.
Thereby, the electrons perform magnetron motion. This magnetron movement generates a magnetron discharge. Plasma is generated by this magnetron discharge.

In this case, high-frequency power is supplied to one of the pair of walls. As a result, a high-frequency electric field directed toward the central axis of the discharge electrode is formed. As a result, high-energy electrons trapped by the lines of magnetic force vibrate at high frequencies. Thereby, a discharge different from the magnetron discharge is generated. As a result, the plasma generation efficiency can be increased as compared with the case where only the magnetron discharge is performed.

Note that the present device includes a case in which there is no magnetic line of force that does not intersect with the pair of walls. In this case, the number of high-energy electrons trapped in the lines of magnetic force is reduced. As a result, the efficiency of plasma generation by magnetron discharge decreases. However, in this device, a high-frequency oscillating discharge is obtained. This compensates for a decrease in plasma generation efficiency due to magnetron discharge.

[0060]

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

[1] First Embodiment [1-1] Configuration FIG. 1 is a side sectional view showing a configuration of a first embodiment of the present invention.

The plasma generating apparatus according to the present embodiment includes a vacuum vessel 11, a gas introduction section 12, an exhaust section 13, a discharge electrode 14, a pair of permanent magnets 15, 16, and a pair of walls 1
7, 18, a first high-frequency oscillator 19, a first matching circuit 20, a second high-frequency oscillator 21, a second matching circuit 22, a blocking capacitor 23, a high-frequency shielding unit 24, a high-frequency shielding It has a cover 25 and a control unit 26.

Here, the vacuum vessel 11 is a vessel in which the plasma generation region 41 is set. In other words,
This is a container that provides a closed plasma generation space. The gas introduction part 12 is a part for introducing a discharge gas into the vacuum vessel 11. The exhaust unit 13 is a part that exhausts the atmosphere inside the vacuum vessel 11.

The discharge electrode 14 is an electrode for forming a high-frequency electric field for magnetron discharge. Permanent magnets 15, 16
Is a magnet forming the magnetic force lines 43 for magnetron discharge. The pair of walls 17 and 18 are walls that define the range of the plasma generation region 41 in the direction of the central axis 42 of the discharge electrode 14. The walls 17, 18 are formed of a conductive material. In this case, for example, the lower wall 18
Are used as electrodes for forming a high-frequency electric field for high-frequency oscillation discharge. Hereinafter, the upper wall 17 is referred to as an upper wall 17, and the lower wall 18 is referred to as a lower wall 18.

The first high-frequency oscillator 19 is an oscillator that outputs high-frequency power for magnetron discharge. The high-frequency oscillator 19 is connected to the discharge electrode 14 via a first matching circuit 20, for example. Here, matching circuit 2
Reference numeral 0 denotes a circuit for matching the first high-frequency oscillator 19 with the discharge electrode 14.

The second high-frequency oscillator 21 is an oscillator that outputs high-frequency power for high-frequency oscillation discharge. The high-frequency oscillator 21 is connected to, for example, a lower wall 18 of the pair of walls 17 and 18 via a second matching circuit 22 and a blocking capacitor 23, for example. Here, the matching circuit 22 is a circuit that matches the second high-frequency oscillator 21 with the lower wall 18. In addition, blocking capacitor 2
Reference numeral 3 denotes a capacitor that removes a DC component from the high-frequency power applied to the lower wall 18.

The high-frequency shielding section 24 is a shielding section that shields a high-frequency electric field formed in the plasma generation region 41 by the discharge electrode 14 and the lower wall 18. High frequency shielding cover 2
Reference numeral 5 denotes a cover that shields a high-frequency electric field formed outside the vacuum vessel 11 by the discharge electrode 14.

The control section 26 is, for example, a control section for electrically controlling the magnitude of the high-frequency power output from the high-frequency oscillators 19 and 21 according to the operation of the operator. The control unit 26 controls the magnitude of the two high-frequency powers so that the ratio between the two becomes a predetermined value. In addition, as the predetermined value, for example, a value that can obtain plasma having a uniform density distribution in the radial direction of the discharge electrode 41 is used.

The vacuum vessel 11 is formed, for example, in a cylindrical shape. And this vacuum container 11 is, for example,
It is arranged so that the central axis faces the vertical direction. The gas introduction part 12 is formed, for example, in a cylindrical shape. The gas inlet 12 is connected to the top plate 11 of the vacuum vessel 11.
1 is provided. The exhaust part 13 is formed, for example, in a cylindrical shape. This exhaust unit 13 is
Is provided on the bottom plate 112.

The discharge electrode 14 is formed in a cylindrical shape. The discharge electrode 14 is provided coaxially with the vacuum vessel 11. The discharge electrode 14 is disposed so as to surround the plasma generation region 41. Further, the discharge electrode 14 is incorporated in the vacuum vessel 11. That is, the vacuum vessel 11 is divided horizontally into two parts. The discharge electrode 14 is inserted between the upper container 27 and the lower container 28 obtained by this division. Hereinafter, the upper container 27 is referred to as an upper container 27, and the lower container 28 is referred to as a lower container 28. In this case, the discharge electrode 14 and the upper container 27 are insulated by a ring-shaped insulator 29. Similarly, the discharge electrode 14 and the lower container 28
Are insulated from each other by a ring-shaped insulator 30.
The upper container 27 and the lower container 28 are connected to a reference potential point. In the figure, a point where the potential is zero, that is, a case where the ground is set is shown as a representative as the reference potential point.

The pair of permanent magnets 15 and 16 are formed in a ring shape. The permanent magnets 15 and 16 are arranged coaxially with the vacuum vessel 11. The permanent magnets 15 and 16 are arranged so as to surround the discharge electrode 14. In this case, the permanent magnet 15 is positioned near the upper end of the discharge electrode 14. On the other hand, the permanent magnet 16 is positioned near the lower end of the discharge electrode 14.

