Patent Publication Number: US-2019189465-A1

Title: Methods and apparatus for physical vapor deposition

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims benefit of U.S. provisional patent application Ser. No. 62/641,007, filed Mar. 9, 2018 and U.S. provisional patent application Ser. No. 62/607,179, filed Dec. 18, 2017, each of which are herein incorporated by reference in their entirety. 
    
    
     FIELD 
     Embodiments of the present disclosure generally relate to substrate processing equipment, and more particularly, to methods and apparatus for depositing materials via physical vapor deposition. 
     BACKGROUND 
     The semiconductor processing industry generally continues to strive for increased uniformity of layers deposited on substrates. For example, with shrinking circuit sizes leading to higher integration of circuits per unit area of the substrate, increased uniformity is generally seen as desired, or required in some applications, in order to maintain satisfactory yields and reduce the cost of fabrication. Various technologies have been developed to deposit layers on substrates in a cost-effective and uniform manner, such as chemical vapor deposition (CVD) or physical vapor deposition (PVD). 
     However, the inventor has observed that with the drive to produce equipment to deposit more uniformly, certain applications may not be adequately served where purposeful deposition is required that is not symmetric or uniform with respect to the given structures being fabricated on a substrate. 
     Accordingly, the inventor has provided improved methods and apparatus for depositing materials via physical vapor deposition. 
     SUMMARY 
     Methods and apparatus for physical vapor deposition are provided herein. In accordance with at least some embodiments, there is provided an apparatus for physical vapor deposition (PVD). The apparatus includes a linear PVD source to provide a stream of material flux comprising material to be deposited on a substrate; and a substrate support having a support surface to support the substrate at a non-perpendicular angle to the stream of material flux, wherein at least one of the substrate support or the linear PVD source are movable in a direction parallel to a plane of the support surface of the substrate support sufficiently to cause the stream of material flux to move completely over a surface of the substrate, when disposed on the substrate support during operation. 
     In accordance with at least some embodiments, there is provided an apparatus for physical vapor deposition (PVD). The apparatus includes a first linear PVD source to provide a first stream of material flux comprising a first material to be deposited at a first non-perpendicular angle on a substrate; a second linear PVD source disposed non-parallel relative to the first linear PVD source to provide a second stream of material flux comprising a second material to be deposited at a second non-perpendicular angle on the substrate; anda substrate support configured to support the substrate, wherein at least one of the substrate support, the first linear PVD source, or the second linear PVD source are movable with respect to each other sufficiently to cause the first stream and the second stream of material flux to move completely over a surface of the substrate during operation. 
     In accordance with at least some embodiments, there is provided a method for physical vapor deposition (PVD). The method includes supporting, using a substrate support, a substrate at a non-perpendicular angle to a linear PVD source; providing, from the linear PVD source, a stream of material flux comprising material to be deposited on the substrate; and moving at least one of the substrate support or the linear PVD source in a direction parallel to a plane of a support surface of the substrate support sufficiently to cause the stream of material flux to move completely over a surface of the substrate. 
     Other and further embodiments of the present invention are described below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the present disclosure, briefly summarized above and discussed in greater detail below, can be understood by reference to the illustrative embodiments of the disclosure depicted in the appended drawings. However, the appended drawings illustrate only typical embodiments of the disclosure and are therefore not to be considered limiting of scope, for the disclosure may admit to other equally effective embodiments. 
         FIGS. 1A-1B  are schematic side and top views, respectively, of an apparatus for physical vapor deposition in accordance with at least some embodiments of the present disclosure. 
         FIG. 2A  is a schematic side view of a feature having a layer of material deposited thereon in accordance with at least some embodiments of the present disclosure. 
         FIG. 2B  is a schematic side view of a substrate having a plurality of features having a layer of material deposited thereon, as depicted in  FIG. 2A , in accordance with at least some embodiments of the present disclosure. 
         FIG. 2C  is a schematic side view of a feature having a layer of material deposited thereon in accordance with at least some embodiments of the present disclosure. 
         FIG. 2D  is a schematic side view of a substrate having a plurality of features having a layer of material deposited thereon, as depicted in  FIG. 2C , in accordance with at least some embodiments of the present disclosure. 
         FIGS. 3A-3B  are two dimensional and three dimensional schematic side views of an apparatus for physical vapor deposition in accordance with at least some embodiments of the present disclosure. 
         FIGS. 3C-3D  respectively depict schematic top and isometric cross-sectional views of a substrate support and deposition structure of an apparatus for physical vapor deposition in accordance with at least some embodiments of the present disclosure. 
         FIG. 4  is a schematic side view of an apparatus for physical vapor deposition in accordance with at least some embodiments of the present disclosure. 
         FIGS. 5A-5B  are schematic side and top views, respectively, of an apparatus for physical vapor deposition in accordance with at least some embodiments of the present disclosure. 
         FIG. 6  is a schematic side view of an apparatus for physical vapor deposition illustrating material deposition angles in accordance with at least some embodiments of the present disclosure. 
