Film forming apparatus

Abstract

To provide a film forming apparatus that can improve film quality.SOLUTION: The magnetic field generating unit 70 causes the plasma P to be incident on a surface SF of the film forming material Ma by maintaining the magnetic field MF such that a zero magnetic field position ZMP at which the magnetic field MF inside a chamber 10 becomes zero is at a predetermined position. The magnetic field generating unit 70 adjusts the zero magnetic field position ZMP to an appropriate position, thereby making the plasma P be an appropriate magnetic field configuration to be incident on the surface SF of the film forming material Ma. The magnetic field generating unit 70 has a directional component in a Z-axis direction in which a substrate 11 and the film forming material Ma face each other, and sets the zero magnetic field position ZMP such that the plasma P is incident on the surface SF of the film forming material Ma, thereby making the plasma P be incident in an appropriate incident mode to vaporize the film forming material Ma evenly.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a film forming apparatus.

Background Art

[0002] As a film forming apparatus, as described in Patent Document 1, a film forming apparatus that forms a film forming material on an object by an ion plating method is known. This film forming apparatus generates plasma in a chamber using a plasma gun and sublimates the film forming material in the chamber. The film forming material adheres to the substrate and continuously deposits, so that a film grows and is formed on the substrate.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Here, in the above-described film forming apparatus, it is required to form a high-quality film with a uniform film thickness. In order to form a high-quality film, it is required that the plasma be incident on the surface of the film forming material in an appropriate manner when it is incident.

[0005] Therefore, an object of the present invention is to provide a film forming apparatus capable of improving film quality.

Means for Solving the Problems

[0006] The film forming apparatus according to the present invention is a film forming apparatus that forms a film forming material on an object by the RPD method, and includes a chamber, a plasma gun that generates plasma in the chamber, an anode that can dispose the film forming material in the chamber and guides the plasma, a magnetic field generating unit that generates a magnetic field in the chamber, and the magnetic field generating unit maintains the magnetic field so that a zero magnetic field position where the magnetic field in the chamber becomes zero is a predetermined position, thereby making the plasma incident on the surface of the film forming material, and the magnetic field generating unit sets the zero magnetic field position so as to have a direction component in a first direction in which the object and the film forming material face each other and the plasma is incident on the surface of the film forming material.

[0007] In the film forming apparatus according to the present invention, the magnetic field generating unit makes the plasma incident on the surface of the film forming material by maintaining the magnetic field so that a zero magnetic field position where the magnetic field in the chamber becomes zero is a predetermined position. In this way, the magnetic field generating unit can adjust the zero magnetic field position to an appropriate position to obtain an appropriate magnetic field configuration for making the plasma incident on the surface of the film forming material. The magnetic field generating unit sets the zero magnetic field position so as to have a direction component in a first direction in which the object and the film forming material face each other and the plasma is incident on the surface of the film forming material. Thereby, the plasma can be incident in an appropriate incident mode for uniformly evaporating the film forming material. From the above, the film quality of the film formed on the object can be improved.

[0008] The magnetic field generating unit may set the zero magnetic field position so that the plasma is incident on the entire surface of the film forming material. Thereby, the film forming material can be uniformly evaporated.

[0009] The magnetic field generating unit may have a ring heater disposed around the anode. Thereby, the magnetic field can be adjusted around the anode.

[0010] The magnetic field generating unit may set the zero magnetic field position at a position below the central axis of the plasma gun with respect to the surface of the film forming material in the first direction. In this case, it is possible to suppress the plasma from spreading too much with respect to the film forming material.

[0011] The magnetic field generating unit may set a zero magnetic field position at a position that is equal to or greater than the width dimension of the film forming material with respect to the surface of the film forming material in the first direction. In this case, a space for the plasma to spread with respect to the film forming material is ensured, and it is possible to suppress the plasma from being incident only on a part of the surface of the film forming material.

[0012] The magnetic field generating unit may set a zero magnetic field position at a position within the inner circumference of the toroidal core on the plasma gun side with respect to the central axis of the film forming material in the second direction in which the central axis of the plasma gun extends. In this case, it is possible to suppress the plasma from being overly biased toward the plasma gun side, and it is possible to suppress the plasma from being incident only on a part of the surface of the film forming material.

[0013] The magnetic field generating unit may set a zero magnetic field position at a position within the inner circumference of the anode on the side opposite to the plasma gun with respect to the central axis of the film forming material in the second direction in which the central axis of the plasma gun extends. In this case, it is possible to suppress the plasma from being overly biased toward the side opposite to the plasma gun, and it is possible to suppress the plasma from being incident only on a part of the surface of the film forming material.

