Method and apparatus for sputtering deposition

Abstract

An apparatus (100) for sputter depositing a target material (108) onto a substrate (116) is disclosed. In one form, the apparatus comprises a substrate guide (118) arranged to guide the substrate along a curved path (C) and a target portion (106) spaced from the substrate guide and arranged to support the target material. The target portion and the substrate guide define a deposition zone (114) therebetween. The apparatus comprises a biasing device (122) for applying an electrical bias to the target material. The apparatus further comprises a confinement device (104) comprising one or more magnetic elements (104a, 104b) arranged to provide a confining magnetic field to confine a plasma (112) to the deposition zone, thereby providing, in use, sputter deposition of a web of the target material onto the substrate, the confining magnetic field being characterized in that magnetic field lines are arranged to substantially follow the curve of the curved path, at least in the deposition zone, so as to confine the plasma around the curve of the curved path.

Description

Technical Field

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

[0002] Deposition is a process by which a target material is deposited on a substrate. An example of deposition is thin film deposition, in which a thin layer (typically 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 is vaporized to generate a vapor that is then condensed onto the substrate surface. An example of PVD is sputtering deposition, in which particles are ejected from a target due to bombardment by high-energy particles (e.g., 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 high-energy electrons to generate a plasma. The bombardment of the target by the ions of the plasma ejects the target material, which can then be deposited on the substrate surface. Sputtering deposition has an advantage over other thin film deposition methods, such as evaporation, in that the target material can be deposited without heating the target material, which can in turn reduce or prevent thermal damage to the substrate.

[0003] Known sputtering deposition techniques employ magnetrons, in which a glow discharge combined with a magnetic field induces an increase in plasma density in a circular region near the target. This increase in plasma density can lead to an increase in deposition rate. However, the use of magnetrons results in a target erosion profile with a circular "racetrack" shape, which limits target utilization and can negatively impact the uniformity of the resulting deposition.

[0004] It would be desirable to provide uniform, controllable and / or efficient sputter deposition to allow for increased utility in industrial applications. Summary of the Invention

[0005] According to a first aspect of the present invention, there is provided a sputtering deposition apparatus comprising:

[0006] a substrate guide arranged to guide the substrate along a curved path;

[0007] Target assembly, comprising:

[0008] a target portion spaced apart from the substrate guide and arranged to support a target material, the target portion and the substrate guide defining a deposition zone therebetween; and

[0009] a biasing device for applying an electrical bias to the target material; and

[0010] A confinement arrangement comprising one or more magnetic elements arranged to provide a confinement magnetic field to confine the plasma to a deposition zone, thereby providing, in use, sputter deposition of target material onto a substrate, the confinement magnetic field being characterized in that the magnetic field lines are arranged to substantially follow the curve of a tortuous path, at least in the deposition zone, so as to confine the plasma to around the curve of the tortuous path.

[0011] By guiding the substrate along a tortuous path, for example, the apparatus provides compact sputter deposition of target material over a large surface area of the substrate in a "roll-to-roll" type system. A roll-to-roll deposition system can be more efficient than a batch process, which can stall deposition between batches.

[0012] When the magnetic field lines substantially follow the curve of the curved path, the plasma can be confined to the deposition zone around the curved path. Consequently, the plasma density can be more uniform in the deposition zone, at least in the direction around the curve of the curved path. This can increase the uniformity of the target material deposited on the substrate. Consequently, the consistency of the processed substrate can be improved, thereby reducing the need for quality control.

[0013] Applying an electrical bias to the target material causes ions from the plasma near the target material to be attracted to the area adjacent to the target material. This can increase the interaction rate between the plasma ions and the target material, thereby improving the efficiency of sputtering deposition. By controlling the electrical bias applied to the target material, the density of plasma ions adjacent to the target material can also be controlled. Precise control of the plasma ions in this way can provide patterned sputtering deposition of the target material on the substrate, wherein a greater density of target material is deposited on a specific portion of the substrate, for example, which overlaps the biased target material. Compared to using a mask to deposit a material pattern on the substrate to protect uncoated areas in the substrate, this can be more efficient and less wasteful. In addition, the inventors surprisingly found that the crystallinity of the target material deposited on the substrate can be controlled by appropriately controlling the electrical bias applied to the target material. In this way, a target material with a desired crystallinity can be deposited directly on the substrate.

[0014] In an example, the bias device is configured to apply an electrical bias having a negative polarity to the target material. This can be used to attract positive ions from the plasma toward the target material to increase the rate of sputtering deposition.

[0015] In an example, the bias device is configured to apply an electrical bias comprising a DC voltage to the target material. This can increase the uniformity of sputter deposition compared to applying an AC voltage to the target material.

[0016] In some examples, the apparatus further includes a plasma generation device configured to generate a plasma. In some cases, the biasing device is configured to apply an electrical bias to the target material at a first power value, and the plasma generation device is configured to generate the plasma at a second power value such that a ratio of the second power value to the first power value is greater than 1. When the ratio of the second power value to the first power value is greater than 1, the target material sputtered and deposited on the substrate tends to have an at least partially ordered structure. This structure can be achieved regardless of the substrate onto which the target material is sputtered, meaning that an apparatus arranged in this manner has practical value for sputtering and depositing at least partially ordered materials (e.g., crystalline materials) on a variety of different substrates.

[0017] In some cases, the ratio of the second power value to the first power value is less than 3.5 or less than 1.5. Such a ratio can facilitate deposition of target material in an at least partially ordered structure without thermally treating the deposited target material. This can simplify deposition of materials having such a structure.

[0018] The first power value is at least one watt per square centimeter, in this example 1 W cm -2 This first power value has been found to be effective for sputtering of the target material to occur.

[0019] In some cases, the first power value is at most fifteen watts per square centimeter, 15W cm -2 , or up to seventy watts per square centimeter, 70W cm -2 For example, up to 15W cm -2 The first power value is applicable to target materials containing ceramics and / or oxides, while up to 70 W cm -2 The first power value is suitable for a metal target material containing lithium, cobalt, or an alloy of lithium and / or cobalt.

[0020] In one example, the target portion is arranged to support multiple target materials, and the biasing device is configured to independently apply an electrical bias to one or more corresponding target materials of the multiple target materials. This increases the flexibility of the device. For example, by controlling the electrical biases associated with different corresponding target materials, the deposition of the different target materials can be controlled. In this way, the device can be used to deposit a larger amount of one of the multiple target materials than another, for example, to deposit a desired combination of target materials on a substrate. Furthermore, independently applying an electrical bias to one or more corresponding target materials can provide further flexibility in depositing a desired pattern of target materials on a substrate, for example, by controlling the relative electrical biases applied to each target material to deposit more or less of each target material.

[0021] In an example, the apparatus further comprises plasma generating means arranged to generate the plasma, and the plasma generating means comprises an inductively coupled plasma source.The inductively coupled plasma source is easy to control, thereby allowing direct control of the sputter deposition itself.

[0022] In an example, the plasma generation device includes one or more elongated antennas extending in a direction substantially perpendicular to the longitudinal axis of the substrate guide. In an example, the plasma generation device includes one or more elongated antennas extending in a direction substantially parallel to the longitudinal axis of the substrate guide. Regardless of the direction in which the elongated antennas extend, the use of elongated antennas can provide for plasma generation along the length of the antennas, which can increase the area of the substrate and / or target material exposed to the plasma. This can increase the efficiency of sputtering deposition and can alternatively or additionally provide for more uniform deposition of target material on the substrate.

[0023] In some examples, one or more magnetic elements are arranged to provide a confining magnetic field to confine the plasma to a curved sheet. By confining the plasma to a curved sheet, the area of the substrate exposed to the plasma can be increased. Consequently, sputter deposition can be performed over a larger surface area of the substrate, which can improve the efficiency of sputter deposition. By providing a curved sheet of plasma, the density of the plasma can be more uniform. In some cases, the uniformity of the plasma increases around the curve of the curved path and across the width of the substrate. This can allow for more uniform sputter deposition of target material onto the substrate.

[0024] In one example, one or more magnetic elements are arranged to provide a confining magnetic field to confine the plasma to a curved sheet having a substantially uniform density, at least in the deposition zone. With a substantially uniform plasma density in the deposition zone, the target material can be deposited on the substrate with a substantially uniform thickness. This can improve the consistency of the deposited substrate and reduce the need for quality control.

