JP2011094180A - Magnet unit, and magnetron sputtering apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnet unit capable of easily regulating the film thickness distribution of a thin film to be deposited on a substrate without increasing the length or the width of a target. <P>SOLUTION: In the magnet unit, a first magnet element consisting of a first magnet and a second magnet having the polarity different from that of the first magnet is fixed on a first yoke plate provided in the short side direction of a cathode electrode; a third magnet, a fourth magnet and a fifth magnet are arranged respectively on a second yoke plate provided on both sides in the longitudinal direction of the cathode electrode; (n-1) pieces of projecting magnets (where n denotes a positive integer equal to or larger than 2) extend inward in the longitudinal direction of the second yoke plate from the inner side of the fourth magnet; (n) pieces of extending magnets are arranged on both sides of the projecting magnets with the predetermined spacing from the fourth magnet; and a magnetic track having (2n-1) pieces of folded-back sections on both ends in the longitudinal direction is formed on the target by the projecting magnets and the extending magnets. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a magnet unit and a magnetron sputtering apparatus, and more particularly to an improvement in the structure of a magnet unit arranged on the back side of the entire surface of a cathode that supports a target on the front side in sputtering, and a magnetron sputtering apparatus provided with the magnet unit.

  In the magnetron sputtering apparatus, a magnetron is generated on a target discharge surface by a magnet unit arranged on the back side of a cathode electrode that supports a target, and the plasma is confined and densified. Then, the plasma ions generated by this apparatus collide with the target, so that the target material is blown off and adheres to the substrate to form a thin film.

  Therefore, the film formation rate strongly depends on the electric field applied to the target and the leakage magnetic field strength. In particular, the magnetron strength of the magnet unit has a strong effect on the plasma density and affects the film thickness distribution of the thin film formed on the substrate. In general, the higher the magnetron intensity, the higher the plasma density of the corresponding target and the higher the sputtering rate, and the higher the deposition rate at the corresponding substrate position.

  FIG. 18A is an explanatory view showing a magnetron sputtering apparatus that forms a film while passing a substrate in front of a target (see Patent Document 1). In FIG. 18A, in this type of pass-through film forming system, the substrate 7 is passed through so as to be orthogonal to the longitudinal direction of a generally rectangular target 601. Therefore, there are few sputtered particles 112 from both ends in the longitudinal direction of the target 601, and the film thickness is reduced at both ends 111 of the substrate 7, leading to deterioration of the film thickness distribution. Therefore, as shown in FIG. 18B, in order to improve the deterioration of the film thickness distribution, the length in the longitudinal direction is increased like the target 602, and the decrease in film thickness is suppressed at both end portions 111 of the substrate 7. For this purpose, a cathode electrode and a magnet unit (not shown) have been expanded.

  However, lengthening the target to improve the film thickness reduction at both ends of the substrate increases the consumption of the target material and increases the running cost.

  From this point of view, various methods for adjusting the film thickness distribution of a thin film formed on a substrate have been proposed. For example, according to Patent Literature 2, a magnet unit composed of a bar magnet fixed in a substantially U-shape to each end of a yoke member on a flat plate made of a ferromagnetic material and a yoke material is appropriately fixed on the base plate. By doing so, it has been proposed that a desired magnetic field can be formed.

  FIG. 15 is a plan view of the magnetron unit described in Patent Document 2. FIG. The magnetron unit 230 includes a base plate 232 and a plurality of magnet units 234 fixed on the base plate in a predetermined arrangement. Each magnet unit has two magnetic pole ends 236 and 238 with different polarities that are oriented in the same direction and spaced apart from each other, and each magnetic pole end faces the opposite side of the base plate 232. Fixed to the base plate 232

  FIG. 16 is a schematic view of a sputtering apparatus applied to the magnetron unit. The sputtering apparatus 210 includes a housing 214 having a sputtering chamber 212 therein, and a circular target 216 disposed on the top of the housing 214. A wafer support pedestal 218 is provided in the housing 214, and the wafer 220 is supported on the wafer support pedestal 218, and is disposed opposite to and parallel to the lower surface of the target 216. A shield 222 is provided between the target 216 and the wafer 220 in order to prevent leakage of target atoms. In FIG. 16, 224 is a DC power source, 228 is a drive unit, 230 is a magnetron unit, 232 is a base plate, and 234 is a magnet unit.

  Further, in Patent Document 3, it is proposed that the first magnetic pole in a rectangular frame shape is provided with a rod-like second magnetic pole and an arm with an angle of 60 degrees is provided in the second magnetic pole short part in order to realize full surface erosion. ing.

