Abstract:
Wafer preparation systems and methods for wafer preparation are provided. The wafer preparation system includes a scrubber unit and a dryer unit arranged vertically with the dryer unit above the scrubber unit. The scrubber unit is configured to receive a wafer for mechanical scrub cleaning, and the dryer unit is configured to receive the wafer from the scrubber unit for drying after the mechanical scrub cleaning. The cleaning and the drying are accomplished with the wafer in a vertical orientation. An edge holder attached to a lifter rod lifts the wafer through the scrubber unit to the dryer unit. The method for wafer preparation includes receiving a wafer in a scrubbing station and lifting the wafer internally from the scrubbing station to the drying station that is located above the scrubbing station in a vertical arrangement.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is related to U.S. patent application Ser. No. 09/540,161, filed on the same day as the instant application and entitled “M ETHOD FOR  P ERFORMING  T WO  W AFER  P REPARATION  O PERATIONS ON  V ERTICALLY  O RIENTED  S EMICONDUCTOR  W AFER IN  S INGLE  E NCLOSURE. ” This cross referenced application is hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to semiconductor wafer preparation systems and method for preparing wafers, more particularly, the present invention relates to the cleaning and drying of semiconductor wafers using space and process efficient systems. 
     2. Description of the Related Art 
     In the fabrication of semiconductor devices, there is a need to perform chemical mechanical polishing (CMP) operations and wafer cleaning. Typically, integrated circuit devices are in the form of multi-level structures. At the substrate level, transistor devices having diffusion regions are formed. In subsequent levels, interconnect metallization lines are patterned and electrically connected to the transistor devices to define the desired functional device. As is well known, patterned conductive layers are insulated from other conductive layers by dielectric materials, such as silicon dioxide. As more metallization levels and associated dielectric layers are formed, the need to planarize the dielectric material grows. Without planarization, fabrication of further metallization layers becomes substantially more difficult due to the higher variations in the surface topography. In other applications, metallization line patterns (e.g., copper metal) are formed in the dielectric material, and then, metal CMP operations are performed to remove excess metallization. After any such CMP operation, it is necessary that the planarized wafer be cleaned to remove particulates and contaminants. 
     In the prior art, wafer cleaning systems typically implement brush stations in which polyvinyl alcohol (PVA) brushes are used to scrub both sides of a wafer. The PVA brush material is configured to be soft enough to prevent damage to the wafer&#39;s delicate surface, yet can provide good mechanical contact with the wafer surface to dislodge residues, chemicals and particulates. Each of the brushes are typically configured to deliver chemicals and or DI water through the brush (TTB). Commonly, two brush stations are used, each with a pair of brushes, to enable the application of chemicals in one brush station and DI water in the other. This dual brush station approach has been shown to improve the cleaning performance as well as increase throughput. One physical layout of the cleaning system is to arrange the brush stations longitudinally (i.e., horizontally). The wafer therefore travels from one brush station to the next along a conveying system. Once the wafer has been processed in both brush stations, the wafer is then conveyed to a next station in which the wafer is subjected to a spin, rinse, and dry (SRD) operation, which is performed in an SRD station or dryer station. Because these stations are arranged horizontally, the machine necessarily occupies a large clean room footprint, in some systems being as long as 6-7 feet by 3 feet wide. 
     In other wafer cleaning systems, such as the one described in U.S. Pat. No. 5,875,507, which is herein incorporated by reference, the illustrated wafer cleaning systems and a dryer system are also arranged horizontally. An end effector robot is configured to handle the wafers and transport them between each cleaning station and the dryer system. This arrangement, although efficient in cleaning wafers in vertical orientations, takes up substantial clean room area. Additionally, this arrangement requires that the robot handle the wafer at each stage of the process. That is, the robot is required to bring wafers into and out of each cleaning station and also into and out of the dryer. This level of interaction, although configured to be as clean as possible, can introduce particulates and can slow down the process. 
     In view of the foregoing, there is a need for wafer preparation systems that are more compact, occupy smaller clean room footprints, and shelter a wafer from excessive transport operations between preparation operations (e.g., such as cleaning, etching, drying and the like). 
