WO2007135794A1

WO2007135794A1 - Slurry for chemical mechanical polishing, method of chemical mechanical polishing and process for manufacturing electronic device

Info

Publication number: WO2007135794A1
Application number: PCT/JP2007/053629
Authority: WO
Inventors: Ryo Ota; Takayuki Nakakawaji; Toranosuke Ashizawa; Naoyuki Koyama
Original assignee: Hitachi Chemical Company, Ltd.
Priority date: 2006-05-19
Filing date: 2007-02-27
Publication date: 2007-11-29
Also published as: US20070270085A1; TW200743666A

Abstract

A slurry for chemical mechanical polishing that in the CMP step of semiconductor device, not only attains low scratch on a surface to be polished of SiO2 film, etc. but also realizes high polishing velocity to thereby achieve high processing efficiency; a method of chemical mechanical polishing by the use of the slurry; and a process for manufacturing an electronic device by the use of the method. There is provided a slurry for chemical mechanical polishing comprising abrasive grains and water, wherein the abrasive grains consist of ceria particle coated composite grains each composed of an organic base grain and ceria particles, and wherein the composite grains exhibit a negative zeta potential. Further, there are provided slurries wherein the abrasive grains consist of ceria particle coated composite grains each composed of a carboxylated polymethyl methacrylate grain and ceria particles, and wherein a planarizing additive is mixed, and wherein the planarizing additive is ammonium poly(meth)acrylate.

Description

Specification

Chemical mechanical polishing slurry, chemical mechanical polishing method, and electronic device manufacturing method

Technical field

[0001] The present invention relates to a CMP slurry used in a chemical mechanical polishing (CMP) process indispensable for a shallow trench isolation (STI) method applied to a semiconductor device manufacturing process, and a process using the slurry. The present invention relates to a mechanical polishing method and a method for manufacturing an electronic device using the method, and enables both low scratching property of the object to be polished and high processing efficiency by high-speed polishing. This also enables high flatness of the workpiece surface.

Background art

[0002] With the recent miniaturization of semiconductor devices and multilayer wiring !, the element isolation method has been developed from LOCOS (Local Oxidation of Silicon) technology, which removes the nitride film by oxidizing part of the silicon surface. The situation is shifting to STI technology that enables integration. In this STI technology, a nitride film mask is formed on a substrate by patterning, then a trench is formed, an interlayer insulating film of oxide silicon (SiO 2) is formed thereon, and an upper surface is formed in a chemical mechanical polishing process. Structure

2

This is a method of manufacturing an electronic device (semiconductor element) that undergoes a step of polishing and removing the remaining nitride film. Chemical mechanical polishing (hereinafter abbreviated as “CMP”) is one of the main processes of this STI technology and contributes greatly to the manufacture of electronic devices (semiconductor elements). Not only processing efficiency and flatness of the surface to be processed, but also polishing selectivity of different materials, slurry cleaning properties, ease of handling, etc. are required. The slurry used for CMP is generally the same as mechanical polishing with silica (SiO 2), in which colloidal silica or fumed silica particles are dispersed in an alkali-based solution.

2

Forces that sometimes polish using chemical etching effects There are many problems with the flatness of the work surface, scratch properties, and management of the end point of polishing. In contrast, ceria (oxy-cerium CeO) abrasive grains have excellent polishing ability for silicon oxide films.

2

Does not require an etching action with an alkaline solvent. There are many advantages such as tightness and particle size distribution that are not strictly controlled.

[0003] In the manufacturing process of the most advanced semiconductor devices, there is a tendency to reduce the size of the barrels used in the polishing process under a situation where further low scratch properties are required, which decreases the polishing efficiency. The problem arises. As one method for improving this, a method using composite particles as abrasive grains for CMP slurry has been proposed. This is because it is difficult to generate scratches on organic mother particles rich in elasticity. By combining finely divided inorganic particles (inorganic particle coated composite particles), it is possible to obtain low scratch properties and increase contact stress. It should be possible to maintain a sufficient polishing rate as possible.

[0004] General inorganic particle-coated composite particles are produced using a wet composite method as disclosed in Patent Document 1. In this method, the pH of an aqueous dispersion containing organic particles and inorganic particles is adjusted so that the zeta potential of the organic particles and the zeta potential of the inorganic particles are opposite to each other. This is a method for producing composite particles by electrostatic adhesion. Since the abrasive grains produced by this method are electrostatically combined, the inorganic particles fall off during the polishing process when the adhesion strength of the inorganic particles to the organic particles is weak, and a sufficient polishing rate cannot be maintained. There is a problem. Furthermore, if an additive intended to flatten the surface to be carburized by polishing (hereinafter referred to as “flattening additive”) is blended, the electrostatic action between the particles is weakened and the composite iron is removed. There is also a problem. On the other hand, a method using a mixture of organic particles and inorganic particles as an abrasive grain has also been proposed, but the organic particles are complex so that they act as hindering polishing, thereby obtaining a sufficient polishing rate. There was a problem that I couldn't!

[0005] A common ceria-based slurry used in STI-CMP is known to contain a leveling additive. As this leveling additive, a water-based high-molecular compound is used. However, it is preferred because it has less adhesion to the material to be polished and piping. By blending the planarizing additive, the polishing selectivity between the silicon oxide film and the silicon nitride film as the polishing stagger film is increased, and the flatness and uniformity of the work surface to be polished can be obtained. On the other hand, there is also a problem that the polishing rate decreases because the flattening additive has a protective action against polishing.

