Abstract:
An apparatus for processing a workpiece in a micro-environment includes a workpiece housing connected to a motor for rotation. The workpiece housing forms a processing chamber where one or more processing fluids are distributed across at least one face of the workpiece by centrifugal force generated during rotation of the housing. An array of workpiece housings are contained within an enclosure. A robot moves workpieces into and out of the workpiece housings.

Description:
This Application is a Continuation of U.S. patent application Ser. No. 09/041,901, filed Mar. 13, 1998 and now pending, and incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The semiconductor manufacturing industry is constantly seeking to improve the processes used to manufacture integrated circuits from wafers. The improvements come in various forms but, generally, have one or more objectives as the desired goal. The objectives of many of these improved processes include: 1) decreasing the amount of time required to process a wafer to form the desired integrated circuits; 2) increasing the yield of usable integrated circuits per wafer by, for example, decreasing the likelihood of contamination of the wafer during processing; 3) reducing the number of steps required to turn a wafer into the desired integrated circuits; and 4) reducing the cost of processing the wafers into the desired integrated circuit by, for example, reducing the costs associated with the chemicals required for the processing 
     In the processing of wafers, it is often necessary to subject one or more sides of the wafer to a fluid in either liquid, vapor or gaseous form. Such fluids are used to, for example, etch the wafer surface, clean the wafer surface, dry the wafer surface, passivate the wafer surface, deposit films on the wafer surface, etc. Control of the physical parameters of the processing fluids, such as their temperature, molecular composition, dosing, etc., is often quite crucial to the success of the processing operations. As such, the introduction of such fluids to the surface of the wafer occurs in a controlled environment. Typically, such wafer processing occurs in what has commonly become known as a reactor. 
     Various reactors have been known and used. These reactors typically have a rotor head assembly that supports the wafer. In addition to introducing the wafer into the processing chamber, the rotor head assembly may be used to spin the wafer during introduction of the processing fluid onto the surface of the wafer, or after processing to remove the processing fluid. 
     During processing, the wafer is presented to the rotor head assembly by a robot in a clean environment in which a number of processing reactors are present. The robot presents the wafer in an exposed state to the rotor head assembly in an orientation in which the side of the wafer that is to be processed is face up. The rotor head assembly inverts the wafer and engages and seals with a cup for processing. As the wafer is processed, the wafer is oriented so that the side of the wafer being processed is face down. 
     These types of reactors are useful for many of the fluid processing steps employed in the production of an integrated circuit. However, there remains a need for more control and efficiency from the reactor. As such, a substantially new approach to processing and reactor design has been undertaken which provides greater control of the fluid processes and provides for more advanced and improved processes. 
     SUMMARY OF THE INVENTION 
     An apparatus for processing a workpiece in a micro-environment is set forth. The apparatus includes a rotor motor and a workpiece housing. The workpiece housing is connected to be rotated by the rotor motor. The workpiece housing further defines a processing chamber where one or more processing fluids are distributed across at least one face of the workpiece by centrifugal force generated during rotation of the housing. 
     In one embodiment, the workpiece housing includes an upper chamber member and a lower chamber member joined to one another to form the processing chamber. The processing chamber preferably generally conforms to the shape of the workpiece and includes at least one fluid outlet at a peripheral region. At least one workpiece support is advantageously provided to support a workpiece in the processing chamber in a position to allow centrifugal distribution of a fluid supplied through an inlet opening into the process chamber. The fluid may be distributed across at least an upper face and/or lower face of the workpiece, when the workpiece housing is rotated. The fluid outlet is positioned to allow extraction of fluid in the processing chamber by centrifugal force. 
     In a second aspect, an apparatus for processing a workpiece has an input/output station, and several workpiece processing stations positioned in an array. At least one of the workpiece processing stations includes a housing having a workpiece chamber in which one or more process fluids are distributed across at least one face of the workpiece by centrifugal force generated by rotation of the workpiece. A robotic arm moves to carry a workpiece from the input/output station to at least one of the workpiece processing stations. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a cross-sectional view of a workpiece housing and a rotor assembly constructed in accordance with one embodiment of the invention. 
     FIG. 2 is an exploded view of a further embodiment of a workpiece housing constructed in accordance with the teachings of the present invention 
     FIG. 3 is a top plan view of the workpiece housing of FIG. 2 when the housing is in an assembled state. 