     SUMMARY OF THE INVENTION 
     Broadly speaking, the present invention fills these needs by providing a wafer preparation system incorporating a scrubber and a dryer that are vertically oriented and configured to accomplish essential wafer processing while minimizing system footprint, minimizing wafer transport operations, and thereby minimizing auxiliary systems such as robots for end effectors. It should be appreciated that the present invention can be implemented in numerous ways, including as a process, an apparatus, a system, a device or a method. Several inventive embodiments of the present invention are described below. 
     In one embodiment, a wafer preparation system is disclosed. The wafer preparation system includes a scrubber unit that is configured to receive a wafer for mechanical scrub cleaning. A dryer unit is located above the scrubber unit in a vertical orientation. The dryer unit is configured to receive the wafer from the scrubber unit after the mechanical scrub cleaning, and then dry the wafer. 
     In another embodiment, a method of wafer preparation is disclosed. The wafer preparation method includes receiving a wafer in a scrubbing station. The method further provides the lifting of the wafer from the scrubbing station to a drying station that is arranged vertically over the scrubbing station. 
     In yet another embodiment, a wafer scrubbing and drying apparatus is disclosed. The wafer scrubbing and drying apparatus includes a scrubber unit that has scrub brushes oriented to scrub a wafer in a vertical orientation. A dryer unit is positioned over a top region of the scrubber unit, and the dryer unit is configured to receive the wafer from the scrubber unit. The wafer is received in a vertical orientation by the dryer from a slot in the top region of the scrubber unit. 
     In still a further embodiment, a semiconductor wafer preparation apparatus is disclosed. The semiconductor wafer preparation apparatus includes a wafer cleaning station and a drying station that is mounted over the wafer cleaning station. 
     The advantages of the present invention are many and substantial. Most notably, the vertical orientation of the wafer preparation system significantly reduces system footprint and required clean room floor space. The vertical orientation represents a significant advancement over prior art that extends preparation systems over a large floor space area and requires repeated robot wafer handling to transport wafers from one preparation station or unit to the next. The present invention not only minimizes required floor space, but minimizes the need for repeated robot handling, reducing both the cost of operation and the potential for contamination. 
     Another advantage of the present invention is the embodiment that provides increased flexibility in wafer preparation processes by accommodating both chemical cleans or etching processes and DI water rinses in both scrubber and dryer units. The vertical orientation of the wafer preparation system incorporates a dual brush set in the scrubber unit which can dispense both chemicals and DI water in whatever combination the wafer process dictates. The dryer unit is also configured to dispense both chemicals and DI water, and in the vertical orientation, the wafer preparation system can incorporate an environment that gets progressively cleaner as the wafer proceeds higher in the system. Thus, the first scrub operation can be the most vigorous and successive etch, clean and rinse operations can be in cleaner conditions, the successive operations being located higher in the vertically oriented system. 
     Finally, a preferred embodiment of the present invention affords a more efficient process with increased throughput over prior art. A single robot can load wafers into the scrubber unit of the wafer preparation system and unload wafers from the dryer unit. In a vertical orientation, multiple wafer preparation systems can be implemented to share resources in smaller floor space areas to maximize the savings and efficiency achieved. 
     Other aspects and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the present invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be readily understood by the following detailed description in conjunction with the accompanying drawings. To facilitate this description, like reference numerals designate like structural elements. 
     FIG. 1A shows a vertically oriented wafer scrubber-dryer unit in accordance with one embodiment of the present invention. 
     FIG. 1B illustrates the load/unload position of the dryer unit in accordance with one embodiment of the invention. 
     FIG. 1C shows the dryer unit in the closed position in accordance with one embodiment of the present invention. 
     FIG. 2A shows a front and side perspective view of the scrubber unit in accordance with one embodiment of the invention. 
     FIG. 2B illustrates the transition of the wafer out of the scrubber unit in accordance with an embodiment of the present invention. 
     FIG. 3A illustrates the scrubber brush assembly in accordance with one embodiment of the invention. 
     FIG. 3B shows a detailed view of the edge holder in accordance with an embodiment of the invention. 
     FIG. 3C shows the wafer being lifted in accordance with one embodiment of the present invention. 
     FIGS. 4A-4C show a side view of the dryer unit in each of the three positions with a detail of the wafer position in the open, the load/unload, and the closed positions in accordance with an embodiment of the invention. 
     FIG. 5 is a graphical representation of a wafer preparation process in accordance with one embodiment of the present invention. 
