JP2002018702A - Polishing molding and polishing surface table using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polishing molding and a polishing surface table using the polishing molding applicable to a machining process and a CMP process for polishing a substrate material for a semiconductor substrate, an oxide monocrystal substrate, various glass substrates, a quartz glass substrate or a ceramic substrate, an optical material requiring precision machining, and the like to attain a polished material surface of high accuracy at much higher speed and to permit stable work without degrading the characteristic even in polishing. SOLUTION: This polishing molding formed of inorganic grains has a sliding- rubbing part and a non-sliding-rubbing part on a face concerned with polishing. Pores existing in the sliding-rubbing part have a diameter of 1 μm or less, and its area is 15-75% of the whole area of the sliding-rubbing part. Further, the area of the non-sliding-rubbing part is 20-80% of the whole area of the face concerned with polishing. The polishing surface table using such a polishing molding is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a silicon wafer,
Polishing molded products used in a processing process for polishing substrate materials such as oxide single crystal substrates, compound semiconductor substrates, various glass substrates, quartz glass substrates, ceramic substrates and optical materials, and in a chemical mechanical polishing (CMP) process; The present invention relates to a polishing platen using the same.

[0002]

2. Description of the Related Art With the development of industries such as optics and electronics, demands for processing magnetic disks, semiconductor substrates, single crystal materials, optical materials, and the like have become extremely strict. Was polished with a polishing pad of a nonwoven fabric type, a suede type, urethane, etc. while continuously flowing a polishing liquid containing free abrasive grains on the surface of the substrate. As the free abrasive used at this time, aluminum oxide, silicon oxide, cerium oxide, zirconium oxide, iron oxide, titanium oxide, manganese oxide,
Chromium oxide, magnesium oxide, tin oxide, silicon carbide and the like are known.

However, in the case of a material polished by a conventional polishing method using a polishing cloth (hereinafter, a material to be polished is referred to as a "material to be polished"), the polishing cloth has a soft surface. There is a disadvantage in that the corners of the material to be polished are polished excessively during polishing and the entire surface of the material to be polished cannot be uniformly polished, resulting in an inefficient finish.

Further, in most cases, a conventional polishing method using a polishing cloth cannot use a polishing liquid containing no free abrasive grains, for example, water or the like whose pH has been adjusted. It is necessary to use a large amount of, as a result, a polishing waste liquid containing a large amount of free abrasive grains is generated, regarding the processing and the like, the efficiency of the polishing treatment, the equipment surface of the waste liquid treatment,
Considering the impact on the environment, it should be improved.

To solve such a problem, for example, Japanese Patent Laid-Open No.
Japanese Patent Publication No. 256581 proposes a fixed-type polishing method using a fixed whetstone in which abrasive grains are fixed with a synthetic resin used as a binder for polishing. According to this, it has been shown that this method is effective against the problem that the entire surface of the material to be polished cannot be uniformly polished, which has occurred in the conventional polishing method using a polishing cloth because a fixed whetstone is used. .

In addition to the method using an organic binder, a vitrified grindstone using an inorganic binder and a metal bond grindstone using a metal as a binder are disclosed. It is shown that this method is effective for the problem that the entire surface of the material to be polished cannot be uniformly polished, which has been caused by the conventional polishing method using a polishing cloth as in the case of using the polishing pad.

However, in such a grindstone, since the abrasive grains are fixed via a binder, the binder is also present on the surface involved in polishing, so that the same situation as so-called clogging is likely to occur. Polishing efficiency and productivity have been reduced. Furthermore, it is extremely difficult to uniformly disperse fine abrasive grains in a grinding stone in the production of a fixed grinding stone using a binder such as an inorganic substance or an organic substance. Will be the same as if
Defects are liable to occur on the surface of the material to be polished, and if the amount of abrasive particles used for uniformly dispersing fine abrasive particles is reduced, the polishing rate is slow, and the polishing efficiency and productivity are reduced. Further, since inorganic materials such as vitreous materials containing a large amount of impurities such as alkali metals as binders, organic materials such as resins, metals and the like are used, depending on polishing conditions, a fixed grindstone to a material to be polished in a polishing process is used. There was also a concern about the effect of impurity contamination from the air.

Accordingly, the present inventors have disclosed, for example,
As disclosed in Japanese Unexamined Patent Publication (Kokai) No. -264015, it has been found that a molded body for polishing mainly composed of silica, which is a kind of inorganic abrasive grains, can be applied to a polishing process, and studied to solve the above-mentioned problems. I found

1) Since the elastic modulus of the molded article for polishing is larger than that of the polishing cloth, the corners of the material to be polished are less likely to be excessively polished during polishing, and the entire surface of the material to be polished is It can be polished uniformly.

[0010] 2) The surface involved in polishing of the molded article for polishing is
Since the surface is roughened by the silica fine powder as a raw material and a large number of pores exist between the silica particles, so-called clogging in polishing can be suppressed.

3) Since the molded body for polishing contains no binder, it has heat resistance, chemical resistance and the like even in the polishing process. Therefore, it is necessary to use the polishing liquid up to a temperature near its boiling point and its type. The polishing efficiency can be increased by appropriately selecting the above and the like to obtain the optimum polishing process.

