KR101509590B1 - Polishing pad for chemical mechanical polishing, preparation method of the same, and apparatus for cmp - Google Patents

Abstract

The present invention relates to a pad body comprising a polymer resin; And a transparent window formed on the pad body, wherein the transparent window comprises at least one selected from the group consisting of a photo-curable resin and a thermosetting resin, a method of manufacturing the same, and a CMP apparatus including the same, When the CMP polishing pad is used, the transparency of the transparent window may be reduced or the protrusion may be minimized during the polishing process, and the polishing end point may be easily detected.

Description

TECHNICAL FIELD The present invention relates to a CMP polishing pad, a method of manufacturing the CMP polishing pad, and a CMP apparatus including the polishing pad.

The present invention relates to a CMP polishing pad, a method of manufacturing the same, and a CMP apparatus including the CMP polishing pad. More particularly, the present invention can minimize the transparency of a transparent window or form protrusions during a polishing process, A method of manufacturing the same, and a CMP apparatus including the same.

BACKGROUND OF THE INVENTION Chemical mechanical polishing (CMP) is a method in which a polishing pad is sandwiched between a polishing pad of a polishing apparatus and a semiconductor substrate by supplying a slurry composition containing abrasive particles and various chemical components, And mechanically polishing the film to be polished on the substrate with the abrasive grains or the like to chemically polish the film to be polished by the action of the chemical component or the like.

In a general CMP process, polishing of the wafer surface is carried out as the wafer is mounted upside down on a carrier in a CMP machine and is pushed downward toward the polishing pad. At this time, the carrier and the wafer are rotated on the rotary polishing pad placed on the polishing table of the CMP apparatus. In the polishing process of the wafer surface, a polishing pad having a transparent window is used to monitor the polishing state of the wafer surface.

Polyurethane is mainly used as a transparent window material. Solid polyurethane window is not only so high in transparency but also easily scratched during the CMP process, so that the light transmittance is continuously decreased. In addition, since the solid polyurethane window has a slower wear rate than the rest of the polishing pad, there is a problem in that a polishing defect can be generated by forming a protrusion on the polishing pad.

In addition, the polyurethane transparent window is not only difficult to be installed on the polishing pad, but also causes a lot of problems even after the installation. Previously, in order to install a polyurethane transparent window, a method of drilling a part of a polishing pad body and sandwiching a transparent window therebetween was used. However, according to this method, the slurry flows into the gap between the pad body and the transparent window, It was not easy to measure the polishing rate.

Further, there has been proposed a method of manufacturing a polishing pad by cutting a resin mass obtained by placing a polyurethane transparent window in a mold and then injecting a resin for producing a pad body into a mold. However, The limit problem of improvement of transparency could not be sufficiently solved.

Accordingly, there is a demand for development of a transparent window material which can realize a higher transparency, lower transparency in polishing process, minimize the formation of protrusions, and can be easily installed on a polishing pad.

The present invention provides a CMP polishing pad capable of minimizing the transparency of a transparent window or minimizing the formation of protrusions in a polishing process and capable of easily detecting a polishing end point.

The present invention also provides a method of manufacturing the CMP polishing pad.

The present invention also provides a CMP apparatus including the CMP polishing pad.

The present invention relates to a pad body comprising a polymer resin; And a transparent window formed on the pad body, the transparent window including a thermosetting resin or a photo-curable resin containing at least one selected from the group consisting of phenol resin, urea resin, melamine resin, epoxy resin and polyester resin. Pad.

In addition, the present invention provides a transparent resin composition comprising a pad body containing a polymer resin and a transparent window including a thermosetting resin or a photo-curing resin containing at least one selected from the group consisting of a phenol resin, a urea resin, a melamine resin, The method comprising the steps of: preparing a CMP polishing pad;

The present invention also relates to the above CMP polishing pad; A rotatable platen; A supply for supplying polishing slurry onto the polishing pad; And a polishing head for introducing a wafer to be polished onto the pad.

Hereinafter, a CMP polishing pad, a method of manufacturing a CMP polishing pad, and a CMP apparatus according to a specific example of the present invention will be described in detail.

