JP6473042B2 - Electromagnet device - Google Patents

Description

  The present invention relates to an electromagnet device used, for example, to control the distribution of plasma density in a plasma processing apparatus.

  Conventionally, in a plasma processing apparatus such as a plasma etching apparatus, it is known that the distribution of plasma density generated in a chamber is controlled by a magnetic field generated by an electromagnet apparatus. Specifically, in a plasma etching apparatus, for example, a Lorentz force is generated by applying an electric field and a magnetic field in directions orthogonal to each other inside a chamber into which an etching gas is introduced. This Lorentz force causes the electrons to be trapped by the magnetic field lines while performing a drift motion. As a result, the collision frequency between the electrons and the molecules and atoms of the etching gas increases, and high-density plasma is generated. This is also called a so-called magnetron discharge.

  As an electromagnet device used in such a plasma processing apparatus, an electromagnet (for example, refer to Patent Document 1) formed by winding a coil around the outer periphery of a rod-shaped yoke made of an iron core, or an annular magnet provided on a plate-shaped yoke. An electromagnet formed by arranging a coil in a groove is known.

JP 2013-149722 A

  In an electromagnet device formed by arranging a coil in an annular groove provided in a plate-like yoke, the coil is fixed to the groove by, for example, a thermosetting resin. The thermosetting resin shrinks due to a heat shrinkage when returning from a high temperature during curing to a room temperature. This shrinkage of the thermosetting resin deforms the yoke. When the yoke is deformed, there is a problem that the magnetic field formed in the chamber of the plasma processing apparatus is not uniform with respect to the plane of the substrate that is the object to be processed, and as a result, the processing on the substrate cannot be performed uniformly.

  The present invention has been made in view of the above problems, and an object thereof is to provide an electromagnet device in which deformation of the yoke is suppressed.

  In order to achieve the above object, an electromagnet apparatus according to a first embodiment of the present invention is an electromagnet apparatus used in a plasma processing apparatus, and includes a yoke having an annular groove on a front surface and an annular coil disposed in the groove. And a resin for fixing the coil to the yoke and for transferring heat, the outer peripheral surface of the groove of the yoke, and the radial direction of the coil A gap is provided between the resin provided on the outside.

  In order to achieve the above object, an electromagnet device according to a second embodiment of the present invention is the electromagnet device according to the first embodiment, wherein the coil is housed inside the groove.

  In order to achieve the above object, an electromagnet device according to a third mode of the present invention is the electromagnet device according to the first mode or the second mode, wherein the coil has a central portion in the width direction of the coil from a center in the width direction of the groove. It arrange | positions in the said groove | channel so that it may be located inside radial direction.

  In order to achieve the above object, an electromagnet device according to a fourth embodiment of the present invention is the electromagnet device according to any one of the first to third embodiments, wherein the coil has a central portion in the depth direction of the coil. It arrange | positions in the said groove | channel so that it may be located in the bottom part side from the depth direction center.

  In order to achieve the above object, an electromagnet device according to a fifth embodiment of the present invention is the electromagnet device according to any one of the first to fourth embodiments, wherein the resin is a resin having good heat resistance and thermal conductivity. .

  In order to achieve the above object, an electromagnet device according to a sixth embodiment of the present invention is the electromagnet device according to any one of the first to fifth embodiments, wherein at least a part of the inner peripheral surface of the groove is the depth of the groove. The groove has a tapered surface formed so that the width of the groove increases as the depth increases.

In order to achieve the above object, an electromagnet device according to a seventh embodiment of the present invention has a wiring for energizing the coil in the electromagnet device of any one of the first to sixth embodiments,
The yoke has a through hole penetrating the inside of the groove and the back side, and the wiring is provided so as to pass through the through hole.

  In order to achieve the above object, an electromagnet device according to an eighth embodiment of the present invention has a cooling plate arranged on the back side of the yoke in the electromagnet device of any one of the first to seventh embodiments.

  In order to achieve the above object, an electromagnet device according to a ninth embodiment of the present invention includes the heat transfer sheet disposed between the back surface of the yoke and the cooling plate in the electromagnet device of the eighth embodiment.

  ADVANTAGE OF THE INVENTION According to this invention, the electromagnet apparatus which can control a spatial magnetic field distribution with high precision by which the deformation | transformation of the yoke was suppressed can be provided. In addition, the present invention can provide a compact and energy saving electromagnet device (with less coil heat generation).

