JP2011034705A - Plasma treatment device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma treatment device capable of forming uniform high-density plasma at low pressure over a large area. <P>SOLUTION: The device uses a cylindrical electrode as one in a plasma generating room opposed to a treatment substrate and arranges a magnetic field generating device at an atmosphere side for generating a point cusp magnetic field. Otherwise, one end of the cylindrical electrode is closed, and permanent magnets are arranged outside the closed site in a state of a ring so as directions of magnetic poles to be alternated and coaxial. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a plasma processing apparatus for sputter deposition applications, and more particularly to high frequency (HF (3-30 MHz)) useful for sputtering and etching of metal or dielectric materials during the manufacturing process of integrated circuits in the semiconductor industry. Alternatively, the present invention relates to a plasma processing apparatus having a high-density plasma source using a VHF (30 to 300 MHz) electrode.

In conventional etching apparatuses, for example, a magnetron type using a magnet, an ECR discharge type using electron cyclotron resonance, and a helicon type plasma generator using a helicon wave have been used. In recent years, there has been a demand for an improvement in plasma processing speed and an increase in the area of the processing substrate, and there is an increasing demand for uniformly generating higher density plasma over a large area.

An example of a uniform plasma generator with a large area is shown in FIG. FIG. 6 is a cross-sectional configuration diagram showing an outline of a conventional plasma processing apparatus (see Patent Document 1). As shown in FIG. 6, the plasma processing apparatus described in Patent Document 1 generates a magnetic field by arranging a plurality of donut-shaped permanent magnets 103 and 104 concentrically in order to form a magnetic neutral line in the vacuum chamber 101. An electric field is formed along the magnetic neutral line formed in the vacuum chamber by the means and the magnetic field generating means, and discharge plasma is generated in the magnetic neutral line. In such an apparatus, it is possible to change the location where the plasma is concentrated by controlling the diameters of the permanent magnets 103 and 104, and this makes it possible to adjust the plasma distribution. In FIG. 6, the upper surface of the vacuum chamber 101 is covered with a flat metal partition wall 102. On the outside of the side wall portion 105 of the cylindrical vacuum chamber 101, a multiple high-frequency coil 106 including a single layer constituting electric field generating means is disposed, and this high-frequency coil 106 is connected to a high-frequency power source 7 having a frequency of 13.56 MHz. A high-frequency electric field is applied along the magnetic neutral line formed in the vacuum chamber 101 by the permanent magnets 103 and 104 to generate discharge plasma in the magnetic neutral line. Further, a substrate electrode 108 is provided at a position separated in parallel to the surface formed by the magnetic neutral line formed in the vacuum chamber 101, and this substrate electrode 108 has a high frequency of 13.56 MHz to which an RF bias is applied. The power supply 109 is connected.

Further, as a uniform plasma generator with a large area, there is one shown in FIG. FIG. 7 is a cross-sectional configuration diagram showing an outline of a conventional plasma processing apparatus (see Patent Document 2). As shown in FIG. 7, the plasma processing apparatus described in Patent Document 2 is a plasma processing apparatus having an upper electrode 201 disposed above a processing substrate 223 and an outer insulating member 203 for supporting the upper electrode 201. In this apparatus, permanent magnets 206 are arranged in a point cusp shape over the entire upper electrode 201 and outer insulating member 203. In such an apparatus, a uniform magnetic flux distribution pattern is formed over the entire upper electrode 201, thereby realizing a uniform distribution of plasma over the entire surface of the wafer 223, and a uniform processing speed over the entire processing substrate. Can be realized.

On the other hand, a hollow cathode discharge is conceivable as a technique suitable for discharge in a pressure region of 0.1 Pa or less. “Hollow cathode discharge” refers to discharge using a thin cylindrical hollow electrode with one end closed and the other open as a cathode. An example of a plasma processing apparatus using hollow cathode discharge is shown in FIG.

