WO2021094721A1

WO2021094721A1 - Method and apparatus for sputter deposition of target material to a substrate

Info

Publication number: WO2021094721A1
Application number: PCT/GB2020/052838
Authority: WO
Inventors: Michael Rendall; Robert Gruar
Original assignee: Dyson Technology Limited
Priority date: 2019-11-15
Filing date: 2020-11-10
Publication date: 2021-05-20
Also published as: GB201916620D0; GB2588933A

Abstract

Apparatus for sputter deposition of target material to a substrate is disclosed. In one form, the apparatus comprises a substrate portion arranged to retain a substrate in a first region and a target portion arranged to retain a target material in a second region, the first region being spaced apart from the second region. The first region and the second region define between them a deposition zone. The apparatus comprises a plurality of gas inlets, each gas inlet being arranged to provide gas locally to a given different one of a respective plurality of different areas of the deposition zone. The apparatus further comprises a gas controller arranged to control, independently for each of the plurality of gas inlets, a flow of gas provided from the respective gas inlet, thereby to allow gas to be provided selectively in each of the plurality of areas of the deposition zone.

Description

METHOD AND APPARATUS FOR SPUTTER DEPOSITION OF TARGET MATERIAL TO A SUBSTRATE

Technical Field The present invention relates to deposition, and more particularly to methods and apparatuses for sputter deposition of target material to a substrate.

Background

Deposition is a process by which target material is deposited on a substrate. An example of deposition is thin film deposition in which a thin layer (typically from around a nanometre or even a fraction of a nanometre up to several micrometres or even tens of micrometres) is deposited on a substrate, such as a silicon wafer or web. An example technique for thin film deposition is Physical Vapor Deposition (PVD), in which target material in a condensed phase is vaporised to produce a vapor, which vapor is then condensed onto the substrate surface. An example of PVD is sputter deposition, in which particles are ejected from the target as a result of bombardment by energetic particles, such as ions. In examples of sputter deposition, a sputter or process gas, such as an inert gas, such as Argon, is introduced into a vacuum chamber at low pressure, and the sputter gas is ionised using energetic electrons to create a plasma. Bombardment of the target by ions of the plasma eject target material which may then deposit on the substrate surface. Reactive sputtering or reactive sputter deposition is a process by which a reactive gas, which may for example be the process gas or be mixed with the process gas, reacts with sputtered target material to deposit a compound material on the substrate. Sputter deposition has advantages over other thin film deposition methods such as evaporation in that target materials may be deposited without the need to heat the target material, which may in turn reduce or prevent thermal damage to the substrate.

Known sputter deposition techniques are limited in the control over and/or the flexibility in the sputter deposition provided. It may be desirable to provide for improved control over and/or flexibility in sputter deposition, for example to provide for a greater control over and/or diversity of the thin films that may be produced by the sputter deposition. Summary

According to a first aspect of the present invention, there is provided an apparatus for sputter deposition of target material to a substrate, the apparatus comprising: a substrate portion arranged to retain a substrate in a first region; a target portion arranged to retain a target material in a second region, the first region being spaced apart from the second region, the first region and the second region defining between them a deposition zone; a plurality of gas inlets, each gas inlet being arranged to provide gas locally to a given different one of a respective plurality of different areas of the deposition zone; and a gas controller arranged to control, independently for each of the plurality of gas inlets, a flow of gas provided from the respective gas inlet, thereby to allow gas to be provided selectively in each of the plurality of areas of the deposition zone.

With the apparatus of the first aspect, the properties of gas within the deposition zone, such as a composition and/or density, may be controlled as desired. For example, a greater quantity of gas may be provided in one of the areas of the deposition zone than in other areas. This improves control of the gas in the deposition zone compared to providing gas indiscriminately to the whole of the deposition zone. Independent control over the provision of gas in each of the plurality of areas of the deposition zone may provide for improved control over and/or flexibility in the resulting sputter deposition. This may, in turn, provide for a greater control over and/or diversity of the products (e.g. thin films) that may be produced by the sputter deposition. In examples, the gas controller is arranged to control, independently for each of the plurality of gas inlets, a flow of process gas provided from the gas inlet. A process gas is for example a gas from which a plasma may be formed during use of the apparatus. By controlling the flow of the process gas, the generation of the plasma can in turn be controlled. This can improve control and/or flexibility of the sputter deposition.

In these examples, the apparatus may comprise a plasma generator, and the apparatus may be arranged such that, for each of the plurality of different areas of the deposition zone, provision of said process gas locally to the area causes plasma to be generated or generated preferentially in the area. In this way, a variation in plasma density may be controlled or adjusted. For example, this may allow for controlled variation in sputter deposition efficiency in different areas of the deposition zone. By generating or preferentially generating plasma in a given area of the deposition zone, sputter deposition or preferential sputter deposition of target material onto a region of the substrate associated with the given area may be performed. Spatial control over the deposition of target material may therefore be provided, which may provide for controlled and configurable deposition of the target material to the substrate. For example, an inhomogeneous pattern of target material may be sputter deposited to the substrate. This sputter deposition may be performed with a greater density and/or at a faster rate than otherwise.

In examples, the gas controller is arranged to control, independently for each of the plurality of gas inlets, a flow of reactive gas provided from the gas inlet. The reactive gas may allow for controlled variation in sputter deposition of a reaction product which is a product of a reaction between the reactive gas and target material ejected from the target. The apparatus may therefore allow sputter deposition to be performed in a flexible manner, for example to provide a desired pattern of target material and/or reaction product on the substrate. In these examples, the plurality of gas inlets and the substrate portion may be arranged such that, for each of the plurality of different areas of the deposition zone, provision of said reactive gas locally to the area causes a reaction product of said reactive gas and said target material to be deposited or deposited preferentially on a region of said substrate associated with the area. This may allow for controlled variation in a reaction product deposited on different regions of the substrate. For example, controllable and/or configurable deposition of the target material and/or reaction product may be performed, e.g. to provide an inhomogeneous pattern of material on the substrate. In this way, the apparatus may be used to produce a wide variety of different architectures, such as thin film architectures. In these examples, the apparatus may comprise a gas source comprising the reactive gas, wherein the reactive gas is a Nitrogen containing gas and/or an Oxygen containing gas. In such cases, the apparatus may be used in the fabrication of energy storage devices or components thereof. In examples, the apparatus comprises the target material and the target material is a Lithium containing material. Such a target material may be used in the fabrication of energy storage devices or components thereof, for example to deposit layers comprising Lithium.