[0014] The magnetic field generating unit may set a zero magnetic field position at a position where the distance from the surface of the film forming material in the first direction is 65 mm to 105 mm. In this case, a space for the plasma to spread with respect to the film forming material is ensured, and it is possible to suppress the plasma from being incident only on a part of the surface of the film forming material.

[0015] The magnetic field generating unit may set a zero magnetic field position at a position where the distance from the central axis of the film forming material in the second direction in which the central axis of the plasma gun extends is 20 mm to 55 mm toward the plasma gun side. In this case, it is possible to suppress the plasma from being overly biased toward the plasma gun side, and it is possible to suppress the plasma from being incident only on a part of the surface of the film forming material.

[0016] The magnetic field generating unit may further include at least one of the electrode of the plasma gun and the steering coil of the plasma gun. In this case, the magnetic field can be adjusted on the plasma gun side.

Advantages of the Invention

[0017] According to the present invention, a film forming apparatus capable of improving film quality is provided.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0019] Hereinafter, a film forming method and a film forming apparatus according to an embodiment of the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant descriptions are omitted.

[0020] First, referring to FIG. 1, the configuration of a film forming apparatus according to an embodiment of the present invention will be described. FIG. 1 is a schematic cross-sectional view showing the configuration of the film forming apparatus 1. As shown in FIG. 1, the film forming apparatus 1 of the present embodiment is an RPD (Reactive Plasma Deposition) film forming apparatus used in a so-called RPD method, which is a type of ion plating method. The feature of the RPD method is that plasma generated at high density using the plasma gun 7 is introduced into the film forming material Ma by the hearth mechanism 2, and the sublimation of the material and the ionization of the sublimated material particles are performed by the same mechanism. In the RPD method, since high-density plasma is used, the ionization rate of the material particles is high, and a thinner film that is denser and has stronger adhesion to the substrate can be formed compared to a general ion plating method. For convenience of explanation, an XYZ coordinate system is shown in FIG. 1. The Y-axis direction is the direction in which the central axis of the plasma gun 7 extends. The Z-axis direction is the position where the substrate and the hearth mechanism described later face each other. The X-axis direction is a direction orthogonal to the Y-axis direction and the Z-axis direction.

[0021] The film forming apparatus 1 may be a so-called horizontal film forming apparatus in which the substrate 11 (object) is disposed and conveyed in the chamber 10 such that the plate thickness direction of the substrate 11 is substantially vertical. In this case, the X-axis and Y-axis directions are horizontal, and the Z-axis direction is vertical and the plate thickness direction. Note that the film forming apparatus 1 may be a so-called vertical film forming apparatus in which the substrate 11 is disposed and conveyed in the chamber 10 in a state where the substrate 11 is inclined from an upright or upright state such that the plate thickness direction of the substrate 11 is the horizontal direction (Z-axis direction in FIG. 1). In this case, the Z-axis direction is horizontal and the plate thickness direction of the substrate 11, the Y-axis direction is horizontal, and the X-axis direction is vertical. The film forming apparatus according to an embodiment of the present invention will be described below using a horizontal film forming apparatus as an example.

[0022] The film forming apparatus 1 includes a chamber 10 (chamber), a transfer mechanism 3, and a film forming mechanism 14.

[0023] Chamber 10 is a member for accommodating substrate 11 and performing film formation processing. Chamber 10 has a transfer chamber 10a for transferring substrate 11 on which a film of film-forming material Ma is to be formed, a film-forming chamber 10b for diffusing film-forming material Ma, and a plasma port 10c for receiving plasma P irradiated in a beam shape from plasma gun 7 into chamber 10. Transfer chamber 10a, film-forming chamber 10b, and plasma port 10c communicate with each other. Transfer chamber 10a is set along a predetermined transfer direction (arrow A in the figure) (in the Y-axis direction). Also, chamber 10 is made of a conductive material and is connected to the ground potential.

[0024] The film-forming chamber 10b has, as wall portions 10W, a pair of side walls along the transfer direction (arrow A), a pair of side walls 10h, 10i along the direction (Z-axis direction) intersecting the transfer direction (arrow A), and a bottom wall 10j arranged to intersect the X-axis direction.

[0025] Transfer mechanism 3 transfers substrate holding member 16 that holds substrate 11 in a state facing film-forming material Ma in the transfer direction (arrow A). For example, substrate holding member 16 is a frame that holds the outer peripheral edge of substrate 11. Transfer mechanism 3 is constituted by a plurality of transfer rollers 15 installed in transfer chamber 10a. Transfer rollers 15 are arranged at equal intervals along the transfer direction (arrow A) and transfer substrate holding member 16 in the transfer direction (arrow A) while supporting it. Note that as substrate 11, a plate-like member such as a glass substrate or a plastic substrate is used.