  FIG. 17A is a partial view of a planar magnetron magnet device described in Patent Document 3. FIG. A planar magnetron magnet device shown in FIG. 17 includes a bar magnetic pole 302, arm magnetic poles 303 to 308 arranged perpendicular to the bar magnetic pole 302, arm magnetic poles 309 and 310, a magnet 316, and a frame. A segment 311, 312 and a side segment 313 are included. The two arm magnetic poles 309 and 310 positioned at the end of the bar magnetic pole 302 are arranged so as to be positioned at an angle α of about 60 degrees with respect to the vertical axis of the bar magnetic pole 302. The magnet 316 is disposed at the end of the bar magnetic pole 302. Also, arm magnetic pole 309 and arm magnetic pole 303, arm magnetic pole 303 and arm magnetic pole 304, arm magnetic pole 304 and arm magnetic pole 305, arm magnetic pole 310 and arm magnetic pole 306, arm magnetic pole 306 and arm magnetic pole 307, arm magnetic pole 307, arm magnetic pole 308 In between there are tongs 321-323, 314 and 324-326, 315 which are perpendicular to the frame segment 311 or 312 and face inward.

Special table 2007-525005 gazette JP-A-9-118980 JP 2006-291357 A

  FIG. 19 is a diagram showing a simplified magnet arrangement 100 for a rectangular target configured using the magnet unit 234 described in FIG. In the rectangular magnet both ends region 102, the magnet units 234 must be arranged so that the erosion track MT110 is folded back. By reducing the radius of curvature for arranging the 234, the number of magnet units 234 that can be arranged decreases, and the magnetic field strength in the region 102 decreases rapidly. When the magnetic field strength is reduced in the region 102, the number of sputtered particles reaching the substrate from the region 102 is reduced, which causes a problem that the film thickness distribution in the region 111 in FIG. 18 is deteriorated. In FIG. 18, when a ferromagnetic material containing at least one of iron, cobalt, and nickel is applied to the targets 601 and 602, the magnetic lines of force easily pass through the target. Due to the difficulty of leakage, the magnetic field strength in the region 102 is further lowered, and it is difficult to perform discharge ignition. That is, even if the magnet unit 234 is applied to the entire rectangular magnet, it is difficult to achieve the object of obtaining a good film thickness distribution regardless of the target material.

  In FIG. 19, in the central region of the magnet array 100, that is, the region 101 where the erosion track MT110 is a straight line, the magnet units 234 are fixed at positions facing each other. At this time, since the opposing magnet units 234 are arranged to have the same polarity, the proximity distance 103 of the opposing magnet units 234 is limited, and the width 104 of the two erosion tracks is widened. There is a problem that a non-erosion region occurs even when the operation is performed.

  In Patent Document 3, as shown in FIG. 17A, the two arm magnetic poles 309 and 310 positioned at the end of the bar magnetic pole 302 are positioned at an angle α of about 60 degrees with respect to the vertical axis of the bar magnetic pole 302. Since the magnet 316 is disposed at the end of the bar magnetic pole 302, the shape of the magnetic track return portion at the end of the magnet cannot be freely changed, and there is no room for adjustment of the film thickness distribution. It was. Further, in Patent Document 3, the tongs 321 to 323 and 314 and 324 to 326 and 315 facing inward are positioned between the arm magnetic pole 307 and the arm magnetic pole 308, so that the race track in the central portion has a waveform. As a result, the distance of the magnetic track is increased, which increases the amount of sputtered particles flying from the center of the magnet, resulting in deterioration of the film thickness distribution. Further, when the tongs 321 to 326 and 314 and 315 shown in FIG. 17A are removed, and further the arms 303 to 308 are removed, the race track 330 shown in FIG. 17B is formed, and the race track 320 shown in FIG. 17A is obtained. It is possible to shorten the race track length near the center of the magnet 301 as compared with the above. By doing so, sputtered particles from the target corresponding to the center of the magnet 301 can be relatively reduced. However, the race track length at the end of the magnet 301 is still short, for example, the region of FIG. There was a problem that the film thickness distribution could not be improved to suppress the film thickness decrease of 111.

  The present invention aims to solve the above problems, and more specifically, a thin film formed on a substrate regardless of the magnetic characteristics of the target, and without increasing the target length, width, or magnetic pole. An object of the present invention is to provide a magnet unit and a magnetron sputtering apparatus that can make the film thickness distribution uniform and make it easy to adjust the magnetic field distribution.

  The configuration of the present invention made to achieve the above object is as follows.