In examples, each of the plurality of areas of the deposition zone is associated with a different one of a respective plurality of regions of the substrate. This may allow for better control over and/or more precise variation in sputter deposition of the target material to the substrate. For example, the target material (or a reaction product formed from a reaction of the target material) may be sputter deposited with different properties, such as a different density or chemical composition, to different regions of the substrate. The apparatus may therefore provide for flexible sputter deposition of material to a substrate. In these examples, the plurality of gas inlets and the substrate portion may be arranged such that, for each of the plurality of different areas of the deposition zone, said provision of said gas locally to the area of the deposition zone causes preferential deposition of material to the associated region of the substrate. In this way, the density of the material sputter deposited to each of the different regions of the substrate may be straightforwardly and/or precisely controlled, e.g. to produce a particular deposition pattern on the substrate. In examples, the gas controller is arranged to control, independently for each of the plurality of gas inlets, a gas, a gas mixture, and/or a gas flow rate provided from the gas inlet. This may allow for greater control over variation of sputter deposition of the target material and/or improved flexibility in the variation of the sputter deposition. For example, individual control over each of the gas inlets may be provided to control the sputter deposition as desired.

The gas controller is configurable such that the plurality of gas inlets provide a variation in gas provision across the deposition zone to cause inhomogeneous deposition of material to the substrate. This allows the apparatus to sputter deposit a non-uniform layer of the material to the substrate. The apparatus may therefore be more flexible than otherwise.

In examples, the substrate portion comprises a substrate conveyance arrangement arranged to convey said substrate relative to the target portion. This may allow for more efficient sputter deposition of the target material to the substrate than if the substrate remains static. For example, the apparatus may form part of a “reel-to- reel” arrangement, which may be more efficient than a batch processing arrangement. In these examples, the substrate conveyance arrangement may be arranged to convey said substrate relative to the target portion in a conveyance direction, and the plurality of gas inlets and the substrate conveyance arrangement may be arranged such that the plurality of gas inlets are arranged along a common axis perpendicular to the conveyance direction. This may allow for more efficient and/or consistent sputter deposition of material to the substrate, with a variation in at least one property of the material across at least part of a width of the substrate. For example, control the sputter deposition of the material to the substrate may be achieved while the substrate is conveyed through the apparatus in a continuous or semi-continuous manner. This may improve control and/or flexibility of sputter deposition. Such an apparatus may be used for a large scale sputter deposition process.

In examples, the apparatus comprises an antenna arrangement comprising at least one antenna for generating plasma when an alternating current is driven through the antenna, said plasma providing for said sputter deposition of material to the substrate. This may be more efficient than other arrangements for plasma generation and/or may produce a more uniform plasma. The plasma produced in this way may have a more consistent variation in plasma density than otherwise. In these examples, the at least one antenna may be common to the plurality of gas inlets. This may be more efficient than other arrangements (e.g. compared to providing a separate antenna for each of the plurality of gas inlets). In these examples, the at least one antenna may be disposed remotely of the deposition zone. This may provide for generation of the plasma remotely from the deposition zone, and subsequent confining of the plasma at least partly within the deposition zone. This may allow for improved efficiency of the sputter deposition process. In these examples, the apparatus may comprise a magnetic confining arrangement arranged to confine said generated plasma to the deposition zone to provide for said sputter deposition of material to the substrate in use. The density of the plasma within the deposition zone may be increased, which may increase the efficiency of the sputter deposition process. The magnetic confining arrangement may comprise at least one magnetic element through which plasma is confined in use between the deposition zone and the at least one antenna. This may further increase the density of the plasma within the deposition zone, which may increase the sputter deposition efficiency.

According to a second aspect of the present invention, there is provided a method of sputter deposition of target material to a substrate, the target material and the substrate defining between them a deposition zone, the method comprising: controlling, independently for each of a plurality of different areas of the deposition zone, a flow of gas provided locally to the area, thereby to provide gas selectively in each of the plurality of areas of the deposition zone.

With the method of the second aspect, the properties of gas within the deposition zone, such as a composition and/or density, may be controlled as desired. For example, a greater quantity of gas may be provided in one of the areas of the deposition zone than other areas. This improves control of the gas in the deposition zone compared to providing gas indiscriminately to the whole of the deposition zone. Independent control over the provision of gas in each of the plurality of areas of the deposition zone may provide for improved control over and/or flexibility in the resulting sputter deposition. This may, in turn, provide for a greater control over and/or diversity of the products (e.g. thin films) that may be produced by the sputter deposition.

According to a third aspect of the present invention, there is provided an apparatus for sputter deposition of target material to a substrate, the apparatus comprising: a substrate portion arranged to retain a substrate in a first region; a target portion arranged to retain a target material in a second region, the first region being spaced apart from the second region, the first region and the second region defining between them a deposition zone; and a plurality of gas inlets; wherein the substrate portion and the plurality of gas inlets are arranged such that, in use, the plurality of gas inlets provide a variation in gas or gas density across the deposition zone to cause inhomogeneous deposition of material to the substrate. With the apparatus of the third aspect, the variation in the gas or gas density may be controlled appropriately to obtain a particular pattern of material inhomogeneously deposited to the substrate. The apparatus may be more flexible and/or more easily controllable than others, and may allow various different material architectures to be created on the substrate. The diversity of the products (e.g. thin films) that may be produced by the sputter deposition may be improved compared to other apparatus that is incapable of inhomogeneously depositing material to a substrate.

According to a fourth aspect of the present invention, there is provided a method of sputter deposition of target material to a substrate, the target material and the substrate defining between them a deposition zone, the method comprising: providing, using a plurality of gas inlets, a variation in gas or gas density across the deposition zone to cause inhomogeneous deposition of target material to the substrate.

With the method of the fourth aspect, the variation in the gas or gas density may be controlled appropriately to obtain a particular pattern of material inhomogeneously deposited to the substrate. The apparatus may be more flexible and/or more easily controllable than others, and may allow various different material architectures to be created on the substrate. The diversity of the products (e.g. thin films) that may be produced by the sputter deposition may be improved compared to other apparatus that is incapable of inhomogeneously depositing material to a substrate.

Further features will become apparent from the following description, given by way of example only, which is made with reference to the accompanying drawings.

Brief Description of the Drawings

Figure l is a schematic diagram that illustrates a part-sectional side view of an apparatus according to a first example;

Figure 2 is a schematic diagram that illustrates a part-cutaway plan view of the apparatus according to the first example;

Figure 3 is a schematic diagram that illustrates a cross section of a magnetic element according to an example; Figure 4 is a schematic diagram that illustrates a part-sectional side view of an apparatus according to a second example;

Figure 5 is a schematic diagram that illustrates a gas controller according to an example;

Figure 6 is a schematic diagram that illustrates a gas controller according to another example;

Figure 7 is a schematic diagram that illustrates a part-sectional side view of an apparatus according to a third example;

Figure 8 is a schematic diagram that illustrates a part-cutaway plan view of the apparatus according to the third example; and

Figure 9 is a schematic flow diagram that illustrates a method according to an example.

