JP5403909B2 - Polishing liquid composition - Google Patents

Description

  The present invention relates to a polishing liquid composition used in chemical mechanical polishing (CMP) or the like performed in the manufacturing process of a semiconductor device. The present invention also relates to a polishing method using the polishing composition and a method for manufacturing a semiconductor device.

  Along with the high integration of semiconductor devices, for example, the storage capacity of semiconductor devices such as memory devices has increased dramatically. Miniaturization of elements is indispensable for realizing high integration of semiconductor devices. In order to realize miniaturization of elements, it is indispensable to improve the flatness of the surface obtained through the polishing step (hereinafter sometimes referred to as “polishing surface”) in the polishing step in the manufacturing process of the semiconductor device. is there.

  As a polishing liquid composition used for polishing an oxide film (for example, a silicon oxide film) or the like constituting a semiconductor device, for example, an aqueous slurry containing abrasive grains and a water-soluble organic compound (for example, Patent Document 1). Reference), aqueous slurry containing abrasive grains and a chelating agent (see, for example, Patent Document 2), and aqueous slurry containing abrasive grains and a specific aminocarboxylic acid (see, for example, Patent Document 3) are known. .

As abrasive grains contained in these aqueous slurries, for example, composite oxide particles containing cerium and zirconium are used (see, for example, Patent Documents 4 and 5). In the composite oxide particles described in Patent Document 4, the oxidation number of cerium in a cerium compound (for example, CeCl ₃ ) as a raw material is 3, and the oxidation number of zirconium in a zirconium compound (ZrOCl ₂ ). Is 4. The composite oxide particles are prepared as follows.

  In aqueous solution, cerium compound and zirconium compound are reacted with ammonia to produce a water-insoluble compound containing cerium and zirconium, and then a coprecipitate is obtained through oxidation treatment, filtration, and centrifugation. . The coprecipitate is repeatedly washed with ultrapure water or the like, dried, and then heat-treated in an oven having an atmospheric temperature of 300 ° C. or higher, whereby composite oxide particles are obtained.

On the other hand, the polishing liquid composition described in Patent Document 5 includes composite oxide particles produced without going through a firing step. Patent Document 5 discloses that this polishing composition can form a surface with high surface accuracy, has a high polishing rate despite the small particle size of the composite oxide particles, and suppresses the occurrence of damage such as scratches. It is stated that it can be done. The oxidation number of cerium in the compound of cerium that is the raw material of the composite oxide particles is 3 or 4, and the oxidation number of zirconium in the compound of zirconium is 4.
WO99 / 43761 WO01 / 80296 JP 2006-156825 A JP 2001-348563 A Japanese Patent No. 3782771

  However, in polishing using these polishing liquid compositions, the polishing liquid composition contains a water-soluble organic compound, a chelating agent or an aminocarboxylic acid, so that the surface flatness is improved, but the polishing speed cannot be sufficiently secured. It was.

  Therefore, the present invention provides a polishing composition capable of forming a polishing surface having high surface flatness by short-time polishing, a polishing method using the same, and a method for manufacturing a semiconductor device.

The polishing liquid composition of the present invention is a polishing liquid composition containing composite oxide particles containing cerium and zirconium, a dispersant, a water-soluble organic compound, and an aqueous medium, and includes a CuKα1 line (λ = 0). In the powder X-ray diffraction spectrum of the composite oxide particles obtained by irradiating with .. 154,050 nm), a peak having a peak within the diffraction angle 2θ (θ is the black angle) region 28.61 to 29.67 ° 1 peak), a peak with a peak in the diffraction angle 2θ region 33.14 to 34.53 ° (second peak), a peak with a peak in the diffraction angle 2θ region 47.57 to 49.63 ° (third peak) ), And a peak (fourth peak) having a peak within a diffraction angle 2θ region of 56.5 to 58.91 °, and the half-width of the first peak is 0.8 ° or less, and the powder In the X-ray diffraction spectrum, Peak a ₁ derived from beam, if at least one peak of the peak a ₂ derived from the zirconium oxide is present, the height of the apex of the peak a _1, a ₂ of the height of the apex of the first peak It is 6.0% or less. However, the apex of the peak a ₁ exists in a diffraction angle 2θ region of 28.40 to 28.59 °, and the apex of the peak a ₂ exists in a diffraction angle 2θ region of 29.69 to 31.60 °.

  The polishing liquid composition of the present invention is a polishing liquid composition containing composite oxide particles containing cerium and zirconium, a dispersant, a water-soluble organic compound, and an aqueous medium, wherein the composite oxide The particles were produced by hydrolyzing the cerium compound and the zirconium compound by mixing a solution containing a cerium compound having an oxidation number of 4 and a zirconium compound having an oxidation number of 4 with a precipitant. Composite oxide particles obtained by separating the precipitate, then calcining, and pulverizing the obtained calcined product.

  In the polishing method of the present invention, the polishing liquid composition of the present invention is supplied between a polishing object and a polishing pad, and the polishing pad is polished while the polishing object and the polishing pad are in contact with each other. A step of polishing the polishing object by moving the object relative to the object;

  The method for manufacturing a semiconductor device of the present invention includes a thin film forming step in which one main surface on a semiconductor substrate forms a thin film and a polishing step in which the thin film is polished with the polishing composition of the present invention. .

  ADVANTAGE OF THE INVENTION According to this invention, the polishing liquid composition which can form the grinding | polishing surface which has high surface flatness by grinding | polishing for a short time, the grinding | polishing method using the same, and the manufacturing method of a semiconductor device can be provided.

  In the polishing liquid composition of the present embodiment, by containing a water-soluble organic compound as an additive, an unprecedented composite oxide particle containing cerium and zirconia can be ground while enabling formation of a highly flat polished surface. By using it as a grain, the polishing rate can be improved.

  The reason is estimated as follows. The composite oxide particles containing cerium and zirconium contained in the polishing liquid composition of the present invention (hereinafter also simply referred to as composite oxide particles) are abrasive grains capable of polishing an object to be polished at high speed, as will be described later. Can act as When the polishing liquid composition of the present invention is applied to the surface to be polished, the water-soluble organic compound is adsorbed on the surface of the composite oxide particles and / or the surface to be polished to form a film. This coating inhibits the action of the composite oxide particles on the surface to be polished. Only after a high polishing load is applied to the surface to be polished, the coating film is destroyed, and the surface of the object to be polished can be polished with the composite oxide particles.

  When polishing an uneven surface as an example of a surface to be polished, if the progress of polishing is estimated from a microscopic viewpoint, a polishing load higher than the set load set in the polishing apparatus is applied to the convex portion in the initial stage. The coating is destroyed and polishing proceeds. On the other hand, since a low load is applied to the concave portion, the concave portion is protected by the coating and is difficult to be polished. That is, the convex portion is selectively polished, the uneven step is reduced, and the flattening proceeds.

  As described above, when the polishing composition of the present embodiment is used, a polished surface with excellent flatness can be obtained in a short time in combination with the effect of the composite oxide particles that enables high-speed polishing. However, these assumptions do not limit the present invention.

  If the set load set in the polishing apparatus is set to such a value that the polishing hardly progresses on a flat surface, the polishing hardly progresses after the uneven step is eliminated. In this case, polishing more than necessary can be easily prevented, which is preferable.

The composite oxide particles contained in the polishing liquid composition of this embodiment are represented by the following composition formula, for example.
Ce _X Zr _1-X O ₂
However, x is a conditional expression 0 <x <1, preferably 0.50 <x <0.97, more preferably 0.55 <x <0.95, and still more preferably 0.60 <x <0.93. Even more preferably, the number satisfies 0.65x <0.90, and even more preferably 0.70x <0.90.

  The following peaks are observed in the spectrum obtained by analyzing the composite oxide particles by the X-ray (Cu-Kα1 ray, λ = 0.154050 nm) diffraction method.

  In the spectrum, at least a peak having a peak within a diffraction angle 2θ region of 28.61 to 29.67 ° (first peak) and a peak having a peak within a diffraction angle 2θ region of 33.14 to 34.53 ° (second peak). Peak), a peak having a peak in the diffraction angle 2θ region 47.57 to 49.63 ° (third peak), and a peak having a peak in the diffraction angle 2θ region 56.45 to 58.91 ° (fourth peak). Peak) is observed.

  From the viewpoint of improving the polishing rate, the composite oxide particles have a peak (first peak) having a peak within at least a diffraction angle 2θ region of 28.61 to 29.39 ° in the spectrum, and a diffraction angle 2θ region of 33.14. Peak having a vertex within ˜34.16 ° (second peak), peak having a vertex within diffraction angle 2θ region 47.57 to 49.08 ° (third peak), and diffraction angle 2θ region 56.45 It is preferable that a peak (fourth peak) having a vertex within ˜58.25 ° is observed, and further, a peak having a vertex within the diffraction angle 2θ region of 28.61 to 29.25 ° (first peak). Peak), peak with a peak in the diffraction angle 2θ region 33.14 to 34.04 ° (second peak), peak with a peak in the diffraction angle 2θ region 47.57 to 48.90 ° (third peak) , And diffraction angle 2θ region 56.45- It is preferable that a peak having a vertex within 8.02 ° (fourth peak) is observed, and a peak having a vertex within the diffraction angle 2θ region of 28.64 to 29.11 ° (first peak), times. Peak (second peak) having an apex within the folding angle 2θ region 33.18 to 33.79, peak (third peak) having an apex within the diffraction angle 2θ region 47.63 to 48.53 °, and diffraction angle It is even more preferable that a peak (fourth peak) having an apex within the 2θ region of 56.51 to 57.60 ° is observed.

