KR20160082930A - Method of manufacturing chemical mechanical polishing pads - Google Patents

Abstract

There is provided a method of manufacturing a chemical mechanical polishing pad, wherein an automated inspection system detects macro irregularities and the permissible skived sheet is further processed to classify the skived sheets as acceptable or suspicious, Thereby forming an abrasive layer.

Description

Technical Field [0001] The present invention relates to a chemical mechanical polishing pad,

The present invention relates generally to the field of manufacturing chemical and mechanical polishing pads. More particularly, the present invention relates to a method of making a chemical mechanical polishing pad comprising an abrasive layer.

In the fabrication of integrated circuits and other electronic devices, multiple layers of conductor, semiconductor, and dielectric material are deposited or removed from the surface of the semiconductor wafer. Thin layer conductors, semiconductors, and dielectric materials can be deposited by a number of deposition techniques. Common deposition techniques in modem fabrication include physical vapor deposition (PVD), chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PECVD), and electrochemical plating (ECP), also known as sputtering.

Since the material layers are sequentially deposited and removed, the topmost surface of the wafer becomes non-planar. Subsequent semiconductor processing (e.g., metallization) requires the wafer to have a planar surface, so the wafer must be planarized. Planarization is useful for removing unwanted surface features 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 a substrate, e.g., a semiconductor wafer. In conventional CMP, the wafer is mounted on the carrier assembly and placed in contact with the polishing pad in the CMP apparatus. The carrier assembly provides a controllable pressure on the wafer and squeezes it toward the polishing pad. The pad is moved (e.g., rotated) relative to the wafer by external thrust. At the same time, a chemical composition ("slurry") or other polishing solution is provided between the wafer and the polishing pad. Thus, the surface of the wafer is polished and planarized by the chemical and mechanical action of the pad surface and slurry.

U.S. Patent No. 5,578,362 (Reinhardt et al.) Discloses an exemplary polishing pad known in the art. Reinhardt's polishing pad comprises a polymer matrix having microspheres dispersed therein. Generally, the microspheres are blended and mixed with the liquid polymer material and transported to the curing mold. The shaped article is then sliced to form a polishing layer. Unfortunately, the abrasive layer formed in this way may exhibit unwanted defects that, when incorporated into the polishing pad, can lead to defects on the polished substrate, including it.

One approach claimed to address concerns about potential defects in the abrasive layer of chemical mechanical polishing pads is disclosed in U.S. Patent No. 7,027,640 to Park et al. A pad driving device for loading the pad on the upper portion and moving the pad; A camera installed to face the pad to convert the pad image into an electrical signal and output a converted electrical signal; A digital image data acquisition device for converting an electrical signal transmitted from the camera into a digital signal; And an image data processing device for processing image data and detecting defects on the pad, the device for detecting or inspecting defects on a pad for use in performing a chemical mechanical polishing of a wafer, The apparatus includes a processor configured to calculate one or more quantitative feature values of light based on image data on any one point obtained from the image data acquisition device and to compare the level values obtained by combining the one or more obtained quantitative feature values and the level obtained from the vertical surface of the pad If the difference between the values is greater than the predetermined value, the position on the pad is determined to be defective.

Nevertheless, the apparatus and method described by Park et al. Are designed for inspection of finished chemical mechanical polishing pads ready for polishing placement using reflected light. The use of reflected light to inspect chemical and mechanical polishing pads and abrasive layers incorporated into such pads in particular has significant drawbacks. The use of reflected light has limited ability to identify sub-surface defects in an incorporated polishing layer whose defect is not adjacent to the polishing layer surface. Nevertheless, as the chemical mechanical polishing pad is used, the surface of the polishing layer is gradually worn. Therefore, defects that were initially far away from the polishing layer surface of a given chemical mechanical polishing pad will become more and more adjacent to the polishing surface during the useful life of the pad. In addition, the chemical mechanical polishing pad, which has conventionally been prepared for polishing, includes a modification to the polishing surface of the polishing layer that promotes polishing of the substrate (e.g., grooves, perforations) It makes automated bad detection using one gray scale complicated.

Therefore, there is still a need for an improved method of manufacturing a low-defect, chemical-mechanical polishing pad having an abrasive layer using an automated inspection method having increased abrasive layer failure verifying capability.