Detailed Description

Details of apparatuses and methods according to examples will become apparent from the following description, with reference to the Figures. In this description, for the purpose 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 connection with the example is included in at least that one example, but not necessarily in other examples. It should further be noted that certain examples are described schematically with certain features omitted and/or necessarily simplified for ease of explanation and understanding of the concepts underlying the examples.

Referring to Figures 1 and 2, there is schematically illustrated an example apparatus 100 for sputter deposition of target material 108 to a substrate 116.

The apparatus 100 may be used for plasma-based sputter deposition for a wide number of industrial applications, such as those which have utility for the deposition of thin films, such as in the production of 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. Therefore, 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 appreciated that the apparatuses and methods described herein are not limited to the production thereof.

Although not shown in the Figures for clarity, it is to be appreciated that the apparatus 100 may be provided within a housing (not shown), which in use may be evacuated to a low pressure suitable for sputter deposition, for example 3x10³ torr. For example, the housing (not shown) may be evacuated by a pumping system (not shown) to a suitable pressure (for example less than lxl 0⁵ torr), and in use gas, which may include a sputter or process gas and/or a reactive gas, may be introduced into the housing (not shown) to an extent such that a pressure suitable for sputter deposition is achieved (for example 3x10 ³ torr).

Returning to the example illustrated in Figures 1 and 2, in broad overview, the apparatus 100 comprises a substrate portion 118, a target portion 106, a plurality of gas inlets 103a - 103c, and a gas controller 160.

It should be noted that the schematic plan view of Figure 2 is at right angles to the schematic side view of Figure 1 (i.e. rotated by 90 degrees about an axis parallel to the Z axis in the sense of Figures 1 and 2). In Figure 2, the substrate 116 and the magnetic element 105a are not shown for clarity.

The substrate portion 118 is arranged to retain a substrate in a first region 118a. The first region 118a is that region or space of the apparatus 100 in which a substrate 116 is provided in use. The substrate portion 118 may comprise a support arrangement (not shown in Figure 1) to support the substrate in the first region 118. The substrate 116 may be passed or conveyed through the first region 118a of the apparatus 100 in a conveyance direction (arrow A in Figure 1). For example, the substrate portion 118 may comprise a substrate conveyance arrangement (not shown in Figures 1 and 2, but see e.g. conveyance arrangement 452 of Figure 6) arranged to, in use, convey the substrate 116 relative to the target portion 106. For example, the conveyance arrangement (not shown in Figures 1 and 2) may comprise a roll-to-roll arrangement wherein a web of substrate 116 is wound out from one roll for processing and wound onto another roll after processing.

In some examples, the substrate 116 may be in the form of a web of substrate 116. In some examples, the web of substrate 116 may be or comprise silicon or a polymer. In some examples, for example for the production of an energy storage device, the web of substrate 116 may be or comprise nickel foil, but it will be appreciated that any suitable metal could be used instead of nickel, such as aluminium, copper or steel, or a metallised material including metallised plastics such as aluminium on polyethylene terephthalate (PET). Other forms of substrate 116 may be used.

The target portion 106 is arranged to retain target material 108 in a second region 106a. The second region 106a is that region or space of the apparatus 100 in which the target material 108 is provided in use. The target portion 106 may comprise a target support 107 arranged to support target material 108. For example, the target support 107 may comprise 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 on the basis of which the sputter deposition onto the substrate 116 is to be performed. For example, the target material 108 may be or comprise material that is to be deposited onto the substrate 116 by sputter deposition. As another example, the target material 108 may be or comprise a material that is to react with a reactive gas to produce a compound that to be deposited on the substrate 116.

In some examples, for example for the production of an energy storage device, the target material 108 may be or comprise, or may be or comprise a precursor material for, a cathode layer of an energy storage device, such as a material which is suitable for storing Lithium ions, such as Lithium Cobalt Oxide, Lithium Iron Phosphate or alkali metal poly sulphide salts. Additionally or alternatively, the target material 108 may be or comprise, or may be or comprise a precursor material for, an anode layer of an energy storage device, such as Lithium metal, Graphite, Silicon or Indium Tin Oxides. Additionally or alternatively, the target material 108 may be or comprise, or may be or comprise a precursor material for, an electrolyte layer of an energy storage device, such as material which is ionically conductive, but which is also an electrical insulator, such as lithium phosphorous oxynitride (LiPON). For example, the target material 108 may be or comprise LiPO as a precursor material for the deposition of LiPON onto the substrate 116, for example, via reaction with Nitrogen gas in the region of the target material 108.

The first region 118a and the second region 106a are spaced apart from one another and define between them a deposition zone 114. The deposition zone 114 may be taken as the area or volume between the first region 118a and the second region 106a in which sputter deposition from the target material 108 onto the web of substrate 116 occurs in use. For example, the deposition zone 114 may be taken as the area or volume between the substrate 116 retained by the substrate portion 118 in use and the target material 108 retained by the target portion 106 in use, in which sputter deposition from the target material 108 onto the web of substrate 116 occurs in use.

In some examples, such as that illustrated in Figures 1 and 2, the apparatus 100 may comprise a plasma generator 101. The plasma generator 101 may be arranged to provide suitable energy for the generation of plasma 112 from process gas. The plasma generator 101 may comprise an antenna arrangement 102. The antenna arrangement 102 may comprise at least one antenna 102a, 102b, for generating plasma when an alternating current is driven through the antenna 102a, 102b in use. In the illustrated example, the antenna arrangement 102 comprises two antennas 102a, 102b. Appropriate radio frequency power may be driven through one or both of the antennas, 102a, 102b, by a radio frequency power supply system (not shown) so as to generate an inductively coupled plasma 112 from process gas in the housing (not shown). In some examples, plasma 112 may be generated by driving a radio frequency current through the one or more antennas 102a, 102b, for example at a frequency between 1MHz and 1GHz; a frequency between 1 MHz and 100MHz; a frequency between 10 MHz and 40 MHz; or at a frequency of approximately 13.56 MHz or multiples thereof. In any event, the radio frequency power causes ionisation of process or sputter gas to produce plasma 112.

