WO2004007146A1

WO2004007146A1 - Polishing apparatus and method of dressing polishing tool

Info

Publication number: WO2004007146A1
Application number: PCT/JP2003/008766
Authority: WO
Inventors: Shunichiro Kojima; Kazuto Hirokawa; Akira Kodera
Original assignee: Ebara Corporation
Priority date: 2002-07-12
Filing date: 2003-07-10
Publication date: 2004-01-22
Also published as: JP2004042213A

Abstract

In a polishing apparatus (201), a polishing tool including abrasive and binder for binding the abrasive is pressed to a substrate (W) held by a top ring (21) and polishes the substrate (W). The polishing apparatus (201) comprises a light source (31) for radiating light rays to a polishing face (15) so as to reduce binding force of the binder that binds abrasive, and a foreign object removing mechanism (32) for forcibly removing foreign objects produced in polishing or foreign objects produced by the radiation. With the structure above, dressing of the polishing face (15) is performed by radiating light rays to the polishing face, and products etc. produced by the dressing are removed. The dressing enables the polishing apparatus (201) to stably supply abrasive to the polishing face and high-speed polishing of the substrate (W).

Description

Specification

Polishing apparatus and dressing method for polishing tool

Technical field

According to the present invention, there is provided a light source for dressing (graining and regenerating) a polishing tool by irradiating a beam of light, a polishing apparatus equipped with a foreign matter removing device for removing foreign substances generated by the dressing and the like, and polishing by irradiating a beam of light. The present invention relates to a dressing process (a light beam irradiation process) for dressing a tool, and a dressing method for an abrasive tool including a foreign matter removal process for removing foreign matter generated by the dressing and the like.

Background technology

In recent years, with the progress of high integration of semiconductor devices, the wiring of circuits has been miniaturized, and the dimensions of integrated devices have been further miniaturized. Therefore, it may be necessary to planarize the surface by removing the film formed on the surface of a substrate such as a semiconductor wafer by polishing, and chemical mechanical polishing (CMP) may be used as a method of this planarization method. Polishing is performed by equipment. This type of chemical mechanical polishing (CMP) apparatus has a turntable with a polishing pad (pad) and a top ring, and a substrate to be polished is interposed between the turntable and the top ring, and the top ring is While applying a constant pressure to the polishing target substrate to the polishing pad (pad) pasted on the turntable, both rotate and the abrasive fluid (slurry) is supplied to the sliding surface of both while the surface of the polishing target substrate Is polished flat and mirror-like.

On the other hand, polishing of semiconductor wafer W or the like using a polishing tool containing so-called fixed abrasive is obtained by fixing abrasive grains such as cerium oxide (C e 0 2) using a binder such as phenol resin, for example. It is being studied. In the case of polishing with such a polishing tool, unlike the conventional chemical mechanical polishing, since the polishing surface is hard, the convex portion of the asperity is preferentially polished and the concave portion is hard to be polished, so that absolute flatness is obtained. It has the advantage of being easy. In addition, depending on the composition of the polishing tool, when the polishing of the convex portion is finished and becomes a flat surface, the polishing speed is significantly reduced, and a so-called self-stop function appears that the polishing does not progress practically. In addition, since polishing using a polishing tool does not use a suspension (slurry) containing a large amount of abrasive grains, there is also an advantage that the load on environmental problems is reduced. Disclosure of invention

Generally, in the polishing of a substrate using a polishing tool (fixed abrasive or fixed abrasive), the surface of the polishing tool is regenerated and dressed (dressing) using a dresser to which diamond particles and the like are fixed. The fixed abrasive grains are allowed to self-generate loose abrasive grains that serve to polish the substrate and semi-free abrasive grains that partially adhere to the polishing surface. However, in the case of polishing a semiconductor wafer using such a polishing tool, the polishing rate is high immediately after dressing but gradually decreases, so that the polishing rate is not stable. In order to stabilize the polishing rate, it is necessary to dress each time before polishing to allow the free abrasive grains to be sufficiently generated, but if dressing is performed before each polishing, it takes a certain time for dressing. Therefore, there is a problem that throughput is practically reduced and productivity is reduced.

In addition, a dresser with diamond particles fixed, which is used for general chemical mechanical polishing, has a problem that the diamond particles fall off to the polishing surface. This may cause scratches on the surface to be polished of the substrate to be polished.

A dressing method by light irradiation has been devised as one of the means for solving the above-mentioned problems, but a product which is generated when the polishing tool is irradiated, a product which is mainly denatured by the binder etc., and a polishing which is generated when the substrate is polished. If a substance (foreign substance) unrelated to so-called polishing, such as a product or an inactive abrasive that has reacted in polishing, intervenes on the actual polishing surface, the polishing speed will be sufficient even if the loose abrasive is allowed to stand on its own. It is difficult to secure the speed and stability of the

The present invention has been made in view of the above-described circumstances, and in a polishing apparatus for polishing a substrate using a polishing tool containing abrasive grains such as diamond particles and a binder, there is a problem that abrasive grains fall off to the polishing surface. Dressing with small light, stably supplying abrasive grains to the polishing surface of the polishing tool, removing foreign substances generated by the dressing, and a polishing apparatus capable of polishing the substrate at a stable high polishing rate. The purpose is to provide Another object of the present invention is to provide a method for draining a polishing tool containing abrasive grains and a binder.

According to a first aspect of the present invention, a polishing apparatus comprises: a polishing tool having a polishing surface including an abrasive and a binder for fixing the abrasive; a movement mechanism for pressing the substrate against the polishing surface to move the substrate relative to the polishing surface; A light source for irradiating the polished surface with a light beam which weakens the adhesion of the binder, And a foreign matter removing mechanism for removing foreign matters generated by the irradiation of light from the polishing surface. The moving mechanism includes a top ring for holding the substrate, a turntable for supporting the polishing tool, and a motor for rotating or swinging them as needed. The foreign matter removing mechanism forcibly removes the foreign matter generated by the polishing process and the foreign matter generated by the irradiation from the polishing surface.

The polishing apparatus according to the first aspect of the present invention comprises a light source and a foreign matter removing mechanism, so that the light source irradiates a light beam on the polishing surface of the polishing tool to weaken the adhesion of the binder to the abrasive grains. Abrasive grains are produced so that the grains can not be held, and foreign substances produced by polishing that inhibit uniform production of abrasive grains by the foreign substance removing mechanism, large particles in the natural abrasive grains, and the polishing surface of the polishing tool By removing large particles remaining on the surface and foreign substances generated by irradiation, it is possible to remove a factor that causes unstable polishing and enable stable abrasive particle supply during polishing. Abrasive tools are typically separate from the debris removal mechanism.

According to a second aspect of the present invention, the polishing apparatus 2 0 3 (FIG. 4) has the first feature, and the foreign matter removing mechanism further comprises a dresser 3 2 A that is formed so as to be pressed against the polishing surface 15 including. This dresser 32 A contains diamond particles and is preferably used at a relatively low pressure, for example 0.5 psi, which prevents the detachment of the diamond particles. In general, dressing is performed, for example, at 0.5 p s i. With this configuration, the foreign matter can be reliably removed by the dresser 32A.

According to the third aspect of the present invention, the polishing apparatus 2 0 4 (FIG. 5) has the first feature, and the foreign matter removing mechanism 3 2 B is a brush formed to be able to be rubbed against the polishing surface 1 5 (Nylon brush) 3 7 has. According to this structure, the foreign matter on the polishing surface 15 can be reliably removed by the brush 37, and the foreign matter on the polishing surface 15 can be reliably removed without causing the scratch on the polishing surface with a simple configuration. be able to.

According to a fourth aspect of the present invention, the polishing apparatus 2 0 5 (FIG. 6) has the first aspect, and the foreign matter removing mechanism generates a pressure-controlled mixed fluid of gas and liquid. A mixed fluid generator 32 C that jets toward the polishing surface 15. With this configuration, the injection pressure and injection amount of the mixed fluid are adjusted according to the size and properties of the foreign matter, and the polishing surface 1

Foreign matter on the polishing surface 15 can be reliably removed without bringing 5 into contact with solids. According to the fifth aspect of the present invention, the polishing apparatus 2 0 6 (FIG. 7) has the first feature, and the foreign matter removing mechanism further comprises ultrasonic wave generation for generating ultrasonic waves toward the polishing surface 15 Vessel 3 2 D. According to this configuration, the output of the ultrasonic wave or the distance between the ultrasonic generator 32 D and the polishing surface 15 is adjusted according to the size, properties, etc. of the foreign matter, and the polishing surface is polished without contacting the solid. Foreign matter on the surface can be reliably removed.

According to a sixth aspect of the present invention, a polishing apparatus 2 0 5 (FIG. 6) has the first feature and further provides a first liquid on the polishing surface when the irradiation is performed. 1 Liquid supply device 3 2 C is provided, and the foreign matter removal mechanism is a second liquid supply device 3 2 C that supplies a second liquid for removing foreign matter onto the polishing surface 15. The first liquid and the second liquid are different. According to this structure, the first liquid (for example, photosensitizer) most suitable for irradiation is supplied at the time of irradiation to promote the spontaneous generation of the abrasive grains, and the second liquid (for example, for oxidation of the binder) most suitable for foreign matter removal. An oxidizing agent having a decomposition action can be supplied at the time of removal of foreign matter to accelerate the removal of foreign matter that inhibits the abrasive grains from being produced.

According to a seventh aspect of the present invention, the polishing apparatus 2 0 7 (FIG. 8) has the first feature, and the foreign matter removing mechanism is a vacuum suction apparatus 3 2 E for sucking the foreign substance with vacuum. . With this configuration, foreign matter can be removed without contacting the foreign matter removal apparatus with the polishing surface 15 or using a second liquid or the like that requires treatment, which makes the polishing work more efficient. be able to.

According to an eighth aspect of the present invention, in the method for dosing a polishing surface of a polishing tool, the polishing surface includes an abrasive and a binder for fixing the abrasive, and is pressed against the substrate and moved relative to the substrate to polish the substrate. It is used for a grinding | polishing process. This dressing method includes a light beam irradiating step of irradiating a light beam which weakens the adhesive force of the binder to the polishing surface, and a foreign matter removing step of forcibly removing the foreign matter generated on the polishing surface. The foreign matter removing step includes the foreign matter removing step for forcibly removing the foreign matter generated on the polishing surface in the polishing step and the foreign matter generated on the polishing surface in the light irradiation step.

According to a ninth aspect of the present invention, the dressing method has the eighth aspect, and the foreign substance removing step further includes the step of pressing a dresser formed of diamond particles against the polishing surface.

