JPH09137155A - Polishing composition and polishing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain fine polishing material particles which can efficiently polish an object formed on a semiconductor substrate without detriment to the properties of a polished surface by incorporating fine polishing material particles and a specific polishing accelerator into an alkaline water soln. SOLUTION: This polishing compsn. is prepd. by incorporating fine polishing material particles (e.g. silicon oxide) and a polishing accelerator comprising a compd. having reducing properties into a water soln. having a pH adjusted to the alkali side. Pref. the accelerator comprises at least one compd. selected from among an inorg. reducing agent (e.g. nitrous acid), an aldehyde reducing agent (e.g. glutaraldehyde), a hydroxyphenyl reducing agent (e.g. hydroquinone), and an amine reducing agent (e.g. 1-phenyl-3-pyrazolidone). Pref. the particles have sizes of 0.01-5μm. The compsn. is used for polishing a silicon film or a silicon oxide film formed on a semiconductor substrate.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polishing composition and a polishing method, and particularly to polishing a silicon or silicon oxide film formed on a semiconductor substrate efficiently without damaging the properties of the polishing surface. The present invention relates to a polishing composition and a polishing method.

[0002]

2. Description of the Related Art In the field of manufacturing semiconductor devices, usually, on a semiconductor substrate such as metal silicon, impurity diffusion, etching, wiring formation, and interlayer insulating film (silicon film, silicon oxide film, etc.) on the wiring are formed. A number of steps such as formation are repeated to stack the wiring. Therefore, a complicated circuit (pattern) is formed on the silicon substrate, and irregularities are generated based on this pattern shape.

In particular, in recent years, the density and precision of electronic parts such as LSI and VLSI have become higher and higher, and the degree of unevenness tends to become more and more severe. Therefore, when patterning by the photolithography method, a situation in which the step due to these irregularities exceeds the limit of the depth of focus during exposure occurs, and in order to prevent this, at some stage in the process of applying lithography or etching, for example, It is important to have a technique in which the above-described interlayer insulating film (base) is sufficiently flattened in advance to reduce the step of the uneven portion as much as possible.

Lift-off method, etch-back method, SOG (spin-on-glass) is used as the above-mentioned planarization method.
Although various methods such as a method have been proposed, one of them is a chemical mechanical polishing (CMP) method. According to this CMP method, for example, C
Interlayer insulation film (silicon oxide film, etc.) by VD (chemical vapor deposition), etc.
After forming the thick film, the surface protrusions are polished with a polishing agent for CMP to flatten the entire surface.

As a polishing agent for this CMP, the metal silicon polishing slurry that has been used for mirror polishing during the production of silicon substrates is currently applied to the above-mentioned insulating film polishing. It was not always suitable for polishing a film.

For example, as the above-mentioned metal silicon polishing slurry, abrasive grains (abrasive fine particles) dispersed in an alkali (sodium hydroxide or the like) aqueous solution have been used. When this is applied to the polishing of an insulating film, However, there is a problem that polishing efficiency is poor and throughput is low. As means for increasing the polishing efficiency, such as increasing the grain size of the abrasive grains, using abrasive grains with high hardness, or using abrasive grains that do not dissolve in strong alkali and using a polishing composition with a high pH value, etc. A method can be considered. However, when using abrasive grains having a large particle diameter or hard abrasive grains, there are problems such as scratches on the polishing surface, defects such as orange peel, and the like, while in the case of a strongly alkaline polishing composition, it is not always possible to prevent contamination. It wasn't practical.

Japanese Unexamined Patent Publication Nos. 2-158682 and 2
JP-A-158683 reports a polishing composition containing an additive (polishing accelerator) as a method for improving polishing efficiency without deteriorating the properties of the polishing surface. These are a composition in which α-alumina abrasive grains are dispersed in water, a metal nitrite as a polishing accelerator, and boehmite,
Although an ammonium salt of an inorganic acid or an organic acid is added, the polishing composition has a pH adjusted to be acidic or neutral, and therefore is suitable for polishing a metal part such as aluminum. When polishing an insulating film such as, the polishing rate is low and not practical.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and the problem is that polishing can be performed efficiently without damaging the properties of the polishing surface such as an interlayer insulating film on a semiconductor substrate. An object is to provide a polishing composition and a polishing method using the same.