     FIG. 6A shows a detailed view of the dryer in accordance with an embodiment of the present invention. 
     FIGS. 6B and 6C show a perspective overhead view of a dryer in accordance with one embodiment of the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     An invention for wafer processing equipment, namely, wafer scrubbing, cleaning, etching, rinsing, and drying is disclosed. In preferred embodiments, a wafer preparation system includes a wafer scrubbing unit that is configured to receive a wafer and then transfer the wafer internally to a dryer unit. The dryer unit, in this preferred embodiment, is positioned over the wafer scrubbing unit. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be understood, however, to one skilled in the art, that the present invention may be practiced without some or all of these specific details. In other instances, well known process operations have not been described in detail in order not to unnecessarily obscure the present invention. 
     FIG. 1A shows a vertically oriented wafer scrubber-dryer unit in accordance with one embodiment of the present invention. As shown, a dryer unit  104  is mounted above a scrubber unit  102  and integrated as a wafer preparation system  100 . The mounting of the dryer unit  104  over the scrubber unit  102  can be done in any number of ways. By way of example, the dryer unit  104  can be bolted to a portion of the scrubber unit  102 , it can be mounted to a housing support, it can be attached to a wall, or it can be suspended over the scrubber unit  102  using appropriate supports. In either case, the dryer unit  104  is positioned over the scrubber unit  102  so as to save valuable clean room space and to achieve other advantages as will be discussed below. 
     In one embodiment, the dryer unit includes a moveable dryer housing  104   a  configured to move towards and away from a fixed dryer housing  104   b  to define positions of open, closed, and load/unload which are described in greater detail below. FIG. 1A shows the dryer unit  104  of the wafer preparation system  100  in the open position. The fixed dryer housing  104   b  is secured to a system support structure  106  that spans and supports both the dryer unit  104  and the scrubber unit  102  of the system  100 . A support mount  106   a , in one embodiment, is positioned between the scrubber unit  102  and the fixed dryer housing  104   b.    
     A wafer  110  is shown entering the dryer unit  104  through a second slot opening  102   c  in the scrubber unit  102 . Fingers  105   b ,  105   c  are configured to support the wafer  110  in the dryer unit  104 , and a pivot finger  105   a  is configured to pivot to the edge of the wafer  110  to secure the wafer  110  in its mounting. In one embodiment, the wafer  110  is lifted through the scrubber unit  102  by an edge holder  114  on a lifter rod  112  driven by a lifter rod controller  108 . 
     The wafer  110  enters the scrubber unit  102  through a first slot opening  102   g  located in a front panel door  102   a . The first slot opening  102   g  is configured to be opened and closed by way of a slider door  102   b  that slides in the required direction  102   b ′ to open or seal the first slot opening  102   g . In general, a wafer  110  to be processed is introduced into the wafer preparation system  100  through the first slot opening  102   g , and the slider door  102   b  closes to seal the system. The wafer  110  is scrubbed in the scrubber unit  102 , and then lifted to the dryer unit  104  by an edge holder  114  mounted on a lifter rod  112 . The wafer  110  exits the scrubber unit  102  through the second slot opening  102   c  and transitions into the dryer unit  104  when it is in the open position as shown in FIG.  1 A. The wafer  110  is mounted and secured in the dryer unit  104  by way of the fingers  105   b ,  105   c , and the pivot finger  105   a . The wafer  110  is dried in the dryer unit  104 , and a clean and dry wafer  110  is removed from the wafer preparation system  100 . As used herein, the term drying should be understood to mean a number of possible operations, such as, spinning a wafer, rinsing a wafer, applying chemicals to a wafer and then rinsing the wafer (e.g., in order to perform etching with chemicals such as HF), and also simply drying. Therefore, the terms “dry,” “drying,” “dryer,” “dryer unit,” and “drying system” are used and should be interpreted to include any one or a combination of the operations defined herein and those having similar applications. 
     FIG. 1B illustrates the load/unload position of the dryer unit  104  in accordance with one embodiment of the invention. As can be seen, the moveable dryer housing  104   a  moves in the direction of the fixed dryer housing  104   b . The wafer  110 , completely within the dryer unit  104 , is supported by fingers  105   b , and  105   c . Pivot finger  105   a  pivots from a raised and unlocked position and downward to attach to the edge of the wafer  110 , thus securing the wafer in a mounting by the fingers  105   b ,  105   c  and the pivot finger  105   a . 
