Patent Publication Number: US-2013247935-A1

Title: Getter reticle

Description:
FIELD 
     Embodiments of the present invention relate to the field of electronic device manufacturing, and in particular, to cleaning the semiconductor processing equipment. 
     BACKGROUND 
     Many semiconductor processing systems, for example, Extreme Ultraviolet lithography (“EUVL”) steppers, plasma etchers, and deposition systems, may have a vacuum chamber and an electrostatic chuck. The electrostatic chuck is typically used for holding, for example, a photomask reticle, blank, or wafer. For example, in a EUV lithography system, the reticle or the wafer needs strong physical contact to the chuck surface to prevent from motion during scanning. Strong physical contact with the surface may result in generating residue particles and other foreign matters (“contaminants”) on the surface. The contaminants can be, for example, metal particles, metal oxide particles, and other residues. Contaminants on the surface of the chuck can cause a significant problem for the operation of the system, such as for EUV lithography printing, plasma etching, or ion beam deposition (“IBD”). Furthermore, the contaminants in the system can be transferred to other photomask reticles or wafers making the problem even worse. Currently, troubleshooting of the contaminated tools requires a lot of time and resources. Typically, such troubleshooting involves many operations, for example, de-installation of the tool, cleaning, and then re-installation of the tool. Accordingly, the cost of the troubleshooting of the contaminated semiconductor processing system is significant. 
     Typically, to clean the semiconductor processing system that contains contaminants, the system is taken apart. For the most semiconductor processing tools, e.g., EUV stepper, etcher, or IBD system, such cleaning requires significant amount of time and efforts. For example, if an electrostatic chuck has contamination issue, the current solution involves removing the chuck out of the vacuum chamber, and cleaning the surface of the chuck ex-situ (outside of the system). This procedure takes tremendous amount of time and cost and significantly reduces production throughput. 
     As described above, contamination by particles or foreign matters is one of the most significant issues in semiconductor fabrication process. As size of the features of the integrated circuits decreases, the contamination issue becomes more severe. For example, the foreign particles for the photolithography process can cause significant pattern placement error (“PPE”). 
     The EUVL process may target next generation lithography by using short wavelength radiation having wavelength, for example, about 13.5 nm that enables printing features having a size smaller than 22 nm half pitch (“hp”). Generally, the limit of the PPE for 21 nm hp node is about 3.6 nm. Accordingly, a particle bigger than 1-2 microns (“μm”) on a reticle back side or on a chuck may cause such PPE that is not acceptable for 21 nm hp processing. Once the surface of the chuck or wafer in the semiconductor processing system becomes contaminated, the conventional procedure requires breaking a vacuum in the system, removing the chuck or wafer from a vacuum chamber, and then wiping the surface. Such procedure is not effective and results in significant semiconductor manufacturing losses. Additionally, tacky films that may be used for removing the foreign matters leave residue on the chuck surface. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention is illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements, in which: 
         FIG. 1A  is a cross-sectional view of a substrate to fabricate a getter reticle according one embodiment of the invention. 
         FIG. 1B  is a view similar to  FIG. 1A , after an electrode layer is deposited on insulating substrate to fabricate a getter reticle according to one embodiment of the invention. 
         FIG. 1C  is a view similar to  FIG. 1B , after a getter layer is deposited onto electrode layer to fabricate a getter reticle according to one embodiment of the invention. 
         FIG. 1D  is a top view of an exemplary embodiment of a getter reticle, as described in  FIG. 1C . 
         FIG. 1E  is a bottom view of an exemplary embodiment of a getter reticle, as described in  FIG. 1C . 
         FIG. 2A  is a cross-sectional view of a getter reticle having an alignment pattern at a back side of a substrate according to one embodiment of the invention. 
         FIG. 2B  is a bottom view of an exemplary embodiment of a getter reticle, as described in  FIG. 2A . 
         FIG. 3A  is a cross-sectional view of a getter reticle having one or more optically reflective films on a back side of the substrate according to one embodiment of the invention. 
         FIG. 3B  is a bottom view of an exemplary embodiment of a getter reticle, as described in  FIG. 3A . 
         FIG. 4A  is a cross-sectional view of a getter reticle according to another embodiment of the invention. 
         FIG. 4B  is a top view of an exemplary embodiment of a getter reticle, as described in  FIG. 4A . 
         FIG. 4C  is a bottom view of an exemplary embodiment of a getter reticle, as described in  FIG. 4A . 
         FIG. 5A  is a cross-sectional view of a getter reticle having alignment pattern features, such as a feature at a back side of a substrate according to another embodiment of the invention. 
         FIG. 5B  is a bottom view of an exemplary embodiment of a getter reticle, as described in  FIG. 5A . 
         FIG. 6A  is a cross-sectional view of a getter reticle having one or more optically reflective films on a back side of the substrate according to another embodiment of the invention. 
         FIG. 6B  is a bottom view of an exemplary embodiment of a getter reticle, as described in  FIG. 6A . 
         FIG. 7A  is a cross-sectional view of a getter reticle having a getter layer on an electrode layer on both sides of an insulating substrate according to another embodiment of the invention. 
         FIG. 7B  is a cross-sectional view of a getter reticle having a getter layer directly deposited on both sides of a conducting or semiconducting substrate according to another embodiment of the invention. 
         FIG. 8  shows an exemplary schematic of an electrostatic apparatus and a getter reticle according to one embodiment of the invention. 
