JP2015211015A - Vacuum processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vacuum processing apparatus capable of prolongation of a maintenance cycle of a deposition preventive plate while reducing influence on a process area in a processing chamber.SOLUTION: A vacuum processing apparatus 1 according to an embodiment of the present invention includes: a processing chamber 20 for performing ion milling of a magnetic material W; a deposition preventive plate 24 provided along the inner wall of the processing chamber 20; and a plurality of magnetic generation means 26 which are arranged on the rear surface side opposite to the inner wall of the processing chamber 20 on the deposition preventive plate 24 and generate the cusp magnetic field on the front surface side of the deposition preventive plate 24.

Description

  The present invention relates to a vacuum processing apparatus that performs milling, sputtering, or vapor deposition of a magnetic material.

  Vacuum processing apparatuses such as a milling apparatus, a sputtering apparatus, and a vapor deposition apparatus are known. As the milling device and sputtering device, there are ion milling device using ion, neutral particles, ion beam sputtering device, high frequency sputtering device and the like, and as the deposition device, electron beam vacuum deposition device, resistance heating type vacuum deposition device and the like There is.

  For example, an ion beam sputtering apparatus deposits sputtered particles ejected from a target on a workpiece by causing the ions to collide with the target. In this ion beam sputtering apparatus, when a magnetic material is used as a target, sputtered particles adhere to the inner wall of a vacuum chamber (processing chamber).

  Further, for example, an ion milling apparatus processes a workpiece by causing ions to collide with the workpiece. Even in this ion milling apparatus, when the workpiece is a magnetic material, sputtered particles generated by the processing adhere to the inner wall of the vacuum chamber (processing chamber).

  In this regard, Patent Document 1 describes that an adhesion preventing plate is provided inside the sputtering apparatus. Further, Patent Document 2 describes that this type of deposition plate is also applied to the inside of a bucket ion source including a permanent magnet for forming a cusp magnetic field for electron confinement.

  By the way, if sputter particles continue to be deposited on the deposition preventive plate, the deposited film peels off and causes generation of dust. Therefore, repair such as replacement of the deposition preventive plate is necessary. This repair requires that the inside of the vacuum chamber be returned to atmospheric pressure, which reduces the operating rate of the sputtering apparatus (see Patent Document 1).

  In this regard, Patent Document 1 describes that a magnetic field generating means is provided on the back surface of the deposition preventing plate disposed on the inner wall surface of the vacuum chamber. As a result, ions are drawn from the plasma generated in the vacuum chamber and collide with the surface of the deposition preventing plate, and the deposited film on the deposition preventing plate is re-sputtered and shaved. The film component thus re-sputtered diffuses into the vacuum chamber and reattaches to the other deposition preventing plate. As a result, it is possible to prevent the deposition from concentrating on a part and to adhere widely to the deposition preventing plate installed in the vacuum chamber. In this way, by diffusing the film adhering to some of the adhesion-preventing plates, it is possible to reduce the deposition rate of deposits adhering to the surface of the adhesion-preventing plates and prolong the replacement cycle of the adhesion-preventing plates it can.

JP 2003-34857 A JP 2012-190658 A

  However, in Patent Document 1, magnetic field generating means is provided on the back surface of the deposition plate, ions are drawn from the process area in the vacuum chamber (processing chamber), and the deposited film on the deposition plate is re-sputtered. May affect ions in the process area and, as a result, may affect the process (milling, sputtering, or vapor deposition).

  Therefore, an object of the present invention is to provide a vacuum processing apparatus capable of extending the maintenance cycle of the deposition preventing plate while reducing the influence on the process area in the processing chamber.

  The vacuum processing apparatus of the present invention includes a processing chamber for performing milling, sputtering, or vapor deposition of a magnetic material, a deposition plate provided along the inner wall of the processing chamber, and an inner wall of the processing chamber in the deposition plate. A plurality of magnetic field generating means arranged on opposite back surfaces and generating a cusp magnetic field on the front surface side of the deposition preventing plate.

  According to this vacuum processing apparatus, since the magnetic field generating means is provided on the back side of the deposition preventive plate, particles generated when the film (magnetic material) deposited on the deposition preventive plate is separated are trapped on the deposition plate. It is possible to prevent the particles from detaching from the deposition plate, in other words, the particles can be prevented from scattering. Therefore, the maintenance cycle of the deposition preventing plate can be extended.