According to a tenth aspect of the invention, the dressing method comprises the eighth aspect and According to the first feature of the present invention, the foreign substance removing step includes the step of rubbing a brush (nylon brush) onto the polishing surface. The dressing method has the eighth feature, and the foreign substance removing step further comprises gas and liquid And b) spraying the pressure-controlled mixed fluid onto the polishing surface.

According to a twelfth feature of the present invention, the dressing method has an eighth feature, and the foreign matter removing step further includes the step of irradiating the polished surface with an ultrasonic wave.

According to a thirteenth feature of the present invention, the dressing method has the eighth feature, and the light irradiation step further includes the step of supplying the first liquid to the polishing surface; Supplying a second liquid different from the liquid to the polishing surface. According to this structure, the first liquid (for example, a photosensitizer) can be supplied to the polishing surface, and the light drawing effect can be promoted or maintained, and the second liquid (for example, oxidation of the binder) can be performed on the polishing surface. An oxidizing agent having a decomposition action can be supplied to remove foreign substances that inhibit the self-generation of abrasive grains.

According to a fourteenth feature of the present invention, the dressing method has the eighth feature, and the foreign matter removing step further includes a step of suctioning the foreign matter under vacuum.

According to a fifteenth feature of the present invention, in the dressing method for the polishing surface of a polishing tool, the polishing surface includes an abrasive and a binder for fixing the abrasive, and is pressed against the substrate and moved relative to the substrate. The dressing method is used in a polishing process for polishing a substrate, and the dressing method includes a beam irradiation process for irradiating a beam of light which weakens the adhesion of the binder to the polishing surface of the polishing tool. It is performed between the polishing steps to be polished, and between one polishing step and the next polishing step. With this configuration, the light irradiation step is performed simultaneously with the polishing step, and is also performed between the polishing step and the next polishing step. Therefore, even if the progress of dressing on the polishing surface is slow, Sufficient dressing can be performed.

According to a sixteenth feature of the present invention, the dressing method has the fifteenth feature, and the polishing process is further performed by rotating the polishing tool, and the polishing process is not performed during the polishing process. The rotation speed is less than 10 rotations per minute. According to this structure, while the polishing process is not performed, the rotational speed of the polishing tool can be determined by preventing the dressing accelerator and the like supplied to the polishing surface during dressing from being easily scattered from the polishing surface. According to a seventeenth aspect of the present invention, the dressing method has the fifteenth or sixteenth features, and further, in the light irradiation process, When the dressing speed is high, the light irradiation step performed simultaneously with the polishing step is performed intermittently, and when the dressing speed is low, the light irradiation step is further performed between the polishing step and the next polishing step. With this configuration, the dressing time can be adjusted to an appropriate value by shortening or increasing the dressing time depending on the dressing speed.

Brief description of the drawing

FIG. 1 is a schematic front view of a polishing apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic plan view of the polishing apparatus of FIG.

FIG. 3 is a schematic front view of a polishing apparatus according to a second embodiment of the present invention.

FIG. 4 is a schematic front view of a polishing apparatus according to a third embodiment of the present invention.

FIG. 5 is a schematic front view of a polishing apparatus according to a fourth embodiment of the present invention.

FIG. 6 is a schematic front view of a polishing apparatus according to a fifth embodiment of the present invention.

FIG. 7 is a schematic front view of a polishing apparatus according to a sixth embodiment of the present invention.

FIG. 8 is a schematic front view of a polishing apparatus according to a seventh embodiment of the present invention.

FIG. 9 is a plan view showing the overall configuration of a polishing apparatus according to an embodiment of the present invention. 10 is a front view of the polishing chamber (areas C and D of FIG. 9) of the polishing apparatus of FIG. '

11 is a perspective view of an optical dressing mechanism of the polishing apparatus of FIG.

12 is a front view around the turntable of the polishing apparatus of FIG.

Fig. 13 is a timing chart showing an example of a series of operation of dressing according to the second method of the polishing apparatus of Fig. 9.

Fig. 14 is a timing chart showing an example of a series of operation of dressing according to the first method of the polishing apparatus of Fig. 9.

Fig.15 is a timing chart showing an example of a series of operation of dressing according to the third method of the polishing apparatus of Fig.9.

Fig. 16 is a timing chart showing a series of operation examples of dressing according to the fourth method of the polishing apparatus of Fig. 9; Fig. 17 is a timing chart showing a series of operation examples of dressing according to the fifth method of the polishing apparatus of Fig. 9.

(Explanation of the code)

1 1: Turntable, 13: Fixed abrasive (abrasive tool), 15: Abrasive surface, 2 1: Topping, 31: Light source, 32: Foreign matter removal device (foreign matter removal mechanism), 32 A: Dresser, 32 B: foreign matter removal device (foreign matter removal mechanism), 32 C: atomizer, 32 D: ultrasonic wave generator, 32 E: vacuum suction device (vacuum suction mechanism), 34: laser light emission port,

35: Laser beam, 37: Nylon brush (brush), 38: Dressing mechanism,

40: pure water supply source 41: supply device 42: gas supply source 43: second chemical liquid supply source 44: first chemical liquid supply source 45: vacuum supply source 144, 145: top ring, 1

46, 147: Turntable: 146 A, 147 A: Fixed abrasive (abrasive tool), 146 B, 147 B: Abrasive surface, 148, 149: Turntable, 150, 15 1: Polishing liquid supply nozzle, 152, 153 : Atomizer, 154, 155, 156, 157: Dresser, 160: Rotary transfer tube, 164, 165: Pusher, 168: Mechanical dressing mechanism, 192, 193: Optical dressing mechanism, 201 to 208: Polishing device, 21 1: motion mechanism, W: substrate (semiconductor wafer).

Form of implementation of the invention

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, members identical or corresponding to each other are denoted by the same reference numerals, and redundant description will be omitted.

FIG. 1 is a schematic front view showing a polishing apparatus 201 according to a first embodiment of the present invention. The polishing apparatus 201 includes a rotating turntable 11 and a fixed abrasive 13 provided on a cooling table 11. In the present embodiment, the fixed abrasive 13 which is a polishing tool is formed including an abrasive (not shown) and a binder (not shown) for fixing (adhering) the abrasive.

As the abrasive grains of the fixed abrasive grain 13, silicon oxide (S i O 2), alumina (A 120)

3), cerium oxide (C e 2 2), silicon carbide (S i C), zirconia (Z r 鉄), iron oxide (F e 〇, F e 34), manganese oxide (Mn 〇 2, Mn 203), magnesium oxide (Mg)), calcium oxide (C aO), barium oxide (Ba)), oxidation Zinc (ZnO), barium carbonate (BaC03), diamond (C), titanium oxide (Ti02) and the like are used.

The binder material is thermosetting (epoxy (EP), phenol (PF), urea (UF), melamine (MF), unsaturated polyester (UP), silicon (S 1), polyurethane (PUR), etc.) Resins, polyvinyl chloride (PVC), polyethylene (PC), polycarbonate (PC), polypropylene (PP), polystyrene (PS), acrylonitrile butadiene styrene (ABS), acrylonitrile styrene (AS) known as general-purpose plastics , Butadiene · Styrene · Methyl methacrylate (MBS), Polymethyl methacrylate (PMMA), Polyvinyl alcohol (PVA), Polyvinylidene chloride (PVDC), Polyethylene terephthalate (PET), Polyamide known as general-purpose engineering plastics (PA), Polyacetal (POM), Polyphenylene Ether (PPE) ), Polybutylene terephthalate (PBT), ultra-high molecular weight polyethylene (UHMW_PE), polyvinylidene fluoride (PVDF), polysulfone (PSF) known as spar engineering plastic, polyether sulfone PES), polyphenylene sulfide (PPS), polyarylate (PAR), polyamideimide (PA I), polyetherimide (PE I), polyetheretherketone (PEEK), polyimide (PI), liquid crystal polymer ( Thermoplastics such as LCP), polytetrafluoroethylene (PTFE), polystyrene methacrylate resin, polycarbonate cellulose acetate, polyacetal polyamide, polypropylene polyethylene, trifluorinated ethylene resin, vinylidene fluoride resin, polyester resin, and aryl phthalate Resin is mentioned. These resins may be used as a mixture of two or more. It is also possible to copolymerize the monomer components of these resins.

Also, materials suitable for use as flexible resins are polyvinyl fluoride, polyvinylidene fluoride, polyvinyl trifluoride ethylene, Biel fluoride, vinylidene fluoride, dichlorofluoroethylene, vinyl chloride , Vinylidene chloride, perfluoro-one-year refines (eg, hexafluoropropylene, perfluorobutene-1), perfluoropente Perfluoro-Hexene-1 etc.), Perfluorobutadiene, Chloro-Trifluoroethylene, Trichloroethylene, Tetrafluoroethylene, Perfluoro-Alkylperfluorovinylethers (eg, Perfluoro) Methylperfluorovinylether, Perfluoroethylperfluorovinylether, perfluoropropylperfluorovinylether, etc., C 1 to C 6 alkyl vinyl ethers, C 6 to C 8 aryl Vinyl ether, alkyl having 1 to 6 carbons, aryl having 6 to 8 carbons, arylperfluorovinyl ether, ethylene, propylene, styrene or the like, or polyvinylidene fluoride, polyvinyl fluoride, vinylidene fluoride-tetraful Foreethylene copolymer, vinyl Fluorene-hexafluoropropylene copolymer, tetrafluoroethylene-ethylene-ethylene copolymer, tetrafluoroethylene-propylene-copolymer, ethylene-croro-trifluoroethylene copolymer, tetrafluoroethylene- Close-up trifluoroethylene copolymer, tetrafluoroethylene-ethylenehexafluoropropyrene copolymer, tetrafluoroethylene-perfluoromethylperfluorovinylether copolymer, tetrafluoro-ethylene copolymer Ethylene-perfluoroethylene-fluorovinylether copolymer, tetrafluoroethylene-perfluoropropylperfluorovinylether copolymer, tetrafluoroethylene-hexafluoropropylene-perfluoromethylborohydride Fluo-vinyl ether copolymer, Tetrafluo To ethylene one hexa full O b propylene - a Pafuruo port propyl Per full O port vinyl ether copolymer, - per full O Roe chill perf Ruo Russia ether copolymer, tetrafurfuryl O b ethylene into single Kisafuruoropuro pyrene. In view of foaming properties, economy, availability and the like, preferably, the above-described polyvinylidene fluoride, polychlorotrifluorethylene, polyvinylidene fluoride hexafluoropropylene copolymer, ethylene-tetratetrachloride are preferable. Fluoroethylene copolymers, Ethylene-monochlorotrifluoroethylene copolymer, Tetrafluoroethylene-perfluoroalkylperfluorovinyl ether copolymers, Tetrafluoroethylene-hexafluoropropylene copolymer It is. More preferably, polyvinylidene fluoride as a partially fluorinated resin, vinylidene fluoride-hexafluoropropylene copolymer, tetrafluoroboron as a perfluoro resin Ethylene / perfluoro alkyl perfluoro vinyl ether copolymers. Since the binder described above is an organic substance, when a predetermined light is irradiated to the polishing surface 15 of the fixed abrasive 13, the molecular bond is broken by the irradiation energy of the light beam, and the holding power to hold the abrasive of the binder weakens. As a result, abrasive grains are produced spontaneously, and light grinding of the polishing surface 15 is performed. By using light reactive fixed abrasive 13 in which the above-mentioned T i 02 or Z n o, etc., which is a photocatalytic substance, is mixed, the self-production of the abrasive can be performed with a lower energy beam (wavelength, light amount) Can be promoted. Polishing involves both abrasive grains released from the fixed abrasive 13 and abrasive grains fixed to the fixed abrasive 13 but exposed to the polishing surface 15 of the fixed abrasive 13. Do. The light dressing of the polishing surface 15 can promote the self-generation of abrasive grains having a polishing action.

