EP1542832A1 - Tampon de polissage avec fenetre pour planarisation - Google Patents

Tampon de polissage avec fenetre pour planarisation

Info

Publication number
EP1542832A1
EP1542832A1 EP03759509A EP03759509A EP1542832A1 EP 1542832 A1 EP1542832 A1 EP 1542832A1 EP 03759509 A EP03759509 A EP 03759509A EP 03759509 A EP03759509 A EP 03759509A EP 1542832 A1 EP1542832 A1 EP 1542832A1
Authority
EP
European Patent Office
Prior art keywords
layer
polishing pad
opening
partially
polishing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP03759509A
Other languages
German (de)
English (en)
Inventor
Robert Swisher
William C. Allison
Alan E. Wang
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
PPG Industries Ohio Inc
Original Assignee
PPG Industries Ohio Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by PPG Industries Ohio Inc filed Critical PPG Industries Ohio Inc
Publication of EP1542832A1 publication Critical patent/EP1542832A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B37/00—Lapping machines or devices; Accessories
    • B24B37/11—Lapping tools
    • B24B37/20—Lapping pads for working plane surfaces
    • B24B37/205—Lapping pads for working plane surfaces provided with a window for inspecting the surface of the work being lapped
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
    • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
    • H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
    • H01L21/302—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to change their surface-physical characteristics or shape, e.g. etching, polishing, cutting
    • H01L21/304—Mechanical treatment, e.g. grinding, polishing, cutting

