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KR-20260062429-A - CHEMICAL MECHANICAL POLISHING SLURRY COMPOSITION FOR POLISHING METAL FILMS AND POLISHING METHOD USING THE SAME

KR20260062429AKR 20260062429 AKR20260062429 AKR 20260062429AKR-20260062429-A

Abstract

One embodiment of the present invention provides a slurry composition for polishing a metal film, comprising an abrasive; deionized water; an oxidizing agent; and a corrosion inhibitor; wherein the etching rate can be significantly reduced while maintaining a high polishing rate of the metal film through the corrosion inhibitor. In addition, the purpose is to provide a standard range for verifying corrosion prevention performance at the slurry stage.

Inventors

  • 김석주
  • 양대훈

Assignees

  • 솔브레인 주식회사

Dates

Publication Date
20260507
Application Date
20241029

Claims (15)

  1. As a slurry composition for polishing metal films, Abrasive; solvent; and Includes a corrosion inhibitor; A slurry composition for polishing a metal film, characterized in that the Ta value of the metal oxide film on the surface of the metal film is less than 15 nm when measured by the following condition 1: [Condition 1] After immersing the metal film in the metal film polishing slurry mixed with an oxidizing agent for 5 minutes, the maximum thickness Ta of the metal oxide film penetrating in the thickness direction from the surface of the metal film is measured using a transmission electron microscope (TEM).
  2. In paragraph 1, A slurry composition for polishing a metal film, characterized in that the minimum thickness Tb of the metal oxide film measured by the above TEM is less than 8 nm.
  3. In paragraph 1, Measured by Atomic Force Microscopy (AFM), A slurry composition for polishing a metal film, characterized in that the roughness Rq value of the metal film after immersion is less than 30 Å.
  4. In paragraph 1, A slurry composition for polishing a metal film, characterized in that the maximum depth of metal oxide penetrating into the metal film from the bottom edge in the thickness direction of the metal oxide film, as measured by the above TEM, is less than 2 nm.
  5. In paragraph 1, A slurry composition for polishing a metal film, characterized in that the interfacial resistance Rf of the metal film and the slurry composition, measured by electrochemical impedance measurement, is 600 to 3000 Ω.
  6. In paragraph 1, A slurry composition for polishing a metal film, characterized in that the etching inhibition value of Formula 1 below is 10 to 200: [Equation 1] (Etching inhibition) = aX/(bY * cZ) The above X is a dimensionless number obtained by dividing the corrosion potential obtained by electrochemical measurement of the slurry composition into units of mV, Y is a dimensionless number obtained by dividing the corrosion current obtained by electrochemical measurement of the slurry composition into units of μA, and Z is the pH of the slurry composition, and When X is less than 600, a=1, and when X is 600 or greater, a=4.5, and When Y is less than 10, b=0.75, and when Y is 10 or greater, b=1, and When the pH of the slurry composition is strongly acidic (less than 2.5), c=1; when the pH is acidic (2.5 or more and less than 6), c=1.75; when the pH is weakly acidic (6 or more and less than 7), c=2; when the pH is weakly basic (7 or more and less than 8), c=1.5; when the pH is basic (8 or more and less than 12), c=1.25; and when the pH is strongly basic (12 or more), c=1.
  7. In paragraph 1, A slurry composition for polishing a metal film, characterized in that the corrosion inhibitor comprises at least two amine groups at the terminals and has a structure comprising an aromatic hydrocarbon ring structure.
  8. In paragraph 1, The above metal film polishing slurry composition is mixed with an oxidizing agent and introduced when applied to a metal film polishing process, and A slurry composition for polishing a metal film, characterized in that the oxidizing agent is at least one selected from the group consisting of hydrogen peroxide, hydrogen peroxide, urea, percarbonate, periodic acid, periodate, perchloric acid, perchlorate, perbromic acid, perbromate, perboric acid, perborate, permanganic acid, permanganate, persulfate, bromate, chlorate, hypochlorite, chromate, iodate, iodic acid, ammonium persulfate, benzoyl peroxide, calcium peroxide, barium peroxide, sodium peroxide, and urea peroxide.
  9. In paragraph 1, A slurry composition for polishing a metal film, characterized in that the abrasive is at least one selected from the group consisting of a metal oxide, a metal oxide coated with an organic or inorganic material, and the metal oxide in a colloidal state.
  10. In paragraph 1, A slurry composition for polishing a metal film, characterized in that the metal oxide comprises at least one selected from the group consisting of silica, ceria, zirconia, alumina, titania, barium titania, germania, mangania, and magnesia.
  11. In paragraph 1, A slurry composition for polishing a metal film, characterized in that the particle size of the abrasive is 10 to 150 nm.
  12. In paragraph 1, A slurry composition for polishing a metal film, characterized in that the content of the abrasive is 0.01 to 10% of the total weight of the slurry composition.
  13. In Paragraph 10, A slurry composition for polishing a metal film, characterized in that the oxidizing agent content is 0.1 to 5%.
  14. A method for polishing a metal film characterized by polishing the metal film using the slurry composition of claim 1.
  15. A method for manufacturing a semiconductor device comprising the step of polishing a metal film according to the method of claim 14.