The permanent magnets 15, 16 are magnetized in the radial direction. In this case, the permanent magnets 15 and 16 are magnetized in opposite directions. That is, it is assumed that the inner portion of the permanent magnet 15 is magnetized to the N pole and the outer portion is magnetized to the S pole. Hereinafter, the inside part is called the inside part,
The outer part is called the outer part. In this case, the inner part of the permanent magnet 16 is magnetized to the S pole, and the outer part is magnetized to the N pole. As a result, in the plasma generation region 41, magnetic lines of force 43 extending from the inner part of the permanent magnet 15 toward the central axis 42 of the discharge electrode 14 and then extending toward the inner part of the permanent magnet 16 are formed. Is done. This line of magnetic force 43 is applied to the discharge electrode 14.
Has a portion that is substantially parallel to the central axis 42. The length of the parallel portion becomes longer as approaching the central axis 42.
In this case, the lines of magnetic force 43 are folded back on the central axis 42 of the discharge electrode 14 at the most, due to the interaction of the lines of magnetic force 43 output from each part of the permanent magnet 15.

The pair of walls 17 and 18 are formed, for example, in a circular flat plate shape. The walls 17 and 18 are provided so as to sandwich the plasma generation region 41 from the center axis direction of the discharge electrode 14. Also, these walls 17, 18
The discharge electrode 14 is disposed perpendicular to the center axis 42 of the discharge electrode 14.
In other words, the walls 17, 18 are arranged horizontally. The upper wall 17 and the vacuum vessel 11 are insulated by an insulator 31. Thereby, the upper wall 17 is set in an electrically floating state.

The upper wall 17 is used, for example, as a gas dispersion plate for dispersing a discharge gas. Therefore, a plurality of gas distribution holes 32 are formed in the upper wall 17. The lower wall 18 is used, for example, as a susceptor when a plasma surface treatment apparatus is constructed using the present apparatus. That is, it is used as a substrate mounting portion on which the substrate is mounted.

The high-frequency shielding section 24 has, for example, two ring-shaped metal shielding plates 33 and 34. The metal shielding plates 33 and 34 are arranged coaxially with the vacuum vessel 11. The metal shielding plates 33 and 34 are provided between the lower wall 18 and the lower container 28 so as to surround the lower wall 18. In this case, the metal shielding plates 33 and 34 are arranged at predetermined intervals in the direction of the central axis 42 of the discharge electrode 14. Further, the lower wall 18 and the high-frequency shielding portion 24 are insulated by an insulator (not shown). Further, the high-frequency shielding portion 24 and the lower container 28 are set to the same potential.

The metal shielding plates 33 and 34 have exhaust holes 35 and 36 for exhausting the atmosphere in the plasma generation region 41.
Are formed. The exhaust holes 35 and 36 are formed so as not to entirely overlap. That is, they are formed so as to partially overlap or not overlap at all. As a result, both a high frequency electric field shielding function and an atmosphere discharging function can be obtained. The high frequency shielding cover 25
Is mounted on the outer wall of the vacuum vessel 11 so as to surround the discharge electrode 14.

In the above configuration, the vacuum vessel 11 corresponds to the vacuum vessel of the present invention, the gas introduction section 12 also corresponds to gas introduction means, and the exhaust section 13 corresponds to exhaust means.
Further, the discharge electrode 14 corresponds to the discharge electrode of the present invention, the permanent magnets 15 and 16 also correspond to magnetic force line forming means, and the pair of walls 17 and 18 also correspond to a pair of walls.
Further, the first high-frequency oscillator 19 and the first matching circuit 20
Corresponds to the first high-frequency power applying means of the present invention, and the second high-frequency oscillator 21, the second matching circuit 22, and the blocking capacitor 23 similarly correspond to the second high-frequency power applying means, and the control unit 26 Also corresponds to the control means.

Further, the plasma generating apparatus according to the present embodiment has the magnetic field lines 4 passing through the center of the plasma generating region 41.
3 is configured to have a shape that does not intersect with the pair of walls 17 and 18. This is performed, for example, by appropriately setting predetermined parameters. The parameters include, for example, the size of the vacuum vessel 11, the positions and sizes of the permanent magnets 15 and 16 (the distance in the direction of the central axis 42 of the discharge electrode 14), the positions of the walls 17 and 18, and the distance (the discharge (Interval in the direction of the central axis 42 of the electrode 14).
The non-intersecting configuration described above is realized, for example, by appropriately setting one or two or more of them.

[1-2] Operation The plasma generation operation in the above configuration will be described.

(1) Plasma Generation Operation by Magnetron Discharge First, the plasma generation operation by magnetron discharge will be described.

In the present embodiment, when plasma is generated, a discharge gas is introduced into the vacuum vessel 11 by the gas introduction unit 12. The discharge gas is supplied to the plasma generation region 4 by a plurality of gas distribution holes 32 formed in the upper wall 17.
1 uniformly dispersed.

In this case, the atmosphere inside the vacuum vessel 11 is exhausted by the exhaust unit 13. Thereby, the inside of the vacuum vessel 11 is set in a reduced pressure state. In this case, the atmosphere in the plasma generation region 41 is exhausted through exhaust holes 35 and 36 formed in the metal shielding plates 33 and 34.

Further, in this case, the first electrode is
The high-frequency power is applied from the high-frequency oscillator 19 through the first matching circuit 20. Thereby, a high-frequency electric field is formed on the surface of the discharge electrode 14 facing the plasma generation region 41.

