Patent Description:
In many industries, it is desirable to deposit films onto surfaces of a substrate to provide desired characteristics to the finished coated product. For example, in the glass industry, it is often desirable to deposit films to provide characteristics to the glass related to transmittance, emissivity, reflectivity, durability, color, photocatalysis and chemical resistance.

One deposition method used to deposit films onto substrates is a sputtering method. During sputtering, a substrate is positioned within a vacuum chamber containing a rotating cylindrical target or planar target that has sputterable target material on its outer surface. An electrical field is created between the target (which acts as a cathode) and an anode in the vacuum chamber. Next, an argon gas is introduced to the vacuum chamber. Electrons in the electrical field ionize the gas atoms and create charged plasma. Sputtering occurs when plasma particles impinge on the surface of the target causing emission of sputterable target material onto a substrate.

Certain sputtering systems include magnets that create a magnetic field. Sputtering systems including magnets are often referred to as magnetron sputtering systems. The magnetic field confines the plasma within a relatively narrowly defined area along a target surface. Typically, magnets are placed behind or within the target and are arranged so that the plasma is confined at the bottom surface of the planar or cylindrical target, facing a substrate being coated directly beneath. The plasma sputters target material from this bottom surface, thereby forming a sputtering zone on the target.

In many cases, the magnets are arranged such that a sputtering zone is formed on the target surface. A problem with many previous sputtering systems is that plasma confined at certain areas tends to be denser than plasma confined at other areas. The denser the plasma, the higher the sputtering rate is of target material confined by the plasma. Thus, certain areas have denser plasma than other areas, the target material is sputtered at different rates. As a result, the target is sputtered in an uneven fashion such that the deposited film is non-uniform.

It would be desirable to provide sputtering apparatuses, systems and methods that sputter target material to deposit films having a more uniform thickness. It would also be desirable to provide sputtering apparatuses, systems and methods that provide a more uniform sputtering rate along the entire sputtering zone.

<CIT> describes a method for processing gas flow to an elongated magnetron. The method involves dividing the flow of the process gas in the case of reactive processes from a reactive gas as a first process gas supply and a working gas as a second process gas part along the racetracks in some process gas flow, with the corresponding plasma zone segments. The plasma stoichiometry is determined in each plasma zone segment for each partial process gas flow and the flow of the process gas portion per sub-process gas flow is set, so that the plasma stoichiometry of each corresponding process gas flow racetrack portion is the same. <CIT> and <CIT> both disclose a magnetron sputtering apparatus wherein gas manifolds are connected to a power supply and thereby become anodes that can assist in controlling and stabilizing the plasma.

In accordance with a first aspect of the present invention, there is provided a method of using a magnetron sputtering apparatus as set out in independent claim <NUM>. Preferred features of the first aspect of the present invention are set out in dependent claims <NUM> to <NUM>. According to a second aspect of the invention, there is provided a magnetron sputtering apparatus as set out in independent claim <NUM>. Preferred features of the magnetron sputtering apparatus of this aspect of the invention are set out in dependent claims <NUM> to <NUM>.

The following detailed description is to be read with reference to the drawings, in which like elements in different drawings have like reference numerals. Skilled artisans will recognize that the examples provided herein have many useful alternatives that fall within the scope of the invention.

The present invention relates to a new gas distribution system that helps provide a more uniform sputtering rate along a sputtering zone on a target. The gas distribution system is part of a magnetron sputtering system. <FIG> each depict a standard magnetron sputtering system <NUM> having different embodiments of the new gas distribution system. Generally, the sputtering system <NUM> includes a vacuum chamber <NUM> defining a controlled environment, a cathode assembly <NUM> including a target <NUM> having one or more sputterable target materials, and the gas distribution system <NUM>.

Sputtering techniques and equipment utilized in magnetron sputtering systems are quite well known in the present art. For example, magnetron sputtering chambers and related equipment are available commercially from a variety of sources (e.g., Grenzebach or Soleras). Examples of useful magnetron sputtering techniques and equipment are also disclosed in <CIT>, issued to Chapin.

The vacuum chamber <NUM> generally includes metallic walls, typically made of steel or stainless steel, operably assembled to form a chamber that can accommodate a vacuum in which the sputtering process may occur. A vacuum source <NUM> is operably connected to the vacuum chamber <NUM> to provide a controlled vacuum environment within the chamber <NUM>.

The vacuum chamber <NUM> comprises a substrate support <NUM> defining a path of substrate travel <NUM> extending substantially horizontally through the chamber <NUM>. Preferably, the substrate support <NUM> is configured for supporting a substrate <NUM> in a horizontal configuration (e.g., wherein a top major surface <NUM> of the substrate <NUM> is upwardly oriented while a bottom major surface <NUM> of the substrate <NUM> is downwardly oriented) while the substrate <NUM> is being coated. In the embodiments shown in <FIG>, the substrate support <NUM> comprises a plurality of spaced-apart transport rollers that rotate to convey the substrate <NUM> along the path of substrate travel <NUM>. While the illustrated substrate support <NUM> comprises a plurality of spaced-apart rollers, it is to be appreciated that other types of substrate supports can be used.

Substrates of various sizes can be used in the present invention. Commonly, large-area substrates are used. Certain embodiments involve a substrate having a length and/or width of at least <NUM> meter, preferably at least <NUM> meter, perhaps more preferably at least <NUM> meters (e.g., between <NUM> meters and <NUM> meters), and in some cases at least <NUM> meters. In some embodiments, the substrate is a jumbo glass sheet having a length and/or width that is between <NUM> meters and <NUM> meters, e.g., a glass sheet having a width of <NUM> meters and a length of <NUM> meters. Substrates having a length and/or width of greater than <NUM> meters are also anticipated.

