JP2008246635A - Manufacturing method of polishing pad - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for effectively manufacturing a polishing pad having a plurality of grooves only in a lengthy polishing region, and also to provide a groove working device used for groove working of the polishing pad. <P>SOLUTION: This manufacturing method to form a plurality of grooves on a lengthy polishing layer surface 1 having the lengthy polishing region 2 and a lengthy light transmittance region 3, is constituted: to set the lengthy polishing layer surface 1 so that a light reflecting member 5 and the lengthy light transmittance region are overlapped on each other, to irradiate light on the lengthy polishing layer surface 1 from a luminous part 8 while moving an optical sensor from one end in the cross direction of the lengthy polishing layer 1 to the other by using a cutting tool furnished on a cutting head 6; to control a cutting blade 10 of the cutting tool so as not to make contact with the lengthy light transmittance region 3 until a light receiving part 9 does not detect reflecting light when the light receiving part 9 detects the reflecting light; to cut the lengthy polishing region 2 by making the cutting blade of the cutting tool contact with the lengthy polishing region 2 again when the light receiving part does not detect the reflecting light again; and to form a plurality of the grooves only on the lengthy polishing region 2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a polishing pad used when planarizing unevenness on a wafer surface by chemical mechanical polishing (CMP), and more particularly, to a method for manufacturing a polishing pad having multiple grooves only in a polishing region. .

  When manufacturing a semiconductor device, a step of forming a conductive layer on the wafer surface and forming a wiring layer by photolithography, etching, or the like, or a step of forming an interlayer insulating film on the wiring layer These steps cause irregularities made of a conductor such as metal or an insulator on the wafer surface. In recent years, miniaturization of wiring and multilayer wiring have been advanced for the purpose of increasing the density of semiconductor integrated circuits, and along with this, technology for flattening the irregularities on the wafer surface has become important.

  As a method for flattening the irregularities on the wafer surface, chemical mechanical polishing (hereinafter referred to as CMP) is generally employed. CMP is a technique of polishing using a slurry-like abrasive (hereinafter referred to as slurry) in which abrasive grains are dispersed in a state where the surface to be polished of a wafer is pressed against the polishing surface of a polishing pad.

  In performing such a CMP process, the slurry that is constantly supplied is uniformly supplied to the upper surface of the wafer and does not stay at a certain position on the surface of the wafer, and is newly supplied. Need to be updated. Therefore, the polishing surface of a conventionally used polishing pad is provided with XY lattice grooves, concentric circular grooves, through holes, non-through holes, polygonal columns, cylinders, spiral grooves, eccentric circular grooves, radial grooves, etc. It has been. These grooves are usually formed using a cutting tool having a groove cutting blade.

  Further, when performing the CMP process, there is a problem of determining the flatness of the wafer surface. In other words, it is necessary to detect when the desired surface characteristics or planar state is reached. Conventionally, with regard to the thickness of the oxide film, the polishing rate, and the like, a test wafer is periodically processed, and after confirming the result, a product wafer is polished.

  However, in this method, the time and cost for processing the test wafer are wasted, and the polishing result differs between the test wafer and the product wafer that have not been processed in advance due to the loading effect peculiar to CMP. If it is not actually processed, it is difficult to accurately predict the processing result.

  Therefore, recently, in order to solve the above-mentioned problems, there is a demand for a method capable of detecting a point in time when desired surface characteristics and thickness are obtained in the CMP process. Various methods are used for such detection. From the viewpoint of measurement accuracy and spatial resolution in non-contact measurement, there is an optical detection method in which a film thickness monitoring mechanism using a laser beam is incorporated in a rotating platen. It is becoming mainstream.

  Specifically, the optical detection method detects an end point of polishing by irradiating a wafer with a light beam through a window (light transmission region) through a polishing pad and monitoring an interference signal generated by the reflection. Is the method.

  In such a method, the end point is determined by monitoring the change in the thickness of the surface layer of the wafer and knowing the approximate depth of the surface irregularities. When such a change in thickness becomes equal to the depth of the unevenness, the CMP process is terminated. Various methods have been proposed for the polishing end point detection method using such optical means and the polishing pad used in the method.

  For example, a polishing pad having at least a part of a transparent polymer sheet that transmits solid and homogeneous light having a wavelength of 190 nm to 3500 nm is disclosed (Patent Document 1). Further, a polishing pad in which a stepped transparent plug is inserted is disclosed (Patent Document 2). Further, a polishing pad having a transparent plug that is flush with the polishing surface is disclosed (Patent Document 3).

  On the other hand, proposals (Patent Documents 4 and 5) for preventing the slurry from leaking from the boundary (seam) between the polishing region and the light transmission region have also been made. However, even when these transparent leakage prevention sheets are provided, the slurry leaks from the boundary (seam) between the polishing region and the light transmission region to the lower part of the polishing layer, and the slurry accumulates on the leakage prevention sheet to cause an optical end point. Problems with detection.

  In order to solve the above problem of slurry leakage, a method of integrally forming a pad body and a window member has been proposed (Patent Document 6). Specifically, a block of a window member is placed in a mold, an opaque resin for forming a pad body is injected into the mold to obtain a molded product, and then a polishing pad is manufactured by slicing. is there.

  Here, the groove is provided on the polishing area surface of the polishing pad as described above, but the groove is not provided on the surface of the light transmission area in order to prevent slurry from accumulating and adversely affecting optical detection. Is preferred. However, when the pad main body and the window member are integrally molded as in Patent Document 6, it is difficult and complicated in the manufacturing process to form the groove only in the pad main body after the pad molding. In order to solve this problem, in Patent Document 6, the polishing pad is fixed on a surface plate equipped with a suction device, and the window member is recessed by suction, and in that state, the pad body is used by using a cutting blade. A method for forming a groove is proposed. In this case, it is described that no groove is formed on the surface of the window member because the tip of the cutting blade does not reach the surface of the window member on the recess.

