Method and apparatus for sputtering a target material onto a substrate

Abstract

An apparatus for sputtering and depositing a target material onto a substrate is disclosed. In one form, the apparatus comprises a substrate portion in which a substrate is provided during use and a target portion in which a target material is provided during use. The target portion and the substrate portion define a deposition zone between them. The apparatus comprises an antenna device and a confinement device for generating a plasma during use. The confinement device comprises a first element between the antenna device and the deposition zone and a second element. The antenna device is located between the second element and the deposition zone. The first element confines the plasma during use toward the deposition zone to provide sputtering deposition of the target material onto the substrate. The second element confines the plasma during use away from the second element, toward the antenna device, and toward the deposition zone via the first element.

Description

Technical Field

[0001] The present invention relates to deposition and, more particularly, to methods and apparatus for sputter depositing a target material onto a substrate. Background Art

[0002] Deposition is the process of depositing a target material on a substrate. An example of deposition is thin film deposition, in which a thin layer (usually from about one nanometer or even a fraction of a nanometer to several micrometers or even tens of micrometers) is deposited on a substrate, such as a silicon wafer or a coil. An example technique for thin film deposition is physical vapor deposition (PVD), in which a target material in a condensed phase evaporates to produce a vapor that then condenses onto the substrate surface. An example of PVD is sputtering deposition, in which particles are ejected from a target due to the bombardment of energetic particles (such as ions). In an example of sputtering deposition, a sputtering gas, such as an inert gas such as argon, is introduced into a vacuum chamber at low pressure, and the sputtering gas is ionized using energetic electrons to produce a plasma. The bombardment of the ions of the plasma on the target ejects the target material, which can then be deposited on the substrate surface. Sputtering deposition is superior to other thin film deposition methods, such as evaporation, because the target material can be deposited without heating the target material, which in turn can reduce or prevent thermal damage to the substrate.

[0003] One known sputtering deposition technique employs a magnetron, in which a glow discharge is combined with a magnetic field that causes an increase in plasma density in a circular region near the target. The increase in plasma density results in an increase in deposition rate. However, the use of a magnetron results in a circular "racetrack" shaped erosion profile of the target, which limits the utilization of the target and can negatively affect the uniformity of the resulting deposition.

[0004] It would be desirable to provide uniform and / or efficient sputtering deposition to improve utility in industrial applications. Summary of the invention

[0005] According to a first aspect of the present invention, there is provided an apparatus for sputtering a target material onto a substrate, the apparatus comprising:

[0006] a substrate portion, wherein in use a substrate is provided;

[0007] a target portion spaced from the substrate portion and in which, in use, target material is provided, the target portion and the substrate portion defining a deposition zone therebetween;

[0008] an antenna arrangement comprising at least one antenna for generating a plasma when, in use, an alternating current is driven through the antenna;

[0009] Restraint devices, including:

[0010] at least one first element disposed between the antenna arrangement and the deposition zone and arranged, in use, to confine plasma from the antenna arrangement towards the deposition zone to provide, in use, sputter deposition of target material onto the substrate; and

[0011] at least one second element is arranged such that the antenna arrangement is located between the at least one second element and the deposition zone and is arranged, in use, to confine the plasma away from the second element, towards the antenna arrangement and thence via the at least one first element towards the deposition zone.

[0012] By using a confinement device, the plasma can be at least partially confined within the deposition zone. As a result, the plasma density within the deposition zone can be increased, which can increase the efficiency of sputtering and depositing the target material on the substrate. It is also possible or alternatively to provide a more uniform density of plasma within the deposition zone. This in turn can allow the target material to be more uniformly deposited on the substrate.

[0013] In an example, at least one of the first elements is a first magnetic element arranged to provide a first confining magnetic field to confine the plasma from the antenna device toward the deposition zone. The first confining magnetic field can be used to effectively confine the plasma at least partially within the deposition zone. For example, the first confining magnetic field can be characterized by magnetic field lines in a configuration to provide a more uniform density of plasma within the deposition zone.

[0014] In these examples, the first magnetic element may be an electromagnet that is controllable to provide a first confining magnetic field. By controlling the electromagnet, the strength of the provided first confining magnetic field may be further controlled. This may allow the plasma density in the deposition zone to be adjusted, which may be used to adjust the deposition of target material on the substrate. Thus, control of sputtering deposition may be improved, increasing the flexibility of the device. In these examples, the device may include a controller that is arranged to control the first confining magnetic field provided by the first magnetic element.

[0015] In an example where at least one of the first elements is a first magnetic element, the first magnetic element may be a solenoid having an opening through which the plasma is confined in use. Confining the plasma through the opening of the solenoid may increase the plasma density in the deposition zone. For example, a certain amount of plasma may be compressed or otherwise contracted to pass through the opening of the solenoid. In such an example, at least one antenna may be elongated, and the opening of the solenoid may be elongated in a direction substantially parallel to the direction in which the at least one antenna is elongated. With this arrangement, plasma may be generated along the length of at least one elongated antenna and may be confined by the elongated opening of the sheet-like solenoid. The sheet may be more uniform than other plasma arrangements and may allow an increase in the area of ​​the substrate and / or target material exposed to the plasma. This may improve the efficiency of sputtering deposition and may alternatively or additionally provide a more uniform deposition of the target material on the substrate. In these examples, the antenna arrangement may include two antennas, and the solenoid may be arranged so that the opening of the solenoid leads to an area defined between the two antennas. This may allow the plasma to be precisely confined at least partially within the deposition zone. For example, the area between the two antennas may correspond to an area with a higher plasma density, which may have a more uniform plasma density over a larger area than would otherwise be the case. Thus, a larger area of ​​the substrate and / or target material may be exposed to the plasma, increasing the efficiency of the sputtering deposition process.