The present invention provides a method of preparing a curable composition comprising the steps of: providing a cured cake formed from a curable material, the curable material comprising a liquid prepolymer and a plurality of trace elements, the plurality of trace elements being dispersed in a liquid prepolymer; Smoothing the cured cake to form a plurality of skived sheets; Providing an automated inspection system comprising a reservoir, a light source emitting the beam, a photodetector, a digital image data acquisition device, and an image data processing device; Loading the plurality of skived sheets into the reservoir; Conveying a plurality of skiveded sheets one at a time to a light source and a photodetector in a skiveded sheet at a time, each said skiveded sheet having a thickness, T _s , between the transmitting surface and their impact surface; the permeate surface and the collision surface is substantially parallel and; wherein the beam emitted from the light source is oriented to impinge on the impact surface, the optical detector detects the light transmitted from the beam that is transmitted through the thickness, T _S out transmission surface Wherein the transmitted light has at least one detectable characteristic, the at least one detectable characteristic comprises an intensity of transmitted light, the at least one detectable characteristic is switched to an electrical signal by a photodetector, The electrical signal from the photodetector is converted into a digital signal by a digital image data acquisition device Said digital signal from a digital image data acquisition device being processed by an image data processing device, said image data processing device being configured to detect macroscopic non-uniformity and classify the skived sheets into acceptable or defective estimates; Wherein the plurality of skived sheets are divided into an allowable sheet population and a bad estimated sheet group, wherein the permissible sheet population includes at least one permissible sheet; A method of manufacturing a chemical mechanical polishing pad having an abrasive layer, comprising: processing an acceptable sheet from an acceptable sheet population to form an abrasive layer of a chemical mechanical polishing pad, the abrasive layer being employed for polishing the substrate .

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an illustration of a skylight sheet perspective view.
2 is a view of a skylighted seat perspective view.
3 is a cross-sectional cut-away view of a chemical mechanical polishing pad incorporating a sheet skimmed into a polishing layer.
4 is a view of the mold cavity perspective view.

details

The method of the present invention provides a significant improvement in the quality of the finished (ready to use) chemical mechanical polishing pad. The method of the present invention performs a first inspection of a skiveded sheet to identify acceptable sheets from a plurality of skived sheets and maps the transmission surface of the failure estimation sheet to obtain an intensive view of the macroscopic non- Facilitating the quality control aspects of the production of chemical mechanical polishing pads using a skived sheet formed of a polymeric material containing trace elements dispersed therein. In this way, operator fatigue is greatly reduced (i.e., the operator does not need to spend infinite time to look for acceptable skiveded sheets to find macroscopic non-uniformity). Therefore, it is possible to increase the concentration of the operator at the point representing the largest value (i. E., To assess the specific non-uniformity in the skived sheet to determine the suitability of use).

The term " poly (urethane) " as used herein and in the appended claims refers to polyurethanes formed by the reaction of (a) (i) isocyanates and (ii) polyols (including diols); And (b) poly (urethanes) formed by the reaction of (i) isocyanates with (ii) polyols (including diols) and (iii) water, amines or combinations of water and amines.

The term " average skived sheet thickness, T _{S- avg} , " as used herein and in the appended claims for the skived sheet 20 having the transmitting surface 14 and the impact surface 17 , the thickness of the Sky the sheet 20 rime measured in the vertical surface 28 of the permeate surface 14 of the impingement surface 17 at the permeate surface 14 of 20, means the average of the T _S ( 3 ).

The term " average " as used herein and in the appended claims for a chemical mechanical polishing pad 110 having a subpad 125 facing a skiveded sheet embedded in an abrasive layer 120 having a polishing surface 114 , the base layer thickness, T _{B- avg} "is measured in the direction perpendicular to the polishing surface 114 of the upper surface 126 of the subpad 125 in lower surface 127 of the subpad 125 subpad ( 125 ), and the average of T _B (see FIG. 3 ).

The term " average total thickness, T _{T - avg} , " as used herein and in the appended claims, for a chemical mechanical polishing pad 110 having a smoothed sheet incorporated with an abrasive layer 120 having a polishing surface 114 , shall mean the average of the thickness, T _T of the chemical mechanical polishing pad 110 measured in the vertical direction with respect to the polishing surface 114 of the lower surface 127 of the subpad 125 in the polishing surface 114 ( 3 ).

Herein and in the appended terms used in the claims, "substantially the circular cross section to" for the skiving sheet 20 is the central axis to the outer periphery 15 of the skiving sheet 20, the skiving of the A the central axis of the outer periphery 15 of the sheet 20 is transmitted through surface 14 faces the sky, the longest radius, r is the Sky the sheet 20 ice of the ice sheet 20 projected onto the 28 of the, means that the shortest radius of the transmission surface Sky the sheet 20 ice projected onto surface 28 of layer 14 of the Sky the sheet 20 ice from a, ≤ 20% longer than r (Fig. 1 & 2 ).