  Also, according to this vacuum processing apparatus, a plurality of magnetic field generating means are arranged on the back side of the deposition plate, and a cusp magnetic field is generated on the front side of the deposition plate, so a strong magnetic field is generated in the vicinity of the deposition plate. And it can suppress that a magnetic flux leaks into the process area in a processing chamber. Therefore, the influence on the process area in the processing chamber can be reduced, and the influence on the process (milling, sputtering, or vapor deposition) can be reduced.

  The plurality of magnetic field generating means described above may be in contact with the back surface of the deposition preventing plate in the processing chamber, or may be in contact with the outer wall of the processing chamber outside the processing chamber. When a plurality of magnetic field generating means are in contact with the back surface of the deposition preventing plate in the processing chamber, the cusp magnetic field on the surface of the deposition preventing plate is stronger than when the plurality of magnetic field generating means are outside the processing chamber. The trapping force of particles on the surface of the plate can be increased. On the other hand, when the plurality of magnetic field generating means are in contact with the outer wall of the processing chamber outside the processing chamber, the particles are not attached to the magnetic field generating means as compared with the case where the plurality of magnetic field generating means are inside the processing chamber. Further, there is no deterioration in the characteristics of the magnetic field generating means due to the temperature inside the processing chamber, and there are no restrictions on the options of the magnetic field generating means due to the Curie temperature.

  Further, the plurality of magnetic field generating means described above may be arranged so that different polarities are alternately arranged. When the magnetic field generating means having the same polarity are arranged, a cusp magnetic field having twice as many cusp portions is generated as compared with the case where the magnetic field generating means having different polarities are arranged alternately. In addition to the strong magnetic field cusp on the surface of the protective plate, a relatively weak magnetic field cusp is also generated on the surface of the protective plate corresponding to the magnetic field generating means. If the generating means are arranged alternately, the leakage of magnetic flux to the process area in the processing chamber can be further reduced.

  Moreover, the above-described vacuum processing apparatus may be configured to further include a ferromagnetic plate on the side opposite to the deposition preventing plate in the plurality of magnetic field generating means. According to this, it is possible to prevent the magnetic flux generated by the plurality of magnetic field generating means from leaking outside the ferromagnetic plate.

  Further, the above-described vacuum processing apparatus may have a form further including an auxiliary deposition plate provided on the surface side of the deposition plate. According to this, in place of the adhesion preventing plate in which the plurality of magnetic field generating means are in contact with the back surface, the auxiliary adhesion preventing plate may be maintained, and the maintenance can be made easier.

  The above-described vacuum processing apparatus further includes an ion beam generating unit that generates an ion beam, and in the processing chamber, the ion beam supplied from the ion beam generating unit collides with a workpiece made of a magnetic material, thereby performing ion milling. It may be an ion milling device that performs the above.

  The above-described vacuum processing apparatus further includes an ion beam generating unit that generates an ion beam, and in the processing chamber, the ion beam supplied from the ion beam generating unit is collided with a target made of a magnetic material and sputtered from the target. An ion beam sputtering apparatus that performs ion beam sputtering by depositing particles on a workpiece may be used.

  Further, the vacuum processing apparatus described above may be a vacuum deposition apparatus that performs vacuum deposition by depositing a magnetic material on a workpiece in a processing chamber.

  ADVANTAGE OF THE INVENTION According to this invention, the maintenance cycle of a protection board can be lengthened, reducing the influence on the process area in a processing chamber.

It is a figure which shows schematic structure of an ion milling apparatus as a vacuum processing apparatus which concerns on one Embodiment of this invention. It is a figure which shows the adhesion prevention board and magnetic field generation | occurrence | production means shown in FIG. It is a figure for demonstrating the effect by the adhesion prevention board shown in FIG. 1 and 2 and a magnetic field generation means. It is a figure which shows the modification of an adhesion prevention board and a magnetic field generation means. It is a figure which shows the modification of an adhesion prevention board and a magnetic field generation means. It is a figure which shows schematic structure of an ion beam sputtering apparatus as a vacuum processing apparatus which concerns on one Embodiment of this invention. It is a figure which shows schematic structure of a vacuum evaporation system as a vacuum processing apparatus which concerns on one Embodiment of this invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals.

  FIG. 1 is a diagram showing a schematic configuration of an ion milling apparatus as a vacuum processing apparatus according to an embodiment of the present invention. An ion milling apparatus 1 shown in FIG. 1 includes an ion beam generating unit 10 and an ion milling processing chamber 20.

  The ion beam generator 10 is an ion source that generates the ion beam B and supplies it to the processing chamber 20. The ion beam generation unit 10 includes a source plasma generation unit 12 that generates a source plasma A that is an inert gas plasma, and an extraction electrode unit 14 that extracts ions in the source plasma A in the source plasma generation unit 12 as an ion beam B. And have.

