Sputtering device

Abstract

To provide a sputtering device that allows improved plasma density, leading to an increased deposition rate.SOLUTION: A sputtering device is provided with: a first target holder 111 and a second target holder 112; a substrate holder 16 provided on a lateral side of a plasma generating region R; a power supply 14 for generating an electric field in the plasma generating region R; a high frequency electromagnetic field generating portion 17 provided in the plasma generating region R on a lateral side opposing the substrate holder 16 across the plasma generating region R to generate a high frequency electromagnetic field in the plasma generating region R; and a plasma raw material gas introducing portion 15 for introducing a plasma raw material gas into the plasma generating region R. There is no means for generating a magnetic field at ends of the first target holder 111 and the second target holder 112 on the side of the high frequency electromagnetic field generating portion 17.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a sputtering apparatus that forms a film by sputtering a target raw material substance with plasma and depositing it on a substrate.

Background Art

[0002] Conventionally, in order to increase the film formation rate in a sputtering apparatus, attempts have been made to devise ways to increase the density of plasma generated near the surface of the target. FIG. 10 shows a schematic configuration of an apparatus described in Patent Document 1 as an example of such a conventional sputtering apparatus.

[0003] The sputtering apparatus 90 shown in FIG. 10 includes a first target holder 911 and a second target holder 912 that arrange two plate-shaped targets T1 and T2 to face each other with a widened gap on one side, and a plasma generation region R, which is a region between the first target holder 911 and the second target holder 912. First main magnetic field generation units 921 and second main magnetic field generation units 922 that are provided on the opposite sides of the targets T1 and T2 (the back sides of the first target holder 911 and the second target holder 912, respectively) sandwiching the plasma generation region R, and generate a magnetic field (this magnetic field is referred to as the "main magnetic field") near the surfaces of the targets T1 and T2. The aforementioned It includes a substrate holder 96 arranged on the wide-gap side of the plasma generation region R.

[0004] The sputtering apparatus 90 further includes a first auxiliary magnetic field generating unit 931 and a second auxiliary magnetic field generating unit 932. The first auxiliary magnetic field generating unit 931 consists of a first-first auxiliary magnet 9311 provided at the end of the first target holder 911 closer to the substrate holder 96, and a first-second auxiliary magnet 9312 provided at the end of the second target holder 912 closer to the substrate holder 96, and generates a first auxiliary magnetic field directed from the first-first auxiliary magnet 9311 to the first-second auxiliary magnet 9312. The second auxiliary magnetic field generating unit 932 consists of a second-first auxiliary magnet 9321 provided at the end of the first target holder 911 opposite to the substrate holder 96, and a second-second auxiliary magnet 9322 provided at the end of the second target holder 912 opposite to the substrate holder 96, and generates a second auxiliary magnetic field directed from the second-first auxiliary magnet 9321 to the second-second auxiliary magnet 9322.

[0005] Furthermore, the sputtering apparatus 90 includes two grounding electrodes 98 positioned on the sides of each of the first target holder 911 and the second target holder 912, sandwiching the target holders; a DC power supply 94 that generates an electric field in the plasma generation region R by applying a voltage between each of the first target holder 911 and the second target holder 912 and the grounding electrodes 98; and a plasma raw material gas supply unit 95 that supplies a plasma raw material gas (e.g., Ar gas) which is the raw material for the plasma into the plasma generation region R. All of the components of the sputtering apparatus 90 described so far, except for the DC power supply 94, are housed in a vacuum vessel 99.

[0006] In this sputtering apparatus 90, plasma is generated when atoms or molecules of the plasma raw material gas supplied from the plasma raw material gas supply unit 95 to the plasma generation region R are ionized into positive ions and electrons by the electric field and main magnetic field generated within the plasma generation region R. Then, on the surfaces of targets T1 and T2, the trajectories of the positive ions are bent toward the first target holder 911 and the second target holder 912 by the main magnetic field, and the positive ions incident on the surfaces of targets T1 and T2, causing targets T1 and T2 to be sputtered. The sputtered particles thus generated mainly fly toward the substrate holder 96 because the surfaces of targets T1 and T2 are tilted toward the substrate holder 96, and are deposited on the surface of the substrate S held by the substrate holder 96. As a result, a film made of the material of targets T1 and T2 is fabricated on the surface of the substrate S.

[0007] When positive ions and electrons generated within the plasma generation region R fly toward the substrate holder 96 or the opposite side, their direction of travel is bent by the Lorentz force received from the first or second auxiliary magnetic field, causing them to return to the plasma generation region R. As a result, in this sputtering apparatus 90, positive ions and electrons are confined within the plasma generation region R, and the plasma density within the plasma generation region R can be increased. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2008-127582 [Overview of the project] [Problems that the invention aims to solve]

[0009] In the sputtering apparatus 90 described above, the plasma density within the plasma generation region R can be further increased by increasing the voltage applied by the DC power supply 94. However, increasing this voltage causes abnormal discharge within the plasma generation region R, so further improvements are needed to increase the plasma density.

