WO2019182057A1 - Suspension é paisse, ensemble suspension épaisse et procédé de polissage - Google Patents

Suspension é paisse, ensemble suspension épaisse et procédé de polissage Download PDF

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Publication number
WO2019182057A1
WO2019182057A1 PCT/JP2019/011853 JP2019011853W WO2019182057A1 WO 2019182057 A1 WO2019182057 A1 WO 2019182057A1 JP 2019011853 W JP2019011853 W JP 2019011853W WO 2019182057 A1 WO2019182057 A1 WO 2019182057A1
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Prior art keywords
polishing
mass
less
preferable
liquid
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PCT/JP2019/011853
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English (en)
Japanese (ja)
Inventor
友洋 岩野
貴彬 松本
友美 久木田
智康 長谷川
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日立化成株式会社
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Priority claimed from PCT/JP2018/011464 external-priority patent/WO2019180887A1/fr
Application filed by 日立化成株式会社 filed Critical 日立化成株式会社
Publication of WO2019182057A1 publication Critical patent/WO2019182057A1/fr

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    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K3/00—Materials not provided for elsewhere
    • C09K3/14—Anti-slip materials; Abrasives
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
    • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
    • H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
    • H01L21/302—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to change their surface-physical characteristics or shape, e.g. etching, polishing, cutting
    • H01L21/304—Mechanical treatment, e.g. grinding, polishing, cutting

Definitions

  • the present invention relates to a polishing liquid, a polishing liquid set, and a polishing method.
  • CMP Chemical Mechanical Polishing
  • STI shallow trench isolation
  • Examples of the most frequently used polishing liquid include silica-based polishing liquids containing silica (silicon oxide) particles such as fumed silica and colloidal silica as abrasive grains.
  • the silica-based polishing liquid is characterized by high versatility, and a wide variety of materials can be polished regardless of insulating materials and conductive materials by appropriately selecting the abrasive content, pH, additives, and the like.
  • a polishing liquid mainly for an insulating material such as silicon oxide the demand for a polishing liquid containing cerium compound particles as an abrasive is also increasing.
  • a cerium oxide-based polishing liquid containing cerium oxide particles as abrasive grains can polish silicon oxide at high speed even with a lower abrasive grain content than a silica-based polishing liquid (see, for example, Patent Documents 1 and 2 below).
  • JP-A-10-106994 Japanese Patent Application Laid-Open No. 08-022970
  • a laminated body having an insulating material (e.g., silicon oxide) disposed on the substrate is polished. In such polishing, the polishing of the insulating material is stopped by the stopper. That is, the polishing of the insulating material is stopped when the stopper is exposed.
  • the polishing amount of the insulating material for example, the film thickness to be removed in the insulating film
  • the degree of polishing is controlled by polishing the insulating material until the stopper is exposed. Yes.
  • an object of the present invention is to provide a polishing liquid, a polishing liquid set, and a polishing method capable of improving the polishing selectivity of an insulating material with respect to a stopper material.
  • the polishing liquid according to one aspect of the present invention contains abrasive grains, polyol, aminocarboxylic acid, aminosulfonic acid, and liquid medium, and the abrasive grains have a positive zeta potential.
  • Such a polishing liquid can improve the polishing selectivity of the insulating material with respect to the stopper material.
  • the constituents of the polishing liquid described above are stored separately in a first liquid and a second liquid, and the first liquid contains the abrasive grains, A liquid medium, and the second liquid includes the polyol, the aminocarboxylic acid, the aminosulfonic acid, and a liquid medium. According to such a polishing liquid set, the same effects as those of the above-described polishing liquid can be obtained.
  • a polishing method is performed using the above polishing liquid or a polishing liquid obtained by mixing the first liquid and the second liquid in the above polishing liquid set.
  • a polishing step for polishing the polishing surface is provided. According to such a polishing method, the same effect as that of the above-described polishing liquid can be obtained.
  • the polishing selectivity of the insulating material with respect to the stopper material can be improved.
  • ADVANTAGE OF THE INVENTION According to this invention, use of the polishing liquid can be provided for the planarization process of the base
  • a numerical range indicated by using “to” indicates a range including the numerical values described before and after “to” as the minimum value and the maximum value, respectively.
  • the upper limit value or lower limit value of a numerical range of a certain step can be arbitrarily combined with the upper limit value or lower limit value of the numerical range of another step.
  • the upper limit value or the lower limit value of the numerical range may be replaced with the values shown in the examples. “A or B” only needs to include either A or B, and may include both.
  • the materials exemplified in this specification can be used singly or in combination of two or more unless otherwise specified.
  • each component in the composition is the total amount of the plurality of substances present in the composition unless there is a specific notice when there are a plurality of substances corresponding to each component in the composition.
  • the term “process” is not limited to an independent process, and is included in this term if the intended effect of the process is achieved even when it cannot be clearly distinguished from other processes.
  • polishing liquid is defined as a composition that touches the surface to be polished during polishing.
  • the phrase “polishing liquid” itself does not limit the components contained in the polishing liquid.
  • the polishing liquid according to the present embodiment contains abrasive grains.
  • Abrasive grains are also referred to as “abrasive particles”, but are referred to herein as “abrasive grains”.
  • Abrasive grains are generally solid particles, and are removed by mechanical action (physical action) of abrasive grains and chemical action of abrasive grains (mainly the surface of the abrasive grains) during polishing. Although it is considered that an object is removed, the present invention is not limited to this.
  • the polishing liquid according to this embodiment is, for example, a polishing liquid for CMP.
  • the polishing liquid according to this embodiment contains abrasive grains, polyol, aminocarboxylic acid, aminosulfonic acid, and a liquid medium, and the zeta potential of the abrasive grains is positive.
  • the polishing selectivity (insulating material polishing rate / stopper material polishing rate) of an insulating material (eg, silicon oxide) with respect to a stopper material (eg, silicon nitride) can be improved.
  • the present inventors presume the factors that achieve such an effect as follows. However, the factors are not limited to the following. That is, zwitterionic compounds such as aminocarboxylic acid and aminosulfonic acid have a cation part (for example, amino group) and an anion part (for example, carboxyl group and sulfonic acid group) in the same molecule.
  • aminocarboxylic acid and aminosulfonic acid When aminocarboxylic acid and aminosulfonic acid are used after using polyol, aminocarboxylic acid and aminosulfonic acid can adhere to the surface of the stopper. At this time, the anion portion adheres to the stopper, and the cation portion faces outward with respect to the stopper. In this case, since the surface of the stopper to which the zwitterionic compound adheres is positively charged, the surface of the stopper repels abrasive grains having a positive zeta potential. Thereby, the polishing rate of the stopper material is suppressed. On the other hand, when the polyol adheres to the surface of the abrasive grains, the surface of the abrasive grains becomes hydrophilic.
  • Insulating materials eg, silicon oxide
  • stopper materials tend to be more hydrophilic than stopper materials, and thus have an affinity for polyols having hydroxyl groups.
  • rate of an insulating material improves.
  • the polishing selectivity of the insulating material with respect to the stopper material is improved.
  • the polishing liquid according to the present embodiment contains abrasive grains having a positive zeta potential in the polishing liquid.
  • Abrasive grains are made of cerium oxide (for example, ceria (cerium (IV) oxide)), silica, alumina, zirconia, yttria, and hydroxides of tetravalent metal elements from the viewpoint of easily polishing an insulating material at a high polishing rate.
  • cerium oxide for example, ceria (cerium (IV) oxide)
  • silica silica
  • alumina alumina
  • zirconia zirconia
  • yttria yttria
  • hydroxides of tetravalent metal elements from the viewpoint of easily polishing an insulating material at a high polishing rate.
  • at least one selected from the group consisting of cerium oxide is included.
  • An abrasive can be used individually by 1 type or in combination of 2 or more types.
  • the “tetravalent metal element hydroxide” is a compound containing a tetravalent metal (M 4+ ) and at least one hydroxide ion (OH ⁇ ).
  • the hydroxide of the tetravalent metal element may contain anions other than hydroxide ions (for example, nitrate ions NO 3 ⁇ and sulfate ions SO 4 2 ⁇ ).
  • a hydroxide of a tetravalent metal element may include an anion (for example, nitrate ion NO 3 ⁇ and sulfate ion SO 4 2 ⁇ ) bonded to the tetravalent metal element.
  • a hydroxide of a tetravalent metal element can be produced by reacting a salt (metal salt) of a tetravalent metal element with an alkali source (base).
  • the tetravalent metal element hydroxide preferably contains cerium hydroxide (tetravalent cerium hydroxide) from the viewpoint of easily improving the polishing rate of the insulating material.
  • Cerium hydroxide can be produced by reacting a cerium salt with an alkali source (base).