In some examples, such as that illustrated in Figures 1 and 2, the antenna arrangement 102 may be disposed remotely of the deposition zone 114. As such, plasma 112 may be generated thereby remotely from the deposition zone 114. The antennas 102a, 102b may extend substantially parallel to one another and may be disposed laterally from one another. This may allow for a precise generation of an elongate region of plasma 112 between the two antennas 102a, 102b. In some examples, the antennas 120a, 120b may be similar in length to the width of the substrate 116 retained by the substrate portion 118. The elongate antennas 102a, 102b may provide for plasma 112 to be generated across the entire width of the substrate 116, which may allow for more efficient sputter deposition. The at least one antenna 102a, 102b may be common to each of the plurality of gas inlets 103 a- 103c, i.e. one antenna 102a, 102b may be associated with (e.g. provide rf power for the ionisation of gas from) multiple of the gas inlets 103 a- 103c. This may allow for efficient deposition, for example as compared to providing a separate antenna for each of the plurality of gas inlets 103 a- 103 c.

In some examples, such as that illustrated in Figures 1 and 2, the apparatus 100 may comprise a magnetic confining arrangement 104. The magnetic confining arrangement 104 may be arranged to confine generated plasma 112 in, to and/or through the deposition zone 114 to provide for sputter deposition of material to the substrate 116.

The magnetic confining arrangement 104 may comprise at least one magnetic element 105a, 105b through which plasma 112 is confined in use. In the illustrated example, the confining arrangement 104 comprises two magnetic elements 105a, 105b. A first magnetic element 105a confines plasma 112 between the antenna arrangement 102 and the deposition zone 114. In this example, the deposition zone 114 is intermediate of the first magnetic element 105a and the second magnetic element 105b. The two magnetic elements 105a, 105b may be arranged such 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 magnetic elements 105a, 105b of the magnetic confining arrangement 104 may provide a confining magnetic field characterised by magnetic field lines (not shown) arranged to follow a path from the antenna arrangement 102 towards and/or through the deposition zone 114. The generated plasma 112 tends to follow the magnetic field lines, and hence may be confined by confining magnetic field to and through the deposition zone 114. For example, ions of the plasma 112 within the confining magnetic field and with some initial velocity will experience a Lorentz force that causes the ion to follow a periodic motion around the magnetic field line. If the initial motion is not strictly perpendicular to the magnetic field, the ion follows a helical path centred on the magnetic field line. The plasma 112 containing such ions therefore tends to follow the magnetic field lines and hence may be confined on a path defined thereby. In some examples, at least one of the magnetic elements 105a, 105b may be an electromagnet controllable to provide the confining magnetic field. For example, one or both of the first magnetic elements 105a, 105b may be an electromagnet 104a, 104b. The apparatus 100 may comprise a controller (not shown) arranged to control a strength of the magnetic field provided by one or more of the electromagnets 105a, 105b. This may allow for the confining magnetic field to be adjusted. This may allow for adjustment of plasma density at the substrate 116 and/or the target material 108 and hence for improved control over the sputter deposition. This may allow for improved flexibility in the operation of the apparatus 100.

In some examples, at least one of the first magnetic elements 105a, 105b may be provided by a solenoid 105a, 105b. Each solenoid 105a, 105b may define an opening (see e.g. opening 350 of Figure 3) through or via which plasma 112 is confined (may pass) in use. In some examples, the solenoid 105a, 105b may be elongate. For example, as perhaps best seen in Figure 3, the opening 350 defined by the solenoid 105a, 105b may be elongate. As perhaps best appreciated from Figure 2, the opening of the solenoid 105a, 105b may be elongate in a direction substantially parallel to a direction in which the antenna 102a, 102b is elongate. The plasma 112 may thereby be confined in the form of a sheet. That is, in a form in which the depth (or thickness) of the plasma 112 is substantially less than its length and/or width. Confining the plasma 112 in the form of a sheet may allow for plasma 112 to be presented across an entire width of the substrate 116, and hence, in turn, for more efficient deposition.

In some examples, the plasma 112 produced may, at least in the deposition zone 114, be high density plasma. For example, the plasma 112 may have, at least in the deposition zone 114, a density of 10¹¹ cm ³ or more, for example. Plasma 112 of high density in the deposition zone 114 may allow for effective and/or high rate sputter deposition.

As mentioned, the apparatus 100 comprises a plurality of gas inlets 103a-103c. As illustrated in Figures 1 and 2, the apparatus 100 may comprise three gas inlets 103a, 103b, 103c. In this example, the gas inlets 103a-103c are arranged along (i.e. arranged in a sequence along) a common axis. In this example, the common axis is substantially perpendicular to the Z axis in the sense of Figures 1 and 2 (e.g. substantially perpendicular to the conveyance direction A of the substrate 116, e.g. substantially parallel to the direction along which the antenna 102a, 102b and the magnetic elements 105a, 105b are elongate).

Each gas inlet 103a-103c is arranged to provide gas 11 la-11 lc locally to a given different one of a respective plurality of different areas 109a, 109b, 109c of the deposition zone 114.

For example, in the example illustrated in Figures 1 and 2, a first gas inlet 103a is arranged to provide gas 111a locally to a first area 109a of the deposition zone 114, a second gas inlet is arranged to provide gas 111b locally to a second area 109b of the deposition zone 114, and a third gas inlet 103c is arranged to provide gas 111c locally to a third area 109c of the deposition zone 114. In the example illustrated in Figures 1 and 2, the areas 109a- 109c of the deposition zone 114 are adjacent to one another and extend in a sequence in a direction perpendicular to the Z axis in the sense of Figures 1 and 2 (e.g. perpendicular to the conveyance direction A).

Each of the plurality of areas 109a-109c of the deposition zone 114 may be associated with (e.g. adjacent to) a different one of a respective plurality of regions 117a- 117c of the substrate 116.

For example, in the example illustrated in Figures 1 and 2, the first area 109a of the deposition zone 114 is associated with (e.g. adjacent to) a first region 117a of the substrate 116, the second area 109b of the deposition zone 114 is associated with (e.g. adjacent to) a second region 117b of the substrate 116, and the third area 109c of the deposition zone 114 is associated with a third region 117c of the substrate 116. In some examples, the areas 109a- 109c and substrate 116 may be arranged such that sputtering occurring in a given area 109a- 109c of the deposition zone 114 may result in deposition onto the associated region 117a-117c of the substrate 112. For example, sputtering occurring in a given area 109a- 109c of the deposition zone 114 may result in deposition onto the associated region 117a-l 17c of the substrate 112 to a greater degree than that to which the sputtering results in deposition onto a region 117a- 117c not associated (e.g. not adjacent to) the given area 109a-109c of the deposition zone 114.

