Patent Description:
In the fabrication of semiconductor devices, physical vapor deposition (PVD) is a process employed for depositing a variety of different materials. As the miniaturization of semiconductor devices continues, the requirements for the various films that are included in such devices generally become more stringent.

Radio frequency (RF) filters, which are key components of wireless communication devices, are one example of semiconductor devices that continue to be miniaturized for better performance. With miniaturization, the deposition uniformity of the films that make up such filters must be tightly controlled. For instance, bulk acoustic wave (BAW) resonators enable precise filtering of the RF signals received from cell phone base stations by mobile phones. With a growing number of signals being received by smartphones (including cell, Wi-Fi, and GPS), and the crowding of available frequencies, BAWs must be highly frequency-selective to avoid slowdowns or interruptions in operation.

The resonant frequency of a BAW device is inversely proportional to the thickness of the piezoelectric layer in the BAW and of the electrodes above and below the piezoelectric layer. This relationship means that deposition uniformity of the piezoelectric and electrode layers is important to BAW device performance repeatability. For example, the target within-wafer uniformity for an aluminum nitride (AIN) piezoelectric layer can be on the order of <NUM>%. By contrast, using conventional PVD techniques, achieving less than <NUM>% within-wafer uniformity for deposited metal films is already a challenge.

Deposition within a PVD process chamber is controlled through a number of variables, including chamber vacuum level, composition of process gases, plasma density and uniformity, bias applied to the wafer, etc. In addition to the above variables, the uniformity and quality of a film deposited via PVD is also highly dependent on the geometry of the PVD process chamber, such as the magnetic profile, and configuration, of the magnetron rotating above the target, the shape of process kit components within the chamber, target-to-wafer spacing, and the like. However, with the exception of target-to-wafer spacing, such geometric factors are generally unchangeable without considerable time and cost to re-engineer some or all such components. Further, any solution based on redesigned process kit components is static, and cannot be tuned or otherwise modified for individual process chambers. As a result, improvements in film uniformity through chamber redesign is a time-consuming and expensive process.

With respect to the prior art, exemplary reference is made to documents <CIT>, <CIT>, <CIT> and <CIT>.

Document <CIT> relates to methods and apparatuses for processing a substrate in a physical vapor deposition (PVD) chamber. In some embodiments, a process kit shield used in a substrate processing chamber may include a shield body having an inner surface and an outer surface, a process kit shield impedance match device coupled between the shield body and ground, wherein the process kit shield impedance match device is configured to adjust a bias voltage of the process kit shield, a cavity formed on the outer surface of the shield body, and one or more magnets disposed within the cavity.

Document <CIT> relates to methods and apparatuses for ionized sputtering of materials. According to the principles of the embodiments described in <CIT>, an IPVD apparatus and method are provided in which a main plasma is formed adjacent to the target to sputter material from the target while an RF element couples energy into the PVD processing chamber to produce a secondary plasma in a volume of the chamber between the main plasma and a substrate. The secondary plasma is supplemental to the main plasma that is typically confined close to the sputtering target. The secondary plasma generally fills the chamber, but primarily occupies at least a portion of the space between the target and the substrate, thereby ionizing the sputtered material particles in flight while they are moving from the target so that the particles can be electrostatically accelerated toward the substrate in the ion-assisted deposition of the sputtered material onto the substrate.

Document <CIT> relates to a method and apparatus for performing physical vapor deposition of a layer or a substrate, composed of a deposition chamber enclosing a plasma region for containing an ionizable gas; an electromagnetic field generating system surrounding the plasma region for inductively coupling an electromagnetic field into the plasma region to ionize the gas and generate and maintain a high density, low potential plasma; a source of deposition material including a solid target constituting a source of material to be deposited onto the substrate; a unit associated with the target for electrically biasing the target in order to cause ions in the plasma to strike the target and sputter material from the target; and a substrate holder for holding the substrate at a location to permit material sputtered from the target to be deposited on the substrate.

Document <CIT> relates to an arrangement for generating a plasma by means of cathode sputtering. This arrangement comprises a magnetron and a target with shielding metal sheets. About these shielding metal sheets are wound two coils with a common center axis of which the one coil is connected to a dc power source and the other coil to a high-frequency source. Through the cooperation of the fields of both coils result helicon or whistler waves.