Definitions

  • the present invention relates to a polishing pad.
  • the polishing pad of the present invention can include a window.
  • the polishing pad of the present invention can be useful for polishing articles and can be especially useful for chemical mechanical polishing or planarization of a microelectronic device, such as a semiconductor wafer.
  • the window of the polishing pad is at least partially transparent and thus, can be particularly useful with polishing or planarizing tools that are equipped with through-the-platen wafer metrology.
  • the polishing or planarization of a non-planar surface of a microelectronic device to an essentially planar surface involves rubbing the non-planar surface with the work surface of a polishing pad using a controlled and repetitive motion.
  • a polishing slurry can be interposed between the rough surface of the article that is to be polished and the work surface of the polishing pad.
  • the fabrication of a microelectronic device such as a semiconductor wafer generally involves the formation of a plurality of integrated circuits on the wafer comprising, for example, silicon or gallium arsenide.
  • the integrated circuits can be formed by a series of process steps in which patterned layers of materials, such as conductive, insulating and semiconducting materials, are formed on the substrate.
  • patterned layers of materials such as conductive, insulating and semiconducting materials
  • semiconductor wafer production can include at least one, and more typically a plurality of polishing steps, which can use one or more polishing pads.
  • a chemical mechanical polishing (CMP) process can include placing the microelectronic substrate in contact with a polishing pad; rotating the pad while a force is applied to the backside of the microelectronic device; and applying an abrasive- containing chemically-reactive solution commonly referred to as a "slurry" to the pad during polishing.
  • a CMP polishing slurry can contain an abrasive material, such as silica, alumina, ceria or mixtures thereof.
  • the rotational movement of the pad relative to the substrate as slurry is provided to the device/pad interface can facilitate the polishing process. In general, polishing can be continued in this manner until the desired film thickness is removed.
  • the CMP process can provide effective polishing at desired polishing rates while reducing or minimizing surface imperfections, defects, corrosion, and erosion.
  • Polishing or planarization characteristics can vary from pad-to-pad, and throughout the operating lifetime of a given pad. Variations in the polishing characteristics of the pads can result in inadequately polished or planarized substrates which are not useful. Thus, it is desirable in the art to develop a polishing pad that exhibits reduced pad-to-pad variation in polishing or planarization characteristics. It is further desirable to develop a polishing pad that exhibits reduced variations in polishing or planarization characteristics throughout the operating life of the pad.
  • in-situ metrology Planarizing tools having the ability to measure the progress of the planarization process while the wafer is held in the tool and in contact with the pad are known in the art. Measuring the progress of planarizing a microelectronic device during the planarizing process can be referred to in the art as "in-situ metrology".
  • United States Patents 5,964,643 and 6,159,073; and European Patent 1,108,501 describe polishing or planarizing tools and in-situ metrology systems.
  • in-situ metrology can include directing a beam of light through an at least partially transparent window located in the platen of the tool; the beam of light can be reflected off the surface of the wafer, back through the platen window, and into a detector.
  • the polishing pad can include a window that is at least partially transparent to the wavelengths used in the metrology system, and essentially aligned with the planten window.
  • a window that is at least partially transparent to the wavelengths used in the metrology system, and essentially aligned with the planten window.
  • One disadvantage with known pads having windows which are coplanar with the polishing surface can include wearing of the window portion at a slower rate than the pad surface.
  • a further disadvantage with known pads having a coplanar window can include scratching of the window as a result of its contact with abrasive particles in the slurry during the polishing or planarization process.
  • a scratched window can generally reduce the transparency of the window and can cause an attenuation of the metrology signal.
  • the present invention includes a polishing pad having a window.
  • the polishing pad can comprise a first layer and a second layer.
  • the first layer can function as the work surface or polishing layer of the pad.
  • At least a portion of the second layer can comprise a window which is at least partially transparent to wavelengths used by the metrology instrumentation of polishing tools.
  • the first layer can absorb at least 2 percent by weight of polishing slurry based on the total weight of the first layer.
  • the polishing pad of the present invention can comprise a first layer and a second layer.
  • the first layer can function as the polishing or working surface of the pad such that the first layer can at least partially interact with the substrate to be polished and the polishing slurry.
  • the first layer can be-porous and permeable to polishing slurry.
  • the second layer can be substantially nonporous and substantially impermeable to polishing slurry.
  • substantially nonporous means generally impervious to the passage of liquid, gas, and bacteria. On a macroscopic scale, a substantially nonporous material exhibits few if any pores.
  • porous means having pore(s) and the term “pore(s)” refers to minute opening(s) through which matter passes.
  • the first layer can include a variety of materials known in the art.
  • suitable materials comprising the first layer can include but are not limited to paniculate polymer and crosslinked polymer binder as described in United States Patent 6,477,926B1; particulate polymer and an organic polymer binder as described in United States Patent Application Serial Number 10/317,982; sintered particles of thermoplastic resin as described in United States Patents 6,062,968; 6,117,000; and 6,126,532; and pressure sintered powder compacts of thermoplastic polymer as described in United States Patents 6,231,434B1; 6,325,703B2; 6,106,754; and 6,017,265.
  • suitable materials comprising the first layer can include polymeric matrices impregnated with a plurality of polymeric microelements, wherein each polymeric microelement can have a void space therein, as described in United States Patents 5,900,164 and 5,578,362.
  • the thickness of the first layer can vary. In alternate non-limiting embodiments, the first layer can have a thickness of at least 0.020 inches, or at least 0.040 inches; or 0.150 inches or less, or 0.080 inches or less.
  • the first layer can include pores such that polishing slurry can be at least partially absorbed by the first layer.
  • the number of pores can vary.
