Apparatus for ejecting fluid onto a substrate and system and method incorporating the same

A fluid dispenser for use in the processing of substrates. The dispenser has a dome shaped body with a convex upper surface and has a number of conduits designed to supply fluid to the surface of a substrate at predetermined points.

FIELD OF THE INVENTION

The present invention relates generally to the field of processing substrates, such as semiconductor wafers, and specifically to fluid dispensers that apply fluids to the surface of substrates during processing.

BACKGROUND OF THE INVENTION

In the field of semiconductor manufacturing, it has been recognized since the beginning of the industry that maintaining the semiconductor wafers free of contaminants during the manufacturing process is a critical requirement to producing quality profitable wafers. As the size of the devices continue to become smaller, the number of semiconductor devices present on a single wafer continues to exponentially grow. As a result of the devices becoming more and more miniaturized, cleanliness requirements have also become increasingly important and stringent. When dealing with reduced size devices, the ratio of the size of a contaminant compared to the size of a device is greater, resulting in an increased likelihood that a contaminated device will not function properly. Thus, increasingly stringent cleanliness and PRE requirements are needed. As a result, improved semiconductor wafer processing techniques that reduce the amount and size of the contaminants present during wafer production are highly desired.

An example of a single-wafer cleaning system that utilizes megasonic energy is disclosed in U.S. Pat. No. 6,039,059 (“Bran”), issued Mar. 21, 2000. An example of a single-wafer cleaner and dryer is disclosed in U.S. Pat. No. 7,100,304 (“Lauerhaas et al.”), issued Sep. 5, 2006. The entireties of Bran and Lauerhaas et al. are hereby incorporated by reference.

In single-wafer processing systems, such as the ones mentioned above, a semiconductor wafer is supported and rotated in a horizontal orientation. A desired processing chemical is then applied to one or both sides/surfaces of the wafer. Nozzles/dispensers are typically placed underneath the wafer and dispense fluid in an upward direction so as to apply the fluid on the bottom surface of the wafer. It is important that the level of contaminants and/or residues left on the surface of the wafer be minimized to the extent possible at all times.

While the dispensers serve the vital function of applying fluids to the surface of the wafer, they also present a problem in that fluid and contaminants will collect on the top surface of the dispenser and get re-deposited back on the wafer. Thereby re-contaminating the wafer and causing semiconductor device failure problems. Additionally, because the wafer spins during the application of fluid, turbulence is created between the bottom surface of the wafer and the top surface of the dispenser that may damage the wafer or may cause more contaminants to remain on the surface of the wafer.

Therefore, there is a need to provide an improved apparatus, system and method for processing substrates that prevents and/or minimizes the deposit of contaminants on the wafer.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a system, apparatus and method that minimizes the deposit of contaminants on the surface of a substrate.

A further object of the present invention is to provide an apparatus that allows for multiple fluids to be discharged through the same apparatus without cleaning out the apparatus.

A still further object of the present invention is to provide a fluid dispenser that minimizes the turbulence between a rotating substrate and the dispenser.

A yet further object of the present invention is to provide an apparatus for dispensing fluid onto a surface of a substrate at predetermined points on the substrate.

Another object of the present invention is to provide a fluid dispenser that simplifies the hardware required in the processing of a substrate.

A still further object of the present invention is to provide a fluid dispenser that improves the cleaning of the backside of substrates.

These and other objects are met by the present invention which in one aspect can be a system for processing substrates comprising: a rotatable support for supporting and rotating a substrate about a rotational center-point; a fluid dispensing apparatus comprising a body with a substantially dome-shaped outer surface and a plurality of conduits terminating as holes in the outer surface of the body, wherein the conduits are adapted to eject fluid out of the holes; and wherein the fluid dispensing apparatus is positioned so that fluid dispensed out of the holes contacts a surface of a substrate on the rotatable support.