  A first yoke plate made of a rectangular parallelepiped magnetic body is provided on the back side of the cathode electrode that supports the rectangular parallelepiped target and in the short side direction of the cathode electrode, and is provided at both ends of the first yoke plate. A first magnet element including a first magnet formed between the first magnet and a second magnet having a polarity different from that of the first magnet is fixed on the first yoke plate, A plurality of magnet elements are arranged at predetermined intervals along the long side direction of the cathode electrode, and second yoke plates made of a rectangular parallelepiped magnetic body are provided on both sides in the longitudinal direction of the cathode electrode, A third magnet, a fourth magnet, and a fifth magnet are arranged along the contours of the three sides of the yoke plate other than that facing the first magnet element, and the second yoke plate Placed in the short side direction N−1 (n is a positive integer of 2 or more) projecting magnets are arranged extending from the inside of the fourth magnet toward the inside in the long side direction of the second yoke plate, N extending magnets are arranged at predetermined intervals on both sides of the projecting magnet, and the third magnet, the fourth magnet, and the fifth magnet having the same polarity as the first magnet are arranged. A magnet, the projecting magnet, and the extended magnet having a polarity different from that of the first magnet constitute a second magnet element, and the second magnet element is fixed on the second yoke plate, In the magnet unit, the projecting magnet and the extending magnet form a magnetic track having 2n-1 folded portions at both ends in the longitudinal direction of the magnetic track on the target. is there.

  According to the present invention, the n extended magnetic pole portions of the inner magnet and the n−1 protruding magnetic pole portions of the outer magnet have 2n−1 folded shapes at both ends in the longitudinal direction of the magnetic track. It is formed. Therefore, the lengths of both ends in the longitudinal direction of the magnetic track are supplemented by 2n−1 folded portions. Regardless of the magnetic properties of the target and without increasing the target length, the film thickness distribution of the thin film formed on the substrate can be made uniform. Further, since the n extended magnets are arranged in parallel with the fifth magnet and the third magnet, and n−1 protruding magnets are arranged between the n extended magnets 56, The shape of the folded portion of the magnetic track can be freely changed. And since two magnetic tracks are formed by the magnetic lines of force going from the second magnet to the first magnets arranged on both sides, the distance between the two magnetic tracks is reduced, and the occurrence of a non-erosion region is prevented. Is possible.

  Furthermore, when relatively increasing the amount of sputtered particles coming from both ends of the target, the necessary number of first magnet elements can be removed to relatively weaken the magnetic force inside the rectangular magnet and suppress the occurrence of spatter. And synergistic correction of the film thickness distribution can be performed. Further, by adjusting the distance between the first magnet and the second magnet of the first magnet element and the distance between the first magnet elements, the magnetic track at the center can be freely changed.

It is a mimetic diagram showing a schematic structure of a magnetron sputtering device concerning the present invention. It is the schematic which shows an example of the mechanism which lets the board | substrate which concerns on this invention pass. It is the schematic which shows the other example of the mechanism in which the board | substrate which concerns on this invention is passed. It is a perspective view which shows the structure of the 1st magnet element which concerns on this invention. It is a perspective view which shows the structure of the 2nd magnet element which concerns on this invention. It is a top view which shows the structure of the magnet unit of 1st Embodiment which concerns on this invention. It is explanatory drawing which shows the magnetic track formed with the magnet unit of 1st Embodiment which concerns on this invention. It is the schematic which shows the magnetic track | truck MT formed with the magnet unit of 1st Embodiment which concerns on this invention. It is the schematic which shows the fixing method of the 1st magnet element which concerns on this invention, and a 2nd magnet element. It is explanatory drawing which shows the dimension relationship of the target and board | substrate which concern on this invention. It is the figure which showed the film thickness distribution from the board | substrate center at the time of mounting the conventional magnet unit. It is the figure which showed the film thickness distribution from the board | substrate center at the time of mounting the magnet unit concerning this invention. It is the figure which showed the film thickness distribution from the board | substrate center at the time of mounting the magnet unit concerning this invention. It is a cross-sectional schematic diagram which shows the structure of the general CIS type | system | group (chalcopyrite type | system | group) solar cell manufactured with the magnetron sputtering apparatus concerning this invention. 6 is a plan view of a magnetron unit described in Patent Document 2. FIG. 10 is a schematic view of a sputtering apparatus applied to a magnetron unit described in Patent Document 2. FIG. 10 is a partial view of a planar magnetron magnet device described in Patent Literature 3. FIG. 10 is a partial view of a planar magnetron magnet device described in Patent Literature 3. FIG. It is explanatory drawing which shows the magnetron sputtering apparatus of patent document 1. It is explanatory drawing which shows the magnetron sputtering apparatus of patent document 1. It is the figure which simplified and showed the magnet arrangement | sequence 100 of patent document 2. As shown in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the embodiments.

  First, a magnetron sputtering apparatus according to the present invention will be described with reference to FIGS. The magnetron sputtering apparatus 1 (hereinafter referred to as “sputtering apparatus”) of this embodiment is common as an apparatus on which a magnet unit 60 described later is mounted. FIG. 1 is a schematic diagram showing a schematic configuration of a magnetron sputtering apparatus according to the present invention. FIG. 2 is a schematic view showing an example of a mechanism for passing the substrate. FIG. 3 is a schematic view showing another example of a mechanism for passing a substrate.

