`
`(19) Japan Patent Office (JP) (12) Unexamined Patent Application Publication (A)
`
` (11) Unexamined Patent Application No. H10 (1998)-102247 (P2015-171425A)
`
`(43) Publication Date: 21 April 1998
`
`
`
`_________________________________________________________________________________________________________
`(51) Int. Cl.6
`
`
`
`ID No.
` F1
`
`
`
`C23C 14/35
`C23C 14/35 C
`
`
`
`
` Search Requested: Not yet. No. of Claims: 20 OL (Total pages: 11)
`
`
`
`
`
`(21) Application No. H8 (1996)-261643
`(71) Applicant 000005821
`(22) Application Date 02 October 1996
`
` MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
` 1006, Oaza Kadoma, Kadoma-shi, Osaka
`(72) Inventor AOKURA, ISAMU
`
` Matsushita Electric Industrial Co., Ltd.
` 1006, Oaza Kadoma, Kadoma-shi, Osaka
`(72) Inventor YAMANISHI, Hitoshi
` Matsushita Electric Industrial Co., Ltd.
` 1006, Oaza Kadoma, Kadoma-shi, Osaka
`(74) Agent Attorney AOYAMA, Tamotsu (and 2 others)
`(cid:3)
`
`(cid:3)
`
`(cid:3)
`
`(54) [Title of the Invention] Device and Method for Sputtering
`
`
`
`
`
`(57) [Abstract]
`PROBLEM TO BE SOLVED. To provide a sputtering
`device and method for holding a target, capable of
`making the progression of erosion on a target occur in an
`approximately uniform manner.
`SOLUTION. A magnet 10 is placed along one edge of
`a target 6, and a facing magnet 10 sandwiching the
`target 6 is set to have the same polarity. Also, the
`progression of erosion on the target 6 becomes
`approximately uniform by configuring a magnet 14
`placed on the rear side surface of the target 6 to face the
`rear side surface of the target 6 with a polarity different
`from the polarity of the facing magnets 10 that are
`sandwiching the target 6, and also such that the magnet
`14 is able to move, back and forth, in an orthogonal
`direction 91 to the one edge of the target.
`
`Page 1 of 24
`
`APPLIED MATERIALS EXHIBIT 1068
`
`

`

`CLAIMS
`[Claim 1] A sputtering device for sputtering using a
`rectangular target 6, characterized by rod-shaped first
`magnets 10 being placed along each of a pair of edges of
`the target 6, as well as by a rod-shaped second magnet 14
`being placed so as to be movable on the rear side surface
`of the target.
`[Claim 2] The sputtering device of claim 1, the polarity
`of the first magnets 10 being arranged such that like poles
`are facing, and the second magnet 14 being set with a
`pole facing the rear surface of the target that differs from
`the magnetic pole with which the first magnets face one
`another.
`[Claim 3] The sputtering device of claim 1 or claim 2,
`the second magnet 14 being set on the rear side surface
`of the target so as to move back and forth in a range
`corresponding to between the first magnets 10.
`[Claim 4] The sputtering device of any of claims 1-3, the
`second magnet 14 being configured from a plurality of
`rod-shaped magnets.
`[Claim 5] A sputtering device that performs sputtering
`using a round target 46, characterized by a third magnet
`15 being placed facing an edge of the target and a fourth
`magnet 16 being placed on the rear side surface of the
`target so as to be able to move in an approximately
`circular pattern.
`[Claim 6] The sputtering device of claim 5, the polarity
`of the third magnet 15 being set such that like poles face
`the center of the target, and the fourth magnet 16 being
`set to face the rear side surface of the target with a pole
`that differs from the pole with which the third magnets
`face the center of the target.
`[Claim 7] The sputtering device of claim 5 or claim 6,
`the fourth magnet 16 being a plurality of magnets.
`[Claim 8] The sputtering device of any of claims 5-7, the
`fourth magnet 16 being configured to move in a spiraling
`pattern.
`[Claim 9] A sputtering device for sputtering using a
`round
`target 46, characterized by a plurality of
`electromagnets 17, 57 being placed facing an edge of the
`target and by being configured such that the magnetic
`polarity of the electromagnets temporally changes.
`[Claim 10] The sputtering device of claim 9, the
`electromagnet being configured such that poles facing
`the inside of the target can be independently controlled.
