JPH1092628A - Coil for generating magnetic field - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coil for generating magnetic fields which can be reduced in volume and weight as much as possible. SOLUTION: A coil for generating magnetic field is constituted by alternately laminating first coils 7A, 7B, and 7C which are formed by winding hollow pipes in multiple layers in the radial direction of the coil and second coils 8A and 8B formed by winding copper wires in multiple layers in the radial direction of the coil in the axial direction of the coil so that the first coils 7A and 7C can be positioned to both end sections of the coil in the axial direction and making cooling water to successively flow through the pipes of the first coils 7A, 7B, and 7C in the axial direction of the coil.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic field generating coil used for a plasma processing apparatus in a semiconductor process.

[0002]

2. Description of the Related Art FIG. 4 is a block diagram of a plasma processing apparatus to which the present invention is applied, wherein 1 is a magnetron, 2 is a waveguide, 3 is a plasma generation chamber, 4 is a magnetic field generating coil, and 5 is a coil. A reaction chamber 6 is an object to be processed.

[0003] Microwaves are generated by a magnetron 1 and are advanced to a plasma generation chamber 3 through a waveguide 2. When the magnetic field generating coil 4 arranged on the outer periphery of the plasma generation chamber 3 is excited, plasma is generated inside the plasma generation chamber 3 by the magnetic field and the microwave. By irradiating the object 6 in the reaction chamber 5 with the plasma, processing such as etching, ashing, and sputtering is performed.

FIG. 5 is a view showing a conventional magnetic field generating coil, wherein reference numeral 20 denotes a copper wire coil in which a copper wire covered with an insulating member is wound multiple times in the radial direction of the coil. A plurality of coils are stacked in the longitudinal direction of the coil. 21
Is a copper cooling plate. The cooling plate 21 and a plurality of laminated coils 20 are alternately arranged in the longitudinal direction, and the cooling plates 21 are arranged at both ends in the longitudinal direction. Reference numeral 22 denotes a cooling water circulation pipe attached to a radially outer peripheral portion of the cooling plate 21. Cooling water flows through the pipe 22 to suppress heat generation of the coil 20. The coil 20 near the cooling plate 21 is effectively cooled, but the cooling effect becomes smaller as the coil 20 is separated from the cooling plate 21 as in a central portion where a plurality of coils 20 are stacked.

The conventional coil 4 for generating a magnetic field is constituted by the copper wire coil 20, the copper cooling plate 21 and the cooling water circulation pipe 22 described above.

[0006]

Generally, the dynamic performance of a coil is evaluated by the magnetic flux density generated by the coil. The magnetic flux density B in the axial direction at the center of the coil is represented by the following equation: B = k · N · I (B) 1) It is represented by Here, N is the number of turns of the coil, I is the current value flowing through the coil, and k is a constant.

By the way, in the conventional magnetic field generating coil shown in FIG. 5, in order to obtain a high magnetic flux density, it is necessary to increase the number of turns N or the current value I of the coil in the above equation (1). However, when the number of turns N of the coil is increased, the radial structure of the magnetic field generating coil is increased. On the other hand, when the current value I of the coil is increased, the temperature inside the coil becomes high due to heat generation, leading to deterioration of insulation of the coil. For this reason, in order to increase the cooling effect, it is necessary to increase the thickness of the cooling plate or increase the number of inserted cooling plates, resulting in a disadvantage that the weight of the magnetic field generating coil increases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a magnetic field generating coil which is as light as possible and has a small volume.

[0009]

Means for Solving the Problems The first invention is applied to a magnetic field generating coil formed in a hollow cylindrical shape. The feature is that a first coil in which a hollow pipe is wound in multiple layers in the radial direction of the coil and a second coil in which copper wire is wound in multiple layers in the radial direction of the coil are alternately arranged in the longitudinal direction of the coil. And disposing the first coil at both ends in the longitudinal direction, and circulating cooling water inside the pipe of the first coil. According to a second aspect of the present invention, in the first aspect, cooling water is supplied to a first coil disposed at one end of the coil in the long axis direction, and the cooling water is supplied from the first coil to the long axis direction. The cooling path is sequentially communicated with another separated first coil, and the cooling water flows out from the first coil disposed at the other end in the long axis direction.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments. In FIG. 1, reference numeral 7A denotes a hollow pipe coil in which a hollow pipe covered with an insulating member is wound multiple times in the radial direction of the coil.
A is, for example, as shown in FIG.
Of abut a central portion in the longitudinal direction in the core 10, as shown in the 7A ₁ side of the hollow pipe in the solid and dashed lines, right as wound left-handed, shows the other 7A ₂ side dashed line It is wound in multiple turns in the radial direction in two adjacent rows of left and right turns. Similarly, hollow pipe coils 7B and 7C are formed, and a plurality of these hollow pipe coils 7A, 7B and 7C are arranged apart from each other in the longitudinal direction of the coil to form a first coil 7. 8A is
This is a copper wire coil in which a copper wire covered with an insulating member is wound multiple times in the radial direction of the coil, and a plurality of the copper wires are laminated in the major axis direction of the coil. Copper wire coils 8A and 8B are spaced apart in the longitudinal direction of the coil to form a second coil 8.