  • the first layer can have a porosity, expressed as percent pore volume, of at least 2 percent by volume based on the total volume of the first layer, or 50 percent or less by volume based on the total volume of the first layer, or from 2 to 50 percent by volume based on the total volume of the first layer.
  • the percent pore volume of the polishing pad layer can be determined using a variety of techniques known in the art. In a non-limiting embodiment, the following expression can be used to calculate percent pore volume:
  • the density can be expressed in units of grams per cubic centimeter, and can be determined by a variety of conventional methods known in the art. In a non-limiting embodiment, the density can be determined in accordance with ASTM D 1622-88.
  • the pore volume can be expressed in units of cubic centimeters per gram, and can be determined using conventional methods and equipment known in the art. In a non- limiting embodiment, pore volume can be measured in accordance with the mercury porosimetry method in ASTM D 4284-88, using an Autopore III mercury porosimeter from Micromeritics can be used.
  • the pore volume measurements can be made under the following conditions: a contact angle of 140°; a mercury surface tension of 480 dynes/cm; and degassing of the polishing pad layer sample under a vacuum of 50 micrometers of mercury.
  • the first layer can have an at least partially open structure such that it can absorb slurry.
  • the first layer can absorb at least 2 percent by weight of polishing slurry based on the total weight of the first layer, or not more than 50 percent by weight, or from 2 percent by weight to 50 percent by weight.
  • the first layer of the polishing pad can have a compressibility greater than the second layer.
  • the term "compressibility” refers to the percent volume compressibility measurement.
  • the percent volume compressibility of the first layer can be at least 0.3 percent; or 3 percent or less; or from 0.3 to 3 percent; when a load of 20 psi is applied.
  • the percent volume compressibility of a pad layer can be determined using various methods known in the art.
  • the percent volume compressibility of a pad layer can be determined using the following expression.
  • the area of the pad layer does not change when the load is placed on it; thus, the preceding equation for volume compressibility can be expressed in terms of pad layer thickness by the following expression.
  • the pad layer thickness can be determined using a variety of known methods.
  • the pad layer thickness can be determined by placing a load (such as, but not limited to, calibrated weights) on the pad sample and measuring the change in thickness of the pad layer as a result of the load.
  • a Mitutoyo Electronic Indicator, Model ID-C112EB can be used.
  • the indicator has a spindle or threaded rod which can be fitted at one end with a flat contact under which the pad layer is placed. The spindle can be fitted at the other end with a device for applying specified loads to the contact area, such as but not limited to a balance pan which accepts calibrated weights.
  • the Indicator displays the displacement of the pad layer resulting from applying the load.
  • the Indicater display is typically representative of inches or millimeters.
  • the Electronic Indicator can be mounted on a stand, such as a Mitutoyo Precision Granite Stand, to provide stability while taking the measurements.
  • the lateral dimensions of the pad layer can be sufficient to permit measurements at least 0.5" from any edge.
  • the surface of the pad layer can be flat and parallel over a sufficient area to permit uniform contact between the test pad layer and the flat contact.
  • the pad layer to be tested can be placed under the flat contact.
  • the thickness of the pad layer can be measured prior to applying the load. Calibrated balance weights can be added to the balance pan for a specific resultant load. The pad layer then can be compressed under the specified load.
  • the Indicator can display the thickness/height of the pad layer under the specified load.
  • the thickness of the pad layer prior to applying the load minus the thickness of the pad layer under the specified load can be used to determine the displacement of the pad layer.
  • a load of 20 psi can be applied to the pad layer.
  • Measurements can be made at a standardized temperature such as room temperature. In a non-limiting embodiment, measurements can be taken at a temperature of 22°C +/-2°C.
  • the above-described method of measuring pad layer thickness can be applicable to a stacked pad assembly or layer(s) comprising the stacked pad assembly.
  • a procedure for measuring percent volume compressibility can include placing the contact on the granite base and adjusting the indicator to read zero. The contact can then be raised and the specimen placed on the granite stand under the contact with the edge of the contact at least 0.5" from any edge of the specimen. The contact can be lowered onto the specimen and the specimen thickness measurement can be taken after 5 +/-1 seconds. Without moving the specimen or the contact, sufficient weight can be added to the pan to cause a force of 20 psi to be applied to the specimen by the contact. The reading for the specimen thickness under load measurement can be made after 15 +/-1 seconds. The measurement procedure can be repeated, making five measurements at different positions on the specimen at least 0.25" apart using 20 psi of compressive force.
  • the softness of the first layer can be determined.
  • the term "softness” refers to the Shore A Hardness of the material. In general, the softer the material, the lower the Shore A Hardness value.
  • the first layer can have a Shore A Hardness of at least 85; or 99 or less, or from 85 to 99.
  • the Shore A Hardness value can be determined using various methods and equipment known in the art. In a non-limiting embodiment, Shore A Hardness can be determined in accordance with the procedure recited in ASTM D 2240, using a Shore "Type A” Durometer having a maximum indicator (available from PCT Instruments, Los Angeles, CA).
  • the test method for Shore A Hardness can include the penetration of a specific type of indentor being substantially forced into the test material under specified conditions.
  • the Shore A Hardness can be inversely related to the penetration depth and can be dependent on the elastic modulus and viscoelastic behavior of the test material.
  • the first layer can comprise grooves or pattern on the work or polishing surface.
  • the types of grooves and/or patterns can vary and can include the various types of grooves and/or patterns known in the art.
  • the process for making the grooves and patterns can also vary and can include the various conventional methods known in the art.
  • the polishing pad of the present invention further comprises a second layer.
  • the second layer can be connected to at least a portion of the first layer.
  • the first layer can be connected to at least a portion of the second layer, and the second layer can be connected to at least a portion of an optional third layer.
  • the second layer can include a variety of materials known in the art.
