CN114318273A

CN114318273A - Method and apparatus for sputter deposition

Info

Publication number: CN114318273A
Application number: CN202111134030.8A
Authority: CN
Inventors: M.E.伦德尔
Original assignee: Dyson Technology Ltd
Current assignee: Dyson Technology Ltd
Priority date: 2020-09-30
Filing date: 2021-09-27
Publication date: 2022-04-12
Also published as: GB2599393A; GB202015461D0

Abstract

A reactive ion source for a sputter deposition system. The reactive ion source comprises: an electrically driven antenna having a substantially elongated shape, a housing at least partially surrounding the antenna, an inlet for supplying a reactant gas into the housing, and an outlet of the housing configured to enable reactant ions to pass through the outlet. The antenna is configured to apply an electromagnetic field to the reactant gas such that a plasma including the reactant ions is formed.

Description

Method and apparatus for sputter deposition

Technical Field

The present invention relates to reactive sputter deposition and, more particularly, to a method and apparatus for reactive sputter deposition of a target material to a surface using a remotely generated plasma.

Background

Deposition is a process by which a target material is deposited on a surface, such as a substrate. Examples of deposition are 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 web. One 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, which is then condensed onto a substrate surface. One example of PVD is sputter deposition, in which particles are ejected from a target as a result of bombardment by energetic particles (e.g., ions). In an example of sputter deposition, a sputtering gas, such as an inert gas, e.g., argon, is introduced into a vacuum chamber at low pressure and the sputtering gas is ionized using energetic electrons to generate a plasma. The target material is ejected by bombardment of the target by ions of the plasma, which can then be deposited on the substrate surface. Sputter deposition has an advantage over other thin film deposition methods (e.g., 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. Known sputter deposition techniques employ a magnetron in which a glow discharge, in combination with a magnetic field, causes an increase in plasma density in a circular region near the target. An increase in plasma density can result in an increase in deposition rate. Reactive sputtering involves performing sputter deposition in the presence of a reactive gas. A reactive gas is defined herein as a gas that is ionized as part of a deposition process that generates reactive ions, which react with the sputtered material as it travels through the chamber and/or is deposited onto the substrate.

Alternatively, some known methods use a source of reactive ions that provide pre-ionized material into a chamber. However, none of these approaches is capable of providing a particularly dense or localized volume of reactive ions in the deposition chamber. It is desirable to provide a reactive ion source that is capable of providing very dense, localized ion regions/geometries to allow for improved throughput and film quality in industrial applications of reactive sputter deposition systems.

WO2011131921 discloses a sputter deposition apparatus in which the density is 10¹¹cm^-3Is generated by an elongated gas plasma source separately from the target. The source is discussed as being optionally used for reactive sputtering. In WO2011131921, the plasma is generated in an atmosphere separate from the atmosphere of the plasma deposition system and requires significant electromagnetic equipment within the plasma chamber in order to be within the plasma chamberThe plasma is shaped and confined in the volume. It would be desirable to provide a reactive ion source capable of generating a plasma within the volume of a plasma chamber that does not require a separate chamber. It is also desirable to provide a reactive ion source that is capable of providing a high density of reactive ions to locations within a plasma chamber without requiring significant electromagnetic equipment to confine the plasma within the plasma chamber.

The present invention seeks to mitigate one or more of the above-mentioned problems. Alternatively or additionally, the present invention seeks to provide an improved source of reactive ions for a sputter deposition system. Alternatively or additionally, the present invention seeks to provide an improved method of depositing or otherwise fabricating a layer of material on a surface. Alternatively or additionally, the present invention seeks to provide an improved method of forming an electrolyte layer on a substrate. The invention also relates to a solid state battery half cell (solid state battery half-cell), a solid state battery cell (solid state battery cell) and a solid state battery manufactured according to such a method.

Disclosure of Invention

According to a first aspect of the present invention, there is provided an ion source, for example an ion source for generating reactive ions in a sputter deposition system. The ion source includes an electrically driven antenna. In an example, the antenna has a substantially elongated shape. In an example, the ion source includes a housing, e.g., a housing that at least partially surrounds an antenna. The ion source includes an inlet for supplying a reactant gas, for example into the housing. The ion source includes an outlet configured to allow the reactive ions to pass through the outlet, for example from the housing. The antenna is configured to apply an electromagnetic field to the reactant gas to form a plasma including the reactant ions.

In an example, the elongate antenna may be elongate in the sense that the portion of the antenna that contributes positively to the generation of plasma has a three-dimensional footprint of a maximum dimension (i.e. a "length" or "cross-sectional length") along one axis that is at least twice, and preferably at least three times, the maximum dimension (e.g. width) taken about any orthogonal axis. For example, an elongate antenna may be relatively elongate and flat such that its length is more than three times its width, and optionally more than five times (possibly more than ten times) its depth. The cross-sectional long dimension of the antenna may exceed 400mm, optionally 1000mm in length. The cross-sectional long dimension may not exceed 1000cm in length.

According to a second aspect of the present invention, there is provided a reactive ion source of a sputter deposition system, comprising:

an electrically driven antenna, wherein the antenna has a substantially elongated shape,

a housing at least partially surrounding the antenna,

an inlet for supplying a reaction gas into the housing, an

An outlet from the housing configured to enable passage of reactive ions through the outlet, wherein the antenna is configured to apply an electromagnetic field to the reactive gas such that a plasma comprising the reactive ions is formed.

For the avoidance of doubt, the following statements relate to the source of reactive ions of the first and second aspects of the invention.

The source of reactive ions may be adapted to be disposed in a sputter deposition chamber. The source of reactive ions may have a compact design.

The terms "reactive gas" and "reactive ion" are well known to those skilled in the art. The reactive gas refers to a gas that generates reactive ions once ionized. The reactant gas may not be particularly reactive in its gaseous form (e.g., diatomic gaseous form), but may be very reactive once ionized.

The plasmonic antenna may be substantially elongate in shape and may extend in a direction having a length. The antenna or a part thereof may have a segment. The segment of the antenna may have a shape that generally extends in a single direction.

The segment of the antenna may extend in a substantially linear direction (e.g., in a generally straight line) between the first and second positions. The plasma antenna may have one or more straight sections. For example, a first straight section and a second straight section (which optionally extend parallel to the first section or in the same general direction as the first section) may be included such that, in use, there is a plasma generation region located between the first and second straight sections.

The antenna comprises an electrical conductor, such as copper. In an example, an antenna may be considered to be an electrical conductor such as some form of wire or tube. In other examples, the electrical conductor comprises other materials. The plasma antenna may be a copper antenna. The plasma antenna may be enclosed in a tube housing, such as a quartz tube.

The plasma antenna may be partially tubular, which may for example help to cool the antenna during use.

The plasma antenna is capable of receiving a voltage of at least 1kV, optionally at least 2kV and optionally 5 kV. The plasma antenna may be powered by an RF power source.

The antenna may be driven at a frequency of at least 1MHz, and optionally at a frequency of 13.56MHz, or at a multiple of 13.56 MHz. The antenna may be driven at a lower frequency than 13.56 MHz; for example, the antenna may be driven at a frequency in the range of 1MHz to 10 MHz.

In an example, at least two segments of the plasma antenna that are laterally spaced apart from each other (and, for example, parallel to each other) can be used to generate the plasma. The two sections of the plasma antenna may be driven by a common RF current source and/or may be electrically coupled to each other.

It will be appreciated that, in use, the plasma antenna, or one or more portions thereof, is configured (i.e. typically as a result of the application of Radio Frequency (RF) power) to excite a gaseous medium, thereby generating a plasma, for example forming a plasma along the length of the antenna. Such a plasma may be generated, for example, in a housing in which the antenna is located. In an example, the plasma may be generated within the housing along the entire length of the antenna. Alternatively or additionally, the plasma may be propagated throughout the process chamber in which the sputtering process (i.e., sputter deposition) occurs. The plasma may be generated in an electrically isolated cavity. An electrically insulating cavity may be defined by the housing.

The shape of the outlet may be designed such that the plasma/reactive ions exit the housing through the outlet faster than the gas molecular stream enters the inlet.

The shape of the outlet may be designed such that a plasma plume comprising the reactive ions is formed therefrom.

The outlet may at least partially comprise a frustoconical shape. The outlet may be substantially in the shape of a "nozzle". This allows the plasma plume to be focused onto the substrate at high density.

The outlet may comprise a substantially elongate shape. This allows the sheet-like geometry of the plasma to propagate from the source. The shape of the outlet may be designed to be substantially of the "letter box" kind. Such wide-angled apertures have particular utility in situations where it is desirable to process larger sized substrates at high throughput, such as in roll-to-roll (or "web") processing.

