Classifications

• • 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
• • 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
  • B24B37/24—Lapping pads for working plane surfaces characterised by the composition or properties of the pad materials
  • B24B37/245—Pads with fixed abrasives
• • 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
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
  • B24D18/00—Manufacture of grinding tools or other grinding devices, e.g. wheels, not otherwise provided for

Definitions

• the present disclosure broadly relates to abrasive articles, methods of their manufacture, and their use in wafer planarization.
• BACKGROUND Abrasive articles are frequently used in micro finishing applications such as semiconductor wafer polishing, microelectromechanical (MEMS) device fabrication, finishing of substrates for hard disk drives, polishing of optical fibers and connectors, and the like.
• semiconductor wafers typically undergo numerous processing steps including deposition of metal and dielectric layers, patterning of the layers, and etching. In each processing step, it may be necessary or desirable to modify or refine an exposed surface of the wafer to prepare it for subsequent fabrication or manufacturing steps.
• the surface modification process is often used to modify deposited conductors (for example, metals, semiconductors, and/or dielectric materials).
• the surface modification process is also typically used to create a planar outer exposed surface on a wafer having an exposed area of a conductive material, a dielectric material, or a combination.
• One method of modifying or refining exposed surfaces of structured wafers treats a wafer surface with a fixed abrasive article.
• the fixed abrasive article is typically contacted with a semiconductor wafer surface, often in the presence of a working fluid, with a motion adapted to modify a layer of material on the wafer and provide a planar, uniform wafer surface.
• the working fluid may be applied to the surface of the wafer to chemically modify or otherwise facilitate the removal of material from the surface of the wafer under the action of the abrasive article.
• Fixed abrasive articles generally have an abrasive layer of abrasive particles bonded together by a binder and secured to a backing.
• the abrasive layer is composed of discrete raised structural elements (for example, posts, ridges, pyramids, or truncated pyramids) termed shaped abrasive composites.
• This type of fixed abrasive article is known in the art variously by the terms "textured, fixed abrasive article” or "structured abrasive article” (this latter term shall be used hereinafter). In order to assess progress during the planarization process it is common practice to use various detection methods.
• Optical detection methods are among the most widely used.
• a laser is typically directed through windows in a platen and a subpad in contact with the structured abrasive article.
• a hole or transparent (uncoated with abrasive layer) portion of the structured abrasive article is aligned with the beam.
• the present disclosure provides a structured abrasive article comprising: an at least translucent film backing; and an abrasive layer disposed on the at least translucent film backing and comprising a plurality of shaped abrasive composites, wherein the shaped abrasive composites comprise abrasive particles dispersed in a binder, wherein the abrasive particles consist essentially of ceria particles having an average primary particle size of less than 100 nanometers, wherein the binder comprises a polyether acid and a reaction product of components comprising a carboxylic (meth)acrylate and a poly(meth)acrylate, and wherein, based on a total weight of the abrasive layer, the abrasive particles are present in an amount of at least 70 percent by weight.
• the average particle size is also less than 100 nanometers.
• the structured abrasive article if viewed perpendicular to the abrasive layer, has an optical transmission in a wavelength range of from 633 to 660 nanometers (for example, 633 nanometers) of at least 3.5 percent.
• the shaped abrasive composites consist essentially of posts lengthwise oriented perpendicular to the at least translucent film backing.
• the present disclosure provides a method of making a structured abrasive article, the method comprising: combining ceria particles, a polyether acid, a carboxylic (meth)acrylate, and solvent to form a dispersion, wherein the ceria particles have an average primary particle size of less than 100 nanometers; combining the dispersion with components comprising a poly(meth)acrylate to form a binder precursor; forming a layer of the binder precursor on an at least translucent film backing; contacting the binder precursor with a production tool having a plurality of precisely-shaped cavities; curing the binder precursor to form an abrasive layer disposed on the at least translucent film backing; separating the abrasive layer from the production tool to provide the structured abrasive article, wherein based on a total weight of the abrasive layer, the
• the carboxylic (meth)acrylate comprises beta- carboxyethyl acrylate.
• the components further comprise a mono(meth)acrylate.
• the components further comprise a free- radical photoinitiator, and curing the binder precursor is achieved by radiation curing.
• the components further comprise a free-radical thermal initiator.
• the method of making a structured abrasive article further comprises thermally post-curing the abrasive layer.