In another aspect the invention can be a system for processing substrates comprising: a rotatable support for supporting and rotating a substrate about a rotational center-point; a fluid dispensing apparatus comprising a body, a first header and a second header; the first header having an inlet adapted to introduce a first fluid into the first header; the second header having an inlet adapted to introduce a second fluid into the second header; a first array of conduits extending from the first header and terminating as holes in an outer surface of the body, the first array of conduits adapted to eject the first fluid from the first header and onto a substrate located on the rotatable support; and a second array of conduits extending from the second header and terminating as holes in the outer surface of the body, the second array of conduits adapted to eject the second fluid from the second header and onto a substrate located on the rotatable support.

In another aspect the invention can be an apparatus for applying a fluid to a surface of a substrate comprising: a body having a first header and a second header; a first inlet for introducing a first fluid into the first header; a second inlet for introducing a second fluid into the second header; a first array of conduits extending from the first header and terminating as holes in an outer surface of the body, the first array of conduits adapted to eject the first fluid; and a second array of conduits extending from the second header and terminating as holes in the outer surface of the body, the second array of conduits adapted to eject the second fluid.

In another aspect the invention can be a method for processing a substrate comprising: supporting a substrate in a horizontal orientation; rotating the substrate; providing a fluid dispensing apparatus adjacent a surface of the substrate, the fluid dispensing apparatus comprising a body with a substantially dome-shaped outer surface and a plurality of conduits terminating as holes in the outer surface of the body, wherein the conduits are adapted to dispense fluid out of the holes; and applying fluid to the surface of the substrate via the fluid dispensing apparatus.

In another aspect the invention can be a method of processing a substrate comprising: supporting a substrate in a horizontal orientation; rotating the substrate; providing a fluid dispensing apparatus adjacent a surface of the substrate, the fluid dispensing apparatus comprising a body having a first header and a second header, a first inlet for introducing a first fluid into the first header, a second inlet for introducing a second fluid into the second header, a first array of conduits extending from the first header and terminating as holes in an outer surface of the body, the first array of conduits adapted to eject the first fluid, a second array of conduits extending from the second header and terminating as holes in the outer surface of the body, the second array of conduits adapted to eject the second fluid; applying a first fluid to the surface of the substrate via the first array of conduits of fluid dispensing apparatus; and applying a second fluid to the surface of the substrate via the second array of conduits of the fluid dispensing apparatus.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring first toFIG. 1, a schematic of an acoustic energy cleaning system1000(hereinafter referred to as “cleaning system1000”) is illustrated according to one embodiment of the present invention. For ease of discussion, the inventive system and methods of the drawings will be discussed in relation to the cleaning of semiconductor wafers. However, the invention is not so limited and can be utilized for any desired wet processing of any flat article.

The cleaning system1000generally comprises a top transducer assembly200, a rotatable support10for supporting a semiconductor wafer50in a substantially horizontal orientation, a top dispenser13and a bottom dispenser14. Preferably, the semiconductor wafer50is supported so its top surface51is the device side of the wafer50while the bottom surface56is the non-device side. Of course, the wafer can be supported so that its top surface51is the non-device side while the bottom surface56is the device side, if desired.

The rotatable support10is designed to contact and engage only a perimeter of the substrate50in performing its support function. However, the exact details of the structure of the rotatable support10are not limiting of the present invention and a wide variety of other support structures can be used, such as chucks, support plates, etc. Additionally, while it is preferred that the support structure support and rotate the semiconductor wafer in a substantially horizontal orientation, in other embodiments of the invention, the system may be configured so that the semiconductor wafer is supported in other orientations, such as vertical or at an angle. In such embodiments, the remaining components of the cleaning system1000, including the transducer assembly200, can be correspondingly repositioned in the system so as to be capable of performing the desired functions and/or the necessary relative positioning with respect to other components of the system as discussed below.

The rotary support10is operably coupled to a motor11to facilitate rotation of the wafer50within the horizontal plane of support. The motor11is preferably a variable speed motor that can rotate the support10at any desired rotational speed ω. The motor11is electrically and operably coupled to the controller12. The controller12controls the operation of the motor11, ensuring that the desired rotational speed ω and desired duration of rotation are achieved.