In light of the above, there is a need in the art for systems and methods that enable improved uniformity of deposition during a PVD process.

In light of the above, a physical vapor deposition (PVD) system and a method of physical vapor deposition in a vacuum chamber according to the independent claims <NUM> and <NUM> are provided. Further aspects, advantages, and features are apparent from the dependent claims, the description, and the accompanying drawings.

It is to be noted, however, that the appended drawings illustrate only exemplary embodiments and are therefore not to be considered limiting of its scope, and may admit to other equally effective embodiments.

In the following description, numerous specific details are set forth to provide a more thorough understanding of the embodiments of the present disclosure. However, it will be apparent to one of skill in the art that one or more of the embodiments of the present disclosure may be practiced without one or more of these specific details. In other instances, well-known features have not been described in order to avoid obscuring one or more of the embodiments of the present disclosure.

<FIG> is a schematic cross-sectional illustration of a physical vapor deposition (PVD) chamber <NUM>, according to various embodiments of the present disclosure. PVD chamber <NUM> is configured to deposit material onto a substrate <NUM> as part of the process of manufacturing electronic circuits, such as integrated circuit chips and displays. More specifically, PVD chamber <NUM> deposits a material from sputtering target <NUM> onto substrate <NUM> during a PVD, or "sputtering," process, in which high-energy ions impact sputtering target <NUM>, causing particles of target material to be ejected from sputtering target <NUM> and deposited as a film on the substrate <NUM>. Examples of materials that can be deposited by PVD chamber <NUM> include, without limitation, various metals, such as aluminum (Al), copper (Cu), tungsten (W), molybdenum (Mo), tantalum (Ta), and/or metal compounds, such as tantalum nitride (TaN), tungsten nitride (W<NUM>N, WN, or WN<NUM>), titanium nitride (TiN), aluminum nitride (AIN), scandium aluminum nitride (ScAlN or ScxAl<NUM>-xN), and the like.

PVD chamber <NUM> includes chamber walls <NUM>. As shown, PVD chamber <NUM> further includes, disposed within chamber walls <NUM>, a substrate support <NUM> coupled to a lift mechanism <NUM>, one or more deposition shields <NUM>, and a coil portion <NUM> of an electromagnet. PVD chamber <NUM> further includes the sputtering target <NUM> mounted on or coupled to chamber walls <NUM>. In the embodiment illustrated in <FIG>, sputtering target <NUM> is electrically separated from chamber walls <NUM> by an insulator <NUM> disposed on an adapter <NUM> that is mounted on the chamber walls <NUM>. Together, sputtering target <NUM>, deposition shields <NUM>, and substrate support <NUM> (when lifted to a processing position proximate target <NUM>) enclose a processing region <NUM> in which plasma is formed during a deposition process performed in PVD chamber <NUM>.

PVD chamber <NUM> further includes one or more vacuum pumps <NUM> fluidly coupled to PVD chamber <NUM> via a respective valve <NUM>, a gas source <NUM> fluidly coupled to PVD chamber <NUM>, a DC power source <NUM> electrically coupled to sputtering target <NUM>, and a DC power source <NUM> electrically coupled to coil portion <NUM>. Vacuum pump(s) <NUM> are configured to produce a targeted level of vacuum during a deposition process performed on substrate <NUM> in PVD chamber <NUM>. Gas source <NUM> is configured to provide one or more process gases during such a deposition process. DC power source <NUM> is electrically coupled to sputtering target <NUM> during the deposition process so that sputtering target <NUM> has a suitable charge for plasma to be generated in processing region <NUM>. DC power source <NUM> is electrically coupled to coil portion <NUM> during the deposition process so that a magnetic field is generated in processing region <NUM> that can improve uniformity of deposition on substrate <NUM>, as described in greater detail below. In some embodiments, substrate support <NUM> can also be coupled to a DC or radio frequency (RF) power source (not shown) to improve uniformity or other film characteristics of material deposited on substrate <NUM>.

