Abstract:
A system for cleaning a substrate includes a carrier and a cleaning station. The carrier is capable of holding the substrate and is movably coupled to a pair of guide tracks extending a length of the system. The cleaning station includes a force applicator, a gate and a dispenser. The force applicator has an applicator length and is coupled to the cleaning station, is rotatable and is adjustable to a first height off the surface of the carrier during cleaning. The gate is a hollow structure disposed at a trailing edge of the force applicator. The gate is set to a height off the carrier surface that is less than or equal to the first height. The gate includes a gate length that at least spans the applicator length. The dispenser is disposed at a leading edge of the force applicator and is configured to supply cleaning solution during cleaning.

Description:
CLAIM OF PRIORITY 
       [0001]    This application is a Divisional application of U.S. patent application Ser. No. 14/031,007, filed on Sep. 18, 2013, entitled “Method and System for Uniformly Applying a Multi-Phase Cleaning Solution to a Substrate,” which is a Divisional application of U.S. patent application Ser. No. 13/028,091, filed on Feb. 15, 2011, (since issued as U.S. Pat. No. 8,567,421) entitled “Method and System for Uniformly Applying a Multi-Phase Cleaning Solution to a Substrate,” which is a Divisional application of U.S. patent application Ser. No. 11/395,851 filed on Mar. 30, 2006, (since issued as U.S. Pat. No. 7,913,703) entitled “Method and Apparatus for Uniformly Applying a Multi-Phase Cleaning Solution to a Substrate,” which (1) claims the benefit of U.S. Provisional Application No. 60/755,377, filed Dec. 30, 2005, and (2) is a continuation-in-part of prior application Ser. No. 10/608,871, filed Jun. 27, 2003, and entitled “Method and Apparatus for Removing a Target Layer from a Substrate Using Reactive Gases.” The disclosure of each of the above-identified applications is incorporated herein by reference. 
       CROSS REFERENCE TO RELATED APPLICATIONS 
       [0002]    This application is related to U.S. patent application Ser. No. 10/816,337, filed on Mar. 31, 2004, and entitled “Apparatuses and Methods for Cleaning a Substrate,” now U.S. Pat. No. 7,441,299; U.S. patent application Ser. No. 11/153,957, filed on Jun. 15, 2005, and entitled “Method and Apparatus for Cleaning a Substrate Using Non-Newtonian Fluids,” U.S. patent application Ser. No. 11/154,129, filed on Jun. 15, 2005, and entitled “Method and Apparatus for Transporting a Substrate Using Non-Newtonian Fluid,” U.S. patent application Ser. No. 11/174,080, filed on Jun. 30, 2005, and entitled “Method for Removing Material from Semiconductor Wafer and Apparatus for Performing the Same,” U.S. patent application Ser. No. 10/746,114, filed on Dec. 23, 2003, and entitled “Method and Apparatus for Cleaning Semiconductor Wafers using Compressed and/or Pressurized Foams, Bubbles, and/or Liquids,” now U.S. Pat. No. 7,648,584; U.S. patent application Ser. No. 11/336,215, filed on Jan. 20, 2006, entitled “Method and Apparatus for removing contamination from a substrate,” U.S. patent application Ser. No. 11/346,894, filed on Feb. 3, 2006, entitled “Method for removing contamination from a substrate and for making a cleaning solution,” and U.S. patent application Ser. No. 11/347,154, filed on Feb. 3, 2006, entitled “Cleaning compound and method and system for using the cleaning compound.” The disclosure of each of the above-identified related applications is incorporated herein by reference. 
     
    
     BACKGROUND 
       [0003]    In the fabrication of semiconductor devices such as integrated circuits, memory cells, and the like, a series of manufacturing operations are performed to define features on semiconductor wafers (“wafers”). The wafers include integrated circuit devices in the form of multi-level structures defined on a silicon substrate. At a substrate level, transistor devices with diffusion regions are formed. In subsequent levels, interconnect metallization lines are patterned and electrically connected to the transistor devices to define a desired integrated circuit device. Also, patterned conductive layers are insulated from other conductive layers by dielectric materials. 
         [0004]    During the series of manufacturing operations, the wafer surface is exposed to various types of contaminants. Essentially any material present in a manufacturing operation is a potential source of contamination. For example, sources of contamination may include process gases, chemicals, deposition materials, and liquids, among others. The various contaminants may deposit on the wafer surface in particulate form. If the particulate contamination is not removed, the devices within the vicinity of the contamination will likely be inoperable. Thus, it is necessary to clean contamination from the wafer surface in a substantially complete manner without damaging the features defined on the wafer. However, the size of particulate contamination is often on the order of the critical dimension size of features fabricated on the wafer. Removal of such small particulate contamination without adversely affecting the features on the wafer can be quite difficult. 
         [0005]    Conventional wafer cleaning methods have relied heavily on mechanical force to remove particulate contamination from the wafer surface. As feature sizes continue to decrease and become more fragile, the probability of feature damage due to application of mechanical force to the wafer surface increases. For example, features having high aspect ratios are vulnerable to toppling or breaking when impacted by a sufficient mechanical force. To further complicate the cleaning problem, the move toward reduced feature sizes also causes a reduction in the size of particulate contamination that may cause damage. 
