JP2012004229A - Polishing aid, polishing agent composition, and method for polishing semiconductor substrate - Google Patents

Abstract

Provided are a polishing aid for an abrasive composition, an abrasive composition, and a method for polishing a semiconductor substrate that can be used regardless of the material of a semiconductor substrate and can improve the polishing rate while suppressing deterioration of the polishing pad. For the purpose.
A polishing aid for polishing composition containing a peroxide, used for polishing a semiconductor substrate, comprising a water-soluble salt (A) containing a transition metal and a chelating agent (B). A polishing aid, wherein the molar ratio of the chelating agent (B) to the water-soluble salt (A) containing the transition metal is 0.5 or more.
[Selection figure] None

Description

  The present invention relates to a polishing aid for a semiconductor substrate, an abrasive composition, and a method for polishing a semiconductor substrate.

  The surface of a semiconductor substrate is mirror-polished several times to ensure performance during the manufacturing process. In the polishing step, which is the final step of polishing, a so-called chemical mechanical polishing (CMP) is performed in which an oxide layer is formed by oxidizing the substrate surface and the oxide layer is mechanically removed in order to produce a final processed surface. In general, the surface of the substrate is polished.

For example, when a semiconductor substrate made of silicon (semiconductor silicon substrate) is polished, it is usually polished using an abrasive composition containing hydrogen peroxide (oxidant) and colloidal silica (abrasive grains).
Further, a semiconductor substrate made of silicon carbide (semiconductor silicon carbide substrate) is difficult to polish because it is less oxidized than a semiconductor silicon substrate. Therefore, when polishing a semiconductor silicon carbide substrate, platinum is used as a catalyst to oxidize the surface of the substrate and etch with halogen-containing molecules (hydrogen halides such as hydrogen fluoride) (Patent Document 1). A method of oxidizing the substrate surface with hydrogen peroxide as a catalyst (Patent Document 2) has been proposed.

JP 2006-114632 A JP 2004-327952 A

However, the method described in Patent Document 1 is not practical because it uses expensive platinum or hydrogen halide, which is considered to have a problem with environmental burden.
The method described in Patent Document 2 is complicated because it uses chromium oxide, and is not practical as in Patent Document 1.

  Further, when manufacturing a semiconductor substrate, it is required to manufacture it in a shorter time, and it is desired to shorten the time required for polishing, that is, to improve the polishing rate. On the other hand, improving the polishing rate may cause early deterioration of the polishing pad, leading to an increase in manufacturing cost. Therefore, it is also desired to suppress the deterioration of the polishing pad.

  The present invention has been made in view of the above circumstances, and can be used regardless of the material of the semiconductor substrate, and can improve the polishing rate while suppressing deterioration of the polishing pad. It is an object to provide a polishing method for an object and a semiconductor substrate.

The polishing aid of the present invention is used for polishing a semiconductor substrate and is a polishing aid for a polishing agent composition containing a peroxide, which comprises a water-soluble salt (A) containing a transition metal and a chelating agent (B ) And the molar ratio of the chelating agent (B) to the water-soluble salt (A) containing the transition metal is 0.5 or more.
Here, it is preferable that the chelating agent (B) is a polycarboxylic acid compound.
Moreover, the abrasive | polishing agent composition of this invention contains the said grinding aid, a peroxide, and an abrasive grain, It is characterized by the above-mentioned.
Further, the semiconductor substrate polishing method of the present invention is characterized by using the above-mentioned abrasive composition.

  ADVANTAGE OF THE INVENTION According to this invention, it is possible to use irrespective of the material of a semiconductor substrate, the polishing aid for abrasive | polishing agent composition which can be used irrespective of the material of a polishing pad, and can improve a grinding | polishing rate, polishing composition, and the polishing method of a semiconductor substrate Can provide.

[Polishing aid]
The polishing aid of the present invention is used for polishing a semiconductor substrate and is an aid for a polishing composition containing a peroxide. In the present specification and claims, “peroxide” includes hydrogen peroxide.
The polishing aid of the present invention contains a water-soluble salt (A) containing a transition metal and a chelating agent (B).

<Water-soluble salt containing transition metal (A)>
In the water-soluble salt (A) containing a transition metal (hereinafter referred to as “component (A)”), examples of the transition metal include simple substances formed by a metal element of Group 3 to 11 in the long-period periodic table. Among these, copper, iron, manganese, cobalt, and silver are preferable, and manganese and cobalt are more preferable because a higher polishing rate is easily obtained when the polishing composition is used.
Examples of water-soluble salts include sulfates, chlorides, nitrates, bromates, and the like, and sulfates, chlorides, and nitrates are preferred because of their particularly good solubility in solvents such as water. Is more preferable.