Furthermore, in this case, the permanent magnets 15, 1
6, the magnetic force lines 43 are formed. This line of magnetic force 43
Has a portion substantially parallel to the central axis of the discharge electrode 14 as described above. Thereby, the plasma generation region 41
Then, a high-frequency electric field and a magnetic field that are substantially orthogonal to each other are formed. As a result, electrons are trapped by the magnetic force lines 43 in the vicinity of the discharge electrode 14 and perform a magnetron motion. The electrons are accelerated by the magnetron motion, and the gas for discharge is discharged. By this magnetron discharge, plasma is generated in the plasma generation region R. Hereinafter, this plasma is referred to as first plasma.

(2) Plasma Generating Operation by High Frequency Oscillating Discharge Next, the plasma generating operation by high frequency oscillating discharge will be described.

In the present embodiment, when plasma is generated, high-frequency power is applied to the lower wall 18 from the second high-frequency oscillator 21 via the second matching circuit 22 and the blocking capacitor 23. As a result, a high-frequency electric field is formed in the plasma generation region 41 toward the central axis 42 of the discharge electrode 14. As a result, the high-energy electrons trapped by the lines of magnetic force 43 are oscillated at a high frequency in the direction of the central axis 42. The high-energy vibration heats high-energy electrons. By this heating, the discharge gas is discharged. Plasma is generated in the plasma generation region 41 by the high-frequency vibration discharge. Hereinafter, this plasma is referred to as a second plasma.

(3) Density of First Plasma Next, the density of the first plasma will be described.

The density of the first plasma depends on the generation efficiency of the magnetron discharge. The generation efficiency of the magnetron discharge depends on, for example, the strength of the high-frequency electric field formed by the discharge electrode 14 and the strength and shape of the magnetic field formed by the permanent magnets 15 and 16. The high-frequency electric and magnetic fields are stronger at the peripheral part than at the central part of the plasma generation region 41. This is because the peripheral portion is closer to the discharge electrode 14 and the permanent magnets 15 and 16 than the central portion of the plasma generation region 41. As a result, the generation efficiency of the magnetron discharge is higher in the peripheral part than in the central part of the plasma generation region 41. As a result, the density of the first plasma is higher in the peripheral part than in the central part of the plasma generation region 41.

However, the generation efficiency of the magnetron discharge depends not only on the strength of the high-frequency electric field and the magnetic field, but also on the magnetic field lines 43.
It also depends on the number of high-energy electrons trapped in the electron. The number of these high energy electrons is as follows:
If it does not intersect with 7,18, it will increase. This is magnetic field line 4
This is because, when 3 intersects the walls 17 and 18, the high-energy electrons trapped by the lines of magnetic force 43 flow out through the walls 17 and 18.

In this embodiment, the lines of magnetic force 43 passing through the center of the plasma generation region R are set so as not to intersect the walls 17 and 18. As a result, outflow of high-energy electrons at the center of the plasma generation region 41 is suppressed. As a result, the efficiency of magnetron discharge generation is increased in the central portion as well as in the peripheral portion. As a result, the generation efficiency of the first plasma is increased in the central portion, as in the peripheral portion. As a result, a high-density first plasma can be obtained in this central portion as well as in the peripheral portion.

(4) Density of Second Plasma Next, the density of the second plasma will be described.

The density of the second plasma depends on the generation efficiency of the high-frequency oscillation discharge. This generation efficiency depends on the magnetic field lines 4
3, the length depends on the length of a portion substantially parallel to the central axis 42 of the discharge electrode 14. That is, if the length of the parallel portion is long, the generation efficiency of the high-frequency vibration discharge is high, and if the length is short, the efficiency is low. This is because the longer the length of the parallel portion, the longer the distance over which high-energy electrons can accelerate.

In the present embodiment, the length of the parallel portion is longer at the center than at the periphery of the plasma generation region 41. Thereby, the generation efficiency of the high-frequency oscillation discharge is higher in the center of the plasma generation region 41 than in the periphery. As a result, the density of the second plasma is higher at the center than at the periphery of the plasma generation region 41.

As described above, when the high-frequency oscillating discharge is generated, the density of the plasma in the central portion of the plasma generation region 41 can be further increased as compared with the case where no high-frequency oscillating discharge is generated.

(5) Control of Plasma Density Next, control of the plasma density will be described.

The density of the first plasma is, as described above,
It depends on the strength of the high-frequency electric field formed by the discharge electrode 14. The strength of the high-frequency electric field depends on the magnitude of the high-frequency power output from the first high-frequency oscillator 19.
The magnitude of this high-frequency power is based on the operation of the worker,
It is controlled by the control unit 26. Thus, the density of the first plasma is controlled by controlling the magnitude of the high-frequency power based on the operation of the operator.

The density of the second plasma depends on the strength of the high-frequency electric field formed by the lower wall 18. The strength of the high-frequency electric field depends on the magnitude of the high-frequency power output from the second high-frequency oscillator 21. The magnitude of the high frequency power is controlled by the control unit 26 based on the operation of the worker. Thus, the density of the second plasma is controlled by controlling the magnitude of the high frequency power based on the operation of the operator.

The density of the first plasma is, as described above,
It becomes higher in the peripheral part than in the central part of the plasma generation region 41.
On the other hand, the density of the second plasma is, as described above,
It is higher at the center than at the periphery of the plasma generation region 42.
Therefore, by appropriately controlling the magnitudes of the two high-frequency powers, it is possible to obtain plasma having a uniform density distribution over the entire plasma generation region 41.

The ratio of the two high-frequency powers when a plasma having a uniform density distribution is obtained is substantially constant regardless of the plasma density. In this embodiment, focusing on this point,
When controlling the magnitudes of the two high-frequency powers, control is performed such that the ratio between the two becomes a predetermined value.
Thus, when one of the two high-frequency powers is designated by the operator, the other is automatically corrected. As a result, a plasma having a uniform density distribution is always obtained over the entire plasma generation region 41.

(6) Difference from Plasma Generation Method Using Parallel Plate Electrodes Next, the difference between the plasma generation method using the walls 17 and 18 and the plasma generation method using ordinary parallel plate electrodes will be described.