[0025] In some examples, one or more magnetic elements are electromagnets. Using electromagnets allows for control over the strength of the confining magnetic field. For example, in some cases, the apparatus includes a controller configured to control the magnetic field provided by the one or more electromagnets. In this way, the density of the plasma in the deposition zone can be adjusted, which can be used to adjust the deposition of the target material on the substrate. This improves control over sputtering deposition, thereby increasing the flexibility of the apparatus.

[0026] In some examples, the confinement device includes at least two magnetic elements arranged to provide a confining magnetic field. This can allow for more precise confinement of the plasma and / or can allow for greater freedom in controlling the confining magnetic field. For example, having at least two magnetic elements can increase the area of the substrate exposed to the plasma and, therefore, increase the area on which target material is deposited. This can improve the efficiency of sputtering deposition. In these examples, the at least two magnetic elements can be arranged such that the region of relatively high magnetic field strength provided between the magnetic elements substantially follows the curve of the tortuous path. This can increase the uniformity of the plasma around the curve of the tortuous path, which in turn can increase the uniformity of the target material sputter-deposited on the substrate.

[0027] In some examples, the target portion is arranged or configurable such that at least a portion of the target portion defines a support surface that forms an obtuse angle relative to a support surface of another portion of the target portion. This can increase the area over which sputter deposition can occur without increasing the footprint of the target portion and without changing the tortuous path. This can improve the efficiency of sputter deposition.

[0028] In an example, the target portion is substantially curved. This can increase the surface area of the target portion exposed to the substrate within the deposition region, which can increase the efficiency with which sputter deposition is achieved and can be more compact than other arrangements.

[0029] In an example, the target portion is arranged to substantially follow or approximate the curve of the curved path. This can improve the uniformity of the target material of the target portion being sputter-deposited onto the substrate along the curve of the curved path. This can reduce the need for quality control.

[0030] In one example, substrate guidance is provided by a curved member that guides the substrate along a curved path. The substrate can be guided by the rotation of the curved member, which can be a drum or roller. In this way, the apparatus can form part of a roll-to-roll process arrangement, which can process substrates more efficiently than a batch process arrangement.

[0031] According to a second aspect of the present invention, there is provided a method of sputtering a target material onto a substrate, the substrate being guided along a curved path by a substrate guide, wherein a deposition zone is defined between the substrate guide and a target portion supporting the target material, the method comprising:

[0032] applying an electrical bias to the target material; and

[0033] A magnetic field is provided to confine the plasma in the deposition zone to cause sputter deposition of target material onto the substrate, the magnetic field being characterized by magnetic field lines arranged to substantially follow the curve of the tortuous path at least in the deposition zone so as to confine the plasma around the tortuous path.

[0034] This method can increase the uniformity of the plasma around the curve of the tortuous path, which in turn can increase the uniformity of the target material deposited on the substrate. By using a tortuous path, the method can be implemented as a roll-to-roll process, which can be performed more efficiently than batch processes. In addition, by applying an electrical bias to the target material, the efficiency of sputtering deposition can be improved. The crystallinity of the target material deposited on the substrate can also or instead be controlled by applying an electrical bias to the target material. Alternatively or additionally, controlling the electrical bias can be used to control the pattern of the target material deposited on the substrate, so that a desired pattern can be deposited in a simple and efficient manner.

[0035] In some cases, the method includes providing a target material comprising at least one of lithium, cobalt, lithium oxide, cobalt oxide, and lithium oxide. These target materials can be used to manufacture a variety of different devices, products, or components.

[0036] In some examples, applying an electrical bias to the target includes applying the electrical bias at a first power value, and the method includes generating the plasma at a second power value such that a ratio of the second power value to the first power value is greater than 1. This ratio can be used to deposit the target material on the substrate in an at least partially ordered structure. This can be simpler than other deposition processes (e.g., those that include post-processing such as thermal treatment).

[0037] Other features will become apparent from the following description, given by way of example only, which refers 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 It shows Figure 1 a schematic diagram of an exemplary device in cross-section but including illustrative magnetic field lines;

[0040] Figure 3 It shows Figure 1 and 2 a schematic diagram of a plan view of a portion of an exemplary apparatus;

[0041] Figure 4 It shows Figure 3 a plan view of a portion of an exemplary apparatus but including a schematic diagram of illustrative magnetic field lines;

[0042] Figure 5 is a schematic diagram showing a cross section of a magnetic element according to an example;

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

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

[0045] Figure 8 is a schematic diagram illustrating a perspective view of a device according to an example; and

[0046] Figure 9 is a schematic flow chart illustrating a method according to an example. DETAILED DESCRIPTION

[0047] Details of the devices and methods according to the examples will become apparent with reference to the accompanying drawings. Throughout this specification, for purposes of explanation, numerous specific details of certain examples are set forth. Reference in the specification to "an example" or similar language means that a particular feature, structure, or characteristic described in conjunction with that example is included in at least one example, but not necessarily in other examples. It should also be noted that some examples are schematically described, with certain features omitted and / or necessarily simplified to facilitate explanation and understanding of the concepts behind the examples.

[0048] refer to Figures 1 to 5 , an exemplary apparatus 100 for sputter-depositing a target material 108 onto a substrate 116 is shown.

[0049] The apparatus 100 can be used for plasma-based sputtering deposition in a variety of industrial applications, such as those useful for thin film deposition, for example, in optical coatings, magnetic recording media, electronic semiconductor devices, LEDs, energy generation devices such as thin film solar cells, and energy storage devices such as thin film batteries. Other applications in which the apparatus 100 can be used include the production of display devices such as OLED (organic light emitting diodes), electroluminescent (ELD) or plasma display panels (PDPs), high performance addressable (HDP) liquid crystal displays (LCDs) or interferometric modulator displays (IMODs), transistors such as thin film transistors (TFTs), isolation coatings, dichroic coatings, or metallized coatings. Thus, while the context of the present disclosure may in some cases relate to the production of energy storage devices or portions thereof, it should be understood that the apparatus 100 and methods described herein are not limited to the production thereof.

[0050] Although not shown in the drawings for the sake of clarity, it will be understood that in some examples the apparatus 100 typically includes a housing (not shown) that is evacuated in use to a low pressure suitable for sputter deposition, such as 3x10 -3 Such a housing can be evacuated by a pumping system (not shown) to a suitable pressure (e.g., less than 1x10 -5 In use, a process or sputtering gas (e.g., argon or nitrogen) may be introduced into the housing using a gas supply system (not shown) to a level such that a pressure suitable for sputter deposition is achieved, e.g., 3×10 -3 Entrust.

[0051] Return to Figures 1 to 5 In the example shown in , generally, the apparatus 100 includes a substrate guide 118 , a target assembly 124 , and a magnetic confinement device 104 .

[0052] The substrate guide 118 is arranged to follow a curved path (the curved path is defined by Figure 1 and Figure 2 ) guides a substrate 116, such as a substrate web.

[0053] exist Figure 1 and Figure 2 In the example of , the substrate guide 118 is provided by a curved member 118 , which in this case is provided by a substantially cylindrical roller or drum of the entire substrate feed assembly 119 . Figure 1 and Figure 2 The flexure 118 is arranged to rotate about an axis 120, which is provided by a shaft, for example. Figure 3 In the example shown, the axis 120 is also the longitudinal axis of the flexure 118 .

[0054] The substrate feed assembly 119 is arranged to feed the substrate 116 onto and from the curved member 118 such that the substrate 116 is carried by at least a portion of the curved surface of the curved member 118 (in this case formed by a roller). Figure 1 and 2 As shown, the substrate feed assembly includes a first roller 110a arranged to feed substrates 116 onto a drum 118, and a second roller 110b arranged to feed substrates 116 from the drum after the substrates 116 have followed the curved path C. The substrate feed assembly 119 may be part of a "roll-to-roll" process arrangement (not shown), in which the substrates 116 are fed from a first reel or spool (not shown) of substrates 116, passed through the apparatus 100, and then fed onto a second reel or spool (not shown) to form a loaded reel (not shown) of processed substrates (not shown).

[0055] In some examples, substrate 116 is or at least includes silicon or a polymer. In some examples, such as for producing energy storage devices, substrate 116 is or at least includes nickel foil. However, it should be understood that any suitable metal may be used in place of nickel, such as aluminum, copper, or steel, or metallized materials including metallized plastics, such as aluminum on polyethylene terephthalate (PET).

[0056] The target assembly 124 of the apparatus 100 includes a target portion 106 arranged to support a target material 108. In some examples, the target portion 106 includes a plate or other support structure that supports or holds the target material 108 in place during sputter deposition. The target material 108 is the material that is sputter-deposited onto the substrate 116. In other words, the target material 108 can be or include a material that is to be deposited onto the substrate 116 by sputter deposition.