The term " substantially parallel " as used herein and in the appended claims for a skiveded sheet 20 refers to a central axis perpendicular to the plane 30 of the impingement surface 17 of the skived sheet 20 , A (and an arbitrary line parallel thereto) will intersect the angle? With the surface 28 of the transmissive surface 14 ; The angle? Is 89 to 91 占 (see FIGS. 1 and 2 ).

The term "substantially perpendicular" as used herein and in the appended claims for the mold cavity 200 has a vertical inner boundary 215, the xy plane 230 inside the lower at an angle of 85 to 95 ° boundary for the (212 (See FIG. 4 ).

The term "macroscopic non-uniformity " as used herein and in the appended claims means a localized area on the transmission surface of a skived sheet that is surrounded by an adjacent area on the transmission surface of the skived sheet, The detected intensity of the transmitted light is higher or lower by an amount > 0.1% of the detectable intensity range of the photodetector than the detected intensity of the light transmitted through the adjacent region; The localized area encompasses a portion of the transmitting surface which is large enough to contain a circle having a diameter of 15.875 mm at the plane of the transmitting surface.

The term " poor density " as used herein and in the appended claims indicates macroscopic non-uniformity in a skived sheet having a significantly reduced trace element concentration relative to the surrounding area of the skived sheet. The poor density represents a significantly higher degree of transparency (i. E., A higher detected intensity of transmitted light) as compared to the surrounding area of the skived sheet.

The term " air hole " as used herein and in the appended claims is intended to encompass air skimmings that contain air that produces significantly higher transparency (i.e., a higher detected intensity of transmitted light) Macroscopic non-uniformity in the sheet.

The term " poorly " as used herein and in the appended claims is intended to encompass all such contaminants that contain external contaminants that produce significantly lower transparency (i.e., lower detected intensity of transmitted light) And macroscopic non-uniformity in the skived sheets.

Preferably, the method of making a chemical mechanical polishing pad having an abrasive layer of the present invention comprises the steps of providing a cured cake formed of a curable material, the curable material comprising a liquid prepolymer and a plurality of trace elements, The trace elements are dispersed in the liquid prepolymer); Smoothing the cured cake to form a plurality of skived sheets; The storage (preferably, said reservoir comprises at least 10 skiveded sheets, more preferably at least 15 skiveded sheets, even more preferably at least 20 skiveded sheets, most preferably at least 30 Providing an automated inspection system including a light source emitting a beam, a photodetector, a digital image data acquisition device, and an image data processing device; Loading the plurality of skived sheets into the reservoir; Conveying a plurality of skiveded sheets one at a time to a light source and a photodetector in a skiveded sheet at a time, each said skiveded sheet having a thickness, T _s , between the transmitting surface and their impact surface; the permeate surface and the collision surface is substantially parallel and; wherein the beam emitted from the light source is oriented to impinge on the impact surface, the optical detector detects the light transmitted from the beam that is transmitted through the thickness, T _S out transmission surface (Preferably, the beam emitted from the light source is impinged upon each of the skived sheets perpendicular to their impact surface), the transmitted light having at least one detectable characteristic, The at least one detectable characteristic includes the intensity of the transmitted light (preferably, the at least one detectable characteristic comprises the intensity of the transmitted light The intensity of the transmitted light is converted into an electrical signal by the photodetector, the electrical signal from the photodetector is converted into a digital signal by the digital image data acquisition device, and the digital image data acquisition device Wherein the digital signal from the image data processing device is configured to detect macroscopic non-uniformities and to classify the skived sheets into acceptable or defective estimates (preferably, Wherein the plurality of skived sheets are divided into an allowable sheet group and a bad estimate sheet group, the permissible sheet group including at least one permissible sheet; Forming an abrasive layer of a chemical mechanical polishing pad by processing an acceptable sheet from an acceptable sheet population, wherein said abrasive layer is employed for polishing the substrate.

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

The mold cavity 200 preferably has a central axis, C _axis 222 , which coincides with the z-axis and intersects the lower internal 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 C _x-sect 224 , the cross section of the mold cavity 200 projected onto the xy plane 230 (see FIG. 4 ).

The cross-section of the mold cavity projected onto the xy plane 230 , C _{x -sect} 224, may have any regular or irregular two-dimensional shape. Preferably, the cross-section of the mold cavity, C _{x -sect,} is selected from polygons and ellipses. More preferably, the mold cavity cross section, C _{x -sect} (224) has a substantially circular cross-section having an average radius, r _C (preferably, r _C is 20 to 100 cm, and; more preferably, r _C is between 25 and 65 cm; most preferably r _C is between 40 and 60 cm. Most preferably, the mold cavity is close to the right-hand cylindrical shaped area having a substantially circular cross-section, C _{x -sect} ( 224 ); The mold cavity has an axis of symmetry, C _{x sym-matched} with the center of the mold cavity axis, C _axis; The right cylindrical area has a cut area, C _x-area , defined as:

C _x-area  = πr _C ²

Where r _C is the cut area of the mold cavity projected on the xy plane, the average radius of C _{x -area} ; r _C is 20 to 100 cm (more preferably 25 to 65 cm, most preferably 40 to 60 cm).

