Sputtering device

Abstract

The present invention provides a sputtering device which is capable of appropriately performing individual control for an antenna and a target. This sputtering device (100) comprises: a target-side power supply (61) that supplies high-frequency power to a target (6); a target-side line (62); an antenna-side power supply (51) that supplies high-frequency power to an antenna (5) which is disposed outside a vacuum chamber (1); an antenna-side line (52); and a shield plate (12) that is disposed between the target-side line and the antenna-side line.

Description

Sputtering device

[0001] This invention relates to a sputtering apparatus.

[0002] A film deposition technique is known in which a target made of film deposition raw materials is sputtered with plasma inside a vacuum chamber to deposit the required film onto a substrate such as glass. As a film deposition apparatus for such processing, a sputtering apparatus is known that performs magnetron sputtering by applying a high-frequency voltage to the target, and also assists in plasma generation by placing a metal member (antenna) to which high-frequency power is applied inside the vacuum chamber to generate a high-density plasma. Such a sputtering apparatus is disclosed, for example, in Patent Document 1.

[0003] Japanese Patent Application Publication No. 2007-224390

[0004] In the above-mentioned Patent Document 1, the antenna-side transmission line supplying high-frequency power to the antenna and the target-side transmission line supplying high-frequency power to the target may interfere with each other via electromagnetic fields. Therefore, individual control of the antenna and the target may become difficult.

[0005] One aspect of the present invention has been made in view of the above-mentioned problems, and its object is to provide a sputtering apparatus that can appropriately perform individual control of the antenna and the target, respectively.

[0006] To solve the above problems, a sputtering apparatus according to embodiment 1 of the present invention comprises a vacuum vessel, a target disposed inside the vacuum vessel, a target-side power supply that supplies high-frequency power to the target, a target-side transmission line connecting the target and the target-side power supply, an antenna disposed outside the vacuum vessel that introduces electromagnetic waves into the vacuum vessel, an antenna-side power supply that supplies high-frequency power to the antenna, an antenna-side transmission line connecting the antenna and the antenna-side power supply, and an electromagnetic shield disposed between the target-side transmission line and the antenna-side transmission line.

[0007] According to one aspect of the present invention, individual control of the antenna and the target can be appropriately performed.

[0008] This is a cross-sectional view showing the schematic configuration of a sputtering apparatus according to Embodiment 1. This is a graph showing the distribution of the current value in the target-side transmission line with respect to the magnitude of the high-frequency power supplied to the antenna. This is a flowchart showing an example of the processing flow related to the inspection method of a sputtering apparatus according to Embodiment 2.

[0009] [Embodiment 1] (Schematic configuration of sputtering apparatus) Figure 1 is a cross-sectional view showing the schematic configuration of a sputtering apparatus 100 according to this embodiment. As shown in Figure 1, the sputtering apparatus 100 includes a vacuum chamber 1. The sputtering apparatus 100 also includes a substrate holder 2 on which a substrate 3 on which film formation is to be performed is placed, and a backing plate 7 that holds a target 6 made of film formation material. During film formation, the substrate holder 2 and the backing plate 7 are arranged so that the substrate 3 placed on the substrate holder 2 and the target 6 held by the backing plate 7 face each other. The distance TS between the substrate 3 and the target 6 is about 50 to 300 mm.

[0010] In this configuration, the substrate holder 2 is typically positioned at the bottom, the backing plate 7 at the top, and the vacuum container 1 and its associated parts are configured and installed such that the surfaces facing inward are parallel to the horizontal plane. Therefore, in this embodiment, when referring to the horizontal direction, vertical direction, or up and down, these terms are used on the premise that the vacuum container 1 and its associated parts are installed in such orientations. However, the orientation of the vacuum container 1 and its associated parts is not necessarily limited to these.

[0011] The vacuum vessel 1 is evacuated by an exhaust device (not shown) and controlled to the required vacuum level. The required vacuum level is selected from a range in which inductively coupled plasma is easily generated, and is usually around 0.1 Pa to 10 Pa.

[0012] The backing plate 7 is a conductive plate-shaped member and is attached to the upper wall surface of the vacuum vessel 1 near the center via an insulating flange 8. The insulating flange 8 maintains the vacuum inside the vacuum vessel 1 while fixing the backing plate 7 to the vacuum vessel 1 and insulating it from the vacuum vessel 1.