The polishing apparatus 201 further includes a light source 31 such as a mercury lamp or a low pressure mercury lamp, and irradiates a predetermined light beam from the light source 31 to cut off the molecular bond of the binder material of the fixed abrasive 13. The self-production of free abrasive grains is as described above. The polishing apparatus 201 further includes a supply device 41 for supplying a first chemical solution (including a drug) as a first fluid onto the polishing surface 15. By supplying an appropriate first chemical solution and combining it with appropriate light irradiation, the spontaneous production of free abrasive grains can be promoted, thereby promoting and maintaining the dressing. Here, the first chemical solution to be supplied is preferably a boron-containing substance such as a borate. By supplying the boron-containing substance, sufficient natural abrasive grains can be obtained in combination with the light irradiation of the fixed abrasive grains, and the dressing can be performed stably. The first chemical solution may be a chemical solution containing an oxidizing agent such as O ₃ or H ₂ O ₂ . The oxidizing agent may be a 〇 ₃ generated by the UV light.

The polishing apparatus 201 comprises a top ring 21. The top ring 21 holds the substrate W which is the object to be polished, and slides while pressing the substrate W against the polishing surface 15 of the fixed abrasive 13. The top ring 21 and the turntable 11 form a motion mechanism 21 1 that presses the substrate against the polishing surface and causes the two to move relative to each other. The polishing apparatus 201 polishes a substrate W such as a semiconductor wafer to be polished by the fixed abrasive 13 on the rotating turntable 11 on one side, while using the light source 31 on the other side. By irradiating a light beam onto the polished surface 15 of the fixed abrasive 13, dressing of the polished surface 15 can be performed. As shown in FIG. 2, the polishing apparatus 201 includes a foreign matter removing apparatus 32. The foreign matter removing device 32 removes foreign matter generated on the polishing surface 15 by mechanical or light dressing of the fixed abrasive 13 and polishing of the substrate W by the fixed abrasive 13. Examples of the foreign matter removing device 32 include a dresser, one having a nylon brush as described later, a 7-tonizer, an ultrasonic wave generator, a vacuum suction device and the like.

FIG. 3 is a schematic front view showing a polishing apparatus 202 according to a second embodiment of the present invention. In the polishing apparatus 202, a laser beam is irradiated to the fixed abrasive 13 using a laser source 33 as a light source. The laser source 33 is provided with a large number of laser light emission ports 34, and uniformly irradiates the laser beam 35 to the irradiation site (abrasive surface 15) of the fixed abrasive 13 (round shape). The laser source 33 can be swung in the direction shown by the arrow 36 (in the direction parallel to the radial direction of the polishing surface 15). As a result, it is possible to avoid the concentration of the laser beam 35 locally, and to give a high energy density to the surface (the polishing surface 15) of the fixed abrasive 13 by the irradiation of the strong laser beam 35. The efficient production of free abrasive grains, that is, the dressing effect can be provided. Also in the present embodiment, the polishing apparatus 202 has a supply apparatus 41 for supplying the first chemical solution onto the polishing surface 15 when light irradiation is performed, and as the first chemical solution, the homing apparatus is used. Good dressing can be performed by supplying a boron-containing substance such as an acid salt and combining it with appropriate laser beam irradiation.

Laser light may be scanned using a laser one-scanning method such as a galvano mirror. By using a galvano- mer, it is possible to irradiate a single laser beam over a wide range. Also, a plurality of combined units of a laser light source and scanning means may be used, and a plurality of laser beams may be applied to one or more scanning means to simultaneously scan a plurality of lasers.

In general, when a resin material as described above is used as a binder, these materials are compounds having a C 1 H or C_C bond. The terminal group (-H) or C- on this surface

By cutting C bond and substituting a desired functional group on this surplus bonding arm, fixed abrasive 1

The abrasive grains can be released on the surface of 5, that is, the spontaneous generation of the free abrasive grains can be promoted, whereby dressing of the fixed abrasive grains 13 is possible. That is, the same effect as in the case of dressing using a diamond tool or the like can be obtained. Generally resin C 1 H, C- The binding energy of C is 98 kcal / mol and 80.6 kcal / mol, respectively. Therefore, when a light beam having photon energy equal to or higher than this energy is irradiated, and the light beam is absorbed by the material to be irradiated to reach the binding energy or more, the molecular bond can be broken.

As a light source satisfying this condition, a 248 nm wavelength, 14 kcal photon energy Kr F excimer laser light, a 193 nm wavelength, 147 Kcal photon energy A r F excimer laser light, a 172 nm wavelength, photon energy 162 kcal There are X e Xeshima lamp light etc. These light sources have narrow wavelength distribution, and can emit high energy rays, but there is a problem of high cost. For this reason, it is possible to use a low-pressure mercury lamp having a broad wavelength distribution but emitting intensely the resonance lines of mercury, 253.7 nm and 184.9 nm. A light source is obtained.

For example, since the C—H bond in the resin molecule is 80.6 kcal / mol as described above, the energy necessary for causing free abrasive grains to self-generate is calculated by breaking the bond. Energy and wavelength relation,

E = h / v where h: blank constant, V: speed

From the above, assuming that all photon energy can be absorbed on the irradiation surface, the above-mentioned molecular bond can be broken by irradiating light having a wavelength of 35 I nm or less.

The above-mentioned light dressing using the photon energy breaks the binding of the binder in the fixed abrasive by the photochemical reaction, so that the fixed abrasive can not be held and the abrasive grains are generated _c. However, the binding of the binder cut by the photochemical reaction If the arm is held as it is, it recombines with the abrasive and the abrasive is fixed again to the binder. For this reason, it is important to prevent the recombination between the binder and the abrasive grains which are cut by the photochemical reaction, and this can stabilize and increase the amount of free abrasive grains. According to the experiments of the present inventors, when an epoxy resin or MB S resin is used as a binder for fixed abrasives, an aqueous solution of sodium borate ion, which is a boron-containing borate, is added and irradiated with ultraviolet light. It turned out that a large light dressing effect could be obtained. This first drug solution is generally a standard buffer (borate pH standard solution, pH =

9. Known as 18 (25 ° 0). Table 1 shows the experimental results in the case of supplying the first chemical solution in the optical dressing of the fixed abrasive using an epoxy resin as a binder.

This experiment was performed using cerium oxide particles as abrasive grains, using an epoxy resin as a binder, and using a low pressure mercury lamp 31 (see FIG. 1) as a light source. In this experiment, first, mechanical dressing of the polishing surface 15 (see Fig. 1 and Fig. 3) of the fixed abrasive 13 is performed by a diamond dresser (not shown in Fig. 1 and Fig. 3) as a dresser. Then, the semiconductor wafer W as the first substrate is polished for 10 minutes, and continuously, that is, the second semiconductor wafer W is continuously subjected to the polishing for 10 minutes without applying mechanical dripping to the polished surface 15. Grind. Thereafter, the first chemical solution is supplied to the polishing surface 15 of the fixed abrasive 13 and irradiated with ultraviolet light for 30 minutes, and after leaving for 30 minutes without irradiation with ultraviolet light, the third semiconductor wafer W ( Polish (see Figure 1 and Figure 3). As the first chemical solution to be supplied, three kinds of pure water, alkaline solution (KOH) and standard buffer solution (borate pH standard solution, pH = 91.8 (25 ° 0) were used. Table 1 shows the polishing rates of the respective semiconductor wafers W in the combinations according to the respective conditions.

That is, in Test Nos. 1 and 2, the first chemical solution to be supplied is pure water only, and Test Nos. 1 and 2 are different in the presence or absence of light irradiation. As a result, in the polishing immediately after mechanical dressing using a diamond tool, polishing speeds 2 6 (A min) and 2 7 (A / min) are obtained, respectively, and in the subsequent polishing of the second sheet, The respective polishing rates were significantly reduced to 3 (A / min) and 5 (A / min), and it was shown that the number of free abrasive grains was extremely small especially in the second polishing. ing. And even in the case of the third polishing, when light irradiation is performed by supplying pure water, the polishing speed is slightly increased to 12 (A / min), but the polishing speed is extremely high. The value is low, and the polishing rate is about 3 (A / min) in the absence of light irradiation, and it has been shown that there is no effect of the increase of the natural abrasive grains by the dressing.

Next, in Test Nos. 3 and 4, the case where the alkali solution was supplied before the third polishing and the case where the light irradiation was performed and the case where it was not performed are shown. The polishing rate of the wafer W in the first and second polishing is the same as described above. In the dressing prior to the third polishing, when an alkaline solution was supplied and light was irradiated, the polishing speed was slightly improved to 18 (A / min), but light was not irradiated. In the case The polishing rate is 8 (A / min), and it is shown that almost no free abrasive grains are produced, that is, the effect of dressing is almost complete.

Tests No. 5 and 6 are the cases where a borate pH standard solution was used as the first chemical solution to be supplied, and the cases with and without light irradiation were compared as described above. The polishing results of the first and second semiconductor wafers W are the same as described above. And, the polishing result of the third semiconductor wafer W is that in the test No. 5 with light irradiation, it is noted that a high polishing rate of 94 A / min is obtained. In this case, the combination of the standard buffer and the light irradiation breaks the molecular bond of the resin by light irradiation, and the effect of the standard buffer terminates the cut portion of this molecular bond, so that the free abrasive grains are produced spontaneously. It is considered to have been done surely. And even in the absence of light irradiation, the polishing rate of 21 (A / min) was obtained by using the borate pH standard solution, which is a large value compared to Test No. 1-4. .

