JP2003165058A - Polishing compact and polishing surface plate using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polishing compact and a polishing surface plate using the same, applicable mainly to the pre-finish process (lapping) of substrate materials or optical materials and capable of achieving a prescribed precision level in their surfaces at higher speeds and with stability. <P>SOLUTION: The polishing compact and the polishing surface plate using the same mainly comprise a zirconia compact containing alumina and a stabilizer and has an abrasive part 2 that polishes and a non-abrasive part 3, and there are specified rates between area and porosity in the parts 2, 3. In the part 2, 60% or more of the inorganic grains are 5 μm or less in diameter, 60% or more of the alumina grains are 5 μm or less in diameter, and 60% or more of the stabilizer-containing zirconia grains are 5 μm or less in diameter. A equation 0.25≤X/(X+Y)≤0.95 holds, where the rate of the area of the alumina grains is X and that of the stabilizer-containing zirconia grains is Y. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a silicon wafer,
Processing process for polishing substrate material such as oxide single crystal substrate, compound semiconductor substrate, various glass substrates, quartz glass substrate, ceramics substrate and optical materials, especially a molded body for polishing suitable for lapping step and polishing using the same It is related to the surface plate.

[0002]

2. Description of the Related Art With the progress of industries such as optics and electronics, the demands for processing magnetic disks, semiconductor substrates, single crystal materials, optical materials, etc. have become extremely strict. In the process), the surface of the material was processed on a lapping platen while continuously flowing a polishing liquid containing free abrasive grains. As loose abrasive grains used at this time, aluminum oxide, iron oxide,
Chromium oxide, zirconium oxide, silicon carbide, diamond and the like are known. A graphite cast iron platen has been generally used as a lapping platen. However, when the lapping process is performed by the conventional method, the abrasive grains used for the lapping may stick into the surface of the material to be polished (hereinafter referred to as “material to be polished”), and pits may locally occur. Further, there is a problem that the finished surface (lapping surface) of the material to be polished has a maximum roughness corresponding to it because the abrasive grains having a large particle size are used to secure the productivity. Further, when abrasive grains having a small particle size are used as a countermeasure against such a problem, there is a problem that productivity is lowered.

To address such a problem, for example, Japanese Patent Laid-Open No. 200
Japanese Patent Laid-Open No. 0-42903 proposes a method of lapping a material to be polished using a polishing liquid containing abrasive grains, in which the abrasive grain size is changed to a smaller side and lapping is performed in two steps. However, according to this method, when the same apparatus is used, for example, the abrasive grains having two kinds of diameters are used properly, which makes management of the apparatus very complicated. There is a problem in that movement occurs, that is, process management becomes complicated.

On the other hand, the graphite cast iron platen has been used as a lapping platen because of its high hardness. However, when lapping is performed using this surface plate, it is difficult to perform the processing sufficiently stably. Therefore, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2000-52238, Attempts have been made to stabilize the performance by controlling the particle size and the existing density of graphite distributed in the board. However, it is needless to say that it is preferable to further improve and stabilize the processing performance in view of workability such as device management and process management.

Further, in Japanese Laid-Open Patent Publication No. 11-239962, it is preferable that the lapping platen is made of a high hardness material, and graphite cast iron, ceramics material and natural stone material are exemplified. Among them, ceramic materials and natural stone materials are characterized by low elongation and a small coefficient of thermal expansion, and it is described that they have excellent corrosion resistance to acid-based polishing liquids as compared with graphite cast iron. . However, no mention has been made of the microstructure of such ceramic materials and natural stone materials, and there is no disclosure of specific performance in lapping.

On the other hand, the inventors of the present invention have proposed various types of polishing compacts composed of inorganic particles such as ceramics from the viewpoints of the material of the inorganic particles, the structure of the entire polishing compact, and the surface structure. It has been shown that it is possible to finish the material surface with high accuracy and high efficiency, and thereafter, we have also examined whether or not such an abrasive compact can be applied to lapping.

[0007]

As described above, the present inventors have found a molded article for polishing suitable for various materials to be polished, particularly for the finishing step. However, the pre-step of the finishing step, that is, the lapping step. It has been desired to improve productivity by further increasing the efficiency of polishing, and it is necessary to stabilize such polishing characteristics. Furthermore, as a requirement other than the polishing performance for the inorganic particles constituting such a polishing molded body, in addition to the ease of handling when using the polishing molded body, the handling of the raw material is easy, the manufacturing process is Since it is also important that it is not complicated and that the manufacturing cost is relatively low, there has been a demand for a molded article for polishing that satisfies these requirements.

The present invention has been made in view of the above problems, and its purpose is to provide a substrate material such as a semiconductor substrate, an oxide single crystal substrate, various glass substrates, a quartz glass substrate, and a ceramic substrate, and precision processing. Applicable mainly to the pre-finishing process (lapping process) of required optical materials, etc., the surface of the material to be polished can be further speeded up to a predetermined surface accuracy, and such characteristics are stable, and further polishing that can solve the above problems The object is to provide a molded product for polishing and a polishing platen using the molded product.

