KR20220046017A - Polishing pad and preparing method of semiconductor device using the same - Google Patents

Abstract

The present invention relates to a polishing pad which comprises a polishing layer. The polishing pad comprises: a first peak in which a nuclear magnetic resonance (NMR) ^13C spectrum of a processed composition, obtained by putting 1 g of the polishing layer in a KOH water solution of the concentration of 0.3 M and causing a reaction for 48 hours under the temperature of 150℃ in a sealed container, appears at 15-18 ppm; a second peak in which the NMR ^13C spectrum appears at 9-11 ppm; and a third peak in which the NMR ^13C spectrum appears at 138-143 ppm, wherein the area ratio of the third peak compared to the second peak is about 5:1 or about 10:1. The polishing pad displays the properties meeting the peak characteristics described above. Accordingly, the present invention is able to, in polishing a subject, realize a polishing rate of a target range and defect-preventive performance.

Description

POLISHING PAD AND PREPARING METHOD OF SEMICONDUCTOR DEVICE USING THE SAME

It relates to a pad applied to a polishing process, and to a technique for applying such a pad to a method of manufacturing a semiconductor device.

A chemical mechanical planarization (CMP) or chemical mechanical polishing (CMP) process may be performed for various purposes in various technical fields. The CMP process is performed on a predetermined polished surface of an object to be polished, and may be performed for the purposes of planarization of the polished surface, removal of aggregated materials, resolution of crystal lattice damage, and removal of scratches and contamination sources.

The CMP process technology of the semiconductor process can be classified according to the quality of the film to be polished or the shape of the surface after polishing. For example, it can be divided into single silicon or polysilicon according to the film quality to be polished, and various oxide films or tungsten (W), copper (Cu), aluminum (Al) classified according to the type of impurities. ), ruthenium (Ru), tantalum (Ta), etc. can be classified into a metal film CMP process. And, according to the shape of the surface after polishing, it can be classified into a process of alleviating the roughness of the substrate surface, a process of flattening a step caused by multi-layer circuit wiring, and an element isolation process for selectively forming circuit wiring after polishing.

The CMP process may be applied in plurality in the manufacturing process of the semiconductor device. A semiconductor device includes a plurality of layers, and each layer includes a complex and fine circuit pattern. In addition, in recent semiconductor devices, individual chip sizes are reduced, and the patterns of each layer are evolving to become more complex and finer. Accordingly, in the process of manufacturing semiconductor devices, the purpose of the CMP process has been expanded to not only planarize circuit wiring, but also separate circuit wiring and improve wiring surface, and as a result, more sophisticated and reliable CMP performance is required. .

The polishing pad used in the CMP process is a process component that processes the polished surface to a required level through friction. can see.

One embodiment of the present invention is based on physical properties such as appropriate hardness, tensile strength, and elongation without deterioration of long-term polishing performance by maintaining the surface state of the polished surface at the same level as that of the initial stage even as time elapses during the polishing process. As a result, a polishing pad that can be applied to a polishing process to achieve a desired level of polishing rate and defect prevention effect is provided.

Another embodiment of the present invention shows a high process efficiency in polishing a semiconductor substrate, and in the final polishing result, a semiconductor device implementing the effect that the polished surface of the semiconductor substrate exhibits an appropriate polishing rate and the lowest level of defects. A manufacturing method is provided.

In one embodiment of the present invention, the core of the processing composition including an abrasive layer, 1 g of the abrasive layer is added to an aqueous solution of potassium hydroxide (KOH) having a concentration of 0.3M, and reacted for 48 hours at 150° C. in a sealed container a first peak in the magnetic resonance (NMR) ¹³ C spectrum of 15 ppm to 18 ppm; a second peak appearing at 9 ppm to 11 ppm; and a third peak appearing at 138 ppm to 143 ppm, wherein an area ratio of the third peak to the second peak is about 5:1 to about 10:1.

An area ratio of the first peak to the second peak may be about 10:1 to about 10:5, and an area ratio of the first peak to the third peak may be about 10:5 to about 10:10.

In another embodiment of the present invention, providing a polishing pad comprising a polishing layer; and arranging the polishing surface of the polishing object to be in contact with the polishing surface of the polishing layer and then polishing the polishing object while rotating relative to each other, wherein the polishing object includes a semiconductor substrate, and the polishing layer includes: 1 g thereof was added to an aqueous solution of potassium hydroxide (KOH) having a concentration of 0.3 M, and the nuclear magnetic resonance (NMR) ¹³ C spectrum of the processed composition was reacted for 48 hours at 150° C. in a sealed container at 15 ppm to 18 ppm. peak; a second peak appearing at 9 ppm to 11 ppm; and a third peak appearing at 138 ppm to 143 ppm, wherein an area ratio of the third peak to the second peak is 5:1 to 10:1.

In the method of manufacturing the semiconductor device, the semiconductor substrate includes a silicon oxide (SiO ₂ ) film, the surface to be polished is the surface of the silicon oxide (SiO ₂ ) film, and the average polishing rate is 1,500 Å/min to 2,500 Å /min, and after the polishing is completed, the surface to be polished may include 5 or less defects.

The polishing pad includes a polishing layer having a chemical bonding structure and a cross-linking structure corresponding to the peak characteristics of the processing composition treated therewith under predetermined conditions, so that the polishing surface of the polishing layer may exhibit appropriate hardness, and accordingly It is possible to exhibit a polishing rate and polishing flatness within a target range in polishing an object to be polished. In addition, even with the lapse of time during the polishing process, the polishing surface maintains a surface state equivalent to the initial level, so that polishing performance is not deteriorated for a long time.

The method of manufacturing a semiconductor device using the polishing pad exhibits high process efficiency in polishing a semiconductor substrate to be polished, and in the final polishing result, the polished surface of the semiconductor substrate exhibits high polishing flatness and the lowest level of defects. effect can be obtained.

1 schematically illustrates a cross-section of the polishing pad according to an exemplary embodiment.
2 schematically illustrates a process diagram of a method of manufacturing a semiconductor device according to an exemplary embodiment.
3 is a schematic diagram for explaining an exemplary preliminary composition, a cured structure, and a processing composition.

Advantages and features of the present invention, and a method of achieving them will become clear with reference to the following examples. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms, Only the present embodiments are provided to complete the disclosure of the present invention, and to fully inform those of ordinary skill in the art to which the present invention belongs, the scope of the invention, the present invention is defined by the scope of the claims will only be

In order to clearly express various layers and regions in the drawings, the thicknesses are enlarged. And in the drawings, for convenience of description, the thickness of some layers and regions are exaggerated. Like reference numerals refer to like elements throughout.

In addition, in the present specification, when a part of a layer, film, region, plate, etc. is said to be “on” or “on” another part, this is not only when it is “directly on” another part, but also when there is another part in the middle. also includes Conversely, when we say that a part is "just above" another part, we mean that there is no other part in the middle. In addition, when a part of a layer, film, region, plate, etc. is said to be "under" or "under" another part, it is not only when it is "under" another part, but also when there is another part in between. include Conversely, when a part is said to be "just below" another part, it means that there is no other part in the middle.

In addition, in the present specification, the peak area ratio of the nuclear magnetic resonance (NMR) spectrum is interpreted as belonging to the right range if the number average value falls within the corresponding range after calculating the area ratio in the same manner at least 5 times for the same polishing layer. In addition, the area ratio of the peak may be obtained as an integration value of the corresponding peak in a nuclear magnetic resonance (NMR) spectrum.

In one embodiment of the present invention, the core of the processing composition including an abrasive layer, 1 g of the abrasive layer is added to an aqueous solution of potassium hydroxide (KOH) having a concentration of 0.3M, and reacted for 48 hours at 150° C. in a sealed container a first peak in the magnetic resonance (NMR) ¹³ C spectrum of 15 ppm to 18 ppm; a second peak appearing at 9 ppm to 11 ppm; and a third peak appearing at 138 ppm to 143 ppm, wherein an area ratio of the third peak to the second peak is about 5:1 to about 10:1.

The polishing layer is a cured product composed of a compound having a predetermined chemical structure, and final polishing such as a polishing rate and degree of defects according to the chemical structure of the compound and each bonding structure and bonding force of the repeating units constituting the chemical structure Performance can be determined. The compound included in the polishing layer includes various types of chemical bonding structures. When the polishing layer is processed under predetermined processing conditions, the bonding may be separated or maintained depending on the bonding strength of each bonding structure. Accordingly, the shape of the nuclear magnetic resonance (NMR) 13C spectrum of the processing composition of the polishing layer is changed.

Specifically, the abrasive layer according to an embodiment is nuclear magnetic resonance (NMR) of the processing composition in which 1 g thereof is added to an aqueous solution of potassium hydroxide (KOH) having a concentration of 0.3 M, and reacted for 48 hours at 150° C. in a sealed container. ) the first peak appearing in the ¹³ C spectrum from 15 ppm to 18 ppm; a second peak appearing at 9 ppm to 11 ppm; and a third peak appearing at 138 ppm to 143 ppm, wherein an area ratio of the third peak to the second peak is about 5:1 to about 10:1. That is, the polishing layer is made of a compound having a chemical bonding structure corresponding to the spectral characteristics, thereby greatly improving the polishing performance of the polishing pad. More specifically, in the abrasive layer, in the nuclear magnetic resonance (NMR) ¹³ C spectrum of the processing composition, the correlation between the area ratio of the second peak and the third peak satisfies the above-mentioned condition. degree, and the corresponding physical properties such as hardness and elongation are exhibited, and as a result, polishing performance such as a desired level of polishing rate (RR) can be realized.