[0006] In order to produce inorganic particle-coated composite particles, in addition to the electrostatic composite method, There is a method of manufacturing by applying mechanical energy. In this method, a composite particle is produced by locally and intermittently melting the surface layer of a particle using a pressing force, a shearing force, and a frictional force. The inorganic particle-coated composite particles produced by this method have high adhesion strength between the particles, so that the inorganic particles are not detached by shearing force or contact stress during polishing, and a planarizing additive is not used. Even when blended, the inorganic particles are not detached by electrostatic action. However, this method has a problem in that the V selectivity and the polishing selectivity are not developed at all when the planarizing additive is not blended, and when the planarizing additive is blended, the polishing rate is greatly reduced.

Patent Document 1: JP 2001-152135 A

Disclosure of the invention

In view of the above, the present invention obtains a low scratch property of the surface to be polished to be polished in the CMP process, realizes a high polishing rate and enables a high processing efficiency, and further improves the processing surface. An object of the present invention is to provide a chemical mechanical polishing slurry capable of obtaining flatness, a mechanical mechanical polishing method using the slurry, and an electronic device manufacturing method using the method.

[0008] The organic mother particles constituting the composite particles of the abrasive grains (A) according to the present invention include polymethyl methacrylate (PMMA) particles into which carboxyl groups or sulfonyl groups have been introduced to make the zeta potential negative. , Polystyrene particles, and copolymer particles thereof. In addition, since the organic mother particles according to the present invention require a certain heat resistant temperature and hardness, crosslinked organic mother particles are preferable. Therefore, for example, monodisperse particles produced by a production method such as a soap-free emulsion polymerization method or a dispersion polymerization method are more preferred. The particle size of the organic mother particles is required to be 0.3 to LO / z m. The reason for this is that if the particle size of the organic mother particles does not reach 0.3 μm, problems such as a significant decrease in the polishing rate, which makes it difficult to combine with the inorganic particles, occur. If the diameter exceeds 10 m, the dispersion state of the slurry becomes very bad, and there is also a problem that it is not possible to supply a slurry having a uniform particle size to the polished surface. The particle diameter of the organic mother particles is most preferably in the range of 1 to 7111.

[0009] The inorganic particles constituting the composite particles used in the abrasive grains (A) according to the present invention include cerium oxide (CeO), manganese trioxide (MnO), cerium hydroxide (Ce (OH)). Raised

2 2 3 4 The strength of ceria particles, which are cerium oxide, have the ability to polish silicon oxide films. STI—CMP process staggered silicon nitride (Si N) film and silicon nitride

3 4

Polishing selectivity (SiO 2 / Si N polishing rate ratio) of the base film is easily obtained by the flattening additive

2 3 4

It has the following features. The inorganic particles according to the present invention have an average particle size in the range of 10 to 500 nm. The reason is that if the average particle size of the inorganic particles does not reach 10 nm, the polishing speed decreases, and if the average particle size of the inorganic particles exceeds 500 nm, scratches on the object to be polished will occur. This is because there arises a problem that the property becomes large. There are a gas phase method, a liquid phase method, and the like as methods for producing inorganic particles, but since the composite particles according to the present invention are produced by a dry composite method, the inorganic particles according to the present invention are produced. In consideration of the properties and the like, it is preferable to use particles that can also generate a gas phase method. Further, since the surface coverage of the organic mother particles by the inorganic particles is higher as the rate is higher, the surface coverage according to the present invention is preferably 20% or more.

[0010] In the chemical mechanical polishing slurry composed of the composite particles used for the abrasive grains (A) according to the present invention and water (B), the composite particles (gunlets) are in contact with water (B). The concentration should be 2 to 10% by weight. The reason is that if the numerical value does not reach 0.2% by weight, a sufficient polishing speed cannot be obtained, and if it exceeds 10% by weight, the dispersion state of the slurry becomes very bad. This is because. A slurry in which the numerical value is 0.5 to 5% by weight is more preferable.

[0011] The flatness additive (C) according to the present invention is adsorbed on the inorganic insulating film when the CMP slurry comes into contact with the inorganic insulating film to be polished, for example, the silicon oxide film or the silicon nitride film. For example, a water-soluble polymer or a surfactant is preferably used, but the slurry for CMP is a silicon oxide film or silicon nitride to be polished. A material that adsorbs to the film when it contacts the film and desorbs from the film due to an increase in polishing surface pressure is preferable. Examples of such flattening additives (C) include poly (meth) acrylic acid, poly (meth) acrylic acid derivatives, poly (meth) acrylic acid ammonium salt, polybutyropyrrolidone, poly (bi) acetal. , Polyvinyl formal, polyvinyl butyral, polyvinyl pyrrolidone iodine complex, polybule (5-methyl-2 pyrrolidinone), polybule (2 piberidinone), polyvinyl (3, 3, 5 trimethyl 2 pyrrolidinone), poly (N bullcarbazole), poly (N— Alkyl-pyrcarbazole), poly (N-alkyl 3-vinylcarba) Sol), poly (N-alkyl-4 bulcarbazole), poly (N beluo 3, 6- dib mouth mocarbazole), polybureol ketone, polyburacetophenone, poly (4 bulupyridine), poly (4 β -Hydroxyethylpyridine), poly (2 butylpyridine), poly (2-j8-bulupyridine), poly (4 butylpyridine), poly (4-hydroxyethylpyridine), poly (4-butylpyridinum salt), poly (Α-methylstyrene mono-co-4-vinylpyridyl-dihydrochloride), poly (1- (3-sulfol) 2-burpyridyl-umbetaine co-p-potassium styrene sulphonate ), Poly (N vinylinoremidazolene), poly (4-bulimidazole), poly (5-bulimidazole), poly (1bule 4-methyloxazolidinone), polybulucate Amides, polybutymethylacetamide, polybutylucacetamide, polybutel-fulacetamide, polybutymethylpropionamide, polybutyrylpropionamide, polybutymethylisobutyramide, polybutymethylbenzylamide, polybutal alcohol, polybutal alcohol derivatives , Polyacrylene, polyacrylonitrile, poly (vinyl acetate), poly (butyrate acetate-co-methyl methacrylate), poly (butyrate acetate-co-pyrrolidine), poly (butyrate acetate-coacetonitrile), poly (butyrate acetate co-N, N (diallyl cyanide), poly (butyl acetate co-N, N diallylamine), poly (vinyl acetate co ethylene) and the like.