[0010] The problem that this invention aims to solve is to provide a sputtering apparatus that can increase the plasma density and thereby increase the film deposition rate. [Means for solving the problem]

[0011] The sputtering apparatus according to the present invention, which was developed to solve the above problems, a) A first target holder and a second target holder, respectively, which hold the first target and the second target so that their surfaces face each other, b) A substrate holder provided on one side of the plasma generation region, which is the region between the first target and the second target held by the first target holder and the second target holder, respectively, c) A first main magnetic field generating unit and a second main magnetic field generating unit are provided on the opposite side of the plasma generation region with respect to the first target and on the opposite side of the plasma generation region with respect to the second target, respectively, with magnets arranged so that opposite poles face each other, and generating a first main magnetic field and a second main magnetic field on the surfaces of the first target and the second target, respectively. d) A power supply that generates an electric field within the plasma generation region by applying a predetermined potential to the first target holder and the second target holder, respectively, e) A high-frequency electromagnetic field generating unit provided on the side of the plasma generation region facing the substrate holder across the plasma generation region, which generates a high-frequency electromagnetic field within the plasma generation region, f) A plasma source gas introduction unit for introducing plasma source gas into the plasma generation region 、 g) An auxiliary magnetic field generating unit provided at the substrate holder-side ends of the first target holder and the second target holder, which generates an auxiliary magnetic field for confining cations and electrons within the plasma generation region, and which directs the auxiliary magnetic field from one side of the first target holder and the second target holder to the other side. Equipped with, The ends of the first target holder and the second target holder on the high-frequency electromagnetic field generation side do not have means for generating a magnetic field. It is characterized by the following:

[0012] In the sputtering apparatus according to the present invention, atoms or molecules of the plasma raw material gas supplied from the plasma raw material gas supply unit to the plasma generation region are subjected to the high-frequency electromagnetic field in addition to the electric field and main magnetic field (the first main magnetic field and the second main magnetic field), thereby promoting ionization.

[0013] There are no magnetic field generating means at the ends of the first target holder and the second target holder on the high-frequency electromagnetic field generating unit side. In other words, the sputtering apparatus according to the present invention does not have anything equivalent to the second auxiliary magnetic field generating unit 932 in the sputtering apparatus 90 described above. This is because if a magnetic field other than the main magnetic field is generated at the end, the high-frequency electromagnetic field generated in the high-frequency electromagnetic field generating unit will be disturbed, and the generation of plasma by the high-frequency electromagnetic field will be hindered. Furthermore, in the present invention, since the magnets are arranged in the first main magnetic field generating unit and the second main magnetic field generating unit so that opposite poles (N pole and S pole) face each other, the magnetic fields near the surface of the first target and near the surface of the second target formed by the first main magnetic field and the second main magnetic field have the effect of confining positive ions and electrons within the plasma generation region. Therefore, positive ions and electrons can be confined within the plasma generation region even without providing a magnetic field generating means equivalent to the second auxiliary magnetic field generating unit 932.

[0014] According to the sputtering apparatus of the present invention, by confining cations and electrons within the plasma generation region in this manner, and by promoting the ionization of atoms or molecules of the plasma raw material gas with the high-frequency electromagnetic field generated by the high-frequency electromagnetic field generation unit, the density of the plasma within the plasma generation region can be increased, thereby increasing the film deposition rate.

[0015] In the sputtering apparatus according to the present invention, the first target and the second target should be held by the first target holder and the second target holder so that their surfaces face each other. That is, the two surfaces may be inclined toward each other or parallel toward each other. When the surfaces of the first target and the second target are not parallel, it is preferable to position the substrate holder on the side with a wider gap between the two targets, as described in Patent Document 1, so that more sputtered particles can be sent toward the substrate holder, but the present invention is not limited to this. In any orientation in which the first target and the second target are positioned, when comparing those with the same orientation, the present invention, which has a high-frequency electromagnetic field generation unit, can achieve a faster film deposition rate than the conventional configuration without a high-frequency electromagnetic field generation unit.

[0016] The first target and / or the second target are not limited to being flat. For example, Either the first target holder or the second target holder is a cylindrical member that holds a cylindrical target on the side surface of the cylindrical member and is rotatable about the axis of the cylinder. Cylindrical It is a target holder, Of the first and second main magnetic field generating units, those whose corresponding target holder is the cylindrical target holder are located inside the cylindrical member. This configuration can be adopted. By performing sputtering while rotating such a cylindrical target holder around the axis of the cylinder, the entire target can be sputtered nearly uniformly, and the utilization efficiency of the target can be increased. As mentioned above, the magnets in the first main magnetic field generating unit and the second main magnetic field generating unit are arranged so that opposite poles face each other (and this state is maintained), so the first main magnetic field generating unit and / or the second main magnetic field generating unit, which are located inside the cylindrical member, do not rotate in conjunction with the rotation of the cylindrical member.

[0017] The potential applied by the power supply to the first target holder and the second target holder may be a direct current (DC) that is continuously applied, or may be a DC (DC pulse) or an alternating current (high frequency) that is repeatedly applied in a pulsed manner. It is also possible to set the potential applied to one of the first target holder and the second target holder as (continuous) DC and the other as a DC pulse or an alternating current.

[0018] For the high-frequency electromagnetic field generation unit, a capacitive coupling type antenna (capacitive coupling type electrode) that generates a high-frequency electromagnetic field by applying a high-frequency voltage between two electrodes or between one electrode and the ground, an inductive coupling type antenna that generates a high-frequency electromagnetic field by flowing a high-frequency current through a conductor, etc. can be used. In particular, it is preferable to use an inductive coupling type antenna that is less likely to cause abnormal discharge even when generating a strong high-frequency electromagnetic field in the high-frequency electromagnetic field generation unit.