It is a schematic sectional side view of the plasma processing apparatus with which the electromagnet apparatus which concerns on embodiment of this invention is used. It is a top view of an electromagnet device concerning an embodiment of the present invention. It is a sectional side view of an electromagnet device concerning an embodiment of the present invention. It is a partial expanded sectional view of an electromagnet device concerning an embodiment of the present invention. It is a perspective view of an electromagnet device concerning an embodiment of the present invention. It is a partial expanded sectional view of an electromagnet device concerning an embodiment of the present invention. It is a figure which shows an example of the cross section of a cooling plate. It is a figure which shows an example of the cross section of a cooling plate.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic sectional side view of a plasma processing apparatus in which an electromagnet device according to an embodiment of the present invention is used. As shown in FIG. 1, the plasma processing apparatus 10 controls a chamber 13, a substrate stage 14 on which a substrate W is placed, an electromagnet apparatus 20 disposed on the upper surface of the chamber 13, and the electromagnet apparatus 20. The controller 11 is provided.

The substrate stage 14 is disposed in the chamber 13, and the substrate W is placed on the upper surface thereof. The chamber 13 is evacuated by a vacuum pump (not shown). A gas introduction unit (not shown) is provided in the chamber 13, and an etching gas or the like is introduced into the chamber 13 by the gas introduction unit.

  The electromagnet device 20 is configured to form a magnetic field in the chamber 13 via a partition wall (a top plate of the chamber 13). The magnetic field formed by the electromagnet device 20 is a substantially concentric magnetic field that is uniform in the circumferential direction of the electromagnet device 20.

  The controller 11 is electrically connected to the electromagnet device 20. The controller 11 is configured to be able to apply an arbitrary coil current to the electromagnet device 20.

  In the plasma processing apparatus 10, for example, a horizontal magnetic field is formed by the electromagnet apparatus 20 in a direction orthogonal to a vertical electric field formed between the substrate stage 14 and the top plate of the chamber 13. Thereby, the plasma density distribution is controlled and the substrate is processed.

  Next, the electromagnet device 20 according to the embodiment of the present invention shown in FIG. 1 will be described in detail. 2 is a top view of the electromagnet device 20, FIG. 3 is a side cross-sectional view of the electromagnet device 20 in the 3-3 cross section shown in FIG. 2, and FIG. 4 is a broken line frame of the electromagnet device 20 shown in FIG. FIG. 5 is a perspective view of an electromagnet device 20. In the following description, the “front surface” of the electromagnet apparatus 20 refers to a surface directed to the substrate W (processing object) of the plasma processing apparatus 10, and the “rear surface” of the electromagnet apparatus 20 refers to a surface opposite to the front surface. Say.

  As shown in FIGS. 2 and 3, the electromagnet device 20 includes a substantially disc-shaped yoke 21, annular coils 23 a, 23 b, 23 c, and 23 d, a cooling plate 40 disposed on the back side of the yoke 21, and a yoke 21 and a heat transfer sheet 45 disposed between the rear surface of 21 and the cooling plate 40.

  The yoke 21 is made of pure iron with Ni plating on the surface, for example. Pure iron is desirable because it has good workability. In the center of the yoke 21, a through-hole 30 for passing a piping such as plasma processing gas is formed in the thickness direction of the yoke 21. The yoke 21 has a substantially disc-shaped back yoke 21a and five yoke side surfaces 21b provided on the front surface of the back yoke 21a. The five yoke side surfaces 21b are formed in annular shapes having different diameters. In other words, the yoke 21 has four annular grooves 22a, 22b, 22c, and 22d concentrically on the front surface thereof. The grooves 22a, 22b, 22c, and 22d are formed such that the groove 22a has the smallest diameter, and the diameters increase in the order of the groove 22b, the groove 22c, and the groove 22d.