[0057] In some examples, such as for the production of an energy storage device, target material 108 is or includes (or is or includes a precursor material for a cathode layer) of an energy storage device, 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, target material 108 is or includes (or is or includes a precursor material for an anode layer) of an energy storage device, such as lithium metal, graphite, silicon, or indium tin oxide. Additionally or alternatively, target material 108 is or includes (or is or includes a precursor material for an electrolyte layer) of an energy storage device, such as a material that is ionically conductive but also an electrical insulator, such as lithium phosphorus oxynitride (LiPON). For example, target material 108 is or includes LiPO, which serves as a precursor material for depositing LiPON onto substrate 116, such as by reaction with nitrogen in the region of target material 108. In some examples, the target material includes at least one of the following: lithium, cobalt, lithium oxide, cobalt oxide, and lithium oxide. For example, to deposit lithium cobalt oxide on a substrate, the target material may include lithium and cobalt, lithium oxide and cobalt, lithium oxide and cobalt oxide, lithium-cobalt alloy, lithium oxide, or LiCoO 2-x , where x is greater than or equal to 0.01 or less than or equal to 1.99.

[0058] The target portion 106 and the substrate guide 118 are spaced apart from one another and define therebetween a deposition zone 114. The deposition zone 114 may be considered to be the area or volume between the substrate guide 118 and the target portion 106 in which sputter deposition of the target material 108 onto the substrate 116 occurs in use.

[0059] In some examples, such as those illustrated, apparatus 100 includes a plasma generation device 102, which may be referred to as a plasma source 102. Plasma generation device 102 is configured to generate plasma 112. Plasma source 102 may be an inductively coupled plasma source, for example, arranged to produce inductively coupled plasma 112. Figure 1 and Figure 2The plasma source 102 shown in FIG. 1 includes antennas 102a, 102b through which an RF power system (not shown) can drive appropriate RF power to generate an inductively coupled plasma 112 from a process gas or sputtering gas within a housing (not shown). In some examples, plasma 112 is generated by driving an RF current through one or more antennas 102a, 102b, for example, at a frequency between 1 MHz and 1 GHz; between 1 MHz and 100 MHz; between 10 MHz and 40 MHz; or, in some examples, at a frequency of approximately 13.56 MHz or multiples thereof. The RF power causes the process gas or sputtering gas to ionize to generate plasma 112. Tuning the RF power driven by one or more antennas 102a, 102b can affect the plasma density of plasma 112 within deposition region 114. Thus, by controlling the RF power at plasma source 102, the sputtering deposition process can be controlled. This, in turn, allows for improved flexibility in the operation of sputtering deposition apparatus 100.

[0060] In some examples, such as Figure 1 and Figure 2 In the example of , the plasma source 102 is disposed remotely from the substrate guide 118, e.g., radially remote from the substrate guide 118. However, the plasma 112 generated by the plasma source 102 is directed toward and then at least partially confined within the sputter deposition region 114 between the substrate guide 118 and the target portion 106.

[0061] The one or more antennas 102a, 102b of the plasma source 102 may be elongated antennas, and in some examples, substantially linear. In some examples, for example Figure 1 and Figure 2 In the example of FIG, one or more antennas 102a, 102b are elongated antennas and extend in a direction substantially parallel to the longitudinal axis 120 of the flexure 108 (e.g., the axis 120 of the roller 118 passing through the origin of the radius of curvature of the roller 118). The one or more elongated antennas 102a, 102b can be curved. For example, such curved elongated antennas 102a, 102b can follow the curve of the curved surface of the flexure 118. In some cases, the one or more curved elongated antennas 102a, 102b extend in a plane substantially perpendicular to the longitudinal axis 120 of the flexure 118. Figure 8 Further discussion, Figure 8 An example of this is shown.

[0062] exist Figure 1 and Figure 2In the example of FIG, the plasma source 102 includes two antennas 102a, 102b for generating an inductively coupled plasma 112. In this example, the antennas 102a, 102b extend substantially parallel to each other and are disposed transversely to each other. This allows for the precise generation of an elongated region of plasma 112 between the two antennas 102a, 102b, which in turn helps precisely confine the generated plasma 112 to at least a deposition region 114, as described in more detail below. The length of the antennas 120a, 120b can be similar to that of the substrate guide 118, and thus similar to the width of the substrate 116 guided by the substrate guide 118. The elongated antennas 102a, 102b can provide for the generation of the plasma 112 within a region having a length corresponding to the length of the substrate guide 118 (and thus corresponding to the width of the substrate 116), and thus can allow for the plasma 112 to be uniform or consistent across the width of the substrate 116. This, in turn, helps provide uniform or consistent sputter deposition, as described in more detail below.

[0063] Figure 1 and Figure 2 The confinement device 104 of the apparatus 100 comprises one or more magnetic elements 104a, 104b. The magnetic elements 104a, 104b are arranged to provide a confining magnetic field to confine the plasma 112 (in this case, including the plasma generated by the plasma generation device 102) in the deposition region 114 so as to provide sputter deposition of the target material 108 onto the substrate 116 in use. The confining magnetic field is characterized by magnetic field lines that are arranged to substantially follow the curve of the curved path C at least in the deposition region 114 so as to confine the plasma 112 to a curve around the curved path C.

[0064] It will be appreciated that magnetic field lines can be used to characterize or delineate the arrangement or geometry of a magnetic field. Thus, it will be appreciated that the confining magnetic field provided by magnetic elements 104 a, 104 b can be described or characterized by magnetic field lines arranged to follow the curve of curved path C. It will also be appreciated that, in principle, the entire or total magnetic field provided by magnetic elements 104 a, 104 b can include portions characterized by magnetic field lines that are not arranged to follow the curve of curved path C. However, the provided confining magnetic field, i.e., the portion of the entire or total magnetic field provided by magnetic elements 104 a, 104 b that confines the plasma in deposition region 114, is characterized by magnetic field lines that follow the curve of curved path C.

[0065] In some examples, where reference is made to the curve of the curved path C, this may be understood as the degree to which the path along which the substrate guide 118 carries the substrate 116 is curved. For example, the curved member 118 (e.g., a roller or drum) carries the substrate 116 along the curved path C. In such an example, the curve of the curved path C is generated by the degree to which the curved surface of the curved member 118 that carries the substrate 116 is curved (e.g., deviates from a plane). In other words, the curve of the curved path C may be understood as the degree to which the curved path C that the curved member 118 causes the substrate 116 to follow is curved. A curve that substantially follows the curved path C may be understood as substantially conforming to or replicating the curved shape of the curved path C. For example, the magnetic field lines may follow a curved path having a common center of curvature with the curved path C, but having a different (in the illustrated example, larger) curvature radius than the curved path C. For example, the magnetic field lines may follow a curved path that is substantially parallel (but radially offset) to the curved path C of the substrate 116. In an example, the magnetic field lines follow a curved path that is substantially parallel (but radially offset) to the curved surface of the curved member 118. For example, Figure 2 , which depicts that the magnetic field lines of the confining magnetic field follow a curved path, at least in the sputter deposition zone 114 , that is substantially parallel (but radially offset) to the curved path C, and thus the magnetic field lines substantially follow the curve of the curved path C.

[0066] The magnetic field lines representing the confining magnetic field may be arranged to follow the curve of the curved path C around most or a significant section or portion of the curved path C. For example, the magnetic field lines may follow the curve of the curved path C over all or a significant portion of an imaginary section of the curved path C, on which the substrate 116 is guided by the curved member 118. In an example, the curved path C represents a portion of the circumference of an imaginary circle, and the magnetic field lines representing the confining magnetic field are arranged to follow the curve of the curved path C 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 the imaginary circle.

[0067] In examples where the substrate guide 118 is provided by a curved member or roller, such as Figure 1 and Figure 2 In an example, the magnetic field lines representing the confining magnetic field are arranged around a majority or a significant segment or portion of the flexure (e.g., over all or a significant portion of an imaginary segment of the flexure that carries or contacts the web of substrate 116 in use) along the curve of the flexure. For example, the flexure 118 may be substantially cylindrical in shape, and the magnetic field lines representing the confining magnetic field may be arranged 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 the flexure along the curve of the flexure. Figure 2In , the magnetic field lines characterizing the confining magnetic field follow a curved path around at least 1 / 4 of the circumference of the substrate guide 118, which in this example comprises a curved member (in this case formed by the surface of a drum).

