KR101009609B1 - Polishing pad and method of manufacturing the same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing pad used for a CMP process such as a silicon wafer, a plate glass for a display, and a manufacturing method thereof. The present invention forms a shape layer 4 for micro molding on a film 3, and The photoreactive resin is coated on and cured to prepare a photoreactive resin layer (1), and the film (3) and the shape layer (4) are separated therefrom and removed to form a pattern (on one side of the photoreactive resin layer (1). 1a) are formed, and one surface on which the patterns 1a are formed in the photoreactive resin layer 1 is polished, and an adhesive layer 2 is formed on the other surface to manufacture a polishing pad.

The present invention can form the pattern 1a in a desired size and shape, and can greatly improve the reproducibility and uniformity of the pattern 1a. Therefore, the polishing pad of the present invention has the advantage of low scratch rate and excellent polishing efficiency.

Polishing, Pads, CMP, Wafers, Patterns, Molding, Micro, Shape, Reproducibility

Description

Polishing pad and method of manufacturing the same

1 is a cross-sectional view of a polishing pad according to the present invention.

2 is a cross-sectional view showing a state in which the shape layer 4 is formed on the film 3.

3 is a cross-sectional view showing a state in which a photoreactive resin layer 1 is formed on the shape layer 4 of FIG. 2.

4 is a cross-sectional view showing a state in which the film 3 and the shape layer 4 are removed from FIG. 3.

5 is a schematic cross-sectional view of a conventional polishing pad.

* Code description for main parts of the drawings

1: photoreactive resin layer 1a: pattern

2: adhesive layer 3: film

4: shape layer

The present invention is useful for chemical mechanical polishing (CMP), particularly for CMP methods of planarizing flat glass or other substrates for silicon wafers or displays used in the manufacture of integrated circuit chips or the like. A polishing pad and a method of manufacturing the same.

The silicon wafer and the like are smoothly processed by the CMP polishing apparatus, and the CMP polishing apparatus includes a lower board having a circular rotating plate on which the polishing pad is mounted, an upper board which adheres the silicon wafer to the polishing pad, and a device for supplying slurry to the polishing pad. do.

Chemical-mechanical polishing, a CMP operation, pushes the surface of the semiconductor wafer on which the integrated circuit will be fabricated in the opposite direction to remove oxides, including deposited Si-based oxides, and creates a very smooth and flat surface on the wafer. As an operation, deionized water and / or chemically active reagents are applied along with the polishing liquid to the interface between the wafer and the polishing pad during the CMP operation.

Conventionally, in Korean Patent Laid-Open No. 2000-70068 as a polishing pad used in a CMP method, a photoreactive resin layer is formed on a substrate by coating or laminating, and then a photomask having a predetermined pattern is formed on the photoreactive resin layer. After positioning, a method of manufacturing a polishing pad is disclosed by irradiating an electromagnetic beam to the photoreactive resin layer on the photomask.

Specifically, a portion of the photoreactive resin layer in which electromagnetic radiation is blocked by the photomask does not cause photoreaction, and thus is removed in a later process to form a pattern 5a, and a portion in which the photomagnetic rays are not blocked by the photomask. A method of manufacturing a polishing pad in which patterns 5a are formed on a surface of the surface as shown in FIG. Is showing.

5 is a schematic cross-sectional view of the polishing pad manufactured by the conventional method.

However, since the conventional method employs a photoelectronic method using an optical mask, it is difficult to control the internal shape according to the depth and depth of the groove on the pattern 5a, and a large-diameter optical mask suitable for an enlarged polishing pad. Difficulties such as manufacturing difficulties and the need to use expensive equipment for photomasks.

The present invention is to provide a method for manufacturing a polishing pad by uniformly forming a pattern of a desired shape by molding on one surface of the photoreactive resin layer (1) to solve the above conventional problems.

In addition, the present invention is to provide a polishing pad having a low scratch occurrence rate and excellent polishing efficiency because the pattern is uniformly formed on the surface of the photoreactive resin layer (1).

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

First, in the present invention, the shape layer 4 for micro-molding is formed on the film 3, a photoreactive resin is coated thereon, and then cured to prepare a photoreactive resin layer 1, and from this film ( 3) and the shape layers 4 are separated and removed to form patterns 1a on one surface of the photoreactive resin layer 1, and one surface on which the patterns 1a are formed on the photoreactive resin layer 1 is polished and An adhesive layer 2 is formed on one surface to manufacture a polishing pad having a structure as shown in FIG. 1.

1 is a cross-sectional view of a polishing pad according to the present invention.

The polishing pad of the present invention is a photoreactive resin layer (1) having a pattern (1a) formed on the surface as shown in Figure 1 and an adhesive layer (2) attached to the rear surface of the photoreactive resin layer (1) It is composed.

In the present invention, first, as shown in FIG. 2, the shape layer 4 for micro molding is formed on the film 3.

Next, as shown in FIG. 3, a photoreactive resin is coated on the shape layer 4 to a predetermined thickness and then cured to prepare a photoreactive resin layer 1.

The photoreactive resin layer 1 is manufactured by irradiating the photoreactive resin with ultraviolet rays to cure the photoreactive resin.

Next, as shown in FIG. 4, the film 3 and the shape layer 4 are separated and removed from the photoreactive resin layer 1, so that a pattern 1a is formed on one surface of the photoreactive resin layer 1. ).

The pattern 1a has the same shape as that of the shape layer 4, and is a recess, a slit, or the like.