[0026] Subsequently, the configuration of film-forming mechanism 14 will be described in detail. Film-forming mechanism 14 attaches particles generated as a result of the sublimation of film-forming material Ma to substrate 11 by the ion plating method. Film-forming mechanism 14 has a plasma gun 7, a steering coil 5, a hearth mechanism 2, and a ring hearth 6.

[0027] The plasma gun 7 is, for example, a pressure-gradient type plasma gun, and its main body is connected to the film deposition chamber 10b through a plasma port 10c provided on the side wall of the film deposition chamber 10b. The plasma gun 7 generates plasma P in the chamber 10. The plasma P generated in the plasma gun 7 is emitted in a beam shape from the plasma port 10c into the film deposition chamber 10b. Thereby, plasma P is generated in the film deposition chamber 10b.

[0028] The plasma gun 7 generates plasma by discharging argon gas introduced through the cathode 60. Between the cathode 60 and the plasma port 10c, a first intermediate electrode (grid) 61 and a second intermediate electrode (grid) 62 are concentrically arranged. An annular permanent magnet 61a for converging the plasma P is built into the first intermediate electrode 61. An electromagnetic coil 62a for converging the plasma P is also built into the second intermediate electrode 62. In this embodiment, the first intermediate electrode 61 is arranged closer to the cathode 60 side than the second intermediate electrode 62, but the positional relationship may be the opposite.

[0029] The steering coil 5 is provided around the plasma port 10c where the plasma gun 7 is mounted. The steering coil 5 guides the plasma P into the film deposition chamber 10b. The steering coil 5 is excited by passing a current through a power source (not shown) for the steering coil.

[0030] The hearth mechanism 2 holds the film-forming material Ma. The hearth mechanism 2 is provided in the film deposition chamber 10b of the chamber 10 and is arranged in the negative direction of the Z-axis direction as viewed from the transfer mechanism 3. The hearth mechanism 2 has a main hearth 17 that is a main anode for guiding the plasma P emitted from the plasma gun 7 to the film-forming material Ma or a main anode for guiding the plasma P emitted from the plasma gun 7 to itself. The configuration of the main hearth will be described later.

[0031] The annular hearth 6 is an auxiliary anode having an electromagnet for inducing plasma P. The annular hearth 6 is disposed around the container 17a of the main hearth 17 that holds the film-forming material Ma. The annular hearth 6 has an annular coil 20, an annular permanent magnet section 9, and an annular container 12, and the coil 20 and the permanent magnet section 9 are accommodated in the container 12. In the present embodiment, the permanent magnet section 9 and the coil 20 are installed in this order in the Z negative direction as viewed from the transport mechanism 3, but they may be installed in the order of the coil 20 and the permanent magnet section 9 in the Z negative direction. The annular hearth 6 controls the direction of the plasma P incident on the film-forming material Ma or the direction of the plasma P incident on the main hearth 17 according to the magnitude of the current flowing through the coil 20.

[0032] The gas supply unit 40 supplies a carrier gas and an oxygen gas into the chamber 10. As substances contained in the carrier gas, for example, noble gases such as argon and helium are adopted. The gas supply unit 40 is disposed outside the chamber 10 and supplies the source gas into the chamber 10 through a gas supply port provided in the side wall (for example, the side wall 10h) of the film-forming chamber 10b. The gas supply unit 40 supplies the carrier gas and the oxygen gas at a flow rate based on a control signal from the control unit.

[0033] The power supply 80 supplies current to the plasma gun 7. Thereby, the plasma gun 7 discharges with a discharge current of a predetermined value. The power supply 80 is connected to the plasma gun 7 that is the cathode and the main hearth 17 that is the anode. The power supply 80 supplies a current having a current value based on a control signal from the control unit 90. The control unit 90 is a device that controls the entire film-forming apparatus 1.

[0034] Next, with reference to FIG. 2, the configuration of the main hearth 17 will be described in detail. The main hearth 17 has a function of sublimating the film-forming material Ma. The main hearth 17 has a cylindrical container 17a extending in the positive direction of the Z-axis filled with the film-forming material Ma. Since the main hearth 17 is maintained at a positive potential with respect to the ground potential of the chamber 10, the main hearth 17 serves as an electrode (anode) in the discharge and can attract the plasma P. A through-hole 17b for filling the film-forming material Ma is formed in the container 17a of the main hearth 17 where the plasma P is incident. And the surface SF of the tip portion of the film-forming material Ma is exposed to the film-forming chamber 10b (see FIG. 1) at one end of the through-hole 17b.