Description

Chemical mechanical polishing slurry composition for polishing metal films and polishing method using the same The present invention relates to a chemical mechanical polishing slurry composition for polishing a metal film, a method for polishing a metal film using the same, and a method for manufacturing a semiconductor device including the polishing method. The need for multilayer wiring structures is becoming increasingly prominent due to the high performance and high integration of semiconductor devices. These multilayer wiring structures require a surface planarization process to maximize the efficiency of the lithography process for each layer, following the multiple deposition and patterning of conductive or insulating films. Planarization processes can be divided into local planarization and global planarization. The accuracy of planarization is directly linked to the performance of semiconductor devices, and advanced technology is required to reduce variability between processes. Molybdenum metal, the workpiece used in these processes, is widely applied in various industrial fields, such as microelectronic devices, interconnects, and photomasks. However, polishing materials and technologies for processing molybdenum are limited, and there is a continuous demand for novel compositions and methods capable of uniform polishing while minimizing surface oxidation issues. Tungsten (W), traditionally used for wiring in semiconductor devices, and molybdenum (Mo), currently used, follow similar mechanisms of forming an oxide film followed by polishing. However, due to its high hardness and chemical stability, tungsten enables stable polishing after the oxide film is formed. In contrast, with molybdenum, if an oxide with a high oxidation state is formed as an additional oxidation reaction proceeds after the oxide film is formed, corrosiveness increases rapidly, resulting in a decrease in polishing performance. Therefore, in the CMP process for molybdenum, it is important to suppress changes in the oxidation state to prevent excessive oxidation. Consequently, in the molybdenum CMP process, it is necessary to develop a slurry composition capable of performing polishing while forming a minimal oxide film or appropriately controlling oxidation states such as the oxidation state. Molybdenum possesses characteristics that differentiate it from other metals such as copper (Cu) and cobalt (Co). In the CMP process, copper exhibits a relatively slow oxidation rate due to the use of oxidation inhibitors, and its low etching rate ensures that the surface remains stable. Cobalt tends to maintain surface stability after polishing due to its high corrosion resistance. However, molybdenum can form oxide films under various pH conditions, which poses a risk of corrosion caused by excessive oxidation. Therefore, CMP processes using molybdenum require a slurry capable of performing uniform polishing while suppressing oxide film formation. A critical factor in the molybdenum CMP process is to minimize the additional oxidation reaction of the oxide film. To achieve this, the selection of an appropriate corrosion inhibitor is necessary; it is essential to use a compound that minimizes fluctuations in the oxidation state when the slurry comes into contact with molybdenum, or one that can control the oxidation state to prevent an increase in the hexavalent oxidation state. Since higher oxidation states significantly increase corrosiveness and degrade polishing properties in molybdenum, the slurry composition must be able to effectively suppress this increase in oxidation state. Corrosion inhibitors play a vital role in protecting the molybdenum surface while inhibiting the formation of these oxides, thereby maintaining a balance between polishing rate and surface characteristics. In the CMP process of molybdenum, it is also very important to establish a reference point for controlling the degree of oxide film formation. It is essential to develop a slurry that can suppress oxide film formation within a range where fluctuations in the oxidation state are minimized when the slurry comes into contact with molybdenum. This prevents corrosion and excessive oxidation of molybdenum and enables a stable polishing process. A slurry composition that satisfies this reference point can solve the oxidation problem of the molybdenum surface while maximizing the performance of the polishing process. To solve such problems, the inventors have developed a novel slurry composition capable of suppressing oxide formation on the molybdenum surface and optimizing polishing characteristics. Furthermore, the developed slurry composition is an invention derived by confirming characteristics that allow for the stable maintenance of the oxidation state of molybdenum through the selection of a corrosion inhibitor compound and the presentation of a reference point within a predetermined range that can determine whether an appropriate level of oxide film is form