  The area of the second peak is 10 to 50% of the area of the first peak, the area of the third peak is 35 to 75% of the area of the first peak, and the area of the fourth peak is 20 of the area of the first peak. It is preferable that it is -65%. From the viewpoint of shortening the planarization time, the area of the second peak is 15 to 45% of the area of the first peak, the area of the third peak is 40 to 70% of the area of the first peak, and the area of the fourth peak is More preferably, it is 25-60% of the area of the first peak, the area of the second peak is 20-40% of the area of the first peak, and the area of the third peak is 45-45 of the area of the first peak. The area of 65% and the fourth peak is more preferably 30 to 55% of the area of the first peak.

There may be a case where at least one of the peak a ₁ derived from cerium oxide and the peak a ₂ derived from zirconium oxide exists in the spectrum. In this case, the peak heights of the peaks a ₁ and a ₂ are both 6.0% or less of the height of the peak of the first peak, preferably 3.0% or less, more preferably from the viewpoint of scratch reduction. Is 1.0% or less, more preferably 0%.

The diffraction angle 2θ region where the apex of the peak a ₁ exists is 28.40 ° to 28.59 °, and the diffraction angle 2θ region where the apex of the peak a ₂ exists is 29.69 ° to 31.60 °. These values for the 2θ region are based on values for cerium oxide and zirconium oxide in the international diffraction data ICDD (International Center for Diffraction Data). Specifically, the diffraction angle 2θ region 28.40 to 28.59 ° where the peak of peak a ₁ exists is a value for cubic cerium oxide. The 2θ region 29.69 to 31.60 ° where the peak of peak a ₂ is present is 2θ (29.69 °) of tetragonal zirconium oxide and 2θ (31.60 °) of monoclinic zirconium oxide. ).

  The half width of the first peak is 0.8 ° or less, but from the viewpoint of improving the polishing rate, 0.7 ° or less is preferable, 0.6 ° or less is more preferable, 0.5 ° or less is more preferable, 0.45 or less is even more preferable. This half-value width correlates with the crystallite size as shown in the Scherrer equation. The full width at half maximum decreases as the crystallite size increases due to crystal growth.

In the composite oxide particles of the present embodiment, as described later, cerium oxide is derived from a cerium compound having an oxidation number of 4, and zirconium oxide is derived from a zirconium compound having an oxidation number of 4, It is considered that one solid phase in which cerium oxide and zirconium oxide are uniformly dissolved is formed, and the X-ray diffraction spectrum is observed. When the cerium oxide in the composite oxide particles is derived from a cerium compound having an oxidation number of 3, like the composite oxide particles contained in the polishing liquid composition described in Patent Document 4, cerium oxide and zirconium oxide are Formation of one solid phase that is uniformly dissolved is not sufficiently performed, and at least one of a peak a ₁ derived from cerium oxide and a peak a ₂ derived from zirconium oxide is observed.

  In addition, in the X-ray diffraction spectrum of the composite oxide particles contained in the polishing liquid composition of the present embodiment, the first peak has a small half width and the first peak is very sharp. As will be described later, this is considered to be because the crystallite size of the solid phase is increased, that is, the crystallinity is improved by performing sufficient firing in the manufacturing process. Since the composite oxide particles contained in the polishing composition described in Patent Document 5 have not undergone sufficient firing during the production process, the crystallinity of the solid phase is not sufficient. The half width of the first peak in the X-ray diffraction spectrum is large and the first peak is broad.

  As described above, the polishing liquid composition of this embodiment has one solid phase in which cerium oxide and zirconium oxide are uniformly dissolved, and includes complex oxide particles having high crystallinity. It is considered that the object to be polished can be polished at a higher speed than the polishing liquid composition.

The atomic ratio (Ce / Zr) in the composite oxide particles is preferably (99/1) to (5/95) from the viewpoint of improving the polishing rate, and (97/3) to (16 / 84), more preferably (96/4) to (40/60), even more preferably (95/5) to (50/50), (94/6) to (60/40) is more preferred, and (93/7) to (70/30) is even more preferred.

In the composite oxide _{(Ce x Zr 1-x O} 2) particles, the atomic ratio x of Ce is for Zr, from the viewpoint of reducing scratches, preferably 0.60 to 0.93, more preferably 0.65 to 0 .90, more preferably 0.70 to 0.90.

  From the viewpoint of further improving the polishing rate, the volume median diameter (D50) of the composite oxide particles is preferably 30 nm or more, more preferably 40 nm or more, and further preferably 50 nm or more. Further, D50 is preferably 1000 nm or less, more preferably 500 nm or less, and still more preferably 250 nm or less, from the viewpoint of further improving the dispersion stability in the polishing composition. Therefore, the volume median diameter (D50) of the composite oxide particles is preferably 30 to 1000 nm, more preferably 40 to 500 nm, and still more preferably 50 to 250 nm.

  Here, the volume median diameter (D50) means a particle diameter at which the cumulative volume frequency calculated by the volume fraction is 50% when calculated from the smaller particle diameter. The volume median diameter (D50) is obtained as a volume-based median diameter measured with a laser diffraction / scattering particle size distribution meter (trade name LA-920, manufactured by Horiba, Ltd.).

  From the viewpoint of further improving the polishing rate, the average primary particle size of the composite oxide particles is preferably 10 nm or more, more preferably 20 nm or more, and further preferably 30 nm or more. The average primary particle diameter of the composite oxide particles is preferably 200 nm or less, more preferably 150 nm or less, and still more preferably 100 nm, from the viewpoint of further improving the mirror surface state of the polishing surface obtained by polishing the polishing object. It is as follows. Therefore, the average primary particle diameter of the composite oxide particles is preferably 10 to 200 nm, more preferably 20 to 150 nm, and still more preferably 30 to 100 nm.

Here, the average primary particle size (nm) means the particle size (true sphere conversion) calculated by the following formula using the specific surface area S (m ² / g) calculated by the BET (nitrogen adsorption) method. .
Average primary particle diameter (nm) = 820 / S

  From the viewpoint of further improving the polishing rate, the content of the composite oxide particles in the polishing composition is preferably 0.1% by weight or more, more preferably 0.2% by weight or more, and further preferably 0.4% by weight. % Or more, and more preferably 0.5% by weight. Further, the content of the composite oxide particles is preferably 8% by weight or less, more preferably 5% by weight or less, and still more preferably 4% by weight or less, from the viewpoint of further improving the dispersion stability and reducing the cost. And more preferably 3% by weight or less. Accordingly, the content of the composite oxide particles is preferably 0.1 to 8% by weight, more preferably 0.2 to 5% by weight, still more preferably 0.4 to 4% by weight, and still more preferably 0.5. ~ 3 wt%.

  The composite oxide particles may be commercially available products or may be prepared in-house. Next, an example of a method for producing composite oxide particles will be described.

  The composite oxide particles include a cerium compound having an oxidation number of 4 (hereinafter also referred to as a cerium (IV) compound) and a zirconium compound having an oxidation number of 4 (hereinafter also referred to as a zirconium (IV) compound). By mixing the solution and a precipitant, the cerium (IV) compound and the zirconium (IV) compound are hydrolyzed, the resulting precipitate is separated, then calcined, and the obtained calcined product is pulverized. Can be obtained.

  The solution containing the cerium (IV) compound and the zirconium (IV) compound is, for example, a water-soluble cerium (IV) compound such as cerium nitrate and a water-soluble zirconium (IV) compound such as zirconium nitrate, respectively. It may be prepared by dissolving in the solvent and mixing.

  If a precipitant (base solution) is added to the solution containing the cerium (IV) compound and the zirconium (IV) compound, the cerium (IV) compound and the zirconium (IV) compound are hydrolyzed, and the precipitate is formed. Generated. It is preferable to add a precipitant while stirring a solution containing a cerium (IV) compound and a zirconium (IV) compound. As the precipitating agent, ammonia solution; alkaline hydroxide solution such as sodium hydroxide solution or potassium hydroxide solution; carbonate solution of sodium, potassium or ammonia; bicarbonate solution or the like is used. The precipitant is preferably an aqueous solution of ammonia, sodium hydroxide or potassium hydroxide, more preferably an aqueous ammonia solution. The normality of the precipitating agent is preferably about 1 to 5N, and more preferably about 2 to 3N.

  The pH of the solution obtained by adding a precipitant to a solution containing a cerium (IV) compound and a zirconium (IV) compound is a composite oxide particle in which cerium oxide and zirconium oxide are in a highly solid solution state. From a viewpoint, 7-11 are preferable, More preferably, it is 7.5-9.5.

  The mixing time of the solution containing the cerium (IV) compound and the zirconium (IV) compound and the precipitating agent is not particularly limited, but is preferably 15 minutes or more, and more preferably 30 minutes or more. The reaction between the solution containing the cerium (IV) compound and the zirconium (IV) compound and the precipitating agent can be performed at any suitable temperature such as room temperature. The precipitate produced by mixing a solution containing a cerium (IV) compound and a zirconium (IV) compound and a precipitating agent is subjected to normal solid / liquid separation such as decantation, drying, filtration and / or centrifugation. Separable from mother liquor by technology. The resulting precipitate is then washed with water or the like.

  The cerium (IV) compound in the solution is preferably simply contained in a state where the cerium (IV) compound is added to the aqueous medium, but the cerium compound containing cerium having an oxidation number of 3 is contained in the aqueous medium. It is possible to electrolytically oxidize trivalent cerium into tetravalent cerium. The cerium (IV) compound is preferably contained in an amount of 85% by weight or more, more preferably 87% by weight or more, further preferably 90% by weight or more in the total amount of the cerium compound, and 95% by weight. Even more preferably, it is contained in an amount of at least%.

  Specific examples of the cerium (IV) compound include water-soluble salts such as cerium sulfate (IV), tetraammonium cerium sulfate (IV), and diammonium cerium nitrate (IV). The cerium salt having an oxidation number of 4 is more easily hydrolyzed than the cerium salt having an oxidation number of 3 and also has a zirconium (IV) compound (for example, an oxidation number from the viewpoint of hydrolysis rate). This is because it is suitable for simultaneous hydrolysis with a zirconium salt of 4).