  • the second layer can be selected from substantially non-volume compressible polymers and metallic films and foils. As used herein and the claims, "substantially non-volume compressible" means that the volume can be reduced by less than 1 % when a load of 20 psi is applied. In a non-limiting embodiment, the method for applying the load and measuring the reduction in volume is previously described herein can be employed.
  • Non-limiting examples of substantially non-volume compressible polymers can include polyolefins, such as but not limited to low density polyethylene, high density polyethylene ultra-high molecular weight polyethylene and polypropylene; polyvinylchloride; cellulose-based polymers, such as but not limited to cellulose acetate and cellulose butyrate; acrylics; polyesters and co-polyesters, such as but not limited to PET and PETG; polycarbonate; polyamides, such as but not limited to nylon 6/6 and nylon 6/12; and high performance plastics, such as but not limited to polyetheretherketone, polyphenylene oxide, polysulfone, polyimide, and polyetherimide; and mixtures thereof.
  • polyolefins such as but not limited to low density polyethylene, high density polyethylene ultra-high molecular weight polyethylene and polypropylene
  • polyvinylchloride such as but not limited to cellulose acetate and cellulose butyrate
  • acrylics such as but not limited to PET and PETG
  • Non-limiting examples of metallic films can include but are not limited to aluminum, copper, brass, nickel, stainless steel, and combinations thereof.
  • the thickness of the second layer can vary. In alternate non-limiting embodiments, the second layer can have a thickness of at least 0.0005, or at least 0.0010; or 0.0650 inches or less, or 0.0030 inches or less.
  • the second layer can be flexible to enhance or increase the uniformity of contact between the polishing pad and the surface of the substrate being polished.
  • a consideration in selecting the material for the second layer can be the capability of a material to provide compliant support to the work surface of the polishing pad such that the first layer substantially conforms to the macroscopic contour or long-term surface of the device being polished.
  • a material having said capability can be desirable for use as the second layer in the present invention.
  • the flexibility of the second layer can vary.
  • the flexibility can be determined using a variety of conventional techniques known in the art.
  • the flexibility of the second layer can be at least 0.5 in 'lb 1 ; or at least 100 in 'lb '1 ; or from 1 ih'lb 1 to 100 ih'lb 1 .
  • the second layer can have a compressibility which allows the polishing pad to substantially conform to the surface of the article to be polished.
  • the surface of a microelectronic substrate can have a "wave" contour as a result of the manufacturing process. It is contemplated that if the polishing pad cannot adequately conform to the "wave" contour of the substrate surface, the uniformity of the polishing performance can be degraded. For example, if the pad substantially conforms the ends of the "wave”, but cannot substantially conform and contact the middle portion of the "wave”, only the ends of the "wave” can be polished or planarized and the middle portion can remain substantially unpolished or unplanarized.
  • the compressibility of the second layer can vary. As previously described, the term “compressibility" refers to the percent volume compressibility measurement.
  • the percent volume compressibility of the second layer can be at least one percent; or three percent or less; or from one to three percent.
  • the percent volume compressibility can be determined using a variety of conventional methods known in the art. In a non-limiting embodiment, the percent volume compressibility is determined as previously described herein.
  • the second layer can distribute the compressive forces experienced by the first layer over a larger area of an optional third layer.
  • the second layer is substantially non-volume compressible.
  • the second layer can function as a substantial barrier to fluid transport between the first layer and an optional third layer at least partially connected to the second layer.
  • a consideration in selecting the material comprising the second layer can be the ability of the material to substantially reduce, minimize or essentially prevent the transport of polishing slurry from the first layer to an optional third layer.
  • the second layer can be substantially impermeable to the polishing slurry such that the optional third layer does not become saturated with polishing slurry.
  • the second layer can be perforated such that polishing slurry can penetrate the first and second layers to wet an optional third layer.
  • the optional third layer can be substantially saturated with polishing slurry.
  • the perforations in the second layer can be formed by a variety of techniques known to the skilled artisan, such as but not limited to punching, die cutting, laser cutting or water jet cutting.
  • the hole size, number and configuration of the perforations can vary.
  • the perforation hole diameter can be at least 1/16 inch with at least 26 holes per square inch in a staggered hole pattern.
  • the first layer can be connected to at least a portion of the second layer to produce a stacked pad assembly.
  • the term "connected to” means to link together or place in relationship either directly, or indirectly by one or more intervening materials.
  • the first and second layers are at least partially connected such that the opening of the first layer can be at least partially aligned with the at least partially transparent window of the second layer.
  • the first layer of the polishing pad can be connected to at least a portion of the second layer using an adhesive.
  • a suitable adhesive for use in the present invention can provide sufficient peel resistance such that the pad layers essentially remain in place during use. Further, the adhesive can be selected to sufficiently withstand shear stresses which are present during the polishing or planarization process and moreover, can sufficiently resist chemical and moisture degradation during use.
  • the adhesive can be applied using conventional techniques known to the skilled artisan. In a non-limiting embodiment, the adhesive can be applied to a lower surface of the first layer and/or an upper surface of the second layer which are parallel facing to one another.
  • the adhesive can be chosen from a wide variety of adhesive materials known in the art, such as but not limited to contact adhesives, pressure sensitive adhesives, structural adhesives, hot melt adhesives, thermoplastic adhesives, and curable adhesives, such as thermosetting adhesives.
  • Non-limiting examples of structural adhesives can be chosen from polyurethane adhesives, and epoxy resin adhesives; such as those based on the diglycidyl ether of bisphenol A.
  • Non-limiting examples of pressure sensitive adhesives can include an elastomeric polymer and a tackifying resin.
  • the elastomeric polymer can be chosen from natural rubber, butyl rubber, chlorinated rubber, polyisobutylene, poly(vinyl alkyl ethers), alkyd adhesives, acrylics such as those based on copolymers of 2-ethylhexyl acrylate and acrylic acid, block copolymers such as styrene-butadiene-styrene, and mixtures thereof.
  • a pressure sensitive adhesive can be applied to a substrate using an organic solvent such as toluene or hexane, or from a water-based emulsion or from a melt.