[0016] In some examples, at least one of the first elements is a first magnetic element, and at least one of the second elements is a second magnetic element, which is arranged to provide a second confining magnetic field to oppose the first confining magnetic field at least in the volume between the first element and the second element, so as to confine the plasma away from the second magnetic element, toward the antenna device, and thus toward the deposition area via the first element. By providing a suitable second confining magnetic field, the second magnetic element can at least partially improve the confinement of the plasma in the deposition area. For example, in the absence of at least one of the second elements, the plasma may not be confined in the deposition area, but may "overflow" from the deposition area. This will reduce the deposition efficiency. This may also or alternatively reduce the power coupling between the plasma and the rf power provided via the antenna device, which may require an increase in the rf power. By providing at least one of the second elements, for example as a second magnetic element, the "overflow" of the plasma can be reduced. The plasma density in the deposition will increase again. The power coupling between the rf power provided by the antenna device and the plasma may also or alternatively be increased.

[0017] In these examples, the second confining magnetic field may be arranged to reduce the magnetic flux of the first confining magnetic field in a volume intermediate the first element and the second element along a direction between the first element and the second element. Reducing the magnetic flux in this way may allow the plasma to be confined in the deposition zone at a higher density. This may improve deposition efficiency.

[0018] In these examples, the second magnetic element may be an electromagnet that is controllable to provide a second confining magnetic field. In examples where the second magnetic element is an electromagnet, the apparatus may include a controller that is arranged to control the second confining magnetic field provided by the second magnetic element. As explained with reference to the first magnetic element, this allows the second confining magnetic field to be appropriately controlled. This may allow the plasma density in the deposition zone to be adjusted, which may be used to adjust the deposition of target material on the substrate.

[0019] In examples, at least one of the second elements is an electrostatic element that can be controlled to provide an electric field to repel at least a portion of the plasma from the electrostatic element toward the antenna device in at least a volume between the first element and the second element, and thereby repel it toward the deposition zone via the first element. This can further improve the plasma at least partially confined within the deposition zone. In these examples, the electrostatic element can be arranged to be positively charged during use, thereby repelling positively charged ions of the plasma. This can reduce the confinement of positively charged ions of the plasma within the deposition zone by reducing or limiting the movement of positively charged ions away from the deposition zone. In these examples, the device may include a controller that is arranged to control the electric field provided by the electrostatic element. The controller can be used to control the extent to which the plasma is repelled by the electrostatic element, thereby controlling the plasma density within the deposition zone. In this way, a desired plasma density can be obtained within the deposition zone, thereby increasing the flexibility of the device.

[0020] In an example, the confinement means comprises at least two of said first elements arranged such that the deposition zone is located between a first one of the first elements and a second one of the first elements, thereby confining the plasma to pass through the deposition zone. By providing at least two first elements at an appropriate distance from each other, a desired plasma density can be obtained.

[0021] In an example, the confinement device includes a third element, the third element is arranged so that the deposition zone is located between the second element and the third element, and the third element is arranged to confine the plasma away from the third element and towards the deposition zone. The third element can further improve the confinement of the plasma at least partially within the deposition zone. In turn, the plasma density in the deposition zone can be increased, which can increase the deposition efficiency of the device.

[0022] In these examples, the third element can be arranged so that the first of the first elements and the second of the first elements and the deposition zone are located between the third element and the second element, so that the third element confines the plasma away from the third element and toward the deposition zone via one of the first of the first elements and the second of the first elements. By appropriate arrangement of the first, second and third elements, the plasma density in the deposition zone can be further increased.

[0023] In an example, the target portion may be controlled to provide a negative charge to the target material in use, thereby attracting positively charged ions of the plasma. This may cause the plasma density to increase towards the target material, which may increase the efficiency of the sputtering deposition.

[0024] In examples, the apparatus comprises a web supply assembly arranged to provide a web of substrate in the substrate portion in use. In these examples, the apparatus may form part of a "roll-to-roll" deposition system, which is more efficient than, for example, batch processing.

[0025] According to a second aspect of the present invention, there is provided a method of sputtering a target material onto a substrate, wherein a deposition zone is defined between the substrate and the target material, the method comprising:

[0026] generating a plasma using an antenna arrangement comprising at least one antenna;

[0027] Using at least one first element disposed between the antenna device and the deposition region, confining plasma from the antenna device toward the deposition region to sputter-deposit the target material onto the substrate; and

[0028] The plasma is confined using at least one second element away from the second element, towards the antenna arrangement and thence via the first element towards the deposition zone, the at least one second element being arranged such that the antenna arrangement is located between the at least one second element and the deposition zone.

[0029] The method can increase the plasma density within the deposition zone, which can improve the efficiency of sputtering deposition. The method can also or alternatively increase the uniformity of the plasma within the deposition zone, which can improve the uniformity of the target material deposited on the substrate.

[0030] According to a third aspect of the present invention, there is provided an apparatus for sputtering a target material onto a substrate, the apparatus comprising:

[0031] sedimentation area;

[0032] an antenna arrangement comprising at least one antenna for generating a plasma when, in use, an alternating current is driven through the antenna;

[0033] Restraint devices, including:

[0034] at least one first element disposed between the antenna arrangement and the deposition zone and arranged, in use, to confine plasma from the antenna arrangement towards the deposition zone, thereby, in use, providing plasma to the deposition zone; and

[0035] at least one second element is arranged such that the antenna arrangement is located between the at least one second element and the deposition zone and is arranged, in use, to confine the plasma away from the second element, towards the antenna arrangement and thence via the at least one first element towards the deposition zone.

[0036] This can increase the plasma density within the deposition zone, which can improve the efficiency of sputtering deposition.The method can also or alternatively increase the uniformity of the plasma within the deposition zone, which can improve the uniformity of the target material deposited on the substrate.

[0037] Further features will become apparent from the following description which is given by way of example only with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 is a schematic diagram showing a cross section of a device according to an example;

[0039] Figure 2 is a diagram showing an example Figure 1 a schematic diagram of a cross section of a portion of a device;

[0040] Figure 3 is a schematic diagram showing a cross section of a device according to yet another example;

[0041] Figure 4 is a schematic diagram showing a cross section of a device according to yet another example;

[0042] Figure 5 It is shown Figure 4 A schematic diagram of a plan view of the equipment;

[0043] Figure 6 is a schematic diagram showing a cross section of a first magnetic element according to an example;

[0044] Figure 7 is a schematic diagram showing a cross section of a device according to yet another example; and

[0045] Figure 8 is a schematic flow chart illustrating a method according to an example. DETAILED DESCRIPTION

[0046] Details of the apparatus and methods according to the examples will become apparent from the following description with reference to the accompanying drawings. In this specification, many specific details of certain examples are set forth for the purpose of explanation. References to "examples" or similar language in the specification mean that a particular feature, structure, or characteristic described in conjunction with the example is included in at least one example, but not necessarily in other examples. It should also be noted that certain examples are schematically described, and certain features are omitted and / or necessarily simplified in order to facilitate explanation and understanding of the concepts behind the examples.