The upper limit of the weight of the flat wrinkle additive is preferably 500 or more, but it is preferably 1 million or less in view of solubility. As the surfactant, a nonionic surfactant and an anionic surfactant can be mentioned, but it is preferable to use a surfactant that does not contain alkali metal. Among these surfactants, in particular, polyethylene glycol type nonionic surfactants, glycols, glycerin fatty acid esters, sorbit fatty acid esters, fatty acid alcohol amides, alcohol sulfate salts, alkyl ether sulfate salts And at least one selected from alkylbenzene sulfonate and alkyl phosphate ester. The addition amount of the planarizing additive is preferably in the range of 0.05 to 5% by weight with respect to 100 parts by weight of the slurry for CMP. The reason is that if the addition amount of the planarization additive is less than the lower limit than this range, the effect of addition may not appear, and if it exceeds the upper limit, the polishing rate may decrease. [0013] A dispersant, a pH adjuster, and the like may be added to the chemical mechanical polishing slurry according to the present invention. The dispersant needs to be selected depending on the inorganic particles constituting the organic particles. For example, in the case where cerium oxide is used as the inorganic particles, a polyacrylic acid ammonium salt or a copolymer component is used. A polymer dispersant containing an acrylic acid ammonium salt is preferred. Other dispersants include triethanolamine lauryl sulfate, ammonium lauryl sulfate, polyoxyethylene alkyl ether triethanolamine sulfate, special polycarboxylic acid type polymer, polyoxyethylene lauryl ether, polyoxyethylene cetyl ether. , Polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene higher alcohol ether, polyoxyethylene octylphenol ether, polyoxyethylene nonylphenyl ether, polyoxyalkylene alkyl ether, polyoxyethylene Derivatives, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sol Vitan tristearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbite tetraoleate, polyethylene glycol nore monolaurate, polyethylene glycol nore monostearate, polyethylene glyconorestearate, polyethylene glycol Noremo noreate, polyoxyethylene alkylamine, polyoxyethylene hydrogenated castor oil, alkyl aranol amide, polybutylpyrrolidone, coconutamine acetate, stearylamine acetate, laurylbetaine, stearylbetaine, lauryldimethylamine Xoxide, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolium methine and the like.

[0014] The amount of the above-mentioned dispersant added is determined based on the dispersibility of particles in the slurry for CMP and sedimentation prevention, and in addition to the relationship between polishing scratches and the amount of dispersant added, ceria particles (acid cerium particles) 100 The amount is preferably in the range of 0.01 to 2.0 parts by weight with respect to parts by weight. The molecular weight of the dispersant is preferably in the range of 100-50,000, and more preferably in the range of 1,000,000 to 10,000. The reason is that if the molecular weight of the dispersing agent is less than 100, a sufficient polishing rate may not be obtained when polishing the silicon oxide film or the silicon nitride film, while the molecular weight of the dispersing agent is 50 , Over 000 In some cases, the viscosity increases and the storage stability of the CMP slurry may decrease.

[0015] The slurry for chemical mechanical polishing according to the present invention uses a composite particle having a negative zeta potential for the abrasive grains, thereby increasing the polishing rate even when the flattening additive (C) is not blended. It is possible to maintain high speed and to obtain sufficient polishing selectivity for obtaining flatness of the work surface. In addition, the slurry for chemical mechanical polishing according to the present invention can be obtained by adding the flattening additive (C) when the zeta potential of the composite particle abrasive grains is positive even when the flattening additive (C) is blended. When the adsorbed amount increases, the polishing rate decreases significantly. By using composite particles with a negative zeta potential for the abrasive grains, the adsorbed amount of the leveling additive (C) is suppressed and a high polishing rate is achieved. And sufficient polishing selectivity can be obtained.

The chemical mechanical polishing slurry, the mechanical mechanical polishing method using the slurry, and the electronic device manufacturing method using the method according to the present invention include abrasive grains (A), water (B), In the slurry for chemical mechanical polishing comprising the abrasive grains (A), the abrasive grains (A) are made of ceria particle-coated composite particles of organic mother particles and ceria particles, and the composite grains have a zeta potential of a negative potential (A ), It is possible to obtain a low scratch property of the surface to be polished in the CMP process and to obtain a high processing efficiency based on a high-speed polishing process.