[0009]

As a result of intensive studies to solve the above-mentioned problems, the present inventors applied a molded article for polishing consisting essentially of inorganic particles to a lapping step of a material to be polished. In doing so, not only the structure of the entire polishing compact but also a microstructure different from the case where the surface of the polishing compact that is involved in polishing with the material to be polished (hereinafter referred to as "polishing surface") is used in the finishing process. By having a certain surface accuracy for various materials to be polished at a higher speed, and because its microstructure, that is, the characteristics of the polished surface is maintained in a certain range even during processing, its performance is improved. Can be stabilized for a long period of time, and in particular, in polishing with loose abrasive grains, even if a change over time occurs in continuous use of abrasive grains during polishing, in order to suppress the decrease in polishing rate corresponding to the change Molded body for polishing When the particle diameter of the inorganic particles constituting the rubbing portion in the surface involved in polishing certain conditions,
Further, they have found that if the pore diameter of the non-rubbing portion satisfies a specific condition, the above problems can be solved and the polishing work can be made more efficient, and the present invention has been completed. That is, in the polishing process of rubbing the polishing compact and / or the material to be polished, the polishing compact and the material to be polished are in direct contact with each other and rubbed against each other (hereinafter, referred to as “sliding friction”). "Part") and a part which is not directly in contact with the material to be polished in the polishing process and is considered to supply the polishing liquid to the rubbing part by allowing the polishing liquid mainly used in the polishing process to stay or flow. , "Non-rubbing part") exists at least on the polishing surface side of the molded article for polishing, and the structure has a specific structure. They have found that it is extremely important that the inorganic particle size of the rubbing part satisfies a specific condition, and that the pore size of the non-rubbing part satisfies a specific condition.

The present invention will be described in detail below.

<Characteristics of Polishing Molded Article> The polishing molded article of the present invention is a polishing molded article composed of inorganic particles, and the surface of the above-mentioned polishing molded article which is involved in polishing is not rubbed with a rubbing portion. And the pores present in the rubbing portion have a diameter of 1 μm or less and the area thereof is 15% of the total area of the rubbing portion.
And a non-rubbed area of 20% or more and 60% or less of the total area of the surface involved in polishing, wherein the inorganic particles are zirconia containing alumina and a stabilizer. The polishing molded body is mainly composed of 60% or more of the particle diameter of the inorganic particles constituting the rubbing portion of the polishing molded body is 5 μm or less, and 60% or more of the particle diameter of the alumina particles is 5 μm or less, 60% or more of the particle size of the zirconia particles containing the stabilizer is 5 μm or less, the area ratio of the alumina particles forming the polishing compact is X, and the area ratio of the zirconia particles containing the stabilizer is Y. And 0.25 ≦ X / (X + Y) ≦
It is 0.95.

The inorganic particles used in the molded article for polishing of the present invention are appropriately selected in consideration of compatibility with the material to be polished, and specifically, aluminum oxide, silicon oxide, cerium oxide, Zirconium oxide, yttrium oxide as a stabilizer, scandium oxide, indium oxide, zirconium oxide in which a rare earth oxide such as cerium oxide, magnesium oxide, calcium oxide or the like is solid-soluted,
Usually, at least one of oxides such as manganese oxide, titanium oxide, magnesium oxide, iron oxide, chromium oxide and yttrium oxide and non-oxides such as silicon carbide, boron carbide and boron nitride is used. You can Here, the compatibility with the material to be polished means, for example, the required finishing surface of the material to be polished with respect to physical properties such as hardness and toughness of the material to be polished and chemical properties such as chemical reactivity. It means to be selected by comprehensively judging accuracy, flatness, polishing rate and the like.

However, in the present invention, in addition to the easiness of handling when using the polishing molded body as a requirement other than the polishing performance for the polishing molded body, the handling of the raw material is easy, and the manufacturing process is complicated. Not considering that the manufacturing cost is relatively low,
Alumina and zirconia containing a stabilizer are suitable as the inorganic particles.

The polishing compact of the present invention essentially contains a binder such as metal, vitrified or resin, which is generally used for obtaining a synthetic grindstone holding and fixing abrasive grains. However, the shape can be maintained even in the lapping process in such a state.

The molded article for polishing of the present invention is substantially composed of the above-mentioned inorganic particles, and in the lapping process, the polishing surface is brought into direct contact with the material to be polished to perform the polishing operation. It is a thing. This polishing compact has a structure as shown in FIG. 1 which is a conceptual view schematically showing a part of the polishing surface and FIG. 2 which shows a cross section of a part of FIG.

Here, the non-rubbing portion on the polishing surface of the molded article for polishing does not come into direct contact with the material to be polished as shown by 3 in FIGS. 1 and 2, and is mainly used for polishing. It is a part that allows the polishing liquid used in processing to stay or flow and supply the polishing liquid to the rubbing part. In some cases, the free abrasive grains used are held and fixed, and there are pores larger than 1 μm. To do. Further, the sliding portion on the polishing surface of the molded article for polishing is a portion other than the non-sliding portion, as shown by 2 in FIGS. 1 and 2, and is in direct contact with the material to be polished. It is a part. Incidentally, these non-rubbed parts,
The rubbing portion can be confirmed by observing the polishing surface of the polishing molded body with a scanning microscope, as shown in Examples.