         FIG. 7  is a schematic side view of an apparatus for physical vapor deposition illustrating material deposition angles in accordance with at least some embodiments of the present disclosure. 
         FIG. 8  is a schematic side view of a portion of an apparatus for physical vapor deposition illustrating material deposition angles in accordance with at least some embodiments of the present disclosure. 
         FIG. 9  depicts schematic top and side views of an apparatus for physical vapor deposition illustrating material deposition angles in accordance with at least some embodiments of the present disclosure. 
         FIG. 10  depicts schematic top and side views of an apparatus for physical vapor deposition illustrating material deposition angles in accordance with at least some embodiments of the present disclosure. 
         FIG. 11  is a schematic side view of an apparatus for physical vapor deposition in accordance with at least some embodiments of the present disclosure. 
         FIG. 12  is a schematic side view of an apparatus for physical vapor deposition in accordance with at least some embodiments of the present disclosure. 
         FIG. 13  is a flowchart of a method for physical vapor deposition using the apparatus described herein in accordance with at least some embodiments of the present disclosure. 
     
    
    
     To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. The figures are not drawn to scale and may be simplified for clarity. Elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation. 
     DETAILED DESCRIPTION 
     Embodiments of methods and apparatus for physical vapor deposition (PVD) are provided herein. Embodiments of the disclosed methods and apparatus advantageously enable uniform angular deposition of materials on a substrate. In such applications, deposited materials are asymmetric or angular with respect to a given feature on a substrate, but can be relatively uniform within all features across the substrate. Embodiments of the disclosed methods and apparatus advantageously enable new applications or opportunities for selective PVD of materials, thus further enabling new markets and capabilities. 
       FIGS. 1A-1B  are schematic side and top views, respectively, of an apparatus  100  for PVD in accordance with at least some embodiments of the present disclosure. Specifically,  FIGS. 1A-1B  schematically depict an apparatus  100  for PVD of materials on a substrate  106  at an angle to the generally planar surface of the substrate  106 . The apparatus  100  generally includes a linear PVD source  102  and a substrate support  104  for supporting the substrate  106 . The linear PVD source  102  is configured to provide a directed stream of material flux (stream  108  as depicted in  FIGS. 1A-1B ) from the source toward the substrate support  104  (and any substrate  106  disposed on the substrate support  104 ). The substrate support  104  has a support surface to support the substrate  106  such that a working surface of the substrate  106  to be deposited on is exposed to the directed stream  108  of material flux. The stream  108  of material flux provided by the linear PVD source has a width greater than that of the substrate support  104  (and any substrate  106  disposed on the substrate support  104 ). The stream  108  of material flux has a linear elongate axis corresponding to the width of the stream  108  of material flux. The substrate support  104  and the linear PVD source  102  are configured to move linearly with respect to each other, as indicated by arrows  110 . The relative motion can be accomplished by moving either or both of the linear PVD source  102  or the substrate support  104 . Optionally, the substrate support  104  may additionally be configured to rotate (for example, within the plane of the support surface), as indicated by arrows  112 . 
     The linear PVD source  102  includes target material to be sputter deposited on the substrate  106 . In some embodiments, the target material can be, for example, a metal, such as titanium, or the like, suitable for depositing titanium (Ti) or titanium nitride (TiN) on the substrate  106 . In some embodiments, the target material can be, for example, silicon, or a silicon-containing compound, suitable for depositing silicon (Si), silicon nitride (SiN), silicon oxynitride (SiON), or the like on the substrate  106 . Other materials may suitably be used as well in accordance with the teachings provided herein. The linear PVD source  102  further includes, or is coupled to, a power source (not shown) to provide suitable power for forming a plasma proximate the target material and for sputtering atoms off of the target material. The power source can be either or both of a DC or an RF power source. 
     Unlike an ion beam or other ion source, the linear PVD source  102  is configured to provide mostly neutrals and few ions of the target material. As such, a plasma may be formed having a sufficiently low density to avoid ionizing too many of the sputtered atoms of target material. For example, for a 300 mm diameter wafer as the substrate  106 , about 1 to about 40 kW of DC or RF power may be provided. The power or power density applied can be scaled for other size substrates. In addition, other parameters may be controlled to assist in providing mostly neutrals in the stream  108  of material flux. For example, the pressure may be controlled to be sufficiently low so that the mean free path is longer than the general dimensions of an opening of the linear PVD source  102  through which the stream  108  of material flux passes toward the substrate support  104  (as discussed in more detail below). In some embodiments, the pressure may be controlled to be about 0.5 to about 5 millitorr. 