  The source plasma generator 12 generates the source plasma A by ionizing the inert gas supplied from the gas supply unit 30. Examples of the inert gas, in other words, the rare gas include argon (Ar), krypton (Xe), xenon (Xe), and the like. Examples of the ionization method of the inert gas include a method using high frequency discharge, a method using microwave discharge, a method using DC discharge, and the like. The method of ionizing the inert gas is not particularly limited as long as the source plasma A can be generated from the inert gas.

  The extraction electrode unit 14 includes an acceleration electrode 14A, a deceleration electrode 14B, and a ground electrode 14C arranged in this order from the source plasma generation unit 12 side. The acceleration electrode 14 </ b> A, the deceleration electrode 14 </ b> B, and the ground electrode 14 </ b> C are supported by the insulator 16 between the source plasma generation unit 12 and the processing chamber 20. The acceleration electrode 14A, the deceleration electrode 14B, and the ground electrode 14C are made of, for example, a conductive plate, and have a large number of holes over the entire surface for extracting the ion beam B. An acceleration voltage (positive voltage) is applied to the acceleration electrode 14A, and a deceleration voltage (negative voltage) is applied to the deceleration electrode 14B. The ground electrode 14C is grounded. A processing chamber 20 is disposed on the downstream side of the ion beam generator 10.

  The processing chamber 20 is a processing chamber that performs ion milling by causing the ion beam B supplied from the ion beam generating unit 10 to collide with a substrate to be processed (workpiece) W. In one embodiment, the substrate W to be processed is a substrate for manufacturing a magnetic head for a hard disk, and is made of a magnetic material such as cobalt, iron cobalt, terbium iron cobalt, or the like. The processing chamber 20 is, for example, a vacuum chamber that is brought into a low pressure state by the exhaust unit 32. The processing chamber 20 is grounded.

  A substrate holder 22 on which the substrate to be processed W is placed is provided in the processing chamber 20. The substrate holder 22 has conductivity and is the same potential as or insulated from the ground potential of the processing chamber 20. A bias voltage source 34 for applying a bias voltage to the substrate holder 22 may be electrically connected to the substrate holder 22.

  In addition, a deposition preventing plate 24 is provided in the processing chamber 20. The deposition preventing plate 24 is made of a nonmagnetic material such as stainless steel or aluminum and has a plate shape. The protection plate 24 is disposed along the inner wall of the processing chamber 20 so as to cover the entire six inner walls of the processing chamber 20. A plurality of magnets (magnetic field generating means) 26 are arranged on the back surface side of the deposition preventing plate 24 facing the inner wall of the processing chamber 20.

  As shown in FIG. 2, the magnets 26 are in contact with the back surface of the deposition preventing plate 24 in the processing chamber 20 and are arranged so that different polarities, that is, N poles and S poles are alternately arranged. Thereby, the magnet 26 generates a cusp magnetic field M on the surface side of the deposition preventing plate 24. The magnet 26 has a substantially rectangular parallelepiped rod shape. As shown in FIG. 1, the magnets 26 are arranged so as to be aligned in a direction intersecting the gravity direction axis, particularly on the side surface of the processing chamber 20.

  Here, in the conventional ion milling apparatus, when the workpiece is a magnetic material, sputtered particles generated by processing adhere to and deposit on the surface of the deposition preventing plate, but the film (magnetic material) deposited on the deposition preventing plate peels off. By doing so, particles are generated. When the number of particles in the processing chamber increases, maintenance such as replacement of the deposition preventing plate is required. Maintenance such as replacement of the protective plate needs to return the processing chamber to atmospheric pressure, lowering the operating rate of the apparatus and increasing the process cost.

  However, according to this ion milling device (vacuum processing device) 1, since the magnet (magnetic field generating means) 26 is provided on the back surface side of the deposition preventing plate 24, as shown in FIG. Particles 29 generated when the film (magnetic material) 28 deposited on the surface peels off can be trapped in the cusp portion of the cusp magnetic field on the surface of the deposition preventing plate 24, and the particles 29 can be trapped from the surface of the deposition preventing plate 24. It is possible to make it difficult to desorb, in other words, it is possible to prevent the particles 29 from being scattered. Therefore, the maintenance cycle of the deposition preventing plate can be extended. As a result, it is possible to suppress a decrease in the operating rate of the apparatus and an increase in process cost due to the maintenance of the deposition preventing plate.