The walls 17 and 18 of the present embodiment have substantially the same shape as a normal parallel plate electrode. However, the method of generating plasma (second plasma) using the walls 17 and 18 is different from the method of generating plasma using a normal parallel plate electrode.

That is, in the ordinary plasma generation method using a parallel plate electrode, the plasma is mainly composed of secondary electrons output when ions are accelerated by the sheath voltage of the plate electrode and then collide with the surface of the plate electrode. And heating of electrons by high-frequency fluctuations of the sheath voltage and heating of electrons by the plasma ohmic resistance.

On the other hand, in the plasma generation method using the walls 17 and 18, the plasma is generated by heating the high-energy electrons trapped by the magnetic lines of force 43 by the high-frequency vibration.

In a plasma generation method using an ordinary parallel plate electrode, when the pressure of the discharge gas is high, it is possible to generate plasma of a somewhat high density. However, when the gas pressure is low, a high-density plasma cannot be generated. Here, the case where the gas pressure is high refers to, for example, the case where the gas pressure is 0.1 Torr or more. On the other hand, the case where the gas pressure is low means, for example, the case where the gas pressure is 30 mTorr or less.

On the other hand, in the present embodiment, the wall 17,
The lines of magnetic force 43 that do not intersect with 18 are formed. Thereby, high energy electrons are efficiently trapped in the magnetic force lines 43. As a result, even when the gas pressure is as low as 1 mTorr, a high-density plasma can be generated.

[1-3] Effects According to the present embodiment described in detail above, the following effects can be obtained.

(1) First, according to the present embodiment, the lines of magnetic force 43 passing through the center of the plasma generation region 41 are
7 and 18 are set so as not to intersect. Thereby, the generation efficiency of the magnetron discharge can be increased in the central portion of the plasma generation region 41 as in the peripheral portion. As a result, high-density first plasma can be generated in the central portion as well as in the peripheral portion. Incidentally, according to the present embodiment, when the magnitude of the high-frequency power applied to the discharge electrode 14 is the same, the density of the first plasma is increased by one digit as compared with the apparatus described in the above-mentioned document. be able to.

(2) According to the present embodiment, the pair of walls 17 and 18 are formed of a conductive material. Thus, the density of the second plasma can be electrically controlled using the walls 17 and 18.

(3) Further, according to the present embodiment, high-frequency power is applied to lower wall 18. Thereby, a high-frequency vibration discharge can be generated. As a result, the density of the plasma can be further increased in the central portion of the plasma generation region 41 as compared with a case where this discharge is not generated.

(4) Further, according to the present embodiment, the upper wall 17 is set in an electrically floating state. Thereby, the sheath voltage on the surface of the upper wall 17 can be reduced. As a result, metal contamination of the upper wall 17 can be reduced by the sheath voltage.

(5) According to the present embodiment, the high-frequency power applied to the discharge electrode 14 and the high-frequency power applied to the upper wall 18 are output from separate high-frequency oscillators 19 and 21. Thus, the magnitudes of the two high-frequency powers can be set independently. As a result, the density of the first plasma and the density of the second plasma can be set independently. Accordingly, a uniform density distribution can be set as the plasma density distribution in the radial direction of the discharge electrode 14.

(6) Further, according to the present embodiment, a control unit 26 for controlling the magnitude of the high frequency power output from high frequency oscillators 19 and 21 is provided. Thereby, the density of the first plasma and the density of the second plasma can be controlled. As a result, the plasma density distribution in the radial direction of the discharge electrode 14 can be controlled.

(7) According to the present embodiment, when controlling the magnitude of the two high-frequency powers, the ratio between the two is controlled so that the ratio always becomes a predetermined value. Thereby, a desired density distribution can be always obtained as the plasma density distribution in the radial direction of the discharge electrode 14. In addition, the burden on the operator when controlling the magnitude of the high frequency power can be reduced.

(8) Further, according to the present embodiment, the top plate 1 of the vacuum vessel 11 is used as the pair of walls 17 and 18.
Instead of 11 and the bottom plate 112, a dedicated wall is provided. Thus, the upper wall 17 can be used as a gas dispersion plate for dispersing the discharge gas. When a plasma surface treatment apparatus is configured using the plasma generation apparatus of the present embodiment, the lower wall 18 can be used as a susceptor for mounting a substrate.

[1-4] Modified Example In the above description, the case where the upper wall 17 is electrically set to the floating state has been described. However, in the present embodiment, this may be connected to the ground.
Even in such a configuration, the plasma space average potential can be reduced. Thereby, metal contamination by another ground electrode can be suppressed.

[2] Second Embodiment FIG. 2 is a side sectional view showing a configuration of a second embodiment of the present invention. In the apparatus shown in FIG. 2, components having substantially the same functions as those of the apparatus shown in FIG. 1 are given the same reference numerals, and detailed description thereof will be omitted. This is the same in the third and subsequent embodiments described below.

In the first embodiment, the case where high frequency power is applied to the lower wall 18 has been described. On the other hand, in the present embodiment, as shown in FIG. 2, high-frequency power is applied to the upper wall 17 and the lower wall 18 is connected to the ground.

According to such a configuration, it is possible to obtain substantially the same effects as those of the previous embodiment, and furthermore,
The following effects can be obtained.

That is, according to the present embodiment, the lower wall 1
8 is connected to ground. Thereby, this lower wall 1
8 can reduce the sheath voltage on the surface.
As a result, damage to the lower wall 18 due to the sheath voltage can be reduced.

When a plasma surface treatment apparatus is constructed using this apparatus, the sheath voltage on the surface of the substrate placed on the lower wall 18 can be reduced. As a result, damage to the substrate due to the sheath voltage can be reduced.