FIG. 8 is a cross-sectional configuration diagram showing an outline of a conventional plasma processing apparatus (see Patent Document 3). As shown in FIG. 8, the plasma processing apparatus described in Patent Document 3 includes a substrate electrode 311 for placing a substrate to be processed 311 disposed in a processing chamber 307, and a high-frequency power source that supplies bias power to the substrate electrode 311. 313, an antenna electrode 301 for injecting electromagnetic waves into the processing chamber 307 through the electrical window 305, a processing gas supply mechanism 308 for supplying a predetermined processing gas into the processing chamber 307, and a dielectric window in the processing chamber 307 And a hollow cathode discharge mechanism 309 made of a recess provided on the 305 side.

Japanese Patent No. 3899146 JP 2003-318165 A JP 2003-68716 A

The conventional plasma processing apparatus described above has the following problems.

In a mechanism using a permanent magnet for generating a magnetic neutral line as disclosed in Patent Document 1, it is necessary to replace the permanent magnet for adjusting the position of the magnetic neutral line generation, and adjustment to make the plasma distribution uniform There is a problem that is difficult.

This point will be described with reference to FIG. As described above, the plasma processing apparatus shown in FIG. 6 controls the diameter of the permanent magnets 103 and 104 to change the location where the plasma concentrates (magnetic neutral line generation position). Therefore, when the diameter of the substrate changes from 200 mm to 300 mm, the location where the plasma concentrates (magnetic neutral line generation position) must be changed. Therefore, the problem of replacing the permanent magnets 103 and 104 occurs.

Further, as shown in FIG. 6, a plurality of high-frequency coils 106 including a single layer for applying a high-frequency electric field in the plasma generation chamber 101 for plasma generation are connected to the side wall portion 105 made of a dielectric of the plasma generation chamber 101. In the method of disposing outside, metal particles generated when a metal material is etched as the processing substrate 108 adheres to the side wall portion 105, so that the electric field transmission efficiency into the plasma processing chamber 101 is deteriorated as the processing amount is increased. In the end, however, the discharge cannot be maintained.

Further, in the device structure in which the permanent magnet 206 is disposed only in the upper electrode 201 and its periphery shown in FIG. 7, the in-plane plasma density is more uniform than the inductively coupled structure because of the capacitively coupled structure using the parallel plate shape. Although it is easy to obtain a distribution, there is a problem that a discharge pressure region that is normally used is relatively high, and discharge in a pressure region of 0.1 Pa or less required for a recent etching apparatus is unsuitable. For example, in the case of a plasma processing apparatus such as ion beam etching that performs etching processing by causing ions generated in plasma to collide with a processing substrate, if the pressure at the time of substrate processing is high, the mean free path is shortened and ions are processed. It is considered that the straightness of the ion beam and the kinetic energy of the ions themselves are impaired by being scattered by other ions before reaching the substrate.

In addition, as described above, the plasma processing apparatus shown in FIG. 7 can easily obtain an in-plane uniform plasma density distribution as compared with the inductively coupled structure. However, since the high-density plasma is generated by the permanent magnet 206 disposed on the upper electrode 201 in the plasma processing apparatus shown in FIG. 7, when the diameter of the substrate changes from 200 mm to 300 mm, the substrate There is a problem that it is difficult to obtain a high-density plasma up to the peripheral part.

This point will be described with reference to FIG. FIG. 9 is a top view showing the relationship between the arrangement of the permanent magnets 206 and the electric field and magnetic field of the plasma processing apparatus shown in FIG. In the plasma processing apparatus shown in FIG. 7, the permanent magnets are arranged at positions corresponding to the corners of a plurality of quadrangular squares, and the polarities of the permanent magnets adjacent to each other in the side direction are opposite to each other. Polarity. These four permanent magnets generate a magnetic field B on the cusp from the N-pole permanent magnet to the S-pole permanent magnet. In this specification, this magnetic field B is referred to as a “point cusp magnetic field”. On the other hand, when a high-frequency current is supplied from the high-frequency power source 213 to the upper electrode 201, plasma is generated by electrostatic coupling of high-frequency power. At that time, electrons in the plasma move in a cyclotron direction in a direction perpendicular to the point cusp magnetic field B created by the permanent magnet disposed on the upper electrode 201 and the electric field E generated by the high-frequency power source 213, and the plasma is confined in a high density. Plasma will be generated. However, if a high-density plasma is to be generated at the periphery of the substrate 223, a grid-like permanent magnet must be disposed on the upper electrode 201 having a diameter much larger than the diameter of the substrate. The problem of increasing the size arises.