     The methods and embodiments disclosed herein advantageously enable deposition of materials with a shaped profile, or in particular, with an asymmetric profile with respect to a given feature on a substrate, while maintaining overall deposition and shape uniformity across all features on a substrate. For example,  FIG. 2A  depicts a schematic side view of a substrate  200  including a feature  202  having a layer of material  204  deposited thereon in accordance with at least some embodiments of the present disclosure. The feature  202  can be a trench, a via, or dual damascene feature, or the like. In addition, the feature  202  can protrude from the substrate rather than extend into the substrate. The material  204  is deposited not just atop a top surface  206  of the substrate  200  (e.g., the field region), but also within or along at least portions of the feature  202  as well. However, the material  204  is deposited to a greater thickness on a first side  210  of the feature  202  as compared to an opposing second side  212  of the feature (as depicted by portion  208  of material). In some embodiments, and depending upon the incoming angle of the stream  108  of material flux, material can be deposited on a bottom  214  of the feature  202 . In some embodiments, and as depicted in  FIG. 2A , little or no material  204  is deposited on a bottom  214  of the feature  202 . In some embodiments, additional material  204  is deposited particularly near an upper corner  216  of the first side  210  of the feature  202 , as compared to an opposite upper corner  218  of the second side  212  of the feature  202 . 
     As shown in  FIG. 2B , which is a schematic side view of a substrate having a plurality of features having a layer of material  204  deposited thereon in accordance with at least some embodiments of the present disclosure, the material  204  is deposited relatively uniformly across a plurality of features  202  formed in the substrate  200 . As shown in  FIG. 2B , the shape of the deposited material  204  is substantially uniform from feature to feature across the substrate  200 , but is asymmetric within any given feature  202 . Thus, embodiments in accordance with the present disclosure advantageously provide controlled/uniform angular deposition of the material  204  on the substrate  200  with a substantially uniform amount of the material  204  deposited on a field region of the substrate  200 . 
     In some embodiments, for example where the substrate support  104  is configured to rotate in addition to moving linearly with respect to the linear PVD source  102 , different profiles of material  204  deposition can be provided. For example,  FIG. 2C  depicts a schematic side view of a substrate  200  including feature  202  having a layer of material  204  deposited thereon in accordance with at least some embodiments of the present disclosure. As described above with respect to  FIGS. 2A-2B , the material  204  is deposited not just atop a top surface  206  of the substrate  200  (e.g., the field region), but also within or along at least portions of the feature  202  as well. However, in embodiments consistent with  FIG. 2C , the material  204  is deposited to a greater thickness on both the first side  210  of the feature  202  as well as the opposing second side  212  of the feature  202  (as depicted by portion  208  of material) as compared to the bottom  214  of the feature  202 . In some embodiments, and depending upon the incoming angle of the stream  108  of material flux, the amount of materials deposited on lower portions of the sidewall (e.g., the first side  210  and the second side  212 ) and the bottom  214  of the feature  202  can be controlled. However, as depicted in  FIG. 2C , little or no material is deposited on the bottom  214  of the feature  202  (as well as on the lower portion of the sidewalls proximate the bottom  214 ). 
     As shown in  FIG. 2D , which is a schematic side view of a substrate having a plurality of features having a layer of material deposited thereon in accordance with at least some embodiments of the present disclosure, the material  204  is deposited relatively uniformly across the plurality of features  202  formed in the substrate  200 . As shown in  FIG. 2D , the shape of the deposited material  204  is substantially uniform from feature to feature across the substrate  200 , but with a controlled material profile within any given feature  202 . Thus, embodiments in accordance with the present disclosure advantageously provide controlled/uniform angular deposition of material on a substrate with a substantially uniform amount of material deposited on a field region of the substrate  200 . 
     Although the above description of  FIGS. 2A-2D  refer to the feature  202  having sides (e.g., the first side  210  and the second side  212 ), the feature  202  can be circular (such as a via). In such cases where the feature  202  is circular, although the feature  202  may have a singular sidewall, the first side  210  and second side  212  can be arbitrarily selected/controlled based upon the orientation of the substrate  200  (e.g, the substrate  106 ) with respect to the linear axis of movement of the substrate support  104  and direction of the stream  108  of material flux from the linear PVD source  102 . Moreover, in embodiments where, for example, the substrate support  104  can rotate, the first side  210  and second side  212  can change, or be blended, dependent upon the orientation of the substrate  106  during processing. 
     The above apparatus  100  can be implemented in numerous ways, and several non-limiting embodiments are provided herein in  FIG. 3A  through  FIG. 12 . While different Figures may discuss different features of the apparatus  100 , combinations and variations of these features may be made in keeping with the teachings provided herein. In addition, although the Figures may show an apparatus having a particular orientation (e.g., vertical or horizontal), such orientations are examples and not limiting of the disclosure. For example, any configuration can be rotated or oriented differently than as shown on the page.  FIGS. 3A-3B  are two dimensional and three dimensional schematic side views of an apparatus  300  for physical vapor deposition in accordance with at least some embodiments of the present disclosure. Certain items shown in  FIG. 3A  have been removed from  FIG. 3B  to enhance the clarity of the disclosure. The apparatus  300  is an exemplary implementation of the apparatus  100  and discloses several exemplary features. 