In some embodiments, the substrate is a square or rectangular glass sheet. The substrate in these embodiments can have any of the dimensions described in the preceding paragraph and/or the following paragraph. In one embodiment, the substrate is a rectangular glass sheet having a width of between <NUM> meters and <NUM> meters, such as about <NUM> meters, and a length of between <NUM> meters and <NUM> meters, such as about <NUM> meters.

Substrates of various thicknesses can be used in the present invention. In some embodiments, the substrate (which can optionally be a glass sheet) has a thickness of <NUM>-<NUM>. Certain embodiments involve a substrate with a thickness of between <NUM> and <NUM>, and perhaps more preferably between <NUM> and <NUM>. In one particular embodiment, a sheet of glass (e.g., soda-lime glass) with a thickness of <NUM> is used.

In certain embodiments, such as those illustrated in <FIG>, the vacuum chamber <NUM> comprises a downward coating configuration adapted for coating a top major surface <NUM> of the substrate <NUM>. In such embodiments, the downward sputtering configuration comprises at least one cathode assembly <NUM> positioned above the path of substrate travel <NUM>. Additionally, the vacuum chamber <NUM> includes a gas distribution system <NUM> positioned above the path of substrate travel <NUM>.

In other embodiments (not shown), the vacuum chamber <NUM> can include an upward coating configuration adapted for coating a bottom major surface <NUM> of the substrate <NUM>. In such embodiments, the upward sputtering configuration comprises at least one lower cathode assembly <NUM> positioned beneath the path of substrate travel <NUM>. Here, the vacuum chamber <NUM> includes a lower gas distribution system <NUM> positioned beneath the path of substrate travel <NUM>. Upward sputtering systems are described in <CIT>, <CIT>, <CIT>, <CIT>, and<CIT>.

The cathode assembly <NUM> generally comprises a cylindrical target <NUM>, a motor <NUM> and a magnet assembly <NUM>. Generally, the cylindrical target <NUM> includes a tubular backing formed of electrically conductive material, such as stainless steel, aluminum or any other suitably conductive material. The outer surface of the cylindrical target <NUM> is normally coated with a sputterable target material, which is intended to be sputtered onto the substrate surface <NUM>.

Sputterable target material includes, but is not limited to, material such as silicon, zinc, tin, silver, gold, chromium, aluminum, copper, nickel, titanium, niobium or combinations thereof. Compounds of various metals, such as nickel-chromium, can be sputtered using targets made of the desired compound. Silicon can also be used as cylindrical target material, for example, by plasma spraying silicon onto a support tube. In some embodiments, the sputterable target material comprises, consists essentially of, or consists of a metallic material. In certain embodiments, the sputterable target material comprises, consists essentially of, or consists of silver.

The cathode assembly <NUM> also includes a motor <NUM> operably connected to the cylindrical target <NUM> by any clamping or bracketing means (not shown) known in the art. The clamping or bracketing device may be any type of clamp, bracket, frame, fastener or support that keeps the cylindrical target <NUM> in a stationary position and does not affect the rotation of the cylindrical target <NUM>. The motor <NUM> can be any motor known in the art (e.g., stepper motor, electric motor, hydraulic motor and/or pneumatic motor) that causes the cylindrical target <NUM> to rotate about its longitudinal axis. Although a cylindrical target <NUM> is illustrated in the figures, skilled artisans would understand that a planar target can instead be used.

The cathode assembly <NUM> further includes a magnet assembly <NUM>. The magnet assembly <NUM> includes any magnet assembly known in the art that generates a plasma confinement field adjacent a surface of the target so that a sputtering zone forms on a target surface. In some cases, the magnet assembly <NUM> is positioned within the target <NUM>. In other cases, the magnet assembly <NUM> is positioned outside the target <NUM>. The sputtering zone can have any desired shape and in the embodiments of the invention is a racetrack-shaped sputtering zone.

The magnetron sputtering system <NUM> includes a new gas distribution system <NUM> that helps provide a generally uniform sputtering rate along an entire sputtering zone. <FIG> illustrates a cylindrical target <NUM> having a general sputtering zone <NUM> on a target surface <NUM>. The sputtering zone <NUM> generally has a first area <NUM>, a second area <NUM> and a third area <NUM>. The second area <NUM> is sandwiched between the first area <NUM> and the third area <NUM>. The sputtering zone <NUM> also extends for a longitudinal distance along a longitudinal axis LA of a cylindrical target. The first area <NUM> extends longitudinally along a longitudinal distance <NUM>, the second area <NUM> extends longitudinally along a longitudinal distance <NUM> and the third area <NUM> extends longitudinally along a longitudinal distance <NUM>. The longitudinal distances <NUM>, <NUM>, <NUM> do not overlap. Likewise, the areas <NUM>, <NUM>, <NUM> do not overlap.

The first area <NUM> has a first sputtering rate, the second area <NUM> has a second sputtering rate and the third area <NUM> has a third sputtering rate when sputtered in an argon atmosphere. In some cases, the first sputtering rate is higher than the second sputtering rate. In other cases, each the first and third sputtering rate is higher than the second sputtering rate. The new gas distribution system helps to provide a more uniform sputtering rate along each of the areas <NUM>, <NUM>, <NUM>.

In some embodiments, which are embodiments of the invention, the gas distribution system <NUM> helps provide a more uniform sputtering rate along a racetrack-shaped sputtering zone <NUM>. <FIG> illustrates a cylindrical target <NUM> having a racetrack-shaped sputtering zone <NUM> on a target surface <NUM>. While a racetrack-shaped sputtering zone is illustrated in the embodiments of the invention, skilled artisans will understand that the sputtering zone can have any desired shape. The plasma confinement field generally forms a race-track shaped electron drift path on a target surface <NUM> which in turn forms the racetrack-shaped sputtering zone <NUM>. The target surface <NUM> is generally the surface that faces the substrate <NUM>. For example, in cases where the target <NUM> is an upper target, the target surface <NUM> is a bottom surface that faces a substrate beneath. In cases where the target <NUM> is a lower target, the target surface <NUM> is an upper surface that faces a substrate above. The cylindrical target <NUM> rotates during sputtering so that its outer circumference of sputterable target material rotates through the racetrack-shaped sputtering zone <NUM>.