     In one embodiment, the load/unload position is a two stage position. In a first stage of the load position, the wafer  110  is lifted into the dryer unit  104  by the edge holder  114  to a position in which the bottom edge of the wafer  110  is slightly above the fingers  105   b  and  105   c . The moveable housing  104   a  is then positioned such that the fingers  105   b  and  105   c  are located under the bottom edge of the wafer  110  at a position to hold the wafer  110  by the edge when lowered. In the second stage of the load position, the wafer  110  is then lowered onto the fingers  105   b  and  105   c  and the pivot finger  105   a  pivots downward to secure the top edge of the wafer  110  and complete the operation of mounting the wafer  110  in the dryer unit  104 . The edge holder  114  is then withdrawn from the dryer unit  104  so that the moveable dryer housing  104   a  can continue to the closed position. 
     FIG. 1C shows the dryer unit  104  in the closed position in accordance with one embodiment of the present invention. The moveable dryer housing  104   a  is positioned so that it meets and overlaps with the fixed dryer housing  104   b  and seals the dryer unit  104 . The wafer  110  is shown inside the sealed dryer unit  104  mounted on the fingers  105   b  and  105   c  and secured by pivot finger  105   a.    
     FIG. 2A shows a front and side perspective view of the scrubber unit  102  in accordance with one embodiment of the invention. The front panel door  102   a  is shown in the open position which allows access to the various components of the scrubber assembly. The first slot opening  102   g  is located in the front panel door  102   a . During scrubbing operations, the front panel door  102   a  is in the closed position and the wafer  110  is inserted into the scrubber unit  102  through the first slot opening  102   g.    
     The second slot opening  102   c  is shown in the top plate  102   f  on the top of the scrubber unit  102 . A top door  102   d  is shown in an open position with directional arrows indicating a direction of movement of the top door  102   d  to the open or closed positions. The top door  102   d  is illustrated connected to a positioning bar  102   e  that controls the movement of the top door  102   d  in accordance with one embodiment of the invention. In another embodiment, the position of the top door  102   d  is controlled by pins, brackets, or other such devices mounted on the bottom of the moveable dryer housing ( 104   a , FIGS. 1A-1C) that would position the top door  102   d  in accordance with the position of the moveable dryer housing  104   a . In yet another embodiment, the top door  102   d  is located within the scrubber unit  102  and positioned by known mechanical operations within the scrubber unit  102 . 
     Four brushes  120  are shown within the scrubber unit  102  configured symmetrically such that there are two brushes  120  on opposite sides of the wafer  110  above two brushes  120  on opposite sides of the wafer  110 . The two brushes  120  closest to the top plate  102   f  define an upper set of brushes  120 , and the two brushes  120  below the upper set of brushes  120  define a lower set of brushes  120 . Above each brush  120  is shown a manifold containing multiple nozzle heads configured to be sprayers  122  above each brush  120 . 
     During a scrub operation, the brushes  120  are configured to scrub opposite sides of the wafer  110  in pairs such that as the lower set of brushes  120  are positioned in contact with and performing a scrub operation on the wafer  110 , the upper set of brushes  120  are retracted away from the wafer  110 . The scrubber  102  is configured to then position the upper set of brushes  120  so that the upper set of brushes  120  are in contact with and performing a scrub operation on the wafer  110  and the lower set of brushes  120  are retracted away from the wafer  110 . A set of sprayers  122  is associated with each brush  120  and remain in a fixed location relative to each brush  120 . The fixed location is above each brush  120 , and the sprayers  122  provide the fluid for the scrubbing operation, fluid for cleaning, or fluid for etching as required. 
     In accordance with one embodiment of the present invention, the vertical orientation of the scrubbing operation promotes a dirty-to-clean progression in the scrubbing process. In a dirty-to-clean progression, the higher the scrubbing operation of the wafer progresses in the scrubber  102 , the cleaner the operation. By way of example, the lower set of brushes begins the operation by performing a scrubbing process and using, for example, some chemical/DI water solution (e.g., hydrofluoric acid (HF) or other such chemicals) to perform an initial scrubbing operation. As described above, the upper set of brushes  120  is retracted away from the wafer  110  while the lower set is in contact with the wafer  110  and performing a scrubbing operation. The sprayers  122 , located above the brushes  120 , can introduce DI water or chemicals into the process. Alternatively, the chemicals or DI water can be introduced through the brush. 