As shown in FIG. 1, the sputtering apparatus 1 of this embodiment is equipped with the vacuum vessel 2 which partitions the process chamber which can be evacuated. An exhaust device such as an exhaust pump is connected to the exhaust port 3 of the vacuum vessel 2 via a conductance valve (not shown). The vacuum vessel 2 is connected with a gas introduction system 4 having a flow rate controller or the like as means for introducing a processing gas (process gas), and the processing gas is supplied from the gas introduction system 4 at a predetermined flow rate. As the processing gas, a single gas or a mixed gas containing a rare gas such as argon (Ar), nitrogen (N ₂ ), or the like can be used.
The vacuum vessel 2 includes a stage 5 that supports the substrate, and a cathode electrode (not shown) that is disposed so as to face the substrate and supports the target 6 on the front side.

  As a material of the target 6 supported on the front side of the cathode electrode, for example, a material having a single composition such as tantalum (Ta), copper (Cu), titanium (Ti), or 2 such as GeSbTe, NiFe, or CoPt is used. The thing of the composite composition which consists of the above composition can be used. The target 6 may be a non-magnetic material such as Ta or Cu, or a magnetic material such as NiFe or CoPt. The target 6 of this embodiment is a rectangular (rectangular) plate material, for example, and is joined to the front surface (lower surface) of the main body of the cathode electrode.

  The cathode electrode is connected to, for example, a high-frequency power source capable of applying a variable voltage via a matching circuit (none is shown). A magnet unit 60 is disposed on the back side of the cathode electrode, and plasma can be formed at a high density by the magnet unit 60. That is, in the sputtering apparatus 1 of the present embodiment, a processing gas is introduced into a processing chamber in the vacuum vessel 2, a high voltage is applied to the cathode electrode from a high frequency power source or the like (discharge power), and the cathode electrode is applied by the magnet unit 60. To form a magnetic field. Thereby, the sputtering apparatus 1 generates plasma in the processing chamber and forms a thin film of the target material on the substrate. Of course, plasma may be generated by direct current discharge, pulse discharge, or the like. The detailed structure of the magnet unit 60 will be described later.

  Further, as shown in FIG. 2, a transport mechanism 8 that allows the substrate 7 to pass therethrough is disposed in front of the target 6. The transport mechanism 8 for the substrate 7 is constituted by, for example, a strip-shaped guide rail. The guide rail 8 extends in a direction orthogonal to the longitudinal direction of the target 6, supports a plurality of substrates 7 thereon, and sequentially guides them onto the stage 5. In the sputtering apparatus 1 of this embodiment, the film is formed while the substrate 7 to be processed passes in front of the target 6. The sputtering apparatus 1 can simultaneously perform sputtering and substrate conveyance. The stage 5 may include a heating mechanism (not shown) such as a heater, or a cooling mechanism (not shown) such as a refrigerator.

  An example of the substrate 7 is a semiconductor wafer, and the substrate 7 is guided on the guide rail 8 in a state of only the substrate or mounted on a tray.

  As shown in FIG. 3, the transport mechanism 9 for the substrate 7 is constituted by a stage rotation mechanism that rotates, for example, a circular stage 5 that supports the substrate 7 along a circle whose tangent is the placement surface. May be. In this configuration example, the stage 5 has a rotating shaft 9 a extending along the longitudinal parallel direction of the rectangular target 6, and the front of the target 6 is placed in front of the substrate 7 by rotating the stage 5 around the rotating shaft 9 a. Pass through.

[First Embodiment]
Next, with reference to FIGS. 4-6, the magnet unit 60 of 1st Embodiment mounted in the said sputtering apparatus 1 is demonstrated. FIG. 4 is a perspective view showing the configuration of the first magnet element of the first embodiment. FIG. 5 is a perspective view showing the configuration of the second magnet element of the first embodiment. FIG. 6 is a plan view showing the configuration of the magnet unit of the first embodiment.

  As shown in FIG. 5, the second magnet element 51 of this embodiment includes a second yoke plate 59 made of a ferromagnetic plate material. Magnets 52, 53, and 54 having the same polarity (the upper end is N pole and the lower end is S pole) in order along the contour on the second yoke plate 59 (the third magnet, the fourth magnet, and the fifth magnet, respectively) Magnets) are sequentially placed in a U-shape 501, of which, from the fourth magnet 53, n is parallel to the third magnet 52 and the fifth magnet 54 and perpendicular to the fourth magnet 53. −1 (n is a positive integer greater than or equal to 2) protruding magnets 55 having the same pole extend. In this embodiment, n = 2, and n-1 = 1 projecting magnet is provided.