The racetrack-shaped sputtering zone <NUM> generally includes two turnaround areas <NUM>, <NUM> and two straightaway areas <NUM>, <NUM>. In particular, the racetrack-shaped sputtering zone <NUM> includes a first turnaround area <NUM>, a first straightaway area <NUM>, a second turnaround area <NUM> and a second straightaway area <NUM>. Also, the first straightaway area <NUM> (or the second straightaway area <NUM>) is sandwiched between the first turnaround area <NUM> and the second turnaround area <NUM>. The racetrack-shaped sputtering zone <NUM> also extends for a longitudinal distance along a longitudinal axis LA of a cylindrical target. The racetrack-shaped sputtering zone <NUM> includes a first turnaround area <NUM> that extends longitudinally along a longitudinal distance <NUM>, a first straightaway area <NUM> that extends longitudinally along a longitudinal distance <NUM>, a second turnaround area <NUM> that extends longitudinally along a longitudinal distance <NUM> and a second straightaway area <NUM> that extends longitudinally along a longitudinal distance <NUM>. In some cases, the two turnaround areas <NUM>, <NUM> have a first sputtering rate and the two straightaway areas <NUM>, <NUM> have a second sputtering rate when sputtered in an argon atmosphere wherein the first sputtering rate is higher than the second sputtering rate. The new gas distribution system <NUM> helps to even out the sputtering rates between the two turnaround areas <NUM>, <NUM> and the two straightaway areas <NUM>, <NUM>.

In certain embodiments compatible with the invention, the gas distribution system <NUM> provides new arrangements of interfaces that each supply a particular gas mixture to a localized area on the sputtering zone. The gas mixture is selected to control the sputtering rate along that localized area. Generally, the gas distribution system <NUM> includes at least a first interface and a second interface. The first interface is positioned to supply gas to a first localized area whereas the second interface is positioned to supply gas to a second localized area. A first gas mixture is supplied to the first interface and a second gas mixture is supplied to the second interface. The first gas mixture and the second gas mixture are selected such that the sputtering rate along the two localized areas are more uniform.

In some embodiments compatible with the invention, the first gas mixture includes inert gas "y" having a first atomic weight and the second gas mixture includes inert gas "x" having a second atomic weight, wherein the first atomic weight is different from the second atomic weight. In some cases, the second atomic weight is heavier than the first atomic weight. A gas mixture with a heavier atomic weight is supplied to a localized area where it is desired to increase the sputtering rate relative to another localized area. Likewise, a gas mixture with a lighter atomic weight is supplied to a localized area where it is desired to decrease the sputtering rate relative to another localized area. Argon is a standard sputtering gas and has an atomic weight of <NUM>. Helium is a lighter gas than argon and has an atomic weight of <NUM>. Krypton is a heavier gas than argon and has an atomic weight of <NUM>.

In certain embodiments compatible with the invention, the plurality of interfaces <NUM> includes at least a first interface, a second interface and a third interface. In some cases, the third interface is sandwiched between the first interface and the second interface. A first gas mixture is supplied to the first interface, a second gas mixture is supplied to the second interface and a third gas mixture is supplied to the third interface. Again, the three gas mixtures are selected such that the sputtering rates along the three localized areas are more uniform. Some embodiments above describe a first interface and a second interface or a first interface, a second interface and a third interface. Each the first interface, the second interface and the third interface in these embodiments can comprise a single interface or a plurality of interfaces or a set of interfaces.

In some embodiments compatible with the invention, the first gas mixture includes inert gas "y" having a first atomic weight, the second gas mixture includes inert gas "x" having a second atomic weight, and the third gas mixture includes inert gas "z" having a third atomic weight. In some cases, each the first atomic weight, the second atomic weight and the third atomic weight are different. In certain cases, the second atomic weight is heavier than the first atomic weight and the third atomic weight is heavier than the first atomic weight but is lighter than the second atomic weight.

In some cases, the plurality of interfaces are arranged to supply gas to a racetrack-shaped sputtering zone on the target. Referring back to the racetrack-shaped sputtering zone <NUM> of <FIG>, the racetrack-shaped sputtering zone <NUM> extends for a longitudinal distance along a longitudinal axis LA of a cylindrical target and includes a first turnaround area <NUM>, a first straightaway area <NUM>, a second turnaround area <NUM> and a second straightaway area <NUM>.

In some cases, the gas distribution system <NUM> has a first interface positioned along either the first turnaround area <NUM> or the second turnaround area <NUM> and a second interface positioned along either the first straightaway area <NUM> or the second straightaway area <NUM>. Traditionally, the turnaround areas <NUM>, <NUM> have a faster sputtering rate in an argon atmosphere than the straightaway areas <NUM>, <NUM>. In order to make the sputtering rate across all these areas more uniform, the first interface can supply a gas mixture including an inert gas "y" having a lighter atomic weight and the second interface can supply a gas mixture including an inert gas "x" with a heavier atomic weight. When the gas mixture supplied to a turnaround area <NUM>, <NUM> has lighter atomic weight that the gas mixture supplied to the straightaway areas <NUM>, <NUM>, the sputtering rate becomes more uniform across each of these areas.

In other cases, the gas distribution system <NUM> has a first interface positioned along either the first turnaround area <NUM> or the second turnaround area <NUM>, a second interface positioned along either the first straightaway area <NUM> or the second straightaway area <NUM> and a third interface that is sandwiched between the first interface and the second interface. In this embodiment, the third interface can serve as an intermediate or transitional interface that supplies a gas mixture including an inert gas "z" having a third atomic weight that is heavier than the first atomic weight but lighter than the second atomic weight.