     FIG. 4 is a cross-sectional view of the workpiece housing taken along line IV—IV of FIG.  3 . 
     FIG. 5 is a cross-sectional view of the workpiece housing taken along line V—V of FIG.  3 . 
     FIG. 6 is a cross-sectional view of the workpiece housing taken along line VI—VI of FIG.  3 . 
     FIGS. 7A and 7B are cross-sectional views showing the workpiece, housing in a closed state and connected to a rotary drive assembly. 
     FIGS. 8A and 8B are cross-sectional views showing the workpiece housing in an open state and connected to a rotary drive assembly. 
     FIG. 9 illustrates one embodiment of an edge configuration that facilitates mutually exclusive processing of the upper and lower wafer surfaces in the workpiece housing. 
     FIG. 10 illustrates an embodiment of the workpiece housing employed in connection with a self-pumping re-circulation system. 
     FIGS. 11 and 12 are schematic diagrams of exemplary processing tools that employ the present invention. 
     FIG. 13 illustrates a batch wafer processing tool constructed in accordance with the principles of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 is a cross-sectional view of one embodiment of a reactor, shown generally at  10 , constructed in accordance with the teachings of the present invention. The embodiment of the reactor  10  of FIG. 1 is generally comprised of a rotor portion  15  and a workpiece housing  20 . The rotor portion  15  includes a plurality of support members  25  that extend downwardly from the rotor portion  15  to engage the workpiece housing  20 . Each of the support members  25  includes a groove  30  that is dimensioned to engage a radially extending flange  35  that extends about a peripheral region of the workpiece housing  20 . Rotor portion  15  further includes a rotor motor assembly  40  that is disposed to rotate a hub portion  45 , including the support members  25 , about a central axis  47 . Workpiece housing  20  is thus secured for co-rotation with hub portion  45  when support members  25  are engaged with flange  35 . Other constructions of the rotor portion  15  and the engagement mechanism used for securement with the workpiece housing  20  may also be used. 
     The workpiece housing  20  of the embodiment of FIG. 1 defines a substantially closed processing chamber  50 . Preferably, the substantially closed processing chamber  50  is formed in the general shape of the workpiece  55  and closely conforms with the surfaces of the workpiece. The specific construction of FIG. 1 includes an upper chamber member  60  having an interior chamber face  65 . The upper chamber member  60  includes a centrally disposed fluid inlet opening  70  in the interior chamber face  65 . The specific construction also includes a lower chamber member  75  having, an interior chamber face  80 . The lower chamber member  75  has a centrally disposed fluid inlet opening  85  in the interior chamber face  80 . The upper chamber member  60  and the lower chamber member  75  engage one another to define the processing chamber  50 . The upper chamber member  60  includes sidewalls  90  that project downward from the interior chamber face  65 . One or more outlets  100  are disposed at the peripheral regions of the processing chamber  50  through the sidewalls  90  to allow fluid within the chamber  50  to exit therefrom through centripetal acceleration that is generated when the housing  20  is rotated about axis  47 . 
     In the illustrated embodiment, the workpiece  55  is a generally circular wafer having upper and lower planar surfaces. As such, the processing chamber  50  is generally circular in plan view and the interior chamber faces  65  and  80  are generally planar and parallel to the upper and lower planar surfaces of the workpiece  55 . The spacing between the interior chamber faces  65  and  80  and the upper and lower planar surfaces of the workpiece  55  is generally quite small. Such spacing is preferably minimized to provide substantial control of the physical properties of a processing fluid flowing through the interstitial regions. 
     The wafer  55  is spaced from the interior chamber face  80  by a plurality of spacing members  105  extending from the interior chamber face  80 . Preferably, a further set of spacing members  110  extend from the interior chamber face  65  and are aligned with the spacing members  105  to grip the wafer  55  therebetween. 