Further, in order to uniformly process the material to be polished in the polishing process, paying attention to the distribution state of the sliding portion and the non-sliding portion on the polishing surface of the polishing compact, FIG. 1 is shown. As described above, since the effect of uniformly processing the material to be polished becomes more remarkable, it is preferable that the non-rubbing portions are uniformly distributed on the polishing surface. Here, being uniformly distributed means that the non-rubbing portions are present in the same number or area ratio in a certain range of the polishing surface of the polishing molded body.

Further, it is preferable that the distribution of the non-rubbing portion on the polishing surface is always maintained even during the polishing process, which allows the polishing process of the material to be polished to be carried out uniformly. Here, the distribution of the non-rubbed portion on the polishing surface is, as shown in the examples, cut the polishing molded body along a plane perpendicular to the normal line direction of the polishing surface of the polishing molded body, The state can be observed with a scanning microscope or the like.

The rubbing portion and non-rubbing portion present on the polishing surface of the molded article for polishing of the present invention have the fine structure as described above, and such a structure should be retained even during the polishing process. If
Performing the polishing process of the material to be polished uniformly, that is, the variation of the polishing process speed among the respective portions to be polished of the material to be polished can be suppressed to be smaller, and the polishing target having excellent uniformity or flatness can be obtained. The material can be obtained, and the wear on each part of the polishing surface of the polishing compact itself can be suppressed from varying, leading to excellent polishing performance uniformity in lapping.

The fine structure of the molded abrasive product of the present invention is such that 60% or more of all particles of alumina particles constituting the rubbing portion and zirconia particles containing a stabilizer have a particle size of 5 μm or less. It is a molded product, and 60% or more of the particle size of alumina particles is 5 μm or less, and 60% or more of the particle size of zirconia particles containing a stabilizer is 5 μm or less.

In the polishing method using the polishing compact of the present invention, abrasive grains having an average particle diameter of 10 μm or less are usually used. Therefore, in consideration of the abrasive grain size, the sliding portion of the polishing compact is considered. 60% or more of the particle diameter of all particles of the zirconia particles containing the alumina particles and the stabilizer constituting the
It is preferable that it is m or less because a decrease in the polishing rate when the abrasive grains are continuously used is suppressed. That is, it is preferable that the number of particles larger than 5 μm is less than 40%. If the proportion of particles larger than 5 μm is 40% or more, it is not preferable because the polishing rate is remarkably lowered when the abrasive grains are continuously used.

Further, it is preferable that 60% or more of the particle diameter of alumina constituting the polishing compact is 5 μm or less, and 60% or more of the particle diameter of zirconia containing a stabilizer is 5 μm or less. Since the plurality of inorganic particles forming the polishing compact have the same particle size distribution, the polishing performance can be stabilized.

In the polishing compact of the present invention, when the area ratio of the alumina particles constituting the polishing compact is X and the area ratio of the zirconia particles containing the stabilizer is Y, 0.25≤ It is further preferable that X / (X + Y) ≦ 0.95. When the area ratio of the alumina particles and the zirconia particles containing the stabilizer is within the above range, the abrasion loss rate of the polishing compact is suppressed to be small.

Further, the ratio is 0.4 ≦ X / (X + Y)
It is more preferable that ≦ 0.9 because the abrasion loss rate of the polishing compact will be further reduced.

If the emphasis is placed on further improving the polishing rate and suppressing the wear of the polishing compact itself for practical use as the polishing performance of the above-described polishing compact of the present invention, the polishing compaction is concerned. It is more preferable that 20% or more of the pore diameter of the non-rubbed portion of the body is 10 μm or more. The upper limit of the pore diameter is not particularly limited, but if many pores with a diameter of more than 3 mm are introduced, damage during polishing is likely to increase. It is preferable that the number of pores substantially within the range of 10 μm to 3 mm is 80% or more.

Further, in the polishing method using the molded article for polishing of the present invention, as described above, the abrasive grains having an average particle diameter of 10 μm or less are usually used. Considering this abrasive grain size, if the stability of the polishing rate due to continuous use of abrasive grains is emphasized as the polishing performance of the above-mentioned polishing compact, if the non-rubbing part of the polishing compact is concerned. Pore size 20-80
More preferably, the percentage is 1 to 10 μm. Within such a range, a decrease in the polishing rate when the abrasive grains are continuously used is further suppressed. Exceeding this range is not preferable because it has a sufficient function as a molded article for polishing, but wear is greater than the above range. If it is less than this range, the reduction of the polishing rate when the abrasive grains are continuously used becomes larger than the above range, which is not preferable.

The areas of the rubbing portion and the non-rubbing portion are determined by observing each portion with a scanning electron microscope or the like, as shown in the examples, and determining the diameters of the inorganic particles and the pores. It can be calculated by calculating the number of particles by the intercept method and then converting it into the area of a predetermined polishing surface.