In some embodiments compatible with the invention, the first gas mixture includes a single inert gas selected from the group consisting of argon, helium neon, krypton, xenon and radon and the first atomic weight is an atomic weight of the single inert gas and/or the second gas mixture includes a single inert gas selected from the group consisting of argon, helium neon, krypton, xenon and radon and the second atomic weight is an atomic weight of the single inert gas and/or the third gas mixture includes a single inert gas selected from the group consisting of argon, helium neon, krypton, xenon and radon and the third atomic weight is an atomic weight of the single inert gas.

In other embodiments compatible with the invention, the first gas mixture includes an inert gas mixture including two or more inert gases selected from the group consisting of argon, helium neon, krypton, xenon and radon and the first atomic weight is an average atomic weight of the two or more inert gases and/or the second gas mixture includes an inert gas mixture including two or more inert gases selected from the group consisting of argon, helium neon, krypton, xenon and radon and the second atomic weight is an average atomic weight of the two or more inert gases and/or the third gas mixture includes an inert gas mixture including two or more inert gases selected from the group consisting of argon, helium neon, krypton, xenon and radon and the third atomic weight is an average atomic weight of the two or more inert gases. In some cases, the first gas mixture includes a reactive gas in addition to the inert gas and/or the second gas mixture includes a reactive gas in addition to the inert gas and/or the third gas mixture includes a reactive gas in addition to the inert gas.

<FIG> illustrate schematics of exemplary gas distribution systems <NUM> having a plurality of interfaces <NUM> with different arrangements. These schematics are not to scale and are intended to illustrate general concepts. The embodiments of <FIG> and <FIG> contemplate the use of a single gas source <NUM>. The single gas source <NUM> houses separate gas sources that supply different gas mixtures. The embodiments of <FIG> and <FIG> contemplate the use of a first gas source 60a and a second gas source 60b. Here, each of the gas sources 60a, 60b houses separate gas sources that supply different gas mixtures. These different embodiments are intended to show that any number of gas sources or arrangement of gas sources can be used to supply the gas mixtures "y," "x," and optically "z" to the interfaces <NUM> using any desired pipe system known in the art.

The embodiments of <FIG> include gas distribution systems <NUM> that have at least a first interface and at least a second interface, wherein the first interface is supplied with first gas mixture including an inert gas "y" and the second interface is supplied with a second gas mixture including an inert gas "x. " In some cases, both the first gas mixture and the second gas mixture are supplied at the same or substantially the same pressure. Likewise, in some embodiments of the invention, both the first gas mixture and the second gas mixture are free of or substantially free of a reactive gas.

The embodiments of <FIG> include gas distribution systems <NUM> that have at least a first interface, at least a second interface and at least a third interface, wherein the first interface is supplied with first gas mixture including an inert gas "y," the second interface is supplied with a second gas mixture including an inert gas "x" and the third interface is supplied with a third gas mixture including an inert gas "z. " In some cases, the first gas mixture, the second gas mixture and the third gas mixture are supplied at the same or substantially the same pressure. Likewise, in some embodiments compatible with the invention, the first gas mixture, the second gas mixture and the third gas mixture are free of or substantially free of a reactive gas.

Each of the interface arrangements shown in <FIG> will now be described in more detail. <FIG> and <FIG> illustrate a gas distribution system <NUM> that includes a plurality of interfaces <NUM> that extend along a longitudinal axis LA of a target having a racetrack-shaped sputtering zone. The plurality of interfaces <NUM> are arranged along each side of the sputtering target. Each side includes first interfaces 62a and second interfaces 62b. In particular, on each side, the first interfaces 62a are provided as outermost interfaces that sandwich a plurality of second interfaces 62b. The first interfaces 62a are positioned to supply a first gas mixture including an inert gas "y" to the turnaround areas <NUM>, <NUM> of the racetrack-shaped sputtering zone. The second interfaces 62b are positioned supply a second gas mixture including an inert gas "x" to the straightaway areas <NUM>, <NUM> of the racetrack-shaped sputtering zone. For example, the first interfaces 62a can be positioned adjacent the first turnaround area <NUM> along a longitudinal distance <NUM> and/or adjacent the second turnaround area <NUM> along a longitudinal distance <NUM>. Also, the second interfaces 62b can be positioned adjacent the first straightaway area <NUM> and/or the second straightaway area <NUM> along a longitudinal distance <NUM>.

<FIG> and <FIG> illustrates a gas distribution system <NUM> that includes a plurality of interfaces <NUM> that extend along a longitudinal axis LA of a target having a racetrack-shaped sputtering zone. The plurality of interfaces <NUM> are arranged to substantially entirely surround the target. In fact, in some cases, the plurality of interfaces <NUM> are also arranged as a racetrack shape that substantially entirely surrounds the racetrack-shaped sputtering zone <NUM>. Again, the first interfaces 62a are positioned to supply a first gas mixture including an inert gas "y" to the turnaround areas <NUM>, <NUM> of the racetrack-shaped sputtering zone and the second interfaces 62b are positioned to supply a second gas mixture including an inert gas "x" to the straightaway areas <NUM>, <NUM> of the racetrack-shaped sputtering zone. Here too, the first interfaces 62a can be positioned adjacent to (e.g., by substantially surrounding) the first turnaround area <NUM> along a longitudinal distance <NUM> and/or adjacent to (e.g., by substantially surrounding) the second turnaround area <NUM> along a longitudinal distance <NUM>. Also, the second interfaces 62b can be positioned adjacent the first straightaway area <NUM> and/or the second straightaway area <NUM> along a longitudinal distance <NUM>.

