KR20220032207A - Polishing pad, manufacturing method thereof and preparing method of semiconductor device using the same - Google Patents

Abstract

The present invention includes a polishing layer having a chemical bond structure and a cross-linked structure corresponding to a GPC measurement value of a processing composition obtained by treating the polishing layer of a polishing pad under a predetermined condition, such that a polishing surface of the polishing layer can exhibit appropriate hardness, thereby indicating a polishing rate and surface characteristics of a target range in the polishing of an object to be polished. In addition, the polishing surface maintains the same level of surface condition as an initial level even as time passes during a polishing process, such that polishing performance is prevented from deteriorating for a long time. A method of manufacturing a semiconductor device using the polishing pad exhibits high process efficiency in the polishing of a semiconductor substrate to be polished. In a final polishing result, the polished surface of the semiconductor substrate exhibits an appropriate polishing rate and the lowest level of defects.

Description

A polishing pad, a method of manufacturing a polishing pad, and a method of manufacturing a semiconductor device using the same

The present invention relates to a polishing pad used in a chemical mechanical planarization (CMP) process, a method of manufacturing the same, and a method of manufacturing a semiconductor device using the same.

In the chemical mechanical planarization (CMP) process of the semiconductor manufacturing process, in a state where a wafer is attached to a head and brought into contact with the surface of a polishing pad formed on a platen, a slurry is supplied to chemically prepare the wafer surface. It is a process of mechanically planarizing the uneven part of the wafer surface by moving the platen and the head relative to each other while reacting.

The chemical mechanical planarization process uses a polishing pad, and it is not only a semiconductor manufacturing process, but also an optical material such as a memory disk, a magnetic disk, an optical lens or a reflective mirror, and a material that requires a high degree of surface flatness such as a glass plate and a metal. can be used in various ways in

With the miniaturization of semiconductor circuits, the importance of the CMP process is further highlighted. The polishing pad plays an important role in realizing CMP performance as one of the essential raw materials in the CMP process of the semiconductor manufacturing process.

The polishing pad requires various performances, and the number of defects in the material after planarization is a factor that greatly affects the yield.

The properties and properties of the polishing pad change depending on the combination and composition of components such as a prepolymer, a curing agent, a foaming agent, and the like, and it will be said that the properties and properties of the prepared polishing pad greatly affect the performance of the CMP process.

In particular, when a polishing pad is to be applied in an actual polishing process, it is cumbersome to consider characteristics such as yield through a direct polishing test.

Accordingly, in order to use the polishing pad in the field, it is necessary to develop a method capable of selecting the polishing pad without a direct polishing test.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a polishing pad, a method of manufacturing the polishing pad, and a method of manufacturing a semiconductor device using the same.

Another object of the present invention is to maintain the surface state of the polished surface at the same level as the initial level even with the lapse of time during the polishing process, so that the polishing performance does not deteriorate for a long time, and based on physical properties such as appropriate hardness, tensile strength and elongation. , to provide a polishing pad that can be applied to a polishing process to achieve a desired level of polishing rate and defect prevention effect.

Another object of the present invention is to depolymerize the polishing layer without conducting a direct polishing test on a polishing pad for application to a CMP polishing process, and measure the average molecular weight of the depolymerized composition, so that the average polishing rate and the pad cutting rate are It is possible to provide a polishing pad capable of classifying excellent polishing pads and a manufacturing method thereof.

Another object of the present invention is to show high process efficiency in polishing a semiconductor substrate, and in the final polishing result, the surface to be polished of the semiconductor substrate exhibits an appropriate polishing rate and the lowest level of defects. provide a way

In order to achieve the above object, in the polishing pad according to an embodiment of the present invention, the polishing layer may have a value of 1 to 2 according to Equation 1:

[Equation 1]

here,

The 1 g of the abrasive layer was placed in 15 ml of 0.3 molar KOH aqueous solution and depolymerized at 150° C. and 48 hours in a sealed container, and the molecular weight of the depolymerized composition was measured by gel permeation chromatography (GPC),

wherein Mw is the weight average molecular weight of the depolymerized composition,

wherein Mn is the number average molecular weight of the depolymerized composition,

The Mp is the peak molecular weight of the depolymerized composition.