From this result, it is shown that the self-generation amount of free abrasive grains is extremely increased by supplying a borate pH standard solution and irradiating light, and a good dressing result is obtained. In the case where an alkaline solution is supplied as the first chemical solution, the polishing rate is somewhat improved, but it is considered that the alkaline abrasive that has penetrated into the fixed abrasive 13 has affected the polishing. Similarly, an improvement in the polishing rate was also observed without light irradiation using a standard buffer solution (borate pH standard solution, pH = 9. 18 (25 t :)). This is considered to be due to the fact that the supply of standard buffer solution (borate pH standard solution) was more effective than the effect of alkaline solution.

Next, fixed abrasive using methyl methacrylate butadiene styrene (MBS) resin will be described. The MBS resin is a copolymer mainly composed of methyl methacrylate butadiene styrene, and is mainly used as a modifier to improve the impact resistance of a vinyl chloride resin or an acrylic resin. In the case of a fixed abrasive using a polyvinyl chloride or acrylic resin to which MBS is added as a binder, the amount of addition is about several to 20% in a general case, and it is a design that places importance on the characteristics of vinyl chloride. On the other hand, the proportion of MB S resin in the resin is 20% or more, 50% or more, and 1 more.

When it is set to 00%, it becomes a tool with a high shock absorption effect. In addition to MBS, Elastomer (EPR, butadiene rubber, ethylene-propylene rubber, etc.) is dispersed. The same effect can also be achieved by using a resin that has been added or a core-shell resin that has an elastomer core as its core. For example, PP block polymer (I immediate act copolymer), PMMA, TPE, HI PS, ABS, AES, SBS, SEBS, SEBS, EVA, CPE, MBS, PET, PBT, TPU, etc. are also simple substances and similar additives. You can expect the effect.

By using the MBS resin as a binder material and combining it with the seri-abrasive particles, fixed-abrasive particles with very low occurrence of scratches during polishing can be obtained. You may mix and use other resin and MB S resin. For example, epoxy resin and MBS resin can be mixed and used as a binder material. That is, since the fixed abrasive is a MBS resin which is a thermoplastic resin, it can be easily molded and the strength of the molded body is also high. And, when the MBS resin is used as a binder material, there is an autogenous action of the abrasive grains, and thereby a high polishing rate can be obtained. For example, a polishing rate of about twice that of fixed abrasive using a conventional epoxy resin (without MBS resin) as a binder material can be obtained. Furthermore, since the resin itself has impact resistance, the force acting on the abrasive grains at the time of polishing is relaxed (suppressed), and scratching does not occur on the substrate, that is, polishing with less defects becomes possible. It is considered that the structure of the MBS resin-bound fixed abrasive spreads due to the water absorption effect, and the ability to hold the abrasive by light irradiation decreases to make the abrasive self-generating easy.

This fixed abrasive is characterized by a faster processing speed and less scratching on the substrate as described above, as compared to fixed abrasives using a general phenol or epoxy resin, and it is possible to manufacture a semiconductor in which the occurrence of scratches is not preferable. It is also possible to apply to the process. In contrast to processes requiring high polishing rates where fixed abrasives with common phenol or epoxy resin require dressing at the same time during polishing, required high polishing rates can be obtained without dressing during polishing. Be In addition, since there is no concern about the falling off of the diamond abrasive when dressing, the scratch by the diamond particles does not occur.

Table 2 shows the experimental results of dressing on the fixed abrasive when the MBS resin is used as the binder, and the other experimental conditions are the same as Table 1. That is, using cerium oxide particles as abrasive grains, using MBS resin as a binder, as a light source for use It uses a low pressure mercury lamp. In addition, as the polishing conditions, the first semiconductor wafer w is one that has been subjected to mechanical dressing processing with a diamond tool and then polished.

The polishing of the second semiconductor wafer W is performed subsequent to the polishing of the first wafer. After that, the first chemical solution is supplied, and the first chemical solution is supplied for dressing with and without light irradiation, and the third semiconductor wafer W is polished.

The comparison results of the polishing rates shown in Table 2 are as follows. First, in Test Nos. 1 and 2, only pure water was used as the first chemical solution to be supplied, and the polishing rates were compared according to the presence or absence of light irradiation. As shown in Table 2, the polishing rate for the first sheet, the polishing rate for the second sheet, and the polishing rate for the third sheet are all the same. In the case of the fixed abrasive using the M 3 B S resin, as described above, the decreasing rate of the polishing rate by the continuous polishing is smaller than that of the fixed abrasive using the epoxy resin as the binder. Then, when pure water is supplied as the first chemical solution and light irradiation is not performed, the polishing rate tends to gradually decrease. However, in the case of light irradiation, the polishing rate does not decrease and is stable. Furthermore, when the standard buffer solution (borate PH standard solution, pH = 9.18 (25)) is supplied as the first chemical solution and light irradiation is performed, the polishing performance up to the initial polishing rate or so is obtained. Improvement was observed. That is, even in the fixed abrasive using the M 3 B S resin, the polishing speed similar to that of the mechanical dressing by the diamond dresser can be obtained by the light dressing combined with the borate solution.

It is also effective to supply an oxidizing agent having an oxidative decomposition action together with light irradiation to the polymer resin as a binder for fixing the abrasive grains as a dressing for the fixed abrasive grains. Examples of oxidizing agents include ozone water, hydrogen peroxide water, peracetic acid, perbenzoic acid, organic peroxides such as tert-butyl hydroperoxide, permanganate compounds such as potassium permanganate, and heavy chromium Acid dichromic acid compounds such as potassium iodate, octagenic acid compounds such as potassium iodate, nitric acid compounds such as nitric acid and iron nitrate, peroxylogous acid compounds such as perchloric acid, transition metal salts such as potassium ferricyanide, ammonium persulfate And other persulfates, heteropolyacids and the like. Among these, hydrogen peroxide water and organic peroxides which do not contain metal elements and whose decomposition products are harmless are preferred in practice. Because of the instability, the above peroxides form radicals and their unpaired electrons easily oxidize binder. In addition, hydrogen peroxide solution is decomposed by ultraviolet light to generate hydroxyl radical. The bond dissociation of H-OH of this hydroxy radical is about 120 kca 1 / mol, which is larger than the bond dissociation energy of R-H of any resin. Accordingly, R—H of the binder resin is converted to R radicals by hydroxy radicals, and the generated R radicals further react with hydroxyl radicals and the like to be oxidatively decomposed. The hydrogen peroxide concentration is 0.010 wt% to 6 wt%, pH is 1 to 14, preferably 8 to 10, and the wavelength of ultraviolet light is preferably 450 nm or less .

The oxidizing agent that exhibits these oxidative decomposition actions oxidizes and degrades the polymer resin that is the binder, breaks the main chain, breaks it down, and lowers the molecular weight to mechanically weaken the surface layer of the fixed abrasive, and the surface layer thereof. Promote the self-generation of abrasive grains by removing A dressing using an oxidizing agent that exhibits this oxidative decomposition action can be given a synergistic effect on the optical dressing that promotes the self-generation of the abrasive grains from the fixed abrasive grains by irradiating the aforementioned light beam.

In addition, it is also effective for photodressing to incorporate a photoinitiator (photosensitizer) into the fixed abrasive or to be contained in the first chemical solution supplied to the fixed abrasive during the light dressing. Under these conditions, when the surface of the fixed abrasive is irradiated with a light beam such as ultraviolet light, the photoinitiator (photosensitizer) absorbs the ultraviolet light and generates radicals or ions by cleavage or hydrogen abstraction to form a fixed abrasive. The surface layer of the binder resin is decomposed to promote the self-generation of the abrasive grains. As photo initiators (photosensitizers), there may be mentioned acetophenone, diacetyl, 2,2'-azobisisobutyronitrile, anthraquinone, iron chloride, 1,1-diphenyl-1-dihydrazine (DPPH), iron dimethylcarbamate, thioxanthone , Tetramethylthiuram sulfide, 1, 4-naphthoquinone, p-nitroadiline, phenanthrene, benzyl, 1, 2 _ benzoanthraquinone, p-benzoquinone, benzophenone, Michler's ketone, 2-methyl anthraquinone, 2-methyl One 1, 1

4 One is naphthoquinone (vitamin K 3) and so on. The concentration of the photoinitiator (photosensitizer) in the fixed abrasive is preferably about 0.5 to 10%, and more preferably 0.1 to 10%.

It is around 5%. In addition, the effective excitation wavelength of UV light compatible with the photoinitiator (photosensitizer) Is, for example, about 257 nm in the case of thioxanthone, and 251 nm in the case of 1,4-naphthoquinone.

Also, in order to promote the light dressing, a photosensitive resin is used for part or all of the resin constituting the fixed abrasive, and a solution capable of dissolving the resin after exposure is used as a first chemical solution supplied at the time of light dressing. It is preferable to supply. Particularly positive photosensitive resins, which react with light irradiation to change their properties, are dissolved or depolymerized in the portion to which light is irradiated during light dressing, so that they can be dissolved after exposure to light. It becomes easier to dissolve in liquid (organic solvent, alkaline aqueous solution, pure water). Therefore, the positive photosensitive resin, the abrasive grains, and, if necessary, another binder resin are mixed to form fixed abrasive grains, thereby irradiating light such as ultraviolet rays, and further, the resin is exposed after exposure. By bringing a soluble solution into contact with the surface of the fixed abrasive, the positive photosensitive resin can be dissolved together with other binder resins to promote the self-generation of the abrasive. The organic solvent used for the solution capable of dissolving the resin after exposure is selected according to the dissolution characteristics of the photosensitive resin after exposure. In the case of using an alkaline or acidic aqueous solution, the dissolution can be promoted by the neutralization reaction of acid and alkali.

When using, for example, photo-degradable PMMA (polymethyl methacrylate) or PMI PK (polymethyl isopropenyl ketone) as a positive photosensitive resin, the molecular weight decreases due to exposure, and the resin is dissolved after exposure. It is dissolved by using a mixture of an organic solvent such as methyl isobutyl ketone and isopropino alcohol as a possible solution. In addition, in the case of using the nopolak resin and the o_diazonaphthoquinone compound which are the dissolution inhibiting type, indene carboxylic acid is generated by exposure to light, and this is dissolved in the alkaline solution. When a photosensitive composition is mixed with polyvinyl alcohol which is a water-soluble resin, it can be dissolved using water as a solution capable of dissolving the resin after exposure. The resin used as the positive type photosensitive resin is preferably one (CH 2 -CR 1 R 2)-in which R 1 is CH 3, R 2 is-H, _CH 3, one CO O H,

— COOCH 3, 1 COOC 2H 5, _COOC 3H 7, 1 C C C 4 H 9, −

C〇OC 5H l l, — COOCH 2 CF 2 CHF — CF 3, — C 6H 5, 1 CO

NH2, CN, one COCH3, or a copolymer of these.