     As depicted in  FIGS. 3A-3B , the linear PVD source may include a chamber or housing  302  having an interior volume. A target  304  of source material to be sputtered is disposed within the housing  302 . The target  304  is generally elongate and can be, for example, cylindrical or rectangular. The target  304  size can vary depending upon the size of the substrate  106  and the configuration of the processing chamber (e.g., deposition chamber  308 , discussed below). For example, for processing a 300 mm diameter semiconductor wafer, the target  304  can be between about 100 to about 200 mm in width or diameter, and can have a length of about 400 to about 600 mm. The target  304  can be stationary or movable, including rotatable along the elongate axis of the target  304 . 
     The target  304  is coupled to a power source  305 . A gas supply (not shown) may be coupled to the interior volume of the housing  302  to provide a gas, such as an inert gas (e.g., argon) or nitrogen (N 2 ) suitable for forming a plasma within the interior volume when sputtering material from the target  304  (creating the stream  108  of material flux). The housing  302  is coupled to a deposition chamber  308  containing the substrate support  104 . A vacuum pump can be coupled to an exhaust port (not shown) in at least one of the housing  302  or the deposition chamber  308  to control the pressure during processing. 
     An opening  306  couples the interior volumes of the housing  302  and the deposition chamber  308  to allow the stream  108  of material flux to pass from the housing  302  into the deposition chamber  308 , and onto the substrate  106 . As discussed in more detail below, the position of the opening  306  with respect to the target  304  as well as the dimensions of the opening  306  can be selected or controlled to control the shape and size of the stream  108  of material flux passing though the opening  306  and into the deposition chamber  308 . For example, the length of the opening is wide enough to allow the stream  108  of material flux to be wider than the substrate  106 . In addition, the width of the opening  306  may be controlled to provide an even deposition rate along the length of the opening  306  (e.g., a wider opening may provide greater deposition uniformity, while a narrower opening may provide increased control over the angle of impingement of the stream  108  of material flux on the substrate  106 ). In some embodiments, a plurality of magnets may be positioned proximate the target  304  to control the position of the plasma with respect to the target  304  during processing. The deposition process can be tuned by controlling the plasma position (e.g., via the magnet position), and the size and relative position of the opening  306 . 
     The housing  302  can include a liner of suitable material to retain particles deposited on the liner to reduce or eliminate particulate contamination on the substrate  106 . The liner can be removable to facilitate cleaning or replacement. Similarly, a liner can be provided to some or all of the deposition chamber  308 , for example, at least proximate the opening  306 . The housing  302  and the deposition chamber  308  are typically grounded. 
     In the embodiment depicted in  FIGS. 3A-3B  the linear PVD source  102  is stationary and the substrate support  104  is configured to linearly move. For example, the substrate support  104  is coupled to a linear slide  310  that can move linearly back and forth along direction of arrow  312  sufficiently within the deposition chamber  308  to allow the stream  108  of material flux to impinge upon desired portions of the substrate  106 , such as the entire substrate  106 . A position control mechanism  322 , such as an actuator, motor, drive, or the like, controls the position of the substrate support  104 , for example, via the linear slide  310 . The substrate support  104  may be moved linearly along a plane such that the surface of the substrate  106  is maintained at a perpendicular distance of about 1 to about 10 mm from the opening  306 . The substrate support  104  can be moved at a rate to control the deposition rate on the substrate  106 . Alternatively, or additionally, the substrate support  104  can be coupled to robot linkage (not shown) that is configured to move the substrate support  104  linearly back and forth sufficiently within the deposition chamber  308  to allow the stream  108  of material flux to impinge upon desired portions of the substrate  106 , such as the entire substrate  106 . 
     Optionally, the substrate support  104  can also be configured to rotate within the plane of the support surface, such that the substrate  106  disposed on the substrate support  104  can be rotated. A rotation control mechanism, such as an actuator, a motor, a drive, a robot, or the like, controls the rotation of the substrate support  104  independent of the linear position of the substrate support  104 . Accordingly, the substrate support  104  can be rotated while the substrate support  104  is also moving linearly through the stream  108  of material flux during operation. Alternatively, the substrate support  104  can be rotated between linear scans of the substrate support  104  through the stream  108  of material flux during operation (e.g., the substrate support  104  can be moved linearly without rotation, and rotated while not moving linearly). 
     In addition, the substrate support  104  can move to a position for loading and unloading of substrates into and out of the deposition chamber  308 . For example, in some embodiments, a transfer chamber  324 , such as a load lock, may be coupled to the deposition chamber  308  via a slot or opening  318 . A substrate transfer robot  316 , or other similar suitable substrate transfer device, can be disposed within the transfer chamber  324  and movable between the transfer chamber  324  and the deposition chamber  308 , as indicated by arrows  320 , to move substrates into and out of the deposition chamber  308  (and onto and off of the substrate support  104 ). In embodiments where the substrate support  104  has a different orientation required for deposition and transfer, the substrate support  104  can further be rotatable or otherwise movable, as indicated by arrows  314 . For example, in the embodiments depicted in  FIGS. 3A-3B , the substrate support  104  can be in a horizontal, and lower, position (in terms of the Figures) when moving substrates between the substrate support  104  and the transfer chamber  324 . In addition, the substrate support  104  can be in a vertical, and upper, position (in terms of the Figures) when moving the substrate  106  relative to the stream  108  of material flux to deposit materials atop the substrate  106 . 