Specific examples of component (A) include sulfates such as copper sulfate, iron sulfate, manganese sulfate, cobalt sulfate, and silver sulfate; chlorides such as copper chloride, iron chloride, manganese chloride, and cobalt chloride; copper nitrate, iron nitrate And nitrates such as manganese nitrate, cobalt nitrate and silver nitrate; and bromates such as copper bromide, iron bromide, manganese bromide and cobalt bromide.
As the component (A), in addition to the above compound, a hydrate of the above compound can also be used.
These (A) components can be used individually by 1 type or in combination of 2 or more types as appropriate.
The blending amount of the component (A) in 100% by mass of the polishing aid is preferably 0.01 to 4% by mass in terms of anhydride from the viewpoint of uniformity of the polished surface and suppression of deterioration of the polishing pad.

<Chelating agent (B)>
Examples of the chelating agent (B) (hereinafter referred to as “component (B)”) include nitrilotriacetic acid, ethylenediaminetetraacetic acid, β-alanine diacetic acid, glutamic acid diacetic acid, aspartic acid diacetic acid, methylglycine diacetic acid, iminodisuccinic acid, Aminocarboxylic acids or salts thereof such as diethylenetriaminepentaacetic acid; hydroxyaminocarboxylic acids or salts thereof such as serine diacetic acid, hydroxyiminodisuccinic acid, hydroxyethylethylenediaminetriacetic acid, dihydroxyethylglycine; hydroxyacetic acid, citric acid, gluconic acid, etc. Hydroxycarboxylic acid or a salt thereof; cyclocarboxylic acid or a salt thereof such as pyromellitic acid, benzopolycarboxylic acid, cyclopentanetetracarboxylic acid; carboxymethyltartronic acid, carboxymethyloxysuccinic acid, Kishijikohaku acid, tartaric monosuccinic acid, ether carboxylic acids or salts thereof, such as tartaric disuccinic acid; oxalic acid or a salt thereof; and compounds of these acid type and the like.
Further, as the component (B), phosphorus-based chelating agents such as tripolyphosphoric acid, hydroxyethanediphosphonic acid, pyrophosphoric acid, or salts thereof can be used.

Among these, as the component (B), a polycarboxylic acid-based compound is preferable because a higher polishing rate can be obtained when an abrasive composition is used.
Among the polycarboxylic acid compounds, amino acids such as nitrilotriacetic acid, ethylenediaminetetraacetic acid, β-alanine diacetic acid, glutamic acid diacetic acid, aspartic acid diacetic acid, methylglycine diacetic acid, iminodisuccinic acid, and diethylenetriaminepentaacetic acid are more preferable. Polycarboxylic acids or salts thereof; hydroxyaminopolycarboxylic acids or salts thereof such as serine diacetic acid, hydroxyiminodisuccinic acid, hydroxyethylethylenediaminetriacetic acid; hydroxypolycarboxylic acids or salts thereof such as citric acid; pyromellitic acid, benzopoly Cyclopolycarboxylic acids such as carboxylic acid and cyclopentanetetracarboxylic acid or salts thereof; carboxymethyltartronic acid, carboxymethyloxysuccinic acid, oxydisuccinic acid, tartaric acid monosuccinic acid, tartaric acid disuccinic acid Ether polycarboxylic acids or salts thereof and the like; oxalic acid or a salt thereof: and their acid-type compounds.

  Among these, aminopolycarboxylic acid or a salt thereof, hydroxyaminopolycarboxylic acid or a salt thereof, hydroxypolycarboxylic acid or a salt thereof, or a compound of these acid types is more preferable.

Examples of the salt include alkali metal salts such as sodium salt and potassium salt; alkanolamine salts such as monoethanolamine salt and diethanolamine salt, and sodium salt and potassium salt are particularly preferable.
(B) A component can be used individually by 1 type or in combination of 2 or more types as appropriate.
The blending amount of the component (B) in 100% by mass of the polishing aid is preferably 0.05 to 4.5% by mass in terms of anhydride from the viewpoint of polishing rate and suppression of deterioration of the polishing pad.