  • hot melt adhesive refers to an adhesive comprised of a nonvolatile thermoplastic material that can be heated to a melt, then applied to a substrate as a liquid.
  • hot melt adhesives can be chosen from ethylene-vinyl acetate copolymers, styrene-butadiene copolymers, ethylene-ethyl acrylate copolymers, polyesters, polyamides such as those formed from the reaction of a diamine and a dimer acid, and polyurethanes.
  • the first layer can comprise an opening.
  • at least a portion of the second layer can comprise a window which is at least partially transparent to wavelengths used by the metrology instrumentation of the planarizing equipment.
  • the size, shape, and positioning of the opening in the first layer and/or the window in the second layer can be dependent upon the metrology instrumentation and polishing apparatus being employed to polish and/or planarize the pad.
  • the opening can be produced by a variety of conventional methods known in the art.
  • the opening can be made by punching, die cutting, laser cutting or water jet cutting.
  • the opening can be formed by molding the first layer.
  • the openings can be die cut into the first layer using an NAEF Model B die press fitted with dies of suitable size and shape, which are commercially available from MS Instruments Company, Stony Brook, NY.
  • the opening in the first layer can be produced prior to stacking together and/or at least partially connecting the first layer with the second layer. At least a portion of the second layer can comprise an at least partially transparent window. In a non-limiting embodiment, the second layer can comprise an at least partially transparent material. In another non-limiting embodiment, the second layer can comprise a substantially non-transparent material; an opening can be cut into the second layer to remove a portion of the second layer; an at least partially transparent material can be inserted into the opening in the second layer. The opening can be made using a variety of methods previously described herein.
  • the second layer can include a metal foil; an opening can be cut into the metal foil to remove a portion of the metal foil; a piece of polyester can be cut into a size and shape that substantially corresponds to the opening; the polyester can be fitted into the opening in the metal foil to form an at least partially transparent window.
  • the second layer can comprise an adhesive assembly.
  • the adhesive assembly can include interposing the second layer between an upper adhesive layer and a lower adhesive layer.
  • the upper adhesive layer of the adhesive assembly can be at least partially connected to the lower surface of the first layer.
  • the lower adhesive layer of the adhesive assembly can be at least partially connected to the upper surface of an optional third layer.
  • the second layer of the adhesive assembly can be selected from the aforementioned suitable materials for the second layer of the polishing pad.
  • the upper and lower adhesive layers of the adhesive assembly can be selected from the non-limiting examples of adhesives previously mentioned herein.
  • the upper and lower adhesive layers each can be contact adhesives.
  • the adhesive assembly can be referred to in the art as two-sided or double coated tape. Non-limiting examples of commercially available adhesive assemblies include those from 3M, Industrial Tape and Specialties Division.
  • At least a portion of the adhesive layer can be removed from the second layer of the adhesive assembly exposing at least a portion of the at least partially transparent middle layer of the adhesive assembly, thereby forming an at least partially transparent window in the second layer.
  • the removal of the adhesive can be performed prior to stacking the layers or after the layers are stacked.
  • the removal process can include a variety of methods known to the skilled artisan, including but not limited to dissolution of the adhesive in solvent or aqueous detergent solution, or physically stripping the adhesive from the second layer.
  • physically stripping the adhesive can be include contacting the adhesive with a material to which the adhesive substantially adheres, and then pulling the material from the second layer, whereby the adhesive is removed with the material.
  • the window of the second layer can be recessed below the polishing surface of the pad by a distance equal to the thickness of the first layer of the pad.
  • the pad assembly can include a coating on at least a portion of the top and/or bottom sides of the window of the second layer.
  • the coating can be at least partially applied with an adhesive in place or following removal of the adhesive.
  • the coating can be at least partially applied prior to stacking the layers or after the layers have been stacked.
  • the coating can provide any one of the following properties, for example: improved transparency of the window area, improved abrasion resistance, improved puncture resistance.
  • the coating can include a resin film, or a cast-in-place resin coating.
  • Non-limiting examples of suitable resin films for use in the present invention can include the materials described above for the second layer.
  • the resin film chosen for the coating can be the same material or different material as that comprising the second pad layer.
  • the resin film can be at least partially adhered to the window area of the second layer by any means known to the skilled artisan, such as the adhesive methods and materials listed above for pad stack adhesives.
  • the coating can be a layer of resin film that can be the same as the material used for the second layer.
  • the coating can be at least partially applied after assembly of the pad stack.
  • the coating can be at least partially applied to both the top and bottom surfaces of the window area of the second layer, and the adhesive can be at least partially adhered using a contact adhesive used as the stack adhesive.
  • the coating can be a cast-in-place resin coating, which can be applied as a liquid, as a solvent solution, dispersion, or aqueous latex; as a melt, or as a blend of resin precursors that can react to form the coating.
  • the application of the liquid can be accomplished by a variety of known methods, including spraying, padding, and pouring.
  • Non-limiting examples of suitable materials for the coating include thermoplastic acrylic resins, thermoset acrylic resins, such as hydroxyl- functional acrylic latexes crosslinked with urea-formaldehyde or melamine-formaldehyde resins, hydroxyl-functional acrylic resins crosslinked with epoxy resins, or carboxyfunctional acrylic latexes crosslinked with carbodiimides or polyimines or epoxy resins; urethane systems, such as hydroxy functional acrylic resin crosslinked with polyisocyanate, moisture-cured isocyanate-terminated resins; carbamate-funtional acrylic resins crosslinked with melamine-formaldehyde resins; epoxy resins, such as polyamide resin crosslinked with bisphenol A epoxy resins, phenolic resins crosslinked with bisphenol A epoxy resins; polyester resins, such as hydroxyl-terminated polyesters crosslinked with melamine-formaldehyde resins or with polyisocyanates or with epoxy crosslinkers.
  • thermoplastic acrylic resins such as hydroxyl