         FIGS. 9A-9C  illustrate a method to in-situ clean a surface of an electrostatic apparatus from the contaminants using a getter reticle according to one embodiment of the invention. 
         FIG. 10A  shows a block diagram of a semiconductor processing system to in-situ clean a surface of an electrostatic apparatus according to one embodiment of the invention. 
         FIG. 10B  illustrates defect density maps before (a) and after (b) in-situ applying a getter reticle on an electrostatic chuck according to one embodiment of the invention. 
         FIG. 11A  is a cross-sectional view of a getter reticle to protect an actual reticle surface from a contamination according to another embodiment of the invention. 
         FIG. 11B  is a cross-sectional view of a getter film placed to protect an actual reticle surface from a contamination according to another embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     In the following description, numerous specific details, such as specific materials, dimensions of the elements, etc. are set forth in order to provide thorough understanding of one or more of the embodiments of the present invention. It will be apparent, however, to one of ordinary skill in the art that the one or more embodiments of the present invention may be practiced without these specific details. In other instances, semiconductor fabrication processes, techniques, materials, equipment, etc., have not been described in great details to avoid unnecessarily obscuring of this description. Those of ordinary skill in the art, with the included description, will be able to implement appropriate functionality without undue experimentation. 
     While certain exemplary embodiments of the invention are described and shown in the accompanying drawings, it is to be understood that such embodiments are merely illustrative and not restrictive of the current invention, and that this invention is not restricted to the specific constructions and arrangements shown and described because modifications may occur to those ordinarily skilled in the art. 
     Reference throughout the specification to “one embodiment”, “another embodiment”, or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases “in one embodiment” or “for an embodiment” in various places throughout the specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. 
     Moreover, inventive aspects lie in less than all the features of a single disclosed embodiment. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this invention. While the invention has been described in terms of several embodiments, those skilled in the art will recognize that the invention is not limited to the embodiments described, but can be practiced with modification and alteration within the spirit and scope of the appended claims. The description is thus to be regarded as illustrative rather than limiting. 
     Methods and apparatuses providing a getter reticle to in-situ clean a surface in semiconductor processing systems are described herein. A getter layer is deposited on an electrode layer on one side of a substrate. The electrode layer is configured to provide a first electrode to hold charges in the getter layer positioned between the first electrode and a second electrode. The getter layer can include a polymer. The electrode layer can include one or more conducting layers, one or more semiconductor layers, or a combination thereof. The electrode layer is configured to apply the getter layer to a contaminated surface with an electrostatic force. In one embodiment, the electrostatic force is optimized to transfer contaminants from the surface to the getter layer. Without the electrode layer, a mechanical force needs to be used to apply the getter layer to a contaminated surface that requires an additional complicated tool structure that may cause a tool design issue, or a contamination issue. The electrode layer of the getter reticle, as described herein, provides very simple and effective way to apply an insulating polymer film to an electrostatic chuck surface with an optimized force. 
     In one embodiment, an optically dark layer in a reflection mode or in a transmission mode is deposited on other side of the substrate. In one embodiment, one or more optically reflective films are deposited on the other side of the substrate. In one embodiment, a getter reticle having a getter layer on an electrode layer on a substrate is moved toward a surface. The getter layer of the getter reticle is attached to the surface by an electrostatic force. Contaminants are transferred from the surface to the getter layer by the electrostatic force. 
     The methods and apparatuses described herein provide a solution to remove the contaminants, for example residue particles and foreign matters, from the semiconductor apparatus surface without taking the system apart using a getter reticle, which significantly reduces the system maintenance time, and improves the system availability. Typically, de-installation and then re-installation of the semiconductor processing system takes away tremendous amount of time and resources. An in-situ cleaning of the system using a getter reticle without taking the system apart, and without breaking a vacuum environment, as described herein, solves the contamination issue for the semiconductor processing system in very short time with minimal resources. 
     For example, a getter reticle, as described herein, can be used to clean any semiconductor processing system, such as a EUV lithography system, a plasma etching system, a sputtering system, a deposition system that uses an electrostatic chuck, a vacuum chamber, or both. In-situ cleaning of the semiconductor processing system provides substantial benefits by, for example, greatly reducing the system down time from about 1-2 weeks to about 1-2 hours. Furthermore, a getter reticle can be used to protect an actual reticle surface from fall-on particles or foreign matters. 
       FIG. 1A  is a cross-sectional view  100  of a substrate to fabricate a getter reticle according one embodiment of the invention. Typically, the substrate is insulating for photomask reticles, and semiconducting or insulating for wafers. In one embodiment, substrate  101  is made of an insulating material, for example, a silica based glass, quartz, any other dielectric material, for example, an interlayer dielectric, an oxide (e.g., silicon oxide), nitride (e.g., silicon nitride), or a combination thereof. In one embodiment, substrate  101  is a photomask substrate. In one embodiment, substrate  101  is an insulating substrate with additives to reduce thermal expansion coefficient, such as a titanium silicate glass substrate, an Ultra Low Expansion (“ULE®”) glass substrate produced by Corning, Inc, located in Corning, N.Y., or other like substrate. In one embodiment, the thickness of substrate  101  is the approximate range of about 1 mm to about 20 mm. In one embodiment, the thickness of substrate  101  is about 0.25 inches. 
