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
  • B24B37/24—Lapping pads for working plane surfaces characterised by the composition or properties of the pad materials
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
  • B24D3/00—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents
  • B24D3/02—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent
  • B24D3/20—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent and being essentially organic
  • B24D3/28—Resins or natural or synthetic macromolecular compounds
  • B24D3/32—Resins or natural or synthetic macromolecular compounds for porous or cellular structure
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/30—Low-molecular-weight compounds
  • C08G18/36—Hydroxylated esters of higher fatty acids
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/65—Low-molecular-weight compounds having active hydrogen with high-molecular-weight compounds having active hydrogen
• • 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
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G2101/00—Manufacture of cellular products
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/249921—Web or sheet containing structurally defined element or component
  • Y10T428/249953—Composite having voids in a component [e.g., porous, cellular, etc.]

Definitions

• the present invention relates to optical materials such as lenses and reflecting mirrors, silicon wafers, glass substrates for hard disks, aluminum substrates, and materials that require high surface flatness such as general metal polishing.
• the present invention relates to a polishing pad that can be processed stably with high polishing efficiency.
• the polishing pad of the present invention is a process for planarizing a silicon wafer and a device having an oxide layer, a metal layer, etc. formed thereon, and further laminating these oxide layers and metal layers. Is preferably used.
• a typical material that requires a high degree of surface flatness is a single crystal silicon disk called a silicon wafer for manufacturing a semiconductor integrated circuit (IC, LSI).
• Silicon wafers have a high surface in each process of stacking and forming oxide layers and metal layers in order to form reliable semiconductor junctions of various thin films used for circuit formation in ic, LSI, and other manufacturing processes.
• a flat finish is required for accuracy.
• a polishing pad is generally fixed to a rotatable support disk called a platen, and a workpiece such as a semiconductor wafer is fixed to a polishing head.
• a polishing operation is performed by generating a relative speed between the platen and the polishing head by both operations, and further continuously supplying a polishing slurry containing the barrels onto the polishing pad.
• the polishing characteristics of the polishing pad are required to be excellent in flatness (planarity) and in-plane uniformity of the object to be polished, and to have a high polishing rate.
• the flatness and in-plane uniformity of the object to be polished can be improved to some extent by increasing the elasticity of the polishing layer. Also, polishing speed! On the other hand, it can be improved by increasing the amount of slurry retained by using a foam containing bubbles.
• Examples of a method for increasing the amount of slurry retained include a method for making the polishing pad itself hydrophilic.
• a method for introducing a hydrophilic group such as a hydroxyl group into a matrix material 2) A method of mixing a matrix material and a hydrophilic substance can be mentioned.
• rack A polishing pad composition containing a bridge elastomer and (B) a substance having a functional group such as a hydroxyl group is disclosed (Patent Document 1).
• a polishing tool in which a hydrophilic substance is further added to the material constituting the polishing tool or a hydrophilic group is added (modified) is disclosed (Patent Document 2).
• a polishing pad made of a thermosetting polymer matrix resin containing a sheet that is hydrophilic and substantially insoluble in water Patent Document 3
• a polishing pad made of a polyurethane composition containing a urethane rosin copolymerized with a compound having a hydrophilic group and containing a hydrophilic agent is disclosed (Patent Document 4).
• the matrix material is polyurethane
• a hydrophilic group containing active hydrogen such as a hydroxyl group reacts with an isocyanate group during the synthesis of the polyurethane, and as a result, an unreacted polyol component becomes a material. There is a risk of remaining inside. And since this residual polyol component brings about a plastic effect, the physical properties of the polishing pad tend to be lowered. Further, in the method (2), it is difficult to uniformly mix the hydrophilic substance into the matrix material, and it is impossible to obtain a polishing pad with uniform physical properties.
• polishing rate fluctuates immediately after use until the end of use, the polishing conditions must be adjusted, resulting in poor polishing efficiency.