The top dispenser13is positioned and oriented so that when a liquid is flowed therethrough, the liquid is applied to the top surface51of the substrate50. When the substrate50is rotating, this liquid forms a layer or film of the liquid across the entirety of the top surface51of the substrate50. The bottom dispenser14is positioned and oriented so that when a liquid is flowed therethrough, the liquid is applied to the bottom surface56of the substrate50. When the substrate50is rotating, this liquid forms a layer or film of the liquid across the entirety of the bottom surface56of the substrate50.

Both the top dispenser13and the bottom dispenser14are operably and fluidly coupled to a liquid supply subsystem16via liquid supply lines17,18A-D. The liquid supply subsystem16is in turn fluidly connected to the liquid reservoirs15A-D. The liquid supply subsystem16controls the supply of liquid to both the top dispenser13and the bottom dispenser14. The bottom dispenser14is operably and fluidly connected all four liquid reservoirs15A-D. As will be discussed in further detail below, this allows for the application of four different liquids to various points on the bottom surface56of the wafer50through the bottom dispenser14.

The liquid supply subsystem16, which is schematically illustrated as a box for purposes of simplicity, comprises the desired arrangement of all of the necessary pumps, valves, ducts, connectors and sensors for controlling the flow and transmission of the liquid throughout the cleaning system1000. The direction of the liquid flow is represented by the arrows on the supply lines17,18A-D. Those skilled in the art will recognize that the existence, placement and functioning of the various components of the liquid supply subsystem16will vary depending upon the needs of the cleaning system1000and the processes desired to be carried out thereon, and can be adjusted accordingly. The components of the liquid supply subsystem16are operably connected to and controlled by the controller12.

The liquid reservoirs15A-D hold the desired liquid to be supplied to the wafer50for the processing that is to be carried out. For cleaning system1000, the liquid reservoirs15A-D will each hold a cleaning liquid, such as for example deionized water (“DIW”), standard clean 1 (“SC1”), standard clean 2 (“SC2”), ozonated deionized water (“DIO3”), dilute or ultra-dilute chemicals, and/or combinations thereof. As used herein, the terms “liquid” and “fluid” include at least liquids, liquid-liquid mixtures, liquid-gas mixtures, and other supercritical and/or dense fluids.

The cleaning system1000further comprises a gas supply subsystem19that is operably and fluidly coupled to a gas source20. The gas supply subsystem19is operably and fluidly connected to the top transducer assembly200via the gas supply line21. The gas supply subsystem19, which is schematically illustrated as a box for purposes of simplicity, comprises the desired arrangement of all of the necessary pumps, valves, ducts, connectors and sensors for controlling the flow and transmission of the gas throughout the cleaning system1000. The direction of the gas flow is represented by the arrows on the supply line21. Those skilled in the art will recognize that the, existence, placement and functioning of the various components of the gas supply subsystem19will vary depending upon the needs of the cleaning system1000and the processes desired to be carried out thereon, and can be adjusted accordingly. The components of the gas supply subsystem19are operably connected to and controlled by the controller12. Thus, the transmission of gas from the gas supply subsystem19is based upon signals received from the controller12.

The gas is supplied to the top transducer assembly200to provide cooling and/or purging to the transducer in the assembly200that converts the electrical energy into the acoustic energy. The gas source15preferably holds an inert gas, such as nitrogen, helium, carbon dioxide, etc. However, the invention is not limited to the use of any specific gas. Furthermore, as with the liquids, it is possible to have multiple gas sources. For example, in some embodiments of the invention, the top transducer assembly200can be operably and fluidly coupled to different gas reservoirs. This would allow the application of different gases as desired.