For example, the area ratio of the third peak to the second peak may be about 5:1 to about 10:1, for example, about 5:1 to 8:1. Through the result that the area ratio of the third peak to the second peak satisfies the above range, it can be seen that the polishing layer is partially decomposed under a predetermined condition to have a repeating unit of chemical bonding force showing the peak, and at the same time as a whole It can be seen that a compound having a chemical structure corresponding to the area ratio is included. Accordingly, the polishing layer may have appropriate hardness and elongation, and as a result, a desired polishing rate and defect reduction effect may be realized.

In one embodiment, the processing composition has an area ratio of the first peak to the second peak of 10:1 to 10:5, and an area ratio of the first peak to the third peak of 10:5 to 10:10 can

For example, the area ratio of the first peak to the second peak may be from about 10:1 to about 10:5, for example, from about 10:1.00 to about 10:1.60, for example, It may be greater than or equal to about 10:1.00 and less than or equal to about 10:1.60.

For example, the area ratio of the first peak to the third peak may be from 10:5 to 10:10, for example, greater than about 10:5.00, less than or equal to about 10:10.00, for example, about 10:5.60 to about 10:9.00.

The area ratio of the third peak to the second peak of the processing composition satisfies the aforementioned range, while the area ratio of the first peak to the second peak and the area ratio of the first peak to the third peak is within this range When satisfying .

In addition, in the processing composition, 1 g of the polishing layer is added to an aqueous solution of potassium hydroxide (KOH) having a concentration of 0.3 M, and the processing composition is prepared by processing under the conditions of reacting for 48 hours at 150° C. in a sealed container. Compared to the processing composition prepared by treatment under other conditions, its nuclear magnetic resonance (NMR) ¹³ C spectrum showed a high correlation with the polishing performance of the final polishing pad.

In the nuclear magnetic resonance (NMR) ¹³ C spectrum of the processing composition, factors such as the type and content of the raw material monomer during the manufacturing process of the polishing layer, process temperature and pressure conditions, and the type and content of additives such as curing agents and foaming agents are comprehensive. can be adjusted and determined.

1 schematically illustrates a cross-section of the polishing pad according to an exemplary embodiment. Referring to FIG. 1A , the polishing pad 100 may include the polishing layer 10 , and may include a cushion layer 20 on one surface of the polishing layer 10 . The polishing layer 10 is in the form of a sheet having a predetermined thickness, and includes a first surface 11 functioning as a polishing surface in direct or indirect contact with a polishing target surface of a polishing object, and the first surface 11 ) may include a second surface 12 that is the back surface.

In one embodiment, the first surface 11 may include a groove 13 machined to a depth smaller than the thickness of the polishing layer 10 . The groove 13 may have a concentric circular structure formed to be spaced apart from the center of the polishing layer 10 by a predetermined distance toward the end of the polishing layer 10 based on the planar structure of the first surface 11 . In another embodiment, the groove 13 may have a radial structure continuously formed from the center to the end of the polishing layer 10 based on the planar structure of the first surface 11 . In another embodiment, the groove 13 may have the concentric circular structure and the radial structure at the same time. The groove 13 controls the fluidity of the polishing liquid or polishing slurry supplied to the first surface 11 during the polishing process using the polishing pad 100 , or a contact area between the polishing surface and the polishing target surface. It can play a role in controlling the polishing result by controlling the physical properties of

In one embodiment, the thickness of the abrasive layer 10 is about 0.8 mm to about 5.0 mm, such as about 1.0 mm to about 4.0 mm, such as about 1.0 mm to 3.0 mm, such as about 1.5 mm to about 3.0 mm, such as about 1.7 mm to about 2.7 mm, such as about 2.0 mm to about 3.5 mm.

The polishing layer 10 may have a porous structure including a plurality of pores. The average particle diameter of the plurality of pores is about 5 μm to about 50 μm, for example, about 5 μm to about 40 μm, for example, about 10 μm to about 40 μm, for example, about 10 μm to about 35 μm It may be μm, but is not limited thereto. The plurality of pores may appear as fine concave portions (not shown) that are partially exposed on the polishing surface of the polishing layer to be distinguished from the grooves 13, which are the grooves 13 during use of the polishing pad. ) together with the abrasive liquid or abrasive slurry to determine the fluidity and mooring space, which can serve as a control factor for polishing properties.

The abrasive surface 11 may have a predetermined surface roughness due to the fine concave portion distinguished from the groove 13 . In one embodiment, the surface roughness (Ra) of the polishing surface 11 may be about 3㎛ to about 1mm. For example, the surface roughness Ra of the polishing surface 11 may be in a range of about 3 μm to about 20 μm, for example, about 3 μm to about 10 μm.

The cushion layer 20 is disposed on the second surface 12 of the polishing layer 10 to relieve an external pressure or impact transmitted to the surface to be polished during the polishing process while supporting the polishing layer 10 . can play a role Through this, it can contribute to preventing damage and defects to the polishing object in the polishing process to which the polishing pad 100 is applied.

In one embodiment, the cushion layer 20 has a thickness of about 0.5 mm to about 2.5 mm, for example, about 0.8 mm to about 2.5 mm, for example, about 1.0 mm to about 2.5 mm, for example. , from about 1.0 mm to about 2.0 mm, for example, from about 1.2 mm to about 1.8 mm.

Referring to FIG. 1B , in one embodiment, the polishing pad 200 includes the polishing layer 10 and the cushion layer 20 , and the polishing layer 10 and the cushion layer It may further include a first adhesive layer 30 disposed on the interface of (20). For example, the first adhesive layer 30 may be derived from a heat-sealing adhesive, but is not limited thereto.

The polishing pad 200 may further include a second adhesive layer 40 disposed on the second surface 12 of the polishing layer 10 . The second adhesive layer 40 is a configuration for attaching the polishing pad to the surface plate of the polishing apparatus, and may be disposed directly on the second surface 12 of the polishing layer 10, as shown in FIG. 1(b). ), it may be disposed on other layers such as the cushion layer 20 on the polishing layer 10 . For example, the second adhesive layer 40 may be derived from a pressure sensitive adhesive, but is not limited thereto.

In one embodiment, the polishing pad may include a through region penetrating the uppermost layer and the lowermost layer. The penetrating region is a configuration for detecting a polishing end point during use of the polishing pad, and light having a predetermined wavelength condition may pass therethrough. In one embodiment, a light-transmitting window may be disposed in the through area. The light transmission window may have a transmittance of more than about 30%, for example, about 40% to about 80%, for light of any one wavelength from about 500 nm to about 700 nm.

The polishing layer may include a cured product of a preliminary composition including a urethane-based prepolymer. In one embodiment, the preliminary composition may further include a curing agent and a foaming agent. The 'prepolymer' refers to a polymer having a relatively low molecular weight in which the polymerization degree is stopped at an intermediate stage to facilitate molding in the production of a cured product. The prepolymer itself undergoes an additional curing process such as heating and/or pressurization, or is mixed with another polymerizable compound, for example, an additional compound such as a heterogeneous monomer or a heterogeneous prepolymer, and reacted, followed by a final cured product can be molded into

In one embodiment, the urethane-based prepolymer may be prepared by reacting an isocyanate compound with a polyol compound.

As the isocyanate compound used in the preparation of the urethane-based prepolymer, one selected from the group consisting of aromatic diisocyanate, aliphatic diisocyanate, cycloaliphatic diisocyanate, and combinations thereof may be used. In one embodiment, the isocyanate compound may include an aromatic diisocyanate.

The isocyanate compound is, for example, 2,4-toluenediisocyanate (2,4-TDI), 2,6-toluenediisocyanate (2,6-toluenediisocyanate, 2,6-TDI) Naphthalene-1,5-diisocyanate, para-phenylenediisocyanate, tolidinediisocyanate, 4,4'-diphenylmethane diisocyanate (4,4) '-diphenylmethanediisocyanate), hexamethylenediisocyanate, dicyclohexylmethanediisocyanate, 4,4'-dicyclohexylmethanediisocyanate (4,4'-dicyclohexylmethanediisocyanate, H ₁₂ MDI), isophoronedi It may include one selected from the group consisting of isocyanate (isoporone diisocyanate) and combinations thereof.

The 'polyol' refers to a compound including at least two or more hydroxyl groups (-OH) per molecule. In one embodiment, the polyol compound may include a dihydric alcohol compound having two hydroxyl groups, that is, a diol or a glycol.

The polyol compound is, for example, selected from the group consisting of polyether polyol, polyester polyol, polycarbonate polyol, acryl polyol, and combinations thereof. may contain one.