  • the coating can be an aqueous acrylic latex, which can be applied following stacking of the pad assembly.
  • the coating can be at least partially applied to the top and bottom surfaces of the window area of the second layer. Application of the coating can be performed following removal of an adhesive from the window area.
  • the window pad of the present invention can be used with a variety of polishing equipment known in the art.
  • a Mirra polisher produced by Applied Materials Inc, Santa Clara CA, can be used wherein the shape of the opening is a rectangle, having a size 0.5" x 2", being positioned with the long axis radially oriented and centered 4" from the center of the pad.
  • the platen for the Mirra polisher is 20" in diameter.
  • a pad for use with this polisher can comprise a circle of a 20-inch diameter having a window located in the area as described.
  • a Teres polisher commercially available from Lam Research Corporation, Fremont, CA, can be employed.
  • This polisher uses a continuous belt instead of a circular platen.
  • the pad for this polisher can be a continuous belt of 12" width and 93.25" circumference, which has a window area suitably sized and positioned to align with the metrology window of the Teres polisher.can be such that it can be at least partially aligned with the at least partially transparent window in the second layer.
  • the polishing pad of the present invention can comprise additional optional layer(s).
  • the additional layer(s) can contain opening(s) that are substantially aligned with the opening in the first layer and the at least partially transparent window in the second layer.
  • the polishing pad of the present invention can comprise a third layer.
  • the third layer can function as the bottom layer of the pad which can be attached to the platen of the polishing apparatus.
  • the third layer can comprise a material that is softer than the first layer.
  • the term "softness” refers to the Shore A Hardness of the material. The softer the material, the lower the Shore A Hardness value.
  • the Shore A Hardness value of the third layer can be lower than the Shore A Hardness value of the first layer.
  • the third layer can have a Shore A Hardness of at least 15.
  • the Shore A Hardness of the third layer can be at least 45, or 75 or less, or from 45 to 75.
  • the Shore A Hardness can be determined using a variety of conventional methods known in the art. In a non-limiting embodiment, the Shore A Hardness can be determined as previously described herein.
  • the third layer can be used to increase the uniformity of contact between the polishing pad and the surface of the substrate undergoing polishing.
  • the material comprising the third layer of the polishing pad can have a compressibility greater than the material comprising the first layer.
  • the term "compressibility" refers to the percent volume compressibility measurement.
  • the percent volume compressibility of the third layer is greater than the percent volume compressibility of the first layer.
  • the percent volume compressibility of the third layer can be less than 20 percent when a load of 20 psi is applied.
  • the percent volume compressibility of the third layer can be less than 10 percent when a load of 20 psi is applied, or less than 5 percent when a load of 20 psi is applied.
  • percent volume compressibility can be determined by a variety of conventional methods known in the art. In a non-limiting embodiment, percent volume compressibility can be determined as previously described herein.
  • the thickness of the third layer can vary. In general, the third layer thickness should be such that the pad is not too thick. A pad which is too thick can be difficult to place on and take off of the planarization equipment. Thus, in alternate non-limiting embodiments, the thickness of the first layer can be at least 0.040 inches, or at least 0.045 inches; or 0.100 inches or less, or 0.080 inches or less, or 0.065 inches or less.
  • the sublayer can comprise a wide variety of materials known in the art. Suitable materials can include natural rubber, synthetic rubbers, thermoplastic elastomer, foam sheet and combinations thereof. The material of the sublayer can be foamed or blown to produce a porous structure. The porous structure can be open cell, closed cell, or combinations thereof.
  • Non-limiting examples of synthetic rubbers can include neoprene rubber, silicone rubber, chloroprene rubber, ethylene-propylene rubber, butyl rubber, polybutadiene rubber, polyisoprene rubber, EPDM polymers, styrene-butadiene copolymers, copolymers of ethylene and ethyl vinyl acetate, neoprene/vinyl nitrile rubber, neoprene/EPDM/SBR rubber, and combinations thereof.
  • Non-limiting examples of thermoplastic elastomers can include polyolefins, polyesters, polyamides, polyurethanes such as those based on polyethers and polyesters, and copolymers thereof.
  • Non-limiting examples of foam sheet can include ethylene vinyl acetate sheets and polyethylene foam sheets, such as but not limited to those which are commercially available from Sentinel Products, Hyannis, NJ; polyurethane foam sheets, such as but not limited to those which are commercially available from Illbruck, Inc., Minneapolis, MN; and polyurethane foam sheets, and polyolefin foam sheets, such as but not limited to those which are available from Rogers Corporation, Woodstock, CT.
  • the sublayer can include non- woven or woven fiber mat, and combinations thereof; such as but not limited to polyolefin, polyester, polyamide, or acrylic fibers, which have been impregnated with a resin.
  • the fibers can be staple or substantially continuous in the fiber mat.
  • Non-limiting examples can include but are not limited to non-woven fabric impregnated with polyurethane as describe in United States Patent 4,728,552, such as polyurethane impregnated felt.
  • a non- limiting example of a commercially available non- woven subpad can be SubaTM IN, from Rodel, Inc. Newark DE.
  • the optional third layer can comprise an opening.
  • the opening can be produced by any suitable means known in the art, such as those previously identified relative to the opening in the first layer. Further, as previously identified, the size, shape and position of the opening can be dependent upon the metrology instrumentation and polishing apparatus employed.
  • the third layer can be at least partially connected to the second layer and can be in contact with the base of the planarizing machine.
  • the third layer can contain an opening that is at least partially aligned with the opening of the first layer and the at least partially transparent or window area of the second layer.
  • the first layer of the polishing pad can be connected to at least a portion of the second layer and the second layer can be connected to at least a portion of a third layer using an adhesive.
  • Suitable adhesives can include those previously recited herein.
  • the polishing pad of the present invention can comprise a first layer, a second layer, and a third layer.
  • the first and third layers each comprise an opening.
  • the opening of the first and third layers can be at least partially aligned with one another.
  • At least a portion of the second layer can include an at least partially transparent window.