  Further, according to the ion milling apparatus 1, a plurality of magnets 26 are arranged on the back surface side of the deposition preventing plate 24, and a cusp magnetic field is generated on the front surface side of the deposition preventing plate 24. It is possible to prevent the magnetic flux from leaking to the process area in the processing chamber 20 that occurs in the vicinity. Therefore, the influence on the process area in the processing chamber 20 can be reduced, and the influence on the process (milling) can be reduced.

  By the way, when magnets with the same polarity are arranged, a cusp magnetic field having twice as many cusp portions as compared with the case where magnets with different polarities are arranged alternately is generated, that is, the deposition plate corresponding to the magnet arrangement position. In addition to the strong magnetic field cusp portion on the surface of the magnet, a relatively weak magnetic field cusp portion is also generated on the surface of the deposition preventing plate corresponding to the gap between the magnets. However, according to this ion milling apparatus 1, since the magnets 26 of different polarities are alternately arranged, the leakage of magnetic flux to the process area in the processing chamber can be further reduced.

  Further, according to the ion milling apparatus 1, since the magnets 26 are arranged on the side surface of the processing chamber 20 so as to be arranged in a direction intersecting the gravity direction axis, the trap efficiency of particles falling due to the influence of gravity is reduced. Can be increased.

  Further, according to the ion milling apparatus 1, since the magnet 26 is in contact with the back surface of the deposition preventing plate 24 in the processing chamber 20, the magnet 26 is outside the processing chamber 20 as in a modification example described later. In comparison, the cusp magnetic field on the surface of the deposition preventing plate 24 is strong, and the trapping force of particles on the surface of the deposition preventing plate 24 can be increased.

  The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, as shown in FIG. 4, the auxiliary protection plate 25 may be further provided on the surface side of the protection plate 24. The auxiliary deposition preventive plate 25 may be made of a nonmagnetic material and has a plate shape like the deposition preventive plate 24. According to this, instead of the deposition preventing plate 24 having the plurality of magnetic field generating means 26 on the back surface, the auxiliary deposition preventing plate 25 may be maintained, and the maintenance can be made easier.

  Further, as shown in FIG. 5, a configuration may be provided in which a ferromagnetic plate 27 having a stronger magnetism than that of the magnetic field generating means 26 is further provided on the opposite side of the plurality of magnetic field generating means 26 from the deposition preventing plate. The ferromagnetic plate 27 may have a plate shape. According to this, it is possible to prevent the cusp magnetic field by the magnetic field generating means 26 from leaking outside the ferromagnetic plate 27, that is, outside the processing chamber 20. An example of the simulation result is described below.

In the simulation example shown in FIG. 5, the effect of the ferromagnetic plate 27 was simulated. The specifications of the simulation example are as follows.
Protection plate 24: Material SU316L (stainless steel), thickness 1 mm
Magnet 26: sectional shape 5 mm × 10 mm, magnetization direction is longitudinal direction, residual magnetic flux density 1000 [Gauss], coercive force −1000 [0e], magnet center interval 30 mm
Ferromagnetic plate 27: material SS400, thickness 2 mm
In this simulation example, when the magnetic field strength at a position 30 mm away from the back surface of the deposition preventing plate 24 via the ferromagnetic plate 27 is calculated, the magnetic field strength is reduced to 0 to 7 [Gauss] in both the vertical and horizontal directions. It was done.

  Further, in the present embodiment, the magnetic field generating means 26 is provided on the back surface of all the deposition preventing plates 24 provided in the processing chamber 20, but at least above the process area, in other words, at least the workpiece W. Any configuration may be used as long as the magnetic field generating means 26 is provided on the back surface portion of the deposition preventing plate corresponding to the upper side. In addition, the magnetic field generating means 26 may be provided at least on the upstream side of the process area from the process area, in other words, at least the back surface portion of the deposition plate corresponding to the ion beam generating unit 10 side of the workpiece W. .

Further, in the present embodiment, the magnetic field generation unit 26 is provided in the processing chamber 20, but the magnetic field generation unit may be provided outside the processing chamber. The magnetic field generation means may simply be in contact with the outer wall of the processing chamber. Thus, when the magnetic field generating means is provided outside the processing chamber, particles do not adhere to the magnetic field generating means as compared with the case where the magnetic field generating means is in the processing chamber. Further, there is no deterioration in the characteristics of the magnetic field generating means due to the temperature inside the processing chamber, and there are no restrictions on the options of the magnetic field generating means due to the Curie temperature.
Alternatively, a recess may be formed in the outer wall of the processing chamber, and a magnetic field generating means may be embedded in the recess. Thus, the cusp magnetic field on the surface of the deposition preventing plate can be strengthened by arranging the magnetic field generating means in the portion where the outer wall of the processing chamber is thin.