For example, the first coil 7 and the second coil 8 are alternately laminated with (7A-8A-7B-8B-7C) on the winding frame 9 in the longitudinal direction of the coil, and First
Are disposed at both ends in the long axis direction. In the magnetic field generating coil according to the present invention constituted by the first coil 7 and the second coil 8, the cooling water is supplied from 7A ₁ side is drained from the other 7A ₂ side. Further, effluent from 7A ₂ is supplied to 7B _1, further drainage from 7B ₂ are supplied to 7C _1. Drainage from the 7C ₁ is taken out to the outside. That is, the cooling water of the first coil 7 is sequentially supplied and discharged in the longitudinal direction of the coil.

Next, the electrical connection of the magnetic field generating coil according to the present invention will be described. That is, as is shown in FIG. 2, other that are Hanare設first coil 7A ₂ disposed at one end of the long axis direction of the coil, the coil 7A ₂ of the first longitudinally the first coil 7B ₁ are electrically connected in the radial direction of the coil (outer chromatography outside) side of the. The further 7B ₂ and 7C ₁ are electrically connected by radial (outer over outer) side of the coil. The first coil 7C ₂ disposed at the other end of the long axis direction, the coil 8B ₆ end of the second coil 8B adjacent to the first coil 7C radial coil (outer -Outside) is electrically connected.

The coils 8B ₆ , 8B ₅ , 8B ₄ ,... Adjacent to the second coil 8B are arranged in the longitudinal direction in the order of the major axis direction (inside-inside) of the coil and in the radial direction of the coil. Outside)
And are electrically connected alternately. That is, the first coil 7A → 7B → 7C and the second coil 8B → 8A are alternately turned on the (outer-outer) side in the radial direction of the coil and the (inner-inside) side on the center side of the coil. Are serially connected. Since the electrical connection is made in series, the potential difference between the plurality of first coils can be reduced.

As is apparent from the above description, the coil for generating a magnetic field according to the present invention comprises a first coil formed by winding a hollow pipe.
And a second coil 8 in which a copper wire is wound in multiple layers in the radial direction of the coil are alternately laminated in the long axis direction of the coil, and the first coil 7 is disposed at both ends in the long axis direction. Set up
In addition, since the cooling water is circulated in the longitudinal direction of the coil inside the pipe of the first coil 7, the entire coil is efficiently cooled by the cooling water flowing in the first coil 7. Of course, since the first coil 7 is a hollow pipe,
Lighter than a conventionally used copper cooling plate, it is possible to obtain a light-weight magnetic field generating coil.

Further focusing on the magnetic flux density of the coil,
In the conventional coil using the copper cooling plate, the total dimension of the thickness of the copper cooling plate used in a plurality of sheets, that is,
Although the dimension of the copper cooling plate in the longitudinal direction of the coil does not contribute to the generation of a magnetic field, which is a so-called dead space, the first coil 7 made of a hollow pipe has a larger number of turns as a coil than the second coil 8. Although somewhat small, a magnetic field is generated by supplying power to the first coil 7, so that this magnetic field can be used effectively.

Of course, the entire coil is efficiently cooled by the cooling water flowing through the first coil, so that even if the current supplied to the coil is increased, the temperature of the coil itself is suppressed from becoming high. Together with this, the use of the first coil increases the number of turns of the entire coil, so that, for example, the volume of the magnetic field generating coil for obtaining the same magnetic flux density as in the related art can be reduced as much as possible. In other words, the coil for generating a magnetic field according to the present invention can increase the supply current value to the coil and increase the number of turns of the entire coil, so that a high magnetic flux density can be obtained.

[0017]

As is apparent from the above description, the coil for generating a magnetic field according to the present invention can be efficiently cooled by the cooling water flowing in the first coil in the longitudinal direction of the coil. Further, since the first coil is a hollow pipe, a light-weight magnetic field generating coil can be obtained. Further, even if the supply current value to the coil is increased, the use of the first coil increases the number of turns of the entire coil in combination with the suppression of the temperature rise of the coil itself. Can be made as small as possible.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention.

FIG. 2 is an electrical connection diagram of FIG.

FIG. 3 is a diagram showing how to wind a first coil 7;

FIG. 4 is a schematic front view showing a plasma processing apparatus to which the present invention is applied;

FIG. 5 is a partial cross-sectional front view showing a conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 magnetron 2 waveguide 3 plasma generation chamber 4 magnetic field generating coil 5 reaction chamber 6 workpiece 7 first coil (= hollow pipe coil) 8 second coil (= copper wire coil)

Claims (2)

[Claims] 1. A coil for generating a magnetic field formed in a hollow cylindrical shape, wherein a first coil in which a hollow pipe is wound in multiple layers in the radial direction of the coil and a copper wire are wound in multiple layers in the radial direction of the coil. A second coil and a second coil are alternately stacked in the longitudinal direction of the coil, the first coil is disposed at both ends in the longitudinal direction, and cooling water is provided inside a pipe of the first coil. For generating a magnetic field. 2. A cooling water is supplied to a first coil disposed at one end of the coil in the longitudinal direction, and another first coil disposed in a longitudinal direction away from the first coil. The cooling passages are sequentially communicated to the coils of the first direction, and the first is disposed at the other end in the long axis direction.
2. The magnetic field generating coil according to claim 1, wherein cooling water flows out of the coil.