DC power source <NUM> can be any suitable power supply configured to deliver DC power to coil portion <NUM>. In some embodiments, DC power source <NUM> is configured to output DC power at a constant power level to coil portion <NUM> during a PVD process. In other embodiments, DC power source <NUM> is configured to output timed pulses of DC power to coil portion <NUM>. In addition, in some embodiments, DC power source <NUM> can be configured to selectively output DC power at different polarities. Thus, in such embodiments, DC power source <NUM> can output positive DC power in some situations and negative DC power in other situations, depending on commands or inputs from a controller associated with PVD chamber <NUM>. As a result, the polarity of the magnetic field generated by coil portion <NUM> can be varied when beneficial to the PVD process.

In some embodiments, DC power source <NUM> is configured to output DC power at a variable power level to coil portion <NUM>. Thus, the magnetic field generated by coil portion <NUM> can be varied in magnitude when beneficial to the PVD process. For example, in one such embodiment, DC power source <NUM> is configured as a programmable power supply that generates a variable DC output in response to a command, such as a command from a controller for the PVD chamber <NUM>. The variable DC output can be implemented by DC power source <NUM> via pulsed DC outputs of different power amplitude. Further, the variable DC output can follow an output profile that changes as a function of time. For example, the variable DC output can follow a profile that includes a particular power ramp-up profile during a beginning period of the PVD process and a power ramp-down profile during an ending period of the PVD process. Alternatively or additionally, the variable DC output can vary with time according to any suitable function, including a step function, a sinusoidal function, or any other suitable time-varying function. Thus, in such an embodiment, a controller for PVD chamber <NUM> can initiate a particular variable DC output with a single command to DC power source <NUM>. In other embodiments, DC power source <NUM> is configured as a controllable power supply configured to generate a particular DC output in response to a particular input value. In such embodiments, a controller associated with PVD chamber <NUM> can transmit inputs that can change in real time and thereby directly control the DC power output of DC power source <NUM> during a PVD process in PVD chamber <NUM>.

Sputtering target <NUM> is a solid metal or other material to be deposited, and is sometimes coupled to and supported by a backing plate (not shown). In operation, sputtering target <NUM> is typically employed as a cathode and is negatively charged, for example by being electrically coupled to DC power source <NUM>. In addition, a magnetron <NUM> is disposed outside PVD chamber <NUM> and proximate sputtering target <NUM>, and is typically enclosed in a water-cooled chamber (not shown). Magnetron <NUM> rotates during a PVD process to trap electrons over the negatively charged sputtering target <NUM>, increasing target sputtering rates, and thus creating higher deposition rates on the substrate101.

Deposition shields <NUM> protect chamber walls <NUM> and other components within PVD chamber <NUM> from receiving deposition of sputtered material. In the embodiment illustrated in <FIG>, deposition shields <NUM> include an upper shield <NUM> mounted on adapter <NUM>, a lower shield <NUM>, and a cover ring <NUM>, but PVD chamber <NUM> can include any other technically feasible configuration of deposition shields or a single deposition shield without exceeding the scope of the present disclosure.

Coil portion <NUM> is a coil of an electromagnet that is disposed within PVD chamber <NUM> and outside of processing region <NUM>. According to various embodiments, during a PVD process in PVD chamber <NUM>, direct current (DC) power is applied to coil portion <NUM> to generate a magnetic field (not shown) that extends into processing region <NUM>. As a result, the distribution and density of plasma in processing region <NUM> can be altered, thereby modifying the rate of deposition onto the surface of substrate <NUM>. Specifically, because the magnetic field generated by coil portion <NUM> is most intense near the periphery of processing region <NUM> and of substrate <NUM>, the biggest changes to deposition rate caused by the magnetic field occur near the circumference of substrate <NUM>. Thus, center-to-edge uniformity issues of a film deposited on substrate <NUM> can be addressed by altering the intensity of the magnetic field generated by coil portion <NUM> by changing the current flowing therethrough.

