Method of fabricating polyurethane foam with micro pores and polishing pad therefrom

Abstract

To provide a method of fabricating a polyurethane foam with micro pores, and a polishing pad therefrom, the method including steps of (a) adding a nonionic surfactant into at least one of a first ingredient including an isocyanate group-containing compound and a second ingredient including an active hydrogen group-containing compound, (b) agitating and mixing the mixture of the first ingredient and the second ingredient while adding a non-reactive gas thereto, (c) discharging the mixture out of a container at a predetermined rate, and (d) injecting the discharged mixture into a mold so as to form a mold body into a predetermined shape.

Description

technical field [0001] The present invention relates to a method of preparing a polyurethane foam having micropores and a polishing pad obtained therefrom, and more particularly to a method of preparing a polishing pad for planarization of semiconductor wafers by chemical mechanical polishing (CMP) and to a polishing pad obtained therefrom polishing pad. Background technique [0002] In recent years, with the high integration of semiconductor elements, the fineness and compactness of the line patterns on them have also increased rapidly. In this regard, an exposure process for transferring a pattern on a semiconductor wafer is an important process, but improvements in the exposure process alone are not enough to satisfy the recent above-mentioned requirements. Also, the number of layers formed on the wafer increases with the rapid development of the trend towards high integration, and the roughness of the wafer surface increases, so that it may be diff...

AI Technical Summary

Problems solved by technology

That is, the processing margin of the preparation process is reduced due to poor retention performance and short maintenance life for keeping each component in the mixture

[0013] There is also the problem that mixing a creamy foam dispersion liquid with another first component liquid makes it difficult to mix the mixture effectively and easily, resulting in harsh preparation conditions and an increase in the overall time of the preparation process

Therefore, in order to prevent changes in the properties of the isocyanate-terminated urethane prepolymer, polysiloxane-based nonionic surfactants that do not contain hydroxyl groups should be selectively used, which results in greatly limiting the ability to satisfy various properties. Selection of required polishing pad composition

Moreover, polysiloxane-based nonionic surfactants containing hydroxyl groups are more widely used and are less costly, so the above-mentioned restrictions on the choice of this surfactant lead to higher production costs, and its processing margin also damaged

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