`[Claim 11] The sputtering device of claim 9 or claim 10,
`the number of electromagnets being an even number of
`four or greater.
`[Claim 12] The sputtering device of any of claims 9-11,
`the coil of the electromagnet being in the atmosphere side
`
`of a vacuum chamber.
`[Claim 13] A sputtering method for sputtering using a
`rectangular target 6 in a state in which, in addition to rod-
`shaped first magnets 10 being placed along each of a pair
`of edges of a target 6, a rod-shaped second magnet 14 is
`placed so as to be movable on the rear side surface of the
`target,
`characterized by sputtering being performed while the
`second magnet is made to move on the rear side surface of
`the target, the direction of the magnetic flux being
`temporally changed, and the plasma density on the surface
`of the target being made temporally approximately
`balanced.
`[Claim 14] The sputtering method of claim 13, the
`polarity of the first magnets being arranged such that like
`poles are facing, and the second magnet 14 being set with
`a pole facing the rear surface of the target that differs from
`the magnetic pole with which the first magnets are facing
`one another.
`[Claim 15] The sputtering method of claim 13 or claim
`14, the second magnet 14 being on the rear side surface
`of a target and configured to move in a spiraling pattern
`in a range corresponding to between the first magnets 10.
`[Claim 16] A sputtering method for sputtering in a state in
`which, in addition to a third magnet 15 being placed facing
`an edge of the target, a fourth magnet 16 is placed so as to
`be movable on the rear side surface of the target,
`characterized by sputtering being performed while the
`fourth magnet moves in an approximately circular pattern
`on the rear side surface of the target, temporally changing
`the direction of magnetic flux and making plasma density
`on the target surface temporally balanced.
`[Claim 17] The sputtering method of claim 16. the
`polarity of the third magnets 15 being set such that like
`poles face the center of the target and the fourth magnet 16
`being set with a pole facing the rear surface of the target
`that differs from the pole with which the third magnets
`face the center of the target.
`[Claim 18] The sputtering method of claim 16 or claim 17,
`the fourth magnet 16 being configured so as to move in a
`spiraling pattern.
`[Claim 19] A sputtering method for sputtering with a
`round target 46 in a state in which a plurality of
`electromagnets 17, 57 are placed facing an edge of the
`target, characterized by the magnetic polarity of the
`electromagnets being temporally changed, the direction of
`magnetic flux being changed, and the direction 93 from
`which electrons inside the plasma receive force being
`changed, and the plasma density on the target surface
`being made approximately uniform when averaged over
`
`Page 2 of 24
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`

`

`time.
`[Claim 20] The sputtering method of claim 19, the
`direction of magnetic flux being changed by temporally
`changing the magnetic polarity of the electromagnet, and
`plasma density on the target surface temporally made
`approximately uniform when averaged over time, by
`rotating 360 degrees the direction 93 from which
`electrons in the plasma receive force.
`
`DETAILED DESCRIPTION OF THE INVENTION
`
`[0001]
`TECHNICAL FIELD TO WHICH THE INVENTION
`BELONGS. The present
`invention pertains
`to a
`magnetron sputtering device and method, one technology
`for forming thin film.
`[0002]
`CONVENTIONAL TECHNOLOGY. A sputtering
`method is a method for producing thin film by generating
`plasma and causing the positive ions of the plasma to
`collide with a target mounted on a negative electrode
`called a cathode. Particles sputtered by the collision adhere
`to the substrate and form a thin film. This sputtering
`method is widely used in film creation processes because
`it is relatively simple to control the composition and to
`operate the device. However, conventional sputtering
`methods have the drawback of being slow to generate film
`in comparison to vacuum deposition methods. Magnetron
`sputtering methods, which use a permanent magnet or
`electromagnet in a magnetic circuit to form a magnetic
`field near a target, were designed for this reason. These
`methods improve the speed of thin film formation and
`make it possible to use sputtering methods in mass
`production processes, manufacturing semiconductor and
`electronic components and the like.
`[0003] Because magnetron sputtering methods have
`problems with inconsistencies in film thickness and
`quality due to localized erosion on the target, devices
`were invented to form an even magnetic field orthogonal
`to an electric field. Fig. 20 shows the configuration of a
`conventional sputtering device. In Fig. 20, 1 indicates a
`chamber, 2 is a vacuum exhaust port of the chamber 1 for
`exhausting with a vacuum pump, 3 is a pipe for
`introducing gas into the chamber 1, and 4 is a gas flow
`control device mounted on the gas introduction pipe 3.
