Abstract:
A workpiece support apparatus for use in a process vessel and process system for treating semiconductor workpieces. The process vessel is to be utilized in an integrated tool for wet chemical treatment of a semiconductor workpiece. The workpiece support apparatus includes a rotor having a central cavity and guide pins mounted at an outer perimeter. A workpiece support having extendable workpiece support fingers is connected to the rotor. The extendable workpiece support fingers are moveable from a first position to a second position. A bellows seal connects the workpiece support to the rotor. A fluid delivery tube is positioned in the central cavity of the rotor and connected to a supply of fluid. When the extendable workpiece support fingers are in the first position, the guide pins of the rotor cannot interfere with the loading of a workpiece onto the extendable workpiece support fingers, and when the extendable workpiece support fingers are in the second position, a pressurized fluid is delivered through the delivery tube to create a low pressure region adjacent an inner surface of the workpiece, lifting the workpiece off the extendable workpiece support fingers, exposing the entire backside of the workpiece for processing.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     Not Applicable  
       TECHNICAL FIELD  
       [0002]     The invention relates to surface preparation, cleaning, rinsing and drying of workpieces, such as semiconductor wafers, flat panel displays, rigid disk or optical media, thin film heads or other workpieces formed from a substrate on which microelectronic circuits, data storage elements or layers, or micro-mechanical elements may be formed. These and similar articles are collectively referred to herein as a “wafer” or “workpiece.” Specifically, the present invention relates to a workpiece support for use in a process vessel and process system for wet chemical treating semiconductor workpieces.  
       BACKGROUND  
       [0003]     Semiconductor wafer processing in the manufacture of integrated circuits and micromachines is increasingly complex. Wafer sizes are getting larger—typically 300 mm presently—and feature sizes for interconnect wiring are getting smaller with higher aspect ratios. Consequently, processes for cleaning and etching wafers in the course of manufacturing is being subjected to more stringent specifications. In particular, wafer etching/cleaning specifications are becoming more stringent as to contamination parameters.  
         [0004]     A significant factor in semiconductor wafer processing, insofar as concerns wafer cleaning and etching, is the interference caused by wafer holder apparatus that can lead to inefficient and deficient cleaning and etching. During wet chemical processing of wafers, such as employed in single wafer processing for cleaning and etching wafers, a wafer typically must be held during the processing. For processes in which the wafer is to be spun during the application of wet chemicals for cleaning or etching, the wafer must be held and restrained against the spinning and chemical application forces to which it is exposed.  
         [0005]     Heretofore, the wafer is typically gripped at its edge or constrained by retainer pins and the locations at which the wafer is gripped or constrained become sources of residual contamination. In etching, the locations of gripping contact can lead to over or under etching compared with the rest of the wafer&#39;s surface. In cleaning, the same can be true. But also when cleaning involves rinsing with DI water, the locations of gripping contact can provide areas on which contaminants are lodged and remain when the wafer is ungripped.  
       SUMMARY  
       [0006]     The present invention provides a single substrate holder for wet chemical processing of substrates, such as semiconductor wafers, which secures the substrate for processing against substrate spinning and chemical delivery forces to which the substrate will be exposed. The substrate holder provides a Bernoulli chuck for a holder in which a Bernoulli fluid, a gas such as N 2 , is directed across the face of the substrate under conditions in which the substrate is drawn to a spin rotor and secured in a processing position. The Bernoulli fluid is applied to the side of a substrate that is not the side to be processed. Consequently, the substrate holder does not secure the substrate in a manner that leads to locations of contamination since there is no substrate gripping contact exposed to the processing chemistry. The substrate holder also protects the side of the substrate that is not being processed from unwanted chemical contact.  
         [0007]     The substrate holder is provided as part of a drive head assembly that is arranged to have a substrate automatically loaded by a tool system automated substrate transfer robot and then transferred to its processing position automatically upon actuation of the Bernoulli fluid flow. Also, the substrate holder is arranged to automatically release the substrate from the processing position for unloading by the tool system automated substrate transfer robot.  