The cleaning system1000further comprises a horizontal actuator250that is operably coupled to the top transducer assembly200. The actuator250is operably coupled to and controlled by the controller12. The actuator250can be a pneumatic actuator, drive-assembly actuator, or any other style desired to effectuate the necessary movement. The horizontal actuator250can horizontally translate the top transducer assembly200between a retracted position and a processing position. When in the retracted position, the top transducer assembly200is withdrawn sufficiently away from the rotatable support10so that the wafer50can be loaded and unloaded without obstruction onto and from the support10. When in the processing position, at least a portion of the top transducer assembly200is spaced from but sufficiently close to the top surface51of the wafer50so that when liquid is supplied to the top surface51of the wafer50, a meniscus of liquid is formed between the top surface51of the wafer50and that portion of the top transducer assembly200. InFIG. 1, the top transducer assembly200is in the processing position. While the actuator200is exemplified in system1000as being horizontal, in other embodiments of the invention, different styles of actuator can be used, for example the actuator200can be a horizontal, vertical, angled translation actuator or a pivotable actuator.

The cleaning system1000also comprises an electrical energy signal source9that is operably coupled to the top transducer assembly200. The electrical energy signal source9creates the electrical signal that is transmitted to the transducer in the top transducer assembly200for conversion into corresponding acoustic energy. The electrical energy signal source9is operably coupled to and controlled by the controller12. As a result, the controller12will dictate the frequency, power level, and duration of the acoustic energy generated by the top transducer assembly200. Preferably, the electrical energy signal source9is controlled so that the acoustic energy generated by the top transducer assembly200has a frequency in the megasonic range.

The controller12may be a processor, which can be a suitable microprocessor based programmable logic controller, personal computer, or the like for process control. The controller12preferably includes various input/output ports used to provide connections to the various components of the cleaning system1000that need to be controlled and/or communicated with. The electrical and/or communication connections are indicated in dotted line inFIG. 2. The controller12also preferably comprises sufficient memory to store process recipes and other data, such as thresholds inputted by an operator, processing times, rotational speeds, processing conditions, processing temperatures, flow rates, desired concentrations, sequence operations, and the like. The controller12can communicate with the various components of the cleaning system1000to automatically adjust process conditions, such as flow rates, rotational speed, movement of the components of the cleaning system1000, etc. as necessary. The type of system controller used for any given system will depend on the exact needs of the system in which it is incorporated.

As will be noted, the top transducer assembly200is generically illustrated as a box. This is done because, in its broadest sense, the invention is not limited to any particular structure, shape and/or assembly arrangement for the transducer assembly200. For example, any of the transducer assemblies disclosed in U.S. Pat. No. 6,039,059 (“Bran”), issued Mar. 21, 2000, U.S. Pat. No. 7,145,286 (“Beck et al.”), issued Dec. 5, 2006, U.S. Pat. No. 6,539,952 (“Itzkowitz”), issued Apr. 1, 2003, and United States Patent Application Publication 2006/0278253 (“Verhaverbeke et al.”), published Dec. 14, 2006, can be used as the top transducer assembly200. Of course, other styles of transducer assemblies can be used, such as those having an elongated transmitter rod supported at an angle to the surface of the wafer.

Referring now toFIG. 2, a preferred structural embodiment of the cleaning system1000is illustrated. Like numbers are used inFIGS. 2-13to indicate the corresponding structural manifestation of the schematically illustrated components ofFIG. 1.

In the cleaning system1000ofFIG. 2, the top transducer assembly200comprises an elongate rod-like transmitter201that is acoustically coupled to a transducer203that is located within housing202. Many of the details of this style of elongate rod-like transmitter201are disclosed in U.S. Pat. No. 6,684,891 (“Bran”), issued Feb. 3, 2004 and U.S. Pat. No. 6,892,738 (“Bran et al.”), issued May 17, 2005, the entireties of which are hereby incorporated by reference. The top transducer assembly200is operably coupled to drive assembly/actuator250that can move the rod-like transmitter201between a retracted position and a processing position. When the rod-like transmitter201is in the retracted position, the rod-like transmitter201is located outside of the process bowl203so that a wafer50can be placed on the rotatable support10without obstruction. More specifically, the drive assembly250withdraws the rod-like transmitter201through an opening in a side wall of the process bowl203. When in the processing position, the rod-like transmitter201is positioned directly above the top surface51of a wafer50on the rotatable support10. The rod-like transmitter201is in the processing position inFIG. 2.