[0019] The sputtering apparatus according to the present invention ,before On the end portions of the first target holder and the second target holder on the substrate holder side, an auxiliary magnetic field generation unit (corresponding to the first auxiliary magnetic field generation unit 931 included in the sputtering apparatus 90) that generates an auxiliary magnetic field directed from one side to the other side of the first target holder and the second target holder is provided. ru. Thereby, cations and electrons can be confined within the plasma generation region. Also, unlike the end portion on the high-frequency electromagnetic field side, even if such an auxiliary magnetic field is generated at the end portion of the plasma generation region on the substrate holder side, it does not interfere with the generation of plasma by the high-frequency electromagnetic field generated by the high-frequency electromagnetic field generation unit. Therefore, by providing an auxiliary magnetic field generation unit on the substrate holder side, the plasma density can be further increased.

[0020] In the sputtering apparatus according to the present invention, among the first main magnetic field generation unit and the second main magnetic field generation unit, one includes one or more permanent magnets, and one pole (N pole or S pole) of the one or more first permanent magnets faces the plasma generation [[ID=十七]] region side, and the other includes one or more permanent magnets, and the other pole of the one or more second permanent magnets faces the plasma generation regionThose facing the side (when the N pole of the first permanent magnet is directed towards the plasma generation region side, the other pole is the S pole, and when the S pole of the first permanent magnet is directed towards the plasma generation region side, the other pole is the N pole). Such a configuration can be adopted. As a result, compared with the case where a magnetron used in many sputtering apparatuses is used as the first main magnetic field generation unit and the second main magnetic field generation unit, it is easier to confine cations and electrons in the plasma generation region sandwiched between the first target holder and the second target holder. Therefore, region the density of the plasma in the plasma generation can be made higher.

Advantages of the Invention

[0021] According to the sputtering apparatus of the present invention, the plasma density can be increased, and thereby the film formation rate can be increased.

Brief Description of the Drawings

[0022] [Figure 1] Schematic configuration diagram showing a first embodiment of a sputtering apparatus according to the present invention. <​​​​​​​​​​​​​​​​​​A graph showing the results of measuring the film deposition rate in the sputtering apparatus of the second embodiment and comparative example. [Figure 8] A schematic cross-sectional view showing a third embodiment of the sputtering apparatus according to the present invention. [Figure 9] A schematic diagram showing a modified example of the sputtering apparatus of the second embodiment. [Figure 10] A schematic diagram showing an example of a conventional sputtering apparatus. [Modes for carrying out the invention]

[0023] An embodiment of the sputtering apparatus according to the present invention will be described using Figures 1 to 9.

[0024] (1) First Embodiment (1-1) Configuration of the sputtering apparatus of the first embodiment The sputtering apparatus 10 of the first embodiment shown in Figure 1 includes a first target holder 111, a second target holder 112, a substrate holder 16, a first main magnetic field generation unit 121, a second main magnetic field generation unit 122, an auxiliary magnetic field generation unit 131, a DC power supply (corresponding to the aforementioned power supply) 14, an inductively coupled antenna (high-frequency electromagnetic field generation unit) 17, a plasma raw material gas introduction unit 15, and a high-frequency power supply (a power supply different from the aforementioned power supply) 171. All components except the DC power supply 14 and the high-frequency power supply 171 are housed in a vacuum chamber 19. When the sputtering apparatus 10 is in operation, the atmosphere inside the vacuum chamber 19 is exhausted by a vacuum pump (not shown).

[0025] Both the first target holder 111 and the second target holder 112 are plate-shaped targets (the one held in the first target holder 111 is called the first target T1). , theThe first target holder 111 and the second target holder 112 hold the second target T2, and also function as electrodes to which a negative potential of a predetermined value is applied by the DC power supply 14. The first target holder 111 and the second target holder 112 are arranged such that the surface of the second target T2, held in the second target holder 112, faces in a direction that is inclined with respect to the surface of the first target T1, held in the first target holder 111.

[0026] Since plasma is generated in the region between the first target T1 held in the first target holder 111 and the second target T2 held in the second target holder 112, this region is called the plasma generation region R.

[0027] The substrate holder 16 is located on the side of the plasma generation region R where the distance between the first target T1 and the second target T2 is wider (to the right of the plasma generation region R in Figure 1). The surface of the substrate holder 16 faces the plasma generation region R, and the substrate S is held on this surface. In this embodiment, the angle between the normal to the surface of the substrate holder 16 (the dashed line in Figure 1) and the surface of the first target holder 111, and the angle θ between the normal and the surface of the second target holder 112, are both 10° (therefore, the angle 2θ between the surface of the first target holder 111 and the surface of the second target holder 112 is 20°). The angle θ is not limited to 10°, but it is preferable to set it to 22.5° or less (2θ to 45° or less) so that the opening on the substrate holder 16 side of the plasma generation region R does not become too large.