4) Since the polishing compact is made of silica used as abrasive grains, it is possible to suppress the influence of impurities on the material to be polished due to the polishing compact in the polishing process.

5) The finish of the polished material is substantially the same as that of the conventional method using a polishing cloth, and the polishing rate is equal to or higher than that of the conventional method. Little deterioration.

6) The surface involved in polishing the molded article for polishing is
Since the surface is roughened by the silica powder that is the raw material, and the material to be polished comes into direct contact, it can be applied to the polishing process of substrate materials using a polishing liquid that does not contain free abrasive grains. It becomes possible.

7) An abrasive containing free abrasive grains, for example, aluminum oxide, silicon oxide, cerium oxide, zirconium oxide, iron oxide, titanium oxide, manganese oxide,
Even when using an abrasive containing free abrasive grains such as one of chromium oxide, magnesium oxide, tin oxide, silicon carbide, or a mixture thereof, a conventional polishing cloth is used. However, a sufficiently high polishing rate can be obtained at a low free abrasive particle concentration.

Japanese Patent Application Laid-Open No. 10-337669 discloses a grindstone constituted only by firing inorganic abrasive grains. According to this document, the material, particle size, porosity, and water absorption of the grindstone are described.
Although it is shown that the same effect as that of Japanese Patent No. 4015 is obtained, the surface accuracy of a silicon wafer exemplified as a material to be polished is about 3 nm in center line average roughness, and the polishing rate is recognized. Not mentioned because there is no.

On the other hand, Japanese Patent Application Laid-Open No. 10-26401
Japanese Patent Application Laid-Open No. 5 (1999) -2005 discloses the results of measuring the surface accuracy of a silicon wafer using a universal surface shape measuring instrument SE-3C (manufactured by Kosaka Laboratories). Was measured using an atomic force microscope (AFM) SPI3600 (manufactured by SII) for more accurate measurement. As a result, it was found that the center line average roughness was 0.6 to 1 nm, and it was possible to obtain a surface accuracy superior to that described in JP-A-10-337669.

As described above, the inventors of the present invention disclosed in Japanese Patent Laid-Open No. 10-26
Japanese Patent Application Laid-Open No. 4015 discloses a polishing body mainly composed of silica, which is a kind of inorganic abrasive, is made of a substrate material such as a silicon wafer, an oxide substrate, a compound semiconductor substrate, various glass substrates, a quartz glass substrate, a ceramic substrate, or an optical material. Although it is very suitable for a processing process or a CMP process for polishing a material or the like, it may be difficult to obtain sufficient characteristics depending on the material to be polished. is there. For example, the present inventors have studied in consideration of the hardness and chemical reactivity of the material to be polished.

[0019]

As described above, the present inventors have found a molded body capable of suitably polishing various materials to be polished. However, the productivity has been improved by further increasing the efficiency of the polishing process. There has been a demand for a shaped body for polishing capable of obtaining a highly accurate surface of a material to be polished at a higher speed for various materials to be polished. Further, in the polishing process having such polishing characteristics, there has been a demand for a molded body for polishing capable of stably working.

The present invention has been made in view of such problems, and has as its object to provide substrate materials such as semiconductor substrates, oxide single crystal substrates, various glass substrates, quartz glass substrates, and ceramic substrates, and precision processing. It can be applied to the processing process and CMP process for polishing required optical materials, etc., and can obtain a highly accurate surface of the material to be polished at higher speed, and its characteristics can be stably operated without deteriorating even in polishing process. An object of the present invention is to provide a molded product and a polishing platen using the same.

[0021]

Means for Solving the Problems The present inventors have disclosed Japanese Patent Laid-Open No.
As disclosed in JP-A-264015 and JP-A-11-104952, it has been found that the polishing rate can be further improved by the polishing molded body having a specific pore structure. The pore structure was defined based on the pore structure measurement results, and the overall structure of the molded article for polishing was shown.

Further, the inventors of the present invention have conducted intensive studies to solve the above-mentioned problems. As a result, not only the structure of the entire polishing compact but also the polishing When the surface of the molded object for polishing with the material to be polished (hereinafter, referred to as a “polishing surface”) has a specific microstructure, the surface of the material to be polished is highly accurate for various materials to be polished. Can be obtained even faster, and its microstructure, that is, the characteristics of the polished surface are maintained within a certain range even in the polishing process,
The present inventors have found that the polishing performance can be stabilized for a long time, the above-mentioned problems can be solved, and the polishing operation can be made more efficient, and the present invention has been completed. That is, in the polishing process of polishing the material to be polished by rubbing the molded body for polishing and / or the material to be polished, a portion where the polishing molded body and the material to be polished are rubbed directly (hereinafter, referred to as “sliding”). A part which is considered to supply the polishing liquid to the rubbing part by staying or flowing the polishing liquid mainly used in the polishing processing without directly contacting the material to be polished in the polishing processing (referred to as "rubbing part"). The non-rubbing portion will be present at least on the polishing surface side of the molded body for polishing, and the structure has a specific structure, and the structure is maintained during polishing. Was found to be extremely important.

Hereinafter, the present invention will be described in detail.