[0068] It will be appreciated that magnetic field lines can be used to depict the arrangement or geometry of a magnetic field. Figure 2 and Figure 4 An exemplary magnetic field provided by exemplary magnetic elements 104a, 104b, 104c is schematically shown in FIG, wherein magnetic field lines (indicated by arrows by convention) are used to depict the magnetic field provided in use. As described above, some magnetic field lines do not substantially follow the curve of the curved member, but the confining magnetic field (i.e., the magnetic field that confines the plasma 112 within the deposition region 114) is characterized by the magnetic field lines being arranged along a curve along the curved path C. Figure 2 and Figure 4 As shown, the magnetic field lines representing the confining magnetic field are curved so as to substantially follow the curve of the curved path C, at least in the deposition zone 114 .

[0069] The magnetic field lines arranged to follow the curve of the curved path C of the substrate 116 limit the plasma 112 generated to enter the deposition zone 114 around the curve of the curved path C. This occurs because the plasma 112 generated tends to follow the magnetic field lines. For example, ions of a plasma within a confined magnetic field and having a certain initial velocity will be subject to the Lorentz force, which causes the ions to move periodically around the magnetic field lines. If the initial motion is not strictly perpendicular to the magnetic field, the ions follow a spiral path centered around the magnetic field lines. Therefore, plasmas containing such ions tend to follow the magnetic field lines and are therefore confined to the path defined by them. Therefore, since the magnetic field lines are arranged to substantially follow the curve of the curved path C, the plasma 112 will be confined to substantially follow the curve of the curved path C and are therefore confined to enter the deposition zone 114 around the curve of the curved path C.

[0070] Confining the generated plasma 112 to substantially conform to the curve of at least a portion of the curved surface of the curved member 118, such as following the curve of the curved path C, allows for a more uniform distribution of the plasma density at the substrate 116, at least in a direction around the curved surface of the curved member 118 (e.g., the curve of the curved path C). This, in turn, can allow for more uniform sputter deposition onto the substrate 116 in a direction around the curved member 118 (e.g., the curved path C). In turn, sputter deposition is thus performed more consistently. This can improve the consistency of the processed substrate and, for example, reduce the need for quality control compared to magnetron-type sputter deposition equipment, in which the magnetic field lines describing the magnetic field generated thereby circulate tightly into and out of the substrate and, therefore, do not allow for a uniform distribution of the plasma density at the substrate.

[0071] Alternatively or additionally, confining the generated plasma 112 to substantially conform to the curve of at least a portion of the curved surface of the curved member 118, such as following the curve of the curved path C, allows the area of the substrate 116 exposed to the plasma 112 to be increased, and thus allows the area in which sputter deposition can be achieved to be increased. For a given degree of deposition, this allows the substrate 116 to be fed through the roll-to-roll apparatus at a faster rate, and thus allows for more efficient sputter deposition.

[0072] In some examples, such as Figure 1 and Figure 2 As shown, a magnet arrangement (or "magnetic confinement arrangement") 104 includes at least two magnetic elements 104a, 104b arranged to provide a magnetic field. In some cases, the at least two magnetic elements 104a, 104b are arranged such that the region of relatively high magnetic field strength defined between the at least two magnetic elements 104a, 104b is in the form of a thin sheet. In this case, the magnet arrangement 104 is configured to confine the plasma 112 in the form of a thin sheet, i.e., a sheet in which the depth (or thickness) of the plasma 112 is significantly less than its length or width. The thickness of the plasma sheet 112 can be substantially constant along the length and width of the sheet. The density of the plasma 112 sheet can be substantially uniform across one or both of its width and length.

[0073] In some examples, the region of relatively high magnetic field strength provided between the at least two magnetic elements 104a, 104b substantially conforms to the curve of at least a portion of the curved surface of the curved member 118, such as substantially following the curve of the curved path C.

[0074] exist Figure 1 and Figure 2 In the example schematically shown in FIG. 1 , two magnetic elements 104a, 104b are located on opposite sides of the drum 118 and are both arranged above the lowermost portion of the drum 118 (at Figure 1 The two magnetic elements 104a, 104b confine the plasma 112 on either side of the curved member 118 to conform to the curve of at least a portion of the curved surface of the curved member 118, for example to follow the curve of the curved path C. Figure 1 and Figure 2In the embodiment of the present invention, the plasma 112 follows the curve of the curved path C on the feed side, which feeds the substrate 116 onto the curved member 118, and on the discharge side, which discharges the substrate 116 from the curved member 118. Thus, having at least two magnetic elements provides a (further) increase in the area of the substrate 116 exposed to the plasma 112 in the sputter deposition zone 114, and thus an increase in the area in which sputter deposition can be achieved. For example, for a given deposition level, this allows the substrate 116 to be fed through the roll-to-roll apparatus at a (still) faster rate, and thus allows for more efficient sputter deposition.

[0075] In some examples, one or more magnetic elements 104a, 104b are electromagnets 104a, 104b. The apparatus 100 includes a controller (not shown) that, in some cases, is used to control, for example, the strength of the magnetic field provided by the one or more electromagnets 104a, 104b. This allows the arrangement of magnetic field lines that delineate the confining magnetic field to be controlled. Furthermore, the plasma density at the substrate 116 and / or target material 108 within the sputter deposition region 114 can be adjusted, thereby improving control over sputter deposition. This, in turn, can allow for improved flexibility in the operation of the sputter deposition apparatus 100.

[0076] In some examples, one or more magnetic elements 104a, 104b are provided by solenoids 104a, 104b. In examples, the cross-section of the solenoids 104a, 104b is elongated. For example, the cross-section of the solenoids 104a, 104b can be elongated in a direction substantially parallel to the axis of rotation of the curved member 118 (e.g., the roller 118). Each solenoid 104a, 104b can define an opening through which the plasma 112 passes (is confined) during use. Figure 1 and Figure 2 In the example schematically illustrated in FIG, there are three solenoids 104a, 104b, and each solenoid 104a, 104b is angled to provide a region of relatively high magnetic field strength between the solenoids 104a, 104b, for example, substantially following the curve of the curved path C. In this way, as Figure 1 As shown, the generated plasma 112 passes through the first solenoid 104a and is located below the roller 118 ( Figure 1 104b.

[0077] although Figure 1 and 2Only two magnetic elements 104a, 104b, and 104c are shown in FIG, but it should be understood that more magnetic elements (not shown), for example, more such solenoids, may be placed along the path of the plasma 112. This may allow for a stronger confinement magnetic field, thereby precisely confining the plasma. Additionally or alternatively, this may allow for more degrees of freedom in controlling the confinement magnetic field.

[0078] In some examples, such as Figure 1 and 2 In the examples in FIG. 1 , the magnet arrangement 104 (e.g., including one or more magnetic elements 104a, 104b) is configured to confine the plasma 112 to the form of a thin sheet. For example, the magnet arrangement 104 is arranged to provide a magnetic field to confine the plasma 112 to the form of a thin sheet. In some examples, the magnet arrangement 104 is configured to confine the plasma 112 to the form of a thin sheet having a substantially uniform density, for example, at least in the deposition region 114. In some cases, the magnet arrangement 104 is configured to confine the plasma 112 to the form of a curved sheet.

[0079] For example, Figure 4 and Figure 5 As shown, in some examples, one or more solenoids 104a, 104b are elongated in a direction substantially perpendicular to the direction of the magnetic field lines generated therein during use. Figures 3 to 5 As perhaps best shown, the solenoids 104a, 104b each have an opening through which the plasma 112 is confined in use (through which the plasma 112 passes in use), wherein the opening is elongated in a direction substantially parallel to the longitudinal axis 120 of the flexure 118. Figure 3 and Figure 4 As perhaps best shown, the elongated antennas 102a, 102b are parallel to and in line with the solenoids 104a, 104b. As described above, the plasma 112 can be generated along the length of the elongated antennas 102a, 102b, and the elongated solenoid 104a confines (e.g., directs) the plasma 112 in a direction away from the elongated antennas 102a, 102b and through the elongated solenoid 104a.

[0080] In this example, plasma 112 is confined (e.g., directed) from elongated antennas 102a, 102b by elongated solenoid 104a into a thin sheet. That is, the depth (or thickness) of plasma 112 is significantly less than its length or width. The thickness of plasma sheet 112 may be substantially constant along both the length and width of the sheet. The density of the plasma sheet 112 may be substantially uniform across one or both of its width and length. In this case, plasma 112 in sheet form is confined by the magnetic field provided by solenoids 104a, 104b around curved member 118 so as to substantially follow the curve of the curved surface of curved member 118, e.g., along the curve of curved path C, into deposition zone 114. Thus, in this example, plasma 112 is confined into the form of a curved sheet. The thickness of this curved sheet 112 of plasma may be substantially constant along both the length and width of the curved sheet. Plasma 112 in curved sheet form may have a substantially uniform density, e.g., the density of plasma 112 in curved sheet form may be substantially uniform across one or both of its length and width.