  • the cerium hydroxide is preferably prepared by mixing a cerium salt and an alkaline solution (for example, an alkaline aqueous solution). Thereby, particles having a very small particle diameter can be obtained, and an excellent polishing scratch reduction effect can be easily obtained.
  • Cerium hydroxide can be obtained by mixing a cerium salt solution (for example, a cerium salt aqueous solution) and an alkali solution. Examples of the cerium salt include Ce (NO 3 ) 4 , Ce (SO 4 ) 2 , Ce (NH 4 ) 2 (NO 3 ) 6 , Ce (NH 4 ) 4 (SO 4 ) 4 and the like.
  • Ce (OH) a X b electron-withdrawing anions (X c ⁇ ) act to improve the reactivity of hydroxide ions, and the abundance of Ce (OH) a X b increases. It is considered that the polishing rate is improved with this.
  • Examples of the anion (X c ⁇ ) include NO 3 ⁇ and SO 4 2 ⁇ . It is considered that the particles containing cerium hydroxide can contain not only Ce (OH) a X b but also Ce (OH) 4 , CeO 2 and the like.
  • the particles containing cerium hydroxide contain Ce (OH) a Xb after the particles are thoroughly washed with pure water and then subjected to FT-IR ATR method (Fourier transformed Infrared Spectrometer Total Reflection method, Fourier transform infrared) This can be confirmed by a method of detecting a peak corresponding to an anion (X c ⁇ ) by a spectrophotometer total reflection measurement method). The presence of an anion (X c ⁇ ) can also be confirmed by XPS (X-ray Photoelectron Spectroscopy, X-ray photoelectron spectroscopy).
  • the lower limit of the content of cerium oxide is based on the whole abrasive grains (the whole abrasive grains contained in the polishing liquid; the same applies hereinafter) from the viewpoint of easily improving the polishing rate of the insulating material.
  • the lower limit of the average particle size of the abrasive grains in the slurry in the polishing liquid or the polishing liquid set described below is preferably 16 nm or more, more preferably 20 nm or more, and more preferably 30 nm or more. More preferably, 40 nm or more is particularly preferable, 50 nm or more is very preferable, 100 nm or more is very preferable, 120 nm or more is more preferable, 150 nm or more is more preferable, and 155 nm or more is still more preferable.
  • the upper limit of the average grain size of the abrasive grains is preferably 1050 nm or less, more preferably 1000 nm or less, still more preferably 800 nm or less, particularly preferably 600 nm or less, and particularly preferably 500 nm or less, from the viewpoint of easily suppressing scratches on the surface to be polished.
  • 400 nm or less is very preferable, 300 nm or less is still more preferable, 200 nm or less is more preferable, and 160 nm or less is still more preferable.
  • the average particle size of the abrasive grains is more preferably 16 to 1050 nm, and further preferably 20 to 1000 nm.
  • the “average particle diameter” of the abrasive grains means the average secondary particle diameter of the abrasive grains.
  • the average particle diameter of the abrasive grains is a volume average particle diameter, and a light diffraction scattering type particle size distribution meter (for example, a product manufactured by Microtrack Bell Co., Ltd.) is used for a polishing liquid or a slurry in a polishing liquid set described later. Name: Microtrack MT3300EXII).
  • the zeta potential (surface potential) of the abrasive grains in the polishing liquid is positive from the viewpoint of suppressing the polishing rate of the stopper material (the zeta potential exceeds 0 mV).
  • the lower limit of the zeta potential of the abrasive is preferably 10 mV or more, more preferably 20 mV or more, further preferably 25 mV or more, particularly preferably 30 mV or more, and particularly preferably 40 mV or more, from the viewpoint of easily suppressing the polishing rate of the stopper material. 50 mV or more is very preferable.
  • the upper limit of the zeta potential of the abrasive grains is not particularly limited, but is preferably 200 mV or less. From these viewpoints, the zeta potential of the abrasive grains is more preferably 10 to 200 mV.
  • the zeta potential of the abrasive grains can be measured using, for example, a dynamic light scattering type zeta potential measuring device (for example, trade name: DelsaNano C, manufactured by Beckman Coulter, Inc.).
  • the zeta potential of the abrasive can be adjusted using an additive. For example, by bringing a monocarboxylic acid (for example, acetic acid) into contact with abrasive grains containing cerium oxide, abrasive grains having a positive zeta potential can be obtained.
  • a monocarboxylic acid for example, acetic acid
  • the abrasive grain which has a negative zeta potential can be obtained by making the material (for example, polyacrylic acid) which has ammonium dihydrogen phosphate, a carboxyl group, etc. with the abrasive grain containing a cerium oxide.
  • the lower limit of the abrasive content is preferably 0.005% by mass or more, more preferably 0.01% by mass or more, based on the total mass of the polishing liquid, from the viewpoint of easily improving the polishing rate of the insulating material.
  • 0.02% by mass or more is more preferable, 0.03% by mass or more is particularly preferable, 0.04% by mass or more is very preferable, 0.05% by mass or more is very preferable, and 0.07% by mass or more is even more preferable.
  • 0.1 mass% or more is more preferable.
  • the upper limit of the abrasive content is preferably 20% by mass or less, more preferably 15% by mass or less, and more preferably 10% by mass based on the total mass of the polishing liquid from the viewpoint of easily obtaining excellent abrasive dispersion stability.
  • the following is more preferable, 5% by mass or less is particularly preferable, 4% by mass or less is very preferable, 3% by mass or less is very preferable, 1% by mass or less is more preferable, 0.5% by mass or less is more preferable, Is more preferably 3% by mass or less, particularly preferably 0.2% by mass or less, and extremely preferably 0.15% by mass or less.
  • the content of the abrasive grains is more preferably 0.005 to 20% by mass, and still more preferably 0.01 to 10% by mass based on the total mass of the polishing liquid.
  • the abrasive grains may include composite particles composed of a plurality of particles in contact with each other.
  • the abrasive grains may include composite particles including first particles and second particles in contact with the first particles, and the composite particles and free particles (eg, contact with the first particles). Second particles).
  • the abrasive includes first particles and second particles in contact with the first particles, and the particle size of the second particles is larger than the particle size of the first particles. It is preferable that the first particles contain cerium oxide and the second particles contain a cerium compound. By using such abrasive grains, it is easy to improve the polishing rate of the insulating material (for example, silicon oxide). As the reason why the polishing rate of the insulating material is improved as described above, for example, the following reasons can be given. However, the reason is not limited to the following.
  • the first particles containing cerium oxide and having a larger particle size than the second particles have a stronger mechanical action (mechanical property) on the insulating material than the second particles.
  • the second particle containing a cerium compound and having a smaller particle size than the first particle has a smaller mechanical action on the insulating material than the first particle, but the specific surface area of the entire particle. Since (surface area per unit mass) is large, the chemical action (chemical property) on the insulating material is strong. Thus, a synergistic effect of improving the polishing rate can be easily obtained by using the first particles having a strong mechanical action and the second particles having a strong chemical action in combination.
  • cerium compound of the second particles examples include cerium hydroxide and cerium oxide.
  • cerium compound of the second particles a compound different from cerium oxide can be used.
  • the cerium compound preferably contains cerium hydroxide from the viewpoint of easily improving the polishing rate of the insulating material.
  • the particle size of the second particles is preferably smaller than the particle size of the first particles.
  • the magnitude relationship between the particle sizes of the first particles and the second particles can be determined from the SEM image of the composite particles.
  • particles having a small particle size have a high reaction activity because they have a larger surface area per unit mass than particles having a large particle size.
  • the mechanical action (mechanical polishing force) of particles having a small particle size is smaller than that of particles having a large particle size.
  • even when the particle size of the second particle is smaller than the particle size of the first particle, it is possible to express the synergistic effect of the first particle and the second particle. Yes, it is possible to easily achieve both excellent reaction activity and mechanical action.
  • the lower limit of the particle size of the first particles is preferably 15 nm or more, more preferably 25 nm or more, further preferably 35 nm or more, particularly preferably 40 nm or more, and particularly preferably 50 nm or more from the viewpoint of easily improving the polishing rate of the insulating material.
  • the upper limit of the particle size of the first particles is preferably 1000 nm or less, more preferably 800 nm or less, from the viewpoint that the dispersibility of the abrasive grains is easily improved and the viewpoint that the surface to be polished is easily suppressed from being damaged.
  • the particle size of the first particles is more preferably 15 to 1000 nm.
  • the above-mentioned range may be sufficient as the average particle diameter (average secondary particle diameter) of 1st particle
  • the lower limit of the particle size of the second particles is preferably 1 nm or more, more preferably 2 nm or more, and further preferably 3 nm or more from the viewpoint of easily improving the polishing rate of the insulating material.