  Zirconium (IV) compounds contained in the solution include zirconium oxychloride (zirconyl chloride), zirconium oxysulfate (zirconyl sulfate), zirconium oxyacetate (zirconyl acetate), zirconium oxynitrate (zirconyl nitrate), zirconium chloride, zirconium nitrate And water-soluble zirconium (IV) salts such as zirconium acetate and zirconium sulfate.

  As described above, when the oxidation number of cerium and zirconium in the solution is 4 and the pH of the solution is increased by adding the base solution as a precipitant to the solution, the cerium (IV) compound and zirconium (IV ) The compound is hydrolyzed in approximately the same pH region, and cerium hydroxide and zirconium hydroxide precipitate almost simultaneously, resulting in a highly mixed precipitate with each other. By heat-treating this precipitate, a portion in which cerium oxide and zirconium oxide are uniformly dissolved to form one solid phase is generated in the precipitate. If the oxidation number of cerium is 3, the pH range in which the cerium (III) compound and the zirconium (IV) compound are hydrolyzed and the hydroxide precipitates is different, so that a precipitate in which the mixing state of both is insufficient is obtained. It is done. When this precipitate is heat-treated, a portion where cerium oxide or zirconium oxide is separated is generated.

  When the total amount of oxide equivalent of cerium element and zirconium element equivalent contained in the solution containing the cerium (IV) compound and zirconium (IV) compound is 100% by weight, the oxide equivalent amount of cerium element Is preferably 7 to 99% by weight, more preferably 20 to 98% by weight, and still more preferably 50 to 96% by weight. The oxide equivalent amount of zirconium element is preferably 1 to 93% by weight, more preferably 2 to 80% by weight, and further preferably 4 to 50% by weight.

  The firing temperature of the precipitate is preferably 900 to 1500 ° C., more preferably 1000 to 1400, from the viewpoint of improving the crystallinity of the solid phase in which cerium oxide and zirconium oxide are uniformly dissolved and ensuring a good polishing rate. It is 1 degreeC, More preferably, it is 1100-1300 degreeC. The heating time is usually preferably 1 to 10 hours, more preferably 2 to 8 hours, and further preferably 3 to 7 hours. Firing can be performed using a heating means such as a continuous firing furnace. The firing temperature is the temperature of the particle surface and is equal to the ambient temperature in the continuous firing furnace.

  The means for pulverizing the fired product is not particularly limited, and examples thereof include pulverizers such as a ball mill, a bead mill, and a vibration mill. The setting conditions of the pulverizing means may be appropriately set in order to form particles having a desired average particle size range or particles having a desired volume particle size range. Examples of the grinding media include zirconia balls.

The polishing liquid composition of the present invention contains a water-soluble organic compound that contributes to the formation of a polished surface having high surface flatness in addition to the composite oxide particles described above. The water-soluble organic compound, -SO ₃ H group, -SO ₃ N _a group (N _a is atomic or atomic group capable of forming a salt by substituting the H atom), - COOH group, --COON _b group (N Examples of _b include water-soluble organic compounds having at least one of atoms or atomic groups that can be substituted with H atoms to form a salt. When the water-soluble organic compound is a salt, the water-soluble organic compound is preferably a nonmetallic salt that does not contain an alkali metal. The water-soluble organic compound contained in the polishing liquid composition may be not only one type but also two or more types.

  Examples of water-soluble organic compounds include acrylic acid polymers, organic acids, salts thereof, acidic amino acids, salts thereof, neutral or basic amino acids, and amphoteric water-soluble low-molecular organic compounds (hereinafter simply referred to as “water-soluble organic compounds”). At least one selected from the group consisting of low molecular organic compounds. The molecular weight of the low molecular weight organic compound is preferably 1000 or less, more preferably 500 or less, and even more preferably 300 or less, from the viewpoint of ensuring the stability of the polishing composition.

  Preferable specific examples of the acrylic acid polymer include polyacrylic acid, polymethacrylic acid, polyammonium acrylate, polyammonium methacrylate, and the like.

  Preferable specific examples of the organic acid and its salt include malic acid, lactic acid, tartaric acid, gluconic acid, citric acid-hydrate, succinic acid, adipic acid, fumaric acid, or ammonium salts thereof.

  Preferable specific examples of acidic amino acids and salts thereof include aspartic acid, glutamic acid, and ammonium salts thereof.

  Preferable specific examples of neutral or basic include glycine, 4-aminobutyric acid, 6-aminohexanoic acid, 12-aminolauric acid, arginine, glycylglycine and the like.

Specific examples of the low molecular weight organic compound include dihydroxyethyl glycine (DHEG), ethylenediaminetetraacetic acid (EDTA), cyclohexanediaminetetraacetic acid (CyDTA), nitrilotriacetic acid (NTA), hydroxyethylethylenediaminetriacetic acid (HEDTA), diethylenetriamine-5 Acetic acid (DTPA), triethylenetetramine hexaacetic acid (TTHA), L-glutamic acid diacetic acid (GLDA), aminotri (methylenephosphonic acid), 1-hydroxyethylidene 1,1-diphosphonic acid (HEDP), ethylenediaminetetra (methylenephosphonic acid) ), Diethylenetriaminepenta (methylenephosphonic acid), β-alanine diacetate (β-ADA), α-alanine diacetate (α-ADA), aspartate diacetate (ASDA), ethylenediamine Succinic acid (EDDS), iminodiacetic acid (IDA), hydroxyethyliminodiacetic acid (HEIDA), 1,3-propanediaminetetraacetic acid (1,3-PDTA), aspartic acid, serine, cysteine, azaserine, asparagine, 2- Aminobutyric acid, 4-aminobutyric acid, alanine, β-alanine, arginine, alloisoleucine, allothreonine, isoleucine, ethionine, ergothioneine, ornithine, canavanine, S- (carboxymethyl) -cysteine, kynurenine, glycine, glutamine, glutamic acid, creatine , Sarcosine, cystathionine, cystine, cysteic acid, citrulline, β- (3,4-dihydroxyphenyl) -alanine, 3,5-diiodotyrosine, taurine, thyroxine, tyrosine, tryptophan, threonine , Norvaline, norleucine, valine, histidine, 4-hydroxyproline, δ-hydroxylysine, phenylalanine, proline, homoserine, methionine, 1-methylhistidine, 3-methylhistidine, lanthionine, lysine, leucine, m-aminobenzoic acid, p -Aminobenzoic acid, β-aminoisovaleric acid, 3-aminocrotonic acid, o-aminocinnamic acid, m-aminoaminobenzenesulfonic acid, p-aminobenzenesulfonic acid, 2-aminopentanoic acid, 4-aminopentanoic acid, 5-aminopentanoic acid, 2-amino-2-methylbutyric acid, 3-aminobutyric acid, isatinic acid, 2-quinolinecarboxylic acid, 3-quinolinecarboxylic acid, 4-quinolinecarboxylic acid, 5-quinolinecarboxylic acid, 2,3 -Quinoline dicarboxylic acid, 2,4-quinoline dicarboxylic acid , Guanidinoacetic acid, 2,3-diaminobenzoic acid, 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,4-diaminobenzoic acid, 3,5-diaminobenzoic acid, 2,4-diaminophenol 3,4-diaminophenol, 2,4,6-triaminophenol, 2-pyridinecarboxylic acid, nicotinic acid, isonicotinic acid, 2,3-pyridinedicarboxylic acid, 2,4-pyridinedicarboxylic acid, 2,5 -Pyridinedicarboxylic acid, 2,6-pyridinedicarboxylic acid, 3,4-pyridinedicarboxylic acid, 3,5-pyridinedicarboxylic acid, 2,4,5-pyridinetricarboxylic acid, 2,4,5-pyridinetricarboxylic acid, 3 , 4,5-pyridinetricarboxylic acid, N-phenylglycine, N-phenylglycine-o-carboxylic acid, phenol-2,4-disulfo Acid, o-phenolsulfonic acid, m-phenolsulfonic acid, p-phenolsulfonic acid, phthalanilic acid, o- (methylamino) phenol, m- (methylamino) phenol, p- (methylamino) phenol, carboxybetaine , Sulfobetaine, imidazolinium betaine, lecithin and the like. Also, one or more protons of these compounds, F, Cl, Br, and atoms of I, etc. or OH, CN, and substituted derivatives thereof in NO atomic groups, such as _2,. Among these, the following chelating agents are more preferable from the viewpoint of suppressing a dishing phenomenon due to excessive polishing and obtaining a polished surface with excellent flatness. Note that the dishing phenomenon is that a portion corresponding to the concave portion of the polished surface obtained by polishing is excessively polished by polishing the concave and convex surface having a plurality of concave portions and a plurality of convex portions. It is a phenomenon of depression in a dish shape. This dishing phenomenon occurs remarkably when the distance between adjacent convex portions is larger, that is, when the ratio of the total area of the concave portions visible when the concave and convex surfaces are viewed in plan is large (when the concave surface density is large).

  Examples of the chelating agent include DHEG, EDTA, CyDTA, NTA, HEDTA, DTPA, TTHA, GLDA, aminotri (methylenephosphonic acid), HEDP, ethylenediaminetetra (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic acid), and β-ADA. , Α-ADA, ASDA, EDDS, IDA, HEIDA, 1,3-PDTA, aspartic acid, serine, cysteine and the like. Among these, DHEG, EDTA, NTA, β-ADA, α-ADA, ASDA, EDDS, HEIDA, aspartic acid, serine, and cysteine are more preferable.

  Among chelating agents, DHEG is more preferable from the viewpoint of ensuring the stability of the polishing composition at the time of concentration.