In addition, in order to promote the light dressing by including the photosensitive resin in the fixed abrasive, Do not add antioxidants, UV absorbers, light stabilizers, radical inhibitors, metal deactivators, peroxide decomposers, etc. contained in resin that is a general binder material. Is preferred. By the dressing described above, the polishing can be stably performed under sufficient abrasive grain self-generation.

When dressing by light irradiation, partially dissolved and incomplete resin may be retained on the surface of the fixed abrasive after irradiation. This resin is a portion which has been denatured into a resin dissolved by irradiation, and has physical properties different from those of the original resin. Therefore, this denatured resin does not have the effect of alleviating the aggression against the surface to be polished of the substrate and the effect of preventing the occurrence of scratches, etc., which the original resin has. In addition, the surface of the fixed abrasive that has been irradiated should be processed uniformly by polishing the substrate. However, when it is finely observed, the incompletely dissolved resin as described above remains, and in fact the processing is It may be uneven. Therefore, if the processing is repeated as it is, the uniformity of the processed surface will gradually be lost, and the polishing performance will be affected. Furthermore, the surface layer of the fixed abrasive is scraped off by mechanical dressing, and when the residue remains on the surface of the fixed abrasive or when the film on the surface to be polished of the substrate is removed by polishing, the removed film is removed. In some cases, the particles may stay on the fixed abrasive.

The polishing apparatus 202 also includes the foreign matter removing apparatus 32 (see FIG. 2) described in the first embodiment. As the foreign matter removing apparatus, there are a dresser and a nylon brush as described later, an atomizer, an ultrasonic wave generator, a vacuum suction apparatus and the like.

FIG. 4 shows a polishing apparatus 203 equipped with a dresser 32 A including diamond particles as a foreign matter removing apparatus according to a third embodiment of the present invention. The polishing apparatus 203 includes a dressing mechanism 38 by light irradiation having a light source 31. In the present polishing apparatus 203, foreign matter unrelated to polishing including the above-mentioned incompletely dissolved resin is pressed against the polishing surface 15 of the fixed abrasive 13 by pressing the dresser 32A onto the polishing surface 15 of the fixed abrasive 13. It becomes possible to expose the abrasive grains more effectively, and efficient polishing can be realized. In addition, if the incompletely dissolved resin is scraped off, it is possible to reproduce at least a homogeneous surface condition on the polishing surface 15 and maintain a uniform surface condition. FIG. 5 is a schematic elevation view showing a polishing apparatus 24 provided with a foreign matter removing apparatus 32 B having a nylon brush 37 according to a fourth embodiment of the present invention. This polishing machine The fixture 24 includes a light dressing mechanism 38 having a light source 31. In the present polishing apparatus 204, the foreign matter unrelated to the polishing including the above-mentioned incompletely dissolved resin is scraped by pressing the nylon brush 3 7 against the polishing surface 15 of the fixed abrasive 13 and rubbing it. It is possible to discharge the abrasive grains more effectively, and to realize efficient polishing. In addition, if the incompletely dissolved resin is scraped off, at least a homogeneous surface condition can be reproduced on the polished surface 15 and a uniform surface condition can be maintained.

The foreign substance removal device 32 B can also be controlled independently of the light dressing mechanism 3 8 that emits light from the light source 31, and the brushing strength of the nylon brush 3 7 can be controlled by the thickness of the brush, It is also possible to adjust by the number. For example, if fine-grained nylon brush 37 is used, the abrasive grains are much smaller (0.2 m or less) compared to nylon brush 37, so they are not scraped off by nylon brush 37. Although it is possible to stagnate, the product etc. is much larger than the abrasive grains, so it is pulled by the brush and is selectively scraped off. The nylon brush 37 is, for example, generally made of nylon 66, manufactured by Toray, model number 2 0 0 T 0. 0 1 2 3 or the like, and one wire diameter is 0.50 to 1 .0 mm, A round bundle of 5 to 10 mm in length and round in cross-sectional shape is made up of a plurality of circular bundles approximately 3 to 5 mm in diameter, or those arranged uniformly over the entire surface. In practice, a fine brush such as a general toothbrush is particularly desirable, and it is desirable to operate at a low pressing pressure. FIG. 6 shows a fifth embodiment of the present invention, in which the N 2 gas and a second liquid or a second chemical solution as pure liquid (pure water or a chemical solution other than pure water) are ejected in a mist form. A polishing apparatus 250 equipped with an atomizer 32 C as a liquid supply device is shown. Instead of spraying the N 2 gas and the second chemical solution for foreign matter removal from the atomizer 32 C, the N 2 gas for the foreign matter removal and the first chemical solution for dosing by light irradiation (the second chemical solution for foreign matter removal Different) may be sprayed. In this case, the atomizer 32 C also acts as a first liquid feeder of the present invention.

The atomizer 32 C supplies N 2 gas and a second chemical solution to remove foreign matter, and performs dressing by light irradiation, when used for the dressing.

(1) A chemical solution (different from the second chemical solution for removing foreign matter) may be supplied. In this case, the atomizer 32 C also acts as a first liquid feeder of the present invention.

The atomizer 32 C can be supplied from each spray nozzle 39 at the tip with uniform fluid flow rate and uniform concentration distribution. For example, a photoinitiator (photosensitizer) as a first chemical solution, which is used to improve the dressing action by the above-described light irradiation, may be dispersed on the fixed abrasive 13 by utilizing this characteristic. At this time, if uniform light irradiation can be realized, uniform surface processing can be performed on the fixed abrasive 13. In this case, the atomizer 32 C is connected to a first chemical solution supply source 44 for supplying a photoinitiator, and the atomizer 32 C also works as a first liquid supplier of the present invention.

Furthermore, the atomizer 32 C is connected to a gas supply source 42 and a second chemical solution supply source 43. The atomizer 32 C changes the pressure of the purge gas (N 2 gas etc.) supplied from the gas supply source 42 and the second chemical solution supply source 43, the flow rate of the second chemical solution, and the pressure, thereby changing from atomized to granular It is possible to realize all spraying conditions up to. In addition, uniform application can be realized regardless of the particle size because the application is by spraying with a purge pressure, and since multiple fluids are used, it is possible to change the concentration itself of the supplied fluid. As a result, depending on the particle size and distribution of the liquid, the concentration distribution of the application to the fixed abrasive 13 is strongly and weakly finished to be processed into fine unevenness after light irradiation, and the unevenness of the unevenness is sprayed It can be controlled by adjusting the degree of As an example, in the case of atomized spray, the machined surface of fixed abrasive 13 13 forms a surface state without fine irregularities or unevenness, and in the case of granular spray, it is tailored to a relatively undulated uneven surface state, etc. The unevenness on the surface can be changed according to the film type of the substrate to be polished, and the polishing according to the purpose can be realized.

In addition, supply of atomizer 32 C to spray nozzle 39 C is made independent for each spray nozzle unit, and each spray can be provided by providing a flow control mechanism (not shown) and a pressure control mechanism (not shown). By changing the spray amount from the nozzle 39 C, the concentration distribution of the fixed abrasive 13 in the radial direction can be changed, and the profile in the radial direction after light irradiation can be changed. This makes it possible to selectively polish only the portion where the substrate W (see FIG. 1) is desired to be polished according to the profile of the processing surface of the fixed abrasive 13.

The polishing apparatus 205 may be equipped with a liquid spray (not shown) as an alternative to the atomizer 32C. The liquid sprayer is arranged in a row facing the polishing surface 15 of the fixed abrasive 13. It has a plurality of spray nozzles (not shown), and high pressure (for example, 5 MP) of pure water supplied from pure water supply source with uniform liquid flow rate and uniform concentration distribution from each spray nozzle. a) Pressure control is performed by a pressure control mechanism (not shown) and supplied onto the polishing surface 15 so that foreign substances such as debris can be removed and washed away. The polishing apparatus 205 may also be equipped with a gas spray that ejects a gas to the fixed abrasive and removes it with the air pressure as an alternative to the liquid spray.

In addition, depending on the type of resin used for fixed abrasive 13, using a second chemical solution different from the first chemical solution used during dressing by light irradiation melts the resin unrelated to the above-mentioned polishing. It is removable. For the second chemical solution, an oxidant or the like exhibiting an oxidative decomposition action is also used. Note that, by using the atomizer 32 C, the second chemical solution can be dispersed uniformly on the polishing surface 15 of the fixed abrasive 13, and uniform light dressing can be performed. The liquid spray may be used instead of the atomizer 32 C.

FIG. 7 shows a polishing apparatus 206 for removing foreign matter by ultrasonic vibration according to a sixth embodiment of the present invention. The polishing apparatus 2006 includes an ultrasonic generator 32 D, and the ultrasonic generator 32 D is usually disposed above the fixed abrasive 13. By interposing pure water between the ultrasonic generator 32 D and the fixed abrasive 13, ultrasonic waves transmitted from the ultrasonic generator 32 D are fixed abrasive 13 via the pure water. The foreign matter retained on the polishing surface 15 of the fixed abrasive 13 can be removed by being transmitted to the polishing surface 15 of the fixed abrasive 13 by the ultrasonic vibration. The polishing apparatus 2006 includes an optical dressing mechanism 38. The ultrasonic generator 32 D can be controlled independently of the optical dressing mechanism 38 performing dressing by light irradiation. By adjusting the output of ultrasonic waves and the distance to the fixed abrasive 13, it is possible to improve the strength of foreign substance removal. In addition, when the resin used for the fixed abrasive 13 is very brittle (the glass transition degree is low), the abrasive abrasive can be generated only by the ultrasonic action. In this case, it is possible to supply a chemical solution or a mixture of these in addition to pure water as a liquid that is interposed between the ultrasonic generator 32 D and the fixed abrasive 13 and serves to transmit ultrasonic waves.

FIG. 8 shows a polishing apparatus for removing foreign matter by vacuum suction according to a seventh embodiment of the present invention. The polishing device 2 07 has a vacuum suction device 3 2 E connected to a vacuum source 4 5 and a vacuum suction device 3 2 E is usually arranged above the fixed particles 1 3 It is done. The polishing apparatus 2 0 7 includes an optical dressing mechanism 3 8 having a light source 3 1. In addition, the vacuum suction device 32 E also sucks up foreign substances not related to the above-mentioned polishing, and a drain (not shown) or a filter (not shown) provided between the vacuum supply source 45 and the vacuum suction device 3 2 E Collect the foreign matter according to the illustration).