A method of manufacturing a polishing pad according to another embodiment of the present invention includes the steps of: i) preparing a prepolymer composition; ii) preparing a composition for preparing an abrasive layer comprising the prepolymer composition, a foaming agent and a curing agent; and iii) preparing an abrasive layer by curing the composition for preparing the abrasive layer, wherein the abrasive layer may have a value of 1 to 2 according to Equation 1 below:

[Equation 1]

here,

The 1 g of the abrasive layer was placed in 15 ml of 0.3 molar KOH aqueous solution and depolymerized at 150° C. and 48 hours in a sealed container, and the molecular weight of the depolymerized composition was measured by gel permeation chromatography (GPC),

wherein Mw is the weight average molecular weight of the depolymerized composition,

wherein Mn is the number average molecular weight of the depolymerized composition,

The Mp is the peak molecular weight of the depolymerized composition.

A method of manufacturing a semiconductor device according to another embodiment of the present invention includes: 1) providing a polishing pad including a polishing layer; and 2) polishing the semiconductor substrate while relatively rotating so that the polished surface of the semiconductor substrate comes into contact with the polishing surface of the polishing layer, wherein the polishing layer may have a value according to Equation 1 of 1 to 2 there is:

[Equation 1]

here,

The 1 g of the abrasive layer was placed in 15 ml of 0.3 molar KOH aqueous solution and depolymerized at 150° C. and 48 hours in a sealed container, and the molecular weight of the depolymerized composition was measured by gel permeation chromatography (GPC),

wherein Mw is the weight average molecular weight of the depolymerized composition,

wherein Mn is the number average molecular weight of the depolymerized composition,

The Mp is the peak molecular weight of the depolymerized composition.

According to the present invention, the polishing pad includes a polishing layer having a chemical bonding structure and a cross-linking structure corresponding to the GPC measurement values of the processing composition treated with the polishing pad under predetermined conditions, so that the polishing surface of the polishing layer can exhibit appropriate hardness. Therefore, it is possible to exhibit a polishing rate and surface characteristics within the target range in polishing the target 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 an appropriate polishing rate and the lowest level of defects. can get

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.

Hereinafter, embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily carry out the present invention. However, the present invention may be embodied in several different forms and is not limited to the embodiments described herein.

It should be understood that numbers expressing quantities of components, properties such as molecular weight, reaction conditions, etc. used in the present invention are modified by the term “about” in all instances.

In the present invention, unless otherwise stated, all percentages, parts, ratios, etc. are by weight.

In the present invention, when "included", it means that other components may be additionally included, rather than excluding other components, unless otherwise stated.

As used herein, “a plurality” refers to more than one.

In the polishing pad according to an embodiment of the present invention, the polishing layer may have a value of 1 to 2 according to Equation 1 below.

[Equation 1]

here,

Put 1 g of the abrasive layer in 15 ml of 0.3 molar KOH aqueous solution, depolymerize in a sealed container at 150° C. for 48 hours, and measure the molecular weight of the depolymerized composition by gel permeation chromatography (GPC), more Specifically, 1 g of an abrasive layer is placed in 15 ml of a 0.3 molar concentration of KOH aqueous solution, and the KOH aqueous solution to which the abrasive layer is administered is placed in a closed pressure vessel having a volume of 45 to 50 ml, 150° C., 3 atm, and 48 hours During depolymerization, the depolymerized composition was extracted with methylene chloride, and the molecular weight of the extract was measured using a GPC apparatus.

Mw is the weight average molecular weight of the depolymerized composition, Mn is the number average molecular weight of the depolymerized composition, and Mp is the peak molecular weight of the depolymerized composition.

The polishing layer includes a cured product obtained by curing a composition including a urethane-based prepolymer, a curing agent, and a foaming agent, and the urethane-based prepolymer may be prepared by reacting a polyol and an isocyanate.

The equivalents of curing reactors such as amine groups (-NH ₂ ) and alcohol groups (-OH) of the curing agent and isocyanate groups (-NCO) of the prepolymer are determined by the type and content of the curing agent that may be included in the preparation of the polishing layer, The structure of the compound in the abrasive layer is determined.

The final urethane-based cured structure of the polishing pad is determined by these factors. By the final urethane-based curing structure, the physical/mechanical properties of the abrasive layer may be expressed as properties such as hardness, tensile strength, and elongation. The characteristics of the physical/mechanical properties of the polishing layer may affect the average polishing rate (Å/min) and the pad cutting rate (㎛/hr) in the CMP polishing process.

The polishing pad is a process product that can be applied to various polishing processes, and the defect rate and production quality of the process product manufactured using the polishing pad are greatly affected by the physical properties of the polishing pad. In various polishing processes, it is necessary to finely control the surface properties of the polishing layer in order to be applied not only to the bulk level polishing process, but also to the micro and nano level fine polishing processes, Even if the absolute numerical difference in each physical property is not large, the resulting abrasive properties may be significantly different.