<Characteristics of Polishing Molded Article> The polishing molded article of the present invention is a polishing molded article substantially composed of inorganic particles, and has a non-sliding portion on a surface of the polishing molded article involved in polishing. A rubbing portion, wherein the pores present in the rubbing portion have a diameter of 1 μm or less, and the area thereof is 15 to of the total area of the rubbing portion.
It is a molded article for polishing in which the area of the non-rubbing portion is 20% to 80% with respect to the total area of the surface engaged in polishing.

The inorganic particles used in the molded article for polishing according to the present invention are appropriately selected in consideration of compatibility with the material to be polished, and specifically include aluminum oxide, silicon oxide, cerium oxide, Zirconium oxide, manganese oxide,
Titanium oxide, magnesium oxide, iron oxide, chromium oxide,
Oxides such as yttrium oxide and non-oxides such as silicon carbide, boron carbide, and boron nitride can be used. Further, as for zirconium oxide, yttrium oxide, scandium oxide, indium oxide, cerium oxide, and the like as a stabilizer. Zirconium oxide in which a rare earth oxide, magnesium oxide, calcium oxide, or the like is dissolved can also be used. These inorganic particles can be used alone or in combination of two or more. Here, the compatibility with the material to be polished means, for example, the physical properties such as hardness and toughness of the material to be polished and the chemical properties such as chemical reactivity, etc. accuracy,
It means that it is selected by comprehensively judging flatness, polishing rate, and the like.

In addition, it is preferable to use such inorganic particles having an average particle diameter of 0.005 to 2 μm for practical use. It is practically difficult to use particles having an average particle size of less than 0.005 μm, as described later.
On the other hand, if the thickness exceeds 2 μm, there may be a problem that a defect occurs on the surface of the material to be polished.

The abrasive compact of the present invention contains a binder such as metal, vitrified resin, and the like, which is generally used for obtaining a synthetic whetstone holding and fixing abrasive grains. Absent. That is, the molded article for polishing of the present invention can maintain its shape substantially without any binder, and forms an aspect for polishing.

The molded article for polishing according to the present invention is substantially composed of the above-mentioned inorganic particles. In the polishing process, the polishing surface is brought into direct contact with the material to be polished to perform the polishing operation. Things. This abrasive compact is
FIGS. 1 and 2 are conceptual views schematically showing a part of a polished surface.
Has a structure as shown in FIG.

Here, the non-sliding 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 at 3 in FIGS. This is a portion where the polishing liquid used in the processing is retained or circulated and the polishing liquid can be supplied to the rubbing portion, and has pores larger than 1 μm. Further, the rubbing portion on the polishing surface of the molded body for polishing is a portion other than the non-rubbing portion as shown in 2 in FIGS. 1 and 2, and is in direct contact with the material to be polished. Part. Incidentally, these non-sliding portions and sliding portions can be confirmed by observing the polished surface of the molded article for polishing with a scanning microscope as shown in Examples.

The rubbing portion (2 in FIG. 1) on the polishing surface of the molded article for polishing according to the present invention is constituted by inorganic particles constituting the molded article for polishing and pores having a diameter of 1 μm or less. The area of the pores having a diameter of 1 μm or less is preferably in the range of 15 to 75% of the total area of the rubbing parts. Deviating from this range, if it is less than 15%, the polishing rate at the time of polishing decreases. If it exceeds 75%, the polishing rate is maintained relatively high, but the consumption of the molded article for polishing is remarkable. Is not preferred.

Further, such a rubbing portion is more preferably constituted by inorganic particles having an average particle diameter of 0.01 to 0.5 μm and pores having a diameter of 1 μm or less. This is because, in the polishing process, the surface accuracy of the material to be polished obtained as the average particle diameter of the inorganic particles is smaller tends to be improved in many cases, but when the powder of the inorganic particles as the raw material is refined. Agglomeration is likely to occur, and it is difficult to obtain a powder having a primary particle diameter of less than 0.005 μm. Therefore, it is actually difficult to obtain a polishing molded article having an average particle diameter of less than 0.005 μm. When the average particle diameter is less than 0.01 μm, it tends to be difficult to process the molded body for polishing, and the average particle diameter is 0.5 μm.
Polishing can be performed with high accuracy even when it is larger than m,
This is because, in order to finish the material to be polished with high precision, it is preferable that the average particle diameter does not exceed 0.5 μm.
In addition, the average particle diameter here means the particle diameter of the inorganic material powder constituting the surface of the molded article for polishing, and for example, as described in Examples, a scanning electron microscope (SEM)
It can be measured for example.

The area of the non-sliding portion (3 in FIG. 1) on the polishing surface of the molded article for polishing is preferably in the range of 20 to 80% with respect to the total area of the polishing surface. If the ratio is out of this range and falls below 20%, the polishing rate during polishing decreases, and the polishing efficiency decreases.
If it exceeds 0%, the polishing rate is maintained at a high level, but it is not preferable because the molded article for polishing becomes extremely worn.

Further, since such a non-sliding portion has a much higher polishing rate, 50% of the pores formed therefrom.
% Or more is preferably composed of pores having a diameter of 10 μm or more. In addition, the upper limit of the pore diameter is not particularly limited, but when a large number of pores having a diameter of more than 3 mm are introduced, damage during polishing is likely to increase.
Among all pores having a diameter of 10 μm or more, substantially 1
It is preferable that the pores within the range of 0 μm to 3 mm are 80% or more.