The outlet may include an aperture configured to be supplied with an electrical charge. The holes may be arranged such that an electrical charge may be directed thereto. The holes may be configured to receive charge during a sputter deposition process or otherwise become charged. A bias voltage may be applied across the aperture.

In use, supplying a charge to the aperture can accelerate the reactive ions passing through the outlet.

The pores can be supplied with a positive or negative charge. The amount of charge applied to the aperture is optionally adjustable so that the amount of charge applied to the aperture can be varied. The aperture may comprise an electromagnetic lens. The aperture may comprise suitable equipment such that when the plasma passes through the aperture, an ion beam is formed. Such suitable equipment may include accelerator grids, screen grids, and neutralizers.

The holes can be supplied with a bias voltage of at least 300V, preferably 400V and more preferably 500V. In general, it is believed that the higher the voltage applied to the aperture, the higher the exit velocity of the reactive ions through the aperture.

The charged holes may have the effect of accelerating ions away from the outlet. When reactive ions from a conventional reactive ion source are used in a conventional sputter deposition process, the reactive ions lose their relative directionality or geometry due to the low vacuum in the sputter deposition chamber, causing the reactive ions to disperse throughout the sputter deposition chamber. In contrast, the present invention allows a directed stream of reactive ions, or a particular geometry of reactive ions (e.g., a plume of reactive ions), to travel over a longer distance in a sputter deposition chamber than would otherwise be possible before dispersing and losing its relative directionality or geometry. Such an ion source may be an example of a linear ion source.

This is a particularly surprising finding to the applicant, since it has previously been thought that when the reactive ions are introduced under process vacuum (e.g. 10 f)^-3mBar or stronger vacuum) sputtering deposition chamber, the reactive ions will be momentarily dispersed at the moment of entry into the chamber. It was previously thought that it was not possible to maintain the flow or directionality of the reactive ions as they enter the chamber without significant electromagnetic confinement of the ions within the chamber.

In use (i.e. at least 10)^-3In a sputter deposition chamber under vacuum of mBar), the ion source may generate a plasma plume capable of propagating over a distance of at least 1cm and maintaining its directionality and/or geometry. Preferably, the source of reactive ions is capable of generating a reactive ion plume extending over a length of at least 1cm, preferably at least 2cm, and preferably at least 3 cm.

The housing may be configured to be supplied with a positive charge. The housing may define an electrically insulating cavity.

A positive charge applied to the housing can accelerate the reactive ions passing through the outlet. Without wishing to be bound by theory, it is believed that the plasma potential is increased such that the reactive ions pass through the outlet to exit the enclosure is energetically favorable. This raising of the plasma potential relative to ground may provide an accelerating voltage to the ions as they exit the chamber. Acceleration of the ions may occur as the ions enter a sheath in front of a grounded object (which may be, for example, a grounded substrate).

In use, the apparatus may cause a plasma to be generated and maintained in a gaseous medium surrounding it. This means that the atmosphere in which the remotely generated plasma is generated is within the volume of space defined by any chamber containing the sputter deposition process equipment. For example, the spatial volume can be within the deposition chamber and within the volume/chamber where most of the equipment necessary for sputter deposition (e.g., the substrate and one or more targets) is located. The device may be in fluid communication with the chamber.

The plasma source may be referred to as a localized plasma source located within the sputter deposition chamber. Applicants have found that surprisingly, a high density plasma can be generated and shaped within a sputter deposition chamber without the need for the plasma to be first generated from and extracted from a (separate) plasma chamber. In other words, the plasma of the present system is generated, maintained and shaped in the working space of the sputter deposition chamber in which it is installed, rather than being generated in a separate, discrete or non-integrated plasma chamber (commonly referred to as a discharge tube) and subsequently extracted into the working space of the chamber, as seen in prior art systems. Thus, at least a portion of the plasma source (i.e., the antenna or the housing) forms an integral or integrated component of the sputter deposition chamber without requiring the housing or antenna to be surrounded by a different plasma chamber (i.e., a plasma chamber separate from any sputter deposition process plasma chamber) or the housing itself to be part of a different plasma chamber. Likewise, the plasma of the present system is generated in the process atmosphere of the sputter deposition chamber, rather than in a separate or otherwise isolated (relative to the sputter deposition chamber) atmosphere.

The device can be greater than 10¹¹cm^-3Is used to form and shape the localized linear plasma formed in the sputter deposition chamber. Alternatively, the device can be greater than 10¹⁴cm^-3Is used to form and shape the localized linear plasma formed in the sputter deposition chamber.

The inlet may be fluidly connected to a source of reactant gas. Providing the inlet with a source of reactive gas advantageously ensures that the housing and the plasma-generating antenna within the housing are provided with a high flow rate and/or a high volume of reactive gas.

Alternatively, the inlet may be open to the atmosphere of the volume in which the sputter deposition process takes place. The volume in which the sputter deposition process occurs can be within the sputter deposition chamber. A reactive gas can be introduced into the sputter deposition chamber and then diffused into the enclosure through the inlet.

A conductive shielding member may be present. Such a shield member may limit (e.g., prevent) the generation of plasma at one or more regions proximate to the antenna. There may be a region adjacent the antenna between the first position and the second position in which the generation of plasma is reduced and/or suppressed due to the at least one shielding member. This may improve electrical efficiency due to reduced undesirable recombination of plasma ions and/or localized plasma proximity to the outlet.

There may be a ferromagnetic or ferrimagnetic material arranged to partially surround the antenna, preferably to increase the magnetic flux density in the plasma generation region. The use of such materials may enhance the generation of plasma at one or more regions and/or localize the plasma to such regions. This may improve electrical efficiency by reducing undesirable recombination of plasma ions and/or localizing the plasma to those areas where it is needed, regardless of the process or use for which the plasma is provided. Ferromagnetic or ferrimagnetic materials arranged to partially surround the antenna in order to increase the magnetic flux density in the plasma generation region may be referred to herein as focusing members.

The focusing member may be shielded (i.e., with shielding) from external magnetic fields (i.e., non-antenna generated magnetic fields/magnetic fields generated external to the plasma antenna assembly). An external magnetic field may be present at the focusing member due to one or more magnets (e.g., electromagnets) located in the plasma generating device confining and/or propagating the plasma to a location remote from the plasma antenna. Thus, the focusing member may be shielded from the magnetic field generated by the one or more magnets.

It will be appreciated that the focusing member may not be completely shielded from external magnetic fields. For example, the effect of the magnetic field produced by the one or more magnets may be measured at the focusing member (i.e., not negligible). However, the shield may reduce the strength/effect of this magnetic field such that the ferromagnetic or ferrimagnetic material of the focusing member is not saturated by the external magnetic field, and thus may effectively redirect the magnetic field generated by the antenna so as to increase the magnetic flux density in the plasma generation region.

The focusing member may be coated with a shielding material. The shielding material may include nickel. The shielding material may be a nickel alloy, such as that of Magnetic Shield Corporation of Bensverval, Illinois, USA

And (3) alloying. Alternatively or additionally, the housing portion containing the antenna may be provided with (e.g. coated with) a shielding material. Alternatively or additionally, one or more separate shielding elements may be provided in the region between the focusing member and the one or more magnets in the plasma generating device.

The ferromagnetic or ferrimagnetic material of the focusing member may be ferrite.

One or more magnets may be provided, for example separate from the plasma antenna. Such one or more magnets may be configured such that the plasma is confined to and/or propagates in a direction orthogonal to the length of the antenna, such as through the exit port and across the sputter deposition chamber. Where the antenna is located at least partially in the sputter deposition chamber, one of the one or more magnets may also be located within the deposition chamber. One or more magnets may be disposed within the sputter deposition chamber to reduce the footprint of the apparatus. In addition, the magnets may be manipulated within the volume of the deposition chamber to regulate, focus, confine, and/or direct the formation of the plasma. Thus, the plasma can be generated and shaped/confined to be in the correct form necessary for the sputter deposition chamber.

One or more magnets may be disposed inside or outside the housing. The one or more magnets are preferably disposed proximate the outlet. Positioning one or more magnets in close proximity to the outlet may improve the directionality and/or geometry of the plasma as it exits the outlet. In use, the one or more magnets may cooperate with the charged aperture and/or the positively charged housing in providing a plasma having a very high geometry or directionality. One or more magnets are optionally in contact with the housing.