The polishing layer is a cured product composed of a compound having a predetermined chemical structure, and the final polishing rate, such as a degree of defects, is determined 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. Using these characteristics, the abrasive layer of the present invention is depolymerized, and the weight average molecular weight (Mw), number average molecular weight (Mn), and peak molecular weight (Mp) of the depolymerized composition are measured and substituted into Equation 1 of the present invention, , when the value is included within the scope of the present invention, the compound constituting the abrasive layer exhibits physical properties due to the chemical structure, and exhibits appropriate tensile and elongation due to the physical properties, resulting in excellent polishing performance I'd say it means you can do it.

Equation 1 is that when the abrasive layer is depolymerized under a specific depolymerization condition, the structure of the compound constituting the abrasive layer is decomposed under the depolymerization condition, and values for the decomposed compounds are checked to determine the physical and/or chemical properties of the abrasive layer This means that you can check the characteristics.

That is, the compound constituting the abrasive layer is a physical and/or chemical index given to the abrasive layer due to its chemical structure. Therefore, in the polishing process to which the polishing pad is applied, the polishing layer may have an inappropriate physical and/or chemical effect on the object to be polished, and thus the final polishing performance may be deteriorated.

The value according to Formula 1 may be 1 to 2, preferably 0.6 to 0.95. When the value according to Equation 1 is too low, the hardness of the polishing layer is excessively high or the elongation is excessively low, and the probability of occurrence of defects such as scratches on the surface of the target film to be polished during polishing may increase. In addition, if the value according to Equation 1 is too high, a problem in that the polishing rate does not reach the target level may occur. That is, when the value according to Equation 1 satisfies within the above range, the abrasive layer can exhibit appropriate hardness and elongation, and based on this, it can exhibit appropriate elasticity and physical properties for the target film to be polished during the polishing process, It can exhibit advantageous effects in polishing rate, pad cutting rate, defect prevention, and the like.

In addition, the abrasive layer may have a tensile strength of 20 to 25N/mm ² and an elongation of 100 to 110%. When the value according to Equation 1 satisfies the range of the present invention, the tensile and elongation values are included within the above range, and when applied to a polishing process, a high polishing rate, an excellent pad cutting rate, and excellent defect prevention properties can be exhibited. there is.

The pad cutting rate may be calculated from the pad cutting amount, and the pad cutting rate may be analyzed by PCR (Pad Cut Rate), that is, the pad cutting force. Specifically, the “pad cutting amount” or “pad cutting force” may be measured from the initial pad height, and measured from the pad height after polishing and conditioning the wafer between CMP for a certain period of time. As the pad cutting amount increases, the pad cutting force increases, and as the pad cutting amount decreases, the pad cutting force decreases.

If the pad cutting rate is too low, the pad life may be reduced, and due to the tendency of semiconductor substrate defects to increase in the CMP polishing process, it may cause a decrease in production yield and process yield. there is. Therefore, it will be said that it is an important task to increase the pad cutting rate under conditions that can increase the average polishing rate.

Accordingly, as described above, the polishing layer of the present invention satisfies the range of Equation 1, has excellent physical properties, has a high average polishing rate, and can exhibit an excellent pad cutting rate.

Specifically, the Mw (weight average molecular weight) of the depolymerized composition may be 2,600 to 4,000, preferably 2,600 to 3,500. In addition, the depolymerized composition may have an Mn (number average molecular weight) of 2,500 to 3,000, preferably 2,500 to 2,800.

In general, in order to apply a polishing pad to a CMP polishing process, it was necessary to check the average polishing rate and pad cutting rate through a direct polishing test on the polishing pad, and to examine whether the polishing pad was applied or not.

When selecting a polishing pad to be used in the polishing process, it is necessary to check the performance through a polishing test, and it will be said that a time-consuming procedure is essential in terms of time and cost.

On the other hand, as in the present invention, after depolymerization, if the value of Equation 1 is used using the GPC measurement result value, the average polishing rate for the polishing pad and the values for the pad cutting rate can be predicted. will say there will be

This will make it possible to predict the performance of the polishing pad without performing a direct polishing test, thereby greatly simplifying the process application of the polishing pad.

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 abrasive 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 the polishing target surface of the object to be polished, and the first surface 11 . It may include a second surface 12, which is the back surface of

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

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

Referring to FIG. 1B , in one embodiment, the abrasive layer 10 includes the cushion layer 20 , and is disposed at the interface between the abrasive layer 10 and the cushion layer 20 . It may further include a first adhesive layer 30 to be used. For example, the first adhesive layer 30 may be derived from a heat-sealing adhesive, but is not limited thereto.

The polishing pad 100 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 may undergo an additional curing process or may be reacted with other polymerizable compounds to form a final cured product.