[0081] Confining the plasma to the form of a curved sheet allows the area of the substrate 116 supported by the curved member 118 to be exposed to the plasma 112 to be increased, thereby increasing the area over which sputter deposition can be achieved. For a given degree of deposition, this allows the substrate 116 to be fed through the roll-to-roll apparatus at a faster rate, thereby providing more efficient sputter deposition.

[0082] Confining the plasma to a curved sheet (e.g., a curved sheet having a substantially uniform density (e.g., at least in the sputter deposition region 114)) may alternatively or additionally allow for a more uniform distribution of the plasma density at the substrate 116, e.g., both in a direction around the curve of the curved member 118 and in a direction along the length of the curved member 118. This, in turn, allows for more uniform sputter deposition on the substrate 116, e.g., in a direction around the surface of the curved member 118 and across the width of the substrate 116. Thus, sputter deposition may be performed more consistently. As a result, the consistency of the processed substrate may be improved and the need for quality control may be reduced, e.g., compared to magnetron-type sputter deposition equipment, in which the magnetic field lines representing the magnetic field generated thereby circulate closely into and out of the substrate and, therefore, do not allow for providing a uniformly distributed plasma density at the substrate.

[0083] In some examples, the confined plasma 112 is a high-density plasma at least in the deposition region 114. For example, the confined plasma 112 (in the form of a curved sheet or other form) has a density of 10 11 cm -3The high density plasma 112 in the deposition region 114 allows for efficient and / or high-speed sputtering deposition.

[0084] Figure 1 and Figure 2 The target assembly 124 also includes a biasing device 122 for applying an electrical bias to the target material 108. For example, the electrical bias refers to a voltage applied to the target material 108. Figure 1 and Figure 2 In an example embodiment, the bias device 122 is configured to apply an electrical bias comprising a direct current (DC) voltage to the target material 108. The DC voltage may be a negative polarity voltage having a value less than zero. In this case, the bias device 122 has a first terminal (not shown) at a first electrical potential and a second terminal (not shown) at a second (different) electrical potential, such that the difference between the first electrical potential and the second electrical potential corresponds to a voltage to be applied to the target material 108. In this case, the first terminal is electrically connected to the target material 108 and the second terminal is electrically connected to ground to apply the voltage to the target material 108.

[0085] By applying an electrical bias to the target material 108, ions of the plasma 112 are attracted toward the target material 108. This increases the interaction between the plasma 112 and the target material 108, which can increase the rate at which particles of the target material 108 are ejected by the plasma 112. Increasing the ejection rate of particles of the target material 108 generally increases the rate at which these particles are deposited on the substrate 116, thereby increasing the sputtering deposition rate of the target material 108. By applying an electrical bias to the target material 108 in the apparatus 100 according to examples herein, in which the plasma is configured to curve around a tortuous path along which the substrate 116 is directed, the target material 108 is deposited in a compact, efficient manner with increased uniformity across the substrate 116.

[0086] By controlling the electrical bias applied to the target material 108 , the rate at which sputter deposition of the target material 108 occurs can be controlled, which can be used to deposit a specific pattern of the target material 108 on the substrate 116 .

[0087] In the illustrative example, it is desired to deposit patches of target material 108 of varying thicknesses on substrate 116 in order to form a specific pattern of target material 108 on substrate 116. This can be performed directly using apparatus 100 by applying an electrical bias having a first magnitude during a first time while a first portion of substrate 116 is conveyed through deposition zone 114 to deposit a first patch of target material 108 having a first thickness on the first portion of substrate 116. Subsequently, an electrical bias having a second magnitude, less than the first magnitude, is applied during a second time while a second portion of substrate 116 is conveyed through deposition zone 114. This causes a second patch of target material 108 having a second thickness less than the first thickness to be deposited on the second portion of substrate 116. This is due to the reduced magnitude of the electrical bias during the second time (during which the second patch of target material 108 is sputter-deposited), which in this example reduces the rate of sputter deposition. It should be understood that this is merely an example, and that control of the electrical bias can be performed in a variety of different ways to directly and effectively deposit a specific pattern of target material 108 on substrate 116.

[0088] Control of the electrical bias applied to the target material 108 by the bias material 122 can also or instead be used to control the crystallinity of the target material 108 deposited on the substrate 116. The crystallinity of a material generally refers to the degree of structural order of the material, such as the degree to which the atoms and molecules of the material are arranged in a regular, periodic pattern. Crystallinity can be measured using various techniques, such as X-ray crystallography or Raman spectroscopy. Crystallinity generally depends on, and in some cases can be defined by, the crystallite size, which can be measured using X-ray diffraction. The crystallite size can be calculated from an X-ray diffraction pattern using the Scherrer equation. The Scherrer equation states that the crystallite size τ of a material is given by:

[0089]

[0090] where τ is the crystallite size, which can be taken as the average size of the ordered (crystalline) domains of the material and can be less than or equal to the gain size of the material; K is the dimensionless shape factor; λ is the X-ray wavelength; β is the line broadening of the peak in the X-ray diffraction pattern in radians (after subtracting the instrumental line broadening); and θ is the Bragg angle.

[0091] In some cases, the biasing device 122 is configured to apply an electrical bias to the target material 108 at a first power value, and the plasma generation device is configured to generate the plasma at a second power value. If the ratio of the second power value to the first power value is less than or equal to 1, the target material 108 deposited on the substrate 116 tends to have an amorphous structure, with relatively little or no structural order as measured using, for example, X-ray diffraction or Raman spectroscopy. The material can be considered to have an amorphous structure, in which the material is non-crystalline and, therefore, the atoms of the material do not form a crystalline lattice. However, if the ratio of the second power value to the first power value is greater than 1, the target material 108 deposited on the substrate 116 generally has an at least partially ordered structure and may have a crystalline structure, in which the atoms of the deposited material form a crystalline lattice in at least one region of the material, and in some cases, throughout the entire material. Based on this, by appropriately controlling the ratio of the second power value to the first power value, the structure of the target material 108 deposited on the substrate 116 can be directly controlled.

[0092] For example, by controlling the ratio to have a value greater than 1, a target material 108 having a crystalline structure can be deposited on the substrate 116 without undergoing subsequent post-processing steps, such as heat treatment. This simplifies the deposition of the crystalline material. In some cases, the structure of the deposited target material 108 is independent of the substrate 116 on which the target material 108 is deposited. In these cases, by providing a ratio greater than 1, an at least partially ordered and, for example, crystalline target material 108 can be deposited regardless of the substrate 116. Thus, the apparatus 100 provides flexibility for depositing target materials 108 having an ordered structure onto a variety of different types of substrates and for a variety of different purposes.

[0093] Increasing the ratio of the second power value to the first power value tends to increase order in the structure of the target material 108 deposited on the substrate 116. Therefore, by controlling this ratio, the structure of the target material 108 deposited on the substrate 116 can be precisely controlled in a simple manner.

[0094] At least a portion, and in some cases all, of the deposited target material 108 may have a hexagonal crystal structure. The crystal structure of the deposited target material 108 may be In the space group, the target material 108 may be LiCoO 2 . The space group structure is a layered structure and can be a layered oxide structure, for example, where the target material 108 is LiCoO2. This structure has many advantages, such as high available capacity and high-speed charge and discharge compared to low-energy structures (belonging to the Fd3m space group of LiCoO2). Due to the enhanced reversibility and smaller structural changes in lithium insertion and extraction, Space groups are believed to have better performance in typical battery applications. Depositing crystalline LiCoO2 in the space group is advantageous for solid-state battery applications as the deposited target material 108. However, this is merely an example, and in other cases, such as for other applications, the deposited target material 108 may have a different chemical and / or crystal structure.