     Fluid inlet openings  70  and  85  provide communication passageways through which one or more processing fluids may enter the chamber  50  for processing the wafer surfaces. In the illustrated embodiment, processing fluids are delivered from above the wafer  55  to inlet  70  through a fluid supply tube  115  having a fluid outlet nozzle  120  disposed proximate inlet  70 . Fluid supply tube  115  extends centrally through the rotor portion  15  and is preferably concentric with the axis of rotation  47 . Similarly, processing fluids are delivered from below the wafer  55  to inlet  85  through a fluid supply tube  125 . Fluid supply tube  125  terminates at a nozzle  130  disposed proximate inlet  85 . Although nozzles  120  and  130  terminate at a position that is spaced from their respective inlets, it will be recognized that tubes  115  and  125  may be extended so that gaps  135  are not present. Rather, nozzles  120  and  130  or tubes  115  and  125  may include rotating seal members that abut and seal with the respective upper and lower chamber members  60  and  75  in the regions of the inlets  70  and  85 . In such instances, care should be exercised in the design of the rotating joint so as to minimize any contamination resulting from the wear of any moving component. 
     During processing, one or more processing fluids are individually or concurrently supplied through fluid supply tubes  115  and  125  and inlets  70  and  85  for contact with the surfaces of the workpiece  55  in the chamber  50 . Preferably, the housing  20  is rotated about axis  47  by the rotor portion  15  during processing to generate a continuous flow of any fluid within the chamber  50  across the surfaces of the workpiece  55  through the action of centripetal acceleration. Processing fluid entering the inlet openings  70  and  85  are thus driven across the workpiece surfaces in a direction radially outward from the center of the workpiece  55  to the exterior perimeter of the workpiece  55 . At the exterior perimeter of the workpiece  55 , any spent processing fluid is directed to exit the chamber  50  through outlets  100  as a result of the centripetal acceleration. Spent processing fluids may be accumulated in a cup reservoir disposed below and/or about the workpiece housing  20 . As will be set forth below in an alternative embodiment, the peripheral regions of the workpiece housing  20  may be constructed to effectively separate the processing fluids provided through inlet  70  from the processing fluids supplied through inlet  85  so that opposite surfaces of wafer  55  are processed using different processing fluids. In such an arrangement, the processing fluids may be separately accumulated at the peripheral regions of the housing  20  for disposal or re-circulation. 
     In the embodiment of FIG. 1, the workpiece housing  20  may constitute a single wafer pod that may be used to transport the workpiece  55  between various processing stations and/or tools. If transport of the housing  20  between the processing stations and/or tools takes place in a clean room environment, the various openings of the housing  20  need not be sealed. However, if such transport is to take place in an environment in which wafer contaminants are present, sealing of the various housing openings should be effected. For example, inlets  70  and  85  may each be provided with respective polymer diaphragms having slits disposed therethrough. The ends of fluid supply tubes  115  and  125  in such instances may each terminate in a tracor structure that may be used to extend through the slit of the respective diaphragm and introduce the processing fluid into the chamber  50 . Such tracor/slitted diaphragm constructions are used in the medical industry in intravenous supply devices. Selection of the polymer material used for the diaphragms should take into consideration the particular processing fluids that will be introduced therethrough. Similar sealing of the outlets  100  may be undertaken in which the tracor structures are inserted into the diaphragms once the housing  20  is in a clean room environment. 
     Alternatively, the outlets  100  themselves may be constructed to allow fluids from the processing chamber to exit therethrough while inhibiting the ability of fluids to proceed from the exterior of housing  20  into chamber  50 . This effect may be achieved, for example, by constructing the openings  100  as nozzles in which the fluid flow opening has a larger diameter at the interior of chamber  50  than the diameter of the opening at the exterior of the housing  20 . In a further construction, a rotational valve member may be used in conjunction with the plurality of outlets  100 . The valve member, such as a ring with openings corresponding to the position of outlets  100 , would be disposed proximate the opening  100  and would be rotated to seal with the outlets  100  during transport. The valve member would be rotated to a position in which outlets  100  are open during processing. Inert gas, such as nitrogen, can be injected into the chamber  50  through supply tubes  115  and  125  immediately prior to transport of the housing to a subsequent tool or processing station. Various other mechanisms for sealing the outlets  100  and inlets  70  and  85  may also be employed. 
