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KR-20260063838-A - SURFACE RECOVERY METHOD OF POLISHING PAD AND POLISHING PAD WITH LESS METAL CONTAMINATION

KR20260063838AKR 20260063838 AKR20260063838 AKR 20260063838AKR-20260063838-A

Abstract

A method for restoring the surface of a polishing pad is provided, comprising the step of conditioning the polishing surface of the polishing pad, wherein the conditioning includes applying steam at 80°C to 110°C to the polishing surface, and wherein, when the polishing surface is analyzed by inductively coupled plasma emission spectrometry (ICP-OES), the increase in titanium (Ti) content after conditioning compared to before conditioning is 100 ppm or less.

Inventors

  • 신유진
  • 김경환
  • 오신일
  • 서장원

Assignees

  • 엔펄스 주식회사

Dates

Publication Date
20260507
Application Date
20241031

Claims (10)

  1. It includes a step of conditioning the polishing surface of the polishing pad, and The above conditioning includes applying steam to the polished surface, and A method for restoring the surface of a polishing pad, wherein, when the polishing surface is analyzed by inductively coupled plasma emission spectrometry (ICP-OES), the increase in titanium (Ti) content after conditioning compared to before conditioning is 100 ppm or less.
  2. In Article 1, The above conditioning is A method for restoring the surface of a polishing pad, comprising sweeping the polishing surface with a disc while applying steam at 80°C to 110°C to the polishing surface.
  3. In Article 1, The above conditioning is A method for restoring the surface of a polishing pad, comprising sweeping the polishing surface with a brush while applying steam at 80°C to 110°C to the polishing surface.
  4. In Article 1, A method for restoring the surface of a polishing pad, wherein, when the polishing surface is analyzed by inductively coupled plasma emission spectrometry (ICP-OES), the increase in aluminum (Al) content after conditioning compared to before conditioning is 10 ppm or less.
  5. In Article 1, A surface recovery method for a polishing pad having △Spk of 1 μm or more according to the equation below: △Spk = Spk2 - Spk1 Here Spk1 is the Spk roughness of the polished surface measured after performing the above conditioning, and Spk2 is the Spk roughness of the polished surface measured after aging the polished surface following the conditioning and performing the conditioning again, and The above aging is to polish five or more wafers having a SiO2 film based on a silica slurry without conditioning under conditions of a platen rotation speed of 93 rpm, a wafer rotation speed of 87 rpm, and a wafer center area reference pressure of 4.1 psi.
  6. It includes a polishing layer having a polished surface, and A polishing pad in which, after conditioning the polishing surface by applying steam at 95°C for 10 minutes, the increase in titanium (Ti) content after conditioning compared to before conditioning is 100 ppm or less when the polishing surface is analyzed by inductively coupled plasma emission spectrometry (ICP-OES).
  7. In Article 6, A polishing pad in which, when the polishing surface is analyzed by inductively coupled plasma emission spectrometry (ICP-OES), the increase in aluminum (Al) content after conditioning compared to before conditioning is 10 ppm or less.
  8. In Article 6, A polishing pad in which, when the polishing surface is analyzed by inductively coupled plasma emission spectrometry (ICP-OES), the titanium (Ti) content after conditioning is 100 ppm or less and the aluminum (Al) content is 10 ppm or less.
  9. In Article 6, A polishing pad having △Spk of 1 μm or more according to the formula below: △Spk = Spk2 - Spk1 Here Spk1 is the Spk roughness of the polished surface measured after performing the above conditioning, and Spk2 is the Spk roughness of the polished surface measured after aging the polished surface following the conditioning and performing the conditioning again, and The above aging is to polish five or more wafers having a SiO2 film based on a silica slurry without conditioning under conditions of a platen rotation speed of 93 rpm, a wafer rotation speed of 87 rpm, and a wafer center area reference pressure of 4.1 psi.
  10. In Article 6, A polishing pad having a polishing rate of 2600 Å/min to 3200 Å/min according to the following formula, when polishing a silicon oxide film of a silicon wafer on the polishing surface using a ceria slurry after the above conditioning: Polishing rate (RR, Å/min) = Change in film thickness before and after polishing (Å) / Polishing time (min).