In the polishing compact of the present invention, it is more preferable that the monoclinic crystal ratio of zirconia containing the stabilizer constituting the polishing compact is 5% or less. The crystal phase of zirconia containing the stabilizer is usually identified by an X-ray diffraction test shown in Examples as a monoclinic phase, a tetragonal phase, a cubic phase, or a mixed phase thereof. This is because if the proportion of the monoclinic phase, that is, the monoclinic rate is 5% or less, the wear rate of the polishing compact is suppressed to be low.

Here, the calculation of the ratio of the crystal phase of zirconia containing a stabilizer in the present specification is carried out by an X-ray diffraction test as shown in the example after polishing evaluation of the surface of the molded article for polishing which is involved in polishing. Is measured by measuring the diffraction integral intensity of a predetermined plane index of a monoclinic phase, a tetragonal phase and a cubic phase of zirconia containing a stabilizer.

In the abrasive compact of the present invention, it is more preferred that the stabilizer for zirconia containing the stabilizer constituting the abrasive compact is yttria. Examples of the stabilizer include yttrium oxide, scandium oxide, indium oxide, rare earth oxides such as cerium oxide, magnesium oxide, calcium oxide and the like as described above, but because of their excellent mechanical properties such as bending strength and hardness. is there.

In the abrasive compact of the present invention, the yttria amount of the zirconia stabilizer containing the stabilizer constituting the abrasive compact is 3 to 8% by weight based on the sum of the yttria amount and the zirconia amount. Is more preferable. The smaller the amount of yttria, the lower the stability of the crystal phase, and especially when it is less than the above range, the monoclinic crystal ratio is likely to occur on the surface involved in polishing of the polishing compact, while the larger the amount of yttria, the stability of the crystal phase. However, the tetragonal phase and further the cubic phase are obtained, but the mechanical properties such as bending strength and hardness are deteriorated and the wear of the polishing compact is affected, so that the above range is more preferable. Of.

<Method for producing molded article for polishing> The method for producing a molded article for polishing of the present invention is not particularly limited as long as it is a method capable of obtaining a molded article for polishing having the above-mentioned characteristics, and inorganic particles Examples of the method include molding the powder of (1), and processing such as firing after molding.

More specifically, the method for producing a molded body for polishing according to the present invention will be described. The raw material powder is molded into a molded body having an appropriate shape and size, and then processed if necessary. To obtain a molded body used for polishing.

Here, when molding is carried out under pressure, for example, a molding method such as press molding can be exemplified, and the pressure condition is not particularly limited, and it can be carried out under known conditions. Further, cast molding, injection molding, extrusion molding and the like can also be applied.

The average particle size of the raw material powder of the inorganic particles constituting the molded body for polishing is not particularly limited, but is not limited to 0.
It is preferable to use those having a diameter of 005 to 10 μm. It is practically difficult to use particles having an average particle size of less than 0.005 μm, as will be described later.
Although it is possible to use particles having a particle size of more than 0 μm, there may be restrictions in producing a molded article for polishing.

Further, the raw material powder may be treated in order to improve the formability of the raw material powder at the time of molding. As a specific method of the treatment, for example, a method of consolidating can be mentioned, but the condition is not particularly limited. In addition, in order to improve the formability of the raw material powder,
Granulation may be performed by a spray drying method, a rolling method, or the like, or a binder, wax, or the like may be added.

When an organic substance such as a wax or a binder is added to the raw material powder before molding in order to improve the moldability of the raw material powder into a molded body made of inorganic particles,
Degreasing is preferably performed during processing into a molded article for polishing. The degreasing method is not particularly limited, and examples thereof include degreasing by heating in an air atmosphere and heating degreasing in an inert atmosphere of nitrogen, argon, helium or the like. At this time, the pressure of the atmospheric gas may be increased pressure or normal pressure, or may be reduced pressure in some cases. Similarly, water may be added in order to improve the moldability and dried before the subsequent firing operation.

Further, a pore-forming agent may be mixed with this raw material powder in order to introduce pores for controlling the pore structure of the polishing compact. As the type of this pore forming agent,
Examples thereof include various organic powders and carbon powders.

Next, the molded body, especially the molded body from which the binder and the pore-forming agent have been removed, is generally weak in strength, and in order to increase its strength and improve its durability for use in polishing, It is preferable to perform processing such as firing by heating on the obtained molded body. However, the method for improving durability is not limited to heating and firing, and for example, a method of introducing a substance into the pores of the molded body can be adopted.

The firing conditions in the case of heating and firing are not particularly limited, but the firing temperature, firing time, firing program, firing atmosphere and the like may be appropriately selected.

As a method for processing a molded body made of inorganic particles into a molded body for polishing, there can be exemplified a method such as heat degreasing, heat firing, mechanical processing, chemical treatment, physical treatment, or a combination thereof. The processing method is not particularly limited as long as it is a processing method that can impart strength that can be used for polishing work as a molded body for polishing.