[0095] During the deposition of the target material 108 in an at least partially ordered structure on the substrate 116, in some cases, crystals of the crystal structure grow substantially epitaxially from the surface of the substrate. Epitaxial growth generally refers to a type of crystal growth in which a new crystalline layer is formed with a well-defined orientation relative to the material crystal structure. Substantially epitaxial growth refers, for example, to the deposition of a new layer that itself includes at least one crystalline region such that a majority (e.g., at least 70%, 80%, 90% or more) of at least one crystalline region of the new layer has the same orientation relative to the substrate 116 on which the material is deposited. Epitaxial growth tends to make it easier for lithium ions to be intercalated and deintercalated. On this basis, the apparatus 100 described herein can be used to deposit the target material 108 containing lithium substantially epitaxially on the substrate 116 to improve the intercalation and deintercalation of lithium ions. This allows the apparatus 100 to be used for the deposition of such target materials, for example, for the production of solid-state batteries.

[0096] The crystals of the at least partially ordered target material 108 deposited on the substrate 116 can be aligned with (101) and (110) planes. The (101) and (110) planes are lattice planes of the crystal structure of the target material 108 and are expressed as Miller indices, as understood by those skilled in the art. In an example, the (101) and (110) planes are substantially parallel to the substrate, e.g., within manufacturing or measurement tolerances. For example, depositing the target material 108 on the substrate 116 in this configuration provides the deposited target material 108 with suitable properties for a variety of different applications.

[0097] In some cases, the ratio of the second power value to the first power value is less than 3.5. For example, the ratio may be between 1 and 3.5. With this ratio, the target material 108 is deposited on the substrate 116 in an at least partially ordered structure (e.g., a crystalline structure). In this case, the at least partially ordered structure of the target material 108 is obtained by sputtering the target material 108 without requiring further processing steps, such as heat treatment. Therefore, the target material 108 having this structure can be deposited more directly and / or efficiently than otherwise.

[0098] In some examples, the first power value is at least 1 watt per square centimeter (1W cm -2 In some cases, such as when the target material 108 comprises ceramic or oxide, the first power value is at most 15 watts per square centimeter (15W cm -2)。In other cases, for example, for a metal target material 108 such as lithium, cobalt, or their alloys, the first power value is at most 70 watts per square centimeter (70 W cm -2 )。In other cases, for example, for other target materials 108, the first power value is as high as 100 watts per square centimeter (100 W cm -2 )。

[0099] The actual power in the plasma may be less than the power used to generate the plasma (where the power used to generate the plasma is referred to as the second power value in this article). In this regard, the generation efficiency of the plasma (defined as the actual power in the plasma divided by the power used to generate the plasma multiplied by 100) can be 50% to 85%, typically about 50%.

[0100] During the steady-state performance of sputter deposition (where the electrical energy supplied to the device 100 for performing sputter deposition is the same as the energy consumed by the device 100 within the error range), the fraction (P P *E PT ) / (P T *E PP ) can be greater than 1, optionally in the range of 1 to 4, possibly in the range of 1 to 3, and in some embodiments, between 1 and 2. In this fraction, P P = the average usage of plasma energy (unit: watt), P T = the power related to the bias on the target (referred to as the first power value here), E PP is a fraction (<1) representing the plasma generation efficiency metric, E PT [[ID=2 June 26]]is a fraction (<1) representing the efficiency metric of supplying electrical energy to the target. The efficiency E PP of generating the plasma can be calculated as the actual power in the plasma divided by the power used to generate the plasma. The efficiency E PT of supplying electrical energy to the target can be calculated as the actual power delivered divided by the power consumed. In a typical setup, it can be assumed that E PT = 1. Preferably, E PT > 0.9.

[0101] During the steady-state performance of sputter deposition, the normalized power ratio parameter PRP N can be greater than 1, optionally in the range of 1 to 4, possibly in the range of 1 to 3, and in some cases between 1 and 2 (where PRP N = N*P P / P T , and where N is the normalization factor, which can satisfy 1.2 < N < 2, or can be only N = 1.7). During the steady-state performance of sputter deposition, the power ratio parameter PRP (where PRP = P P / PT ) may be greater than 0.5, optionally in the range of 0.5 to 2, possibly in the range of 0.6 to 1.5, and in some cases between 0.6 and 1. These PRP N and the PRP value provide for effective and efficient sputtering deposition of the target material 108 onto the substrate 116 .

[0102] exist Figures 1 to 5 In the example shown, the target portion 106 and the target material 108 supported thereby are substantially planar. However, in some examples (as described in more detail below), the target portion can be arranged or configured such that at least a portion of the target portion defines a support surface that forms an obtuse angle relative to a support surface of another portion of the target portion. For example, the target portion can be generally curved. For example, the target portion can be arranged to substantially follow a curve that is curved along a path C.

[0103] Figure 6 Such an example device 600 is shown. Many of the illustrated components of the device 600 are similar to Figures 1 to 5 The components of the apparatus 100 shown in and described above are identical and will not be described again. Identical features are given the same reference numerals and it should be understood that reference to Figures 1 to 5 Any features of the described examples can be applied to Figure 6 However, in Figure 6 In the example shown, the target portion 606 of the target assembly 124 is substantially curved. In this example, the target material 608 supported by the target portion 606 is therefore substantially curved. In this case, any portion of the curved target portion 606 forms an obtuse angle with any other portion of the curved target portion 606 along the direction of the curve. In some examples, different portions of the target portion 606 can support different target materials, for example, to provide a desired arrangement or composition of the web deposited onto the substrate 116.

[0104] exist Figure 6 In the example of FIG, the curved target portion 606 substantially follows the curve of the curved path C. In this manner, the curved target portion 606 substantially conforms to and replicates the curved shape of the curved path C. Figure 6 In this embodiment, the curved target portion 606 has a curve that is substantially parallel to the curved path C but radially offset. In this case, the curve of the curved target portion 606 has a common center of curvature with the curved path C, but has a different (in this case, larger) radius of curvature than the curved path C. Thus, the curved target portion 606 again substantially follows the curve of the curved plasma 112 that is confined around the curved member 118 in use. In other words, in some examples, for example Figure 6In the example of FIG. 5 , the plasma 112 can be confined by the magnetic elements 104 a , 104 b of the confinement device to be positioned between the path C of the substrate 116 and the target portion 606 and to substantially follow the curves of both the curved path C and the curved target portion 606 .

[0105] for Figures 1 to 5 The target portion 108 of the device 100 is shown, and it should be understood that Figure 6 The example target portion 606 (and accordingly the target material 608 supported thereby) can extend substantially across the entire length of the flexure 118 (e.g., in a direction parallel to the longitudinal axis 120 of the drum 118). This maximizes the surface area of the substrate 116 carried by the drum 118 on which the target material 608 can be deposited.

[0106] As mentioned earlier, Figure 6 The plasma 112 is confined to substantially follow the curves of both the curved path C and the curved target portion 606. In this example, the area or volume between the curved path C and the curved target portion 606 is correspondingly curved around the curved member 118. Thus, Figure 6 The deposition zone 614 represents the curved volume in which, in use, sputter deposition of target material 608 onto substrate 116 carried by curved member 118 occurs. This allows increasing the surface area of substrate 116 carried by curved member 118 present in deposition zone 614 at any one time. This, in turn, allows increasing the surface area of substrate 116 on which target material 608 can be deposited. This, in turn, allows increasing the area over which sputter deposition can be achieved without significantly increasing the footprint of target portion 606 or changing the dimensions of curved member 118. For example, for a given degree of deposition, this allows a web of substrate 116 to be fed through a reel-to-reel apparatus at a (still) faster rate, and thus allows for more efficient sputter deposition, but also in a space-saving manner.

[0107] Figure 7 An example device 700 is shown. Many of the illustrated components of the device 700 are similar to Figures 1 to 6 The components of the apparatus 100, 700 shown and described above are identical and will not be described again. Identical features are given the same reference numerals and it should be understood that reference to Figures 1 to 6 Any features of the described examples can be applied to Figure 7 However, in Figure 7 In the example shown, the target portion 706 of the target assembly 124 is arranged or configurable such that at least one portion 706 a of the target portion 706 defines a surface that forms an obtuse angle with respect to a surface of another portion 706 b of the target portion 706 .

[0108] In some examples, the angle formed by the first portion 706a of the target portion 706 and the second (e.g., adjacent) portion 706b of the target portion 706 is fixed to an obtuse angle. The obtuse angle can be selected so that the first portion 706a and the second portion 706b are arranged together to approximate the curve of the curved path C. Figure 7 , the target portion 706 includes three portions 706a, 706b, and 706c (e.g. Figure 7 116 ). The first portion 706a is arranged toward the feed side of the curved path C, the second portion 706b is arranged toward the center portion of the curved path C, and the third portion 706c is arranged toward the discharge side of the curved path C. The three portions 706a, 706b, and 706c are arranged together to approximate the curve of the curved path C. Thus, the deposition zone 714 approximates a curved volume within which sputter deposition of target material 708a, 708b, and 708c onto the substrate 116 occurs during use. As a result, the surface area of the web of substrate 116 present in the deposition zone 714 at any given moment is increased. This allows, for example, an increase in the area available for sputter deposition without significantly increasing the footprint of the target portion 706 or changing the dimensions of the curved member 118.