  The coils 23a, 23b, 23c, and 23d are formed to have different diameters. That is, the coils 23a, 23b, 23c, and 23d are formed such that the diameter of the coil 23a is the smallest and the diameter increases in the order of the coil 23b, the coil 23c, and the coil 23d. The coils 23a, 23b, 23c, and 23d are disposed inside the grooves 22a, 22b, 22c, and 22d, respectively. Here, “disposed inside” means that the coils 23a, 23b, 23c, and 23d do not protrude from the grooves 22a, 22b, 22c, and 22d and are completely disposed in the grooves 22a, 22b, 22c, and 22d. Means that Magnetic field lines generated by energizing the coils 23a, 23b, 23c, and 23d pass through the back yoke 21a and the yoke side surface 21b of the yoke 21, so that the coils 23a, 23b, 23c, and 23d have grooves 22a, 22b, By being arranged inside 22c and 22d, the magnetic field lines can easily pass through the yoke 21. For this reason, variation in magnetic field distribution can be suppressed as compared with the case where the coils 23a, 23b, 23c, and 23d are arranged so as to protrude from the grooves 22a, 22b, 22c, and 22d.

  Epoxy resins 24a, 24b, 24c, and 24d are provided in the grooves 22a, 22b, 22c, and 22d, respectively. The epoxy resins 24a, 24b, 24c, and 24d are provided so as to enclose the coils 23a, 23b, 23c, and 23d, and fix the coils 23a, 23b, 23c, and 23d to the yoke 21 and transfer heat. Here, the present invention is not limited to the epoxy resins 24a, 24b, 24c, and 24d, and for example, a thermosetting resin such as a silicone resin or a urethane resin can be employed. It is preferable to use an epoxy resin having good heat resistance, coefficient of thermal expansion, and thermal conductivity.

  As described above, the thermosetting resin contracts due to a thermosetting reaction and thermal contraction when returning from a high temperature during curing to room temperature. This shrinkage of the thermosetting resin may deform the yoke 21. One mode of this deformation is that the thermosetting resin provided on the radially outer side of the coils 23a, 23b, 23c, and 23d pulls the outer peripheral surfaces of the grooves 22a, 22b, 22c, and 22d of the yoke 21 radially inward. Caused by. Therefore, in the electromagnet device 20 according to the present embodiment, as shown in FIGS. 3 and 4, epoxy resins 24 a, 24 b, 24 c, 24 d provided on the radially outer sides of the coils 23 a, 23 b, 23 c, 23 d, Clearances 27a, 27b, 27c, and 27d are provided between the outer peripheral surfaces of the grooves 22a, 22b, 22c, and 22d of the yoke 21, respectively. On the other hand, the radially inner sides of the coils 23a, 23b, 23c, and 23d are fixed to the yoke 21 via the epoxy resins 24a, 24b, 24c, and 24d.

  As shown in FIG. 4, for example, a fluorine-based release agent 29 is applied to the outer peripheral surface of the groove 22a. The release agent 29 is applied to the outer peripheral surface of the groove 22a before filling the groove 22a with the epoxy resin 24a. Thereby, when the epoxy resin 24a contracts by thermally curing the epoxy resin 24a, the epoxy resin 24a is easily peeled from the outer peripheral surface of the groove 22a. For this reason, the gap 27a is formed while the stress applied to the yoke 21 is suppressed. Although omitted in the figure, the release agent 29 is similarly applied to the outer peripheral surfaces of the grooves 22b, 22c, and 22d.

  By peeling the epoxy resins 24a, 24b, 24c, and 24d from the outer peripheral surfaces of the grooves 22a, 22b, 22c, and 22d, the stress on the radially inner side of the yoke 21 caused by the shrinkage of the epoxy resins 24a, 24b, 24c, and 24d is caused. It can be reduced and the yoke 21 can be prevented from being deformed.

  The coils 23a, 23b, 23c, and 23d are arranged such that the center portions in the width direction of the coils 23a, 23b, 23c, and 23d are located radially inward from the center in the width direction of the grooves 22a, 22b, 22c, and 22d. In addition, the coils 23a, 23b, 23c, and 23d are arranged so that the center portions in the depth direction are located closer to the bottom than the centers in the depth direction of the grooves 22a, 22b, 22c, and 22d.