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

The isocyanate compound used in the preparation of the urethane-based prepolymer may be one selected from the group consisting of aromatic isocyanate, aliphatic isocyanate, cycloaliphatic isocyanate, and combinations thereof. For example, the isocyanate compound may include an aromatic diisocyanate, and for example, the isocyanate compound may include an aromatic diisocyanate and an alicyclic 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 hydroxyl groups (-OH) per molecule. In one embodiment, the polyol compound is a dihydric alcohol compound having two hydroxyl groups, that is, diol or glycol; Alternatively, it may include a trihydric alcohol compound having three hydroxyl groups, that is, a triol compound.

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, polypropylene triol, 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. The weight average molecular weight (Mw) of the high molecular weight polyol may be, for example, about 500 g/mol or more, about 1,800 g/mol or less, for example, about 700 g/mol or more, about 1,800 g/mol or less. 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, it represents the GPC measurement value of the processing composition in which the polishing layer is treated under a predetermined condition by the appropriate cross-linking structure of the polyol compound. 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 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 polytetramethylene ether glycol (PTMG) and diethylene glycol (DEG).

The preliminary composition has an isocyanate group content (NCO%) of 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% by weight, For example, it may be from about 8% to about 10% by weight, such as from about 8.5% to about 10% by weight. The content of isocyanate groups means a percentage of the weight of isocyanate groups 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, when measuring gel permeation chromatography (GPC) of the preliminary composition, Mw (weight average molecular weight) is 4,200 to 4,300, Mn (number average molecular weight) is 4,000 to 4,100, Mp (peak molecular weight) is 3,000 to 3,100.

Specifically, the abrasive layer formed by curing the preliminary composition having properties according to the GPC measurement result of the preliminary composition under predetermined process conditions can implement a desired level of polishing rate and have properties suitable for realizing a defect reduction effect. It may be more advantageous to show

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 bonding structure characteristics in the cured structure of the polishing layer may be determined by the reaction process conditions for preparing the urethane-based prepolymer; 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 (ABCBA) and a second prepolymer (ABCBD). 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 by the condition 1 to obtain a final processing composition 70 including structure 1 (ABC), structure 2 (BAEDAB) and structure 3 (CBA) 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, after 1 g of the polishing layer is administered to 15 ml of a solution having a 0.3 molar concentration of KOH, it is depolymerized at 150° C. for 48 hours in a closed space, and the GPC measurement value of the depolymerized composition is the above for preparing the polishing layer. It is different from the measured GPC value of the preliminary composition.

This is because the preliminary composition is organically related to various process conditions and processing conditions for obtaining the processing composition, as well as the type and content of monomers for preparing the urethane-based prepolymer, as well as various process conditions during the preparation of the preliminary composition and the manufacturing process of the polishing layer. , and when depolymerized under the above conditions, dissociation does not occur in the same part as the binding site of the binding structure of the preliminary composition, and as dissociation occurs in a different part by the depolymerization conditions, there is a difference in GPC measurement values will show

However, the technical purpose of the polishing pad according to one embodiment is to depolymerize the processing composition under the above conditions, and when the GPC measurement value of the depolymerized composition satisfies the above-mentioned range, the resultant polishing performance by the polishing pad is It is in revealing the correlation of realizing the desired level, and within the range that satisfies this purpose, even if slightly different types and contents of monomers, slightly different process conditions, etc. are applied, it can be considered that it is out of the scope of the object of the present invention. there is no

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 'urethane-reacted at one end' 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.

The preliminary composition may further include unreacted 2,6-TDI at both ends. The meaning of 'unreacted at both ends' means that both isocyanate groups of the diisocyanate have not reacted, and the unreacted 2,6-TDI at both ends is a free monomer remaining in the preliminary composition. Since the preliminary composition includes unreacted 2,6-TDI at both ends, an appropriate crosslinked structure or chain extension structure can be formed during the curing process of the preliminary composition, and thus, the above-described peak properties of the processing composition The resulting softening control index may be advantageous to indicate the desired range.

The GPC measurement value of the preliminary composition is, 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 chemical bonding structure of the urethane-based prepolymer, and the preparation of the urethane-based prepolymer It can be comprehensively determined by reaction process conditions for

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 about 1:0.85 to about 1:0.99, for example, about 1:0.89 to about 1:0.99, for example about 1:0.90 to about 1:0.96.

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 ( It may include one selected from the group consisting of tetrafluoroethylene, CClF ₂ -CClF ₂ ), and combinations thereof.

