JP2018051733A - Polishing pad, method for manufacturing the same, and method for manufacturing polished article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polishing pad that has appropriate disintegration property and maintains a stable polishing rate, and to provide a method for manufacturing the same and a method for manufacturing a polished article using the polishing pad.SOLUTION: A polishing pad 10 includes a substrate 12 and a resin part 11 arranged on the substrate 12. The resin part 11 includes: a resin containing acryl phenolic resin and/or polyurethane acrylate; a fixed abrasive grain 13 contributing to polishing an object to be polished; and a filler material 14 hardly contributing to polishing the object to be polished.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a polishing pad, a method for manufacturing the same, and a method for manufacturing a polished product.

In recent years, materials such as silicon carbide (SiC), gallium nitride (GaN), diamond, sapphire (Al ₂ O ₃ ), and aluminum nitride (AlN), which are wide band gap semiconductors, have attracted attention as next-generation power semiconductor device materials. Yes. For example, silicon carbide (SiC) has excellent physical properties such as three times the band gap and about seven times the dielectric breakdown electric field strength compared to Si semiconductors, and operates at higher temperatures than current silicon semiconductors. It is excellent in that it is excellent in performance, small size, and high energy saving effect. For sapphire wafers, electronic devices with optical elements, such as high-performance overhead projectors, due to their chemical stability, optical properties (transparency), mechanical strength, thermal properties (thermal conductivity), etc. The importance as an industrial part is increasing. For the full-scale spread of these next-generation power devices, the substrate diameter and mass production have been promoted, and the importance of substrate processing technology has increased accordingly. In such a substrate processing process, similarly to Si, first, a cylindrical single crystal (ingot) used for a wafer is sliced to be cut into a disk shape. Next, the surface of the sliced disk-shaped single crystal is flattened. First, in order to roughly flatten the surface, lapping is performed using a lapping platen. Thereafter, in order to further improve the flatness of the surface of the disk-shaped single crystal and to remove a fine flaw on the surface to make a mirror surface, a polishing process is performed.

  In such polishing process, a method using a polishing sheet obtained by printing a polishing layer composition containing abrasive particles on one surface of a base film by screen printing and curing with ionizing radiation (for example, Patent Document 1), using a polishing sheet in which a plurality of polishing structures in which abrasive particles (fixed abrasive grains) having a primary particle diameter of less than 3 μm are dispersed in a saturated copolymerized polyester resin are used, free abrasive grains are used. A method of polishing without using it is known (see, for example, Patent Document 2).

JP 2003-145433 A JP 2009-72832 A

  However, in the polishing sheets described in Patent Documents 1 and 2, only the abrasive particles exposed on the surface of the polishing layer (polishing structure) function as fixed abrasive grains, and the abrasive particles embedded in the polishing layer serve as abrasive grains. Since it does not act, the polishing rate can decrease over time. When the polishing rate changes with time, it becomes necessary to change the polishing conditions each time. Therefore, there is room for further study on the stability of the polishing rate in the prior art.

  In this regard, the polishing layer has a desired disintegration, and the polishing particles embedded in the polishing layer are newly exposed by gradually scraping the polishing layer surface at a desired speed with polishing. It is conceivable to improve the stability of the polishing rate. The disintegration property of the polishing layer is considered to depend on the volume ratio of the abrasive particles in the polishing layer, and the disintegration property is considered to improve as the volume ratio of the abrasive particles increases.

  However, simply increasing the volume ratio of the abrasive particles in the polishing layer causes a problem that the disintegration property is extremely increased and the life of the polishing pad is extremely decreased. This is presumably because the abrasive particles are released from the abrasive layer collapsed with the polishing, and the released abrasive particles work to promote the collapse of the abrasive layer. In addition, when relatively expensive particles such as diamond are used as abrasive particles from the viewpoint of the polishing rate, even if the volume ratio of the abrasive particles is increased from the viewpoint of improving disintegration, the disintegration is too high and the polishing pad is increased. There is also a problem that it is difficult to tolerate from the viewpoint of cost if the lifespan of the product is reduced. On the other hand, if the volume ratio of the abrasive particles is simply reduced, the viscosity of the composition used to produce the abrasive layer changes, making it difficult to produce by screen printing and other techniques, and the disintegration also decreases. In addition, there arises a problem that the polishing rate is lowered.