  As shown in FIG. 4, the inner peripheral surfaces of the grooves 22a and 22b have tapered surfaces 44a and 44b that increase in width as the depth of the grooves 22a and 22b increases. That is, the taper surfaces 44a and 44b form a relatively wide width on the bottom side of the grooves 22a and 22b, and form a relatively narrow width on the inlet side (opposite to the bottom side) of the grooves 22a and 22b. As illustrated, part of the inner peripheral surfaces of the grooves 22a and 22b may be formed in a tapered shape, or the entire inner peripheral surface may be formed in a tapered shape. The taper angle is preferably about 2 ° or more and about 3 ° or less. Thereby, it can suppress that coil 23a, 23b and epoxy resin 24a, 24b drop | omit from groove | channel 22a, 22b. Although not shown in the figure, the outer peripheral surfaces of the grooves 22c and 22d similarly have a tapered surface whose width increases along the depth direction.

As shown in FIG. 3, the back yoke 21 a of the yoke 21 has through holes 28 a, 28 b, 28 c, 28 that pass through the inside of the grooves 22 a, 22 b, 22 c, 22 d and the back side of the yoke 21.
d is formed. As shown in FIG. 2, each of the through holes 28a, 28b, 28c, and 28d includes three holes. There are a total of 4 wires comprising two wires (see FIG. 6) for energizing the coils 23a, 23b, 23c, and 23d and two temperature sensors (not shown) that detect the temperatures of the coils 23a, 23b, 23c, and 23d. The wires are arranged on the back side of the yoke 21 through the three holes of the through holes 28a, 28b, 28c, and 28d from the coils 23a, 23b, 23c, and 23d.

  As shown in FIGS. 2 and 3, the cooling plate 40 is disposed on the back side of the yoke 21 and is fastened to the yoke 21 by a fastening member 50 such as a bolt. The cooling plate 40 has holes 43a, 43b, and 43c that penetrate in the thickness direction. The holes 43a, 43b, 43c are formed so as to be disposed at positions corresponding to the positions of the through holes 28a, 28b, 28c when the cooling plate 40 is fastened to the back surface of the yoke 21. Therefore, wiring for energizing the coils 23a, 23b, and 23c (see FIG. 6) and wiring for a temperature sensor (not shown) that detects the temperature of the coils 23a, 23b, and 23c are connected from the coils 23a, 23b, and 23c to the through holes 28a, 28b, 28c and holes 43a, 43b, 43c are disposed on the back side of the cooling plate 40. The cooling plate 40 is not disposed on the back side of the position where the through hole 28d of the yoke 21 is formed. For this reason, wiring for energizing the coil 23d (see FIG. 6) and wiring for a temperature sensor (not shown) for detecting the temperature of the coil 23d are arranged on the back side of the yoke 21 only through the through hole 28d.

  As shown in FIGS. 2 and 5, the cooling plate 40 has a water cooling pipe 41 through which water passes, and the water cooling pipe 41 has an inlet 41 a and an outlet 41 b positioned outside the cooling plate 40.

  As shown in FIG. 3, a recess 21 c is formed on the back surface of the yoke 21. A heat transfer sheet 45 for transferring the heat of the yoke 21 to the cooling plate 40 is disposed in the recess 21c. That is, the heat transfer sheet 45 is disposed between the back surface of the yoke 21 and the cooling plate 40 so that one surface of the heat transfer sheet 45 contacts the yoke 21 and the other surface contacts the cooling plate 40. The heat transfer sheet 45 is disposed over substantially the entire area between the back surface of the yoke 21 and the cooling plate 40. The cooling plate 40 is fastened by the fastening member 50 so as to be in close contact with the heat transfer sheet 45. The depth of the recess 21c gives an appropriate crushing pressure to the heat transfer sheet 45, thereby maintaining the heat transfer characteristics.

  Heat generated by energizing the coils 23a, 23b, 23c, and 23d is transmitted to the yoke 21 through the epoxy resins 24a, 24b, 24c, and 24d. The heat transmitted to the yoke 21 is efficiently transmitted from the back yoke 21a to the cooling plate 40 by the heat transfer sheet 45. In this way, heat generated by energizing the coils 23a, 23b, 23c, and 23d is efficiently removed.

  When the controller 11 shown in FIG. 1 is arranged on the back side of the cooling plate 40, the cooling plate 40 can also remove heat from an amplifier or the like included in the controller 11.