[0017] Further, the chemical mechanical polishing slurry, the mechanical mechanical polishing method using the slurry, and the electronic device manufacturing method using the method according to the present invention are flat on the chemical mechanical polishing slurry. In addition to the above effect, the addition of the additive (C) also has an effect that the flatness of the work surface to be polished can be obtained.

Brief Description of Drawings

FIG. 1 is a schematic cross-sectional view of an inorganic particle-coated composite particle according to the present invention.

FIG. 2 is a schematic cross-sectional view of polishing using composite particles.

Explanation of symbols

[0019] 1 ... ceria particles, 2 ... organic mother particles, 3 ... composite particles, 4 "slurry, 5-Si wafer, 6 ... pad.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, examples of the present invention will be described in detail, but the present invention is not limited to the examples. As a method for producing dry composite particles of organic mother particles and inorganic particles, there are, for example, a composite method using a mechano-fusion system manufactured by Hosoka Micron Corporation and a hybridization system manufactured by Nara Machinery Co., Ltd. These composite methods are technologies that produce composite particles by mechanically bonding them at a molecular level by applying frictional pressure and shearing force based on mechanical energy to multiple different material particles. . These methods are characterized by a simple process and a high degree of freedom in combination as compared with a method for producing wet composite particles.

Next, a polishing test method performed for confirming the operation and effect of the example according to the present invention will be described. The polishing test is to measure the polishing rate for silicon dioxide (SiO 2) film using a polishing device (IMRTECH10DVT) manufactured by Engis Co., Ltd.

2

m) A polishing pad (IC1000 / Suba400 manufactured by Yutta Noose Co., Ltd.) is pasted on the top, and the same pad is also pasted on the bottom of the guide ring. Set the silicon dioxide silicate film wafer of the workpiece to be polished on the bottom of the polishing weight, place it on the polishing pad in the guide ring, and guide ring and polish by frictional resistance of the contact surface as the surface plate rotates Polishing is performed by rotating the weight in the same direction as the rotation of the surface plate. The polishing load was adjusted by the number of polishing weights, the load was 30 kPa, the number of rotations of the surface plate was 150 / min, and the polishing time was 2 minutes. During polishing, the slurry was continuously dripped (15 ml / min) with a tube pump and supplied. The polished silicon dioxide silicon wafer was subjected to ultrasonic cleaning with pure water for 10 minutes and dried. The film thickness of the silicon dioxide film was measured by measuring the difference in film thickness before and after polishing using an optical interference type film thickness measuring device and calculating the polishing rate.

[Examples 1 to 3]

Examples 1 to 3 of the slurry for chemical mechanical polishing according to the present invention are all made of polymethyl methacrylate (PMMA) monodisperse particles (5) as organic mother particles and ceria (CeO) particles as inorganic particles.

The composite particles are produced so that the zeta potential of the composite particles becomes a negative potential by using composite particle abrasive particles obtained by combining double particles (14 nm) by the dry composite particle manufacturing method. The zeta potential of the produced composite particle abrasive grains is difficult to measure for high-concentration slurry, large-diameter particles, composite particles, etc. with the ordinary laser Doppler method. This was measured using ESA-9800 manufactured by Matec Applied Sciences. composite The zeta potential of the particles was −40 mV in Example 1, −20 mV in Example 2, and 5 mV in Example 3. The slurries of these examples are obtained by introducing the carboxyl group into the organic mother particles and changing the concentration to obtain the negative potential composite particles in which the zeta potential is adjusted. The above polishing test was carried out at an abrasive concentration (weight ratio of abrasive grains to water) of 1% by weight. In order to investigate the polishing selectivity of the workpiece to be polished, SiO

2 In addition to the film weno, a Si N film wafer is taken up as a polishing stagger film, and the polishing rate ratio

3 4

A comparison was made. Measurement items are polishing rate and polishing selectivity (Polishing rate of SiO film and Si N film)

2 3 4

Ratio).

[0023] Comparative Examples 1 and 2 were prepared using conventional polymethyl methacrylate to obtain positive-potential composite particles.

(PMMA) monodisperse particles and composite particles in which hydroxyl groups are introduced into PMMA monodisperse particles. Comparative Example 3 is a single nanoceria used as an inorganic particle for comparison of polishing rate.

Table 1 shows the evaluation results of the chemical mechanical polishing slurries of Examples 1 to 3 and Comparative Examples 1 to 3.

[table 1]

As shown in Table 1, the chemical mechanical polishing slurries of Examples 1 to 3 have excellent polishing ability with a very high SiO film polishing rate as compared with the nano-ceramic alone of Comparative Example 3.