• a non-foamed urethane polishing material that can efficiently polish a semiconductor wafer and is excellent in flatness, it comprises an isocyanate-terminated urethane prepolymer and an active hydrogen-containing compound, Polishing in which isocyanate-terminated urethane prepolymers use aromatic diisocyanates as polyisocyanates and low molecular polyol power in polyol components consisting of high molecular polyols and low molecular polyol powers such as diethylene glycol, 1,3-butylene glycol, etc.
• An abrasive comprising a material composition is disclosed (Patent Document 5).
• the abrasive described in Patent Document 5 has a non-foaming urethane force, and such a non-foamed abrasive has a low polishing rate, so that grooves are formed on the polished surface. It is very difficult to stabilize the polishing speed due to the presence of sand and polishing debris locally. is there.
• the polishing cloth described in Patent Document 6 is worn out and has a low hardness immediately (because the bubbles are not uniform and the bubble diameter is large), so that the flatness and in-plane uniformity are not sufficient and the polishing speed changes further. It is inevitable that will grow.
• the conventional polishing pad has a problem of center throw (a phenomenon in which the wafer central portion is difficult to be polished).
• Patent Document 1 Japanese Patent Application Laid-Open No. 2002-134445
• Patent Document 2 Japanese Patent Laid-Open No. 2003-11066
• Patent Document 3 Japanese Patent Laid-Open No. 2002-59358
• Patent Document 4 Japanese Unexamined Patent Publication No. 2003-128910
• Patent Document 6 JP 2001-277101 A
• An object of the present invention is to provide a polishing pad having a good polishing rate, no center throw, and excellent life characteristics. It is another object of the present invention to provide a method for manufacturing a semiconductor device using the polishing pad.
• the polishing pad of the present invention has a high molecular weight polyol component, which is a raw material component of the polyurethane resin foam, on a polishing pad having a polishing layer made of a polyurethane resin foam having fine bubbles.
• the polishing pad has a good polishing rate and excellent life characteristics. And it is characterized by solving the center throw problem.
• the reason why center throw occurs when a conventional polishing pad is used is as follows. Usually, the generated polishing debris is removed from the surface of the polishing pad in order to retain and renew the polishing slurry. The grooves are provided with fine holes to leave. Then, as the polishing operation is performed, the fine particles in the polishing slurry clog the fine holes in the polishing slurry. Therefore, it is necessary to grind the polishing pad surface by dressing and update it to a new surface.
• the present inventors have used a hydrophobic high molecular weight polyol A having a number average molecular weight of 550 to 800 (hereinafter also referred to as "polyol 8") as a high molecular weight polyol component which is a raw material component of a polyurethane resin foam.
• Each of the polyol ⁇ and the polyol ⁇ has a molecular weight peak value, and has at least two peak values when both polyol components are mixed.
• the number average molecular weight of the polyol A is 600 to 800.
• the number average molecular weight of polyol B is preferably 1000 to 1200! /.
• the polyurethane resin foam is preferably a reaction cured product of an isocyanate-terminated polymer comprising a high-molecular-weight polyol component and an isocyanate component, and a chain extender.
• the polyurethane resin foam includes an isocyanate-terminated polymer A containing polyol A and an isocyanate component, an isocyanate-terminated polymer B containing polyol B and an isocyanate component, and a chain extension. It is preferable to be a reaction-cured product with an agent! A polyurethane resin foam obtained by the prebolimer method is preferred because of its excellent polishing characteristics.
• Polyol A and polyol B are hydrophobic. As a result, when contacting the polishing pad surface force slurry, it is possible to suppress a decrease in surface hardness due to swelling or decomposition.
• polyol A and polyol B are polytetramethylene glycol from the viewpoint of hydrolysis resistance and excellent mechanical strength.
• the chain extender is preferably an aromatic diamine.
• aromatic diamine is preferably a non-halogen aromatic diamine in consideration of environmental aspects and the like.