The polyol compound is, for example, polytetramethylene ether glycol (PTMG), polypropylene ether glycol, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol , 2-methyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, diethylene glycol (DEG), dipropylene glycol (DPG), tripropylene glycol, polypropylene glycol, and may include one selected from the group consisting of combinations thereof.

The polyol compound may have a weight average molecular weight (Mw) of about 100 g/mol to about 3,000 g/mol. For example, the polyol may have a weight average of from about 100 g/mol to about 3,000 g/mol, such as from about 100 g/mol to about 2,000 g/mol, such as from about 100 g/mol to about 1,800 g/mol. It may have a molecular weight (Mw).

In one embodiment, the polyol compound is a low molecular weight polyol having a weight average molecular weight (Mw) of about 100 g/mol or more and less than about 300 g/mol, and a weight average molecular weight (Mw) of about 300 g/mol or more and about 1800 g/mol or less. molecular weight polyols. In one embodiment, the high molecular weight polyol may include a first high molecular weight polyol having a weight average molecular weight (Mw) of about 500 g/mol or more and about 800 g/mol or less; and a second high molecular weight polyol having a weight average molecular weight (Mw) greater than about 800 g/mol and less than or equal to about 1,800 g/mol. In this case, the polyol compound can form an appropriate cross-linked structure in the urethane-based prepolymer, and the abrasive layer formed by curing the preliminary composition including the urethane-based prepolymer under predetermined process conditions. can That is, the nuclear magnetic resonance (NMR) ¹³ C spectrum of the processing composition obtained by treating the polishing layer under predetermined conditions due to the appropriate cross-linking structure of the polyol compound may exhibit the above-described peak area ratio characteristics, and corresponding excellent polishing properties can be implemented.

The urethane-based prepolymer may have a weight average molecular weight (Mw) of about 500 g/mol to about 3,000 g/mol. The urethane-based prepolymer may have a weight average molecular weight (Mw) of, for example, about 600 g/mol to about 2,000 g/mol, for example, about 800 g/mol to about 1,000 g/mol. When the urethane-based prepolymer has a degree of polymerization corresponding to the aforementioned weight average molecular weight (Mw), the abrasive layer formed by curing the preliminary composition under predetermined process conditions has a chemical bonding structure for realizing the excellent polishing properties described above. may be more advantageous.

In one embodiment, the isocyanate compound for preparing the urethane-based prepolymer may include an aromatic diisocyanate compound, and the aromatic diisocyanate compound is, for example, 2,4-toluene diisocyanate (2,4-TDI) and 2,6-toluenediisocyanate (2,6-TDI). In addition, the polyol compound for preparing the urethane-based prepolymer may include, for example, polytetramethylene ether glycol (PTMG) and diethylene glycol (DEG).

In another embodiment, the isocyanate compound for preparing the urethane-based prepolymer may include an aromatic diisocyanate compound and an alicyclic diisocyanate compound, for example, the aromatic diisocyanate compound is 2,4-toluene diisocyanate (2 ,4-TDI) and 2,6-toluene diisocyanate (2,6-TDI), and the alicyclic diisocyanate compound may include dicyclohexylmethane diisocyanate (H ₁₂ MDI). In addition, the polyol compound for preparing the urethane-based prepolymer may include, for example, polytetramethylene ether glycol (PTMG) and diethylene glycol (DEG).

In the preliminary composition, relative to 100 parts by weight of the total amount of the isocyanate compound in the total components for preparing the urethane-based prepolymer, the total amount of the polyol compound may be about 100 parts by weight to about 250 parts by weight, for example, about 120 parts by weight parts by weight to about 250 parts by weight, for example, about 120 parts by weight to about 240 parts by weight, for example, about 150 parts by weight to about 240 parts by weight, for example, about 190 parts by weight to about 240 parts by weight.

In the preliminary composition, when the isocyanate compound for preparing the urethane-based prepolymer includes the aromatic isocyanate compound, and the aromatic isocyanate compound includes 2,4-TDI and 2,6-TDI, the 2,6 The content of -TDI may be about 1 part by weight to about 40 parts by weight, for example, about 1 part by weight to about 30 parts by weight, for example, about 3 parts by weight based on 100 parts by weight of the 2,4-TDI. It may be in an amount of from about 1 part by weight to about 28 parts by weight, for example, from about 1 part by weight to about 10 parts by weight.

In the preliminary composition, when the isocyanate compound for preparing the urethane-based prepolymer includes the aromatic isocyanate compound and the alicyclic isocyanate compound, the content of the alicyclic isocyanate compound is about 100 parts by weight of the total aromatic isocyanate compound. It may be 5 parts by weight to about 30 parts by weight, for example, about 10 parts by weight to about 25 parts by weight.

The preliminary composition has an isocyanate group content (NCO%) of about 5% to about 11% by weight, for example, about 5% to about 10% by weight, for example, about 5% to about 8.5% by weight. can The isocyanate group content means a percentage of the weight of isocyanate groups (-NCO) present as free reactive groups without urethane reaction in the total weight of the preliminary composition. The isocyanate group content (NCO%) of the preliminary composition is the type and content of the isocyanate compound and polyol compound for preparing the urethane-based prepolymer, the process conditions such as temperature, pressure, and time of the process for preparing the urethane-based prepolymer, and the urethane-based prepolymer It can be designed by comprehensively controlling the type and content of additives used in the manufacture of

In one embodiment, the nuclear magnetic resonance (NMR) ¹³ C spectrum of the preliminary composition shows a fourth peak and a fifth peak in the order of increasing the peak position (ppm) value from 16 ppm to 20 ppm, and the fourth peak to the fourth peak The area ratio of the 5 peaks may be from about 1:1 to about 10:1.

Specifically, the nuclear magnetic resonance (NMR) ¹³ C spectrum of the preliminary composition may have a fourth peak in a range of 17.5 ppm to 20.0 ppm and a fifth peak in a range of 16 ppm to 17.5 ppm. For example, the area ratio of the fourth peak to the fifth peak is from about 1:1 to about 10:1, such as from about 3:1 to 10:1, such as from about 3.5:1 to about 9 1:1, for example about 3.5:1 to 8:1. The polishing layer formed by curing the preliminary composition having such peak characteristics under predetermined process conditions may be more advantageous in exhibiting properties suitable for realizing a desired level of polishing rate, polishing flatness, and defect reduction effect.

The preliminary composition is a composition including the urethane-based prepolymer, the chemical structure of the urethane-based prepolymer itself; and/or the chemical bonding structure in the cured structure of the polishing layer may vary according to the concentration of free functional groups contained in the urethane-based prepolymer and free reactive groups contained in the remaining unreacted monomers. On the other hand, even if the type or content of the monomer constituting the urethane-based prepolymer and the remaining unreacted monomer are the same, the chemical bond structure in the cured structure of the polishing layer and the peak characteristic of the nuclear magnetic resonance (NMR) ¹³ C spectrum resulting from the urethane-based prepolymer are the same. reaction process conditions for prepolymer preparation; curing process conditions for producing the abrasive layer; Or it may vary depending on the processing conditions for preparing the processing composition.

3 is a schematic diagram illustrating an example of the preliminary composition 50, the cured structure 60 forming the polishing layer, and the processing composition 70 in order to explain this. Referring to FIG. 3 , the preliminary composition 50 is prepared by reacting a monomer A, a monomer B, a monomer C, and a monomer D, and illustratively includes a first prepolymer (A-B-C-B-A) and a second prepolymer (A-B-C-B-D). and unreacted monomer D. When the type of the monomer for preparing the preliminary composition 50 is changed, the chemical structure of the prepolymer is also changed. In addition, even when the same monomer is used as a raw material, the structure of the prepolymer and the type of unreacted monomer may vary depending on reaction conditions such as temperature, pressure, and time for preparing the preliminary composition 50 . Then, after adding the additive E to the preliminary composition 50, the cured structure 60 having a relatively longer chain structure and a crosslinked structure than the prepolymer by curing under a curing process condition of a predetermined temperature, pressure and time. to form The chemical structure of the hardening structure 60 may also vary depending on the type of the additive and/or process conditions for manufacturing the polishing layer. Then, the cured structure 60 is treated under Condition 1 to obtain a processing composition 70 . At least a portion of the bonding structure of the cured structure 60 is broken and dissociated under the condition 1 to obtain a final processing composition 70 comprising Structure 1 (A-B-C), Structure 2 (B-A-E-D-A-B) and Structure 3 (C-B-A) will become In this case, the processing composition treated under conditions other than condition 1 will include structures having a chemical structure different from those of structures 1, 2 and 3 above.