The area of the above-mentioned rubbing portion and the non-rubbing portion can be determined by observing each portion with a scanning electron microscope or the like, as shown in Examples, and determining the diameters of the inorganic particles and pores formed. After the calculation based on the number by the intercept method, it can be obtained by converting the area per predetermined polishing surface.

Further, in order to uniformly polish the material to be polished in the polishing process, attention is paid to the distribution state of the rubbing portion and the non-rubbing portion on the polishing surface of the molded article for polishing, as shown in FIG. As described above, since the effect of uniformly polishing the material to be polished becomes more remarkable, it is preferable that the non-sliding portions are uniformly distributed on the polished surface. Here, "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 molded article for polishing.

It is preferable that the distribution of the non-sliding portion on the polished surface is always maintained during the polishing process, so that the material to be polished can be polished uniformly. Here, the distribution of the non-rubbing portion on the polishing surface is, as shown in the examples, cutting the polishing body at a plane perpendicular to the normal direction of the polishing surface of the polishing body,
The state of the polished surface can be observed with a scanning microscope or the like.

If the above points are specifically shown, the ratio of the area of the non-sliding portion to the area of the polished surface is A, and the ratio of the area of the rubbing portion to the area of the polished surface is B, and A / (A + B)
(= R), there is a relation of 0.2 ≦ r ≦ 0.8, and r ′ obtained by averaging individual R values is 0.3 ≦ r ′ ≦ 0.7. When the variation of r is within ± 10% of the average value of r, r ′, the polishing is performed more quickly and the material to be polished is more uniformly polished. In addition, variations in the polishing rate, consumption of the molded body for polishing, and the like are further suppressed, which leads to more excellent polishing performance uniformity, which is more preferable.

The rubbing portion and the non-rubbing portion present on the polishing surface of the molded article for polishing according to the present invention have the above-mentioned microstructure, and such a structure is maintained during polishing. If
Polishing of the material to be polished uniformly, that is, a variation in the polishing rate between each portion to be polished of the material to be polished can be suppressed to be smaller, and a material to be polished having excellent homogeneity or flatness can be obtained. This also leads to excellent uniformity of polishing performance, for example, it is possible to suppress variation in wear of each part of the polishing surface of the polishing compact itself.

<Method for Producing Polishing Molded Article> The method for producing a polishing molded article of the present invention is not particularly limited as long as it is a method capable of obtaining a polishing molded article having the above characteristics. Examples of the method include forming a powder, and performing a processing such as baking after the molding.

More specifically, the method for producing a molded article for polishing according to the present invention will be described. The raw material powder is molded into a molded article having an appropriate shape and size by applying pressure or the like, and then processed as necessary. To form a molded body used for polishing.

Here, in the case of molding 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 performed under known conditions. Also, casting, injection molding, extrusion molding and the like can be applied.

Further, the raw material powder may be subjected to a treatment in order to improve the formability of the raw material powder at the time of molding. As a specific processing method, for example, a method of consolidation may be mentioned, but the conditions are not particularly limited. Similarly, to improve the moldability of the raw material powder,
Granulation may be performed by a spray drying method, a tumbling 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 formability of the raw material powder into a molded body composed of inorganic particles,
It is preferable to degrease when 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 degreasing by heating in an inert atmosphere such as nitrogen, argon, and helium. At this time, the pressure of the atmosphere gas may be under pressure or under normal pressure, and may be under reduced pressure in some cases. Similarly, it is also possible to add water in order to improve the moldability, and to dry it before the subsequent baking operation.

Further, a pore-forming agent may be added to the raw material powder in order to introduce pores for controlling the pore structure of the molded article for polishing. As the type of this pore former,
Various organic powders, carbon powders and the like can be exemplified.

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

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

Examples of a method for processing a molded body made of inorganic particles into a molded body for polishing as described above include a method using heat degreasing, heat baking, machining, chemical treatment, physical treatment, or a combination thereof. The processing method is not particularly limited as long as it is a processing method capable of imparting strength that can be used for polishing work as a molded body for polishing.

In particular, it is necessary to ensure that the surface of the molded article for polishing with the material to be polished is always within a predetermined range during the polishing process, so that a state excellent in uniformity of physical properties is obtained. It is more preferable to consider the following method.

That is, in order for the microstructure of the surface involved in polishing to always exist within a predetermined range of conditions, a surface parallel to a direction perpendicular to the surface involved in polishing of the molded body for polishing is provided in the molded body for polishing. It is necessary to uniformly disperse the pores inside. For example, in the above-described production method, when a pore-forming agent is mixed, it is desirable to size and classify the mixture so that the particle size is within the above-mentioned 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 molded body as much as possible as a base material of the molded body for polishing. May be granulated by any method to obtain a relationship corresponding to the particle size of the pore-forming agent, that is, a relationship for bringing 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, the mixing ratio thereof, and the like.