         [0006]    Particulate contamination of sufficiently small size can find its way into difficult to reach areas on the wafer surface, such as in a trench surrounded by high aspect ratio features or bridging of conductive lines, etc. Thus, efficient and non-damaging removal of contaminants during modern semiconductor fabrication represents a continuing challenge to be met by continuing advances in wafer cleaning technology. It should be appreciated that the manufacturing operations for liquid crystal displays (i.e., flat panel displays) suffer from the same shortcomings of the integrated circuit manufacturing discussed above. 
         [0007]    Cleaning methods that use multi-phase cleaning solutions (i.e., foam, emulsions, etc.) that are comprised of a dispersed phase, continuous phase and solids overcome many of the problems associated with conventional wafer cleaning methods. When a force is applied against the multi-phase cleaning solution, the solids dispersed within the continuous phase come into contact or interact with the particulate contaminants on the wafer surface. As the cleaning solution, with the solids, is removed from the wafer surface the particulate contaminants are also removed. 
         [0008]    There are several inherent challenges with using multi-phase cleaning solutions to clean wafer surfaces. One is that it is difficult to ensure that the solution is uniformly applied across the entire wafer surface. Uneven application of the solution may result in an uneven cleaning profile on the wafer surface due to non-uniform rinsing of the wafer surface. 
         [0009]    Another is that it is difficult to uniformly apply force against the solution across the wafer surface so that the embedded solids actually come into contact with the contaminant particulates during cleaning. As discussed earlier, the solids must come within the vicinity of the contaminant particles before they can interact and effectuate the removal of the particles. 
         [0010]    In view of the forgoing, there is a need for an apparatus and method for uniformly applying a multi-phase cleaning solution (i.e., foam, emulsions, etc.) across a wafer surface during the cleaning of the wafer surfaces. 
       SUMMARY 
       [0011]    Broadly speaking, the present invention fills these needs by providing improved apparatuses, methods, and systems for uniformly applying a multi-phase cleaning solution (i.e., foam, emulsions, etc.) across a wafer surface during the cleaning of the wafer surfaces. It should be appreciated that the present invention can be implemented in numerous ways, including as an apparatus, a method and a system. Several inventive embodiments of the present invention are described below. 
         [0012]    In one exemplary embodiment, a system for cleaning a substrate having surface contaminants thereon, is disclosed. The system includes a carrier and a cleaning station. The carrier is capable of holding the substrate and is movably coupled to a pair of guide tracks extending along a length of the system. The cleaning station includes a force applicator, a gate and a dispenser. The force applicator has an applicator length and is operatively connected to the cleaning station above a surface of the carrier and the pair of guide tracks. The force applicator is rotatable. The force application is set to a first height off the surface of the carrier as the substrate is being cleaned. The gate is disposed at an adjacent orientation and at a trailing edge of the force applicator. The gate is a hollow structure and is set to a height off the surface of the carrier. The height of the gate is less than or equal to the first height. The gate includes a gate length that extends to at least span the applicator length. The dispenser is disposed at an adjacent orientation to a leading edge of the force applicator. The dispenser is configured to supply a cleaning solution during cleaning of the substrate. 
         [0013]    In still another embodiment, a system for cleaning a substrate having surface contaminants, is disclosed. The system includes a vacuum chuck and a cleaning station. The vacuum chuck is configured to hold the substrate and impart a rotational velocity to the substrate, during the cleaning. The cleaning station includes a force applicator and a gate. The force applicator has an applicator length that covers a diameter of the substrate, when present, and is operatively connected to the cleaning station above a surface of the vacuum chuck. The force applicator is rotatable along an axis of rotation that is parallel to the surface of the substrate. The force applicator is set to a first height off the surface of the vacuum chuck as the substrate is being cleaned. The gate is affixed to a trailing edge of the force applicator via one or more arm extensions. The gate is defined as a hollow structure and is set to a height off the surface of the vacuum chuck. The height of the gate is less than or equal to the first height at which the force applicator is disposed. A gate length of the gate extends to at least span the applicator length. 
         [0014]    Other aspects will become apparent from the following detailed description, taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    The present invention will be readily understood by the following detailed description in conjunction with the accompanying drawings, and like reference numerals designate like structural elements. 
           [0016]      FIG. 1A  is a side view of an apparatus for uniformly applying a multi-phase cleaning solution (i.e., foam, emulsions, etc.) across the surface of a substrate, in accordance with one exemplary embodiment of the present invention. 
           [0017]      FIG. 1B  shows a top view of the apparatus, in accordance with one embodiment of the present invention. 
           [0018]      FIG. 2A  shows a cross-sectional view of a force applicator and gate, in accordance with one embodiment of the present invention. 
           [0019]      FIG. 2B  is an illustration showing a side view of a force applicator with a straight line baffle pattern, in accordance with one embodiment of the present invention. 
           [0020]      FIG. 2C  is a depiction of a side view of a force applicator with a diagonal baffle pattern, in accordance with one embodiment of the present invention. 
           [0021]      FIG. 3A  is an illustration of a side view of an apparatus for uniformly applying a multi-phase cleaning solution across the surface of a substrate  108 , in accordance with one embodiment of the present invention. 