         [0008]     The present invention also provides a processing reactor or tool comprised of a wet chemical processing vessel for use with the drive head in a processing station adapted to be installed on a tool system base platform. The processing station may also include a second processing vessel above the first processing vessel and the drive head is adapted to serve either or both vessels. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]      FIG. 1  is a cross section of a workpiece support with extendable support fingers retracted in a processing position according to one aspect of the present invention.  
         [0010]      FIG. 2  is a cross section of a workpiece support with extendable support fingers lowered in a loading/unloading position according to another aspect of the present invention.  
         [0011]      FIG. 3  is a partial exploded view of a workpiece resting on extendable support fingers before the creation of a low pressure zone adjacent the inner surface of the workpiece.  
         [0012]      FIG. 4  is a partial exploded view of a workpiece which has been lifted off the support fingers and into close proximity with the rotor by the creation of a low pressure zone adjacent the inner surface of the workpiece.  
         [0013]      FIG. 5  is a partial exploded view showing the relationship between the workpiece, the support finger and the guide pin before the creation of a low pressure zone adjacent the inner surface of the workpiece.  
         [0014]      FIG. 6  is a top perspective view of a rotor according to the present invention.  
         [0015]      FIG. 7  is a bottom perspective view of the rotor illustrated in  FIG. 6 .  
         [0016]      FIG. 8  is a partial exploded view of the fluid delivery tube positioned in a central cavity of the rotor according to one aspect of the present invention.  
         [0017]      FIG. 9  is a partial exploded view.  
         [0018]      FIG. 10  is a cross sectional view of a process chamber with the drive head assembly in a load position according to the present invention.  
         [0019]      FIG. 11  is a cross sectional view of the process chamber illustrated in  FIG. 10  with the drive head assembly in a first backside processing position.  
         [0020]      FIG. 12  is a cross sectional view of the process chamber illustrated in  FIG. 10  with the drive head assembly in a second backside processing position.  
         [0021]      FIG. 13  is a cross sectional view of a process chamber of the present invention with the drive head assembly in an inverted position for loading the workpiece for device side processing of the workpiece.  
         [0022]      FIG. 14  is a cross sectional view of the rotor illustrated in  FIG. 13 .  
         [0023]      FIG. 15  is a partial exploded view of the circled area designated B in  FIG. 14 .  
         [0024]      FIG. 16  is a partial exploded view of the standoffs used in the rotor of  FIG. 14  when the drive head assembly is inverted in the position shown in  FIG. 13 .  
         [0025]      FIG. 17  is a cross sectional view of a rotor according to another embodiment of the present invention.  
         [0026]      FIG. 18  is a partial exploded view of the circled area designated A in  FIG. 17 .  
         [0027]      FIG. 19  is a perspective view of a bowl to be used in one embodiment of the present invention.  
         [0028]      FIG. 20  is a cross sectional view of the bowl illustrated in  FIG. 14 .  
         [0029]      FIG. 21  is a perspective view of a tool having first and second processing vessels according to one embodiment of the present invention.  
         [0030]      FIG. 22  is a cross sectional view of the tool illustrated in  FIG. 21  with the drive head assembly in an inverted position between the two processing vessels for loading/unloading of the workpiece.  
         [0031]      FIG. 23  is a cross sectional view of the tool illustrated in  FIG. 21  with the drive head assembly between the two processing vessels for loading/unloading of the workpiece.  
         [0032]      FIG. 24  is a cross sectional view of the tool illustrated in  FIG. 22  with the drive head assembly elevated and the workpiece positioned for processing in the upper vessel.  
         [0033]      FIG. 25  is a cross sectional view of the tool illustrated in  FIG. 23  with the drive head assembly lowered and the workpiece positioned for processing in the lower vessel.  
         [0034]      FIG. 26  illustrates two processing stations arranged side-by-side on a tool platform base.  