[3] Third Embodiment FIG. 3 is a side sectional view showing a configuration of a third embodiment of the present invention.

In the second embodiment, the case where the lower wall 18 is grounded has been described. On the other hand, in the present embodiment, as shown in FIG. 3, the lower wall 18 is set to an electrically floating state.

According to such a configuration, the sheath voltage on the lower wall 18 and the surface of the substrate can be further reduced as compared with the second embodiment. Thereby, damage to the lower wall 18 and the substrate due to the sheath voltage can be further reduced.

[4] Fourth Embodiment FIG. 4 is a side sectional view showing a configuration of a fourth embodiment of the present invention.

In the first, second and third embodiments,
When applying high frequency power to the upper wall 17 or the lower wall 18,
The case where the application is performed using the high-frequency oscillator 21 has been described. In other words, the description has been given of the case where the application is performed using the high-frequency power supply that can output the high-frequency power by itself. On the other hand, in the present embodiment, as shown in FIG. 4, the voltage is applied using the high-frequency resonance circuit 51.

The high-frequency resonance circuit 51 includes the discharge electrode 1
It is configured to resonate with the high-frequency power output from the high-frequency oscillator 19 for four. The high-frequency resonance circuit 51 includes, for example, a variable capacitor 52 and a coil 53
And a distributed capacitor 54. Here, the variable capacitor 52 is a capacitor for adjusting the resonance frequency. The variable capacitor 52 and the coil 53 are connected in series. The series circuit is inserted between the upper wall 17 and the ground. Distribution capacity 54
Is a distributed capacitance formed between the upper wall 17 and the ground. In the figure, this distributed capacitance 54 is represented by one capacitor for convenience.

In this embodiment, the second high frequency oscillator 21 is not provided. For this reason, the control unit 26 controls only the magnitude of the high-frequency power output from the high-frequency oscillator 19.

In such a configuration, the high-frequency resonance circuit 51 resonates with the high-frequency power applied from the high-frequency oscillator 19 to the discharge electrode 14. Thus, high-frequency power is also applied from the high-frequency oscillator 19 to the upper wall 17 via the high-frequency resonance circuit 51.

According to such a configuration, one high-frequency oscillator can be used. Thus, the circuit configuration of the device can be simplified, and the manufacturing cost of the circuit can be reduced.

FIG. 4 illustrates the case where the lower wall 18 is grounded. However, in the present embodiment, the lower wall 18 may be made to be in an electrically floating state as in the third embodiment.

In FIG. 4, the case where the high-frequency resonance circuit 51 is connected to the upper wall 17 has been described. However, in the present embodiment, the high-frequency resonance circuit 51 may be connected to the lower wall 18 as in the first embodiment.

[5] Fifth Embodiment FIG. 5 is a side sectional view showing a configuration of a fifth embodiment of the present invention.

In the first to fourth embodiments, the case where high-frequency power is applied to one of the two walls 17 and 18 has been described. On the other hand, in the present embodiment, as shown in FIG. 5, both of the two walls 17, 18 are connected to the ground. In the present embodiment,
Since no high-frequency power is applied, the control unit 26 becomes unnecessary.

According to such a configuration, the sheath voltage on the surfaces of the walls 17 and 18 can be reduced. Thereby, damage to the walls 17 and 18 due to the sheath voltage can be reduced. Similarly, when the lower wall 18 is used as a susceptor, damage to the substrate due to sheath voltage can be reduced.

[6] Sixth Embodiment FIG. 6 is a side sectional view showing a configuration of a sixth embodiment of the present invention.

In the fifth embodiment, a pair of walls 1
The case where both 7 and 18 are connected to the ground has been described.
On the other hand, in the present embodiment, as shown in FIG. 6, the upper wall 17 is set to an electrically floating state.

According to such a configuration, the sheath voltage on the surface of the upper wall 17 can be reduced as compared with the fifth embodiment. Thereby, metal contamination from upper wall 17 due to the sheath voltage can be further reduced as compared with this embodiment.

[7] Seventh Embodiment FIG. 7 is a side sectional view showing a configuration of a seventh embodiment of the present invention.

In the sixth embodiment, the case where only the upper wall 17 is electrically set in the floating state has been described. On the other hand, in the present embodiment, as shown in FIG. 7, the lower wall 18 is also set to an electrically floating state.

According to such a configuration, the sheath voltage on the lower wall 18 and the surface of the substrate can be reduced as compared with the sixth embodiment. Thus, according to this embodiment, damage to the lower wall 18 and the substrate due to the sheath voltage can be reduced.

[8] Eighth Embodiment FIG. 8 is a side sectional view showing a configuration of an eighth embodiment of the present invention.

In the first to seventh embodiments, the case where the positions of the pair of walls 17 and 18 are fixed has been described. Here, the position of the pair of walls 17 and 18 refers to the position of the discharge electrode 14 in the direction of the central axis 42 (the same applies hereinafter). On the other hand, in the present embodiment, as shown in FIG. 8, a position adjuster 55 capable of adjusting the position of the upper wall 17 and a position adjuster 56 capable of adjusting the position of the lower wall 18 are provided. It was done.

As the configuration of the position adjusting units 55 and 56,
Various configurations are conceivable. For example, a configuration is considered in which the walls 17, 18 are held by a slide mechanism, and the walls 17, 18 are slid in the direction of the central axis 42 of the discharge electrode 14 by the slide mechanism. Further, the walls 17 and 18 are held by a lifting mechanism, and the wall 1 is
It is conceivable to drive the electrodes 7 and 18 up and down in the direction of the central axis 42 of the discharge electrode 14. In the figure, the position adjustment unit 55,
56 is shown conceptually.

According to such a configuration, after assembling the device, the positions of the pair of walls 17, 18 can be adjusted. Thereby, after assembling the device, the pair of walls 17,
The lines of magnetic force 43 that do not intersect with 18 can be formed. As a result, the formation of such lines of magnetic force 43 becomes easy.