[0009]

As a result of intensive studies to solve the above problems, the present inventor has found that in the polishing of interlayer insulating films of semiconductor devices, fine abrasive particles and reducing substances are added to an alkaline aqueous solution. The present invention was completed based on the finding that the above problems can be solved by containing the above-mentioned substance and using it as an abrasive composition.

That is, the present invention provides a polishing composition comprising fine particles of an abrasive and a compound having a reducing property as a polishing accelerator in an aqueous solution whose pH is adjusted to the alkaline side.

The present invention also provides a polishing method for polishing a silicon or silicon oxide film formed on a semiconductor substrate using the above polishing composition.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.

The fine abrasive particles used in the present invention can be used without particular limitation as long as they can be generally used in an abrasive composition for semiconductor devices and the like.
Specific examples thereof include aluminum oxide (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), zirconium oxide (ZrO ₂ ), and cerium oxide (CeO ₂ ). Among them, silicon oxide and cerium oxide are particularly preferable as a material suitable for precisely polishing a thin film having a thickness of about 1 μm in a semiconductor which does not like contamination.

These fine abrasive particles can be obtained by a conventional method. For example, as the silicon oxide fine particles, those obtained by pulverizing and calcining calcined silica gel, so-called silica sols obtained by growing a silicic acid solution prepared by an ion exchange method under alkaline conditions, those obtained by high-temperature oxidation of metal silicon powder, and silicon tetrachloride are used. It can be obtained by various production methods such as high-temperature hydrolyzed product, ethyl silicate hydrolyzed product, etc., and any of these methods can be used without particular limitation.

If the particle size of the abrasive fine particles is large, the polishing rate is high but the particles tend to precipitate. On the other hand, if the particle size is small, the polishing rate is slow and the particles tend to thicken or aggregate. Generally, 0.01 to 5 μm is preferable, but 0.01 to 5 μm is particularly preferable.
0.1 μm is preferred. The cerium oxide fine particles are suitable especially when polishing at a high speed is required, and have a particle size of 0.0
It is preferably about 5 to 1 μm.

By increasing the concentration of the abrasive fine particles to a certain degree, the number of contact points with the material to be abraded increases and the polishing rate can be expected to be improved. Causes a decrease in polishing rate. Further, the relationship between the polishing rate and the concentration of fine particles of the polishing material changes depending on the pad used for polishing, the polishing pressure, the speed, and the like. Therefore, it is necessary to determine the content of the abrasive fine particles under these comprehensive conditions, and the optimum concentration range cannot be uniquely determined. However, the content of the abrasive fine particles is generally about 2 to 50% by weight based on the polishing composition. It is preferable that the amount is 2 to 20% by weight.

In the polishing composition of the present invention, in order to stably disperse the abrasive fine particles, and to chemically polish the insulating film, specifically, to enhance the polishing effect and improve the finish of the polished surface, the pH of the alkaline side is increased. Must be adjusted. A pH adjuster is usually used for this purpose. As pH adjusters, sodium hydroxide, potassium hydroxide, ammonia,
Examples thereof include hydrazine, hydroxylamine, monomethylamine and the like. From the viewpoint of polishing effect, potassium hydroxide and ammonia are particularly preferable. In the field of semiconductors, metal contamination that causes wiring defects is particularly disliked. From this point, a non-metal compound alkali (eg, ammonia) is preferably used. Therefore, it is desirable to select the pH adjusting agent according to the purpose of polishing.

These pH adjusters are used to adjust the pH of the polishing composition.
Is added in a range of 8 to 11, preferably 9.5 to 10.5. When the pH is less than 8, it is difficult to stably disperse the abrasive fine particles, and when the pH is more than 11, it is difficult to obtain a sufficient polishing effect. Specifically, for example, when silicon oxide (silica) particles are used as abrasive fine particles, p
When H is around 7 (neutral), the silica particles are remarkably thickened and the dispersion stability of the particles is impaired. On the other hand, when the pH exceeds 11, the silica particles form a silicate and are dissolved in the solution. There is a problem that the mechanical polishing effect is lost because the polishing agent has a problem of promoting the polishing by the pH adjusting agent. In the case of using abrasive fine particles which are harder and have a larger particle size, mechanical polishing by the fine particles themselves is used. Because the speed of
Although the relative polishing rate is not significantly increased by adding the H-adjusting agent, the properties of the insulating film surface after polishing are excellent.