Next, the wiring configuration of the coils 23a, 23b, 23c, and 23d shown in FIG. 2 will be described. FIG. 6 is a partially enlarged cross-sectional view of the electromagnet device 20. The coil 23a has wirings 52a and 53a, and the coil 23b has wirings 52b and 53b. Although not shown, the coils 23c and 23d also have wirings in the same manner. Since the coils 23a, 23b, 23c, and 23d are electrically connected to the controller 11 through separate wirings, the controller 11 can independently control the coils 23a, 23b, 23c, and 23d. For this reason, the controller 11 can form an arbitrary concentric magnetic field on the front side of the electromagnet device 20 by applying an arbitrary current to the coils 23a, 23b, 23c, and 23d. As a result, in the plasma processing apparatus 10 shown in FIG. 1, the distribution of the plasma formed in the chamber 13 can be adjusted.

  Next, the cooling structure of the cooling plate 40 shown in FIGS. 2 to 6 will be described. 7 and 8 are views showing an example of a cross section of the cooling plate 40. FIG. For convenience of explanation, the yoke 21 and the heat transfer sheet 45 shown in FIG. 3 are simplified and shown in FIGS.

  As shown in FIG. 7, the cooling plate 40 disposed on the back side of the yoke 21 via the heat transfer sheet 45 has a groove 60 on the side (front side) in contact with the heat transfer sheet 45. The groove 60 is provided with a water cooling pipe 61 through which a cooling medium such as water flows. A gap between the water cooling pipe 61 and the groove 60 is filled with a sealing agent 62, and the water cooling pipe 61 is fixed inside the groove 60 by the sealing agent 62. Thereby, the cooling medium flowing through the water-cooled pipe 61 is generated by energizing the coils 23a, 23b, 23c, and 23d (see FIG. 3 and the like) via the yoke 21, the heat transfer sheet 45, and the sealant 62. Can be absorbed efficiently. The illustrated arrow A1 indicates the movement of heat. The cooling plate 40 is made of, for example, aluminum, and the water cooling pipe 61 is made of stainless steel (SUS) or the like.

  Further, the cooling plate 40 shown in FIG. 8 has a recess 65 on the side (front side) in contact with the heat transfer sheet 45, and a groove 60 is formed in the recess 65. A water cooling pipe 61 is provided in the groove 60. A gap between the water cooling pipe 61 and the groove 60 is filled with a sealing agent 62. Furthermore, a pressing plate 66 configured to press the water-cooled pipe 61 against the groove 60 is provided in the recess 65. The holding plate 66 is fixed to the cooling plate 40 by a holding screw 63. Thereby, the water-cooled pipe 61 is fixed in the groove 60 by the sealant 62 and the pressing plate 66. The heat generated by energizing the coils 23a, 23b, 23c, and 23d (see FIG. 3 and the like) passes through the yoke 21, the heat transfer sheet 45, and the sealant 62 in the same manner as the cooling plate 40 shown in FIG. Thus, it is efficiently absorbed by the cooling medium flowing through the water cooling pipe 61. Further, in the cooling plate 40 shown in FIG. 8, the pressing plate 66 can securely fix the water cooling pipe 61 in the groove 60.

  As described above, the electromagnet device 20 according to the present embodiment includes the epoxy resins 24a, 24b, 24c, 24d and the grooves 22a, 22b, 22c, provided on the radially outer sides of the coils 23a, 23b, 23c, 23d. Since the gaps 27a, 27b, 27c, and 27d are provided between the outer peripheral surface of 22d, the deformation of the yoke 21 due to the contraction of the epoxy resins 24a, 24b, 24c, and 24d can be suppressed. In addition, when a current is applied to the coils 23a, 23b, 23c, and 23d during the plasma processing, the coils 23a, 23b, 23c, and 23d generate heat, and the yoke 21 is heated. At this time, the stress caused by the difference in thermal expansion coefficient between the coils 23a, 23b, 23c, and 23d and the yoke 21 causes the epoxy resins 24a, 24b, 24c, and 24d to adhere to the outer peripheral surfaces of the grooves 22a, 22b, 22c, and 22d. It can be relaxed compared to the case.

  Further, since the release agent 29 is applied to the outer peripheral surfaces of the grooves 22a, 22b, 22c, 22d, when the epoxy resins 24a, 24b, 24c, 24d are thermally cured, the epoxy resins 24a, 24b, 24c, 24d are formed. It is easily peeled off from the outer peripheral surfaces of the grooves 22a, 22b, 22c and 22d. Therefore, the gaps 27a, 27b, 27c, and 27d can be easily formed while reducing the stress applied to the yoke 21.