[0028] The first main magnetic field generator 121 is located on the back side of the first target holder 111 (i.e., on the opposite side of the plasma generation region R, with the first target T1 in between), and generates a magnetic field within the plasma generation region R, including the surface of the first target T1. Similarly, the second main magnetic field generator 122 is located on the back side of the second target holder 112 (i.e., on the opposite side of the plasma generation region R, with the second target T2 in between), and generates a magnetic field within the plasma generation region R, including the surface of the second target T2. In this embodiment, the first main magnetic field generator 121 and the second main magnetic field generator 122 use magnetrons made from permanent magnets. A magnetron is a magnetic field generator that has been used in many sputtering apparatuses in the past. In the first main magnetic field generator 121, a magnet is positioned at a location corresponding to the center of the first target holder 111 so that its south pole faces the plasma generation region R, and magnets are positioned at two opposite ends of the first target holder 111 so that their north poles face the plasma generation region R. In the second main magnetic field generation unit 121, a magnet is positioned at the center of the second target holder 112 such that its north pole faces the plasma generation region R, and magnets are positioned at the two opposing ends of the second target holder 112 such that their south poles face the plasma generation region R. As a result, the magnets in the first main magnetic field generation unit 121 and the second main magnetic field generation unit 122 are positioned so that their opposite poles face each other across the plasma generation region R. Alternatively, the magnets in the first main magnetic field generation unit 121 and the second main magnetic field generation unit 122 may be positioned so that the poles of all the magnets are opposite to those described above.

[0029] The first target holder 111, the second target holder 112, the first main magnetic field generation unit 121, and the second main magnetic field generation unit 122 are each provided with a cooling water supply mechanism (not shown) for cooling them.

[0030] The auxiliary magnetic field generating unit 131 is a permanent magnet provided at the ends of the first target holder 111 and the second target holder 112 closer to the substrate holder 16, and generates a magnetic field (referred to as the "auxiliary magnetic field") directed from one side of the first target holder 111 and the second target holder 112 to the other side at the end of the plasma generation region R closer to the substrate holder 16. In the example shown in Figure 1, the auxiliary magnetic field generating unit 131 consists of a first auxiliary magnet 1311 provided on the first target holder 111 and positioned so that its north pole faces the plasma generation region R (in the same direction as the magnets at both ends of the first main magnetic field generating unit 121), and a second auxiliary magnet 1312 provided on the second target holder 112 and positioned so that its south pole faces the plasma generation region R (in the same direction as the magnets at both ends of the second main magnetic field generating unit 122). Furthermore, if the magnets of the first main magnetic field generating unit 121 and the second main magnetic field generating unit 122 are arranged in the opposite direction to that of the above example, the first auxiliary magnet 1311 and the second auxiliary magnet 1312 are also arranged in the opposite direction to that of the above example.

[0031] The ends of the first target holder 111 and the second target holder 112 opposite to the substrate holder 16 (towards the inductively coupled antenna 17) do not have auxiliary magnetic field generating units similar to the auxiliary magnetic field generating unit 131.

[0032] The DC power supply 14 is connected in parallel to the first target holder 111 and the second target holder 112, and continuously applies a negative DC potential to these two target holders. This generates a DC electric field between the power supply and ground within the plasma generation region R, which includes the surfaces of the first target T1 and the second target T2. Alternatively, instead of the DC power supply 14, a DC pulse power supply or a high-frequency power supply (separate from the high-frequency power supply 171) may be used to apply a high-frequency voltage between the first target holder 111 and the second target holder 112 and ground, thereby generating a high-frequency electric field within the plasma generation region R.

[0033] The inductively coupled antenna 17 is positioned to the side of the plasma generation region R, facing the substrate holder 16 across the plasma generation region R. In this embodiment, the inductively coupled antenna 17 consists of a U-shaped linear conductor, and a high-frequency current supplied from the high-frequency power supply 171 flows through the linear conductor, generating a high-frequency electromagnetic field in the region including the plasma generation region R. An impedance matching unit 172 is provided between the high-frequency power supply 171 and the inductively coupled antenna 17.

[0034] Two grounded electrodes 18 are placed on each side of the first target holder 111 and the second target holder 112, flanking the target holders. The walls of the vacuum container 19 are made of a conductive material and are grounded.

[0035] The plasma raw material gas introduction section 15 introduces the plasma raw material gas into the plasma generation region R. In this embodiment, the plasma raw material gas used is either Ar (argon) gas or a mixed gas of Ar and N2 (nitrogen).

[0036] (1-2) Operation of the sputtering apparatus of the first embodiment The operation of the sputtering apparatus 10 is described below. First, the first target T1 is held in the first target holder 111, the second target T2 in the second target holder 112, and the substrate S in the substrate holder 16. In this state, the gas (atmosphere) inside the vacuum chamber 19 is discharged to the outside by a vacuum pump. After that, the plasma raw material gas is supplied from the plasma raw material gas introduction section 15 into the plasma generation region R.

[0037] Furthermore, a DC electric field is generated within the plasma generation region R by applying a DC voltage from the DC power supply 14 between the first target holder 111 and the second target holder 112 and the ground electrode 18 and the wall of the vacuum vessel 19 (which is grounded as described above). In addition, a high-frequency electromagnetic field is generated within the plasma generation region R by passing a high-frequency current from the high-frequency power supply 171 to the inductively coupled antenna 17. The first main magnetic field generation unit 121 and the second main magnetic field generation unit 122 generate a main magnetic field within the plasma generation region R. Near the end of the plasma generation region R on the substrate holder 16 side, an auxiliary magnetic field is generated by the auxiliary magnetic field generation unit 131.

[0038] Atoms or molecules of the plasma source gas are ionized into positive ions and electrons by a DC electric field, a high-frequency electromagnetic field, and a main magnetic field. This generates plasma. Then, on the surfaces of targets T1 and T2, the electric fields (DC, DC pulses, or high frequency) applied to targets T1 and T2 attract positive ions toward the target surface, and the positive ions are incident on the surfaces of targets T1 and T2. As a result, targets T1 and T2 are sputtered. The sputtered particles thus generated mainly fly toward the substrate holder 16, as the surfaces of targets T1 and T2 are tilted toward the substrate holder 16, and are deposited on the surface of the substrate S held by the substrate holder 16. As a result, a film made of the material of targets T1 and T2 is fabricated on the surface of the substrate S.