     Depending upon the configuration of the substrate support  104 , and in particular of the support surface of the substrate support  104  (e.g., vertical, horizontal, or angled), the substrate support  104  may be configured appropriately to retain the substrate  106  during processing. For example, in some embodiments, the substrate  106  may rest on the substrate support  104  via gravity. In some embodiments, the substrate  106  may be secured onto the substrate support  104 , for example, via a vacuum chuck, an electrostatic chuck, mechanical clamps, or the like. Substrate guides and alignment structures may also be provided to improve alignment and retention of the substrate  106  on the substrate support  104 . 
       FIGS. 3C-3D  respectively depict schematic top and isometric cross-sectional views of a substrate support and deposition structure of an apparatus for physical vapor deposition in accordance with at least some embodiments of the present disclosure.  FIG. 3D  is an isometric cross-sectional view of the substrate support and deposition structure taken along line I-I in  FIG. 3C . 
     A deposition structure  326  may be disposed around the substrate  106  and the substrate support  104  within the deposition chamber  308 . For example, the deposition structure  326  may be coupled to the substrate support  104 . In some embodiments, the deposition structure  326  and a front surface of the substrate  106  form a common planar surface. The deposition structure  326  reduces deposits or particles from accumulating on the edge and backside of the substrate  106  during the scanning of the substrate  106 . Furthermore, use of the deposition structure  326  reduces deposits or particles from accumulating on the substrate support  104  and hardware and equipment in the vicinity of the substrate support  104 . In some embodiments, a voltage source (not shown) may be coupled to a portion of the deposition structure  326  to apply a charge to a portion of the deposition structure  326 . In some embodiments, the voltage source may be used to apply a voltage or charge to a removable structure  328  associated with the deposition structure  326 . Although the stream  108  of material flux comprises mostly neutrals, applying a charge to the portion of the deposition structure  326  or the removable structure  328  may further reduce deposits or particles that accumulate on the edge and backside of the substrate during the scanning of the substrate  106  due to any ionized particles. 
     In some embodiments, the deposition structure  326  includes a removable structure  328  disposed in an opening  330  of the deposition structure  326 . The removable structure  328  can have a shape that corresponds to the substrate  106 . For example, in embodiments where the substrate  106  is a circular substrate, such as a semiconductor wafer, the removable structure  328  is a removable ring structure. As depicted in  FIGS. 3C-3D , the substrate  106  is exposed through the opening  330 . 
     The removable structure  328  has an outside edge surface  332  and an inside edge surface  334 . A circumference of the inside edge surface  334  is greater than a circumference of the substrate support  104 . Furthermore, in some embodiments, the removable structure  328  has an exterior surface  336  aligned with a front surface  338  of the deposition structure  326 . Furthermore, in some embodiments, a front surface  340  of the substrate  106  may be aligned with the front surface  338  of the deposition structure  326  and the exterior surface  336  of the removable structure  328 . Therefore, in some embodiments, the exterior surface  336  of the removable structure  328 , the front surface  338  of the deposition structure  326 , and the front surface  340  of the substrate  106  form a planar surface. In some embodiments, the exterior surface  336  is not aligned with the front surface  338  of the deposition structure  326  and/or the front surface  340  of the substrate  106 . 
     As depicted in  FIG. 3D , the removable structure  328  includes a groove  342 . The groove  342  may be formed in at least a portion of a circumference of the removable structure  328 . In some embodiments, the groove  342  is formed in the entire circumference of the removable structure  328 . The groove  342  may include an angled surface  344  functional to direct the particles associated with the stream  108  of material flux away from a backside  346  of the substrate  106 . Moreover, the angled surface  344  is functional to direct particles associated with the stream  108  of material flux away from the substrate support  104 . In some embodiments, particles associated with the stream  108  of material flux may be directed by the angled surface  344  toward a surface  348  associated with the groove  342 . The groove  342  may be formed having a shallower or deeper depth than shown in  FIG. 3D . Furthermore, while the surface  348  is illustrated as being straight, the surface  348  may alternatively be formed at an angle similar to the angled surface  344 . 
     The removable structure  328  can include a ledge  350 . The ledge  350  may be in contact with a backside  352  of the deposition structure  326 . In some embodiments, the ledge  350  is removably press fit against the deposition structure  326 , on the backside  352  of the deposition structure  326 . 