2

In addition, when the absolute value of the negative zeta potential of the composite particles was further increased, the polishing selectivity was increased. In Comparative Examples 1 and 2, since the zeta potential of the composite particles is positive, the polishing rate is very fast, but the polishing selectivity cannot be obtained. [0026] In Examples 1 to 3, since the zeta potential of the composite particles is set to a negative potential, a force group using a PMMA introduced with a carboxyl group as an organic mother particle has a sulfo group or You may use the organic mother particle which introduce | transduced the other functional group which becomes a negative potential. Further, the same effect can be obtained by using organic mother particles obtained by introducing functional groups into force polystyrene particles using PMMA as a base material for the organic mother particles of Examples 1 to 3. In Examples 1 to 3, the dry composite particles described above were used. However, even when wet composite particles obtained by heteroaggregation were used, higher speed polishing was possible, and a large polishing selectivity was obtained. I helped. In the present specification, for convenience, the barrel used in the examples is described as if it was a composite particle alone. However, in the dry composite particle manufacturing method, it is not 100% composite, so it is actually composite. This includes nanoceria that has not been treated. If the surface coverage of the composite particles is the same, the higher the amount of non-composited nanoceria, the higher the polishing rate of the SiO film.

2

Tend to be faster. Therefore, the same effect can be obtained even with a slurry that uses nanoceria-encapsulated particles. In this example, the SiO film that is the workpiece to be polished

2

, A thermal oxide film using HDP—TEOS (High Density Plasma-Tetra Ethoxy Silane), which has a gettering action by lowering the softening temperature, and an oxide silicon film such as 03—TEOS, SOG (Spin on Glass), etc. It can also be used.

[Examples 4 to 7]

[0027] Next, the relationship between the abrasive concentration of the composite particles and the polishing rate in the chemical mechanical polishing slurry was evaluated. The polishing test was performed under the same conditions as in Examples 1 to 3. The slurry for chemical mechanical polishing of Examples 4 to 7 is a composite particle abrasive of PMMA monodispersed particles (5), inorganic particles and CeO particles (14 nm) used in Example 2, and has a zeta potential. -20mV

2

The thing of was used. The barrel concentration, which is the weight ratio of the barrel to water, was 0.2% by weight in Example 4, 1.5% by weight in Example 5, 5% by weight in Example 6, and 10% by weight in Example 7. did.

[0028] Comparative Examples 4 and 5 both use the composite particles of the granule used in Example 2, but Comparative Example 4 has an abrasive concentration of 0. 1% by weight, and Comparative Example 5 was also 20% by weight, and the same polishing test as in Examples 1 to 3 was performed. The evaluation results of Examples 4 to 7 and Comparative Examples 4 and 5 are shown in Table 2.

[0029] As shown in Table 2, each of the chemical mechanical polishing slurries of Examples 4 to 7 has an excellent polishing ability that the SiO film polishing rate is very high as compared with Comparative Example 4. On the other hand, abrasive

2

In Comparative Example 4 having a grain concentration of 0.1% by weight, the polishing rate is greatly reduced, and a practically sufficient polishing rate cannot be obtained. In addition, Comparative Example 5 with the 20% by weight of the granule concentration is almost saturated with no difference in polishing rate as compared with Example 7 having the 10% by weight of the barrel density. Further, although Comparative Example 5 is not described in the table, it has been found that the dispersion state of the barrel is very bad.

[Example 8 11]

[0030] Next, in the chemical mechanical polishing slurry, the relationship between the abrasive grain size and the polishing rate of the composite particles. Evaluate the clerk. The polishing test was performed under the same conditions as described above. The slurry for chemical mechanical polishing of Examples 8 to 11 is composed of PMMA monodispersed particles as organic matrix particles and CeO particles (as inorganic particles) (

2

The average particle diameter of the PMMA monodispersed particles used as the organic mother particles is 0 in Example 8.

In Example 9, 1.5 m, in Example 10, 5 μm, and in Example 11, 10 μm. Since the average particle size of the inorganic particles is 14 nm, which is sufficiently smaller than the mother particle, the average particle size of the above-mentioned PMMA monodispersed particles should be the average particle size of the composite particles that are abrasive grains as they are. Can do. Since PMMA has a carboxyl group introduced, the produced composite particles have a negative zeta potential. In addition to the polishing rate, the scratches on the polished wafer were observed.

[0031] Comparative Examples 6 and 7 use composite particle abrasive grains of PMMA monodisperse particles as organic mother particles and Ce02 particles (14 nm) as inorganic particles, the abrasive concentration is 1% by weight, and the zeta of the composite particles. The negative potential was the same as in Examples 8 to 11. However, the particle size of the PMMA monodispersed particles of the organic mother particles, that is, the particle size of the composite particles was 0.15 m in Comparative Example 6. In Comparative Example 7, it is 20 μm.

[0032] Table 3 shows the evaluation results of Examples 8 to 11 and Comparative Examples 6 and 7, which were carried out under the same conditions as the polishing test method described above.

[Table 3]

As Table 3 shows, the slurry for chemical mechanical polishing in Examples 8 to 11 is the polishing rate of the SiO film.

2

The wafer was extremely fast, and the polished wafer was not damaged and showed excellent performance. In Example 9 where the average particle size of the composite particles was 1.5 m, the fastest polishing rate was obtained. On the other hand, in Comparative Example 6 in which the average particle size of the composite particles was 0.15 m, the polishing rate was greatly reduced, and it was difficult to obtain a sufficient polishing rate. Further, in Comparative Example 7 in which the average particle size of the composite particles was 20 m, a sufficient polishing rate was obtained, but many scratches were observed on the polished work surface, and the dispersion state of the slurry was very bad. . In the dry composite particle manufacturing method, it is not easy to composite when the average particle size of the organic mother particle is less than m: 1 Most preferred is about ~ 7 / ζ πι. The average particle size of composite particle abrasive grains is largely related to the type of polishing pad, especially the pattern of the polishing pad made of porous urethane resin and its surface roughness, so it is suitable for the polishing pad used. It is necessary to select the diameter.