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 trace elements, wherein the plurality of trace elements are dispersed in the liquid prepolymer. Preferably, the curable material comprises a liquid prepolymer and a plurality of trace elements, wherein the plurality of trace elements are uniformly dispersed in the liquid prepolymer.

Preferably, the liquid prepolymer is polymerized (i. E., Cured) to form a poly (urethane), polysulfone, polyethersulfone, nylon, polyether, polyester, polystyrene, acrylic polymer, polyurea, polyamide, polyvinyl chloride (Alkyl) acrylates, poly (alkyl) methacrylates, polyamides, polyetherimides, polyacrylamides, polyamides, polyamides, A polymer, a protein, a polysaccharide, a polyacetate, and a combination of at least two of the above-mentioned, formed of polyketone, epoxy, silicone, ethylene propylene diene monomer. Preferably, the liquid prepolymer is polymerized to form a material comprising poly (urethane). More preferably, the liquid prepolymer is polymerized to form a material comprising a polyurethane. Most preferably, the liquid prepolymer polymerizes (cures) to form a polyurethane.

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

Preferably, the polyisocyanate is selected from the group consisting of methylene bis 4,4'-cyclohexyl-isocyanate; Cyclohexyl diisocyanate; Isophorone diisocyanate; Hexamethylene diisocyanate; Propylene-1,2-diisocyanate; Tetramethylene-1,4-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; Methylcyclohexylenediisocyanate; Triisocyanates of hexamethylene diisocyanate; Triisocyanates of 2,4,4-trimethyl-1,6-hexane diisocyanate; Strution of hexamethylene diisocyanate; 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 in conjunction with the present invention is a polyol. Exemplary polyols include, for example, polyether polyols, hydroxy-terminated polybutadienes (including partially and fully hydrogenated derivatives), polyester polyols, polycaprolactone polyols, polycarbonate polyols, and mixtures thereof do.

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 may have saturated or unsaturated bonds and substituted or unsubstituted aromatic and cyclic groups. Preferably, the polyol of the present invention includes PTMEG. Suitable polyester polyols include, but are not limited to, polyethylene adipate glycols; Polybutylene adipate glycol; Polyethylene propylene adipate glycol; o-phthalate-1,6-hexanediol; Poly (hexamethylene adipate) glycol; And mixtures thereof. The hydrocarbon chain may have a saturated or an unsaturated bond, or a substituted or unsubstituted aromatic and cyclic group. Suitable polycaprolactone polyols include, but are not limited to, 1,6-hexanediol-initiated polycaprolactones; Diethylene glycol disclosed polycaprolactone; Trimethylol propane disclosed polycaprolactone; Neopentyl glycol disclosed polycaprolactone; 1,4-butanediol-initiated polycaprolactone; PTMEG-initiated polycaprolactone; And mixtures thereof. The hydrocarbon chain may have a saturated or an unsaturated bond, or a substituted or unsubstituted aromatic and cyclic group. Suitable polycarbonates include, but are not limited to, polyphthalate carbonates and poly (hexamethylene carbonate) glycols.

Preferably, the plurality of trace elements are selected from the group consisting of trapped gaseous foam, hollow core polymer material (i.e., microspheres), liquid filled hollow core polymer material, water soluble material (e.g., cyclodextrin) For example, mineral oil). Preferably, the plurality of trace elements are microspheres such as polyvinyl alcohol, pectin, polyvinylpyrrolidone, hydroxyethylcellulose, methylcellulose, hydroxymethylcellulose, carboxymethylcellulose, hydroxypropylcellulose, polyacrylic acid , Polyacrylamide, polyethylene glycol, polyhydroxyether acrylate, starch, maleic acid copolymer, polyethylene oxide, polyurethane, cyclodextrin and combinations thereof (e.g., Expancel ™ from Akzo Nobel, Sundsvall, Sweden) . The microspheres may be chemically modified to change solubility, swelling and other properties, for example, by branching, blocking and cross-linking. Preferably, the microspheres have an average diameter of less than 150 mu m, more preferably less than 50 mu m. Most preferably, the microspheres 48 have an average diameter of less than 15 [mu] m. Note that the average diameter of the microspheres can vary and mixtures of microspheres 48 of different sizes or different sizes can be used. The most preferred materials for the microspheres are acrylonitrile and copolymers of vinylidene chloride (e.g., Expancel (R), available from Akzo Nobel).

