Classifications

• • 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
  • C09K3/1454—Abrasive powders, suspensions and pastes for polishing
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09G—POLISHING COMPOSITIONS; SKI WAXES
  • C09G1/00—Polishing compositions
  • C09G1/02—Polishing compositions containing abrasives or grinding agents
• • 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
  • C09K3/1409—Abrasive particles per se
• • 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
  • C09K3/1436—Composite particles, e.g. coated particles
• • 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
  • C09K3/1454—Abrasive powders, suspensions and pastes for polishing
  • C09K3/1463—Aqueous liquid suspensions
• • H10P52/402—
• • H10P52/403—
• • H10P95/04—
• • H10P95/062—

Definitions

• the present invention relates to a polishing composition used, for example, in the manufacturing process of a semiconductor device and to a polishing method using the same.
• Patent Document 1 discloses a polishing composition that contains phosphoric acid or a phosphoric acid derivative.
• Patent Document 2 discloses a polishing composition that contains colloidal silica and an organic acid having a sulfonate group or a phosphonate group and has a pH of 2.5 to 5.
• a polishing composition used in an application to polish silicon nitride contains colloidal silica in which an organic acid is immobilized and has a pH of 6 or less.
• Another aspect of the present invention provides a polishing method for polishing silicon nitride using the polishing composition according to the above described aspect.
• a polishing composition that can polish silicon nitride at a high rate of speed, and a polishing method using the same.
• a polishing composition according to the present embodiment is prepared by mixing with water colloidal silica in which an organic acid is immobilized. Therefore, the polishing composition contains colloidal silica in which an organic acid is immobilized.
• the polishing composition is mainly used in an application to polish silicon nitride, more specifically an application to polish an object-to-be-polished, such as a semiconductor wiring substrate, the surface of which includes silicon nitride.
• the immobilization of an organic acid on the surface of colloidal silica in the polishing composition is carried out by chemically bonding a functional group of the organic acid to the surface of colloidal silica.
• the immobilization of an organic acid on colloidal silica cannot be achieved by only allowing colloidal silica and an organic acid to merely coexist.
• the immobilization of a sulfonic acid, a kind of organic acid, on colloidal silica can be carried out, for example, by a method described in “Sulfonic acid-functionalized silica through quantitative oxidation of thiol groups”, Chem. Commun. 246-247 (2003).
• colloidal silica in which a sulfonic acid is immobilized on its surface can be obtained by coupling a silane coupling agent having a thiol group, such as 3-mercaptopropyl trimethoxysilane, to colloidal silica, followed by oxidizing the thiol group with hydrogen peroxide.
• the immobilization of a carboxylic acid on colloidal silica can be carried out, for example, by a method described in “Novel Silane Coupling Agents Containing a Photolabile 2-Nitrobenzyl Ester for Introduction of a Carboxy Group on the Surface of Silica Gel”, Chemistry Letters, 3, 228-229 (2000).
• colloidal silica in which a carboxylic acid is immobilized on its surface can be obtained by coupling a silane coupling agent including photoreactive 2-nitrobenzyl ester to colloidal silica, followed by photoirradiation.
• the average primary particle size of colloidal silica in the polishing composition is preferably 5 nm or more, more preferably 7 nm or more, and further preferably 10 nm or more. As the average primary particle size of colloidal silica increases, there is the advantage of improving the rate of polishing silicon nitride with the polishing composition.
• the average primary particle size of colloidal silica in the polishing composition is also preferably 100 nm or less, more preferably 90 nm or less, and further preferably 80 nm or less. As the average primary particle size of colloidal silica decreases, there is the advantage of being able to suppress the occurrence of scratches on the surface of an object-to-be-polished after polishing using the polishing composition.
• the value of the average primary particle size of colloidal silica is calculated based on, for example, the specific surface area of colloidal silica measured by the BET method.
• the average secondary particle size of colloidal silica in the polishing composition is preferably 10 nm or more, more preferably 20 nm or more, and further preferably 30 nm or more. As the average secondary particle size of colloidal silica increases, there is the advantage of improving the rate of polishing silicon nitride with the polishing composition.
• the average secondary particle size of colloidal silica in the polishing composition is also preferably 150 nm or less, more preferably 120 nm or less, and further preferably 100 nm or less. As the average secondary particle size of colloidal silica decreases, there is the advantage of being able to suppress the occurrence of scratches on the surface of an object-to-be-polished after polishing using the polishing composition.
• the value of the average secondary particle size of colloidal silica can be measured by, for example, a light scattering method using laser light.
• Non-spherical colloidal silica may be one in which two or more primary particles are associated.
• the average degree of association of colloidal silica in the polishing composition is preferably 1.2 or more and more preferably 1.5 or more. As the average degree of association of colloidal silica increases, there is the advantage of improving the rate of polishing silicon nitride with the polishing composition.