  However, in the method of Patent Document 6, since the window member needs to be sufficiently recessed by suction, the window member may be deformed or the pad body and the window member may be peeled off. Moreover, it is difficult to form a groove in a portion close to the periphery of the window member. Further, in the case of a long polishing pad, the surface plate provided with the suction device becomes very large, and there is a problem that the manufacturing disadvantage is large.

Japanese National Patent Publication No. 11-512977 Japanese Patent Laid-Open No. 9-7985 Japanese Patent Laid-Open No. 10-83977 JP 2001-291686 A Japanese translation of PCT publication No. 2003-510826 JP 2002-1647 A

  An object of this invention is to provide the method of manufacturing efficiently the polishing pad which has many groove | channels only in a long polishing area | region. Moreover, it aims at providing the groove processing apparatus used for the groove processing of the said polishing pad.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the above object can be achieved by the production method shown below, and have completed the present invention.

That is, the first aspect of the present invention is a polishing pad manufacturing method including a step of forming multiple grooves by cutting on a surface of a long polishing layer having a long polishing region and a long light transmission region.
On the surface plate having the light reflecting member, a long polishing layer is installed so that the light reflecting member and the long light transmission region overlap,
Using a cutting tool equipped with a cutting head with an optical sensor having a light emitting part and a light receiving part,
1) While irradiating the surface of the long polishing layer from the light emitting part while moving the cutting tool from one end to the other end in the width direction of the long polishing layer,
2) When the light receiving part does not detect the reflected light, the cutting blade of the cutting tool is brought into contact with the long polishing region and cut.
3) When the light receiving unit detects the reflected light, control so that the cutting blade of the cutting tool does not contact the long light transmission region until at least the light receiving unit does not detect the reflected light.
4) When the light receiving part stops detecting the reflected light again, the cutting blade of the cutting tool is again brought into contact with the long polishing region and cut.
5) When the cutting tool reaches the other end of the long polishing layer, the cutting blade is separated from the long polishing region, and the long polishing layer or the cutting head is moved by a predetermined length in a predetermined direction,
The present invention relates to a method for producing a polishing pad, wherein the operations of 1) to 5) are repeated to form multiple grooves only in a long polishing region.

  The above method is characterized in that a cutting tool provided with a light head and a light sensor having a light receiving portion in a cutting head is used. The long polishing region is opaque and the long light transmission region is transparent. When the optical sensor is moving on the long polishing region, the reflected light from the long polishing region does not reach the light receiving unit, and when the optical sensor is moving on the long light transmitting region, the optical sensor is fixed. The light reflected by the light reflecting member provided on the board is adjusted so as to reach the light receiving unit. As a result, the optical sensor can detect whether it is a long polishing area or a long light transmission area depending on whether or not light reaches the light receiving part, and the cutting tool is selected only for the long polishing area. Thus, a groove can be formed. According to the above method, a long polishing pad having grooves only in the long polishing region can be continuously and efficiently manufactured, and the groove processing apparatus can be made compact, resulting in an increase in manufacturing space. There is an advantage that there is nothing.

  Further, the groove processing apparatus of the present invention supports and fixes a polishing pad including a long polishing layer having a long polishing region and a long light transmission region, and a light reflecting member at a portion corresponding to the long light transmission region. A cutting tool equipped with a surface plate having a light emitting part and a light receiving part in the cutting head, and when the cutting tool has finished moving from one end to the other in the width direction of the long polishing layer, the polishing pad is moved to a predetermined length. A control unit for moving in the conveying direction, a supply roll for feeding the polishing pad, and a recovery roll for winding the grooved polishing pad are provided.

  The optical sensor is preferably installed on the cutting head so that the position where the light emitted from the light emitting part is reflected by the light reflecting member surface and the tip of the cutting blade are aligned on the same straight line. Thereby, not only can the cutting scratches be prevented on the surface of the long light transmission region, but also the groove can be formed close to the boundary between the long polishing region and the long light transmission region.

Further, the second aspect of the present invention is a polishing pad manufacturing method including a step of forming multiple grooves by cutting on a surface of a long polishing layer having a long polishing region and a long light transmission region.
On the surface plate having the light reflecting member, a long polishing layer is installed so that the light reflecting member and the long light transmission region overlap,
Using a cutting tool provided with optical sensors A and B having a light emitting part and a light receiving part at the front and rear of the cutting head,
1) While irradiating the surface of the long polishing layer from the light emitting portions of the optical sensors A and B while moving the cutting tool from one end to the other end in the width direction of the long polishing layer,
2) When the light receiving portions of the optical sensors A and B do not detect the reflected light, the cutting blade of the cutting tool is brought into contact with the long polishing region and cut.
3) When the light receiving portion of the optical sensor A detects the reflected light, the cutting blade of the cutting tool is controlled so as not to contact the long light transmission region,
4) When the light receiving parts of the optical sensors A and B stop detecting the reflected light again, the cutting blade of the cutting tool is again brought into contact with the long polishing region and cut.
5) When the cutting tool reaches the other end of the long polishing layer, the cutting blade is separated from the long polishing region, and the long polishing layer or the cutting head is moved by a predetermined length in a predetermined direction,
The present invention relates to a method for producing a polishing pad, wherein the operations of 1) to 5) are repeated to form multiple grooves only in a long polishing region.

Further, the third aspect of the present invention is a polishing pad manufacturing method comprising a step of forming multiple grooves by cutting on the surface of a long polishing layer having a long polishing region and a long light transmission region,
On the surface plate having the light reflecting member, a long polishing layer is installed so that the light reflecting member and the long light transmission region overlap,
Using a cutting tool provided with optical sensors A and B having a light emitting part and a light receiving part at the front and rear of the cutting head,
1) While irradiating the surface of the long polishing layer from the light emitting portions of the optical sensors A and B while moving the cutting tool from one end to the other end in the width direction of the long polishing layer,
2) When the light receiving portions of the optical sensors A and B do not detect the reflected light, the cutting blade of the cutting tool is brought into contact with the long polishing region and cut.
3) When the light receiving portion of the optical sensor A detects the reflected light, the cutting blade of the cutting tool is controlled so as not to contact the long light transmission region,
4) When the light receiving part of the optical sensor B detects the reflected light, the cutting blade of the cutting tool is again brought into contact with the long polishing region for cutting,
5) When the cutting tool reaches the other end of the long polishing layer, the cutting blade is separated from the long polishing region, and the long polishing layer or the cutting head is moved by a predetermined length in a predetermined direction,
The present invention relates to a method for producing a polishing pad, wherein the operations of 1) to 5) are repeated to form multiple grooves only in a long polishing region.