According to an embodiment of the invention, there is provided a pad body comprising a polymer resin; And a transparent window formed on the pad body, the transparent window including a thermosetting resin or a photo-curable resin containing at least one selected from the group consisting of phenol resin, urea resin, melamine resin, epoxy resin and polyester resin. A pad may be provided.

The present inventors have found that when a photocurable resin or a specific thermosetting resin is used as a material of a transparent window to be applied to a CMP polishing pad, a significantly improved light transmittance can be realized as compared with a transparent window using a conventional polyurethane polymer, And it is confirmed through experiments that the transparency of the transparent window is reduced or the protrusion is minimized during the polishing process, and the invention is completed.

In particular, due to the material properties of the photocurable resin or the specific thermosetting resin in the transparent window, the light transmittance can be greatly improved, the polishing end point can be more easily detected, and the grindability to the pad body is high, It is possible to prevent the occurrence of excessive scratches on the development or transparent window surface. When the photo-curing resin is used, the curing can be performed in a short time. When the thermosetting resin is used, it can be easily cured even at a low temperature. Therefore, when the photo-curing resin and / or the thermosetting resin is used The transparent window can be easily inserted into the pad body or easily positioned inside the pad body.

Specifically, the transparent window may have a light transmittance of 90% or more, preferably 93% or more at one wavelength in the range of 200 to 1,000 nm, including the photo-curing resin or the polymer resin including the thermosetting resin .

In addition, the polymer resin including the photocurable resin or the thermosetting resin included in the transparent window may have a hardness higher than that of the polymer resin included in the pad body, so that the transparent window exhibits higher abrasiveness than the pad body A phenomenon in which a transparent window is protruded in an actual polishing process, a phenomenon in which an excessive scratch is generated on a transparent window surface, or a phenomenon that a polished target film is damaged due to a protruding transparent window can be prevented.

As shown in FIG. 1, the CMP polishing pad may include a pad body and a transparent window provided on the pad body.

The pad body may be incorporated with a polymeric resin known to be applicable to a CMP polishing pad without any particular limitation, including polyurethane, polyacrylic, polymethacryl, polycarbonate, nylon resin, polyester, polyimide , Polyaramid, polystyrene, polyvinyl alcohol, polyacrylamide, polyethylene oxide, maleic acid copolymer, methylcellulose, carboxymethylcellulose, copolymers thereof, or mixtures thereof.

Such a pad body can be manufactured using the above-mentioned polymer resins, and the manufacturing method widely known in the art can be used without any limitation. For example, when the pad body is made of a polyurethane compound, a pre-polymer method or a one shot method may be used. In the case of the prepolymer method, a urethane prepolymer is formed by reacting a polyol component and an isocyanate component, and then the urethane prepolymer, the diamine or the diol, the foaming agent and the catalyst are mixed and cured to prepare a polyurethane resin . According to the one-shot method, a polyurethane resin can be formed by mixing a polyol component, an isocyanate component, a diamine or a diol, a blowing agent, a catalyst, and the like, followed by curing.

There is no particular limitation on the size and thickness of the pad body. The size and thickness of the pad body can be appropriately adjusted according to the size of the wafer to be polished, the polishing rate, the polishing conditions, etc., but preferably a radius of 10 cm to 100 cm and a thickness of 0.1 to 5 mm Lt; / RTI >

Meanwhile, the transparent window may include a photo-curing resin or a thermosetting resin.

Specific examples of the photocurable resin include an epoxy acrylate resin, a polyester acrylate resin, a urethane-based acrylate resin, a urethane-based methacrylate resin, a silicone acrylate resin, an alkyl acrylate resin or a mixture thereof, Include urethane acrylate resin or urethane methacrylate resin.

Specific examples of the thermosetting resin include a phenol resin, a urea resin (urea resin), a melamine resin, an epoxy resin, a polyester resin or a mixture thereof, preferably an epoxy resin.

The photo-curing resin and the thermosetting resin described above have a transparent property, and thus can provide a transparent window capable of more effectively detecting the polishing end point on the polishing pad. In addition, a transparent window manufactured using a polymer resin including a photo-curable resin or a thermosetting resin has excellent grindability and can prevent a phenomenon in which a transparent window protrudes during polishing or an excessive scratch on a transparent window surface.