     FIG. 2 is a perspective view of a further reactor construction wherein the reactor is disposed at a fixed processing station and can open and close to facilitate insertion and extraction of the workpiece. The reactor, shown generally at  200 , is composed of separable upper and lower chamber members,  205  and  210 , respectively. As in the prior embodiment, the upper chamber member  205  includes a generally planar chamber face  215  having a centrally disposed inlet  220 . Although not shown in the view of FIG. 2, the lower chamber member  210  likewise has a generally planar interior chamber face  225  having a central inlet  230  disposed therethrough. The upper chamber member  205  includes a downwardly extending sidewall  235  that, for example, may be formed from a sealing polymer material or may be formed integrally with other portions of member  205 . 
     The upper and lower chamber members,  205  and  210 , are separable from one another to accept a workpiece therebetween. With a workpiece disposed between them, the upper and lower chamber members,  205  and  210 , move toward one another to form a chamber in which the workpiece is supported in a position in which it is spaced from the planar interior chamber faces  215  and  225 . In the embodiment of the reactor disclosed in FIGS. 2-8B, the workpiece, such as a semiconductor wafer, is clamped in place between a plurality of support members  240  and corresponding spacing members  255  when the upper and lower chamber members are joined to form the chamber (see FIG.  7 B). Axial movement of the upper and lower chamber members toward and away from each other is facilitated by a plurality of fasteners  307 , the construction of which will be described in further detail below. Preferably, the plurality of fasteners  307  bias the upper and lower chambers to a closed position such as illustrated at FIG.  7 A. 
     In the disclosed embodiment, the plurality of wafer support members  240  extend about a peripheral region of the upper chamber member  205  at positions that are radially exterior of the sidewall  235 . The wafer support members  240  are preferably disposed for linear movement along respective axes  245  to allow the support members  240  to clamp the wafer against the spacing members  255  when the upper and lower chamber members are in a closed position (see FIG.  7 A), and to allow the support members  240  to release the wafer from such clamping action when the upper and lower chamber members are separated (see FIG.  8 A). Each support member  240  includes a support arm  250  that extends radially toward the center of the upper chamber member  205 . An end portion of each arm  250  overlies a corresponding spacing member  255  that extends from the interior chamber face  215 . Preferably, the spacing members  255  are each in the form of a cone having a vertex terminating proximate the end of the support arm  250 . Notches  295  are disposed at peripheral, portions of the lower chamber member  210  and engage rounded lower portions  300  of the wafer support members  240 . When the lower chamber member  210  is urged upward to the closed position, notches  295  engage end portions  300  of the support members  240  and drive them upward to secure the wafer  55  between the arms  250  of the supports  240  and the corresponding spacing members  255 . This closed state is illustrated in FIG.  5 . In the closed position, the notches  295  and corresponding notches  296  of the upper chamber member (see FIG. 2) provide a plurality of outlets at the peripheral regions of the reactor  200 . Radial alignment of the arm  250  of each support member  240  is maintained by a set pin  308  that extends through lateral grooves  309  disposed through an upper portion of each support member. 
     The construction of the fasteners  307  that allow the upper and lower chamber members to be moved toward and away from one another is illustrated in FIGS. 2,  6  and  7 B. As shown, the lower chamber member  210  includes a plurality of hollow cylinders  270  that are fixed thereto and extend upward through corresponding apertures  275  at the peripheral region of the upper chamber member  205  to form lower portions of each fastener  307 . Rods  280  extend into the hollow of the cylinders  270  and are secured to form an upper portion of each fastener  307 . Together, the rods  280  and cylinders  270  form the fasteners  307  that allow relative linear movement between the upper and lower chamber members,  205  and  210 , along axis  283  between the open and closed position. Two flanges,  285  and  290 , are disposed at an upper portion of each rod  280 . Flange  285  functions as a stop member that limits the extent of separation between the upper and lower chamber members,  205  and  210 , in the open position. Flanges  290  provide a surface against which a biasing member, such as a spring (see FIG. 6) or the like, acts to bias the upper and lower chamber members,  205  and  210 , to the closed position. 
     With reference to FIG. 6, the spring  303  or the like, has a first end that is positioned within a circular groove  305  that extends about each respective fastener  307 . A second end of each spring is disposed to engage flange  290  of the respective fastener  307  in a compressed state thereby causing the spring to generate a force that drives the fastener  307  and the lower chamber member  210  upward into engagement with the upper chamber member  205 . 