• the present disclosure provides a method of conditioning an oxide surface of a wafer, the method comprising: providing a structured abrasive article comprising: an at least translucent film backing; and an abrasive layer disposed on the at least translucent film backing and comprising a plurality of shaped abrasive composites, wherein the shaped abrasive composites comprise abrasive particles dispersed in a binder, wherein the abrasive particles consist essentially of ceria particles having an average primary particle size of less than 100 nanometers, wherein the binder comprises a polyether acid and a reaction product of components comprising a carboxylic (meth)acrylate and a poly(meth)acrylate, and wherein based on a total weight of the abrasive layer, the abrasive particles are present in an amount of at least 70 percent by weight; conditioning the abrasive layer; contacting the at least translucent film backing with a subpad, the subpad having a first window extending
• the visible light beam comprises a laser beam.
• Addition of ceria to slurries used in manufacture of prior structured abrasive articles is generally limited due to pronounced increase in shear viscosity of the slurry with increasing ceria content.
• Such surfactants can be detrimental to performance of the structured abrasive article in chemical mechanical planarization (that is, CMP) processes.
• structured abrasive articles made according to methods of the present disclosure typically exhibit low shear increase in viscosity, thereby permitting the incorporation of high levels of ceria.
• surfactant is typically not required to achieve a good quality ceria dispersion.
• problems encountered with shortened pot-life for example, premature initiation of polymerization of the poly(meth)acrylate by the ceria mineral
• problems encountered with shortened pot-life for example, premature initiation of polymerization of the poly(meth)acrylate by the ceria mineral
• structured abrasive articles according to the present disclosure can be fabricated with sufficient optical transmittance and clarity across the entire surface of the structured abrasive article that it is possible to use optical endpoint detection (for example, laser interferometry endpoint detection) during wafer planarization without needing to provide windows or perforations in the structured abrasive article to allow passage of the laser beam therethrough.
• optical endpoint detection for example, laser interferometry endpoint detection
• Fig. 2 is a schematic side view of an exemplary method of conditioning a surface of a wafer according to the present disclosure
• Figs. 3-5 show silicon wafer polishing performance of exemplary structured abrasives according to the present disclosure
• Figs. 6-8 are photographs showing various structured abrasive articles in contact with a piece of paper having lettering thereon.
• the at least translucent film backing may be flexible, rigid, or in between.
• backing materials are suitable for this purpose, including both flexible backings and backings that are more rigid.
• Useful at least translucent film backings include backing films selected from polymer films, treated versions thereof, and combinations thereof.
• Exemplary at least translucent backing films include films made from polyester (for example, polyethylene terephthalate or polycaprolactone), co-polyester, polycarbonate, polyimide, polyamide, polypropylene, polyethylene, cellulosic polymers, and blends and combinations thereof.
• the ceria particles may have an average particle size, on a volume basis, in a range of from 1, 5, 10, 20, 30, or 40 nanometers up to 50, 60, 70, 80, 90, 95 nanometers, or more.
• Individual shaped abrasive composites may have the form of any of a variety of geometric solids or be irregularly shaped.
• the shaped abrasive composites are precisely-shaped (as defined above).
• the shaped abrasive composite is formed such that the base of the shaped abrasive composite, for example, that portion of the shaped abrasive composite is in contact with, and secured to, the at least translucent film backing.
• the proximal portion of the shaped abrasive composite typically has the same or larger a larger surface area than that portion of the shaped abrasive composite distal from the base or backing.
• the linear spacing of the shaped abrasive composites may range from about 1 shaped abrasive composite per linear cm to about 200 shaped abrasive composites per linear cm.
• the linear spacing may be varied such that the concentration of composites may be greater in one location than in another. For example, the concentration may be greatest in the center of the abrasive article.
• the areal density of the composite may range, in some embodiments, from about 1 to about 40,000 composites per square centimeter.
• One or more areas of the backing may be exposed, that is, have no abrasive coating contacting the at least translucent film backing.
• the shaped abrasive composites may be set out in a "random" array or pattern.
• the composites are not in a regular array of rows and columns as described above.
• the shaped abrasive composites may be set out in a manner as described in PCT Publications WO 95/07797 (Hoopman et al.) and WO 95/22436 (Hoopman et al.). It will be understood, however, that this "random" array may be a predetermined pattern in that the location of the composites on the abrasive article may be predetermined and corresponds to the location of the cavities in the production tool used to make the abrasive article.
• Structured abrasive articles according to the present disclosure may be generally circular in shape, for example, in the form of an abrasive disc. Outer edges of the abrasive disc are typically smooth, or may be scalloped.