  The present invention has been made in view of the above circumstances, and by having an appropriate disintegration, a polishing pad capable of maintaining a stable polishing rate, a method for manufacturing the same, and polishing using the polishing pad It aims at providing the manufacturing method of a processed article.

  The present inventors diligently studied to solve the above problems. As a result, the present inventors have found that the above problem can be solved by using a filler that does not substantially contribute to the polishing of an object to be polished apart from fixed abrasive grains, and have completed the present invention.

That is, the present invention is as follows.
[1]
A substrate and a resin portion disposed on the substrate;
The resin portion includes a resin, fixed abrasive grains that contribute to polishing of the object to be polished, and a filler that hardly contributes to polishing of the object to be polished.
Polishing pad.
[2]
The resin includes an acrylic phenol resin and / or polyurethane acrylate,
The polishing pad according to [1].
[3]
The fixed abrasive is diamond abrasive, cerium oxide abrasive, alumina abrasive, silicon carbide abrasive, silicon oxide abrasive, zirconia abrasive, iron oxide abrasive, manganese oxide abrasive, magnesium oxide abrasive, calcium oxide Including at least one selected from the group consisting of abrasive grains, barium oxide abrasive grains, zinc oxide abrasive grains, barium carbonate abrasive grains, and calcium carbonate abrasive grains,
The polishing pad according to [1] or [2].
[4]
The filler includes at least one selected from the group consisting of silica and titanium oxide,
The polishing pad according to any one of [1] to [3].
[5]
The content of the fixed abrasive is 30 to 60% by mass with respect to the total amount of the resin part.
The polishing pad according to any one of [1] to [4].
[6]
The content of the filler is 5 to 35% by mass with respect to the total amount of the resin part.
The polishing pad according to any one of [1] to [5].
[7]
The base material includes a polyester film,
The polishing pad according to any one of [1] to [4].
[8]
An adhesive layer is further provided on the side opposite to the resin part of the base material,
The polishing pad according to any one of [1] to [6].
[9]
An adhesion step of adhering a curable composition comprising a resin, a fixed abrasive that contributes to polishing of the object to be polished, and a filler that does not easily contribute to polishing of the object to be polished on the substrate;
Curing the attached curable composition to obtain a resin part,
Manufacturing method of polishing pad.

  According to the present invention, it is possible to provide a polishing pad capable of maintaining a stable polishing rate by having appropriate disintegration, a method for manufacturing the same, and a method for manufacturing a polished product using the polishing pad. Can do.

It is a schematic front view which shows an example of the polishing pad of this embodiment.

  Hereinafter, a form for carrying out the present invention (hereinafter simply referred to as “the present embodiment”) will be described in detail with reference to the drawings as necessary. In the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. Further, the positional relationship such as up, down, left and right is based on the positional relationship shown in the drawings unless otherwise specified. Further, the dimensional ratios in the drawings are not limited to the illustrated ratios.

[Polishing pad]
The polishing pad of the present embodiment includes a base material and a resin portion disposed on the base material, and the resin portion includes a resin, fixed abrasive grains that contribute to polishing of an object to be polished, and the object to be polished. And a filler that hardly contributes to polishing of the polished article.

  FIG. 1 is a schematic front view showing an example of the polishing pad of the present embodiment. As shown in FIG. 1, the polishing pad 10 includes a base material 12 and a resin portion 11 disposed on the base material 12. In FIG. 1, a plurality of dots by the resin portion 11 are arranged on the surface of the base material 12 to form an uneven pattern (positive pattern). However, the resin portion 11 may form a concavo-convex pattern together with the substrate 12 as shown in FIG. 1 or may be a uniform layer formed on the substrate surface. Further, the uneven pattern may be a pattern (negative pattern) formed by the resin portion 11 formed so that a uniform layer is punched into dots. In addition, the polishing pad of this embodiment may have an adhesive layer described later as necessary.

  As shown in FIG. 1, in the polishing pad of this embodiment, the disintegration property of the resin part is controlled due to the presence of the filler 14 that does not easily contribute to polishing. Are gradually scraped off to form a new polished surface in which the fixed abrasive grains 13 embedded in the resin portion 11 are exposed.