[0039] In the sputtering apparatus 10 of this embodiment, in addition to the DC electric field and the main magnetic field, a high-frequency electromagnetic field from the inductively coupled antenna 17 acts, which can promote the ionization of atoms or molecules of the plasma raw material gas more effectively than when the inductively coupled antenna 17 is absent.

[0040] Of the positive ions and electrons generated in the plasma generation region R, those that fly toward the substrate holder 16 are deflected back into the plasma generation region R by the Lorentz force they receive from the auxiliary magnetic field generated near the substrate holder 16 end of the plasma generation region R by the auxiliary magnetic field generation unit 131. This confines the positive ions and electrons within the plasma generation region R. As a result, electrons and charged particles in the plasma are prevented from flying to the surface of the substrate S, and the temperature of the substrate S surface is prevented from rising. On the other hand, no auxiliary magnetic field is generated near the inductively coupled antenna 17 end of the plasma generation region R. However, positive ions and electrons that fly toward the inductively coupled antenna 17 can be confined within the plasma generation region R by the magnetic fields near the surfaces of the first target T1 and the second target T2 formed by the first main magnetic field generation unit 121 and the second main magnetic field generation unit 122.

[0041] As described above, the sputtering apparatus 10 of this embodiment promotes the ionization of atoms or molecules of the plasma raw material gas by the inductively coupled antenna 17, while confining cations and electrons within the plasma generation region R by the components of the magnetic fields directed from one side to the other of the first target holder 111 and the second target holder 112, which are included in the auxiliary magnetic field generated by the auxiliary magnetic field generation unit 131 and the main magnetic field, thereby increasing the plasma density within the plasma generation region R.

[0042] In the sputtering apparatus 10 of this embodiment, if an auxiliary magnetic field is generated at the end of the plasma generation region R on the side of the inductively coupled antenna 17, moving from one side of the first target holder 111 and the second target holder 112 to the other, the high-frequency electromagnetic field generated by the inductively coupled antenna 17 will be disturbed, hindering the generation of plasma by the high-frequency electromagnetic field. As a result, the plasma density within the plasma generation region R cannot be increased. Therefore, as described above, in the sputtering apparatus 10 of this embodiment, an auxiliary magnetic field generation unit is not provided at the end of the first target holder 111 and the second target holder 112 on the side of the inductively coupled antenna 17.

[0043] (2) Second Embodiment (2-1) Configuration and operation of the sputtering apparatus of the second embodiment Figure 2 shows the configuration of the sputtering apparatus 20 of the second embodiment. This sputtering apparatus 20 has the same configuration as the sputtering apparatus 10 of the first embodiment, except that the configuration of the first main magnetic field generation unit 221 and the second main magnetic field generation unit 222 and the inductively coupled antenna 27 differs from the configuration of the first main magnetic field generation unit 121 and the second main magnetic field generation unit 122 and the inductively coupled antenna 17 of the sputtering apparatus 10 of the first embodiment. Therefore, only the configuration of the first main magnetic field generation unit 221 and the second main magnetic field generation unit 222 and the inductively coupled antenna 27 will be described below.

[0044] The first main magnetic field generator 221 is equipped with multiple permanent magnets, all of which have the same pole (N pole in the example shown in Figure 2) facing the plasma generation region R. The second main magnetic field generator 222 is also equipped with multiple permanent magnets, all of which have the same pole, but with the opposite pole (S pole in the example shown in Figure 2) facing the plasma generation region R compared to the multiple permanent magnets of the first main magnetic field generator 221. With this configuration, a main magnetic field is generated throughout the entire plasma generation region R, with one main magnetic field generator 221 and the other main magnetic field generator 222 directing from one to the other. Due to this main magnetic field, positive ions and electrons flying toward the substrate holder 16 or the inductively coupled antenna 27 are subjected to a Lorentz force from the main magnetic field, bending their direction of travel, and thus confining these positive ions and electrons within the plasma generation region R. As in the first embodiment, the first main magnetic field generator 221 and the second main magnetic field generator 222 are also provided with a cooling mechanism (not shown) using cooling water.

[0045] The inductively coupled antenna 27 is a planar antenna made of a metal plate made of a good conductor such as copper. A metal fiber sheet may also be used for the inductively coupled antenna 27 because it is less susceptible to thermal expansion. In this embodiment, the inductively coupled antenna 27 has a rectangular shape, and high-frequency current is introduced via rod-shaped feed terminals 271 attached along both short sides (Figure 3).

[0046] The operation of the sputtering apparatus 20 in the second embodiment is basically the same as the operation of the sputtering apparatus 10 in the first embodiment. As described above, positive ions and electrons can be confined within the plasma generation region R by the main magnetic fields generated by the first main magnetic field generation unit 221 and the second main magnetic field generation unit 222, so the plasma density within the plasma generation region R can be further increased.