  Among amphoteric, water-soluble, low-molecular-weight organic compounds, especially DHEG has an anion group, a cation group, and a nonion group in a balanced state in the molecule. It is presumed that the hydrophilicity is not greatly reduced and the effect of the dispersant is hardly affected. Further, DHEG can sufficiently suppress aggregation of the composite oxide particles and the like, and can ensure the dispersion stability of the composite oxide particles even when the concentration of the composite oxide particles is high. Therefore, the polishing composition of this embodiment containing DHEG can also be provided as a high concentration polishing composition with stable quality.

  The low molecular weight organic compound is usually used in the production of the polishing liquid composition in the form of a free acid or a salt, but a salt having high solubility in an aqueous medium is preferably used in the production of the polishing liquid composition.

  Specific examples of the salt include ammonium compound salts, lithium salts, sodium salts, potassium salts, cesium salts, and the like. From the viewpoint of obtaining preferable electrical characteristics of LSI, ammonium compound salts are more preferable.

  Preferable examples of amines constituting the ammonium compound salt include ammonia, a primary amine having a linear or branched saturated or unsaturated alkyl group having 1 to 10 carbon atoms, a secondary amine, a tertiary amine, or A primary amine having at least one aromatic ring having 6 to 10 carbon atoms, a secondary amine, a tertiary amine, an amine having a cyclic structure such as piperidine and piperazine, and a tetraalkylammonium compound such as tetramethylammonium. Can be mentioned.

  From the viewpoint of obtaining a polished surface with excellent flatness, the content of the water-soluble organic compound contained in the polishing composition of the present embodiment is preferably 0.02 to 15% by weight, more preferably 0.05 to 10%. % By weight, more preferably 0.1 to 8% by weight, and still more preferably 0.2 to 6% by weight.

  In the polishing composition of the present invention, a substance added as a water-soluble organic compound and a substance added as a dispersant described later may be the same as well as different from each other. When the substance added as the water-soluble organic compound is the same as the substance added as the dispersant described later, the water-soluble organic compound is used so that suitable dispersibility and suitable flatness of the polishing surface can be realized. Water-soluble organic compound within the range of the total amount of the preferable content of the organic organic compound (for example, 0.02 to 15% by weight) and the preferable content of the dispersant (for example, 0.0005 to 0.5% by weight) What is necessary is just to select the total amount of a dispersing agent.

  The weight ratio of the water-soluble organic compound to the composite oxide particles (water-soluble organic compound / composite oxide particles) in the polishing composition of the present embodiment is from the viewpoint of forming a polished surface having high surface flatness. 1/30 or more is preferable, more preferably 1/20 or more, and still more preferably 1/10 or more. The weight ratio is preferably 15/1 or less, more preferably 12/1 or less, and even more preferably 10/1 or less, from the viewpoint of further improving the polishing rate. Accordingly, the weight ratio is preferably 1/30 to 15/1, more preferably 1/20 to 12/1, and still more preferably 1/10 to 10/1.

  Further, in the case of a polishing liquid composition containing DHEG as a water-soluble organic compound, the content of DHEG contained in the polishing liquid composition is 0.1 to 15% by weight from the viewpoint of obtaining a polished surface with better flatness. Is preferable, more preferably 0.2 to 10% by weight, still more preferably 0.5 to 8% by weight, and still more preferably 1.0 to 6% by weight.

  In the polishing composition of the present embodiment, the weight ratio of DHEG and composite oxide particles (DHEG / composite oxide particles) is preferably 1/5 or more from the viewpoint of effectively suppressing the occurrence of dishing. Preferably it is 1/4 or more, more preferably 1/3 or more. The weight ratio (DHEG / composite oxide particles) is preferably 15/1 or less, more preferably 12/1 or less, and even more preferably 10/1 or less, from the viewpoint of further improving the polishing rate. Accordingly, the weight ratio is preferably 1/5 to 15/1, more preferably 1/4 to 12/1, and still more preferably 1/3 to 10/1.

  Examples of the aqueous medium contained in the polishing liquid composition of the present embodiment include water, a mixed medium of water and a solvent, and the solvent includes a solvent that can be mixed with water (for example, alcohol such as ethanol). Is preferred. Among these, water is preferable as the aqueous medium, and ion-exchanged water is more preferable.

  The dispersant contained in the polishing composition of this embodiment is preferably water-soluble. The water-soluble dispersant is preferably at least one selected from the group consisting of a cationic surfactant, an anionic surfactant, a nonionic surfactant, and an acrylic acid polymer. More preferably, the dispersant is at least one selected from the group consisting of an anionic surfactant, a nonionic surfactant, and an acrylic acid polymer. The dispersant is more preferably an acrylic acid polymer. The dispersant may be physically adsorbed on the surface of the composite oxide particle before being mixed with the aqueous medium, or may be chemically bonded to the surface of the composite oxide particle.

  Examples of the cationic surfactant include aliphatic amine salts and aliphatic ammonium salts.

  Examples of the anionic surfactant include fatty acid soaps, carboxylates such as alkyl ether carboxylates, sulfonates such as alkylbenzene sulfonates and alkylnaphthalene sulfonates, higher alcohol sulfates, alkyl ether sulfates. And sulfate ester salts such as alkyl phosphate esters and the like.

  Nonionic surfactants include, for example, ether types such as polyoxyethylene alkyl ether, ether ester types such as glycerin ester polyoxyethylene ether, ester types such as polyethylene glycol fatty acid ester, glycerin ester, and sorbitan ester. Can be mentioned.

  The acrylic acid polymer may be a homopolymer or a copolymer. The homopolymer preferably includes a homopolymer containing the structural unit (A) derived from the monomer (a) such as acrylic acid, a non-metallic salt of acrylic acid, or an acrylic ester. As the copolymer, preferably, the structural unit (A) derived from at least one monomer (a) selected from the group consisting of acrylic acid, a non-metallic salt of acrylic acid, and an acrylic ester, and the following monomer ( Each structural unit derived from at least two types of monomers (a) selected from the group consisting of a copolymer comprising the structural unit (B) derived from b), acrylic acid, a non-metallic salt of acrylic acid, and an acrylic ester Mention may be made of copolymers comprising (A).

  Examples of acrylic acid nonmetal salts include ammonium acrylate salts and amine acrylate salts. The acrylic acid polymer may contain one or more kinds of structural units derived from these acrylates.

  When the acrylic acid polymer is a copolymer, it contains more than 50 mol% of the structural unit (A), preferably more than 70 mol%, and more than 80 mol%. More preferably, it is more preferable to contain more than 90 mol%.

  The monomer (b) is a monomer having a carboxylic acid (salt) group and having a polymerizable double bond, such as itaconic acid, itaconic anhydride, methacrylic acid, maleic acid, Maleic anhydride, fumaric acid, fumaric anhydride, citraconic acid, citraconic anhydride, glutaconic acid, vinyl acetic acid, allyl acetic acid, phosphinocarboxylic acid, α-haloacrylic acid, β-carboxylic acid, or salts thereof, methacrylic And alkyl methacrylates such as methyl acrylate, ethyl methacrylate, and octyl methacrylate.

  When the acrylic acid polymer is a salt, for example, an acid type acrylic acid monomer may be polymerized alone or copolymerized with the monomer (b) and then neutralized with a predetermined alkali. can get. Examples of the salt include an ammonium salt of a copolymer of acrylic acid and 2-acrylamido-2-methylpropanesulfonic acid.

  From the viewpoint of further improving the dispersion stability, the acrylic acid polymer is preferably at least one selected from the group consisting of polyacrylic acid and ammonium polyacrylate, and more preferably ammonium polyacrylate.

  From the viewpoint of further improving dispersion stability, the acrylic acid polymer preferably has a weight average molecular weight of 500 to 50,000, more preferably 500 to 10,000, and even more preferably 1,000 to 10,000.

The weight average molecular weight is a value calculated based on a peak in a chromatogram obtained by applying a gel permeation chromatography (GPC) method under the following conditions.
Column: G4000PWXL + G2500PWXL (Tosoh Corporation)
Eluent: (0.2 M phosphate buffer) / (CH ₃ CN) = 9/1 (volume ratio)
Flow rate: 1.0 mL / min
Column temperature: 40 ° C
Detector: RI detector Standard material: Polyacrylic acid equivalent

  The content of the dispersant in the polishing composition is preferably 0.0005% by weight or more, more preferably 0.001% by weight or more, and still more preferably 0.002% by weight from the viewpoint of further improving the dispersion stability. That's it. The content of the dispersant in the polishing composition is preferably 0.5% by weight or less, more preferably 0.1% by weight or less, and still more preferably 0.05% by weight or less. Therefore, the content of the dispersant is preferably 0.0005 to 0.5% by weight, more preferably 0.001 to 0.1% by weight, and still more preferably 0.002 to 0.05% by weight.

  The polishing composition of this embodiment may further contain at least one optional component selected from a pH adjuster, a preservative, and an oxidizing agent as long as the effects of the present invention are not hindered. .

  Examples of the pH adjuster include basic compounds and acidic compounds. Examples of basic compounds include ammonia, potassium hydroxide, water-soluble organic amines and quaternary ammonium hydroxides. Examples of the acidic compound include inorganic acids such as sulfuric acid, hydrochloric acid, nitric acid and phosphoric acid, and organic acids such as acetic acid, oxalic acid, succinic acid, glycolic acid, malic acid, citric acid and benzoic acid.

  Examples of preservatives include benzalkonium chloride, benzethonium chloride, 1,2-benzisothiazolin-3-one, (5-chloro-) 2-methyl-4-isothiazolin-3-one, hydrogen peroxide, or hypochlorite Examples include acid salts.

  Examples of the oxidizing agent include peroxides such as permanganic acid and peroxo acid, chromic acid, nitric acid, and salts thereof.