In the composition of the present invention, a compound having a reducing property is used as a polishing accelerator. Here, the “compound having a reducing property” means a substance that reduces another substance and is itself oxidized. In the present invention, an inorganic or organic reducing agent, a saccharide such as glucose, or the like can be applied as the reducing substance. As the organic reducing agent, at least one selected from aldehyde reducing agents, hydroxyphenyl reducing agents and amine reducing agents is preferably used.

Particularly, the inorganic reducing agent is preferable in that it has a strong reducing power and an excellent polishing promoting effect, and at least it is selected from the inorganic reducing agent, an aldehyde type reducing agent, a hydroxyphenyl type reducing agent and an amine type. A mixture with one is more preferably used.

Here, the inorganic reducing agent is specifically sulfurous acid, nitrous acid and phosphorous acid, or their alkali metal salts or ammonium salts, as well as first metal halides such as tin chloride and iron chloride, and other submetals. Examples include chloric acid and the like. Specific examples of the alkali metal salt include potassium salt, sodium salt, lithium salt and the like.

Specific examples of the aldehyde-based reducing agent include formaldehyde, acetaldehyde, glutaraldehyde, glyoxal and the like.

The hydroxyphenyl-based reducing agent is specifically catechol, p-hydroxyphenylglycine, 4-
Aminophenol, 2,4-diaminophenol, p-
Examples thereof include hydroxydiethylaminophenol, p-dimethylaminophenol, p-methylaminophenol sulfate, hydroquinone, and trisphenol compounds (eg, tris (4-hydroxyphenyl) methane).

Specific examples of the amine-based reducing agent include 1-phenyl-3-pyrazolidine, tetramethylethylenediamine, ascorbic acid, hydroxyamine, methylamine and p-phenylenediamine.

Suitable reducing compounds for use in the present invention differ depending on the pH adjusting agent used. For example, when potassium hydroxide, sodium hydroxide or the like is used as the pH adjusting agent, nitrous acid or Alkali metal salts of sulfurous acid, hydroquinone and the like are preferable, and when ammonia is used as a pH adjuster, ammonium salts of sulfurous acid or nitrous acid, p-methylaminophenol sulfate and the like are preferably used.

The reducing compounds may be used alone or as a mixture of two or more kinds, and they are mixed from the viewpoint of improving the polishing promoting effect of the polishing composition and other overall effects. Systems are preferred. For example, a polishing composition using a hydroxyphenyl-based reducing agent such as p-methylaminophenol sulfate and hydroquinone may be discolored during storage, but an inorganic reducing agent such as sulfite should be mixed and used. As a result, both the discoloration preventing effect and the polishing promoting effect can be improved.

These reducing compounds are preferably added in a proportion of 0.001 to 0.5 mol, more preferably 0.01 to 0.1, relative to 1 kg of the polishing composition.
It is about mol, particularly about 0.03 mol. If it is less than 0.001 mol, the polishing promoting effect is not sufficiently exhibited, while on the other hand, it is less than 0.
If it exceeds 5 moles, agglomeration of abrasive fine particles easily occurs,
Since the viscosity is increased, the dispersion stability is impaired. Further, there is a problem that the polishing composition is insufficiently supplied between the pad and the object to be polished, resulting in uneven polishing. 2
When a mixture of two or more reducing agents is used, the mixing ratio of each is not particularly limited, and the total amount thereof may be set within the above range.
It is particularly preferable to mix the other reducing agent in an amount of 0.1 to 10 mol, particularly 1 to 2 mol, based on mol, from the viewpoint of the polishing promoting effect.

In the present invention, it is preferable to add an amino acid in addition to the above-mentioned reducing compound. Examples of these amino acids include alanine, glycine, tyrosine, cystine, glutamic acid, threonine and the like.

The amount of the amino acid blended is 0.001 to 0.10 per 1 kg of the polishing composition in order to sufficiently exert the polishing promoting effect and to obtain stable dispersibility of the polishing composition.
It is preferably blended in a ratio of 5 mol, more preferably 0.01 to 0.1 mol, and especially about 0.02 mol. Further, in terms of polishing efficiency, it is particularly preferably used by mixing with an inorganic reducing agent, and 0.1 to 10 moles, particularly 1 to 2 moles are preferable relative to 1 mole of the inorganic reducing agent.