[0035] As the film-forming material Ma, for example, conductive materials such as ITO (indium tin oxide doped with tin oxide) and IWO (indium oxide doped with tungsten oxide) are used. When the film-forming material Ma is made of a conductive substance, when the plasma P is irradiated on the main hearth 17, the plasma P directly enters the film-forming material Ma, the surface SF of the tip portion of the film-forming material Ma is heated and sublimated, and the film-forming material particles Mb ionized by the plasma P diffuse into the film-forming chamber 10b (see FIG. 1). The film-forming material particles Mb diffused into the film-forming chamber 10b are ionized by the plasma P, move in the positive direction of the Z-axis of the film-forming chamber 10b, and adhere to the surface of the substrate 11 in the transfer chamber 10a (see FIG. 1). Note that the film-forming material Ma is a solid object formed into a cylindrical shape with a predetermined length, and a plurality of film-forming materials Ma are filled into the hearth mechanism 2 at one time. And as the sublimation (film-forming) speed becomes constant, the film-forming material Ma is sequentially pushed out from the Z-negative direction side of the hearth mechanism 2 so that the tip portion of the film-forming material Ma at the forefront side maintains a predetermined positional relationship with the upper end of the main hearth 17.

[0036] The film-forming material Ma may be an insulating substance such as silicon oxide or tin oxide, for example. When the film-forming material Ma is made of an insulating substance, the plasma P enters the upper end portion 17c of the main hearth 17. Thereby, the main hearth 17 is heated and the film-forming material Ma is heated and sublimated.

[0037] As shown in FIG. 2, the film forming apparatus 1 includes a magnetic field generating unit 70. The magnetic field generating unit 70 is a means for generating a magnetic field MF in the chamber 10. In the present embodiment, the magnetic field generating unit 70 includes a ring hearth 6, a steering coil 5 of the plasma gun 7, electrodes 61 and 62 of the plasma gun 7, and a control unit 90. The ring hearth 6 generates a magnetic field MF1 near the main hearth 17 and the film forming material Ma. The magnetic field MF1 spreads from the positive end of the ring hearth 6 in the Z-axis direction so as to diffuse toward the positive side in the Z-axis direction. The steering coil 5 generates a magnetic field MF2. The magnetic field MF2 spreads around the steering coil 5 from the inner peripheral side toward the positive side in the Y-axis direction. The electrodes 61 and 62 generate a magnetic field MF3. The magnetic field MF3 spreads from the tip side of the plasma gun 7 so as to diffuse toward the positive side in the Y-axis direction. The magnetic field generating unit 70 generates a magnetic field MF (cusp magnetic field) for adjusting the distribution of the plasma P by combining these magnetic fields MF1, MF2, and MF3. The control unit 90 controls the magnetic fields MF1, MF2, and MF3 by controlling the currents flowing through the coil 20 of the ring hearth 6, the steering coil 5, and the coil 62a of the second intermediate electrode 62. Therefore, the control unit 90 can control the magnetic field MF by controlling the currents supplied to the coils 20, 5, and 62a.

[0038] The magnetic field generating unit 70 maintains the magnetic field MF so that the zero magnetic field position ZMP where the magnetic field MF in the chamber 10 becomes zero is at a predetermined position, thereby causing the plasma P to be incident on the surface SF of the film forming material Ma (see FIGS. 3 to 5). The plasma P is emitted from the plasma gun 7 and is incident on the surface SF of the film forming material Ma and the positive end surface of the ring hearth 6 in the Z-axis direction. However, at the zero magnetic field position ZMP, the magnetic flux does not extend in any direction in the three-dimensional direction. The method for specifying the zero magnetic field position ZMP is not particularly limited. For example, the zero magnetic field position ZMP can be specified by specifying the brightest point of the plasma P based on an image of the plasma P (or by using a sensor or the like). Also, the zero magnetic field position ZMP can be specified by measuring the inside of the chamber 10 with a gauss meter.