In particular, in order to obtain a state in which the physical properties are excellent by ensuring that the surface of the molded article for polishing with the material to be polished that is involved in polishing is always within a predetermined condition range during polishing. It is more preferable to consider the method shown below.

That is, in order to make the microstructure of the surface involved in polishing always exist within the predetermined condition range, in the polishing compact, it is parallel to the direction perpendicular to the surface of the polishing compact involved in polishing. It is necessary to uniformly disperse the pores in the plane. For example, in the above-mentioned production method, when the pore-forming agent is mixed, it is desirable to perform sizing and classification so that the particle diameter falls within the predetermined range. Similarly, in order to uniformly disperse the pores, it is necessary to disperse the pore-forming agent and the raw material powder as uniformly as possible in the microstructure of the compact as the base material of the polishing compact, for which the raw material powder is used. It may be one means to granulate by a certain method so as to have a relationship corresponding to the particle size of the pore-forming agent, that is, a relationship that brings the mixed state into an appropriate state. In this case, the relationship between the particle diameters should be appropriately determined in consideration of the specific gravity of the granulated powder, the specific gravity of the pore-forming agent, their mixing ratio, and the like.

Further, when molding the raw material powder, a method of introducing an organic substance or carbon fiber having a predetermined diameter so as to be perpendicular to the surface of the polishing molded body involved in polishing, or a hollow having a predetermined outer and inner diameter A method of mixing particles can also be exemplified. Here, the inner diameter of the hollow particles conforms to the pore diameter introduced into the polishing compact, and the outer diameter, that is, the particle diameter of the hollow particles has a predetermined dispersion state on the surface where the hollow portion of the hollow particles is involved in polishing of the polishing compact. The diameter has been taken into consideration.

However, if it is possible to produce a molded article for polishing having the above-mentioned characteristics without intentionally adopting such a method, it is not necessary to employ it and the method is not limited to these methods.

<Structure of Polishing Surface Plate> Next, a method of incorporating this polishing molded body as a polishing surface plate and further polishing by using it will be described.

First, a polishing platen is formed by using the polishing compact and the accessory components for polishing. Here, the accessory parts are structures of various materials and shapes that make up the polishing platen, and a polishing compact is arranged and fixed to the accessory parts by the method shown below. The surface plate is formed. As a method for fixing the both, any method can be used without limitation as long as it is a method that can achieve the object of the present invention, such as a method of adhering and fixing with an adhesive, a method of forming irregularities on an auxiliary component and embedding it in the fixing place You can

As for the number of the polishing compacts when fixing the polishing compacts to the accessory parts for polishing, one or two or more may be used, and more preferably two or more. The reason may be as follows.
However, these ideas do not limit the invention.

1) This is to improve the speed by appropriately discharging the polishing liquid used in the polishing process during the polishing process. Therefore, when two or more polishing compacts are used to form the polishing platen, the polishing liquid can be discharged from the gap between the polishing compacts. Further, when one piece is used, it is preferable to have a structure of an appropriate groove capable of discharging the polishing liquid on the side of the polishing surface of the polishing compact.

2) When the polishing platen is formed by using two or more polishing compacts, the supply of the polishing liquid to the sliding surfaces of the polishing compacts and the material to be polished is improved, and The polishing rate of the entire surface of the polishing material is not biased, and efficient processing can be performed.

When the polishing platen is formed by using two or more polishing compacts, it is possible to use a plurality of types of polishing compacts. The plural types do not only mean that the raw material of the inorganic particles and the average particle size are different, but also include the case where the physical properties, the microstructure, etc. of the molded article for polishing are different. At this time, it is preferable that the plurality of types of polishing compacts are arranged in consideration of the symmetry in the polishing process with respect to the accessory parts to be incorporated. By doing so, it is possible to obtain uniform performance in polishing even when a plurality of types of polishing compacts are used.

The shape of the polishing compact to be used is not particularly limited as described above, and any shape can be adopted as long as the polishing compact can be attached to an accessory component for polishing. . For example, columnar pellets, prismatic columnar pellets such as square columnar pellets and triangular pellets, fan-shaped columnar pellets, or ring-shaped pellets obtained by punching out the center of the pellets can be exemplified. Any shape that can be formed by combining and curves can be exemplified. Further, the size is not particularly limited as long as it is within a range that is normally used, and is determined according to the size of an accessory component for incorporating a molded body for polishing in a polishing surface plate, but usually one side The size may be within a range of 5 mm square or more. Even a molded compact for polishing having a size smaller than this range has sufficient polishing performance, but a plurality of polishing plates must be used, and the number of polishing plates will be too large to be practical. There is.

The aspect of the arranging method when arranging the polishing compact used in the present invention as a polishing platen is particularly limited as long as it has a combination of the polishing compacts having the characteristics described above. Not a thing, for example, a method of combining and integrating small pieces of a molded article for polishing,
There is a method of embedding it in a large disc.

