Patent Publication Number: US-11043365-B2

Title: Interchangeable magnet pack

Description:
CROSS-REFERENCE 
     This application is a continuation of U.S. patent application Ser. No. 15/046,340, now issued as U.S. Pat. No. 10,573,500, entitled “Interchangeable Magnet Pack” and filed on Feb. 17, 2016, which is a continuation-in-part of U.S. patent application Ser. No. 13/316,358, now issued as U.S. Pat. No. 9,347,129, entitled “Interchangeable Magnet Pack” and filed on Dec. 9, 2011. Both of these references are hereby incorporated by reference for all that they disclose or teach. 
    
    
     BACKGROUND 
     Generally, sputtering is a process carried out in a vacuum chamber that is filled with selected gasses. The sputtering process causes a substrate to be coated with a material from a target located within a sputtering chamber. Electrons in the chamber strike and ionize an inert gas, forming positive ions. The positive ions are then attracted to the negative target. When the ions strike the target, the ions transfer energy to the target material, causing material from the target to eject. Some of the ejected material adheres to and coats the substrate. 
     SUMMARY 
     Provided herein is an apparatus that includes a target, wherein the target includes a nonuniform erosion profile. The apparatus also includes a number of interchangeable magnetic and non-magnetic inserts. The interchangeable magnetic and non-magnetic inserts are configured to control a pass through flux based on the nonuniform erosion profile. These and various other features and advantages will be apparent from a reading of the following detailed description. 
    
    
     
       DRAWINGS 
         FIG. 1A  is a cross section of a sputtering apparatus with a programmable magnet pack, according to one aspect of the present description. 
         FIG. 1B  is an enlarged cross section of the target and the substrate, illustrating a simplified exemplary erosion profile, according to one aspect of the present description. 
         FIG. 2  is a perspective view of an exemplary programmable magnet pack, according to one aspect of the present description. 
         FIG. 3  is a perspective cross sectional portion of an exemplary programmable magnet pack, according to one aspect of the present description. 
         FIG. 4A  is a perspective view of various inserts that may be used with a programmable magnet pack, according to one aspect of the present description. 
         FIG. 4B  is a perspective cross section of the programmable magnet pack with inserts inside cells on a template, according to one aspect of the present description. 
         FIG. 5A  depicts an exemplary template having a plurality of cells having a circular cross-section, according to one aspect of the present description. 
         FIG. 5B  depicts an exemplary template having a plurality of cells having a square cross-section, according to one aspect of the present description. 
         FIG. 5C  depicts an exemplary template having a plurality of cells having a hexagonal cross-section, according to one aspect of the present description. 
         FIG. 5D  depicts an exemplary template having a plurality of cells having a rectangular cross-section, according to one aspect of the present description. 
         FIG. 5E  depicts an exemplary template having a plurality of cells having a triangular cross-section, according to one aspect of the present description. 
         FIG. 6  depicts a flowchart of an exemplary process of controlling a sputtering process by optimizing the positions and arrangements of magnetic and non-magnetic inserts within a magnet pack, according to one aspect of the present description. 
     
    
    
     DESCRIPTION 
     Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings. While the embodiments will be described in conjunction with the drawings, it will be understood that they are not intended to limit the embodiments. On the contrary, the embodiments are intended to cover alternatives, modifications and equivalents. Furthermore, in the following detailed description, numerous specific details are set forth in order to provide a thorough understanding. However, it will be recognized that the embodiments may be practiced without these specific details. In other instances, well-known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects of the embodiments. 
     Embodiments of the present invention relate to a programmable magnet pack for use in sputtering. The programmable magnet pack includes a cover, a yoke, and a template having a number of cells. A number of removable magnetic inserts and a number of removable non-magnetic inserts are disposed within the cells on the template. The removable inserts may be rearranged to customize or shape magnetic field profiles emanating from the magnet pack. Thus the magnetic fields may be modified to alter sputtering characteristics. The magnetic field may thereby be adjusted to optimize sputtering from different target materials, using shields and chosen hardware geometries that are desired for different applications. The yoke provides a return path for the magnetic field generated by the arrangement of inserts disposed into the template. The cover protects the various inserts disposed within the cells of the template from damage and also allows for the inserts to come as close as possible to a sputtering target. The cells and inserts may be fashioned in any shape. 