[0039] The magnetic field generation unit 70 can keep the position of the zero magnetic field position ZMP constant by maintaining the generation mode of the magnetic field MF. That is, the position of the zero magnetic field position ZMP changes as the distribution of the magnetic flux of the magnetic field MF changes. Therefore, when the magnetic field generation unit 70 maintains the distribution of the magnetic flux of the magnetic field MF at a certain distribution, the zero magnetic field position ZMP is also maintained at a constant position. Specifically, the control unit 90 can keep the zero magnetic field position ZMP constant by maintaining the current values for the respective coils 20, 5, 62a at constant values. As the distribution of the magnetic flux of the magnetic field MF changes, the behavior of the plasma P in the chamber 10 changes, and the incident mode of the plasma P on the surface SF of the film-forming material Ma also changes. For this reason, a correlation is established between the position of the zero magnetic field position ZMP and the incident mode of the plasma P on the surface SF. The incident mode of the plasma P on the surface SF is determined by, for example, the incident direction of the plasma P on the surface SF and the incident range of the plasma P on the surface SF.

[0040] As shown in FIG. 3, the magnetic field generation unit 70 has a direction component in the Z-axis direction (first direction), which is the direction in which the substrate 11 (see FIG. 1) and the film-forming material Ma face each other, and sets the zero magnetic field position ZMP so that the plasma P is incident on the surface SF of the film-forming material Ma. The plasma P is incident on the surface SF of the film-forming material Ma from a plurality of incident directions D1. However, these incident directions D1 have a direction component that goes from the positive side to the negative side in the Z-axis direction. In the examples shown in FIGS. 3 and 4, the incident direction D1 is substantially parallel to the Z-axis direction. On the other hand, in the example shown in FIG. 5, the incident direction D1 has an incident direction D1 that is mainly inclined with respect to the Z-axis direction.

[0041] The magnetic field generation unit 70 may set the zero magnetic field position ZMP so that the plasma P is incident on the entire surface SF of the film forming material Ma. In the example shown in FIG. 3, the positive end face of the film forming material Ma in the Z-axis direction is exposed from the main hearth 17 on the inner peripheral side of the main hearth 17. In this way, the entire area from the edge on the outer peripheral side to the central position of the exposed surface SF is covered with the plasma P. This situation means that the plasma P is incident on the entire surface SF of the film forming material Ma. On the other hand, in the examples shown in FIGS. 4 and 5, there are portions on the surface SF that are not covered with the plasma P. This situation does not correspond to the plasma P being incident on the entire surface SF of the film forming material Ma.

[0042] Next, with reference to FIG. 2, a suitable position for setting the zero magnetic field position ZMP will be described. In the following description, as shown in FIGS. 2 to 5, the position of the zero magnetic field position ZMP when viewed from the direction perpendicular to the central axis CL1 of the plasma gun 7 and the central axis CL2 of the main hearth 17 (here, the X-axis direction) will be described. When the positions of the central axis CL1 and the central axis CL2 in the X-axis direction are the same, the position of the zero magnetic field position ZMP in the X-axis direction is set at the same position as the central axes CL1 and CL2. When the X-axis directions of the central axis CL1 and the central axis CL2 are different, the position of the zero magnetic field position ZMP in the X-axis direction is set at a position between the central axis CL1 and the central axis CL2.

[0043] The magnetic field generation unit 70 may set the zero magnetic field position ZMP at a position below the central axis CL1 of the plasma gun 7 with respect to the surface SF of the film forming material Ma in the Z-axis direction. A reference line SLA1 extending in the Y-axis direction is set at the position of the central axis CL1 of the plasma gun 7. At this time, the zero magnetic field position ZMP is set on the reference line SLA1 or at a position on the negative side of the reference line SLA1 in the Z-axis direction.

[0044] The magnetic field generation unit 70 may set a zero magnetic field position ZMP at a position equal to or greater than the width dimension H of the film forming material Ma with respect to the surface SF of the film forming material Ma in the Z-axis direction. A reference line SLA2 parallel to the Y-axis direction is set at a position separated from the surface SF by the width dimension H in the Z-axis direction. At this time, the zero magnetic field position ZMP is set on the reference line SLA2 or at a position on the positive side of the Z-axis direction from the reference line SLA2. In the present embodiment, the surface SF of the film forming material Ma is always pushed out so as to be constant. Note that the surface SF does not necessarily have to be always constant. In this case, the reference position STP serving as a reference on the negative side in the Z-axis direction when defining the range of the width dimension H may be set on the surface SF of the film forming material Ma when film formation starts. In this case, even when the position of the surface SF of the film forming material Ma drops downward due to evaporation, the reference position STP remains constant. Alternatively, the reference position STP may be set at the position of the upper end portion 17c on the positive side in the Z-axis direction of the main hearth 17.