[Examples 12 to 14]

Here, the slurry for chemical mechanical polishing to which the leveling additive is added is evaluated. In Examples 12 to 14, each of the chemical mechanical polishing slurries of Examples 1 to 3 is blended with poly (meth) acrylic acid ammonium salt as a planarizing additive. The amount thereof for water 0.3 wt ^_0/0, Roita value of the slurry is 5 with ammonia, the abrasive concentration is the weight ratio cannon particle of water 1. obtained by a 0% Yes, the zeta potential before compounding the leveling additive is −40 mV in Example 12, −20 mV in Example 13 and 5 mV in Example 14.

[0035] Comparative Example 8 to LO: The slurry of Comparative Examples 1 to 3 is blended with poly (meth) acrylate ammonium salt as a planarizing additive. The blending amount is 0.3% by weight with respect to water, the pH value of the slurry is 5 with ammonia, and the barrel concentration, which is the weight ratio of the barrel to water, is 1.0% by weight. .

[0036] Table 4 shows the evaluation results of Examples 12 to 14 and Comparative Examples 8 to 10 which were carried out under the same conditions as the polishing test method described above.

[Table 4]

As shown in Table 4, each of the chemical mechanical polishing slurries of Examples 12 to 14 has excellent polishing ability with a very high polishing rate of the SiO film compared to Nanoceria alone of Comparative Example 10.

2

Have power. Comparative Examples 8 and 9 used composite particles having a positive zeta potential. However, if a leveling additive having a protective action for polishing is blended, the polishing rate is greatly reduced. On the other hand, the chemical mechanical polishing slurries of Examples 12 to 14 using composite particles having a negative zeta potential showed a significant speed although a slight decrease in the polishing rate was observed even when a planarizing additive was added. There is no decrease, and polishing selectivity can be maintained.

[0038] In Examples 12 to 14, since the zeta potential of the composite particles is set to a negative potential, the sulfonyl group becomes a negative potential in the functional group using the organic mother particles in which a carboxyl group is introduced into PMMA. Organic mother particles into which other functional groups are introduced may be used. In addition, the same effect can be obtained by using organic mother particles in which a functional group is introduced into force polystyrene particles using PMMA as a base material for the organic mother particles of Example 12 having a force of 14. In Examples 12 to 14, the pH value of the slurry containing the flat koji additive was set to 5. However, if the pH value is within the range of 4 to 8, the same results as in Examples 12 to 14 can be obtained. . The planarizing additive is not limited to poly (meth) acrylic acid ammonium salt, but is added to an inorganic insulating film such as a SiO film or a SiN film placed as a workpiece to be polished when blended. Adsorbed when contacted, polished surface

2 3 4

Any type that desorbs due to an increase in pressure may be used.

[Examples 15 to 18]

[0039] Here, the relationship between the abrasive concentration of the composite particles and the polishing rate in the slurry for mechanical mechanical polishing to which the flat additive is added is evaluated. Examples 15 to 18 are composite particles of PMMA monodispersed particles (5 μ) used in Examples 2 and 13 and inorganic particles with CeO particles (14 nm).

2

This is an oval granule with a zeta potential of 20 mV, and is blended with poly (meth) acrylic acid ammonium salt as a flattening additive. Its amount is 0.3 wt ^_0/0 in water, pH value of the slurry is obtained by a 5 with ammonia, the abrasive concentration indicating the weight ratio cannon particle of water, in Example 15 0.2% by weight, 1.0% in Example 16, 5% in Example 17, and 10% in Example 18.

[0040] Comparative Examples 11 and 12 both use the composite particles of the above-mentioned composite particles used in Examples 2 and 13, but the comparative example 11 has a particle concentration that is a weight ratio to water. 1% by weight and 20% by weight in Comparative Example 2.

[0041] For the above Examples 15 to 18 and Comparative Examples 11 and 12, the above-mentioned polishing test method Table 5 shows the results of evaluation conducted under the same conditions as the method.

[Table 5]

As Table 5 shows, each of the chemical mechanical polishing slurries of Examples 15 to 18 has an excellent polishing ability with a very high SiO film polishing rate as compared with Comparative Example 11. Abrasive grain concentration

2

If it is less than 0.2% by weight, as shown in Comparative Example 11, the polishing rate rapidly decreases, and a practically sufficient rate cannot be obtained. On the other hand, when the 氐氐 grain concentration is 20 wt% as in Comparative Example 12, the polishing rate is different from that in Comparative Example 12 where the abrasive concentration is 10 wt%. It is almost saturated without being seen. Further, in Comparative Example 12 in which the barrel concentration was 20% by weight, although not shown in the table, the dispersion state of the barrel was extremely deteriorated. In addition, according to the result of evaluating the average particle size of the abrasive grains of the composite particles with respect to the slurry containing the flattening additive, it was found that the average particle size of the composite particle granules did not reach 0.3 m. The polishing speed was greatly reduced, and it was difficult to obtain a practical polishing speed. Moreover, when the average particle size of the composite particles was 20 μm, the polishing rate was sufficient, but many scratches were observed, and the dispersion state of the slurry became very poor. From the above results, it was found that the average particle size of the composite particle can be in the range of 0.3 to 10 μm. Further, the type of polishing pad, especially the polishing pad made of porous urethane resin Depending on the pattern and surface roughness, it is preferable to select a slurry for mechanical mechanical polishing using abrasive grains of composite particles having an optimum particle size that matches this.