           [0022]      FIG. 3B  is an illustration showing a top view of an apparatus for uniformly applying a multi-phase cleaning solution across the surface of a substrate, in accordance with one embodiment of the present invention. 
           [0023]      FIG. 4A  is an illustration of a side view of an apparatus for uniformly applying a multi-phase cleaning solution  110  across the surface of a substrate  108 , in accordance with one embodiment of the present invention. 
           [0024]      FIG. 4B  is an illustration of a top view of an apparatus for uniformly applying a multi-phase cleaning solution across the surface of a substrate, in accordance with one embodiment of the present invention. 
           [0025]      FIG. 5A  is an illustration of a side view of a plurality of powered rollers supporting and rotating a substrate as a force applicator and gate uniformly applies a multi-phase cleaning solution across the surface of the substrate, in accordance with one embodiment of the present invention. 
           [0026]      FIG. 5B  is an illustration of a top view of a set of four powered rollers supporting and rotating a substrate as a force applicator and gate uniformly applies a multi-phase cleaning solution across the surface of the substrate, in accordance with one embodiment of the present invention. 
           [0027]      FIG. 5C  is an illustration of a side view of a vacuum chuck used to support and rotate a substrate as a force applicator and gate uniformly applies a multi-phase cleaning solution across the surface of the substrate, in accordance with one embodiment of the present invention. 
           [0028]      FIG. 6A  is an illustration of a top view of a system for cleaning a substrate having surface contaminants, in accordance with one exemplary embodiment of the present invention. 
           [0029]      FIG. 6B  is an illustration of a top view of a system for cleaning a substrate having surface contaminants, in accordance with one embodiment of the present invention. 
           [0030]      FIG. 6C  is an illustration of a side view of a system for cleaning a substrate having surface contaminants, in accordance with one embodiment of the present invention. 
           [0031]      FIG. 7  shows a flow chart of a method for uniformly applying a multi-phase cleaning solution (i.e., foam, emulsions, etc.) across the surface of a substrate, in accordance with one embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0032]    An invention is described for apparatuses, methods, and systems for uniformly applying a multi-phase cleaning solution (i.e., foam, emulsions, etc.) across a wafer surface during the cleaning of the wafer surfaces. It will be obvious, 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. 
         [0033]    As used herein, a multi-phase cleaning solution includes a continuous phase, dispersed phase and solids which are disseminated throughout the continuous phase. In one embodiment, the dispersed phase refers to gas bubbles that are dispersed throughout the continuous phase (e.g., foam). In another embodiment, the dispersed phase refers to liquid droplets that are dispersed throughout the continuous phase (e.g., emulsion). In one embodiment, the dispersed phase provides an intermediary to bring solids in close proximity with contaminant particles on a substrate surface. For further explanation of the composition of the cleaning solution and its mechanisms see U.S. patent application Ser. No. 11/346,894, filed on Feb. 3, 2006, entitled “Method for removing contamination from a substrate and for making a cleaning solution,” U.S. patent application Ser. No. 11/347,154, filed on Feb. 3, 2006, entitled “Cleaning compound and method and system for using the cleaning compound” and U.S. patent application Ser. No. 11/336,215, filed on Jan. 20, 2006, entitled “Method and Apparatus for removing contamination from a substrate.” The solids interact with the particles during cleaning to effectuate their removal. A substrate, as used herein, denotes both semiconductor wafers and flat panel display surfaces (e.g., liquid crystal displays, etc.) that may become contaminated during manufacturing operations. 
         [0034]      FIG. 1A  is a side view of an apparatus for uniformly applying a multi-phase cleaning solution (i.e., foam, emulsions, etc.) across the surface of a substrate, in accordance with one exemplary embodiment of the present invention. As depicted in this embodiment, the apparatus includes a force applicator  106  and a gate  104 . The force applicator  106  is configured to apply a force uniformly against the cleaning solution  110  as the applicator  106  moves in parallel fashion across the surface of the substrate  108 . Typically, the force applicator  106  is positioned so that the distance between the applicator  106  and the surface of the substrate  108  is between about 0.1 millimeter (mm) and 10 centimeters (cm). The gate  104  is configured to follow the trailing edge of the force applicator  106  and to substantially planarize the cleaning solution  110  as it moves across the surface of the substrate  108 . Typically, the gate  104  is positioned so that the distance between the gate  104  and the surface of the substrate  108  is between about 0.1 mm and 5.0 mm. In one embodiment, the force applicator  106  and gate  104  are positioned at about the same distance off the substrate surface. 
         [0035]    In one embodiment, the force applicator  106  and the gate  104  are configured to operate in unison when moving across the substrate  108 . Therefore, as the force applicator  106  and gate  104  moves across the surface of the substrate  108 , the cleaning solution  110  is simultaneously being applied against the surface of the substrate  108  and planarized so that the solution  110  assumes a uniform thickness profile on the substrate surface. In another embodiment, the force applicator  106  moves independently from the gate  104 . 