• the structured abrasive articles may also be in the form of an oval or of any polygonal shape such as triangular, square, rectangular, and the like.
• the abrasive articles may be in the form of a belt.
• the abrasive articles may be provided in the form of a roll, typically referred to in the abrasive art as abrasive tape rolls. In general, the abrasive tape rolls may be indexed or moved continuously during the wafer planarization process.
• the subpad, and any platen on which it rests should have at least one appropriately sized window (for example, an opening or transparent insert) to permit a continuous optical path from a light source (for example, a laser) through the platen and subpad.
• a light source for example, a laser
• Wafer holder 233 extends alongside of wafer 240 at ring portion 233 a. Ring portion 233 a (which is optional) may be a separate piece or may be integral with wafer holder 233.
• Wafer 240 is brought into contact with the abrasive layer 120 of structured abrasive article 100, and the wafer 240 and abrasive layer 120 are moved relative to one another.
• the progress of polishing/abrading is monitored using laser beam 250 which passes through second window 222, first window 212, and structured abrasive article 100 and is reflected off oxide surface 242 wafer 240 and then retraces its path.
• Optional working fluid 260 may be used to facilitate the abrading process.
• Rt is typically measured using a laser interferometer such as a Wyko RST PLUS interferometer (Wyko Corp., Arlington, AZ), or a Tencor prof ⁇ lometer (KLA-Tencor Corp., San Jose, CA). Scratch detection may also be measured by dark field microscopy. Scratch depths may be measured by atomic force microscopy.
• a laser interferometer such as a Wyko RST PLUS interferometer (Wyko Corp., Arlington, AZ), or a Tencor prof ⁇ lometer (KLA-Tencor Corp., San Jose, CA).
• Wafer surface processing may be conducted in the presence of a working fluid, which may be selected based upon the composition of the wafer surface.
• the working fluid typically comprises water.
• the working fluid may aid processing in combination with the abrasive article through a chemical mechanical polishing process. During the chemical portion of polishing, the working fluid may react with the outer or exposed wafer surface. Then during the mechanical portion of processing, the abrasive article may remove this reaction product.
• the slurry was cooled to room temperature, and then 0.46 gram of free-radical photoinitiator (phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, available as IRGACURE 819 from Ciba Specialty Chemicals of Tarrytown, NY), 0.15 gram of thermal free-radical initiator (2,2'-azobis(2,4-dimethylvaleronitrile, available as VAZO 52 from E.
• free-radical photoinitiator phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, available as IRGACURE 819 from Ciba Specialty Chemicals of Tarrytown, NY
• thermal free-radical initiator 2,2'-azobis(2,4-dimethylvaleronitrile, available as VAZO 52 from E.
• SLURRY 1 was coated between the cavities of production tool and roll of translucent polycarbonate/PBT based film backing material (7 mils (0.18 mm) thickness available as BAYFOL CR6-2 from Bayer Corp., Pittsburgh, PA) using a casting roll and a nip roll (nip force of 600 pounds (136 kg) 16.7 pounds per lineal inch (2.99 kg per lineal cm)) and then passed through an ultraviolet light (UV) source (V Bulb, Model EPIQ available from Fusion Systems), at a line speed of 10 feet/inch (3.0 m) and a total exposure of 6000 watts/inch (2.36 kJ/hr-cm).
• UV ultraviolet light
• the resultant structured abrasive article (SAl) was removed from the production tool after being UV cured.
• Example 1 was repeated, except that Abrasive Slurry 1 was replaced by Abrasive Slurry 2, resulting in structured abrasive article SA2.
• Example 2 was repeated, except that before polishing the thermal oxide blanket wafers SA2 was first conditioned in situ using a pad conditioner (available as CMP - 20000TS from Morgan Advanced Ceramics of Allentown, PA) for 60 seconds, at a platen speed of 30 rpm, 5 sweep/min, from 2.75 to 12.50 inch across the web, and a working fluid (deionized water containing 2.5 weight percent L-proline adjusted to a pH of 10.5 with potassium hydroxide) flow rate of 100 milliliters per minute.
• a pad conditioner available as CMP - 20000TS from Morgan Advanced Ceramics of Allentown, PA
• a working fluid deionized water containing 2.5 weight percent L-proline adjusted to a pH of 10.5 with potassium hydroxide

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Physics & Mathematics (AREA)
• Condensed Matter Physics & Semiconductors (AREA)
• General Physics & Mathematics (AREA)
• Computer Hardware Design (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Power Engineering (AREA)
• Polishing Bodies And Polishing Tools (AREA)
• Mechanical Treatment Of Semiconductor (AREA)
• Grinding-Machine Dressing And Accessory Apparatuses (AREA)

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• 2009
  • 2009-07-30 KR KR1020117006536A patent/KR101602001B1/ko not_active Expired - Fee Related
  • 2009-07-30 WO PCT/US2009/052188 patent/WO2010025003A2/en not_active Ceased
  • 2009-07-30 CN CN200980134338.3A patent/CN102138203B/zh not_active Expired - Fee Related
  • 2009-07-30 EP EP09810426.8A patent/EP2327088B1/en not_active Not-in-force
  • 2009-07-30 JP JP2011525047A patent/JP5351967B2/ja not_active Expired - Fee Related
  • 2009-08-11 TW TW098126988A patent/TWI429735B/zh not_active IP Right Cessation
  • 2009-08-12 US US12/539,798 patent/US8251774B2/en not_active Expired - Fee Related

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