Next, one surface on which the patterns 1a are formed in the photoreactive resin layer 1 is polished, and the adhesive layer 2 is formed on the other surface to manufacture a polishing pad having a cross-sectional structure as shown in FIG. 1.

In the present invention, since the patterns 1a are formed on the surface of the polishing pad by a micro molding method instead of the photo electronic method by a conventional mask, a desired size and shape of the pattern can be formed, and the uniformity and reproducibility of the pattern are also excellent.

In the present invention, the surface roughness and scratch occurrence rate of the polished silicon wafer were evaluated as follows.

Surface Average Roughness of Silicon Wafers

Carl Zeiss, a type of confocal laser scanning microscope (LSM) facility, LSM 5 PASCAL, a topography software package for LSM, or similar performance. Measure by using LSM equipment.

Specifically, the center line average roughness (Ra) value of 10 irregularities formed on the surface according to JIS B 0601 by scanning the surface area range (width 1,000 μm x length 1000 μm) of the polished silicon wafer with a laser Is measured and the ten point average roughness Rz of the surface of the polished silicon wafer is obtained from the arithmetic mean value.

Hereinafter, the ten point average roughness Rz is called surface average roughness.

Scratch Rate (%)

The number of scratches generated when scratching a silicon wafer with 100 square inch area by polishing pad is identified and substituted into the following equation.

Scratch Rate (%) = (Scratch Count / 100 Sq Inch) x 100

However, if the number of scratches exceeds 100, leave it at 100.

The scratch reading is judged by visual judgment by a skilled expert, and in the case of a faint defect that is difficult to read whether it is scratched with the naked eye, it may rely on the additional measurement of an optical microscope equipped with dark field illumination and image analysis software.

In addition, the scratch judges the scratch that the ratio of the length in the longitudinal direction and the width direction to be 10 to 1 or more.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

However, the present invention is not particularly limited by the following examples.

Example 1

A shape layer 4 having a hemispherical shape was formed on the polyester film 3 as shown in FIG. 2 for micro molding.

The maximum diameter of the said shape layer was 10 micrometers, the height was 20 micrometers, and the space | interval was 50 micrometers.

Next, a photoreactive resin (copolymerizable polyester urethane resin) is coated on the shape layer 4 to a thickness of 20 mm, and then irradiated with ultraviolet rays thereon to cure the photoreactive resin. The strata 1 were prepared.

Next, the polyester film 3 and the shape layer 4 are separated and removed from the photoreactive resin layer 1 to form grooves patterns 1a on one surface of the photoreactive resin layer 1, The surface on which the patterns 1a were formed was polished, and an adhesive layer 2 was formed on the other surface to prepare a polishing pad.

100 square inches of the silicon wafer was polished under the following conditions using the prepared polishing pad.

Polishing condition

-Polishing machine: GNP Technology's Poli-500 Polisher

-Polishing time: 10 minutes

Down force: 250g / cm2 (3.5psi) on the wafer surface

-Polishing Table Speed: 120rpm

Wafer Carrier Speed: 120rpm

Slurry flow rate: 700 ml / min

-Slurry type: Nalco 2731, silica slurry diluted with DIW and slurry at 15: 1

Table 1 shows the results of measuring surface average roughness and scratch rate of the polished (polished) silicon wafer.

Comparative Example  One

The photoreactive resin used in Example 1 was coated on the polyester film to a thickness of 20 mm to form a photoreactive resin layer, and then light was alternately blocked and passed through ultraviolet rays at intervals of 100 μm on the photoreactive resin layer. The mask was arranged and irradiated with ultraviolet rays to prepare a polishing pad having a cross-sectional structure as shown in FIG. 5.

The grooves formed on the surface of the polishing pad had a maximum diameter of 50 μm, a depth of 30 μm, and a space of 100 μm.

100 square inches of the silicon wafer was polished under the same polishing conditions as in Example 1 using the prepared polishing pad.

Table 1 shows the results of measuring the surface average roughness and scratch rate of the polished (polished) silicon wafer as described above.

Measurement results of polished wafer properties division Example 1 Comparative Example 1 Surface Average Roughness of Polished Wafers 13.76 14.30 Scratch Rate (%) 0.10 0.16

Example 1 was finer and more uniform in pattern and was better than scratch rate and polishing performance (surface average roughness of the polished wafer).

The present invention can form the pattern 1a in a desired size and shape, and can greatly improve the reproducibility and uniformity of the pattern 1a. Therefore, the polishing pad of the present invention has the advantage of low scratch rate and excellent polishing efficiency.

Claims (4)

Forming the shape layer 4 for micro-molding on the film (3), apply a photoreactive resin on it and cured to produce a photoreactive resin layer (1), from which the film (3) and the shape layer The patterns 1a are formed on one surface of the photoreactive resin layer 1 by separating and removing the portions 4, and one surface on which the patterns 1a are formed of the photoreactive resin layer 1 is polished, and the adhesive layer 2 is formed on the other surface. Method for producing a polishing pad, characterized in that to form a). The method for manufacturing a polishing pad according to claim 1, wherein the photoreactive resin is cured by irradiating ultraviolet rays to produce a photoreactive resin layer (1). The method of manufacturing a polishing pad according to claim 1, wherein the pattern (1a) is one selected from grooves and slits. Polishing comprising a photoreactive resin layer (1) prepared by the method of claim 1 and having patterns (1a) formed on the surface thereof and adhered to the back side of the photoreactive resin layer (1). pad.

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