Coil portion <NUM> can be any technically feasible conductive coil that is substantially centered about a center point 103A of substrate support <NUM>, i.e., the distance from the center point 103A to the center of the coil portion <NUM> is substantially equal around the center point 103A. In some cases, the distance from the center point 103A to the center of the coil portion <NUM> can be offset so that the center point 103A is not the central axis of the coil portion <NUM>, or the coil portion <NUM> may not be circular in plan view, i.e., from above. In these cases, the coil portion <NUM> architecture is modified to address non-uniformity of deposition across the substrate surface. For example, where the deposited thickness or other property of the sputter deposited field is offset from being symmetric about the center of the substrate, the magnetic field produced by coil portion can be offset in an opposite direction by physically displacing all, or part of the coil in the opposite direction. Likewise, where annular non-uniformities in thickness or other properties of the sputter deposited film on the substrate are present, changes in the current in the coil portion <NUM>, or the spacial alignment of the coil portion with respect it the center point 103A, can be used to spread the annular region out or reduce its radial expanse. In some embodiments, coil portion <NUM> overlaps a plane <NUM> that corresponds to the location of substrate <NUM> when substrate support <NUM> positions substrate <NUM> in a processing position, i.e., the location of substrate <NUM> during a PVD process. Thus, in such embodiments, plane <NUM> passes through coil portion <NUM>, as shown in <FIG>. In the embodiment illustrated in <FIG>, each turn of coil portion <NUM> is not in contact with other turns of coil portion <NUM>. In other embodiments, the turns of coil portion <NUM> are in contact with one or more other turns of coil portion <NUM>. The number of turns included in coil portion <NUM> is based on a target intensity of magnetic field to be generated by coil portion <NUM>. Furthermore, the target intensity can be a function of multiple factors, including diameter of substrate <NUM>, distance of coil portion <NUM> from processing region <NUM>, magnitude of DC current applied to coil portion <NUM>, duration of the PVD process, and the like. While the embodiment of coil portion <NUM> illustrated in <FIG> includes <NUM> turns, coil portion <NUM> can include any suitable number of turns, depending on at least the above factors. Thus, various configurations of coil portion <NUM> can be implemented in different embodiments of the disclosure, as described below in conjunction with <FIG>.

<FIG> is a schematic cross-sectional illustration of coil portion <NUM>, in which coil portion <NUM> is mounted on a surface <NUM> of one of deposition shields <NUM> of PVD chamber <NUM>, according to various embodiments of the present disclosure. In the embodiment illustrated in <FIG>, coil portion <NUM> is mounted on the surface <NUM> of lower shield <NUM> facing the chamber wall <NUM>, and thus surrounds the substrate support <NUM>. As shown, coil portion <NUM> can be positioned on lower shield <NUM> to overlap plane <NUM>, i.e., portions of the turns thereof lie on either side of plane <NUM>. In addition, coil portion <NUM> can include multiple layers <NUM> and <NUM> of turns <NUM>, here, first turns of a first radius and second turns of a different radius. In the embodiment illustrated in <FIG>, coil portion <NUM> includes two layers <NUM> and <NUM>, but in other embodiments, coil portion <NUM> can include more than two such layers or fewer than two layers of turns <NUM>. Furthermore, in the embodiment illustrated in <FIG>, turns <NUM> are formed with wire or other conductor that is circular in cross-section, but in other embodiments, turns <NUM> can be formed with wire or conductor that is square or rectangular in cross-section.

In some embodiments, coil portion <NUM> is mounted on any other suitable surface within PVD chamber <NUM> instead of surface <NUM> of lower shield <NUM>. For instance, coil portion <NUM> can be mounted on a different surface of lower shield <NUM>, or on a surface of any other deposition shield <NUM> that is outside of processing region <NUM>. Thus, in alternative embodiments, coil portion <NUM> is mounted on an outer surface <NUM> of upper shield <NUM>, on a lower surface <NUM> of lower shield <NUM>, etc..

Because coil portion <NUM> of the electromagnet described herein is disposed within the vacuum-containing portion of PVD chamber <NUM>, cooling of coil portion <NUM> is limited. As a result, the magnitude of DC power applied thereto by DC power source <NUM> can be limited due to the potential for overheating of coil portion <NUM> during longer duration recipes. In some embodiments, coil portion <NUM> is mounted on or within a structure in PVD chamber <NUM> that enables a cooling liquid to reduce heating of coil portion <NUM>. One such embodiment is illustrated in <FIG>.