<FIG> and <FIG> illustrates a gas distribution system <NUM> that includes a plurality of interfaces <NUM> that extend along a longitudinal axis LA of a target having a racetrack-shaped sputtering zone. The plurality of interfaces <NUM> are arranged along each side of the sputtering target. Each side of interfaces <NUM> also partially surrounds ends of the target. Again, the first interfaces 62a are positioned to supply a first gas mixture including an inert gas "y" to the turnaround areas <NUM>, <NUM> of the racetrack-shaped sputtering zone and the second interfaces 62b are positioned to supply a second gas mixture including an inert gas "x" to the straightaway areas <NUM>, <NUM> of the racetrack-shaped sputtering zone. Also, the first interfaces 62a can be positioned adjacent to (e.g., by partially surrounding) the first turnaround area <NUM> along a longitudinal distance <NUM> and/or adjacent to (e.g., by partially surrounding) the second turnaround area <NUM> along a longitudinal distance <NUM>. Also, the second interfaces 62b can be positioned adjacent the first straightaway area <NUM> and/or the second straightaway area <NUM> along a longitudinal distance <NUM>.

<FIG> and <FIG> illustrate a gas distribution system <NUM> that includes a plurality of interfaces <NUM> that extend along a longitudinal axis LA of a target having a racetrack-shaped sputtering zone. The plurality of interfaces <NUM> are arranged along each side of the sputtering target. Each side includes first interfaces 62a, second interfaces 62b and third interfaces 62c. Each third interface <NUM> is sandwiched between a first interface 62a and a plurality of second interfaces 62b and thus serves as an intermediate or transitional interface. In particular, on each side, first interfaces 62a are provided as outermost interfaces that sandwich an intermediate interface 62c and a plurality of second interfaces 62b. The first interfaces 62a are positioned to supply a first gas mixture including an inert gas "y" to the turnaround areas <NUM>, <NUM> of the racetrack-shaped sputtering zone. The second interfaces 62b are positioned to supply a second gas mixture including an inert gas "x" to the straightaway areas <NUM>, <NUM> of the racetrack-shaped sputtering zone. The third interfaces 62c are positioned to supply a third gas mixture including an inert gas "z" to the turnaround areas <NUM>, <NUM> but are sandwiched in between the first interfaces 62a and the second interfaces 62b. For example, both the first interfaces 62a and the third interfaces 62c can be positioned adjacent the first turnaround area <NUM> along a longitudinal distance <NUM> and/or adjacent the second turnaround area <NUM> along a longitudinal distance <NUM>. Also, the second interfaces 62b can be positioned adjacent the first straightaway area <NUM> and/or the second straightaway area <NUM> along a longitudinal distance <NUM>.

<FIG> and <FIG> illustrate a gas distribution system <NUM> that includes a plurality of interfaces <NUM> that extend along a longitudinal axis LA of a target having a racetrack-shaped sputtering zone. The plurality of interfaces <NUM> are arranged to substantially entirely surround the target. In fact, in some cases, the plurality of interfaces <NUM> are also arranged as a racetrack shape that substantially entirely surrounds the racetrack-shaped sputtering zone <NUM>. The interfaces <NUM> include first interfaces 62a, second interfaces 62b and third interfaces 62c. Each third interface <NUM> is sandwiched between a first interface 62a and a plurality of second interfaces 62b and thus serves as an intermediate or transitional interface. The first interfaces 62a are positioned to supply a first gas mixture including an inert gas "y" to the turnaround areas <NUM>, <NUM> of the racetrack-shaped sputtering zone. The second interfaces 62b are positioned to supply a second gas mixture including an inert gas "x" to the straightaway areas <NUM>, <NUM> of the racetrack-shaped sputtering zone. The third interfaces 62c are positioned to supply a third gas mixture including an inert gas "z" to the turnaround areas <NUM>, <NUM> but are sandwiched in between the first interfaces 62a and the second interfaces 62b. The first interfaces 62a and the second interfaces 62c can be positioned adjacent to (e.g., by substantially surrounding) the first turnaround area <NUM> along a longitudinal distance <NUM> and/or adjacent to (e.g., by substantially surrounding) the second turnaround area <NUM> along a longitudinal distance <NUM>. Also, the second interfaces 62b can be positioned adjacent the first straightaway area <NUM> and/or the second straightaway area <NUM> along a longitudinal distance <NUM>.

<FIG> and <FIG> illustrate a gas distribution system <NUM> that includes a plurality of interfaces <NUM> that extend along a longitudinal axis LA of a target having a racetrack-shaped sputtering zone. The plurality of interfaces <NUM> are arranged along each side of the sputtering target. Each side of interfaces <NUM> also partially surrounds ends of the target. Again, the first interfaces 62a are positioned to supply a first gas mixture including an inert gas "y" to the turnaround areas <NUM>, <NUM> of the racetrack-shaped sputtering zone. The second interfaces 62b are positioned to supply a second gas mixture including an inert gas "x" to the straightaway areas <NUM>, <NUM> of the racetrack-shaped sputtering zone. The third interfaces 62c are positioned to supply a third gas mixture including an inert gas "z" to the turnaround areas <NUM>, <NUM> but are sandwiched in between the first interfaces 62a and the second interfaces 62b. Also, the first interfaces 62a and third interfaces 62c can be positioned adjacent to (e.g., by partially surrounding) the first turnaround area <NUM> along a longitudinal distance <NUM> and/or adjacent to (e.g., by partially surrounding) the second turnaround area <NUM> along a longitudinal distance <NUM>. Also, the second interfaces 62b can be positioned adjacent the first straightaway area <NUM> and/or the second straightaway area <NUM> along a longitudinal distance <NUM>.