  The second and third aspects of the present invention are applications of the first aspect of the present invention, and are characterized in that a cutting tool provided with two optical sensors having a light emitting part and a light receiving part in a cutting head is used. By using two optical sensors, even when a cutting blade having a wide blade width, such as a circular rotary blade, is used, it is possible to prevent the surface of the long light transmission region from being scratched, and the long polishing region and the long light. Grooves can be formed close to the boundary of the transmission region.

  The polishing pad of the present invention includes a long polishing layer having a long polishing region and a long light transmission region. The polishing pad of the present invention may be only the long polishing layer, or may be a laminate of the long polishing layer and other layers (for example, a cushion layer, a transparent support film, etc.).

  The long polishing region is not particularly limited as long as it is a foam having fine bubbles. For example, polyurethane resin, polyester resin, polyamide resin, acrylic resin, polycarbonate resin, halogen resin (polyvinyl chloride, polytetrafluoroethylene, polyvinylidene fluoride, etc.), polystyrene, olefin resin (polyethylene, polypropylene, etc.), epoxy resin 1 type, or 2 or more types of mixtures, such as a photosensitive resin, is mentioned. Polyurethane resin is a particularly preferable material for forming a long polishing region because it has excellent wear resistance and a polymer having desired physical properties can be easily obtained by variously changing the raw material composition. Hereinafter, the polyurethane resin will be described on behalf of the foam.

  The polyurethane is composed of an isocyanate component, a polyol component (high molecular weight polyol, low molecular weight polyol), and a chain extender.

  As the isocyanate component, a known compound in the field of polyurethane can be used without particular limitation. As the isocyanate component, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 2,2′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, aromatic diisocyanates such as p-phenylene diisocyanate, m-phenylene diisocyanate, p-xylylene diisocyanate, m-xylylene diisocyanate, ethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 1,6-hexamethylene diisocyanate, etc. Aliphatic diisocyanate, 1,4-cyclohexane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate Isocyanate, alicyclic diisocyanates such as norbornane diisocyanate. These may be used alone or in combination of two or more.

  Examples of the high molecular weight polyol include polyether polyols typified by polytetramethylene ether glycol, polyester polyols typified by polybutylene adipate, polycaprolactone polyol, and a reaction product of a polyester glycol such as polycaprolactone and alkylene carbonate. Polyester polycarbonate polyol, polyester polycarbonate polyol obtained by reacting ethylene carbonate with polyhydric alcohol and then reacting the resulting reaction mixture with organic dicarboxylic acid, and polycarbonate polyol obtained by transesterification reaction between polyhydroxyl compound and aryl carbonate Etc. These may be used alone or in combination of two or more.

  In addition to the above-described high molecular weight polyol as a polyol component, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, 1,4 -Low molecular weight polyols such as cyclohexanedimethanol, 3-methyl-1,5-pentanediol, diethylene glycol, triethylene glycol, 1,4-bis (2-hydroxyethoxy) benzene may be used in combination. Low molecular weight polyamines such as ethylenediamine, tolylenediamine, diphenylmethanediamine and diethylenetriamine may be used.

  The ratio of the high molecular weight polyol to the low molecular weight polyol in the polyol component is determined by the properties required for the long polishing region produced therefrom.

  When a polyurethane foam is produced by a prepolymer method, a chain extender is used for curing the prepolymer. The chain extender is an organic compound having at least two active hydrogen groups, and examples of the active hydrogen group include a hydroxyl group, a primary or secondary amino group, and a thiol group (SH). Specifically, 4,4′-methylenebis (o-chloroaniline) (MOCA), 2,6-dichloro-p-phenylenediamine, 4,4′-methylenebis (2,3-dichloroaniline), 3,5 -Bis (methylthio) -2,4-toluenediamine, 3,5-bis (methylthio) -2,6-toluenediamine, 3,5-diethyltoluene-2,4-diamine, 3,5-diethyltoluene-2 , 6-diamine, trimethylene glycol-di-p-aminobenzoate, 1,2-bis (2-aminophenylthio) ethane, 4,4′-diamino-3,3′-diethyl-5,5′-dimethyl Diphenylmethane, N, N′-di-sec-butyl-4,4′-diaminodiphenylmethane, 3,3′-diethyl-4,4′-diaminodiphenylmethane, m-xyl Diamines, N, N'-di-sec-butyl-p-phenylenediamine, m-phenylenediamine, and polyamines exemplified by p-xylylenediamine, or the above-described low molecular weight polyol components and low molecular weight polyamine components Can be mentioned. These may be used alone or in combination of two or more.

  The ratio of the isocyanate component, the polyol component, and the chain extender in the present invention can be variously changed depending on the molecular weight of each, the desired physical properties of the long polishing region, and the like.

  Polyurethane foam can be produced by either the prepolymer method or the one-shot method, but an isocyanate-terminated prepolymer is synthesized in advance from an isocyanate component and a polyol component, and this is reacted with a chain extender. The method is suitable because the physical properties of the resulting polyurethane are excellent.

  The polyurethane foam is produced by curing a cell-dispersed urethane composition obtained by mixing a first component containing an isocyanate group-containing compound and a second component containing an active hydrogen group-containing compound. In the prepolymer method, the isocyanate-terminated prepolymer becomes an isocyanate group-containing compound, and the chain extender becomes an active hydrogen group-containing compound. In the one-shot method, the isocyanate component becomes an isocyanate group-containing compound, and the chain extender and the polyol component become active hydrogen group-containing compounds.