[0047] refer to Figure 1 , schematically illustrates an example apparatus 100 for sputter-depositing a target material 108 onto a substrate 116 .

[0048] The apparatus 100 can be used for plasma-based sputtering deposition for a large number of industrial applications, such as for thin film deposition applications, such as for the production of optical coatings, magnetic recording media, electronic semiconductor devices, LEDs, energy generating devices such as thin film solar cells, and energy storage devices such as thin film batteries. Thus, while the context of the present disclosure may in some cases relate to the production of energy storage devices or portions thereof, it will be understood that the apparatus 100 and methods described herein are not limited to the production thereof.

[0049] Although not shown in the figures for the sake of clarity, it should be understood that the apparatus 100 may be disposed within a housing (not shown) which, in use, may be evacuated to a low pressure suitable for sputtering deposition, such as 3×10 -3 For example, the housing (not shown) may be evacuated to a suitable pressure (e.g., less than 1×10 -5 Torr), and in use, a process gas or sputtering gas, such as argon or nitrogen, may be introduced into a housing (not shown) using a gas supply system (not shown) to achieve a pressure suitable for sputtering deposition (e.g., 3×10 -3 to the extent that the

[0050] Back to Figure 1 In the illustrated example, in general terms, the apparatus 100 includes a base portion 118 , a target portion 106 , an antenna assembly 102 , and a limiting assembly 104 .

[0051] The base portion 118 is a portion of the apparatus 100 where the base 116 is provided in use. In some examples, the base portion 118 may include a base guide ( Figure 1 ), to guide the substrate 116 through the apparatus 100. For example, a substrate guide ( Figure 1 ) can be in the transmission direction ( Figure 1 The guide substrate 116 is provided on the substrate 116 (as indicated by the arrow A).

[0052] In some examples, substrate 116 can be in the form of a roll of substrate 116. In some examples, the roll of substrate 116 can be or include silicon or a polymer. In some examples, such as for the production of energy storage devices, the roll of substrate 116 can be or include nickel foil, but it should be understood that any suitable metal can be used instead of nickel, such as aluminum, copper, or steel, or metallized materials including metallized plastics, such as aluminum on polyethylene terephthalate (PET).

[0053] The target portion 106 is a portion of the apparatus 100 in which a target material 108 is provided in use. The target portion 106 may include a target support 107 arranged to support the target material 108. For example, the target support 107 may include a plate or other support structure that supports or holds the target material 108 in place during sputter deposition. The target material 108 may be a material based on which sputter deposition is performed on the substrate 116. For example, the target material 108 may be or include a material that is deposited onto the substrate 116 by sputter deposition.

[0054] In some examples, such as for the production of an energy storage device, the target material 108 can be or include a cathode layer of the energy storage device, or can be or include a precursor material therefor, such as a material suitable for storing lithium ions, such as lithium cobalt oxide, lithium iron phosphate, or an alkali metal polysulfide salt. Additionally or alternatively, the target material 108 can be or include an anode layer of the energy storage device, or can be or include a precursor material therefor, such as lithium metal, graphite, silicon, or indium tin oxide. Additionally or alternatively, the target material 108 can be or include an electrolyte layer of the energy storage device, or can be or include a precursor material therefor, such as a material that is ionically conductive but also an electrical insulator, such as lithium phosphorus oxynitride (LiPON). For example, the target material 108 can be or include LiPO as a precursor material for depositing LiPON onto the substrate 116, such as by reacting with nitrogen in a region of the target material 108.

[0055] The target portion 106 and the substrate portion 118 are spaced apart from one another and define a deposition zone 114 therebetween. The deposition zone 114 may be considered to be an area or volume between the substrate portion 118 and the target portion 106 where, in use, sputter deposition from the target material 108 onto a web of substrate 116 occurs. For example, the deposition zone 114 may be considered to be an area or volume between a substrate 116 received in use in the apparatus 100 and a target material 108 received in use in the apparatus 100 where, in use, sputter deposition from the target material 108 onto a web of substrate 116 occurs.

[0056] The antenna arrangement 102 includes at least one antenna 102a, 102b for generating a plasma when an alternating current is driven through the antennas 102a, 102b in use. In the example shown, the antenna arrangement 102 includes two antennas 102a, 102b. Suitable RF power can be driven through one or both of the antennas 102a, 102b by an RF power system (not shown) to generate an inductively coupled plasma 112 from a process or sputtering gas in a housing (not shown). In some examples, the plasma 112 can be generated by driving an RF current through one or more antennas 102a, 102b, for example, at a frequency between 1 MHz and 1 GHz; a frequency between 1 MHz and 100 MHz; a frequency between 10 MHz and 40 MHz; or at a frequency of about 13.56 MHz or multiples thereof. In any case, the RF power causes ionization of the process or sputtering gas to generate the plasma 112.

[0057] In the illustrated example, the antenna device 102 is disposed away from the deposition zone 114. In this way, the plasma 112 can be generated away from the deposition zone 114. The antennas 102a, 102b can extend substantially parallel to each other and can be disposed transversely to each other. This can allow an elongated region of plasma 112 to be precisely generated between the two antennas 102a, 102b, which in turn can help to precisely confine the generated plasma 112 to the deposition zone 114, as described in more detail below. In some examples, the length of the antennas 120a, 120b can be similar to the width of the substrate 116 carried in the substrate portion 118. The elongated antennas 102a, 102b can generate plasma 112 over an area having a length corresponding to the width of the substrate 116, and thus can allow the plasma 112 to be uniformly or uniformly available over the width of the substrate 116. As described in more detail below, this can in turn help to provide uniform or consistent sputtering deposition.