`The number 5 indicates discharge gas introduced into the
`chamber 1 from the gas introduction pipe 3. The number 6
`indicates a target, 7 is a sputtering electrode, 8 is a
`discharge power supply, 9 is a magnet holder, 10 is a
`magnet, and 11 is a substrate holder. The number 12
`indicates a substrate upon which a thin film is formed.
`
`[0004] The operations of a sputtering device configured as
`above are explained below. First, a vacuum pump is used
`to exhaust the inside of the chamber 1 from the vacuum
`exhaust port to a level of 10-7 Torr. Next, discharge gas 5 is
`introduced into the chamber 1 through the gas introduction
`pipe 3 connected to one end of the chamber 1, maintaining
`pressure inside the chamber 1 at 10-2 — 10-3 Torr. A
`negative voltage or high frequency voltage is applied to the
`target 6 attached to the sputtering electrode 7 from a DC or
`high-frequency power supply for sputtering 8, and the
`electric field from the power supply 8 and the magnetic
`field from the magnet 10 housed in the magnet holder 9
`work to generate plasma from discharge close to the front
`surface of the target 6. The phenomenon of sputtering
`occurs, and with the sputter particles released from the
`target 6 a thin film is formed on a substrate 12 placed in a
`substrate holder 11. However, with a sputtering device
`when a target 6 is a ferromagnetic material a large portion
`of magnetic flux generated from a magnet 10 passes
`through the inside of the target 6, and very little magnetic
`flux contributes to plasma formation. This causes a
`problematic decrease in the speed of film creation. Thus, as
`disclosed in Japanese Unexamined Patent Publication No.
`Sho 61 (1985)-124567, an effort has been made to avoid
`slowing the speed of film creation in ferromagnetic
`material by placing a magnet on the rear surface of a target
`in addition to a magnet placed on the front surface of the
`target. Fig. 21 shows a sputtering electrode configuration
`wherein magnets 10, 13 are placed on the front and back
`sides of a target 16. With this configuration magnetic flux
`generated from the magnet 13 placed on the rear surface of
`the target 6 fills the inside of the ferromagnetic target 6 and
`magnetic flux generated by the magnet 10 placed on the
`front surface of the target is prevented from passing
`through the inside of the target 6. As a result, a decrease in
`the speed of film creation on the ferromagnetic target 6 is
`prevented.
`[0005]
`PROBLEM THE INVENTION PURPORTS TO
`SOLVE. However, although it was possible to improve the
`rate of film generation on targets of ferromagnetic material,
`because the magnetic flux faced the same direction across
`the entire surface of the target, electrons in the plasma
`received force in the same direction across the entire
`surface of the target. The density of electrons in the plasma
`therefore became non-uniform in the target surface, and as
`a result erosion on the target progressed rapidly in the
`direction in which electrons received force and slowly in
`the opposite direction. As a result, problems developed
`with non-uniform progression of erosion. This not only
`caused extremely inefficient use of target material but
`made it impossible to ensure evenness in the thickness of
`thin film created on the surface of a substrate. The present
`
`Page 3 of 24
`
`

`

`invention aims to solve these problems and to provide a
`sputtering device and method which make it possible to
`cause erosion of the target to progress in an approximately
`uniform manner, regardless of magnetic material.
`[0006]
`MEANS OF SOLVING THE PROBLEM. In order to
`attain the above objective, the present invention is
`configured as follows. According to a sputtering device
`of Embodiment 1 of the present invention, a sputtering
`device for performing sputtering using a rectangular
`target is configured such that in addition to rod-shaped
`first magnets placed along each of a pair of edges of the
`target, a rod-shaped second magnet is placed so as to be
`movable on the rear side surface of the target. According
`to Embodiment 3, it is possible to configure Embodiment
`1 or 2 such that the second magnet is on the rear surface
`side of the target and moves back and forth in a range
`corresponding to between the first magnets. According to
`Embodiment 4 of the present invention, it is possible to
`configure any of Embodiments 1-3 such that the second
`magnet is a plurality of rod-shaped magnets.