• the average degree of association of colloidal silica in the polishing composition is also preferably 4.0 or less, more preferably 3.0 or less, and further preferably 2.5 or less. As the average degree of association of colloidal silica decreases, there is the advantage of being able to suppress the occurrence of defects and the increase in surface roughness on the surface of an object-to-be-polished after polishing using the polishing composition.
• the content of colloidal silica in the polishing composition is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and further preferably 1% by mass or more. As the content of colloidal silica increases, there is the advantage of improving the rate of polishing silicon nitride with the polishing composition.
• the content of colloidal silica in the polishing composition is also preferably 20% by mass or less, more preferably 15% by mass or less, and further preferably 10% by mass or less. As the content of colloidal silica decreases, there are the advantages of being able to reduce the material cost of the polishing composition, and also of being able to suppress the occurrence of aggregation of colloidal silica.
• the pH value of the polishing composition is required to be 6 or less. When the pH is above 6, it is difficult to polish silicon nitride at a high rate of speed using a polishing composition. In terms of a further improvement in the rate of polishing silicon nitride with the polishing composition, the pH value of the polishing composition is preferably 5 or less, more preferably 4.5 or less, and further preferably 4 or less.
• the pH value of the polishing composition is also preferably 1 or more, more preferably 1.5 or more, further preferably 2 or more, and particularly preferably 2.5 or more.
• the pH of the polishing composition increases, there is the advantage of being able to increase the ratio of the rate of polishing silicon nitride with the polishing composition to the rate of polishing polycrystalline silicon with the polishing composition, that is, there is the advantage of being able to polish more preferentially silicon nitride relative to polycrystalline silicon.
• a pH adjuster may be used to adjust the pH of the polishing composition to the desired value thereof.
• the pH adjuster used may be either an inorganic acid or an organic acid, or a chelating agent.
• hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid preferred are hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid.
• Organic sulfuric acids such as methanesulfonic acid, ethanesulfonic acid, and isethionic acid, may be also used.
• dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, phthalic acid, malic acid, and tartaric acid
• tricarboxylic acids such as citric acid.
• Salts such as an ammonium salt and alkali metal salt of an inorganic acid or organic acid, may be used as a pH adjuster in place of an inorganic acid or organic acid, or in combination with an inorganic acid or organic acid.
• a pH buffering action can be expected.
• the polishing composition can polish silicon nitride at a high rate of speed, whereas is not required to polish polycrystalline silicon at a high rate of speed. Such ability can be required when the polishing composition is used in an application to polish an object-to-be-polished the surface of which includes not only silicon nitride but also polycrystalline silicon.
• the ratio of the rate of polishing silicon nitride to the rate of polishing polycrystalline silicon is preferably 2 or more, more preferably 4 or more, further preferably 6 or more, and particularly preferably 8 or more.
• a polishing composition of the present embodiment contains colloidal silica in which an organic acid, such as a sulfonic acid or a carboxylic acid, is immobilized, and has a pH of 6 or less.
• the zeta-potential of colloidal silica in which an organic acid is immobilized is negative under a pH of 6 or less.
• the zeta-potential of silicon nitride is positive under the same condition as above, that is, a pH of 6 or less.
• the rate of polishing silicon nitride with the polishing composition is further improved.
• the average primary particle size of colloidal silica in the polishing composition is 100 nm or less, and specifically 90 nm or less or 80 nm or less, the occurrence of scratches on the surface of an object-to-be-polished after polishing using the polishing composition is favorably suppressed.
• the average secondary particle size of colloidal silica in the polishing composition is 10 nm or more, and specifically 20 nm or more or 30 nm or more, the rate of polishing silicon nitride with the polishing composition is further improved.
• the average secondary particle size of colloidal silica in the polishing composition is 150 nm or less, and specifically 120 nm or less or 100 nm or less, the occurrence of scratches on the surface of an object-to-be polished after polishing using the polishing composition is favorably suppressed.
• the rate of polishing silicon nitride with the polishing composition is further improved.
• the rate of polishing silicon nitride with the polishing composition is further improved.
• the average degree of association of colloidal silica in the polishing composition is 4.0 or less, and specifically 3.0 or less or 2.5 or less, the occurrence of defects and the increase in surface roughness on the surface of an object-to-be-polished after polishing using the polishing composition is favorably suppressed.
• the rate of polishing silicon nitride with the polishing composition is further improved.
• the content of colloidal silica in the polishing composition is 20% by mass or less, and specifically 15% by mass or less or 10% by mass or less, the material cost of the polishing composition is reduced, and the occurrence of aggregation of colloidal silica is also suppressed.