  • the window can be at least partially coated on both sides with contact adhesive, and the layers can be pressed together to form a stacked pad assembly.
  • the adhesive can then be physically stripped from the top and bottom surface of the window area of the second layer using a material to which the adhesive substantially adheres.
  • a material to which the adhesive substantially adheres is Teslin ® SP-100 0, a synthetic sheet material which is commercially available from PPG Industries, Inc, Pittsburgh, PA.
  • the polishing pads of the present invention can be used in combination with polishing slurrys, such as polishing slurries, which are known in the art.
  • suitable slurries for use with the pad of the present invention include but are not limited to the slurries disclosed in United States Patent Application having Serial Numbers 09/882,548 and 09/882, 549, which were both filed on June 14, 2001 and are pending.
  • the polishing slurry can be interposed between the first layer of the pad and the substrate to be polished.
  • the polishing or planarizing process can include moving the polishing pad relative to the substrate being polished.
  • a variety of polishing slurrys or slurries are known in the art.
  • suitable slurries for use in the present invention include slurries comprising abrasive particles.
  • Abrasives that can be used in the slurries include particulate cerium oxide, paniculate alumina, particulate silica and the like.
  • Examples of commercial slurries for use in the polishing of semiconductor substrates include but are not limited to ILD1200 and ILD1300 available from Rodel, Inc.
  • the polishing pad of the present invention can be utilized with an apparatus for planarizing an article having a non-planar surface.
  • the planarizing apparatus can include a retaining means for holding the article; and a motive power means for moving the pad and the retaining means with respect to the other such that movement of the pad and the retaining means causes the slurry and the planarizing surface of the pad to contact and planarize the non-planar surface of the article.
  • the planarizing apparatus can include a means of renewing the polishing or planarizing surface of the pad.
  • a non-limiting example of a suitable renewing means includes a mechanical arm equipped with an abrasive disk which abrades the work surface of the pad.
  • the planarizing apparatus can include an apparatus for conducting in-situ metrology of the article being polished or planarized.
  • Commercial polishing or planarizing apparatuses are available from equipment manufacturers such as Applied Materials, LAM Research, SpeedFam-IPEC, and Ebara Corp.
  • the pad of the present invention can be placed on a cylindrical metal base; and can be connected to at least a portion of the base with a layer of adhesive. Suitable adhesives can include a wide variety of known adhesives.
  • the pad can be placed on the cylindrical metal base or platen of a polishing or planarizing apparatus that includes a means of conducting in-situ metrology of the article being polished. The pad can be placed such that its window can be aligned with the metrology window of the platen.
  • a first layer was prepared according to Recipe A described below.
  • a 2" 2" rectangular hole was cut into the first layer using a straight-edge and a scalpel-style utility knife.
  • a second layer was formed using High Performance Double Coated Tape 9500PC, commercially obtained from 3M Industrial Tape and Specialties
  • the adhesive layer of the tape was adhered to the bottom side of the first layer such that the rectangular opening in the first layer was substantially spanned by the tape.
  • a third layer was formed using a 0.060" thick sheet of polyurethane foam, having trade name PORON 4701-50, commercially obtained from Rogers
  • V ⁇ T rectangular hole was cut into the third layer using a straight-edge and a scalpel-style utility knife.
  • the third layer was adhered to the second layer by removing the release paper from the second layer and applying the third layer to the adhesive film thus exposed.
  • the third layer was positioned such that the rectangular openings in the first layer and the third layer were substantially aligned.
  • the three-layer stack assembly was then pressed together and passed through a calendar roll set.
  • a window was formed by removing a portion of the adhesive on the upper and lower sides of the second layer.
  • the adhesive was removed by contacting it with a V 2 "x2" rectangular piece of Teslin SP-1000, commercially available from PPG Industries, Incorporated, pressing the piece by hand to ensure good contact between the adhesive and the Teslin SP-1000, then peeling away the Teslin SP-1000.
  • the adhesive selectively adhered to the Teslin SP-1000, leaving the substantially clear film of the window free of adhesive.
  • the resulting pad stack had a rectangular window having a size of 1 /2"x2" .
  • Step 1 Particulate crosslinked polyurethane was prepared using the ingredients listed in
  • ARITHANE PHP-75D prepolymer obtained from Air Products and Chemicals, Inc, which describes it as the isocyanate functional reaction product of toluene diisocyanate and poly(tetramethylene glycol).
  • Charge 1 was added to an open container and warmed with stirring on a hot plate until the contents of the container reached a temperature of 35°C. Stirring was continued at this temperature until the ingredients formed a substantially homogeneous solution. The container was then removed from the hot plate.
  • Charge 2 was warmed to a temperature of 55°C using a water bath then added to Charge 1. The contents were mixed for a period of three (3) minutes with a motor driven impeller until uniform. The contents of the container were then quickly poured into 10 kilograms of deionized water at a temperature of 40°C, with concurrent vigorous stirring of the deionized water. Upon completion of the addition of the contents of the container, vigorous mixing of the deionized water was continued for an additional 60 minutes.
  • the wet particulate crosslinked polyurethane was classified using a stack of two sieves.
  • the top sieve had a mesh size of 50 mesh (300 micron sieve openings), and the bottom sieve had a mesh size of 140 mesh (105 micron sieve openings).
  • the isolated particulate crosslinked polyurethane from the 140 mesh was dried overnight in an oven at a temperature of 80°C.
  • a polishing pad comprising particulate crosslinked polyurethane and crosslinked polyurethane binder was prepared using the ingredients summarized in the following Table B.
  • the mold was fed through a pair of rollers at ambient temperature to form a sheet that was 0.100" thick.
  • the sheet was cured at a temperature of 25° C and 80% relative humidity for 18 hours, followed by a temperature of 130°C for 1 hour. Circular pads with a 22.5" diameter were cut from the sheet then the upper and lower surfaces of the pad were made parallel using a milling machine.
  • the resulting pad was used as the first layer in Example 1.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Manufacturing & Machinery (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Mechanical Treatment Of Semiconductor (AREA)
  • Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
  • Laminated Bodies (AREA)