When arranging two or more of such polishing compacts on the polishing platen, it is desirable to arrange the polishing surface of the disposed polishing compacts so as to match the shape of the material to be polished. In this case, it is possible to select an accessory that matches the shape of the accessory. For example, when the material to be polished is a flat substrate material, it is desirable to flatten the contact surface of the polishing molded body with the material to be polished. desirable. This is because the material to be polished and the molded compact for polishing can be brought into direct contact with each other when polishing is performed using the obtained polishing platen, so that many contact surfaces can be taken. Is.
In particular, in the case of flattening, it is preferable to arrange so that there is no variation with respect to the height in the vertical direction from the polishing platen.

<Polishing Method Using Polishing Surface Plate> In this way, the polishing compact is incorporated into the polishing surface plate, and in the method of polishing using the polishing surface plate of the present invention. As long as it is used as a surface plate in the polishing process, its shape, polishing conditions, use of a polishing liquid, etc. are not particularly limited. For example, when a polishing liquid is used, a polishing liquid that has been conventionally used may be used, for example, water, a potassium hydroxide aqueous solution, a sodium hydroxide aqueous solution, a neutral solution such as an aqueous solution containing an amine or an organic acid, An alkaline or acidic aqueous solution, or an organic solution can be used in some cases,
The temperature is not particularly limited as long as it is in the range of the temperature lower than the boiling point of these polishing liquids. Of course, oxides such as aluminum oxide, silicon oxide, cerium oxide, zirconium oxide, manganese oxide, titanium oxide, magnesium oxide, iron oxide, chromium oxide, yttrium oxide, tin oxide, which are usually used as loose abrasive grains, Non-oxides such as silicon carbide, boron carbide, and boron nitride can be used. Furthermore, for zirconium oxide, rare earth oxides such as yttrium oxide, scandium oxide, indium oxide, and cerium oxide as stabilizers, magnesium oxide, and oxides can be used. Zirconium oxide in which calcium or the like is dissolved may be used. Further, the polishing processing conditions such as the flow rate of the polishing liquid, the processing pressure, the relative speed of the material to be polished and the surface plate during the polishing processing (the rotation speed of the polishing surface plate) are not particularly limited.

Here, the polishing surface plate is used for polishing the incorporated polishing compact by directly contacting the material to be polished, and has sufficient strength in the polishing process. Not only does it have the same shape as the material to be polished, but it may have a non-planar shape as required. For example, a flat plate shape, a disk shape, a ring shape, a cylindrical shape and the like can be mentioned.

Further, since the polishing cloth is not used in the polishing method, the interruption of the polishing operation due to the deterioration of the performance of the polishing cloth, which has been found in the conventional method during the polishing, can be prevented by the polishing method of the present invention. The use of the molded product has the advantages that the durability is improved and the replacement frequency can be reduced, so that the work efficiency of the polishing process can be improved.

The polishing compact of the present invention and the polishing platen using the same are used for semiconductor substrates, oxide substrates, various glass substrates,
It is also useful for polishing substrate materials such as quartz glass substrates, magnetic head materials, various glasses, metal materials, optical materials such as lenses, and stone materials used in the construction field and the like.

[0059]

The present invention will be described in more detail with reference to examples, but the present invention is not limited to these. In addition, each evaluation was implemented by the method shown below. —Relative Density of Polishing Molded Body— A 100 mm × 100 mm × 15 mm (thickness) flat plate sample was prepared and used as a sample. The bulk density W2 of the polishing compact was calculated from the weight of this sample measured by an electronic balance and the shape dimension measured by a micrometer. Next, JIS-R
According to -205, a part of the polishing compact was crushed to obtain the true density W1, and the relative density was calculated from the previously calculated bulk density W2 of the polishing compact by the following formula.

Relative density (%) = (W2 / W1) × 100-Microstructure of polishing surface of molded article for polishing-Embedded molded article for polishing with acrylic resin and cut with microtome to prepare observation sample did. This observation sample was observed with a scanning electron microscope ISI DS-130 (manufactured by Akashi Seisakusho). An electron micrograph taken at various magnifications was used to determine the average diameter by the intercept method in consideration of each of the inorganic particles and the pores. In addition, the line length that crosses each of the inorganic particles and the pores at this time was defined as the diameter, and the area ratio was calculated based on the sum of the diameters. From each total, the ratio of the area of the non-rubbing portion to the area of the polishing surface is A, the ratio of the area of the rubbing portion to the area of the polishing surface is B, and the ratio A
/ (A + B) (= r) was calculated. ~ Average particle size of inorganic particles constituting the molded body for polishing ~ According to the observation of the microstructure of the polishing surface of the molded body for polishing, the average particle size is calculated on the number basis by the intercept method considering only the inorganic particle portion. It was ~ Grain size distribution of the rubbing part of the polishing compact ~ According to the observation of the fine structure of the polishing surface of the polishing compact, the particle size is calculated by the intercept method considering only the inorganic particle part, and a circle is assumed. Then, the area conversion was carried out to obtain an area-based particle size distribution and an average particle size. -Structure of the rubbing portion of the polishing molded body-A scanning electron microscope observation was performed according to the observation of the fine structure of the polishing surface of the polishing molded body, and the pores and inorganic particle portions of 1 μm or less were considered. By the intercept method, the ratio of the area of the pores in the rubbing portion to the area of the rubbing portion was calculated from the ratio of the line length crossing each of the inorganic particles and the pore portion of 1 μm or less. -Area ratio of alumina particles in the rubbing portion of the polishing molded body-Scanning electron microscope observation is performed according to the microstructure observation of the polishing molded body, and alumina particles and zirconia particles containing a stabilizer are considered. It was determined by the intercept method. -Structure of the non-rubbed portion of the polishing compact-By scanning electron microscope observation according to the observation of the fine structure of the polishing surface of the polishing compact, and by the intercept method in consideration of pores larger than 1 μm. The proportion of the non-rubbed portion was calculated from the proportion of the line length crossing the pore portion larger than 1 μm. -Crystal phase fraction of the surface involved in polishing of the molded body for polishing-X-ray diffractometer (manufactured by Mac Science Co., model: MXP-
X-ray diffraction test (CuKα ray, 40 kV,
30 mA) was performed, and the respective diffraction integrated intensities of the surfaces of the zirconia-containing monoclinic, tetragonal, and cubic phases of the stabilizer described in the following equation were measured and determined by the following equation.