Meanwhile, as shown in FIG. 2, the CMP polishing pad may further include a cushion layer bonded to the pad body by an adhesive. The cushion layer may include various polymer resins, but may preferably include a polyurethane resin, a polyethylene resin, a natural rubber, a synthetic rubber, or the like. For example, the pad body and the base layer may be formed by a method such as an adhesive, a double-sided tape, a thermal fusion bonding, or a pressure bonding method. .

According to another embodiment of the present invention, a thermosetting resin or a thermosetting resin containing at least one selected from the group consisting of a phenol resin, an urea resin, a melamine resin, an epoxy resin and a polyester resin is added to a pad body containing a polymer resin The method comprising the steps of: providing a transparent window including a transparent window;

By using the photo-curing resin or the thermosetting resin as a transparent window material, a transparent window can be formed on the pad body by various methods and the problem of installing the transparent window of the polyurethane based polymer can be solved. The CMP polishing pad manufactured by the above manufacturing method can easily detect the polishing end point by including a transparent window having an improved transmittance and minimizes the transparency of the transparent window or the formation of protrusions during the polishing process .

The step of providing the transparent window including the specific thermosetting resin or the photo-curable resin on the pad body including the polymer resin may be carried out by a method and an apparatus known to be commonly used for installing a transparent window on the polishing pad without any limitation Can be used.

For example, the step of installing the transparent window including the specific thermosetting resin or the photo-curable resin on the pad body including the polymer resin may include forming a transparent window on the pad body And then injecting and curing the specific thermosetting resin or photo-curing resin. Alternatively, a transparent window obtained by curing the specific thermosetting resin or the photo-curable resin may be inserted into a transparent window mounting portion Or fixing a transparent window obtained by curing the specific thermosetting resin or photo-curable resin to a certain mold, and then injecting and curing a polymer resin for forming the pad body There is also water.

Specifically, the step of installing the transparent window on the pad body includes: forming a transparent window mounting part on the pad body; Injecting a polymer resin comprising a thermosetting resin or a photocurable resin containing at least one selected from the group consisting of phenol resin, urea resin, melamine resin, epoxy resin and polyester resin into the transparent window mounting portion; And curing the injected polymer resin.

According to the method of manufacturing a CMP polishing pad, a liquid polymer composition is injected into a specific region (a transparent window mounting portion) for providing a transparent window to the pad body, and is cured by applying a photopolymerizable resin or a thermosetting resin to the transparent window , A transparent window having the above-described characteristics can be easily positioned inside the pad body through a simple process.

The pad body may be manufactured using the above-mentioned polymer resins, and the synthetic method well-known in the art can be used without any limitation. The steps of manufacturing the pad body from the polyurethane compound, and the size and thickness of the pad body are as described above.

The step of forming the transparent window mounting part on the pad body may be widely used without any limitations on a method and an apparatus commonly known to be used for providing a transparent window on the pad body. For example, A step of injecting and curing a polymer resin for forming a pad body into a mold having a shape capable of forming a window mounting portion, or a step of forming a structure (for example, a hexahedral block or the like) Placing the pad in a mold for manufacturing the pad body, and injecting and hardening the polymer resin to form the pad body.

In the step of curing the injected polymer resin, the wavelength and intensity of light to be applied can be appropriately controlled according to the photocurable resin used, and the heating temperature and time to be applied can be appropriately controlled according to the thermosetting resin used. The photo-curing resin or the thermosetting resin may contain additives such as a curing agent and a cross-linking agent which are conventionally used.

In addition, in the step of installing the transparent window on the pad body, not only the step of injecting and hardening the liquid polymer composition into the transparent window mounting portion but also the method of forming or installing the transparent polyurethane window, Can be used without.

Accordingly, the step of installing the transparent window on the pad body includes: forming a transparent window mounting part on the pad body; And fixing the cured transparent window to the transparent window mounting portion. The above-mentioned CMP polishing pad can be manufactured by fixing a transparent window obtained by curing the specific thermosetting resin or photo-curing resin to a transparent window mounting portion formed in the pad body.

In the step of fixing the cured transparent window, an adhesive or an adhesive tape commonly used for bonding a photo-curable resin or a thermosetting resin can be used without any limitations. desirable.