[0058] The limiting device 104 includes at least one first element 105 a and at least one second element 103 .

[0059] At least one first element 105a is disposed between the antenna arrangement 102 and the deposition region 114. The first element 105a is arranged to confine the plasma 112 from the antenna arrangement 104 towards the deposition region 114, thereby providing sputter deposition of the target material 108 to the substrate 116.

[0060] In some examples, the confined plasma 112 may be a high-density plasma at least in the deposition region 114. For example, the confined plasma 112 may have a density of, for example, 10 11 cm -3 The high density plasma 112 in the deposition region 114 may allow for efficient and / or high rate sputtering deposition.

[0061] In some examples, at least one first element 105a may be a first magnetic element 105a arranged to provide a first confining magnetic field to confine plasma from the antenna device 102 toward the deposition region 114. The confining magnetic field may be characterized by magnetic field lines ( Figure 1 105a), which is arranged along the path from the antenna device 102 toward the deposition area 114. The generated plasma 112 tends to follow the magnetic field lines and is therefore restricted by at least one first element from the antenna device 102 toward the deposition area 114. For example, plasma ions in the confining magnetic field and with a certain initial velocity will be subject to the Lorentz force, which causes the ions to perform periodic motion around the magnetic field lines. If the initial motion is not strictly perpendicular to the magnetic field, the ions will follow a spiral path centered on the magnetic field lines. Therefore, the plasma containing such ions tends to follow the magnetic field lines and is therefore restricted to the path or plane defined thereby. Therefore, the first magnetic element 105a can be appropriately arranged so that the plasma 112 is restricted to the deposition area 114 by the confining magnetic field.

[0062] In some examples, at least one magnetic element 105a may be arranged to provide a confining magnetic field characterized by magnetic field lines that follow a path substantially parallel to substrate 116 and / or target material 108, at least in deposition region 114. This may allow for a more uniform distribution of plasma 112 over deposition region 114, which in turn may allow for a more uniform deposition of target material 112.

[0063] In some examples, as shown, the confinement device may include two first elements 105a, 105b. The first elements 105a, 105b may be arranged so that the deposition zone 114 is located between the first 105a of the first elements 105a, 105b and the second 105b of the first elements 105a, 105b, thereby confining the plasma 112 through the deposition zone 114. For example, the first elements 105a, 105b may be magnetic elements 105a, 105b. The magnetic elements 105a, 105b may be arranged to provide a confining magnetic field together, which confines the plasma 112 from the antenna device 102 to pass through the deposition zone 114 (i.e., substantially from one side of the deposition zone 114 to the other side). For example, at least two magnetic elements 105a, 105b may be arranged so that a region of relatively high magnetic field strength is provided between the magnetic elements 105a, 105b. The region of relatively high magnetic field strength may extend through the deposition zone 114. The confining magnetic field generated by the magnetic elements 105a, 105b can be characterized by magnetic field lines that follow a path substantially parallel to the substrate 116 and / or the target material 108, at least in the deposition zone 114. This can allow for a more uniform plasma density to be provided across substantially the entire deposition zone 114, which in turn can allow for a more uniform deposition of the target material 116 across substantially the entire deposition zone 114.

[0064] In some examples, at least one of the first magnetic elements 105a, 105b may be an electromagnet that is controllable to provide a first confining magnetic field. For example, one or both of the first magnetic elements 105a, 105b may be electromagnets 104a, 104b. The device 100 may include a controller (not shown) that is arranged to control the strength of the magnetic field provided by one or more electromagnets 105a, 105b. This may allow control of the confining magnetic field, such as the arrangement of magnetic field lines that characterize the confining magnetic field. This may allow adjustment of the plasma density at the substrate 116 and / or the target material 108, and thus allow improved control of the sputtering deposition. This may increase the flexibility of the operation of the device 100.

[0065] In some examples, at least one of the first magnetic elements 105a, 105b can be provided by a solenoid 105a, 105b. Each solenoid 105a, 105b can define an opening ( Figure 5 Not shown, but see Figure 6 The opening 650 is formed so that the plasma 112 can pass through or through the opening (can pass through) during use.

[0066] In some examples, the solenoids 105a, 105b may be elongated. Figure 6 As shown, the opening 650 defined by the solenoids 105a, 105b may be elongated. Figure 5As best understood in the drawings, the opening 505 of the solenoids 105a, 105b can be elongated in a direction substantially parallel to the direction in which the antennas 102a, 102b are elongated. As described above, the plasma 112 can be generated along the length of the elongated antennas 102a, 102b, and the elongated solenoid 105a can confine the plasma 112 in a direction away from the elongated antennas 102a, 102b and through the elongated solenoid 105a. The plasma 112 can be confined from the elongated antennas 102a, 102b by the elongated solenoid 105a in a sheet shape. That is, in a form in which the depth (or thickness) of the plasma 112 is significantly less than its length and / or width. The thickness of the plasma 112 sheet can be substantially constant along the length and width of the sheet. The density of the plasma 112 sheet can be substantially uniform in one or both of its width and length directions. The sheet-shaped plasma 112 can be restricted to and / or pass through the deposition zone 114 by the magnetic field provided by the solenoids 105a, 105b. The plasma 112 can thus be restricted to a sheet shape. Restricting the plasma 112 to a sheet shape can allow the substrate 116 and / or the target material 108 to be exposed to the plasma 112 to increase the area, and thus the area where sputtering deposition can be achieved to increase. This can allow, for example, an increase in the deposition rate per unit area of ​​the substrate, and thus in turn allow more efficient deposition. This can alternatively or additionally allow a more uniform distribution of plasma density at the substrate 116 and / or the target material 108 on the deposition zone 114. This in turn can allow more uniform sputtering deposition on the substrate 116. Therefore, sputtering deposition can be performed more consistently. This can, for example, improve the consistency of the processed substrate, and can, for example, reduce the need for quality control.