[0061] monoclinic fraction _{(%) = {I M (} 111) +
_{I M (11-1)} / {} I M (111) + I M (11-
1) + _{IT + C} (111)} × 100 In the above formula, the diffraction integrated intensities of the (111) and (11-1) planes of the monoclinic phase of zirconia containing a stabilizer are respectively I _M ( 111), I _M (11-1), and the sum of the diffraction integrated intensities of the tetragonal phase (111) and the cubic phase (111) is I _{T + C} (111). -Compressive strength-Based on JIS-R-1608, 10 mm x 10 mm x
A 7 mm (thickness) sample was prepared, and Shimadzu Autograph IS
Using a -10T (manufactured by Shimadzu Corporation), a load was applied at a crosshead speed of 0.5 mm / min for measurement. -Evaluation of Depletion Rate of Polishing Molded Body-For Examples and Comparative Examples, polishing molded bodies having the characteristics shown in Tables 1, 3 and 5 (columns having a diameter of 25 mm and a thickness of 10 mm) were polished. Device PLANOPOL / PEDEMAX
2 (manufactured by Struers) was mounted on a lower platen (diameter 300 mm) of 100 pieces, the surface of the molded article for polishing was flattened, and evaluation was carried out at a lower platen rotation speed of 300 rpm. Before evaluating the wear rate, the polishing rate was obtained using the polishing solution shown below, and this was continued while exchanging the polishing solution for each batch, and then the polishing rate was stabilized, and then the evaluation of the wear rate was started. Using a quartz substrate (45 mm × 45 mm square) as a material to be polished and a polishing liquid, polishing was continuously performed without changing the polishing liquid while flowing at a flow rate of 200 ml / min, and the wear rate was calculated. At the same time, the consumption of the polishing compact was measured as the amount of change in thickness per unit time. The case where this wear was not practically applicable was marked with x, and the case where it was within the allowable range was marked with o.

As the polishing liquid, an aqueous solution containing 10% by weight of alumina abrasive grains having an average particle diameter about 3 times the average particle diameter of the inorganic particles constituting the polishing compact was used. -Ablation rate-It was calculated by the following formula from the polishing amount (volume conversion) of the material to be polished and the consumption amount (volume conversion) of the polishing compact.

Abrasion rate = abrasion amount of abrasive compact / abrasion amount of material to be abraded: When this abrasion rate cannot be put to practical use, x: When the abrasion rate is within the allowable range, the abrasion rate of Comparative Example 2 is represented. Standard (1.0)
Is shown as a relative value. <Manufacture of molded article for polishing> Powders having the characteristics shown in Tables 1, 3, and 5 are used as raw materials, and in some cases, organic powder (for example,
Polyvinyl alcohol powder, potato starch, butyl methacrylate powder, paraffin wax powder, etc.) are mixed, and the powder is mixed at 50 to 3000 kg / cm.
After molding at a pressure of ² , it was finally fired at 700 to 1700 ° C. to obtain a molded body for polishing. These polishing compacts were evaluated by the method described above, and the results are shown in Tables 1 and 2,
Table 5 shows the components of the raw materials. <Polishing by Polishing Molded Body and Evaluation Thereof> Examples 1 to 9 and Comparative Examples 1 to 7 Quartz (shape: 45 mm × 45 mm square) was used as a material to be polished, and a polishing molded body and a polishing liquid were used and described above. Polishing was performed according to the evaluation of the wear rate of the molded article for polishing. The results are shown in Table 2.
It was shown to.

From the above examples and comparative examples, the following can be seen.

Comparing Examples 1 to 9 with Comparative Example 6 and Comparative Example 7, in Comparative Example 6 and Comparative Example 7 according to the conventional method, from Comparative Example 6 to the polishing described in Examples of the present invention. It can be seen that the polishing rate is inferior when the surface precision obtained by the molded body is approximated, and the surface precision is inferior when Comparative Example 7 is close to the polishing rate described in the example of the present invention. In other words, it can be seen that the polishing compact of the present invention according to the example has both the polishing rate and the surface accuracy in comparison with Comparative Examples 6 and 7 according to the conventional method.