FIG. 9 is a plan view showing the overall configuration of a polishing apparatus 20 according to an embodiment of the present invention. The polishing apparatus 2 0 8 is equipped with the polishing apparatus of the fifth embodiment. The polishing apparatus of the fifth embodiment can be replaced by the polishing apparatus according to the first to fourth and sixth to seventh embodiments. As shown in this figure, the polishing apparatus 2 0 8 is equipped with 4 loading / unloading stages 1 0 2 for placing wafer cassettes 1 0 1 for stocking a large number of semiconductor wafers W (see FIG. 1). ing. The loading Z unloading stage 102 may have a mechanism that can move up and down. In order to be able to reach each wafer cassette 101 on the Dono Unloading stage 2, a transport logo 104 is disposed on the traveling mechanism 103.

The transfer robot 104 has two hands at the top and the bottom. The lower hand of the two hands of the transfer robot 104 is an adsorption type hand for vacuum-adhering the semiconductor wafer W (see FIG. 1), and is only when the semiconductor wafer W is received from the wafer cassette 101. Used for The suction type hand can accurately transfer the wafer W regardless of the deviation of the wafer W in the cassette. On the other hand, the upper hand of the transfer port pot 104 is a drop-in type hand that holds the peripheral portion of the wafer W, and is used only when the semiconductor wafer W is returned to the wafer cassette 101. Since the drop-in type hand does not collect dust as in the suction type hand, the wafer w can be transferred while maintaining the clean degree of the back surface of the wafer W. By placing the clean wafer W after cleaning in this manner on the upper side, the wafer W is not further contaminated.

On the opposite side of the transport robot 1 0 4 with the traveling mechanism 1 0 3 as the axis of symmetry, the two cleaning machines 1 0 5 and 1 0 6 for cleaning the semiconductor wafer W are arranged. There is. Each washing machine 105, 106 is disposed at a position where the hand of the transport robot 104 can reach. Also, these cleaning machines 105, 106 are high on the wafer W It has a spin-dry function that allows it to be rapidly rotated and dried, which makes it possible to cope with two-stage cleaning and three-stage cleaning of wafers W without replacing modules.

Between the two cleaning machines 1 0 5 and 1 0 6, there are provided four semiconductor wafer W mounting tables 1 07 1 08 1 10 9 1 10 1 at a position where the transfer robot 1 04 can reach. 8 Stations 1 1 2 are arranged. At positions where it is possible to reach the washing machine 1 05 and the three mounting tables 1 07, 1 09, 1 1 0, there is arranged a transport robot 1 1 4 having two hands. In addition, at positions where the washing machine 6 and the three mounting tables 108, 1 09, and 1 10 can be reached, the transport robot 1 15 having two hands is disposed.

The loading table 107 is used to mutually transfer the semiconductor wafer W between the transfer robot 104 and the transfer robot 114, and the loading table 108 is between the transfer robot 104 and the transfer robot 115. Used to transport the semiconductor wafer W in On these mounting tables 107 and 108, detection sensors 116 and 117 for detecting the presence or absence of the semiconductor wafer W are provided, respectively.

The mounting table 109 is used to transfer the semiconductor wafer W from the transfer robot 155 to the transfer robot 114, and the transfer table 110 transfers the semiconductor wafer W from the transfer robot 114 to the transfer port bot 115. Used to These mounting tables 1 09 and 1 10 include detection sensors 1 18 1 and 1 1 9 that detect the presence or absence of a semiconductor wafer W, and rinse nozzles 1 for preventing the semiconductor wafer W from drying or cleaning the wafer W 1 20 and 1 2 1 are provided respectively.

These mounting tables 1 09 and 1 10 are disposed in a common waterproof cover, and a shutter 1 22 is provided in the transport opening provided on the cover. The mounting table 109 is positioned vertically above the mounting table 110, and the wafer W after cleaning is mounted on the mounting table 1 09 and the wafer W before cleaning is mounted on the mounting table 110. . Such a configuration prevents contamination of the wafer W due to the drop of rinse water. In the figure, sensors 1 1 6 1 1 7 1 1 8 1 1 9 and rinse nozzle 1 2

The positions 0, 1 2 1 and 10 12 22 are shown schematically and their positions and shapes are not shown exactly.

It is adjacent to the cleaning machine 105 at a position where the hand of the transfer robot 1 14 can reach. As such the washer 124 is arranged. In addition, the cleaning machine 125 is disposed adjacent to the cleaning machine 106 at a position where the hand of the transfer robot 115 can reach. These cleaning machines 124 and 125 are cleaning machines capable of cleaning both sides of the wafer W.

The upper hand of the transfer robot 114 and the transfer robot 115 is used to transfer the semiconductor wafer W, which has been cleaned once, to the mounting table of the cleaning machine or wafer station 112. On the other hand, the lower hand is used to transport the semiconductor wafer W which has not been cleaned and the semiconductor wafer W before being polished. By using the lower hand to transfer the wafer W to and from the reversing device 140 described later, the upper hand is not contaminated by the rinse water droplets from the upper wall of the reversing device. As shown in FIG. 9, shutters 105a, 106a, 124a, and 125a are attached to the wafer W inlets of the cleaning machines 105, 106, 124, and 125, respectively, and the wafer W is carried in. It can be opened only when it is

The polishing apparatus 208 is provided with a housing 126 so as to surround each device, and the inside of the housing 126 is divided into a plurality of areas by partition walls 128, partition walls 130, partition walls 132, partition walls 134 and partitions 136. , And region B).

Between the area A in which the wafer cassette 101 and the transfer robot 104 are arranged and the area B in which the cleaning machines 105 and 106 and the mounting tables 107, 108, 109 and 110 are arranged, the area A and A partition wall 128 is disposed to separate the degree of cleanliness with the region B. The partition wall 128 is provided with an opening for transporting the semiconductor wafer W between the area A and the area B, and a shirt 138 is provided in the opening. The above-mentioned cleaning machines 105, 106, 124, 125, the mounting tables 107, 108, 109, 110 of the wafer station 1 12, and the transfer bumps 114, 115 are all arranged in the area B, The pressure in B is adjusted to a pressure lower than the pressure in area A.

As shown in the figure, the reversing machine 140 for reversing the semiconductor wafer W is disposed at a position where the hand of the transfer robot 1 14 can reach within the area C divided from the area B by the partition wall 134. , Inverting machine 140 by the transfer robot 1 14 Then, the semiconductor wafer w is transferred. Also, at the position where the hand of the transfer port pot 115 can reach inside the area C, the reversing unit 14 1 that reverses the semiconductor wafer W is disposed. The semiconductor wafer W is transported by the robot pot 115. Inverting machine 140 and inverting machine 14 1 are chuck mechanism for chucking semiconductor wafer W, reversing mechanism for reversing the front and back of semiconductor wafer W, and semiconductor wafer W chucked by the above chuck mechanism? It has a detection sensor (not shown) to check whether it is.

A polishing chamber separated from the area B is formed by the partition walls 134, and the polishing chamber is further divided into two areas C and D by the partition walls 136. In addition, an opening for transporting a semiconductor wafer is provided in the partition wall 134 which separates the region B and the regions C and D. In this opening, the reversing unit 140 and the reversing unit 141 are provided. The shirts Yui 1 4 2, 1 4 3 will be provided.

As shown in FIG. 9, in the two areas C and D, turntables 1 4 6 and 1 4 7, turntables 1 4 8 and 1 4 9, and one semiconductor wafer are held and a semiconductor wafer One top ring 1 4 4 1 4 5 is placed to polish while pressing against the turntable 1 4 7 1 4 8.

That is, in the region C, the top ring 14 4, the turntables 1 4 6 and 1 4 8, the polishing liquid supply nozzle 1 5 0 for supplying the polishing liquid to the turntable 1 4 6, and the nitrogen gas To perform mechanical dressing of the atomizer 1 52 with a plurality of injection nozzles (not shown) connected to the supply source (not shown) and the second chemical solution supply source (not shown), and the turntable 1 46 The dresser 1 5 4 and the dresser 1 5 6 for performing mechanical dressing of the set table 1 4 8 are arranged.

Similarly, in the area D, the top ring 1 4 5, the setting table 1 4 7, the turntable 1 4 9, and the polishing liquid supply nozzle 1 5 for supplying the polishing liquid to the turntable 1 4 7 1 and an atomizer 1 53 having a plurality of injection nozzles (not shown) connected to a nitrogen gas supply source (not shown) and a second chemical solution supply source (not shown), and a machine of the turn table 1 4 7 A dresser 1 5 5 for performing the dynamic dressing and a dresser 1 5 7 for performing the mechanical dressing of the turntable 1 4 9 are disposed. Polishing fluid supply nozzle 1 5 0 1 5 1 is a polishing fluid used for polishing or mechanical dret Dressing fluid (for example, water) to be used for shinging is supplied onto turntables 1 46 and 147, respectively. Also, a mixed fluid in which nitrogen gas and a second chemical solution (pure water or a chemical solution other than pure water) are mixed is sprayed onto the turntables 1 46, 1 4 7 from the atomizers 1 52, 1 53. . The nitrogen gas from the nitrogen gas supply source and the second chemical solution from the second chemical solution supply source are adjusted to a predetermined pressure by a regu- lator, not shown, or an air operator valve, and the atomizer is in a state where both are mixed 1 It is supplied to 52, 15 3 injection nozzles not shown. In this case, it is preferable that the spray nozzles of the atomizers 1 52 and 1 5 3 jet fluid toward the outer peripheral side of the turntables 1 4 6 and 1 4 7. Note that other inert gases can be used instead of nitrogen gas. Alternatively, only the second chemical solution may be injected from the atomizers 15 2 and 15 3. An atomizer may be provided on the turntables 1 4 8 and 1 4 9. By providing an atomizer on the evening tables 1 4 8 and 1 4 9, the surfaces of the turntables 1 4 8 and 1 4 9 can be kept cleaner.

The mixed nitrogen gas and the second chemical solution (pure water or a chemical solution other than pure water) are: (1) liquid particleization, (2) liquid particle solidification, (3) liquid evaporation and gasification (these 1, 2 and 3 In the state of being atomized or atomized, the spray nozzles of the atomizers 1 52, 1 5 3 are sprayed toward the turntables 1 4 6, 1 4 7). The pressure, temperature, or pressure of the nitrogen gas and / or the second chemical solution (pure water or a chemical solution other than pure water) determines whether the mixed fluid is jetted in the state of liquid fine particleization, fine particle solidification, or gasification. It is determined by the shape of the puzzle. Therefore, change the condition of the fluid to be injected by changing the pressure, temperature, nozzle shape, etc. of nitrogen gas and Z or the second chemical solution (pure water or a chemical solution other than pure water) appropriately by means of a constant temperature. Can. A wet type wafer film thickness measuring machine may be installed in place of the turntables 1 4 8 and 1 4 9. In that case, it is possible to measure the film thickness of the wafer W immediately after polishing, and it is also possible to control the polishing process to the next wafer W by increasing the amount of shaving of the wafer W or using measured values.