       FIG. 1B  is a view  110  similar to  FIG. 1A , after an electrode layer  103  is deposited on insulating substrate  101  to fabricate a getter reticle according to one embodiment of the invention. Electrode layer  103  acts as an electrode for holding charges in a dielectric material that is positioned between electrode layer  103  and other electrode, as described in further detail below. In one embodiment, electrode layer  103  has one or more conducting layers, one or more semiconductor layers, or a combination thereof. 
     The electrode layer  103  can be deposited on substrate  101  using one of the techniques known to one of ordinary skill in the semiconductor manufacturing, for example, by sputtering, chemical vapor deposition (“CVD”), atomic layer deposition (“ALD”), electron beam evaporation, molecular beam epitaxy (“MBE”), and other like deposition techniques. 
     The electrode layer can be made of any conducting material, for example, metals, metal compounds, nitrides, oxides, oxynitrides, carbides, and other materials. For example, the conducting material for the conducting layer can be chromium (Cr), copper (Cu), ruthenium (Ru), nickel (Ni), cobalt (Co), iron (Fe), manganese (Mn), titanium (Ti), aluminum (Al), hafnium (Hf), tantalum (Ta), tungsten (W), Vanadium (V), Molybdenum (Mo), palladium (Pd), gold (Au), silver (Au), platinum Pt, or any combination thereof. 
     In at least some embodiments, electrode layer  103  includes one or more layers made of Cr, chromium nitride (“CrN”) titanium nitride (“TiN”), tantalum nitride (“TaN”), or any combination thereof. In one embodiment, the conducting material for electrode layer  103  is polysilicon. In one embodiment, electrode layer  103  of one or more conducting, one or more semiconducting, or a combination thereof layers has a sheet resistance that does not exceed 10 4  Ohm/square. In at least some embodiments, the thickness of the electrode layer  103  is from about 50 nanometers (“nm”) to about 100 nm. 
       FIG. 1C  is a view  120  similar to  FIG. 1B , after a getter layer  105  is deposited onto electrode layer  103  to fabricate a getter reticle according to one embodiment of the invention. In one embodiment, getter layer  105  includes one or more polymer films. As shown in  FIG. 1C , an adhesion layer  107  is formed between getter layer  103  and electrode layer  103 . In at least some embodiments, the adhesion layer is applied to bond the getter layer and the electrode layer together and prevent the getter layer from peeling off the electrode layer. The getter layer can be any of thermosetting resins including an epoxy resin, a phenolic resin, a polyimide resin, a urea resin, a melanine resin, an unsaturated polyester resin, a diacryloylphthalic acid polymer resin, and other like resins, or a combination thereof. In one embodiment, getter layer  105  is polymer. In one embodiment, getter layer is made of one or more polyamide films. In one embodiment, getter layer  105  has the adhesion strength less than 0.05 Newtons (“N”)/10 millimeters (“mm”). In one embodiment, getter layer  105  includes a porous polymer layer having porosity of from about 30% to about 90%. 
     In at least some embodiments, the getter layer deposited on the electrode layer, e.g., one or more conducting or semiconducting layers on the substrate has one or more porous polymer films with negligible tackiness of less than about 0.05 Newtons (“N”)/10 millimeters (“mm”) to avoid leaving residue while cleaning a surface. 
     In at least some embodiments, getter layer  105  has the thickness from about 100 μm to about 900 μm. In at least some embodiments, getter layer  105  is mechanically placed onto electrode layer  103  using one of techniques known to one of ordinary skill in the art of semiconductor manufacturing. 
     As shown in  FIG. 1C , a getter reticle has electrode layer  103  made of, for example, one or more conducting or semiconducting films between substrate  101  made of, for example, glass, and getter layer  105  made of one or more polymer films. The one or more conducting or semiconducting films introduced between the electrically insulating substrate and the one or more polymer films can provide electrostatic attraction force between a surface of an electrostatic chuck or any other electrostatic apparatus and a getter reticle. The one or more polymer films can be used to actually remove contaminants (e.g., foreign particles) from the surface of the electrostatic chuck or any other apparatus providing an electrostatic force. The electrode layer made of one or more conducting or semiconducting films, or bulk material having sheet resistance less than 10 4  Ohm/sq can work as an electrode to hold charges in a dielectic layer, such as getter layer  105  that is placed adjacent to a surface of an apparatus having one or more electrodes (e.g, an electrostatic chuck). The adhesion strength between the electrode layer and the substrate is enough for them not be separated by an electrostatic chucking force. The adhesion strength between the electrode layer and the getter layer is enough for them withstand separation by an electrostatic chucking force. 
       FIG. 1D  is a top view  140  of an exemplary embodiment of a getter reticle, as described in  FIG. 1C . As shown in  FIG. 1D , the getter reticle having getter layer  105  on electrode layer  103  on substrate  101  has a rectangular or square shape. 
       FIG. 1E  is a bottom view  150  of an exemplary embodiment of a getter reticle, as described in  FIG. 1C . As shown in  FIG. 1E , a getter reticle  109  has a rectangular or square shape. 
     Conventional cleaning semiconductor wafers are circular and may not be used to in-situ clean reticle semiconductor processing systems due to the geometric difference. On the other hand, a reticle substrate (e.g., blank) may not be used for in-situ electrostatic chuck cleaning. An electrostatic force to hold the blank on the chuck cannot be generated due to the lack of electrical conductivity of the reticle substrate. In one embodiment, the getter reticle to in-situ clean a surface of the electrostatic chuck (or any other apparatus having an electrostatic force) in a vacuum chamber, as described herein, complies with dimensions requirements for automatic loading of the reticle into the semiconductor processing system (e.g., an EUVL stepper, plasma etcher, IBD, or other vacuum systems using electrostatic chuck). 