         [0035]      FIG. 27  is a top plan view of a wet chemical processing tool configured in accordance with one embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0036]     Referencing  FIGS. 1 and 2 , the drive head  10  comprises a stationary part  12  and a rotating part  14 . The stationary part comprises a motor  52  and bearing support plate  16  and a protective cover  18 . The rotating part comprises a rotor  20 , a workpiece support  22  and a bellows seal  24 . The rotor  20  is rotatably joined to a motor and bearing assembly  26 . The workpiece support  22  is carried by the rotor  20  and is mounted such that it can be extended and retracted relative to the rotor  20  as well as rotated with the rotor  20 . The bellows seal  24  is joined to inside surfaces of the rotor  20  and the workpiece support  22  to isolate the interior region between them.  
         [0037]     Several coil springs  32  are located between and bear against the workpiece support  22  and the rotor  20  to urge the workpiece support to a retracted position as shown in  FIG. 1 . The workpiece support  22  and the rotor  20  have opposing peripheral lips  28 ,  30  located so as to limit how far the workpiece support  22  can be retracted. Several pneumatic cyclinders  40  are mounted to the support plate  16  such that their cylinder rods  42  can be extended to contact the wafer support  22 . The cylinders  40  are shown in  FIG. 1  retracted such that the opposing lips of the workpiece support  22  and the rotor  20  contact one another. The cylinders  40  are shown in  FIG. 2  extended such that the workpiece support  22  is extended axially away from the drive head stationary part  12 .  
         [0038]     The workpiece support  22  comprises a spring support plate  44  and a peripheral skirt  46  that extends axially from the spring support plate  44 . The workpiece support  22  also comprises several workpiece support fingers  48  that are mounted to the skirt  46  as shown in  FIGS. 3 and 4 . The rotor  20  has several radial guide pins  50  mounted at its perimeter as shown in  FIG. 5 . As shown in  FIGS. 6 and 7 , the radial guide pins  50  are spaced 90 degrees apart around the periphery of the rotor  20  so as to hold the position of a workpiece W when the rotor  20  is spun.  
         [0039]     Also as shown in  FIGS. 6 and 7 , the locations of the support fingers  48  is staggered relative to the guide pins  50 . As shown in  FIGS. 3 and 4 , the workpiece support fingers  48  are L-shaped with a vertical leg  48   a  attached to an annular rim  46   a  of skirt  46  and a horizontal leg  48   b  that extends radially inward. Consequently, the vertical leg  48   a  of each support finger  48  is located beyond the perimeter of a workpiece W and the inner end of each support finger  48  is located within the perimeter of a workpiece W. The inner end of the support finger  48  is provided with a workpiece contact surface  48   c  and a sloped workpiece centering surface  48   d.    
         [0040]     As shown in  FIGS. 1, 3  and  4 , the relative lengths to which the support fingers  48  and the guide pins  50  extend beyond their respective mountings are such that the guide pins  50  will confine a workpiece W when the workpiece support  22  is retracted. And as shown in  FIG. 2 , those relative lengths are also such that the guide pins  50  will not confine a workpiece W when the workpiece support  22  is extended. As shown in  FIG. 2 , when the workpiece support  22  is extended there is sufficient clearance between the support fingers  48  and the guide pins  50  that a workpiece W can be inserted and removed without contacting or interfering with either one. Consequently, when the workpiece support  22  is extended by actuating the pneumatic cylinders  40 , a workpiece W may be inserted into the gap between the support fingers and guide pins and approximately centered and lowered onto the workpiece contacts surfaces  48   c . If the workpiece W is slightly off-center it will contact one or more of the support finger centering surfaces  48   c  and slide into a loaded position as shown in  FIG. 3 . Once the workpiece W is loaded onto the support fingers  48  as shown in  FIG. 3 , the workpiece support  22  may be retracted by deactivating the pneumatic cylinders  40 , enabling the coil springs  32  to return the workpiece support  22  to the position shown in  FIG. 1 , to position the workpiece for processing.  