[0045] In the Y-axis direction (second direction) in which the central axis CL1 of the plasma gun 7 extends, the magnetic field generation unit 70 may set a zero magnetic field position ZMP at a position within the inner circumference of the ring hearth 6 on the plasma gun 7 side with respect to the central axis CL2 of the film forming material Ma. A reference line SLB1 extending in the Z-axis direction is set at the position of the inner circumference of the ring hearth 6 at the position of the end portion 6a on the plasma gun 7 side (negative side in the Y-axis direction). At this time, the zero magnetic field position ZMP is set on the reference line SLB1 or at a position on the positive side of the Y-axis direction from the reference line SLB1.

[0046] In the Y-axis direction in which the central axis CL1 of the plasma gun 7 extends, the magnetic field generation unit 70 may set a zero magnetic field position ZMP at a position within the inner circumference of the main hearth 17 on the side opposite to the plasma gun 7 with respect to the central axis CL2 of the film forming material Ma. A reference line SLB2 extending in the Z-axis direction is set at the position of the inner circumference of the ring hearth 6 at the position of the end portion 17d on the side opposite to the plasma gun 7 side (positive side in the Y-axis direction). At this time, the zero magnetic field position ZMP is set on the reference line SLB2 or at a position on the negative side of the Y-axis direction from the reference line SLB2.

[0047] Next, with reference to FIGS. 3 to 5, the position of the zero magnetic field position ZMP and the mode of the plasma P will be described. In the example shown in FIG. 3, the zero magnetic field position ZMP is set at a position between the reference line SLA1 and the reference line SLA2 in the Z-axis direction. The zero magnetic field position ZMP is set at a position between the reference line SLB1 and the reference line SLB2 in the Y-axis direction. In this case, the plasma P can spread sufficiently before reaching the film-forming material Ma. As a result, the plasma P is incident on the entire surface SF of the film-forming material Ma.

[0048] In the example shown in FIG. 4, the zero magnetic field position ZMP is set at a position on the negative side of the Z-axis direction with respect to the reference line SLA2 in the Z-axis direction. The zero magnetic field position ZMP is set at a position between the reference line SLB1 and the reference line SLB2 in the Y-axis direction. In this case, the plasma P cannot spread sufficiently before reaching the film-forming material Ma. As a result, the plasma P is incident not on the entire surface SF of the film-forming material Ma but on a partial range.

[0049] In the example shown in FIG. 5, the zero magnetic field position ZMP is set at a position between the reference line SLA1 and the reference line SLA2 in the Z-axis direction. The zero magnetic field position ZMP is set at a position on the positive side of the Y-axis direction with respect to the reference line SLB2 in the Y-axis direction. In this case, the plasma P will be incident on the film-forming material Ma in a state biased toward the positive side in the Y-axis direction. The plasma P is incident on the surface SF of the film-forming material Ma in an obliquely inclined state. As a result, the plasma P is incident not on the entire surface SF of the film-forming material Ma but on a partial range.

[0050] Next, the suitable range of the zero magnetic field position ZMP based on the simulation results of film formation will be described. As a result of the intensive research conducted by the inventors of the present application, it has been found that the range of current in which the plasma P is incident on the surface of the film-forming material Ma and a transparent conductive film with low resistance and high transmittance can be formed is that the steering coil 5 is "10 A to 20 A" and the toroidal hearth 6 is "20 A to 40 A". From these current value ranges, a simulation of film formation was performed. At this time, the magnetic field formed in the chamber 10 was calculated. The conditions for the simulation other than the coil current at this time are as follows. The size of the chamber 10 was set to "X: 610 mm × Y: 500 mm × Z: 560 mm".

[0051] The distance from the central axis CL2 of the film-forming material Ma to the zero magnetic field position ZMP on the plasma gun 7 side in the Y-axis direction is defined as "Y". The distance from the surface SF of the film-forming material Ma in the Z-axis direction is defined as "Z". When the steering coil current is set to "20 A" and the toroidal hearth current is set to "20 A" as "Condition 1", it becomes "Z: 70.2 mm, Y: 38.0 mm". When the steering coil current is set to "15 A" and the toroidal hearth current is set to "25 A" as "Condition 2", it becomes "Z: 79.8 mm, Y: 38.6 mm". When the steering coil current is set to "10 A" and the toroidal hearth current is set to "40 A" as "Condition 3", it becomes "Z: 98.1 mm, Y: 49.8 mm". In "Condition 1", the zero magnetic field position ZMP is closest to the film-forming material Ma side. In "Condition 3", the zero magnetic field position ZMP is closest to the plasma gun 7 side. From the said results, it has been found that it is appropriate to set "Y" in the range of 38.0 mm to 49.8 mm and "Z" in the range of 70.2 mm to 98.1 mm as the range of the zero magnetic field position ZMP.