• the polyurethane resin foam does not have a hydroxyl group! / ⁇
• Silicon-based surfactant is contained in an amount of 0.05% by weight or more and less than 5% by weight. Is more preferably 0.5 to 4% by weight.
• the amount of the silicone-based nonionic surfactant is less than 0.05% by weight, a foam having fine bubbles tends not to be obtained.
• the amount is 5% by weight or more, the number of bubbles in the foam becomes too large, and it is difficult to obtain a polyurethane resin foam having high hardness.
• the polyurethane resin foam preferably has a specific gravity of 0.7 to 0.88, more preferably 0.73 to 0.85.
• the specific gravity is less than 0.7, the surface hardness of the polishing layer is lowered, and the flatness of the material to be polished (WENO) tends to be lowered or the life characteristics tend to be deteriorated.
• WENO flatness of the material to be polished
• the specific gravity exceeds 0.88, the dressing waste when dressing becomes large, and if the dressing waste becomes a groove, it clogs the micropores, causing clogging, and a center throw is likely to occur.
• the polyurethane resin foam preferably has a Asker D hardness of 45 to 60 degrees, more preferably 50 to 55 degrees.
• Asker D hardness is less than 45 degrees, the flatness of the material to be polished decreases, and when it is greater than 60 degrees, the flatness is good, but the in-plane uniformity of the material to be polished tends to decrease. is there.
• the polyurethane resin foam preferably has a tensile strength of 15 to 25 MPa, more preferably 20 to 25 MPa.
• tensile strength is less than 15 MPa, the flatness characteristic of the polishing pad tends to deteriorate, and when it exceeds 25 MPa, scratches tend to occur on the surface of the material to be polished.
• the polyurethane resin foam preferably has a tensile elongation at break of 50 to 150%, more preferably 80 to 130%. If the tensile elongation at break is less than 50%, the surface wear becomes larger than necessary and the life of the polishing pad is shortened, and the fuzz on the surface of the polishing layer after dressing is removed immediately during wafer polishing; The speed tends to decrease. On the other hand, when it exceeds 150%, the “stickiness” of the polyurethane resin becomes too large, and the polishing dust becomes large, and clogging is likely to occur.
• the dressing speed of the polishing pad of the present invention is preferably 6 to 17 ⁇ mZmin, more preferably 6 to 10 ⁇ mZmin from the viewpoint of life characteristics and prevention of clogging.
• the present invention relates to a semiconductor device manufacturing method including a step of polishing a surface of a semiconductor wafer using the polishing pad.
• FIG. 1 is a schematic configuration diagram showing an example of a polishing apparatus used in CMP polishing.
• the polishing pad of the present invention has a polishing layer having the strength of polyurethane resin foam having fine bubbles.
• the polishing pad of the present invention may be a laminated body of a polishing layer and other layers (for example, a cushion layer, etc.), which may be only the polishing layer.
• the polyurethane resin foam has at least an isocyanate component and a high molecular weight polyol component as raw material components, and the high molecular weight polyol component includes a hydrophobic high molecular weight polyol A having a number average molecular weight of 550 to 800 and a number average molecular weight. Contains 950 to 1300 hydrophobic high molecular weight polyol B.
• the polyol A is not particularly limited as long as it has a number average molecular weight of 550 to 800 and does not contain a hydrophilic group other than a hydroxyl group that reacts with an isocyanate group.
• Polyol B does not contain any hydrophilic group other than a hydroxyl group that reacts with an isocyanate group and is not particularly limited as long as it is a polyol having a number average molecular weight of 950 to 1300.
• Hydrophilic groups other than hydroxyl groups are generally functional groups and salts containing elements such as oxygen, nitrogen, and sulfur.
• -NH, -CONH, -NHCONH, -SH, -SOH, —OS Functional groups such as OH, — (CH 2 CH 0) n—, —COOH, —SO M (M: alkali metal)
• polyol A and polyol B examples include hydroxy-terminated polyester polyol, polycarbonate polyol, polyester polyol polycarbonate polyol, polyether polyol, polyether polycarbonate polyol, polyester amide, phenol resin polyol, epoxy polyol, and polybutadiene polyol. And polyisoprene polyol.