         [0041]     As shown in  FIGS. 1 and 8 , a drive head spin motor  52 , located in a motor compartment  54  of motor support plate  16  is fastened to rotor  20 . A solid cap  56  is threaded into a cap compartment  58  of rotor  20  and fastened to the output shaft of motor  52 . This assembly spins the rotor  20  when the motor  52  operates. A center tube  60  extends axially through motor  52  and axially communicates with an axial passage  62  through cap  56  so as to provide an axial passage for a Bernoulli fluid delivery tube  64 . Tube  64  extends through the center tube  60  to coupling  66  that provides for communication with a supply of fluid. Tube  64  terminates adjacent the exposed surface  68  of cap  56  in a nozzle  69 . The Bernoulli nozzle shown in  FIG. 8  is a series of small diameter fluid delivery ports  70  that extend radially through the wall of tube  64 . The fluid exiting the delivery ports  70  is directed parallel to the plane of the workpiece W.  
         [0042]     When a workpiece W is loaded and ready for processing, the position shown in  FIGS. 3 and 8 , and pressurized fluid is delivered through tube  64  and exits the radial ports  70 , a Bernoulli effect is created that produces a low pressure region between the workpiece W and the combined surfaces of cap surface  68  and the adjacent surface  72  of rotor  20 . As a result of the low pressure region being created, the workpiece W is drawn toward the adjacent surface  72  of rotor  20  to the position shown in  FIG. 4 . Consequently, the workpiece W is lifted from contact with the support fingers  48  such that the entire surface area  74  of the workpiece is exposed for processing. When the workpiece W is lifted from contact with the support fingers  48 , the radial guide pins  50  maintain the workpiece W in an axially-centered position. Consequently, when the rotor  20  is spun by operation of motor  52 , the workpiece W will remain in an axially-centered position by the radial guide pins  50 . Because the ends of the bellows seal  32  are fastened to the rotor  20  and the wafer support skirt  46  as shown in  FIG. 3 , the wafer support  22  will rotate with the rotor  20 .  
         [0043]     During processing, processing fluid, which may liquids or gases, will impinge upon the exposed surface  74  of workpiece W. Also, during processing, the workpiece W will ordinarily be spun and, consequently, processing fluid will be directed by centrifugal force across the workpiece W and flung radially off the workpiece periphery. The Bernoulli fluid discharged from the nozzle  69  will also flow radially outward toward the periphery of the workpiece. Bernoulli fluid flowing outward from the workpiece W periphery will block processing fluid from contacting the inner surface  73  of the workpiece.  
         [0044]     Consequently, for processing a workpiece W such as a semiconductor wafer that has a device side and a backside, if the device side of a workpiece is to be exposed to processing fluid, the workpiece would be loaded onto the support fingers  48  such that the exteriorly-exposed workpiece surface  74  would be the device side (i.e., the backside of the workpiece W would be adjacent surface  72  of the rotor  20 ). And, consequently, if the non-device side, or backside, of the workpiece is to be exposed to processing fluid, workpiece W would be loaded onto the support fingers  48  such that the exteriorly-exposed surface  74  would be the backside (i.e., the device side of the workpiece W would be adjacent surface  72  of the rotor  20 ).  
         [0045]     For some process conditions, the rotor shown in  FIGS. 1-8  may be modified as shown in  FIG. 9 . As shown in  FIG. 9 , the workpiece W is shown in solid line lifted from the support fingers  48  under the influence of the Bernoulli effect and in dotted line (W′) in the absence of Bernoulli fluid flow. The outer edge of the rotor  20  is modified from that shown in  FIGS. 1-8  by the addition of a flow diverter  76 . Flow diverter  76  is an annulus that has a workpiece support surface  78   a  that extends beyond the exposed surface  72  of rotor  20 , and a series of fluid discharge ports  80  that extend from the terminus of the Bernoulli flow passage  82  to a circumferential discharge passage  84 . Wafer support surface  78  supports the workpiece W at its outermost region, often called an “exclusion zone,” which is a peripheral area that is not used for device manufacture. As a consequence of being drawn against support surface  78 , the workpiece will spin in synchronism with the rotor.  