[0052] In the actual film forming apparatus 1, in order to adjust the incident position of the plasma P, considering the deviation from the above simulation model, it is found that it is appropriate to set "Y" in the range of 20 mm to 55 mm and "Z" in the range of 65 mm to 105 mm as the range of the zero magnetic field position ZMP. Note that the current range of each coil is not limited to the current range in the above simulation, and by adjusting the current outside the current range, the zero magnetic field position ZMP can be set within the ranges of the reference lines SLA1, SLA2, SLB1, and SLB2 described in FIGS. 2 to 5.

[0053] Next, the operation and effects of the film forming apparatus 1 according to the present embodiment will be described.

[0054] In the film forming apparatus 1 according to the present embodiment, the magnetic field generation unit 70 maintains the magnetic field MF so that the zero magnetic field position ZMP where the magnetic field MF in the chamber 10 becomes zero is at a predetermined position, thereby causing the plasma P to be incident on the surface SF of the film forming material Ma. In this way, the magnetic field generation unit 70 can form an appropriate magnetic field configuration for causing the plasma P to be incident on the surface SF of the film forming material Ma by adjusting the zero magnetic field position ZMP to an appropriate position. The magnetic field generation unit 70 has a direction component in the Z-axis direction in which the substrate 11 and the film forming material Ma face each other, and sets the zero magnetic field position ZMP so that the plasma P is incident on the surface SF of the film forming material Ma. Thereby, the plasma P can be incident in an appropriate incident mode for uniformly evaporating the film forming material Ma. From the above, the film quality of the film formed on the substrate 11 can be improved. Note that depending on the material of the film, electrical characteristics, optical characteristics, etc. can also be improved.

[0055] The magnetic field generation unit 70 may set the zero magnetic field position ZMP so that the plasma P is incident on the entire surface SF of the film forming material Ma. Thereby, the film forming material Ma can be uniformly evaporated.

[0056] The magnetic field generation unit 70 may have a ring-shaped hearth 6 disposed around the main hearth 17. Thereby, the magnetic field MF can be adjusted around the main hearth 17.

[0057] The magnetic field generation unit 70 may set a zero magnetic field position ZMP at a position below the central axis CL1 of the plasma gun 7 with respect to the surface SF of the film forming material Ma in the Z-axis direction. In this case, it is possible to suppress the plasma P from spreading too much with respect to the film forming material Ma.

[0058] The magnetic field generation unit 70 may set a zero magnetic field position ZMP at a position equal to or greater than the width dimension H of the film forming material Ma with respect to the surface SF of the film forming material Ma in the Z-axis direction. In this case, a space for the plasma P to spread with respect to the film forming material Ma can be secured, and it is possible to suppress the plasma P from being incident only on a part of the surface SF of the film forming material Ma.

[0059] The magnetic field generation unit 70 may set a zero magnetic field position ZMP at a position within the inner circumference of the ring hearth 6 on the plasma gun 7 side with respect to the central axis CL2 of the film forming material Ma in the Y-axis direction in which the central axis CL1 of the plasma gun 7 extends. In this case, it is possible to suppress the plasma P from being too biased toward the plasma gun 7 side, and it is possible to suppress the plasma P from being incident only on a part of the surface SF of the film forming material Ma.

[0060] The magnetic field generation unit 70 may set a zero magnetic field position ZMP at a position within the inner circumference of the main hearth 17 on the side opposite to the plasma gun 7 with respect to the central axis CL2 of the film forming material Ma in the Y-axis direction in which the central axis CL1 of the plasma gun 7 extends. In this case, it is possible to suppress the plasma P from being too biased toward the side opposite to the plasma gun 7, and it is possible to suppress the plasma P from being incident only on a part of the surface SF of the film forming material Ma.

[0061] The magnetic field generation unit 70 may set a zero magnetic field position ZMP at a position where the distance from the surface SF of the film forming material Ma in the Z-axis direction is 65 mm to 105 mm. In this case, a space for the plasma P to spread with respect to the film forming material Ma can be secured, and it is possible to suppress the plasma P from being incident only on a part of the surface SF of the film forming material Ma.

[0062] The magnetic field generation unit 70 may set a zero magnetic field position ZMP at a position where the distance from the central axis CL2 of the film forming material Ma is 20 mm to 55 mm toward the plasma gun 7 side in the Y-axis direction in which the central axis CL1 of the plasma gun 7 extends. In this case, it is possible to suppress the plasma P from being overly biased toward the plasma gun 7 side and to suppress the plasma P from being incident only on a part of the surface SF of the film forming material Ma.

[0063] The magnetic field generation unit 70 may further include at least one of the electrodes 61 and 62 of the plasma gun 7 and the steering coil 5 of the plasma gun 7. In this case, the magnetic field MF can be adjusted on the plasma gun 7 side.