  The cell-dispersed urethane composition is prepared by a mechanical foaming method (including a mechanical floss method). In particular, a mechanical foaming method using a silicone surfactant which is a copolymer of polyalkylsiloxane and polyether and does not have an active hydrogen group is preferable. As such a silicon-based surfactant, SH-192, L-5340 (manufactured by Toray Dow Corning Silicon) and the like are exemplified as suitable compounds. The addition amount of the silicon-based surfactant is preferably 0.05 to 5% by weight in the polyurethane foam. When the amount of the silicon-based surfactant is less than 0.05% by weight, a fine-bubble foam tends to be not obtained. On the other hand, if it exceeds 5% by weight, it tends to be difficult to obtain a polyurethane foam with high hardness due to the plastic effect of the silicon surfactant.

  In addition, you may add stabilizers, such as antioxidant, a lubricant, a pigment, a filler, an antistatic agent, and another additive as needed.

An example of a method for preparing the cell-dispersed urethane composition will be described below. The method for preparing such a cell dispersed urethane composition has the following steps.
1) Foaming process for producing a cell dispersion of isocyanate-terminated prepolymer A silicon-based surfactant is added to the isocyanate-terminated prepolymer (first component), and the mixture is stirred in the presence of a non-reactive gas to remove the non-reactive gas. Disperse as fine bubbles to obtain a cell dispersion. When the prepolymer is solid at normal temperature, it is preheated to an appropriate temperature and melted before use.
2) Curing agent (chain extender) mixing step A chain extender (second component) is added to the above cell dispersion, mixed and stirred to prepare a cell dispersed urethane composition.

  As the non-reactive gas used to form the fine bubbles, non-flammable gases are preferable, and specific examples include nitrogen, oxygen, carbon dioxide, rare gases such as helium and argon, and mixed gases thereof. In view of cost, it is most preferable to use air that has been dried to remove moisture.

  A known stirring device can be used without particular limitation as a stirring device for dispersing non-reactive gas in the form of fine bubbles and dispersed in the first component containing the silicon-based surfactant. Specifically, a homogenizer, a dissolver, 2 A shaft planetary mixer (planetary mixer) is exemplified. The shape of the stirring blade of the stirring device is not particularly limited, but it is preferable to use a whipper type stirring blade because fine bubbles can be obtained.

  You may add the catalyst which accelerates | stimulates well-known polyurethane reactions, such as a tertiary amine type | system | group, to a cell dispersion | distribution urethane composition. The type and addition amount of the catalyst are selected in consideration of the flow time for pouring the cell-dispersed urethane composition into the long mold after the mixing step or the curing time after discharging it onto the belt conveyor.

  The long light transmission region enables highly accurate optical end point detection in a state where polishing is performed, and the light transmittance is preferably 40% or more over the entire wavelength range of 300 to 800 nm, more preferably light. The transmittance is 50% or more. In addition, the long light transmission region needs to sufficiently transmit the light emitted from the light emitting unit of the optical sensor.

  Examples of the material for the long light transmission region include thermosetting resins such as polyurethane resin, polyester resin, phenol resin, urea resin, melamine resin, epoxy resin, and acrylic resin; polyurethane resin, polyester resin, polyamide resin, cellulose Thermoplastic resins such as polyethylene resins, acrylic resins, polycarbonate resins, halogen resins (polyvinyl chloride, polytetrafluoroethylene, polyvinylidene fluoride, etc.), polystyrene, and olefin resins (polyethylene, polypropylene, etc.); ultraviolet rays and electron beams Examples thereof include a photocurable resin that is cured by light, and a photosensitive resin. These resins may be used alone or in combination of two or more. Among these, it is preferable to use a thermosetting resin, and it is particularly preferable to use a thermosetting polyurethane resin.

Although the manufacturing method in particular of a long polishing layer is not restrict | limited, For example, it can manufacture with the following method.
1) While sending out the face material, a long light transmission region is disposed on the face material. Then, the cell-dispersed urethane composition is continuously discharged onto a face material not provided with the long light transmission region, and another face material is laminated on the discharged cell-dispersed urethane composition to obtain a thickness. A method of integrally forming a long polishing region made of a polyurethane foam by curing the cell-dispersed urethane composition while uniformly adjusting the thickness.
2) A face material is disposed in a long mold, and a long light transmission region is disposed on the face material. Then, the foam-dispersed urethane composition is discharged onto a face material on which the long light transmission region is not disposed, and the discharged foam-dispersed urethane composition is cured to form a long polishing region made of a polyurethane foam. A method of forming integrally.
3) A long polishing region made of polyurethane foam is produced by a casting method or a continuous molding method. And the through-hole for providing a long light transmission area | region in this long grinding | polishing area | region is formed. Then, a method of integrally forming the long light transmission region by pouring the raw material of the long light transmission region into the through hole and curing it.
4) A cylindrical resin block in which the first cylindrical polishing region, the cylindrical light transmission region, and the second cylindrical polishing region are laminated in this order is manufactured by a casting method. A method for producing a long polishing layer comprising a long polishing region and a long light transmission region by slicing the surface portion of the resin block with a predetermined thickness while rotating about the axis of the resin block.

  The thickness of the long polishing layer is not particularly limited, but is usually about 0.8 to 4 mm, and preferably 1.2 to 2.5 mm. Moreover, although the width | variety of a long polishing layer is suitably adjusted according to the polishing apparatus to be used, it is about 50-90 cm normally. Moreover, the width | variety of a long light transmission area | region is about 0.5-3 cm normally.

  The average cell diameter of the polyurethane foam is preferably 30 to 80 μm, more preferably 30 to 60 μm. When deviating from this range, the polishing rate tends to decrease, or the planarity of the polished material (wafer) after polishing tends to decrease.

  Moreover, it is preferable that the specific gravity of a long grinding | polishing area | region is 0.5-1.0. When the specific gravity is less than 0.5, the strength of the surface of the long polishing region decreases, and the planarity (flatness) of the material to be polished tends to deteriorate. On the other hand, when the ratio is larger than 1.0, the number of fine bubbles on the surface of the long polishing region decreases, and the planarization characteristics are good, but the polishing rate tends to deteriorate.