Reversing machine 1 4 0, 1 4 1 and top ring 1 4 4, 1 4 5 below the cleaning room (area

The reactor 10 is disposed to transport the wafer W between B) and the polishing chamber (areas C and D). Wichi Tari Transporter 1 6 0, Wafer There are four stages at which W is to be placed at equal intervals, so that multiple wafers W can be loaded at the same time.

The wafer W transferred to the reversing machine 140, 1 4 1 has a phase difference between the center of the stage of the rotary transport 1 600 and the center of the wafer W chucked by the reversing machine 1 40, 1 4 1 At the same time, the lifts 16 2 and 16 3 installed below the rotary transport 160 move up and down and are transported onto the rotary transport 160. The wafer W placed on the stage of the rotary transporter 160 is transferred downward of the top rings 1 44 and 1 45 by changing the position of the opening-tari transport 160 by 90 °. Be done. The top rings 1 4 4 and 4 5 have been rocked in advance to the positions of 1 o'clock 1 o'clock 1 o'clock. When the centers of the top rings 1 4 4 and 1 4 5 are in phase with the centers of the wafers W mounted on the rotary conveyer 1 6 0 as described above, pushers 1 6 4 and 1 6 4 disposed below them. The wafer W is transferred from the Tari Transporter 160 to the top rings 14 4 and 1 4 5 by lifting and lowering of the 1 6 5.

The polishing apparatus 2008 is a light source such as a mercury lamp that irradiates light onto the areas C and D and the polished surfaces of the fixed abrasives 1 4 6 A and 1 4 7 A 1 4 6 B and 1 4 7 B 1 9 4 (refer to FIG. 11 below) and a first chemical solution supply nozzle 1 as a first liquid supply machine for supplying a first chemical solution as a first liquid onto the polishing surface 14 46 B, 14 7 B. 6 A light dressing mechanism 192 is provided having (see FIG. 11 below).

Next, with reference to FIG. 10, the polishing chamber (areas C and D in FIG. 9) of the present polishing apparatus 2 0 8 will be described in more detail. In the following, only area C will be described, but basin D can be considered the same as basin C. The figure also shows the relationship between the top ring 1444 of the basin C and the turntables 1446 and 14.8. As shown, the top ring 14 4 is suspended from the top ring head 1 72 by the rotatable top ring drive shaft 1 70. Top ring head

1 2 2 is supported by a positionable rocking shaft 1 7 4 and the top ring 1

4 4 is accessible to both evening tables 1 4 6 and 1 4 8.

Also, the dresser 1 5 4 is suspended from the dresser head 1 7 8 by a rotatable dresser drive shaft 1 7 6. Dresser head 1 7 8 is a positionable rocking shaft It is supported by 180 which allows the dresser 15 to move between a standby position to stand by and a dressing position to perform mechanical dressing on the turntable 146. Similarly, the dresser 1 56 is suspended from the dresser head 1 84 by a rotatable dresser drive shaft 1 82. The dresser head 1 8 4 is supported by a positionable swing shaft 1 8 6 so that the dresser 1 5 6 is in a standby position to stand by and a dressing position to perform mechanical dressing on the turntable 1 4 8 It is possible to move between.

The upper surface of the turntable 146 is constituted by fixed abrasives 1 46 A in which abrasive grains and pores or a pore agent are bonded by a binder (predetermined resin), and the fixed abrasives 1 46 A The polishing surface 1 46 B is configured to polish the semiconductor wafer W (see FIG. 1) held by the top ring 14 4. Such fixed abrasives 1 46 A are obtained, for example, by spray-drying a mixed liquid of a slurry-like abrasive (in which abrasive grains are dispersed in a liquid) and an emulsion-like resin mixed and dispersed, and this mixed powder It is obtained by filling a forming jig and applying pressure and heat treatment. As the abrasive, preferably, ceria (C eO 2) or silica (S i 0 2) having an average particle size of 0.5 m or less is preferably used. Further, as the binder, as described above, a thermoplastic resin or a thermosetting resin can be used, and in particular, a thermoplastic resin is preferable.

In addition, the upper surface of the cooling table 148 is formed of a soft non-woven fabric (not shown), and this non-woven fabric constitutes a cleaning surface for cleaning the abrasive particles attached to the surface of the semiconductor wafer W after polishing. Ru. The non-woven fabric constitutes a cleaning surface for cleaning the abrasive particles attached to the surface of the semiconductor wafer W after polishing.

The semiconductor wafer W polished by the fixed abrasives 1 46 A as described above is moved to the small-diameter turntable 14 8, where buff cleaning is performed. That is, while rotating the top ring 1 4 4 and the turntable 1 4 8 independently of each other, the polished semiconductor wafer W held by the top ring 1 4 4 is subjected to a spring table.

Press the soft non-woven fabric on top of the sheet. At this time, a liquid not containing abrasive grains, for example, pure water or an alkaline solution, preferably an alkaline solution containing alkaline liquid or PHA 9 or more, is supplied to the non-woven fabric from a cleaning solution supply nozzle (not shown). Thereby, the abrasive grains attached to the surface of the semiconductor wafer W after polishing can be effectively removed. FIG. 11 is a perspective view showing an overall configuration of a light dressing mechanism 92 for dressing by light irradiation. The light dressing mechanism 192 includes: a light source lamp 194 for irradiating light onto the polishing surface 1 4 6 B of the fixed abrasive 14 6 A; and a first chemical solution for supplying the first chemical solution onto the polishing surface 1 4 6 B 1) An optical dresser 198 comprising the chemical solution nozzle 196 and an arm 188 for driving. The light dresser unit 1 9 8 is connected and fixed to a driving arm 1 8 8 via a cylinder (not shown) for up and down movement. The light dresser unit 1 9 8 moves up and down with the vertical movement cylinder to adjust the distance between the light source lamp 1 9 4 and the polishing surface 1 4 6 B of the fixed abrasive 1 4 6 A to be subjected to the light dressing. . The driving arm 1 88 moves in the horizontal plane to position the light dresser unit 1 9 8 on the polishing surface 1 4 6 B of the fixed abrasive 1 14 6 A to be subjected to the light dressing.

FIG. 12 shows a front elevational view around the turntable 146 of the polishing apparatus 2008 of the present invention. The turntable 1 4 6 is provided with fixed abrasive 1 4 6 A as a polishing tool, and the wafer W to be polished held by the top ring 1 4 4 is placed on the top ring head 1 7 2 by the swing shaft 1 7 0 The sliding surface of the fixed abrasive 1 4 6 A is pressed by the descent of the top head 1 72 2 by the swinging of the cylinder and the cylinder for vertical movement (not shown), and it is pressed against the polished surface 1 4 6 B to rotate the semiconductor wafer W Polishing progresses.

Further, the polishing apparatus 2 0 8 is provided with a mechanical dressing mechanism 1 6 8 and an optical dressing mechanism 1 9 2. The mechanical dressing mechanism 1 6 8 has a dresser 1 54 which is, for example, a diamond dresser, which makes dressing by mechanically contacting the polishing surface 1 4 6 B of the fixed abrasive 1 4 6 A. The light dressing mechanism 192 has a light source 194 such as a mercury lamp and a first chemical solution supply nozzle 196, and performs light dressing by light irradiation. Here, the usual dressing is performed by light irradiation using the light dressing mechanism 192 and is performed before or during the polishing of the wafer W. A mechanical dressing mechanism 1 6 8 is used to remove the large irregularities formed on the fixed abrasive surface and to planarize the entire polishing surface. Usually, polishing of a plurality of wafers W is performed. It will be done later if necessary. In addition, while monitoring the flatness of the polishing surface 1 46 B of the fixed abrasive 1 146 A using a fixed abrasive surface measuring device (not shown), for example, mechanical contact when changing to irregularities of 1 m or more Do dressing by It is also good.

Next, a dressing method of fixed abrasive as a polishing tool will be described. As the timing for carrying out the dressing, the first method (In-S in-situ method) in which dressing is carried out simultaneously with substrate polishing and the second method in which dressing is carried out between substrate polishing and the start of the next polishing (Ex—Situ method). In the fixed abrasives until now, in the conditioning before the next polishing, sufficient polishing abrasives enough to withstand the next substrate polishing can not be produced by itself, and the polishing rate decreases with time, etc. Stability was not obtained. Therefore, it relied on the first method (I n-S i t u method) in which abrasive grains are constantly scraped out during polishing to stabilize the abrasive grain supply amount. Depending on the binder resin of the fixed abrasive, which is the counterpart of the dressing according to the light irradiation of the present invention, the self-generating amount of the abrasive can not be sufficiently secured, and the first method (In-S itu method) is used. If the fixed abrasive should be placed on a turntable of about the same size as the wafer diameter, dressing can not be performed during polishing, so dressing is performed only with the second method (Ex-S in-situ method). To

13 to 17 show examples of the operation sequence of the polishing apparatus 208 (see FIG. 9) according to the present invention. The abscissa represents the passage of time T, and the ordinate represents the dresser 154 (or 155), the top ring 144 (or 145), the light dressing mechanism 192 (or 193), and the foreign matter removing device 152 (or 153). (Refer to Fig. 9 above.) OFF indicates that operation is stopped, and ON indicates operation. 13 to 17, the dressing by the dresser 154 is a mechanical dressing of the polishing surface of the fixed abrasive, and the dressing by the optical dressing mechanism 192 is a dressing by irradiating the polishing surface of the fixed abrasive with light. (1) It is light dressing performed while supplying the chemical solution to the polishing surface. Foreign matter removal is performed using an atomizer 1 52 as a foreign matter removal device.

Figure 13 shows the case of dressing by the second method (Ex- Situ method). In this case, first, mechanical dressing for shape correction is performed by the dresser 154 (see FIG. 9) (0 to t 1), and light dressing by light irradiation is performed after the mechanical dressing is completed (tl to!: 2 ), Light dressing (OD) at regular intervals (t 2— Intermittently at t 1) (tl to!: 2, t 3 to t 4, t 5 to t 6, '') (light irradiation step of the present invention). At the end of the first light dressing (t 2), polishing (P) (Polishing step of the present invention) is performed on the semiconductor wafer placed on the top ring 144 (see FIG. 9), and Intermittently at regular intervals (t 3 _ t 2) (t 2 to t 3, t 4 to!: 5, t 6 to t 7, · ·). Policing is performed between light dressing and the next light dressing, and light dressing and polishing are alternately performed. Removal of foreign matter by the atomizer 152 is performed at the same time as the light dressing, and is performed intermittently (t1 to t2, t3 to t4) at the same fixed interval (t2−t1) as the light dressing. , T5 to t6,, (foreign substance removing step of the present invention).