<FIG> is a schematic partial cross-sectional illustration of coil portion <NUM> and an associated annular structure <NUM> that enables cooling of coil portion <NUM> via a cooling liquid, according to various embodiments of the present disclosure. In the embodiment illustrated in <FIG>, coil portion <NUM> is mounted on a surface of or positioned inside annular structure <NUM>, which is disposed within PVD chamber <NUM>.

Annular structure <NUM> is a substantially annulus-shaped structure that is disposed proximate deposition shields <NUM> and outside processing region <NUM>. In <FIG>, a cross-section of only one portion of annular structure <NUM> is shown, but annular structure <NUM> extends around the circumference of deposition shields <NUM>. As shown, annular structure <NUM> is disposed between chamber walls <NUM> and deposition shields <NUM>. In the embodiment illustrated in <FIG>, annular structure <NUM> is coupled to and suspended below adapter <NUM> by one or more pylons <NUM>. In such embodiments, the one or more pylons can each be configured as a machined part of adapter <NUM> or can be a separately assembled part that is coupled to adapter <NUM>. Alternatively, annular structure <NUM> can be suspended in PVD chamber <NUM> using one or more supports coupled to inner surfaces of chamber walls <NUM>.

Annular structure <NUM> includes at least one conduit <NUM> for transmission of a cooling liquid within annular structure <NUM> and a cavity <NUM> in which coil portion <NUM> is disposed. In the embodiment illustrated in <FIG>, conduit <NUM> includes multiple channels <NUM> that are separated from each other by a divider <NUM>. Alternatively, conduit <NUM> includes three or more channels <NUM>. In some embodiments, each of channels <NUM> is fluidly coupled to a supply conduit <NUM> that is formed within one of pylons <NUM> and to a return conduit (not shown) that is also formed within one of pylons <NUM>. Supply conduit <NUM> and the return conduit are then fluidly coupled to a cooling liquid recirculating system, such as a pump and heat exchanger. Alternatively, in some embodiments one of channels <NUM> is fluidly coupled to supply conduit <NUM> and the other of channels <NUM> is fluidly coupled to the return conduit. In such embodiments, the flow of cooling liquid in one of channels <NUM> can be arranged to flow in one direction around annular structure <NUM> and in an opposite direction in the other of channels <NUM>, thereby distributing cooling more evenly around the circumference of annular structure <NUM>.

In some embodiments, coil portion <NUM> is disposed in cavity <NUM>, which is fluidly separated from conduit <NUM> by a cover <NUM>. Cover <NUM> can one or more welded metal strips that seal cavity <NUM> from conduit <NUM> and are partially supported by and welded to divider <NUM>. For example, cover <NUM> can be configured of two distinct pieces, thus including a separate piece to cover each of channels <NUM>, so that cover <NUM> is less likely to flex or otherwise deflect when undergoing stresses associated with thermal cycling. In some embodiments, cavity <NUM> is fluidly separated from the vacuum-containing portion of PVD chamber <NUM> by a cover plate <NUM>. Thus, in such embodiments, cavity <NUM> is separated from the vacuum in the PVD chamber <NUM> when vacuum is present in PVD chamber <NUM>, and may, for example be maintained at a different pressure than the pressure in the sputtering chamber, for example atmospheric or above atmospheric pressure, to enhance conductive heat transfer therefrom into annular structure <NUM> and thus into any coolant flowing in the conduit <NUM>.

Conduit <NUM> is fluidly separated from the vacuum-containing portion of PVD chamber <NUM>, for example by a cover plate (not shown) or by a portion <NUM> of annular structure <NUM>. In the embodiment illustrated in <FIG>, portion <NUM> of annular structure <NUM> fluidly separates conduit <NUM> from the vacuum-containing portion of PVD chamber <NUM>. As a result, there are two welds separating cooling liquid in conduit <NUM> from the vacuum-containing portion of PVD chamber <NUM>: the weld sealing conduit <NUM> from cavity <NUM> and the weld sealing cavity <NUM> from the vacuum-containing portion of PVD chamber <NUM>. Therefore, the failure of two welds must occur before cooling liquid in conduit <NUM> can leak into the vacuum-containing portion of PVD chamber <NUM>. Alternatively, in some embodiments, some or all of annular structure <NUM> is formed via a 3D printing process. In such embodiments, conduit <NUM> can be formed without a separately welded cover <NUM>, which further reduces the potential for leakage of the cooling liquid from conduit <NUM>.