Specifically, in order to prevent a gap between the pad body and the transparent window, it is preferable to use a foam-type adhesive tape having a foam sheet as a base and an adhesive layer on both sides. As a concrete example of such a foam sheet EPT # 140, EPT # 310, EPT # 320, or EPT # 450 of die and spinning. A specific example of the adhesive tape for forming the double-sided adhesive layer is an adhesive tape for acrylic foam structure of Sumitomo 3M Y-4950, Y-4930, Y-4630F, Y-4620 and Y-4608.

In addition, the step of installing the transparent window on the pad body may include the steps of placing a cured transparent window on the mold and injecting the polymer resin for the pad body into the mold to form a resin molded product; And manufacturing a sheet-like polishing pad from the resin molding.

In the step of placing the cured transparent window on the mold and injecting the polymer resin for pad body into the mold to form the resin moldings, the methods of manufacturing the resin moldings for manufacturing the polishing pad previously used can be used without any limitation. The transparent window may be made of a polymer resin including a photo-curable resin or a thermosetting resin, and may be appropriately adjusted in size or thickness in consideration of a polishing condition or a light transmittance. The mold can be suitably adjusted according to the shape of the polishing pad to be manufactured.

In the step of producing a sheet-shaped polishing pad from the resin molding, the resin molding separated from the mold may be sliced or cut to produce a polishing pad of a desired size and thickness.

The method of manufacturing the CMP polishing pad may further include forming a cushion layer on the pad body. The pad body having the transparent window mounting portion may further include a cushion layer for firmly coupling the pad body and the transparent window. The cushion layer may be coupled to the transparent window mounting pad through the adhesive portion. The cushion layer may include various polymer resins, but may preferably include a polyurethane resin, a polyethylene resin, a natural rubber, a synthetic rubber, or the like. For example, the pad body and the base layer may be formed by a method such as an adhesive, a double-sided tape, a thermal fusion bonding, or a pressure bonding method. .

According to another embodiment of the present invention, the CMP polishing pad; A rotatable platen; A supply for supplying polishing slurry onto the polishing pad; And a polishing head for introducing a wafer to be polished onto the pad.

Such a CMP apparatus includes a CMP polishing pad including a transparent window including a photo-curable resin and / or a thermosetting resin, so that it is possible to easily detect the polishing end point, and the transparency of the transparent window is lowered during the polishing process, The phenomenon of being formed can be minimized.

Accordingly, such a CMP apparatus may further include a polishing end point detection apparatus. Such a polishing end point detection apparatus means an apparatus capable of analyzing light or other radiation reflected from an object surface to inspect or monitor the polishing process.

In addition, the CMP apparatus may further include a pad conditioner for removing residues generated by the polishing of the wafer and maintaining a constant state of the polishing pad.

According to the present invention, there is provided a CMP polishing pad capable of minimizing the transparency of a transparent window or minimizing the formation of protrusions during polishing and capable of easily detecting a polishing end point, a method for manufacturing the same, and a CMP apparatus including the same do.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a simplified top view of an embodiment of an inventive polishing pad.
2 schematically shows a side view of a polishing pad of an embodiment of the invention.

The invention will be described in more detail in the following examples. However, the following examples are illustrative of the present invention, and the present invention is not limited by the following examples.

< Example  And Comparative Example : CMP  Preparation of polishing pad &gt;

Example 1

(1) Manufacturing of transparent window

50 g of an epoxy resin (YD-128: an epoxy resin derived from bisphenol A, Kuko Chemical Co., Ltd.) and 60.8 g of a curing agent (D-230: polyehtheramine, Kuko Chemical Co., Ltd.) * Height 10 cm) and left at 80 캜 for 2 hours to prepare a thermosetting resin block for a transparent window.

(2) Preparation of resin composition for manufacturing pad body and CMP polishing pad

3297g of polyether urethane prepolymer (Adiprene L-325, Chemtura) and 749g of a curing agent (MOCA: 3,3'-dichloro-4,4'-diaminodiphenylmethane) were mixed to prepare a resin composition for manufacturing a pad body.