  When the resin part has a fixed abrasive and a resin and does not have a filler that does not easily contribute to polishing, and the resin itself has low disintegration, the fixed abrasive protruding from the surface contributes to polishing. However, since the disintegration property of the resin is suppressed, the internal fixed abrasive is hardly exposed on the surface, and the polishing rate can be lowered with time. On the other hand, if the resin part has fixed abrasive grains and a resin and does not have a filler that does not contribute to polishing, and the resin itself is highly disintegratable, the resin part is fixed by the collapse of the resin part. As the abrasive grains are exposed and desorbed, the desorbed (freed) fixed abrasive grains polish the resin to further accelerate the collapse of the resin part, and the decay progresses at an accelerated rate, thereby reducing the life of the polishing pad. Shorter.

  In addition, as a method for controlling the disintegration property of the resin part, a method of changing the hardness or brittleness by selecting a resin used for the resin part, or a change of the brittleness of the resin part by increasing the ratio of the fixed abrasive used for the resin part. And a method of physically controlling disintegration, such as a method of adding a component such as white alumina that contributes to resin disintegration (instead of polishing of the object to be polished) into the slurry flowing during polishing; A method of chemically controlling disintegration by using a resin that reacts accordingly can be considered.

  On the other hand, the polishing pad of this embodiment tried to physically control the collapse of the resin portion by having the filler that does not contribute to the polishing of the object to be polished separately from the fixed abrasive. Therefore, the disintegration property is moderately controlled without changing the resin properties required during production such as screen printing. In particular, when the resin part has fixed abrasive grains and a part of the fixed abrasive grains is replaced with a filler that hardly contributes to polishing as compared with a polishing pad having no filler, the polishing rate is usually Is considered to be low. However, it is surprising that the polishing pad of the present embodiment has a high polishing rate and can maintain a stable polishing rate over time. This factor is not particularly limited to the following, but by using a filler that does not easily contribute to polishing, by reducing the brittleness of the resin itself in the resin part, or by increasing the proportion of fixed abrasive grains in the resin part. It is not necessary to reduce the brittleness of the resin part, and it is not necessary to increase the proportion of the fixed abrasive used in the resin part from the viewpoint of improving disintegration, so that it is possible to suppress the release of the fixed abrasive grains from the resin part. In addition, the filler that does not contribute to polishing improves the disintegration property, so that it is easy to form a new polished surface in which the fixed abrasive grains embedded in the resin portion are exposed. Conceivable.

〔Base material〕
Although it does not specifically limit as a base material, For example, polyester-type films, such as a polyethylene terephthalate film, a polypropylene terephthalate film, a polybutylene terephthalate film; A polyethylene (PE) film, a polypropylene (PP) film, an ethylene propylene copolymer film, etc. A polyolefin-based film; a polyether ether ketone (PEEK) film and a polyphenylene sulfide (PPS) film. The substrate is not particularly limited as long as it can form a resin described later on the upper surface, and a polyester film is preferable from the viewpoint of chemical resistance, heat resistance, economy, and the like.

(Resin part)
The resin portion is disposed on the substrate and includes a resin, fixed abrasive grains that contribute to polishing of the object to be polished, and a filler that does not easily contribute to polishing of the object to be polished. Here, “contributing to polishing” and “difficult to contribute to polishing” mean a polishing rate A when using a slurry containing abrasive grains contributing to polishing as free abrasive grains, and a filler that hardly contributes to polishing. In comparison with the polishing rate B in the case of using a slurry containing a free abrasive grain, the polishing rate B is 0.1 or less when the polishing rate A is 1. Here, the measurement conditions of the polishing rates A and B are the same including the content (mass basis) of the free abrasive grains in the slurry, except that the free abrasive grains are different.

(Fixed abrasive)
The fixed abrasive is not particularly limited, for example, diamond abrasive, cerium oxide abrasive, alumina abrasive, silicon carbide abrasive, silicon oxide abrasive, zirconia abrasive, iron oxide abrasive, manganese oxide abrasive, Examples thereof include at least one selected from the group consisting of magnesium oxide abrasive grains, calcium oxide abrasive grains, barium oxide abrasive grains, zinc oxide abrasive grains, barium carbonate abrasive grains, and calcium carbonate abrasive grains. Among these, diamond abrasive grains are preferable. By using such fixed abrasive grains, the polishing rate tends to be further improved.

  The content of the fixed abrasive is preferably 30 to 60% by mass, more preferably 35 to 55% by mass, and further preferably 40 to 50% by mass with respect to the total amount of the resin part. When the content of the fixed abrasive is 30% by mass or more, the polishing rate tends to be further improved. Moreover, when the content of the fixed abrasive is 60% by mass or less, the stability of the polishing rate tends to be further improved.