One or more magnets may be used to confine, shape and/or propagate the plasma generated by the antenna as a linear plasma, for example optionally across a deposition chamber, so as to take the form of a thin plasma sheet or plate originating from the antenna. This is in contrast to prior art inefficient large area plasma processing apparatus in which many antennas and magnets are arranged to produce an unfocused plasma cloud or beam that can come into contact with the process surface or target. It may be that the plasma is magnetized to an appropriate level and the magnetic field is oriented relative to the antenna such that the RF power applied by the antenna propagates over a much larger spatial range than is typical in other plasma generating systems. It has been surprisingly found that the plasma of embodiments of the present invention can be manipulated with magnetic field strengths as low as 4.8 gauss, which is orders of magnitude less than the operating range of the prior art (50-200 gauss). Manipulating the plasma by using much lower magnetic field strengths allows multiple plasma sources to be used within a single process chamber without harmful or unintended cross-interference of the plasma sources, thereby allowing multiple simultaneous plasma processes to be performed in the same process chamber.

In an example, the plasma is shaped by one or more magnets. In an example, there is a single plasma source (i.e., a reactive ion source) that generates the plasma sheet. In such a case, the plasma may have a substantially uniform density along the entire length of the antenna. This is in contrast to prior art multi-antenna inductively coupled plasmas, which require multiple tuned antennas and magnets for wide area plasma processing.

The reactive ion source optionally further comprises a rotatable mounting means. The rotatable mounting arrangement allows the reactive ion source to be rotatably mounted within the sputter deposition system. The reactive ion source may be configured to be rotatably mounted within the sputter deposition system.

The source of reactive ions may be rotated to allow the outlet to be oriented toward the surface of a substrate disposed in the sputter deposition chamber. This allows for a higher density of reactive ions closer to the substrate. This is particularly important during reactive sputtering of materials, which require a sufficient amount of reactive ions to form. An example of one such material is lithium phosphorus oxynitride ("LiPON"). In this example, the sputter deposition ion source will use nitrogen as the reactive gas. The quality of LiPON films formed as thin films by reactive sputtering processes depends on the availability of reactive nitrogen ions that coordinate to the film structure as it is formed. In fact, when forming a high quality film, the aim is to form as many bonds as possible between the nitrogen ions and the phosphate groups of the sputtered material. Therefore, the higher the density of the reactive nitrogen ions near the substrate, the higher the probability of forming bonds and, therefore, the higher the quality of the formed film.

A reactive ion source can additionally or alternatively be used in the ion implantation apparatus. The ability of the reactive ion source to rotate may allow it to be used alternatively or additionally as an ion implantation device. Ion implantation is a low temperature process by which ions of an element are accelerated into a solid target (which may be a substrate and/or a layer of material deposited onto the substrate), thereby changing the physical, chemical or electrical properties of the target. Ion implantation is particularly useful in preparing the surface of a deposited layer of a thin film device so that the surface of the deposited layer provides a high quality interface to any subsequently deposited material layers. In use, the source of reactive ions optionally acts as a source of reactive ions during deposition, but also acts as an ion implantation device during or before/after deposition. An apparatus capable of performing both functions advantageously saves space in any sputter deposition chamber in which it is located when compared to a sputter deposition system having both a reactive ion source and an ion implantation apparatus. In the case where the reactive ion source is used as an ion implantation device, electrons may be removed from the plasma before it passes through the outlet, so that only positively charged reactive ions exit the outlet.

Preferably, in use, the source of reactive ions may have an ionization efficiency of at least 40%. Ionization efficiency is defined as the percentage of inert gas molecules that are converted into reactive ions by the device. The inert gas molecules are optionally split into atoms before being converted into reactive ions. The ionization efficiency is optionally at least 60%, and preferably at least 70%.

The ionization efficiency is optionally substantially 99%. The ionization efficiency is optionally substantially 100%.

The source of reactive ions may be a source of ultrapure ions. The source of ultrapure ions has very small amounts of contaminants present therein. Ion sources with very high ionization efficiency typically generate a reactive ion volume in which very small amounts of contaminants are present. The contaminant may be, for example, a stable, unionized diatomic gas.

When a particularly pure source of reactive ions is required, it is important to have a high ionization efficiency. For example, there are two common problems in the deposition of lithium phosphorus oxynitride "LiPON" using reactive sputtering techniques. The first problem is that the reactive ion density near the surface of the substrate/deposited film is not high enough to incorporate a sufficient amount of nitrogen ions into the atomic structure formed. This results in not all deposited films being formed as LiPON. A second problem caused by the relatively low purity of the source of reactive ions during LiPON production is that diatomic N is formed as the material is formed₂Is injected or otherwise incorporated into the surface of the material. Diatomic N₂The implantation or inclusion of (a) disrupts the atomic structure of the formed LiPON and results in a low quality film with a large number of structural and atomic defects.

The reactive ion source may also be applied to coating processes based on Plasma Enhanced Chemical Vapor Deposition (PECVD) techniques.

The reactive ion source may also be used as a "plasma-assisted" tool for other coating processes, such as are commonly used in evaporative coating process tools.

The source of reactive ions may also be used for plasma etching, and may be used for reactive ion etching or inductively coupled etching. In this regard, the reaction gas may include any one of methane, hydrogen, fluorine, chlorine, or sulfur hexafluoride.

According to a third aspect of the present invention there is provided a method of manufacturing a layer of material, the method comprising:

generating and maintaining a plasma comprising reactive ions from the source of reactive ions of the first or second aspect of the invention in the gaseous medium of the sputter deposition chamber, remote from the one or more sputter targets of material;

generating sputtered material from one or more targets using the plasma; and is

The sputtered material is deposited on a substrate, thereby forming a layer of material on the substrate.

It will be appreciated that the method of the third aspect of the invention optionally incorporates the use of the apparatus of the first or second aspects of the invention. Any feature relating to the first/second aspect of the invention is also optionally applicable to and/or relevant to the third aspect of the invention.

The target may be lithium phosphate (Li)₃PO₄). The target may alternatively be a combination of an elemental lithium target and one or more composite targets. The target assembly may include multiple targets with different regions of lithium and/or phosphorous containing compounds, elemental lithium and/or lithium oxide. In other examples, the deposition additionally occurs in a reactive oxygen atmosphere.

The reaction gas may be nitrogen. Nitrogen gas may be introduced through the inlet such that a plasma including reactive nitrogen ions is formed. The plasma may be used to deposit nitride films, such as for depositing LiPON.

As mentioned above, the term reactant gas refers to a gas that is ionized as part of a deposition process to produce reactant ions. Therefore, there may be a case where the reaction gas is an inert gas. The reactive gas may be a diatomic gas. For example, oxygen gas may be introduced into the sputtering process to deposit an oxide film, such as aluminum oxide by sputtering an aluminum target in the presence of oxygen gas, or silicon dioxide by sputtering a silicon target in the presence of oxygen gas.

The substrate may be a polymer substrate, such as PEN or PET. The substrate may be particularly suitable for roll-to-roll and/or "web handling" applications.

The substrate may have a thickness of from 0.1 to 10 μm. The deposit thus formed on the surface/substrate may have a thickness of from 0.001 to 10 μm. The step of sputtering material onto the surface may be performed such that at any given time, at any time, there is 1cm²The maximum temperature reached on an area of square base material (measured on the surface opposite to the one on which the material is deposited and averaged over a period of 1 second) does not exceed 500 degrees celsius.

The temperature of the substrate optionally does not exceed 200 ℃ at any point in time throughout the deposition process.

According to a fourth aspect of the present invention, there is provided a method of manufacturing a layer of material, the method comprising:

generating and sustaining a plasma comprising reactive ions in a gaseous medium of a sputter deposition chamber, away from one or more sputter targets of material;

accelerating at least some of the ions of the plasma through an outlet;

generating sputtered material from one or more targets by a plasma; and

the sputtered material is deposited on the substrate, thereby forming a layer of material on the substrate that includes a chemistry of reactive ions.

It will be appreciated that the method of the fourth aspect of the invention optionally incorporates the use of a source of reactive ions according to the first or second aspects of the invention. Any feature relating to the first/second aspect of the invention is also optionally applicable to and/or relevant to the fourth aspect of the invention.

The generation of sputtered material from the target by the plasma may be performed by the plasma originating from a plasma source providing reactive ions to the chamber. Alternatively, the generation of sputtered material may be performed by a plasma originating from a separate second plasma source. The second plasma source may be at a remote plasma source. The second plasma source may be provided with a process gas, such as Ar. The second plasma source may provide a plasma that primarily includes process ions (e.g., Ar + ions) that do not chemically react with the reactive ions in the sputtered material or chamber.