Then, the obtained thermosetting resin block for the transparent window was placed in a cylindrical mold having a diameter of 60 cm and a height of 10 cm, and the resin composition for manufacturing the pad body was injected into the mold at all times. The mold was allowed to stand at 65 DEG C for 15 minutes, and the obtained product was cut to a thickness of 2 mm to prepare a CMP polishing pad.

Example 2

(1) Preparation of resin composition for manufacturing pad body and CMP pad body

3297g of polyether urethane prepolymer (Adiprene L-325, Chemtura) and 749g of a curing agent (MOCA: 3,3'-dichloro-4,4'-diaminodiphenylmethane) were mixed to prepare a resin composition for manufacturing a pad body.

A block (width 1.5 cm * length 4 cm * height 10 cm) made of SUS (steel use stainless) was placed in a cylindrical mold (diameter 60 cm and height 10 cm) to secure a space for introducing the transparent window, Was injected into the mold, and the mold was allowed to stand at 65 DEG C for 15 minutes to prepare a body pad.

Then, the body pad is removed from the mold, the SUS block is removed from the body pad, the body pad is cut to a thickness of 2 mm, and the transparent pad is adhered to the cushion layer using a transparent thin- .

(2) Introduction of transparent window

100 g of urethane acrylate resin (M-8F1: Aekyoung Chemical Co., Ltd.) for transparent window formation was injected so as to fill the groove in the transparent window size in the polishing pad body, and ultraviolet rays were irradiated for 30 seconds at 1000 mJ / , And then a transparent window was introduced on the CMP polishing pad by removing the cushion layer and the double-sided adhesive tape on the transparent window mounting portion.

Comparative Example 1

(1) Manufacturing of transparent window

50 g of a polyether urethane prepolymer (Adiprene L-325, Chemtura) and 60.8 g of a curing agent (D-230: polyehtheramine, Kukdo Chemical Co., Ltd.) were mixed and the mixture was injected into a mold (1.5 cm wide × 4 cm high × 10 cm high) And allowed to stand at 80 DEG C for 2 hours to prepare a thermosetting resin block for a transparent window.

(2) Preparation of resin composition for manufacturing pad body and CMP polishing pad

3297g of polyether urethane prepolymer (Adiprene L-325, Chemtura) and 749g of a curing agent (MOCA: 3,3'-dichloro-4,4'-diaminodiphenylmethane) were mixed to prepare a resin composition for manufacturing a pad body.

Then, the obtained thermosetting resin block for the transparent window was placed in a cylindrical mold having a diameter of 60 cm and a height of 10 cm, and the resin composition for manufacturing the pad body was injected into the mold at all times. The mold was allowed to stand at 65 DEG C for 15 minutes, and the obtained product was cut to a thickness of 2 mm to prepare a CMP polishing pad.

Reference example

3297 g of a polyether urethane prepolymer (Adiprene L-325, Chemtura) and 749 g of a curing agent (MOCA: 3,3'-dichloro-4,4'-diaminodiphenylmethane) were mixed and injected into a cylindrical mold (diameter 60 cm and height 10 cm). The mold was allowed to stand at 65 DEG C for 15 minutes, and the obtained product was cut to a thickness of 2 mm to prepare a CMP polishing pad.

< Experimental Example : CMP  Measurement of physical properties of polishing pad>

Experimental Example 1 : Transmittance  Measure

The transmittance was measured by passing a laser beam having a wavelength of 650 nm through the CMP pads of the examples and comparative examples using N & K (transmittance measuring instrument).

Experimental Example 2 : Save Modulus of elasticity  And Tan  δ value measurement

The storage elastic modulus and tan delta value of the CMP pads of Examples and Comparative Examples were measured using a dynamic mechanical analyzer (DMA) of TA Corporation.

Experimental Example 3 : Hardness measurement

The hardness of the CMP pads of the Examples and Comparative Examples was measured using a Shore D type Shore hardness tester (3100 manufactured by Zwick Corporation) based on ASTM 2240. Specifically, an initial hardness value obtained by lowering the weight by using the hardness meter and a hardness value after 15 seconds were recorded.