  • the upper limit of the particle size of the second particles is preferably 50 nm or less, more preferably 30 nm or less, from the viewpoint that the dispersibility of the abrasive grains is easily improved and the viewpoint that the surface to be polished is easily suppressed from being scratched. 25 nm or less is more preferable, 20 nm or less is particularly preferable, 15 nm or less is extremely preferable, and 10 nm or less is very preferable. From these viewpoints, the particle size of the second particles is more preferably 1 to 50 nm. The above-mentioned range may be sufficient as the average particle diameter (average secondary particle diameter) of a 2nd particle.
  • the first particle can have a negative zeta potential.
  • the second particle can have a positive zeta potential.
  • an aqueous dispersion (a mixture of abrasive grains and water) in which the content of the abrasive grains is adjusted to 1.0% by mass is centrifuged at 5.8. It is preferable to give a liquid phase (supernatant liquid) whose absorbance with respect to light having a wavelength of 380 nm exceeds 0 when centrifuged at ⁇ 10 4 G for 5 minutes. In this case, it is easy to improve the polishing rate of the insulating material (for example, silicon oxide).
  • the insulating material for example, silicon oxide
  • the reason is not limited to the following. That is, when the absorbance with respect to light having a wavelength of 380 nm in the liquid phase obtained by centrifuging the aqueous dispersion exceeds 0, in such centrifugation, the composite particles are easily selectively removed, and the free particles are separated from the solid content.
  • the abrasive grains contain free particles in addition to the composite particles. Since the free particles have a smaller particle size than the composite particles, the diffusion rate is high, and the free particles are preferentially adsorbed on the surface of the insulating material to cover the surface.
  • the composite particles not only act directly on the insulating material, but also act on the free particles adsorbed on the insulating material and can indirectly act on the insulating material (for example, adsorbing on the insulating material). Physical action can be transferred to the insulating material via the free particles). It is assumed that this makes it easier to improve the polishing rate of the insulating material.
  • the above-mentioned absorbance with respect to light having a wavelength of 380 nm is preferably in the following range.
  • the lower limit of the absorbance is preferably 0.001 or more, more preferably 0.0015 or more, and further preferably 0.002 or more from the viewpoint of further improving the polishing rate of the insulating material.
  • the upper limit of the absorbance is preferably 0.5 or less, more preferably 0.4 or less, still more preferably 0.3 or less, and particularly preferably 0.25 or less, from the viewpoint of further improving the polishing rate of the insulating material.
  • the absorbance is more preferably greater than 0 and not greater than 0.5.
  • the absorbance can be adjusted by adjusting the content of free particles in the abrasive grains. For example, increasing the surface area of the first particle that is in contact with the second particle, adjusting the dispersion state to be insufficient when the first particle is brought into contact with the second particle (decreasing the dispersion time)
  • the absorbance can be reduced by reducing the number of rotations in stirring the liquid containing the first particles and the second particles, weakening the electrostatic repulsive force generated between the particles, or the like.
  • abrasive grains having an absorbance of 0 with respect to the above-described light having a wavelength of 380 nm may be used.
  • Such abrasive grains can be obtained by removing free particles by centrifugation.
  • Abrasive grains are prepared from an aqueous dispersion (a mixture of abrasive grains and water) in which the content of the abrasive grains is adjusted to 1.0 mass% from the viewpoint of further improving the polishing rate of an insulating material (for example, silicon oxide).
  • an insulating material for example, silicon oxide.
  • the lower limit of the light transmittance is preferably 50% / cm or more, more preferably 60% / cm or more, further preferably 70% / cm or more, particularly preferably 80% / cm or more, and extremely 90% / cm or more. Preferably, 92% / cm or more is very preferable.
  • the upper limit of the light transmittance is 100% / cm.
  • the composite particle including the first particle and the second particle is obtained by bringing the first particle and the second particle into contact with each other using a homogenizer, a nanomizer, a ball mill, a bead mill, a sonicator, or the like, and mutually opposite charges. It can be obtained by contacting the first particles having the second particles with the second particles, contacting the first particles with the second particles in a state where the content of the particles is small, and the like.
  • the lower limit of the content of the cerium oxide in the first particle is the entire first particle (the entire first particle contained in the polishing liquid; the same applies hereinafter) from the viewpoint of easily improving the polishing rate of the insulating material.
  • 50 mass% or more is preferable, 70 mass% or more is more preferable, 90 mass% or more is further preferable, and 95 mass% or more is particularly preferable.
  • the first particle may be in an aspect substantially composed of cerium oxide (an aspect in which 100% by mass of the first particle is substantially cerium oxide).
  • the lower limit of the content of the cerium compound in the second particle is based on the entire second particle (the entire second particle contained in the polishing liquid; the same applies hereinafter) from the viewpoint of easily improving the polishing rate of the insulating material. 50 mass% or more is preferable, 70 mass% or more is more preferable, 90 mass% or more is further more preferable, and 95 mass% or more is especially preferable.
  • the second particle may be in an aspect substantially composed of a cerium compound (an aspect in which 100% by mass of the second particle is substantially a cerium compound).
  • the content of the first particles in the abrasive grains containing composite particles is preferably in the following range based on the entire abrasive grains.
  • the lower limit of the content of the first particles is preferably 50% by mass or more, more preferably more than 50% by mass, still more preferably 60% by mass or more, and 70% by mass from the viewpoint of easily improving the polishing rate of the insulating material.
  • % Or more is particularly preferable, 75% by weight or more is very preferable, 80% by weight or more is very preferable, 85% by weight or more is even more preferable, and 90% by weight or more is more preferable.
  • the upper limit of the content of the first particles is preferably 95% by mass or less, more preferably 93% by mass or less, and still more preferably 91% by mass or less from the viewpoint of easily improving the polishing rate of the insulating material. From these viewpoints, the content of the first particles is more preferably 50 to 95% by mass.
  • the content of the second particles in the abrasive grains containing composite particles is preferably in the following range based on the entire abrasive grains.
  • the lower limit of the content of the second particles is preferably 5% by mass or more, more preferably 7% by mass or more, and still more preferably 9% by mass or more from the viewpoint of easily improving the polishing rate of the insulating material.
  • the upper limit of the content of the second particles is preferably 50% by mass or less, more preferably less than 50% by mass, still more preferably 40% by mass or less, and further preferably 30% by mass or less from the viewpoint of easily improving the polishing rate of the insulating material.
  • the content of the second particles is more preferably 5 to 50% by mass.
  • the content of cerium oxide in the abrasive grains containing composite particles is preferably in the following range based on the entire abrasive grains.
  • the lower limit of the cerium oxide content is preferably 50% by mass or more, more preferably more than 50% by mass, still more preferably 60% by mass or more, and 70% by mass from the viewpoint of easily improving the polishing rate of the insulating material.
  • the above is particularly preferable, 75% by mass or more is very preferable, 80% by mass or more is very preferable, 85% by mass or more is more preferable, and 90% by mass or more is more preferable.
  • the upper limit of the cerium oxide content is preferably 95% by mass or less, more preferably 93% by mass or less, and still more preferably 91% by mass or less from the viewpoint of easily improving the polishing rate of the insulating material. From these viewpoints, the content of cerium oxide is more preferably 50 to 95% by mass.
  • the content of cerium hydroxide in the abrasive grains containing composite particles is preferably in the following range based on the entire abrasive grains.
  • the lower limit of the cerium hydroxide content is preferably 5% by mass or more, more preferably 7% by mass or more, and still more preferably 9% by mass or more from the viewpoint of easily improving the polishing rate of the insulating material.
  • the upper limit of the cerium hydroxide content is preferably 50% by mass or less, more preferably less than 50% by mass, still more preferably 40% by mass or less, and further preferably 30% by mass or less from the viewpoint of easily improving the polishing rate of the insulating material.
  • cerium hydroxide is more preferably 5 to 50% by mass.
  • the content of the first particles is preferably in the following range based on the total amount of the first particles and the second particles.
  • the lower limit of the content of the first particles is preferably 50% by mass or more, more preferably more than 50% by mass, still more preferably 60% by mass or more, and 70% by mass from the viewpoint of easily improving the polishing rate of the insulating material. % Or more is particularly preferable, 75% by weight or more is very preferable, 80% by weight or more is very preferable, 85% by weight or more is even more preferable, and 90% by weight or more is more preferable.
  • the upper limit of the content of the first particles is preferably 95% by mass or less, more preferably 93% by mass or less, and still more preferably 91% by mass or less from the viewpoint of easily improving the polishing rate of the insulating material. From these viewpoints, the content of the first particles is more preferably 50 to 95% by mass.
  • the content of the second particles is preferably in the following range based on the total amount of the first particles and the second particles.