[0013] On the surface (upper surface) of the backing plate 7 opposite to the side holding the target 6, a magnet 71 for generating a magnetic field around the target 6 and a conductive housing 72 surrounding the magnet 71 are provided. The upper surface of the housing 72 is exposed to the outside of the vacuum vessel 1, and a target-side line 62 described later is connected to the upper surface of the housing 72. Further, a refrigerant path 73 through which a refrigerant (for example, cooling water) for cooling the target 6 passes is formed between the magnet 71 and the housing 72. Also, on the inner surface of the insulating flange 8, an anode 74 is provided which covers the outer edge of the target 6 while having a gap with the target 6.

[0014] The raw material of the target 6 may be any raw material applicable in sputtering by high-frequency power. The raw material of the target 6 is, for example, an oxide. Examples of the oxide include, for example, LATP (as an example of the composition, Li １．４ Al ０．４ Ti １．６ (PO ４ ) ３ ) or LLZO (as an example of the composition, Li ７ La ３ Zr ２ O １２ ). Also, the raw material of the target 6 may be an insulator.

[0015] The substrate holder 2 is grounded. The substrate holder 2 may be provided with a heater for heating the substrate 3 in order to control the crystallinity etc. of the film formed on the surface of the substrate during film formation. Also, a bias voltage may be applied to the substrate holder 2.

[0016] The sputtering apparatus 100 is appropriately provided with a gas supply line 110 for introducing a required gas into the vacuum vessel 1. In the present embodiment, at least an argon gas introduction line for supplying a gas containing argon and an oxygen gas introduction line for supplying a gas containing oxygen are provided.

[0017] The sputtering apparatus 100 is positioned outside the vacuum vessel 1 and further includes an antenna 5 that introduces electromagnetic waves into the vacuum vessel 1. The antenna 5 is a metal member that extends horizontally near the side wall 1a of the vacuum vessel 1. Here, the side wall 1a of the vacuum vessel 1 is an electromagnetic wave transmitting member that allows electromagnetic waves generated from the antenna 5 to pass through. Therefore, when a high-frequency current flows through the antenna 5, an induced electric field is generated inside the vacuum vessel 1, and an inductively coupled plasma is generated. In other words, the antenna 5 is an ICP support antenna that assists in the generation of plasma inside the vacuum vessel 1. The antenna 5 is covered with a tubular insulating cover 4.

[0018] As described above, the antenna 5, which generates an inductively coupled plasma inside the vacuum vessel 1, is placed outside the vacuum vessel 1. This prevents the antenna 5 from being directly exposed to the plasma, thus preventing high-frequency power from being transmitted from the antenna 5 to the target 6 via the plasma. Therefore, even when supplying high-frequency power to both the antenna 5 and the target 6, individual control of each of them can be appropriately performed.

[0019] (High-frequency power supply system) In this embodiment, in a sputtering apparatus that supplies high-frequency power to a target 6 to generate plasma around the target 6, an ICP assist configuration (antenna 5 and a supply system that supplies high-frequency power to antenna 5) is provided to assist in plasma generation. That is, high-frequency power is supplied to both the target 6 and antenna 5.

[0020] Specifically, the sputtering apparatus 100 comprises a target-side power supply 61, a target-side transmission line 62, an antenna-side power supply 51, and an antenna-side transmission line 52. The target-side power supply 61 is a high-frequency power supply that supplies high-frequency power to the target 6. The target-side transmission line 62 is a wire that electrically connects the target 6 and the target-side power supply 61. The antenna-side power supply 51 is a high-frequency power supply that supplies high-frequency power to the antenna 5. The antenna-side transmission line 52 is a wire that electrically connects the antenna 5 and the antenna-side power supply 51.

[0021] The sputtering apparatus 100 further includes a target-side matching box 63 and an antenna-side matching box 53 for impedance matching in the target-side transmission line 62 and the antenna-side transmission line 52, respectively.

[0022] The frequency of the high-frequency power supplied from the target-side power supply 61 and the antenna-side power supply 51 is generally 13.56 MHz, but is not limited to this.