Further, when molding the raw material powder, a method of introducing an organic substance or a carbon fiber having a predetermined diameter so as to be perpendicular to a polishing surface of the molded article for polishing, or a hollow having a predetermined outer diameter. A method of mixing particles can also be exemplified. Here, the inner diameter of the hollow particles conforms to the diameter of the pores introduced into the molded article for polishing, and the outer diameter, that is, the particle diameter of the hollow particles, is determined in such a manner that the hollow portion of the hollow particles is in a predetermined dispersed state on the surface involved in polishing of the molded article for polishing. Is the diameter considered so that

However, even if such a method is not dared to be adopted, there is no particular need to employ any method as long as a molded article for polishing having the above-mentioned characteristics can be produced, and the method is not limited to these methods.

<Structure of Polishing Surface Plate> Next, a method of assembling the molded body for polishing as a polishing surface plate and further performing polishing using the platen will be described.

First, a polishing surface plate is formed using the polishing molded body and the auxiliary components for polishing. Here, ancillary parts are structures of various materials and shapes constituting a polishing platen, and a molded article for polishing is arranged on this ancillary part by a method described below, and fixed by polishing. A surface plate is formed. As a method for fixing both, a method of bonding and fixing with an adhesive, a method of forming irregularities on ancillary parts and embedding in the fixing place, such as a method that can achieve the object of the present invention, can be used without limitation. Can be.

Regarding the number of the molded bodies for polishing when the molded articles for polishing are fixed to the accessory parts for polishing, one or more than two molded bodies may be used, and more preferably two or more are used. The reasons may be as follows.
However, these ideas do not limit the invention.

1) This is because the polishing rate is improved by appropriately discharging the polishing liquid used in the polishing process during polishing. Therefore, when the polishing platen is formed by using two or more polishing compacts, the polishing liquid can be discharged from the gap between the polishing compacts. When one is used, it is preferable to provide an appropriate groove structure capable of discharging the polishing liquid on the side of the polishing surface of the molded article for polishing.

2) When the polishing platen is formed by using two or more polishing bodies, the supply of the polishing liquid to the rubbing surface of the polishing body and the material to be polished is improved, Polishing can be performed efficiently without bias in the polishing rate of the entire polishing material.

When a polishing platen is formed by using two or more polishing compacts, a plurality of types of polishing compacts can be used. At this time, it is preferable that a plurality of types of abrasive compacts are arranged with respect to the attached components in consideration of symmetry in polishing.
In this manner, even when a plurality of types of molded bodies for polishing are used, uniform polishing performance can be obtained during polishing.

The shape of the abrasive compact to be used is not particularly limited as described above, and any shape can be adopted as long as the abrasive compact can be attached to an accessory part for polishing. . For example, columnar pellets, square columnar pellets such as quadrangular columnar pellets and triangular pellets, fan-shaped columnar pellets, or ring-shaped pellets obtained by punching out the center thereof can be exemplified. And any shape that can be formed by combining the curve with the curve. The size is not particularly limited as long as it is within a range usually used, and is determined according to the size of an accessory part for incorporating a molded body for polishing in a polishing table.

The mode of the method of arranging the molded article for polishing used in the present invention as a polishing platen is not particularly limited as long as the polishing molded article having the characteristics described above is combined. Rather than, for example, a method of combining and integrating small pieces of the molded body for polishing,
There is a method of embedding in a large disk.

When two or more such compacts for polishing are arranged on the polishing platen, it is desirable to arrange the polished surface of the disposed compact for polishing 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, if the material to be polished is a flat substrate material, it is desirable to flatten the contact surface of the molded body for polishing with the material to be polished, and if it is a curved surface, it is preferable to make it a curved surface suitable for it. desirable. This is because, when polishing using the obtained polishing surface plate, the material to be polished and the molded body for polishing can be directly in contact with each other, so that a large contact surface can be obtained. It is.
In particular, in the case of flattening, it is preferable to arrange them so that there is no variation in the vertical height from the polishing platen.

<Polishing Method Using Polishing Surface Plate> In this manner, the molded body for polishing is incorporated into the polishing surface plate. In the method of polishing using the polishing surface plate of the present invention, There is no particular limitation on the shape, polishing conditions, whether or not a polishing liquid or the like is used, as long as the surface plate is used in the polishing process. For example,
When using a polishing liquid, it is possible to use a polishing liquid that has been used conventionally, for example, water, potassium hydroxide aqueous solution, sodium hydroxide aqueous solution, neutral and alkaline, such as an aqueous solution containing an amine or an organic acid, An acidic aqueous solution and, in some cases, an organic solution can be used, and the temperature thereof is not particularly limited as long as it is within a range lower than the boiling point of these polishing liquids. Of course, aluminum oxide, silicon oxide, cerium oxide, zirconium oxide, manganese oxide, titanium oxide, magnesium oxide, iron oxide, chromium oxide, yttrium oxide, oxides such as tin oxide, which are usually used as free abrasive grains, Non-oxides such as silicon carbide, boron carbide and boron nitride can be used. Further, for zirconium oxide, rare earth oxides such as yttrium oxide, scandium oxide, indium oxide and cerium oxide, magnesium oxide, oxide Zirconium oxide or the like in which calcium or the like is dissolved may be used. The polishing conditions such as the flow rate of the polishing liquid, the processing pressure, and the relative speed during the polishing of the material to be polished and the surface plate (the rotation speed of the polishing surface plate) are not particularly limited.