     The reactor  200  is designed to be rotated about a central axis during processing of the workpiece. To this end, a centrally disposed shaft  260  extends from an upper portion of the upper chamber member  205 . As will be illustrated in further detail below in FIGS. 7A-8B, the  365  shaft  260  is connected to engage a rotary drive motor for rotational drive of the reactor  200 . The shaft  260  is constructed to have a centrally disposed fluid passageway (see FIG. 4) through which a processing fluid may be provided to inlet  220 . Alternatively, the central passageway may function as a conduit for a separate fluid inlet tube or the like. 
     As illustrated in FIGS. 3 and 4, a plurality of optional overflow passageways  312  extend radially from a central portion of the upper chamber member  205 . Shaft  260  terminates in a flared end portion  315  having inlet notches  320  that provide fluid communication between the upper portion of processing chamber  310  and the overflow passageways  312 . The flared end  315  of the shaft  260  is secured with the upper chamber member  205  with, for example, a mounting plate  325 . Mounting plate  325 , in turn, is secured to the upper chamber member  205  with a plurality of fasteners  330  (FIG.  5 ). Overflow passages  312  allow processing fluid to exit the chamber  310  when the flow of fluid to the chamber  310  exceeds the fluid flow from the peripheral outlets of the chamber. 
     FIGS. 7A and 7B are cross-sectional views showing the reactor  200  in a closed state and connected to a rotary drive assembly, shown generally at  400 , while FIGS. 8A and 8B are similar cross-sectional views showing the reactor  200  in an opened state. As shown, shaft  260  extends upward into the rotary drive assembly  400 . Shaft  260  is provided with the components necessary to cooperate with a stator  405  to form a rotary drive motor assembly  410 . 
     As in the embodiment of FIG. 1, the upper and lower chamber members  205  and  210  join to define the substantially closed processing chamber  310  that, in the preferred embodiment, substantially conforms to the shape of the workpiece  55 . Preferably, the wafer  55  is supported within the chamber  310  in a position in which its upper and lower faces are spaced from the interior chamber faces  215  and  225 . As described above, such support is facilitated by the support members  240  and the spacing members  255  that clamp the peripheral edges of the wafer  55  therebetween when the reactor  200  is in the closed position of FIGS. 7A and 7B. 
     It is in the closed state of FIGS. 7A and 7B that processing of the wafer  55  takes place. With the wafer secured within the processing chamber  310 , processing fluid is provided through passageway  415  of shaft  260  and inlet  220  into the interior of chamber  310 . Similarly, processing fluid is also provided to the chamber  310  through a processing supply tube  125  that directs fluid flow through inlet  230 . As the reactor  200  is rotated by the rotary drive motor assembly  410 , any processing fluid supplied through inlets  220  and  230  is driven across the surfaces of the wafer  55  by forces generated through centripetal acceleration. Spent processing fluid exits the processing chamber  310  from the outlets at the peripheral regions of the reactor  200  formed by notches  295  and  296 . Such outlets exist since the support members  240  are not constructed to significantly obstruct the resulting fluid flow. Alternatively, or in addition, further outlets may be provided at the peripheral regions. 
     Once processing has been completed, the reactor  200  is opened to allow access to the wafer, such as shown in FIGS. 8A and 8B. After processing, actuator  425  is used to drive an actuating ring  430  downward into engagement with upper portions of the fasteners  307 . Fasteners  307  are driven against the bias of spring  303  causing the lower chamber member  210  to descend and separate from the upper chamber member  205 . As the lower chamber member  210  is lowered, the support members  240  follow it under the influence of gravity, or against the influence of a biasing member, while concurrently lowering the wafer  55 . In the lower position, the reactor chamber  310  is opened thereby exposing the wafer  55  for removal and/or allowing a new wafer to be inserted into the reactor  200 . Such insertion and extraction can take place either manually, or by an automatic robot. 