• polyester polyol examples include polypropylene adipate, polybutylene adipate, polyhexamethylene adipate, and poly-strength prolataton polyol.
• polyether polyol examples include polyhexamethylene glycol (PHMG), polytetramethylene glycol (PTMG), and polypropylene glycol (PPG).
• PHMG polyhexamethylene glycol
• PTMG polytetramethylene glycol
• PPG polypropylene glycol
• polyether polycarbonate polyol examples include diols such as 1,3 propanediol, 1,4 butanediol, 1,6 hexanediol, polypropylene glycol and Z or polytetramethylene glycol, phosgene, and diallyl carbonate. (Eg diphenol carbonate) or cyclic carbonate (eg propylene carbonate)
• polyester polycarbonate polyol examples include a reaction product of a polyester glycol such as poly force prolatatone polyol and an alkylene carbonate, an ethylene carbonate reacted with a polyhydric alcohol, and the reaction mixture obtained in the following is an organic dicarboxylic acid. Examples of the product obtained by reacting with an acid are shown.
• the polyol A may be one kind of the above polyol or a combination of two or more kinds.
• the polyol B may be one kind of the above polyol or a combination of two or more kinds.
• the high-molecular-weight polyol component is preferably only polyol A and polyol B.
• the high-molecular-weight polyol component usually contains a polyol component other than the above, which is usually used as a polyol-based compound.
• the isocyanate component a compound known in the field of polyurethane can be used without particular limitation.
• the isocyanate component includes 2,4 toluene diisocyanate, 2,6 toluene diisocyanate, 2,2'-dimethanemethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-di-methanemethane diisocyanate, 1,5-naphthalene diisocyanate, p-phenylene diisocyanate, m-phenylene diisocyanate, p-xylylene diisocyanate, m-xylylene Aromatic diisocyanates such as range isocyanate, ethylene diisocyanate, aliphatic diisocyanates such as 2,2,4 trimethylhexamethylene diisocyanate, 1,6 hexamethylene diisocyanate, 1, 4-cyclohexane diisocyanate, 4,4'-dic
• the isocyanate component in addition to the above diisocyanate compound, a polyfunctional polyisocyanate compound having three or more functions can be used.
• a polyfunctional polyisocyanate compound having three or more functions.
• the multifunctional isocyanate compound a series of diisocyanate duct compounds are commercially available as Desmodur N (manufactured by Bayer) and trade name Deuranate (manufactured by Asahi Kasei Kogyo).
• low molecular weight poly All components and low molecular weight polyamine components may be used alone or in combination of two or more.
• the blending amount of the low molecular weight polyol component or the low molecular weight polyamine component is not particularly limited, and is appropriately determined depending on the properties required for the polishing pad (polishing layer) to be produced.
• the molecular weight of the low molecular weight polyol component or the low molecular weight polyamine component is less than 500, preferably 250 or less.
• a chain extender is used for curing the prepolymer.
• the chain extender is an organic compound having at least two or more active hydrogen groups, and examples of the active hydrogen group include a hydroxyl group, a primary or secondary amino group, and a thiol group (SH).
• non-halogen aromatic diamines such as 3,5 bis (methylthio) 2,4 toluene diamine and 3,5 bis (methylthio) 2,6 toluene diamine.
• the ratio of the isocyanate component, the polyol component, and the chain extender in the present invention can be variously changed depending on the molecular weight of each, the desired physical properties of the polishing pad, and the like.
• the number of isocyanate groups in the isocyanate component relative to the total number of active hydrogen groups (hydroxyl groups + amino groups) of the polyol component and the chain extender is 0.80 ⁇ : L 20 More preferably, it is 0.99 ⁇ : L15.