That is, the nuclear magnetic resonance (NMR) ¹³ C spectrum of the processing composition in which 1 g of the abrasive layer was added to an aqueous solution of potassium hydroxide (KOH) having a concentration of 0.3 M and reacted for 48 hours at 150° C. in a sealed container. The peak characteristics of the preliminary composition for preparing the polishing layer and the type and content of monomers for preparing the urethane-based prepolymer of the preliminary composition, as well as various process conditions during the preparation of the preliminary composition and the preparation of the polishing layer, and The processing conditions for obtaining the processing composition, etc. are organically related and comprehensively appearing. However, the technical purpose of the polishing pad according to an embodiment is that the resulting polishing performance of the polishing pad is a desired level when the peak characteristic of the nuclear magnetic resonance (NMR) ¹³ C spectrum of the processing composition satisfies the above-mentioned condition. It is in revealing the correlation of implementing

In one embodiment, the isocyanate compound for preparing the urethane-based prepolymer may include an aromatic diisocyanate compound, and the aromatic diisocyanate compound is 2,4-toluene diisocyanate (2,4-TDI) and 2,6- toluene diisocyanate (2,6-TDI). In this case, the urethane-based prepolymer has a first unit structure derived from urethane-reacted 2,4-TDI at one end, a second unit structure derived from 2,6-TDI reacted with urethane at one end, and urethane-reacted 2,4 at both ends. It may include at least one of a third unit structure derived from -TDI. Here, the meaning of 'one-terminal urethane-reacted' means that one isocyanate group among the two isocyanate groups of the diisocyanate is urethane-reacted, and the meaning of 'urethane-reacted at both ends' means that both isocyanate groups of the diisocyanate are urethane-reacted. will be. In addition, the 'unit structure' refers to a structural unit included in at least one chemical structure of the main chain of the prepolymer.

In one embodiment, the urethane-based prepolymer may include a plurality of prepolymers having different repeating structures, and each prepolymer may independently include at least one of the first unit structure, the second unit structure, and the third unit structure. can Accordingly, the polishing layer including the cured product of the preliminary composition may be more advantageous in achieving a desired level of polishing performance.

Nuclear magnetic resonance (NMR) ¹³ C spectrum peak characteristics of the preliminary composition, as described above, the type and content of monomers constituting the urethane-based prepolymer, the type and content of unreacted monomers remaining in addition to the urethane-based prepolymer, the urethane-based prepolymer chemical It may be comprehensively determined by the bonding structure, reaction process conditions for preparing the urethane-based prepolymer, and the like.

The curing agent is a compound for chemically reacting with the urethane-based prepolymer to form a final cured structure in the polishing layer, and may include, for example, an amine compound or an alcohol compound. Specifically, the curing agent may include one selected from the group consisting of aromatic amines, aliphatic amines, aromatic alcohols, aliphatic alcohols, and combinations thereof.

For example, the curing agent is 4,4'-methylenebis(2-chloroaniline) (4,4'-methylenebis(2-chloroaniline); MOCA), diethyltoluenediamine (DETDA), diaminodiphenyl Methane (diaminodiphenylmethane), dimethyl thio-toluene diamine (DMTDA), propanediol bis p-aminobenzoate (propanediol bis p-aminobenzoate), Methylene bis-methylanthranilate, diaminodiphenylsulfone (diaminodiphenylsulfone), m -xylylenediamine, isophoronediamine, ethylenediamine, diethylenetriamine, triethylenetetramine, polypropylenediamine, polypropylenetriamine (polypropylenetriamine), bis (4-amino-3-chlorophenyl) methane (bis (4-amino-3-chlorophenyl) methane), and may include one selected from the group consisting of combinations thereof.

The amount of the curing agent is about 18 parts by weight to about 27 parts by weight, for example, about 19 parts by weight to about 26 parts by weight, for example, about 20 parts by weight to about 26 parts by weight based on 100 parts by weight of the preliminary composition. can When the content of the curing agent satisfies the above range, it may be more advantageous to realize the desired performance of the polishing pad.

When the curing agent includes an amine compound, a molar ratio of isocyanate (NCO) groups in the preliminary composition to amine (NH ₂ ) groups in the curing agent may be from about 1:0.60 to about 1:0.99, for example, about 1:0.60 to about 1:0.90, for example, greater than or equal to about 1:0.60, less than about 1:0.90.

The foaming agent may include one selected from the group consisting of a solid foaming agent, a gaseous foaming agent, a liquid foaming agent, and a combination thereof as a component for forming a pore structure in the polishing layer. In one embodiment, the foaming agent may include a solid foaming agent, a gas phase foaming agent, or a combination thereof.

The average particle diameter of the solid blowing agent is about 5 μm to about 200 μm, for example, about 20 μm to about 50 μm, for example, about 21 μm to about 50 μm, for example, about 21 μm to about 40 μm. can be The average particle diameter of the solid foaming agent means the average particle diameter of the thermally expanded particles themselves when the solid foaming agent is thermally expanded particles as described below, and the solid foaming agent is an unexpanded particle as described below. In this case, it may mean the average particle diameter of the particles after being expanded by heat or pressure.

The solid blowing agent may include expandable particles. The expandable particles are particles having a property of being expandable by heat or pressure, and the size in the final abrasive layer may be determined by heat or pressure applied during the manufacturing process of the abrasive layer. The expandable particles may include thermally expanded particles, unexpanded particles, or a combination thereof. The thermally expanded particles are particles pre-expanded by heat, and refer to particles having little or no size change due to heat or pressure applied during the manufacturing process of the abrasive layer. The unexpanded particles are non-expanded particles, and refer to particles whose final size is determined by being expanded by heat or pressure applied during the manufacturing process of the abrasive layer.

The expandable particles may include a resin material; And it may include an expansion-inducing component present in the interior enclosed by the shell.

For example, the outer shell may include a thermoplastic resin, and the thermoplastic resin is selected from the group consisting of a vinylidene chloride-based copolymer, an acrylonitrile-based copolymer, a methacrylonitrile-based copolymer, and an acrylic copolymer. may be more than one species.

The expansion-inducing component may include one selected from the group consisting of a hydrocarbon compound, a chlorofluoro compound, a tetraalkylsilane compound, and combinations thereof.

Specifically, the hydrocarbon compound is ethane, ethylene, propane, propene, n-butane, isobutene, n-butene, isobutene, n-pentane, isopentane, neopentane, n-hexane, heptane, petroleum ether, and their It may include one selected from the group consisting of combinations.

The chlorofluoro compound is trichlorofluoromethane (trichlorofluoromethane, CCl ₃ F), dichlorodifluoromethane (dichlorodifluoromethane, CCl ₂ F ₂ ), chlorotrifluoromethane (chlorotrifluoromethane, CClF ₃ ), tetrafluoroethylene ( tetrafluoroethylene, CClF ₂ -CClF ₂ ) and a combination thereof may include one selected from the group consisting of.

The tetraalkylsilane compound is selected from the group consisting of tetramethylsilane, trimethylethylsilane, trimethylisopropylsilane, trimethyl-n-propylsilane, and combinations thereof. may contain one.

The solid foaming agent may optionally include inorganic component-treated particles. For example, the solid blowing agent may include inorganic component-treated expandable particles. In one embodiment, the solid foaming agent may include silica (SiO ₂ ) particle-treated expandable particles. The inorganic component treatment of the solid foaming agent can prevent aggregation between a plurality of particles. The inorganic component-treated solid foaming agent may have different chemical, electrical, and/or physical properties on the surface of the foaming agent surface than the inorganic component-treated solid foaming agent.

The amount of the solid foaming agent is about 0.5 parts by weight to about 10 parts by weight, for example, about 1 part by weight to about 3 parts by weight, for example, about 1.3 parts by weight to about 2.7 parts by weight based on 100 parts by weight of the urethane-based prepolymer. parts, for example from about 1.3 parts by weight to about 2.6 parts by weight.

The type and content of the solid foaming agent may be designed according to the desired pore structure and physical properties of the polishing layer.

The gas-phase foaming agent may include an inert gas. The gas-phase foaming agent may be used as a pore-forming element by being added during a reaction between the urethane-based prepolymer and the curing agent.

The type of the inert gas is not particularly limited as long as it does not participate in the reaction between the urethane-based prepolymer and the curing agent. For example, the inert gas may include one selected from the group consisting of nitrogen gas (N ₂ ), argon gas (Ar), helium gas (He), and combinations thereof. Specifically, the inert gas may include nitrogen gas (N ₂ ) or argon gas (Ar).

The type and content of the gas-phase foaming agent can be designed according to the desired pore structure and physical properties of the abrasive layer.

In one embodiment, the foaming agent may include a solid foaming agent. For example, the foaming agent may be formed of only a solid foaming agent.

The solid foaming agent may include expandable particles, and the expandable particles may include thermally expanded particles. For example, the solid foaming agent may consist only of thermally expanded particles. In the case of not including the unexpanded particles but only the thermally expanded particles, the variability of the pore structure is reduced, but the predictability is increased, so it may be advantageous to implement homogeneous pore properties over the entire area of the abrasive layer.

In one embodiment, the thermally expanded particles may be particles having an average particle diameter of about 5 μm to about 200 μm. The average particle diameter of the thermally expanded particles is about 5 μm to about 100 μm, for example, about 10 μm to about 80 μm, for example, about 20 μm to about 70 μm, for example, about 20 μm to about 50 μm. μm, for example from about 30 μm to about 70 μm, such as from about 25 μm to 45 μm, such as from about 40 μm to about 70 μm, such as from about 40 μm to about 60 μm there is. The average particle diameter is defined as the D50 of the thermally expanded particles.