Further, from the examples and the comparative examples, the following can be found among the molded articles for polishing.

Comparing Examples 1 to 6 and Comparative Examples 1 to 3,
It can be seen that the wear rate of Examples 1 to 6 is suppressed to be smaller than that of Comparative Examples 1 to 3.

Comparing Example 7 with Comparative Examples 4 to 5, it can be seen that the wear rate of Example 7 is suppressed to be smaller than that of Comparative Examples 4 to 5.

Comparing Examples 8-9 with Comparative Examples 6-7,
It can be seen that the wear rate is suppressed to be smaller in Examples 8 to 9.

Comparing Examples 7 to 9 with Comparative Example 4, it can be seen that in Comparative Example 4, although the polishing rate is high, the abrasion of the polishing compact is remarkable.

[0071]

[Table 1]

[Table 2]

[Table 3]

[Table 4]

[Table 5]

[Table 6]

According to the present invention, a pre-finishing process (lapping process) for a substrate material such as a semiconductor substrate, an oxide single crystal substrate, various glass substrates, a quartz glass substrate, a ceramics substrate, or an optical material that requires precision processing. It can be mainly applied to, and the surface of the material to be polished can be moved at a higher speed with a predetermined surface accuracy, and such characteristics are stable. It is also useful because it has durability in processing.

[Brief description of drawings]

FIG. 1 is a conceptual diagram schematically showing a part of a polishing surface of a polishing molded body of the present invention.

FIG. 2 is a view showing a cross section in the direction from X to X ′ in FIG.

[Explanation of symbols]

In FIGS. 1 and 2, the reference numerals in the drawings are commonly used. 1: Abrasive molded body 2: Rubbed portion 3: Non-rubbed portion

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01L 21/304 622 B24B 37/04 A // B24B 37/04 C04B 35/10 E (72) Inventor Kondo Chi 2-7-3-B-409 Tachibanadai, Aoba-ku, Yokohama-shi, Kanagawa Prefecture (72) Masayuki Kudo 3-18-6 Nakamachi, Machida-shi, Tokyo (72) Yuko Yokomizo 1-Wakabadai, Asahi-ku, Yokohama-shi, Kanagawa 2-901 (72) Inventor Mutsumi Asano 23-4-508 F-Term (reference) 3-4-508 Asahi-machi, Sagamihara-shi, Kanagawa 3C058 AA02 AA09 CB01 CB03 DA17 3C063 AB05 BA02 BA22 BA24 BB03 BB07 BC01 BC08 BD01 CC02 CC19 EE10 FF08 FF23 4G030A AA36 BA19 CA01 CA04 CA09 GA04 GA05 GA11 GA14 GA22 5D112 AA02 BA09 GA14

Claims (7)

[Claims] 1. A molded article for polishing comprising inorganic particles, comprising:
The surface of the molded article for polishing that is involved in polishing has a rubbing portion and a non-rubbing portion, and the pores present in the rubbing portion have a diameter of 1 μm or less and the area thereof is the entire area of the rubbing portion. Of 1
In a molded article for polishing, the content of which is less than 5% and the area of the non-rubbing portion is 20% or more and 60% or less of the total area of the surface involved in polishing, the inorganic particles contain alumina and a stabilizer. A polishing compact mainly composed of zirconia, in which 60% or more of the particle diameter of inorganic particles constituting the rubbing portion of the polishing compact is 5 μm or less, and 60% or more of the particle diameter of alumina particles is 5 μm. Below, 60% or more of the particle diameter of zirconia particles containing a stabilizer is 5 μm.
0.25 ≦ X / (X + Y), where X is the area ratio of the alumina particles constituting the polishing compact and Y is the area ratio of the zirconia particles containing the stabilizer.
A molded article for polishing, wherein ≦ 0.95. 2. The molded article for polishing according to claim 1, wherein
20% or more of the pore diameter of the non-rubbing part of the said grinding | polishing molded object has a diameter of 10 micrometer or more. 3. The molded article for polishing according to claim 2,
20 to 80% of the pore diameter of the non-rubbed portion of the polishing compact
Is 1 to 10 μm. 4. The polishing compact according to any one of claims 1 to 3, wherein the monoclinic crystal ratio of zirconia containing a stabilizer constituting the polishing compact is 5% or less. Molded body for polishing. 5. The molded article for polishing according to claim 4,
A zirconia stabilizer containing a stabilizer, which constitutes the abrasive compact, is yttria. 6. The molded article for polishing according to claim 5,
A molded article for polishing, characterized in that the yttria amount of the stabilizer for zirconia containing the stabilizer which constitutes the molded article for polishing is 3 to 8% by weight based on the total amount of yttria and zirconia. 7. A polishing platen comprising the molded body for polishing according to claim 1 and an accessory component.