  Moreover, it is preferable that the hardness of a long grinding | polishing area | region is 45 to 65 degree | times with an Asker D hardness meter. When the D hardness is less than 45 degrees, the planarity (flatness) of the material to be polished tends to deteriorate. On the other hand, when the angle is larger than 65 degrees, the planarity is good, but the uniformity (uniformity) of the material to be polished tends to deteriorate.

  Hereinafter, a method for manufacturing a polishing pad including a step of forming multiple grooves by cutting only on the surface of a long polishing region will be described with reference to the drawings.

In the groove forming method of the present invention, on the surface plate having the light reflecting member, a long polishing layer is installed so that the light reflecting member and the long light transmission region overlap,
Using a cutting tool equipped with a cutting head with an optical sensor having a light emitting part and a light receiving part,
1) While irradiating the surface of the long polishing layer from the light emitting part while moving the cutting tool from one end to the other end in the width direction of the long polishing layer,
2) When the light receiving part does not detect the reflected light, the cutting blade of the cutting tool is brought into contact with the long polishing region and cut.
3) When the light receiving unit detects the reflected light, control so that the cutting blade of the cutting tool does not contact the long light transmission region until at least the light receiving unit does not detect the reflected light.
4) When the light receiving part stops detecting the reflected light again, the cutting blade of the cutting tool is again brought into contact with the long polishing region and cut.
5) When the cutting tool reaches the other end of the long polishing layer, the cutting blade is separated from the long polishing region, and the long polishing layer or the cutting head is moved by a predetermined length in a predetermined direction,
The above-mentioned operations 1) to 5) are repeated to form multiple grooves only in the long polishing region.

  FIG. 1 is a schematic cross-sectional view showing a state in which a long polishing layer 1 is installed on a surface plate 4 having a light reflecting member 5 so that the light reflecting member 5 and the long light transmission region 3 overlap each other.

  The platen 4 is not particularly limited as long as it can support the long polishing layer 1, and may be a flat plate or a belt conveyor. The surface plate 4 may have a mechanism for fixing and releasing the long polishing layer 1 by suction.

  The light reflecting member 5 is not particularly limited as long as it has a function of reflecting light. For example, a member having fine irregularities formed on the reflecting surface, a metal film serving as a reflecting layer, and a resin film layer serving as a diffusion layer. The thing laminated | stacked etc. are mentioned. The width of the light reflecting member 5 needs to be equal to or larger than the width of the long light transmission region 3.

  FIGS. 2A and 2B are a schematic side view and a schematic front view of a cutting head 6 including an optical sensor 7 having a light emitting portion 8 and a light receiving portion 9.

  As the optical sensor 7, a general one can be used without particular limitation. For example, a photo interrupter including a light emitting unit 8 made of a light emitting diode (LED) and a light receiving unit 9 made of a photodiode can be mentioned. The light emitting unit 8 and the light receiving unit 9 are each inclined at a predetermined angle so that the light emitted from the light emitting unit 8 is reflected by the surface of the light reflecting member 5 and reaches the light receiving unit 9. The optical sensor 7 is arranged so that the position where incident light is reflected by the surface of the light reflecting member 5 is aligned with the tip of the cutting blade 10 or in front of the tip of the cutting blade 10. Thereby, the surface of the long light transmission region 3 is less likely to be damaged by cutting, and a groove can be formed to the vicinity of the boundary between the long polishing region 2 and the long light transmission region 3.

  In particular, when the circular rotary blade 10 as shown in FIG. 2A is used, the optical sensor 7 is used when the circular rotary blade 10 reaches the boundary point P between the long polishing region 2 and the long light transmission region 3. It is preferable to arrange the light receiving unit 9 so as to receive the reflected light. Thereby, not only can the cutting scratches be prevented from being applied to the surface of the long light transmission region 3, but a groove can be formed up to the boundary between the long polishing region 2 and the long light transmission region 3.

  As the cutting blade 10, a general one can be used without particular limitation, and examples thereof include a circular rotary blade, a cutter, a diamond foil, and the like. The material of the cutting blade 10 is not particularly limited, and examples thereof include carbon steel, alloy steel, high speed steel, cemented carbide, cermet, stellite, ultra high pressure sintered body, and ceramic. Further, the blade angle, the front clearance angle, and the lateral clearance angle can be appropriately changed depending on conditions such as the material to be processed, the groove shape, and the blade material. Further, the cutting blade 10 may be a single blade or a multi-blade unit in which a plurality of single blades are stacked at a predetermined interval.

  FIG. 3 is a schematic configuration diagram showing an example of steps of the groove forming method of the present invention. FIG. 4 is a schematic configuration diagram showing an example of the groove processing apparatus of the present invention. For example, the groove processing apparatus of the present invention supports and fixes a polishing pad including a long polishing layer 1 having a long polishing region 2 and a long light transmission region 3, and corresponds to the long light transmission region 3. A cutting tool having a surface plate (belt conveyor) 4 having a light reflecting member 5 and an optical sensor 7 having a light emitting portion 8 and a light receiving portion 9 in the cutting head 6, and the cutting tool from one end in the width direction of the long polishing layer 1. When it has finished moving to the other end, it has a control unit for moving the polishing pad in the conveying direction by a predetermined length, a supply roll 11 for feeding the polishing pad, and a collection roll 12 for winding the grooved polishing pad.

  First, the cutting tool is moved from one end to the other end in the width direction of the long polishing layer 1 while irradiating light from the light emitting portion 8 toward the surface of the long polishing layer 1. When the cutting blade 10 is moving on the long polishing region 2, the long polishing region 2 absorbs light emitted from the light emitting unit 8, so the light receiving unit 9 does not detect the reflected light. At that time, the cutting tool is controlled so that the cutting blade 10 is brought into contact with the long polishing region 2 to perform cutting.