Further, according to such a configuration, the positions of the pair of walls 17, 18 can be adjusted independently. Thereby, the position adjustment work can be facilitated.

[9] Ninth Embodiment The appearance of the ninth embodiment is the same as that of the first embodiment, for example. The difference lies in the relationship between the magnetic force lines 43 and the pair of walls 17 and 18.

That is, in the first embodiment, the pair of walls 17 and 18 extends over the entire plasma generation region 41.
The case has been described in which the magnetic force lines 43 are formed so as not to intersect. On the other hand, in the present embodiment, the plasma generation region 4
The magnetic field lines 43 are formed only in the peripheral portion of No. 1 and are not formed in the central portion.

Even with such a configuration, high-density plasma can be generated at the center of the plasma generation region.
This is because high-energy electrons trapped by the magnetic force lines 43 can be vibrated at high frequencies.

That is, in the present embodiment, all lines of magnetic force 43 intersect with the pair of walls 17 and 18 at the center of the plasma generation region 41. So, in this part,
The number of high-energy electrons trapped in the lines of magnetic force 43 decreases. As a result, the generation efficiency of the first plasma is reduced in this portion.

However, in the present embodiment, the lower wall 1
High-frequency power is applied to 8. Thereby, the magnetic force lines 43
The high-energy electrons trapped in are vibrated at high frequencies. As a result, a second plasma is generated. The generation efficiency of the second plasma is higher at the center than at the periphery of the plasma generation region 41. As a result, in the central portion of the plasma generation region 41, the decrease in the generation efficiency of the first plasma is compensated for by the second plasma. As a result, high-density plasma can be generated also in the center of the plasma generation region 43.

In the above description, the case where the present embodiment is applied to the apparatus shown in FIG. 1 has been described. However, the present embodiment can be applied to devices other than the device shown in FIG. 1 as long as the device has a configuration in which high-frequency power is applied to one of the pair of walls 17 and 18. Therefore, the present embodiment can be applied to the apparatus shown in FIGS. 2, 3, and 4.

[10] Comparison of Performance FIG. 9 is a diagram showing a comparison result of the performance of a plurality of plasma generating apparatuses.

Here, as the plurality of plasma generators, for example, the plasma generator of the first embodiment (the apparatus shown in FIG. 1) and the plasma generator of the fourth embodiment (shown in FIG. 4) Apparatus), the plasma generation apparatus of the sixth embodiment (the apparatus shown in FIG. 6), and a plasma generation apparatus that does not use magnetron discharge.

As a plasma generating apparatus not using a magnetron high-frequency discharge, for example, the apparatus shown in FIG. 10 is used. The illustrated device is obtained by removing the discharge electrode 14 from the device shown in FIG. In such a configuration,
Only the second plasma is generated by the high-frequency vibration of the high-energy electrons trapped by the magnetic force lines 43.

As shown in FIG. 9, the performance comparison items include the plasma generation efficiency, the controllability of the plasma density distribution, the increase in the diameter of the apparatus, and the cost of the apparatus.
Here, the plasma generation efficiency indicates the increase in the density of the plasma. The controllability of the plasma density distribution indicates the difficulty of making the plasma density distribution uniform. The increase in the diameter of the device indicates the compatibility with a substrate having a large diameter.

The performance is represented by a double circle, a circle, and a triangle. Here, a double circle indicates that performance is the best, a circle indicates that performance is second, and a triangle indicates that performance is third.

(1) Comparison of Plasma Generation Efficiency As shown in FIG. 9, the plasma generation efficiency was as shown in FIG.
1 and 4 are higher than the 0 device. This is because the first plasma and the second plasma are generated in the apparatus shown in FIGS. 1 and 4, while the first plasma is generated only in the apparatus shown in FIG. 6, and the first plasma is generated in the apparatus shown in FIG. This is because only two plasmas are generated. The plasma generation efficiency of the apparatus of FIG. 1 is higher than that of the apparatus of FIG. this is,
The device of FIG. 1 has a higher upper wall 17 or lower wall 1 than the device of FIG.
This is because the supply efficiency of high-frequency power to the power supply 8 is good.

Incidentally, assuming that the plasma generation efficiency of the apparatus of FIG. 6 is 1, the plasma generation efficiency of the apparatus of FIG. 1 is 4 or more, and the plasma generation efficiency of the apparatus of FIG. 4 is 4. As a result, the density of the plasma is higher than that of the apparatus shown in FIGS.
1 is higher, and the device of FIG. 1 is higher than the device of FIG.

(2) Controllability of Plasma Density Distribution The controllability of plasma density distribution is expressed by the range of plasma density distribution that can be electrically controlled. This range is shown in FIG.
The device of FIG. 1 is wider than the device of FIG. This is because the apparatus of FIG. 1 can control the density of the first plasma and the second plasma independently, whereas the apparatus of FIG. 4 cannot control them independently. . Thus, the difficulty in making the plasma density distribution uniform is lower in the apparatus of FIG. 1 than in the apparatus of FIG.

In the apparatus shown in FIG. 6 and the apparatus shown in FIG. 10, the plasma density is higher than that of the conventional apparatus, and the plasma density distribution becomes uniform. However, these devices cannot electrically control the plasma density distribution. This is because the apparatus of FIG. 6 controls only the density of the first plasma, and the apparatus of FIG. 10 controls only the density of the second plasma.

(3) Comparison of Large Diameter of Apparatus Large diameter of the apparatus is represented by the size of the aperture. This increase in diameter is easier to achieve with the device of FIG. 4 than with the devices of FIGS. This is because the former cannot electrically control the plasma density distribution, whereas the latter can. Also, this increase in diameter is easier to achieve in the apparatus of FIG. 1 than in the apparatus of FIG. This is because the latter has better control over the plasma density distribution than the former.
Accordingly, the apparatus shown in FIG. 4 is better than the apparatuses shown in FIGS. 6 and 10, and the apparatus shown in FIG. 1 is better than the apparatuses shown in FIGS.