In one embodiment, the density of the thermally expanded particles is from about 30 kg/m to about 80 kg/m, such as from about 35 kg/m to about 80 kg/m, such as from about 35 kg/m to about 75 kg/m, For example, it may be from about 38 kg/m to about 72 kg/m, such as from about 40 kg/m to about 75 kg/m, such as from about 40 kg/m to about 72 kg/m.

In one embodiment, the foaming agent may include a gas phase foaming agent. For example, the foaming agent may include a solid foaming agent and a gas phase foaming agent. Matters regarding the solid foaming agent are the same as described above.

The gas-phase foaming agent may include nitrogen gas.

The vapor-phase foaming agent may be injected through a predetermined injection line while the urethane-based prepolymer, the solid-state foaming agent, and the curing agent are mixed. The injection rate of the gas phase blowing agent is from about 0.8 L/min to about 2.0 L/min, such as from about 0.8 L/min to about 1.8 L/min, such as from about 0.8 L/min to about 1.7 L/min. , for example, from about 1.0 L/min to about 2.0 L/min, such as from about 1.0 L/min to about 1.8 L/min, such as from about 1.0 L/min to about 1.7 L/min there is.

The composition for preparing the polishing layer may further include other additives such as a surfactant and a reaction rate controlling agent. The names such as 'surfactant' and 'reaction rate regulator' are arbitrary names based on the main role of the corresponding substance, and each corresponding substance does not necessarily perform only a function limited to the role by the corresponding name.

The surfactant is not particularly limited as long as it is a material that serves to prevent aggregation or overlapping of pores. For example, the surfactant may include a silicone-based surfactant.

The surfactant may be used in an amount of about 0.2 parts by weight to about 2 parts by weight based on 100 parts by weight of the urethane-based prepolymer. Specifically, the surfactant is about 0.2 parts by weight to about 1.9 parts by weight, for example, about 0.2 parts by weight to about 1.8 parts by weight, for example, about 0.2 parts by weight to about 1.7 parts by weight based on 100 parts by weight of the urethane-based prepolymer. It may be included in an amount of, for example, about 0.2 parts by weight to about 1.6 parts by weight, for example, about 0.2 parts by weight to about 1.5 parts by weight, for example, about 0.5 parts by weight to 1.5 parts by weight. When the surfactant is included in an amount within the above range, pores derived from the gas-phase foaming agent may be stably formed and maintained in the mold.

The reaction rate controlling agent serves to promote or delay the reaction, and depending on the purpose, a reaction accelerator, a reaction retarder, or both may be used. The reaction rate controlling agent may include a reaction accelerator. For example, the reaction accelerator may be one or more reaction accelerators selected from the group consisting of a tertiary amine-based compound and an organometallic compound.

Specifically, the reaction rate controlling agent is triethylenediamine, dimethylethanolamine, tetramethylbutanediamine, 2-methyl-triethylenediamine, dimethylcyclohexylamine, triethylamine, triisopropanolamine, 1,4-diazabicyclo( 2,2,2)octane, bis(2-methylaminoethyl)ether, trimethylaminoethylethanolamine, N,N,N,N,N''-pentamethyldiethylenetriamine, dimethylaminoethylamine, dimethylamino Propylamine, benzyldimethylamine, N-ethylmorpholine, N,N-dimethylaminoethylmorpholine, N,N-dimethylcyclohexylamine, 2-methyl-2-azanovonein, dibutyltin dilaurate, Contains at least one selected from the group consisting of stannous octoate, dibutyltin diacetate, dioctyltin diacetate, dibutyltin maleate, dibutyltin di-2-ethylhexanoate and dibutyltin dimercaptide can do. Specifically, the reaction rate controlling agent may include at least one selected from the group consisting of benzyldimethylamine, N,N-dimethylcyclohexylamine and triethylamine.

The reaction rate controlling agent may be used in an amount of about 0.05 parts by weight to about 2 parts by weight based on 100 parts by weight of the urethane-based prepolymer. Specifically, the reaction rate controlling agent is about 0.05 parts by weight to about 1.8 parts by weight, for example, about 0.05 parts by weight to about 1.7 parts by weight, for example, about 0.05 parts by weight to about 100 parts by weight of the urethane-based prepolymer. 1.6 parts by weight, such as about 0.1 parts by weight to about 1.5 parts by weight, such as about 0.1 parts by weight to about 0.3 parts by weight, such as about 0.2 parts by weight to about 1.8 parts by weight, for example, about 0.2 parts by weight to about 1.7 parts by weight, such as about 0.2 parts by weight to about 1.6 parts by weight, such as about 0.2 parts by weight to about 1.5 parts by weight, such as about 0.5 parts by weight to about 1 parts by weight. It can be used in negative amounts. When the reaction rate controlling agent is used in the above-described content range, the curing reaction rate of the preliminary composition may be appropriately controlled to form an abrasive layer having pores of a desired size and hardness.

When the polishing pad includes a cushion layer, the cushion layer serves to absorb and disperse an external impact applied to the polishing layer while supporting the polishing layer, thereby causing damage to the polishing object during the polishing process to which the polishing pad is applied. And it is possible to minimize the occurrence of defects.

The cushion layer may include, but is not limited to, nonwoven fabric or suede.

In one embodiment, the cushion layer may be a resin-impregnated nonwoven fabric. The nonwoven fabric may be a fiber nonwoven fabric including one selected from the group consisting of polyester fibers, polyamide fibers, polypropylene fibers, polyethylene fibers, and combinations thereof.

The resin impregnated into the nonwoven fabric is a polyurethane resin, polybutadiene resin, styrene-butadiene copolymer resin, styrene-butadiene-styrene copolymer resin, acrylonitrile-butadiene copolymer resin, styrene-ethylene-butadiene-styrene copolymer resin, silicone rubber resin , it may include one selected from the group consisting of a polyester-based elastomer resin, a polyamide-based elastomer resin, and combinations thereof.

In the polishing pad according to an embodiment, the hardness (Shore D) of the polishing surface of the polishing layer may be less than about 50, for example, about 35 or more, less than about 50, for example, about 40 to may be 49. The tensile strength of the abrasive layer may be less than about 20 N/mm2, for example, about 10N/mm2 or more, and less than about 20N/mm2, for example, about 10N/mm2 to about 19N/mm2. . The elongation of the polishing layer may be about 200% or more, for example, about 200% to about 300%. The cutting rate of the abrasive layer may be about 80 μm/hr or more, for example, about 80 μm/hr to about 100 μm/hr, for example, about 80 μm/hr to about 95 μm/hr can be For example, the hardness of the polishing surface; tensile strength and elongation of the abrasive layer; And when the cutting rate of the abrasive layer simultaneously exhibits the aforementioned range, it may be evaluated as exhibiting physical and mechanical properties corresponding to the peak properties of the processing composition. In this case, the polishing pad including the polishing layer may be applied to a semiconductor device process to realize excellent polishing performance.

Hereinafter, a method for manufacturing the polishing pad will be described.

In another embodiment according to the present invention, preparing a preliminary composition comprising a prepolymer; preparing a composition for preparing an abrasive layer including the preliminary composition, a foaming agent and a curing agent; and curing the composition for preparing the polishing layer to prepare a polishing layer.

The preparing of the preliminary composition may be a process of preparing a urethane-based prepolymer by reacting a diisocyanate compound and a polyol compound. The diisocyanate compound and the polyol compound are the same as those described above with respect to the polishing pad.

The isocyanate group content (NCO%) of the pre-composition is from about 5% to about 11% by weight, for example from about 5% to about 10% by weight, for example from about 5% to about 8.5% by weight. can In this case, it may be more advantageous to obtain an abrasive layer having the above-described chemical bonding structure. The content of isocyanate groups in the preliminary composition may be derived from terminal isocyanate groups of the urethane-based prepolymer, unreacted unreacted isocyanate groups in the diisocyanate compound, and the like.

The viscosity of the preliminary composition may be from about 100 cps to about 1,000 cps at about 80° C., for example, from about 200 cps to about 800 cps, for example, from about 200 cps to about 600 cps, for example, It may be from about 200 cps to about 550 cps, for example, from about 300 cps to about 500 cps.

The foaming agent may include a solid foaming agent or a gas phase foaming agent. The types of the foaming agent, etc. are the same as those described above with respect to the polishing pad.

When the foaming agent includes a solid foaming agent, preparing the composition for preparing an abrasive layer may include preparing a first preliminary composition by mixing the preliminary composition and the solid foaming agent; and mixing the first preliminary composition and a curing agent to prepare a second preliminary composition.

The viscosity of the first preliminary composition may be from about 1,000 cps to about 2,000 cps at about 80° C., for example, from about 1,000 cps to about 1,800 cps, for example, from about 1,000 cps to about 1,600 cps. may be, for example, about 1,000 cps to about 1,500 cps.

When the foaming agent includes a gaseous foaming agent, preparing the composition for preparing an abrasive layer may include preparing a third preliminary composition including the preliminary composition and the curing agent; and injecting the gas-phase foaming agent into the third preliminary composition to prepare a fourth preliminary composition.

In one embodiment, the third preliminary composition may further include a solid foaming agent.

In one embodiment, the process of manufacturing the polishing layer includes: preparing a mold preheated to a first temperature; and injecting and curing the composition for preparing the polishing layer into the preheated mold; and post-curing the cured composition for preparing the polishing layer under a second temperature condition higher than the preheating temperature.