• the rate of polishing silicon nitride with the polishing composition is further improved.
• the pH value of the polishing composition is 1 or more, and specifically 1.5 or more, 2 or more, or 2.5 or more, the ratio of the rate of polishing silicon nitride with the polishing composition to the rate of polishing polycrystalline silicon with the polishing composition is increased.
• the ratio of the rate of polishing silicon nitride with the polishing composition to the rate of polishing polycrystalline silicon with the polishing composition is 2 or more, and specifically 4 or more, 6 or more, or 8 or more, in the case where the polishing composition is used in an application to polish an object-to-be-polished the surface of which includes silicon nitride and polycrystalline silicon, silicon nitride is more preferentially polished relative to polycrystalline silicon.
• a polishing composition of the above embodiment may contain, in addition to colloidal silica in which an organic acid is immobilized, any other abrasive grains.
• a polishing composition of the above embodiment may further contain a water-soluble polymer.
• the water-soluble polymer can control the rate of polishing an object-to-be-polished with the polishing composition by adhering to the surface of colloidal silica or the surface of the object-to-be-polished, and also has a function to stabilize insoluble components to be produced during polishing in the polishing composition.
• water-soluble polymers examples include a compound having a polyoxyalkylene chain, more specifically, polyethylene glycol, polypropylene glycol, polyoxyethylene alkyl ether, polyoxyethylene lauryl ether sulfate, polyoxyethylene lauryl ether acetate, polyoxyethylene alkyl phosphate, and a silicone oil having a polyoxyalkylene chain.
• a compound having a polyoxyalkylene chain more specifically, polyethylene glycol, polypropylene glycol, polyoxyethylene alkyl ether, polyoxyethylene lauryl ether sulfate, polyoxyethylene lauryl ether acetate, polyoxyethylene alkyl phosphate, and a silicone oil having a polyoxyalkylene chain.
• polyethylene glycol and polypropylene glycol preferred are preferred.
• the content of water-soluble polymer in the polishing composition is preferably 0.001 g/L or more, more preferably 0.005 g/L or more, and further preferably 0.01 g/L or more.
• the content of water-soluble polymer increases, there is the advantage of being able to increase the ratio of the rate of polishing silicon nitride with the polishing composition to the rate of polishing polycrystalline silicon with the polishing composition, that is, there is the advantage of being able to polish more preferentially silicon nitride relative to polycrystalline silicon.
• the content of water-soluble polymer in the polishing composition is preferably 10 g/L or less, more preferably 5 g/L or less, and further preferably 1 g/L or less. As the content of water-soluble polymer decreases, there is the advantage of improving the rate of polishing polycrystalline silicon with the polishing composition.
• a polishing composition of the above embodiment may further contain an oxidizing agent, such as hydrogen peroxide.
• a polishing composition of the above embodiment may further contain a known additive, such as a preservative and a fungicide, as required.
• a known additive such as a preservative and a fungicide
• preservatives and fungicides include: isothiazoline antiseptics, such as 2-methyl-4-isothiazolin-3-one and 5-chloro-2-methyl-4-isothiazolin-3-one; para-oxybenzoates; and phonoxyethanol.
• a polishing composition of the above embodiment may be either a one-component type or a multi-component type including a two-component type.
• a polishing composition of the above embodiment may be prepared by diluting an undiluted solution of the polishing composition, for example, 10-fold or more, with a diluent, such as water.
• a polishing composition of the above embodiment may be used in applications other than polishing silicon nitride.
• Examples 1 to 14 and Comparative Examples 1 to 4 colloidal silica was mixed into water, and a pH adjuster was properly added thereto to prepare a polishing composition.
• a pH adjuster was properly added thereto to prepare a polishing composition.
• water adjusted to a pH of 2 using a pH adjuster was prepared as a polishing composition.
• the details of colloidal silica and a pH adjuster used in each polishing composition, and the results of pH measurement in each polishing composition are shown in Table 1.
• colloidal silica in which a sulfonic acid is immobilized
• B colloidal silica in which an organic acid is not immobilized.
• the average degree of association of colloidal silica used in each example was 2.
• polishing rate when the surface of a silicon nitride film blanket wafer and the surface of a polysilicon film blanket wafer with a diameter of 200 mm were polished for 60 seconds using each polishing composition under the polishing conditions described in Table 2 is shown in the column entitled “polishing speed” in Table 1.
• the value of the polishing rate was obtained by dividing by polishing time the difference in the thickness of each wafer before and after polishing, measured using a spectrometric film thickness measurement system of DAINIPPON SCREEN MFG. CO., LTD., “Lambda Ace VM-2030”.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Composite Materials (AREA)
• Mechanical Treatment Of Semiconductor (AREA)
• Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
• Physics & Mathematics (AREA)
• Condensed Matter Physics & Semiconductors (AREA)
• General Physics & Mathematics (AREA)
• Manufacturing & Machinery (AREA)
• Computer Hardware Design (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Power Engineering (AREA)