(4) Comparison of the cost of the device The cost of the device is represented by low cost. This cost is low for both devices. However, among these, FIGS.
The device of FIG. 10 is cheaper than the device of FIG. This is because the former device is provided with only one high-frequency oscillator, whereas the latter device is provided with two.

[11] Other Embodiments The nine embodiments of the present invention have been described in detail. However, the present invention is not limited to the embodiment as described above.

(1) For example, in the above embodiment, the case where the pair of walls 17 and 18 are formed of a conductive material has been described. However, in the present invention, this may be formed of a material having an insulating property. In such a configuration, in this case, metal contamination from the walls 17 and 18 can be eliminated.

(2) In the above embodiment, the wall 1
The case where the electrodes 7 and 18 are disposed horizontally and the discharge electrodes 14 are disposed vertically has been described. However, in the present invention, the wall 1
The discharge electrodes 14 may be disposed horizontally while the electrodes 7 and 18 are disposed vertically.

(3) Further, in the above embodiment, the wall 1
The case has been described where 7, 18 are provided separately from the top plate 111 and the bottom plate 112 of the vacuum vessel 11. However, in the present invention, the top plate 111 and the bottom plate 112 are used as the walls 17 and 18.
May be used.

(4) In addition, it goes without saying that the present invention can be variously modified and implemented without departing from the scope of the invention.

[0168]

As described in detail above, according to the first aspect of the present invention, the lines of magnetic force passing through the central portion of the plasma generation region are set so as not to intersect with the pair of walls. Thus, high-density plasma can be generated at the center of the plasma generation region as well as at the periphery.

According to the plasma generating apparatus of the second aspect, in the apparatus of the first aspect, the pair of walls are formed of a conductive material. This makes it possible to electrically control the plasma density using this wall.

According to the third aspect of the present invention, the high frequency power is applied to one of the pair of walls. Thereby, the plasma generation efficiency at the center of the plasma generation region can be increased.

According to the plasma generating device of the fourth aspect, in the device of the third aspect, the other of the pair of walls is connected to the reference potential point. As a result, metal contamination from the surface of another electrode connected to the reference potential point can be reduced.

According to the plasma generating apparatus of the fifth aspect, in the apparatus of the third aspect, the other of the pair of walls is set in an electrically floating state. Thereby, damage to the other of the pair of walls due to the sheath voltage can be reduced.

According to the plasma generating apparatus of the sixth aspect, in the apparatus of the fourth or fifth aspect, the other of the pair of walls is used as a holding section for holding an object to be processed. Thus, damage to the processing object due to the sheath voltage can be reduced.

According to the plasma generating apparatus of the present invention, the high-frequency power applied to the discharge electrode and the high-frequency power applied to one of the pair of walls are supplied from separate high-frequency power sources. Is output. This gives 2
The magnitudes of the two high-frequency powers can be set independently. As a result, a uniform density distribution can be set as the plasma density distribution in the radial direction of the discharge electrode.

According to the plasma generating apparatus of the eighth aspect, in the apparatus of the third aspect, the high frequency power of one of the pair of walls is supplied from the high frequency power supply of the discharge electrode via the high frequency resonance circuit. Thereby, the number of high frequency power supplies can be reduced to one.

According to the plasma generating apparatus of the ninth aspect, in the apparatus of the second aspect, both of the pair of walls are connected to the reference potential point. Thereby, metal contamination from the electrode connected to the reference potential point can be suppressed.

[0177] According to the plasma generating apparatus of the tenth aspect, in the apparatus of the first aspect, a control unit for controlling the magnitude of the high frequency power applied to the discharge electrode is provided. Thereby, the density of the first plasma can be controlled.

[0178] According to the plasma generating apparatus of the eleventh aspect, in the apparatus of the seventh aspect, a control unit for controlling the magnitude of the high frequency power output from the first and second high frequency power supplies is provided. This makes it possible to control the densities of the first and second plasmas. As a result, the plasma density distribution in the radial direction of the discharge electrode can also be controlled.

According to the plasma generating apparatus of the twelfth aspect, when the magnitude of the high frequency power output from the first and second high frequency power supplies is controlled in the apparatus of the eleventh aspect, the ratio between the two is always constant. Control is performed so as to be a predetermined value. Thereby, when controlling the density of the plasma, it is possible to always control while maintaining a desired plasma density distribution. In addition, the burden on the operator when controlling the magnitude of the high frequency power can be reduced.

According to the plasma generating apparatus of the thirteenth aspect, in the apparatus of the eighth aspect, by controlling the magnitude of the high frequency power applied to the discharge electrode, the high frequency power is applied to one of the pair of walls. The magnitude of the high frequency power can also be controlled automatically. Thus, the burden on the operator when controlling the magnitude of the high-frequency power can be reduced.

According to the plasma generating apparatus of the present invention, the positions of the pair of walls can be adjusted. Thereby, after assembling the device, it is possible to form magnetic lines of force that do not cross the pair of walls. As a result, formation of such lines of magnetic force is facilitated.

According to the plasma generating apparatus of the present invention, one of the pair of walls is used as a gas dispersion plate. Thereby, the discharge gas can be uniformly dispersed in the plasma generation region. When the other of the pair of walls performs a predetermined process on the object using the plasma, the wall is used as a holder for the object. Thus, when a plasma processing apparatus is configured using this apparatus, the configuration can be simplified.

According to the plasma generating apparatus of the sixteenth aspect, high-frequency power is supplied to one of the pair of walls. Thereby, not only a magnetron discharge but also a high-frequency vibration discharge can be generated. As a result, even when there is no line of magnetic force that does not intersect with the pair of walls, high-density plasma can be generated at the center of the plasma generation region.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a configuration of a first exemplary embodiment of the present invention.