  Thereafter, when the cutting blade 10 reaches the boundary between the long polishing region 2 and the long light transmission region 3, the light emitted from the light emitting portion 8 passes through the long light transmission region 3, and the transmitted light is light. Reflected by the surface of the reflecting member 5, the light receiving unit 9 detects the reflected light. When detected, the cutting tool is controlled so that the cutting blade 10 does not contact the long light transmission region 3. The control is performed until at least the light receiving unit 9 does not detect the reflected light.

Examples of a method for controlling the cutting blade 10 so as not to contact the long light transmission region 3 include the following methods.
1) As shown in FIG. 3, the movement of the cutting head 6 in the width direction is stopped, and the cutting head 6 is raised at least until the cutting blade 10 is separated from the surface of the long polishing layer 1. Thereafter, the cutting head 6 is moved in the width direction until at least the light receiving unit 9 does not detect the reflected light. When the light receiving unit 9 stops detecting the reflected light again, the movement of the cutting head 6 in the width direction is stopped, and the cutting head 6 is lowered until the cutting blade 10 contacts the surface of the long polishing layer 1. The control method may be performed while adjusting the moving speed without stopping the movement of the cutting head 6 in the width direction.
2) The movement of the cutting head 6 in the width direction is stopped, and only the cutting blade 10 is raised until at least the cutting blade 10 is separated from the surface of the long polishing layer 1. Thereafter, the cutting head 6 is moved in the width direction until at least the light receiving unit 9 does not detect the reflected light. When the light receiving unit 9 stops detecting the reflected light again, the movement of the cutting head 6 in the width direction is stopped and the cutting blade 10 is lowered until it contacts the surface of the long polishing layer 1. The control method may be performed while adjusting the moving speed without stopping the movement of the cutting head 6 in the width direction.

  In the above control, when the optical sensor 7 is disposed so that the position where the incident light is reflected by the surface of the light reflecting member 5 is ahead of the tip of the cutting blade 10, the light receiving unit 9 detects the reflected light again. Since the cutting blade 10 is still located on the long light transmission region 3 when it disappears, the long light transmission region 3 may be damaged if the cutting head 6 or the cutting blade 10 is lowered as it is. Therefore, it is preferable to correct the groove processing start position so as not to damage the long light transmission region 3. For example, in the case of FIG. 2A, additional control for moving the cutting head 6 in the width direction by the length d is performed.

  Thereafter, when the light receiving unit 9 stops detecting the reflected light again, the cutting blade 10 of the cutting head 6 is again brought into contact with the long polishing region 2 to perform cutting. When the long polishing layer 1 has a plurality of long light transmission regions 3, the above operation is repeated.

  When the cutting tool reaches the other end of the long polishing layer 1, the cutting blade 10 is moved away from the long polishing region 2, and the long polishing layer 1 or the cutting head 6 is moved by a predetermined length in a predetermined direction to obtain a new one. The above operation is repeated on the surface of the long polishing layer 1. As shown in FIG. 4, when a belt conveyor is used as the surface plate 4, the polishing pad is moved in the transport direction while being wound up by the collection roll 12. When a flat plate is used as the surface plate 4, the cutting head 6 is usually moved in a predetermined direction. The structure of the groove is generally regular, but the groove pitch, groove width, groove depth, etc. may be changed for each range in order to make the slurry retention / renewability desirable. Is possible.

Further, instead of the cutting tool, a cutting tool provided with optical sensors A (13) and B (14) having a light emitting portion 8 and a light receiving portion 9 as shown in FIG. Also good. The groove forming method is almost the same as described above. In particular,
1) While irradiating the surface of the long polishing layer from the light emitting portions of the optical sensors A and B while moving the cutting tool from one end to the other end in the width direction of the long polishing layer,
2) When the light receiving portions of the optical sensors A and B do not detect the reflected light, the cutting blade of the cutting tool is brought into contact with the long polishing region and cut.
3) When the light receiving portion of the optical sensor A detects the reflected light, the cutting blade of the cutting tool is controlled so as not to contact the long light transmission region,
4) When the light receiving parts of the optical sensors A and B stop detecting the reflected light again, the cutting blade of the cutting tool is again brought into contact with the long polishing region and cut.
5) When the cutting tool reaches the other end of the long polishing layer, the cutting blade is separated from the long polishing region, and the long polishing layer or the cutting head is moved by a predetermined length in a predetermined direction,
The above operations 1) to 5) are repeated to form multiple grooves only in the long polishing region.

  When the circular rotary blade 10 as shown in FIG. 5 is used, the optical sensor A (13) has a light receiving portion when the circular rotary blade 10 reaches the boundary point P between the long polishing region 2 and the long light transmission region 3. It is preferable to arrange so that 9 receives reflected light. Further, it is preferable that the optical sensor B (14) is disposed at a symmetrical position of the optical sensor A (13) with the tip of the circular rotary blade 10 as a reference. Thereby, not only can the cutting scratches be prevented from being applied to the surface of the long light transmission region 3, but a groove can be formed up to the boundary between the long polishing region 2 and the long light transmission region 3. Further, when two optical sensors are used, there is an advantage that it is not necessary to correct the groove processing start position as in the case where one optical sensor is used.

Further, instead of the cutting tool, a cutting tool having optical sensors A (13) and B (14) having a light emitting portion 8 and a light receiving portion 9 as shown in FIG. Also good. The groove forming method is almost the same as described above. In particular,
1) While irradiating the surface of the long polishing layer from the light emitting portions of the optical sensors A and B while moving the cutting tool from one end to the other end in the width direction of the long polishing layer,
2) When the light receiving portions of the optical sensors A and B do not detect the reflected light, the cutting blade of the cutting tool is brought into contact with the long polishing region and cut.
3) When the light receiving portion of the optical sensor A detects the reflected light, the cutting blade of the cutting tool is controlled so as not to contact the long light transmission region,
4) When the light receiving part of the optical sensor B detects the reflected light, the cutting blade of the cutting tool is again brought into contact with the long polishing region for cutting,
5) When the cutting tool reaches the other end of the long polishing layer, the cutting blade is separated from the long polishing region, and the long polishing layer or the cutting head is moved by a predetermined length in a predetermined direction,
The above operations 1) to 5) are repeated to form multiple grooves only in the long polishing region.