The gas controller 160 is arranged to control, independently for each of the plurality of gas inlets 103 a- 103 c, a flow of gas 111 a- 111c provided from the gas inlet 103a-103c, thereby to allow gas 11 la-111c to be provided selectively in each of the plurality of areas 109a-109c of the deposition zone 114. As also described in more detail hereinafter, independent control over the provision of gas to each area 109a-109c of the deposition zone 114 may provide for improved control over and/or flexibility in the resulting sputter deposition. This may, in turn, for example, provide for a greater control over and/or diversity of the products (e.g. thin films) that may be produced by the sputter deposition. This may find utility, for example, in the production of energy storage devices or components thereof.

The gas controller 106 may be configurable such that the plurality of gas inlets 103a-103c provide a variation in gas provision across the deposition zone 114 to cause inhomogeneous deposition of material to the substrate 116. For example, the deposition may be inhomogeneous in a direction perpendicular to the Z axis in the sense of Figures 1 and 2 (e.g. perpendicular to the conveyance direction A of the substrate 116).

In some examples, the gas controller 106 may be arranged to control, independently for each of the plurality of gas inlets 103 a- 103c, a gas, a gas mixture, and/or a gas flow rate provided from the gas inlet 103a-103c. This in turn may allow independent and individual control over the type of gas, the specific mixture of gas, and/or the flow rate of gas into (and hence the local pressure of gas in) each of the plurality of areas 109a-109c of the deposition zone 114.

In some examples, the gas controller 106 may be arranged to control, independently for each of the plurality of gas inlets 103 a- 103c, a flow of sputter or process gas, such as Argon or Neon, provided from the gas inlet 103 a- 103c to the associated area 109a-109c of the deposition zone 114.

The process gas is gas from which a plasma 112 is formed in the apparatus 100 in use to provide for sputter deposition of the target material 108 to the substrate 116. In some examples, provision of a process gas locally to a given area 109a- 109c of the deposition zone 114 may cause plasma 112 to be generated locally in that area 109a- 109c, whereas plasma may not be generated locally in an area 109a- 109c in which process gas is not locally provided from the associated gas inlet 103a-103c. In other examples, provision of a process gas locally to a given area 109a- 109c of the deposition zone 114 may cause plasma 112 to be generated preferentially (e.g. to a greater extent) in that area 109a-109c, for example as compared to the extent to which plasma 112 is generated in an area 109a- 109c in which process gas is not locally provided. The generation or preferential generation of plasma 112 in a given area 109a- 109c of the deposition zone 114 may in turn provide for sputter deposition or preferential sputter deposition of target material 108 onto the region 117a-117c of the substrate 116 associated with the given area 109a-109c. For example, the preferential generation of plasma 112 in a given area 109a- 109c may provide for sputter deposition of target material 108 onto the region 117a-117c of the substrate 116 associated with the given area 109a-109c to a greater degree and/or at a faster rate as compared to an area 109a- 109c in which plasma is not preferentially generated.

The independent control by the gas controller 106 over the provision of process gas in each of the different areas 109a-109c of the deposition zone 114 may therefore allow for spatial control over the deposition of target material 108 to the substrate 116. For example, the gas controller 106 may provide a controlled variation in deposition of target material 108 to the substrate 116 along a direction parallel to the direction along which the plurality of gas inlets 103a-103c (and/or the plurality of areas 109a-109c of the deposition zone 114) are arranged. For example, the gas controller 106 may provide controlled variation in deposition of target material 108 to the substrate 116 in a direction parallel to the Z axis (and e.g. the conveyance direction A) in the sense of Figures 1 and 2. The gas controller 106 may therefore provide for controlled and configurable deposition (e.g. inhomogeneous deposition) of target material 108 to the substrate 116. This may, in turn, allow for the controlled production of a wide variety of deposition product (e.g. thin film) architectures. For example, architectures may be produced in which the thickness of the deposited target material may vary (in a controlled and desired way) across the substrate (i.e. in a direction parallel to the X axis in the sense of Figures 1 and 2). This may have utility, for example, in the production of thin film structures for energy storage devices.

In some examples, the gas controller 106 may be arranged to control, independently for each of the plurality of gas inlets 103 a- 103 c, a flow of a reactive gas, such as a Nitrogen containing gas such as Nitrogen, Ammonia or Nitrous Oxide, and/or an oxygen containing gas such as Oxygen or Ozone, from the gas inlet 103 a- 103c. The reactive gas is a gas that reacts with sputtered target material 108 to produce a reaction product which may be deposited on the substrate 116, i.e. the reactive gas is a gas that provides for reactive sputtering. For example, provision of a reactive gas locally to a given area 109a-109c of the deposition zone 114 may cause a reaction product of the reactive gas and the target material 108 to be deposited or preferentially deposited (i.e. deposited to a higher degree and/or at a faster rate) locally on the region of the substrate 117a- 117c associated with that area 109a- 109c, for example as compared to an area 109a- 109c of the deposition zone 114 in which a reactive gas is not locally provided.

The independent control by the gas controller 106 over the provision of reactive gas in each of the different areas 109a-109c of the deposition zone 114 may therefore allow for spatial control over the deposition of a reaction product of the reactive gas and the target material 108 to the substrate 116.

For example, the gas controller 106 may provide a controlled variation in deposition of the reaction product to the substrate 116 along a direction parallel to the direction along which the plurality of gas inlets 103 a- 103 c (and/or the plurality of areas 109a-109c of the deposition zone 114) are arranged (e.g. along a direction parallel to the X axis in the sense of Figures 1 and 2). The gas controller 106 may therefore provide for controlled and configurable deposition (e.g. inhomogeneous deposition) of the reaction product to the substrate 116. This may, in turn, allow for the controlled production of a wide variety of thin film architectures. For example, architectures may be produced in which the presence or absence or thickness of the deposited reaction product may vary (in a controlled and desired way) across the substrate (i.e. in a direction parallel to the X axis in the sense of Figures 1 and 2). Such architectures may have utility, for example, in the production of thin film structures for energy storage devices.

In some examples, the gas controller 106 may be arranged to control, independently for each of the plurality of gas inlets 103 a- 103c, a mixture or composition of process gas and reactive gas provided by the gas inlet 103a-103c. This may provide for more flexibility in the control of material that is deposited on each of the regions 117a- 117c of the substrate 116.

In some examples, the reactive gas may be a nitrogen containing gas or an oxygen containing gas. In some examples, the target material may be a Lithium containing material. As described, this may allow, for example, for flexible production of thin films for energy storage devices. For example, the apparatus 100 may be configured or configurable for the deposition of solid electrolyte material, for example for the production of a thin film energy storage device or a component thereof.