  The pH at 25 ° C. of the polishing composition of the present embodiment is not particularly limited, but is preferably 2 to 10, more preferably 3 to 9, more preferably 4 to 8, since the polishing rate can be further improved. More preferably, it is 4.5-7. Here, the pH at 25 ° C. can be measured using a pH meter (Toa Denpa Kogyo Co., Ltd., HM-30G), and is a value one minute after immersion of the electrode in the polishing composition.

  The content of each component described above is the content at the time of use, but the polishing liquid composition of the present embodiment is stored and supplied in a concentrated state as long as the stability is not impaired. May be. In this case, it is preferable in that the manufacturing and transportation costs can be further reduced. The concentrate may be used after appropriately diluted with the above-mentioned aqueous medium as necessary.

  When the polishing liquid composition of the present embodiment is the concentrated liquid, the content of the composite oxide particles is preferably 1% by weight or more, more preferably 2% by weight or more from the viewpoint of further reducing production / transport costs. More preferably, it is 3% by weight or more, and still more preferably 4% by weight or more. In addition, the content of the composite oxide particles in the concentrate is preferably 20% by weight or less, more preferably 15% by weight or less, still more preferably 10% by weight or less, and still more from the viewpoint of further improving the dispersion stability. Preferably it is 8 weight% or more. Therefore, the content of the composite oxide particles in the concentrate is preferably 1 to 20% by weight, more preferably 2 to 15% by weight, still more preferably 3 to 10% by weight, and even more preferably 4 to 8%. % By weight.

  When the polishing composition of the present embodiment is the concentrated solution, the content of the low molecular weight organic compound is preferably 0.08% by weight or more, more preferably 0.8%, from the viewpoint of further reducing production and transportation costs. It is 2% by weight or more, more preferably 0.5% by weight or more, and even more preferably 1% by weight or more. In addition, the content of the low molecular weight organic compound in the concentrate is preferably 40% by weight or less, more preferably 20% by weight or less, still more preferably 15% by weight or less, and still more preferably, from the viewpoint of further improving the dispersion stability. Preferably it is 12 weight% or more. Therefore, the content of the low molecular weight organic compound in the concentrate is preferably 0.08 to 40% by weight, more preferably 0.2 to 20% by weight, still more preferably 0.5 to 15% by weight, More preferably, it is 1 to 12% by weight.

  When the polishing liquid composition containing DHEG as the low-molecular organic compound is the concentrated liquid, the content of DHEG is preferably 0.4% by weight or more, more preferably 1 from the viewpoint of further reducing production and transportation costs. % By weight or more, more preferably 2% by weight or more, and even more preferably 3% by weight or more. The content of DHEG in the concentrate is preferably 40% by weight or less, more preferably 20% by weight or less, still more preferably 15% by weight or less, and still more preferably 12% from the viewpoint of further improving the dispersion stability. % By weight or more. Therefore, the content of DHEG in the concentrate is preferably 0.4 to 40% by weight, more preferably 1 to 20% by weight, still more preferably 2 to 15% by weight, and even more preferably 3 to 12% by weight. %.

  When the polishing liquid composition of the present embodiment is the concentrated liquid, the content of the dispersant is preferably 0.001% by weight or more, more preferably 0.003% by weight, from the viewpoint of further reducing production / transport costs. % Or more, more preferably 0.005% by weight or more, and still more preferably 0.01% by weight or more. The content of the dispersant in the concentrate is preferably 1.0% by weight or less, more preferably 0.3% by weight or less, and still more preferably 0.2% by weight from the viewpoint of further improving the dispersion stability. Or even more preferably 0.1% by weight or less. Therefore, the content of the dispersant in the concentrate is preferably 0.001 to 1.0% by weight, more preferably 0.003 to 0.3% by weight, and still more preferably 0.005 to 0.2% by weight. And even more preferably 0.01 to 0.1% by weight.

  Next, an example of the manufacturing method of the polishing liquid composition of this embodiment is demonstrated.

  An example of the manufacturing method of the polishing liquid composition of this embodiment is not restrict | limited at all, For example, complex oxide particle | grains, a dispersing agent, a water-soluble organic compound (for example, DHEG), an aqueous medium, and as needed And can be prepared by mixing with optional components.

  The mixing order of these components is not particularly limited, and all the components may be mixed at the same time, or a composite oxide particle slurry in which composite oxide particles are dispersed in an aqueous medium in which a dispersant is dissolved in advance. After the preparation, a mixture containing the low molecular organic compound and the remaining aqueous medium may be mixed with the slurry. From the viewpoint of sufficiently preventing aggregation of the composite oxide particles, the latter is preferable.

  The dispersion of the composite oxide particles in the aqueous medium can be performed using, for example, a stirrer such as a homomixer, a homogenizer, an ultrasonic disperser, a wet ball mill, or a bead mill. When coarse particles formed by aggregation of composite oxide particles are contained in the aqueous medium, it is preferable to remove the coarse particles by centrifugation, filter filtration, or the like. The dispersion of the composite oxide particles in the aqueous medium is preferably performed in the presence of a dispersant.

  Next, a method for manufacturing the semiconductor device of this embodiment will be described.

  The manufacturing method of the semiconductor substrate of this embodiment includes a thin film forming step in which one main surface on the semiconductor substrate forms a crocodile thin film, and a concavo-convex surface in which the thin film semiconductor substrate forms a concavo-convex pattern on the opposite surface of the crocodile surface. A formation process and the grinding | polishing process of grind | polishing an uneven surface using the polishing liquid composition of this embodiment are included. The thin film forming process is performed a plurality of times as necessary.

  Also, the manufacturing method of the semiconductor substrate of this embodiment includes a thin film forming step of forming a thin film having an uneven surface on one main surface on the semiconductor substrate, and the polishing liquid composition of this embodiment on the uneven surface. Polishing process using and polishing. The thin film forming process is performed a plurality of times as necessary.

  As a thin film formed in a thin film formation process, conductor layers, such as an insulating layer, a metal layer, and a semiconductor layer, are mention | raise | lifted, for example. Examples of the material contained in the insulating layer include silicon oxide, silicon nitride, and polysilicon.

  The thin film forming method may be appropriately selected according to the material constituting the thin film, and examples thereof include a CVD method, a PVD method, a coating method, and a plating method.

  Examples of the method for forming the uneven surface include conventionally known lithography methods. In the lithography method, photoresist application, exposure, development, etching, photoresist removal, and the like are performed in this order. In addition, the uneven surface may be formed corresponding to the unevenness in the lower layer.

  For polishing the uneven surface, the polishing composition of the present embodiment is supplied to the uneven surface and / or the surface of the polishing pad, for example, a polishing pad is brought into contact with the uneven surface, and a predetermined pressure (load) is applied to the uneven surface. This can be done by relatively moving at least one of the thin film having an uneven surface and the polishing pad. The polishing treatment can be performed by a conventionally known polishing apparatus.

  The polishing composition may be used as it is, or may be used after being diluted if it is a concentrated solution. When diluting the concentrate, the dilution factor is not particularly limited, and may be appropriately determined according to the concentration of each component in the concentrate, polishing conditions, and the like.

  As a specific example of the dilution rate, 1.5 times or more is preferable, more preferably 2 times or more, still more preferably 3 times or more, and still more preferably 4 times or more. It is preferably 20 times or less, more preferably 15 times or less, still more preferably 10 times or less, and even more preferably 8 times or less. Therefore, the dilution factor is preferably 1.5 to 20 times, more preferably 2 to 15 times, still more preferably 3 to 10 times, and even more preferably 4 to 8 times.

  Examples of the material of the semiconductor substrate include elemental semiconductors such as Si or Ge, compound semiconductors such as GaAs, InP, or CdS, mixed crystal semiconductors such as InGaAs, HgCdTe, and the like.

  The material or material of the thin film in which the polishing composition of the present embodiment is more preferably used includes a metal such as aluminum, nickel, tungsten, copper, tantalum, or titanium; a semimetal such as silicon; A glassy material such as glass, glassy carbon, or amorphous carbon; a ceramic material such as alumina, silicon dioxide, silicon nitride, tantalum nitride, or titanium nitride; a semiconductor device such as a resin such as a polyimide resin. A conventionally well-known thing is mention | raise | lifted as a material. Among these, the thin film preferably contains silicon for the reason that polishing with the polishing composition of the present embodiment works well, more preferably selected from the group consisting of silicon oxide, silicon nitride, and polysilicon. And at least one selected from the group consisting of silicon oxide and more preferably silicon oxide. Examples of silicon oxide include quartz, glass, silicon dioxide, and tetraethoxysilane (TEOS). The thin film containing silicon oxide may be doped with elements such as phosphorus and boron. Specific examples of such a thin film include BPSG (Boro-Phospho-Silicate Glass) film and PSG (Phospho-Silicate Glass). ) Membrane and the like. Since these elementally doped silicon oxide films are easier to polish than silicon oxide films that are not elementally doped, in the polishing composition, a larger amount of water solution is used to promote planarization. It is necessary to contain an organic compound. However, the polishing composition containing a large amount of the water-soluble organic compound has a problem that the composite oxide particles aggregate and settle. In an example of the polishing composition of this embodiment containing DHEG as the water-soluble organic compound, the aggregation of the composite oxide particles is sufficiently suppressed even when the DHEG content is, for example, 0.2 to 20% by weight. And dispersion stability is extremely high. Therefore, an example of the polishing composition is particularly suitable for polishing BPSG films, PSG films, and the like.

  The manufacturing method of the semiconductor device of the present embodiment allows the convex portions to be polished quickly, and from the viewpoint of enabling the formation of a polished surface with higher flatness, when the entire surface of the concave and convex surfaces is formed from the same material. Useful.