As the combination of the compound having reducing properties and the amino acid, it is most preferable to combine an inorganic reducing agent with an aldehyde reducing agent, a hydroxyphenyl reducing agent, or an amino acid because of excellent polishing promoting effect. Specifically, when potassium hydroxide is used as the pH adjuster, a combination of potassium sulfite and hydroquinone, or a combination of potassium nitrite and at least one selected from alanine, threonine and glutamic acid is preferable. . When ammonia is used as the pH adjuster, a combination of ammonium sulfite and catechol, 1-phenyl-3-pyrazolidone, 4-aminophenol or 2,4-diaminophenol is preferable.

The polishing-promoting effect of these reducing agents differs depending on the combination with the pH adjusting agent and the abrasive fine particles, and in particular, the characteristics change with respect to the base strength of the pH adjusting agent.

If desired, a bactericide, an activator, a water-soluble compound for stabilizing dispersion, or a polymer compound may be added to the polishing composition of the present invention within a range that does not impair the effects of the present invention. You can In this case, it is preferable that these compounds have low reactivity with the compound having the above-mentioned reducing property.

The polishing composition of the present invention can be prepared, for example, by the following method.

First, fine abrasive particles are uniformly dispersed in water. In the case where the abrasive fine particles are powder, the measured powder of water is stirred by a high-speed stirring homogenizer or the like, and the separated powder is added thereto to uniformly disperse the powder. As a dispersion method, a sand mill, a ball mill, a roll mill,
It can be carried out by a known method such as Microfluidizer. At this time, in order to increase the dispersion efficiency, a concentration higher than the concentration of the abrasive fine particles finally contained (for example, 3
0 wt% or more) is preferable.

Further, when the abrasive fine particles are not powders but silica sol synthesized by heating an aqueous solution of silicic acid under alkaline conditions, these are already commercially available in a uniformly dispersed form. Can be used as is.

After that, an alkaline aqueous solution for pH adjustment is added to the liquid in which the fine abrasive particles are uniformly dispersed. At this time, the polishing composition becomes highly viscous near the neutralization point and becomes difficult to stir. Therefore, it is also preferable to add the fine abrasive particle dispersion to an alkaline aqueous solution.

Next, after adding water or an alkaline aqueous solution of a reducing compound, if necessary, other additives are added, and then the above-mentioned alkaline aqueous solution for pH adjustment or water is added to obtain the final concentration of fine abrasive particles. The final polishing composition can be obtained by adjusting the pH (for example, about 12% by weight) and the pH (for example, pH = about 10).

The thus obtained polishing composition of the present invention can be used to polish an interlayer insulating film, a flattening film, a surface protective film and the like formed on a semiconductor substrate.
As a result, a polishing method with improved polishing efficiency can be obtained without changing the surface properties of the objects to be polished.

The polishing composition of the present invention can be suitably used for polishing various silicon films, silicon oxide films and glass. For example, it is formed by a method such as a CVD method, a sputtering method, a coating method or a thermal oxidation method. Various oxide films such as SiO
₂ films, organic SOG film, PSG film, BPSG film, BSG
It is suitable for polishing a film, a Si ₃ N ₄ film, a polysilazane film, etc., but is not limited to these.

Since the polishing composition of the present invention uses a compound having a reducing property as a polishing accelerator, it can be physically and efficiently polished while reducing the above various oxide films and the like.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

[0042]

【Example】

(Example 1) 3 kg of fumed silica ("Roleoseal CP-102"; manufactured by Tokuyama Soda Co., Ltd.) having a particle diameter of 0.005 to 0.05 µm was dispersed in 7 kg of pure water, and then an ultrasonic homogenizer (US-150T) was used. Irradiation was carried out at 200 g / 5 min using Nippon Seiki Seisakusho Co., Ltd. to prepare an abrasive dispersion having a concentration of 30% by weight.

Then, a 10 wt% aqueous potassium hydroxide solution was added to the above dispersion to adjust the pH to 10, and this was used as a silica dispersion stock solution.

Then, potassium nitrite as a reducing agent 8.
A solution prepared by dissolving 5 g in 2 kg of pure water was mixed while stirring 2 kg of the above silica dispersion stock solution, and the above potassium hydroxide aqueous solution and pure water were added, and dilution and pH adjustment were repeated until pH = 10.5. , Abrasive particle concentration 12
5 kg of a polishing composition of wt% was prepared.

After completion of the preparation, the product filtered by a cartridge type filter having a pore size of 2 μm was used for evaluation. At this time, the content of the reducing agent was 0.02 mol / kg.

A CZ-P type silicon wafer was thermally oxidized to form a silicon oxide film having a thickness of 1 μm, which was used as an object to be polished.