The exit may comprise an aperture and the acceleration of the ions may be caused by applying an electric charge to the aperture. This generates an electric field. The charged pores may be positively or negatively charged. The method may include generating an electric field that accelerates the ions.

The charged holes have the effect of accelerating ions away from the outlet. When reactive ions are used in a sputter deposition process, the reactive ions may lose their relative directionality or geometry due to the low vacuum in the sputter deposition chamber, resulting in the reactive ions being dispersed throughout the sputter deposition chamber. This allows a directed stream of reactive ions, or a particular geometry of reactive ions (e.g., a reactive ion plume), to propagate over a longer distance in the sputter deposition chamber before dispersing and losing its relative directionality or geometry.

Accelerating the ions through the outlet may be caused by applying a positive charge to a housing that substantially surrounds the antenna that generates the plasma.

A positive charge applied to the housing may accelerate the reactive ions through the outlet. As mentioned above, it is believed that the plasma potential increases so that the reactive ions exit the enclosure through the outlet are energetically favorable, and this increase in plasma potential can provide an accelerating voltage to the ions as they exit the chamber. Acceleration of ions may occur due to ions having an elevated plasma potential entering a sheath in front of a grounded object (which may be, for example, a grounded substrate).

Preferably, the remotely generated plasma has a substantially sheet-like profile and shape. In such a case, the plasma may have a substantially uniform density along its entire profile. As the plasma exits the outlet, it may take the form of a directional plume. The plasma plume or sheet may maintain its directionality and/or its geometry over a length within the sputter deposition chamber.

The distance at which the plasma plume or sheet maintains its directionality and/or geometry may be at least 1cm, optionally at least 2cm, and optionally at least 3 cm.

The plasma exiting the outlet may be referred to as a remotely generated plasma. The remotely generated plasma may or may not have high energy.

The remotely generated plasma may have a high density. In this regard, the plasma may have a plasma density of at least 10¹¹cm^-3The ion density of (a). The remotely generated plasma may have a high density. In this regard, the plasma may have a plasma density of at least 10¹⁴cm^-3The ion density of (a).

The outlet may optionally be disposed substantially adjacent to the substrate. The outlet is preferably less than 3cm from the substrate, preferably less than 2cm from the substrate, and preferably less than 1cm from the substrate. Positioning the outlet close to the substrate in this manner results in the formation of a high density plasma close to the substrate.

Preferably, the ions in the plasma pass through the outlet with sufficient velocity so that they can be used for ion implantation. The velocity sufficient for ion implantation may be that of ions with energies significantly greater than 1 keV. The step of removing electrons from the generated plasma may be performed such that only positive ions exit the outlet. Alternatively, electrons in the plasma may be removed after the plasma passes through the outlet.

Positioning the outlet proximate the substrate optionally allows ions in the plasma accelerated through the outlet to be used for ion implantation (ion implantation was previously discussed in relation to the first aspect of the invention). Ion implantation requires relatively high velocity ions. The velocity of the ions as they exit the exit is relatively high and remains high over distances on the order of a few centimeters in length.

Alternatively, the outlet may be provided at a position remote from the substrate. This causes the plume of reactive ions to disperse to some extent within the sputter deposition chamber to generate a plasma cloud or beam. The plasma cloud or beam may optionally be in contact with a process surface or target.

The method optionally includes the step of rotating the outlet. The outlet may be rotatably mounted to and/or otherwise rotatable relative to the surface of the substrate. Without wishing to be bound by theory, it is believed that for most materials, the depth of ion implantation into the material varies depending on the angle of incidence of the reactive ion source with respect to the surface of the material. The ability to rotate the outlet relative to the substrate allows the ion implantation to be adjusted to a desired implantation depth for different materials, which may be part of the substrate or previously deposited onto the substrate. This advantageously allows the composition of the material (i.e. how many ions are introduced) to be adjusted at different depths, as well as modifying the atomic structure and/or atomic ordering of the material itself. This is particularly advantageous as a technique for preparing a surface of a material for depositing another material onto said surface. It is also particularly useful for modifying materials having a high surface area to volume ratio, such as films. Ion implantation is therefore of particular application to multilayer thin film devices, such as solid state batteries.

The outlet may comprise suitable equipment such that an ion beam is formed as the plasma passes through the outlet. Such suitable equipment may include an accelerator grid, a screen grid, a neutralizer and/or one or more electromagnetic lenses.

The outlet may be translatably mounted relative to the surface of the substrate. This allows the outlet to be rastered or scanned over the surface of the substrate. This advantageously allows substrates of different sizes and shapes to be used with the same source of reactant ions.

The material sputtered from the target optionally passes through a remotely generated plasma (e.g., plasma sheet, cloud, beam) before being deposited onto the substrate.

The outlet is optionally disposed substantially transverse to the substrate. Positioning the outlet substantially transverse or otherwise perpendicular to the substrate results in a plume or sheet of plasma propagating over substantially the entire contour of the surface area of the substrate. This helps ensure that the deposition material is continuously formed over the entire surface area of the substrate.

According to a fifth aspect of the present invention, there is provided a method of manufacturing a layer of electrolyte material for a solid state battery, the method comprising:

generating and maintaining a plasma comprising reactive nitrogen ions in a gaseous medium of a sputter deposition chamber away from one or more material sputtering targets, wherein the one or more targets comprise a compound or element of lithium,

generating sputtered material from one or more targets using the plasma; and is

The sputtered material is deposited on a substrate, thereby forming a layer of material including nitrogen and lithium on the substrate.

The generated plasma may comprise at least 50% ionized material. In an example, the generated plasma is a particularly highly ionized plasma comprising a high percentage, e.g. at least 70%, of ionized material. The percentage refers to the proportion of neutral particles that are ionized into charged particles. Pure plasmas typically have such a high percentage of ionized material. Applicants have found that remotely generated plasmas are particularly useful in generating pure plasmas of reactive ions (e.g., nitrogen). Providing a pure source of reactive ions is particularly important when depositing lithium phosphorus oxynitride "LiPON" using reactive sputtering techniques. In the deposition of LiPON, embodiments of the present invention are particularly able to address two issues. The first problem is that the reactive ion density near the surface of the substrate/deposited film is not high enough to incorporate a sufficient amount of nitrogen ions into the atomic structure formed. This results in not all of the deposited films being LiPON. A second problem caused by conventional relatively low purity sources of reactant ions during LiPON generation is the atomic N as the material is formed₂Is injected into the surface of the material. N of an atom₂The implantation of (a) destroys the atomic structure of the formed LiPON and results in lower quality films with a large number of structural and atomic defects. Remotely generated plasma comprising a high percentage of reactive nitrogen ions (and thus being very pure) has proven to help alleviate these aforementioned problems and allow rapid deposition of high quality LiPON films using reactive sputtering processes.

The generation of the plasma may result in the gaseous medium of the chamber being substantially free of diatomic N₂(i.e. less than 1%, and optionally less than 0.1% of the nitrogen atoms in the gaseous medium of the chamber in this state).

According to a sixth aspect of the invention there is provided a method of manufacturing a solid state battery half cell, the method comprising:

making a battery cathode, and

forming an electrolyte on the battery cathode using the method of any of the third, fourth or fifth aspects of the invention.

The cathode is optionally an alkali metal-containing compound, such as LiCoO₂(lithium cobalt oxide). The method can include generating a plasma away from one or more targets (e.g., elemental lithium or cobalt targets, or ceramic targets of lithium and/or cobalt) comprising a target material; one or more plasma targets are exposed to a plasma, thereby generating sputtered material from the one or more targets, optionally in a reactive atmosphere including a reactive gas (e.g., oxygen), thereby forming a battery cathode. The same equipment used to form any reactive ions (e.g., nitrogen ions) required during deposition of the electrolyte, if used under reactive sputtering conditions, can be used to generate any reactive ions (e.g., oxygen ions) required during deposition of the cathode. The apparatus may be a source of the reactive ions of the first or second aspect of the invention.

According to a seventh aspect of the invention there is provided a cathode half cell manufactured according to the method of the sixth aspect of the invention.

According to an eighth aspect of the present invention, there is provided a method of manufacturing a solid state battery cell, the method comprising:

fabricating a cathode half-cell according to the sixth aspect of the invention; and the number of the first and second groups,

the cathode half cell is contacted with an anode or an anode forming material is deposited on the electrolyte.

According to a ninth aspect of the invention, there is provided a solid state battery cell manufactured according to the method of the eighth aspect of the invention.

It will of course be appreciated that features described in relation to one aspect of the invention may be incorporated into other aspects of the invention. For example, the method of the invention may incorporate any feature described with reference to any other method of the invention, and vice versa.