  • the lower limit of the content of the second particles is preferably 5% by mass or more, more preferably 7% by mass or more, and still more preferably 9% by mass or more from the viewpoint of easily improving the polishing rate of the insulating material.
  • the upper limit of the content of the second particles is preferably 50% by mass or less, more preferably less than 50% by mass, still more preferably 40% by mass or less, and further preferably 30% by mass or less from the viewpoint of easily improving the polishing rate of the insulating material.
  • the content of the second particles is more preferably 5 to 50% by mass.
  • the content of the first particles in the polishing liquid is preferably in the following range based on the total mass of the polishing liquid.
  • the lower limit of the content of the first particles is preferably 0.005% by mass or more, more preferably 0.008% by mass or more, and further preferably 0.01% by mass or more from the viewpoint of easily improving the polishing rate of the insulating material.
  • 0.05% by mass or more is particularly preferable, 0.08% by mass or more is very preferable, and 0.09% by mass or more is very preferable.
  • the upper limit of the content of the first particles is preferably 5% by mass or less, more preferably 3% by mass or less, still more preferably 1% by mass or less, from the viewpoint of easily increasing the storage stability of the polishing liquid.
  • Mass% or less is particularly preferable, 0.3 mass% or less is very preferable, 0.2 mass% or less is very preferable, and 0.1 mass% or less is even more preferable. From these viewpoints, the content of the first particles is more preferably 0.005 to 5% by mass.
  • the content of the second particles in the polishing liquid is preferably in the following range based on the total mass of the polishing liquid.
  • the lower limit of the content of the second particles is preferably 0.005% by mass or more from the viewpoint of further improving the chemical interaction between the abrasive grains and the surface to be polished and improving the polishing rate of the insulating material, 0.008 mass% or more is more preferable, and 0.009 mass% or more is still more preferable.
  • the upper limit of the content of the second particles makes it easy to avoid agglomeration of the abrasive grains, and further improves the chemical interaction between the abrasive grains and the surface to be polished, thereby effectively utilizing the characteristics of the abrasive grains.
  • 5% by mass or less is preferable, 3% by mass or less is more preferable, 1% by mass or less is more preferable, 0.5% by mass or less is particularly preferable, 0.1% by mass or less is extremely preferable, 05% by mass or less is very preferable, 0.04% by mass or less is more preferable, 0.035% by mass or less is more preferable, 0.03% by mass or less is further preferable, and 0.02% by mass or less is particularly preferable. 0.01 mass% or less is very preferable. From these viewpoints, the content of the second particles is more preferably 0.005 to 5% by mass.
  • the content of cerium oxide in the polishing liquid containing abrasive grains including composite particles is preferably in the following range based on the total mass of the polishing liquid.
  • the lower limit of the cerium oxide content is preferably 0.005% by mass or more, more preferably 0.008% by mass or more, and still more preferably 0.01% by mass or more from the viewpoint of easily improving the polishing rate of the insulating material.
  • 0.05 mass% or more is particularly preferable, 0.08 mass% or more is extremely preferable, and 0.09 mass% or more is very preferable.
  • the upper limit of the cerium oxide content is preferably 5% by mass or less, more preferably 3% by mass or less, still more preferably 1% by mass or less, and 0.5% by mass from the viewpoint of easily increasing the storage stability of the polishing liquid. % Or less is particularly preferable, 0.3% by mass or less is very preferable, 0.2% by mass or less is very preferable, and 0.1% by mass or less is even more preferable. From these viewpoints, the content of the cerium oxide is more preferably 0.005 to 5% by mass.
  • the content of cerium hydroxide in the polishing liquid containing abrasive grains including composite particles is preferably in the following range based on the total mass of the polishing liquid.
  • the lower limit of the content of cerium hydroxide is preferably 0.005% by mass or more from the viewpoint of further improving the chemical interaction between the abrasive grains and the surface to be polished and improving the polishing rate of the insulating material, 0.008 mass% or more is more preferable, and 0.009 mass% or more is still more preferable.
  • the upper limit of the content of cerium hydroxide makes it easier to avoid agglomeration of the abrasive grains, and further improves the chemical interaction between the abrasive grains and the surface to be polished, effectively utilizing the characteristics of the abrasive grains.
  • 5% by mass or less is preferable, 3% by mass or less is more preferable, 1% by mass or less is more preferable, 0.5% by mass or less is particularly preferable, 0.1% by mass or less is extremely preferable, 05% by mass or less is very preferable, 0.04% by mass or less is more preferable, 0.035% by mass or less is more preferable, 0.03% by mass or less is further preferable, and 0.02% by mass or less is particularly preferable. 0.01 mass% or less is very preferable. From these viewpoints, the content of cerium hydroxide is more preferably 0.005 to 5% by mass.
  • the polishing liquid according to this embodiment contains an additive.
  • the “additive” refers to a substance contained in the polishing liquid in addition to the abrasive grains and the liquid medium.
  • the polishing liquid according to this embodiment contains a polyol (excluding a compound corresponding to aminocarboxylic acid or aminosulfonic acid).
  • a polyol is a compound having two or more hydroxyl groups in the molecule.
  • Polyols include polyglycerin, polyvinyl alcohol, polyalkylene glycol (polyethylene glycol, etc.), polyoxyalkylene glycol, polyoxyalkylene sorbitol ether (polyoxypropylene sorbitol ether, etc.), polyoxyalkylene condensate of ethylenediamine (ethylenediamine tetrapolyoxy) Ethylene polyoxypropylene), 2,2-bis (4-polyoxyalkylene-oxyphenyl) propane, polyoxyalkylene glyceryl ether, polyoxyalkylene diglyceryl ether, polyoxyalkylene trimethylol propane ether (polyoxyethylene trimethylol propane ether) Propane ether, etc.), pentaerythritol polyoxyalkylene ether (pentaerythritol) Le polyoxypropylene ether), such as polyoxyalkylene methyl glucoside and the like.
  • the polyol may contain a polyol having
  • the polyol preferably contains a polyether polyol (polyol having a polyether structure) from the viewpoint of easily improving the polishing selectivity of the insulating material with respect to the stopper material.
  • the polyether polyol preferably has a polyoxyalkylene group.
  • the number of carbon atoms of oxyalkylene in the polyoxyalkylene group of the polyol is preferably 1 or more and more preferably 2 or more from the viewpoint of easily improving the polishing selectivity of the insulating material with respect to the stopper material.
  • the number of carbon atoms of the oxyalkylene in the polyoxyalkylene group is preferably 5 or less, more preferably 4 or less, and even more preferably 3 or less from the viewpoint of easily improving the polishing selectivity of the insulating material with respect to the stopper material. From these viewpoints, the carbon number is more preferably 1 to 5.
  • the polyoxyalkylene group may be a homopolymer chain or a copolymer chain.
  • the copolymer chain may be a block polymer chain or a random polymer chain.
  • the polyol contains at least one selected from the group consisting of polyoxyalkylene trimethylol propane ether, pentaerythritol polyoxyalkylene ether, and polyalkylene glycol from the viewpoint of easily improving the polishing selectivity of the insulating material with respect to the stopper material. It is more preferable that it contains at least one selected from the group consisting of polyoxyethylene trimethylol propane ether, pentaerythritol polyoxyethylene ether, and polyethylene glycol, from polyoxyethylene trimethylol propane ether and polyethylene glycol. More preferably, at least one selected from the group consisting of:
  • the polyol satisfies at least one of the following characteristics from the viewpoint of easily improving the polishing selectivity of the insulating material with respect to the stopper material.
  • the polyol preferably contains a compound different from the ⁇ -glucose polymer.
  • the polyol preferably contains a compound having no structural unit derived from ⁇ -glucose.
  • the polyol preferably contains a compound having no cyclic structure (six-membered ring, five-membered ring, etc.). It is preferable that a polyol contains the compound which does not have a glucooxide bond.
  • the polyol preferably includes a compound having a hydroxyl group bonded to a primary carbon atom, and more preferably includes a compound having only a hydroxyl group bonded to a primary carbon atom as the hydroxyl group.
  • the polyol preferably contains a compound having no hydroxyl group bonded to a secondary carbon atom.
  • the polyol preferably contains a compound not having a plurality of structural units having a hydroxyl group.
  • the polyol preferably contains a compound having a number of hydroxyl groups within the following range.
  • the lower limit of the number of hydroxyl groups is preferably 2 or more and more preferably 3 or more from the viewpoint of easily improving the polishing selectivity of the insulating material with respect to the stopper material.
  • the upper limit of the number of hydroxyl groups is preferably 5 or less, more preferably 4 or less, and even more preferably 3 or less, from the viewpoint of easily improving the polishing selectivity of the insulating material with respect to the stopper material. From these viewpoints, the number of hydroxyl groups is more preferably 2 to 5.