The transducer203of the top transducer assemblies200is acoustically coupled to the transmitter201. This can be done through a direct bonding or an indirect bonding that utilizes intermediary transmission layers. The transducer203is operably coupled to a source of an electrical energy signal. The transducer203can be a piezoelectric ceramic or crystal, as is well known in the art.

It can be seen that the rotatable support10is located within the process bowl203. The rotatable support10supports a wafer50(shown inFIG. 1) in a substantially horizontal orientation in the gaseous atmosphere of the process bowl203, which surrounds the periphery of the wafer50. The rotatable support10is operably connected to the motor assembly11. The motor assembly rotates the wafer about the central axis. The motor assembly11can be a direct drive motor or a bearing with offset belt/pulley drive.

The rotatable support10supports the wafer50(shown inFIG. 1) at an elevation and position between the elongate rod-like transmitter201of the top transducer assembly200and the top surface26of the dispenser14. When the wafer50is so supported, the transmitter201of the top transducer assembly200extends in a substantially parallel orientation over the top surface51of the wafer50in a close spaced relation. This close spaced relationship is such that when liquid is applied to the top surface51from the top dispenser13, a meniscus of liquid is formed between a portion of the transmitter201and the top surface51of the wafer50. The dispenser14is used for applying various fluids to the bottom surface56of the substrate50. The invention is not so limited however, and the dispenser14could be used to apply fluid to any surface of the substrate50. The top surface26of the dispenser14is a substantially dome-shaped surface and comprises a plurality of holes22a-c,32a-c,42a-c,52a-c(shown inFIG. 3). As will be discussed in further detail below, each of the holes22a-c,32a-c,42a-c,52a-cis connected to a conduit that is adapted to eject fluid from the dispenser14and onto the surface of the wafer50.

The cleaning system1000further comprises a sensor8. The sensor8is provided for determining the presence of a substrate on the support10. The sensor is operably and communicably coupled to the controller12. More specifically, the sensor8generates a signal indicative of the presence of the wafer50(shown inFIG. 1) and transmits this signal to the controller12for processing. While the sensor8is shown as being on the top surface26of the dispenser14, the sensor8can be mounted almost anywhere in the cleaning system1000so long as it can perform its function.

Referring toFIGS. 3-12, the dispenser14is illustrated removed from the cleaning system1000so that its details are more clearly visible. It should be understood that the dispenser14, in and of itself, is a novel device and can constitute an embodiment of the invention, independent of the remaining components of the cleaning system1000.

Referring now toFIGS. 3 and 4concurrently, the dispenser14comprises a dome-like shaped body30having a top surface26and a bottom surface27. In the illustrated embodiment, the body30is a plano-convex shaped structure. The invention is not so limited however, and the body30could be any shape resulting in an upper surface that has a convex curvature in both the longitudinal direction (along line A-A) and the transverse direction (along line B-B). Such alternative shapes include, without limitation, convex-convex, par-spherical, oblate-par-spheroidal, ellipsoidal, and so forth. Additionally, rather than being a convex curved surface, the top surface26could be made of small planar sections arranged so as to resemble a surface having curvature. The convex curved shape of the top surface26allows for fluid and contaminants that may fall onto the dispenser14to more easily flow off of the top surface26and away from the substrate being processed than would a planar surface. The dispenser14has a height of about 1.3 inches and a diameter of about 5.5 inches. The dispenser14can be made of Teflon, PTFE, PFA and/or other inert non-contaminating materials. The invention is not so limited however, and the specific dimensions and materials of the dispenser14will vary according to the process requirements.

The dispenser14further comprises a plurality of holes22a-c,32a-c,42a-c,52a-cfor ejecting fluid onto the surface of a substrate to be processed. In some embodiments, the holes22a-e,32a-c,42a-c,52a-chave a diameter that is between 0.05 inches and 0.09 inches. The invention however, is not so limited and the exact size and shape of the holes22a-c,32a-c,42a-c,52a-ccan vary. The exact shape and size of the holes22a-c,32a-c,42a-c,52a-cwill be dictated by the process requirements.