`[0007] According to a sputtering device of Embodiment 5
`of the present invention a sputtering device for sputtering
`using a circular target is configured such that, in addition
`to third magnets being placed facing edges of the target, a
`fourth magnet is placed on the rear side surface of the
`target so as to be able to move in an approximately
`circular pattern. According to Embodiment 6 of the
`present invention, it is possible to configure Embodiment
`5 such that the polarity of the third magnet is arranged
`with like poles facing the center of the target and the
`fourth magnet is set with a pole facing the rear surface of
`the target that differs from the pole with which the third
`magnet faces the center of the target. According to
`Embodiment 7 of the present invention, it is possible to
`configure the fourth magnet in Embodiment 5 or 6 as a
`plurality of magnets. According to Embodiment 8 of the
`present invention, it is possible to configure any of
`Embodiments 5-7 such that the fourth magnet moves in a
`spiraling pattern.
`[0008] According to a sputtering device of Embodiment 9
`of the present invention a sputtering device for sputtering
`a circular target is configured with a plurality of
`electromagnets placed facing edges of the target such that
`the magnetic poles of the electromagnets temporally
`change. According to Embodiment 10 of the present
`invention it is possible to configure Embodiment 9 such
`that poles of the electromagnets facing the inside of the
`target can each be controlled independently. According to
`Embodiment 11 it is possible to configure Embodiment 9
`or 10 such that the number of electromagnets is an even
`
`number of 4 of more. According to Embodiment 12 it is
`possible to configure any of Embodiments 9-11 such that
`the coil of the electromagnet is in the atmosphere side of a
`vacuum chamber.
`[0009] According to a sputtering method of Embodiment
`13 of the present invention, with a sputtering method for
`sputtering using a rectangular target in a state in which rod-
`shaped first magnets are placed along each of a pair of
`edges of the target, and in addition a rod-shaped second
`magnet is placed so as to be able to move on the rear side
`surface of the target, sputtering is done while the second
`magnet is moved over the rear side surface of the target,
`temporally changing the direction of magnetic flux and
`temporally making the plasma density on the target surface
`approximately balanced. According to Embodiment 14 of
`the present invention it is possible to configure
`Embodiment 13 by arranging the polarity of the first
`magnets with like poles facing and setting the second
`magnets with a pole facing the rear surface of the target
`that differs from the magnetic pole with which the first
`magnets face one another. According to Embodiment 15 of
`the present invention, it is possible to configure
`Embodiment 13 or 14 such that the second magnet moves
`back and forth on the rear side surface of a target in a range
`corresponding to between the first magnets.
`[0010] According to a sputtering method of Embodiment
`16 of the present invention a sputtering method for
`sputtering using a round target in a state in which a third
`magnet is placed facing an edge of the target and a fourth
`magnet is also placed so as to be movable on the rear side
`surface of the target is configured such that sputtering is
`done while the fourth magnet moves in an approximately
`circular pattern on the rear side surface of the target,
`temporally changing the direction of magnetic flux and
`temporally making plasma density on the target surface
`approximately balanced. According to Embodiment 17 of
`the present invention it is possible to also configure
`Embodiment 16 such that the polarity of the third
`magnets is arranged with like poles facing the center of
`the target and setting the fourth magnet with a pole facing
`the rear surface of the target that differs from the pole
`with which the third magnets face the center of the target.
`According to Embodiment 18 of the present invention it
`is possible to configure Embodiment 16 or 17 such that
`the fourth magnet moves in a spiraling pattern.
`[0011] According to a sputtering method of Embodiment
`19 of the present invention a sputtering method for
`sputtering a round target in a state in which a plurality of
`electromagnets are placed facing the edge of a target is
`configured so as to temporally change the magnetic pole
`of the electromagnets, change the direction of magnetic
`
`Page 4 of 24
`
`

`

`flux, change the direction from which electrons in
`plasma receive force, and to temporally make the plasma
`density on a target surface approximately uniform.
`According to Embodiment 20 of the present invention, it
`is possible, by temporally changing the magnetic pole of
`electromagnets, to configure Embodiment 19 so as to
`change the direction of magnetic flux, to rotate the
`direction from which electrons in the plasma receive
`force 360 degrees, and to make plasma density on a
`target surface, averaged over time, approximately
`uniform.
`[0012]
`WORKING EXAMPLES OF THE INVENTION.
`Embodiments of the present invention are explained
`below with reference to Fig. 1-19.