[0023] The sputtering apparatus 100 further includes a shield box 11 that covers at least a portion of the target-side transmission line 62 and the antenna-side transmission line 52. The shield box 11 suppresses leakage of electromagnetic fields generated in the target-side transmission line 62 and the antenna-side transmission line 52 to the outside. The shield box 11 covers the target-side transmission line 62 that connects the target-side matching box 63 and the housing 72. The shield box 11 also covers a portion of the antenna-side transmission line 52 that connects the antenna-side matching box 53 and the antenna 5.

[0024] The sputtering apparatus 100 further includes a shielding plate 12 (electromagnetic shield) positioned between the target-side transmission line 62 and the antenna-side transmission line 52. The shielding plate 12 blocks the electromagnetic fields generated in the target-side transmission line 62 and the antenna-side transmission line 52. In other words, the shielding plate 12 plays a role in suppressing the intrusion of high-frequency power between the target-side transmission line 62 and the antenna-side transmission line 52. The shielding plate 12 is formed from a conductive material (for example, aluminum). In this embodiment, the shielding plate 12 divides the space within the shielding box 11 into a space where the target-side transmission line 62 is located and a space where the antenna-side transmission line 52 is located.

[0025] As described above, in this embodiment, an electromagnetic shield is provided between the target-side line 62 and the antenna-side line 52, which are the wirings for supplying high-frequency power. This prevents high-frequency power from entering each other between the target-side line 62 and the antenna-side line 52. Therefore, even when supplying high-frequency power to both the antenna 5 and the target 6, individual control of each of the antenna 5 and the target 6 can be appropriately performed.

[0026] This makes it possible to use a target 6 (e.g., an insulator) that requires a high-frequency power supply in sputtering using an ICP-assisted antenna. Depending on the structure of the sputtering apparatus 100 (especially the antenna length), typically, if the antenna power is 200W or more, a peak-to-peak current of several tens of amperes flows through the antenna 5, causing power from the antenna-side supply system to enter the target-side supply system. Therefore, it is particularly beneficial to provide electromagnetic shielding when the antenna power is 200W or more.

[0027] Furthermore, the shielding plate 12 is grounded. In this embodiment, the shielding plate 12 is electrically connected to the grounded vacuum container 1. This allows for proper shielding of the electric field generated in the target line 62 and the antenna line 52. Therefore, interference of high-frequency power between the target line 62 and the antenna line 52 caused by electrostatic induction can be suppressed.

[0028] (Modification) The sputtering apparatus 100 may also include, instead of the shield box 11, a conductive first shield box (first housing) surrounding the target-side transmission line 62 and a conductive second shield box (second housing) surrounding the antenna-side transmission line 52. In this case, the walls of the first shield box and the second shield box function as electromagnetic shields.

[0029] (Experimental Data) The following describes experimental data on electromagnetic interference between the target-side supply system and the antenna-side supply system, as investigated by the inventors. The inventors measured the current value flowing through the target-side transmission line 62 when a predetermined power was supplied to the antenna 5 as a value indicating interference between the target-side supply system and the antenna-side supply system.

[0030] Figure 2 is a graph showing the distribution of the current value in the target transmission line 62 with respect to the magnitude of the high-frequency power supplied to the antenna 5. In Figure 2, the horizontal axis represents the power (W) supplied to the antenna 5, and the vertical axis represents the current value (A) flowing through the target transmission line 62. Graph G1 in Figure 2 shows experimental data when no electromagnetic shielding is provided between the target transmission line 62 and the antenna transmission line 52. Graph G2 in Figure 2 shows experimental data when electromagnetic shielding is provided between the target transmission line 62 and the antenna transmission line 52.

[0031] The high-frequency power supplied to target 6 was set to 50W. In addition, Ar and O were introduced into the vacuum chamber 1. ２ The flow rates were set to 9.5 sccm and 0.5 sccm, respectively. The vacuum level inside vacuum chamber 1 was set to 0.8 Pa. Substrate 3 was a silicon substrate, and the distance TS was set to 95 mm.

