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KR-20260064277-A - POLISHING PAD WITH IMPROVED TRANSMITTANCE, METHOD FOR PREPARING THE SAME, AND WINDOW BLOCK USED THEREIN

KR20260064277AKR 20260064277 AKR20260064277 AKR 20260064277AKR-20260064277-A

Abstract

A polishing pad according to one embodiment comprises a top pad having one or more window blocks, wherein the window blocks comprise a polyurethane resin, the polyurethane resin comprises an isocyanate component and a polyol component, and the polyol component comprises 60 mol% or more of the compound of Formula (1). The polishing pad according to the above embodiment can improve the transmittance of the window blocks to increase the accuracy of thickness measurement, and the hardness of the window blocks is excellent, thereby improving the efficiency and reliability of the CMP process.

Inventors

  • 이도형
  • 서장원
  • 윤종욱
  • 김영환
  • 김경환
  • 박상규

Assignees

  • 엔펄스 주식회사

Dates

Publication Date
20260507
Application Date
20241031

Claims (10)

  1. It includes a top pad having one or more window blocks, and The above window block comprises polyurethane resin, and The above polyurethane resin includes an isocyanate component and a polyol component, and The above polyol component comprises 60 mol% or more of the compound of the following formula (1), Polishing pad: (1) Here R is an alkyl having 1 to 6 carbon atoms, and n is an integer from 500 to 3000.
  2. In Article 1, A polishing pad in the above formula (1), where R is methyl or ethyl and n is 800 to 1200.
  3. In Article 1, The above polyol component is A polishing pad containing 90 mol% or more of the compound of the above formula (1).
  4. In Article 1, A polishing pad in which the above polyol component does not contain or contains 10 mol% or less of the compound of the following formula (2): (2) Here p is an integer from 1 to 3, and m is an integer between 500 and 3000.
  5. In Article 1, The above window block is It has a thickness of 1.0 mm to 2.0 mm, A polishing pad having a transmittance of 30% or more for light with a wavelength of 440 nm.
  6. In Article 1, The above window block is The Ra roughness is 0.4 μm to 0.7 μm, and A grinding pad having a hardness of 40 Shore D to 80 Shore D.
  7. Includes polyurethane resin, The above polyurethane resin includes an isocyanate component and a polyol component, and The above polyol component contains 60 mol% or more of the compound of the following formula (1), and Window block for abrasive pads with a transmittance of 30% or more: (1) Here R is an alkyl having 1 to 6 carbon atoms, and n is an integer from 500 to 1500.
  8. In Article 7, In the above formula (1), R is methyl or ethyl and n is 800 to 1200, and The above polyol component is The compound of the above formula (1) comprises 90 mol% or more, Window block for a polishing pad that does not contain or contains 10 mol% or less of the compound of formula (2) below: (2) Here p is an integer from 1 to 3, and m is an integer between 500 and 3000.
  9. In Article 7, The window block for the polishing pad above is The transmittance for light with a wavelength of 440 nm is 70% or higher, and Window block for abrasive pads having a hardness of 40 Shore D to 80 Shore D.
  10. A step of manufacturing a window block using an isocyanate component, a polyol component, and a curing agent; and The above window block includes the step of combining with a top pad and surface processing, The above polyol component comprises 60 mol% or more of the compound of the following formula (1), Method for manufacturing a polishing pad: (1) Here R is an alkyl having 1 to 6 carbon atoms, and n is an integer from 500 to 3000.

Description

Polishing pad with improved transmittance, method for preparing the same, and window block used therein An embodiment relates to a polishing pad used in a chemical mechanical polishing (CMP) process of a semiconductor device, a method for manufacturing the same, and a window block used therein. The importance of the Chemical Mechanical Polishing (CMP) process is continuously increasing due to the rise in semiconductor chip integration density and the miniaturization of semiconductor circuits. Precision is critical for enhancing the performance and efficiency of semiconductor chips, and the CMP process plays a decisive role among them. Polishing pads, a key auxiliary material for performing the CMP process, play a core role, and maintaining the thickness and uniformity of the top pad is essential to ensure the precision of the semiconductor chip circuits. The technology for measuring the thickness of the top pad during the CMP process plays a crucial role in enhancing process precision, thereby significantly improving process efficiency and stability. Among these methods, interferometric measurement, which calculates film thickness using the interference spectrum of light reflected from the wafer surface, is a widely used technique. To this end, a window is formed on the top pad to allow light transmission, enabling the measurement of light reflected from the wafer surface. Korean Patent Registration No. 1120647 discloses a polishing pad having a window formed inside by reacting an aliphatic polyisocyanate, a hydroxyl-containing material, and a curing agent. The window block generally uses a non-foamed polyurethane material and can maintain a basically transparent state because it has no pores inside. However, transmittance decreases due to fine scratches generated during the surface processing, which becomes a major problem that makes it difficult to use in the CMP process. Various approaches are being researched to enhance the transparency of polishing pad windows. For example, transmittance can be improved by minimizing scratches through the optimization of surface processing and by controlling the structure of polymer chains through the adjustment of raw material selection and synthesis conditions. These technical approaches improve the performance of polishing pads used in the CMP process and contribute to increasing the precision and reliability of the semiconductor chip manufacturing process. Figure 1 shows the transmittance spectrum according to the composition of the window block for the polishing pad in Test Example 1. Figure 2 shows the transmittance spectrum according to the thickness of the window block for the polishing pad in Test Example 2. 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. Furthermore, the molecular weights of polymers described in this specification may be interpreted as number-average molecular weight or weight-average molecular weight, for example, as number-average molecular weight. In numerical ranges defining the size, physical properties, etc., of components described in this specification, if a numerical range in which only the upper limit is defined a