  When the circular rotary blade 10 as shown in FIG. 6 is used, the optical sensor A (13) has a light receiving portion when the circular rotary blade 10 reaches the boundary point P between the long polishing region 2 and the long light transmission region 3. It is preferable to arrange so that 9 receives reflected light. Further, it is preferable that the optical sensor B (14) is further arranged behind the symmetrical position of the optical sensor A (13) by the width of the long light transmission region 3 with respect to the tip of the circular rotary blade 10. . By arranging in this way, when the light receiving unit 9 of the optical sensor B (14) detects the reflected light, the Q point of the circular rotary blade 10 is positioned on the other end of the long light transmission region 3. become. Thereby, not only can the cutting scratches be prevented from being applied to the surface of the long light transmission region 3, but a groove can be formed up to the boundary between the long polishing region 2 and the long light transmission region 3. Further, when two optical sensors are used, there is an advantage that it is not necessary to correct the groove processing start position as in the case where one optical sensor is used.

  According to any one of the above groove processing methods, multiple grooves can be formed continuously and efficiently only in the long polishing region.

On the other hand, it is also possible to perform groove processing using a light transmission type optical sensor. In this case, a surface plate having a light transmitting member is used instead of the light reflecting member, and the long polishing layer is installed on the surface plate so that the light transmitting member and the long light transmitting region overlap. Further, the light emitting part of the optical sensor is provided on the cutting head, and the light receiving part of the optical sensor is provided on the lower surface side of the light transmitting member. And almost the same as the above groove processing method,
1) While irradiating the surface of the long polishing layer from the light emitting part while moving the cutting tool from one end to the other end in the width direction of the long polishing layer,
2) When the light receiving part does not detect the light, the cutting blade of the cutting tool is brought into contact with the long polishing area and cut.
3) When the light receiving unit detects the light, control so that the cutting blade of the cutting tool does not contact the long light transmission region until at least the light receiving unit does not detect the light,
4) When the light receiving part stops detecting the light again, the cutting blade of the cutting tool is again brought into contact with the long polishing region and cut.
5) When the cutting tool reaches the other end of the long polishing layer, the cutting blade is separated from the long polishing region, and the long polishing layer or the cutting head is moved by a predetermined length in a predetermined direction,
The above operations 1) to 5) are repeated to form multiple grooves only in the long polishing region.

  Contrary to the above, it is also possible to perform groove processing by applying the above method by providing the light receiving portion of the optical sensor on the cutting head and the light emitting portion of the optical sensor on the lower surface side of the light transmitting member. .

  The obtained long polishing layer 1 is cut into, for example, a several-meter workpiece by a cutting machine. The length is appropriately adjusted according to the polishing apparatus to be used, but is usually about 5 to 10 m. Note that the groove processing may be performed after the length is adjusted in advance.

  The polishing pad of the present invention may be a laminate of the long polishing layer and a cushion sheet (cushion layer).

  The cushion sheet supplements the characteristics of the polishing layer. The cushion sheet is necessary for achieving both planarity and uniformity in a trade-off relationship in CMP. Planarity refers to the flatness of a pattern portion when a wafer with minute irregularities generated during pattern formation is polished, and uniformity refers to the uniformity of the entire wafer. Planarity is improved by the characteristics of the foam sheet, and uniformity is improved by the characteristics of the cushion sheet. In the polishing pad of the present invention, it is preferable to use a cushion sheet that is softer than the polishing region.

  Examples of the cushion sheet include a fiber nonwoven fabric such as a polyester nonwoven fabric, a nylon nonwoven fabric, and an acrylic nonwoven fabric, a resin-impregnated nonwoven fabric such as a polyester nonwoven fabric impregnated with polyurethane, a polymer resin foam such as polyurethane foam and polyethylene foam, a butadiene rubber, Examples thereof include rubber resins such as isoprene rubber and photosensitive resins.

  Examples of the means for bonding the long polishing layer and the cushion sheet include a method in which the long polishing layer and the cushion sheet are sandwiched and pressed with a double-sided tape. In addition, it is preferable not to provide a cushion sheet in a portion corresponding to the long light transmission region.

  The double-sided tape has a general configuration in which adhesive layers are provided on both sides of a substrate such as a nonwoven fabric or a film. In consideration of preventing the penetration of the slurry into the cushion sheet, it is preferable to use a film for the substrate. Examples of the composition of the adhesive layer include rubber adhesives and acrylic adhesives. Considering the content of metal ions, an acrylic adhesive is preferable because the metal ion content is low. In addition, since the foam sheet and the cushion sheet may have different compositions, the composition of each adhesive layer of the double-sided tape can be made different to optimize the adhesive strength of each layer.

  Further, the polishing pad of the present invention may be a laminate of the long polishing layer and a transparent support film. The transparent support film is not particularly limited, but is preferably a resin film having high transparency, heat resistance, and flexibility. Examples of the material of the resin film include polyester; polyethylene; polypropylene; polystyrene; polyimide; polyvinyl alcohol; polyvinyl chloride; fluorine-containing resin such as polyfluoroethylene; nylon; cellulose; general-purpose engineering plastics such as polycarbonate; And special engineering plastics such as polyetheretherketone and polyethersulfone.

  The thickness of the transparent support film is not particularly limited, but is preferably about 20 to 200 μm from the viewpoints of strength and winding. The width of the transparent support film is not particularly limited, but is preferably about 60 to 250 cm in consideration of the required size of the long polishing layer. The length of the transparent support film can be appropriately set according to the required length of the long polishing layer, but is usually about 10 to 15 m because lead portions (about 2 m in the front and rear directions) are required.