The liquid prepolymer used in the process 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 include, but are not limited to, diethyltoluenediamine ("DETDA"); 3,5-dimethylthio-2,4-toluenediamine and isomers thereof; 3,5-diethyltoluene-2,4-diamine and isomers thereof (for example, 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"); Methylene-bis 2-chloroaniline ("MBOCA"); 4,4'-methylene-bis- (2-chloroaniline) ("MOCA"); 4,4'-methylene-bis- (2,6-diethylaniline) ("MDEA"); 4,4'-methylene-bis- (2,3-dichloroaniline) ("MDCA"); 4,4'-diamino-3,3'-diethyl-5,5'-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 isomers thereof.

The curing agent may also include diols, triols, tetraols, and hydroxy-terminated curing agents. Suitable diols, triols, and tetraol groups include ethylene glycol; Diethylene glycol; Polyethylene glycol; Propylene glycol; Polypropylene glycol; Low molecular weight polytetramethylene ether glycol; 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; 1,5-pentanediol; 1,6-hexanediol; Resorcinol-di- (beta-hydroxyethyl) ether; Hydroquinone-di- (beta -hydroxyethyl) ether; And mixtures thereof. Preferred hydroxy-terminated curing agents include 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 diamine curing agent may include one or more saturated, unsaturated, aromatic, and cyclic groups. Additionally, the hydroxy-terminated diamine curing agent may include one or more halogen groups.

Preferably, in the method of the present invention, the cured cake is skimmed into a plurality of skived sheets of a desired thickness using a sky bar blades having a cutting edge. Preferably, the stripping compound is applied as a cutting edge of the skyburst blade, and the cutting edges are polished using a strip before skiving the cake into the plurality of skived sheets. The strapping compound used in the process of the present invention preferably comprises an aluminum oxide abrasive dispersed in a fatty acid. More preferably, the stripping compound used in the process of the present invention comprises 70 to 82 wt% aluminum oxide abrasive dispersed in 18 to 35 wt% fatty acid. The strip used in the method of the present invention is preferably a leather strip. Most preferably, the strip used in the method of the present invention is a leather strip designed for use with a rotary tool (e.g., Dremel ^® rotary tool).

Preferably, in the method of the present invention, the cured cake is heated to promote the skiving process. Preferably, the cured cakes are heated using an infrared heating lamp during the skiving process in which the cured cake is skived to a plurality of skived sheets.

Preferably, in the method of the present invention, the cured cake is skived to form a plurality of skived sheets, and the average thickness T _{S- avg} of the _skiveded sheet is 500 to 5,000 mu m (preferably 750 to 4,000 mu m More preferably 1,000 to 3,000 mu m, most preferably 1,200 to 2,100 mu m).

Preferably, in the method of the present invention, the automated inspection system includes a reservoir designed to hold, store, and dispense a skived sheet. Preferably, the reservoir comprises at least 10 skived sheets (more preferably at least 15 skived sheets; even more preferably at least 20 skived sheets; most preferably, at least 30 skive beds The sheet having a design capacity for holding the sheet. The storage design capability allows the operator to load a number of skived sheets into an automated inspection system. Once a plurality of skived sheets have been loaded into the repository, the operator may perform other tasks while the automated inspection system processes the plurality of skived sheets and classifies them as acceptable or faulty estimates.

Preferably, in the method of the present invention, the automated inspection system transports the skived sheets one at a time from the storage; Delivering the skived sheets one at a time between the light source and the photodetector; Includes mechanisms to return the skived sheets one at a time, back to storage. Preferably, at least one linear motor is included in the mechanism. More preferably, the mechanism includes at least one liner motor having a linear graduation resolution of < RTI ID = 0.0 > 1 < / RTI >

Preferably, in the method of the present invention, the automated inspection system includes a light source that emits a beam. Preferably, the beam emitted by the light source represents an emission spectrum comprising wavelengths of visible, ultraviolet and infrared regions. The light source may be a broad band source (e.g., a white light source) or a narrow band source (e.g., 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, and the beam has a wavelength of 460 to 490 nm (preferably 460 to 480 nm, more preferably 460 to 470, most preferably, 463 to 467 nm) And an emission spectrum having an overall width FWHM at a maximum half of? 50 nm (preferably? 40 nm; more preferably? 35 nm; most preferably? 30 nm). One of ordinary skill or ordinary skill in the art will be able to select an appropriate light source to provide a beam having an emission spectrum in a desired region. Preferably, in the method of the present invention, the automated inspection system comprises a light source, wherein the light source is a light emitting diode.