Experimental Example 4 : Measurement of wear index

The hardness of the CMP pads of Examples and Comparative Examples was measured using a Taber type abrasion tester manufactured by TABER industry. Specifically, the abrasion index was measured by rotating the CMP pads of Examples and Comparative Examples under a constant load (abbreviated as 1 Kg of each weight) by abrasion wheel H-18 to measure the loss weight, and the abrasion index Was obtained by the following general formula (1).

[General formula]

Wear Index = (Wear Loss Weight (mg) / Test Rotation) * 1000

The results of Experimental Examples 1 to 4 are shown in Table 1 below.

Transmittance (%) DMA data Hardness
Shore D Wear index Storage modulus
(40 DEG C)
(Mpa) Tan δ
(40 DEG C) Example 1 97 393 0.08 39 104 Example 2 94 430 0.073 41 111 Comparative Example 1 85 473 0.096 51 79 Reference example - 451 0.11 49 83

As shown in Table 1, the CMP polishing pad of the embodiment includes a transparent window made of a photo-curing resin or a thermosetting resin, so that it can exhibit a light transmittance of 93% or more and can more easily detect the polishing end point have.

In addition, since the CMP polishing pad of the embodiment exhibits a low storage elastic modulus and a low Tan δ value as well as a low hardness and a high wear index as compared with the polishing pad of Reference Example and Comparative Example 1, And it is possible to prevent a phenomenon in which a transparent window protrudes in an actual polishing process or an excessive scratch occurs on a transparent window surface.

On the other hand, the CMP polishing pad of Comparative Example 1 exhibited a light transmittance of only 85%, and it is relatively difficult to confirm the polishing end point as compared with the polishing pad of the embodiment. The transparent window of Comparative Example 1 exhibited a higher hardness and a lower wear index than the pad body (Reference Example), so that a transparent window protruded during the actual polishing process or excessive scratches on the transparent window surface, or due to the projected transparent window, The film may be damaged or the like.

Claims (13)

A pad body including a polymer resin including polyurethane; And
A transparent window comprising a thermosetting mixture of a mixture of epoxy resin and polyether amine derived from bisphenol A,
The transparent window has a light transmittance of 93% or more at one wavelength in the range of 200 to 1,000 nm,
The thermosetting resin including the epoxy resin derived from the bisphenol A has a higher hardness than the polymer resin contained in the pad body,
The transparent window is formed on the pad body.
delete delete The method according to claim 1,
The polymer resin contained in the pad body may be at least one selected from the group consisting of polyacryl, polymethacryl, polycarbonate, nylon resin, polyester, polyimide, polyaramid, polystyrene, polyvinyl alcohol, polyacrylamide, polyethylene oxide, , Methyl cellulose, carboxymethyl cellulose, and copolymers thereof. &Lt; Desc / Clms Page number 13 &gt;
delete The method according to claim 1,
And a cushion layer bonded to the pad body by an adhesive.
Providing a transparent window comprising a thermosetting mixture of an epoxy resin derived from bisphenol A and a polyetheramine in a pad body containing a polymer resin containing polyurethane,
The transparent window has a light transmittance of 93% or more at one wavelength in the range of 200 to 1,000 nm,
Wherein the thermosetting resin including an epoxy resin derived from bisphenol A has a higher hardness than a polymer resin contained in the pad body.
8. The method of claim 7,
The step of installing the transparent window on the pad body includes:
Forming a transparent window mount on the pad body;
Injecting a mixture of an epoxy resin derived from bisphenol A and a polyether amine into the transparent window mounting portion; And
And curing a mixture of an epoxy resin and a polyether amine derived from the injected bisphenol-A.
8. The method of claim 7,
The step of installing the transparent window on the pad body includes:
Forming a transparent window mount on the pad body; And
And fixing the cured transparent window to the transparent window mounting portion.
8. The method of claim 7,
The step of installing the transparent window on the pad body includes:
Placing a cured transparent window on a mold and injecting a polymer resin for a pad body into the mold to form a resin molding; And
And forming a polishing pad in a sheet form from the resin molding.
8. The method of claim 7,
Further comprising forming a cushion layer on the pad body.
A CMP polishing pad of claim 1;
A rotatable platen;
A supply for supplying polishing slurry onto the polishing pad; And
And a polishing head for introducing a wafer to be polished onto the pad.
13. The method of claim 12,
Further comprising a polishing end point detection device.

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