For example, the solid electrolyte layer desired to be deposited may be Lithium phosphorus oxy-nitride (LiPON). In this case, the target may be or comprise LhPCL (LiPO), and the reactive gas may be or comprise a Nitrogen containing gas such as Nitrogen, Ammonia, or Nitrous Oxide. Sputtered LiPO may react with the Nitrogen containing gas to produce LiPON. The gas controller 160 may control the Nitrogen containing gas to be provided from, say, the first and third gas inlets 103a, 103c, but not to be provided from the second gas inlet 103b. Accordingly, the Nitrogen containing gas may be provided locally to the first and third areas 109a, 109c of the deposition zone 114, but not provided locally to the second area 109b of the deposition zone 114. The Nitrogen containing gas may react with the sputtered LiPO target material in (e.g. preferentially in) the first and third areas 109a, 109c to form LiPON, which accordingly may be deposited (e.g. deposited preferentially) onto the first and third regions 117a, 117c of the substrate 116. The Nitrogen containing gas not being provided locally in the second area 109b of the deposition zone 114 may result in the deposition (e.g. preferential deposition) of the LiPO target material onto the second region 117b of the substrate 116. Accordingly, a thin film may be produced that has an inactive, LiPO, region bounded by active, LiPON, regions. It will be appreciated that any number of combinations of spatial deposition may be achieved by appropriate selection of the areas 109a- 109c to which the Nitrogen containing gas is controlled to be locally provided. Improved control over and/or flexibility in the production of thin films may therefore be provided.

Alternatively, or additionally, the apparatus 100 may be configured or configurable for the deposition of a cathode materials, for example for the production of a thin film energy storage device. Examples of cathode materials include Lithium Cobalt Oxide - L1C0O2 (LCO), and Lithium Nickel Cobalt Manganese Oxide - LiNiCoMn02 (NMC).

As an example, the cathode layer desired to be deposited may be LCO or NMC. In this case, the target may be or comprise LiCo or LiNiCoMn, and the reactive gas may be or comprise an oxygen containing gas such as Oxygen or Ozone. Sputtered LiCo may react with the Oxygen containing gas to produce LCO. Sputtered LiNiCoMn may react with the Oxygen containing gas to produce NMC. Taking LiCo as an example target material, control over the provision of the Oxygen containing gas locally to one more given areas 109a- 109c by the gas controller 160 may in turn control the preferential deposition of LCO to the regions 117a- 117c of the substrate 116 associated with the given areas, and the preferential deposition of LiCo to regions associated with areas to which the Oxygen containing gas is controlled not to be provided. Accordingly, a thin film may be produced that has active cathode regions and non-active cathode regions as desired. Improved control over and/or flexibility in the production of thin film energy storage devices may therefore be provided.

As mentioned, the substrate portion 106 may comprise a substrate conveyance arrangement (not shown in Figures 1 and 2) arranged to convey the substrate 116 relative to the target portion 106. This may provide that material may be deposited on the substrate 116, e.g. a web of substrate 116, in a continuous or semi-continuous manner. This may improve the efficiency of sputter deposition for a large area substrate 116. As mentioned, the substrate 116 may be conveyed relative to the target portion 106 in a conveyance direction A, and the plurality of gas inlets 103 a- 103c may be arranged along a common axis perpendicular to the conveyance direction A (e.g. as shown in Figures 1 and 2). This may provide that control of the deposition of material to the substrate (via the individual control of the provision of gas from each of the plurality of gas inlets 10-3a-103c) can be achieved while the substrate 116 is conveyed through the apparatus 100 in a continuous or semi-continuous manner. This arrangement may therefore provide for control over and/or flexibility in an efficient deposition process suitable for large scale production.

Referring to Figure 4, there is illustrated an apparatus 400 according to a second example. The apparatus 400 of Figure 4 is substantially the same as the apparatus 100 described with reference to Figures 1 and 2, and like features are provided with like reference signs. However, the substrate portion 118 of the apparatus 400 of Figure 4 comprises an example substrate conveyance arrangement 452.

The substrate conveyance arrangement 452 is arranged to convey a web of substrate 116 relative to the target portion 106. In this example, the substrate conveyance arrangement 452 comprises a first roller 410a, a drum 419 arranged to rotate about a rotation axis 420, and a second roller 410b. The first roller 410a is arranged to feed the web of substrate 116 onto the drum 419, and the second roller 410b is arranged to feed the web of substrate 116 from the drum 719, after the web of substrate 116 has passed the deposition zone 114. The conveyance direction A may be taken as the general direction in which the substrate 116 is conveyed, relative to the target portion 106 (or the second region 106a in which the target material 108 is retained by the target portion 106), when the substrate 116 passes through the deposition zone 114. The substrate conveyance arrangement 452 may be part of a “reel-to-reel” process arrangement (not shown), where the web of substrate 116 is fed from a first reel or bobbin (not shown) of substrate web 116, passes through the first region 118a of the apparatus 400, and is then fed onto a second reel or bobbin (not shown) to form a loaded reel of processed substrate web (not shown). The substrate conveyance arrangement 452 may improve the efficiency with which substrate 116 may be processed, for example as compared to batch processing.

In this example, the plurality of gas inlets 103a-103c are arranged along a common axis substantially perpendicular to the conveyance direction A (only one gas inlet 103a is visible in Figure 4). This may provide that control of the deposition of material to the substrate can be achieved while the substrate 116 is conveyed through the apparatus 100 in a continuous or semi-continuous manner, thereby providing for efficient yet controlled deposition.

As mentioned, the gas controller 160 is arranged to control, independently for each of the plurality of gas inlets 103 a- 103 c, a flow of gas provided from the gas inlet 103 a- 103c. Referring to Figures 5 and 6 there are illustrated two examples of a gas controller 560, 660. The gas controllers 550, 660 of either of the examples of Figures 5 and 6 may be used as the gas controller 160 in any of the examples described above with reference to Figures 1 to 4. Like features are provided with like reference signs.

Referring first to Figure 5, the example gas controller 560 comprises a gas source 562, a feed pipe 568, valves 566a-566c, and a control unit 564.

The gas source 562 may be or comprise a container that contains a gas, such as process gas and/or reactive gas. The feed pipe 568 provides gas from the gas source 562 to the valves 566a-566c. Each valve 566a-566c is independently controllable to adjust a flow of the gas from the feed pipe 568 to a respective different one of the plurality of gas inlets 103a-103c, and hence to adjust a flow of gas provided by the gas inlet 103a-103c. For example, a first valve 566a is controllable to adjust a flow of gas 111a provided by the first gas inlet 103a, a second valve 556b is controllable to adjust a flow of gas 111b provided by the second gas inlet 103b, and a third valve 556c is controllable to adjust a flow of gas 111c provided by the third gas inlet 103c. The control unit 564 is communicatively coupled to each of the valves 566a-566c and arranged to independently control each of the valves 564. For example, the control unit 564 may control each of the valves 556a-566c to independently and individually control the flow rate (or presence or absence) of gas provided by each of the gas inlets 103a- 103c.