         [0046]     During processing, the Bernoulli fluid will travel from the nozzle  79  ( FIG. 8 ) radially outward through the Bernoulli passage  82  to its terminus and then exit the system through discharge ports  80  and discharge passage  84 . Unlike the rotor configuration shown in  FIGS. 1-8 , the  FIG. 9  rotor configuration, Bernoulli fluid flow is diverted before reaching the workpiece peripheral edge to avoid interrupting the protective rim/workpiece interface at the edge of the workpiece W. Consequently, the  FIG. 9  modification will provide a physical barrier to processing fluids, preventing processing fluids from reaching the interiorly-exposed surface  73  of the workpiece W.  
         [0047]      FIGS. 10-12  show the drive head assembly  10 , as described with reference to  FIGS. 1-8 , mounted by a lift/rotate  100  over a processing vessel  102 . The lift/rotate actuator  100  includes an arm  104  that attaches the drive head  10  to an elevator mechanism  106 . The elevator mechanism  106  may also include a mechanism for rotating the drive head  10  from a position as shown in  FIGS. 10-12  to a position shown in  FIG. 13 .  
         [0048]     In  FIG. 10 , the rotor  20  and workpiece support  22  are arranged for loading or unloading a workpiece W onto or from the support fingers  48 . As described in the foregoing, the relationship between the support fingers  48  and the radial pins  50  provides sufficient clearance that a workpiece end effector may insert and remove the workpiece from the drive head  10 .  FIGS. 11 and 12  show the drive head  10  lowered by the lift/rotate elevator mechanism  106  sufficient to locate the workpiece W within the vessel  102  for processing. Vessel  102  has one or more processing fluid inlets and one or more processing fluid discharge outlets. As shown in  FIGS. 10-12 , two fluid discharge outlets  108  and  110  are provided. Also as shown in  FIGS. 10-12 , one fluid inlet  112  is provided with a multi-fluid distributor  114 .  
         [0049]     As shown in  FIGS. 11 and 12 , the workpiece W is located in the loaded position, and Bernoulli fluid has been applied to draw the workpiece up closely adjacent the rotor  20  as previously described. During processing, one or more processing fluids, which may be liquids or gases or both, are directed by the distributor  114  against the exposed surface of the workpiece W. The workpiece W will be spun during processing and, consequently, the processing fluids will contact the workpiece and flow under centrifugal force outward to the periphery of the workpiece, and flung radially off the workpiece. With the drive head  10  in the position shown in  FIG. 11 , the processing fluids flung from the workpiece W will contact the vessel and be directed down through passage  116  to the discharge outlet  108 . With the drive head in the position shown in  FIG. 12 , the processing fluids flung from the workpiece will contact the vessel and be directed down through passage  118  to the discharge outlet  110 . A deflector  120  is located between the entries to passages  116  and  118  to separate their respective inlets.  
         [0050]     It is typical in the semiconductor fabrication industry to transfer semiconductor wafers in a “face-up” position in which the device side of the wafer faces up. And it is typical to load semiconductor wafers into/onto a wafer support associated with a processing vessel in a “face-up” condition. Accordingly, the arrangement shown in  FIGS. 10-12 , in accordance with that custom, would be appropriate for processing semiconductor wafers in the device side “face-up” orientation such that (as shown) the backside of the wafer W is presented to the processing fluids. This arrangement would be appropriate for cleaning and etching the backside of semiconductor wafers. The advantage of the drive head  10  described in the foregoing is that the backside of a wafer W can be contacted with processing fluids in a manner such that the backside is completely exposed due to the Bernoulli effect lifting the wafer clear of the support fingers  48 . In addition, a further advantage is that the device side of the wafer W does not contact any structure and therefore that side is maintained in an unmarred condition. Referring specifically to the  FIG. 9  modifications of the rotor  20 , these modifications afford entirely adequate protection of the device side of a wafer W because the diverter  76  only contacts the peripheral “exclusion zone” on which no devices are manufactured.  