[0067] Back to Figure 1 As described above, the antenna device 102 may include two antennas 102a, 102b. The antennas 102a, 102b may be spaced apart from each other and define a region 101 between them. The region 101 may be a region 101 where the plasma 112 is preferentially generated by the antennas 105a, 105b in use. The antennas 102a, 102b may be spaced apart from each other in a direction substantially perpendicular to the direction in which each antenna 102a, 102b is elongated. The antennas 102a, 102b may be spaced apart from each other in a direction substantially perpendicular to the direction in which the plasma 112 is confined by the confinement device 104. The solenoid 105a may be arranged so that the opening 505 of the solenoid 105a leads to the region 101 defined between the two antennas 102a, 102b. This may allow the plasma 112 to be precisely confined by the first solenoid 105a away from the antenna device 102 toward the deposition area 114.

[0068] As shown, there may be two solenoids 105a, 105b with a deposition zone 114 located between them. As shown, the generated plasma 112 may pass from the antenna assembly 102 through the first solenoid 105a, into the deposition zone 114, and toward and through the second solenoid 105b. The second solenoid 105b may have any of the features or combinations of features described above for the first solenoid 105a.

[0069] Despite Figure 1 Only two first magnetic elements 105a, 105b are shown in FIG, but it should be understood that further first magnetic elements (not shown), for example further solenoids (not shown) such as solenoids 105a, 105b, may be placed along the path of the plasma 112. This may allow for an enhancement of the confining magnetic field, and thus for precise confinement, and / or may allow for more degrees of freedom in the control of the confining magnetic field.

[0070] At least one first element 105a, 105b itself may not be able to completely confine the plasma 112 in the deposition region 114. As an illustrative example, in Figure 1 In the embodiment of the present invention, the plasma 112 extends out of the first element 105b, i.e., toward the side of the first element 105b opposite to the side toward which the deposition zone 114 is deposited. The plasma can, for example, reach the chamber wall that falls onto the housing (not shown). This "overflow" of plasma 112 from the deposition zone 114 can lead to a reduction in the density of plasma 112 in the deposition zone 114. This in turn can lead to a reduction in deposition efficiency, i.e., can lead to slower deposition. Alternatively or in addition, this can reduce the power coupling between the plasma and the rf power provided via the antennas 102a, 102b, which may require an increase in the rf power provided to the antennas to compensate. In order to mitigate this potential reduction in plasma density and / or power coupling caused by this "overflow" in the region of the first element 105a, the confinement device 104 includes at least one second element 103.

[0071] The at least one second element 103 is arranged such that the antenna arrangement 102 is located between the at least one second element 103 and the deposition zone 114. That is, the second element 103 may be arranged such that the antennas 102a, 102b are located between the second element 103 and the deposition zone 114. The second element 103 is arranged to confine the plasma 112 away from the second element 103, towards the antenna arrangement 102 (i.e. the antennas 102a, 102b), and thereby towards the deposition zone 115 via the at least one first element 105a. The at least one second element 103 may thus result in an increase in the plasma (ion) density in the deposition zone 114, for example compared to a situation where the second element 103 is not provided. This in turn may allow for an increase in the deposition efficiency of the target material 108 to the substrate 116. Alternatively or additionally, this may allow for an improvement in the power coupling between the antennas 102a, 102b and the plasma 112 in the deposition zone 114, and may therefore allow for relatively less power to be provided to the antennas. As described in more detail below, a similar arrangement may optionally be provided to prevent or reduce such "overflow" in the region of the second first element 105b and correspondingly further increase the plasma density in the deposition zone 114, which may allow further corresponding improvements in deposition efficiency and / or power coupling.

[0072] Similar to the first element 105a, the second element 103 may be elongated and extend in a direction parallel to the direction in which the antennas 102a, 102b and / or the first element 105a are elongated (possibly in a direction parallel to the direction in which the antennas 102a, 102b and / or the first element 105a are elongated). Figure 6 This allows the density of the plasma 112 in the deposition zone to be increased in a uniform manner across the width of the substrate 118 by the second element 103.

[0073] In some examples, at least one second element 103 may be or include an electrostatic element 103. The electrostatic element 103 may be controlled to provide an electric field, thereby repelling at least a portion of the plasma 112 from the electrostatic element 103 toward the antenna device 102, and thereby repelling it via the first element 105a, toward the deposition area 114, at least in a volume intermediate the first element 105a and the second element 103. For example, the electrostatic element 103 may be arranged to be positively charged in use, thereby repelling positively charged ions of the plasma 112 toward the deposition area. Repelling the plasma 112 from the second element 103 by providing a suitable electric field may in turn prevent the plasma 112 from being confined away from the antennas 102a, 102b to the deposition area 114, and instead cause the plasma 112 to be preferentially confined by the first element 105a toward the deposition area 114. Thus, the second element 103 may cause the plasma 112 to be confined away from the second magnetic element 103, toward the antenna device 102, and thereby toward the deposition area 114 via the first element 105a.

[0074] In some examples, the apparatus may include a controller (not shown) arranged to control the electric field provided by the electrostatic element 103. For example, a positive voltage may be applied to the electrostatic element 103 by a suitable voltage source (not shown) so as to repel positively charged ions of the plasma 112 toward the deposition region. The controller (not shown) may be arranged to control the voltage provided to the electrostatic element 103, thereby controlling the extent to which the plasma 112 is repelled from the electrostatic element 103, and thus controlling the extent to which the plasma density in the deposition region 114 is increased.

[0075] In some examples, the apparatus 100 may be arranged to bias the target material 108 with a negative charge during use. This may be provided by a suitable voltage source (not shown), which may be controlled by a controller (not shown). The negative bias on the target material 108 coupled with the positive bias on the second element 103 may cause the plasma to be confined toward the deposition region 104.

[0076] In some examples, the second element 103 may be or include a second magnetic element 103. The second magnetic element 103 may be arranged to provide a second confining magnetic field. The second magnetic field may be opposite to the first confining magnetic field provided by the first element 105a in at least a volume 230 between the first element 105a and the second element 103. This may result in the plasma 112 being confined away from the second magnetic element 103, toward the antenna device 102, and thus toward the deposition area 114 via the first element 105a.