[Fillers that are difficult to contribute to polishing]
The filler that does not easily contribute to polishing (hereinafter, also simply referred to as “filler”) is not particularly limited as long as it can be said to be “difficult to contribute to polishing” in relation to the fixed abrasive, for example, , Silica, and at least one selected from the group consisting of titanium oxide. By using such a filler, the disintegration property of the resin part tends to be further improved.

  The content of the filler is preferably 5 to 35% by mass, more preferably 7.5 to 30% by mass, and further preferably 10 to 25% by mass with respect to the total amount of the resin part. When the content of the filler is 5% by mass or more, the disintegration property of the resin part is further increased, and the stability of the polishing rate tends to be further improved. Further, when the filler content is 35% by mass or less, the number of fixed abrasive grains is relatively increased, so that the polishing rate tends to be further improved and the life of the polishing pad tends to be further improved.

  The content of the filler is preferably 10 to 70% by volume, more preferably 20 to 60% by volume, and still more preferably, with respect to 100% by volume of the total volume of the fixed abrasive and the filler. It is 25-50 volume%. When the content of the filler is 10% by volume or more, the disintegration property of the resin part is further improved, and the stability of the polishing rate tends to be further improved. Further, when the filler content is 70% by volume or less, the number of fixed abrasive grains is relatively increased, so that the polishing rate tends to be further improved. In addition, the viscosity of the curable composition described later tends to depend on the total volume rather than the total mass of the fixed abrasive and the filler.

[Resin pattern]
The resin part may be formed as a uniform layer on the surface of the base material, or may be formed alone or together with the base material so as to form a concavo-convex pattern (see FIG. 1). Among these, from the viewpoint of supplying or discharging a liquid component used during polishing such as slurry to the polishing surface, it is preferable that the resin portion forms a regular uneven pattern. By having a regular pattern, uniform polishing is possible, and polishing with excellent surface quality can be achieved. The “regular pattern” refers to a pattern obtained by arranging a plurality of small patterns as a unit. Further, the surface of the resin portion opposite to the base material is a polishing surface for polishing the object to be polished.

  The concavo-convex pattern is not particularly limited as long as it is a pattern having a portion (convex portion) that contacts the object to be polished and a portion (concave portion) that does not contact the object to be polished. For example, a resin portion as shown in FIG. 11 is a positive pattern formed independently on the substrate 12 (pattern having dot-shaped convex portions); a negative pattern in which the resin portion is continuously formed on the substrate (pattern having dot-shaped concave portions) A pattern having a donut-shaped convex part; a pattern having a substantially C-shaped convex part; a pattern having concentric circles and a part that contacts the object to be polished and a part that does not contact the object to be polished; A pattern having a part that contacts the object and a part that does not contact the object to be polished; a pattern having a part that contacts the object to be polished and a part that does not contact the object to be polished; Parts and cover Pattern and a portion which does not contact the Migakubutsu; or include pattern composed of a combination of these. Among these, a pattern having a dot-like convex portion or a pattern having a dot-like concave portion is preferable. By having such a concavo-convex pattern, the polishing rate tends to be further improved.

  In addition, the three-dimensional shape of the dot in the case of a pattern having a dot-like convex part is not particularly limited, and for example, hemispherical, substantially hemispherical, spherical cap shape, substantially spherical cap shape, spherical belt shape, substantially spherical belt shape, semi-elliptical shape Body shape, substantially semi-ellipsoidal shape, columnar shape (columnar shape, substantially columnar shape, elliptical columnar shape, substantially elliptical columnar shape, polygonal columnar shape), frustum shape (conical truncated cone shape, substantially truncated cone shape, elliptical truncated cone shape, substantially elliptical truncated cone shape) Trapezoidal and polygonal frustum-shaped). Among the above, the frustum shape may be a frustum shape extending from the substrate side toward the polishing surface side, or may be a frustum shape extending from the polishing surface side toward the substrate side. In addition, the three-dimensional shape of the space in the concave portion in the case of the pattern having the dot-shaped concave portion can be exemplified by the same three-dimensional shape as in the case of the pattern having the dot-shaped convex portion.