In each of the embodiments of <FIG>, in some cases, the first gas mixture "y" includes a single inert gas selected from the group consisting of argon, helium neon, krypton, xenon and radon and the first atomic weight is an atomic weight of the single inert gas and/or the second gas mixture "x" includes a single inert gas selected from the group consisting of argon, helium neon, krypton, xenon and radon and the second atomic weight is an atomic weight of the single inert gas and/or the third gas mixture "z" includes a single inert gas selected from the group consisting of argon, helium neon, krypton, xenon and radon and the third atomic weight is an atomic weight of the single inert gas. In other cases, the first gas mixture "y" includes an inert gas mixture including two or more inert gases selected from the group consisting of argon, helium neon, krypton, xenon and radon and the first atomic weight is an average atomic weight of the two or more inert gases and/or the second gas mixture "x" includes an inert gas mixture including two or more inert gases selected from the group consisting of argon, helium neon, krypton, xenon and radon and the second atomic weight is an average atomic weight of the two or more inert gases and/or the third gas mixture "z" includes an inert gas mixture including two or more inert gases selected from the group consisting of argon, helium neon, krypton, xenon and radon and the third atomic weight is an average atomic weight of the two or more inert gases. In some cases, the first gas mixture "y" includes a reactive gas in addition to the inert gas and/or the second gas mixture "x" includes a reactive gas in addition to the inert gas and/or the third gas mixture "y" includes a reactive gas in addition to the inert gas.

In some embodiments of the invention, the gas distribution system <NUM> is used in a non-reactive sputtering process. In these embodiments, the gas distribution system <NUM> does not introduce reactive gases such as oxygen or nitrogen into the sputtering chamber. Instead, the gas distribution system <NUM> only introduces inert gases. In other words, the gas distribution system supplies gas that is free of or substantially free of a reactive gas. The non-reactive sputtering process can be either a non-reactive sputtering process for depositing metallic film or a non-reactive sputtering process for depositing dielectric film.

In certain embodiments compatible with the invention, each of the first gas mixture "y," the second gas mixture "x," and the third gas mixture "y" is substantially free of a reactive gas. For example, in some cases, the first gas mixture "y" consists essentially of or consists of a single inert gas selected from the group consisting of argon, helium neon, krypton, xenon and radon and the first atomic weight is an atomic weight of the single inert gas. The second gas mixture "x" consists essentially of or consists of a single inert gas selected from the group consisting of argon, helium neon, krypton, xenon and radon and the second atomic weight is an atomic weight of the single inert gas. The third gas mixture "z" consists essentially of or consists of a single inert gas selected from the group consisting of argon, helium neon, krypton, xenon and radon and the third atomic weight is an atomic weight of the single inert gas.

In other cases, the first gas mixture "y" consists essentially of or consists of an inert gas mixture including two or more inert gases selected from the group consisting of argon, helium neon, krypton, xenon and radon and the first atomic weight is an average atomic weight of the two or more inert gases. The second gas mixture "x" consists essentially of or consists of an inert gas mixture including two or more inert gases selected from the group consisting of argon, helium neon, krypton, xenon and radon and the second atomic weight is an average atomic weight of the two or more inert gases. The third gas mixture "z" consists essentially of or consists of an inert gas mixture including two or more inert gases selected from the group consisting of argon, helium neon, krypton, xenon and radon and the third atomic weight is an average atomic weight of the two or more inert gases.

In certain cases, the gas distribution system <NUM> is used with a sputtering target that includes sputterable material having a sputtering rate that is not modified by surface chemistry of the sputterable material. In certain embodiments of the invention, the gas distribution system <NUM> is used in a non-reactive sputtering process for depositing a metallic film such as metallic silver or metallic titanium. In these embodiments, the sputterable material in the sputtering target consists essentially of or consists of a metallic material such as metallic silver or metallic titanium. The gas distribution system <NUM> is used to sputter deposit a more uniform metallic film onto the substrate.

In some embodiments compatible with the invention, the gas distribution system <NUM> includes a plurality of interfaces <NUM> that each introduces gas at the same or substantially the same pressure. For example, the interface that supplies the first gas mixture "y" will supply gas at the same or substantially the same pressure as the interface that supplies a second gas mixture "x.

In other embodiments compatible with the invention, the plurality of interfaces <NUM> can include one or more interfaces that introduce gas continuously, for example at a continuous flow rate and/or at a continuous pressure. In some cases, all of the interfaces introduce gas continuously at the same flow rate. In other cases, certain of the interfaces introduce gas continuously at one flow rate whereas other interfaces introduce gas at another flow rate. Also, in some cases, all of the interfaces introduce gas continuously at the same pressure. In other cases, certain of the interfaces introduce gas continuously at one pressure whereas other interfaces introduce gas at another pressure.

In other embodiments compatible with the invention, the plurality of interfaces <NUM> can include one or more interfaces that introduce gas non-continuously, for example by pulsing, such as by pulsing the flow rate or flow burst lengths and/or by pulsing the pressure. In some cases, all of the interfaces introduce gas by pulsing the flow rate or the flow burst lengths. In other cases, certain of the interfaces introduce gas continuously at one flow rate whereas other interfaces introduce gas by pulsing the flow rate or flow burst lengths. Also, in some cases, all of the interfaces introduce gas by pulsing the pressure. In other cases, certain of the interfaces introduce gas continuously at one pressure whereas other interfaces introduce gas by pulsing the pressure. Any desired combination of pulsing or non-pulsing can be provided to different arrangements of interfaces to help to adjust the local sputtering rates to help promote sputtering uniformity.

The plurality of interfaces <NUM> shown in <FIG> can be provided as part of one or more gas delivery members. The gas delivery members can be configured as any desired structure that delivers gas through a plurality of interfaces. For example, the plurality of interfaces can be provided as part of the gas delivery member structure. Examples of gas delivery members include, but are not limited to, tubes, shafts, ducts, bars and beams. Likewise, the interfaces can be formed as manifolds, nozzles, openings or other structures that supply gas. The gas delivery members can also have one or more internal partitions (not shown) to ensure that different gas mixtures are separated and supplied to the appropriate interface.