       FIG. 2A  is a cross-sectional view  200  of a getter reticle having an alignment pattern at a back side of a substrate according to one embodiment of the invention. As shown in  FIG. 2A , the getter reticle has a getter layer  205  adjacent to an electrode layer  203  deposited on a front side of a substrate  201 , as described above with respect to  FIGS. 1A-1D . As shown in  FIG. 2A , an optically dark layer  207  is deposited on a back side of the substrate  201 . In one embodiment, a pattern having features, such as a feature  209 , is formed on the back side of the substrate  201 . In one embodiment, optically dark layer  207  contains one or more optically dark films in a reflection mode or in a transmission mode. The one or more optically dark films on substrate  201  can be, for example, Cr, Cr compounds, Ta, Ta compounds, W, W compounds, noble metals (Pt, Ag, Rh, etc.), noble metal compounds, etc. In one embodiment, the optically dark layer  207  contains at least one optically dark film in a reflection mode or in a transmission mode that is partially coated (patterned). In one embodiment, optically dark layer  207  is deposited onto the substrate to absorb a EUV light in a transmission mode or in a reflection mode. In one embodiment, optically dark layer  207  is a patterned layer. In one embodiment, the thickness of the optically dark layer  207  is in the approximate range of less than 50% reflectivity for a reflection mode system, or less than 10% transmittance for a transmission mode system at each actinic wavelength. In one embodiment, the pattern features, such as a feature  209 , at the back side of the substrate having the optically dark layer  207  deposited thereon act as marks to align (e.g., horizontally, vertically) the getter reticle to the surface of an apparatus (e.g., an electrostatic chuck, or any other apparatus having an electrostatic force). In one embodiment, optically dark layer  207  is a photomask layer. The optically dark layer can be deposited onto the substrate using one of techniques known to one of ordinary skill in the art of semiconductor manufacturing. In one embodiment, optically dark layer  207  acts as an absorber of the EUV light to align the getter reticle to the surface that needs to be cleaned. 
       FIG. 2B  is a bottom view  220  of an exemplary embodiment of a getter reticle, as described in  FIG. 2A . In one embodiment, the getter reticle having optically dark layer  207  on a back side of substrate  201  has a rectangular or square shape to comply with dimensions requirements for automatic loading of the photomask reticle into the semiconductor processing system (e.g. an EUVL stepper, plasma etcher, IBD, or other vacuum systems using electrostatic chuck). 
       FIG. 3A  is a cross-sectional view  300  of a getter reticle having one or more optically reflective films on a back side of the substrate according to one embodiment of the invention. As shown in  FIG. 3A , a getter layer  305  is deposited adjacent to an electrode layer  303  on a front side of a substrate  301 , as described above, and one or more optically reflective films  307  on a back side of the substrate. As shown in  FIG. 3A , an optically dark layer  309  is deposited on one or more optically reflective films  307 . Optically dark layer  309  can be, for example, the optically dark layer, as described with respect to  FIGS. 2A and 2B . 
     In one embodiment, one or more optically reflective films  307  include a layer of one material and a layer of another material formed in alternating order on the substrate  301 . In one embodiment, the one or more optically reflective films include a layer made of silicon and a layer made of a metal, for example, molybdenum (“Mo”), nickel (“Ni”), titanium (“Ti”), cobalt (“Co”), or any combination thereof that are formed in alternating order on the substrate. In one embodiment, the thickness of each of the layers is in the approximate range of 1 nm to 300 nm. In one embodiment, one or more optically reflective films  307  are deposited onto the substrate to reflect a EUV light to improve aligning of the getter reticle to a surface of the apparatus (e.g., electrostatic chuck, or any other apparatus providing an electrostatic force) based on the pattern features, such as a feature  311 , at the back side of the substrate  301  that mimics a real photomask reticle and complies with reticle loading requirements of the semiconductor processing system (e.g., an EUVL stepper, plasma etcher, IBD, or other vacuum systems using electrostatic chuck). The one or more optically reflective films can be deposited onto the substrate using one of techniques known to one of ordinary skill in the art of semiconductor manufacturing. The optically dark layer can be deposited onto the one or more optically reflective films using one of techniques known to one of ordinary skill in the art of semiconductor manufacturing. 
       FIG. 3B  is a bottom view  320  of an exemplary embodiment of a getter reticle, as described in  FIG. 3A . As shown in  FIG. 3B , the getter reticle having optically dark layer  309  on one or more optically reflective films  307  on a back side of substrate  301  has a rectangular or square shape to comply with dimensions requirements for automatic reticle loading in the semiconductor processing system (e.g., an EUVL stepper, plasma etcher, IBD, or other vacuum systems using electrostatic chuck). 
       FIG. 4A  is a cross-sectional view  400  of a getter reticle according to another embodiment of the invention. As shown in  FIG. 4A , a getter layer  403  is directly deposited onto a  401 . In one embodiment, substrate  401  has one or more conducting layers, one or more semiconductor layers, or a combination thereof. In one embodiment, substrate  401  includes a semiconductor, e.g., silicon, germanium, or any other semiconductor, having a sheet resistance that does not exceed 10 4  Ohm/square. In at least some embodiments, substrate  101  comprises any material to make any of integrated circuits, passive (e.g., capacitors, inductors) and active (e.g., transistors, photo detectors, lasers, diodes) microelectronic devices. Substrate  401  may include insulating (e.g., dielectric) materials that separate such active and passive microelectronic devices from a conducting layer or layers that are formed on top of them. In one embodiment, substrate  101  is a monocrystalline silicon (“Si”) substrate that includes one or more dielectric layers e.g., silicon dioxide, silicon nitride, sapphire, and other dielectric materials. 