  Although it does not specifically limit as resin which comprises a resin part, For example, polyurethane-type resins, such as a polyurethane which has an ether or ester bond in a molecule | numerator, a polyurethane polyurea, a polyurethane acrylate; Polyacrylate, an acrylphenol type resin, a polyacrylonitrile Acrylic resins; vinyl resins such as polyvinyl chloride, polyvinyl acetate, and polyvinylidene fluoride; polysulfone resins such as polysulfone and polyethersulfone; acylated cellulose resins such as acetylated cellulose and butyryl cellulose; polyamides Resin; and polystyrene resin. Among these, acrylic resins and polyurethane resins are preferable, and acrylic phenol resins and / or polyurethane acrylates are more preferable. By using such a resin, the polishing rate tends to be further improved. In addition, resin which comprises a resin part may be used individually by 1 type, or may use 2 or more types together.

(Adhesive layer)
The polishing pad of this embodiment may further include an adhesive layer for attaching the polishing pad to the polishing surface plate of the polishing machine on the side opposite to the resin portion of the substrate. The adhesive layer may include an adhesive or a pressure-sensitive adhesive used for a conventionally known polishing pad. Examples of the material for the adhesive layer include various thermoplastic adhesives such as acrylic adhesives, nitrile adhesives, nitrile rubber adhesives, polyamide adhesives, polyurethane adhesives, polyester adhesives, and silicone adhesives. Agents. The adhesive layer may be a double-sided tape, for example.

[Anchor layer]
The polishing pad of this embodiment may have an anchor layer between the base material and the resin portion. By having an anchor layer, it exists in the tendency which improves the adhesiveness of a base material and a resin part more. Although it does not specifically limit as a material which comprises an anchor layer, For example, an acrylic resin coating agent is mentioned.

[Production method of polishing pad]
The polishing pad manufacturing method of the present embodiment includes a resin, a fixed abrasive that contributes to the polishing of the object to be polished, and a filler that hardly contributes to the polishing of the object to be polished on the substrate. An adhering step for adhering the adhesive composition, and a curing step for curing the adhering curable composition to obtain a resin portion.

[Adhesion process]
In the attaching step, a curable composition containing a resin, fixed abrasive grains that contribute to polishing of the object to be polished, and a filler that hardly contributes to polishing of the object to be polished is attached on the base material. At this time, the curable composition may be adhered on the base material so that the resin portion forms a desired uneven pattern.

  The method for attaching the curable composition on the substrate is not particularly limited. For example, a gravure coater method, a small diameter gravure coater method, a reverse roll coater method, a transfer roll coater method, a kiss coater method, a die coater method, a screen. Examples thereof include a printing method and a spray coating method. Among these, the screen printing method is preferable from the viewpoint of easy formation of a complicated uneven pattern.

(Curable composition)
Although it does not specifically limit as a curable composition, For example, the photocurable composition containing a photoinitiator and a polymeric compound, the thermosetting composition containing a thermal polymerization initiator and a polymeric compound, a thermosetting resin And a curable composition containing a UV curable resin, a two-component mixed curable resin, and the like. Moreover, the curable composition may contain the crosslinking agent etc. which have 2 or more of polymerizable functional groups as needed.

  Although it does not specifically limit as a polymeric compound, For example, (meth) acrylate, epoxy (meth) acrylate, urethane (meth) acrylate, polyester (meth) acrylate is mentioned.

  Although it does not specifically limit as a photoinitiator, For example, a benzophenone series compound, an acetophenone series compound, and a thiotisanthone series compound are mentioned. The thermal polymerization initiator is not particularly limited, and examples thereof include azo compounds such as 2,2'-azobisbutyronitrile and peroxides such as benzoyl peroxide (BPO).

  Although it does not specifically limit as a thermosetting resin, For example, a phenol resin, an epoxy resin, an acrylic resin, a urea resin, a formaldehyde resin etc. are mentioned.

  Although it does not specifically limit as UV curable resin, For example, a prepolymer with a number average molecular weight of about 1000 to 10000 is good, and examples of the material include acrylic (methacrylic) esters, urethane-modified products thereof, thiocols, etc. Depending on the case, a reactive diluent or an organic solvent can be used. Further, the two-component mixed type curable resin is not particularly limited, but for example, prepolymers having different physical properties can be used.

[Curing process]
A hardening process is a process of hardening the adhering curable composition and obtaining a resin part. Although it does not specifically limit as a hardening method, For example, photocuring, thermosetting, etc. are mentioned. In the obtained resin part, a part of the fixed abrasive grains and the filler are exposed on the surface, and the other fixed abrasive grains and the filler are embedded in the resin.