  • the lower limit of the molecular weight of the polyol is preferably 100 or more, more preferably 200 or more, still more preferably 300 or more, and particularly preferably 330 or more, from the viewpoint of easily improving the polishing selectivity of the insulating material with respect to the stopper material.
  • the upper limit of the molecular weight of the polyol is preferably 500000 or less, more preferably 100000 or less, still more preferably 80000 or less, particularly preferably 50000 or less, extremely preferably 30000 or less, and 25000 or less from the viewpoint of easily improving the polishing rate of the insulating material.
  • the molecular weight of the polyol is more preferably from 100 to 500,000, further preferably from 100 to 20000, and particularly preferably from 100 to 5000.
  • the molecular weight of the polyol may be a weight average molecular weight.
  • the weight average molecular weight of the compound having a hydroxyl group and a polyoxyalkylene group may exceed 1000, 2000 or more, 3000 or more, or 4000 or more.
  • the weight average molecular weight can be measured, for example, under the following conditions by gel permeation chromatography (GPC) using a standard polystyrene calibration curve.
  • the lower limit of the hydroxyl value of the polyol is preferably 1 mgKOH / g or more, more preferably 3 mgKOH / g or more, still more preferably 5 mgKOH / g or more, and 10 mgKOH / g from the viewpoint of easily improving the polishing selectivity of the insulating material with respect to the stopper material.
  • the above is particularly preferable, and 15 mgKOH / g or more is extremely preferable.
  • the upper limit of the hydroxyl value of the polyol is preferably 1000 mgKOH / g or less, more preferably 800 mgKOH / g or less, still more preferably 750 mgKOH / g or less, and 700 mgKOH / g from the viewpoint of easily improving the polishing selectivity of the insulating material with respect to the stopper material.
  • the following are particularly preferred: From these viewpoints, the hydroxyl value of the polyol is more preferably 1 to 700 mgKOH / g.
  • the lower limit of the polyol content is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, based on the total mass of the polishing liquid, from the viewpoint of easily improving the polishing selectivity of the insulating material with respect to the stopper material.
  • 0.2% by mass or more is more preferable, 0.3% by mass or more is particularly preferable, and 0.4% by mass or more is extremely preferable.
  • the upper limit of the polyol content is preferably 5.0% by mass or less, more preferably 3.0% by mass or less, based on the total mass of the polishing liquid, from the viewpoint of easily improving the polishing rate of the insulating material. 0 mass% or less is still more preferable, and 1.0 mass% or less is especially preferable. From these viewpoints, the polyol content is more preferably 0.05 to 5.0% by mass based on the total mass of the polishing liquid.
  • the polishing liquid according to this embodiment contains an aminocarboxylic acid.
  • a compound corresponding to aminosulfonic acid shall not belong to aminocarboxylic acid.
  • An aminocarboxylic acid can be used individually by 1 type or in combination of 2 or more types.
  • the molecular weight of the aminocarboxylic acid is preferably 300 or less, more preferably 250 or less, even more preferably 200 or less, particularly preferably 180 or less, and particularly preferably 175 or less, from the viewpoint of easily improving the polishing selectivity of the insulating material with respect to the stopper material.
  • 170 or less is very preferable, 150 or less is even more preferable, and 130 or less is more preferable.
  • the molecular weight of the aminocarboxylic acid may be 120 or less and may be 100 or less.
  • the molecular weight of the aminocarboxylic acid may be 50 or more, may be 60 or more, and may be 70 or more.
  • the molecular weight of the aminocarboxylic acid may be 50-300.
  • the isoelectric point (pI) of aminocarboxylic acid is preferably smaller than 7.0 from the viewpoint of easily improving the polishing selectivity of the insulating material with respect to the stopper material.
  • the upper limit of the isoelectric point of the aminocarboxylic acid is preferably 6.8 or less, more preferably 6.5 or less, and particularly preferably 6.3 or less, from the viewpoint of easily improving the polishing selectivity of the insulating material with respect to the stopper material. 6.0 or less is very preferable.
  • the upper limit of the isoelectric point of aminocarboxylic acid is 5.9 or less, 5.8 or less, 5.7 or less, 5.65 or less, 5.6 or less, 5.5 or less, or 5.1 or less, Good.
  • the lower limit of the isoelectric point of the aminocarboxylic acid may be 2.0 or more, 2.5 or more, 3.0 or more, or 4.0 or more.
  • the isoelectric point of the aminocarboxylic acid may be 2.0 or more and less than 7.0.
  • the isoelectric point of aminocarboxylic acid can be measured with a potentiometer (for example, “Hiranuma Automatic Titrator COM-1750 Series” manufactured by Hiranuma Sangyo Co., Ltd.) according to JIS K 0113.
  • the lower limit of the acid dissociation constant of aminocarboxylic acid (pKa, negative common logarithm of the equilibrium constant Ka (logarithm of the reciprocal number)) may be a value greater than 0, 1.0 or more, 1.5 or more, 2.0 As described above, it may be 2.1 or more, or 2.3 or more.
  • the upper limit of the acid dissociation constant of aminocarboxylic acid may be 8.0 or less, 7.0 or less, 5.0 or less, 4.0 or less, 3.0 or less, or 2.5 or less.
  • the acid dissociation constant means the first-stage pKa1 (the same applies hereinafter).
  • the aminocarboxylic acid has an amino group as a cation part and a carboxyl group as an anion part.
  • the aminocarboxylic acid may be at least one selected from the group consisting of neutral aminocarboxylic acids and acidic aminocarboxylic acids.
  • Neutral amino acids include aliphatic amino acids such as glycine, alanine, valine, leucine and isoleucine; oxyamino acids such as serine and threonine; sulfur-containing amino acids such as cysteine, cystine and methionine; aromatic amino acids such as phenylalanine, tyrosine and tryptophan
  • An acetic acid amino acid amide such as asparagine and glutamine
  • Examples of acidic amino acids include aspartic acid and glutamic acid.
  • Aminocarboxylic acid preferably includes at least one selected from the group consisting of glycine, valine, serine, cysteine, glutamine, and glutamic acid from the viewpoint of easily improving the polishing selectivity of the insulating material with respect to the stopper material, More preferably, it contains at least one selected from the group consisting of valine and cysteine.
  • the lower limit of the content of aminocarboxylic acid is preferably 0.01% by mass or more, preferably 0.02% by mass or more, based on the total mass of the polishing liquid, from the viewpoint of easily improving the polishing selectivity of the insulating material with respect to the stopper material. Is more preferable, it is more preferable to exceed 0.02 mass%, 0.03 mass% or more is particularly preferable, 0.05 mass% or more is very preferable, 0.08 mass% or more is very preferable, 0.1 The mass% or more is even more preferable.
  • the upper limit of the content of aminocarboxylic acid is preferably 1.0% by mass or less, more preferably 0.8% by mass or less, based on the total mass of the polishing liquid, from the viewpoint of easily improving the polishing rate of the insulating material. 0.5 mass% or less is still more preferable, 0.4 mass% or less is especially preferable, 0.3 mass% or less is very preferable, and 0.2 mass% or less is very preferable. From these viewpoints, the content of aminocarboxylic acid is more preferably 0.01 to 1.0% by mass based on the total mass of the polishing liquid.
  • the polishing liquid according to this embodiment contains aminosulfonic acid.
  • Aminosulfonic acid can be used individually by 1 type or in combination of 2 or more types.
  • the molecular weight of aminosulfonic acid is preferably 300 or less, more preferably 250 or less, still more preferably 200 or less, particularly preferably 180 or less, and particularly preferably 175 or less, from the viewpoint of easily improving the polishing selectivity of the insulating material with respect to the stopper material. preferable.
  • the molecular weight of aminosulfonic acid may be 170 or less, 150 or less, 130 or less, 120 or less, or 100 or less.
  • the molecular weight of aminosulfonic acid may be 50 or more, may be 60 or more, and may be 70 or more.
  • the molecular weight of aminosulfonic acid may be 50-300.
  • Aminosulfonic acid has an amino group as a cation part and has a sulfonic acid group as an anion part.
  • the aminosulfonic acid include sulfamic acid, aliphatic aminosulfonic acid, aromatic aminosulfonic acid and the like.
  • aliphatic aminosulfonic acid examples include aminomethanesulfonic acid, aminoethanesulfonic acid (for example, 1-aminoethanesulfonic acid and 2-aminoethanesulfonic acid (also called taurine)), aminopropanesulfonic acid (for example, 1-aminoethanesulfonic acid). Aminopropane-2-sulfonic acid, 2-aminopropane-1-sulfonic acid) and the like.
  • Aromatic aminosulfonic acid is defined as an aromatic compound having an amino group and a sulfonic acid group (preferably an aromatic hydrocarbon).