Referring to Figure 6, the example gas controller 660 comprises a first gas source 562 and a second gas source 670, a first feed pipe 568 and a second feed pipe 672, a first set of valves 566a-566c and a second set of valves 666a-666c, and a control unit 664.

The first gas source 562 may be or comprise a container that contains a gas, such as process gas and/or reactive gas. The second gas source 670 may be or comprise a container that contains a gas, such as process gas and/or reactive gas. The first gas source 562 may provide a different gas to the second gas source 670. For example, the first gas source may provide a process gas and the second gas source may provide a reactive gas. The first feed pipe 568 provides gas from the first gas source 562 to the first set of valves 566a-566c. The second feed pipe 672 provides gas from the second gas source 670 to the second set of valves 666a-666c. Each valve 566a-566c of the first set of valves is independently controllable to adjust a flow of the gas from the first feed pipe 568 to a respective different one of the plurality of gas inlets 103a-103c. Each valve 666a-666c of the second set of valves is independently controllable to adjust a flow of the gas from the second feed pipe 670 to a respective different one of the plurality of gas inlets 103a-103c. The control unit 664 is communicatively coupled to each of the valves 566a-566c, 666a-666c and arranged to independently control each of the valves 566a-566c, 666a-666c. Control of the valves 566a-566c, 666a-666c may provide independent control of the gas, the gas mixture, and/or the flow rate of the gas or gas mixture, provided by each gas inlet 103 a- 103c. It will be appreciated that in other examples (not shown) other arrangements of a gas controller 160 may be used to provide control, independently for each of the plurality of gas inlets 103 a- 103 c, a flow of gas provided from the gas inlet 103 a- 103 c, thereby to allow gas 11 la-111c to be provided selectively in each of the plurality of areas of the deposition zone 114.

Referring to Figures 7 and 8, there is illustrated an apparatus 700 according to another example. The apparatus 700 in the example of Figures 7 and 8 is substantially the same as the apparatus 100 described with reference to Figures 1 and 2 and like features are given like reference signs. However, in the example apparatus 700 of Figures 7 and 8, the plurality of gas inlets 103a-103c are arranged along a common axis that is at right angles to the common axis along which the plurality of gas inlets 103a- 103c are arranged in the example apparatus 100 described with reference to Figures 1 and 2.

Each gas inlet 103a-103c is arranged to provide gas locally to a given different one of a respective plurality of different areas 709a, 709b, 709c of the deposition zone 114. In this example, the gas inlets 103a-103c are arranged along (i.e. arranged in a sequence along) a common axis, which common axis is substantially parallel to the Z axis in the sense of Figures 7 and 8 (e.g. substantially perpendicular to the direction along which the antenna 102a, 102b and/or the magnetic element 105a, 105b are elongate). The Z axis in Figures 7 and 8 is orientated in the same way with respect to the substrate 116, the target portion 106, the antenna arrangement 104 and the confining arrangement 104, as the Z axis in Figures 1 and 2.

The gas controller 160, 560, 660 is arranged to control, independently for each of the plurality of gas inlets 103 a- 103 c, a flow of gas provided from the gas inlet 103 a- 103c, thereby to allow gas to be provided selectively in each of the plurality of areas 709a, 709b, 709c of the deposition zone 114. In this example, the areas 709a-709c of the deposition zone 114 are adjacent to one another and extend in a sequence in a direction parallel to the Z axis in the sense of Figures 7 and 8.

In this example, each of the plurality of areas 709a-709c of the deposition zone 114 are associated with (e.g. adjacent to) a different one of a respective plurality of regions 717a-717c of the substrate 116. Sputtering (reactive or otherwise) occurring in a given area 109a-109c of the deposition zone 114 may result in deposition onto the associated region 717a-717c of the substrate 116.

Similarly to as described with reference to Figures 1 and 2, independent control over the provision of gas (e.g. process gas and/or reactive gas) locally to a given area 709a-709c of the deposition zone 114 may provide for control over, or flexibility in, a spatial variation in deposition of material to the substrate 116. For example, in the example of Figures 7 and 8, the gas controller 160, 560, 660 may provide a controlled variation in deposition of material to the substrate 116 along a direction parallel to the direction along which the plurality of gas inlets 103 a- 103 c (and/or the plurality of areas 709a-709c of the deposition zone 114) are arranged (e.g. along a direction parallel to the Z axis in the sense of Figures 7 and 8). The gas controller 160, 560, 660 may therefore provide for controlled and configurable deposition (e.g. inhomogeneous deposition) of material to the substrate 116. This may, in turn, allow for the controlled production of a wide variety of thin film architectures. For example, architectures may be produced in which the presence or absence or thickness of the deposited material may vary (in a controlled and desired way) along the substrate 116 (i.e. in a direction parallel to the Z axis in the sense of Figures 1 and 2). As another example, layering of deposited target material 108 and the reaction product may be achieved by suitable control of the timing of the presence and absence of the reactive gas in a given areas 709a-709c. Such architectures may find utility in the production of energy storage devices or components thereof, for example.

In and of the examples described herein, the apparatus 100, 400, 700 may allow for improved control over and/or flexibility in sputter deposition, for example to provide for a greater control over and/or diversity of the deposition products (e.g. thin films) that may be produced.

Referring to Figure 9, there is illustrated schematically a flow diagram representing a method of sputter deposition of target material 108 to a substrate 116. The target material 108 and the substrate 116 define between them a deposition zone 114.

In step 902, the method comprises controlling, independently for each of a plurality of different areas 109a-109c, 709a-709c of the deposition zone 114, a flow of gas provided locally to the area 109a- 109c, 709a-709c, thereby to provide gas selectively in each of the plurality of areas 109a-109c, 709a-709c of the deposition zone 114.

The method may be performed by an apparatus 100, 400, 700, for example any one of the example apparatuses 100, 400, 700 described above with reference to Figures 1 to 8. Specifically, the method may be performed by the gas controller 160, 560, 660, for example the control unit 564, 664 of the gas controller 160, 650, 660 controlling valves 556a-556c, 666a-666c as described above with reference to Figures 5 and 6.

Similarly to as described with reference to Figures 1 to 8, independent control over the flow of gas provided locally to each of a plurality of different areas 109a- 109c, 709a-709c of the deposition zone 114 may allow for improved control over and/or flexibility in sputter deposition, for example to provide for a greater control over and/or diversity of the thin films that may be produced by the method.

The above examples are to be understood as illustrative examples of the invention.