On the other hand, according to the plasma processing apparatus shown in FIG. 8, by providing the hollow cathode discharge mechanism 309 in the processing chamber 307, discharge is performed in a pressure region of 0.1 Pa or less, and high quality is applied to the entire surface of the substrate to be processed 311. Although the treatment can be performed uniformly, there is a problem that high-density plasma cannot be generated.

An object of the present invention is to provide a plasma processing apparatus capable of solving at least one of the problems of the background art as described above. More specifically, the object of the present invention is to
Even when the diameter of the substrate is 300 mm or more, the apparatus is not increased in size, and it is possible to generate high-density plasma at a low pressure of 0.1 Pa or less while achieving uniformity of plasma density, and a plasma processing apparatus By using a capacitively coupled structure, the plasma processing apparatus that prevents the reduction in the efficiency of electric field transfer into the plasma processing chamber that occurs when etching metal materials, as seen in the inductively coupled structure, is provided. That is.

In order to achieve the above object, in the plasma processing apparatus of the present invention, a vacuum vessel composed of a top plate, a bottom plate, and a side wall, a substrate holder provided in the vacuum vessel, and the side wall A plurality of permanent magnets arranged outside to form a cusp magnetic field inside the side wall, a cylindrical electrode provided inside the side wall, a first high frequency power source for supplying high frequency power to the electrode, And the permanent magnets are arranged at positions corresponding to the corners of a plurality of quadrangular squares in a grid pattern, and the polarities of the permanent magnets adjacent in the side direction of the quadrangles are opposite polarities. The permanent magnet generates a point cusp magnetic field with a closed magnetic flux at a location close to the inner surface of the side wall.
The present invention includes the following configuration as a preferred embodiment.
The vacuum vessel is divided into a processing region for processing the object to be processed and a plasma generation region for generating plasma by the electrodes by a partition plate having a communicating hole, and the permanent magnet is configured to generate the plasma. It is provided in the area.
A DC power supply for supplying a DC voltage is connected to the partition plate.
A second high frequency power supply for supplying high frequency power to the substrate holder is connected. A plurality of permanent magnets for forming a cusp magnetic field inside the top plate are arranged outside the top plate.
The permanent magnets are arranged in a ring shape at concentric positions, and the polarities of the adjacent permanent magnets are opposite to each other, and the permanent magnets are located near the inner surface of the top plate. A circular linear cusp magnetic field with a closed magnetic flux is generated.
The permanent magnet is arranged at a position corresponding to each corner of a quadrangular quadrilateral in a grid pattern, and the polarity of the permanent magnet adjacent in the side direction of each quadrangle is opposite, Permanent magnets generate a point cusp field with closed magnetic flux near the inner surface of the top plate

  According to the present invention, a hollow cathode discharge is generated in a pressure region of 0.1 Pa or less in a vacuum vessel by applying high-frequency power from a high-frequency power source to a cylindrical electrode provided inside the side wall of the vacuum vessel. A cusp magnetic field is formed inside the side wall of the vacuum vessel by the permanent magnet provided on the outer side wall of the vessel, and high density plasma can be created by this cusp magnetic field. In addition, in the conventional method of obtaining a point cusp magnetic field by arranging permanent magnets in a grid pattern on the upper electrode, a point cusp magnetic field cannot be formed due to the location where the permanent magnet is interrupted at the end of the grid pattern. For this reason, the plasma density at the end may be lowered and the plasma may become unstable. However, according to the present invention, permanent magnets can be continuously arranged in the circumferential direction without interruption, and high-density plasma can be stably generated.