         [0036]    As depicted in the present embodiment, the force applicator  106  is in the shape of a cylindrical drum and positioned so that the axis of rotation of the applicator  106  is parallel to the surface of the substrate  108 . It should be understood that the force applicator  106  can take any shape so long as the applicator  106  can be utilized to uniformly apply a cleaning solution  110  to the surface of a substrate  108 . In one embodiment, the force applicator  106  is a solid and smooth structure without any internal cavity regions. In another embodiment, the force applicator  106  is a hollow structure with internal channels and multiple openings dispersed throughout the surface of the applicator  106 . The channels and openings being configured to dispense a cleaning solution  110  or other liquids to the surface of the substrate  108  during cleaning operations. In one embodiment, the force applicator  106  is made out of polyvinyl alcohol (PVA) foam. Some examples of other materials that the applicator  106  can be made out of include polymers (e.g., Teflon™, polyvinyl alcohol, polyurethane, polytetrafluoroethylene, polyethylene terephthalate, polyvinylidine difluoride, polyetheretherketone, polyvinyl chloride, etc.), rubber, ceramics, stainless steel, tool steel, and aluminum. It should be appreciated that the force applicator  106  can be made out of essentially any material so long as the material is non-reactive with the cleaning solution  110  and can function to uniformly apply a force against the solution  110  on the surface of a substrate  108 . 
         [0037]    Continuing with  FIG. 1A , in the present embodiment, the gate  104  is positioned substantially orthogonal to the surface of the substrate  108  and bent at a  45  degree angle towards the top of the force applicator  106 . However, it should be understood that the gate  104  can be positioned in essentially any fashion and bent in any angle so long as the gate  104  can function to planarize the cleaning solution  110  on the substrate  108  surface. In one embodiment, the gate  104  is a solid structure without an internal cavity region. In another embodiment, the gate  104  is a hollow structure. Some examples of materials that that the gate  104  can be made out of include glass, stainless steel, aluminum, ceramics, rubber, and polymers (e.g., Teflon™, polyvinyl alcohol, polyurethane, polytetrafluoroethylene, polyethylene terephthalate, polyvinylidine difluoride, polyetheretherketone, polyvinyl chloride, etc.). It should be appreciated, however, that the gate  104  can be made of any material so long as the material is non-reactive with the cleaning solution  110  and does not hinder the planarization of the cleaning solution  110  on the surface of the substrate  108 . 
         [0038]    As depicted in the present embodiment, a cleaning solution  110  dispenser  102  is positioned proximate to the leading edge of the force applicator  106 . As the force applicator  106  rotates, the dispenser  102  supplies the multi-phase cleaning solution  110  directly to the substrate surface. In one embodiment, the solution  110  is applied directly to the force applicator  106 . Then by virtue of the force applicator  106  rotation, the cleaning solution  110  is applied against the surface of the substrate  108 . In one embodiment, the dispenser  102  is configured to move in unison with the force applicator  106  and the gate  104  across the substrate surface during a cleaning operation. In one embodiment, the force applicator  106  is configured to rotate towards the surface of the substrate  108 . In another embodiment, force applicator  106  is configured to rotate away from the top surface of the substrate  108 . The rotational velocity of the force applicator  106  can be set to any value so long as the cleaning solution  110  is applied to the substrate surface with sufficient force to effectuate the desired cleaning of the substrate surface without losing an unacceptable amount of the cleaning solution  110 . 
         [0039]      FIG. 1B  shows a top view of the apparatus, in accordance with one embodiment of the present invention. As depicted in this embodiment, the force applicator and gate  104  are shown to stretch lengthwise to cover the entire diameter of the substrate  108 . The dispenser  102  is shown as a nozzle that is positioned towards the midpoint of the force applicator  106  and configured to supply the cleaning solution  110  to the leading edge of the applicator  106 . In one embodiment, the dispenser  102  is a manifold that stretches the entire length of the force applicator  106  and configured to supply the cleaning solution  110  directly to the substrate surface. In another embodiment, the dispenser  102  is the manifold as described above and configured to supply the cleaning solution  110  to both the substrate surface and the applicator  106 . 
         [0040]    As depicted in the present embodiment, the substrate  108  is rotated in a counter-clockwise direction as the force applicator  106  and gate  104  moves across the surface of the substrate  108 . In one embodiment, the substrate  108  is rotated in a clockwise direction as the force applicator  106  and gate  104  moves across the substrate surface. Typically, the substrate  108  rotates at between about 4 and 8 rotations per minute (rpm). 
         [0041]      FIG. 2A  shows a cross-sectional view of a force applicator and gate, in accordance with one embodiment of the present invention. As depicted in this embodiment, the force applicator  106  includes a plurality of baffles  202  that protrude out from the applicator  106  and are aligned with the axis of rotation  235  of the force applicator  106 . The baffles  202  are configured to drive the cleaning solution  110  against the substrate surface by supplying a sweeping action that carries and forces the cleaning solution  110  against the substrate surface. In one embodiment, the baffles  202  are evenly spaced from one another. In another embodiment, the baffles  202  are randomly spaced from one another. 