         [0051]     In addition to the foregoing, the drive head  10  and lift/rotate  106  assemblies enable the drive head  10  to be rotated so that it is inverted to the position shown in  FIG. 13 . When the drive head  10  is inverted as shown in  FIG. 13 , a semiconductor wafer W can be loaded onto the support fingers  48  with the device side facing up, consistent with conventional practice. As will be described in detail following, several standoffs are provided in the rotor to support the wafer when it is placed in the position shown in  FIG. 13 , the wafer is secured to the rotor  20 , and the drive head  10  is rotated to the position shown in  FIG. 10 . Then the wafer W can be processed as described with reference to  FIGS. 10-12 , the difference being, however, that the device side of the wafer W is now presented to the processing fluid, rather than the backside. So in summary: if a wafer backside is to be exposed to processing fluid, the wafer is loaded onto the drive head  10  by being deposited onto the support fingers  48  with the device side facing upward (i.e., adajacent to the rotor surface) as seen in  FIGS. 10-12 ; but if the wafer device side is to be exposed to processing fluid, the wafer is loaded onto the drive head by being deposited onto standoffs (as described following) with the device side facing upward (i.e., the backside adjacent the rotor surface) as seen in  FIG. 13  with the drive head inverted.  
         [0052]     The rotor/wafer support assembly shown in  FIGS. 14-16  is identical with the assembly shown in  FIGS. 1-9 , except for the provision of several standoffs  122  for supporting a workpiece W when the drive head  10  is inverted to the position shown in  FIG. 13 . Each standoff  122 , comprises a lift pin  124 , a lift pin sleeve  126  and a lift pin coil spring  128 . The lift pin  124  extends through both ends of the sleeve  126  and includes a collar against which the spring  128  bears to maintain the lift pin  124  in a normally retracted position as shown in  FIG. 14 . As shown in  FIG. 15 , the outer end of pin  124  is configured to contact and support a workpiece W. The inner end of pin  124  extends a sufficient length beyond the sleeve  126  to enable the workpiece support spring plate  16  to contact and displace it against the spring force of spring  128 .  
         [0053]     When a workpiece is to be loaded onto the drive head  10  in the inverted position shown in  FIG. 13 , the pneumatic cylinders  40  are actuated to extend their cylinder rods  42  to bear against the spring plate  16 . The support  22  is then extended to a position as shown in  FIG. 16  at which the workpiece contact end is located between the radial pins  50  and the support finger guide surface  48   c . At this extended position, a workpiece W may be loaded onto the drive head  10  by an end effector that inserts the workpiece between the pins  50  and the guide surface  48   c  and then lowers the workpiece onto the lift pins  124 . Then, the pneumatic cylinders  40  are deactivated so as to permit the springs  32  to force the support  22  to retract, thereby releasing the lift pin  124  so that it will retract and lower the workpiece W from that shown in  FIG. 16  to that shown in  FIG. 14 . When the workpiece is in the position shown in  FIG. 14 , it is confined between the several guide pins  50  and the guide surfaces  48   c  of the several support fingers  48 . The Bernoulli fluid flow is then activated to draw the workpiece to the rotor and then the drive head can be rotated 180 deg. to the position shown in  FIG. 10 , with the workpiece ready for processing.  