It is typical sectional drawing which shows the structure of the plasma processing apparatus by one Embodiment of this invention. It is typical sectional drawing which shows the structure of the plasma processing apparatus by another embodiment of this invention. It is a figure which shows magnetic force line distribution generate | occur | produced with the structure of FIG. It is the typical sectional view showing the composition of the plasma treatment device by another embodiment of the present invention, and the figure showing the line of magnetic force generated by this composition. It is a figure which shows the example of arrangement | positioning of the permanent magnet in the electrode upper surface of FIG. It is a figure which shows another example of arrangement | positioning of the permanent magnet in the electrode upper surface of FIG. It is a cross-sectional block diagram which shows the outline of the plasma processing apparatus of the past (patent document 1 description). It is a cross-sectional block diagram which shows the outline of the plasma processing apparatus of the past (patent document 2 description). It is a cross-sectional block diagram which shows the outline of the plasma processing apparatus of the past (patent document 3 description). It is the top view which showed the arrangement | positioning of the permanent magnet 206 which generate | occur | produces a point cusp magnetic field, and the relationship between an electric field and a magnetic field. It is the figure which showed the state of the plasma sheath and e (electron) at the time of generating plasma in a vacuum vessel with a parallel plate cathode electrode. It is the figure which showed the state of the plasma sheath and e (electron) at the time of generating plasma in a vacuum vessel with a hollow cathode electrode.

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

FIG. 1 is a schematic cross-sectional view showing the configuration of a preferred first embodiment of the plasma processing apparatus of the present invention. The plasma processing apparatus shown in FIG. 1 is disposed outside the side wall 1c, a vacuum vessel 1 composed of a top plate 1a, a bottom plate 1b, and a side wall 1c, a substrate holding mechanism 6 provided in the vacuum vessel 1. A plurality of permanent magnets 3 for forming a cusp magnetic field inside the side wall 1c, a cylindrical electrode 7 provided inside the side wall 1c, and a first high frequency power source 12 for supplying high frequency power to the cylindrical electrode 7 It consists of.

The substrate holding mechanism 6 includes a substrate holder 15. For example, the substrate holder 15 is installed inside the vacuum vessel 1 by a fixed shaft 16. The substrate holder 15 and the fixed shaft 16 are grounded. However, when a bias voltage such as a high frequency is to be applied to the substrate 15, the substrate holding mechanism 6 is sandwiched between the vacuum vessel 1 and the fixed shaft 16 with an insulator or the like interposed therebetween. It may be a floating potential. A mechanism (not shown) for cooling or heating the substrate 17 may be provided inside the substrate holder 15 and the fixed shaft 16. The substrate 17 to be processed is placed on the substrate holder 15. The permanent magnet 13 is fixed to the permanent magnet fixing sheet 18 and provided outside the side wall 1 c of the vacuum vessel 1. The side wall 1c of the vacuum vessel 1 provided with the permanent magnet 13 and the top plate 1a are covered with an RF shielding cover 8 having one end connected to the ground. Further, the top plate 1a and the permanent magnet 13 are covered with the RF shielding cover 8 in order to prevent an electric shock due to a voltage applied to the top plate 1a and the grid 4, and to prevent harm caused by a magnetic field generated by the permanent magnet 13 to the outside. This is to prevent the RF applied to the electrode 7 from being radiated to the outside.