[0032] As shown in graph G1 of Figure 2, when no electromagnetic shielding is provided, the current flowing through the target-side transmission line 62 increases as the power supplied to the antenna 5 increases. This indicates that the magnetic field generated around the antenna-side transmission line 52 induces an induced current in the target-side transmission line 62. In other words, without electromagnetic shielding, a portion of the high-frequency power supplied to the antenna 5 enters the target-side supply system as spatially conducted noise, making it difficult to perform individual control of both the antenna 5 and the target 6.

[0033] On the other hand, as shown in graph G2 of Figure 2, when an electromagnetic shield is provided, the current flowing through the target-side transmission line 62 is approximately constant with respect to the power supplied to the antenna 5. This indicates that the magnetic field generated around the antenna-side transmission line 52 is canceled out by the electromagnetic shield, reducing the influence of the magnetic field on the target-side transmission line 62. In other words, it can be seen that by providing an electromagnetic shield, it is possible to suppress the intrusion of high-frequency power supplied to the antenna 5 into the target-side power supply system. Similarly, it can be inferred that it is also possible to suppress the intrusion of high-frequency power supplied to the target 6 into the antenna-side power supply system. Therefore, it is understood that by providing an electromagnetic shield, individual control of the antenna 5 and the target 6 can be appropriately performed.

[0034] [Embodiment 2] Another embodiment of the present invention will be described below. For the sake of convenience of explanation, components having the same function as those described in the above embodiment will be denoted by the same reference numerals, and their descriptions will not be repeated.

[0035] In this embodiment, a method for inspecting the sputtering apparatus 100 will be described. Specifically, a method for determining whether or not there is interference between the target-side supply system and the antenna-side supply system via electromagnetic fields will be described.

[0036] As shown in Figure 1, the sputtering apparatus 100 further includes a control unit 20. The control unit 20 controls the operation of each part of the sputtering apparatus 100 (antenna-side power supply 51, target-side power supply 61, etc.). The control unit 20 also determines whether or not there is interference between the target-side supply system and the antenna-side supply system via electromagnetic fields.

[0037] Furthermore, the sputtering apparatus 100 includes an antenna-side detection unit 21 for detecting current and / or voltage values ​​in the antenna-side transmission line 52, and a target-side detection unit 22 for detecting current and / or voltage values ​​in the target-side transmission line 62.

[0038] FIG. 3 is a flowchart showing an example of the flow of processing related to the inspection method of the sputtering apparatus 100. As shown in FIG. 3, first, the antenna-side detection unit 21 detects the current value and / or voltage value in the antenna-side line 52 when a predetermined power is supplied to the target 6 as an antenna-side detection value (detection step S1). Alternatively, the target-side detection unit 22 detects the current value and / or voltage value in the target-side line 62 when a predetermined power is supplied to the antenna 5 as a target-side detection value (detection step S1). The control unit 20 acquires the antenna-side detection value from the antenna-side detection unit 21 or acquires the target-side detection value from the target-side detection unit 22.

[0039] Next, the control unit 20 determines whether the antenna-side detection value or the target-side detection value exceeds the corresponding threshold value (S2). If the antenna-side detection value or the target-side detection value does not exceed the corresponding threshold value (NO in S2), the process returns to S1. If the antenna-side detection value or the target-side detection value exceeds the corresponding threshold value (YES in S2), the control unit 20 controls the antenna-side power supply 51 and the target-side power supply 61 to stop the power supply to the target 6 and the antenna 5 (stop step S3).

[0040] According to the above configuration, when the antenna-side detection value or the target-side detection value exceeds the corresponding threshold value, the control unit 20 determines that the space conduction noise cannot be shielded due to some malfunction, and can perform interlock. Thereby, it is possible to make the operator or user (during maintenance) aware of forgetting to attach the electromagnetic shield during maintenance.

[0041] 〔Example of realization by software〕 The function of the sputtering apparatus 100 (hereinafter referred to as the "apparatus") can be realized by a program for causing a computer to function as the apparatus, and by a program for causing a computer to function as each control block of the apparatus (particularly each part included in the control unit 20).

[0042] In this case, as hardware for executing the above program, the above device includes a computer having at least one control device (e.g., a processor) and at least one storage device (e.g., a memory). By executing the above program with this control device and storage device, each function described in each of the above embodiments is realized.

[0043] The above program may be recorded on one or more computer-readable recording media, rather than being temporary. This recording medium may or may not be included in the above device. In the latter case, the above program may be supplied to the above device via any wired or wireless transmission medium.