The molar ratio of the component (B) to the component (A) is 0.5 or more, and preferably 1.0 or more. When the molar ratio of the component (B) to the component (A) is 0.5 or more, the metal complex can be favorably formed with the component (A) and the component (B). The metal complex further activates hydrogen peroxide released from the peroxide contained in the abrasive composition described later. As a result, the surface of the semiconductor substrate is easily oxidized, so that the semiconductor substrate can be polished regardless of the material and a high polishing rate can be obtained. In addition, the formation of the metal complex makes it difficult for the transition metal to be released from the component (A). Therefore, it can suppress that the polishing pad used in the case of grinding | polishing deteriorates with a transition metal.
In addition, the molar ratio of (B) component with respect to (A) component is calculated | required from following formula (1).
(A) molar ratio of component (B) to component = molar amount of component (B) / molar amount of component (A) (1)

  As the proportion of the component (B) increases, the influence of the transition metal derived from the component (A) on the deterioration of the polishing pad can be suppressed. Considering the effect of improving the polishing rate, the upper limit value of the molar ratio of the component (B) to the component (A) is preferably substantially 100 or less, and more preferably 10 or less.

<Other ingredients>
The polishing aid of the present invention may contain other components other than the components (A) and (B) described above.
Examples of other components include a solvent and a surfactant.
Examples of the solvent include pure water, ultrapure water, ethanol, isopropyl alcohol, and the like.
Examples of the surfactant include anionic surfactants such as linear alkylbenzene sulfonates, alkyl sulfates and alkyl ether sulfates; alkylene oxide adducts of higher alcohols, nonionic surfactants such as pluronic surfactants, and the like. Can be mentioned.

<Preparation method>
The method for preparing the polishing aid of the present invention is not particularly limited, and can be prepared by sequentially mixing each component according to a conventional method.
In particular, it is preferable to prepare by dissolving the remaining components in the solvent described above. At that time, in polishing a general semiconductor substrate, the total content of the component (A) and the component (B) in 100% by mass of the polishing aid is 0.3% by mass or more in terms of anhydride. It is preferable to adjust to 0.3 to 5% by mass. When the total content of the component (A) and the component (B) is 0.3% by mass or more, a higher polishing rate can be obtained when an abrasive composition is used. On the other hand, if it is 5 mass% or less, the precipitation from the solvent of the complex which consists of (A) component and (B) component can be suppressed.
When the polishing aid of the present invention is used for polishing a highly hard and hardly oxidizable semiconductor silicon carbide substrate, the total content of the component (A) and the component (B) is calculated in terms of anhydride. It is more preferable to prepare the polishing aid so as to be 0.6 to 5% by mass because a better polishing rate can be obtained.

As described above, the polishing aid of the present invention can be used regardless of the material of the semiconductor substrate when it is used as an abrasive composition. In addition, since the polishing rate can be improved, the semiconductor substrate can be polished in a short time.
The reason why such an effect is obtained is not clear, but is presumed as follows.
The polishing aid of the present invention contains the component (A) and the component (B) in an amount of 0.5 or more in molar ratio to the component (A). These (A) component and (B) component tend to form a metal complex in the polishing aid or during polishing. In particular, when the molar ratio of the component (B) to the component (A) is 0.5 or more, the metal complex can be satisfactorily formed. And this metal complex activates more the hydrogen peroxide contained in the abrasive | polishing agent composition mentioned later. As a result, the surface of the semiconductor substrate is easily oxidized, and polishing can be performed regardless of the material of the semiconductor substrate, and a high polishing rate can be obtained.

[Abrasive composition]
The abrasive composition of the present invention contains the above-described polishing aid of the present invention, a peroxide, and abrasive grains.
The content of the polishing aid in 100% by mass of the abrasive composition is such that the total content of the component (A) and the component (B) is 0.03 to 3% by mass in terms of anhydride. Preferably, it is 0.05-2 mass%. If the total content of the component (A) and the component (B) in the abrasive composition is 0.03% by mass or more, a higher polishing rate can be obtained. On the other hand, if it is 3 mass% or less, deterioration of a polishing pad can be suppressed for a long time.

<Peroxide>
The peroxide serves as an oxidant and oxidizes the surface of the semiconductor substrate to form an oxide layer.
The peroxide is not particularly limited as long as it is hydrogen peroxide or can be dissolved in water to generate hydrogen peroxide. For example, hydrogen peroxide, percarbonate, perboric acid, or alkali metals thereof. Examples thereof include salts (sodium salt, potassium salt, etc.) or ammonium salts.
Among these, hydrogen peroxide, sodium percarbonate, and sodium perborate are preferable, and hydrogen peroxide is particularly preferable because of easy handling and generation efficiency of hydrogen peroxide.
A peroxide can be used individually by 1 type or in combination of 2 or more types as appropriate.