     The ability of a magnetic field emanating from a magnet behind a target to shape the plasma that controls the erosion profile and redeposition of a sputter target is limited by the amount of magnetic flux that is able to pass through the target. Pass through flux (“PTF”) of a target is commonly quoted as a percentage of flux strength that passes through the target under a uniform testing condition. Pass through flux of a target decreases with increasing thickness of the target. Pass through flux is generally inversely related to the magnetic moment of the target material. Pass through flux is also affected by the magnetic permeability of the target material. 
     Thus, a much stronger back-side magnet is generally required to control the plasma deposition of a high moment magnetic material of the recording layer or SUL as compared to a non-magnetic seed layer or interlayer. Furthermore, the high permeability of a magnetic material can redirect the flux flow and broaden or otherwise change the shape of the flux profile emanating from the front (plasma) side of the target as compared to that entering the back (magnet) side of the target. 
     As material is sputtered from a magnetic target, the target is eroded and becomes thinner. Correspondingly, there is less material affecting the flux passing through the target. The PTF correspondingly increases and the broadening of the magnetic flux may be reduced. Also correspondingly, the magnetic field affecting the plasma confinement is changed and the sputter profile of the target changes. For a case where the target erosion profile was initially optimized for factors such as maximum target utilization, deposition thickness uniformity on the substrate, and target redeposition minimization, the profile changes as the target erodes will deoptimize those properties. 
     To compensate for the overall increase in magnetic field penetrating through the target to the plasma, it may be desirable to correspondingly decrease the magnetic field emanating from the back-side magnet so as to maintain a more constant magnetic field at the plasma that defines the target erosion profile. Similarly, one can pull the magnet away from the back of the target to effectively thicken the target spacing (e.g. change the “z-position”). 
     However, in an effort to make uniform deposition thickness on a substrate using a finite sized, shielded target, it is geometrically necessary to sputter more material from the radial band of target larger than the substrate diameter, as compared to the amount of material sputtered from the center of the target. Correspondingly, this band of the target erodes faster than other locations. As it erodes, the flux in that region increases and becomes less spread out, forming an increasingly deep and narrow trench in the target. If the magnet is simply pulled away from the target, the PTF in that band can be maintained as it erodes, but other bands with less erosion become deoptimized and sputter too slowly, resulting in redeposition, poor target utilization, sputter thickness nonuniformity, and related issues. 
     To reduce this trenching while maintaining the sputter uniformity and avoiding redeposition, the magnetic field emanating from the target may be lowered more rapidly in the erosion trench area. This serves to maintain a broad shallow trench that increases utilization and maintains a more constant magnetic field profile defining the plasma at the front side of the target. This maintains sputter thickness uniformity, increases the target&#39;s useful lifetime, and reduces redeposition throughout the target&#39;s life. 
     The programmable mag pack enables, for example, reduction of the magnetic moment or removal of magnetic inserts of cells only at the radius of the developing trench. In another embodiment, the z-position of magnetic cells could be increased only in the region of the trenching. Several advantages of the programmable designs are that the trenching occurs at different rates and radii depending on the PTF and magnet strength, so that the programmed magnetic settings may be tuned to each target material&#39;s magnetic properties. Thus, each new material does not require a new mag pack. Different shield openings (e.g. apertures) different target to substrate spacings, different chamber gas pressures, and different sputter powers change the sputter radial thickness profile, and magnets do not need to be designed for each process change. Different disk sizes (eg+1.8″ vs˜2.5″ vs˜3.5″, etc.) have good utilization and uniformity with trenching at different radii. In various embodiments, the trench generally may be at larger radius to increase uniformity of disks, especially the larger (e.g. 3.5″)disks. 
       FIG. 1A  is a cross section of an exemplary sputtering apparatus  100  with a programmable magnet pack  106 , according to an embodiment of the present invention. In some embodiments, a shield  102  may direct the flow of gas over the surface of a target  104 . In various embodiments the shield  102  may be a redeposition shield, which reduces material redepositing back onto the surface of the target  104 . 