[0044] Also, part or all of the functions of each of the above control blocks can also be realized by a logic circuit. For example, an integrated circuit in which a logic circuit functioning as each of the above control blocks is formed is also included in the scope of the present invention. In addition to this, for example, it is also possible to realize the functions of each of the above control blocks by a quantum computer.

[0045] Also, each process described in each of the above embodiments may be executed by AI (Artificial Intelligence). In this case, the AI may operate in the above control device, or may operate in another device (e.g., an edge computer or a cloud server, etc.).

[0046] (Supplementary Notes) The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope indicated in the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0047] (Summary) A sputtering apparatus according to aspect 1 of the present invention comprises a vacuum vessel, a target disposed inside the vacuum vessel, a target-side power supply that supplies high-frequency power to the target, a target-side transmission line connecting the target and the target-side power supply, an antenna disposed outside the vacuum vessel that introduces electromagnetic waves into the vacuum vessel, an antenna-side power supply that supplies high-frequency power to the antenna, an antenna-side transmission line connecting the antenna and the antenna-side power supply, and an electromagnetic shield disposed between the target-side transmission line and the antenna-side transmission line.

[0048] In the sputtering apparatus according to embodiment 2 of the present invention, the electromagnetic shield may be grounded in embodiment 1.

[0049] The sputtering apparatus according to embodiment 3 of the present invention further comprises, in embodiment 1 or 2 above, a conductive first housing surrounding the target-side transmission line and a conductive second housing surrounding the antenna-side transmission line, wherein the electromagnetic shield may be the walls of the first housing and the second housing.

[0050] A sputtering apparatus inspection method according to aspect 4 of the present invention is a sputtering apparatus inspection method according to any one of aspects 1 to 3 above, comprising: a detection step of (i) detecting the current value and / or voltage value in the antenna-side line when a predetermined power is supplied to the target as an antenna-side detection value, or (ii) detecting the current value and / or voltage value in the target-side line when a predetermined power is supplied to the antenna as a target-side detection value; and a stop step of stopping the power supply to the target and the antenna when the antenna-side detection value or the target-side detection value exceeds a threshold.

[0051] A program according to aspect 5 of the present invention is a program for causing a computer to execute the sputtering apparatus inspection method described in aspect 4, wherein the program causes the computer to execute the detection step and the stop step.

[0052] 1 Vacuum container 2 Circuit board holder 3 Circuit board 4 Insulating cover 5 Antenna 6 Target 7 Backing plate 12 Shielding plate (electromagnetic shield) 20 Control unit 21 Antenna-side detection unit 22 Target-side detection unit 51 Antenna-side power supply 52 Antenna-side transmission line 61 Target-side power supply 62 Target-side transmission line

Claims

1. A sputtering apparatus comprising: a vacuum vessel; a target disposed inside the vacuum vessel; a target-side power supply that supplies high-frequency power to the target; a target-side transmission line connecting the target and the target-side power supply; an antenna disposed outside the vacuum vessel that introduces electromagnetic waves into the vacuum vessel; an antenna-side power supply that supplies high-frequency power to the antenna; an antenna-side transmission line connecting the antenna and the antenna-side power supply; and an electromagnetic shield disposed between the target-side transmission line and the antenna-side transmission line.

2. The sputtering apparatus according to claim 1, wherein the electromagnetic shield is grounded.

3. The sputtering apparatus according to claim 1, further comprising a conductive first housing surrounding the target-side transmission line and a conductive second housing surrounding the antenna-side transmission line, wherein the electromagnetic shield is the walls of the first housing and the second housing.

4. A sputtering apparatus inspection method according to any one of claims 1 to 3, comprising: a detection step of (i) detecting the current value and / or voltage value in the antenna-side line when a predetermined power is supplied to the target as an antenna-side detection value, or (ii) detecting the current value and / or voltage value in the target-side line when a predetermined power is supplied to the antenna as a target-side detection value; and a stop step of stopping the power supply to the target and the antenna when the antenna-side detection value or the target-side detection value exceeds a threshold.

5. A program for causing a computer to execute the inspection method of a sputtering apparatus described in claim 4, wherein the program causes the computer to execute the detection step and the stop step.

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