         [0054]      FIG. 17  illustrates a modified rotor  20  structure. In this configuration, the rotor  20  is fabricated with a top plate  20   a  and a chemically-resistant plastic bottom plate  20   b . Bellows seal  24  is fastened between the upper edge of bottom plate  20   b  and top plate  20   a . Bottom plate  20   b  has an annular recessed section  20   c  for weight reduction. Top plate  20   a  is fastened to the spin motor (not shown in this Fig).  FIG. 17  also illustrates a modified support  22  structure. In this configuration, the support  22  is fabricated with a top plate  22   a  and a chemically-resistant plastic rim or skirt section  22   b . Bellows seal  24 , also chemically-resistant, is fastened between the upper edge of skirt  22   b  and top plate  22   a . In this configuration, as well as in the other configurations illustrated in the drawings, bellows seal  24  protects the interior regions of the drive head from vapors and other fluids that might emanate from the processing vessel.  
         [0055]      FIG. 18  illustrates the provision of a standoff pin  130  to limit the distance to which the Bernoulli fluid can draw the workpiece W toward the rotor  20  to a predetermined space S. Several such pins  130  would be located around the periphery of the rotor such that they would contact the workpiece in the “exclusion zone” of the workpiece. This series of pins  130  would be provided as an alternative to the structure shown in  FIG. 9 . As a consequence of being drawn against the standoff pins  130 , the workpiece will spin in synchronism with the rotor.  
         [0056]     With reference to the  FIG. 13  embodiment, when the Bernoulli fluid flow is activated, the Bernoulli effect would cause the workpiece W to be drawn against the standoff pins  130  of  FIG. 18 , when those pins are provided, or against the diverter workpiece surface  78   a  of  FIG. 9 , when the diverter of  FIG. 9  is provided. In the absence of some means of contacting the workpiece during operation, such as shown in  FIG. 9  (surface  78   a ) or  FIG. 18  (pins  130 ), the workpiece might not spin at all while the rotor spins, or might rotate only slightly (i.e., at a spin rate less than the spin rate of the rotor). In some processes, it would be essential that the workpiece spin to a significant degree and, so, such means would be an important addition to the drive head. Furthermore, in some processes, it would be essential that the workpiece spin in synchronism with the rotor (i.e., at approximately the same spin rate) such that the surface of the workpiece would not be marred or scraped by such means.  
         [0057]     All other elements of the rotor structure  20  and support structure  22  shown in  FIGS. 17 and 18  are as described in the foregoing description with respect to the other Figs.  
         [0058]     A preferred embodiment of the bowl  170  for use in the vessel  102  of the present invention is shown in  FIGS. 19 and 20 . A process fluid delivery system  180  is centrally positioned in a lower portion of the bowl  170 . The process fluid delivery system  180  is pivotable and includes swing arm  181  which pivots about along an axis defined by vertically disposed standpipe  182 . At one end of the swing arm  181  is at least one nozzle  183 , and preferably a plurality of nozzles  183  for spraying process fluid into the bowl  170 , and particularly onto a lower planar surface of a workpiece W positioned in the process chamber  140 . The nozzles  183  are connected (via passageways in the vertical standpipe  182  and swing arm  181 ) to supply sources of process fluids. Examples of process fluids that can be used in the present invention include: nitric acid, sulfuric acid, hydrofluoric acid, phosphoric acid, potassium hydroxide and de-ionized water. The pivotable delivery system  180  permits process fluid to be uniformly applied to the workpiece W from the center point radially outward to the outer edge of the workpiece W. An exhaust port  184  is positioned in the bottom of the bowl  170  below the swing arm  181 , and is connected to drain  185  for removing gaseous fluids which may build up in the process chamber  140  during processing.  