     The target  104  overlies the programmable magnet pack  106 . The programmable magnet pack  106  creates magnetic fields  108  overlying the target  104  and emanating from a number of cells  208  (see  FIG. 2 ). Plasma  110  is confined by the magnetic fields  108 . Electrons  112  strike atoms within the plasma  110 , forming ions  114 . In an embodiment, the ions  114  may comprise positively charged ions. In embodiments of the present invention, the programmable magnet pack  106  may be configured (see below) to customize or shape the magnetic fields  108  into predetermined and desired forms. In further embodiments, the spacing between the target  104  and the programmable magnet pack  106  may be adjustable (e.g. the z-height may be selected). As a result, the sputtering characteristics of the sputtering apparatus  100  may be selectively altered. 
     The positive ions  114  are attracted towards the negatively biased target  104 . The ions  114  strike the surface of the target  104 , releasing target material  116  from the target  104 . The shield  102  directs the target material  116  through an aperture  118  (e.g. shield opening) and onto a substrate  120 . In various embodiments, a reactive gas (not shown), e.g. oxygen, is added within the sputtering apparatus  100 . The reactive gas may combine with the target material  116  before collecting on the substrate  120 . The target material  116  collects on the substrate  120 , forming a thin film (not shown). Thus, the substrate  120  overlies the aperture  118 . In some embodiments, the diameter of target  104  is greater than the diameter of the aperture  118 , and the diameter of aperture  118  is greater than or equal to the diameter of the substrate  120 . 
       FIG. 1B  is an enlarged cross section of the target  104  and the substrate  120 , illustrating a simplified exemplary erosion profile. As material is sputtered from the target  104 , the target is eroded and becomes thinner. In various embodiments, in order to deposit a uniform thickness on a workpiece (e.g. substrate  120 ), more material is sputtered from an outer diameter  130  of the target  104  than from an inner diameter  132  of the target  104 . As a result a radial band (e.g. trench  134 ) at an outer diameter of the target erodes faster than other locations, such as the center of the target. The illustration of substrate  120   FIG. 1B  is merely exemplary, and it is understood that various embodiments may include a substrate with smaller or larger diameters with respect to the trench  134  and the target  104 . 
     As erosion continues, a pass through flux becomes stronger in areas of greater erosion than areas of lesser erosion. For example, a pass through flux  136  in the area of the trench  134  is stronger than a pass through flux  138  in an inner diameter of the target  104 . As a result of the stronger and pass through flux  136 , the area of the trench  134  erodes faster than other locations (e.g. the area of the weaker pass through flux  138 ). As the erosion continues, the flux in that region continues to increase and becomes less spread out, forming an increasingly deep and narrow trench  140 . The deep and narrow trench  140  deoptimizes factors such as maximum target utilization, deposition thickness and uniformity on the substrate, and target redeposition minimization. 
     To control the size of the trench  134  and prevent the formation of the deep and narrow trench  140 , the strength of the magnetic field coming from the target  104  ( FIG. 1A ) may be reduced in the area of the trench  134  (e.g. the area of greater erosion). By adjusting the magnetic flux in response to variations in the erosion profile, the magnetic flux may be tuned to a radially nonuniform magnetic flux using embodiments of the present invention. The lower magnetic field in the area of the trench  134  (figuratively partially represented by dashed line  142 ), maintains a broad and shallow trench that will increase target utilization and maintain a more consistent magnetic field profile defining the plasma at the front side of the target. 
     As a result, of variations in the diameter of the substrate  120  and differences in the control and tuning of the magnetic field, the diameters of the trench  134  and the substrate  120  may differ between embodiments. For example, the diameter of the substrate  120  may be narrower than the outer or inner diameters of the trench  134  in some embodiments. In other embodiments, the diameter of the substrate  120  may be wider than the outer or inner diameters of the trench  134 . Still further embodiments, may include any variation in diameters between the substrate  120  and the trench  134 . 
     It is understood that  FIG. 1B  is very simply and figuratively drawn for purposes of clarity and illustration. For example, erosion profiles in other embodiments may be much more complicated, including multiple areas of comparatively greater and lesser erosion. In addition, the magnetic field profile  142  and pass through fluxes  136 , 138  are figurative oversimplifications for purposes of illustration, and should not be limiting. For example, magnetic field profiles and pass through fluxes in other embodiments may be much more complicated, including many areas of greater and lesser magnitude. 