Abstract

L'invention concerne un tampon de polissage comprenant une fenêtre. Ce tampon de polissage comporte une première couche et une seconde couche. La première couche, qui est pourvue d'une ouverture, peut servir de surface de travail ou de couche de polissage du tampon. Une partie au moins de la seconde couche comprend une fenêtre au moins partiellement transparente.
EP03759509A 2002-09-25 2003-09-18 Tampon de polissage avec fenetre pour planarisation Withdrawn EP1542832A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US41336702P 2002-09-25 2002-09-25
US413367P 2002-09-25
PCT/US2003/030139 WO2004028744A1 (fr) 2002-09-25 2003-09-18 Tampon de polissage avec fenetre pour planarisation

Publications (1)

Publication Number Publication Date
EP1542832A1 true EP1542832A1 (fr) 2005-06-22

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EP03759509A Withdrawn EP1542832A1 (fr) 2002-09-25 2003-09-18 Tampon de polissage avec fenetre pour planarisation

Country Status (8)

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US (1) US20040102141A1 (fr)
EP (1) EP1542832A1 (fr)
JP (2) JP2005538571A (fr)
KR (1) KR20050052513A (fr)
CN (1) CN100417493C (fr)
AU (1) AU2003275237A1 (fr)
TW (1) TWI287836B (fr)
WO (1) WO2004028744A1 (fr)

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Also Published As

Publication number Publication date
CN1684798A (zh) 2005-10-19
TW200522185A (en) 2005-07-01
WO2004028744A1 (fr) 2004-04-08
US20040102141A1 (en) 2004-05-27
KR20050052513A (ko) 2005-06-02
JP2008229843A (ja) 2008-10-02
JP2005538571A (ja) 2005-12-15
TWI287836B (en) 2007-10-01
CN100417493C (zh) 2008-09-10
AU2003275237A1 (en) 2004-04-19

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