Drawings

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings, which may be briefly summarized as follows:

FIG. 1a is a schematic side view of a plasma deposition process apparatus, in which examples of first and second aspects of the invention are shown;

FIG. 1b is a schematic side view of another example of the first and second aspects of the present invention;

FIG. 1c shows a plan view of an antenna of an exemplary remote plasma generation based reactive ion source of the present invention;

FIG. 1d shows a perspective view of an exemplary plasma generation based reactive ion source of the present invention;

fig. 2 shows a remote ion source similar to that shown in fig. 1a to 1d, wherein the antenna further comprises a shielding member;

fig. 3 shows a remote ion source similar to that shown in fig. 1a to 1d and fig. 2, wherein the antenna further comprises a focusing member;

fig. 4 shows a remote plasma ion source 406 similar to that shown in fig. 1a to 1d, fig. 2 and fig. 3, wherein the remote plasma ion source is rotatable;

fig. 5 shows a remote plasma ion source 406 similar to that shown in fig. 1a to 1d, fig. 2 and 3, and fig. 4, wherein the remote plasma ion source is translatable;

FIG. 6 is a schematic diagram of an example of a method of fabricating a layer of material according to a third aspect of the invention;

FIG. 7 is a schematic view of an example of a method of fabricating a layer of material according to a fourth aspect of the invention;

fig. 8 is a schematic view of an example of a method of manufacturing an electrolyte material layer for a solid-state battery according to a fifth aspect of the invention;

fig. 9 is a schematic diagram of an example of a method of manufacturing a half-cell of a solid-state battery according to a sixth aspect of the invention;

fig. 10 is a schematic view of an example of a cathode half-cell manufactured according to a method of the sixth aspect of the invention, the cathode half-cell so manufactured being an example according to the seventh aspect of the invention;

fig. 11 is a schematic view of an example of a method of manufacturing a solid-state battery cell according to an eighth aspect of the invention;

fig. 12a is a schematic view of an example of a solid state battery cell manufactured according to a method of an eighth aspect of the invention, the solid state battery cell so manufactured being an example according to a ninth aspect of the invention; and is

Fig. 12b is a schematic view of another example of a solid-state battery cell manufactured according to the method of the eighth aspect of the invention, and the solid-state battery cell thus manufactured is an example according to the ninth aspect of the invention.

Detailed Description

Reference in the specification to "an example" (or "an embodiment" or similar language) means that a particular feature, structure, or characteristic described in connection with the example is included in at least one example, but not necessarily in other examples. It should also be noted that certain examples are schematically depicted, where certain features are omitted and/or have to be simplified in order to facilitate explanation and understanding of concepts behind the examples.

Fig. 1a is a schematic side view of a plasma deposition process apparatus 100. Within the plasma deposition apparatus, examples of the first and second aspects of the invention are shown. In some examples of the invention, the example apparatus may be an apparatus for use in the example methods of the invention.

The apparatus 100 may be considered as an example of a plasma reactor. The apparatus 100 can be used for plasma-based sputter deposition for a variety of industrial applications, such as those that can be used for thin film deposition, such as 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. Thus, while the context of the present disclosure may in some cases relate to the production of an energy storage device or portion thereof, it should be understood that the apparatus 100 and methods described herein are not limited to the production thereof. The components of the apparatus shown in figure 1 may be housed within the same process chamber 113, the process chamber 113 housing a relatively large volume space 122. The process chamber 113 may be pumped down to a suitable pressure (e.g., less than 1x 10) by a pumping system (not shown)^-5Torr) and, in use, a process or sputtering gas (e.g., argon) may be introducedGas or nitrogen) is introduced into the process chamber 113 to an extent such that a pressure suitable for sputter deposition is achieved (e.g., 3x 10)^-3Tray).

Referring to fig. 1a, a plasma deposition process apparatus is generally designated by reference numeral 100 and includes a plasma target assembly 102, the plasma target assembly 102 including a target 104, a remote plasma generation based reactive ion source 106, a series of magnets 108 for confining the plasma generated by the remote plasma generator 106, a target power supply 110, a remote plasma source power supply 112, and a housing 118. The remote plasma generation based reactive ion source 106 includes two pairs of Radio Frequency (RF) antennas 116 located inside a quartz tube 117. The sputter deposition chamber 113 includes a vacuum outlet 120 connected to a series of vacuum pumps located outside the chamber so that a chamber volume 122 defined by the sputter deposition chamber 113 can be evacuated. The sputter deposition chamber 113 is also provided with a gas inlet 124, which gas inlet 124 may be connected to a gas supply (not shown) for introducing one or more gases into the chamber volume 122. In other examples, the gas inlet 124 may be disposed above the surface of the target assembly 102. As can be seen from fig. 1a, the plasma is generated away from the target 104. As such, the plasma may be described as remotely generating the plasma.

In the example of the reactive ion source 106 based on remote plasma generation shown in fig. 1a, the antenna 116 is held within a housing 118. The enclosure 118 has an inlet 126 through which gases in the sputter deposition chamber 113 and within the chamber volume 122 can flow (by diffusion and/or magnetic-based effects and gradients) into the enclosure 118 and into a plasma generation region 125 (not shown in fig. 1 a) between the antennas 116. The plasma generated by the antenna is then accelerated across the electrostatic plate 107 and exits the housing through the outlet 128. The chargeable plate 107 is formed as a hole surrounding the outlet 128. The chargeable plates have a negative bias applied to them. The applied negative bias is 500V. When the plasma leaves the housing 118, it has a substantially plume-like or sheet-like shape, depending on the shape of the outlet 128, and the shape of the outlet 128 is designed such that the plasma has a plume-like shape. The plasma is then optionally confined or further shaped by the magnet 108. The magnet 108 is remote from the housing 118. This allows the plasma exiting the outlet 128 to be shaped away from the housing 118. The magnet 108 is disposed proximate the antenna 114 and the housing 118, and the magnet 108 is capable of generating an axial magnetic field strength of from 4.8 gauss to 500 gauss when powered by a power source 11a (e.g., a dc power source) associated therewith. The magnet 108 provides a magnetic field within the process chamber volume 122 for propagating or otherwise confining or shaping the plasma generated by the reactive ion source 106 such that it extends or moves from the plasma generation region 125 and across the processing region B of the process chamber volume 122. The general shape of the confined plasma made by the remote plasma generator 106 is shown by the dashed line B in fig. 1 a. A series of magnets 108 are used to confine the plasma to a desired shape/volume.

In other examples of the invention, the chargeable plate 107 may not take the form of an aperture, but may take any other shape or form while still being proximate to the outlet. The chargeable plates 107 may have a positive bias applied to them. The applied bias may alternatively be 300V, or 400V. In other examples, the chargeable plate 107 is configured to be applied with a variable voltage, and the aperture may comprise a magnetic lens. In still other examples, the aperture includes an accelerator grid, a mesh grid, and a neutralizer such that an ion beam is formed as the plasma passes through the aperture.

Another example of the invention is shown in fig. 1 b. This example is similar to the example described in fig. 1a, but with a number of differences, which will now be briefly described. The remote plasma generation based reactive ion source 106 'is directly supplied with reactive gas through the inlet 126'. The inlets are not exposed to the sputter deposition chamber volume 122, but are fed from a gas supply system (not shown) separate from the sputter deposition chamber 113. This advantageously allows a high concentration of gas to be supplied to the remote plasma generation based reactive ion source 106'. The shell 118' is positively charged. Without wishing to be bound by theory, it is believed that the positive charge of the housing 118' causes any positive ions generated by the remote plasma source to be repelled out of the outlet by the positive charge of the housing. The gas that may be supplied through inlet 126' is substantially entirely comprised of a reactant gas, in this case nitrogen. The magnet assembly 108 'is disposed on the housing 118'. In these examples, the purpose of the magnet 108 ' is to accelerate and focus the ions of the plasma as they exit the outlet 128 ', such that the plasma of reactive ions maintains its directionality and geometry (i.e., its sheet or plume-like shape) as it exits the outlet 128 '. In this example, the magnet assembly 108' includes an electromagnet.

The target material 104 comprises a precursor material for the electrolyte layer of the energy storage device, for example a material that is ionically conductive but also electrically insulating, for example lithium phosphorus oxynitride (LiPON). The target material 104 includes LiPO (Li3PO4) as a precursor material for depositing LiPON onto the substrate 135, for example via reaction with nitrogen gas emitted from the reactive ion source 101 in the region of the target material 104. The source of reactive ions 101 is arranged to generate a plasma B. A magnetic confinement arrangement (not shown in fig. 1 a) may also be provided to control and shape the plasma generated by the plasma generating arrangement 102. The apparatus is configured to allow the generation of a plasma B of an elongated area.