  The step (H) between the protrusions and the recesses adjacent to each other (see, for example, FIG. 4A) is preferably 50 to 2000 nm, more preferably 100 to 1500 nm. “Step (H)” means the distance between the apex of the convex portion and the bottom point of the concave portion, and can be determined by a profile measuring device (trade name HRP-100, manufactured by KLA Tencor).

  The material of the polishing pad used in the polishing process is not particularly limited, and conventionally known materials can be used. Examples of the material for the polishing pad include non-foamed and non-foamed organic polymer foams such as non-woven fabric and hard foamed polyurethane. Among them, hard foamed polyurethane is preferred.

From the viewpoint of further improving the polishing rate, the supply rate of the polishing liquid composition is preferably 0.01 g / min or more per 1 cm ^{2 of the} surface to be polished, more preferably 0.05 g / min or more, and further preferably 0.1 g / min. More than a minute. In addition, the supply rate of the polishing composition is preferably 10 g / min or less, more preferably 5 g / min or less, and further preferably 3 g / min, per 1 cm ^{2 of} the uneven surface, from the viewpoint of cost reduction and waste liquid treatment. It is as follows. Therefore, the supply rate of the polishing composition is preferably 0.01 to 10 g / min, more preferably 0.05 to 5 g / min, still more preferably 0.1 to 3 g / min per 1 cm ^{2 of the} surface to be polished. .

  The polishing liquid composition of the present embodiment is not limited to the one-liquid type supplied to the market in a state where all components are mixed in advance, and may be a two-liquid type mixed at the time of use. In the two-pack type polishing composition, the aqueous medium is divided into a first aqueous medium and a second aqueous medium, and the polishing liquid composition comprises composite oxide particles, a dispersant, and a first aqueous medium. An aqueous medium composition (I) containing, and an aqueous medium composition (II) containing a water-soluble organic compound and a second aqueous medium. The aqueous medium composition (I) may contain a part of the water-soluble organic compound in addition to the composite oxide particles and the dispersant. The aqueous medium composition (II) may contain part of the composite oxide particles and part of the dispersant in addition to the water-soluble organic compound.

  The mixing of the aqueous medium composition (I) and the aqueous medium composition (II) may be performed before supply to the uneven surface, or may be separately supplied and mixed on the uneven surface. The aqueous medium composition (II) (additive aqueous solution) used together with the aqueous medium composition (I) and containing the water-soluble organic compound and the second aqueous medium acts as a planarization promoting liquid during polishing. To do.

  Next, the content and the like of each component of an example of a two-pack type polishing liquid composition will be described. However, in this example, the aqueous medium composition (I) does not contain a water-soluble organic compound, and the aqueous medium composition (II) does not contain composite oxide particles and a dispersant.

  The content of each component in the two-part polishing liquid composition is that of the one-part polishing liquid composition when the aqueous medium composition (I) and the aqueous medium composition (II) are mixed. As long as it is the same, the content of the composite oxide particles in the aqueous medium composition (I), the content of the dispersant in the aqueous medium composition (I), the content in the aqueous medium composition (II) For example, the content of the water-soluble organic compound is preferably as follows.

  From the viewpoint of further improving the polishing rate, the content of the composite oxide particles in the aqueous medium composition (I) is preferably 0.1% by weight or more, more preferably 0.2% by weight or more, and still more preferably 0. .4% by weight or more, more preferably 0.5% by weight or more. Further, the content of the composite oxide particles in the aqueous medium composition (I) is preferably 8% by weight or less, more preferably 5% by weight or less, from the viewpoint of further improving the dispersion stability and cost reduction. More preferably, it is 4 weight% or less, More preferably, it is 3 weight% or less. Accordingly, the content of the composite oxide particles is preferably 0.1 to 8% by weight, more preferably 0.2 to 5% by weight, still more preferably 0.4 to 4% by weight, and still more preferably 0.5. ~ 3 wt%.

  From the viewpoint of further improving the dispersion stability, the content of the dispersant in the aqueous medium composition (I) is preferably 0.0005% by weight or more, more preferably 0.001% by weight or more, and still more preferably 0.00. 002% by weight or more. Further, the content of the dispersant in the aqueous medium composition (I) is preferably 0.5% by weight or less, more preferably 0.1% by weight or less, and still more preferably 0.05% by weight or less. Therefore, the content of the composite oxide particles is preferably 0.0005 to 0.5% by weight, more preferably 0.001 to 0.1% by weight, and still more preferably 0.002 to 0.05% by weight. .

  The content of the water-soluble organic compound in the aqueous medium composition (II) (additive aqueous solution) is preferably 0.04 to 60% by weight, more preferably 0. 0% from the viewpoint of obtaining a polished surface with excellent flatness. It is 1 to 50% by weight, more preferably 0.2 to 40% by weight, and still more preferably 0.4 to 30% by weight.

  The mixing ratio of the aqueous medium composition (I) and the aqueous medium composition (II) (additive aqueous solution) (weight of the aqueous medium composition (I) / weight of the aqueous medium composition (II)) is: Is preferably 1/2 to 50/1, more preferably 2/1 to 40/1, still more preferably 5/1 to 30/1, and still more preferably from the viewpoint of supply accuracy and a uniform mixed solution. Preferably it is 10/1-20/1.

  The pH of the aqueous medium composition (I) at 25 ° C. is preferably from 2 to 11, more preferably from 3 to 10, more preferably from 4 to 10, and even more preferably from 5 to 9 from the viewpoint of further improving the dispersion stability. It is.

  The preferred pH of the aqueous medium composition (II) at 25 ° C. varies depending on the type of the water-soluble organic compound, but polishing obtained by mixing the aqueous medium composition (II) and the aqueous medium composition (I). What is necessary is just to determine so that pH of a liquid composition may become the preferable pH mentioned above. For example, when the water-soluble organic compound is DHEG, the pH of the aqueous medium composition (II) at 25 ° C. is preferably 3 to 10, more preferably 3 from the viewpoint of further improving the dispersion stability of the composite oxide particles. It is -8, More preferably, it is 4-7, More preferably, it is 4-6.

  Whether the polishing composition is a one-component type or a two-component type, the polishing load set in the polishing apparatus equipped with the polishing pad has an adverse effect on the flattening caused by the load being too large and From the viewpoint of suppressing the occurrence of scratches, it is preferably 100 kPa or less, more preferably 70 kPa or less, and even more preferably 50 kPa or less. The set polishing load is preferably 5 kPa or more, more preferably 10 kPa or more, from the viewpoint of shortening the polishing time. Therefore, the set polishing load is preferably 5 to 100 kPa, more preferably 10 to 70 kPa, and still more preferably 10 to 50 kPa.

  The number of rotations of the polishing pad is preferably 30 to 200 rpm, more preferably 45 to 150 rpm, and still more preferably 60 to 100 rpm. As for the rotation speed of a grinding | polishing target object, 130-200 rpm is preferable, More preferably, it is 45-150 rpm, More preferably, it is 60-100 rpm.

  The polishing step can be used for any polishing in the manufacturing process of a semiconductor device. As specific examples, for example, (1) polishing performed in a step of forming an embedded isolation film, (2) polishing performed in a step of planarizing an interlayer insulating film, and (3) embedded metal wiring (for example, damascene wiring) Etc.) and (4) polishing performed in the step of forming the embedded capacitor. Especially, it is preferable that the polishing process performed in the manufacturing method of the semiconductor device of this embodiment is applied to (1) and (2).

  The manufacturing method of the semiconductor device of the present embodiment may include a cleaning process, a heat treatment process, an impurity diffusion process, and the like, if necessary.

  Examples of the semiconductor device include a memory IC (Integrated Circuit), a logic IC, and a system LSI (Large-Scale Integration).

  Next, polishing performed in the process of forming the buried element isolation film in the manufacturing process of the semiconductor device will be described with reference to the drawings.

As shown in FIG. 1A, a silicon nitride (Si ₃ N ₄ ) film 2 is formed on a silicon dioxide oxide film (not shown) formed by exposing the semiconductor substrate 1 to oxygen in an oxidation furnace, for example, by CVD. (Chemical vapor deposition method). Next, as shown in FIG. 1B, a shallow trench is formed using a photolithography technique. Next, as shown in FIG. 1C, an oxide film (SiO ₂ film) 3 for filling the trench is formed by, for example, a CVD method using silane gas and oxygen gas. The surface opposite to the side of the semiconductor substrate 1 of the oxide film 3 formed in this way has irregularities having a level difference H formed corresponding to the irregularities of the lower layer. Next, the oxide film 3 is polished by CMP until the surface of the silicon nitride film 2 and the surface of the oxide film 3 are substantially flush (see FIG. 1D). The polishing composition of this embodiment is used when polishing by this CMP method.

  Next, polishing performed in the step of planarizing the interlayer insulating film in the manufacturing process of the semiconductor device will be described with reference to the drawings.

As shown in FIG. 2A, a metal thin film (for example, an Al thin film) 19 is formed on one main surface of the semiconductor substrate 11 by sputtering, for example. In the example shown in FIG. 2A, a source 12 and a drain 13 are formed in the semiconductor substrate 11 as an impurity diffusion region doped with impurities. In this figure, below the metal thin film 19, there are a gate electrode 15 whose surface is silicided, sidewalls 14 disposed at both ends of the gate electrode 15, insulating layers 16 and 17 made of SiO _{2 and the} like. A tungsten plug 18 is disposed through the insulating layers 16 and 17 to connect the metal thin film 19 and the gate electrode 15 to each other.

  Next, as shown in FIG. 2B, the metal thin film 19 is patterned using a photolithography technique and a dry etching technique to form an extraction electrode 20. Thereby, the CMOS structure is completed.