     In one embodiment, substrate  401  includes a conducting material having a sheet resistance that does not exceed 10 4  Ohm/square. The conducting material can be, for example, polysilicon, metal, metal compounds, nitrides, oxides, oxynitrides, carbides, and other conducting materials. In one embodiment, the conductive material is a metal, for example, copper (Cu), ruthenium (Ru), nickel (Ni), cobalt (Co), chromium (Cr), iron (Fe), manganese (Mn), titanium (Ti), aluminum (Al), hafnium (Hf), tantalum (Ta), tungsten (W), Vanadium (V), Molybdenum (Mo), palladium (Pd), gold (Au), silver (Au), platinum Pt, or any combination thereof. In at least some embodiments, the conducting material includes Cr, chromium nitride (“CrN”), titanium nitride (“TiN”), tantalum nitride (“TaN”), or any combination thereof. In one embodiment, the thickness of substrate  401  is the approximate range of about 1 mm to about 20 mm. In one embodiment, the thickness of substrate  401  is about 0.25 inches. In one embodiment, at least a portion of the substrate  401  acts as an electrode for holding charges in a dielectric material that is positioned between electrode layer  103  and other electrode, as described in further detail below. 
     As shown in  FIG. 4A , a getter layer  403  is deposited on conducting substrate  401 . In one embodiment, an adhesion layer (not shown) is formed between getter layer  403  and substrate  401 . In at least some embodiments, the adhesion layer is applied to bond the getter layer and the substrate together and prevent the getter layer from peeling off the substrate. The getter layer  403  can be, for example, a getter layer  105 , as described in  FIG. 1C . In at least some embodiments, getter layer  403  is mechanically placed onto substrate  401  using one of techniques known to one of ordinary skill in the art of semiconductor manufacturing. 
     In one embodiment, substrate  401  provides electrostatic attraction force between a surface of an electrostatic chuck (or any other electrostatic apparatus) and a getter reticle. Getter layer  403  is used to actually remove contaminants (e.g., foreign particles) from the surface of the electrostatic chuck (or any other apparatus providing an electrostatic force), as described above. In one embodiment, substrate  401  works as an electrode to hold charges in getter layer  403  placed adjacent to a surface of the apparatus having one or more electrodes (e.g., an electrostatic chuck). The adhesion strength between the getter layer and the substrate is enough to withstand separation by an electrostatic chucking force. 
       FIG. 4B  is a top view  410  of an exemplary embodiment of a getter reticle, as described in  FIG. 4A . As shown in  FIG. 4B , the getter reticle having getter layer  403  on substrate  401  has a rectangular or square shape. 
       FIG. 4C  is a bottom view  420  of an exemplary embodiment of a getter reticle, as described in  FIG. 4A . As shown in  FIG. 4C , a getter reticle  405  has a rectangular or square shape to comply with dimensions requirements for automatic reticle loading into the semiconductor processing system, as described above. 
       FIG. 5A  is a cross-sectional view  500  of a getter reticle having alignment pattern features, such as a feature  507  at a back side of a substrate according to another embodiment of the invention. As shown in  FIG. 5A , the getter reticle has a getter layer  503  directly deposited on a front side of a conducting or semiconducting substrate  501 , as described above with respect to  FIGS. 4A-4B . As shown in  FIG. 5A , an optically dark layer  505  in a reflection mode or in a transmission mode is deposited on a back side of the substrate  501 . In one embodiment, a pattern having features, such as a feature  507 , is formed on the back side of the substrate  501 . The optically dark layer  505  can be, for example, an optically dark layer  207 , as described in  FIG. 2A . In one embodiment, optically dark layer  505  is deposited onto substrate  501  to absorb a EUV light in a transmission mode or in a reflection mode. In one embodiment, optically dark layer  505  is a patterned layer. In one embodiment, pattern features, such as feature  507  at the back side of the substrate having the optically dark layer  505  deposited thereon act as marks to align (e.g., horizontally, vertically) the getter reticle to the surface of an apparatus (e.g., an electrostatic chuck, or any other apparatus having an electrostatic force). In one embodiment, optically dark layer  505  is a photomask layer. The optically dark layer can be deposited onto the substrate using one of techniques known to one of ordinary skill in the art of semiconductor manufacturing. 
       FIG. 5B  is a bottom view  520  of an exemplary embodiment of a getter reticle, as described in  FIG. 5A . In one embodiment, the getter reticle having optically dark layer  505  on a back side of substrate  501  has a rectangular or square shape to comply with dimensions requirements for automatic loading of the photomask reticle into the semiconductor processing system (e.g. an EUVL stepper, plasma etcher, IBD, or other vacuum systems using electrostatic chuck). 
       FIG. 6A  is a cross-sectional view  600  of a getter reticle having one or more optically reflective films on a back side of the substrate according to another embodiment of the invention. As shown in  FIG. 5A , the getter reticle has a getter layer  603  directly deposited on a front side of a conducting or semiconducting substrate  601 , as described above with respect to  FIGS. 4A-4B . As shown in  FIG. 6A , one or more optically reflective films  605  are deposited on a back side of the substrate  601 . The one or more optically reflective films  605  can be, for example one or more optically reflective films  307 , as described in  FIGS. 3A and 3B . As shown in  FIG. 6A , an optically dark layer  607  is deposited on one or more optically reflective films  607 . Optically dark layer  309  can be, for example, the optically dark layer  505 , as described with respect to  FIGS. 5A and 5B . 