[Other processes]
The manufacturing method of the polishing pad of this embodiment may have other processes as needed. For example, you may have the process of volatilizing and removing at least one part of the volatile component in a curable composition after an adhesion process and before a hardening process. In addition, after the adhesion step, before the curing step and / or after the curing step, there is a step of removing a part of the curable composition or the resin portion in order to form a desired uneven pattern. It may be. An example of the removal method is cutting.

[Production method of polished product]
The manufacturing method of the polishing processed product according to this embodiment is not particularly limited as long as it includes a polishing step of polishing an object to be polished using the polishing pad in the presence of loose abrasive grains. The polishing process may be primary lapping polishing (rough lapping), secondary lapping (finish lapping), or polishing polishing, and may also serve as a plurality of polishing. May be.

  The object to be polished is not particularly limited. For example, materials such as semiconductor devices and electronic components, in particular, Si substrates (silicon wafers), SiC (silicon carbide) substrates, GaAs (gallium arsenide) substrates, glass, hard disks and LCDs. A thin substrate (object to be polished) such as a substrate for (liquid crystal display) can be mentioned. Among these, the manufacturing method of the polished product of the present embodiment is a method of manufacturing difficult-to-process materials that are difficult to polish, such as materials that can be applied to power devices, LEDs, and the like, for example, sapphire, SiC, GaN, and diamond. Can be suitably used. Among these, a semiconductor wafer is preferable, and a SiC substrate, a sapphire substrate, or a GaN substrate is preferable from the viewpoint of more effectively utilizing the effects of the polishing pad of the present embodiment. The material is preferably a difficult-to-cut material such as SiC single crystal and GaN single crystal, but may be a single crystal of sapphire, silicon nitride, aluminum nitride, or the like.

[Polishing process]
The polishing step is a step of polishing an object to be polished using the polishing pad in the presence of loose abrasive grains. As a polishing method, a conventionally known method can be used and is not particularly limited.

  In the polishing method, first, a polishing pad is mounted at a predetermined position of a polishing apparatus. At the time of mounting, the polishing pad is mounted so as to be fixed to the polishing apparatus through the above-described adhesive layer. Then, while pressing the object to be polished held on the holding surface plate disposed so as to face the polishing pad as the polishing surface plate to the polishing surface side, polishing while supplying a polishing slurry containing diamond abrasive grains from the outside Rotate the pad and / or holding platen. Thus, the processed surface (surface to be polished) of the object to be polished is polished by the action of the abrasive grains supplied between the polishing pad and the object to be polished.

  The polishing slurry preferably includes diamond abrasive grains and a dispersion medium for dispersing the diamond abrasive grains. Although the content rate of the diamond abrasive grains in the polishing slurry is not particularly limited, it is 0 with respect to the total amount of the polishing slurry from the viewpoint of performing the polishing process more effectively and suppressing the thickness of the work-affected layer in the object to be polished. It is preferable that it is 0.01-1.0 mass%.

  Note that the free abrasive grains used in polishing are not limited to diamond abrasive grains, and may be, for example, silica or alumina. The average particle size of the free abrasive grains is preferably 0.5 to 20 μm, more preferably 1 to 18 μm, still more preferably 2 to 15 μm, and particularly preferably 5 to 13 μm. When the average particle diameter of the diamond abrasive grains is within the above range, the polishing rate can be further improved and the occurrence of scratches on the workpiece surface can be further suppressed.

  Examples of the dispersion medium include water and an organic solvent, and an organic solvent is preferable from the viewpoint of further suppressing deterioration of the object to be polished. As the organic solvent, an organic solvent having a boiling point of about 110 to 300 ° C. is generally suitable. As the type of organic solvent, commercially available organic solvents such as aliphatic and aromatic, cyclic hydrocarbons, esters, ethers, amines, amides, and ketones can be appropriately selected according to the resin and workability. A solvent is used individually by 1 type or in combination of 2 or more types. Further, the solvent may contain other additives as necessary. Examples of such additives include polar compounds, and specific examples include nonionic surfactants, anionic surfactants, carboxylic acid esters, carboxylic acid amides, and carboxylic acids. Furthermore, various silicones and inorganic fine powders can be added as an antifoaming agent, a dispersing agent, a leveling agent, and a viscosity improving material.

