Chemical Mechanical Polishing Pads Comprising Liquid Organic Material Encapsulated in Polymer Shell and Methods For Producing The Same

Abstract

There is provided a chemical mechanical polishing (CMP) pad including a core of a polymer shell encapsulating a liquid organic material having one of a boiling point and a decomposition point of 130° C. or more in a polymer matrix, the CMP pad having open pores formed by the core on a polishing surface thereof, and a method of producing the CMP pad. The CMP pad having a high hardness and a high density improves polishing efficiency and flatness of a wafer and maintains a uniform size of the core, thereby producing pads having high polishing efficiency and stable polishing performance.

Description

TECHNICAL FIELD[0001]The present invention relates to a chemical mechanical polishing (CMP) pad, and more particularly, to a CMP pad formed of a polymer matrix containing a liquid organic material encapsulated in a polymer shell and a method of producing the same.BACKGROUND ART[0002]Generally, a polishing process includes abrading a rough surface to form a flat surface such as glass. While repetitively and regularly polishing a surface of an object with a polishing pad, a fine-grain slurry existing in an interface between the polishing pad and the object allows the object to be polished. Particularly, in a process of manufacturing a semiconductor, since planarization of a wafer has a great effect on semiconductor integration, a chemical mechanical polishing (CMP) process has to be performed for wafer planarization.[0003]There are three conventional methods in technology with respect to polishing pads used in a CMP process.[0004]One is a urethane pad filled with one of natural felt s...

AI Technical Summary

Benefits of technology

[0019]Accordingly, an aspect of the present invention provides a polishing pad with a high hardness, high density, high polishing efficiency, and stable polishing function and a method of producing the polishing pad, together with convenience of producing the polishing pad.Technical Solution

Problems solved by technology

Though the pad described above shows excellent flatness, since the pad has low hardness, a polishing speed is low.

However, when mixing with the different subsidiary, uniform distribution is difficult due to low density of the subsidiary, which makes it difficult to uniformly prepare a pad with a regular density deviation.

Also, as polishing progresses, an error of flatness increases.

Due to the hollow shape, it is difficult to prepare a pad with a high hardness to improve polishing efficiency.

However, there is no site for collecting slurry in the pad, thereby deteriorating polishing efficiency.

However, there is needed a time for generating a space for collecting slurry, thereby causing deterioration of polishing efficiency.

Also, a life of the pad is short due to deterioration of property of matter, due to water solubility of water-soluble materials.

However, it has been known that the embedded liquid micro elements initially mixed with a urethane polymer matrix do not have a certain size.

Since it is required to form uniform slurry collecting spaces within a short urethane reaction time, liquid incompatible with urethane is required and it is difficult to control the size of uniform slurry collecting spaces with a small change in a producing process.

Also, since liquid incompatible with a polymer matrix is used, adhesive strength is deteriorated due to a phenomenon in which liquid material is transferred toward a surface of the pad.

Also, a life of the pad is short due to deterioration of properties of the urethane matrix and hardness of the pad itself is reduced since only liquid exists in the space.

Therefore, it is difficult to satisfy a requirement of wafer planarization in a semiconductor process.

However, there is problem in which bubbles generated by micro globoids and water are expanded or foamed during a urethane reaction, thereby deforming bubbles to weaken density and hardness thereof.

Also, since gases are used as slurry collecting spaces, hardness and density of the pad are not increased.

In this case, it is difficult to increase hardness of a polishing pad itself prepared by mixing inert gases, dishing and erosion may be caused due to low hardness, in a CMP process, and it is difficult to improve flatness of wafers.

However, the pad makes a scratch on a polished surface of an object and has a low polishing speed due to insufficient amount of slurry during a polishing process.

However, when a polyurethane matrix includes pores or bubbles, deviation of density increases due to heterogeneity of distribution, thereby generating a difference in a polishing function for each lot and a difference in density for each portion in the same lot and a problem of an error in flatness, the error increasing as the polishing process progresses.

However, generally, though polishing efficiency of pads is high, the polishing efficiency is deteriorated as time goes by.

Also, it is difficult to stably prepare the pads with a high hardness and high density, due to a low density of hollow subsidiary materials.

However, polishing efficiency of the pads is relatively low.

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