For example, in some examples, there may be provided an apparatus 100, 400, 700 for sputter deposition of target material 108 to a substrate 116, the apparatus 100, 700 comprising: a substrate portion 118 arranged to retain a substrate 116 in a first region 118a; a target portion 106 arranged to retain a target material 108 in a second region 106a, the first region 118a being spaced apart from the second region 106a, the first region 118a and the second region 106a defining between them a deposition zone 114; and a plurality of gas inlets 103a-103c; wherein the substrate portion 118 and the plurality of gas inlets 103 a- 103 c are arranged or controllable or configurable such that, in use, the plurality of gas inlets 103 a- 103c provide a variation in gas or gas density (e.g. process and/or reactive gas) across the deposition zone 114 to cause inhomogeneous deposition of material to the substrate 116. This may allow for non- uniform yet controlled deposition, e.g. to produce films whose properties vary across the film. As described, this may find utility, for example, in the manufacture of thin film energy storage devices.

In some examples, there may be provided a method of sputter deposition of target material 108 to a substrate 116, the target material 108 and the substrate 116 defining between them a deposition zone 114, the method comprising: providing, using a plurality of gas inlets 103a-103c, a variation in gas or gas density (e.g. process and/or reactive gas) across the deposition zone 114 to cause inhomogeneous deposition of material to the substrate 116. This may allow for non-uniform yet controlled deposition, e.g. to produce films whose properties vary across the film. As described, this may find utility, for example, in the manufacture of thin film energy storage devices. It is to be understood that any feature described in relation 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 of the examples, or any combination of any other of the examples. Furthermore, equivalents and modifications not described above may also be employed without departing from the scope of the invention, which is defined in the accompanying claims.

Claims

1. Apparatus for sputter deposition of target material to a substrate, the apparatus comprising: a substrate portion arranged to retain a substrate in a first region; a target portion arranged to retain a target material in a second region, the first region being spaced apart from the second region, the first region and the second region defining between them a deposition zone; a plurality of gas inlets, each gas inlet being arranged to provide gas locally to a given different one of a respective plurality of different areas of the deposition zone; and a gas controller arranged to control, independently for each of the plurality of gas inlets, a flow of gas provided from the respective gas inlet, thereby to allow gas to be provided selectively in each of the plurality of areas of the deposition zone.

2. The apparatus according to claim 1, wherein the gas controller is arranged to control, independently for each of the plurality of gas inlets, a flow of process gas provided from the gas inlet.

3. The apparatus according to claim 2, wherein the apparatus comprises a plasma generator, and wherein the apparatus is arranged such that, for each of the plurality of different areas of the deposition zone, provision of said process gas locally to the area causes plasma to be generated or generated preferentially in the area.

4. The apparatus according to any one of claim 1 to claim 3, wherein the gas controller is arranged to control, independently for each of the plurality of gas inlets, a flow of reactive gas provided from the gas inlet.

5. The apparatus according to claim 4, wherein the plurality of gas inlets and the substrate portion are arranged such that, for each of the plurality of different areas of the deposition zone, provision of said reactive gas locally to the area causes a reaction product of said reactive gas and said target material to be deposited or deposited preferentially on a region of said substrate associated with the area.

6. The apparatus according to claim 4 or claim 5, wherein the apparatus comprises: a gas source comprising the reactive gas, wherein the reactive gas is a Nitrogen containing gas and/or an Oxygen containing gas.

7. The apparatus according to any one of claim 1 to claim 6, wherein the apparatus comprises the target material and the target material is a Lithium containing material.

8. The apparatus according to any one of claim 1 to claim 7, wherein each of the plurality of areas of the deposition zone is associated with a different one of a respective plurality of regions of the substrate.

9. The apparatus according to claim 8, wherein the plurality of gas inlets and the substrate portion are arranged such that, for each of the plurality of different areas of the deposition zone, said provision of said gas locally to the area of the deposition zone causes preferential deposition of material to the associated region of the substrate.

10. The apparatus according to any one of claim 1 to claim 9, wherein the gas controller is arranged to control, independently for each of the plurality of gas inlets, a gas, a gas mixture, and/or a gas flow rate provided from the gas inlet.

11. The apparatus according to any one of claim 1 to claim 10, wherein the gas controller is configurable such that the plurality of gas inlets provide a variation in gas provision across the deposition zone to cause inhomogeneous deposition of material to the substrate.

12. The apparatus according to any one of claim 1 to claim 11, wherein the substrate portion comprises a substrate conveyance arrangement arranged to convey said substrate relative to the target portion.

13. The apparatus according to claim 12, wherein the substrate conveyance arrangement is arranged to convey said substrate relative to the target portion in a conveyance direction, and wherein the plurality of gas inlets and the substrate conveyance arrangement are arranged such that the plurality of gas inlets are arranged along a common axis perpendicular to the conveyance direction.

14. The apparatus according to any one of claim 1 to claim 13, wherein the apparatus comprises an antenna arrangement comprising at least one antenna for generating plasma when an alternating current is driven through the antenna, said plasma providing for said sputter deposition of material to the substrate.

15. The apparatus according to claim 14, wherein the at least one antenna is common to the plurality of gas inlets.

16. The apparatus according to claim 14 or claim 15, wherein the at least one antenna is disposed remotely of the deposition zone.

17. The apparatus according to any one of claim 14 to claim 16, wherein the apparatus comprises a magnetic confining arrangement arranged to confine said generated plasma to the deposition zone to provide for said sputter deposition of material to the substrate in use.

18. The apparatus according to claim 17, wherein the magnetic confining arrangement comprises at least one magnetic element through which plasma is confined in use between the deposition zone and the at least one antenna.

19. Method of sputter deposition of target material to a substrate, the target material and the substrate defining between them a deposition zone, the method comprising: controlling, independently for each of a plurality of different areas of the deposition zone, a flow of gas provided locally to the area, thereby to provide gas selectively in each of the plurality of areas of the deposition zone.

20. Apparatus for sputter deposition of target material to a substrate, the apparatus comprising: a substrate portion arranged to retain a substrate in a first region; a target portion arranged to retain a target material in a second region, the first region being spaced apart from the second region, the first region and the second region defining between them a deposition zone; and a plurality of gas inlets; wherein the substrate portion and the plurality of gas inlets are arranged such that, in use, the plurality of gas inlets provide a variation in gas or gas density across the deposition zone to cause inhomogeneous deposition of material to the substrate.

21. A method of sputter deposition of target material to a substrate, the target material and the substrate defining between them a deposition zone, the method comprising: providing, using a plurality of gas inlets, a variation in gas or gas density across the deposition zone to cause inhomogeneous deposition of target material to the substrate.