[0047] (2-2) Experiments using the sputtering apparatus of the second embodiment and comparative example Next, the results of experiments conducted using the sputtering apparatus 20 of the second embodiment and the comparative sputtering apparatus 80 shown in Figure 4 are presented. The comparative sputtering apparatus 80 is the sputtering apparatus 20 of the second embodiment with a second auxiliary magnetic field generation unit 832 added. The second auxiliary magnetic field generation unit 832 consists of a second-first auxiliary magnet 8321, which is a permanent magnet provided at the end of the first target holder 111 closer to the inductively coupled antenna 27, and a second-second auxiliary magnet 8322, which is a permanent magnet provided at the end of the second target holder 112 closer to the inductively coupled antenna 27. The second-first auxiliary magnet 8321 is positioned so that its north pole faces the plasma generation region R side, and the second-second auxiliary magnet 8322 is positioned so that its south pole faces the plasma generation region R side.

[0048] <Experiment 1> First, for the sputtering apparatus 20 of the second embodiment and the sputtering apparatus 80 of the comparative example, the intensity of the magnetic flux density at each position on the center line (dash-dotted line in Figures 2 and 4), which is the normal to the surface of the substrate holder 16 and is equidistant from the surfaces of the first target holder 111 and the second target holder 112, was measured, specifically the component perpendicular to the center line (vertical component) and the component parallel to the center line (parallel component). The measurement results for the sputtering apparatus 20 of the second embodiment are shown in Figure 5A, and the measurement results for the sputtering apparatus 80 of the comparative example are shown in Figure 5B. In both cases, the vertical component of the magnetic flux density is significantly larger than the parallel component. In the second embodiment, the vertical component of the magnetic flux density near the substrate holder 16 side end of the plasma generation region R (the component of magnetic flux density from the substrate holder 16 side end of one of the first target holder 111 and the second target holder 112 to the substrate holder 16 side end of the other) is larger than in other locations, being 0.03T or higher. In contrast, the vertical component of magnetic flux density near the end of the plasma generation region R on the inductively coupled antenna 27 side (the component of magnetic flux density from the end of the first target holder 111 and the second target holder 112 on the inductively coupled antenna 27 side to the end of the other target holder 112) is smaller than in other locations, being 0.015T or less. On the other hand, in the comparative example, the vertical component of magnetic flux density is larger than in other locations at both the substrate holder 16 side and the inductively coupled antenna 27 side of the plasma generation region R, being 0.03T or more.

[0049] <Experiment 2> For both the sputtering apparatus 20 of the second embodiment and the sputtering apparatus 80 of the comparative example, Ar gas was supplied as the plasma raw material gas at a flow rate of 100 sccm and the pressure was set to 0.5 Pa. Under these conditions, a pulsed DC voltage with an ON time of 3 microseconds and a voltage of -220V during the ON time was applied from the DC power supply 14 between the first target holder 111 and ground, and between the second target holder 112 and ground, at a repetition frequency of 80 kHz. At the same time, high-frequency power (frequency 13.56 MHz) was supplied from the high-frequency power supply 171 to the inductively coupled antenna 27. In the sputtering apparatus 20 of the second embodiment, it was confirmed that plasma was stably generated by the inductively coupled antenna when the high-frequency power was in the range of 100 to 1500 W. In particular, when the high-frequency power was 1100 W or higher, it was inferred from the change in the matching position in the impedance matcher 172 that plasma in the inductively coupled mode was being generated. On the other hand, in the comparative example sputtering apparatus 80, plasma could not be stably generated by the inductively coupled antenna 27 even when the high-frequency power was within any range of 100 to 600 W. This is thought to be due to the influence of the magnetic field structure near the inductively coupled antenna 27 being different from that of the sputtering apparatus 20 in this embodiment, indicating that optimizing the magnetic field structure near the inductively coupled antenna is important.

[0050] <Experiment 3> Next, with the sputtering apparatus 20 of the second embodiment, targets T1 and T2 made of Al were mounted in the first target holder 111 and the second target holder 112, and a mixed gas of Ar and N2 (with an N2 content in the range of 0-40%; if the content is 0%, it is Ar gas) was supplied as the plasma raw material gas. Under the same conditions as in Experiment 2, a DC voltage was applied by the DC power supply 14, and a high-frequency power of 2000 W and a frequency of 13.56 MHz was supplied to the inductively coupled antenna 27 from the high-frequency power supply 171. The same experiment was performed with the comparative example sputtering apparatus 80, but since Experiment 2 confirmed that an inductively coupled plasma using the inductively coupled antenna 27 could not be generated, high-frequency power was not supplied to the inductively coupled antenna 27. Therefore, the comparative example is substantially the same as the conventional sputtering apparatus 90 without the inductively coupled antenna 27.

[0051] Figure 6 shows a photograph of the film obtained in this experiment. In both the second embodiment and the comparative example, a silver film was obtained when the N2 content was 0%, and a transparent film was obtained when the N2 content was 27% and 40%, respectively. The silver film is a film of elemental Al, and the transparent film is a film of AlN.

[0052] Figure 7 shows the results of measuring the film deposition rate (the thickness of the obtained film divided by the time required for film deposition) in the experiment for the second embodiment and the comparative example. It can be seen that the film deposition rate is faster in the second embodiment than in the comparative example, regardless of the N2 content.

[0053] (3) Third Embodiment Figure 8 shows the configuration of the sputtering apparatus 30 of the third embodiment. The configuration of the first target holder 311, second target holder 312, first main magnetic field generation unit 321, and second main magnetic field generation unit 322 of this sputtering apparatus 30 differs from the configuration of the first target holder 111, second target holder 112, first main magnetic field generation unit 211, and second main magnetic field generation unit 212 in the sputtering apparatus 10 of the first embodiment.