In one embodiment, the temperature difference between the first temperature and the second temperature may be about 10 °C to about 40 °C, for example, about 10 °C to about 35 °C, for example, about 15 °C to about 35°C.

In one embodiment, the first temperature may be about 60 °C to about 100 °C, for example, about 65 °C to about 95 °C, for example, about 70 °C to about 90 °C.

In one embodiment, the second temperature may be from about 100°C to about 130°C, for example, from about 100°C to 125°C, for example, from about 100°C to about 120°C.

The step of curing the composition for preparing an abrasive layer under the first temperature is about 5 minutes to about 60 minutes, for example, about 5 minutes to about 40 minutes, for example, about 5 minutes to about 30 minutes, for example, , from about 5 minutes to about 25 minutes.

The step of post-curing the composition for preparing an abrasive layer cured under the first temperature under the second temperature is about 5 hours to about 30 hours, for example, about 5 hours to about 25 hours, for example, about 10 hours to about 10 hours. about 30 hours, such as about 10 hours to about 25 hours, such as about 12 hours to about 24 hours, such as about 15 hours to about 24 hours.

The abrasive layer finally prepared through the process of manufacturing the polishing layer is the core of the processing composition, 1 g thereof is added to a 0.3 M aqueous potassium hydroxide (KOH) solution, and reacted for 48 hours at 150° C. in a sealed container. a first peak in the magnetic resonance (NMR) ¹³ C spectrum of 15 ppm to 18 ppm; a second peak appearing at 9 ppm to 11 ppm; and a third peak appearing at 138 ppm to 143 ppm, wherein an area ratio of the third peak to the second peak is about 5:1 to 10:1.

For example, the area ratio of the third peak to the second peak may be from about 5:1 to about 10:1, for example, from about 5:1 to about 8:1.

In one embodiment, the processing composition has an area ratio of the first peak to the second peak of 10:1 to 10:5, and an area ratio of the first peak to the third peak is 10:5 to 10:10 can For example, the area ratio of the first peak to the second peak may be from about 10:1 to about 10:5, for example, from about 10:1.00 to about 10:1.60, for example, It may be greater than or equal to about 10:1.00, less than or equal to about 10:1.60, for example, from about 10:1.80 to 10:2.50, such as greater than about 10:1.80, less than or equal to about 10:2.50. For example, the area ratio of the first peak to the third peak may be from 10:5 to 10:10, for example, greater than about 10:5.00 and less than or equal to about 10:10.00.

The method of manufacturing the polishing pad may include processing at least one surface of the polishing layer.

The step of machining at least one surface of the abrasive layer may include the steps of (1) forming a groove on at least one surface of the abrasive layer; line turning (2) at least one surface of the abrasive layer; and roughening at least one surface of the polishing layer (3).

In the step (1), the groove (groove) is a concentric circular groove formed spaced apart from the center of the polishing layer at a predetermined interval; and at least one of a radial groove continuously connected from the center of the polishing layer to an edge of the polishing layer.

In the step (2), the line turning may be performed by using a cutting tool to cut the abrasive layer by a predetermined thickness.

In step (3), the roughening may be performed by processing the surface of the abrasive layer with a sanding roller.

The method of manufacturing the polishing pad may further include laminating a cushion layer on the back surface of the polishing surface of the polishing layer. Matters regarding the cushion layer are the same as those described above with respect to the polishing pad.

The abrasive layer and the cushion layer may be laminated using a heat-sealing adhesive.

The heat sealing adhesive is applied on the back surface of the polishing surface of the polishing layer, the heat sealing adhesive is applied on the surface to be in contact with the polishing layer of the cushion layer, and the surfaces to which each heat sealing adhesive is applied are in contact After laminating the abrasive layer and the cushion layer to the surface, the two layers may be fused using a pressure roller.

In another embodiment according to the present invention, providing a polishing pad comprising a polishing layer; and arranging the polishing surface of the polishing object to be in contact with the polishing surface of the polishing layer and then polishing the polishing object while rotating relative to each other, wherein the polishing object includes a semiconductor substrate, and the polishing layer includes: 1 g thereof was added to an aqueous solution of potassium hydroxide (KOH) having a concentration of 0.3 M, and the nuclear magnetic resonance (NMR) ¹³ C spectrum of the processed composition was reacted for 48 hours at 150° C. in a sealed container at 15 ppm to 18 ppm. peak; a second peak appearing at 9 ppm to 11 ppm; and a third peak appearing at 138 ppm to 143 ppm, wherein an area ratio of the third peak to the second peak is from about 5:1 to about 10:1.

Matters regarding the polishing layer and its processing composition are the same as those described above with respect to the polishing pad. By applying the polishing pad provided with the polishing layer having the above-described characteristics in the method for manufacturing the semiconductor device, the semiconductor device manufactured through this method can implement excellent functions derived from the excellent polishing result of the semiconductor substrate.

2 is a schematic diagram schematically illustrating a method of manufacturing a semiconductor device according to an exemplary embodiment. Referring to FIG. 2 , in the step of providing the polishing pad including the polishing layer, the polishing pad 110 may be provided on the surface plate 120 .

The polishing object may include a semiconductor substrate, and the semiconductor substrate 130 may be disposed such that a surface to be polished thereof is in contact with a polishing surface of the polishing layer of the polishing pad 110 . In this case, the polished surface of the semiconductor substrate 130 and the polished surface of the polishing layer may be in direct contact or indirectly contacted through a fluid slurry or the like.

In an embodiment, the method of manufacturing the semiconductor device may further include supplying a polishing slurry 150 to the polishing surface of the polishing layer of the polishing pad 110 . For example, the polishing slurry 150 may be supplied onto the polishing surface through the supply nozzle 140 .

The flow rate of the abrasive slurry 150 sprayed through the supply nozzle 140 may be from about 10 ml/min to about 1,000 ml/min, for example, from about 10 ml/min to about 800 ml/min, for example For example, it may be about 50ml / min to about 500ml / min, but is not limited thereto.

The polishing slurry 150 may include a silica slurry or a ceria slurry.

The semiconductor substrate 130 may be in contact with the polishing surface by being pressed with a predetermined load while being mounted on the polishing head 160 . The load applied to the polishing surface of the semiconductor substrate 130 by the polishing head 160 on the polishing surface may be selected depending on the purpose, for example, in the range of about 0.01 psi to about 20 psi. For example, it may be about 0.1 psi to about 15 psi, but is not limited thereto. When the polished surface of the polishing layer and the polished surface of the semiconductor substrate are in contact with each other under the above-described load, the polishing layer exhibits hardness and elongation represented by the above-described peak characteristics, and the corresponding elasticity and contact area are It may be provided on the to-be-polished surface of the substrate, and accordingly, it may be advantageous for the polishing rate and the defect-preventing effect of the semiconductor substrate to be realized at the desired level.

The semiconductor substrate 130 and the polishing pad 110 may be rotated relative to each other while the polishing target surface and the polishing surface are in contact with each other. In this case, the rotation direction of the semiconductor substrate 130 and the rotation direction of the polishing pad 110 may be in the same direction or may be opposite to each other. The rotation speed of the semiconductor substrate 130 and the polishing pad 110 may be selected depending on the purpose in the range of about 10 rpm to about 500 rpm, respectively, for example, may be about 30 rpm to about 200 rpm, but is limited thereto. it's not going to be When the rotational speeds of the semiconductor substrate and the polishing pad respectively satisfy the above ranges, the polishing layer exhibits hardness and elongation represented by the above-described peak characteristics, and corresponding elasticity and contact area of the semiconductor substrate to be polished It may be provided on the surface, and accordingly, it may be advantageous to realize the polishing rate and the defect prevention effect of the semiconductor substrate at the desired level.

In one embodiment, in the method of manufacturing the semiconductor device, in order to maintain the polishing surface of the polishing pad 110 in a state suitable for polishing, the polishing pad is simultaneously polished with the semiconductor substrate 130 through the conditioner 170 . It may further include the step of processing the polishing surface of (110).

In one embodiment, in the method of manufacturing the semiconductor device, the semiconductor substrate includes a silicon oxide (SiO ₂ ) film, the surface to be polished is a surface of the silicon oxide (SiO ₂ ) film, and after the polishing on the surface to be polished is completed There are less than 5 surface defects, and the average polishing rate of the silicon oxide (SiO ₂ ) film may be 1,500 Å/min to 2,500 Å/min, for example, about 1,500 Å/min or more, about 2,500 Å It can be less than /min.

The semiconductor device manufacturing method can implement the above-described polishing rate and defect prevention performance by applying a polishing pad having a polishing layer having the above-described characteristics to a semiconductor substrate having a silicon oxide (SiO ₂ ) film as a polishing object.

Hereinafter, specific embodiments of the present invention are presented. However, the examples described below are only for specifically illustrating or explaining the present invention, and the present invention is not limited thereto.