Referring now toFIG. 5, a top view of the dispenser14is illustrated to more clearly show the positioning of the holes22a-c,32a-c,42a-c,52a-cin the top surface26of the dispenser14. For ease of discussion, the longitudinal center-line A-A and the transverse center-line B-B of the body30of the dispenser14are shown. The intersection of the longitudinal center-line A-A and the transverse center-line B-B will be referred to as the central axis point of the body30of the dispenser14. Conceptually, the dispenser14may be divided into a front end1and a back end3. It should be understood that the division of the dispenser14into front and back is for ease of discussion only, and the dispenser14is in reality one structure. The holes22a-c,32a-c,42a-c,52a-care positioned on the top surface26so as to form a matrix of four rows by three columns. Each row is referred to as an array. In the illustrated embodiment, each array comprises three of the holes22a-c,32a-c,42a-c,52a-c. The first and second arrays of holes22a-c,32a-care on one side of the longitudinal center-line A-A, while the third and fourth arrays of holes42a-c,52a-care on the other side of the longitudinal center-line A-A. As will be discussed in more detail below, during the processing of a substrate it is possible to use only one array at a time, and each array can be adapted to dispense a different type of fluid. The first column of holes22a,32a,42a,52ais on the back end3of the dispenser14(to the right of the transverse center-line B-B), while the second and third columns of holes22b-c,32b-c,42b-c,52b-c, are on the front end1of the dispenser14(to the left side of the transverse center-line B-B).

Referring now toFIG. 6, a cross-sectional side view of dispenser14along axis C-C ofFIG. 5is illustrated. Also illustrated, for purposes of discussion, is the horizontal plane E. The horizontal plane E is substantially parallel to the bottom surface56of a wafer50positioned on the rotatable support to be processed (shown inFIG. 13). The holes22a-c,32a-c,42a-c,52a-care the openings of the conduits23a-c,33a-c,43a-c,53a-cin the top surface26of the body30of the dispenser14. For ease of discussion, only one array of the conduits53a-cis shown in this cross-sectional view. However, the features of the conduits53a-cshown in this view are identical across all four arrays. The variations between the arrays will be discussed with reference toFIGS. 9-12. The array of the conduits53a-cis fluidly connected to a header54. The header54is in turn connected to a liquid reservoir15A-D (shown inFIG. 1) via a fluid inlet passageway55. Thus, fluid is supplied to the header54and into each conduit53a-cwhere it will then exit through the holes52a-cat an angle θa-c. Although only one header54is shown illustrated, there are four headers24,34,44,54, within the body30of the dispenser14. Each header24,34,44,54is connected to an array of the conduits23a-c,33a-c,43a-c,53a-cand has a separate fluid inlet25,35,45,55(shown inFIG. 8). Thus, dispenser14is a single head unit capable of ejecting four different fluids via the four headers24,34,44,54. The invention is not so limited, however, and less or more than four headers may be used, including no header. For example, each conduit23a-c,33a-c,43a-c,53a-cmay be fluidly connected directly with the source of fluid.

The headers24,34,44,54are located, within the body30of the dispenser14. While the body of the dispenser14is illustrated as a solid structure with the headers formed as cylindrical cavities within the body30, the invention is not so limited. In other embodiments of the invention, the body30may be a shell-like structure wherein the headers24,34,44,54are separate tubular components and all fluid passageways are formed by flexible fluid conduit. Moreover, in some embodiments, the headers24,34,44,54can be located exterior to the body30, if desired.