[0054] The first target holder 311 consists of a cylindrical member. Figure 8 shows the entire sputtering apparatus 30 in a cross-section perpendicular to the axis of the cylindrical member. The cylindrical member extends in a direction perpendicular to the plane of the paper in Figure 8. The target T1 is held around the entire circumference of the side surface of this cylindrical member. The first target holder 311 can be rotated around the axis of the cylinder using a motor (not shown). The second target holder 312 has a similar configuration to the first target holder 311, and the target T2 is held around the entire circumference of the side surface of the cylinder and can be rotated around the axis of the cylinder. As the first target holder 311 and the second target holder 312 rotate, the targets T1 and T2 also rotate. Both the first target holder 311 and the second target holder 312 are made of a conductive material and are in contact with a conductor connected to the DC power supply 14, sliding against it during rotation.

[0055] The first main magnetic field generating unit 321 is located inside the cylinder of the first target holder 311, and three magnets are arranged in a direction inclined with respect to the intermediate line between the first target holder 311 and the second target holder 312 (a line perpendicular to the surface of the substrate holder 16; the dashed line in Figure 8). The magnetic poles of these three magnets are arranged so that the S pole, N pole, and S pole face outwards from the cylinder in that order. The second main magnetic field generating unit 322 is located inside the cylinder of the second target holder 312, and three magnets are arranged symmetrically with respect to the intermediate line with respect to the first main magnetic field generating unit 321. However, the magnetic poles of the three magnets in the second main magnetic field generating unit 322 are of opposite polarity to the three magnets in the opposing first main magnetic field generating unit 321, and are arranged in the order of N pole, S pole, and N pole. Furthermore, the first main magnetic field generating unit 321 and the second main magnetic field generating unit 322 do not rotate (even when the first target holder 311 and the second target holder 312 are rotating).

[0056] Cooling water flows inside the cylinders of the first target holder 311 and the second target holder 312, cooling the targets T1 and T2, the first main magnetic field generating unit 321, and the second main magnetic field generating unit 322.

[0057] The sputtering apparatus 30 of the third embodiment is further provided with a ground potential shield plate 34 on the outside of the first target holder 311 and the second target holder 312. The shield plate 34 is open on the side facing the inductively coupled antenna 17 and has an opening 341 at a position facing the substrate holder 16. The sputtering apparatus 30 is also provided with an auxiliary magnetic field generation unit 331, which consists of a first auxiliary magnet 3311 and a second auxiliary magnet 3312 arranged so that their poles are opposite each other across the opening 341. By arranging the auxiliary magnetic field generation unit 331 in this way, horizontal magnetic field lines are formed with respect to the opening 341 of the shield plate 34, and the plasma generated between the first target holder 311 and the second target holder 312 is confined. As a result, electrons and charged particles in the plasma are prevented from flying to the surface of the substrate S, and the temperature of the substrate S surface is prevented from rising.

[0058] The ends of the first target holder 311 and the second target holder 312 opposite to the substrate holder 16 (towards the inductively coupled antenna 17) do not have auxiliary magnetic field generating units similar to the auxiliary magnetic field generating unit 331. Although the sputtering apparatus 30 of the third embodiment does not have a ground electrode 18, a ground electrode may be provided near the first target holder 311 and the second target holder 312.

[0059] The operation of the sputtering apparatus 30 in the third embodiment is the same as that of the sputtering apparatus 10 in the first embodiment, except that the first target holder 311 and the second target holder 312 are rotated during the sputtering process. By rotating the first target holder 311 and the second target holder 312 in this way, the entire surface of targets T1 and T2 held by them can be sputtered uniformly.

[0060] (4) Variations The present invention is not limited to the embodiments described above, and various modifications are possible.

[0061] For example, in the sputtering apparatus 10 of the first embodiment and the sputtering apparatus 30 of the third embodiment, a planar inductively coupled antenna 27 made of a metal plate or metal fiber, as used in the second embodiment, may be used instead of the U-shaped inductively coupled antenna 17. Furthermore, the inductively coupled antenna is not limited to U-shaped or planar types; a coil made by winding a linear conductor many times or other inductively coupled antennas may also be used.

[0062] A capacitively coupled antenna (electrode) may be used instead of an inductively coupled antenna as the high-frequency electromagnetic field generator. However, an inductively coupled antenna is preferable to a capacitively coupled antenna because it is less likely to cause abnormal discharge even when generating a strong high-frequency electromagnetic field.

[0063] In the sputtering apparatus 10 of the first embodiment, the first main magnetic field generating unit 221 and the second main magnetic field generating unit 222 used in the second embodiment may be used instead of the first main magnetic field generating unit 121 and the second main magnetic field generating unit 122, which are magnetrons. Furthermore, the first main magnetic field generating unit and the second main magnetic field generating unit in each embodiment are not limited to the above examples, and various magnetic field generating means can be used.

[0064] In the sputtering apparatus 20 of the second embodiment, the first main magnetic field generating unit 221 and the second main magnetic field generating unit 222 used, and in the sputtering apparatus 30 of the third embodiment, the first main magnetic field generating unit 321 and the second main magnetic field generating unit 322 used, each used multiple permanent magnets. However, one or both of these main magnetic field generating units may use only one permanent magnet.

[0065] The auxiliary magnetic field generation unit 131 is not essential in the present invention and may be omitted, as shown in the sputtering apparatus 20A illustrated in Figure 9. Although Figure 9 shows an example in which the auxiliary magnetic field generation unit 131 is omitted from the sputtering apparatus 20 of the second embodiment, the auxiliary magnetic field generation unit may also be omitted in other configurations such as the first embodiment and the third embodiment.