<Examples and Comparative Examples>

Example 1

2,4-TDI and 2,6-TDI were mixed in relative weight ratios as shown in Table 1 below, respectively, based on 100 parts by weight of the total weight of the diisocyanate component. PTMG and DEG were mixed in relative weight ratios as shown in Table 1 below, respectively, based on 100 parts by weight of the total weight of the polyol component. A mixed raw material was prepared by mixing the total amount of the polyol in an amount of 220 parts by weight based on 100 parts by weight of the total amount of the diisocyanate. The mixed raw material was put into a four-neck flask and reacted at 80° C. to prepare a preliminary composition including a urethane-based prepolymer. The content of isocyanate groups (NCO groups) in the preliminary composition was adjusted to 6% by weight. 4,4'-methylenebis(2-chloroaniline) (MOCA) as a curing agent was mixed in the preliminary composition, and the molar ratio of the NH2 groups of the MOCA to the NCO groups in the preliminary composition was 0.75. In addition, 1.0 parts by weight of a solid foaming agent (Akzonobel Corporation), which is an expandable particle, was mixed in the preliminary composition. The preliminary composition was injected into a mold having a width of 1,000 mm, a length of 1,000 mm, and a height of 3 mm, and was injected into a mold preheated to 90° C., but was injected at a discharge rate of 10 kg/min. Then, the preliminary composition was subjected to a post-curing reaction under a temperature condition of 110° C. to prepare an abrasive layer.

Example 2

2,4-TDI, 2,6-TDI, and H ₁₂ MDI were mixed in relative weight ratios as shown in Table 1 below, respectively, based on 100 parts by weight of the total weight of the diisocyanate component. PTMG and DEG were mixed in relative weight ratios as shown in Table 1 below, respectively, based on 100 parts by weight of the total weight of the polyol component. A mixed raw material was prepared by mixing the total amount of the polyol in an amount of 220 parts by weight based on 100 parts by weight of the total amount of the diisocyanate. The mixed raw material was put into a four-neck flask and reacted at 80° C. to prepare a preliminary composition including a urethane-based prepolymer. The content of isocyanate groups (NCO groups) in the preliminary composition was adjusted to 8.0% by weight. 4,4'-methylenebis(2-chloroaniline) (MOCA) as a curing agent was mixed in the preliminary composition, and the molar ratio of the NH2 groups of the MOCA to the NCO groups in the preliminary composition was 0.70. In addition, 1.0 parts by weight of a solid foaming agent (Akzonobel Corporation), which is an expandable particle, was mixed with the preliminary composition. The preliminary composition was injected into a mold having a width of 1,000 mm, a length of 1,000 mm, and a height of 3 mm, and was injected into a mold preheated to 100° C., but was injected at a discharge rate of 10 kg/min. Then, the preliminary composition was subjected to a post-curing reaction under a temperature condition of 110° C. to prepare an abrasive layer.

Comparative Example 1

2,4-TDI, 2,6-TDI, and H ₁₂ MDI were mixed in relative weight ratios as shown in Table 1 below, respectively, based on 100 parts by weight of the total weight of the diisocyanate component. PTMG and DEG were mixed in relative weight ratios as shown in Table 1 below, respectively, based on 100 parts by weight of the total weight of the polyol component. A mixed raw material was prepared by mixing the total amount of the polyol in an amount of 150 parts by weight based on 100 parts by weight of the total amount of the diisocyanate. The mixed raw material was put into a four-neck flask and reacted at 80° C. to prepare a preliminary composition including a urethane-based prepolymer. The content of isocyanate groups (NCO groups) in the preliminary composition was adjusted to 9% by weight. 4,4'-methylenebis(2-chloroaniline) (MOCA) as a curing agent was mixed in the preliminary composition, and the molar ratio of NH2 groups of MOCA to NCO groups in the preliminary composition was 0.96. In addition, 1.0 parts by weight of a solid foaming agent (Akzonobel Corporation), which is an expandable particle, was mixed in the preliminary composition. The preliminary composition was injected into a mold having a width of 1,000 mm, a length of 1,000 mm, and a height of 3 mm, preheated to 90° C., and injected at a discharge rate of 10 kg/min, and at the same time nitrogen (N ₂ ) gas as a gaseous foaming agent was 1.0L/ Min was injected for the same time as the injection time of the pre-composition at an injection rate. Then, the preliminary composition was subjected to a post-curing reaction under a temperature condition of 110° C. to prepare an abrasive layer.

Comparative Example 2

2,4-TDI, 2,6-TDI, and H ₁₂ MDI were mixed in relative weight ratios as shown in Table 1 below, respectively, based on 100 parts by weight of the total weight of the diisocyanate component. PTMG and DEG were mixed in relative weight ratios as shown in Table 1 below, respectively, based on 100 parts by weight of the total weight of the polyol component. A mixed raw material was prepared by mixing the total amount of the polyol in an amount of 150 parts by weight based on 100 parts by weight of the total amount of the diisocyanate. The mixed raw material was put into a four-neck flask and reacted at 80° C. to prepare a preliminary composition including a urethane-based prepolymer. The content of isocyanate groups (NCO groups) in the preliminary composition was adjusted to 9.2% by weight. 4,4'-methylenebis(2-chloroaniline) (MOCA) as a curing agent was mixed in the preliminary composition, and the molar ratio of NH2 groups of MOCA to NCO groups in the preliminary composition was 0.94. In addition, 1.0 parts by weight of a solid foaming agent (Akzonobel Corporation), which is an expandable particle, was mixed with the preliminary composition. The preliminary composition was injected into a mold having a width of 1,000 mm, a length of 1,000 mm, and a height of 3 mm, and was injected into a mold preheated to 95° C., but was injected at a discharge rate of 10 kg/min. Then, the preliminary composition was subjected to a post-curing reaction under a temperature condition of 110° C. to prepare an abrasive layer.

Each of the polishing layers of Examples 1 and 2 and Comparative Examples 1 and 2 was processed to a thickness of 2 mm, and a concentric grooving process was performed on the polishing surface. Next, a cushion layer with a thickness of 1.1 mm of a structure impregnated with a urethane-based resin is prepared on a polyester resin nonwoven fabric, a heat-sealing adhesive is applied to the back surface of the polishing surface and the attachment surface of the cushion layer, and laminated together using a pressure roller did. Thus, the final polishing pad was manufactured.

<Evaluation>

Experimental Example 1: Experimental Example 1: Nuclear magnetic resonance (NMR) of preliminary composition ¹³ C spectrum

For each of the preliminary compositions of Examples 1 and 2 and Comparative Examples 1 and 2, 5 mg of the preliminary composition was dissolved in CDCl ₃ and a nuclear magnetic resonance (NMR) apparatus (JEOL 500 MHz, 90 ° pulse) at room temperature using ¹³ C-NMR analysis was performed.

Experimental Example 2: Nuclear magnetic resonance (NMR) of the processing composition ¹³ C spectrum

For each of the polishing layers of Examples 1 and 2 and Comparative Examples 1 and 2, 1 g of the polishing layer was added to 15 ml of an aqueous sodium hydroxide (KOH) solution having a concentration of 0.3 M, and in a closed container having a volume of 48 ml. In, the processing composition was prepared by reacting for 48 hours under a temperature condition of 150 °C. 5 mg of the processing composition was dissolved in CDCl ₃ and ¹³ C-NMR analysis was performed at room temperature using a nuclear magnetic resonance (NMR) apparatus (JEOL 500 MHz, 90° pulse).

Experimental Example 3: Evaluation of physical properties of the polishing layer or polishing pad

(1) hardness

After processing each of the abrasive layers of Examples 1 and 2 and Comparative Examples 1 and 2 to a thickness of 2 mm, the samples were prepared by cutting each of the horizontal and vertical sections to a size of 5 cmХ5 cm. After storing the sample at a temperature of 25° C. for 12 hours, Shore D hardness was measured using a durometer.

(2) Tensile strength

After processing the polishing layers of Examples 1 and 2 and Comparative Examples 1 and 2 to a thickness of 2 mm, the samples were prepared by cutting the width and length of 4 cmХ1 cm. The sample was measured for the highest strength value just before breaking at a speed of 50 mm/min using a universal testing machine (UTM).

(3) elongation

After processing the polishing layers of Examples 1 and 2 and Comparative Examples 1 and 2 to a thickness of 2 mm, the samples were prepared by cutting the width and length of 4 cmХ1 cm. After measuring the maximum strain length just before fracture of the sample at a speed of 50 mm/min using a universal testing machine (UTM), the ratio of the maximum strain length to the initial length was expressed as a percentage (%).

(4) cutting rate

For each polishing pad prepared as described above using the polishing layers of Examples 1 and 2 and Comparative Examples 1 and 2, pre-conditioning the polishing pad with deionized water for 10 minutes ( After pre-conditioning), it was conditioned while spraying deionized water for 1 hour. The thickness change in the conditioning process was measured, and the thickness change amount (㎛/hr) was calculated as the cutting rate of the polishing pad. The equipment used for conditioning was AP-300HM from CTS, the conditioning pressure was 6 lbf, the rotation speed was 100-110 rpm, and the disk used for conditioning was a CI-45 from Sasol Corporation.

Experimental Example 4: Evaluation of polishing performance

After preparing each polishing pad to which the polishing layers of Examples 1 and 2 and Comparative Examples 1 and 2 were applied, polishing performance was evaluated as follows.