In the embodiment illustrated in <FIG>, coil portion <NUM> includes wire or other conductors that are substantially square in cross-section. Alternatively, in other embodiments, coil portion <NUM> can include conductors that are circular or rectangular in cross-section.

In some embodiments, cavity <NUM> is exposed to atmosphere, even though cavity <NUM> is disposed within PVD chamber <NUM>. One such embodiment is illustrated in <FIG> is a schematic cross-sectional illustration of coil portion <NUM> and an electrical lead <NUM> connected thereto, according to embodiments of the present disclosure, taken at a section other than the section of <FIG>. Also shown in <FIG> is a channel <NUM> through which electrical lead <NUM> passes from coil portion <NUM> to DC power source <NUM>. For clarity, only a single electrical lead <NUM> is depicted in <FIG>, but generally two electrical power connections run between coil portion <NUM> and DC power source <NUM> so that current can be flowed through the wires of the coil portion <NUM> and around the substrate support <NUM>. As shown, channel <NUM> is formed in adapter <NUM> and one of pylons <NUM>. Thus, channel <NUM> enables electrical connection of coil portion <NUM> through adapter <NUM> and the pylon <NUM>. In the embodiment illustrated in <FIG>, channel <NUM> is at atmospheric pressure and is fluidly coupled to cavity <NUM>. As a result, cavity <NUM> is also at atmospheric pressure. Consequently, leakage of cooling liquid around cover <NUM> from either of channels <NUM> will cause cavity <NUM> to fill and then overflow outside of PVD chamber <NUM>, which can be readily detected, and heat transfer between the wires of the coil portion <NUM> and the annular structure <NUM> is enhanced as compared to where the coil portion <NUM> is in vacuum.

In some embodiments, coil portion <NUM> includes two separately powered coils that are configured to generate magnetic fields with opposing poles. That is, the north pole of the magnetic field generated by the first separately powered coil is positioned adjacent to the south pole of the magnetic field generated by the second separately powered coil. One such embodiment is illustrated in <FIG>.

<FIG> schematically illustrates adjacent portions of two separately powered coils <NUM> and <NUM> disposed within a PVD chamber <NUM>, according to an embodiment of the present disclosure. Similar to previously described embodiments, coils <NUM> and <NUM> are disposed within PVD chamber <NUM> and outside of processing region <NUM>, for example between an outer surface <NUM> of a deposition shield <NUM> and a chamber wall <NUM> of PVD chamber <NUM>. In some embodiments, coil <NUM> and coil <NUM> are separately powered, that is, each can be electrically coupled to a different respective DC power source. Thus, coil <NUM> is coupled to a first DC power source <NUM> and coil <NUM> is coupled to a second DC power source <NUM>.

As a result of coil <NUM> and coil <NUM> being powered separately, the polarity of coil <NUM> can be opposite that of coil <NUM>. For example, when DC current is applied to coil <NUM> so that the DC current flows into the page in <FIG> at each cross-section <NUM> of coil <NUM>, the north pole of the electromagnet that includes coil <NUM> is in the +Y direction. Further, when DC current is applied to coil <NUM> so that the DC current flows out the page in <FIG> from each cross-section <NUM> of coil <NUM>, the north pole of the electromagnet that includes coil <NUM> is in the -Y direction. Therefore, modulation of the current flowing through coil <NUM> can generate changes in the shape and intensity of the magnetic field generated by the electromagnet that includes coil <NUM>. As noted previously, changes to the shape and intensity of the magnetic field in processing region <NUM> directly affects deposition rate of material on a substrate in PVD chamber <NUM> in the edge region of the substrate.