As shown in FIG. 9, the permanent magnets 3 are arranged outside the side wall 1b of the vacuum vessel 1 at positions corresponding to the corners of a plurality of quadrangular squares, and in the lateral direction of each quadrilateral. The polarities of the adjacent permanent magnets 3 are opposite to each other, and the permanent magnets 3 are arranged to generate a point cusp magnetic field with a closed magnetic flux at a location close to the inner surface of the side wall 1c. This sheet 18 is preferably made of metal. The other magnetic pole of each permanent magnet is directed to face the central axis of the cylindrical electrode. Further, a small gap, preferably about 1 mm, is provided between the permanent magnet and the cylindrical electrode. In order to adjust the strength of the magnetic field on the inner surface of the cylindrical electrode 3, the height of the permanent magnet 13 can be changed. For example, the height of the permanent magnet 13 may be shortened toward the outer edge of the permanent magnet fixing sheet 18. Similarly, by selecting the permanent magnets 13 having different magnetic field strengths, the magnetic field strength at the inner surface of the electrode 3 can be varied by arranging them in a radial pattern in a contrasting pattern. The plurality of permanent magnets 13 are fixed to a cylindrical sheet 18 having a diameter larger than that of the cylindrical electrode. The permanent magnets 13 are arranged on the regular polygon at equal distances from each other so that their polarities are alternately changed. The spacing between any two adjacent permanent magnets is not critical and can vary in the range of 10 mm to 50 mm. The cross-sectional shape of each permanent magnet 13 is square or circular. If the cross-sectional shape is a circular shape, its diameter can vary in the range of 5 mm to 40 mm. If the cross-sectional shape is a square shape, equivalent dimensions are adopted. The height of the permanent magnet 13 is not an important matter and can be in the range of 5 mm to 30 mm. Furthermore, the strength of the permanent magnet's magnetic field is likewise not important. Typically, the strength of the permanent magnet is selected to produce a magnetic field with a strength of approximately 100 to 600 gauss on the inner surface of the cylindrical electrode.

    Also, by selecting permanent magnets with different magnetic field strengths, the magnetic field strength at the inner surface of the electrode can be varied by arranging them in a radial pattern in a contrasting pattern. Note that a mechanism for carrying in or carrying out the substrate 17 is not shown. In order to perform substrate processing with the plasma processing apparatus shown in FIG. 1, the vacuum vessel 1 is first evacuated to a predetermined pressure using an exhaust mechanism (configured by a vacuum pump) (not shown), and then a gas supply mechanism (not shown). The gas is introduced to a predetermined pressure using.

FIGS. 10 and 11 are views showing the state of the plasma sheath and e (electrons) when plasma is generated in the vacuum vessel by the parallel plate cathode electrode and the hollow cathode electrode. As shown in FIG. 10, when plasma in the vacuum vessel 1 using parallel plate cathode electrodes is generated, a plasma sheath is generated in the top plate 1a (cathode), and e (electrons) in the plasma is the plasma. Although reflected by the sheath, the bottom plate (anode) does not generate a plasma sheath, so e (electrons) in the plasma is not reflected.

On the other hand, when RF power is applied to the cylindrical electrode 7 by the RF power source 12, plasma is formed in the vacuum vessel 2 by hollow cathode cathode discharge as shown in FIG. In the case of the hollow cathode cathode discharge, e (electrons) in the plasma is reflected by the plasma sheath generated on both sides of the side wall 1b of the vacuum vessel 1, and the e (electrons) is confined, so that a low voltage is generated in the vacuum vessel 1. In addition, low-pressure discharge is possible. At that time, electrons in the plasma move in a cyclotron direction in a direction perpendicular to the point cusp magnetic field B created by the permanent magnet 3 and the electric field E generated by the RF power source 12 as shown in FIG. As a result, a high-density plasma is confined. Thus, according to the plasma processing apparatus described in the first embodiment, high-density plasma can be generated at a low pressure of 0.1 Pa or less.

FIG. 2 is a schematic view of a plasma processing apparatus according to the second embodiment. FIG. 3 shows the distribution shape of the lines of magnetic force of the permanent magnets mounted in FIG. A major feature of the plasma processing apparatus of the second embodiment is that a processing region (processing chamber) for processing an object to be processed (processing substrate) 17 by a partition plate (grid) 4 having holes communicating with the vacuum vessel 1. 5 and the plasma generation region (plasma generation chamber 2) in which plasma is generated by the electrode 7, and the permanent magnet 13 and the cylindrical electrode 7 are provided in the plasma generation region (plasma generation chamber) 2. is there. The other configuration is the same as that of the plasma processing apparatus shown in FIG.

The grid 4 is a partition plate having a communicating hole, and one end is connected to the DC power source 14. By installing the grid 4, it is possible to prevent the plasma generated in the plasma generation chamber 2 from diffusing to the processing chamber 5 side and to extract only ions in the plasma.