In addition, in the electromagnet apparatus 20 which concerns on this embodiment, although the peeling agent 29 is used, it is not restricted to this. For example, by arranging spacers between the epoxy resins 24a, 24b, 24c, 24d provided on the radially outer side of the coils 23a, 23b, 23c, 23d and the outer peripheral surfaces of the grooves 22a, 22b, 22c, 22d, etc. Epoxy resin 2 in grooves 22a, 22b, 22c, 22d
The gaps 27a, 27b, 27c, and 27d may be formed by preventing the 4a, 24b, 24c, and 24 from adhering to the grooves 22a, 22b, 22c, and 22d.

  In the electromagnet device 20 according to the present embodiment, the coils 23a, 23b, 23c, and 23d are housed in the grooves 22a, 22b, 22c, and 22d, so the coils 23a, 23b, 23c, and 23d are the grooves 22a, 22b, and 22c. , 22d, the variation in the magnetic field distribution can be further suppressed as compared with the case where the magnetic field distribution is arranged so as to protrude from 22d.

  In the electromagnet device 20 according to the present embodiment, the coils 23a, 23b, 23c, and 23d are such that the central portions in the width direction of the coils 23a, 23b, 23c, and 23d are more radial than the center in the width direction of the grooves 22a, 22b, 22c, and 22d. It arrange | positions so that it may be located inside. As a result, the coils 23a, 23b, 23c, and 23d are arranged at positions closer to the yoke 21, so that the epoxy resins 24a, 23a, 23b, 23c, and 23d are formed from the radially inner side of the coils 23a, 23b, 23c, and 23d with no gap between them. Heat generated by energizing the coils 23a, 23b, 23c, and 23d through the 24b, 24c, and 24d can be efficiently transmitted to the yoke 21.

  In the electromagnet device 20 according to the present embodiment, the coils 23a, 23b, 23c, and 23d are such that the central portions in the depth direction of the coils 23a, 23b, 23c, and 23d are greater than the central portions in the depth direction of the grooves 22a, 22b, 22c, and 22d. It arrange | positions so that it may be located in the bottom part side. As a result, the coils 23a, 23b, 23c, and 23d are disposed closer to the yoke 21, so that heat generated by energizing the coils 23a, 23b, 23c, and 23d is generated by the epoxy resins 24a, 24b, 24c, and 24d. Is efficiently transmitted to the yoke 21.

  In the electromagnet device 20 according to the present embodiment, a resin having good heat resistance, for example, epoxy resins 24a, 24b, 24c, and 24d, is used as the thermosetting resin, so that the coils 23a, 23b, 23c, and 23d are energized. It can suppress that the intensity | strength of epoxy resin 24a, 24b, 24c, 24d falls by the heat | fever which generate | occur | produces by this. Further, since the epoxy resins 24a, 24b, 24c, and 24d have a relatively small coefficient of thermal expansion, the amount of expansion of the epoxy resins 24a, 24b, 24c, and 24d due to the heat generated by energizing the coils 23a, 23b, 23c, and 23d. Can be made relatively small, and fluctuations in the positions of the coils 23a, 23b, 23c, 23d due to expansion of the epoxy resins 24a, 24b, 24c, 24d can be suppressed. Further, since a resin having good (high) thermal conductivity, such as epoxy resins 24a, 24b, 24c, and 24d, is used as the thermosetting resin, heat generated by energizing the coils 23a, 23b, 23c, and 23d. Can be efficiently transmitted to the yoke 21. In this embodiment, an epoxy resin is used. However, the present invention is not limited to this, and other resins having good heat resistance and thermal conductivity can be used. Here, the thermosetting resin having good heat resistance and thermal conductivity used in the present embodiment desirably has a thermal conductivity of about 0.5 w / m · k or more, and has a glass transition temperature of about It is desirable to have heat resistance of 150 ° C. or higher.

  In the electromagnet device 20 according to the present embodiment, at least a part of the inner peripheral surfaces of the grooves 22a, 22b, 22c, and 22d has a tapered surface that increases in width as the depth of the grooves 22a, 22b, 22c, and 22d increases. Therefore, even if the radially inner side and the back side of the epoxy resins 24a, 24b, 24c, 24d are peeled from the grooves 22a, 22b, 22c, 22d, the epoxy resins 24a, 24b, 24c, 24d are formed in the grooves 22a, It is possible to prevent the coils 23a, 23b, 23c, and 23d from dropping from the grooves 22a, 22b, 22c, and 22d by being caught on the tapered surfaces of 22b, 22c, and 22d.