Here, the polishing platen is used to polish a molded body for polishing directly in contact with a material to be polished, has sufficient strength in the polishing process, and is used for polishing. Not only has the same shape as the abrasive material,
It may have a non-planar shape if necessary. For example, a flat plate shape, a disk shape, a ring shape, a cylindrical shape, and the like can be given.

Since the polishing method of the present invention does not use a polishing cloth, the polishing operation is not interrupted due to the replacement of the polishing cloth due to the performance deterioration of the polishing cloth observed in the conventional method. The use of a molded body for use has an advantage that durability can be improved and the frequency of replacement can be reduced, so that the efficiency of the polishing operation can be improved.

Further, with respect to the polishing waste liquid containing free abrasive grains generated in the conventional method using a polishing cloth, free abrasive grains are not used or only a small amount is used by using the molded article for polishing according to the present invention. In addition, the amount of free abrasive grains in polishing waste liquid and the amount of particles generated by polishing is reduced, and the problem of waste liquid treatment is reduced. The loose abrasive used here is not particularly limited, and its material, particle size and the like are appropriately selected according to the purpose.

The molded article for polishing of the present invention and the platen for polishing using the same include semiconductor substrates, oxide substrates, various glass substrates,
It is also useful for polishing substrate materials such as quartz glass substrates, magnetic head materials, various types of glass, metal materials, optical materials such as lenses, stone materials used in the field of construction, and the CMP process. Of these, the polished material can be used effectively because there is no surface sagging compared to the conventional method using a polishing cloth, and it is preferably used for a substrate material or a CMP process, and is used for flattening a semiconductor structure or the like. Particularly useful.

[0066]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto. In addition, each evaluation was implemented by the method shown below.

-Relative Density of Polished Molded Article-A flat sample of 100 mm x 100 mm x 15 mm (thickness) was prepared and used as a sample. The bulk density W2 of the compact for polishing was calculated from the weight of this sample measured with an electronic balance and the shape and dimensions measured with a micrometer. Next, JIS-R
According to -2205, a part of the abrasive compact was pulverized to obtain a true density W1, and a relative density was calculated from the bulk density W2 of the abrasive compact previously calculated by the following equation.

Relative density (%) = (W2 / W1) × 100—Microstructure of polished surface of molded body for polishing—Embedded abrasive body with acrylic resin and cut with microtome to prepare sample for observation did. This observation sample was observed with a scanning electron microscope ISI DS-130 (manufactured by Akashi Seisakusho). The average diameter of electron micrographs taken at various magnifications was determined by an intercept method in consideration of each of the inorganic particles and pores. At this time, the line length crossing each of the inorganic particles and the pores was defined as the diameter, and the area ratio was calculated based on the sum of the diameters. From the sum of each, the ratio of the area of the non-sliding portion to the area of the polished surface is A, and the ratio of the area of the rubbing portion to the area of the polished surface is B, and the ratio A
/ (A + B) (= r) was calculated.

In this operation, ten surfaces were measured at regular intervals in the normal direction to the surface involved in polishing of the molded body for polishing, and the measured values were averaged to obtain an average value of r (= r '). In addition, the maximum and minimum of the variation with respect to the average value were calculated from the maximum value, the minimum value of r and the average value r ′ when measuring 10 surfaces by the following formula.

Maximum variation (%): ｛(maximum value−average value)
/ Average｝ × 100 Minimum (%) of fluctuation: ｛(minimum-average) / average｝ ×
100—average particle diameter of inorganic particles constituting the molded article for polishing— It was determined by an intercept method in consideration of only the inorganic particle portion, based on observation of the microstructure of the polished surface of the molded article for polishing.

Configuration of the rubbing portion of the molded article for polishing A scanning electron microscope observation was performed in accordance with the observation of the fine structure of the polished surface of the molded article for polishing, and pores and inorganic particles of 1 μm or less were observed. 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 portions of 1 μm or less by taking the intercept method into consideration.

Configuration of Non-Sliding Part of Polishing Molded Body Scanning electron microscope observation is performed according to the observation of the microstructure of the polished surface of the polishing molded body, and a pore portion larger than 1 μm is taken into consideration. The line length crossing the pore portion larger than 1 μm was defined as the pore diameter by the intercept method, and the ratio of the pores of 10 μm or more in the non-rubbing portion to the area of the non-rubbing portion was calculated in terms of the number.

-Compression strength- According to JIS-R-1608, 10 mm x 10 mm x
7mm (thickness) sample was prepared and Shimadzu Autograph IS
Using -10T (manufactured by Shimadzu Corporation), a load was applied at a crosshead speed of 0.5 mm / min, and the measurement was performed.