Furthermore, the means 112 for powering the plasma source may be of the RF, (direct current) DC or pulsed DC type. The power applied to the antenna 144 was 5 kV.

For the avoidance of doubt, in some examples of the invention, the target 104 of the target assembly 103 does not function as a cathode when power is applied to the target assembly 103 from an RF, DC or pulsed DC power supply, wherein the source of reactive ions also functions as a source of ions for sputtering of the target 104 in a sputter deposition process.

For the avoidance of doubt, in some examples, the reactive ion source 106 based on remote plasma generation is simply used as a means of generating reactive ions. In still other examples, a remote plasma generation based reactive ion source 106 is additionally used to generate a plasma B for sputtering material from the target 104. In still other examples, an additional remote plasma generating device (not shown) is used to generate a plasma for sputtering material from the target 102.

Fig. 1c illustrates a plan view of an antenna of a remote plasma generation based reactive ion source according to some embodiments of the present invention. The plasma generation system 132 is located in the sputter deposition chamber volume 122 within the plasma generation region. The plasma-generating system 3 comprises an antenna 114 and a cover 117. The plasma generation system 132 is connected to the impedance matching network 112 and the signal generator 111. This allows the antenna to be powered to a particular frequency for more efficient plasma generation. In contrast to the prior art example of a process chamber (in which the plasma is generated within an included plasma generation system and then drawn into the process chamber), the plasma generation system 132 of this example is within and open to the sputter deposition chamber volume 122 in which the plasma is to be applied for processing by the target assembly 102 and/or substrate assembly 135. In other words, the plasma is locally generated in the atmosphere of the process chamber 122. The plasma-generating device is not sealed from the atmosphere of the process chamber 122 by a housing 118, which housing 118 is shown by a dashed outline 118. The cross-sectional length dimension L of the antenna is 400 mm. For clarity, the inlet 126 and outlet 128 of the housing 118 are not shown in FIG. 1 c.

The antenna 114 is shown as a single loop wire extending through the process chamber 113 in two

straight sections

119, 121, the two

straight sections

119, 121 being connected by a curved portion 123 outside the process chamber 113. The

straight sections

119, 121 are offset in the process chamber 113 to induce plasma ignition in the region between the

straight sections

119, 121 of the antenna 114. The antenna 114 is constructed of a formed metal tube (e.g., copper tube), but alternative conductive materials may be used, such as brass or aluminum or graphite, as well as different cross-sectional shapes, such as rods, strips, wires, or composite components. In an example of the invention, the antenna 114 is selected such that it can transmit RF frequencies in the process chamber volume 122.

A housing 127 surrounds the antenna 114 and isolates the antenna 114 from the process chamber volume 122. The housing 117 comprises an elongated tube having a defined interior space or volume. The housing 117 extends through the process chamber volume 122 such that the tube is connected to the walls of the process chamber 113. The housing 127 has suitable vacuum seals around the ends of the housing 127 and the walls of the process chamber 113 so that the interior volume is open to the atmosphere at one or both ends. The means for supporting and effecting vacuum sealing and air cooling have been omitted from the figures for the sake of clarity.

Fig. 1d illustrates a perspective view of a reactive ion source 106 based on plasma generation according to some examples of the invention. It clearly shows the plasma formation region 125 which is formed between the two

straight sections

121, 119 of the antenna, but not in the region enclosed by the housing 127. Also shown is an outlet 128 through which the plasma generated in the plasma region 125 flows 128. The plasma is accelerated by the charged holes 107 as it exits the outlet 128. The outlet has a substantially elongated shape, which can also be described as a "letter box" shape. The combination of the high density of the plasma within the housing 118, and any electrical or magnetic forces applied to the plasma, causes the plasma to exit the outlet 128 with a high degree of directionality in direction D. The plasma forms a substantially sheet-like shape (not shown) as it exits the outlet 128 in the direction D.

When reactive ions from a conventional reactive ion source are used in a conventional sputter deposition process, the reactive ions lose their relative directionality or geometry due to the low vacuum in the sputter deposition chamber, resulting in the reactive ions being dispersed throughout the sputter deposition chamber. In contrast, some examples of the invention generate a directional flow of reactive ions, or a particular geometry of reactive ions (e.g., a plume of reactive ions), that travel a longer distance in the chamber volume 122 than would otherwise be possible. The source of reactive ions is a linear ion source.

In use, the reactive ion source generates a plasma plume that can propagate over a distance D of at least 1cm and maintain its directionality and/or geometry. Even if the reaction ion source is in a vacuum degree of 10^-3Also in a mBar or stronger sputter deposition chamber.

In use, the reactive ion source is capable of producing a density greater than 10 formed in a sputter deposition chamber¹¹cm^-3Localized linear plasma.

The enclosure 118 is configured to be in fluid connection with any sputter deposition chamber volume 122 in which it is located. This allows the use of a plasma generated by the reactive ion source such that the plasma is generated and sustained in the gaseous medium surrounding it. This means that the remotely generated plasma is generated in an atmosphere within the volume of space defined by any chamber containing the sputter deposition process equipment. This is much simpler than the setup of a non-inventive reactive ion source, which requires that the remote plasma be generated in an environment separate or otherwise separated from the gaseous medium of the chamber 133 itself, as described in WO 2011131921.

In still other examples, the reactant gas is oxygen. In another example, the gas flowing through inlet 126' is a mixture of a reactant gas and an inert process gas (e.g., argon). The housing may comprise a positively charged housing 118 'and a negatively charged plate 107, or only a positively charged housing 118'. This allows such embodiments of the present invention to provide maximum acceleration of the ions as they exit the exit 128'. In some examples, the outlet 128 has a frustoconical or "nozzle" like shape. The source of reactive ions is capable of generating a reactive ion plume extending over a longer distance D of at least 3 cm. The apparatus is capable of forming and shaping a density of greater than 10 formed in a sputter deposition chamber¹⁴cm^-3Localized linear plasma.

In another example, the target 104 includes the material Li₃PO₄. In short, the chamber 122 is evacuated until a sufficiently low pressure is reached. The power provided by the power supply 112 is used to power the remote plasma generator 106 to generate the plasma. An electrical power is applied to the target 104 such that the plasma interacts with the target 104 causing Li3PO4 to be sputtered from the target 104 onto the substrate 128. In this example, the substrate 128 comprises a polymer sheet disposed in the plasma chamber 113. In other examples, the polymer sheet may enter the plasma chamber 113 through an input port and exit from an output port as part of a roll-to-roll or "web handling apparatus" (not shown). Li₃PO₄As an amorphous material onto a substrate.

Fig. 2 shows a remote ion source 203 similar to that shown in fig. 1a to 1d, wherein the antenna further comprises a shielding member. The main differences of the arrangement of fig. 2 compared to the arrangement of fig. 1a to 1d will now be described. The antenna 209 is enclosed in a quartz tube housing 210, the quartz tube housing 210 carrying a steel shield member 230 that prevents the generation of plasma. There is a single shield member 230 formed of a semi-cylinder of stainless steel material that extends approximately 180 degrees around the circumference of the antenna. Thus, in the arrangement shown in fig. 2, there is a first location 231 along the length of the antenna at which the plasma 224 is generated and a spaced apart second location 232 at which the plasma 224 is also generated. In both positions, the plasma extends around the circumference of the antenna by approximately 180 degrees without any significant influence of the magnetic/electric field from the other sources. Along the length of the antenna between the first position 231 and the second position 232, there is a third position 233, in which third position 233 the plasma is also generated approximately 180 degrees around the antenna. At each of the first, second and third positions along the length of the antenna there is also a portion of the shield member 230 which limits the generation of plasma around the other 180 degrees of the antenna. The shield member (and the region where the plasma is generated on the opposite side of the antenna from the shield member) also extends to the left of the first location 231 (as shown in fig. 2) and to the right of the second location 232 of the plasma.

It will be appreciated that, in use, other magnetic/electric field sources will be required to affect the shape and position of the plasma, particularly when the plasma generated by the antenna is confined, guided or otherwise manipulated for use in processes requiring the plasma to be present in a particular desired region remote from the plasma antenna. As such, in use, the shape and location of the plasma will be non-uniform and/or will differ from that shown in the drawings.