[0064] Here, in the present embodiment, as a mechanism for arranging the substrate 11, a mechanism for continuously transporting the substrate 11 (continuous film forming type) is adopted. In such a continuous film forming type, film formation is performed while flowing the substrate 11 in the plasma emission direction of the plasma gun 7. Since the film distribution in the plasma P emission direction is likely to occur, it is preferable to flow the substrate 11 in this direction. In the continuous film forming type, compared with the film forming apparatus according to the comparative example (when the zero magnetic field position ZMP is outside the predetermined range), the direction of the film thickness distribution to be homogenized is the direction (X-axis direction) intersecting the direction in which the substrate 11 flows. Note that the mechanism for arranging the substrate 11 is not limited to the continuous film forming type, and a batch type in which the substrate 11 is arranged in the chamber 10 each time may be used.

[0065] When the film forming material Ma is an insulating material, the plasma P is incident on the tip of the main hearth 17. However, by setting the zero magnetic field position ZMP within the range of the reference lines SLA1, SLA2, SLB1, and SLB2, the plasma P can be suitably incident on the entire tip of the main hearth 17.

[0066] The present invention is not limited to the above-described embodiment of the film forming apparatus.

[0067] The position, size, orientation, angle, etc. of each component of the above-described film-forming apparatus may be appropriately changed without departing from the gist of the present invention. For example, the emission direction of the plasma gun 7 does not have to be parallel to the Y-axis and may be inclined. The magnetic field generation unit does not have to include all of the toroidal hearth, the electrodes of the plasma gun, and the steering coil, and some of them may be omitted.

Explanation of Reference Numerals

[0068] 1... Film-forming apparatus, 5... Steering coil, 6... Toroidal hearth, 7... Plasma gun, 10... Chamber, 11... Substrate (object), 17... Main hearth (anode), 61... First intermediate electrode (electrode), 62... Second intermediate electrode (electrode), 70... Magnetic field generation unit, Ma... Film-forming material, SF... Surface, ZMP... Zero magnetic field position.

Claims

1. A film forming apparatus for forming a film forming material on an object by an RPD method, comprising: a chamber; a plasma gun for generating plasma in the chamber; an anode disposed in the chamber for disposing the film forming material and guiding the plasma; a magnetic field generating unit for generating a magnetic field in the chamber; the magnetic field generating unit maintains the magnetic field in the chamber such that a zero magnetic field position where the magnetic field becomes zero is at a predetermined position, and thereby causes the plasma to be incident on the surface of the film forming material; the magnetic field generating unit has a direction component in a first direction in which the object and the film forming material face each other, and sets the zero magnetic field position so that the plasma is incident on the surface of the film forming material. A film forming apparatus.

2. The film forming apparatus according to claim 1, wherein the magnetic field generating unit sets the zero magnetic field position so that the plasma is incident on the entire surface of the film forming material.

3. The film forming apparatus according to claim 1, wherein the magnetic field generating unit has a ring hearth disposed around the anode.

4. The film forming apparatus according to claim 1, wherein the magnetic field generating unit sets the zero magnetic field position at a position below the central axis of the plasma gun with respect to the surface of the film forming material in the first direction.

5. The film forming apparatus according to claim 1, wherein the magnetic field generating unit sets the zero magnetic field position at a position equal to or greater than the width dimension of the film forming material with respect to the surface of the film forming material in the first direction.

6. The film forming apparatus according to claim 1, wherein the magnetic field generating unit sets the zero magnetic field position at a position within the inner circumference of the ring hearth on the plasma gun side with respect to the central axis of the film forming material in a second direction in which the central axis of the plasma gun extends.

7. The film forming apparatus according to claim 1, wherein the magnetic field generating unit sets the zero magnetic field position at a position within the inner circumference of the anode on the side opposite to the plasma gun with respect to the central axis of the film forming material in a second direction in which the central axis of the plasma gun extends.

8. The film forming apparatus according to claim 1, wherein the magnetic field generating unit sets the zero magnetic field position at a position where the distance from the surface of the film forming material in the first direction is 65 mm to 105 mm.

9. The film forming apparatus according to claim 1, wherein the magnetic field generating unit sets the zero magnetic field position at a position where the distance from the central axis of the film forming material is 20 mm to 55 mm toward the plasma gun side in a second direction in which the central axis of the plasma gun extends.

10. The film forming apparatus according to claim 3, wherein the magnetic field generating unit further includes at least one of an electrode of the plasma gun and a steering coil of the plasma gun.

Images