FIG. 2 is a side sectional view showing a configuration of a second exemplary embodiment of the present invention.

FIG. 3 is a side sectional view showing a configuration of a third exemplary embodiment of the present invention.

FIG. 4 is a side sectional view showing a configuration of a fourth embodiment of the present invention.

FIG. 5 is a side sectional view showing a configuration of a fifth embodiment of the present invention.

FIG. 6 is a side sectional view showing a configuration of a sixth embodiment of the present invention.

FIG. 7 is a side sectional view showing a configuration of a seventh embodiment of the present invention.

FIG. 8 is a side sectional view showing a configuration of an eighth embodiment of the present invention.

FIG. 9 is a diagram showing a comparison result of performance of a plurality of plasma generation devices.

FIG. 10 is a side sectional view showing a configuration of a plasma generation apparatus that does not use magnetron discharge.

[Explanation of symbols]

11: vacuum container, 111: top plate, 112: bottom plate, 12 ...
Gas introduction part, 13 ... exhaust part, 14 ... discharge electrode, 15,
16: permanent magnet, 17, 18: wall, 19, 21: high frequency oscillator, 20, 22: matching circuit, 23: blocking capacitor, 24: high frequency shielding part, 25: high frequency shielding cover, 29, 30, 31: insulator , 32 ... gas dispersion holes, 3
3, 34: metal shielding plate, 35, 36: exhaust hole, 41: plasma generation region, 42: central axis, 43: magnetic force line, 51:
High frequency resonance circuit, 52 variable capacitor, 53 coil, 54 distributed capacitance, 55, 56 position adjustment unit.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI H01L 21/31 H01L 21/302 C (72) Inventor Tetsu Iizuka 6-5-10-201, Koriyama, Taihaku-ku, Sendai City, Miyagi Prefecture

Claims (16)

[Claims] A vacuum vessel in which a plasma generation region is set; a gas introducing means for introducing a discharge gas into the vacuum vessel; an exhaust means for exhausting an atmosphere inside the vacuum vessel; A cylindrical discharge electrode disposed so as to surround the plasma generation region; first high-frequency power applying means for applying high-frequency power to the discharge electrode; and a substantially parallel central axis of the discharge electrode. A magnetic field line forming means for forming a magnetic field line such that the length of the parallel portion becomes longer as approaching the central axis; and And a pair of walls defining a range of the plasma generation region in the direction of the central axis, wherein the lines of magnetic force passing through a central portion of the plasma generation region do not intersect the pair of walls. Plasma generating apparatus characterized by being configured to have. 2. The plasma generating apparatus according to claim 1, wherein said pair of walls are formed of a conductive material. 3. The plasma generating apparatus according to claim 2, further comprising second high frequency power applying means for applying high frequency power to one of said pair of walls. 4. The plasma generating apparatus according to claim 3, wherein the other of said pair of walls is connected to a reference potential point. 5. The device according to claim 3, wherein the other of the pair of walls is set in an electrically floating state.
The plasma generation apparatus according to any one of the preceding claims. 6. The method according to claim 4, wherein the other of the pair of walls is used as a holding unit for holding the object when the object is subjected to a predetermined process using the plasma. Or the plasma generating apparatus according to 5. 7. The first high-frequency power applying means includes a first high-frequency power supply for outputting high-frequency power applied to the discharge electrode, and the second high-frequency power applying means includes one of the pair of walls. 4. The plasma generating apparatus according to claim 3, further comprising a second high-frequency power supply that outputs a high-frequency power applied to the power supply. 8. The high-frequency power output means outputs the high-frequency power applied to the discharge electrode, the second high-frequency power application means includes a high-frequency power output from the high-frequency power supply. The plasma generation apparatus according to claim 3, further comprising a high-frequency resonance circuit that resonates with the plasma. 9. The plasma generating apparatus according to claim 2, wherein each of said pair of walls is connected to a reference potential point. 10. The plasma generating apparatus according to claim 1, further comprising control means for controlling the magnitude of the high-frequency power applied from said first high-frequency power application means to said discharge electrode. 11. The plasma generation apparatus according to claim 7, further comprising control means for controlling the magnitude of the high frequency power output from said first and second high frequency power supplies. 12. When the control means controls the magnitude of the high-frequency power output from the first and second high-frequency power supplies, the control means controls the ratio between the two to always be a predetermined value. The plasma generation apparatus according to claim 11, wherein the plasma generation apparatus is configured. 13. The plasma generation apparatus according to claim 8, further comprising control means for controlling the magnitude of the high frequency power output from said high frequency power supply. 14. The plasma generating apparatus according to claim 1, further comprising a position adjusting means for adjusting a position of said pair of walls in a central axis direction of said discharge electrode. 15. One of the pair of walls is used as a gas dispersion plate for dispersing the discharge gas in the plasma generation region, and the other performs predetermined processing on the workpiece using the plasma. 2. The plasma generating apparatus according to claim 1, wherein when applied, the apparatus is used as a holding unit for holding the object to be processed. 16. A vacuum vessel having a plasma generation region set therein, gas introducing means for introducing a discharge gas into the vacuum vessel, and exhaust means for exhausting an atmosphere inside the vacuum vessel. A cylindrical discharge electrode disposed so as to surround the plasma generation region; first high-frequency power application means for applying high-frequency power to the discharge electrode; and magnetic field lines forming magnetic lines of force in the plasma generation region. A pair of means formed of a conductive material and disposed so as to sandwich the plasma generation region from a central axis direction of the discharge electrode, and defining a range of the plasma generation region in the central axis direction. And a second high frequency power applying means for applying high frequency power to one of the pair of walls.