     In one embodiment, one or more optically reflective films  605  are deposited onto the substrate  601  to reflect a EUV light, and to align the getter reticle to a surface of the apparatus (e.g., electrostatic chuck, or any other apparatus providing an electrostatic force) mimicking a real photomask reticle to comply with reticle loading requirements of the semiconductor processing system (e.g., an EUVL stepper, plasma etcher, IBD, or other vacuum systems using electrostatic chuck). The one or more optically reflective films can be deposited onto the conducting or semiconducting substrate using one of techniques known to one of ordinary skill in the art of semiconductor manufacturing. The optically dark layer can be deposited onto the one or more optically reflective films using one of techniques known to one of ordinary skill in the art of semiconductor manufacturing. 
       FIG. 6B  is a bottom view  620  of an exemplary embodiment of a getter reticle, as described in  FIG. 6A . As shown in  FIG. 6B , the getter reticle having optically dark layer  607  on one or more optically reflective films  605  on a back side of conducting or semiconducting substrate  601  has a rectangular or square shape to comply with dimensions requirements for automatic reticle loading in the semiconductor processing system (e.g., an EUVL stepper, plasma etcher, IBD, or other vacuum systems using electrostatic chuck). 
       FIG. 7A  is a cross-sectional view  700  of a getter reticle having a getter layer on an electrode layer on both sides of an insulating substrate according to another embodiment of the invention. The getter reticle has a getter layer  701  adjacent to an electrode layer  703  deposited on a front side of an insulating substrate  701 , as described above with respect to  FIGS. 1A-1D . The electrode layer  703  is configured to provide a first electrode to hold charges in the getter layer  701  positioned between the electrode layer  703  and a surface of an apparatus having one or more electrodes (not shown), as described in further detail below. 
     In one embodiment, an adhesion layer (not shown) is formed between getter layer  701  and electrode layer  703 , as described in  FIG. 1C . As shown in  FIG. 7A , the getter reticle has a getter layer  709  on an electrode layer  705  that is deposited on a back side of the substrate  701 . Depositing of a getter layer on a electrode layer on a substrate is described above with respect to  FIGS. 1A-1B . The electrode layer  705  is configured to hold charges in the getter layer  709  positioned between the electrode layer  705  and a surface of an apparatus having one or more second electrodes (not shown), as described in further detail below. 
     In one embodiment, the getter reticle has a rectangular or square shape to comply with dimensions requirements for automatic loading of the photomask reticle into the semiconductor processing system (e.g., an EUVL stepper, plasma etcher, IBD, or other vacuum systems using electrostatic chuck), as described above. A getter layer on an electrode layer on each of the sides the insulating substrate can be used to clean a surface of the apparatus with an electrostatic force. 
       FIG. 7B  is a cross-sectional view  710  of a getter reticle having a getter layer directly deposited on both sides of a conducting or semiconducting substrate according to another embodiment of the invention. The getter reticle has a getter layer  713  deposited on a front side of the conducting or semiconducting substrate  711 , as described above with respect to  FIGS. 4A-4C . At least a front portion of the conducting or semiconducting substrate  711  is configured to hold charges in the getter layer  713  positioned between the substrate  711  and a surface of an apparatus having one or more second electrodes (not shown), as described in further detail below. 
     In one embodiment, an adhesion layer (not shown) is formed between getter layer  713  and substrate  711 , as described in  FIG. 4A . As shown in  FIG. 7B , the getter reticle has a getter layer  715  deposited on a back side of the substrate  711 . Depositing of a getter layer directly on a conducting or semiconducting substrate is described above with respect to  FIGS. 4A-4C . 
     At least a back portion of the conducting or semiconducting substrate  711  is configured to hold charges in the getter layer  715  positioned between the substrate  711  and a surface of an apparatus having one or more second electrodes (not shown), as described in further detail below. In one embodiment, the getter reticle has a rectangular or square shape to comply with dimensions requirements for automatic loading of the photomask reticle into the semiconductor processing system (e.g., an EUVL stepper, plasma etcher, IBD, or other vacuum systems using electrostatic chuck), as described above. A getter layer on each of the sides the conducting or semiconducting substrate can be used to clean a surface of the apparatus with an electrostatic force. 
       FIG. 8  shows an exemplary schematics of an electrostatic apparatus and a getter reticle according to one embodiment of the invention. As shown in  FIG. 8 , an electrostatic apparatus  807  has electrodes, such as an electrode  805  and an electrode  803 . Electrostatic apparatus  807  can be an electrostatic chuck, or any other apparatus that provides an electrostatic force to hold objects. Getter reticle  802  can be located parallel to the surface  811 . 
     As shown in  FIG. 8 , a getter reticle  801  has a getter layer  809  facing a surface  811  of the apparatus. Getter reticle  801  can be any of getter reticles described above. In one embodiment, getter reticle  801  has a getter layer  809  on an electrode layer on an insulating substrate, as described above. In one embodiment, getter reticle  801  has a getter layer  809  directly deposited onto conducting or semiconducting, as described above. In one embodiment, a getter layer of the getter reticle as described herein can be attached to the surface of the apparatus by an electrostatic force generated between the electrode layer of the getter reticle and one or more electrodes of the apparatus. In one embodiment, a getter layer of the getter reticle as described herein can be attached to the surface of the apparatus by an electrostatic force generated between the conductive or semiconductive substrate of the getter reticle and one or more electrodes of the apparatus. 