In order to perform substrate processing with the plasma processing apparatus described above, first, the vacuum vessel 1 is evacuated to a predetermined pressure using an exhaust mechanism (configured by a vacuum pump) (not shown), and then a gas supply mechanism (not shown) is used. , Gas is introduced to a predetermined pressure. Next, RF power is applied to the cylindrical electrode 7 from the RF power source 12, and plasma is generated in the plasma generation chamber 2 by hollow cathode cathode discharge. As a result, as shown in FIG. 11, e (electrons) in the plasma is reflected by the plasma sheath generated on both sides of the side wall 1 b of the vacuum vessel 1, and the e (electrons) are confined, so that the inside of the vacuum vessel 1 is contained. A low voltage and low pressure discharge is possible. At that time, electrons in the plasma move in a cyclotron direction in a direction orthogonal to the point cusp magnetic field B created by the permanent magnet 3 arranged outside the side wall 1c shown in FIG. 9 and the electric field E generated by the RF power source 12. As a result, a high-density plasma is confined.

In the second embodiment, since the DC power source 14 is connected to the grid 4, plasma is generated by low-pressure discharge in each partition plate 4 by hollow cathode cathode discharge. As described above, according to the plasma processing apparatus of the second embodiment, the substrate 7 can be processed by the plasma generated by the cylindrical electrode 7 and the plasma generated by the grid 4. It is also conceivable that the plasma generated by the cylindrical electrode 7 becomes nonuniform at the center and the periphery of the substrate 17 when the diameter of the substrate is 300 mm or more. In such a case, the plasma generated by the grid 4 is effective in adjusting plasma that is not uniform at the center and the periphery of the substrate 17.

  FIG. 3 shows an example of lines of magnetic force generated by the magnetic circuit shown in FIG. Since the point cusp magnetic field is generated on the surface of the cylindrical electrode 7 in the plasma generation chamber 2 and this magnetic field acts as a local magnetic mirror, charged particles in the plasma other than those having particularly large energy are used. Thus, a phenomenon occurs in which the magnetic mirror cannot be passed through and is pushed back toward the inside of the plasma generation chamber 2. Since the magnetic field exists only in the immediate vicinity of the magnetic field generator, only the loss at the wall of the vacuum vessel 1 is reduced without affecting the properties of the plasma that has freely diffused into the plasma generation chamber 2. The cylindrical electrode 7 operates as a hollow cathode. By combining this cylindrical electrode 7 and the point cusp magnetic field, it becomes possible to obtain a higher plasma density at a lower pressure than in the prior art.

  FIG. 4 is a schematic cross-sectional view showing the configuration of the plasma processing apparatus according to the third embodiment, and a diagram showing the distribution of the lines of magnetic force generated in this configuration. A major feature of the plasma processing apparatus according to the third embodiment is that a plurality of permanent magnets 13 for forming a cusp magnetic field inside the top plate 1 a are provided outside the top plate 1 a of the vacuum vessel 1. Other configurations are the same as those of the plasma processing apparatus shown in FIGS. In the above configuration, preferably, one end of the cylindrical electrode 7 is closed as shown in FIG. 4, and the permanent magnet 13 is disposed outside the closed portion, so that the side wall of the electrode 7 and the entire closed flat portion are formed. It contributes to plasma generation, has a high density, and has a parallel plate arrangement due to the closed flat surface portion, so that more uniform plasma generation can be performed. The arrangement of the permanent magnets 13 on the electrodes 7 may be arranged such that the ring-shaped permanent magnets 13 have alternating magnetic pole directions and concentric circles as shown in FIG. As described above, a plurality of permanent magnets 13 similar to those used on the outer surface of the cylindrical electrode 7 are arranged on an arc having a concentric circle so as to replace the ring-shaped permanent magnets of FIG. 5a. May be. In the ring-shaped permanent magnet of FIG. 5a, the correction of the magnetic field strength in the discharge space can only be done by changing the ring-shaped magnet or adjusting the overall height, and the correction of the local plasma density. However, in FIG. 5b, the plasma density can be locally corrected by changing the height of the permanent magnet at the location where the plasma density is weak.