Hard urethane foam ("Chemomet-I"; manufactured by Buehler) was used on a polishing platen (pad), and the above polishing composition prepared was dropped at a constant rate of 50 ml / min and polished for 2 minutes. I went. Relative linear velocity between the object to be polished and the pad 48 m / min, polishing pressure 150 g / c
Polishing was performed under the condition of m ² .

After the completion of polishing, the surface of the substrate was washed with pure water, and the polishing rate and the properties of the oxide film surface were evaluated according to the following criteria. Table 1 shows the results.

[Polishing rate] From the difference in the thickness of the oxide film before and after polishing, the amount of polishing per minute was expressed as the polishing rate. The film thickness of the oxide film was measured using an optical film thickness meter (Nanospec; manufactured by Nanometric Co., Ltd.) based on the measurement result of the refractive index of the oxide film surface by an ellipsometer.

[Properties of oxide film surface] A scratch, orange peel and cloudiness of the oxide film surface after polishing were visually observed using a differential interference microscope. The thing was marked as x.

(Examples 2 to 10) Except that the type and content of the reducing agent and amino acid were changed as shown in Table 1,
The test was conducted in the same manner as in Example 1. Table 1 shows the results.

Comparative Example 1 A test was conducted in the same manner as in Example 1 except that no reducing agent was used. Table 1 shows the results.

[0053]

[Table 1] (Examples 11 to 20) As Example 1 except that ammonia was used as the pH adjuster instead of the above potassium hydroxide, and the type and content of the reducing agent were changed as shown in Table 2. Was tested. Table 2 shows the results.

Comparative Example 2 A test was conducted in the same manner as in Example 11 except that no reducing agent was used. Table 2 shows the results
Shown in

[0055]

[Table 2] Example 21 Particle size 0.01 to 0.02 μm, pH =
Silica sol with 9.0 to 10.5 and abrasive particle concentration of 30% by weight (“Adelite AT-30”; Asahi Denka Co., Ltd.)
1.33 kg of potassium nitrite as a reducing agent and 3 g of D, L-glutamic acid were dissolved in pure water in advance, and the mixture was further stirred into a solution adjusted to pH = 10 with a 10 wt% potassium hydroxide aqueous solution. Mixed.

Thereafter, the total weight is 1.9 kg and pH = 1.
The above potassium hydroxide aqueous solution and pure water were added to adjust the concentration to 0.3.

After stirring for another hour, the total weight was 2
The mixture was diluted to kg to prepare a polishing composition having a pH of 10.3 and an abrasive fine particle concentration of 20% by weight. At this time, the total content of the reducing agent and the amino acid is 0.04 mol / kg.
Met.

A coating liquid for forming an insulating film (OCD TYPE-10; manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied onto a silicon wafer and baked at 400 ° C. for 30 minutes in an N ₂ atmosphere to form an oxide film. This was used as the object to be polished.

Subsequent operations and tests were carried out in the same manner as in Example 1. Table 3 shows the evaluation results.

(Examples 22 to 26) Tests were carried out in the same manner as in Example 1 except that the types and contents of reducing agents and amino acids were changed as shown in Table 3. Table 3 shows the results.

(Comparative Example 3) A test was conducted in the same manner as in Example 21 except that the reducing agent and the amino acid were not used. Table 3 shows the results.

[0062]

[Table 3] (Example 27) Cerium oxide having a particle size of 0.7 μm (“Luminox E101”; manufactured by Seimi Chemical Co., Ltd.) 1k
g to 3 kg of pure water, and then a high-speed stirring homomixer (“TK homomixer 16A”; Tokushu Kikai Kogyo Co., Ltd.)
Manufactured by K.K.) for 20 minutes at 6000 rpm.

Then, a solution prepared by dissolving 21.3 g of potassium nitrite in 100 g of pure water was added, and further 10% by weight was added.
PH of 1 by adding aqueous potassium hydroxide solution and pure water
0.0, Abrasive fine particle concentration 20% by weight, polishing composition 5
kg was prepared. At this time, the content of the reducing agent was 0.05 mol / kg.

Subsequent operations and tests were carried out in the same manner as in Example 1. Table 4 shows the results.

Example 28 A test was conducted in the same manner as in Example 27, except that the types and contents of reducing agent and amino acid were changed as shown in Table 4. Table 4 shows the results.