         [0042]    It should be appreciated that the baffles  202  can be designed so that they protrude out from the applicator  106  at any angle, relative to the longitudinal surface of the force applicator  106 , so long as the baffles  202  can function to drive the cleaning solution  110  against the substrate surface with sufficient force to effectuate the desired cleaning. In one embodiment, the force applicator  106  includes a series of channels that travel the length of the applicator  106  and serve the same function as the baffles  202 . In one embodiment, the baffles  202  are affixed to the force applicator  106  using an adhesive material. Examples of materials that can be used to make the baffles  202  include rubber, ceramics, polymers (i.e., Teflon™, polyvinyl alcohol, polyurethane, polytetrafluoroethylene, polyethylene terephthalate, polyvinylidine difluoride, polyetheretherketone, polyvinyl chloride, etc.), and solid metals (i.e., aluminum, steel, etc.). 
         [0043]    Continuing with  FIG. 2A , in the present embodiment, the gate  104  is placed proximate to the force applicator  106  at a trailing position that is far enough away from the baffles  202  so that the baffles  202  do not contact the gate  104 . Additionally, the force applicator  106  is positioned so that the baffles  202  do not contact the surface of the substrate  108 . Typically, the applicator  106  maintains a distance of between about 0.1 mm and 100 mm off the substrate surface. The force applicator  106  is configured to rotate towards the substrate surface. 
         [0044]      FIG. 2B  is an illustration showing a side view of a force applicator with a straight line baffle pattern, in accordance with one embodiment of the present invention. In this embodiment, the baffles  202  are shown as stretching uninterrupted in linear fashion along the longitudinal surface of the force applicator  106 . It should be understood that the width (distance the baffle protrudes from the force applicator  106 ) and thickness of the baffles  202  can vary in accordance with the particular cleaning application that the force applicator  106  is utilized for. In one embodiment, each baffle includes intermittent gaps or openings. 
         [0045]      FIG. 2C  is a depiction of a side view of a force applicator with a diagonal baffle pattern, in accordance with one embodiment of the present invention. In this embodiment, the baffles  202  are shown as diagonal lines stretching along the length of the force applicator  106 . It should be understood that the baffle patterns can take any form so long as the resulting baffle pattern can adequately drive a cleaning solution  110  against the substrate surface with sufficient force to effectuate the desired cleaning profile. 
         [0046]      FIG. 3A  is an illustration of a side view of an apparatus for uniformly applying a multi-phase cleaning solution across the surface of a substrate  108 , in accordance with one embodiment of the present invention. As depicted in this embodiment, the apparatus includes a gate  104  that is affixed to the force applicator  106  via arm extensions  302  that are operatively connected to the rotational axes on the edge surfaces of the force applicator  106 . The gate  104  has a partial annular shape that arches from just above the substrate surface to just over the top surface of the force applicator  106 . A cleaning solution dispenser  102  is attached to the portion of the gate  104  positioned over the force applicator  106 . The dispenser  102  is configured to supply a cleaning solution  110  simultaneously to the applicator  106  and the substrate surface. In one embodiment, the dispenser  102  is detached from the gate  104  and configured so that the position of the dispenser  102  can be adjusted depending on the requirements of the cleaning application. 
         [0047]    As depicted herein, the arm extensions  302  are shown to be affixed to two points on the gate  104  and the rotational axis  235  of the force applicator  106 . The gate  104  and force applicator  106  move in unison parallel to the substrate surface, uniformly applying a force (using the force applicator  106 ) against the cleaning solution  110  and planarizing (using the gate  104 ) the cleaning solution  110  on the substrate surface. In one embodiment, the gate  104  is attached to the force applicator  106  via a single point of contact. For example, the gate  104  can be attached via a single arm extension to the axis of rotation  235  on both sides of the force applicator  106 . In another embodiment, the gate  104  is attached to the force applicator  106  via a plurality of arm extensions  302  at a plurality of points on the gate  104 . In one embodiment, the arm extensions  302  are configured to enable the adjustment of the distance of the gate  104  relative to the substrate surface. As discussed above, typically, the gate  104  is positioned so that the distance between the gate  104  and the surface of the substrate  108  is between about 0.1 mm and 5.0 mm. 
         [0048]      FIG. 3B  is an illustration showing a top view of an apparatus for uniformly applying a multi-phase cleaning solution across the surface of a substrate, in accordance with one embodiment of the present invention. As depicted in this embodiment, the gate  104  is shown to be affixed to the side surfaces of the leading edge of the force applicator  106 . Two cleaning solution dispensers  102  are positioned proximate to the force applicator  106  and are configured to supply the cleaning solution  110  to the substrate surface adjacent to the force applicator  106 . In this embodiment, the gate  104  is shown to overlap the two sides of the force applicator  106 . It should be understood that the length of the gate  104  relative to the force applicator  106  may vary so long as the gate  104  can adequately function to planarize the cleaning solution  110  across the entire length of the substrate  108  as the gate  104  moves across the substrate surface. 