The first column of conduits23a,33a,43a,53a, is at a first angle θa relative to the horizontal plane E. The second, column of conduits23b,33b,43b,53bis at a second angle θb relative to the horizontal plane E. The third column of conduits23c,33c,43c,53cis at a third angle θc relative to the horizontal plane E. The first and second angles θa and θb are preferably between 35° to 45°, more preferably between 40° and 45°, and most preferably equal to 40°. The third angle θc is preferably between 30° to 35°, more preferably between 33° and 35°, and most preferably equal to 33°. The angles θa-c, however will vary depending on the desired point of contact between the ejected fluid and the bottom surface56of the wafer, the distance between the dispenser14and the wafer, the angle of the bottom surface of the wafer relative to the top surface of the dispenser, the respective sizes of the wafer and the dispenser, and the position of the conduits23a-c,33a-c,43a-c,53a-con the dispenser14.

Turning now toFIG. 7, a cross-sectional side view of the dispenser14is shown along axis D-D ofFIG. 5. This side view is shown to illustrate the details of the sensor hole28. The sensor hole28provides a cavity for holding the sensor8(shown inFIG. 2). The sensor hole28extends from the top surface26of dispenser14to the bottom surface27of dispenser14. The upper portion48of sensor hole28is wider than the lower portion58of sensor hole27. The sensor8rests in the upper portion48of the sensor hole28, while the lower portion58is used for the electrical connections and other components that connect the sensor8to the controller12(shown inFIG. 1). When fully assembled, the sensor8rests in the sensor hole28which is hermetically sealed so that fluid does not enter the sensor hole28. The seal is accomplished using any conventional means known in the art including using gaskets, o-rings, and the like. The upper portion48of the sensor hole28has a diameter that is between 0.39 inches and 0.41 inches. The lower portion58of the sensor hole28has a diameter that is about 0.125 inches. The sensor hole28extends through the body30at an angle of about 28 degrees relative to a horizontal plane. The invention is not so limited, however, and the exact shape and size of the sensor hole28are determined according to the type and size of sensor8to be used.

Referring now toFIG. 8, a bottom view of the dispenser14is shown. The dispenser14comprises four bolt holes41for bolts that may be used for securing together the components of dispenser14and for mounting the dispenser14in the cleaning system1000. The dispenser14comprises four fluid inlet passageways25,35,45,55. The fluid inlet passageways25,35,45,55are passageways that extend into the headers24,34,44,54, respectively. As will be discussed in further detail during operation, the fluid inlet passageways25,35,45,55are each fluidly coupled to its own liquid reservoir15A-D (shown inFIG. 1). Alternatively, all four fluid inlet passageways25,35,45,55may be connected with one liquid reservoir.

This allows for the ejection of four different fluids through a single head unit without having to purge the unit.

Referring now toFIGS. 9-12concurrently, a schematical view of the dispenser14is illustrated so that the positioning of each array of the conduits23a-c,33a-c,43a-c,53a-crelative to a vertical plane F can be described. The vertical plane F is a plane that intersects the longitudinal center-line A-A of the dispenser14(shown inFIG. 5). All of the conduits23a-c,33a-c,43a-c,53a-cin the four arrays are angled towards the longitudinal center-line A-A so that the fluid dispensed through the holes22a-c,32a-c,42a-c,52a-cwill strike a surface of the wafer50directly above the longitudinal center-line A-A.

Referring now toFIG. 9, The first array of conduits23a-care connected to the first header24. The first conduit23aof the first header24is at an angle βa relative to the vertical plane F. The second conduit23bof the first header24is at an angle βb relative to the vertical plane F. The third conduit23cof the first header24is at an angle βc relative to the vertical plane F. In one embodiment of the present invention, βa is about 15.5°, βb is about 18° and βc is about 12.5°. The invention is not so limited however, and the angles of the conduits23a-cis dependent upon the positioning of the wafer50relative to the dispenser14and the position of the holes22a-con the dispenser14. The angle should be one that results in the ejected fluid initially contacting the wafer50along a line where the vertical plane F would intersect the surface56of the wafer50.

Referring now toFIG. 10, the second array of conduits33a-care shown connected to a second header34. The first conduit33aof the second header34is at an angle Ωa relative to the vertical plane F. The second conduit33bof the second header34is at an angle Ωb relative to the vertical plane F. The third conduit33cof the second header34is at an angle Ωc relative to the vertical plane F. In one embodiment of the present invention, Ωa is about 5.3°, Ωb is about 6.2° and Ωc is about 4.3°. Again, positioning of the conduits33a-cis not limited to any particular angle, so long as the ejected fluid initially contacts the wafer50at a predetermined point intersected by the vertical plane F.