  • Aromatic amino sulfonic acids include amino benzene sulfonic acids (eg, alteranilic acid (also known as 2-aminobenzene sulfonic acid), methanyl acid (also known as 3-aminobenzene sulfonic acid), and sulfanilic acid (also known as 4-aminobenzene sulfonic acid).
  • diaminobenzenesulfonic acid for example, 2,4-diaminobenzenesulfonic acid and 3,4-diaminobenzenesulfonic acid
  • aminonaphthalenesulfonic acid and the like.
  • the aromatic aminosulfonic acid preferably contains sulfanilic acid from the viewpoint of easily improving the polishing selectivity of the insulating material with respect to the stopper material.
  • the pKa of aminosulfonic acid is preferably larger than 0 from the viewpoint of easily improving the polishing selectivity of the insulating material with respect to the stopper material.
  • the lower limit of the pKa of aminosulfonic acid is preferably 0.2 or more, more preferably 0.5 or more, from the viewpoint that the polishing rate of the insulating material is easily improved and the polishing selectivity of the insulating material with respect to the stopper material is easily improved. Is more preferable, 0.7 or more is particularly preferable, and 0.9 or more is very preferable.
  • the lower limit of the pKa of aminosulfonic acid is preferably 5.0 or less, more preferably 4.0 or less, still more preferably 3.5 or less, from the viewpoint of easily improving the polishing selectivity of the insulating material with respect to the stopper material. 2 or less is particularly preferable. From these viewpoints, the pKa of aminosulfonic acid is more preferably greater than 0 and not greater than 5.0.
  • the lower limit of the pKa of aminosulfonic acid may be 3.0 or less, 2.5 or less, 2.0 or less, 1.5 or less, 1.2 or less, or 1.0 or less.
  • the pH of a 1% by mass aqueous solution of aminosulfonic acid is preferably 4 or less.
  • the pH of a 1% by mass aqueous solution of aminosulfonic acid is more preferably 3 or less, further preferably 2 or less, and particularly preferably 1.5 or less.
  • the aminosulfonic acid preferably contains at least one selected from the group consisting of sulfamic acid, aliphatic aminosulfonic acid, and aromatic aminosulfonic acid from the viewpoint of easily improving the polishing selectivity of the insulating material with respect to the stopper material. More preferably, it contains at least one selected from the group consisting of sulfamic acid and aromatic aminosulfonic acid, and more preferably contains sulfamic acid.
  • the lower limit of the content of aminosulfonic acid is preferably 0.001% by mass or more, preferably 0.005% by mass or more, based on the total mass of the polishing liquid, from the viewpoint of easily improving the polishing selectivity of the insulating material with respect to the stopper material. Is more preferably 0.01% by mass or more, particularly preferably exceeding 0.01% by mass, extremely preferably 0.02% by mass or more, very preferably exceeding 0.02% by mass, 0.025 mass% or more is still more preferable, and 0.03 mass% or more is more preferable.
  • the upper limit of the content of aminosulfonic acid is preferably 1.0% by mass or less, more preferably 0.8% by mass or less, based on the total mass of the polishing liquid, from the viewpoint of easily improving the polishing rate of the insulating material. 0.5% by mass or less is more preferable, 0.4% by mass or less is particularly preferable, 0.3% by mass or less is extremely preferable, 0.2% by mass or less is very preferable, and 0.1% by mass or less is even more preferable. Preferably, 0.05 mass% or less is more preferable. From these viewpoints, the content of aminosulfonic acid is more preferably 0.001 to 1.0% by mass based on the total mass of the polishing liquid.
  • the total amount of aminocarboxylic acid and aminosulfonic acid is preferably in the following range based on the total mass of the polishing liquid.
  • the lower limit of the total amount of aminocarboxylic acid and aminosulfonic acid is preferably 0.01% by mass or more, more preferably 0.03% by mass or more, from the viewpoint of easily improving the polishing selectivity of the insulating material with respect to the stopper material.
  • 05 mass% or more is more preferable, 0.08 mass% or more is particularly preferable, 0.1 mass% or more is very preferable, 0.15 mass% or more is very preferable, and 0.2 mass% or more is even more preferable.
  • the upper limit of the total amount of aminocarboxylic acid and aminosulfonic acid is preferably 1.0% by mass or less, more preferably 0.8% by mass or less, and more preferably 0.5% by mass or less from the viewpoint of easily improving the polishing rate of the insulating material. Is more preferable, 0.4 mass% or less is particularly preferable, 0.3 mass% or less is very preferable, and 0.25 mass% or less is very preferable. From these viewpoints, the total amount of aminocarboxylic acid and aminosulfonic acid is more preferably 0.01 to 1.0% by mass.
  • the polishing liquid according to this embodiment may contain any additive (except for compounds corresponding to polyol, aminocarboxylic acid or aminosulfonic acid).
  • optional additives include water-soluble polymers, oxidizing agents (for example, hydrogen peroxide), dispersing agents (for example, phosphoric acid inorganic salts), and the like.
  • Water-soluble polymer is defined as a polymer that dissolves 0.1 g or more in 100 g of water.
  • water-soluble polymers examples include polyacrylic acid polymers such as polyacrylic acid, polyacrylic acid copolymers, polyacrylic acid salts, and polyacrylic acid copolymer salts; polymethacrylic acid such as polymethacrylic acid and polymethacrylic acid salts. Examples include acid polymers.
  • the liquid medium in the polishing liquid according to this embodiment is not particularly limited, but water such as deionized water or ultrapure water is preferable.
  • the content of the liquid medium may be the remainder of the polishing liquid excluding the content of other components and is not particularly limited.
  • the lower limit of the pH of the polishing liquid according to the present embodiment is preferably 2.0 or more, more preferably 2.2 or more, still more preferably 2.5 or more, from the viewpoint of easily obtaining excellent abrasive dispersion stability. 3.0 or more is particularly preferable, 3.1 or more is very preferable, and 3.2 or more is very preferable.
  • the upper limit of pH is preferably 6.0 or less, more preferably less than 6.0, further preferably 5.5 or less, particularly preferably 5.0 or less, from the viewpoint of easily obtaining excellent abrasive dispersion stability.
  • the pH of the polishing liquid is more preferably 2.0 to 6.0, and further preferably 2.0 to 4.5.
  • the pH of the polishing liquid is defined as the pH at a liquid temperature of 25 ° C.
  • the pH of the polishing liquid can be adjusted by an acid component such as an inorganic acid or an organic acid; an alkali component such as ammonia, sodium hydroxide, tetramethylammonium hydroxide (TMAH), imidazole, or alkanolamine.
  • a buffer may be added to stabilize the pH.
  • a buffer may be added as a buffer (a solution containing a buffer). Examples of such a buffer include acetate buffer and phthalate buffer.
  • the pH of the polishing liquid according to this embodiment can be measured with a pH meter (for example, model number PHL-40 manufactured by Toa DKK Corporation). Specifically, for example, after calibrating two pH meters using a phthalate pH buffer solution (pH: 4.01) and a neutral phosphate pH buffer solution (pH: 6.86) as standard buffers, Then, the pH meter electrode is put into the polishing liquid, and the value after 2 minutes has passed and stabilized is measured.
  • the temperature of the standard buffer solution and the polishing solution are both 25 ° C.
  • the polishing liquid according to the present embodiment may be stored as a one-part polishing liquid containing at least abrasive grains, polyol, aminocarboxylic acid, aminosulfonic acid, and a liquid medium.
  • the slurry includes, for example, at least abrasive grains and a liquid medium.
  • the additive liquid contains at least a polyol, an aminocarboxylic acid, an aminosulfonic acid, and a liquid medium, for example.
  • the polyol, aminocarboxylic acid, aminosulfonic acid, optional additive, and buffering agent are preferably included in the additive liquid among the slurry and the additive liquid.
  • the constituents of the polishing liquid may be stored as a polishing liquid set divided into three or more liquids.
  • the slurry and additive liquid are mixed immediately before or during polishing to prepare a polishing liquid.
  • the one-component polishing liquid may be stored as a polishing liquid storage liquid in which the content of the liquid medium is reduced, and may be diluted with the liquid medium during polishing.
  • the multi-liquid type polishing liquid set may be stored as a slurry storage liquid and an additive liquid storage liquid with a reduced content of the liquid medium, and may be diluted with the liquid medium during polishing.
  • the polishing method according to the present embodiment is a surface to be polished using the one-part polishing liquid or a polishing liquid obtained by mixing a slurry and an additive liquid in the polishing liquid set ( A polishing step for polishing the surface to be polished of the substrate) may be provided.
  • the surface to be polished may contain silicon oxide and may further contain silicon nitride.
  • the polishing method according to the present embodiment may be a method for polishing a substrate having an insulating material and silicon nitride.