• the number of isocyanate groups is less than 0.80, the required hardness tends not to be obtained. Meanwhile, 1.20 over In such a case, it is not preferable because poor curing due to unreacted isocyanate occurs and the polishing characteristics tend to deteriorate.
• Polyurethane resin foam can be manufactured by applying a known urethane resin technology such as a melting method or a solution method. However, in consideration of cost, working environment, etc., it can be manufactured by a melting method. preferable.
• Polyurethane resin foam can be produced by either the pre-polymer method or the one-shot method. Isocyanate component and polyol component strength In advance, an isocyanate-terminated prepolymer is synthesized and then reacted with a chain extender. The resulting polyurethane has excellent physical properties and is suitable.
• an isocyanate-terminated prepolymer having a molecular weight of about 800 to 5,000 is preferable because of its excellent processability and physical properties.
• the polyurethane resin foam is produced by mixing and curing a first component containing an isocyanate group-containing compound and a second component containing an active hydrogen group-containing compound.
• the isocyanate-terminated prepolymer force S isocyanate group-containing compound is obtained, and the chain extender is an active hydrogen group-containing compound.
• an isocyanate component strength, a sulfonate group-containing compound is obtained, and a chain extender and a polyol component are active hydrogen group-containing compounds.
• Examples of the method for producing a polyurethane resin foam include a method of adding hollow beads, a mechanical foaming method, and a chemical foaming method.
• a mechanical foaming method using a silicone-based surfactant which is a copolymer of polyalkylsiloxane and polyether and does not have an active hydrogen group is preferred.
• a silicon-based surfactant L5340 (manufactured by Nippon Yuka), SH-192 (manufactured by Toray Dowco-Nungsilicon) and the like are exemplified as suitable compounds.
• stabilizers such as antioxidants, lubricants, pigments, fillers, antistatic agents, and other additives may be included!
• a chain extender (second component) is added to the above cell dispersion, mixed and stirred to obtain a foaming reaction solution.
• the foaming reaction liquid is poured into a mold.
• the foaming reaction liquid poured into the mold is heated and reacted and cured.
• the non-reactive gas used to form the fine bubbles is preferably a non-flammable gas. Specifically, nitrogen, oxygen, carbon dioxide gas, rare gases such as helium and argon, and these A mixed gas is exemplified, and the use of air that has been dried to remove moisture is most preferable in terms of cost.
• a stirrer for dispersing non-reactive gas in the form of fine bubbles and dispersing in the first component containing the silicon-based surfactant a known stirrer can be used without particular limitation, and specifically, a homogenizer. Examples include dissolvers, two-axis planetary mixers (planetary mixers), etc.
• the shape of the stirring blade of the stirring device is not particularly limited, but it is preferable that fine bubbles are obtained by using a Whisper type stirring blade.
• the stirring in the mixing step is preferably an agitator that does not introduce large bubbles, even if it does not form bubbles.
• a stirring device a planetary mixer is preferable. It is also suitable to adjust the stirring conditions, such as adjusting the rotation speed of the stirring blades as necessary, even if the same stirring device is used as the stirring device for the foaming step and the mixing step.
• a known catalyst that promotes a polyurethane reaction such as tertiary amine can be used.
• the type and amount of catalyst to be selected are selected in consideration of the flow time for pouring into a predetermined mold after the mixing step.
• the polyurethane resin foam is manufactured by a batch method in which each component is weighed and put into a container and stirred, or each component and a non-reactive gas are continuously supplied to the stirring device. It may be a continuous production method in which a foamed dispersion is sent out to produce a molded product.
• the polymer used as a raw material for the polyurethane resin foam is put into a reaction vessel, and then a chain extender is added and stirred, and then poured into a casting mold of a predetermined size to prepare a block.
• a thin sheet may be formed by a method of slicing using a slicer or a band saw slicer, or in the casting step described above.
• the raw resin may be dissolved and extruded from a T-die, directly to obtain a sheet-like polyurethane resin foam.