  The inner magnet 502 arranged inside the U-shaped outer peripheral magnet 501 extends toward the fourth magnet 53 in parallel with the third magnet 52 and the fifth magnet 54 and in parallel with the fourth magnet. N extending magnets 56 are provided which are in close proximity to the fourth magnet 53 of the U-shaped outer peripheral magnet 501. Specifically, the internal magnet 502 has the extended magnet 56 at its end and includes n−1 long piece magnets 57. In this embodiment, n = 2, n = 2 extending magnets 56 (the upper end is S pole and the lower end is N pole), and n-1 = 1 long magnet 57 (the upper end is S pole and the lower end). Has N poles).

  The internal magnet 502 includes n−1 long magnets 57 and n−1 or more coupled magnets 58 that connect the n extended magnetic poles 56. In this embodiment, one long piece magnet 57 is connected to two extended magnetic poles 56 by two coupled magnets 58, but one coupled magnet 58 parallel to the fourth magnet is provided. It may be provided between the long piece magnet 57 and the two extended magnets 56. The long piece magnet 57, the combined coupling magnet 58, and the extended magnetic pole 56 have the same polarity (the upper end is the S pole and the lower end is the N pole).

  Alternatively, the long piece magnet 57 may be omitted, and the coupling end of the coupling magnet 58 may be brought to the end of the second magnet element 51 opposite to the fourth magnet. At this time, since the distance between the coupling magnet 58 and the protruding magnet 55 increases, it is possible to extend the folding distance by suppressing the decrease in the magnetic field intensity by extending the protruding magnet 58. In any case, in order to generate the folded shape, the overlapping amount of the protruding magnet 55 and the extending magnet 56 extending in parallel with the fourth magnet 53 is preferably 5 mm or more. This is because a plurality of wraps are not generated below this.

  Further, the third magnet 52 and the fifth magnet 54 are perpendicular to the fourth magnet 53 so as to be positioned between the n extended magnets 56 from the fourth magnet 53 of the U-shaped magnet 501. The n−1 protruding magnets 55 are protruded inwardly in parallel with each other. In the present embodiment, since two extending magnets 56 are arranged, one protruding magnet 55 protrudes inside both ends of the U-shaped magnet 501. As described above, since the two extending magnets 56 are arranged in parallel with the fifth magnet 54 and the third magnet 52 and the protruding magnet 53 is arranged between the two extending magnets 56, the end portion The shape of the folded part of the race track can be freely changed.

  Next, the first magnet element will be described with reference to FIG. As shown in FIG. 4, the first magnet element 41 has first magnets 42 and 44 (the upper end is N pole and the lower end is S pole) fixed to both ends of a rectangular yoke plate 45, and the first magnet element 41 has a first magnet element 41 at the center of the yoke plate 45. Two magnets 43 (the upper end is an S pole and the lower end is an N pole) are fixed, and the first magnet and the second magnet have different magnetic poles.

  Next, the whole structure of the 1st magnet element 41 and the 2nd magnet element 51 is demonstrated using FIG. FIG. 6 shows a combination magnet unit 60 in which the first magnet element 41 and the second magnet element 51 are combined. The second magnet element 51 is installed at both ends on the base plate 61 so that the fourth magnet 53 faces the outermost side, and the first magnet element 41 is fixed in parallel therebetween. In this embodiment, twelve first magnet elements 41 are fixed between two second magnet elements 51 disposed at both ends. In addition, the space | interval of the 1st magnets 42 and 44 of the 1st magnet element 41 and the 2nd magnet 43, and the space | interval of the 1st magnet element 41 can each be adjusted suitably. Thereby, the magnetic track in the center can be freely changed.

  In FIG. 6, the first magnet 42, the third magnet 52, the fourth magnet 53, the fifth magnet 54, and the protruding magnet 56 have the same polarity, the second magnet 43 having the same polarity, the long piece magnet 57, and the extension. The respective magnets are arranged so as to have a different polarity from the magnet 55 and the coupling magnet 58.

  That is, the magnet unit 60 of the first embodiment includes an outer magnet group 62 and an inner magnet group 63, and the outer magnet group 62 and the inner magnet group 63 are in a different polarity relationship. For this reason, the magnetic track MT generated on the target is formed with n n protruding magnets and n−1 extending magnets so as to form 2n−1 folded portions at both ends in the longitudinal direction of the magnetic track MT. It becomes possible to do.

  The magnetic track MTL (FIG. 6) other than the folded shape portion of the magnetic track MT will be described. Most of the magnetic flux constituting the magnetic track MTL is generated from the first magnet element 41. For this reason, it is possible to increase or decrease the number of the first magnet elements 41 to increase or decrease the magnetic flux density on the magnetic track MTL and adjust the generation amount of sputtered particles. For example, if the number of installed first magnet elements 41 is reduced, the magnetic flux density of the folded portion of the magnetic track MT is relatively increased, so that it is possible to increase sputtered particles from both ends of the magnet unit 60. .