         [0049]      FIG. 4A  is an illustration of a side view of an apparatus for uniformly applying a multi-phase cleaning solution  110  across the surface of a substrate  108 , in accordance with one embodiment of the present invention. In this embodiment, the apparatus includes a force applicator  402  and a gate  104 . The force applicator  402  includes two cylindrical drums that are encased by a flexible sheet. The cylindrical drums are configured to rotate in unison and impart a force to the flexible sheet so that the sheet rotates around both drums. It should be appreciated that the force applicator  402  can include any number of drums so long as the resulting applicator  402  can function to supply enough force to effectuate the desired cleaning of the substrate surface. Examples of materials that can be used to make the flexible sheet include polymers (e.g Teflon™, polyvinyl alcohol, polyurethane, polytetrafluoroethylene, polyethylene terephthalate, polyvinylidine difluoride, polyetheretherketone, polyvinyl chloride, etc.) and rubber. However, it should be understood that essentially any flexible material can be used to make the sheet so long as the material does not chemically react with the cleaning solution  110  and can effectuate the desired cleaning of the substrate surface. 
         [0050]      FIG. 4B  is an illustration of a top view of an apparatus for uniformly applying a multi-phase cleaning solution across the surface of a substrate, in accordance with one embodiment of the present invention. As depicted in this embodiment, force applicator  402  and gate  104  are shown to stretch lengthwise to cover the entire diameter of the substrate  108 . The cleaning solution manifold  420  is positioned adjacent to the force applicator  402  and also stretches lengthwise to cover the entire diameter of the substrate surface. In one embodiment, the manifold stretches lengthwise to cover only a portion of the diameter of the substrate surface. As depicted, the manifold  420  is configured to supply the cleaning solution  110  directly to the substrate surface as the substrate  108  is being rotated at between about 4 to 8 revolutions a minute. In one embodiment, the manifold  420  is configured to supply the cleaning solution  110  to both the substrate surface and the force applicator  402 . 
         [0051]    In one embodiment, the manifold  420  is configured to be attached to the force applicator  402  and to move in unison with the applicator  402  and gate  104  across the substrate  108 . In another embodiment, the manifold  420  is detached from the force applicator  402  but configured to move in unison with the force applicator  402  and gate  104  across the substrate  108 . 
         [0052]      FIG. 5A  is an illustration of a side view of a plurality of powered rollers supporting and rotating a substrate as a force applicator and gate uniformly applies a multi-phase cleaning solution across the surface of the substrate, in accordance with one embodiment of the present invention. In this embodiment, the substrate  108  is shown as being supported by a plurality of powered rollers  502  that are configured to impart a set rotational velocity to the substrate  108  as the force applicator  106  and gate  104  moves across the surface of the substrate  108 . Typically, the rollers  502  are configured to rotate the substrate  108  at between about 4 and 8 rpm depending on the requirements of the cleaning application. 
         [0053]      FIG. 5B  is an illustration of a top view of a set of four powered rollers supporting and rotating a substrate as a force applicator and gate uniformly applies a multi-phase cleaning solution across the surface of the substrate, in accordance with one embodiment of the present invention. As depicted in this embodiment, the substrate  108  is supported by a set of four powered rollers  502  spaced along the circumference of the substrate  108 . It should be understood that fewer or greater numbers of powered rollers  502  may be utilized so long as the substrate  108  is adequately supported during cleaning operations and the rollers  502  are capable of imparting the required rotational velocity to the substrate  108 . 
         [0054]      FIG. 5C  is an illustration of a side view of a vacuum chuck used to support and rotate a substrate as a force applicator and gate uniformly applies a multi-phase cleaning solution across the surface of the substrate, in accordance with one embodiment of the present invention. As depicted in this embodiment, the substrate  108  is supported by a vacuum chuck  504  that is configured to impart a rotational velocity of between about 4 to 8 rpm to the substrate  108  and provide a vacuum against the bottom surface of the substrate  108  to bind the substrate  108  to the surface of the chuck  504  during cleaning operations. In one embodiment, the chuck  504  emits an electrostatic force to bind the substrate  108  to the surface of the chuck  504  during cleaning. In another embodiment, the chuck  504  provides a layer of adhesive material that binds to the bottom of the substrate  108 . 
         [0055]      FIG. 6A  is an illustration of a top view of a system for cleaning a substrate having surface contaminants, in accordance with one exemplary embodiment of the present invention. In this embodiment, the system includes three distinct cleaning zones. The first zone includes a pair of powered rollers  502  affixed to the base of the system containment housing  620 , a force applicator  106 , a gate  104  affixed to the trailing edge of a force applicator  106 , a manifold  420  affixed to the leading edge of the force applicator  106 , and a tandem roller unit  603 . The second zone includes six rinse nozzles  610  that are positioned above the substrate  108  and configured to dispense a liquid to rinse a cleaning solution  110  from the top surface of the substrate  108  as the substrate  108  moves underneath the nozzles  610 . Examples of liquids that can be dispensed by the nozzles  610  include Deionized Water (DIW), Ammonium Peroxide (NH 4 OH), Hydrogen Peroxide (H 2 O 2 ), and SC-1 solution (NH 4 OH/H 2 O 2 /H 2 O). However, it should be understood that essentially any liquid can be used so long as the liquid can adequately remove the cleaning solution  110  from the substrate surface per the requirements of the cleaning operation. The third zone includes a plurality of proximity head units  612  that are configured to effectuate a final cleaning and drying of the top and/or bottom surfaces of the substrate  108 . A description of proximity head units and their method of operation can be found in co-pending application Ser. No. 10/261,839 entitled, “Method and Apparatus for Drying Semiconductor Wafer Surfaces Using a Plurality of Inlets and Outlets Held in Close Proximity to the Wafer Surfaces” published in 2004-0069329A1, co-pending application Ser. No. 10/330,843 entitled “Meniscus, Vacuum, IPA Vapor, Drying Manifold” published in 2004-0060580A1 as well as U.S. Patents including U.S. Pat. Nos. 6,988,327, 6,954,993, and 6,988,326 all assigned to Lam Research Corporation and are incorporated herein by reference. 