`Embodiment 1. Fig. 1 shows the configuration of a
`sputtering device for implementing a sputtering method
`of Embodiment 1 of the present invention. In Fig. 1 the
`number 1 indicates a vacuum chamber, 2 is a vacuum
`exhaust port provided to the chamber 1 and opening to a
`vacuum pump, 3 is a gas introduction pipe provided to the
`chamber 1, and 4 is a gas flow control device mounted on
`the gas introduction pipe 3. The number 5 indicates
`discharge gas, usually argon gas, introduced into the
`chamber 1 from the gas introduction pipe 3. The number
`6 indicates a rectangular target placed inside a chamber 1;
`7 is a supporting electrode for supporting the target 6,
`mounted on the chamber 1 by means of an insulating body
`80; 8 is a DC or high frequency discharge source for
`discharge that applies to negative voltage or high
`frequency voltage in the sputtering electrode; 9 is a pair
`of magnet holders placed inside the chamber 1 along a
`pair of edges that run in the longitudinal direction of the
`target 6; and 10 is a pair of rod-shaped magnets placed
`along a pair of edges of the target 6 and supported by a
`pair of magnet holders. The number 11 is a substrate
`holder placed inside the chamber 1 in a position facing
`the target 6. The number 12 indicates a substrate upon
`which a thin film is formed, supported by a substrate
`holder 11. The number 14 indicates rod-shaped magnets
`placed inside a sputtering electrode 7 as well as on the
`rear side surface of a target and also along the longitudinal
`direction of the target 6, and this magnet 14 is provided
`with a movement mechanism that moves on the rear side
`surface of the target 6 in a direction orthogonal to the
`longitudinal direction of the target 6.
`[0013] Fig. 2 shows a plane figure of part of the
`sputtering electrode inside the sputtering device shown in
`Fig 1. In addition, Fig. 3 shows an A—A’ cross-section
`of Fig. 2. Each magnet 10 is placed on the outer side of a
`
`rectangular target 6 along each edge in the longitudinal
`direction as shown in Fig. 2, facing and sandwiching the
`target 6, the polarity of a pair of magnets 10 arranged to be
`the same. In Fig. 2, N poles in a pair of magnets 10 are
`configured to face one another. Also, a magnet 14 placed
`on the rear side surface of a target 6 is arranged to face the
`rear surface of the target with a polarity that is the reverse
`of the polarity with which the magnets 10 are facing and
`sandwiching the target. In Fig. 2, because magnets 10 are
`facing N poles, the S pole of a magnet 14 on the rear side
`surface of a target is configured to face the rear surface of
`the target. A magnet 14 on the rear side surface of a target
`is configured so as to be able to move, back and forth, in
`an orthogonal direction to the longitudinal direction of the
`target 6, i.e., direction 91, with time moving as shown in
`Fig. 4 from (A) through (B) to (C), and then from (C)
`through (B) to (A). In short, in a range corresponding to
`the space between a pair of magnets 10 on the rear side
`surface of a target 6, the magnet 14 gradually distances
`from the vicinity of a magnet 10 on one side and
`approaches a magnet 10 on the other side. Then, when
`positioned in the vicinity of the magnet 10 on the other
`side, the magnet 14 conversely gradually distances from
`the vicinity of the magnet 10 on that side and approaches
`the magnet 10 on the first side. The magnet 14 is then
`positioned in the vicinity of the magnet 10 on the first side.
`During this time it is desirable that the magnet 14 moves
`with uniform velocity in order to temporally make the
`plasma density approximately balanced.
`[0014] By means of the above configuration the strength
`and direction of the magnetic field are changed on all
`points on the target 6. By way of example, Fig. 5 uses solid
`and dotted lines to show temporal change in magnetic flux
`density in the A-A’ direction at a distance of 2mm from the
`front surface of the target when the moving speed of
`magnets 14 placed on the rear side surface of the target is
`set to 50mm/s, for a position at the center of the target 6
`and a position 50mm away from the center of the target 6
`on line A-A’ in Fig. 2, respectively. The left-facing
`movement of the magnet 14 in Fig. 3 is shown as positive.
`As can be seen in Fig. 5, the strength and direction of the
`magnetic field are temporally changed on all points on the
`target 6.