In some embodiments, one or more gas delivery members are positioned along each side of a sputtering target. For example, in <FIG> and <FIG>, a first gas delivery member <NUM> is positioned on one side of the target <NUM> and a second gas delivery member <NUM> is positioned on an opposite side of the target. The gas delivery members of <NUM>, <NUM> can include interfaces arranged according to any of the embodiments already described, for example the embodiments of <FIG>, <FIG>, <FIG> or <FIG>. In <FIG> and <FIG>, a single gas delivery member <NUM> is provided and is positioned to substantially entirely surround the target <NUM>. The single gas delivery member can include interfaces arranged according to any of the embodiments already described, for example the embodiments of <FIG>, <FIG>, <FIG> or <FIG>. In <FIG> and <FIG>, a first gas delivery member <NUM> is positioned on one side of the target <NUM> and a second gas delivery member <NUM> is positioned on an opposite side of the target, wherein both gas delivery members <NUM>, <NUM> also partially surround ends of the target. The gas delivery members of <NUM>, <NUM> can include interfaces arranged according to any of the embodiments already described, for example the embodiments of <FIG>, <FIG>, <FIG> or <FIG>.

Other embodiments of the invention provide a gas distribution system <NUM> having certain gas delivery members that are anodic. In such cases, the gas distribution system <NUM> includes a plurality of gas distribution members, wherein the plurality of gas distribution members includes a plurality of anodic gas distribution members. Each anodic gas distribution member can be provided using principles and embodiments discussed in Applicant's own <CIT>.

Each anodic gas distribution member is insulated from the other gas distribution members and from the grounded sputtering chamber. Applicant has discovered that by using a plurality of anodic gas distribution members, different voltages can be applied to different anodic gas distribution members to help control local sputtering rates. For example, when a higher voltage is supplied to an anodic gas distribution member, the higher voltage will collect more electrons from the local plasma to reduce the local sputtering rate.

In some cases, the gas distribution system <NUM> includes one or more anodic gas distribution members arranged so as to reduce the local sputtering rate at turnaround areas <NUM>, <NUM> of a racetrack-shaped sputtering zone. As such, in some cases, the gas distribution system <NUM> includes at least one anodic gas distribution member, wherein the anodic gas distribution member is insulated from other gas distribution members and the sputtering chamber. The anodic gas distribution member supplies gas to either the first turnaround area <NUM> or the second turnaround area <NUM> and receives a voltage that reduces a local sputtering rate as compared to other gas distribution systems that are not anodic or that are anodic but receive a lower voltage.

A first anodic gas distribution member and a second anodic gas distribution member, wherein the first anodic gas distribution member is insulated from the second anodic gas distribution member, and wherein the first anodic gas distribution remember receives a first voltage and the second anodic gas distribution member receives a second voltage, wherein the first voltage is different than the second voltage.

<FIG> illustrates one embodiment of the present invention of a gas distribution system including anodic gas distribution members. A plurality of gas distribution members 54a, 54b and 54c are arranged along one side of a sputtering target and a plurality of gas distribution members 56a, 56b and 56c are arranged along an opposite side of the sputtering target. In some embodiments of the present invention, gas distribution members 54a, 56a, 54c, 56c are anodic whereas gas distribution members 54b, 56b are not anodic. The anodic members 54a, 56a, 54c, 56c supply gas to turnaround areas <NUM>, <NUM> of a racetrack-shaped sputtering zone. Preferably, the anodic members 54a, 56a, 54c, 56c are provided with a voltage that reduces the sputtering rate along the turnaround areas <NUM>, <NUM> relative to the sputtering rate along the straightaway areas <NUM>, <NUM>.

In another embodiment of the present invention, also shown in <FIG>, all of the gas distribution members 54a, 54b, 54c, 56a, 56b, 56c are anodic. Here, the gas distribution members 54a, 56a, 54c, 56c receive a first voltage whereas gas distribution members 54b, 56b receive a second voltage, wherein the first voltage and the second voltage are different. In many cases, it is desirable to reduce the sputtering rate at the turnaround areas <NUM>, <NUM> relative to the straightaway areas <NUM>, <NUM>, so the first voltage is higher than the second voltage.

In some cases, the gas delivery members shown in <FIG> can include the plurality of interfaces arrangement shown in either <FIG> or <FIG>. In such cases, the gas delivery members 54a, 54c, 56a, 56c can include first interfaces 62a that supply a first gas mixture including an inert gas "y" and the gas delivery members 54b, 56c can include second interfaces 62b that supply a second gas mixture including an inert gas "x.

<FIG> illustrates another embodiment of the present invention of a gas distribution system including anodic gas distribution members. A plurality of gas distribution members 55a, 55b, 55c, 55d are arranged to substantially entirely surround a sputtering target. In some embodiments of the present invention, gas distribution members 55b, 55d are anodic whereas gas distribution members 55a, 55c are not anodic. The anodic members 55b, 55d supply gas to turnaround areas <NUM>, <NUM> of a racetrack-shaped sputtering zone whereas non-anodic members 55a, 55c supply gas to straightaway areas <NUM>, <NUM>. Preferably, the anodic members 55b, 55d are provided with a voltage that reduces the sputtering rate along the turnaround areas <NUM>, <NUM> relative to the sputtering rate along the straightaway areas <NUM>, <NUM>.

In another embodiment of the present invention, also shown in <FIG>, all of the gas distribution members 55a, 55b, 55c, 55d are anodic. Here, the gas distribution members 55b, 55d receive a first voltage whereas gas distribution members 55a, 55c receive a second voltage, wherein the first voltage and the second voltage are different. In many cases, it is desirable to reduce the sputtering rate at the turnaround areas <NUM>, <NUM> relative to the straightaway areas <NUM>, <NUM>, so the first voltage is higher than the second voltage.

Also, in some cases, the gas delivery members shown in <FIG> can include the plurality of interfaces arrangement shown in either <FIG> or <FIG>. In such cases, the gas delivery members 55b, 55d can include first interfaces 62a that supply a first gas mixture including an inert gas "y" and the gas delivery members 55a, 55c can include second interfaces 62b that supply a second gas mixture including an inert gas "x.