Fig. 3 shows a remote ion source 303 similar to that shown in fig. 1a to 1d and fig. 2, wherein the antenna further comprises a focusing member. The main differences of the arrangement of fig. 3 compared to the arrangements of fig. 1a to 1d and fig. 2 will now be described. In some examples, the reactive ion source includes a ferrite focusing member 340. A focusing member 340 is also disposed in the housing 310 and partially surrounds the length of the antenna 309.

The focusing member 340 and antenna 309 in the upper section 338A are arranged to mirror the focusing member 340 and antenna 309 in the lower section 338B, with the open sides of each of the focusing members 340 facing generally inward.

In use, the antenna 309 is driven by RF current and generates a time-varying magnetic field. The magnetic field ionizes the gas outside the enclosure and generates an inductively coupled plasma in the plasma generation region 325 between the upper segment 338A and the lower segment 338B.

The focusing members 340 each have the effect of increasing the magnetic flux density in angular regions of the antenna 309 that are not shielded from the walls of the housing 310 (i.e., not surrounded by the focusing member 310/the focusing member 310 is open). The arrangement of the two focusing members 340 thus functions to increase the magnetic flux density in the plasma generation region 325.

The focusing member 340 also has the effect of reducing the magnetic field induced in the regions above the upper segment 338A and below the lower segment 338B, so less energy is lost into these regions. The focusing member 340 thus improves the efficiency of the plasma generation system as a whole. It will be appreciated that the increase and enhancement is compared to a similar antenna assembly without the focusing member 340.

To take full advantage of the presence of the focusing member 340, the ferrite material of the focusing member 340 should preferably not be saturated by external magnetic fields (i.e., not the magnetic field generated by the antenna 309). Such an external magnetic field may be generated by a magnet 108 that confines and propagates the plasma when used in a remote plasma generator 106.

Therefore, the focusing members 340 are each provided with shielding elements (not shown in fig. 3) to shield them from such external magnetic fields. In this embodiment, the shielding element is in the form of a nickel alloy coating disposed on the outwardly facing surface of the focusing member 340. An example of a nickel-containing material that may be used is Magnetic Shield Corporation of Bensverval, Illinois, USA

And (3) alloying.

The same ferrite material as that making up the focusing member 340 forms a ferrite shield 346 that completely surrounds the antenna 309, thereby forming a shielding section of the plasma antenna assembly 338.

In other embodiments, alternative or additional shielding may be provided. For example, portions of the housing 310 may be provided with (e.g., coated with) a shielding material, and/or one or more separate shielding elements may be provided in the region between the focusing member and the magnet 108.

Fig. 4 shows a remote plasma ion source 406 similar to that shown in fig. 1a to 1d, fig. 2 and fig. 3, wherein the remote plasma ion source is rotatable. The main differences of the arrangement of fig. 4 compared to the arrangements of fig. 1a to 1d, 2 and 3 will now be described. Like parts are marked with the same reference numerals having the same last two digits. For example, inlet 426 in FIG. 4 is the same as inlet 126 in FIG. 1 a. The example of the invention shown in fig. 4 shows a remote plasma ion source 406 that may be rotated about an axis 443. This allows the plume G of ions to rotate through the angle a. Enabling the plume G to be at various angles a to the material 446 already deposited on the substrate 404 allows the ion source to be used alternatively or additionally as an ion implantation device. This is because the depth to which ions in the ion beam G can be implanted into the material 446 depends on the crystal structure (or lack thereof) of the material 446 and the angle a at which the ions are incident on the surface of the material 446. Ion implantation is a low temperature process by which ions of an element are accelerated into a solid target (which may be a substrate and/or a layer of material deposited onto the substrate), thereby changing the physical, chemical or electrical properties of the target. Ion implantation is particularly useful in preparing the surface of a deposited layer of a thin film device so that the surface of the deposited layer provides a high quality interface to any subsequently deposited material layers. In some examples, the ion source functions as a reactive ion source during deposition, but also as an ion implantation device during or before/after deposition. An apparatus capable of both of these functions advantageously saves space in any sputter deposition chamber in which it is located when compared to a sputter deposition system having both a reactive ion source and an ion implantation apparatus.

Fig. 5 shows a remote plasma ion source 506 similar to that shown in fig. 1a to 1d, fig. 2, fig. 3 and fig. 4. The main differences of the arrangement of fig. 5 compared to the arrangements of fig. 1a to 1d, fig. 2, fig. 3 and fig. 4 will now be described. Like parts are marked with the same reference numerals having the same last two digits. For example, the inlet 526 in FIG. 5 is the same as the inlet 126 in FIG. 1 a. Fig. 5 shows a remote plasma ion source 506 that is translatable in a direction 545. This allows the plume G of ions to be rasterized or otherwise translated or scanned across the surface of the material 446. Enabling the plume G to translate in this manner allows the reactive ion source to be used with substrates 504 of different shapes and sizes.

An example of a method of manufacturing a material layer according to the third aspect of the invention will now be described with reference to figure 6. The method is generally designated by reference numeral 1001 and includes generating and sustaining 1002 a plasma including reactive ions from a reactive ion source in a gaseous medium of a sputter deposition chamber, remote from one or more sputtering targets of material. The example method also includes generating 1003 sputtered material from the one or more targets using the plasma; and depositing 1004 the sputtered material on the substrate, thereby forming a material layer on the substrate.

A source of reactive ions may be used as an example of the first aspect of the invention described herein. The target was Li3PO 4. The reaction gas is nitrogen. The plasma was used to deposit LiPON films. The substrate had a thickness of 5 μm and was made of PET. The substrate is suitable for roll-to-roll or web handling applications. The area is 1cm²The maximum temperature (measured on the surface opposite to the surface on which the material is deposited, and averaged over a period of 1 second) reached at any given time for any given square base material of not more than 200 ℃.

In other examples, a reactive ion source as an example of the second aspect of the invention may be used. The substrate had a thickness of 1 μm and was made of PEN. Lithium oxide targets are used as well as targets comprising phosphorus containing compounds. In still other examples, an elemental lithium target is used and the deposition is conducted under a reactive oxygen atmosphere.

In other examples, such as other examples where the deposited material layer is alumina, the target is aluminum and the reactant gas is oxygen. In other examples, such as other examples where the deposited material layer is silicon dioxide, the target is silicon and the reactant gas is oxygen.

An example of a method of manufacturing a material layer according to the fourth aspect of the invention will now be described with reference to figure 7. The method is generally designated by reference numeral 2001 and includes generating and maintaining 2002 a plasma including reactive ions in a gaseous medium of a sputter deposition chamber, remote from one or more sputtering targets of material; accelerating 2003 at least some ions of the plasma through an outlet; generating 2004 sputtered material from one or more targets using a plasma; and depositing 2005 a sputter material on the substrate, thereby forming a layer of material including a chemistry of reactive ions on the substrate.

A source of reactive ions is used as exemplified in the first aspect of the invention. The generation of sputtered material is performed by a plasma originating from a separate second plasma source, which is a remote plasma source.

The exit comprises an aperture and acceleration of the ions may be induced by applying an electrical charge to the aperture. The charged holes have the effect of accelerating ions away from the outlet so that a directed stream of reactive ions propagates over a distance within the gaseous medium of the sputter deposition chamber. In other examples, the outlet includes an accelerator grid, a mesh grid, a neutralizer, and/or one or more electromagnetic lenses such that an ion beam is formed as the plasma passes through the outlet.

The remotely generated plasma has a substantially sheet-like profile and shape. The plasma has a substantially uniform density over its profile. The sheet maintained its directionality and geometry over a distance of 1cm (from the exit). The ion density of the remotely generated plasma is about 10¹¹cm^-3。

The outlet is positioned less than 1cm from the substrate. This results in the formation of a high density plasma near the substrate. The plasma source is provided with a process gas comprising argon. Ions in the plasma may be used for ion implantation. This is because the exit is very close to the substrate (i.e. less than 1cm from the substrate in this example) and the ions maintain their directionality and high velocity over a short distance within the volume of the sputter deposition chamber. Thus, the ions impact the surface of the substrate or material deposited on the substrate, the impact of which causes the ions to be implanted into the material they impact. The ions exit the outlet at energies greater than 1 keV.

The method further comprises the step of rotating the outlet. The outlet is rotatably mounted relative to the surface of the substrate. This allows the process to be tuned so that ions are implanted at different depths into the substrate surface (or the surface of a material deposited on the substrate). Ion implantation is described in more detail in the preceding paragraphs of the specification.