       FIG. 2  is a perspective view of the programmable magnet pack  106 , according to an embodiment of the present invention. In an embodiment, the main assembly stack of the programmable magnet pack  106  consists of a cover  202 , a template  204 , and a yoke  206 . 
     The template  204  may include cells  208  that allow for the insertion of various removable and interchangeable inserts  418  (see  FIG. 4A ). In some embodiments, the template  204  may comprise such materials as, but is not limited to, Aluminum Grade 6061, Copper, or Stainless Steel Grade 300+. 
     The cover  202  protects the various removable and interchangeable inserts  418  (see  FIG. 4A ) within the cells  208  on the template  204  from damage and also allows for the various removable and interchangeable inserts  418  (see  FIG. 4A ) to come as close to the target  104  ( FIG. 1A ) as possible. In an embodiment, the cover  202  may comprise such materials as, but is not limited to, Aluminum Grade 6061, Copper, or Stainless Steel Grade 300+. 
     The yoke  206  provides a return path for a magnetic field that is customized or shaped by the various removable and interchangeable inserts  418  (see  FIG. 4A ) within the cells  208  on the template  204 . In various embodiments, the yoke  206  may comprise such materials as, but is not limited to, Stainless Steel Grade 538, Stainless Steel Grade 400+, or Steel. 
       FIG. 3  is a perspective cross sectional view of a portion of the programmable magnet pack  106 , according to an embodiment of the present invention. The programmable magnet pack  106  is depicted as partially assembled. In an embodiment, the cover  202  is removably connected to the template  204  via a fastener  314  that is inserted into a fastener hole  310  located on the cover  202 . In various embodiments, a cylinder  312  may extend through the template  204  and yoke  206 . The cylinder  312  allows for the fastener  314  inserted into the fastener hole  310  to extend through the template  204  and yoke  206 , allowing for the cover  202 , template  204 , and yoke  206  to be removably connected together via the fastener  314 . 
     In another embodiment, the various removable inserts  418  (see  FIG. 4A ) may be longer than the height of the cells  208  and may physically touch the cover  202  when disposed within a cell  208 . The cover  202  has a reduced thickness  311  to account for any removable inserts  418  (see  FIG. 4A ) disposed within cells  208  that may be longer than the height of the cell  208 . The reduced thickness  311  allows for the cover  202  to be removably connected to the template  204  via the fastener  314  that is inserted into the fastener hole  310  when at least one removable inserts  418  (see  FIG. 4A ) is longer than the height of the cell  208 . 
       FIG. 4A  is a perspective view of various removable and interchangeable inserts  418  that may be used with the programmable magnet pack, according to an embodiment of the present invention. The removable and interchangeable inserts  418  may be full length magnetic inserts  420 , partial length magnetic inserts  426 , full length non-magnetic inserts  428 , or partial-length non-magnetic inserts  430 . 
     The cells  208  ( FIG. 3 ) may be divided into any number of subunits or blocks that may be filled with the magnetic and/or non-magnetic inserts. Each of the inserts may vary in length so that the strength and direction of the magnetic moment in each of the cells  208  may be tailored by adjusting the length, moment, and polar orientation of one or more inserts that may be used to fill or partially fill the length of one or more of the cells  208 . 
     The full length magnetic inserts  420  and partial length magnetic inserts  426  may include a north pole  422  and a south pole  424 . For purposes of illustration, the magnetic inserts are shown with distinct north and south poles. However, it is understood that the inserts do not have distinct north and south particles on either side and evenly divided through the middle of the insert. Instead, the north pole  422  represents the general location from which the magnetic field lines emerge, and the south pole  424  represents the general location from which the magnetic lines reenter. The full length magnetic inserts  420  and the partial length magnetic inserts  426  may comprise a permanent magnetic material, including but not limited to, Neodymium, Samaraium Cobalt, Ceramic, or Alnico. In one embodiment, the full length magnetic inserts  420  and partial length magnetic inserts  426  may comprise Rare-Earth (Neodymium) Magnet Grade N52. 