`[0015] In Fig. 2, when magnetic flux faces to the right,
`electrons in the plasma receive force facing toward the
`bottom of Fig. 2. Also, when magnetic flux faces to the
`left, electrons in the plasma receive force facing toward the
`top of Fig. 2. Thus, by temporally changing the direction of
`magnetic flux it becomes possible to increase the plasma
`density confining the plasma on the target surface,
`increasing the rate of erosion and the rate of generating
`film on the substrate. Furthermore, plasma density on the
`target surface is temporally balanced, and as shown in Fig.
`
`Page 5 of 24
`
`

`

`6 the erosion portion 6a of the target 6 is approximately
`uniform, greatly increasing the efficient use of material.
`[0016] Embodiment 2. Fig. 7 shows a sputtering device
`for implementing a sputtering method of Embodiment 2
`of the present invention. A general configuration is the
`same as Embodiment 1 but differs in that the rod-shaped
`magnet 14 on the rear side surface of a target 6 is in
`multiple, for example two magnets. Therefore, as Fig. 7
`shows, two magnets 14 separated by a prescribed
`distance are able to move as shown in Fig. 6 by the same
`movement mechanism as in Embodiment 1. In other
`words, in Fig. 7 the left-side magnet 14 on the rear side
`surface of the target gradually distances from the
`vicinity of the left-side magnet 10 on the rear surface of
`the target, moving to the right as one with the right-side
`magnet 14 on the rear side surface of the target 6. This
`right-side magnet 14 approaches the right-side magnet
`10 on the rear surface of the target 6. Then, when
`positioned in the vicinity of that magnet 10, the right-
`side magnet 14 conversely gradually distances from the
`vicinity of the right-side magnet 10 and moves left as
`one with the left-side magnet 14. The left-side magnet
`14 approaches the left-side magnet 10, and is positioned
`in the vicinity of that magnet 10. It is desirable that the
`moving speed of these two magnets 14 during this time
`be made uniform for the purpose of making plasma
`density temporally approximately balanced. This
`Embodiment 2 can exhibit the same effects as
`Embodiment 1, and furthermore when a target is large,
`i.e., when the space between the magnets 10 is wide,
`providing multiple magnets 14 can prevent a decrease in
`magnetic flux on the target surface and limit a decrease
`in the rate of film creation.
`[0017] Embodiment 3. Fig. 8 shows a portion of a
`sputtering electrode of a sputtering device for
`implementing a sputtering method of Embodiment 3 of
`the present invention. Similar to Fig. 2, Fig. 8 is a plane
`figure of a portion of a sputtering electrode of the
`sputtering device of Embodiment 1 shown in Fig 1. In
`addition, Fig. 9 shows a cross-section of A—A’ in Fig.
`8. Embodiment 3 differs from Embodiment 2 in that the
`target is not a rectangular target but a circular target.
`Circular magnets 15 placed along the circumferential
`edge of a round target 46 follow along the circumference
`of the target 46 and are placed so as to face the center of
`the target 46 across from identical poles. In Fig. 8, for
`example, N poles are placed to face the center of the
`target 46. Three circular magnets 16 spaced at 120
`degrees are placed on the rear side surface of a target 46.
`The three magnets 16 are arranged so as to be able to
`
`move in an approximately circular pattern, maintaining
`the intervals of 120 degrees. Specifically, the circular
`magnets 16 are preferably placed so as to be able to move
`in different concentric circles of the radius from the
`center of the target 6, each magnet at a constant angular
`velocity in the same direction, and are arranged with a
`polarity facing toward the front surface of the target that
`is the reverse of the polarity with which the magnets 15
`face the center. Thus, in Fig. 8 S poles are facing the rear
`surface of the target 46.
`[0018] In Fig. 8, because the magnetic flux is facing the
`center of the target, electrons in the plasma receive force
`moving toward the circumference of the target 46 with the
`movement of the three magnets 16 placed on the rear side
`surface of the target. These three magnets 16 each move in
`different peripheries of the radius from the center of the
`target 46, so plasma density is made approximately
`uniform, averaged over time, on each point on the target
`surface. As shown in Fig. 10, the corroded portion 46a of
`the target 46 is made approximately uniform. Note, 47 is a
`circular sputtering electrode and corresponds to the
`sputtering electrode 7 of Fig. 1. In the explanation above,
`the three magnets 16 placed on the rear side surface of the
`target are described as three magnets placed 120 degrees
`apart, but the effects are the same with any multiple.