In the electromagnet device 20 according to the present embodiment, wirings for energizing the coils 23a, 23b, 23c, and 23d are disposed on the back side of the yoke 21 and the cooling plate 40 through the through holes 28a, 28b, 28c, and 28d. Thereby, the influence of the magnetic field produced by the wiring can be suppressed, and a uniform magnetic field can be formed in the circumferential direction on the front side of the electromagnet device 20.

  In the electromagnet device 20 according to the present embodiment, since the cooling plate 40 is disposed on the back side of the yoke 21, the heat generated by energizing the coils 23a, 23b, 23c, and 23d can be removed from the yoke 21. it can. Furthermore, since the electromagnet device 20 according to the present embodiment includes the heat transfer sheet 45 disposed between the back surface of the yoke 21 and the cooling plate 40, heat removal from the yoke 21 can be performed more efficiently.

  The electromagnet device 20 according to the embodiment described above is described as having four grooves 22a, 22b, 22c, 22d and four coils 23a, 23b, 23c, 23d, etc., but is not limited to this. There may be at least one of 22a, 22b, 22c, 22d and coils 23a, 23b, 23c, 23d and the like.

  In the embodiment described above, a plasma etching apparatus is used as an example of the plasma processing apparatus 10. However, the present invention is not limited to this, and an apparatus that uses a magnetic force to generate plasma, such as a sputtering apparatus or plasma CVD (Chemical Vapor Deposition). ) The electromagnet device 20 can be applied to a device or the like.

  As mentioned above, although embodiment of this invention was described, embodiment of the invention mentioned above is for making an understanding of this invention easy, and does not limit this invention. The present invention can be changed and improved without departing from the gist thereof, and the present invention includes the equivalents thereof. In addition, any combination or omission of each component described in the claims and the specification is possible within a range where at least a part of the above-described problems can be solved or a range where at least a part of the effect can be achieved. is there.

DESCRIPTION OF SYMBOLS 10 ... Plasma processing apparatus 20 ... Electromagnet apparatus 21 ... Yoke 22a, 22b, 22c, 22d ... Groove 23a, 23b, 23c, 23d ... Coil 24a, 24b, 24c, 24d ... Epoxy resin 27a, 27b, 27c, 27d ... Gap 28a , 28b, 28c, 28d ... through hole 29 ... release agent 40 ... cooling plate 44a, 44b ... tapered surface 45 ... heat transfer sheet 52a, 52b ... first wiring 53a, 53b ... second wiring

Claims (9)

An electromagnet device used in a plasma processing apparatus,
A yoke having an annular groove on the front surface;
An annular coil disposed in the groove;
A resin for enclosing the coil, fixing the coil to the yoke and transferring heat;
An electromagnet device, wherein a gap is provided between an outer peripheral surface of the groove of the yoke and the resin provided on the radially outer side of the coil.   The electromagnet device according to claim 1, wherein the coil is housed in the groove.   3. The electromagnet device according to claim 1, wherein the coil is disposed in the groove such that a central portion in the width direction of the coil is positioned radially inward from a center in the width direction of the groove.   The said coil is arrange | positioned at the said groove | channel so that the depth direction center part of the said coil may be located in the bottom part side from the depth direction center of the said groove | channel, It was described in any one of Claim 1 thru | or 3 Electromagnet device.   The electromagnet device according to any one of claims 1 to 4, wherein the resin is a resin having good heat resistance and thermal conductivity.   The at least part of the inner peripheral surface of the groove has a tapered surface formed so that the width of the groove becomes wider as the depth of the groove becomes deeper. Electromagnet device. Having wiring for energizing the coil;
The yoke has a through-hole penetrating the inside of the groove and the back side;
The electromagnet device according to claim 1, wherein the wiring is provided so as to pass through the through hole.   The electromagnet apparatus according to any one of claims 1 to 7, further comprising a cooling plate disposed on a back side of the yoke.   The electromagnet apparatus according to claim 8, further comprising a heat transfer sheet disposed between a back surface of the yoke and the cooling plate.

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