     After a first scrub operation using the lower set of brushes  120  is complete, the upper set of brushes  120  move toward the wafer as the lower set of brushes  120  move away. Using the upper set of brushes  120 , a second scrub operation can be performed. By way of example, the second scrub operation can include the use of another chemical (e.g., that may be weaker) or DI water to remove most of the chemicals and particulates. In addition, the sprayers  122  can also assist in removing any chemicals and/or particulates. 
     FIG. 2B illustrates the transition of the wafer  110  out of the scrubber unit  102  in accordance with an embodiment of the present invention. The wafer  110  is lifted through the scrubber unit  102  by the edge lifter  114  attached to the lifter rod  112 . The top door  102   d  must be in the open position enabling the wafer  110  to exit the scrubber unit  102  through the top slot  102   c  in the top plate  102   f . Upon exiting the scrubber unit  102 , the wafer transitions to the dryer unit  104  as discussed in greater detail below. 
     FIG. 3A illustrates the scrubber brush assembly  200  in accordance with one embodiment of the invention. The scrubber brush assembly  200  includes 4 brushes  120  configured in an upper set of brushes  120  and a lower set of brushes  120  as defined above. During the scrubbing operation, the brushes  120  are configured to rotate to produce the desired scrubbing action. As described above, only the upper set of brushes  120  or the lower set of brushes  120  is in contact with and performing a scrubbing operation on a wafer  110  at any one time. When the lower set of brushes is performing a scrubbing operation, the upper set of brushes is retracted away from the wafer  110 . When the upper set of brushes  120  is performing a scrubbing operation, the lower set of brushes  120  is retracted away from the wafer  110 . The positioning and rotation of the brushes is controlled by the brush control assembly  202 . 
     The wafer  110  is supported in place during the scrub operation by wafer drive rollers  206   a ,  206   b . The wafer drive rollers  206   a ,  206   b  are mounted to roller arms  204   a ,  204   b . In addition to the scrub operation being accomplished by the rotation of the brushes  120  against the wafer  110 , the wafer drive rollers  206   a ,  206   b  drive a rotation of the wafer  110 . During the scrubbing operation, the edge holder  114  is retracted away from the wafer  110 . The wafer drive rollers  206   a ,  206   b , support the wafer  110  and, driven by a motor  208 , rotate the wafer  110 . The wafer  110  can also be moved up or down to accomplish off-center scrubbing by raising or lowering the roller arms  204   a ,  204   b.    
     When the scrubbing operation is completed, the edge holder  114  is raised into position by the lifter rod  112  which is driven by lifter rod controller  108 ′. The lifter rod controller  108 ′ in the illustrated embodiment is a servo motor, but in other embodiments it can be pneumatic, hydraulic, a linear actuator, or any suitable mechanical device to controllably raise and lower the wafer  110  through the scrubber unit  102  and to the dryer unit  104  overhead (see FIG.  1 ). 
     FIG. 3B shows a detailed view of the edge holder  114  in accordance with an embodiment of the invention. The edge holder  114  is attached to an end of the lifter rod  112 , and is configured to support the wafer  110  by a small portion of the edge of the wafer  110 . The interior of the edge holder  114  as seen in the cross sectional view is configured in a “V” shape. This design is configured to minimize the contact area with the surface of the wafer  110  (e.g., the active region) while providing ample support to lift the wafer  110  through the scrubber unit  102  and position it in the dryer unit  104  as described above. 
     FIG. 3C shows the wafer  110  being lifted in accordance with one embodiment of the present invention. At the end of the scrub operation, the edge holder  114  is lifted by the lifter rod  112  which is driven by the lifter rod controller  108 ′ or  108 . When the edge holder is positioned to support the wafer  110 , the brushes  120  are retracted by the brush control assembly  202 . The lifter rod  112  proceeds to lift the edge holder  114  in direction  210   a  resulting in the wafer  110  rising through the scrubber brush assembly  200  in direction  210   b . As the wafer  110  rises, support of the wafer  110  is transferred from the wafer drive rollers  206   a ,  206   b  to the edge holder  114 , and in this manner, the wafer is lifted through the scrubber unit  102  to the dryer unit  104  above. 