     FIG. 9 illustrates an edge configuration that facilitates separate processing of each side of the wafer  55 . As illustrated, a dividing member  500  extends from the sidewall  235  of the processing chamber  310  to a position immediately proximate the peripheral edge  505  of the wafer  55 . The dividing member  500  may take on a variety of shapes, the illustrated tapered shape being merely one configuration. The dividing member  500  preferably extends about the entire circumference of the chamber  310 . A first set of one or more outlets  510  is disposed above the dividing member  500  to receive spent processing fluid from the upper surface of the wafer  55 . Similarly, a second set of one or more outlets  515  is disposed below the dividing member  500  to receive spent processing fluid from the lower surface of the wafer  55 . When the wafer  55  rotates during processing, the fluid through supply  415  is provided to the upper surface of the wafer  55  and spreads across the surface through the action of centripetal acceleration. Similarly, the fluid from supply tube  125  is provided to the lower surface of the wafer  55  and spreads across the surface through the action of centripetal acceleration. Because the edge of the dividing member  500  is so close to the peripheral edge of the wafer  55 , processing fluid from the upper surface of the wafer  55  does not proceed below the dividing member  500 , and processing fluid from the lower surface of the wafer  55  does not proceed above the dividing member  500 . As such, this reactor construction makes it possible to concurrently process both the upper and lower surfaces of the wafer  55  in a mutually exclusive manner using different processing fluids and steps. 
     FIG. 9 also illustrates one manner in which the processing fluids supplied to the upper and lower wafer surfaces may be collected in a mutually exclusive manner. As shown, a fluid collector  520  is disposed about the exterior periphery of the reactor  200 . The fluid collector  520  includes a first collection region  525  having a splatter stop  530  and a fluid trench  535  that is structured to guide fluid flung from the outlets  510  to a first drain  540  where the spent fluid from the upper wafer surface may be directed to a collection reservoir for disposal or re-circulation. The fluid collector  520  further includes a second collection region  550  having a further splatter stop  555  and a further fluid trench  560  that is structured to guide fluid flung from the outlets  515  to a second drain  565  where the spent fluid from the lower wafer surface may be directed to a collection reservoir for disposal or re-circulation. 
     FIG. 10 illustrates an embodiment of the reactor  200  having an alternate configuration for supplying processing fluid through the fluid inlet opening  230 . As shown, the workpiece housing  20  is disposed in a cup  570 . The cup  570  includes sidewalls  575  exterior to the outlets  100  to collect fluid as it exits the chamber  310 . An angled bottom surface  580  directs the collected fluid to a sump  585 . Fluid supply line  587  is connected to provide an amount of fluid to the sump  585 . The sump  585  is also preferably provided with a drain valve  589 . An inlet stem  592  defines a channel  595  that includes a first end having an opening  597  that opens to the sump  585  at one end thereof and a second end that opens to the inlet opening  230 . 
     In operation of the embodiment shown in FIG. 10, processing fluid is provided through supply line  587  to the sump  585  while the reactor  200  is spinning. Once the sump  585  is full, the fluid flow to the sump through supply line  587  is eliminated. Centripetal acceleration resulting from the spinning of the reactor  200  provides a pressure differential that drives the fluid through openings  597  and  230 , into chamber  310  to contact at least the lower surface of the wafer  55 , and exit outlets  100  where the fluid is re-circulated to the sump  585  for further use. 
     There are numerous advantages to the self-pumping re-circulation system illustrated in FIG.  10 . The tight fluid loop minimizes lags in process parameter control thereby making it easier to control such physical parameters as fluid temperature, fluid flow, etc. Further, there is no heat loss to plumbing, tank walls, pumps, etc. Still further, the system does not use a separate pump, thereby eliminating pump failures which are common when pumping hot, aggressive chemistries. 
     FIGS. 11 and 12 illustrate two different types of processing tools, each of which may employ one or more processing stations including the reactor constructions described above. FIG. 11 is a schematic block diagram of a tool, shown generally at  600 , including a plurality of processing stations  605  disposed about an arcuate path  606 . The processing stations  605  may all perform similar processing operations on the wafer, or may perform different but complementary processing operations. For example, one or more of the processing stations  605  may execute an electrodeposition process of a metal, such as copper, on the wafer, while one or more of the other processing stations perform complementary processes such as, for example, clean/dry processing, pre-wetting processes, photoresist processes, etc. 
     Wafers that are to be processed are supplied to the tool  600  at an input/output station  607 . The wafers may be supplied to the tool  600  in, for example, S.M.I.F. pods, each having a plurality of the wafers disposed therein. Alternatively, the wafers may be presented to the tool  600  in individual workpiece housings, such as at  20  of FIG.  1 . 