         [0056]    In one embodiment, the force applicator  106 , gate  104 , rinse nozzles  610 , and proximity head units  612  are configured to operate within a single cleaning zone. It should be appreciated that the system containment housing  620  can be configured to have cleaning zones that are different from those described in this embodiment. The types (e.g., bevel edge cleaning, surface cleaning with brushes, etc.) and numbers of cleaning zones that can be incorporated into the system housing  620  is limited only by their operational compatibility with the force applicator  106 /gate  104  unit and the space available in the system containment housing  620 . 
         [0057]    As depicted in  FIG. 6A , a substrate carrier  604  is provided which includes an opening sized to fit a substrate  108  and includes four clips  606  that are configured to support the substrate  108  during transport between one zone and another. The substrate carrier  604  moves on top of two guide tracks  602  that run the length of the system containment housing across all three cleaning zones. In one embodiment, the substrate carrier  604  does not have an opening for the substrate  108  but instead has a plurality of clips  606  that are configured to support the substrate  108  in an elevated profile off the top surface of the substrate carrier  604 . In one embodiment, the carrier  604  runs on a plurality of powered wheels that are configured to move the carrier  604  from one cleaning zone to the next. In another embodiment, the carrier  604  is driven by a motorized chain belt system mounted adjacent to one of the guide tracks  602  in the containment housing. 
         [0058]    Continuing with  FIG. 6A , the force applicator with the affixed gate and manifold dispenser is mounted on a mechanical arm  605  that is attached to the side wall of the containment housing. The mechanical arm  605  is configured to move the applicator  106 , gate  104 , and manifold dispenser  420  in unison across the substrate surface. Concurrent with moving across the substrate  108 , the manifold dispenser is configured to supply a cleaning solution  110  to the substrate surface proximate to the leading edge of the applicator  106 . As the applicator  106  comes into contact with the cleaning solution  110 , the applicator  106  is configured to rotate and supply a force against the cleaning solution  110  uniformly across the diameter of the substrate  108 . The gate  104  affixed to the trailing edge of the applicator  106  is configured to planarize the cleaning solution  110  to a predetermined height off the substrate surface as it moves across the substrate  108 . In one embodiment, the motorized arm  605  is configured to allow adjustment of the distance (typically between about 0.1 mm and 100 mm) that the applicator  106  and gate  104  sits above the substrate surface. In one embodiment, the applicator  106 , gate  104 , and manifold dispenser are mounted on a motorized carrier  604  that is configured to move translationally across the substrate surface. 
         [0059]    As depicted in the embodiment shown in  FIG. 6A , a plurality of chemical feed lines are attached to the manifold dispenser  420  and the mechanical arm  605 . The chemical feed lines are configured to supply the cleaning solution  110  that is dispensed by the manifold dispenser. In one embodiment, the chemical feed lines are configured to supply cleaning solution  110  to one or more spray dispensers that are affixed to the force applicator  106 . 
         [0060]    Still with  FIG. 6A , the tandem roller unit  603  includes two rollers and is affixed to a mechanical arm  605 . The mechanical arm  605  is configured to rotate the unit towards the base of the containment housing and align the rollers to the edge of the substrate  108 . The rollers are configured to provide support for the substrate  108 . In one embodiment, the rollers are powered and configured to impart a rotational velocity to the substrate  108  of between about 4 and 8 rpm. In another embodiment, the rollers are not powered and are configured to rotate freely as the substrate  108  is rotated by the powered rollers  502 . 
         [0061]      FIG. 6B  is an illustration of a top view of a system for cleaning a substrate having surface contaminants, in accordance with one embodiment of the present invention. As with the system discussed above, the system depicted in this embodiment includes three distinct cleaning zones. The first zone includes a force applicator  106 , a gate  104  positioned at the trailing edge of a force applicator  106 , and two cleaning solution dispensers  102  positioned adjacent to the leading edge of the force applicator  106 . The second cleaning zone includes six rinse nozzles that are positioned above the substrate surface and configured to dispense a liquid to rinse a cleaning solution  110  off the top surface of the substrate  108  as the substrate  108  moves underneath the nozzles. The third zone includes proximity head units that are configured to effectuate a final cleaning and drying of the top and/or bottom surfaces of the substrate  108 . 