Silicon oxide (SiO ₂ ) was deposited on a silicon wafer having a diameter of 300 mm by a chemical vapor deposition (CVD) process. The polishing pad was attached to the CMP equipment, and the surface of the silicon oxide layer of the silicon wafer was installed to face the polishing surface of the polishing pad. While supplying the calcined ceria slurry onto the polishing pad at a rate of 250 mL/min, the silicon wafer is pressed onto the polishing surface under a load of 4.0 psi, and the rotation speed of the polishing pad and the silicon wafer is set to 150 rpm, respectively. The silicon oxide film was polished for 60 seconds. After polishing, the silicon wafer was removed from the carrier, mounted on a spin dryer, washed with distilled water, and dried with nitrogen for 15 seconds.

(1) Average polishing rate

The film thickness change before and after grinding|polishing was measured using the optical interference type thickness measuring apparatus (SI-F80R, Kyence Corporation) with respect to the dried silicon wafer. Then, the polishing rate was calculated using the following equation. In this way, the polishing rate was measured a total of 5 times, and a number average value was obtained, which was set as the average polishing rate.

Polishing rate (Å/min) = Polishing thickness of silicon wafer (Å) / Polishing time (min)

(2) defects

Polishing was carried out in the same manner as the polishing rate measurement method, and the number of defects such as scratches was derived by visually observing the polished surface of the polishing object. Specifically, after polishing, the silicon wafer is moved to a cleaner, 1% hydrogen fluoride (HF) and purified water (DIW); Each of 1% nitric acid (H ₂ NO ₃ ) and purified water (DIW) was used for washing for 10 seconds. Thereafter, it was moved to a spin dryer, washed with purified water (DIW), and dried with nitrogen (N ₂ ) for 15 seconds. Changes in defects before and after polishing the dried silicon wafers were visually observed using a defect measuring device (Tenkor, XP+).

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

item Example 1 Example 2 Comparative Example 1 Comparative Example 2 pre-composition
Furtherance diisocyanate 2,4-TDI 96 80 73 71 2,6-TDI 4 5 17 16 H ₁₂ MDI - 15 10 13 Total 100 100 100 100 polyol PTMG (Mw 1000) 90.0 97.5 90.8 89.9 DEG (Mw 106) 10.0 2.5 9.2 10.1 Total 100 100 100 100 Pre-composition NCO group content (wt%) 6 8.0 9 9.2 amine curing agent Molar ratio of NH ₂ of curing agent to NCO in the preliminary composition 0.75 0.70 0.96 0.94 process conditions Prepolymer Preparation Reaction Temperature (℃) 80 80 80 80 Curing mold preheat temperature (℃) 90 100 90 95 Post-curing temperature (℃) 110 110 110 110 pre-composition
¹³ C NMR peak position
(ppm) 4th peak (17.5~20) 17.627 17.713 17.694 17.682 5th peak (16~17.5) 17.226 17.293 17.026 16.997 area ratio 4th peak: 5th peak 3.89:1 6.02:1 3.18:1 1.67:1 processing composition
¹³ C NMR peak position
(ppm) 1st peak (15~18) 16.263 17.093 16.549 16.196 2nd peak (9-11) 10.06 10.000 10.292 9.930 3rd peak (138~143) 140.824 143.104 141.082 160.853 area ratio 3rd peak: 2nd peak 5.31:1 5.25:1 3.15:1 3.34:1 1st peak: 2nd peak 10:1.08 10:1.60 10:1.72 10:1.66 1st peak: 3rd peak 10:5.74 10: 8.40 10: 5.40 10: 5.52 abrasive layer
or
polishing pad
Properties Hardness (Shore D) 43 45 58.4 56.2 Tensile strength (N/㎟) 14.5 18.5 21.4 22.2 Elongation (%) 230.8 240.2 94.4 107.5 Polishing pad cutting rate (㎛/hr) 84.5 90.2 51.2 51.3 grinding performance Average polishing rate (Å/min) 2357 2345 3724 3324 Number of defects (ea) 4 5 0.5 One

Referring to Table 1, the abrasive layers of Examples 1 and 2 include a nuclear magnetic resonance (NMR) ¹³ C spectrum of the processing composition treated under predetermined conditions, a first peak appearing at 15 ppm to 18 ppm; a second peak appearing at 9 ppm to 11 ppm; and a third peak appearing at 138 ppm to 143 ppm, wherein an area ratio of the third peak to the second peak is 5:1 to 10:1 as a pad to which an abrasive layer is applied, and corresponding hardness, tensile strength, elongation and It can be seen that the polishing result of the semiconductor substrate is very good based on the characteristics such as the killing rate.

In contrast, in the case of the abrasive layers of Comparative Examples 1 and 2, the area ratio of the third peak to the second peak was out of the range of 5:1 to 10:1, compared to the abrasive layers of Examples 1 and 2 It can be seen that the hardness and tensile strength are high, and the elongation and cutting rate are low. Accordingly, it can be confirmed that the polishing pads of Comparative Examples 1 and 2 were inferior in terms of average polishing rate and defects because the polishing pads of Examples 1 and 2 did not impart the desired level of polishing performance to the surface to be polished. there is.

100, 110, 200: polishing pad
10: abrasive layer
11: first page
12: 2nd page
13: Home
20: cushion layer
30: first adhesive layer
40: second adhesive layer
50: preliminary composition
60: cured structure
70: processing composition
120: surface plate
130: semiconductor substrate
140: supply nozzle
150: polishing slurry
160: abrasive head
170: conditioner

Claims (10)

comprising an abrasive layer;
Nuclear magnetic resonance (NMR) ¹³ C spectrum of the processing composition in which 1 g of the polishing layer was added to a 0.3 M aqueous solution of potassium hydroxide (KOH) and reacted at 150° C. for 48 hours in a sealed container is shown at 15 ppm to 18 ppm first peak; a second peak appearing at 9 ppm to 11 ppm; and a third peak appearing at 138 ppm to 143 ppm,
wherein the area ratio of the third peak to the second peak is 5:1 to 10:1;
polishing pad. According to claim 1,
an area ratio of the first peak to the second peak is 10:1 to 10:5,
an area ratio of the first peak to the third peak is 10:5 to 10:10;
polishing pad. According to claim 1,
The polishing layer includes a cured product of a preliminary composition including a urethane-based prepolymer,
The nuclear magnetic resonance (NMR) ¹³ C spectrum of the preliminary composition shows a fourth peak and a fifth peak in the order of increasing the peak position (ppm) value from 16 ppm to 20 ppm,
wherein the area ratio of the fourth peak to the fifth peak is 1:1 to 10:1;
polishing pad. 4. The method of claim 3,
The preliminary composition comprises a reactant of an isocyanate compound and a polyol compound,
The isocyanate compound includes an aromatic diisocyanate compound,
The polyol compound is a low molecular weight polyol having a weight average molecular weight (Mw) of about 100 g/mol or more and less than about 300 g/mol, and a high molecular weight polyol having a weight average molecular weight (Mw) of about 300 g/mol or more and about 1800 g/mol or less. ,
polishing pad. 5. The method of claim 4,
The aromatic isocyanate compound includes 2,4-toluene diisocyanate (2,4-TDI),
The preliminary composition comprises a urethane-based prepolymer comprising at least one of a first unit structure derived from 2,4-TDI reacted with urethane at one end and a second unit structure derived from 2,4-TDI reacted with urethane at both ends. ,
polishing pad. 4. The method of claim 3,
The isocyanate group content of the preliminary composition is 5% to 11% by weight,
polishing pad. providing a polishing pad comprising an abrasive layer; and
arranging the polishing surface of the polishing object to be in contact with the polishing surface of the polishing layer and then polishing the polishing object while rotating relative to each other; and
The polishing object includes a semiconductor substrate,
The polishing layer had a nuclear magnetic resonance (NMR) ¹³ C spectrum of 15 ppm to 18 ppm of the processing composition in which 1 g thereof was added to an aqueous solution of potassium hydroxide (KOH) having a concentration of 0.3 M and reacted at 150° C. for 48 hours in a sealed container. a first peak appearing in ; a second peak appearing at 9 ppm to 11 ppm; and a third peak appearing at 138 ppm to 143 ppm,
wherein the area ratio of the third peak to the second peak is 5:1 to 10:1;
polishing pad. 8. The method of claim 7,
The semiconductor substrate includes a silicon oxide (SiO ₂ ) film,
The surface to be polished is the surface of the silicon oxide (SiO ₂ ) film,
The average polishing rate of the silicon oxide film is 1,500 Å/min to 2,500 Å/min,
5 or less surface defects after the completion of polishing on the surface to be polished,
A method of manufacturing a semiconductor device. 8. The method of claim 7,
The rotational speed of the polishing object and the polishing pad is 10rpm to 500rpm, respectively,
A method of manufacturing a semiconductor device. 8. The method of claim 7,
Further comprising the step of supplying a polishing slurry on the polishing surface of the polishing layer,
The supply flow rate of the polishing slurry is 10 ml / min to 1,000 mL / min,
A method of manufacturing a semiconductor device.

Images