Preferably, in the method of the present invention, the automated inspection system includes a photodetector capable of switching at least one detectable characteristic of light transmitted from the beam transmitted through the thickness, T _s , out of the transmitting surface of the skiveded sheet . More preferably, in the method of the invention, the automated inspection system includes a photodetector capable of switching the intensity of light transmitted from the beam transmitted through the thickness, T _s , out of the transmitting surface of the skived sheet. Most preferably, in the method of the present invention, the automated inspection system includes a photodetector capable of switching the thickness out of the transmission surface of the skived sheet, the intensity of the light transmitted from the beam transmitted through T _s , and the wavelength spectrum do. Preferably, the photodetector is an optoelectronic switching device, which converts at least one detectable characteristic of the transmitted light incident thereon to an electrical signal. Preferably, the photodetector is an array of charge coupled devices (CCDs). Preferably, the charge coupled devices (CCDs) used are selected from monochrome and color CCDs. More preferably, the photodetector comprises an array of at least 5 (most preferably, at least 8) optoelectronic conversion devices. Most preferably, the photodetector has at least eight charge coupled devices (CCDs) having a resolution of? 20 μm (preferably? 16 μm) and a view field of? 100 mm (preferably? 120 mm) ) ≪ / RTI > array of image sensors.

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

The heterogeneous nature of a sheet that has been skimmed from a polymeric material cake containing a plurality of trace elements makes a reference to a hypothetical standard sheet impractical. That is, the presence of a variety of harmless production artifacts in such a skived sheet can be used for standard values for use in automated systems for inspection of skived sheets for incorporation into a polishing layer from a chemical mechanical polishing pad Makes simple grayscale comparisons ineffective.

General purpose and special purpose image data processing devices suitable for use with the present invention are well known in the art. Preferably, the image data processing device in the automated inspection system used in the present invention comprises 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 controllers (e.g., a mouse, keyboard) and at least one output display.

Preferably, the image data processing device is configured to detect macroscopic non-uniformities in the skived sheets and to classify the skived sheets into acceptable or defective estimates. Preferably, the classification of the skived sheets as acceptable or defective estimates is performed by an image data processing apparatus based on a quality control reference menu. During manufacture of the skived sheet, various defects can occur, including, for example, poor density, poor air holes and poor coverage. Note that any one or combination of these defects may constitute macroscopic non-uniformity in the skived sheet depending on the size of the corresponding portion of the transmission surface. Note that various types of defects will exist differently in the photodetector. In poor density and air holes, the defective area will be more transparent than the surrounding area of the skived sheet. In poor containment, the defective area will be less transparent than the surrounding area of the skived sheet. Whether such defects are permissible depends, for example, on a number of conditions, including the substrate on which the chemical mechanical polishing pad incorporating the skived sheet is to be subjected to polishing. Some substrates are more sensitive than others, requiring more rigorous control over the homogeneity of the smoothed sheet to be used as the polishing layer in the chemical mechanical polishing pads made for their polishing.

Preferably, in the method of the present invention, the step (the polishing layer 120 to form a polishing layer 120 of the processed at least one acceptable sheet of the chemical mechanical polishing pad 110 is employed for the removal of the substrate (A) forming at least one groove into an acceptable sheet to form a groove pattern, and (b) forming at least one of the steps of: (a) forming a perforation at least partially extending through the thickness of the permissible sheet, T _s To form a polishing surface 114. [0034] More preferably, the step of forming the polishing layer 120 of the in the process of the present invention, processing the at least one acceptable sheet of the chemical mechanical polishing pad 110 (the polishing layer 120 is employed for the removal of the substrate Includes forming a polishing surface 114 by machining at least one groove into an acceptable sheet to form a groove pattern. Most preferably the step of forming the polishing layer 120 of the in the process of the present invention, processing the at least one acceptable sheet of the chemical mechanical polishing pad 110 (the polishing layer 120 is employed for the removal of the substrate Comprises forming a polishing surface 114 by machining at least one groove into an acceptable sheet to form a groove pattern; The groove pattern is employed for polishing the substrate (see FIG. 3 ).

Preferably, the chemical mechanical polishing pad 110 produced using the method of the present invention is preferably employed for rotation about the central axis 112 (see FIG. 3 ). Preferably, at least one groove is arranged to form the polishing surface 114 such that at least one groove passes over the substrate during rotation of the pad 110 relative to the central axis 112 during polishing. Preferably, the at least one groove is selected from a curved groove, a linear groove, and combinations thereof. Preferably, at least one groove represents a depth of? 10 mils (preferably 10 to 150 mils). Preferably, the at least one groove has a depth selected from? 10 mils,? 15 mils and 15 to 150 mils; A width selected from? 10 mils and 10 to 100 mils; And at least two grooves having a combination of pitches selected from? 30 mils,? 50 mils, 50-200 mils, 70-200 mils, and 90-200 mils.