`However, it is desirable that the spacing be at uniform
`angles. Also, the magnets 16 placed on the front side
`surface of the target do not need to have a circular surface,
`but can, for example, have a fan shape with an arc-shaped
`circumference corresponding to the circular-shaped
`magnets 15. The three magnets 16 are not limited to
`always moving in the same direction as one, and the
`direction in which the three magnets 15 move as one may
`be changed at prescribed intervals of time.
`[0019] Embodiment 4. Fig. 11 shows a portion of a
`sputtering electrode of a sputtering device for
`implementing a sputtering method of Embodiment 4 of the
`present invention. Like Fig. 2, Fig. 11 is a plane view of
`part of the sputtering electrode within the sputtering device
`of Embodiment 1 shown in Fig 1. Embodiment 4 differs
`from Embodiment 3 in that there are three magnets 16
`moving on the rear side surface of the target 46 and instead
`of moving in approximately circular patterns in concentric
`circles, one circular magnet 16 moves in an approximately
`circular pattern not in a concentric circle but in a spiral
`shape, and moreover, moves back and forth. Magnets 15
`are placed, as in Fig. 8, along the circumference of a target
`46 so as to face the center of the target 46 across from
`identical poles. Magnets 16 placed on the rear side surface
`of the target 46 move while describing a spiraling pattern
`from the center toward the outermost periphery of the
`
`Page 6 of 24
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`

`

`target 46. When the magnets 16 reach a predetermined
`position on the outermost periphery they move,
`conversely, while describing a spiraling pattern from the
`outermost periphery to the center of the target 46.
`Constant angular velocity is desirable for the purpose of
`making plasma density temporally approximately
`balanced. Magnets 16 are arranged as in Embodiment 3 to
`face toward the rear surface of the target 46 with a
`polarity that differs from the polarity with which the
`magnets 15 face the center. According to this type of
`configuration, plasma density on the target surface is
`made approximately uniform, when time-averaged, with
`the movement in a spiral pattern of magnets 16 placed on
`the rear side surface of a target, increasing the efficient
`use of the material of the target 46. In the above
`invention, the magnet 16 placed on the rear side surface of
`a target is described with an example involving one
`magnet, but multiple magnets may be placed and the
`magnets may be caused to move as one in the same
`direction in a spiral pattern.
`[0020] Embodiment 5. Fig. 12 shows a portion of a
`sputtering electrode of a sputtering device for
`implementing a sputtering method of Embodiment 5 of
`the present invention. Fig. 12, like Fig. 2, is a plane view
`of part of a sputtering electrode within the sputtering
`device of Embodiment 1 shown in Fig 1. In addition, Fig.
`13 shows a C—C’ cross-section of Fig. 12. In
`Embodiment 5, unlike in Embodiment 4, magnets are not
`placed on the rear side surface of the target 46, but rather
`the polarity of eight circular electromagnets 17 placed on
`the circular shape of the front surface of the target 46 is
`changed each time. Eight electromagnets 17 are placed at
`equal intervals along the circumference of a target 46, all
`of the same shape. The electromagnets 17 are each
`configured for magnetization purposes from magnetic
`bodies 17a, coils 17b wrapped around the magnetic bodies
`17a, and power sources 17c for flowing current to the
`coils 17b. Also provided is a control unit 17d for
`controlling the eight power sources 17c, and using this
`control unit 17d to control the direction in which current
`flows to the coils 17b of the eight electromagnets 17, the
`poles generated by each of the electromagnets 17 toward
`the surface of the target 46 can be controlled
`independently.
`[0021] Fig. 14 (A) through (C) show temporal change in
`the magnetic polarity generated by each electromagnet 17
`toward the surface of a target 46. By changing polarity,
`the direction of the magnetic flux indicated by 92 changes
`in Fig. 14 from (A) through (B) to (C), and then from (C)
`through (B) to (A). This change from (A) to (C) and from
`(C) to (A) repeats any number of times. As polarity
`changes, the direction in which electrons in plasma
`receive force, indicated by 93, changes. Due to temporal
`
`changes in the direction 93 in which electrons in plasma
`receive force, plasma density is made approximately
`uniform, when time-averaged, and an erosion portion 46b
`of the type shown in Fig. 15 is obtained of a target 4