• the average cell diameter of the polyurethane resin foam is preferably 70 ⁇ m or less, more preferably 30 to 60 / ⁇ ⁇ .
• the planarity (flatness) of the polished material after polishing tends to decrease.
• the polishing surface of the polishing pad (polishing layer) of the present invention that is in contact with the material to be polished preferably has a surface shape that holds and renews the slurry.
• the polishing layer which also has foam strength, has many openings on the polishing surface, and has the function of holding and renewing the slurry.
• the polished surface has an uneven structure.
• the concavo-convex structure is not particularly limited as long as it is a shape that holds and renews slurry.
• ⁇ ⁇ groove, concentric groove, through hole, non-through hole, polygonal column, cylinder, spiral groove examples include eccentric circular grooves, radial grooves, and combinations of these grooves.
• the concavo-convex structure is generally regular, but it is also possible to change the groove pitch, groove width, groove depth, etc. for each range to make the slurry retention and renewability desirable. .
• the method for producing the concavo-convex structure is not particularly limited.
• a mechanical cutting method using a jig such as a tool of a predetermined size, a resin is applied to a mold having a predetermined surface shape.
• a method of producing by pouring and curing, a method of producing a resin by pressing a resin with a press plate having a predetermined surface shape, a method of producing using photolithography, a method of producing using a printing method, carbonic acid For example, a production method using a laser beam using a gas laser or the like.
• the thickness variation of the polishing layer is preferably 100 m or less.
• the polishing layer has a large undulation, and there are parts with different contact conditions with the material to be polished, which adversely affects the polishing characteristics.
• the ability to dress the surface of the polishing layer using a dresser in which diamond barrels are electrodeposited and fused in the initial stage of polishing exceeds the above range. As a result, the dressing time becomes longer and the production efficiency is lowered.
• Examples of a method for suppressing the variation in the thickness of the polishing layer include a method of puffing the surface of the polishing sheet sliced to a predetermined thickness. Further, when puffing, it is preferable to carry out stepwise with abrasives having different particle sizes.
• the polishing pad of the present invention may be one in which the polishing layer and a cushion sheet are bonded together.
• the cushion sheet (cushion layer) supplements the characteristics of the polishing layer.
• Cushion sheets are necessary in order to achieve both trade-off planarity and formality in CMP.
• Planarity refers to the flatness of the pattern portion when a material having fine irregularities generated during pattern formation is polished, and the uniformity refers to the uniformity of the entire material to be polished.
• the planarity is improved by the characteristics of the polishing layer, and the formality is improved by the characteristics of the cushion sheet.
• the cushion sheet is preferably softer than the polishing layer.
• the cushion sheet examples include polyester non-woven fabric, nylon non-woven fabric, and atari.
• Non-woven fabrics such as polyester nonwoven fabrics impregnated with polyurethane, polymer-impregnated foams such as polyurethane foam and polyethylene foam, rubber-based resins such as butadiene rubber and isoprene rubber, photosensitive resins Such as fat
• Examples of means for bonding the polishing layer and the cushion sheet include a method in which the polishing layer and the cushion sheet are sandwiched and pressed with a double-sided tape.
• the double-sided tape has a general configuration in which adhesive layers are provided on both sides of a substrate such as a nonwoven fabric or a film. In consideration of preventing the slurry from penetrating into the cushion sheet, it is preferable to use a film for the substrate.
• the composition of the adhesive layer include rubber adhesives and acrylic adhesives. Considering the content of metal ions, an acrylic adhesive is preferable because the metal ion content is low. Further, since the composition of the polishing layer and the cushion sheet may be different, the composition of each adhesive layer of the double-sided tape can be made different so that the adhesive force of each layer can be optimized.
• the polishing pad of the present invention may be provided with a double-sided tape on the surface to be bonded to the platen.
• a double-sided tape one having a general structure in which an adhesive layer is provided on both sides of a base material can be used as described above.
• the substrate include a nonwoven fabric and a film. In consideration of peeling from the platen after use of the polishing pad, it is preferable to use a film for the substrate.