     Each of the processing stations  605  may be accessed by a robotic arm  610 . The robotic arm  610  transports the workpiece housings, or individual wafers, to and from the input/output station  607 . The robotic arm  610  also transports the wafers or housings between the various processing stations  605 . 
     In the embodiment of FIG. 11, the robotic arm  610  rotates about axis  615  to perform the transport operations along path  606 . In contrast, the tool shown generally at  620  of the FIG. 12 utilizes one or more robotic arms  625  that travel along a linear path  630  to perform the required transport operations. As in the embodiment of FIG. 10, a plurality of individual processing stations  605  are used, but more processing stations  605  may be provided in a single processing tool in this arrangement. 
     FIG. 13 illustrates one manner of employing a plurality of workpiece housings  700 , such as those described above, in a batch processing apparatus  702 . As shown, the workpiece housings  700  are stacked vertically with respect to one another and are attached for rotation by a common rotor motor  704  about a common rotation axis  706 . The apparatus  702  further includes a process fluid delivery system  708 . The delivery system  708  includes a stationary manifold  710  that accepts processing fluid from a fluid supply (not shown). The stationary manifold  710  has an outlet end connected to the input of a rotating manifold  712 . The rotating manifold  712  is secured for co-rotation with the housings  700  and, therefore, is connected to the stationary manifold  710  at a rotating joint  714 . A plurality of fluid supply lines  716  extend from the rotating manifold  712  and terminate at respective nozzle portions  718  proximate inlets of the housings  700 . Nozzle portions  718  that are disposed between two housings  700  are constructed to provide fluid streams that are directed in both the upward and downward directions. In contrast, the lowermost supply line  716  includes a nozzle portion  718  that directs a fluid stream only in the upward direction. The uppermost portion of the rotating manifold  712  includes an outlet  720  that provides processing fluid to the fluid inlet of the uppermost housing  700 . 
     The batch processing apparatus  702  of FIG. 13 is constructed to concurrently supply the same fluid to both the upper and lower inlets of each housing  700 . However, other configurations may also be employed. For example, nozzle portions  718  may include valve members that selectively open and close depending on whether the fluid is to be supplied through the upper and/or lower inlets of each housing  700 . In such instances, it may be desirable to employ an edge configuration, such as the one shown in FIG. 9, in each of the housings  700  to provide isolation of the fluids supplied to the upper and lower surfaces of the wafers  55 . Still further, the apparatus  702  may include concentric manifolds for supplying two different fluids concurrently to individual supply lines respectively associated with the upper and lower inlets of the housings  700 . 
     Numerous substantial benefits flow from the use of the disclosed reactor configurations. Many of these benefits arise directly from the reduced fluid flow areas in the reactor chambers. Generally, there is a more efficient use of the processing fluid since very little of the fluids are wasted. Further, it is often easier to control the physical parameters of the fluid flow, such as temperature, mass flow, etc., using the reduced fluid flow areas of the reactor chambers. This gives rise to more consistent results and makes those results repeatable. 
     The foregoing constructions also give rise to the ability to perform sequential processing of a single wafer using two or more processing fluids sequentially provided through a single inlet of the reaction chamber. Still further, the ability to concurrently provide different fluids to the upper and lower surfaces of the wafer opens the opportunity to implement novel processing operations. For example, a processing fluid, such as HF liquid, may be supplied to a lower fluid inlet of the reaction chamber for processing the lower wafer surface while an inert fluid, such as nitrogen gas, may be provided to the upper fluid inlet. As such, the HF liquid is allowed to react with the lower surface of the wafer while the upper surface of the wafer is effectively isolated from HF reactions. Numerous other novel processes may also be implemented. 
     The present invention has been illustrated with respect to a wafer. However, it will be recognized that the present invention has a wider range of applicability. By way of example, the present invention is applicable in the processing of disks and heads, flat panel displays, microelectronic masks, and other devices requiring effective and controlled wet processing. 
     Numerous modifications may be made to the foregoing system without departing from the basic teachings thereof. Although the present invention has been described in substantial detail with reference to one or more specific embodiments, those of skill in the art will recognize that changes may be made thereto without departing from the scope and spirit of the invention as set forth in the appended claims.