     In some embodiments, the ledge  350  is coupled to the deposition structure  326 , on the backside  352  of the deposition structure  326 . For example, the removable structure  328  may include one or more through holes  353 . In some embodiments, a plurality of through holes  353  are disposed in the ledge  350 . The plurality of through holes  353  may receive a retainer element  356 , such as a fastener, screw, or the like. Each of the retainer elements  356  may be received by a hole  358  in the deposition structure  326 . Therefore, the deposition structure  326  may include a plurality of the holes  358 . In another embodiment, the holes  358  may be through holes so that the retainer elements  356  may be inserted from the front surface  338  of the deposition structure  326  and retainably attached to the ledge  350  using a nut, fastener or threads. 
     The substrate plane structure having the removable structure  328 , e.g., a removable ring, is advantageously straightforward to maintain. Specifically, advantageously, rather than removing the entire substrate plane structure when preventive maintenance is required, the removable structure  328  can be removed to complete the required preventative maintenance. Furthermore, because the substrate plane structure and the removable structure  328  pieces advantageously provide a modular unit, the costs associated with maintaining and replacing the modular unit may be advantageously reduced compared to maintaining and replacing conventional substrate plane structures formed as one contiguous unit. In addition, advantageously, the removable structure  328 , for example, may be made from different materials compared to the remainder of the substrate plan structure. For example, use of particular material types for the removable structure  328  may advantageously mitigate accumulation of deposits and particles on the edge of the substrate  106  or a wafer. 
       FIG. 4  is a schematic side view of an apparatus  400  for physical vapor deposition in accordance with at least some embodiments of the present disclosure. The apparatus  400  is an exemplary implementation of the apparatus  100  and discloses several exemplary features. The apparatus  400  is similar to and operates in similar fashion as the apparatus  300  described above except that the orientation of the substrate  106  remains constant relative to the deposition and loading/unloading positions, as compared to the orthogonal relative positions in the apparatus  300 . In addition, in the orientation of the page,  FIGS. 3A-3B  depicts a vertically configured system (e.g., the substrate support  104  moves vertically), and  FIG. 4  depicts a horizontally configured system (e.g., the substrate support  104  moves horizontally). 
     As depicted in  FIG. 4 , a plurality of lift pins  402  can be provided proximate the opening  318  to facilitate transferring the substrate  106  between the substrate support  104  and a substrate transfer robot (e.g., as discussed above with respect to  FIGS. 3A-B ). 
     In addition, the target can have a different configuration than the cylindrical target  304  depicted in other Figures. Specifically, target  404  can be a rectangular target having, for example, a planar rectangular face of target material to be sputtered. The aforementioned target configuration can also be used in any of the other embodiments disclosed herein. 
       FIGS. 5A-5B  are schematic side and top views, respectively, of an apparatus for physical vapor deposition in accordance with at least some embodiments of the present disclosure. The apparatus is an exemplary implementation of the apparatus  100  and discloses several exemplary features. The apparatus of  FIGS. 5A-5B  is similar to and operates in similar fashion as the apparatus  300  described above except that the linear slide  310  (and position control mechanism  322 , not shown) extend from the top of the deposition chamber  308 , rather than from the bottom. 
     In addition, as depicted in  FIG. 5B , the linear slide  310  can include a plurality of linear slide members  502 . Each linear slide member  502  can be coupled to the substrate support  104  at a first end, for example, via a cross member  504 . An opposing end of the linear slide members  502  can be coupled to the position control mechanism  322  to facilitate control of the substrate support  104 . 
     In embodiments of a PVD apparatus as disclosed herein, the general angle of incidence of the stream  108  of material flux can be controlled or selected to facilitate a desired deposition profile of material on the substrate. In addition, the general shape of the stream  108  of material flux can be controlled or selected to control the deposition profile of material deposited on the substrate. In some embodiments, material can be deposited on a top surface of the substrate and a first sidewall of a feature on the substrate (e.g., substantially as depicted in  FIGS. 2A-2D ). In some embodiments, depending upon the deposition angle, material can further be deposited on a bottom surface of the feature  202 . In some embodiments, depending upon the deposition angle, material can further be deposited on an opposing sidewall surface of the feature  202 , with greater deposition on a first sidewall (e.g., first side  210 ) as compared to the opposing sidewall (e.g., second side  212 ) of the feature  202 . 
     For example,  FIG. 6  is a schematic side view of an apparatus for physical vapor deposition illustrating material deposition angles in accordance with at least some embodiments of the present disclosure. The position of the target  304  within the housing  302  with respect to the opening  306  coupling the housing  302  to the deposition chamber  308  defines a general angle of incidence of the stream  108 , as depicted by dashed line  606 , in a plane orthogonal to the length of the opening  306  (e.g., in the plane of the page, where the opening  306  runs in a direction into and out of the page). However, the general angle of incidence is not the angle of incidence of all particles in the stream  108  of material flux, since the particles can come from different locations on the target and can generally travel through the opening along a line of sight from the location on the target where the particle originated. For example, arrows  602  and  604  show typical boundaries of the stream  108  of material flux from the target that can pass through the opening. Particles travelling in other directions will not pass through the opening  306  and will be retained within the housing  302 , and a portion  608  of the stream  108  of material flux that passes through the opening  306  impinges upon the substrate  106  (see  FIGS. 6 and 7 ). 