In other examples, the outlet is disposed at a location remote from the substrate. This causes a plume of reactive ions to diffuse within the sputter deposition chamber to create a plasma cloud or beam. In some examples, sputtered material from the target may pass through the beam before it is deposited on the substrate. In still other examples, the outlet is positioned transverse to the substrate such that a large area of plasma propagates over the entire surface area of the substrate.

In other examples, a reactive ion source is used as an example of the second aspect of the invention. In still other examples, a reactive ion source is used which is not part of the first or second aspects of the invention and the generation of sputtered material is performed by a plasma derived from a plasma source which is not a remote plasma source. In still other examples, sputtering of the target is performed by a plasma derived from a plasma source that provides reactive ions into the chamber. The outlet is translatably mounted with respect to the base. In the overall method of manufacturing the cathode layer, the outlet is rasterized or scanned over the outlet. This allows the use of substrates of different sizes and shapes. In other examples, the acceleration of ions through the outlet is caused by applying a positive charge to a housing surrounding the antenna that generates the plasma. The outlet is positioned less than 3cm from the substrate. The remotely generated plasma may have a plasma density of about 10¹⁴cm^-3Higher ion density. Electrons may be removed from the plasma before or after the plasma exits the outlet. The energy of the ions exiting the outlet may be less than 1 keV.

An example of a method of manufacturing an electrolyte material layer for a solid-state battery according to the fifth aspect of the invention will now be described with reference to fig. 8. The method is generally designated by reference numeral 3001 and includes generating and maintaining 3002 a plasma containing reactive nitrogen ions in a gaseous medium of a sputter deposition chamber, away from one or more material sputter targets, wherein the one or more targets include a compound or element of lithium; generating 3003 sputtered material from one or more targets using a plasma; and depositing 3004 a sputter material on the substrate, thereby forming a layer of material comprising nitrogen and lithium on the substrate.

The plasma produced is a particularly pure plasma comprising a very high percentage of substantially 100% ionized material (e.g., greater than 99%). This results in sufficient reactive nitrogen being present so that the deposited material layer includes nitrogen coordination bonds into the formed material. The material formed was LiPON. The number of nitrogen coordination bonds formed is the number of bonds necessary to form LiPON with the desired or optimal stoichiometric ratio. A particularly pure plasma is substantially free of (i.e., comprises less than 1%) diatomic N₂. Thus, substantially no N₂Ions are implanted into the surface of the formed material Layer (LiPON). This results in the formation of very high quality LiPON films.

An example of a method of manufacturing a solid-state battery half-cell according to a sixth aspect of the invention will now be described with reference to fig. 9. The method is generally designated by reference numeral 4001 and comprises making 4002 a battery cathode and forming 4003 an electrolyte on the battery cathode using the method of the examples of any of the third, fourth, or fifth aspects of the invention.

The cathode is LiCoO₂. Methods of making the cathode include generating a plasma away from one or more targets (e.g., elemental lithium or cobalt targets, or ceramic targets of lithium and/or cobalt) comprising a target material; one or more plasma targets are exposed to a plasma, thereby generating sputtered material from the one or more targets, optionally in a reactive atmosphere including a reactive gas (such as oxygen), thereby forming a battery cathode. The same equipment (i.e., the same source of reactant ions) is used to generate the reactant ions for forming the electrolyte and to produce the oxygen ions for forming the cathode. In other examples of the invention, the cathode is notAnd alkali metal-containing compounds thereof.

An example of a cathode half-cell according to the seventh aspect of the invention is schematically illustrated with reference to fig. 10. An exemplary cathode half-cell was fabricated using the method described with reference to fig. 9. Referring to fig. 10, a battery cathode 742 is shown on a substrate 728 (which includes a current collector layer 729). Fig. 10 additionally shows an electrolyte layer 744 deposited on top of the cell cathode 742. The material deposited for the electrolyte 744 is lithium phosphorus oxynitride (LiPON). In other examples, the deposited material is another suitable electrolyte material.

An example of a method of manufacturing a solid-state battery cell according to an eighth aspect of the invention will now be described with reference to fig. 11. The method is generally referred to by reference numeral 5001 and comprises fabricating 5002 a cathode half-cell according to the sixth aspect of the invention and contacting the cathode half-cell with an anode 5003 or depositing an anode-forming material on an electrolyte.

Referring to fig. 12a and 12b, an example of a solid state battery cell manufactured according to the ninth aspect of the invention is schematically shown. The solid-state battery cell of this example was manufactured using the method described with reference to fig. 11. Referring to fig. 12a, reference numerals 828 and 828 'are base materials, reference numerals 829 and 829' are current collector layers, reference numeral 842 is a cathode material, in this case LiCoO₂And reference numeral 844 is LiPON, which functions as both an electrolyte and an anode. Alternatively, in other examples, the current collector material serves as the anode material.

Alternatively, in the second example of the ninth aspect of the present invention, another anode material may be deposited. This is schematically shown in fig. 12 b. Referring to fig. 12b, 828 and 828 'are substrate materials, 829 and 829' are current collector layers, 842 is cathode material, in this example LiCoO ₂844 is LiPON, which acts as an electrolyte, 846 is a suitable anode material.

The above examples are to be understood as illustrative examples of the invention. 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 example, or any combination of other examples. Where in the foregoing description, integers or elements are mentioned which have known, obvious or foreseeable equivalents, then such equivalents are herein incorporated as if individually set forth. The reader will also appreciate that integers or features of the invention that are described as preferable, advantageous, convenient or the like are optional and do not limit the scope of the independent claims. Further, it should be understood that such optional integers or features, while potentially beneficial in some embodiments of the invention, may not be desirable in other embodiments and therefore may not be present. 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. A reactive ion source for a sputter deposition system, comprising:

an electrically driven antenna, wherein the antenna has a substantially elongated shape;

a housing at least partially surrounding the antenna;

an inlet for supplying a reaction gas into the housing; and

an outlet of the housing configured to enable reactive ions to pass through the outlet, wherein the antenna is configured to apply an electromagnetic field to the reactive gas such that a plasma including reactive ions is formed.

2. The source of reactant ions of claim 1, wherein the outlet comprises a substantially elongated shape.

3. The source of reactant ions of claim 1, wherein the outlet comprises an aperture configured to be supplied with an electrical charge.

4. The source of reactant ions of claim 1, wherein the housing is configured to be supplied with a positive charge.

5. The source of reactive ions of claim 1, wherein, in use, the plasma is generated and maintained in a gaseous medium surrounding it.

6. The source of reactant ions of claim 1, wherein the inlet is fluidly connected to a source of reactant gas.

7. The source of reactant ions of any preceding claim, wherein the antenna comprises a conductive shielding member.

8. The source of reactant ions according to any preceding claim, wherein the ferromagnetic or ferrimagnetic focusing member is arranged to partially surround a segment of the antenna.

9. The source of reactant ions of claim 1, wherein the source of reactant ions further comprises one or more magnets disposed separately from the antenna.

10. The reactive ion source of claim 1, wherein said reactive ion source further comprises a rotatable mounting such that said reactive ion source can be rotatably mounted within a sputter deposition system.

11. The source of reactant ions of claim 1 wherein the source of reactant ions has an ionization efficiency of at least 70% in use.

12. A method of manufacturing a layer of material, the method comprising:

generating and sustaining a plasma comprising reactive ions from a source of reactive ions according to any preceding claim, in a gaseous medium of a sputter deposition chamber, remote from one or more sputter targets of material;

generating sputtered material from the one or more targets using the plasma; and

depositing a sputtered material on a substrate, thereby forming a material layer on the substrate.

13. A method of manufacturing a layer of material, the method comprising:

accelerating at least some of the ions of the plasma through an outlet;

generating sputtered material from the one or more targets by the plasma; and is

Depositing a sputtered material on a substrate, thereby forming a layer of material on the substrate that includes a chemistry of the reactive ions.

14. The method of claim 13, wherein the outlet is optionally positioned substantially adjacent to the substrate.

15. The method of claim 13, wherein the ions pass through the outlet with sufficient velocity to enable the ions to be used for ion implantation.

16. The method of claim 13, wherein the method includes the step of rotating the outlet.

17. A method of manufacturing a layer of electrolyte material for a solid state battery, the method comprising:

depositing a sputtered material on a substrate, thereby forming a layer of material including nitrogen and lithium on the substrate.

18. A method of manufacturing a half-cell of a solid state battery, the method comprising:

manufacturing a battery cathode; and

forming an electrolyte on the battery cathode using the method of any one of claims 12 to 17.

19. A method of manufacturing a solid state battery cell, the method comprising:

fabricating a cathode half-cell according to the method of claim 18; and

contacting the cathode half cell with an anode or depositing an anode-forming material on the electrolyte.