  According to the present invention, it has become possible to generate high-density plasma at a low pressure with better uniformity over a wider range than before. An effective method for determining the configuration of the magnetic circuit is the calculation of the lines of magnetic force. This calculation can be easily executed by, for example, a finite element method. A plasma density measurement method such as a Langmuir probe is effective for confirming the results experimentally. As described above, by devising the structure of the magnetic circuit, the range in which the uniformity of the plasma is good widens, and the processing of a large-area substrate can be performed more easily than before. In addition, by changing the height of each permanent magnet depending on the use conditions, it is possible to finely adjust the region where the plasma uniformity is good.

  As is apparent from the above description, according to the present invention, a cylindrical electrode is disposed in the plasma generation chamber facing the processing substrate, and the point cusp shape is formed so as to cover the cylindrical electrode on the atmosphere side of the plasma generation chamber. Arrange the magnetic circuit structure arranged in With such a magnetic circuit structure, uniform and high-density plasma can be created at low pressure, and uniform processing of a large area substrate can be realized. In addition, the plasma density can be finely set by adjusting the height of the permanent magnet, and a plasma processing apparatus can be realized that can easily adjust the range of uniformity of the plasma density in an optimal manner.

Examples of the plasma processing apparatus obtained by using the present invention include a plasma etching apparatus, a sputtering film forming apparatus, a plasma CVD apparatus, and an ashing apparatus. In particular, the plasma etching apparatus can be applied to an ion beam etching apparatus for performing fine processing of an element such as MRAM containing a magnetic material.

1 Vacuum container 2 Plasma generation chamber (plasma generation region)
3 Magnetic circuit 4 Grid 5 Processing chamber (processing area)
6 Substrate holding mechanism 7 Electrode 8 RF shielding cover 9 Insulator 11 Magnetic field lines generated by magnetic circuit 3 RF power source 13 Permanent magnet 14 DC power source 15 Base holder 16 Fixed shaft 17 Substrate 18 Permanent magnet fixing sheet

Claims (7)

  A vacuum vessel constituted by a top plate, a bottom plate, and a side wall, a substrate holding mechanism provided in the vacuum vessel, and a plurality of cusp magnetic fields that are arranged outside the side wall to form a cusp magnetic field inside the side wall A permanent magnet, a cylindrical electrode provided on the inner side of the side wall, and a first high-frequency power source for supplying high-frequency power to the electrode, wherein the permanent magnet has a quadrangular quadrilateral shape. The permanent magnets are arranged at positions corresponding to the respective corners, and the polarities of the permanent magnets adjacent in the side direction of the respective squares are opposite to each other, and the permanent magnets are closed at a location close to the inner side surface of the side wall. Generating a point cusp magnetic field accompanied by a magnetic flux.   The vacuum vessel is divided into a processing region for processing the object to be processed and a plasma generation region for generating plasma by the electrodes by a partition plate having a communicating hole, and the permanent magnet is configured to generate the plasma. The plasma processing apparatus according to claim 1, wherein the plasma processing apparatus is provided in a region.   The plasma processing apparatus according to claim 2, wherein a DC power supply for supplying a DC voltage is connected to the partition plate.   The plasma processing apparatus according to any one of claims 1 to 3, wherein a second high-frequency power supply for supplying high-frequency power to the substrate holding mechanism is connected.   5. The plasma processing apparatus according to claim 1, wherein a plurality of permanent magnets for forming a cusp magnetic field are disposed inside the top plate outside the top plate. 6.   The permanent magnets are arranged in a ring shape at concentric positions, and the polarities of the adjacent permanent magnets are opposite to each other, and the permanent magnets are located near the inner surface of the top plate. 6. The plasma processing apparatus according to claim 5, wherein a circular linear cusp magnetic field with a closed magnetic flux is generated.   The permanent magnet is arranged at a position corresponding to each corner of a quadrangular quadrilateral in a grid pattern, and the polarity of the permanent magnet adjacent in the side direction of each quadrangle is opposite, The plasma processing apparatus according to claim 5, wherein the permanent magnet generates a point cusp magnetic field with a magnetic flux closed at a location near the inner surface of the top plate.