  • the one-part polishing liquid or a slurry and an additive liquid in the polishing liquid set are mixed.
  • a polishing step of selectively polishing the insulating material with respect to silicon nitride may be provided using the polishing liquid obtained in this manner.
  • the base may have, for example, a member containing an insulating material and a member containing silicon nitride.
  • the polishing method according to the present embodiment may be a method for polishing a substrate having a first member including silicon nitride and a second member including an insulating material and disposed on the first member.
  • the polishing step is a step of polishing the second member until the first member is exposed using the one-part polishing liquid or a polishing liquid obtained by mixing the slurry and the additive liquid in the polishing liquid set. You may have.
  • the first member and the second member are obtained using the one-component polishing liquid or the polishing liquid obtained by mixing the slurry and the additive liquid in the polishing liquid set after the first member is exposed.
  • “Selectively polishing material A with respect to material B” means that the polishing rate of material A is higher than the polishing rate of material B under the same polishing conditions. More specifically, for example, the material A is polished with a polishing rate ratio of the polishing rate of the material A to the polishing rate of the material B of 10 or more.
  • the polishing liquid is supplied between the material to be polished and the polishing pad in a state where the material to be polished of the substrate having the material to be polished is pressed against the polishing pad (polishing cloth) of the polishing surface plate.
  • the surface to be polished of the material to be polished is polished by relatively moving the substrate and the polishing surface plate.
  • at least a part of the material to be polished is removed by polishing.
  • Examples of the substrate to be polished include a substrate to be polished.
  • Examples of the substrate to be polished include a substrate in which a material to be polished is formed on a substrate related to semiconductor element manufacturing (for example, a semiconductor substrate on which an STI pattern, a gate pattern, a wiring pattern, etc. are formed).
  • Examples of the material to be polished include an insulating material such as silicon oxide (excluding a material corresponding to a stopper material); a stopper material such as silicon nitride.
  • the material to be polished may be a single material or a plurality of materials. When a plurality of materials are exposed on the surface to be polished, they can be regarded as materials to be polished.
  • the material to be polished may be in the form of a film (film to be polished), and may be a silicon oxide film, a silicon nitride film, or the like.
  • the polishing liquid according to this embodiment is preferably used for polishing a surface to be polished containing silicon oxide.
  • a stopper polishing stop layer disposed under the insulating material, and a substrate (semiconductor substrate or the like) disposed under the stopper
  • the insulating material can be polished.
  • the stopper material constituting the stopper is preferably silicon nitride, which is a material having a lower polishing rate than the insulating material.
  • Examples of a method for producing a material to be polished by the polishing liquid according to this embodiment include a low pressure CVD method, a quasi-atmospheric pressure CVD method, a plasma CVD method, and other CVD methods; a spin coating method in which a liquid material is applied to a rotating substrate. Etc.
  • the polishing method according to this embodiment will be described by taking a polishing method of a substrate (for example, a substrate having an insulating material formed on a semiconductor substrate) as an example.
  • a polishing apparatus a general polishing apparatus having a holder capable of holding a substrate having a surface to be polished and a polishing surface plate to which a polishing pad can be attached can be used.
  • Each of the holder and the polishing surface plate is provided with a motor capable of changing the rotation speed.
  • a polishing apparatus for example, a polishing apparatus (model number: FREX300) manufactured by Ebara Corporation can be used.
  • polishing pad general nonwoven fabric, foam, non-foam, etc.
  • the material of the polishing pad is polyurethane, acrylic resin, polyester, acrylic-ester copolymer, polytetrafluoroethylene, polypropylene, polyethylene, poly-4-methylpentene, cellulose, cellulose ester, polyamide (for example, nylon (trade name)) And aramid), polyimide, polyimide amide, polysiloxane copolymer, oxirane compound, phenol resin, polystyrene, polycarbonate, epoxy resin and the like.
  • the material of the polishing pad is preferably at least one selected from the group consisting of foamed polyurethane and non-foamed polyurethane, particularly from the viewpoint of further improving the polishing rate and flatness. It is preferable that the polishing pad is grooved so that the polishing liquid accumulates.
  • the upper limit of the rotation speed of the polishing platen is preferably 200 min ⁇ 1 or less so that the substrate does not pop out, and the upper limit of the polishing pressure (working load) applied to the substrate causes polishing flaws. From the viewpoint of sufficiently suppressing this, 15 psi (103 kPa) or less is preferable.
  • limiting in this supply amount it is preferable that the surface of a polishing pad is always covered with polishing liquid.
  • the substrate after polishing is preferably washed well under running water to remove particles adhering to the substrate.
  • dilute hydrofluoric acid or ammonia water may be used in addition to pure water, and a brush may be used in combination to increase cleaning efficiency.
  • the lower limit of the polishing rate ratio of the insulating material (for example, silicon oxide) to the stopper material (for example, silicon nitride) is preferably 10 or more.
  • the polishing rate ratio is less than 10
  • the polishing rate of the insulating material relative to the polishing rate of the stopper material is small, and it tends to be difficult to stop polishing at a predetermined position when forming the STI.
  • the polishing rate ratio is 10 or more, the polishing can be easily stopped, which is more suitable for the formation of STI.
  • the lower limit of the polishing rate ratio of the insulating material to the stopper material is more preferably 15 or more, further preferably 20 or more, and particularly preferably 25 or more.
  • This embodiment can also be used for polishing a premetal insulating material.
  • the premetal insulating material include silicon oxide, phosphorus-silicate glass, boron-phosphorus-silicate glass, silicon oxyfluoride, and fluorinated amorphous carbon.
  • This embodiment can also be applied to materials other than insulating materials such as silicon oxide.
  • materials include high dielectric constant materials such as Hf-based, Ti-based, and Ta-based oxides; semiconductor materials such as silicon, amorphous silicon, SiC, SiGe, Ge, GaN, GaP, GaAs, and organic semiconductors; GeSbTe Inorganic conductive materials such as ITO; Polymer resins such as polyimides, polybenzoxazoles, acrylics, epoxies, and phenols.
  • This embodiment can be applied not only to a film-like object to be polished, but also to various substrates composed of glass, silicon, SiC, SiGe, Ge, GaN, GaP, GaAs, sapphire, plastic, and the like.
  • image display devices such as TFTs and organic ELs
  • optical parts such as photomasks, lenses, prisms, optical fibers, and single crystal scintillators
  • optical elements such as optical switching elements and optical waveguides
  • a light emitting element such as a solid-state laser and a blue laser LED
  • a magnetic storage device such as a magnetic disk and a magnetic head.
  • cerium oxide slurry Preparation of cerium oxide slurry> Mixing cerium oxide particles (first particles) with Wako Pure Chemical Industries, Ltd. trade name: ammonium dihydrogen phosphate (molecular weight: 99.99), 5.0 masses of cerium oxide particles. A cerium oxide slurry (pH: 7) containing% (solid content) was prepared. The compounding amount of ammonium dihydrogen phosphate was adjusted to 1% by mass based on the total amount of cerium oxide particles.
  • the resulting precipitate (precipitate containing cerium hydroxide) was subjected to solid-liquid separation by centrifuging (4000 min ⁇ 1 , 5 minutes) and then removing the liquid phase by decantation. After mixing 10 g of particles obtained by solid-liquid separation and 990 g of water, the particles are dispersed in water using an ultrasonic cleaning machine, and contain cerium hydroxide particles (second particles). A hydroxide slurry (particle content: 1.0 mass%) was prepared.
  • the average particle size (average secondary particle size) of the cerium hydroxide particles in the cerium hydroxide slurry was measured using a product name: N5 manufactured by Beckman Coulter, Inc., it was 10 nm.
  • the measuring method is as follows. First, about 1 mL of a measurement sample (cerium hydroxide slurry, aqueous dispersion) containing 1.0 mass% cerium hydroxide particles was placed in a 1 cm square cell, and then the cell was placed in N5. The refractive index of the N5 soft measurement sample information was set to 1.333, the viscosity was set to 0.887 mPa ⁇ s, the measurement was performed at 25 ° C., and the value displayed as Unimodal Size Mean was read.
  • the cerium hydroxide particles contained at least a part of particles having nitrate ions bonded to the cerium element. Moreover, since the particles having hydroxide ions bonded to the cerium element are contained in at least a part of the cerium hydroxide particles, it was confirmed that the cerium hydroxide particles contain cerium hydroxide. From these results, it was confirmed that the hydroxide of cerium contains hydroxide ions bonded to the cerium element.
  • the cerium hydroxide slurry and deionized water were mixed while stirring at a rotation speed of 300 rpm using a two-blade stirring blade to obtain a mixed solution. Subsequently, the cerium oxide slurry is mixed with the mixed solution while stirring the mixed solution, and then irradiated with ultrasonic waves using an ultrasonic cleaner (device name: US-105) manufactured by SNDI Co., Ltd. Stir.