FIG. 14 shows the case of dressing according to the first method (I n-S i t u method). In this case, first perform mechanical dressing for shape correction by the dresser 154 (see Fig. 9) (0 to! 1), and after the mechanical dressing is completed, the light dressing by light irradiation before polishing is compared to the one before polishing. As a light dressing, perform a predetermined interval (t2-t1) (t1 to t2). Policing is performed after a predetermined interval (t2−t1), and poling is performed intermittently at fixed intervals (t3−t2) (t2 to t3, t4 to t5, t6 to t7 , * ·). In addition, after the predetermined interval (t 2 _ t 1) has elapsed, the light dressing is continued without interruption for a predetermined interval (t 3- t 2), and then performed at the same timing as the polishing (t 2 to t 3, t 4-t5, t6-t7, · · ·. That is, after the first predetermined interval (t2-t1), the light dressing is intermittently performed at the same fixed interval (t3-t2) as the polishing. Foreign substance removal is started at the same time as light dressing (t1) and is continued continuously thereafter.

Figure 15 shows the case of dressing by the third method (In-S intermittent intermittent dressing method). The third method is the first method (In_S itu method) (Fig. 14) with intermittent dressing added as follows. The differences from FIG. 14 will be mainly described below. The light dressing by light irradiation is performed intermittently after the light dressing (t1 to t2) before poling, intermittently for 2 times of the duration tX, and including the rest time ty. Intermittent operation is performed intermittently at a predetermined cycle (t4-t2). In the intermittent operation of the light dressing, the timing of start is the top ring 144 (Fig. 9). Refer to the timing of the start of the poling by The foreign substance removal operation is performed at the same timing as the light dressing. Mechanical dressing and polishing are performed as in Figure 14.

Figure 16 shows the case of dressing by the fourth method (continuous light dressing). The differences from FIG. 14 will be mainly described below. The light dressing by light irradiation is performed before the start of polishing for a predetermined time (t 1 to t 2), and then the continuous operation is continued. That is, while dressing is being performed, light dressing is performed, and while dressing is interrupted, light dressing is also performed. The foreign substance removal operation is performed at the same timing as the light dressing. Mechanical dressing and poling are performed as in Figure 14.

Figure 17 shows the case of dressing according to the fifth method (In_Sitte method with advance dressing). The method shown in this figure is an extension of the first method in Figure 14. In the first method, the polishing and the optical dressing are performed at the same timing in each polishing step, but in the fifth method, the timing of the start of the light dressing is earlier by the time tz than the timing of the start of the poling The setting and the advance light dressing of the interval tz are performed. The foreign substance removal operation is performed at the same timing as the light dressing. Mechanical dressing and polishing are performed as in Figure 14.

The effect of this method is that sufficient polishing abrasive grain self-generation is carried out before starting polishing, and polishing processing is performed with a predetermined polishing efficiency from the beginning without worrying about the rising of polishing immediately after the start of polishing. Is possible. As a result, efficient and stable polishing can be realized.

If the light dressing effect by the light irradiation is strong, the light dressing may be performed only during or after the polishing, or intermittently during the polishing, but if the light dressing effect is weak, the polishing may be performed. Not only inside but also between polishing and the next polishing, it is necessary to carry out light writing. In the meantime, a form in which light dressing is constantly performed is preferable. Here, the mechanical dressing is dressing by a mechanical dresser (for example, a diamond dresser as described above) mainly contributing to the shape correction of the polishing surface. Light dressing is dressing by light irradiation Ru. At the time of light dressing by light irradiation, it is preferable to simultaneously operate the foreign matter removal apparatus of the present invention.

In Figures 13 to 17, light dressing is performed after shape correction of the polished surface by mechanical dressing. In order to polish the first wafer W after the shape correction, for example, also the 10th wafer W under the same conditions, light draining with light is performed after the shape correction. In addition, after shape correction by mechanical dressing, the surface of the polishing surface may be too rough, so polishing the semiconductor wafer with few scratches by making the abrasive particles spontaneously from the polishing surface softly by light dressing by light irradiation. be able to.

In Figure 16, light exposure by light irradiation is performed continuously both during polishing and during non-polishing. The light dressing by light can effectively dress the polishing surface surface so that it does not generate large particle size foreign matter and large unevenness, and therefore it is effective in preventing scratches on the wafer W. , Dressing speed (dressing ability) may be slow. In such a case, it is always possible to cause new abrasive grains to spontaneously grow on the polished surface by performing light-dressing with light continuously both at the time of polishing and at the time of non-polishing. The light dressing with light shown in Fig. 16 and Fig. 17 may be performed intermittently without being constantly applied. Also, as shown in FIG. 12 described above, when the fixed abrasive 14A is placed on the turntable 146, the optical dressing mechanism 132 for performing the optical dressing by the light irradiation is the substrate polishing means. It can also be placed in a position different from the top ring 1 4 4 as the cover in advance so as to cover the evening table 1 4 6 so that it can be constantly drained with or without polishing. .

However, in this case, to apply dressing to the entire surface of the fixed abrasive, it is necessary to rotate the turntable 14 6. However, if the rotation is too fast, the first chemical solution or the like that promotes the dressing action by the light irradiation will flow out of the turntable 14 due to the centrifugal force. As a result, the conditioning effect is diminished by that amount, and the necessary amount of abrasive grains can not be secured. In order to avoid such a situation, it is desirable to rotate, for example, the turntable 1 46 at a low rotational speed of 10 or less per minute while the substrate is not polished. If it does so, it is not necessary The loss of the essential first chemical solution and the like can be suppressed, and a sufficient conditioning effect can be obtained.

Also, at the same time, the same general CMP polishing pad is also used, but the upper surface of the pad must always be kept wet, in order to efficiently supply pure water or chemical solution for wetting over the entire surface of the pad. It is preferable to keep the rotating table 1 46 rotate, and the fixed abrasive should be kept wet as well, and when supplying a liquid for wet storage even during continuous polishing, It is good to rotate the turntable 1 46.

INDUSTRIAL APPLICABILITY As described above, according to the present invention, since the light source and the foreign matter removing device are provided, the light source irradiates a light beam on the polishing surface of the polishing tool, and the binder is polished Weakening the adhesion of the particles, making it impossible to hold the abrasive particles in the binder, causing the abrasive particles to grow spontaneously, and further preventing the abrasive particles from being produced uniformly by the foreign matter removing device, foreign matter produced by polishing, or Since foreign substances generated by irradiation can be forcibly removed, factors that cause unstable polishing can be removed, and stable abrasive grains can be supplied at the time of polishing, good polishing performance can be obtained.

【table 1】

【Table 2】

1st 2nd 3rd Test No. Supply chemical solution Light irradiation [k / min] [Ά / min] [k / min]

1 Pure water only 119. 2 102. 2 102. 5

2 Pure water only 119. 2 101. 8 93. 7 Standard buffer solution

3 Yes 126. 0 100. 8 117. 8

(Borate PH standard solution)

Claims

The scope of the claims

1. A polishing device,

Abrasive tool having a polishing surface comprising abrasive grains and a binder for fixing the abrasive grains,

A moving mechanism for pressing the substrate against the polishing surface and moving the substrate relative to polish the substrate, a light source for irradiating the polishing surface with a light beam that weakens the adhesion of the binder, and

A polishing apparatus that includes a foreign matter removal mechanism that removes foreign matter generated by light irradiation from the polished surface.

2. The polishing apparatus according to claim 1, wherein the foreign matter removing mechanism includes a dresser formed to be able to be pressed against the polishing surface, and the dresser includes diamond particles.

3. The polishing apparatus according to claim 1, wherein the foreign matter removing mechanism includes a brush formed to be able to be rubbed on the polishing surface.

4. The polishing apparatus according to claim 1, wherein the foreign matter removing mechanism includes a mixed fluid generator which jets a mixed fluid of gas and liquid toward the polishing surface.

5. The polishing apparatus according to claim 1, wherein the foreign matter removing mechanism includes an ultrasonic generator that generates ultrasonic waves toward the polishing surface.

6. The polishing apparatus according to claim 1, further comprising a first liquid supply that supplies the first liquid onto the polishing surface, wherein the foreign matter removing mechanism polishes the second liquid for removing the foreign matter. The polishing apparatus according to claim 1, further comprising: a second liquid feeder configured to supply the first liquid, wherein the first liquid and the second liquid are different.

7. The polishing apparatus according to claim 1, wherein the foreign matter removing mechanism includes a vacuum suction mechanism for sucking foreign matter by vacuum.

8. A method of dressing the polishing surface of the polishing tool,

The polishing surface includes an abrasive and a binder for fixing the abrasive, and is used in a polishing process that is pressed against the substrate and moved relative to the substrate to polish the substrate.

The method includes a light irradiation step of irradiating a light beam which weakens the adhesion of the binder to the polishing surface, and a foreign matter removing step of forcibly removing foreign matter generated on the polishing surface.

9. The method according to claim 8, wherein the foreign matter removing step includes the step of pressing a dresser containing diamond particles against the polishing surface.

10. The method according to claim 10, wherein the foreign matter removing step includes the step of rubbing a brush on a polishing surface.

The method according to claim 8, wherein the foreign matter removing step comprises the step of spraying a pressure-controlled mixed fluid consisting of gas and liquid onto the polishing surface.

The method according to claim 10, wherein the foreign matter removing step includes the step of irradiating the polished surface with an ultrasonic wave.

The method according to claim 8, further comprising: supplying a first liquid to the polishing surface during the light beam irradiation step; and supplying a second liquid to the polishing surface during the foreign matter removing step. The method according to claim 8, further comprising a step, wherein the first liquid and the second liquid are different.

The method according to claim 8, wherein the foreign matter removing step includes a step of suctioning the foreign matter under vacuum.

Dressing method of the polishing surface of the polishing tool

The method includes the step of irradiating the polishing surface of the polishing tool with a beam of light that weakens the adhesion of the binder, wherein the beam of irradiation comprises: during the polishing process of polishing the substrate with the polishing tool; A dressing method performed between the step and the next polishing step.

The polishing process is performed by rotating the polishing tool, and the number of revolutions of the polishing tool is 10 or less per minute while the polishing process is not performed. The dressing method described in.

The light irradiation step performed simultaneously with the polishing step is intermittently performed when the dressing speed in the light irradiation step is large, and when the dressing speed is small, the light irradiation step is further performed between the polishing step and the next polishing step. The method according to claim 15, wherein the light irradiation step is performed.