[Examples 19 to 22]

[0043] Next, the relationship between the concentration of the leveling additive in the slurry for chemical mechanical polishing and the polishing selectivity was evaluated. To examine the polishing selectivity, polish the SiO film wafer to the workpiece to be polished.

2

The polishing rate was compared by taking a Si N film wafer as the stock film. Example 1

3 4

The slurry for chemical mechanical polishing used in 9-22 is a composite particle of PMMA monodispersed particles (5 μm) with zeta potential of −20 mV used in Example 13 and CeO particles (14 nm) on inorganic particles.

2

Using the abrasive grains, the abrasive concentration, which is the weight ratio of the abrasive grains to water, is set to 1.0% by weight, and poly (meth) acrylic acid ammonium salt added as a leveling agent is added. The pH value of the slurry is adjusted to 5 by using ammonia. However, regarding the leveling agent concentration, which is the ratio of poly (meth) acrylic acid ammonium salt as a leveling agent to water, 0.05% by weight in Example 19 and 0.3% by weight in Example 20 In Example 21, 1.0% by weight, and in Example 22, 5.0% by weight.

[0044] Comparative Examples 13 and 14 use the same composite particle abrasive as in Examples 19 to 22 with a leveling agent concentration of 1.0% by weight. The strength of the flattening agent concentration, which is the ratio of the poly (meth) acrylic acid ammonium salt as a leveling agent to water, is 0.001% by weight for Comparative Example 13 and 10% by weight for Comparative Example 14 The pH value of the slurry was adjusted to 5 with ammonia. [0045] Examples 19 to 22 and Comparative Examples 13 and 14 were carried out under the same conditions as in the above polishing test method for confirming the effects of the examples. Table 6 shows the results.

[Table 6]

[0046] As Table 6 shows, the chemical mechanical polishing slurries of Examples 19 to 22 were applied to the SiO film. Since the polishing rate for the SiN film, which is a staggered film with a very high polishing rate, is low.

3 4

Because of the high polishing selectivity, it was clear that high flatness was obtained in chemical mechanical polishing. On the other hand, Comparative Example 13 in which the leveling agent concentration is 0.01% by weight is the SiO film polishing rate.

2

Although the speed is very fast, it is sufficiently flat because it polishes even the SiN film, which is a staggered film.

3 4

There was a shortcoming that cannot be obtained. In Comparative Example 14 where the leveling agent concentration is 10% by weight, the polishing selectivity is large and excellent high flatness can be obtained.

2

It has also been found that when the process becomes very slow, there is a problem that the machining efficiency is greatly reduced.

[0047] From the results of the polishing test methods of the above examples, the chemical mechanical polishing slurry described in the claims of this application, the mechanical mechanical polishing method using the slurry, and the electron using the method The device manufacturing method has excellent polishing ability for SiO film and low scratch resistance.

2

An effect that sufficiently satisfies the polishing selectivity can be obtained. In this example, the power explained in connection with CMP in the STI method. The present invention is also used as an abrasive in a process that requires reduction of scratches such as CMP in an interlayer dielectric (ILD). Is also applicable.

Industrial applicability

[0048] The present invention can be applied to an abrasive used in a process in which scratch reduction is required in CMP (STI—CMP in addition to STI-CMP, etc.) in a semiconductor device which is an electronic device. .

Claims

The scope of the claims

[1] In the slurry for chemical mechanical polishing composed of the cannonball (A) and water (B), the cantilever (A) is made of ceria particle-coated composite particles of organic mother particles and ceria particles, A slurry for chemical mechanical polishing, wherein the composite particles have a negative zeta potential.

[2] The chemical mechanical polishing according to claim 1, wherein the organic mother particles in which a carboxyl group or a sulfonyl group is introduced are used for the organic mother particles constituting the ceria particle-coated composite particles. Slurry.

[3] In a slurry for chemical mechanical polishing composed of a cannonball (A) and water (B), a ceria particle-coated type comprising carboxyl group-introduced polymethyl methacrylate particles and ceria particles in the cannonball (A) A slurry for chemical mechanical polishing characterized by using composite particles.

[4] The particle (A) applies a pressure force and a shearing force to the mixed powder of carboxyl group-introduced polymethyl methacrylate particles and ceria particles to locally and intermittently form the surface layer of the particles. 4. The slurry for chemical mechanical polishing according to claim 3, wherein ceria particle-coated composite particles produced by melting are used.

5. The slurry for chemical mechanical polishing according to claim 3, wherein the particle (A) has a concentration of 0.2 to 10% by weight with respect to water (B).

6. The slurry for chemical mechanical polishing according to claim 3, wherein the bullet (A) is a composite particle having an average particle size of 0.3 to 10 μm.

[7] In a chemical mechanical polishing slurry composed of the abrasive grains (A), water (B), and the planarizing additive (C), the abrasive grains (A) contain organic matrix particles and ceria particles. A slurry for chemical mechanical polishing, wherein ceria particle-coated composite particles are used, and the zeta potential of the composite particles is a negative potential.