     As described above in reference to FIGS. 1A-1C, one embodiment of the dryer unit  104  has 3 positions: open, load/unload, and closed. FIGS. 4A-4C show a side view of the dryer unit  104  in each of the three positions with a detail of the wafer position in the open, the load/unload, and the closed positions in accordance with an embodiment of the invention. In FIG. 4A, the dryer unit  104  is in the open position. The moveable dryer housing  104   a  is at the greatest separation distance (D open ) possible from the fixed dryer housing  104   b . The only direction the moveable dryer housing  104   a  can move from this position (e.g., during operation) is toward the fixed dryer housing  104   b  and this movement is represented by directional arrow  252 . The wafer  110  is shown in the side view supported by edge holder  114  on the end of lifter rod  112 . Pivot finger  105   a  is shown in the raised or unlocked position. Fingers  105   b ,  105   c  are represented by a single structure from the side. 
     The wafer detail of FIG. 4A shows that the wafer  110  is actually above the fingers  105   b ,  105   c  which are represented as dots on a platen  250 . From this position, the moveable dryer housing  104   a  can proceed to the load/unload position. 
     FIG. 4B shows the load/unload position. The moveable dryer housing  104   a  has moved to a position closer to the fixed dryer housing  104   b , the distance between the housings now represented by D L/U . From the load/unload position, the moveable dryer housing  104   a  can be moved either away from or towards the fixed dryer housing  104   b  as represented by bi-directional arrow  254 . In the load/unload position, the wafer  110  is positioned on the fingers  105   b ,  105   c , and the pivot finger  105   a  pivots from a raised, unlock position, downward to attach to the edge of the wafer  110 , securing the wafer in a mounting by the fingers  105   b ,  105   c  and the pivot finger  105   a . As can be seen in the wafer detail, the wafer is mounted and secured by the pivot finger  105   a  and fingers  105   b ,  105   c  to the platen  250 . The lifter rod  112  then retracts the edge holder  114  away from the wafer  110  and out of the dryer unit  104 . 
     FIG. 4C shows the dryer unit  104  in the closed position. The moveable dryer housing  104   a  is mated to the fixed dryer housing  104   b  which seals the dryer unit  104 . As will be described in greater detail below, the wafer  110  is securely mounted on the platen  250  by the pivot finger  105   a  and fingers  105   b ,  105   c  and within the fixed dryer housing  104   b  portion of the sealed dryer unit  104 . 
     FIG. 5 is a graphical representation of a wafer preparation process  300  in accordance with one embodiment of the present invention. The wafer  110  is manipulated (e.g., moved to or from desired positions) by an end effector  304 , and the wafer is secured to the end effector  304  by way of vacuum holds  306  or other such apparatus or processes to secure a wafer to an end effector  304  or other robotic arm designed to efficiently transport wafers while maintaining clean room standards and integrity. The wafer  110  is inserted  302   a  into the scrubber unit  102 , and positioned  302   b  in the scrubber assembly. In one embodiment, multiple scrubbing processes are accomplished with each process resulting in the wafer becoming cleaner and cleaner. After the scrub process is completed, the wafer is transitioned  302   c  (from within the scrubber unit  102 ) into the dryer unit  104  overhead, and positioned  302   d  for the drying process. In one embodiment, the processes completed in the dryer unit  104  include spinning the wafer  110 , rinsing the wafer  110 , etching the wafer  110 , drying the wafer  110 , and the like. At the completion of the drying process, the wafer  110  is extracted  302   e  by the end effector  304 , being secured to the end effector by vacuum holds  306  or other such securing apparatus or methods as described above. In one embodiment, the end effector  304  is attached to the same robot as is the end effector  304  that inserted  302   a  the wafer  110  at the beginning of the illustrated wafer preparation process  300 . Alternatively, two or more end effectors can be used. 