  In the present invention in which a plurality of first magnet elements 41 can be arranged, the second magnet elements 51 can be extended in the longitudinal direction of the magnet unit 60, in other words, in the arrangement direction of the first magnet elements 41. For example, when it is desired to further expand the folded portion of the magnetic track MT, that is, when the overlapping amount of the protruding magnet 55 and the extending magnet 56 is to be increased, the longitudinal extension of the second magnet element 51 is set to the number of the first magnet elements. This can be done by omitting or shortening the arrangement distance.

  Next, the operation of the magnet unit 60 of the first embodiment will be described with reference to FIG. FIG. 7B is an explanatory diagram showing a state of formation of magnetic lines of force of a general magnet unit. FIG. 8 is an explanatory diagram showing a magnetic track formed by the magnet unit of the first embodiment.

  As shown in FIG. 7A, the outer peripheral magnet 62 and the inner magnet 63 generate a large number of curved magnetic field lines (magnetrons) M on the front surface of the target 6. As shown in FIG. 7B, a magnetic track MT that is a set of regions parallel to the target surface among the tangent lines of the magnetic force lines M generated on the target is formed.

  In the magnet unit according to the present invention, as shown in FIG. 6, n extending magnets 56 are extended to both ends of the inner magnet 63, and the inner ends of the outer peripheral magnet 62 are directed inward in the longitudinal direction. n-1 protruding magnets 55 are protruded. Therefore, 2n-1 folded shapes are formed by the n extending magnets 56 and the n-1 protruding magnets 55 at both ends in the longitudinal direction of the magnetic track MT. In the magnet unit 60 of the present embodiment, since two extending magnets 56 and one protruding magnet 55 are alternately arranged at each end, as shown in FIG. 8, the longitudinal direction of the magnetic track MT Thus, three wavy folded portions U are formed at both ends.

  The numbers of the extending magnets 56, the protruding magnets 55, and the folded-back portion U in the present embodiment are examples, and the present invention can be understood by substituting a positive integer of 2 or more for n. For example, when there are three extending magnets 56, there are two projecting magnets 55 positioned between adjacent extending magnets 56, and five folded portions U are formed at both ends in the longitudinal direction of the magnetic track MT. The Similarly, when there are four extending magnets 56, there are three projecting magnets 55 positioned between adjacent extending magnets 56, and seven folded portions U are formed at both ends in the longitudinal direction of the magnetic track MT. Is done.

  Thus, according to the magnet unit 60 of the first embodiment, the magnetic track length can be adjusted without changing the target width and the target length. That is, in the present embodiment, the magnetic track lengths at both ends of the target can be extended by appropriately changing the protruding lengths of the extending magnets 56 at both ends and the protruding magnets 55 provided on both inner sides of the outer peripheral magnet 501.

  Therefore, the magnetic field lines at both ends in the longitudinal direction of the magnetic track MT are supplemented by the number 2n-1 of the folded portions U, so that the target length can be increased on the substrate 7 regardless of the magnetic characteristics of the target 6 and without increasing the target length. The film thickness distribution of the thin film to be formed can be made uniform.

  Further, when the magnet unit 60 of the present embodiment is mounted on the sputtering apparatus 1 that can transport the substrate 7 in a direction orthogonal to the longitudinal direction of the target 6, the film thickness of the outer peripheral portion of the substrate corresponding to the longitudinal direction of the target 6 is reduced. Can be suppressed.

  Next, a method for fixing the first magnet element 41 and the second magnet element 51 will be described with reference to FIG. FIG. 9A is a view of the magnet unit 60 shown in FIG. 6 as viewed from the “arrow view of (A)”. A screw hole 91 is arranged on the surface opposite to the magnet fixing surface in both the yoke portions 45 and 59 of the first and second magnet elements. The number of screw holes may be prepared in a number suitable for the repulsive force between magnets and the attractive force to the target.

  Next, in the base plate 61 for fixing the first and second magnet elements, a through hole 92 larger than the screw hole diameter and a countersink hole 93 of a size that can accommodate the screw head are arranged on a common axis. The first and second magnet elements are fixed to the base plate by screws 94.

  Another fixing method will be described with reference to FIG. FIG. 9B is a view of the magnet unit 60 shown in FIG. 6 as viewed from the “arrow view of (B)”. A rectangular protrusion 96 is disposed on the surface of the yoke portion 45 of the first magnet element 41 opposite to the magnet fixing surface, while a rectangular groove 95 is disposed on the base plate. The rectangular groove width 95 is wider than the rectangular protrusion width 96 and can be fitted. As a result, the first magnet element 41 can be inserted by sliding from the side surface of the base plate, the magnet can be easily attached and detached, and it does not collide with other magnets.