[0077] For example, refer to Figure 2 , schematically showing Figure 11, a portion of the device 100 is schematically shown, according to an example, magnetic field lines (indicated by arrow lines as usual), which characterize the interaction of a first confining magnetic field provided by a first magnetic element 105a (solenoid 105a) and a second confining magnetic field provided by a second magnetic element 103. The second magnetic element 103 is arranged to have a polarity opposite to that of the first magnetic element 105a. Therefore, at least in a volume 230 between the first element 105a and the second element 103, the magnetic field provided by the second magnetic element 103 is opposite to the first confining magnetic field provided by the first element 105a. The second confining magnetic field provided by the second element 103a correspondingly reduces the flux of the first confining magnetic field provided by the first magnetic element 105a in the volume 230 located behind the first element 105a relative to the deposition area 114. For example, the second confining magnetic field provided by the second element 103a in the volume 230 can reduce the magnetic flux of the first confining magnetic field provided by the first magnetic element 105a along the direction between the first element 105a and the second element 103. Reducing the flux of the first confining magnetic field provided by the first magnetic element 105a in the volume 230 behind the first element 105a relative to the deposition zone 114 can in turn prevent the plasma 112 from being confined away from the antennas 102a, 102b to the deposition zone 114, and instead cause the plasma 112 to be preferentially confined toward the deposition zone 114. Therefore, the second element 103 can cause the plasma 112 to be confined away from the second magnetic element 103, toward the antenna device 102, and thus toward the deposition zone 114 via the first element 105a.

[0078] In some examples, the second element 103 may include a permanent magnet having a suitable pole facing the first element 105a to oppose the magnetic field generated thereby. In some examples, the second element 103 may include a plurality of permanent magnets, such as arranged in an array, such as each permanent magnet having a suitable pole facing the first element 105a to oppose the magnetic field generated thereby.

[0079] In some examples, the second element 103 may be or include one or more electromagnets that are controllable to provide a second confining magnetic field. For example, the second element 103 may include a solenoid array (not shown) that is controllable to present a suitable pole facing the first element 105a to oppose the magnetic field generated thereby. The device 100 may include a controller (not shown) that is arranged to control the second confining magnetic field provided by the second magnetic element 103. This may allow control of the interaction of the second confining magnetic field with the first confining magnetic field, and thus control the extent to which the plasma 112 is confined away from the second element 103 toward the deposition region 114.

[0080] refer to Figure 3 , shows a device 300 according to an example. The device 300 can be the same as the device 300 described above. Figure 1and / or Figure 2 The described apparatus 100 is substantially identical and like features are indicated by like reference numerals. Figure 3 The restriction device 304 of the illustrated example device 300 further comprises a third element 303 .

[0081] Similar to the second element 103, the third element 303 confines the plasma away from the third element 303 toward the deposition area 114. The third element 303 can be connected to the reference Figure 1 and Figure 2 The second element 103 described above may be the same as, or may have any one of the features or feature combinations of, the second element 103. Figure 3 As shown, the third element 303 is arranged so that the deposition zone 114 is located between the second element 102 and the third element 303. The third element 203 is arranged to confine the plasma 112 away from the third element 303 and toward the deposition zone 114. In this example, the third element 303 is arranged so that the first element 105a of the first elements 105a, 105b and the second element 105b of the first elements 105a, 105b and the deposition zone 114 are located between the third element 303 and the second element 103, so that the third element 303 confines the plasma 112 away from the third element 303 and toward the deposition zone 114 via the second element 105b of the first elements 105a, 105b.

[0082] Therefore, providing the third element 303 may lead to a (further) increase in the plasma density in the deposition region 114, for example compared to a case where the third element 303 is not provided (ie according to Figure 1 ). This in turn may allow for increased deposition efficiency of the target material 108 to the substrate 116 and / or allow for increased power coupling from the antennas 102a, 102b to the plasma 112 in the deposition region 114.

[0083] refer to Figure 4 and Figure 5 , with a cross-sectional view ( Figure 4 ) and floor plan ( Figure 5 ) shows an example device 400 according to an example. The device 300 can be the same as the device 400 described above. Figure 3 The described apparatus 300 is substantially identical and like features are indicated by like reference numerals. Figure 4 and 5 The example device 400 shown comprises a further antenna arrangement 402 comprising a third antenna 102c and a fourth antenna 102d.

[0084] As shown, the third element 203 is arranged such that the further antenna arrangement 402 is located between the third element 203 and the deposition zone 114, and the third element 203 confines the plasma away from the third element 203 (towards the further antenna arrangement 402), and thereby towards the deposition zone 114 via the first element 105b. The third and fourth antennas 102c, 102d of the further antenna arrangement 402 may be substantially the same as the first and second antennas 102a, 102b of the antenna arrangement 102 described above. It should be understood that the arrangement and function of the third element 203, the further antenna arrangement 402 and the first element 105b may be substantially the same as the arrangement and function of the second element 103, the antenna arrangement 102 and the first element 105a described above, but the former are arranged on the other side of the deposition zone 114 compared to the latter. Providing the third and fourth antennas 102a, 102d in this manner may allow for a more uniform plasma density and / or distribution over the deposition zone 114, and thus may in turn provide improved deposition.

[0085] refer to Figure 6 , shows a cross-section of an example of a first magnetic element 105a, 105b. As shown, the first magnetic element 105a, 105b is a solenoid and includes an opening 650 through which the plasma is confined in use. The first magnetic element 105a, 105b and the opening 650 defined thereby are elongated. As described above, the first element 105a, 105b can be elongated in a direction parallel to the direction in which the antenna assembly 102, 402 is elongated, thereby providing a sheet of plasma 112 confined in the deposition region 114.

[0086] In reference Figure 1-6 In the depicted example, plasma 112, substrate 116, and target 108 are substantially planar, but this is not required, and in other examples, plasma 112, substrate 116, and / or target portion 108 may be substantially curved.