         [0062]    As depicted in  FIG. 6B , the force applicator  106  is attached to motorized drive units  608  on both sides of the system containment unit. The motorized drive units  608  are configured to rotate the force applicator  106  towards the substrate surface during a cleaning operation. As the substrate carrier  604  transports the substrate  108  translationally from the first cleaning zone to the second cleaning zone, the force applicator  106  is configured to uniformly apply a force against the cleaning solution  110  on the substrate surface. In one embodiment, the motorized drive units  608  are configured to enable adjustment of the vertical distance that the force applicator  106  is off the top surface of the substrate  108 . Typically, the distance maintained between the force applicator  106  and substrate surface during a cleaning operation is between about 0.1 mm and 100 mm. In another embodiment, the position of the force applicator  106  is fixed and cannot be adjusted. In yet another embodiment, the substrate carrier  604  is configured to allow the adjustment of the distance between the carrier  604 /substrate  108  and the force applicator  106 . 
         [0063]    Continuing with  FIG. 6B , the gate  104  is positioned at the trailing point adjacent to the force applicator  106 . As depicted in this embodiment, the gate  104  is affixed to both sides of the system containment unit. The gate  104  is configured to planarize the cleaning solution  110  on the substrate surface as the carrier  604  moves the substrate  108  translationally from the first cleaning zone to the second cleaning zone. In one embodiment, the gate  104  is configured to enable adjustment of the vertical distance between the gate  104  and the top surface of the substrate  108 . Typically, the distance between the gate  104  and the substrate surface is maintained at a range of between about 0.1 mm and 5.0 mm. In another embodiment, the position of the gate  104  is fixed and cannot be adjusted. 
         [0064]      FIG. 6C  is an illustration of a side view of a system for cleaning a substrate having surface contaminants, in accordance with one embodiment of the present invention. As depicted herein, the substrate  108  is supported by clips  606  attached to a substrate carrier  604 . The substrate carrier  604  includes a plurality of wheels that are configured to transport the carrier  604  on guide tracks  602  translationally from one cleaning zone to the next. In one embodiment the carrier  604  is configured to supply the power to the rotate the wheels. In a different embodiment, the carrier  604  is attached to a chain drive that pulls the carrier  604  along on the guide track. 
         [0065]    Continuing with  FIG. 6C , as discussed above, the first cleaning zone  630  includes a cleaning solution dispenser  102 , force applicator  106 , and a gate  104 . The dispenser supplies the cleaning solution  110  directly to the substrate surface on the leading edge of the force applicator  106 . As the carrier  604  transports the substrate  108  along the guide track, the force applicator  106  applies a force against the cleaning solution  110  and the gate  104  at the trailing point of the force applicator  106  simultaneously planarizes the cleaning solution  110  to a desired height off the substrate surface. 
         [0066]    As the substrate  108  is transported to the second cleaning zone  632 , a plurality of spray dispensers spread across over the entire diameter of the substrate  108  supplies fluids to the rinse off the cleaning solution  110  from the substrate surface. The rinsate is collected in a catch basin at the base of the system containment unit  614 . Typically, deionized water (DIW) is used as the rinsing liquid for this application. Moving from the second cleaning zone  632  into the third cleaning zone  634 , proximity head units  612  are positioned above and below the substrate surface to provide the final rinse and drying of the substrate surfaces. In one embodiment, the proximity head units  612  are configured to be long enough to provide coverage of the entire diameter of the substrate  108 . 
         [0067]      FIG. 7  shows a flow chart of a method for uniformly applying a multi-phase cleaning solution (i.e., foam, emulsions, etc.) across the surface of a substrate, in accordance with one embodiment of the present invention. Diagrams of the apparatus and system utilized in this method are shown in  FIGS. 1A ,  1 B,  6 A, and  6 B. Method  700  begins with operation  702  where a cleaning solution is applied to the surface of a substrate. As discussed previously, the substrate can be either a semiconductor wafer or a LCD flat panel, or other material requiring critical removal of discrete particles. The cleaning solution has a dispersed phase, a continuous phase and solids dispersed throughout the continuous phase. In one embodiment, the cleaning solution is supplied by a cleaning solution dispenser positioned proximate to the leading edge of a force applicator  106 . In another embodiment, the cleaning solution is supplied by a manifold dispenser that stretches to match the length of the force applicator. 
         [0068]    In one embodiment, the substrate is supported and rotated at between about 4 and 8 rpm using a plurality of powered rollers while the cleaning solution is being applied. In a different embodiment, the substrate is supported and rotated using a vacuum chuck. The vacuum chuck configured to provide a vacuum against the bottom surface of the substrate to prevent the substrate from moving during the rotation and/or cleaning operations. 
         [0069]    The method then proceeds to operation  704  where a force is applied against the cleaning solution such that the force partially controls the containment of the solution and subjects the cleaning solution to a substantially planar profile over the surface of the substrate. A force applicator supplies the force and a gate planarizes the cleaning solution over the substrate surface as the applicator and gate moves in unison across the substrate surface. In one embodiment, the position of the force applicator is configured to be fully adjustable to a distance between about 0.1 mm and 100 mm from the surface of the substrate. In another embodiment, the position of the gate is configured to be fully adjustable to a distance between about 0.1 mm and 5.0 mm from the substrate surface. In one embodiment, the applicator and gate are positioned at approximately the same distance form the substrate surface. 
         [0070]    Although a few embodiments of the present invention have been described in detail herein, it should be understood, by those of ordinary skill, that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. Therefore, the present examples and embodiments are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details provided therein, but may be modified and practiced within the scope of the appended claims.