[0066] In the sputtering apparatus 10 of the first embodiment and the sputtering apparatus 20 of the second embodiment, two target holders were arranged so that two flat plate-shaped targets were not parallel to each other, but they may also be arranged parallel to each other. Also, in the sputtering apparatus 30 of the third embodiment, two target holders were arranged so that the axes of two cylindrical targets were parallel to each other, but they may also be arranged not parallel to each other.

[0067] In the sputtering apparatus 10 of the first embodiment and the sputtering apparatus 20 of the second embodiment, two flat plate-shaped targets were used, and in the sputtering apparatus 30 of the third embodiment, two cylindrical targets were used. However, one of the two targets may be flat plate-shaped and the other cylindrical. [Explanation of Symbols]

[0068] 10, 20, 20A, 30, 80, 90... Sputtering equipment 111, 311, 911… First target holder 112, 312, 912… Second target holder 121, 221, 321, 921... First main magnetic field generation unit 122, 222, 322, 922... Second main magnetic field generation unit 131, 331... Auxiliary magnetic field generation unit 1311, 3311… First auxiliary magnet 1312, 3312... Second auxiliary magnet 14, 94…DC power supply 15, 95... Plasma raw material gas introduction section 16, 96... Circuit board holder 17, 27… Inductively coupled antennas 171...High frequency power supply 172... Impedance Matcher 18, 98...ground electrode 19, 99...Vacuum container 271... Power supply terminal 832, 932... Second auxiliary magnetic field generation unit 8321, 9321… Second-first auxiliary magnet 8322, 9322… Second-second auxiliary magnet 931...First auxiliary magnetic field generation unit 9311…1st-1 Auxiliary Magnet 9312…1st-2nd auxiliary magnet R...Plasma generation region S... Circuit board T1…Target 1 T2…Second target

Claims

1. a) A first target holder and a second target holder, respectively, which hold the first target and the second target so that their surfaces face each other, b) A substrate holder provided on one side of the plasma generation region, which is the region between the first target and the second target held by the first target holder and the second target holder, respectively, c) A first main magnetic field generating unit and a second main magnetic field generating unit are provided on the opposite side of the plasma generation region with respect to the first target and on the opposite side of the plasma generation region with respect to the second target, respectively, with magnets arranged so that opposite poles face each other, and generating a first main magnetic field and a second main magnetic field on the surfaces of the first target and the second target, respectively. d) A power supply that generates an electric field within the plasma generation region by applying a predetermined potential to the first target holder and the second target holder, respectively, e) A high-frequency electromagnetic field generating unit provided on the side of the plasma generation region facing the substrate holder across the plasma generation region, which generates a high-frequency electromagnetic field within the plasma generation region, f) A plasma source gas introduction unit for introducing plasma source gas into the plasma generation region, g) An auxiliary magnetic field generating unit provided at the substrate holder-side ends of the first target holder and the second target holder, which generates an auxiliary magnetic field that confines cations and electrons within the plasma generation region and directs from one side of the first target holder and the second target holder to the other side; Equipped with, The ends of the first target holder and the second target holder on the high-frequency electromagnetic field generation side do not have means for generating a magnetic field. A sputtering apparatus characterized by the following features.

2. The sputtering apparatus according to claim 1, characterized in that the first target holder and the second target holder each hold the first target and the second target such that their surfaces are inclined and facing each other.

3. The sputtering apparatus according to claim 2, characterized in that the substrate holder is provided on the side with the wider spacing of the plasma generation region.

4. The sputtering apparatus according to any one of claims 1 to 3, characterized in that the auxiliary magnetic field generating unit comprises a first auxiliary magnet provided at the end of the first target holder closer to the substrate holder, and a second auxiliary magnet provided at the end of the second target holder closer to the substrate holder.

5. Either one or both of the first target holder and the second target holder is a cylindrical member that holds a cylindrical target on the side surface of a cylindrical member and is rotatable about the axis of the cylinder, Of the first and second main magnetic field generating units, those whose corresponding target holder is the cylindrical target holder are located inside the cylindrical member. The sputtering apparatus according to feature 1.

6. Furthermore, a shielding plate is provided on the outside of the first target holder and the second target holder, and has an opening at a position facing the substrate holder. The auxiliary magnetic field generating unit includes a first auxiliary magnet and a second auxiliary magnet arranged to face each other across the opening. The sputtering apparatus according to feature 5.

7. The sputtering apparatus according to any one of claims 1 to 6, characterized in that the high-frequency electromagnetic field generating unit is an inductively coupled high-frequency antenna.

8. The sputtering apparatus according to any one of claims 1 to 7, characterized in that one of the first main magnetic field generating unit and the second main magnetic field generating unit comprises one or more permanent magnets, with one pole of the one or more first permanent magnets facing toward the plasma generation region, and the other comprises one or more permanent magnets, with the other pole of the one or more second permanent magnets facing toward the plasma generation region.

9. The magnitude of the magnetic flux density component extending from the substrate holder side end of one of the first target holder and the second target holder to the substrate holder side end of the other target holder is 0.03T or greater, The magnitude of the magnetic flux density component extending from the end of the first target holder and the second target holder on the high-frequency electromagnetic field generation side to the end of the other target holder on the high-frequency electromagnetic field generation side is 0.015T or less. The sputtering apparatus according to any one of claims 1 to 8, characterized in that it is the same as described above.

Images