[0109] In some examples, the angle formed between the first portion 706a of the target portion 706 and the second (e.g., adjacent) portion 706b of the target portion 706 is configurable. For example, the first portion 706a and the second portion 706b can be mechanically connected by a hinge element 724 or other such component that allows the angle between the first portion 706a and the second portion 706b to be changed. Similarly, the second portion 706b and the third portion 706c can be mechanically connected by a hinge element 726 or other such component that allows the angle between the second portion 706b and the third portion 706c to be changed. An actuator and an appropriate controller (not shown) can be provided to move the first portion 706a and / or the third portion 706c relative to the second portion 706b, i.e., to change the angle formed between the first portion 706a and / or the third portion 706c relative to the second portion 706b. This allows control of the plasma density experienced by the target material 708a, 708c of the first portion 706a or the third portion 706c of the target portion, thereby allowing control of the deposition rate during use.

[0110] Alternatively or additionally, the confining magnetic field provided by the magnetic elements 104a, 104b may be controlled by a controller (not shown) to alter the profile of the plasma 112 and thereby control the plasma density experienced by the target material 708a, 708b, 708c of the first, second, or third portions 706a, 706b, 706c of the target portion, thereby allowing for in-use control of the deposition rate.

[0111] In some examples, the target material provided on one portion 706a, 706b, 706c of the target portion 700 is different from the target material provided on another portion 706a, 706b, 706c of the target portion. This can allow a desired arrangement or composition of target materials to be sputter-deposited onto the web of substrate 116. Controlling the plasma density experienced by one or more target portions 706a, 706b, 706c, for example by controlling the angle formed by the first portion 706a or the third portion 706c with the second portion 706b, and / or controlling the profile of the confined plasma by controlling the magnetic elements 104a, 104b, can allow control over the type or composition of target material sputter-deposited onto the web of substrate 116. This allows for flexible sputter deposition.

[0112] exist Figure 7 In the example of FIG, the biasing devices 122a, 122b, 122c are configured to independently apply an electrical bias to one or more corresponding target materials in the plurality of target materials 708a, 708b, 708c. Figure 7 In the embodiment of the present invention, each target material 708a, 708b, 708c has its own bias device 122a, 122b, 122c. For example, each bias device 122a, 122b, 122c can be a separate DC voltage source. In other cases, a single bias device is configured to apply an electrical bias to multiple target materials, but is configured to independently control the electrical bias applied to each target material.

[0113] In this example, the rate of each corresponding target material 708a, 708b, 708c can also be independently controlled by controlling the electrical bias applied by the biasing devices 122a, 122b, 122c to each corresponding target material 708a, 708b, 708c. This allows a greater amount of one target material 708a, 708b, 708c to be ejected than another target material 708a, 708b, 708c. This increases the flexibility of the apparatus 100 because it allows the apparatus 100 to be used to deposit different proportions of each corresponding target material 708a, 708b, 708c on the substrate 116. For example, by applying a greater electrical bias using the first biasing device 122a than using the second and third biasing devices 122b, 122c, more of the first target material 708a can be deposited on the substrate 116 than the second and third target materials 708b, 708c.

[0114] In this example, the electrical bias applied by biasing devices 122a, 122b, 122c is controllable over time. This further increases the flexibility of apparatus 600, as it allows apparatus 600 to be used to deposit different combinations of target materials 708a, 708b, 708c over time. Furthermore, due to the independent control of the electrical bias applied to each of target materials 708a, 708b, 708c, the pattern of target materials 708a, 708b, 708c deposited on substrate 116 can be controlled. This allows apparatus 600 to be used to deposit a desired pattern on substrate 116 in a simple and efficient manner.

[0115] exist Figures 1 to 7 In the example shown, the magnetic field lines representing the confining magnetic field are all curved so as to substantially follow the curve of the curved path C, at least in the deposition zone 114. However, this is not necessarily the case, and in other arrangements, the magnetic field lines representing the confining magnetic field are arranged so as to substantially follow the curve of the curved path C, at least in the deposition zone 114, so as to confine the plasma 112 to the curve around the curved path C. For example, in some cases, the magnetic field lines representing the confining magnetic field are arranged so that the imaginary line extending perpendicular to each magnetic field line and connecting the magnetic field lines is curved so as to substantially follow the curve of the curved path C, at least in the deposition zone.

[0116] Figure 8 An example of a device 800 having such a magnetic field is shown. Many of the illustrated components of the device 800 are similar to Figures 1 to 7 The components of the apparatus 100, 600, 700 shown and described above are identical and will not be described again. Identical features are given the same reference numerals and it should be understood that reference to Figures 1 to 7 Any features of the described examples can be applied to Figure 8 However, in Figure 8 In the example shown, the magnetic element 804a of the magnetic confinement device 804 is arranged to provide a confinement magnetic field, wherein the magnetic field lines ( Figure 8 The black arrows in the figure are themselves substantially straight, but are arranged so that the dashed lines 806 extending perpendicular to each magnetic field line and connecting the magnetic field lines are curved so that at least in the deposition area (for clarity, Figure 8 (not explicitly indicated in the figure) basically follows the curve of the curved path C.

[0117] In this example, the plasma generation device 802 includes an elongated antenna 802a that is curved and extends in a direction substantially perpendicular to the longitudinal axis 120 of the curved member or drum 118. Figure 8 In the example of FIG. 1 , the longitudinal axis 120 of the flexure 118 is also the axis of rotation of the flexure 118. For clarity, Figure 8Only one antenna 802a is shown in FIG, but it is understood that more than one such antenna 802a may be used. Figure 8 The curved antenna 802a substantially follows the curve of the curved path C and, in this case, is parallel to but radially and axially offset from the curved path C due to being radially and axially offset from the curved surface of the curved member 118 that guides the substrate along the curved path C. The curved antenna 802a can be driven with RF power to generate a plasma having a substantially curved shape (for clarity, Figure 8 not shown in the figure).

[0118] Figure 8 The magnetic element 804a in the embodiment includes a solenoid 804a. For clarity, Figure 8 Only one magnetic element 804a is shown, but it should be understood that another such magnetic element (not shown) may be placed, for example. Figure 8 The curved member 118 is shown on the side opposite the solenoid 804a. The solenoid 804a has an opening, and the plasma ( Figure 8 The opening is curved and elongated in a direction substantially perpendicular to the longitudinal axis (rotational axis) 120 of the flexure 118. The flexure solenoid 804a in this example substantially follows the curve of the curved path C and is parallel to but radially and axially offset from the curved surface of the flexure 118. Figure 8 , a bending solenoid 804a is disposed intermediate the bending antenna 802a and the bending member 118. The bending solenoid 804a provides a confined magnetic field in which the magnetic field lines are arranged such that an imaginary line extending perpendicular to each magnetic field line and connecting the magnetic field lines is curved so as to substantially follow the curve of the curved path C, at least within the deposition zone.

[0119] Plasma is generated along the length of the curved antenna 802a ( Figure 8 (not shown), and the bending solenoid 804a confines the plasma in a direction away from the bending antenna 802a and through the bending solenoid 804a. Figure 8In the illustrated example, the plasma is confined to a curved sheet by a curved solenoid 804a. In this case, the length of the curved sheet extends in a direction parallel to the longitudinal (rotational) axis 120 of the curved member 118. The curved sheet-shaped plasma is confined by the magnetic field provided by the solenoid 804a to surround the curved member 118 and replicate the curve of the curved member 118. The thickness of the plasma curved sheet can be substantially constant along the length and width of the curved sheet. The curved sheet-shaped plasma can have a substantially uniform density, for example, the density of the curved sheet-shaped plasma can be substantially consistent across one or both of its length and width. As described above, the confined curved sheet-shaped plasma allows for an increased area over which sputter deposition can be performed, thereby achieving more efficient sputter deposition, and / or a more uniform plasma density distribution at the substrate 116, for example, along the direction of the curved member curve and across the width of the substrate 116. This, in turn, allows for more uniform sputter deposition on the substrate 116, for example, along the direction of the curved member curve and across the length of the substrate 118, which can improve substrate processing consistency.