     FIG. 6A shows a detailed view of the dryer  104  in accordance with an embodiment of the present invention. As described above, the dryer  104  includes a moveable dryer housing  104   a  and a fixed dryer housing  104   b . In one embodiment, the moveable dryer housing  104   a  is mechanically positioned to one of an open, a load/unload, or a closed position. The wafer  110  is transitioned into the dryer  104  as described above, and is mounted on the platen  250  and secured with fingers  105 . The platen  250  is attached to a spin motor  352  using a mounting block  354 , and is configured to spin with the wafer  110  secured thereon. As shown in FIG. 6A, a set of nozzles  350  is provided to direct rinsing fluid at the back side of the wafer  110 . 
     In one embodiment, the wafer  110  is transitioned to the dryer  104  when the dryer  104  is in the open position. The wafer  110  is lifted through the scrubber  102  (see FIG. 1A) after completion of the scrub operation, and enters the dryer  104  configured above the scrubber  102  while the dryer  104  is in the open position. The moveable dryer housing  104   a  is moved to the load/unload position, and the wafer  110  is mounted on the platen  250  using fingers  105  as described above in reference to FIGS. 1A-1C. The active side (e.g., the side having devices fabricated thereon) of the wafer  110  is positioned facing the moveable dryer housing  104   a , and once the wafer  110  is mounted, the moveable dryer housing  104   a  is moved again to mate with the fixed dryer housing  104   b  and seal the dryer  104  in a closed position. 
     In the closed position, the dryer  104  is configured to perform any of a spin, rinse, etch, or drying operation of the wafer  110 . For more information on the structure and functionality of the dryer  104 , reference can be made to U.S. Pat. No. 6,012,470, issued Jan. 11, 2000, which is hereby incorporated by reference. 
     FIGS. 6B and 6C show a perspective overhead view of a dryer  104  in accordance with one embodiment of the invention. FIG. 6B shows the dryer  104  in the load/unload position, and FIG. 6C shows the dryer  104  in the closed position. In one embodiment, a servo motor  359  is located on the side of the dryer  104  and controls the positioning of the moveable dryer housing  104   a . In the load/unload position (FIG.  6 B), the wafer  110  is mounted to the platen  250  using fingers  105   b ,  105   c . As described above, a pivot finger  105   a  is used to secure the wafer  110  in the mounting. Once the wafer  110  is positioned and the edge holder  114  (see FIGS. 3A-3B) is withdrawn from the dryer  104 , the servo motor  359  drives the moveable housing  104   a  to the fixed housing  104   b  and the closed position. The back side of the wafer  110  is the side that faces the fixed housing  104   b , and is rinsed by a set of nozzles  350  directing a rinsing fluid or process chemical. The active side of the wafer  110  faces the platen  250  and is rinsed (or etched followed by a rinse) by nozzles  358  directing a fluid at that side of the wafer  110 . FIGS. 6B-6C show a representative nozzle  358  directing the fluid at the active side of the wafer  110  in accordance with one embodiment, and nozzles  358  can be positioned in any suitable location or in any suitable configuration in accordance with the needs of the desired process and the size of the wafer  110 . 
     A drain  360  is shown in FIGS. 6B-6C for removal of fluid from the dryer unit  104 . A drain  360  is necessary in the drying environment to remove fluids, but in a preferred embodiment, it would not be visible from an overhead perspective as a drain  360  would be most effective when positioned in the lowest portion of the dryer  104 . 
     Once a wafer  110  is processed through the preparation system  100 , the wafer can be processed through other well known fabrication operations. These operations include, as is well known, deposition or sputtering of oxide materials and conductive materials (e.g., aluminum, copper, mixtures, and the like). The process, also known as “the backside” process also includes etching operations. These etching operations are designed to define the network of metallization lines, vias, and other geometric patterns necessary to define the interconnect structure of an integrated circuit device. In between these operations, some chemical mechanical polishing (CMP) operations are also needed to planarize the surface to enable more efficient fabrication. After any of such operations, the wafer will need to be cleaned and dried before proceeding to a next operation in the process of making an integrated circuit device. Once complete, the wafer is cut into dies, each die representing one integrated circuit chip. The chips are then placed into suitable packages and integrated into a desired end device, such as a consumer electronic end product. 
     While this invention has been described in terms of several preferred embodiments, it will be appreciated that those skilled in the art upon reading the preceding specifications and studying the drawings will realize various alterations, additions, permutations and equivalents thereof. It is therefore intended that the present invention includes all such alterations, additions, permutations, and equivalents as fall within the true spirit and scope of the invention.