In <FIG>, coil <NUM> and coil <NUM> are shown physically separated from each other. In other embodiments, coil <NUM> and coil <NUM> can be in physical contact with each other, but are electrically insulated from each other, for example with an insulative coating therebetween. Thus, in some embodiments, coil <NUM> and coil <NUM> can each be disposed in a single cavity in an annular structure, such as cavity <NUM> in <FIG>. Alternatively, in some embodiments, coil <NUM> and/or coil <NUM> is formed as a thin film deposited on a surface of deposition shield <NUM>.

<FIG> is a flow chart of process steps for depositing a film on a substrate using a PVD process, according to various embodiments of the disclosure. Although the method steps are described in conjunction with the PVD chambers illustrated in <FIG>, persons skilled in the art will understand that the method steps may be performed with any suitably configured deposition system.

A method <NUM> begins in step <NUM>, in which substrate <NUM> is positioned in processing region <NUM> of PVD chamber <NUM>. For example, in some embodiments, a controller associated with PVD chamber <NUM> or a system that includes PVD chamber <NUM> causes substrate <NUM> to be placed on substrate support <NUM>. The controller then causes substrate support <NUM> to be raised to a processing position proximate processing region <NUM>.

In step <NUM>, the controller causes plasma to be generated in processing region <NUM> as part of a PVD process. For example, the controller causes gas source <NUM> to introduce one or more process gases into PVD chamber <NUM> and DC power source <NUM> to apply DC power to sputtering target <NUM>.

In step <NUM>, while the plasma is present in processing region <NUM>, the controller causes DC power source <NUM> to apply DC power to coil portion <NUM>, thereby modifying the magnetic field within processing region <NUM>. In some embodiments, in step <NUM> a cooling liquid is also flowed through channels of an annular structure on which coil portion <NUM> is mounted. In such embodiments, the flow of the cooling liquid can be continuous, i.e., the flow of cooling liquid continues when plasma is not present in processing region <NUM>.

In the embodiment described above, plasma is first generated in processing region <NUM>, then DC power is applied to coil portion <NUM>. In alternative embodiments, DC power is applied to coil portion <NUM> prior to or coincident with the initial generation of plasma in processing region <NUM>.

Implementation of method <NUM> enables a PVD process in which thickness uniformity of a material deposited on substrate <NUM> can be modified without redesign of one or more components within the PVD chamber. That is, the application of DC power to coil portion <NUM> provides one or more additional process tuning parameters for tuning the thickness uniformity of a PVD-deposited film. In particular, center-to-edge thickness uniformity issues can be addressed by increasing or decreasing the DC power applied through coil portion <NUM>, changing the polarity of power applied to coil portion <NUM>, and/or changing a time-variable profile of power applied to coil portion <NUM>.

Aspects of the present embodiments may be embodied as a system, method or computer program product. Accordingly, aspects of the present disclosure may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a "circuit," "module" or "system. " Furthermore, aspects of the present disclosure may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code embodied thereon.

Claim 1:
A physical vapor deposition (PVD) system, comprising:
a vacuum processing chamber (<NUM>) comprising:
a sputtering target (<NUM>);
a substrate support (<NUM>) disposed within the vacuum processing chamber configured to position a substrate (<NUM>) proximate to the sputtering target;
a deposition shield (<NUM>) disposed within the vacuum processing chamber;
a processing region (<NUM>) disposed within the vacuum processing chamber and bounded by a surface of the target, a surface of the substrate support, and an inner surface of the deposition shield;
a coil portion (<NUM>) of an electromagnet, wherein the coil portion is disposed within the vacuum processing chamber and outside the processing region;
an annular structure (<NUM>) on which the coil portion is disposed, wherein the annular structure (<NUM>) is disposed within the vacuum processing chamber and outside of the processing region, wherein the annular structure (<NUM>) comprises at least one conduit (<NUM>) for transmission of a cooling liquid within the annular structure, and a cavity (<NUM>) in which the coil portion is disposed, and wherein the at least one conduit (<NUM>) is sealed from the coil portion; and
a cover plate (<NUM>) that fluidly separates the coil portion from a vacuum containing portion of the vacuum processing chamber.