<FIG> illustrates another embodiment of the present invention of a gas distribution system including anodic gas distribution members. A plurality of gas distribution members 55a, 55b, 55c, 55d, 55d, 55e, 55f, <NUM>, <NUM> are arranged to substantially entirely surround a sputtering target. In some embodiments of the present invention, gas distribution members 55b, 55c, 55d, 55e, 55f, <NUM>, <NUM> are anodic whereas gas distribution members 55a, 55e are not anodic. The anodic members 55b, 55c, 55d, 55e, 55f, <NUM>, <NUM> supply gas to turnaround areas <NUM>, <NUM> of a racetrack-shaped sputtering zone whereas non-anodic members 55a, 55e supply gas to straightaway areas <NUM>, <NUM>. Preferably, the anodic members 55b, 55c, 55d, 55e, 55f, <NUM>, <NUM> are provided with a voltage that reduces the sputtering rate along the turnaround areas <NUM>, <NUM> relative to the sputtering rate along the straightaway areas <NUM>, <NUM>. In particular embodiments of the present invention, anodic members 55b, 55d, 55f, <NUM> receive a first voltage and anodic members 55c, <NUM> receive a second voltage. For example, the anodic members 55c, <NUM> can serve as transitional or intermediate anodic members that have a lower voltage than anodic members 55b, 55d, 55f, <NUM>. Thus, in some cases, the first voltage is higher than the second voltage.

In another embodiment of the present invention, also shown in <FIG>, all of the gas distribution members 55a, 55b, 55c, 55d, 55d, 55e, 55f, <NUM>, <NUM> are anodic. Here, the gas distribution members 55c, <NUM> receive a first voltage, gas distribution members 55b, 55e, 55f, <NUM> receive a second voltage and gas distribution members 55a, 55e receive a third voltage, wherein the first voltage, the second voltage and the third voltage are different. In many cases, the first voltage is higher than the second voltage and the second voltage is higher than the third voltage.

Also, in some cases, the gas delivery members shown in <FIG> can include the plurality of interfaces arrangement shown in either <FIG> or <FIG>. In such cases, the gas delivery members 55c, <NUM> can include first interfaces 62a that supply a first gas mixture including an inert gas "y," the gas delivery members 55b, 55e, 55f, <NUM> can include third interfaces 62c that supply a third gas mixture including an inert gas "z" and the gas delivery members 55a, 55e include the second interfaces 62b that supply the second gas mixture "x.

<FIG> illustrates another embodiment of the present invention of a gas distribution system including anodic gas distribution members. A plurality of gas distribution members 54a, 54b and 54c are arranged along one side of a sputtering target and a plurality of gas distribution members 56a, 56b and 56c are arranged along an opposite side of the sputtering target. Also, gas distribution members 54a, 54c, 56a, 56c are arranged to partially surround ends of the sputtering target. In some embodiments of the present invention, gas distribution members 54a, 56a, 54c, 56c are anodic whereas gas distribution members 54b, 56b are not anodic. The anodic members 54a, 56a, 54c, 56c supply gas to turnaround areas <NUM>, <NUM> of a racetrack-shaped sputtering zone. Preferably, the anodic members 54a, 56a, 54c, 56c are provided with a voltage that reduces the sputtering rate along the turnaround areas <NUM>, <NUM> relative to the sputtering rate along the straightaway areas <NUM>, <NUM>.

Also, in some cases, the gas delivery members shown in <FIG> can include the plurality of interfaces arrangement shown in either <FIG> or <FIG>. In such cases, the gas delivery members 54a, 56a, 54c, 56c can include first interfaces 62a that supply a first gas mixture including an inert gas "y" and the gas delivery members 54b, 56b include the second interfaces 62b that supply the second gas mixture "x.

In each of the embodiments of <FIG>, each of the anodic members are insulated from other anodic members and non-anodic members. Each anodic member can be provided with a voltage from a single voltage source or a plurality of different voltage sources. Likewise, each voltage source(s) can be a set voltage or an adjustable voltage. Also, each of the anodic members can be provided with the same voltage or with different voltages. Even further, each of the anodic members can be provided with a continuous voltage or with a pulsed voltage. A pulsed voltage can be pulsed in voltage intensity and/or in voltage frequency. Any desired combination of set or adjustable voltages or pulsing or non-pulsing voltages can be provided to different arrangement of interfaces help to adjust the local sputtering rates to help promote sputtering uniformity.

Claim 1:
A method of using a magnetron sputtering apparatus (<NUM>), the magnetron sputtering apparatus (<NUM>) comprising a target (<NUM>), a gas distribution system (<NUM>), and a vacuum chamber (<NUM>) within which a controlled environment is established, the target (<NUM>) comprising one or more sputterable materials, wherein the target (<NUM>) includes a sputtering zone (<NUM>) that extends longitudinally along a longitudinal axis, wherein the sputtering zone (<NUM>) is a racetrack-shaped sputtering zone (<NUM>) comprising a straightaway area (<NUM>, <NUM>) sandwiched between a first turnaround area (<NUM>) and a second turnaround area (<NUM>), wherein the gas distribution system (<NUM>) comprises a plurality of gas distribution members, wherein the plurality of gas distribution members includes a first gas distribution member (54a) and a second gas distribution member (54b), wherein the first gas distribution member (54a) is insulated from the second gas distribution member (54b), the first gas distribution member (54a) comprising an anodic gas distribution member, the second gas distribution member (54b) comprising either an anodic gas distribution member or a non-anodic gas distribution member, the method comprising:
operating the first gas distribution member (54a) to supply gas to either the first turnaround area (<NUM>) or the second turnaround area (<NUM>) and operating the second gas distribution member (54b) to supply gas to the straightaway area (<NUM>, <NUM>); and
operating the magnetron sputtering apparatus (<NUM>) such that the first gas distribution member (54a) receives a first voltage and the second gas distribution member (54b) receives no voltage or a second voltage, the first voltage being higher than the no voltage or the second voltage such that the first voltage reduces a sputtering rate of the first turnaround area (<NUM>) or the second turnaround area (<NUM>) relative to a sputtering rate of the straightaway.