  The content of the peroxide is preferably 0.1 to 10% by mass in terms of pure content and more preferably 0.5 to 10% by mass in terms of pure content in 100% by mass of the abrasive composition. If the peroxide content is 0.1% by mass or more in terms of pure matter, sufficient oxidizing power can be obtained and the polishing rate becomes good. On the other hand, if the peroxide content is 10% by mass or less in terms of pure content, the deterioration of the polishing pad and the self-decomposition of the peroxide are suppressed, and the working efficiency is improved.

<Abrasive>
Examples of the abrasive grains include colloidal silica, diamond, silicon carbide, alumina, and cerium oxide. These can also be used in the state of a slurry.
The abrasive grains may be appropriately selected and used according to the type of semiconductor substrate to be polished and the required polishing accuracy.

  0.01-20 mass% is preferable in 100 mass% of abrasive | polishing agents composition, and, as for content of an abrasive grain, 0.1-10 mass% is more preferable. When the content of the abrasive grains is 0.01% by mass or more, a good polishing rate can be obtained. On the other hand, if the content of abrasive grains is 20% by mass or less, non-uniformity of the polished surface caused by excessive agglomeration or settling of abrasive grains can be suppressed.

<Other ingredients>
The abrasive composition of the present invention may contain other components as necessary.
Examples of other components include a solvent and a surfactant.
Examples of the solvent include the solvents exemplified above in the description of the polishing aid.

Examples of the surfactant include the surfactants exemplified above in the description of the polishing aid.
The content of the surfactant is preferably 0.01 to 5% by mass in 100% by mass of the abrasive composition.

<Preparation method>
The method for preparing the abrasive composition of the present invention is not particularly limited, and can be prepared by sequentially mixing each component according to a conventional method.
The polishing aid and the peroxide are preferably mixed immediately before polishing, and more preferably mixed on the object to be polished at the time of polishing. Thereby, decomposition | disassembly of the hydrogen peroxide generate | occur | produced from a peroxide can be suppressed, and an abrasive | polishing agent composition can be prepared more stably.

Since the activation effect of hydrogen peroxide by the polishing aid of the present invention is enhanced at a pH of weak acid or higher, the pH of the polishing composition is preferably 5 or more and less than 14, more preferably 5 or more and less than 12.
The pH of the abrasive composition is inorganic alkali agents such as ammonia, potassium hydroxide, and sodium hydroxide; organic alkali agents such as tetramethylammonium hydroxide and tetraethylammonium hydroxide; inorganic acids such as sulfuric acid, hydrochloric acid, and nitric acid; acetic acid PH adjusting agents such as organic acids such as citric acid, p-toluenesulfonic acid and glycolic acid may be used.

The pH of the abrasive composition indicates the pH of the abrasive composition after standing for 10 minutes at 25 ° C. immediately after the preparation of the abrasive composition.
In the abrasive composition of the present invention, the pH value immediately after preparation is not constant due to the interaction between the polishing aid and the peroxide. Therefore, in the present invention, the pH of the abrasive composition 10 minutes after the preparation, in which the pH of the abrasive composition shows a substantially constant value, is measured.

As described above, since the polishing composition of the present invention contains the above-described polishing aid of the present invention, it can be used regardless of the material of the semiconductor substrate. In particular, it can be suitably used for polishing a semiconductor substrate made of silicon carbide which is not easily oxidized. In addition, since the abrasive | polishing agent composition of this invention does not use a hydrogen halide and chromium oxide, there are few loads to an environment or a human body.
Moreover, since the abrasive | polishing agent composition of this invention can improve a grinding | polishing rate, it can grind | polish a semiconductor substrate in a short time.
In addition, since the transition metal derived from the component (A) contained in the polishing aid is difficult to be released, rapid deterioration of the polishing pad can be suppressed.

[Semiconductor substrate polishing method]
The semiconductor substrate polishing method of the present invention is a method using the above-described abrasive composition of the present invention.
Examples of the material for the semiconductor substrate include silicon, silicon carbide, zinc oxide, gallium nitride, sapphire, diamond, gallium arsenide, and indium phosphide.
Among these, since the surface of a semiconductor substrate made of silicon carbide (semiconductor silicon carbide substrate) is difficult to be oxidized, for example, it is difficult to polish sufficiently even if a conventional abrasive composition for a semiconductor silicon substrate is used. Met.
However, if it is the abrasive | polishing agent composition of this invention, hydrogen peroxide can be activated with the metal complex formed with (A) component and (B) component contained in a grinding | polishing adjuvant. Therefore, the surface of the semiconductor substrate is easily oxidized, and polishing can be performed regardless of the material of the semiconductor substrate, and a high polishing rate can be obtained.