Next, as shown in FIG. 3A, an oxide film (SiO ₂ film) 21 is formed by, for example, a CVD method using silane gas and oxygen gas. The opposite surface of the oxide film 21 to the surface facing the semiconductor substrate 11 has an unevenness having a step H formed corresponding to the unevenness of the lower layer. Next, the oxide film 21 is polished by CMP (see FIG. 3B). The polishing composition of this embodiment is used when polishing by this CMP method.

(Preparation of abrasive slurry)
(1) Ce _0.75 Zr _0.25 O ₂ particle slurry The fired product A (Ce _0.75 Zr _0.25 O ₂ particles) is wet-ground by a bead mill in water to which a dispersant (ammonium polyacrylate, weight average molecular weight 6000) has been added. Thus, a slurry of Ce _0.75 Zr _0.25 O ₂ particles having a volume median diameter of 150 nm (Ce _0.75 Zr _0.25 O ₂ particles: 25% by weight) was prepared. The fired product A is obtained by firing unfired Ce _0.75 Zr _0.25 O ₂ particles (trade name Actalys 9320, manufactured by Rhodia) in a continuous firing furnace at 1160 ° C. for 6 hours. The fired product A is obtained using a cerium (IV) compound and a zirconium (IV) compound as raw materials.

(2) CeO ₂ particle slurry CeO ₂ particles (product of Baikowski, purity 99.9%), which is a fired product by a bead mill, in water to which a dispersant (ammonium polyacrylate, weight average molecular weight 6000) is added. A slurry of CeO ₂ particles having a volume median diameter of 130 nm (CeO ₂ particles: 40% by weight) obtained by wet pulverization was prepared. The CeO ₂ particles are obtained using a cerium (IV) compound as a raw material.

(3) Ce _0.87 Zr _0.13 O ₂ particle slurry The fired product B (Ce _0.87 Zr _0.13 O ₂ particles) is wet-ground by a bead mill in water to which a dispersant (ammonium polyacrylate, weight average molecular weight 6000) has been added. A slurry of Ce _0.87 Zr _0.13 O ₂ particles having a volume median diameter of 150 nm (Ce _0.87 Zr _0.13 O ₂ particles: 25% by weight) was prepared. The fired product B is obtained by firing unfired Ce _0.87 Zr _0.13 O ₂ particles (manufactured by Rhodia) at 1100 ° C. for 6 hours in a continuous firing furnace. The fired product B is obtained using a cerium (IV) compound and a zirconium (IV) compound as raw materials.

(4) Ce _0.80 Zr _0.20 O ₂ particle slurry The fired product C (Ce _0.80 Zr _0.20 O ₂ particles) is wet-ground by a bead mill in water to which a dispersant (ammonium polyacrylate, weight average molecular weight 6000) has been added. Thus, a slurry of Ce _0.80 Zr _0.20 O ₂ particles having a volume median diameter of 150 nm (Ce _0.80 Zr _0.20 O ₂ particles: 25 wt%) was prepared. The fired product C is obtained by firing unfired Ce _0.80 Zr _0.20 O ₂ particles (trade name Actalys 9315, manufactured by Rhodia) at 1160 ° C. for 6 hours in a continuous firing furnace. The fired product C is obtained using a cerium (IV) compound and a zirconium (IV) compound as raw materials.

(5) Ce _0.62 Zr _0.38 O ₂ particle slurry The fired product D (Ce _0.62 Zr _0.38 O ₂ particles) is wet-ground by a bead mill in water to which a dispersant (ammonium polyacrylate, weight average molecular weight 6000) is added. Thus, a slurry of Ce _0.62 Zr _0.38 O ₂ particles having a volume median diameter of 150 nm (Ce _0.62 Zr _0.38 O ₂ particles: 25% by weight) was prepared. The fired product D is obtained by firing unfired Ce _0.62 Zr _0.38 O ₂ particles (trade name Actals 9330, manufactured by Rhodia) in a continuous firing furnace at 1240 ° C. for 6 hours. The fired product D is obtained using a cerium (IV) compound and a zirconium (IV) compound as raw materials.

The volume median diameters of the composite oxide particles and CeO ₂ particles were calculated as volume-based median diameters measured with a laser diffraction / scattering particle size distribution meter (trade name LA-920, Horiba Seisakusho).

The results of analyzing the composite oxide particles and CeO ₂ particles by X-ray diffraction are shown in Table 1 below. The measurement conditions by the powder X-ray diffraction method were as follows.
(Measurement condition)
Apparatus: Rigaku Co., Ltd., powder X-ray analyzer RINT2500VC
X-ray generation voltage: 40 kV
Radiation: Cu-Kα1 line (λ = 0.154050 nm)
Current: 120 mA
Scan Speed: 10 ° / min
Measurement step: 0.02 ° / min

  The height of the apex of each peak, the half width of the first peak, and the area of each peak are calculated from the obtained powder X-ray diffraction spectrum using the powder X-ray diffraction pattern comprehensive analysis software JADE (MDI) attached to the powder X-ray diffractometer. ). The calculation process by the software is performed based on an instruction manual (Jade (Ver. 5) software, instruction manual Manual No. MJ13133E02, Rigaku Corporation) of the software.

  When the peak derived from cerium oxide and / or the peak derived from zirconium oxide is present in the spectrum as the shoulder peak of the peak derived from the composite oxide, for example, the peak separation is performed by the above software, and the peak of each peak is obtained. The height and area of each peak can be determined.

Example 1
A polishing liquid composition was prepared as follows so as to have the composition shown in Table 2 below. First, DHEG (trade name Kyrest GA, manufactured by Kyrest Co., Ltd.) was mixed with ion-exchanged water. A slurry composition was prepared by adding a Ce _0.87 Zr _0.13 O ₂ particle slurry to the obtained mixed liquid while stirring the mixed liquid, and adjusting the pH to 6.2 with a 10% aqueous ammonia solution.

(Examples 2 and 3, Reference Example 1 )
Example 1 except that a Ce _0.80 Zr _0.20 O ₂ particle slurry, a Ce _0.75 Zr _0.25 O ₂ particle slurry, or a Ce _0.62 Zr _0.38 O ₂ particle slurry was used instead of the Ce _0.87 Zr _0.13 O ₂ particle slurry. Then, a polishing composition was prepared so as to have the composition shown in Table 2 below.

(Example 4 )
A polishing composition was prepared as follows so as to have the composition shown in Table 2 below. First , EDTA · 2NH ₄ (manufactured by Dojindo Laboratories) was mixed with ion-exchanged water. A slurry composition was prepared by adding a Ce _0.75 Zr _0.25 O ₂ particle slurry to the obtained mixed liquid while stirring the mixed liquid, and further adjusting the pH to 6.2 with a 10% aqueous ammonia solution.

(Example 5 )
A polishing composition was prepared as follows so as to have the composition shown in Table 2 below. First, L-aspartic acid (manufactured by Wako Pure Chemical Industries, Ltd.) was mixed with ion-exchanged water. While stirring the liquid mixture, 10% aqueous ammonia was added to the resulting liquid mixture to dissolve L-aspartic acid, and Ce _0.75 Zr _0.25 O ₂ particle slurry was further added. Finally, pH 6 was added with 10% aqueous ammonia. A polishing composition was prepared by adjusting to 0.0.

(Comparative Example 1)
CeO ₂ particle slurry was used instead of Ce _0.87 Zr _0.13 O ₂ particle slurry, and the content of DHEG (trade name: Kirest GA, manufactured by Cylest Co., Ltd.) was changed, and EDTA 2NH ₄ (Dojindo Laboratories Co., Ltd.) A polishing liquid composition shown in Table 2 below was prepared in the same manner as in Example 1 except that the product was added.

(Comparative Example 2)
A polishing liquid composition having the composition shown in Table 2 below was prepared in the same manner as in Example 1. That is, a slurry composition was prepared by adding Ce _0.75 Zr _0.25 O ₂ particle slurry to ion-exchanged water while stirring the ion-exchanged water, and adjusting the pH to 6.2 with 1% nitric acid.

(Sample for evaluation)
As an evaluation sample, a commercially available wafer for CMP characteristic evaluation (trade name: STI MIT 864, diameter 200 mm) was prepared. This sample for evaluation will be described with reference to FIGS. 4A and 5A to 5D are partially enlarged sectional views of the evaluation sample, FIG. 4B is a top view of the evaluation sample, and FIG. 4C is a partially enlarged view of FIG. 4B. As shown in FIG. 4A, the evaluation sample includes a silicon substrate and a silicon nitride film (hereinafter referred to as “Si ₃ N ₄ film”) having a thickness of 150 nm disposed thereon. The Si ₃ N ₄ film is formed by a CVD method. A groove having a depth of 500 nm (150 nm + 350 nm) is formed in the stacked body. On the Si ₃ N ₄ film, a silicon oxide film having a thickness of 600 nm (hereinafter referred to as “HDP film”) is disposed. The HDP film is formed by HDP-CVD (High Density Plasma Chemical Vapor Deposition). As shown in FIG. 4B, the plane of the HDP film is divided into 61 regions (20 mm × 20 mm), and each region is further divided into 25 small regions (4 mm × 4 mm). (FIG. 4C). In FIG. 4B, a black area (hereinafter referred to as “center”) is an area where thickness is measured as described later. In FIG. 4C, D20, D50, D90, and D100 20, 50, 90, and 100 respectively represent the ratio (convex surface density) of the total area of the convex portions visible when the small region is viewed in plan to the small region. Show. Partial enlarged cross-sectional views of the respective small regions are shown in FIGS. As shown in these drawings, a linear projection / recess pattern having a convex portion width of 20 μm and a concave portion width of 80 μm is formed on D20 (FIG. 5A), and a convex portion width of 50 μm and a concave portion width of 50 μm is formed on D50 (FIG. 5B). A linear uneven pattern is formed, and a linear uneven pattern having a convex portion width of 90 μm and a concave portion width of 10 μm is formed in D90 (FIG. 5C). Since D100 (FIG. 5D) consists entirely of convex portions, the concave-convex pattern is not formed.