     The full length non-magnetic inserts  428  and the partial length non-magnetic inserts  430  may be solid and made from various materials allowing a user to shunt the magnetic field or use as a counter weight for the purpose of rotation stability, for example in embodiments where the programmable magnetic pack rotates. Full length non-magnetic inserts  428  and the partial length non-magnetic inserts  430  may comprise but are not limited to, such materials as, Stainless Steel (e.g. any grade), Aluminum, Copper, and Nylon. 
     Partial length non-magnetic inserts  430  and partial-length magnetic inserts  426  may be interposably stacked in a cell  208  (see  FIG. 4B ) on the template  204  (see  FIG. 4B ) to form a stacked insert  427 . The stacked insert  427  may have combinations of one or more partial length non-magnetic inserts  430  or partial length magnetic inserts  426 , stacked in various orders and orientations. 
     Thus in some embodiments, a single insert may be placed in some or all of the array slots (e.g. cells  208 ) to tailor (e.g. program) the magnetic field emanating from the mag pack as desired. In some embodiments, the moment of inserts may be varied from 0 (nonmagnetic) to a maximum available magnetic strength to further control the magnetic field profile, wherein the Ms may have more than one value. In some embodiments, the polarity of some inserts may be differently aligned (e.g. opposite) compared to other inserts, to further control the magnetic field profile. 
     In some embodiments, two half-height inserts may be used in some or all of the array slots to further control the magnetic field profile. In some embodiments, three or more inserts of different length may be used to partially or completely fill some or all of the array slots, to further control the magnetic field profile. In some embodiments, inserts with opposite, different, or no moment may be used in some or all of the array slots to further control the magnetic field profile. In various embodiments, the programmable magnet pack can provide a three dimensional array of magnets that can deliver a large range of desired magnetic field profiles to optimize magnetron sputter properties, target utilization, and defect reduction. For example, the interchangeable magnetic and non-magnetic inserts may be configured to reduce a magnetic field in thinner target areas, thereby reducing trenching of the target and maintaining sputter uniformity of the substrate. The magnetic and non-magnetic inserts may also be configured to reduce the magnetic moment at a radius (e.g. inner, outer, middle, etc.) of the trench. 
     In further embodiments, the programmable mag pack may be movable so that the distance between the target and the mag pack “z-height” may be adjusted as the target life is reduced, so that the target utilization and sputter rate may be further adjusted throughout the life of the target. In further embodiments the z-position of a subset of the slots, cells or inserts may be independently or individually controlled so as to further dynamically optimize the field profile as target life is reduced. In other embodiments, the mag pack cells or slots may be accessed and adjusted manually from behind the target structure without breaking vacuum in the sputter chamber. 
       FIG. 4B  is a perspective cross sectional view of a portion of the programmable magnet pack  106  with removable and interchangeable inserts  418  ( FIG. 4A ) inside of cells  208  on the template  204 , according to an embodiment of the present invention. The programmable magnet pack  106  is shown as assembled in this  FIG. 4B . 
     Each full length magnetic insert  420  and each partial length magnetic insert  426  may be placed within a cell  208  with either its north pole  422  ( FIG. 4A ) closest to the cover  202  or its south pole  424  ( FIG. 4A ) closest to the cover  202 . Any number of removable and interchangeable inserts  418  ( FIG. 4A ) may be placed in each cell  208  and variably stacked to obtain a desired erosion profile and desired sputtering performance. The maximum number of removable and interchangeable inserts  418  ( FIG. 4A ) placed in a cell  208  may be limited, for example, by the thickness of the template  204  and/or the length of the inserts. There are a number of possible removable and interchangeable insert arrangements  418  ( FIG. 4A ). For example, in one embodiment, a cell  208  may be filled with a full length magnetic insert  420  or one or more stacked partial length magnetic inserts  426  or partial length non-magnetic inserts  430 . Each full length magnetic insert  420  or partial length magnetic insert  426  may have either its north pole  422  ( FIG. 4A ) or south pole  424  ( FIG. 4A ) facing the cover  202 . 