The means for polishing is not particularly limited, and a normal polishing apparatus used for polishing a semiconductor substrate can be used.
When using the abrasive composition of the present invention, the abrasive composition may be applied to or dropped on the polishing pad, or the components constituting the abrasive composition on the polishing pad (polishing aid, peroxide) Material, abrasive grains, etc.) may be dropped individually.

  The polished semiconductor substrate is washed with alcohol, water or the like to remove the abrasive composition and polishing residue adhering to the semiconductor substrate, and then dried by a known method.

As described above, according to the method for polishing a semiconductor substrate of the present invention, the semiconductor substrate can be polished sufficiently in a short time regardless of the material. In addition, rapid deterioration of the polishing pad can be suppressed.
The method for polishing a semiconductor substrate of the present invention is particularly suitable as a method for polishing a semiconductor silicon substrate or a semiconductor silicon carbide substrate.

  Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto. Note that “%” indicates “mass%” converted to an anhydride unless otherwise specified.

[Raw materials]
The following compounds were used as the component (A) and the component (B) used for the preparation of the polishing aid.
A1: Cobalt sulfate heptahydrate (manufactured by Wako Pure Chemical Industries, Ltd., special grade), formula weight: 281.1 (anhydride conversion: 155.0).
A2: Manganese sulfate pentahydrate (manufactured by Kanto Chemical Co., Ltd., special grade), formula weight: 241.1 (anhydride conversion: 151.0).
A3: Copper sulfate pentahydrate (manufactured by Kanto Chemical Co., Ltd., special grade), formula weight: 249.7 (anhydride conversion: 159.6).
A4: iron sulfate heptahydrate (manufactured by Kanto Chemical Co., Ltd., special grade), formula weight: 278.1 (anhydride conversion: 151.9).
A5: Calcium chloride dihydrate (manufactured by Kanto Chemical Co., Ltd., special grade), formula weight: 147.0 (anhydride conversion: 111.0).

B1: Ethylenediaminetetraacetic acid (manufactured by Kanto Chemical Co., Ltd., special grade), molecular weight: 292.2.
B2: Trisodium citrate dihydrate (Kanto Chemical Co., Ltd., grade 1), molecular weight: 294.1 (anhydride conversion: 258.1).
B3: iminodisuccinic acid tetrasodium (IDS-4Na, Baypure CX-100 manufactured by LANXESS Corporation), molecular weight: 337.1, 34% aqueous solution.
B4: Hydroxyethane diphosphonate sodium (HEDP, manufactured by Rhodia BRIQUEST ADPA-60SH), molecular weight: 294.0, 60% aqueous solution.
B5: Sodium acetate (Wako Pure Chemical Industries, special grade), molecular weight: 82.0.

[Examples 1 to 16, Comparative Examples 1 to 6]
<Preparation of polishing aid>
Polishing aids having the compositions shown in Tables 1 to 3 were prepared as follows according to a conventional method.
Add a specified amount of ultrapure water to a beaker (capacity 100 mL) containing a magnetic stirrer, adjust the temperature to 25 ° C., and rotate the magnetic stirrer while rotating the magnetic stirrer. Were sequentially blended to obtain a polishing aid.

In addition, “(A) component blending amount [mass%]” and “(B) component blending amount [mass%]” in the table are the equivalents of the respective components in 100% by weight of the polishing aid in terms of anhydride. Value (mass%), and “(A) + (B) [mass%]” is the sum of the contents of the components (A) and (B) in 100% by mass of the polishing aid. “(B) / (A) [molar ratio]” is the ratio of the molar amount of the component (B) to the component (A). “Abrasive (A) + (B) [mass%]” means (A) component and (B) in 100 mass% of the abrasive composition when the prepared polishing aid was subjected to a polishing test described later. It is the value (mass%) which converted the sum total of content of an ingredient into an anhydride.
The “balance amount” is the amount of ultrapure water whose blending amount is adjusted so that the total amount of the polishing aid as the final product is 100% by mass.
The obtained polishing aid was subjected to the following evaluations and measurements.