[0120] refer to Figure 9 , schematically illustrates an example method for sputter-depositing a target material 108, 608, 708a, 708b, 708c onto a substrate 116. In the method, the substrate 116 is guided by a substrate guide 118 along a curved path C. A deposition region 114, 614, 714 is defined between the substrate guide 118 and the target portion 106, 606, 706a, 706b, 706c supporting the target material 108, 608, 708a, 708b, 708c. For example, the target material 108, 608, 708a, 708b, 708c, the substrate 116, the deposition region 114, 614, 714, the target portion 106, 606, 706a, 706b, 706c, the substrate guide 118, and / or the curved path C may be reference Figures 1 to 8 In some examples, the method is performed by reference to Figures 1 to 8 Executed by one of the described devices 100, 600, 700, 800.

[0121] Figure 9 The method includes: in step 902, applying an electrical bias to the target material 108, 608, 708a, 708b, 708c. Figures 1 to 8 The above-mentioned bias devices 122, 122a, 122b, and 122c are used to provide electrical bias.

[0122] In step 904, Figure 9The method includes providing a magnetic field to confine the plasma in the deposition region 114, 614, 714, thereby causing the target material 108, 608, 708a, 708b, 708c to be sputter-deposited onto the substrate 116. The magnetic field is characterized in that the magnetic field lines are arranged to substantially follow the curve of the curved path C at least in the deposition region 114, 614, 714, so as to confine the plasma 112 to the curve around the curved path C. For example, the plasma can be generated by reference to Figures 1 to 8 is restricted by one of the above-mentioned magnetic restriction devices 104, 804.

[0123] As described above, confining the generated plasma 112 in this manner allows for a more uniform distribution of the plasma density at the substrate 116, at least in the direction around the curve of the curved path C. This, in turn, allows for a more uniform sputter deposition of the target material 108, 608, 708a, 708b, 708c onto the substrate 116 in the direction around the surface of the curved member 118. Consequently, sputter deposition can be performed more consistently. This can improve the consistency of the processed substrate and reduce the need for quality control. For example, this can be compared to magnetron sputter deposition, in which the magnetic field lines representing the magnetic field generated by magnetron sputter deposition tightly circulate into and out of the substrate and, therefore, do not provide a uniformly distributed plasma density at the substrate.

[0124] Furthermore, confining the generated plasma 112 in this manner so as to follow the curve of a tortuous path can increase the area of the substrate 116 exposed to the plasma 112, and thus increase the area over which sputter deposition can be achieved. For example, for a given degree of deposition, this can allow the substrate 116 (e.g., in the form of a web) to be fed through a roll-to-roll apparatus at a faster rate, and thus allow for more efficient sputter deposition.

[0125] The electrical bias applied to the target material can be further improved. Figure 9 The efficiency of sputtering deposition in the example of is improved. This causes the plasma to be attracted to the target material, thereby increasing the sputtering rate. By appropriately controlling the electrical bias, the target material can be sputter-deposited onto the substrate in a desired structure (such as a crystalline structure), for example without the need for further post-processing steps. Therefore, sputtering deposition is further improved in this case. In addition, flexibility is provided because the method can be used to deposit a specific pattern of target material on the substrate by controlling the electrical bias, for example, depositing a larger amount of target material on one part of the substrate than on another part.

[0126] In an example, method 900 includes providing a target material comprising at least one of lithium, cobalt, lithium oxide, cobalt oxide, and lithium oxide. In such an example, method 900 can be used to produce various components including these materials, such as energy storage devices.

[0127] As reference Figures 1 to 5 Discussed in detail, based on Figure 9 In some examples, step 902 includes applying an electrical bias at a first power value, and the method includes generating the plasma at a second power value such that a ratio of the second power value to the first power value is greater than 1. Such a ratio can be used to efficiently deposit the target material on the substrate in an at least partially ordered structure, such as a crystalline structure.

[0128] The above examples should be understood as illustrative examples. It should be understood that any feature described with respect to any one example may be used alone or in combination with other features described, and may also be used in combination with one or more features of any other example or any combination of other examples. In addition, equivalents and modifications not described above may also be employed within the scope of the appended claims.

Claims

1. A sputtering deposition apparatus comprising: a substrate guide arranged to guide the substrate along a curved path; Target assembly, comprising: a target portion spaced apart from the substrate guide and arranged to support a target material, the target portion and the substrate guide defining a deposition zone therebetween; and a biasing device for applying an electrical bias to the target material; and confinement means comprising one or more magnetic elements arranged to provide a confining magnetic field to confine a plasma in the deposition zone, thereby providing, in use, sputter deposition of the target material onto the substrate, the confining magnetic field being characterized in that magnetic field lines are arranged, at least in the deposition zone, to substantially follow the curve of a tortuous path so as to confine the plasma around the curve of the tortuous path, The apparatus further comprises a plasma generating device configured to generate plasma, The biasing device is configured to apply the electrical bias to the target material at a first power value, and the plasma generation apparatus is configured to generate the plasma at a second power value such that a ratio of the second power value to the first power value is greater than 1.

2. The device according to claim 1, wherein The biasing device is configured to apply an electrical bias having a negative polarity to the target material.

3. The device according to claim 1, wherein The bias device is configured to apply an electrical bias comprising a DC voltage to the target material.

4. The device according to claim 1, wherein A ratio of the second power value to the first power value is less than 3.5 or less than 1.

5.

5. The apparatus according to claim 1, wherein The first power value is at least one watt per square centimeter, 1W cm -2 .

6. The apparatus of claim 1, wherein the first power value is at most 15 watts per square centimeter, 15 W cm -2 , or at most seventy watts per square centimeter, 70W cm -2 .

7. The apparatus according to claim 1, wherein The plasma generating device includes an inductively coupled plasma source.

8. The apparatus according to claim 1, wherein The plasma generation device includes one or more elongated antennas extending in a direction substantially perpendicular to a longitudinal axis of the substrate guide.

9. The apparatus according to claim 1, wherein The plasma generation device includes one or more elongated antennas extending in a direction substantially parallel to a longitudinal axis of the substrate guide.

10. The apparatus according to any one of claims 1 to 3, wherein The target portion is arranged to support a plurality of target materials, and the biasing device is configured to independently apply an electrical bias to one or more respective target materials of the plurality of target materials.

11. The apparatus according to any one of claims 1 to 3, wherein The one or more magnetic elements are arranged to provide the confining magnetic field to confine the plasma in the form of a curved sheet.

12. The apparatus according to any one of claims 1 to 3, wherein The one or more magnetic elements are arranged to provide the confining magnetic field to confine the plasma in the form of a curved sheet having a substantially uniform density at least in the deposition zone.

13. The apparatus according to any one of claims 1 to 3, wherein One or more of the magnetic elements is an electromagnet.

14. The apparatus according to claim 13, wherein The apparatus comprises a controller arranged to control the magnetic field provided by one or more of the electromagnets.

15. The apparatus according to any one of claims 1 to 3, wherein The confinement arrangement comprises at least two of the magnetic elements arranged to provide the confinement magnetic field.

16. The apparatus according to claim 15, wherein The at least two magnetic elements are arranged such that a region of relatively high magnetic field strength provided between the magnetic elements substantially follows the curve of the curved path.

17. The apparatus according to any one of claims 1 to 3, wherein The target portion is arranged or configurable to be arranged such that at least a portion of the target portion defines a support surface that forms an obtuse angle with respect to a support surface of another portion of the target portion.

18. The apparatus according to any one of claims 1 to 3, wherein The target portion is substantially curved.

19. The apparatus according to any one of claims 1 to 3, wherein The target portion is arranged to substantially follow or approximate a curve of the curved path.

20. The apparatus according to any one of claims 1 to 3, wherein The substrate guide is provided by a curved member that guides the substrate along the curved path.

21. A method of sputter depositing a target material onto a substrate, the substrate being guided along a curved path by a substrate guide, wherein: A deposition zone is defined between the substrate guide and a target portion supporting a target material, the method comprising: applying an electrical bias to the target material; and providing a magnetic field to confine the plasma in the deposition zone to cause sputter deposition of target material onto the substrate, the magnetic field being characterized by magnetic field lines arranged to substantially follow a curve of a tortuous path at least in the deposition zone so as to confine the plasma around the tortuous path, Wherein applying an electrical bias to the target includes applying the electrical bias at a first power value, and the method includes generating the plasma at a second power value such that a ratio of the second power value to the first power value is greater than 1.

22. The method of claim 21 , comprising providing a target material having at least one of: lithium; cobalt; lithium oxide; cobalt oxide; and Lithium cobalt oxide.

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