  In addition, from the viewpoint of suppressing a temperature rise due to friction between the polishing pad and the object to be polished during polishing, a solvent that does not contain abrasive grains and may contain additives is appropriately supplied to the polishing surface of the polishing pad. Also good. Examples of the solvent and additives include those described above.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. The present invention is not limited in any way by the following examples.

[Polishing test 1]
A polishing pad was installed at a predetermined position of the polishing apparatus via a double-sided tape, and a polishing test was performed in which a 2-inch silicon wafer as an object to be polished was polished under the following conditions. In the polishing test 3, the polishing rates when the polishing time was 10 minutes and 20 minutes were calculated.
(Polishing conditions)
Surface plate rotation speed: 60 rpm
Surface pressure: 150 gf / cm ²
Lubricant flow rate: 100cc / min
Lubricant: Solvent pure water, white alumina 2% by mass

[Polishing test 2]
A polishing pad was installed at a predetermined position of the polishing apparatus via a double-sided tape, and a polishing test was performed to polish a 2-inch sapphire C wafer as an object to be polished under the following conditions. In the polishing test 3, the polishing rates when the polishing time was 10 minutes and 20 minutes were calculated.
(Polishing conditions)
Surface plate rotation speed: 60 rpm
Surface pressure: 150 gf / cm ²
Lubricant flow rate: 100cc / min
Lubricant: Solvent pure water, 1% by weight of white alumina

[Polishing test 3]
A polishing pad was installed at a predetermined position of the polishing apparatus via a double-sided tape, and a polishing test was performed to polish a 2-inch sapphire C wafer as an object to be polished under the following conditions. In the polishing test 3, the lubrication used was changed according to the polishing time, and the polishing rates when the polishing time was 20 minutes, 40 minutes, 60 minutes, 80 minutes, 100 minutes, and 120 minutes were calculated.
(Polishing conditions)
Surface plate rotation speed: 60 rpm
Surface pressure: 150 gf / cm ²
Lubricant flow rate: 100cc / min
Lubricant 1: (0 to 20 minutes) Solvent pure water, white alumina 0 mass%
Lubricant 2: (20-40 minutes) Solvent pure water, white alumina 0 mass%
Lubricant 3: (40-60 minutes) Solvent pure water, 4% by weight of white alumina
Lubricant 4: (60-80 minutes) Solvent pure water, 1% by mass of white alumina
Lubricant 5: (80 to 100 minutes) Solvent pure water, white alumina 2% by mass

(Polishing rate)
The polishing rate (unit: μm / h) is the thickness removed by polishing from the polishing amount obtained from the decrease in the mass of the object before and after polishing in the polishing tests 1 and 2, the polishing area and specific gravity of the object to be polished. Was calculated and evaluated as the thickness removed per hour. The thickness was calculated from the polishing amount obtained from the decrease in the mass of the object to be polished before and after processing, the polishing area and specific gravity of the object to be polished. The polishing test was performed on three silicon wafers, and the weighted average was used as the polishing rate.

[Example 1]
45 parts by mass (28% by volume) of diamond abrasive grains (28% by volume, manufactured by Trustwell Co., Ltd.) as fixed abrasive grains, and spherical silica (average particle diameter: 9 μm manufactured by Toagosei Co., Ltd.) 11 as a filler that hardly contributes to polishing .4 parts by mass (9.5% by volume) and 40 parts by mass of an acrylic phenol resin (Arakawa Chemical Industries, Ltd.) were mixed to prepare a curable composition.

  On a polyethylene terephthalate film (Toyobo Co., Ltd., product name Cosmo Shine A4300, thickness 250 μm) as a base material, dot-shaped convex hemispherical dots are regularly formed in an uneven pattern by screen printing. The curable composition was applied so as to be aligned. Thereafter, the curable composition was cured by heating to form a resin portion.

Finally, a double-sided tape (manufactured by 3M, product name film base double-sided pressure-sensitive adhesive tape 442JS) was attached as an adhesive layer on the side opposite to the resin part of the base material to obtain a polishing pad of Example 1. In the obtained polishing pad, the dot diameter was 2 mm, the closest distance between adjacent dots was 500 mm, and the uneven pattern per unit area was 18 pieces / cm ² .