<Polishing test 1: Semiconductor silicon substrate>
A semiconductor silicon substrate (manufactured by KN Platz Co., Ltd., size: 4 inches) was affixed to a polishing board with wax (manufactured by Nikka Seiko Co., Ltd., “Arco wax”) and fixed. For the polishing process, a polishing machine (Buehler, “AutoMet2000, EcoMet3000”) and a polishing pad (Buehler, “MasterTex”) were used. Consists of 30% hydrogen peroxide (manufactured by Kanto Chemical Co., Ltd., for electronic industry), 0.1% sodium hydroxide (manufactured by Kanto Chemical Co., Ltd., special grade), colloidal silica polishing slurry (Buehler, “MasterMet”) 30% hydrogen peroxide (manufactured by Kanto Chemical Co., Ltd., for electronics industry), 0.1% sodium hydroxide (Kanto) Chemical Co., Ltd., special grade) Aqueous solution, colloidal silica polishing slurry, and polishing aid prepared above simultaneously dripped onto the polishing pad at a rate of 1 g / min each, polishing load: 15 pounds, rotation speed 150 rpm, polishing time The substrate surface was polished under conditions of 10 minutes.
Thereafter, the substrate was removed from the polishing board, washed with isopropyl alcohol, and dried at a humidity of 60%.

(Measurement of polishing rate)
The mass of the semiconductor substrate before and after polishing was measured, the rate of change was converted to the thickness of the substrate, and the polishing rate was calculated by the following formula (2). A case where the polishing rate is 0.5 μm / h or more is considered acceptable. The results are shown in Tables 1-3. In Formula (2), W ₀ is the mass [g] of the semiconductor substrate before polishing, W ₁ is the mass [g] of the semiconductor substrate after polishing, and D ₀ is the thickness [μm] of the semiconductor substrate before polishing. , T is the polishing time [h].
Polishing rate [μm / h] = (W ₀ −W ₁ ) / W ₀ × D ₀ / T (2)

(Evaluation of deterioration of polishing pad)
The raised state of the surface of the polishing pad after the polishing test was visually observed, and the deterioration of the polishing pad was evaluated according to the following evaluation criteria. The results are shown in Tables 1-3.
○: Brushed is not damaged.
X: Brushed is damaged.

<Polishing test 2: Semiconductor silicon carbide substrate>
Instead of a semiconductor silicon substrate, a semiconductor silicon carbide substrate (manufactured by Nippon Steel Corp., size: 2 inches, polytype 4H, Si surface finish polished) is used, and polishing conditions are polishing load: 20 pounds, rotation speed The surface of the substrate was polished in the same manner as the polishing test 1 except that the speed was changed to 150 rpm and the polishing time was 15 minutes.
Then, the polishing rate was measured in the same manner as in the polishing test 1 to evaluate the deterioration of the polishing pad. The results are shown in Tables 1-3. In addition, about the grinding | polishing test 2, the case where a grinding | polishing rate is 0.01 micrometer / h or more is set as a pass.

As is clear from Tables 1 and 2, in each example, the semiconductor silicon substrate and the semiconductor silicon carbide substrate could be sufficiently polished in a short time. Moreover, deterioration of the polishing pad could be suppressed.
On the other hand, in the case of Comparative Example 1, it was possible to suppress the deterioration of the polishing pad, but a sufficient polishing rate was not obtained in polishing the semiconductor silicon substrate. Moreover, it was difficult to polish the semiconductor silicon carbide substrate.
In Comparative Examples 2 and 3, the polishing pad was damaged in a short time, and each substrate could not be polished.
In the case of Comparative Example 4, although the deterioration of the polishing pad could be suppressed, a sufficient polishing rate could not be obtained in polishing the semiconductor silicon substrate. Moreover, it was difficult to polish the semiconductor silicon carbide substrate.
In Comparative Examples 5 and 6, an acceptable level of polishing rate was obtained in polishing the semiconductor silicon substrate, but the polishing pad was easily deteriorated. Moreover, it was difficult to polish the semiconductor silicon carbide substrate, and the polishing pad was liable to deteriorate.

Claims (4)

A polishing aid for a polishing agent composition used for polishing a semiconductor substrate and containing a peroxide,
The molar ratio of the chelating agent (B) to the water-soluble salt (A) containing the transition metal is 0.5 or more, containing the water-soluble salt (A) containing the transition metal and the chelating agent (B). A polishing aid characterized by   The polishing aid according to claim 1, wherein the chelating agent (B) is a polycarboxylic acid compound.   A polishing composition comprising the polishing aid according to claim 1, a peroxide, and abrasive grains.   A method for polishing a semiconductor substrate, comprising using the abrasive composition according to claim 3.