[Polishing Test] In the examples, a molded product for polishing (a cylindrical shape having a diameter of 25 mm and a thickness of 10 mm) having the characteristics shown in Tables 1 to 4 was prepared using a polishing apparatus PLANOPOL / PEDEMAX2 (Struer).
s product) on the lower platen (diameter 300mm) 100 pieces,
The surface of the molded article for polishing was flattened. Using a material to be polished (45 mm × 45 mm square) shown in Tables 5 to 9 under a lower platen rotation speed of 300 rpm and a predetermined processing pressure, the table 5 was used.
Polishing was performed while flowing at a flow rate of 200 ml / min using the polishing liquids shown in Nos. 9 to 9. The surface of the material to be polished after the polishing was observed with an optical microscope, and the case where the surface was extremely smooth and free of defects such as scratches and pits was evaluated as ○, and the case where the surface could not be polished without being smooth was evaluated as ×. At the same time, the state of consumption of the abrasive compact was measured as the amount of change in thickness per unit time. The case where the consumption was remarkable was evaluated as x, and the case where the consumption was within the allowable range was evaluated as ○.

The polishing liquids shown in Tables 5 to 9 are as follows.

Polishing liquid a: KOH aqueous solution (pH = 10.
8, liquid temperature: 60 ° C.) Polishing liquid b: aqueous solution containing 5% by weight of alumina abrasive grains having an average particle diameter of 0.3 μm (room temperature) Polishing liquid c: 5% by weight of ceria abrasive particles having an average particle diameter of 0.4 μm
Aqueous solution (room temperature)-polishing rate-The polishing rate was calculated from the weight loss of the material to be polished before and after the polishing test. This operation was surfaced to a depth of about 0.2 mm in the direction normal to the surface involved in polishing of the molded body for polishing, and was repeated 10 times. The average value was used as the polishing rate, and in Examples 6 and 8, the standard deviation of the measured values of the polishing rates of 10 was also determined.

-Surface Accuracy- The surface roughness of the material to be polished after the polishing treatment was measured by a repulsive force measuring method in a contact mode using an atomic force microscope (AFM) SPI3600 (manufactured by SII). In the measurement, the center line average roughness (Ra) was arbitrarily measured in three regions in a range of 5 μm × 5 μm of the material to be polished to obtain an average value.

-Transmittance of polishing waste liquid-The turbidity of the polishing waste liquid generated by the polishing test was measured using a spectrophotometer (model: Ubest-55, manufactured by JASCO Corporation) at a wavelength of 600 nm with reference to purified water. Was evaluated. In the measurement results, when the transmittance is high, it indicates that the amount of free abrasive grains in the polishing waste liquid is small, and when it is low, it indicates that the amount is large.

<Production of molded body for polishing> Powders having the characteristics shown in Tables 1 to 4 were used as raw materials, and in some cases, organic powders (for example, polyvinyl alcohol powder, potato starch, butyl methacrylate powder, paraffin wax powder, etc.)
Or more) and mix the powder with 50-3000 kg /
After molding at a pressure of cm ² , finally 700 to 1700
It baked at ℃, and obtained the abrasive compacts 1-25. These abrasive compacts were evaluated by the method described above, and the results are shown in Table 1 of the abrasive compact mainly containing silica and Table 2 of the abrasive compact mainly containing zirconia in Table 2. , Table 3
Table 4 shows the characteristics of the microstructure of the polished surface of the polishing compact mainly containing ceria, and Table 4 shows the characteristics of the polished surface of the polishing compact mainly containing a mixture of zirconia and alumina.

[0080]

[Table 1]

[0081]

[Table 2]

[0082]

[Table 3]

[0083]

[Table 4]

Further, the molded article for polishing 1 was photographed with a scanning electron microscope according to the method described above, and the photographed images shown in FIGS. 3 and 4 were obtained. As shown in FIG. 3, the rubbing portion 5 and the non-rubbing portion 6 are present on the surface of the molded article 1 for polishing, and according to FIG. Indicates that there are many small pores.

<Polishing by Polishing Molded Body and Its Evaluation> Examples 1 to 3 and Comparative Examples 1 to 3 As shown in Table 5, silicon (shape: 45 mm × 45)
mm square) as a material to be polished, using a molded body for polishing and a polishing liquid, in accordance with the polishing test described above, and a processing pressure of 6 mm.
Polishing was performed at 00 g / cm ² . Table 5 shows the smoothness, polishing rate, and center line average roughness (Ra) of the material to be polished obtained by the polishing test, and also shows the transmittance of the polishing waste liquid after the polishing test.

[0086]

[Table 5]

As shown in Table 5, in Examples 1 to 3, polishing is performed smoothly at high speed with little consumption of the compact. On the other hand, in Comparative Example 1, although the smoothness was obtained, the molded article was significantly consumed. In Comparative Example 2, a smooth surface cannot be obtained. In Comparative Example 3, although the polishing rate was high, it was found that some processing defects occurred and the smoothness deteriorated.

Examples 4-5, Comparative Examples 4-6 As shown in Table 6, borate glass (shape: 45 mm ×
(45 mm square) was used as a material to be polished, and polished at a processing pressure of 100 g / cm ² using a molded article for polishing and a polishing liquid in accordance with the polishing test described above. Table 6 shows the smoothness, polishing rate, and center line average roughness (Ra) of the material to be polished obtained by the polishing test, and also shows the transmittance of the polishing waste liquid after the polishing test.