Preferably, the skiveded sheet incorporated into the polishing layer 120 into the chemical mechanical polishing pad 110 contains <1 ppm abrasive particles incorporated therein.

Preferably, the acceptable sheet processing step comprises providing a subpad 125 having a top surface 126 and a bottom surface 127 ; Providing the adhesive 123 (preferably, the adhesive is selected from at least one of a pressure-sensitive adhesive, a hot-melt adhesive and a contact adhesive; more preferably, the adhesive is selected from a pressure-sensitive adhesive and a hot- Most preferably, the adhesive is a hot melt adhesive); And the upper surface 126 of the subpad 125 to the base surface 117 of the polishing layer 120 using the adhesive 123 (see FIG. 3 ).

Preferably, in the method of the present invention, at least one permissible sheet is machined to form an abrasive layer 120 of the chemical mechanical polishing pad 110 , wherein the abrasive layer 120 is employed to abrade the substrate Further comprises providing a pressure-sensitive planarizing adhesive layer ( 170 ) applied to a lower surface ( 127 ) of the subpad ( 125 ).

Preferably, in the method of the present invention, at least one permissible sheet is machined to form an abrasive layer 120 of the chemical mechanical polishing pad 110 , wherein the abrasive layer 120 is employed to abrade the substrate Providing a pressure sensitive planarizing adhesive layer ( 170 ) applied to a lower surface ( 127 ) of the subpad ( 125 ); And between the step of providing a release liner 175 is applied over the pressure-leveling adhesive layer 170 (the pressure-leveling adhesive layer 170 is the bottom surface of the subpad 125, 127 and release liner 175 (See FIG. 3 ).

The incorporation of the subpad 125 into the chemical mechanical polishing pad 110 of the present invention is desirable for certain abrasive applications. Those of skill in the art will be able to choose appropriate material and subpad thickness, T _B, for subpad 125 for use in an intended polishing process. Preferably, the subpad 150 has an average subpad thickness, T _B-avg , of? 15 mils (more preferably 30 to 100 mils; most preferably 30 to 75 mils).

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 present invention, at least one permissible sheet is machined to form an abrasive layer 120 of the chemical mechanical polishing pad 110 , wherein the abrasive layer 120 is employed to abrade the substrate Further comprises providing at least one additional layer (not shown) facing the abrasive layer 120 and the pressure-sensitive, planarizing adhesive layer 170 and sandwiched therebetween. At least one additional layer (not shown) may be incorporated into the chemical mechanical polishing pad 110 using an additional layer adhesive (not shown). Additional layer adhesives can be selected from pressure sensitive adhesives, hot melt adhesives, contact adhesives, and combinations thereof. Preferably, the further layer adhesive is a hot melt adhesive or a pressure sensitive adhesive. More preferably, the further layer adhesive is a hot melt adhesive.

Preferably, the chemical mechanical polishing pad 110 of the present invention is specifically designed to promote polishing of a substrate selected from at least one of a magnetic substrate, an optical substrate, and a semiconductor substrate. Preferably, the sheet incorporated as the polishing layer 120 into the chemical mechanical polishing pad 110 comprises at least one of a magnetic substrate, an optical substrate and a semiconductor substrate (more preferably a semiconductor substrate, most preferably a semiconductor wafer) Lt; RTI ID = 0.0 &gt; polishing &lt; / RTI &gt;

In the method of the present invention, the population of bad estimation sheets includes at least one bad estimation sheet, the at least one bad estimation sheet contains at least one detected macroscopic non-uniformity; The image data processing device is preferably further configured to generate and store in the non-volatile memory a map of at least one bad estimation sheet, wherein at least one location for the detected macroscopic non-uniformity is determined.

Preferably, the method further comprises the step of selecting a selection sheet from the bad estimate sheet population; The population of bad estimate sheets includes at least one bad estimate sheet, the at least one bad estimate sheet contains at least one detected macroscopic non-uniformity; The image data processing device is preferably further configured to generate and store in the non-volatile memory a map of at least one bad estimation sheet, wherein at least one location for the detected macroscopic non-uniformity is determined.