         [0059]     The reactor comprising the drive head  10  and the reactor vessel  102  can be augmented by the addition of a second processing apparatus. As shown in  FIGS. 21-25 , an additional processing vessel  120  is provided above the vessel  102 . The lift/rotate actuator  100  positions the drive head  130  between the two vessels for workpiece loading/unloading. With a workpiece W loaded onto the drive head, the drive head may insert the workpiece into either vessel, as shown in  FIGS. 24 and 25 , or sequentially into both vessels. When accessing the upper vessel  120 , the drive head would be located in the inverted position as shown in  FIGS. 13, 22  and  24 . Then the drive head would be elevated by the lift/rotate  100  to place the workpiece W into the upper vessel  120  as shown in  FIG. 24 . In the inverted position shown in  FIG. 24 , the workpiece may be processed with fluids directed from above the workpiece. For example, with the upper vessel  120  configured as a rinse rim having a rinse fluid collection channel  121  opening inward as shown in  FIGS. 22-25 , an overhead rinse delivery apparatus (not shown) can apply a rinsing fluid, such as DI water, onto the workpiece W. Because the workpiece spins during processing, as described hereinabove, the rinse fluid runs radially outward under the influence of centrifugal force and is flung from the workpiece perimeter into the collection channel  121 . Collection channel  121  is provided with an appropriate drain through which the collected rinse fluid drains. As shown, rinse rim  120  is supported from a tool platform base structure  150  by support legs  152 . Support legs  150  may be secured directly to the platform base structure  150  or they may be secured to an upper section of the lower vessel  102  as shown in  FIG. 21 . The lower vessel  102  and the lift/rotate  100  are also secured to the tool platform base structure  150  as shown in  FIGS. 21-25 . Likewise, lift/rotate  100  and vessel  102  illustrated in  FIGS. 1 and 2  is secured to a tool platform base structure  150 .  
         [0060]      FIG. 26  illustrates two processing stations arranged side-by-side on a tool platform base  150 . One station  200  illustrates the lift/rotate  100  and processing vessel  102  with the drive head absent for clarity of the arrangement. The other stations  202  illustrates the lift/rotate  100 , the lower processing vessel  102 , the upper processing vessel  102 , and the drive head  10  in the inverted position with a workpiece W in place for processing in the upper vessel. As shown in  FIG. 26 , the base  150  is provided with a series of cutouts  150   a - d  into which processing stations can be registered and positioned. Appropriate indexing holes and pegs can be provided to register the processing station components, such as lift/rotated, processing vessels, and related support apparatus.  
         [0061]      FIG. 27  is an isometric view showing a portion of a system or integrated tool  200  configured in accordance with an embodiment of the invention. In this embodiment, the integrated tool  200  includes a frame  209 , a dimensionally stable mounting module  250  mounted to the frame, and a plurality of wet chemical processing stations  220 , each having a process vessel  102  and a lift/rotate actuator  100 . The process vessels  102  are configured to perform a variety of functions including but not limited to electrochemical processing, electroless processing, etching and/or rinsing. The system  200  can also include a transport system  212  that has a robot  213  with one or more end-effectors  217 . The transport system  212  is mounted to the mounting module  250 . The mounting module  250  supports the process vessels  102 , the lift/rotate actuator  100 , and the transport system  212 . In one embodiment (shown in  FIG. 1 ), the mounting module  250  includes a dimensionally stable deck or base  150  and a dimensionally stable platform  252  (located for example below the deck  150 ). The transport system  212  is mounted to the platform  252 . A track  214  is also mounted to the platform  252 . In another embodiment (not shown) the transport system  212  can be mounted directly to the deck  150 . A modular load/unload system  215  is attached to the mounting module  250  at one end. In operation, the robot  213  takes workpieces from the load/unload module  215 , travels along the track  214 , and places the workpieces into one or more process vessels  102  for treatment. Other aspects of the system  200  are disclosed in pending U.S. application Ser. Nos. 10/691,688, filed on Oct. 22, 2003, and Ser. No. 10/690,864, filed on Oct. 21, 2003. The disclosures of these Applications are fully incorporated herein by reference.  
         [0062]     From the foregoing, it will be appreciated that specific embodiments of the invention have been described herein for purposes of illustration, but that various modifications may be made without deviating from the spirit and scope of the invention, including, but not limited to, variations in size, materials, shape, form, function and manner of operation, assembly and use.