  The polishing pad of the present invention may be provided with a double-sided tape on the surface to be bonded to the platen. As the double-sided tape, a tape having a general configuration in which an adhesive layer is provided on both surfaces of a base material can be used as described above. As a base material, a nonwoven fabric, a film, etc. are mentioned, for example. In consideration of peeling from the platen after use of the polishing pad, it is preferable to use a film for the substrate. Examples of the composition of the adhesive layer include rubber adhesives and acrylic adhesives. Considering the content of metal ions, an acrylic adhesive is preferable because the metal ion content is low.

The schematic sectional drawing which shows the state which installed the elongate grinding | polishing layer on the surface plate which has a light reflection member. The (a) schematic side view and (b) schematic front view of a cutting head provided with the optical sensor which has a light emission part and a light-receiving part. The schematic block diagram which shows an example of the process of the groove | channel formation method of this invention. The schematic block diagram which shows an example of the groove processing apparatus of this invention. The schematic side view of the cutting head provided with optical sensor A and B which has a light emission part and a light-receiving part. The schematic side view of the cutting head provided with optical sensor A and B which has a light emission part and a light-receiving part.

Explanation of symbols

1: long polishing layer 2: long polishing region 3: long light transmission region 4: surface plate 5: light reflecting member 6: cutting head 7: optical sensor 8: light emitting unit 9: light receiving unit 10: cutting blade (circular) Rotating blade)
11: Supply roll 12: Collection roll 13: Optical sensor A
14: Optical sensor B

Claims (5)

In the manufacturing method of a polishing pad including a step of forming multiple grooves by cutting on the surface of a long polishing layer having a long polishing region and a long light transmission region,
On the surface plate having the light reflecting member, a long polishing layer is installed so that the light reflecting member and the long light transmission region overlap,
Using a cutting tool equipped with a cutting head with an optical sensor having a light emitting part and a light receiving part,
1) While irradiating the surface of the long polishing layer from the light emitting part while moving the cutting tool from one end to the other end in the width direction of the long polishing layer,
2) When the light receiving part does not detect the reflected light, the cutting blade of the cutting tool is brought into contact with the long polishing region and cut.
3) When the light receiving unit detects the reflected light, control so that the cutting blade of the cutting tool does not contact the long light transmission region until at least the light receiving unit does not detect the reflected light.
4) When the light receiving part stops detecting the reflected light again, the cutting blade of the cutting tool is again brought into contact with the long polishing region and cut.
5) When the cutting tool reaches the other end of the long polishing layer, the cutting blade is separated from the long polishing region, and the long polishing layer or the cutting head is moved by a predetermined length in a predetermined direction,
A method for producing a polishing pad, wherein the operations of 1) to 5) are repeated to form multiple grooves only in the long polishing region. A surface plate, a light emitting unit, and a light receiving unit that support and fix a polishing pad including a long polishing layer having a long polishing region and a long light transmission region, and have a light reflecting member in a portion corresponding to the long light transmission region A cutting tool provided with an optical sensor having a cutting head, and a control unit for moving the polishing pad in the conveying direction by a predetermined length when the cutting tool has finished moving from one end to the other in the width direction of the long polishing layer A groove processing apparatus having a supply roll for feeding the polishing pad, and a recovery roll for winding the grooved polishing pad. The grooving apparatus according to claim 2, wherein the optical sensor is installed on the cutting head such that a position where the light emitted from the light emitting portion is reflected by the light reflecting member surface and the tip of the cutting blade are aligned on the same straight line. In the manufacturing method of a polishing pad including a step of forming multiple grooves by cutting on the surface of a long polishing layer having a long polishing region and a long light transmission region,
On the surface plate having the light reflecting member, a long polishing layer is installed so that the light reflecting member and the long light transmission region overlap,
Using a cutting tool provided with optical sensors A and B having a light emitting part and a light receiving part at the front and rear of the cutting head
1) While irradiating the surface of the long polishing layer from the light emitting portions of the optical sensors A and B while moving the cutting tool from one end to the other end in the width direction of the long polishing layer,
2) When the light receiving portions of the optical sensors A and B do not detect the reflected light, the cutting blade of the cutting tool is brought into contact with the long polishing region and cut.
3) When the light receiving portion of the optical sensor A detects the reflected light, the cutting blade of the cutting tool is controlled so as not to contact the long light transmission region,
4) When the light receiving parts of the optical sensors A and B stop detecting the reflected light again, the cutting blade of the cutting tool is again brought into contact with the long polishing region and cut.
5) When the cutting tool reaches the other end of the long polishing layer, the cutting blade is separated from the long polishing region, and the long polishing layer or the cutting head is moved by a predetermined length in a predetermined direction,
A method for producing a polishing pad, wherein the operations of 1) to 5) are repeated to form multiple grooves only in the long polishing region. In the manufacturing method of a polishing pad including a step of forming multiple grooves by cutting on the surface of a long polishing layer having a long polishing region and a long light transmission region,
On the surface plate having the light reflecting member, a long polishing layer is installed so that the light reflecting member and the long light transmission region overlap,
Using a cutting tool provided with optical sensors A and B having a light emitting part and a light receiving part at the front and rear of the cutting head,
1) While irradiating the surface of the long polishing layer from the light emitting portions of the optical sensors A and B while moving the cutting tool from one end to the other end in the width direction of the long polishing layer,
2) When the light receiving portions of the optical sensors A and B do not detect the reflected light, the cutting blade of the cutting tool is brought into contact with the long polishing region and cut.
3) When the light receiving portion of the optical sensor A detects the reflected light, the cutting blade of the cutting tool is controlled so as not to contact the long light transmission region,
4) When the light receiving part of the optical sensor B detects the reflected light, the cutting blade of the cutting tool is again brought into contact with the long polishing region for cutting,
5) When the cutting tool reaches the other end of the long polishing layer, the cutting blade is separated from the long polishing region, and the long polishing layer or the cutting head is moved by a predetermined length in a predetermined direction,
A method for producing a polishing pad, wherein the operations of 1) to 5) are repeated to form multiple grooves only in the long polishing region.

Images