     In another embodiment, a cell  208  may be filled with a full length non-magnetic insert  428 . In another embodiment, a cell  208  may include a partial length magnetic insert  426  or partial length non-magnetic inserts  430  closest to the yoke  206 , and with partial length magnetic inserts  426  and/or partial length non-magnetic inserts  430  in the remaining portion of the cell  208 . In another embodiment, a cell  208  may be stacked with a partial length magnetic inserts  426  or partial length non-magnetic insert  430  closest to the cover  202 , and with partial length magnetic inserts  426  and/or partial length non-magnetic inserts  430  in the remaining portion of the cell  208 . In some embodiments one or more cells  208  may be empty, while one or more other cells may contain magnetic inserts and non-magnetic inserts. 
     The combination of one or more of the magnetic inserts, non-magnetic inserts, and empty cells is used to adjust the magnetic flux, as previously discussed. By adjusting the magnetic flux in response to variations in the erosion profile of the target, the magnetic flux may be tuned to a radially nonuniform magnetic flux. The radially nonuniform magnetic flux is therefore configured by the arrangement of the inserts within the cells to provide a substantially uniform sputter thickness. For example, the substantially uniform sputter thickness may include a sputter thickness variation of less than five percent across a substrate. 
     Magnetic inserts  420 ,  426  and non-magnetic inserts  428 ,  430  may also be disposed or inserted in any number of configurations inside each cell  208 . Partial length magnetic and non-magnetic inserts may be of any length (e.g. ½, ⅓, ⅔, ¼, ¾, ⅕, ⅖, ⅗, ⅘, etc.) and stacked in any combination of the lengths (e.g. stacking a ⅕ with a ⅓). It should be understood that the fractional example lengths are examples and should be non-limiting. For example, various embodiments may use varying units of measurement to distinguish the magnetic and non-magnetic inserts. It should also be understood that any number of magnetic and non-magnetic inserts may be stacked within a cell, and magnetic orientations and strengths may also differ between magnetic inserts within the same cell. 
       FIG. 5A  depicts an exemplary template  204  having a plurality of cells  532  having a circular cross-section, according to an embodiment of the present invention. Removable and interchangeable inserts  418  ( FIG. 4A ) with corresponding circular cross-sections can be placed inside of the cells  532  on the template  204 . For example, magnetic inserts  420 ,  426  ( FIG. 4A ) and non-magnetic inserts  428 ,  430  ( FIG. 4A ) having a circular cross-section can be placed inside of the cells  532  on the template  204 . 
       FIG. 5B  depicts an exemplary template  204  having a plurality cells  534  having a square cross-section, according to an embodiment of the present invention. Removable and interchangeable inserts  418  ( FIG. 4A ) with corresponding square cross-sections can be placed inside of the cells  534  on the template  204 . For example, magnetic inserts  420 ,  426  ( FIG. 4A ) and non-magnetic inserts  428 ,  430  ( FIG. 4A ) having a square cross-section can be placed inside of the cells  534  on the template  204 . 
       FIG. 5C  depicts an exemplary template  204  having a plurality of cells  536  having a hexagonal cross-section, according to an embodiment of the present invention. Removable and interchangeable inserts  418  ( FIG. 4A ) with corresponding hexagonal cross-sections can be placed inside of the cells  536  on the template  204 . For example, magnetic inserts  420 ,  426  ( FIG. 4A ) and non-magnetic inserts  428 ,  430  ( FIG. 4A ) having a hexagonal cross-section can be placed inside of the cells  536  on the template  204 . 
       FIG. 5D  depicts an exemplary template  204  having a plurality of cells  538  having a rectangular cross-section, according to an embodiment of the present invention. Removable and interchangeable inserts  418  ( FIG. 4A ) with corresponding rectangular cross-sections can be placed inside of the cells  538  on the template  204 . For example, magnetic inserts  420 ,  426  ( FIG. 4A ) and non-magnetic inserts  428 ,  430  ( FIG. 4A ) having a rectangular cross-section can be placed inside of the cells  538  on the template  204 . 
       FIG. 5E  depicts an exemplary template  204  having a plurality of cells  540  having a triangular cross-section, according to an embodiment of the present invention. Removable and interchangeable inserts  418  ( FIG. 4A ) with corresponding triangular cross-sections can be placed inside of the cells  540  on the template  204 . For example, magnetic inserts  420 ,  426  ( FIG. 4A ) and non-magnetic inserts  428 ,  430  having a triangular cross-section can be placed inside of the cells  540  on the template  204 . 