[Example 2]
30 parts by mass (18.5% by volume) of diamond abrasive grains (manufactured by Trust Well, average particle size 9 μm) as fixed abrasive grains, and spherical silica (manufactured by Toagosei Co., Ltd., average particle diameter 9 μm) that is difficult to contribute to polishing ) 22.7 parts by mass (19% by volume) and 40 parts by mass of an acrylic phenol resin (Arakawa Chemical Industries, Ltd.) were mixed to prepare a curable composition. Other steps were performed in the same manner as in Example 1 to obtain a polishing pad of Example 2.

[Comparative Example 1]
As fixed abrasive, 60 parts by mass (37.5% by volume) of diamond abrasives (manufactured by Trustwell, average particle size 9 μm) and 40 parts by mass of acrylic phenol resin (manufactured by Arakawa Chemical Industries) are mixed and cured. A composition was prepared. Other steps were performed in the same manner as in Example 1 to obtain a polishing pad of Comparative Example 2.

  Table 1 shows the results of conducting polishing tests 1 and 2 using the polishing pads obtained in Examples 1 and 2 and the results of carrying out polishing test 1 using the polishing pads obtained in Comparative Example 1. . Table 2 shows the results of polishing test 3 using the polishing pad obtained in Comparative Example 1.

  As can be seen from Table 1, the polishing pad of Comparative Example 1 has a high polishing rate for the first 10 minutes, but has a low polishing rate for the following 10 minutes. This is presumably because although the fixed abrasive grains on the surface of the polishing pad contribute to the polishing at first, the fixed abrasive grains deposited on the surface gradually decrease due to low disintegration and the polishing rate is lowered. The result of a polishing test performed while changing the concentration of white alumina contained in the lubricant relative to Comparative Example 1 is shown in Table 2, and the above tendency appears more remarkably. That is, initially, the fixed abrasive grains on the surface of the polishing pad contribute to the polishing, so that the polishing rate is large, but the polishing rate is quickly lowered due to the low disintegration property. Although recovery of the polishing rate can be seen by increasing the amount of white alumina added and improving disintegration, if the amount of white alumina added is reduced, the disintegration becomes lower and the polishing rate becomes lower.

  On the other hand, although the polishing pads of Example 1 and Example 2 have a smaller content of fixed abrasive grains that contribute to polishing compared to Comparative Example 1, as can be seen from Table 1, the polishing rates for the first 10 minutes are compared. The value was the same as in Example 1, and no significant reduction in the polishing rate was observed in the subsequent 10 minutes. This is presumably because the polishing pads of the examples have appropriate disintegration properties.

  The polishing pad of the present invention has industrial applicability as a polishing pad for lapping and polishing of optical materials, semiconductor devices, hard disk glass substrates and the like, particularly lapping and polishing of sapphire and SiC.

  DESCRIPTION OF SYMBOLS 10 ... Polishing pad, 11 ... Resin part, 12 ... Base material, 13 ... Fixed abrasive, 14 ... Filler which is hard to contribute to grinding | polishing

Claims (9)

A substrate and a resin portion disposed on the substrate;
The resin portion includes a resin, fixed abrasive grains that contribute to polishing of the object to be polished, and a filler that hardly contributes to polishing of the object to be polished.
Polishing pad. The resin includes an acrylic phenol resin and / or polyurethane acrylate,
The polishing pad according to claim 1. The fixed abrasive is diamond abrasive, cerium oxide abrasive, alumina abrasive, silicon carbide abrasive, silicon oxide abrasive, zirconia abrasive, iron oxide abrasive, manganese oxide abrasive, magnesium oxide abrasive, calcium oxide Including at least one selected from the group consisting of abrasive grains, barium oxide abrasive grains, zinc oxide abrasive grains, barium carbonate abrasive grains, and calcium carbonate abrasive grains,
The polishing pad according to claim 1. The filler includes at least one selected from the group consisting of silica and titanium oxide,
The polishing pad of any one of Claims 1-3. The content of the fixed abrasive is 30 to 60% by mass with respect to the total amount of the resin part.
The polishing pad of any one of Claims 1-4. The content of the filler is 5 to 35% by mass with respect to the total amount of the resin part.
The polishing pad according to claim 1. The base material includes a polyester film,
The polishing pad of any one of Claims 1-4. An adhesive layer is further provided on the side opposite to the resin part of the base material,
The polishing pad according to claim 1. An adhesion step of adhering a curable composition comprising a resin, a fixed abrasive that contributes to polishing of the object to be polished, and a filler that does not easily contribute to polishing of the object to be polished on the substrate;
Curing the attached curable composition to obtain a resin part,
Manufacturing method of polishing pad.