[0087] refer to Figure 7 , schematically shows a device 700 according to an example. The device 700 is similar to the above reference Figure 4 and 5 The example device 400 is described in detail and like features are indicated by like reference numerals. Figure 7 In the device 700, the base portion 718 is arranged along a curved path ( Figure 7 The arrow C in FIG. 1 guides the substrate 116 , and the confinement device 704 is arranged to confine the plasma to follow the curve of the curved path C.

[0088] The base portion 718 may include a base guide 719, which may be or include a curved member. Figure 7In the example shown, the curved member may be in the form of a roller 719 of an entire web supply assembly 721. The roller 719 may be arranged to rotate about an axis 720. The web supply assembly 721 may be arranged to supply a web of substrate 116 to and from the roller 719 such that the web of substrate 116 is carried by at least a portion of the curved surface of the roller 719. In some examples, the web supply assembly 721 includes a first roller 710a arranged to supply a web of substrate 116 to the roller 719 and a second roller 710b arranged to supply the web of substrate 116 from the roller 719 after the web of substrate 116 has followed the curved path C. The web supply assembly 721 can be part of a "roll-to-roll" processing apparatus (not shown), in which a web of substrate 116 is supplied from a first roll or spool (not shown) of substrate web 116, passes through the apparatus 700, and then is supplied onto a second roll or spool (not shown) to form a loaded roll (not shown) of processed substrate web.

[0089] In this example, the limiting device 704 is arranged such that the limiting magnetic field provided by the first elements 105a, 105b can be characterized by magnetic field lines arranged as a curve along the curved path C. For example, the magnetic field lines ( Figure 7 116) may follow a curved path having a common center of curvature with curved path C but having a different radius of curvature than curved path C (larger in the example shown). For example, the magnetic field lines may follow a curved path that is substantially parallel to curved path C of substrate 116 but radially offset therefrom. The magnetic field lines characterizing the confining magnetic field may be arranged to follow a curve along curved path C around a majority or a significant portion of curved path C, such as over all or a majority of an imaginary portion of curved path C that guides substrate 116, such as around at least about 1 / 16 or at least about 1 / 8 or at least about 1 / 4 or at least about 1 / 2 of the circumference of an imaginary circle. In an example where the first elements 105a, 105b are provided by solenoids, similar to reference 116, Figures 1 to 6 As described above, the confinement device 704 can confine the plasma 112 into the form of a curved sheet.

[0090] For a given equipment footprint, confining the plasma 112 to a curve along the curved path C of the substrate 116 can allow an increased area of ​​the substrate 116 to be exposed to the plasma 112, and thus an increased area over which sputter deposition can be achieved. For example, for a given degree of deposition, this can allow a web of substrate 116 to be fed through a roll-to-roll equipment at a faster rate, thereby achieving more efficient sputter deposition.

[0091] In some examples (not shown), the target portion 706 may be curved and may substantially follow the curve of the curved path C. This may allow for maximizing the surface area of ​​the web of substrate 116 carried by the drum 118 onto which the target material 108 is deposited.

[0092] exist Figure 7 In the example of , the first element 105a is arranged between the antenna device 102 and the deposition zone 114 and is arranged to confine the plasma 112 from the antenna device 102 towards the deposition zone 114, thereby providing sputtering deposition of the target material 108 to the substrate 116. The second element 103 is arranged so that the antenna device 102 is located between the second element 103 and the deposition zone 114, and is arranged to confine the plasma 112 away from the second element 103, towards the antenna device 201, and thereby via the first element 105a towards the deposition zone 114. The third element 303 is arranged so that the deposition zone is located between the third element 303 and the second element 103. The third element 303 is arranged so that the further antenna device 402 is located between the third element 303 and the deposition zone 114. The third element 303 is arranged to confine the plasma 112 away from the third element 303, towards the further antenna device 402, and thereby via the second first element 105b towards the deposition zone 114. Thus, the second element 103 and / or the third element 303 serve to increase the plasma density in the deposition region 114 compared to a situation where no second and / or third element 103, 303 is provided. This in turn may allow for increased deposition efficiency of the target material 108 onto the substrate 116 and / or increased power coupling between the antenna arrangement 102 or further antenna arrangement 402 and the plasma 112 in the deposition region 114, and may therefore allow for relatively less power to be provided to the antenna, thereby providing a more efficient device.

[0093] refer to Figure 8 , schematically illustrates an example method of sputter-depositing a target material 108 onto a substrate 116. In this method, a deposition region 114 is defined between the substrate 116 and the target material 108. The target material 108, the substrate 116, and the deposition region 114 may be, for example, a reference Figures 1 to 7 In some examples, the method can be performed by referring to Figures 1 to 7 The invention may be performed by any one of the devices 100, 300, 400, 700 described herein.

[0094] In step 802, the method includes generating a plasma 112 using an antenna device 102 including at least one antenna 102a, 102b. For example, the antenna device 102 may be the one described above with reference to Figures 1 to 7 An antenna arrangement 102 is described.

[0095] In step 804, the method includes confining the plasma 112 from the antenna device 201 toward the deposition area 114 using at least one first element 105a disposed between the antenna device 201 and the deposition area 114, thereby causing the target material 108 to be sputter-deposited onto the substrate 116. For example, the first element 105a may be the one described above with reference to Figures 1 to 7 A first element 105a is described.

[0096] In step 806, the method includes using at least one second element 103 to confine the plasma 112 away from the second element 103 toward the antenna device 102, and thus toward the deposition area 114 via the first element 105a, the second element 103 being arranged such that the antenna device 102 is located between the at least one second element 103 and the deposition area 114. For example, the second element 103 can be the one described above with reference to Figures 1 to 7 The second element 103 is described.

[0097] As described above, confining the plasma 112 away from the second element 103, towards the antenna device 102, and thus via the first element 105a towards the deposition zone 114, can result in an increase in the plasma (ion) density in the deposition zone 114, for example compared to when confinement using the second element 103 is not performed. This in turn can allow for an increased efficiency in the deposition of the target material 108 to the substrate 116. Alternatively or in addition, this can allow for an improvement in the power coupling between the antennas 102a, 102b and the plasma 112 in the deposition zone 114, and thus can allow for relatively less power to be provided to the antennas. More efficient sputtering deposition can therefore be provided.