(Polishing conditions)
Polishing tester: Single-side polishing machine (Part No .: LP-541, manufactured by Lapmaster SFT, surface plate diameter 540 mm)
Polishing pad: Part No. IC-1000 / Suba400 (made by Nitta Haas Co., Ltd.)
Surface plate rotation speed: 100 rpm
Head rotation speed: 110 rpm (Rotation direction is the same as the surface plate)
Polishing load: 30 kPa (setting value)
Polishing liquid supply amount: 200 mL / min (0.6 g / (cm ² · min))

  Using the polishing composition shown in Table 2, the sample for evaluation was polished under the above polishing conditions. After polishing the object to be polished, it was washed with running water using ion-exchanged water, and then ultrasonically washed (100 kHz, 3 min) while immersed in the ion-exchanged water. Further, it was washed with running water with ion-exchanged water, and finally dried by a spin dry method.

The end of polishing was determined using a torque measurement method. In this method, the end of polishing is determined by using a friction coefficient change between the surface to be polished and the polishing pad. Actually, the end of polishing was determined not by measuring the friction coefficient but by using the change in the drive current value of the surface plate on which the object to be polished was placed. At the initial stage of polishing, only the HDP film comes into contact with the polishing pad. However, at the end of polishing, the nitride film Si ₃ N ₄ is exposed and the friction coefficient changes, so that the driving current value of the surface plate also changes. When the nitride film Si ₃ N ₄ is exposed, the current value is saturated. The time when the saturation state was reached was defined as the polishing end point (EP), and polishing was further completed for 30 seconds (see FIG. 7). Therefore, the polishing time is (to the time taken to reach +30 in the EP from the time of polishing start) seconds. FIG. 7 shows an example of the change over time of the platen drive current value. The polishing time of Example 1 is 72 seconds, the polishing time of Example 2 is 93 seconds, the polishing time of Example 3 is 105 seconds, the polishing time of Reference Example 1 is 131 seconds, the polishing time of Example 4 is 85 seconds, The polishing time of Example 5 was 87 seconds, the polishing time of Comparative Example 1 was 150 seconds, and the polishing time of Comparative Example 2 was 85 seconds.

About the sample for evaluation after grinding | polishing, the residual film thickness in center was measured using the optical interference type film thickness meter (Brand name: VM-1000, Dainippon Screen Mfg. Co., Ltd. product). FIG. 6 shows a conceptual diagram of the sample for evaluation after polishing. As shown in FIG. 6, the measured remaining film thickness is ₃ of the film thickness (t1) of the convex HDP film, the film thickness (t2) of the Si ₃ N ₄ film, and the film thickness (t3) of the HDP film of the concave part. It is a kind.

Based on the obtained measurement results, the flatness was evaluated based on the criteria shown in Table 4 below. The evaluation results are shown in Table 3. The symbols (◯ and x) in Table 3 are based on the judgment criteria in Table 4. “Step Height” in Tables 4 and 3 is the difference between the film thickness at the convex part and the film thickness at the concave part after polishing, and the film thickness (t1) of the HDP film at the convex part. Using the values of the film thickness (t2) of the Si ₃ N ₄ film and the film thickness (t3) of the HDP film in the recess, it can be calculated from the following formula (see FIG. 6). The units of thickness in the following formula are all “nm”.
Step Height = {Si ₃ N ₄ film thickness (convex portion) + HDP film thickness (convex portion) +350} −HDP film thickness (concave portion) = (t2 + t1 + 350) −t3

  In general, the larger the convex surface density (the smaller the concave surface density), the thicker the remaining film in the convex portion, and the smaller the convex surface density (the higher the concave surface density), the more easily the concave portion is scraped and dishing phenomenon occurs. It is easy to happen. Therefore, the evaluation as to whether or not the polishing was sufficiently performed was performed based on the measurement results regarding D90 and D100 (no recess), and the evaluation of the dishing suppression effect was performed based on the measurement results regarding D20.

As shown in Table 3, in the samples for evaluation polished using the polishing liquid compositions of Examples 1 to 5 , the film thickness (t1) of the HDP film at the convex portion and the Si ₃ N ₄ film in all regions The film thickness (t2), the HDP film thickness (t3) in the recess, and the Step Height all met the criterion (circle) shown in Table 4. Therefore, in the polishing using the polishing liquid compositions of Examples 1 to 5 , it was confirmed that the occurrence of dishing was suppressed, the polishing was sufficiently performed, and a polishing surface with high flatness of the polishing surface was obtained. . Further, the polishing time was shorter than when the polishing composition of Comparative Example 1 was used.

In the evaluation sample polished using the polishing liquid composition of Comparative Example 1, the HDP film thickness (t1) and the Si ₃ N ₄ film thickness (t2) in the convex portion and the concave portion in all regions All of the HDP film thickness (t3) and Step Height were in accordance with the criterion (circle) shown in Table 4. However, in the polishing using the polishing liquid composition of Comparative Example 1, the polishing time was longer than when the polishing liquid compositions of Example 1 and Comparative Example 2 were used.

When the polishing liquid composition of Comparative Example 2 was used, the polishing time was shorter than when the polishing liquid composition of Example 3 was used, but dishing due to excessive polishing occurred in most areas, and the polishing surface It was found that there was a problem with the flatness of the.

  From the above results, it is found that if the uneven surface is polished using a polishing liquid composition containing predetermined composite oxide particles containing cerium and zirconium, a dispersant, a water-soluble organic compound, and an aqueous medium, It was confirmed that a polished surface with excellent properties could be formed in a short time.

  By polishing using the polishing composition of the present invention, a polished surface with excellent flatness can be formed in a short time. Therefore, the polishing liquid composition of the present invention is useful as a polishing liquid composition used in various semiconductor device manufacturing processes, and is particularly useful for the manufacture of ICs and LSIs.

A to D are process cross-sectional views illustrating an example of a method for manufacturing a semiconductor device of the present embodiment or an example of a polishing method of the present embodiment. A and B are process cross-sectional views illustrating another example of the semiconductor device manufacturing method of the present embodiment or another example of the polishing method of the present embodiment. A and B are process cross-sectional views illustrating another example of the semiconductor device manufacturing method of the present embodiment or another example of the polishing method of the present embodiment. A is a partially enlarged sectional view of an evaluation sample used in the examples of the present invention, B is a plan view of the evaluation sample, and C is an enlarged view of a part of B. A to D are partially enlarged sectional views of samples for evaluation used in the examples of the present invention. Conceptual diagram of the sample for evaluation after polishing Graph showing time-dependent change of platen drive current value

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,11 Semiconductor substrate 2 Silicon nitride film 3, 16, 17, 21 Oxide film 12 Source 13 Drain 14 Side wall 15 Gate electrode 18 Tungsten plug 19 Metal thin film 20 Lead electrode

Claims (9)

A polishing composition comprising a composite oxide particle containing cerium and zirconium, a dispersant, a water-soluble organic compound, and an aqueous medium,
In the powder X-ray diffraction spectrum of the composite oxide particles obtained by irradiating with CuKα1 rays (λ = 0.154050 nm),
Diffraction angle 2θ (θ is a black angle) region 28. 729 to 2. 8. Peak having a peak within 8.870 ° (first peak),
Diffraction angle 2θ region 33. Peaks have vertices 293-3 3.471 in ° (second peak),
Diffraction angle 2θ region 4 7.824 to 4 8.049 ° peak (third peak) and Diffraction angle 2θ region 5 6.762 to 5 7.012 ° peak (fourth) Each peak),
The half-width of the first peak is 0.300 to 0.347 ;
In the powder X-ray diffraction spectrum , the peak is derived from cerium oxide , the peak is derived from a peak a ₁ having a diffraction angle 2θ region of 28.40 to 28.59 ° , and zirconium oxide, and the peak is a diffraction angle 2θ. region from 29.69 to 31.60 peak a ₂ present in ° is not present, the polishing composition. The area of the second peak is 10 to 50% of the area of the first peak,
The area of the third peak is 35 to 75% of the area of the first peak,
The polishing liquid composition according to claim 1, wherein an area of the fourth peak is 20 to 65% of an area of the first peak.   The polishing liquid composition according to claim 1, wherein the water-soluble organic compound contains a zwitterionic water-soluble low-molecular organic compound.   The polishing composition according to any one of claims 1 to 3, wherein a volume median diameter of the composite oxide particles is 30 to 1000 nm.   In the total amount of the polishing liquid composition, 0.1 to 8% by weight of the composite oxide particles, 0.0005 to 0.5% by weight of the dispersant, and 0.02 to 15% by weight of the water-soluble organic compound are contained. The polishing liquid composition according to any one of claims 1 to 4.   The composite oxide particles are contained in an amount of 1 to 20% by weight, the dispersant is 0.001 to 1.0% by weight, and the water-soluble organic compound is 0.08 to 40% by weight in the total amount of the polishing composition. Item 5. The polishing composition according to any one of Items 1 to 4. The aqueous medium includes a first aqueous medium and a second aqueous medium,
An aqueous medium composition (I) comprising the composite oxide particles, the dispersant, and the first aqueous medium;
An aqueous medium composition (II) comprising the water-soluble organic compound and the second aqueous medium;
The polishing composition according to any one of claims 1 to 4, which is a two-component type.   The polishing liquid composition according to any one of claims 1 to 7 is supplied between a polishing object and a polishing pad, and the polishing pad is in a state where the polishing object and the polishing pad are in contact with each other. A polishing method comprising a step of polishing the polishing object by causing relative movement with respect to the polishing object. A thin film forming process in which one main surface on the semiconductor substrate forms a thin film on the alligator;
A method for manufacturing a semiconductor device, comprising: a polishing step of polishing the thin film using the polishing composition according to claim 1.

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