       FIGS. 9A-9C  illustrate a method to in-situ clean a surface of an electrostatic apparatus from the contaminants using a getter reticle according to one embodiment of the invention. As shown in a view  900  of  FIG. 9A , an electrostatic apparatus  903  has electrodes, such as an electrode  905  and an electrode  907 . Electrostatic apparatus  903  can be an electrostatic chuck, or any other apparatus that provides an electrostatic force to hold objects. As shown in  FIG. 9A , contaminants  909 , for example residue particles and foreign matters, are located on the surface of the apparatus  903 . As shown in  FIG. 9A , a getter reticle  901  having a getter layer  911  as described herein is moved toward a surface of the electrostatic apparatus  903 . In one embodiment, the apparatus  903  is moved toward getter reticle  901 . In one embodiment, getter reticle  901  is moved toward apparatus  903 . In yet another embodiment, getter reticle  901  and apparatus  903  are moved toward each other. The getter reticle  901  is aligned parallel to the apparatus  903 . The getter reticle can be aligned in a horizontal and vertical direction parallel to the apparatus  903  using, for example, a pattern features (not shown) on a back side of the substrate, as described herein. As shown in a view  910  of  FIG. 9B , the getter layer  911  faces toward the electrostatic chuck surface. Next, the getter layer of the getter reticle is attached to the surface of the electrostatic apparatus by an electrostatic force, as described herein. 
     The getter layer  911  of the getter reticle  901  is strongly engaged with the surface by an electrostatic force, as shown in  FIG. 9B . The electrostatic force can be generated by applying a voltage  913  to the electrodes, such as electrode  905  and electrode  907 . The electrostatic force is optimized to be strong enough to at least overcome the getter reticle weight gravity. In one embodiment, the electrostatic force is optimized by adjusting the voltage applied to the electrodes. The getter layer  911  can be attached to the surface with the electrostatic force generated by applying a voltage to the electrodes. Contaminants  909  on the chuck surface are squeezed, embedded in or adhered on the polymeric surface by applying an electrostatic force between the chuck apparatus and the reticle for a predetermined time, as shown in  FIG. 9B . 
     Next, the contaminants  909  are removed from the surface of the apparatus  903 , and the getter reticle is detached from the surface. The contaminants  909  are transferred to the getter polymer layer  911 , as shown in a view  920  of  FIG. 9C . Particles or foreign matters are transferred from the chuck surface to the getter reticle surface, and are completely removed from the chuck surface after the getter reticle moves away from the chuck apparatus. 
     In alternate embodiments, the getter reticle can be detached from the surface by reducing a voltage applied to the electrodes  907  and  905 , changing a polarity of the voltage, or turning the voltage off. When the electrostatic force is turned off, the getter reticle will be detached from the chuck surface, and the foreign matters will be removed from the chuck surface as well. 
       FIG. 10A  shows a block diagram of a semiconductor processing system  1000  to in-situ clean a surface of an electrostatic apparatus according to one embodiment of the invention. As shown in  FIG. 10A , the system  1000  has an vacuum chamber  1001 . Vacuum chamber  1001  has an outlet  1006  connected to a vacuum pump system (not shown) to evacuate the air including volatile compounds produced during semiconductor processing. Vacuum chamber  1001  has an electrostatic apparatus  1003  having a surface to which a getter reticle  1005  is attached using an electrostatic force  1011 , as described herein. Typically, the peak-to-valley value indicating the flatness of the surface of the electrostatic chuck is less than 30 nm to hold a bowed reticle as flat as possible in a vacuum chamber. Typically, the chuck surface and the reticle back side are fully contacted to transfer the chuck flatness to the reticle. Accordingly, maintaining the cleanliness of an electrostatic chuck is as important as a reticle surface. 
     Vacuum chamber  1001  has a wafer holder  1004 , and an EUV source  1002 . Reticle  1005  is aligned to surface of the chuck  1003  using the features of the pattern (not shown) on the back side of the substrate and EUV light  1013 , as described herein. In one embodiment, the system  1000  is an EUVL stepper, plasma etcher, IBD, or other vacuum systems using electrostatic chuck system. In one embodiment, the system is an EUVL stepper and getter reticle  1005  replaces an actual photomask reticle on the surface of the electrostatic chuck. 
     Contaminants  1009  on the chuck surface are squeezed, embedded in or adhered on the polymeric surface by electrostatic force  1011  between the chuck apparatus and the getter reticle  1005 , removed from the surface of the apparatus  1003 , and the getter reticle is detached from the apparatus  1003 , as described above. Electrostatic force  1011  is generated by applying a voltage to the electrodes (not shown) typically located in an electrostatic chuck fixture. The getter reticle  1005  can be removed from the chuck apparatus  1003  by turning a voltage applied to the electrodes of the electrostatic chuck off, changing the direction of the force (e.g., by changing the polarity of the voltage) while maintaining the vacuum environment in the chamber  1001 . Contaminants from the surface of the chuck apparatus are transferred to the getter reticle. The getter reticle provides an advantage of cleaning off any foreign matter from the semiconductor apparatus (electrostatic chuck) surface in-situ, avoiding taking the tool or apparatus apart, and breaking vacuum environment. Additionally advantage of cleaning the electrostatic chuck using the getter reticle as described herein is that the cleaning does not require additional equipment because the existing electrostatic chuck can provide all the required performance and capability. 