[0098] The above examples should be understood as illustrative examples of the present invention. It should be understood that any feature described with respect to any one example can be used alone or in combination with other features described, and can also be used in combination with one or more features of any other example, or in combination with any combination of any other example. In addition, equivalents and modifications not described above may also be adopted without departing from the scope of the present invention as defined by the appended claims.

Claims

1. An apparatus for sputtering a target material onto a substrate, the apparatus comprising: a base portion in which a base is provided in use; a target portion spaced from the substrate portion and in use providing a target material in the target portion, the target portion and the substrate portion defining a deposition zone therebetween; an antenna arrangement comprising at least one antenna for generating a plasma when, in use, an alternating current is driven through the antenna; Restraint devices, including: at least one first element disposed between the antenna arrangement and the deposition zone and arranged, in use, to confine plasma from the antenna arrangement towards the deposition zone to provide, in use, sputter deposition of target material onto the substrate; and at least one second element arranged such that the antenna arrangement is located between the at least one second element and the deposition zone and arranged to confine the plasma, in use, away from the second element, towards the antenna arrangement and thence via the at least one first element towards the deposition zone, Wherein, at least one of the second elements is an electrostatic element which is controllable to provide an electric field to repel at least a portion of the plasma from the electrostatic element towards the antenna device and thereby via the first element towards the deposition zone in at least a volume between the first and second elements.

2. The device according to claim 1, wherein: At least one of said first elements is a first magnetic element arranged to provide a first confining magnetic field to confine plasma from the antenna arrangement towards the deposition region.

3. The device according to claim 2, wherein: The first magnetic element is an electromagnet controllable to provide the first confining magnetic field.

4. The device according to claim 3, wherein: The apparatus comprises a controller arranged to control a first confining magnetic field provided by a first magnetic element.

5. The device according to any one of claims 2 to 4, wherein: The first magnetic element is a solenoid having an opening through which, in use, the plasma is confined.

6. The device according to claim 5, wherein: The at least one antenna is elongated, and the opening of the solenoid is elongated in a direction substantially parallel to the direction in which the at least one antenna is elongated.

7. The device according to claim 6, wherein: The antenna arrangement comprises two antennas, and wherein the solenoid is arranged such that an opening of the solenoid opens into a region defined between the two antennas.

8. The apparatus according to any one of claims 2 to 4 and 6 to 7, wherein: At least one of the second elements is a second magnetic element, which is arranged to provide a second confinement magnetic field to be opposite to the first confinement magnetic field at least in a volume between the first element and the second element, thereby confining the plasma away from the second magnetic element, towards the antenna device, and thereby via the first element towards the deposition area.

9. The device according to claim 8, wherein: The second confining magnetic field is arranged to reduce the magnetic flux of the first confining magnetic field in a volume between the first element and the second element along a direction between the first element and the second element.

10. The device according to claim 9, wherein: The second magnetic element is an electromagnet controllable to provide the second confining magnetic field.

11. The device according to claim 10, wherein: The apparatus comprises a controller arranged to control a second confining magnetic field provided by the second magnetic element.

12. The device according to claim 11, wherein The electrostatic element is arranged to be positively charged in use so as to repel positively charged ions of the plasma.

13. The device according to claim 11 or 12, wherein: The apparatus comprises a controller arranged to control the electric field provided by the electrostatic element.

14. The apparatus according to any one of claims 1 to 4, 6 to 7 and 9 to 12, wherein: The confinement device comprises at least two of the first elements arranged such that the deposition zone is located between a first one of the first elements and a second one of the first elements, thereby confining the plasma to pass through the deposition zone.

15. The device according to claim 14, wherein: The confinement arrangement comprises a third element arranged such that the deposition zone is located between a second element and a third element, the third element being arranged to confine the plasma away from the third element and towards the deposition zone.

16. The device according to claim 15, wherein: The third element is arranged so that the first one of the first elements and the second one of the first elements and the deposition zone are located between the third element and the second element, so that the third element confines the plasma away from the third element and toward the deposition zone via one of the first one of the first elements and the second one of the first elements.

17. The apparatus of any one of claims 1 to 4, 6 to 7, 9 to 12, and 15 to 16, wherein: The target portion is controllable to provide a negative charge to the target material in use, thereby attracting positively charged ions of the plasma.

18. The apparatus of any one of claims 1 to 4, 6 to 7, 9 to 12, and 15 to 16, wherein: The apparatus comprises a web supply assembly arranged, in use, to provide a web of substrate in the substrate portion.

19. A method of sputter depositing a target material onto a substrate, wherein a deposition zone is defined between the substrate and the target material, the method comprising: generating a plasma using an antenna arrangement comprising at least one antenna; Using at least one first element disposed between the antenna device and the deposition zone, confining plasma from the antenna device toward the deposition zone to cause sputter deposition of the target material onto the substrate; as well as confining the plasma away from the second element, toward the antenna device, and thereby via the first element toward the deposition zone using at least one second element, the at least one second element being arranged such that the antenna device is located between the at least one second element and the deposition zone; Wherein, at least one of the second elements is an electrostatic element which is controllable to provide an electric field to repel at least a portion of the plasma from the electrostatic element towards the antenna device and thereby via the first element towards the deposition zone in at least a volume between the first and second elements.

20. An apparatus for sputter-depositing a target material onto a substrate, the apparatus comprising: Sedimentary area; an antenna arrangement comprising at least one antenna for generating a plasma when, in use, an alternating current is driven through the antenna; Restraint devices, including: at least one first element disposed between the antenna arrangement and the deposition zone and arranged, in use, to confine plasma from the antenna arrangement towards the deposition zone, thereby, in use, providing plasma to the deposition zone; and at least one second element arranged such that the antenna arrangement is located between the at least one second element and the deposition zone and arranged to confine the plasma, in use, away from the second element, towards the antenna arrangement and thence via the at least one first element towards the deposition zone, Wherein, at least one of the second elements is an electrostatic element which is controllable to provide an electric field to repel at least a portion of the plasma from the electrostatic element towards the antenna device and thereby via the first element towards the deposition zone in at least a volume between the first and second elements.

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