Description

Surface recovery method of polishing pad and polishing pad with less metal contamination An embodiment relates to a method for surface recovery of a polishing pad used in a chemical mechanical polishing (CMP) process of a semiconductor device. Furthermore, the present invention relates to a polishing pad with low metal contamination during conditioning. Recently, as the individual chip size of semiconductor devices has been miniaturized, chip integration density has increased, and the miniaturization of circuit patterns formed on the chips has become more advanced, the importance of the chemical mechanical polishing (CMP) process is on the rise. In the CMP process, a polishing slurry is supplied to a rotating polishing pad, and the supplied polishing slurry is uniformly distributed on the surface of the polishing pad by the rotation of the pad. As the surface of the rotating polishing pad, on which the polishing slurry is distributed, comes into contact with the surface of the rotating polishing target (substrate, semiconductor device, rotary pattern, etc.), polishing of the surface of the polishing target is performed. Chemical polishing is performed on the surface of the polishing target through the polishing slurry. In addition, mechanical polishing is performed on the surface of the rotating polishing target through physical contact with the surface of the rotating polishing pad. This CMP process is designed to flatten the surface of an object to be polished or to remove aggregated material, scratches, and contaminants formed on the surface. In this CMP process, polishing pads are used to polish the surface of the object. The polishing pads used in the CMP process are process components that machine the surface of the object to a target level through friction, and they are a factor that determines the uniformity of thickness, flatness, and quality of the surface of the polished object after polishing is complete. As the CMP process is repeatedly performed, the polishing performance of these polishing pads deteriorates due to wear. Polishing pads with such degraded performance must be replaced with new ones and subsequently discarded. Consequently, since these degraded pads cannot be reused and are instead discarded, periodic replacement costs are incurred, and environmental pollution caused by their disposal intensifies. Accordingly, the importance of conditioning processes is increasing, as they enable the reuse of polishing pads with degraded polishing performance and minimize the amount of discarded pads. Figures 1 and 2 show the oxide film polishing rate (RR) according to the conditioning method of the polishing pad of Preparation Example 1. Figures 3 to 6 show profiles of oxide film polishing rates (RR) according to the conditioning method of the polishing pad of Preparation Example 1. Figure 7 shows the surface morphology according to the conditioning method of the polishing pad of Preparation Example 1. Figures 8 to 11 show surface images according to the conditioning method of the polishing pad of Preparation Example 1. In describing the embodiments below, detailed descriptions of related known configurations or functions are omitted if it is determined that such descriptions could obscure the essence of the embodiments. Additionally, the sizes of each component in the drawings may be exaggerated or omitted for illustrative purposes and may differ from the actual sizes applied. In this specification, the description that one component is formed above or below another component, or is connected or coupled to one another, includes both direct formation, connection, or coupling between these components and indirect formation, connection, or coupling through the interposition of another component. Furthermore, it should be understood that the criteria for the "above" and "below" of each component may vary depending on the direction in which the object is observed. In this specification, terms referring to each component are used to distinguish them from other components and are not intended to limit the embodiments. Additionally, in this specification, singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as "first," "second," etc. are used to describe various components, and said components should not be limited by said terms. These terms are used for the purpose of distinguishing one component from another. In this specification, the use of the term "comprising" is intended to specify characteristics, regions, steps, processes, elements, and components, and unless specifically stated otherwise, it does not exclude the existence or addition of other characteristics, regions, steps, processes, elements, or components. For convenience, the molecular weights of compounds or polymers described in this specification are indicated in units of molar mass, but they may be understood as relative masses based on carbon-12. Furthermor