Applications Claiming Priority (3)

Related Parent Applications (1)

Related Child Applications (1)

Publications (1)

Family

ID=45723334

Family Applications (2)

Family Applications After (1)

Country Status (7)

Cited By (27)

Families Citing this family (26)

Citations (4)

Family Cites Families (42)

• 2010
  • 2010-08-23 JP JP2010186427A patent/JP5695367B2/ja active Active
• 2011
  • 2011-08-10 KR KR1020137006921A patent/KR101571224B1/ko active Active
  • 2011-08-10 CN CN201180040355.8A patent/CN103180101B/zh active Active
  • 2011-08-10 WO PCT/JP2011/068217 patent/WO2012026329A1/ja not_active Ceased
  • 2011-08-10 EP EP18179047.8A patent/EP3398716A1/en active Pending
  • 2011-08-10 EP EP15003612.7A patent/EP3059050B1/en active Active
  • 2011-08-10 EP EP11819793.8A patent/EP2610031B1/en active Active
  • 2011-08-10 US US13/818,058 patent/US20130146804A1/en not_active Abandoned
  • 2011-08-10 KR KR1020187008000A patent/KR101908265B1/ko active Active
  • 2011-08-10 KR KR1020157008625A patent/KR101843237B1/ko active Active
  • 2011-08-16 TW TW100129174A patent/TWI485236B/zh active
  • 2011-08-16 TW TW105143846A patent/TWI620813B/zh active
  • 2011-08-16 TW TW104112342A patent/TWI573865B/zh active
• 2018
  • 2018-04-30 US US15/967,011 patent/US10508222B2/en active Active

Patent Citations (5)

Also Published As

Similar Documents

Legal Events