Referring now toFIG. 11, the third array of the conduits43a-cis shown connected to the third header44. Because dispenser14is symmetrical about its longitudinal center-line A-A, the angles of the conduits43a-cconnected to the third header44are a mirror of the conduits33a-cconnected to the second header34as discussed above with respect toFIG. 10. The first conduit43ais at an angle −Ωa, the second conduit43bis at an angle −Ωb and the third conduit43cis at an angle −Ωc.

Similarly,FIG. 12is an illustration of the fourth array of the conduits53a-cconnected to the fourth header54. The conduits53a-cthat are connected to the fourth header54are a mirror image and angled to the same degree (towards the center-line) as the conduits23a-cconnected to the first header24, discussed above with respect toFIG. 9. The first conduit53ais at an angle −βa, the second conduit53bis at an angle −βb and the third conduit53cis at an angle −βc.

Referring now toFIG. 13, a schematic illustrating a liquid ejection profile according to one embodiment of the present invention is shown. The dispenser14is illustrated positioned below the wafer50. The wafer50is positioned substantially horizontal and parallel with the dispenser14. The wafer50has a transverse center-line, a longitudinal center-line, and a rotational, center-point C where the two center-lines intersect. Although in this case the rotational center-point C of the wafer is the actual center-point, in alternative embodiments, the rotational center-point C does not have to be the actual center-point of the wafer. The rotational center-point of the wafer50is offset from the center axis point (at the apex) of the body30of the dispenser14. The longitudinal centerline of the wafer50and the longitudinal centerline of the dispenser14are aligned. Fluid is ejected through the conduits23a-c,33a-c,43a-c,53a-cand out of the holes22a-c,32a-c,42a-c,52a-c. The ejected fluid strikes the bottom surface56of the wafer50at the predetermined points a, b, c. Point a is the rotational center point of the wafer50. In the illustrated embodiment, point b is equal to ⅓ the radius of the wafer50. Point c is equal to ⅔ the radius of the wafer50. While the fluid is ejected, the wafer50is rotated about its rotational center-point, and a film of fluid covers the bottom surface of the wafer50. As discussed above, the dispenser14comprises four separate arrays of the conduits23a-c,33a-c,43a-c,53a-c, thus each array may be used to dispense a different fluid from the other. As such, after a first fluid is dispensed, a second, third and fourth fluids may be dispensed in turn onto the surface of the wafer50. Alternatively, four fluids can be dispensed at the same time onto the surface of the wafer50.

In one embodiment of the present invention, each fluid inlet passageway25,35,45,55is connected to a separate liquid reservoir15A-D so that a different fluid can be introduced into each header24,34,44,54. For example, liquid reservoir15A could be filled with deionized water (“DIW”), liquid reservoir15B could be filled with standard clean 1 (“SC1”), liquid reservoir15C could be filled with standard clean 2 (“SC2”) and liquid reservoir15D could be filled with ozonated deionized water (“DIO3”). In that embodiment, the conduits23a-c, which are connected to the liquid reservoir15A via the fluid inlet passageway25and the first header24(shown inFIG. 9), would eject DIW onto the bottom surface56of the wafer50. The conduits33a-c, which are connected to the liquid reservoir15B via the fluid passageway35and the second header34(shown inFIG. 10) would eject SC1. The conduits43a-c, winch are connected to the liquid reservoir15C via the fluid passageway45and third header44(shown inFIG. 11), would eject SC2. The conduits53a-c, which are connected to the liquid reservoir15D via the fluid inlet passageway55and the fourth header54(shown inFIG. 12) would eject DIO3. Thus, four fluids are ejected via single head unit, i.e. dispenser14. The fluid flow rate can be about 1800 ml/min., however the flow rate will vary according to the process requirements.