[8] The chemical mechanical polishing according to [7], wherein the organic mother particles in which a carboxyl group or a sulfonyl group is introduced are used for the organic mother particles constituting the ceria particle-coated composite particles. Slurry.

[9] In a chemical mechanical polishing slurry composed of abrasive grains (A), water (B), and a planarizing additive (C), carboxyl group-introduced polymethyl methacrylate particles are added to the abrasive grains (A). A slurry for chemical mechanical polishing characterized by using ceria particle-coated composite particles of selenium and ceria.

[10] The surface of the particles is locally and intermittently applied to the ceria particle-coated composite particles by applying pressure and shearing force to a mixed powder of carboxyl group-introduced polymethyl methacrylate particles and ceria particles. 10. The slurry for chemical mechanical polishing according to claim 9, wherein ceria particle-coated composite particles produced by melting the layer are used.

11. The chemical mechanical polishing slurry according to claim 9, wherein the particle (A) has a concentration of 0.2 to 10% by weight with respect to water (B).

12. The slurry for chemical mechanical polishing according to claim 9, wherein the bullet (A) is a composite particle having an average particle size of 0.3 to 10 μm.

13. The chemical mechanical polishing slurry according to claim 9, wherein the leveling additive (C) has a concentration of 0.05 to 5% by weight with respect to water (B).

14. The chemical mechanical polishing slurry according to claim 9, wherein the planarizing additive (C) is a poly (meth) acrylic acid ammonium salt.

[15] In a chemical mechanical polishing slurry composed of the cannonball (A) and water (B), the cantilever (A) is made of ceria particle-coated composite particles of organic mother particles and ceria particles, A chemical mechanical polishing method comprising: contacting and polishing a chemical mechanical polishing slurry in which a zeta potential of the composite particles is negative and a material to be polished.

[16] The chemical mechanical polishing slurry using the organic mother particles in which a carboxyl group or a sulfonyl group is introduced into the organic mother particles constituting the ceria particle-coated composite particles is contacted and polished. The chemical mechanical polishing method according to claim 15, wherein:

[17] In a slurry for chemical mechanical polishing composed of the cannonball (A) and water (B), the cantilever (A) is a ceria particle-coated type composed of carboxyl group-introduced polymethyl methacrylate particles and ceria particles. A chemical mechanical polishing method, comprising composite particles, wherein a chemical mechanical polishing slurry and a material to be polished are contacted and polished.

[18] In a chemical mechanical polishing slurry comprising an abrasive grain (A), water (B), and a planarizing additive (C), the abrasive grain (A) comprises organic matrix particles and ceria particles. A chemical mechanical polishing method comprising using a ceria particle-coated composite particle, and contacting and polishing a slurry for chemical mechanical polishing in which the composite particle has a negative zeta potential and a material to be polished.

[19] The organic mother particles constituting the ceria particle-coated composite particles are bonded to carboxyl groups or residues. 19. The chemical mechanical polishing method according to claim 18, wherein the slurry for chemical mechanical polishing using the organic mother particles into which the sulfonyl group is introduced and the material to be polished are contacted and polished.

[20] In a chemical mechanical polishing slurry comprising abrasive grains (A), water (B), and a planarizing additive (C), the abrasive grains (A) are carboxyl group-introduced polymethyl methacrylate particles. Is a ceria particle-coated composite particle consisting of a ceria particle and a slurry for chemical mechanical polishing.

'Chemical mechanical polishing method characterized by polishing.

[21] In the slurry for chemical mechanical polishing composed of the cannonball (A) and water (B), the cantilever (A) is made of ceria particle-coated composite particles of organic mother particles and ceria particles. A method of manufacturing an electronic device, comprising: contacting and polishing a chemical mechanical polishing slurry having a zeta potential of the composite particles being negative and a material to be polished.

[22] A step of contacting and polishing the slurry for chemical mechanical polishing using the organic mother particles in which carboxyl groups or sulfonyl groups are introduced into the organic mother particles constituting the ceria particle-coated composite particles, and the material to be polished. 22. The method for manufacturing an electronic device according to claim 21, wherein the method is included.

[23] In a slurry for chemical mechanical polishing composed of the cannonball (A) and water (B), the cantilever (A) is a ceria particle-coated type composed of carboxyl group-introduced polymethyl methacrylate particles and ceria particles. A method for producing an electronic device, comprising a step of contacting and polishing a slurry for chemical mechanical polishing and a material to be polished, which are composite particles.

[24] In a chemical mechanical polishing slurry comprising an abrasive grain (A), water (B), and a planarizing additive (C), the abrasive grain (A) comprises organic matrix particles and ceria particles. A method for producing an electronic device, comprising using a ceria particle-coated composite particle, and contacting and polishing a chemical mechanical polishing slurry having a negative zeta potential of the composite particle and a material to be polished.

[25] A step of contacting and polishing a slurry for chemical mechanical polishing using an organic mother particle in which a carboxyl group or a sulfonyl group is introduced into the organic mother particle constituting the ceria particle-coated composite particle, and the material to be polished. 25. The method for manufacturing an electronic device according to claim 24, further comprising:

[26] In a chemical mechanical polishing slurry comprising abrasive grains (A), water (B), and a planarizing additive (C), the abrasive grains (A) are carboxyl group-introduced polymethyl methacrylate particles. And ceria particles A method for producing an electronic device, comprising a step of contacting and polishing a slurry for chemical mechanical polishing and a material to be polished.