• the composition of the adhesive layer include rubber adhesives and acrylic adhesives. Considering the metal ion content, the acrylic adhesive is preferable because the metal ion content is low.
• the semiconductor device is manufactured through a step of polishing the surface of the semiconductor wafer using the polishing pad.
• a semiconductor wafer is generally a laminate of a wiring metal and an oxide film on a silicon wafer.
• the method and apparatus for polishing a semiconductor wafer are not particularly limited.
• a polishing surface plate 2 that supports a polishing pad (polishing layer) 1 and a support table that supports a semiconductor wafer 4 (polishing). Head) 5 and a polishing material equipped with a backing material for uniformly pressing the wafer and a polishing agent 3 supply mechanism.
• the polishing pad 1 is attached to the polishing surface plate 2 by pasting with a double-sided tape, for example.
• the polishing surface plate 2 and the support table 5 face each other with the polishing pad 1 and the semiconductor wafer 4 supported on each of them. Are arranged in such a manner as to have rotating shafts 6 and 7, respectively. Further, a pressurizing mechanism for pressing the semiconductor wafer 4 against the polishing pad 1 is provided on the support base 5 side. During polishing, the semiconductor wafer 4 is pressed against the polishing pad 1 while rotating the polishing surface plate 2 and the support base 5, and polishing is performed while supplying slurry.
• the flow rate of the slurry, polishing load, polishing platen rotation speed, and wafer rotation speed are not particularly limited, and are adjusted as appropriate.
• semiconductor devices are manufactured by dicing, bonding, knocking, and the like.
• the semiconductor device is used for an arithmetic processing device, a memory, and the like.
• the number average molecular weight of the polyol component was measured by GPC (gel “permeation” chromatography) and converted by standard polystyrene.
• the polyurethane foam resin foam produced is cut into a 4cm x 8.5cm strip (thickness: optional) as a sample for measuring specific gravity in an environment with a temperature of 23 ° C ⁇ 2 ° C and humidity of 50% ⁇ 5%. It was left for 16 hours. The specific gravity was measured using a hydrometer (manufactured by Sartorius). [0082] (Measurement of hardness)
• the produced polyurethane resin foam was punched in the shape of dumbbell No. 3 in accordance with JIS K7312-1996 to obtain a sample.
• the sample was trained for 24 hours under conditions of 22 ° C and 66% RH, and then a tensile test was performed. Tensile break elongation and tensile strength were measured.
• An Instron universal tester (type 4300, manufactured by Instron) was used as the tensile tester, and the software used was a video extensometer controlled by Series IX.
• the surface of the prepared polishing pad was uniformly dressed while being rotated using a diamond dresser (Asahi Diamond Co., Ltd., M type # 100, 20cm ⁇ circle).
• the dresser load at this time was 450 gZcm 2
• the polishing platen rotation speed was 30 rpm
• the dresser rotation speed was 15 rpm
• the dressing time was lOOmin.
• the dressing speed was calculated from the thickness of the polishing pad before and after the dressing.
• polishing characteristics were evaluated using the prepared polishing pad.
• the polishing rate was calculated from the time obtained by polishing 0.5 ⁇ m of a 1- ⁇ m thermal oxide film on an 8-inch silicon wafer.
• Table 2 shows the polishing rates for the 10th, 50th, 100th, 300th and 500th wafers.
• An interferometric film thickness measuring device (manufactured by Otsuka Electronics Co., Ltd.) was used for measuring the thickness of the oxide film.
• silica slurry SS12 Cabot
• the polishing load was 350 gZcm 2
• the polishing platen rotation speed was 35 rpm
• the wafer rotation speed was 30 rpm.
• In-plane uniformity is Using a 1- ⁇ m thick thermal oxide film deposited on an 8-inch silicon wafer, perform polishing for 2 minutes under the above polishing conditions. As shown in Fig. 2, the film before and after polishing at 25 specific positions on the wafer The maximum polishing rate and the minimum polishing rate were determined from the measured thickness, and the values were substituted into the following formula. In-plane uniformity is shown in Table 2 for the 10th, 50th, 100th, 300th and 500th sheets of Ueno. The smaller the in-plane uniformity value, the higher the uniformity of the wafer surface.
• In-plane uniformity (%) ⁇ (Maximum polishing rate, Minimum polishing rate) / (Maximum polishing rate + Minimum polishing rate) ⁇ X 100
• PTMG polytetramethylene glycol
• DEG diethylene glycol
• PTMG650 ZPTMG1000 35Z65 (weight ratio).
• a foam sheet is cut out using this polyurethane resin foam blocking force slicer, a concentric groove process is performed to produce a polishing layer, and a commercially available non-woven fabric is impregnated with polyurethane on the back.
• a polishing pad was prepared by laminating materials (cushion layers).
• Example 1 instead of MOCA28.7 parts by weight, Etacure 300 (Albemarle, 3,5 bis (methylthio) 2,6 toluenediamine and 3,5 bis (methylthio) -Mixture with 2,4-toluenediamine) 25.
• a polishing pad was prepared in the same manner as in Example 1 except that 2 parts by weight were used.
• the container was mixed with 100 parts by weight of the isocyanate-terminated prepolymer (G) and 6 parts by weight of silicone surfactant L5340 (4.6% by weight in polyurethane resin), and adjusted to 60 ° C. To this, 25.5 parts by weight of MOCA previously melted at 120 ° C. was added while stirring vigorously so as to take in bubbles. After stirring for about 1 minute, the mixed solution was put into a pan-shaped open mold, and post-cured in an oven at 100 ° C for 16 hours to obtain a polyurethane resin foam block. Thereafter, a polishing pad was produced in the same manner as in Example 1.
• the polishing pad of the present invention can effectively eliminate clogging by dressing, and therefore can suppress the occurrence of center throw. Further, since the surface wear of the polishing layer is moderate, the polishing speed is not deteriorated because the life characteristics of the polishing pad are good. On the other hand, since the polishing pad of Comparative Example 1 is difficult to dress, clogging cannot be sufficiently removed. As a result, center throw occurs and the polishing rate gradually decreases. Since the polishing pad of Comparative Example 2 is easily dressed, the groove depth becomes insufficient when 500 wafers are polished, a center throw occurs, and the polishing rate decreases remarkably. Since the polishing pad of Comparative Example 3 is difficult to dress, clogging cannot be removed sufficiently.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Mechanical Engineering (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Medicinal Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Health & Medical Sciences (AREA)
• Power Engineering (AREA)
• General Physics & Mathematics (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Computer Hardware Design (AREA)
• Physics & Mathematics (AREA)
• Manufacturing & Machinery (AREA)
• Condensed Matter Physics & Semiconductors (AREA)
• Mechanical Treatment Of Semiconductor (AREA)
• Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
• Polyurethanes Or Polyureas (AREA)
• Manufacture Of Macromolecular Shaped Articles (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=37808668

Family Applications (1)

Country Status (6)

Cited By (1)

Families Citing this family (20)

Citations (4)

Family Cites Families (74)

• 2005
  • 2005-08-30 JP JP2005249046A patent/JP4884725B2/ja not_active Expired - Fee Related
• 2006
  • 2006-07-27 TW TW095127529A patent/TW200709896A/zh not_active IP Right Cessation
  • 2006-08-22 WO PCT/JP2006/316372 patent/WO2007026569A1/ja not_active Ceased
  • 2006-08-22 US US12/065,219 patent/US8309466B2/en active Active
  • 2006-08-22 CN CN2006800321010A patent/CN101253022B/zh not_active Expired - Fee Related
  • 2006-08-22 KR KR1020087004863A patent/KR100949561B1/ko not_active Expired - Fee Related

Patent Citations (4)

Also Published As

Similar Documents

Legal Events