     In some embodiments, at least one of the width of the opening or the position of the opening can be controlled to allow altering the relative position of the opening and the target within the housing. For example,  FIG. 7  is a schematic side view of an apparatus for physical vapor deposition illustrating material deposition angles in accordance with at least some embodiments of the present disclosure. In some embodiments, at least one movable shutter is provided (two movable shutters  702 ,  704  shown in  FIG. 7 ) on the housing  302  and/or the deposition chamber  308 . Shutters  702 ,  704  are movable linearly as indicated by arrows  706 ,  708 . By control of one or both shutters  702 ,  704 , the width of the opening  306  and/or the relative position of the opening  306  can be controlled. For example, moving one shutter, e.g.,  702 , with respect to the other shutter, e.g.,  704 , can change the width of the opening  306 . Alternatively, moving both shutters  702 ,  704  together can change the position of the opening  306  with respect to the target  304  without altering the width of the opening  306 . Alternatively, moving both shutters  702 ,  704  to different locations can change both the position and the width of the opening  306 . 
     As an example,  FIG. 8  is a schematic side view of a portion of an apparatus for physical vapor deposition illustrating material deposition angles in accordance with at least some embodiments of the present disclosure. As shown in  FIG. 8 , to control the size of the stream  108  of material flux, in addition to the angle of incidence, several parameters can be predetermined, selected, or controlled. For example, a diameter  812  or width of a target  802  can be predetermined, selected, or controlled (e.g., the substrate can have a given diameter). In addition, a first working distance  814  from the target  802  to the sidewall of the housing  302  containing the opening  306  (or to the shutters  702 ,  704 ), can be predetermined, selected, or controlled. A second working distance  816  from the opening  306  to the substrate  106  can also be predetermined, selected, or controlled. Lastly, the size of the opening  306  can be predetermined, selected, or controlled. Taking these parameters into account, the minimum and maximum angles of incidence can be predetermined, selected, or controlled as shown in  FIG. 8 . In addition, in embodiments with one or more movable shutters  702 ,  704 , the shutters  702 ,  704  may be controlled to adjust the minimum and/or maximum angles of incidence of particles from the stream  108  of material flux. 
     For example, with a given target diameter  812  of target  802 , working distance  814 , and second working distance  816 , the size of the opening  306  can be set to control a width of the stream  108  of material flux that passes through the opening  306  and impinges upon the substrate  106 . For example, the opening  306  (and other parameters discussed above) can be set to control the minimum and maximum angles of incidence of material from the stream  108  of material flux. For example, lines  806  and  804  represent possible paths of material from a first portion of the target  802  that can pass through the opening  306 . Lines  808  and  810  represent possible paths of material from a second portion of the target  802  that can pass through the opening  306 . The first and second portions of the target  802  represent the maximum spread of materials with line of sight paths to the opening  306 . The overlap of paths of materials that can travel via line of sight through the opening  306  are bounded by lines  806  and  810 , which represent the minimum and maximum angles of incidence of material from the stream  108  of material flux that can pass through the opening  306  and deposit on the substrate  106 . The angles of 45 degrees and 65 degrees are illustrative. For example, the angle of impingement may generally range between about 10 to about 65 degrees, or more. 
     The above discussion with respect to  FIGS. 6-8  refer to the shape and angles of incidence of materials from the stream  108  of material flux along planes orthogonal to the axial length of the opening  306  (e.g., side views of the stream  108  of material flux).  FIG. 9  depicts schematic top and side views of an apparatus for physical vapor deposition illustrating top and side view of material deposition angles in accordance with at least some embodiments of the present disclosure. As depicted in  FIG. 9 , right panel, a side view of the stream  108  of material flux is shown, which corresponds to  FIGS. 6-8  above.  FIG. 9 , left panel, depicts a top view showing the stream  108  of material flux from a top view, parallel to the axial length of the target  304  (and opening  306 ), referred to herein as in a lateral direction (e.g., side to side along the axial length of the target). As shown in the top view of  FIG. 9 , left panel, the angles  902  of incidence of material from the stream  108  of material flux can vary greatly and also are not controlled as the angles are along the side dimensions discussed above. 
     In some embodiments, the lateral angles of incidence can also be controlled. For example,  FIG. 10  depicts schematic top and side views of an apparatus for physical vapor deposition illustrating material deposition angles  1004  in accordance with at least some embodiments of the present disclosure. The teachings of  FIG. 10  can be incorporated in any of the embodiments disclosed herein. As depicted in  FIG. 10 , physical structure such as baffles, or collimator  1002 , can be interposed between the target  304  and the opening  306  such that the stream  108  of material flux travels through the structure (e.g., collimator  1002 ). Any materials with an angle to great to pass through the structure will be blocked from passing through the opening  306 , thus limiting the permitted angular range of materials passing through the opening  306 . 