[0089]

[Table 6]

As shown in Table 6, in Examples 4 and 5, polishing is performed smoothly at high speed with little consumption of the molded body.
On the other hand, in Comparative Example 4, the polishing rate is reduced. In Comparative Example 5, although the smoothness was obtained, the molded article was significantly consumed. In Comparative Example 6, a smooth surface cannot be obtained.

Examples 6 to 8 As shown in Table 7, borate glass (shape: 45 mm ×
(45 mm square) was used as a material to be polished, and polished at a processing pressure of 100 g / cm ² using a molded article for polishing and a polishing liquid in accordance with the polishing test described above. Table 7 shows the smoothness, polishing rate and its standard deviation, center line average roughness (Ra) of the material to be polished obtained by the polishing test, and also shows the transmittance of the polishing waste liquid after the polishing test.

[0092]

[Table 7]

As shown in Table 7, Examples 6 and 7
It can be seen from the results that when the A / (A + B) values are equal, the polishing rate is further increased when the ratio of the pores having a size of 10 μm or more in the non-rubbing portion is large. Also, from the results of Example 6 and Example 8, it can be seen that the polishing rate is further stabilized by reducing the variation of the A / (A + B) value with respect to the average value Rav.

Examples 9 to 12, Comparative Examples 7 to 8 As shown in Table 8, quartz (shape: 45 mm × 45 mm
Corner) as a material to be polished, using a molded body for polishing and a polishing liquid, in accordance with the polishing test described above, and a processing pressure of
Polishing was performed at 0 g / cm ² . Table 8 shows the smoothness, polishing rate, and center line average roughness (Ra) of the material to be polished obtained by the polishing test, and also shows the transmittance of the polishing waste liquid after the polishing test.

[0095]

[Table 8]

As shown in Table 8, in Examples 9 to 12, polishing is performed smoothly at high speed with little consumption of the molded body.
On the other hand, in Comparative Example 7, although the smoothness was obtained, the molded article was significantly consumed. In Comparative Example 8, a smooth surface cannot be obtained.

Examples 13 to 15 and Comparative Examples 9 to 10 As shown in Table 9, borate glass (shape: 45 mm ×
(45 mm square) was used as a material to be polished, and polished at a processing pressure of 100 g / cm ² using a molded article for polishing and a polishing liquid in accordance with the polishing test described above. Table 9 shows the smoothness, polishing rate, and center line average roughness (Ra) of the material to be polished obtained by the polishing test, and also shows the transmittance of the polishing waste liquid after the polishing test.

[0098]

[Table 9]

As shown in Table 9, in Examples 13 to 15, polishing is performed smoothly at high speed with little consumption of the molded body. On the other hand, in Comparative Example 9, although the smoothness was obtained, the molded article was significantly consumed. In Comparative Example 10, a smooth surface cannot be obtained.

[0100]

According to the present invention, a polishing waste liquid containing a large amount of free abrasive grains is hardly generated during the polishing process, and a semiconductor substrate, an oxide single crystal substrate, various glass substrates, a quartz glass substrate, The surface of a material to be polished, such as a substrate material such as a ceramic substrate or an optical material requiring precision processing, can be obtained at a higher speed with a high precision equal to or higher than that of the conventional method, and such excellent effects can be stably performed. be able to. In addition, since it has durability in the polishing process, it is useful for the polishing process.

[Brief description of the drawings]

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

FIG. 2 is a diagram illustrating an upper part of a cross section in a direction from X to X ′ in FIG. 1;

FIG. 3 is an image obtained by photographing the molded article for polishing 1 of the present invention with a scanning electron microscope. The photographing magnification is a magnification at which the length of the bar is 100 μm as shown in FIG.

FIG. 4 is a part of an image obtained by enlarging a portion surrounded by a square in FIG. The photographing magnification is a magnification at which the length of the bar is 1 μm as shown in FIG.

[Explanation of symbols]

1 and 2, the reference numerals in the drawings are commonly used. 1: Polishing molded body 2: rubbing part 3: non-rubbing part 4: polishing molding 5: rubbing part 6: non-rubbing part 7: enlarged part shown in FIG.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3C058 AA09 CB03 CB10 DA12 DA17 3C063 AA02 AB05 BA22 BB01 BB07 BD01 BH07 CC02 CC19 EE10 FF09 FF20

Claims (5)

[Claims] 1. A molded article for polishing comprising inorganic particles, comprising:
The surface of the molded article for polishing has a rubbing portion and a non-rubbing portion on a surface involved in polishing, and the pores present in the rubbing portion have a diameter of 1 μm or less and the area thereof is the total area of the rubbing portion. Of 1
5 to 75%, and the molded body for polishing, wherein the area of the non-sliding portion is 20 to 80% with respect to the total area of the surface engaged in polishing. 2. The rubbed part has an average particle diameter of 0.01 to 0.5.
The molded article for polishing according to claim 1, comprising inorganic particles having a particle diameter of μm. 3. The molded article for polishing according to claim 1, wherein 50% or more of the fine pores present in the non-rubbing portion are fine pores having a diameter of 10 μm or more. 4. A molded article for polishing according to claim 1, wherein the non-rubbing portions are uniformly distributed on a surface involved in polishing. 5. A polishing platen comprising the molded article for polishing according to claim 1 and ancillary components.