  In the present embodiment, the plurality of magnets are arranged so that the different poles, that is, the N pole and the S pole are alternately arranged. However, the plurality of magnets may be arranged so that the same poles are arranged.

  In the present embodiment, a (permanent) magnet is exemplified as the magnetic field generating means. However, in the present invention, any magnetic field generating means such as an electromagnet is applicable.

  Further, in the present embodiment, the ion milling apparatus 1 is illustrated, but the features of the present invention (the deposition plate 24 and the magnetic field generating means 26) can also be applied to the ion beam sputtering apparatus 2 shown in FIG. In the ion beam sputtering apparatus 2, in the processing chamber 20, the ion beam B supplied from the ion beam generation unit 10 is collided with a target T made of a magnetic material, and sputtered particles C from the target T are made to be processed substrates (workpieces). ) Deposit on W. The substrate to be processed W is placed on a conductive substrate holder 22, and a bias voltage is applied to the substrate holder 22 by a bias voltage source 34. Similarly, the target T is placed on a conductive target holder 23, and a bias voltage is applied to the target holder 23 by a bias voltage source 35.

  Further, the features of the present invention (the deposition preventing plate 24 and the magnetic field generating means 26) can also be applied to the vacuum evaporation apparatus 3 shown in FIG. In the vacuum deposition apparatus 3, the magnetic material S is deposited on the workpiece substrate (workpiece) W in the processing chamber 20. The substrate to be processed (workpiece) W is placed on the substrate holder 22, and the magnetic material S is placed on the heater 21.

  DESCRIPTION OF SYMBOLS 1 ... Ion milling apparatus (vacuum processing apparatus), 2 ... Ion beam sputtering apparatus (vacuum processing apparatus), 3 ... Vacuum deposition apparatus (vacuum processing apparatus), 10 ... Ion beam generation part, 12 ... Source plasma generation part, 14 ... Extraction electrode portion, 14A ... acceleration electrode, 14B ... deceleration electrode, 14C ... ground electrode, 16 ... insulator, 20 ... processing chamber, 21 ... heater, 22 ... substrate holder, 23 ... target holder, 24 ... adhesion plate, 25 ... auxiliary deposition plate, 26 ... magnet (magnetic field generating means), 27 ... ferromagnetic plate, 28 ... film (magnetic material), 29 ... particle, 30 ... gas supply part, 32 ... exhaust part, 34, 35 ... bias voltage Source: A ... Source plasma, B ... Ion beam, C ... Sputtered particles, M ... Cusp magnetic field, S ... Magnetic material, T ... Target (magnetic material), W ... Substrate (workpiece, magnetic material) ).

Claims (9)

A processing chamber for milling, sputtering or vapor deposition of magnetic material;
A deposition plate provided along the inner wall of the processing chamber;
A plurality of magnetic field generating means arranged on the back side facing the inner wall of the processing chamber in the deposition preventing plate, and generating a cusp magnetic field on the surface side of the deposition preventing plate;
A vacuum processing apparatus.   The vacuum processing apparatus according to claim 1, wherein the plurality of magnetic field generating units are in contact with a back surface of the deposition preventing plate in the processing chamber.   The vacuum processing apparatus according to claim 1, wherein the plurality of magnetic field generating units are in contact with an outer wall of the processing chamber outside the processing chamber.   The vacuum processing apparatus according to claim 1, wherein the plurality of magnetic field generation units are arranged so that different polarities are alternately arranged.   The vacuum processing apparatus according to any one of claims 1 to 4, further comprising a ferromagnetic plate on a side opposite to the deposition preventing plate in the plurality of magnetic field generating means.   The vacuum processing apparatus of any one of Claims 1-5 further provided with the auxiliary | assistant deposition board provided in the surface side of the said deposition board. An ion beam generator for generating an ion beam;
In the processing chamber, ion milling is performed by causing an ion beam supplied from the ion beam generating unit to collide with a workpiece made of the magnetic material.
The vacuum processing apparatus of any one of Claims 1-6. An ion beam generator for generating an ion beam;
In the processing chamber, ion beam sputtering is performed by colliding an ion beam supplied from the ion beam generating unit with a target made of the magnetic material and depositing sputtered particles from the target on a workpiece.
The vacuum processing apparatus of any one of Claims 1-6.   The vacuum processing apparatus according to claim 1, wherein in the processing chamber, vacuum deposition is performed by depositing the magnetic material on a workpiece.

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