Comparative Example 4 A test was conducted in the same manner as in Example 27 except that no reducing agent was used. Table 4 shows the results
Shown in

[0067]

[Table 4] As is clear from Tables 1 to 4, when a reducing agent is added, the polishing rate and surface properties are excellent, and especially when a mixed system of an inorganic reducing agent and another reducing agent is used, the reducing agent is added. The polishing rate was improved as compared with the case where it was not performed, and in some cases, the effect was more than doubled.

[0068]

As described in detail above, according to the present invention, by adding a reducing compound to an alkaline aqueous solution in which fine abrasive particles are dispersed, a covering material such as an interlayer insulating film formed on a semiconductor substrate can be obtained. The polishing can be efficiently performed without damaging the properties of the polishing surface of the polishing body.

Claims (19)

[Claims] 1. A polishing composition comprising abrasive fine particles and a reducing compound as a polishing accelerator in an aqueous solution whose pH is adjusted to the alkaline side. 2. The reducing compound is at least one selected from an inorganic reducing agent, an aldehyde reducing agent, a hydroxyphenyl reducing agent, and an amine reducing agent.
The polishing composition according to claim 1, which is a seed. 3. The reducing compound is at least one selected from an inorganic reducing agent, an aldehyde reducing agent, a hydroxyphenyl reducing agent, and an amine reducing agent.
The polishing composition according to claim 2, which is a mixture with a seed. 4. At least one selected from an aldehyde-based reducing agent, a hydroxyphenyl-based reducing agent and an amine-based reducing agent is used in an amount of 0.1 to 1 with respect to 1 mol of an inorganic reducing agent.
The polishing composition according to claim 3, which is blended at a ratio of 0 mol. 5. The inorganic reducing agent according to claim 2, wherein the inorganic reducing agent is at least one selected from sulfurous acid, nitrous acid and phosphorous acid, or an alkali metal salt or ammonium salt thereof. Polishing composition. 6. The polishing composition according to claim 2, wherein the aldehyde-based reducing agent is glutaraldehyde. 7. The hydroxyphenyl reducing agent is hydroquinone, N- (p-hydroxyphenyl) glycine, or 4,
-Aminophenol, 2,4-diaminophenol, catechol and at least one selected from p-methylaminophenol sulfate.
4. The polishing composition according to any one of 4 above. 8. The polishing composition according to claim 2, wherein the amine-based reducing agent is 1-phenyl-3-pyrazolidone. 9. The polishing composition according to claim 1, wherein the compound having a reducing property is blended in a proportion of 0.001 to 0.5 mol with respect to 1 kg of the polishing composition. Stuff. 10. The abrasive fine particles have a particle size of 0.01 to 5 μm.
The polishing composition according to any one of claims 1 to 9, which is m. 11. A potassium hydroxide is used to add p to the alkali side.
The polishing solution according to any one of claims 1 to 5, 7, 9 and 10, wherein the H-adjusted aqueous solution contains a mixture of an alkali metal salt of nitrous acid and hydroquinone as a reducing compound. Composition. 12. Ammonium sulfite as a reducing compound, catechol, 4-aminophenol, 2,4-diaminophenol, and N- (p-hydroxyphenyl) in an aqueous solution whose pH is adjusted to the alkaline side with ammonia. ) Glycine and at least one selected from the group consisting of 1 to 5, 7, 9 to 10.
The polishing composition according to any one of 1. 13. A mixture of ammonium sulfite and 1-phenyl-3-pyrazolidone as a reducing compound in an aqueous solution whose pH has been adjusted to the alkaline side with ammonia. 10. The polishing composition according to any one of 10 to 10. 14. The polishing composition according to claim 1, which further contains an amino acid. 15. The polishing composition according to claim 14, wherein the amino acid is at least one selected from β-alanine, threonine and D, L-glutamic acid. 16. An amino acid is blended in a proportion of 0.001 to 0.5 mol with respect to 1 kg of a polishing composition,
The polishing composition according to claim 14 or 15. 17. A mole of a compound having a reducing property,
Amino acids are mixed in a ratio of 0.1 to 10 mol,
The polishing composition according to any one of claims 14 to 16. 18. A potassium hydroxide is added to the alkali side with potassium hydroxide.
The H-adjusted aqueous solution contains an alkali metal salt of nitrous acid as a compound having a reducing property.
18. The polishing composition according to any one of 17. 19. A polishing method of polishing a silicon or silicon oxide film formed on a semiconductor substrate using the polishing composition according to claim 1.