       FIG. 6  depicts a flowchart  600  of an exemplary process of controlling a sputtering process by optimizing the positions and arrangements of magnetic and non-magnetic inserts within a magnet pack. In a block  602 , a number of magnetic inserts are configured to control a pass through flux of a target based on a nonuniform erosion profile of the target. For example, in  FIG. 4B  magnetic inserts are arranged within cells of the template in order to control the pass through flux and erosion profile of the target, as illustrated in  FIG. 1B . 
     In a block  604 , a number of non-magnetic inserts are configured to control the pass through flux of the target based on the nonuniform erosion profile of the target. For example, in  FIG. 4B  non-magnetic inserts are arranged within cells of the template in order to control the pass through flux and erosion profile of the target, as illustrated in  FIG. 1B . 
     In a block  606 , the number of magnetic inserts is reconfigured to control the pass through flux of the target based on a change to the nonuniform erosion profile of the target. For example,  FIGS. 2 and 3  illustrate how the magnetic inserts can be reconfigured by opening the magnet pack, reconfiguring the magnetic inserts into various combinations (as exemplified in  FIG. 4B ), and reassembling the magnet pack in order to control the pass through flux and erosion profile of the target, as illustrated in  FIG. 1B . 
     In a block  608 , the number of non-magnetic inserts is reconfigured to control the pass through flux of the target based on the change to the nonuniform erosion profile of the target. For example,  FIGS. 2 and 3  illustrate how the non-magnetic inserts can be reconfigured by opening the magnet pack, reconfiguring the non-magnetic inserts into various combinations (as exemplified in  FIG. 4B ), and reassembling the magnet pack in order to control the pass through flux and erosion profile of the target, as illustrated in  FIG. 1B . 
     In various embodiments, the target is sputtered after the configuring and after the reconfiguring. For example,  FIGS. 1A and 1B  illustrate a sputtering process and the shaping of the PTF in response to a nonuniform erosion profile, exemplified by the trenches.  FIG. 4  further illustrates how arrangement and rearrangement of the magnetic and non-magnetic inserts might appear in various configuring and reconfiguring. It is understood that the configurations/reconfigurations of the magnetic and non-magnetic inserts is merely exemplary, and any combination, position, and/or shape may be used to adjust and tune the PTF and sputtering. 
     In some embodiments, the reconfiguring includes reducing the pass through flux of the target in an area greater than an outer diameter of a substrate, and in still further embodiments, the reconfiguring includes reducing the pass through flux of the target in an area of greater target erosion. For example,  FIG. 1B  illustrates the shaping of the PTF in response to the trenches. In addition,  FIG. 1B  and the corresponding description describe the variations in possible diameters between the substrate and the trenches, as caused by the location and strength of the PTF. 
     In various embodiments, the configuring and the reconfiguring maintains a substantially uniform sputter thickness of a substrate. For example, magnetic and non-magnetic inserts as illustrated in  FIGS. 4A and 4B  are positioned within cells of the programmable magnet pack in order to adjust the sputtering process illustrated in  FIG. 1  to create a uniform thickness of the substrate. As sputtering causes the target to have various thickness differences, the magnetic and non-magnetic inserts are reconfigured in order to maintain uniform substrate sputter thicknesses. 
     In an embodiment, a nonuniform shape of the magnetic flux is maintained based on further changes to the nonuniform erosion profile of the target. For example,  FIG. 1B  illustrates variations in the magnetic flux caused by the differences in thickness of the target caused by nonuniform erosion during sputtering. As a result of the nonuniform erosion profile, magnetic and non-magnetic inserts are used to optimize the magnetic flux into a nonuniform shape. 
     While particular embodiments have been described and/or illustrated, and while these embodiments and/or examples have been described in considerable detail, they are not intended to restrict or in any way limit the scope of the concepts presented herein. Additional adaptations and/or modifications may be possible, and these adaptations and/or modifications may also be encompassed. Accordingly, departures may be made from the foregoing embodiments and/or examples without departing from the scope of the concepts presented herein. The implementations described above and other implementations are within the scope of the following claims.