     Combinations and variations of the above embodiments include apparatus having more than one target to facilitate deposition at multiple angles. For example,  FIG. 11  is a schematic side view of an apparatus for physical vapor deposition in accordance with at least some embodiments of the present disclosure. As depicted in  FIG. 11 , two linear PVD sources  102 ,  102 ′ in respective housing  302 ,  302 ′ may be provided, such that targets  304 ,  304 ′ can have respective streams  108 ,  108 ′ of material flux that are separately, e.g., simultaneously or sequentially, directed through respective openings  306 ,  306 ′ to impinge of the substrate  106 . The target materials can be the same material or different materials. In addition, process gases provided to the separate linear PVD sources  102 ,  102 ′ can be the same or different. The size of the targets, location of the targets, location and size of the openings, can be independently controlled to independently control the impingement of materials from each stream  108 ,  108 ′ of material flux onto the substrate  106 . 
       FIG. 12  is a schematic side view of an apparatus for physical vapor deposition in accordance with at least some embodiments of the present disclosure.  FIG. 12  is similar to the embodiment of  FIG. 11  except that the two targets  304 ,  304 ′ are provided within the same linear PVD source  102 . 
     In each of the embodiments of  FIGS. 11-12 , the relative angles of the targets  304 ,  304 ′, and thus the direction of the streams  108 ,  108 ′ of material flux are illustrative and other angles can be chosen independently, including in directions such that the targets  304 ,  304 ′ are not parallel to each other. 
       FIG. 13  is a flowchart of a method for PVD using the apparatus described herein in accordance with at least some embodiments of the present disclosure. In operation, a substrate (e.g., the substrates  106 ,  200 ) is disposed on the support surface of the substrate support  104  at  1300 , and a stream of material flux (e.g., stream  108 ) can be provided from a linear PVD source (e.g., the linear PVD sources  102 ,  102 ′) at  1302 . For the example, in some embodiments the substrate can be supported at a non-perpendicular angle to the linear PVD source. Alternatively or additionally, the linear PVD source can provide the stream  108  of material flux at an the non-perpendicular angle, in a manner as described above. The stream of material flux passes into the deposition chamber  308  through the opening  306  between the linear PVD source and the deposition chamber  308 . Optionally, the range of angles of travel of the material within the elongate dimension of the stream  108  of material flux can be limited (e.g., as disclosed in  FIG. 10 ). 
     The substrate support  104 , at  1304 , can be moved linearly from a first position (for example, where the stream  108  of material flux is proximate the first side  210  of the substrate  200 ), through the stream  108  of material flux to a second position (for example, where the stream  108  of material flux is proximate the second side  212  of the substrate  200  opposite the first side  210 ). Alternatively, or additionally, the linear PVD source can be moved in a similar manner as the substrate support  104 , e.g., from the first position to the second position. 
     The first position can position the substrate completely out of the stream  108  of material flux, or at least a portion of the stream  108  of material flux. The second position can also position the substrate completely out of the stream  108  of material flux, or at least a portion of the stream  108  of material flux. The amount of deposition of material on the substrate depends upon the deposition rate and the rate of speed of the linear movement of the substrate through the stream  108  of material flux. The substrate can pass through the stream  108  of material flux once (e.g., move from the first position to the second position once) or multiple times (e.g., move from the first position to the second position, then move from the second position to the first position, etc.) in order to deposit a desired thickness of material on the substrate. Optionally, the substrate can be rotated between passes (e.g., after reaching the first position or the second position at the end of linear movement) or while passing through the stream  108  of material flux (e.g., at the same time as the linear movement from the first position to the second position). 
     In embodiments where two streams  108 ,  108 ′ of material flux are provided (e.g., as shown in  FIGS. 11-12 ), the streams  108 ,  108 ′ can be alternated or provided simultaneously. In addition, the orientation of the substrate can be rotationally fixed or variable. For example, in some embodiments, the two streams  108 ,  108 ′ of material flux can alternately provide the same material or different materials to be deposited asymmetrically on the substrate as shown in  FIGS. 2A-2B . The substrate can be rotationally fixed while the first stream (e.g., the stream  108 ) of material flux is provided in a first pass through the first stream of material flux. The substrate can then be rotated 180 degrees and subsequently be rotationally fixed while the second stream (e.g., the stream  108 ′) of material flux is provided in a first pass through the second stream of material flux. If desired, after completion of the first pass through the second stream of material flux, the substrate can again be rotated 180 degrees and then held rotationally fixed in a second pass through the first stream of material flux. The rotation of the substrate and passes through either the first or the second streams of material flux can continue until a desired thickness of material is provided. In cases where the first and second streams of material flux provide different materials to be deposited, the rate of movement of the substrate support can be the same or different when passing through the first stream of material flux as compared to passing through the second stream of material flux. 
     In some embodiments, the substrate can be rotated continuously while passing through the first or the second stream of material flux (e.g., at the same time as the linear movement from the first position to the second position or from the second position to the first position) to achieve a deposition profile similar to that shown in  FIGS. 2C-2D . 
     While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof.