JP2016128205A - Method for the production of chemical mechanical polishing pad - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an improved method for producing a low-defect chemical mechanical polishing pad having polishing layers, using an automated test method with an increased polishing layer defect identification capability.SOLUTION: There is provided a method for the production of a chemical mechanical polishing pad 110, in which an automated test system is configured to detect macro-inhomogeneity in cut sheets and classify the cut sheets as either acceptable or suspect, where the acceptable cut sheets are further processed to form polishing layers 120 of the chemical mechanical polishing pad.SELECTED DRAWING: Figure 3

Description

  The present invention relates generally to the field of manufacturing chemical mechanical polishing pads. In particular, the present invention relates to a method of manufacturing a chemical mechanical polishing pad that includes a polishing layer.

  In the assembly of integrated circuits and other electronic devices, multiple layers of conductor material, semiconductor material, and insulator material are deposited on or removed from the surface of the semiconductor wafer. Thin layers of conductor material, semiconductor material and insulator material can be deposited by several deposition techniques. Common deposition techniques in modern processing include physical vapor deposition (PVD), also known as sputtering, chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), and electrochemical plating (ECP). Including.

  As the material layers are sequentially deposited and removed, the top surface of the wafer becomes non-planar. Since subsequent semiconductor processing (eg, metallization) requires the wafer to have a flat surface, the wafer needs to be planarized. Planarization is useful for removing undesired surface topography and surface defects such as rough surfaces, agglomerated materials, crystal lattice damage, scratches and contaminated layers or materials.

  Chemical mechanical planarization, or chemical mechanical polishing (CMP), is a common technique used to planarize substrates such as semiconductor wafers. In conventional CMP, a wafer is mounted on a carrier assembly and placed in contact with a polishing pad in a CMP apparatus. The carrier assembly provides a controllable pressure on the wafer to press the wafer against the polishing pad. This pad is moved (eg, rotated) relative to the wafer by an external driving force. At the same time, a chemical composition (“slurry”) or other polishing solution is provided between the wafer and the polishing pad. Thus, the wafer surface is polished and planarized by the chemical and mechanical action of the pad surface and slurry.

  In US Pat. No. 5,578,362, Reinhardt et al. Disclose typical polishing pads known in the art. Reinhardt's polishing pad includes a polymer matrix having microspheres dispersed throughout. Generally, the microspheres are blended and mixed with a liquid polymer material and transferred to a mold for curing. Next, a polishing layer is formed by slicing the molded product. Unfortunately, the polishing layer thus formed may exhibit unwanted defects that can cause defects in the polished substrate when incorporated into a polishing pad.

  One alleged approach to address concerns regarding potential defects in the polishing layer of a chemical mechanical polishing pad is disclosed by Park et al. In US Pat. No. 7,027,640. Park et al. Is an apparatus for detecting or inspecting defects on a pad for use in performing chemical mechanical polishing of a wafer: a pad drive device for mounting and moving the pad; A camera installed toward the pad for converting the image into an electrical signal and outputting the converted electrical signal; a digital image data acquisition device for converting the electrical signal sent from the camera into a digital signal; and An apparatus including an image data processing device for processing image data to detect defects on a pad is disclosed, wherein the image data processing device is an arbitrary one acquired from an image data acquisition device. A level value obtained by calculating one or more quantitative characteristic values of light based on the image data on the points and combining the acquired one or more quantitative characteristic values; A location on the pad where the difference from the level value obtained from the normal surface of the pad is greater than a predetermined value is determined as a defect.

  Nonetheless, the apparatus and method described by Park et al. Is designed for the inspection of a finished chemical mechanical polishing pad of a ready to polish configuration using reflected light. The use of reflected light to inspect a chemical mechanical polishing pad and the polishing layer incorporated in the pad has particularly significant disadvantages. The use of reflected light has limited performance in identifying defects below the surface of the incorporated polishing layer (these defects are not in close proximity to the surface of the polishing layer). Nevertheless, as the chemical mechanical polishing pad is used, the surface of the polishing layer gradually wears. Thus, defects that were initially far from the surface of the polishing layer of a given chemical mechanical polishing pad gradually approach the polishing surface during the life of the pad. Further, chemical mechanical polishing pads that are ready for polishing have traditionally included modifications to the polishing surface of the polishing layer (eg, grooves, perforations) that facilitate polishing of the substrate. Complicates automatic defect detection using the gray scale described by et al.

  Accordingly, there remains a need for an improved method of manufacturing low defect chemical mechanical polishing pads having a polishing layer that uses an automated inspection method with enhanced identification capabilities of polishing layer defects.

The present invention is a method of manufacturing a chemical mechanical polishing pad having a polishing layer comprising: providing a cured cake formed from a curable material [wherein the curable material comprises a liquid prepolymer and a plurality of microscopic materials. Including a plurality of microelements dispersed in the liquid prepolymer]; cutting the cured cake to form a plurality of cutting sheets; an automatic inspection system: a magazine section; A light source; a photodetector; a digital image data acquisition device; and a system including an image data processing apparatus; mounting a plurality of cutting sheets in a magazine; a light source one at a time for a plurality of cutting sheets and it is transported between the light detector [wherein the respective cutting sheet has a thickness T _S between the permeate surface and the collision surface; the transmission surface and the collision surface is Are substantially parallel; light issued from the light source is placed in the correct position to impinge on the impact surface; and the light detector, transmission from rays sent from the transmitting surface through the thickness T _S Placed in the correct position to detect light; the transmitted light has at least one detectable property; the at least one detectable property includes the intensity of the transmitted light; One detectable property is converted to an electrical signal by the photodetector; the electrical signal from the photodetector is converted to a digital signal by the digital image data acquisition device; the digital signal from the digital image data acquisition device is Processed by an image data processor; this image data processor detects macro non-uniformity and is acceptable or suspected of cutting sheets Configured to classify as misalignment; the plurality of cutting sheets are classified into an acceptable sheet population and a suspected sheet population; the acceptable sheet population is at least one acceptable sheet And processing an acceptable sheet from the population of acceptable sheets to form a polishing layer of a chemical mechanical polishing pad, wherein the polishing layer is adapted to polish a substrate. A method comprising:

It is a perspective view of a cutting sheet. It is a perspective view of a cutting sheet. It is a cross-sectional view of a chemical mechanical polishing pad incorporating a cutting sheet as a polishing layer. It is a perspective view of a mold cavity.

DETAILED DESCRIPTION The method of the present invention provides a significant improvement in the quality of a finished (ready to use) chemical mechanical polishing pad. The method of the present invention performs an initial inspection of a cutting sheet to identify acceptable sheets from a plurality of cutting sheets to facilitate intensive visual inspection of macro-non-uniformity-containing portions of a suspicious sheet. By mapping the transmission surface of a suspicious sheet, the quality control aspect of chemical mechanical polishing pad production using a cutting sheet formed from a polymer material containing microelements dispersed in the polymer material is greatly improved. In this way, operator fatigue is greatly reduced (i.e., the operator does not have to spend endless time staring at an acceptable cutting sheet to find the location of the macro non-uniformity). Thus, this has become possible and the operator's concentration has increased where it has the greatest value (ie, evaluating specific non-uniformities in the cutting sheet to determine suitability for use).

  The term “poly (urethane)” as used herein and in the appended claims is formed by the reaction of (a) (i) an isocyanate and (ii) a polyol (including a diol). Polyurethanes; and (b) (i) isocyanates and (ii) polyols (including diols) and (iii) poly (urethanes) formed by the reaction of water, amines or a combination of water and amines .

The term “average cutting sheet thickness T _S-avg ” is used herein and in the appended claims in connection with a cutting sheet (20) having a transmission surface (14) and an impingement surface (17). The thickness T of the cutting sheet (20) measured in the direction perpendicular to the plane (28) of the transmission surface (14) from the transmission surface (14) to the collision surface (17) of the cutting sheet (20). Mean of _S. (See FIG. 3).

The term “average base layer thickness T _B-avg ” refers to a chemical mechanical polishing pad (110) having a subpad (125) interfaced with a cutting sheet incorporated as a polishing layer (120) having a polishing surface (114). ) In relation to the polishing surface (114) from the bottom surface (127) of the subpad (125) to the top surface (126) of the subpad (125), as used herein and in the appended claims. measured in the direction, it means an average thickness T _B of the subpad (125). (See FIG. 3).

The term “average total thickness T _T-avg ” is used herein and in connection with a chemical mechanical polishing pad (110) having a cutting sheet incorporated as a polishing layer (120) having a polishing surface (114). Of the chemical mechanical polishing pad (110), measured in a direction perpendicular to the polishing surface (114), from the polishing surface (114) to the bottom surface (127) of the subpad (125). Means the thickness T _T. (See FIG. 3).

  The term “substantially circular cross-section” as used herein and in the appended claims in connection with a cutting sheet (20) is the outer circumference of the cutting sheet (20) from the central axis A ( The longest radius r of the cutting sheet (20) projected on the plane (28) of the transmission surface (14) of the cutting sheet (20) up to 15) is the outer periphery (15) of the cutting sheet (20) from the central axis A. This means that it is ≦ 20% longer than the shortest radius r of the cutting sheet (20) projected on the plane (28) of the transmission surface (14) of the cutting sheet (20). (See FIGS. 1 and 2).

  The term “substantially parallel” as used herein and in the appended claims in connection with the cutting sheet (20) is the plane (30) of the impact surface (17) of the cutting sheet (20). ) Is perpendicular to the plane (28) of the transmission surface (14) at an angle γ (where the angle γ is between 89 and 91 °). It means to cross. (See FIGS. 1 and 2).

  The term “substantially vertical” as used herein and in the appended claims in relation to a mold cavity (200) is such that the vertical inner boundary (215) is the xy plane (230). Means rising from the bottom internal boundary (212) at an angle between 85 and 95 °. (See FIG. 4).

  The term “macro non-uniformity” as used herein and in the appended claims refers to a localized region on the transmission surface of a cutting sheet surrounded by an adjacent region on the transmission surface of the cutting sheet. What is meant here is that the detected intensity of light transmitted through this localized region is ≧ 0.1 of the detectable intensity range of the photodetector over the detected intensity of light transmitted through the adjacent region. % Higher or lower; and this localized region includes a portion of the transmission surface that is large enough to plug a circle having a diameter of 15.875 mm in the plane of the transmission surface.

  The term “density defect” as used herein and in the appended claims refers to the macro non-uniformity of a cutting sheet with a significantly reduced microelement concentration relative to the peripheral area of the cutting sheet. Say. A density defect shows remarkably high transparency (namely, high detection intensity of transmitted light) compared with the peripheral region of a cutting sheet.

  The term “air hole” as used herein and in the appended claims refers to air that produces significantly higher transparency (ie, higher detected intensity of transmitted light) compared to the peripheral area of the cutting sheet. It means the macro non-uniformity of the cutting sheet due to inclusion.

  The term “inclusion defect”, as used in this specification and the appended claims, refers to an extraneous that results in significantly less transparency (ie, low detected intensity of transmitted light) compared to the peripheral area of the cutting sheet. It refers to the macro non-uniformity of the cutting sheet due to contaminants.

Preferably, the method of manufacturing a chemical mechanical polishing pad having a polishing layer of the present invention comprises: providing a cured cake formed from a curable material [wherein the curable material comprises a liquid prepolymer and a plurality of microscopic materials. Including a plurality of microelements dispersed in the liquid prepolymer]; cutting the cured cake to form a plurality of cutting sheets; an automatic inspection system comprising: a magazine section (preferably Wherein the magazine section holds at least 10 cutting sheets; more preferably at least 15 cutting sheets; even more preferably at least 20 cutting sheets; most preferably at least 30 cutting sheets. A light source that emits light; a photodetector; a digital image data acquisition device; and an image data processor Mounting a plurality of cutting sheets on the magazine section; conveying the plurality of cutting sheets one at a time between the light source and the light detector [where each cutting sheet is A thickness T _S between the transmission surface and the collision surface; the transmission surface and the collision surface are substantially parallel; so that the light emitted from the light source impinges on the collision surface. And the photodetector is placed in the correct position to detect the transmitted light from the light beam transmitted from the transmission surface through the thickness T _S (preferably now emitted from the light source). The light beam impinges on each cutting sheet perpendicular to its impact surface); this transmitted light has at least one detectable property; this at least one detectable property determines the intensity of the transmitted light. Including (preferably this small At least one detectable property further includes the wavelength spectrum of the transmitted light); the intensity of this transmitted light is converted to an electrical signal by a photodetector; the electrical signal from this photodetector is digital image data Converted to a digital signal by an acquisition device; the digital signal from the digital image data acquisition device is processed by an image data processor; the image data processor detects macro non-uniformities and allows a cutting sheet Configured to classify as either obtainable or suspected (preferably where this classification is performed based on a menu of quality control criteria); Classified into a group and a group of suspicious sheets; this group of acceptable sheets includes at least one acceptable sheet]; And processing an acceptable sheet from the population of acceptable sheets to form a polishing layer of a chemical mechanical polishing pad, wherein the polishing layer is adapted to polish a substrate .

  Preferably, the cured cake used in the method of the present invention is prepared in a mold having a mold cavity (200) defined by a bottom inner boundary (212) and a vertical inner boundary (215). (See, for example, FIG. 4). Preferably, the bottom inner boundary (212) is in the xy plane (230) and the vertical inner boundary (215) is substantially perpendicular to the xy plane (230).

Preferably, the mold cavity (200) has a central axis C _axis (222) that coincides with the z-axis and intersects the bottom inner boundary (212) of the mold cavity (200) at the center point (221). Preferably, the center point (221) is located at the geometric center of the cross section C _x-sett (224) of the mold cavity (200) projected onto the xy plane (230). (See FIG. 4).

The mold cavity cross-section C _x-sect (224) projected onto the xy plane (230) may be any regular or irregular two-dimensional shape. Preferably, the mold cavity cross-section C _x-sect is selected from polygons and ellipses. More preferably, the cross-section _{C x-sect} of the mold cavity (224) has an average radius _r having a _C (preferably wherein _{r C} is an 20 to 100; more preferably, _{r C} is 25 Most preferably, r _C is 40-60 cm), and is a substantially circular cross-section. Most preferably, the mold cavity has a substantially circular cross-section C _x-sect (224) and is close to a just cylindrical region [where the mold cavity is the center axis C _axis of the mold cavity and Having a coincident axis of symmetry C _x-sym ; this exactly cylindrical region has the following formula:
C _x-area = πr _C ²
(Wherein, _{r C} is an average radius of the cross-sectional area _{C x-area} of the mold cavity which is projected to the x-y plane; and _{r C} is 20 to 100 (more preferably 25～65Cm; most preferably 40-60 cm) having a cross-sectional area C _x-area defined as)].

  Preferably, the curable material used to provide the cured cake in the method of the present invention comprises a liquid prepolymer and a plurality of microelements, wherein the plurality of microelements are in the liquid prepolymer. Is distributed. Preferably, the curable material includes a liquid prepolymer and a plurality of microelements, wherein the plurality of microelements are uniformly dispersed in the liquid prepolymer.

  Preferably, the liquid prepolymer is polymerized (ie cured) to produce poly (urethane), polysulfone, polyethersulfone, nylon, polyether, polyester, polystyrene, acrylic polymer, polyurea, polyamide, polyvinyl chloride, Formed from polyvinyl fluoride, polyethylene, polypropylene, polybutadiene, polyethyleneimine, polyacrylonitrile, polyethylene oxide, polyolefin, polyalkyl acrylate, polyalkyl methacrylate, polyamide, polyetherimide, polyketone, epoxy, silicone, ethylene propylene diene monomer Forming a material selected from polymers, proteins, polysaccharides, polyacetates and combinations of said at least two. Preferably, the liquid prepolymer forms a material comprising poly (urethane) by polymerization. More preferably, the liquid prepolymer is polymerized to form a material comprising polyurethane. Most preferably, the liquid prepolymer forms a polyurethane by polymerizing (curing).

  Preferably, the liquid prepolymer comprises a polyisocyanate-containing material. More preferably, the liquid prepolymer comprises the reaction product of a polyisocyanate (eg, diisocyanate) and a hydroxyl-containing material.

  Preferably, the polyisocyanate is methylene bis-4,4′-cyclohexyl-isocyanate; cyclohexyl diisocyanate; isophorone diisocyanate; hexamethylene diisocyanate; propylene-1,2-diisocyanate; 1,6-hexamethylene-diisocyanate; dodecane-1,12-diisocyanate; cyclobutane-1,3-diisocyanate; cyclohexane-1,3-diisocyanate; cyclohexane- 1,4-diisocyanate; 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane; methylcyclohexylene diisocyanate; triisocyanate of hexamethylene diisocyanate; 2,4,4- Trimethyl-1, Hexane diisocyanate triisocyanate; hexamethylene diisocyanate uretdione; ethylene diisocyanate; 2,2,4-trimethylhexamethylene diisocyanate; 2,4,4-tri-methylhexamethylene diisocyanate Dicyclohexylmethane diisocyanate; and combinations thereof. Most preferably, the polyisocyanate is aliphatic and has less than 14 percent unreacted isocyanate groups.

  Preferably, the hydroxyl-containing material used according to the present invention is a polyol. Typical polyols include, for example, polyether polyols, hydroxy-terminated polybutadienes (including partially and fully hydrogenated derivatives), polyester polyols, polycaprolactone polyols, polycarbonate polyols, and mixtures thereof.

  Preferred polyols include polyether polyols. Examples of polyether polyols include polytetramethylene ether glycol (“PTMEG”), polyethylene propylene glycol, polyoxypropylene glycol, and mixtures thereof. The hydrocarbon chain can have saturated or unsaturated bonds, and substituted or unsubstituted aromatic and cyclic groups. Preferably, the polyol of the present invention comprises PTMEG. Suitable polyester polyols include, but are not limited to, polyethylene adipate glycol; polybutylene adipate glycol; polyethylene propylene adipate glycol; o-phthalate-1,6-hexanediol; poly (hexamethylene adipate) glycol; and mixtures thereof. Not. The hydrocarbon chain can have saturated or unsaturated bonds, or substituted or unsubstituted aromatic and cyclic groups. Suitable polycaprolactone polyols are 1,6-hexanediol-initiated polycaprolactone; diethylene glycol-initiated polycaprolactone; trimethylolpropane-initiated polycaprolactone; neopentyl glycol-initiated polycaprolactone; 1,4-butanediol-initiated polycaprolactone; PTMEG-initiated polycaprolactone And mixtures thereof; but are not limited to these. The hydrocarbon chain can have saturated or unsaturated bonds, or substituted or unsubstituted aromatic and cyclic groups. Suitable polycarbonates include, but are not limited to, polyphthalate carbonate and poly (hexamethylene carbonate) glycol.

  Preferably, the plurality of microelements are selected from encapsulated cells, hollow core polymer materials (ie, microspheres), liquid filled hollow core polymer materials, water soluble materials (eg, cyclodextrins) and insoluble phase materials (eg, mineral oil). Is done. Preferably, the plurality of microelements are polyvinyl alcohol, pectin, polyvinylpyrrolidone, hydroxyethylcellulose, methylcellulose, hydropropylmethylcellulose, carboxymethylcellulose, hydroxypropylcellulose, polyacrylic acid, polyacrylamide, polyethylene glycol, polyhydroxyether acrylate, starch , Microspheres such as maleic acid copolymer, polyethylene oxide, polyurethane, cyclodextrin and combinations thereof (for example, Expancel ™ from Akzo Nobel, Sundsvall, Sweden). Microspheres can be chemically modified, for example, by branching, blocking, and crosslinking to change solubility, swellability, and other properties. Preferably, the microspheres have an average diameter that is less than 150 μm, and more preferably an average diameter that is less than 50 μm. Most preferably, the microspheres 48 have an average diameter that is less than 15 μm. Note that the average diameter of the microspheres can be varied, and various sizes or mixtures of various microspheres 48 can be used. The most preferred material for the microspheres is a copolymer of acrylonitrile and vinylidene chloride (eg, Expancel® available from Akzo Nobel).

  The liquid prepolymer used in the method of the present invention optionally further comprises a curing agent. Preferred curing agents include diamines. Suitable polydiamines include both primary and secondary amines. Preferred polydiamines are diethyltoluenediamine (“DETDA”); 3,5-dimethylthio-2,4-toluenediamine and its isomers; 3,5-diethyltoluene-2,4-diamine and its isomers (eg, 3 , 5-diethyltoluene-2,6-diamine); 4,4′-bis- (sec-butylamino) -diphenylmethane; 1,4-bis- (sec-butylamino) -benzene; 4,4′-methylene -Bis- (2-chloroaniline); 4,4'-methylene-bis- (3-chloro-2,6-diethylaniline) ("MCDEA"); polytetramethylene oxide-di-p-aminobenzoate; N, N′-dialkyldiaminodiphenylmethane; p, p′-methylenedianiline (“MDA”); m-phenylenediamine (“MPDA”); Tylene-bis-2-chloroaniline (“MBOCA”); 4,4′-methylene-bis- (2-chloroaniline) (“MOCA”); 4,4′-methylene-bis- (2,6-diethyl) Aniline) ("MDEA"); 4,4'-methylene-bis- (2,3-dichloroaniline) ("MDCA"); 4,4'-diamino-3,3'-diethyl-5,5'- Including, but not limited to: dimethyldiphenylmethane; 2,2 ′, 3,3′-tetrachlorodiaminodiphenylmethane; trimethylene glycol di-p-aminobenzoate; and mixtures thereof. Preferably, the diamine curing agent is selected from 3,5-dimethylthio-2,4-toluenediamine and its isomers.

  Curing agents can also include diols, triols, tetraols and hydroxy-terminated curing agents. Suitable diol, triol, and tetraol groups are: ethylene glycol; diethylene glycol; polyethylene glycol; propylene glycol; polypropylene glycol; low molecular weight polytetramethylene ether glycol; 1,3-bis (2-hydroxyethoxy) benzene; -Bis- [2- (2-hydroxyethoxy) ethoxy] benzene; 1,3-bis- {2- [2- (2-hydroxyethoxy) ethoxy] ethoxy} benzene; 1,4-butanediol; -Pentanediol; 1,6-hexanediol; resorcinol-di- (β-hydroxyethyl) ether; hydroquinone-di- (β-hydroxyethyl) ether; and mixtures thereof. Preferred hydroxy-terminated curing agents are 1,3-bis (2-hydroxyethoxy) benzene; 1,3-bis- [2- (2-hydroxyethoxy) ethoxy] benzene; 1,3-bis- {2- [2 -(2-hydroxyethoxy) ethoxy] ethoxy} benzene; 1,4-butanediol; and mixtures thereof. The hydroxy-terminated and diamine curing agents can contain one or more saturated, unsaturated, aromatic, and cyclic groups. Furthermore, the hydroxy-terminated and diamine curing agents can contain one or more halogen groups.

  Preferably, in the method of the present invention, the cured cake is cut into a plurality of cutting sheets having a desired thickness using a sky bar blade having a cutting edge. Preferably, the leather abrasive compound is applied to the edge of the Skybar blade and the edge is sharpened with leather abrasive before cutting the cake into a plurality of cutting sheets. The leather abrasive compound used in the method of the present invention preferably comprises aluminum oxide abrasive grains dispersed in a fatty acid. More preferably, the leather sharpening compound used in the method of the present invention comprises 70-82 wt% aluminum oxide abrasive grains dispersed in 18-35 wt% fatty acid. The leather abrasive used in the method of the present invention is preferably leather leather abrasive. Most preferably, the leather abrasive used in the method of the present invention is a leather abrasive designed for use with a rotating tool (eg, a Dremel® rotating tool).

  Preferably, in the method of the present invention, the cured cake is heated to facilitate the cutting operation. Preferably, the cured cake is heated using an infrared heating lamp during a cutting operation in which the cured cake is cut into a plurality of cutting sheets.

Preferably, in the method of the present invention, the cured cake is cut so that a plurality of cutting sheets are formed, where the average thickness T _S-avg of the cutting sheets is 500 to 5,000 μm (preferably 750 to 4,000 μm; more preferably 1,000 to 3,000 μm; most preferably 1,200 to 2,100 μm).

  Preferably, in the method of the present invention, the automatic inspection system includes a magazine portion designed to hold, store and dispense cutting sheets. Preferably, the magazine section holds at least 10 cutting sheets (more preferably at least 15 cutting sheets; even more preferably at least 20 cutting sheets; most preferably at least 30 cutting sheets). Design capacity for With this magazine section design capacity, the operator can mount a large number of cutting sheets on the automatic inspection system. Once multiple sheets are installed in the magazine section, the operator performs other tasks while the automatic inspection system treats and classifies multiple sheets as either acceptable or suspect. be able to.

  Preferably, in the method of the present invention, the automatic inspection system moves the cutting sheets from the magazine section one at a time; conveys the cutting sheets one at a time between the light source and the photodetector; and It includes a mechanism for returning cutting sheets one by one to the magazine. Preferably, the mechanism includes at least one linear motor. More preferably, the mechanism includes at least one linear motor having a linear scale resolution of ≦ 1 μm.

  Preferably, in the method of the present invention, the automatic inspection system includes a light source that emits light. Preferably, the light emitted by the light source exhibits an emission spectrum including wavelengths in the visible, ultraviolet and infrared regions. The light source may be a broadband light source (eg, a white light source) or a narrow band light source (eg, a narrow band blue light source). Preferably, the light source is a narrow band blue light source. More preferably, the light source is a narrow band blue light source whose light beam has a peak wavelength of 460-490 nm (preferably 460-480 nm; more preferably 460-470 nm; most preferably 463-467 nm) and An emission spectrum having a full width at half maximum of ≦ 50 nm (preferably ≦ 40 nm; more preferably ≦ 35 nm; most preferably ≦ 30 nm) and FWHM is shown. One skilled in the art will be able to select a suitable light source to provide a light beam having an emission spectrum in the desired region. Preferably, in the method of the present invention, the automatic inspection system includes a light source that is a light emitting diode.

Preferably, in the method of the present invention, the automatic inspection system, an optical detector capable of converting at least one detectable property of the transmitted light from the light rays sent from the transmitting surface of the cutting sheet through the thickness T _S Including. More preferably, in the method of the present invention, the automatic test system includes an optical detector capable of converting the intensity of transmitted light from light transmitted from the transmitting surface of the cutting sheet through the thickness T _S. Most preferably, in the method of the present invention, the automatic test system includes an optical detector capable of converting the intensity and wavelength spectrum of the transmitted light from the light beam transmitted from the transmitting surface of the cutting sheet through the thickness T _S. Preferably, the photodetector is a photoelectric conversion device that converts at least one detectable property of transmitted light incident thereon into an electrical signal. Preferably, the photodetector is an array of charge coupled devices (CCD). Preferably, the charge coupled device (CCD) used is selected from monochrome and color CCDs. More preferably, the photodetector comprises an array of at least 5 (most preferably at least 8) photoelectric conversion devices. Most preferably, the photodetector comprises an array of at least 8 charge coupled device (CCD) image sensors having a resolution of ≦ 20 μm (preferably ≦ 16 μm) and a field of view of ≧ 100 mm (preferably ≧ 120 mm). Including.

  The digital image data acquisition device converts the electrical signal output from the photodetector into a digital signal. Digital image data acquisition devices suitable for use with the present invention are well known in the art.

  The heterogeneous composition of the cutting sheet from a cake of polymeric material containing multiple microelements makes reference to a hypothetical standard sheet impractical. That is, the presence of various harmless production artifacts of such cutting sheets is a simple gray to standard value for use in automated systems for inspecting cutting sheets with respect to incorporation of chemical mechanical polishing pads as polishing layers. Disable scale comparison.

  General purpose and special purpose image data processing devices suitable for use in the present invention are well known in the art. Preferably, the image data processing device in the automatic inspection system used in the method of the present invention includes a central processing unit coupled to a non-volatile data storage device.

  Preferably, the central processing unit is further coupled to one or more user input interface controls (eg, mouse, keyboard) and at least one output display.

  Preferably, the image data processing device is configured to detect macro non-uniformity of the cutting sheet and classify the cutting sheet as either acceptable or suspicious. Preferably, the classification of the cutting sheet as either acceptable or suspicious is performed by the image data processing device based on a menu of quality control criteria. For example, various defects can occur during the manufacture of the cutting sheet, including density defects, air hole defects, and inclusion defects. It should be noted that any one or combination of these defects can constitute macro non-uniformity in the cutting sheet depending on the size of the part affected by the transmission surface. Note that the various defect types appear differently for the photodetector. For density defects and air holes, the defect area is more transparent than the peripheral area of the cutting sheet. For inclusion defects, the defect area is less transparent than the peripheral area of the cutting sheet. Whether such defects are acceptable depends on several conditions, including, for example, a substrate on which a chemical mechanical polishing pad incorporating a cutting sheet is subject to polishing. Some substrates are more cumbersome than others, and therefore require more control over the uniformity of the cutting sheet used as the polishing layer of the chemical mechanical polishing pads produced for these polishings.

Preferably, in the method of the present invention, at least one acceptable sheet is processed to form a polishing layer (120) of the chemical mechanical polishing pad (110) [where the polishing layer (120) is is adapted to polish the substrate] is, a) forming a groove pattern cut at least one groove in a sheet acceptable, and (b) at least halfway through the thickness T _S of the sheet acceptable Forming the polishing surface (114) by at least one of forming perforations extending up to. More preferably, in the method of the present invention, at least one acceptable sheet is processed to form a polishing layer (120) of the chemical mechanical polishing pad (110) [where the polishing layer (120) is Adapted for polishing a substrate] includes forming a polishing surface (114) by cutting at least one groove in an acceptable sheet to form a groove pattern. Most preferably, in the method of the present invention, at least one acceptable sheet is processed to form the polishing layer (120) of the chemical mechanical polishing pad (110) [where the polishing layer (120) is Adapted to polish the substrate] cut at least one groove into an acceptable sheet to form a groove pattern [where the groove pattern is adapted to polish the substrate. ] Forming a polishing surface (114). (See FIG. 3).

  Preferably, the chemical mechanical polishing pad (110) manufactured using the method of the present invention is preferably adapted for rotation about the central axis (112). (See FIG. 3). Preferably, the polishing surface (114) is formed by arranging at least one groove such that at least one groove sweeps over the substrate by rotation of the pad (110) about the central axis (112) during polishing. To do. Preferably, the at least one groove is selected from curved grooves, linear grooves and combinations thereof. Preferably, the at least one groove exhibits a depth of ≧ 10 mil (preferably 10 to 150 mil). Preferably, the at least one groove has a depth selected from ≧ 10 mil, ≧ 15 mil and 15 to 150 mil; a width selected from ≧ 10 mil and 10 to 100 mil; and ≧ 30 mil, ≧ 50 mil, 50 to 200 mil, 70 A groove pattern including at least two grooves having a combination of pitches selected from ˜200 mil and 90 ˜200 mil is formed.

  Preferably, the cutting sheet incorporated as a polishing layer (120) in the chemical mechanical polishing pad (110) contains <1 ppm abrasive particles incorporated therein.

  Preferably, processing the acceptable sheet further: providing a subpad (125) having a top surface (126) and a bottom surface (127); an adhesive (123) (preferably wherein the adhesive is Selected from at least one of pressure sensitive adhesives, hot melt adhesives and contact adhesives; more preferably, the adhesive is selected from pressure sensitive adhesives and hot melt adhesives; most preferably the adhesives Providing a hot melt adhesive; and laminating the top surface (126) of the subpad (125) to the base surface (117) of the polishing layer (120) using an adhesive (123). . (See FIG. 3).

  Preferably, in the method of the invention, at least one acceptable sheet is processed to form the polishing layer (120) of the chemical mechanical polishing pad (110) [where the polishing layer (120) is a substrate. Is further adapted to include: providing a pressure sensitive platen adhesive layer (170) applied to the bottom surface (127) of the subpad (125).

  Preferably, in the method of the invention, at least one acceptable sheet is processed to form the polishing layer (120) of the chemical mechanical polishing pad (110) [where the polishing layer (120) is a substrate. Is further adapted to: provide a pressure sensitive platen adhesive layer (170) applied to the bottom surface (127) of the subpad (125); and apply on the pressure sensitive platen adhesive layer (170). Providing a release liner (175) wherein the pressure sensitive platen adhesive layer (170) is placed between the bottom surface (127) of the subpad (125) and the release liner (175). (See FIG. 3).

Incorporation of the subpad (125) into the chemical mechanical polishing pad (110) of the present invention is desirable for certain polishing applications. Those skilled in the art will know to select the thickness T _B of suitable construction materials and subpad subpad (125) for use in the intended polishing process. Preferably, the subpad (150) has an average subpad thickness TB _-avg of ≧ 15 mil (more preferably 30-100 mil; most preferably 30-75 mil).

  Preferably, the adhesive (123) is selected from the group consisting of a pressure sensitive adhesive, a hot melt adhesive, a contact adhesive, and combinations thereof. More preferably, the adhesive (123) is selected from the group consisting of a pressure sensitive adhesive and a hot melt adhesive. Most preferably, the adhesive (123) is a reactive hot melt adhesive.

  Preferably, in the method of the invention, at least one acceptable sheet is processed to form the polishing layer (120) of the chemical mechanical polishing pad (110) [where the polishing layer (120) is a substrate. Is further adapted to provide: at least one additional layer (not shown) connected to and in between the polishing layer (120) and the pressure sensitive platen adhesive layer (170). Including that. This at least one additional layer (not shown) can be incorporated into the chemical mechanical polishing pad (110) using an additional layer adhesive (not shown). The additional layer adhesive can be selected from pressure sensitive adhesives, hot melt adhesives, contact adhesives, and combinations thereof. Preferably, this additional layer adhesive is a hot melt adhesive or a pressure sensitive adhesive. More preferably, the additional layer adhesive is a hot melt adhesive.

  Preferably, the chemical mechanical polishing pad (110) of the present invention is specifically designed to facilitate polishing of a substrate selected from at least one of a magnetic substrate, an optical substrate and a semiconductor substrate. Preferably, the cutting sheet incorporated as a polishing layer (120) in the chemical mechanical polishing pad (110) is a substrate selected from at least one of a magnetic substrate, an optical substrate and a semiconductor substrate (more preferably a semiconductor substrate; most preferably Are adapted for polishing semiconductor wafers).

  In the method of the present invention, if the suspicious sheet population includes at least one suspicious sheet and the at least one suspicious sheet contains at least one detected macro-uniformity, image data processing The apparatus is preferably further configured to create a map of at least one suspicious sheet and store it in a non-volatile memory, wherein the location of the at least one detected macro non-uniformity is Is positioned.

  Preferably, the method of the invention further comprises: selecting a selected sheet from a group of suspicious sheets, wherein the group of suspicious sheets comprises at least one suspicious sheet, and the at least one suspicious sheet is The image data processor is preferably further configured to create and store a map of at least one suspicious sheet in non-volatile memory. Where at least one of the detected macro non-uniformity locations is located.

  Preferably, the method of the invention further comprises: selecting a selected sheet from a group of suspicious sheets, wherein the group of suspicious sheets comprises at least one suspicious sheet, and the at least one suspicious sheet is The image data processor is preferably further configured to create and store a map of at least one suspicious sheet in non-volatile memory. Where the at least one detected macro non-uniformity location is located; and the automatic inspection system is further: a display, on which an image of the selected sheet is displayed Includes display. The image displayed on the selection sheet on the display unit may be an entire image of the transmission surface of the selection sheet. Preferably, the image of the selected sheet is a partial image showing an enlarged view of at least one detected macro non-uniformity. Preferably, the partial image of the selection sheet displayed on the display unit includes the entire macro non-uniformity and the peripheral region of the transmission surface of the selection sheet. Preferably, the partial image of the selected sheet displayed on the display can be enlarged to enhance the details of the displayed image to facilitate visual inspection of the selected sheet. Preferably, the method of the invention further comprises: performing a visual inspection of the selected sheet [where this visual inspection is facilitated by an image of the selected sheet displayed on the display]; and (i) a visual inspection Reclassify the selected sheet as acceptable based on [where this selected sheet is then added to the group of acceptable sheets]; or (ii) select the selected sheet as defective based on visual inspection This includes any of the following: [where this selected sheet is then added to the group of defective sheets].

Claims (9)

A method of manufacturing a chemical mechanical polishing pad having a polishing layer comprising:
Providing a cured cake formed from a curable material, wherein the curable material comprises a liquid prepolymer and a plurality of microelements, wherein the plurality of microelements are dispersed in the liquid prepolymer. There];
Cutting the cured cake to form a plurality of cutting sheets;
Automatic inspection system:
Magazine section;
A light source that emits light;
Photodetector;
A digital image data acquisition device; and a system including an image data processing device;
Mounting multiple cutting sheets on the magazine;
Transporting a plurality of cutting sheets one at a time between the light source and the photodetector [where,
Each cutting sheet have a thickness T _S and between the permeate surface and the collision surface; the transmission surface and the impact surface are substantially parallel;
Rays issued from the light source is placed in the correct position to impinge on the impact surface; and the photodetector, the correct position so as to detect the transmitted light from the light rays transmitted from the transmitting surface through the thickness T _S Placed in;
This transmitted light has at least one detectable property;
This at least one detectable property includes the intensity of transmitted light;
This transmitted light intensity is converted into an electrical signal by a photodetector;
The electrical signal from this photodetector is converted to a digital signal by a digital image data acquisition device;
The digital signal from the digital image data acquisition device is processed by an image data processor; the image data processor detects macro non-uniformity and either accepts the cut sheet or is suspect. Configured to classify;
The plurality of cut sheets are classified into an acceptable sheet population and a suspicious sheet population;
This acceptable sheet population includes at least one acceptable sheet]; and processing acceptable sheets from the acceptable sheet population to form a polishing layer of a chemical mechanical polishing pad. Wherein the polishing layer is adapted to polish the substrate.   The group of suspicious sheets includes at least one suspicious sheet; the at least one suspicious sheet contains at least one detected macro non-uniformity; and the image data processor further includes at least one The method of claim 1, wherein the map is configured to create and store a map of suspicious sheets in a non-volatile memory; wherein the at least one detected macro non-uniformity location is located. .   The method of claim 2, further comprising selecting a selection sheet from a population of suspect sheets.   The method of claim 3, wherein the automatic inspection system further comprises a display unit on which an image of the selected sheet is displayed. Furthermore,
Performing a visual inspection of the selected sheet [where this visual inspection is facilitated by the image of the selected sheet displayed on the display]; and (i) selecting the selected sheet as acceptable based on the visual inspection. Reclassify [where this selected sheet is then added to the acceptable sheet population]; or (ii) classify the selected sheet as a defect based on visual inspection [where then this selection 5. The method of claim 4, wherein the sheet is added to a population of defective sheets.   The method of claim 4, wherein the image of the selected sheet is a partial image showing an enlarged view of at least one detected macro non-uniformity. Furthermore,
Performing a visual inspection of the selected sheet [where this visual inspection is facilitated by the image of the selected sheet displayed on the display]; and (i) selecting the selected sheet as acceptable based on the visual inspection. Reclassify [where this selected sheet is then added to the acceptable sheet population]; or (ii) classify the selected sheet as a defect based on visual inspection [where then this selection 7. The method of claim 6, comprising: a sheet is added to a group of defective sheets. Processing acceptable sheets,
Forming a polishing surface by cutting at least one groove in an acceptable sheet to form a groove pattern, wherein the groove pattern is adapted to polish a substrate;
The method of claim 1 comprising: Further processing acceptable sheets,
Providing a subpad;
9. The method of claim 8, comprising: providing an adhesive; and laminating the subpad with an adhesive to an acceptable sheet.