  • an ultrasonic cleaner device name: US-105 manufactured by SNDI Co., Ltd. Stir.
  • the test liquid was prepared by adjusting the content of abrasive grains (total amount of particles) in the test slurry to 0.1% by mass (diluted with ion-exchanged water). 7.5 g of the test solution was placed in a centrifuge (trade name: Optima MAX-TL) manufactured by Beckman Coulter, Inc., treated for 5 minutes at a centrifugal acceleration of 5.8 ⁇ 10 4 G and a set temperature of 25 ° C., and the supernatant liquid Got.
  • a centrifuge (trade name: Optima MAX-TL) manufactured by Beckman Coulter, Inc.
  • the cell After putting about 4 mL of the supernatant into a 1 cm square quartz cell, the cell was placed in a spectrophotometer (device name: U3310) manufactured by Hitachi, Ltd. Absorbance was measured in the wavelength range of 200 to 600 nm, and the absorbance value at a wavelength of 380 nm was read from the obtained chart. Absorbance was 0.002. Moreover, when the value of the light transmittance in wavelength 500nm was read from the obtained chart, it was 92% / cm or more.
  • Example 1 ⁇ Preparation of polishing liquid for CMP> (Example 1)
  • the cerium hydroxide slurry and deionized water were mixed while stirring at a rotation speed of 300 rpm using a two-blade stirring blade to obtain a mixed solution.
  • the cerium oxide slurry is mixed with the mixed solution while stirring the mixed solution, and then irradiated with ultrasonic waves using an ultrasonic cleaner (device name: US-105) manufactured by SNDI Co., Ltd. Stir.
  • the polishing slurry for CMP containing 0.1% by weight of abrasive grains, 0.50% by weight of polyol, 0.20% by weight of glycine and 0.03% by weight of sulfamic acid Got.
  • the polishing liquid for CMP contains composite particles containing, as abrasive grains, cerium oxide particles and cerium hydroxide particles in contact with the cerium oxide particles.
  • the cerium oxide particles and the cerium hydroxide The mass ratio with the particles was 10: 1 (cerium oxide: cerium hydroxide).
  • the polishing liquid for CMP contained cerium hydroxide particles (free particles) that were not in contact with the cerium oxide particles in addition to the composite particles described above as abrasive grains.
  • Example 2 A polishing slurry for CMP was prepared in the same manner as in Example 1 except that glycine was changed to the aminocarboxylic acid shown in Table 1.
  • Example 5 A polishing slurry for CMP was prepared in the same manner as in Example 1 except that polyoxyethylene trimethylolpropane ether was changed to polyethylene glycol (manufactured by NOF Corporation, PEG 4000, weight average molecular weight 4000).
  • Example 1 A polishing slurry for CMP was prepared in the same manner as in Example 5 except that aminocarboxylic acid and aminosulfonic acid were not used (deionized water was increased).
  • Example 2 A polishing slurry for CMP was prepared in the same manner as in Example 1 except that no polyol and aminosulfonic acid were used (deionized water was increased).
  • ⁇ Zeta potential of abrasive grains> An appropriate amount of a polishing slurry for CMP was put into Delsa Nano C manufactured by Beckman Coulter Co., Ltd., and the measurement was performed twice at 25 ° C. The average value of the displayed zeta potential was obtained as the zeta potential. As a result, the zeta potential of the abrasive grains was +55 mV.
  • ⁇ Average particle size of abrasive grains> A trade name manufactured by Microtrack Bell Co., Ltd .: An appropriate amount of CMP polishing liquid was put into Microtrack MT3300EXII, and the average particle size of the abrasive grains was measured. The displayed average particle size value was obtained as the average particle size (average secondary particle size). The average grain size of the abrasive grains in the CMP polishing liquid was 155 nm.
  • ⁇ PH of polishing liquid for CMP The pH of the polishing liquid for CMP was evaluated under the following conditions. The results are shown in Tables 1 and 2. Measurement temperature: 25 ° C Measuring device: manufactured by Toa DKK Corporation, model number PHL-40 Measurement method: Two-point calibration using a standard buffer (phthalate pH buffer, pH: 4.01 (25 ° C.); neutral phosphate pH buffer, pH: 6.86 (25 ° C.)) Thereafter, the electrode was put into a polishing slurry for CMP, and the pH after being stabilized for 2 minutes or more was measured with the measuring device.
  • a standard buffer phthalate pH buffer, pH: 4.01 (25 ° C.); neutral phosphate pH buffer, pH: 6.86 (25 ° C.)
  • a pattern wafer, which will be described later, polished until the silicon nitride film was exposed was polished for 30 seconds using the CMP polishing liquid.
  • the silicon nitride film and the silicon oxide film are exposed on the surface to be polished.
  • Wafer cleaning After CMP, the wafer was cleaned with water, and then dried with a spin dryer.
  • Non-pattern wafer A TEOS wafer having a TEOS film (silicon oxide film) with a thickness of 1 ⁇ m formed by a CVD method on a silicon substrate was used.
  • a pattern wafer on which a simulated pattern was formed a 764 wafer (trade name, diameter: 300 mm) manufactured by SEMATECH was used.
  • a silicon nitride film is stacked on a silicon substrate as a stopper (stopper film), and then a trench is formed in an exposure process, and an insulating film is formed on the silicon substrate and the silicon nitride film so as to fill the stopper and the trench. It was a wafer obtained by laminating a silicon oxide film (SiO 2 film).
  • the silicon oxide film was formed by the HDP (High Density Plasma) method.
  • the line & space is a simulated pattern in which an active portion masked by a stopper film that is a convex portion and a trench portion in which a groove that is a concave portion is formed are alternately arranged.
  • the line and space has a pitch of 100 ⁇ m means that the total width of the line portion and the space portion is 100 ⁇ m.
  • the line and space is 100 ⁇ m pitch and the convex pattern density is 50%” means a pattern in which convex width: 50 ⁇ m and concave width: 50 ⁇ m are alternately arranged.
  • the silicon nitride film is formed by polishing the wafer using a known CMP polishing liquid having self-stopping properties (a characteristic that the polishing speed decreases when the residual step amount of the simulated pattern decreases).
  • An exposed wafer was used.
  • HS-8005-D4 (trade name) manufactured by Hitachi Chemical Co., Ltd.
  • HS-7303GP (trade name) manufactured by Hitachi Chemical Co., Ltd.
  • water are mixed at 1: 1.2: 7.8.
  • a wafer in a state of being polished using a polishing liquid blended at a ratio until a convex silicon nitride film in a 100 ⁇ m pitch 50% density pattern was exposed was used.
  • polishing selectivity ratio of silicon oxide to silicon nitride (the polishing rate of silicon oxide / the polishing rate of silicon nitride) was calculated. The results are shown in Tables 1 and 2. The residual film thickness of the TEOS film (silicon oxide film) polished and cleaned under the above conditions was measured. Further, the residual film thickness of the silicon nitride film on the convex portion of the patterned wafer polished and cleaned under the above conditions was measured.
  • polishing rate of the film to be polished (initial film thickness of the film to be polished (nm) ⁇ remaining film thickness of the film to be polished (nm)) / polishing time (min))

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Abstract

L'invention concerne une suspension épaisse contenant un abrasif, un polyol, un acide aminé carboxylique, un acide aminé sulfonique et un milieu liquide, le potentiel zêta de l'abrasif étant positif.
PCT/JP2019/011853 2018-03-22 2019-03-20 Suspension é paisse, ensemble suspension épaisse et procédé de polissage WO2019182057A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JPPCT/JP2018/011464 2018-03-22
PCT/JP2018/011464 WO2019180887A1 (fr) 2018-03-22 2018-03-22 Liquide de polissage, ensemble liquide de polissage et procédé de polissage
PCT/JP2018/035464 WO2019181015A1 (fr) 2018-03-22 2018-09-25 Liquide de polissage, ensemble liquide de polissage et procédé de polissage
JPPCT/JP2018/035464 2018-09-25

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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015052988A1 (fr) * 2013-10-10 2015-04-16 日立化成株式会社 Agent de polissage, ensemble d'agent de polissage et procédé pour base de polissage
WO2015098197A1 (fr) * 2013-12-26 2015-07-02 日立化成株式会社 Abrasif, ensemble abrasif, et procédé de polissage d'un substrat

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015052988A1 (fr) * 2013-10-10 2015-04-16 日立化成株式会社 Agent de polissage, ensemble d'agent de polissage et procédé pour base de polissage
WO2015098197A1 (fr) * 2013-12-26 2015-07-02 日立化成株式会社 Abrasif, ensemble abrasif, et procédé de polissage d'un substrat

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