Preferably, the method further comprises the step of selecting a selection sheet from the bad estimate sheet population; The population of bad estimate sheets includes at least one bad estimate sheet, the at least one bad estimate sheet contains at least one detected macroscopic non-uniformity; The image data processing device is preferably further configured to generate and store a map of at least one bad estimation sheet in a non-volatile memory, wherein a position is determined for at least one detected macroscopic non-uniformity; The automated inspection system further comprising a display; An image of the selected sheet is displayed on the display. The displayed image of the selected sheet on the display may be the entire image of the transmitting surface of the selected sheet. Preferably, the image of the selection sheet is a partial image representing an enlargement of at least one detected macroscopic non-uniformity. Preferably, the partial image of the selected sheet displayed on the display includes the entire macroscopic non-uniformity and the peripheral area of the transmissive surface of the selected sheet. Preferably, the partial image of the selected sheet displayed on the display is enlarged to enhance the details of the displayed image to facilitate visual inspection of the selected sheet. Preferably, the method of the present invention includes performing a visual inspection of the selected sheet, said visual inspection being facilitated by an image of a selected sheet displayed on the display; And (i) reclassifying the selection sheet as acceptable based on the visual inspection (the selection sheet is then added to an acceptable sheet set); Or (ii) classifying the selected sheet as defective based on the visual inspection (the selected sheet is then added to the defective sheet group).

Claims (9)

A method of making a chemical mechanical polishing pad having an abrasive layer, comprising the steps of:
Providing a cured cake formed of a curable material, wherein the curable material comprises a liquid prepolymer and a plurality of trace elements, wherein the plurality of trace elements are dispersed in the liquid prepolymer step;
Skiving the cured cake to form a plurality of skived sheets;
Providing an automated inspection system comprising a reservoir, a light source emitting the beam, a photodetector, a digital image data acquisition device, and an image data processing device;
Loading the plurality of skived sheets into the reservoir;
Conveying the plurality of skived sheets one by one, between the light source and the photodetector, one skiveded sheet at a time,
Each of the Sky The ice sheet has a thickness (T _S) between the permeate surface and the collision surface (impinging surface); The transmissive surface and the impingement surface being substantially parallel;
The beam emitted from the light source is oriented to impinge on the impingement surface; The photodetector being oriented to detect light transmitted from the beam that is transmitted through the thickness T _S out of the transmitting surface;
The transmitted light having at least one detectable characteristic;
Wherein the at least one detectable characteristic comprises an intensity of transmitted light;
The intensity of the transmitted light being converted to an electrical signal by the photodetector;
Wherein the electrical signal from the photodetector is converted into a digital signal by the digital image data acquisition device;
Wherein the digital signal from the digital image data acquisition device is processed by the image data processing device and the image data processing device is configured to detect macroscopic non-uniformity and classify the skiveded sheet as acceptable or defective;
Wherein the plurality of skived sheets are divided into an allowable sheet population and a bad estimate sheet group;
The permissible sheet population comprising at least one permissible sheet; And
Machining an acceptable sheet from said allowable sheet population to form an abrasive layer of said chemical mechanical polishing pad, said abrasive layer being employed for polishing a substrate. The system according to claim 1, wherein the defect estimation sheet group includes at least one defect estimation sheet; Wherein the at least one bad estimation sheet contains at least one detected macroscopic non-uniformity; Wherein the image data processing device is further configured to generate and store a map of the at least one bad estimation sheet in a non-volatile memory, wherein a position for the at least one detected macrosomonal non-uniformity is determined, . 3. The method of claim 2, further comprising employing a selection sheet from the defect estimating sheet population. 4. The method of claim 3, wherein the automated inspection system further comprises a display, wherein an image of the selection sheet is displayed on the display. The method of claim 4,
Performing a visual inspection of said selection sheet, said visual inspection being facilitated by said image of said selection sheet displayed on said display; And
(i) reclassifying the selection sheet as permissible based on the visual inspection, wherein the selection sheet is then added to the allowable sheet population; Or (ii) classifying the selection sheet as defective based on the visual inspection, wherein the selection sheet is then added to the defective sheet population. &Lt; RTI ID = 0.0 &gt; Way. 5. The method of claim 4, wherein the image of the selection sheet is a partial image that represents an enlargement of at least one detected macroscopic non-uniformity. The method of claim 6,
Performing a visual inspection of the selection sheet, the visual inspection being facilitated by the image of the selection sheet displayed on the display; And
(i) reclassifying the selection sheet as permissible based on the visual inspection, wherein the selection sheet is added to the allowable sheet population; Or (ii) classifying the selection sheet as defective based on the visual inspection, wherein the selection sheet is added to the defective sheet population. &Lt; RTI ID = 0.0 &gt; . The method of claim 1, wherein machining the permissible sheet comprises:
And forming at least one groove in the allowable sheet to form a groove pattern to form a polishing surface,
Wherein the groove pattern is employed for polishing the substrate. 9. The method of claim 8, wherein machining the permissible sheet comprises:
Providing a subpad;
Providing an adhesive; And
Further comprising laminating the subpad to the permissible sheet using the adhesive. &Lt; Desc / Clms Page number 20 &gt;

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