  Instead of the rectangular protrusion or the rectangular groove, the protrusion 98 having a trapezoidal cross section or the groove 97 having a trapezoidal cross sectional shape may be used.

  Of course, also in this case, a screw hole 91 is provided in the projecting portion, and a through hole 92 and a counterbore hole 93 are provided coaxially in the base plate and can be fixed by screws 94.

  As described above, according to the magnet unit 60 of the present embodiment, it is possible to increase the erosion track length at both ends of the target in the longitudinal direction as compared with the conventional magnet unit. Therefore, according to the magnet unit 60 of the present embodiment, the number of sputtered particles from both ends of the target is larger than that of the conventional magnet unit, and the film due to the decrease in film thickness in the region 111 in FIG. Deterioration of the thickness distribution can be suppressed.

  In order to increase target utilization efficiency, the magnet unit 60 may be swung along the longitudinal direction.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these Examples.

[Example 1]
In the first embodiment, a plurality of silicon substrates are supported on the guide rail using the sputtering apparatus 1 in FIG. 1 and the transport mechanism (guide rail) 8 in FIG. 2, and the guide rail is set in a direction orthogonal to the longitudinal direction of the target. A CoPt magnetic film was formed on each substrate.

  A CoPt alloy was used as the target 6 supported by the cathode electrode, and Ar gas was introduced into the vacuum vessel 2 as a processing gas.

  FIG. 11 is an explanatory diagram showing the film formation state of the embodiment in the prior art. As shown in FIGS. 11A and 11B, when a conventional magnet unit is mounted on the sputtering apparatus 1, the film thickness is reduced at the outer peripheral portion of the substrate corresponding to both ends of the target 6 in the longitudinal direction (x direction). Was seen.

  On the other hand, as shown in FIGS. 12A and 12B, when the magnet unit 60 according to the embodiment of the present invention is mounted on the sputtering apparatus 1, folded portions U are formed at both ends of the magnetic track MT. . As a result, the length of the magnetic track is increased, and the magnetic lines of force at both ends of the magnetic track MT are reinforced and extended, so that a decrease in film thickness at the outer periphery of the substrate corresponding to both ends in the longitudinal direction of the target 6 can be suppressed.

  As described above, by using the magnet unit 60 according to the present invention, the magnetic lines of force at both ends in the longitudinal direction of the target 6 are reinforced and extended, and the sputtered particles from both sides in the longitudinal direction of the target 6 are relatively increased. The film thickness distribution deposited on the passing substrate is improved without stretching.

  FIG. 10 is an explanatory diagram showing the dimensional relationship between the target and the substrate.

When performing film formation with a good film thickness distribution using conventional technology,
W / P ≧ 2.8
W / D ~ 4.5
W / T ≧ 7
This dimension is common.

  For example, P = 200 mm, W = 600 mm, D = 130 mm, and T = 80 mm.

On the other hand, when the present invention is applied,
2.5 ≧ W / P ≧ 1.7
W / D ~ 4.5
6.3 ≧ W / T ≧ 4.3
With this dimension relationship, a distribution of Range / Mean <3% was obtained. In other words, the effect of increasing the magnetic field strength at both ends means that the target width (W) can be reduced and the running cost can be reduced. In this dimension, the target was used at 50 kWh, but no non-erosion region was generated on the target surface.

  The dimensions of the magnet unit 60 mainly used in this example were 430 mm in the longitudinal direction, 90 mm in the direction perpendicular to the longitudinal direction, and 12 first magnet elements.

[Example 2]
In the second embodiment, among the twelve first magnet elements 41 as shown in FIG. 13, a total of two second first magnet elements 41 are removed from the center of the magnet unit 60 to weaken the magnetic field near the center of the magnet unit 60. This indicates that the film thickness distribution can be easily improved.

As a result, the magnetic field intensity at the center of the magnet unit 60 decreased by about 20%, and a film thickness distribution as shown in FIG. 13B was obtained. This is because the magnetic field strength at the center portion decreases, so that the sputtered particles from both sides in the longitudinal direction of the target 6 relatively increase, and the film thickness distribution deposited on the passing substrate is improved without increasing the target length. The Further, when the target surface was confirmed after the target was used for 64 kWh, no non-erosion region was generated.