       FIG. 10B  is a view  1020  illustrating defect density maps before (a) and after (b) in-situ applying a getter reticle on an electrostatic chuck according to one embodiment of the invention. As shown in  FIG. 10B , the defect density are reduced by about a factor of 5× after using the getter reticle having a silica based glass which is electrically insulating. This verifies that the getter reticle having a conducting or semiconducting layer between the insulating substrate and a getter layer, as described herein, provides enough electrostatic force to remove particles or foreign matters from the electrostatic chuck surface. 
       FIG. 11A  is a cross-sectional view  1100  of a getter reticle used to protect an actual reticle surface from additional contamination according to another embodiment of the invention. As shown in  FIG. 11A , a getter reticle  1103  having a getter layer  1102 , as described herein is attached to a backside film  1104  of an actual EUV photomask reticle  1101  to protect the back side of actual photomask reticle  1101  from any falling on contaminants  1105 , such as particles or foreign matters. As shown in  FIG. 11B , a getter polymer layer  1203 , as described herein is directly placed on a backside film  1202  of the actual photomask reticle  1201  to protect the back side of actual photomask reticle  1201  from any falling on contaminants  1205 , such as particles or foreign matters. Because a getter polymer layer does not leave a residue, the getter polymer layer can be attached to the backside film of an actual reticle during reticle shipping, handling and storage to protect from falling on any contaminants. 
       FIG. 12  shows a block diagram of an exemplary embodiment of a data processing system  1200  to control an in-situ cleaning a surface of an electrostatic apparatus using a getter reticle according to one embodiment of the invention. The semiconductor processing system, for example, semiconductor processing system  1000 , can be connected to a data processing system, for example, data processing system  1200 . In at least some embodiments, the data processing system controls the semiconductor processing system to perform operations involving moving a getter reticle toward a surface, aligning the getter reticle to the surface, attaching the getter layer to the surface by an electrostatic force, removing foreign residues from the surface, and detaching the getter reticle from the surface, as described herein. 
     In alternative embodiments, the data processing system may be connected (e.g., networked) to other machines in a Local Area Network (LAN), an intranet, an extranet, or the Internet. The data processing system may operate in the capacity of a server or a client machine in a client-server network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. The data processing system may be a personal computer (PC), a tablet PC, a set-top box (STB), a Personal Digital Assistant (PDA), a cellular telephone, a web appliance, a server, a network router, switch or bridge, or any machine capable of executing a set of instructions (sequential or otherwise) that specify actions to be taken by that data processing system. Further, while only a single data processing system is illustrated, the term “data processing system” shall also be taken to include any collection of data processing systems that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies described herein. The exemplary data processing system  1200  includes a processor  1202 , a main memory  1204  (e.g., read-only memory (ROM), flash memory, dynamic random access memory (DRAM) such as synchronous DRAM (SDRAM) or Rambus DRAM (RDRAM), etc.), a static memory  1206  (e.g., flash memory, static random access memory (SRAM), etc.), and a secondary memory  1218  (e.g., a data storage device), which communicate with each other via a bus  1230 . 
     Processor  1202  represents one or more general-purpose processing devices such as a microprocessor, central processing unit, or the like. More particularly, the processor  1202  may be a complex instruction set computing (CISC) microprocessor, reduced instruction set computing (RISC) microprocessor, very long instruction word (VLIW) microprocessor, processor implementing other instruction sets, or processors implementing a combination of instruction sets. Processor  1202  may also be one or more special-purpose processing devices such as an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal processor (DSP), network processor, or the like. Processor  1202  is configured to execute the processing logic  1226  for performing the operations described herein. 
     The computer system  1200  may further include a network interface device  1208 . The computer system  1200  also may include a video display unit  1210  (e.g., a liquid crystal display (LCD), a light emitting diode display (LED), or a cathode ray tube (CRT)), an alphanumeric input device  1212  (e.g., a keyboard), a cursor control device  1214  (e.g., a mouse), and a signal generation device  1216  (e.g., a speaker). 
     The secondary memory  1218  may include a machine-accessible storage medium (or more specifically a computer-readable storage medium)  1231  on which is stored one or more sets of instructions (e.g., software  1222 ) embodying any one or more of the methodologies or functions described herein. The software  1222  may also reside, completely or at least partially, within the main memory  1204  and/or within the processor  1202  during execution thereof by the computer system  1200 , the main memory  1204  and the processor  1202  also constituting machine-readable storage media. The software  1222  may further be transmitted or received over a network  1220  via the network interface device  1208 . 
     While the machine-accessible storage medium  1231  is shown in an exemplary embodiment to be a single medium, the term “machine-readable storage medium” should be taken to include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) that store the one or more sets of instructions. The term “machine-readable storage medium” shall also be taken to include any medium that is capable of storing or encoding a set of instructions for execution by the machine and that cause the machine to perform any one or more of the methodologies of the present invention. The term “machine-readable storage medium” shall accordingly be taken to include, but not be limited to, solid-state memories, and optical and magnetic media. 
     In the foregoing specification, embodiments of the invention have been described with reference to specific exemplary embodiments thereof. It will be evident that various modifications may be made thereto without departing from the broader spirit and scope of embodiments of the invention as set forth in the following claims. The specification and drawings are, accordingly, to be regarded in an illustrative sense rather than a restrictive sense.