The sputtering apparatus of the present invention is not limited to the magnetic film formation shown in Examples 1 and 2, and can be used for manufacturing solar cells, for example. A CIS solar cell that has recently been attracting attention will be described as an example. FIG. 14 is a schematic cross-sectional view showing the structure of a general CIS solar cell. The sputtering apparatus of the present invention forms a lower electrode 172 (for example, Mo film) on the substrate 171, forms a p-type semiconductor layer 173 (for example, Cu (In, Ga) Se ₂ ) on the lower electrode 172, and vapor deposition method. For example, it can be used for forming a transparent electrode 175 (for example, ITO (Indium Tin Oxide)) on an n-type semiconductor layer 174 (for example, CdS). In addition, the sputtering apparatus of the present invention can be used as long as sputtering film formation can be applied to the antireflection film 176, for example. Further, by arranging a plurality of magnet units of the present invention in a direction perpendicular to the longitudinal direction and swinging them, uniform film formation on a large substrate becomes possible.

  The present invention can be applied not only to the magnetron sputtering apparatus illustrated but also to plasma processing apparatuses such as a dry etching apparatus, a plasma asher apparatus, a CVD apparatus, and a liquid crystal display manufacturing apparatus. In addition to the exemplified magnetic films and solar cells, materials used for film formation in HDD head processes such as oxide films and nitride films can also be developed.

DESCRIPTION OF SYMBOLS 1 Magnetron sputtering apparatus 2 Vacuum container 6 Target 7 Substrate 8, 9 Conveyance mechanism 41 1st magnet element 42, 44 1st magnet 43 2nd magnet 45 Yoke 51 2nd magnet element 52 3rd magnet 53 4th magnet 54 5th magnet 55 Projection magnet 56 Extension magnet 57 Long piece magnet 58 Coupling magnet 59 Yoke 60 Magnet unit 61 Base plate 62 Outer magnet 63 Internal magnet M Magnetic field line MT Magnetic track U Folding shape

Claims (8)

  A first yoke plate made of a rectangular parallelepiped magnetic body is provided on the back side of the cathode electrode that supports the rectangular parallelepiped target and in the short side direction of the cathode electrode, and is provided at both ends of the first yoke plate. A first magnet element including a first magnet formed between the first magnet and a second magnet having a polarity different from that of the first magnet is fixed on the first yoke plate, A plurality of magnet elements are arranged at predetermined intervals along the long side direction of the cathode electrode, and second yoke plates made of a rectangular parallelepiped magnetic body are provided on both sides in the longitudinal direction of the cathode electrode, A third magnet, a fourth magnet, and a fifth magnet are arranged along the contours of the three sides of the yoke plate other than that facing the first magnet element, and the second yoke plate Placed in the short side direction N−1 (n is a positive integer of 2 or more) projecting magnets are arranged extending from the inside of the fourth magnet toward the inside in the long side direction of the second yoke plate, N extending magnets are arranged at predetermined intervals on both sides of the projecting magnet, and the third magnet, the fourth magnet, and the fifth magnet having the same polarity as the first magnet are arranged. A magnet, the projecting magnet, and the extended magnet having a polarity different from that of the first magnet constitute a second magnet element, and the second magnet element is fixed on the second yoke plate, 2. A magnet unit, wherein a magnetic track having a number of folded portions of 2n-1 on both ends in a longitudinal direction is formed on the target by the protruding magnet and the extending magnet.   The said 3rd magnet, the 4th magnet, and the 5th magnet are arrange | positioned in the U-shape along the outline of 3 sides of the said 2nd yoke board, The said 1st magnet is characterized by the above-mentioned. Magnet unit.   The projecting magnet is arranged in parallel with the third magnet and the fifth magnet and perpendicular to the fourth magnet, and inward from the fourth magnet. The magnet unit according to 1 or 2.   The extending magnet is arranged in parallel with the third magnet and the fifth magnet so as to have a predetermined distance from the fourth magnet and to have an overlapping portion of 5 mm or more with the protruding magnet. The magnet unit according to claim 1, wherein the magnet unit is provided.   Between the extended magnets, n−1 internal magnets are arranged in parallel with the third magnet and the fourth magnet at a predetermined interval from the extended magnet, and the internal magnet and the extended magnet are arranged. The magnet unit according to claim 1, wherein n-1 or more coupled magnets are coupled to each other.   The magnet unit according to any one of claims 1 to 5, wherein the first magnet element and the second magnet element can be fixed to and detached from a base plate.   A groove is formed in the base plate, and the groove is formed in the first yoke plate on the side opposite to the side where the first magnet and the second magnet of the first magnet magnet element are fixed. The magnet unit according to any one of claims 1 to 6, wherein a rectangular protrusion that fits into the shape is formed. In a processing chamber that can be evacuated,
A substrate to be processed;
A cathode electrode that is arranged to face the substrate, supports the target, and is supplied with electric power for discharge;
A transport mechanism for passing the substrate in front of the target;
With
A magnetron sputtering apparatus, wherein the magnet unit according to any one of claims 1 to 7 is disposed on a back side of the cathode electrode.