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 of '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 about 50 or more, for example, about 50 to about 75, for example, about 55 to about 65 can be The tensile strength of the abrasive layer may be about 20 N/mm2 or more, for example, from about 20N/mm2 to about 30N/mm2, for example, from about 20N/mm2 to about 26N/mm2. The elongation of the polishing layer may be about 100% or more, for example, about 100% to about 200%. The cutting rate of the abrasive layer may be about 80 μm/hr or less, for example, about 40 μm/hr to about 80 μm/hr, for example, about 40 μm/hr to about 60 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% by weight, For example, it may be from about 8% to about 10% by weight, such as from about 8.5% to about 10% by weight. 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 the polishing layer includes: 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 comprises: 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 manufactured through the process of preparing the abrasive layer may have a value of 1 to 2 according to Equation 1:

[Equation 1]

here,

Put 1 g of the abrasive layer in 15 ml of 0.3 molar KOH aqueous solution, depolymerize in a sealed container at 150° C. for 48 hours, and measure the molecular weight of the depolymerized composition by gel permeation chromatography (GPC), more Specifically, 1 g of an abrasive layer is placed in 15 ml of a 0.3 molar concentration of KOH aqueous solution, and the KOH aqueous solution to which the abrasive layer is administered is placed in a closed pressure vessel having a volume of 45 to 50 ml, 150° C., 3 atm, and 48 hours During depolymerization, the depolymerized composition was extracted with methylene chloride, and the molecular weight of the extract was measured using a GPC apparatus.

Mw is the weight average molecular weight of the depolymerized composition, Mn is the number average molecular weight of the depolymerized composition, and Mp is the peak molecular weight of the depolymerized composition.

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 at least one surface of the abrasive layer (2); 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 the respective heat sealing adhesives are applied are in contact After laminating the abrasive layer and the cushion layer to the surface, the two layers may be fusion-bonded 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: The polishing layer may provide a method of manufacturing a semiconductor device having a value of 1 to 2 according to Equation 1:

[Equation 1]

here,

Put 1 g of the abrasive layer in 15 ml of 0.3 molar KOH aqueous solution, depolymerize in a sealed container at 150° C. for 48 hours, and measure the molecular weight of the depolymerized composition by gel permeation chromatography (GPC), more Specifically, 1 g of an abrasive layer is placed in 15 ml of a 0.3 molar concentration of KOH aqueous solution, and the KOH aqueous solution to which the abrasive layer is administered is placed in a closed pressure vessel having a volume of 45 to 50 ml, 150° C., 3 atm, and 48 hours During depolymerization, the depolymerized composition was extracted with methylene chloride, and the molecular weight of the extract was measured using a GPC apparatus.

Mw is the weight average molecular weight of the depolymerized composition, Mn is the number average molecular weight of the depolymerized composition, and Mp is the peak molecular weight of the depolymerized composition.

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 a supply nozzle 140 .

The flow rate of the abrasive slurry 150 sprayed through the supply nozzle 140 may be about 10 ml/min to about 1,000 ml/min, for example, about 10 ml/min to about 800 ml/min, for example For example, it may be about 50 cm 3 /min to about 500 cm 3 /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 according to the purpose, for example, in the range of about 0.01 psi to about 20 psi, for example, 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 is 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 for the polishing rate and the defect prevention effect of the semiconductor substrate to be realized 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 polishing on the surface to be polished is completed The number of surface defects is less than 5, and the average polishing rate of the silicon oxide (SiO ₂ ) film may be 2,500 Å/min to 4,000 Å/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.

Example 1

Example 1

A preliminary composition including a urethane-based prepolymer was prepared by mixing the diisocyanate component and the polyol component in the composition ratio shown in Table 1 below, putting it in a four-necked flask, and reacting it at 80°C. 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 the NH2 groups of the MOCA to the 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 with the preliminary composition. The preliminary composition had 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

A preliminary composition including a urethane-based prepolymer was prepared by mixing the diisocyanate component and the polyol component in the composition ratio shown in Table 1 below, putting it into a four-neck flask, and reacting it at 80°C. 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.

Example 3

A preliminary composition including a urethane-based prepolymer was prepared by mixing the diisocyanate component and the polyol component in the composition ratio shown in Table 1 below, putting it in a four-necked flask, and reacting it at 80°C. The content of isocyanate groups (NCO groups) in the preliminary composition was adjusted to 9.5% 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 0.92. 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

A preliminary composition including a urethane-based prepolymer was prepared by mixing the diisocyanate component and the polyol component in the composition ratio shown in Table 1 below, putting it in a four-necked flask, and reacting it at 80°C. 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 with the preliminary composition. The preliminary composition had 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.

Comparative Example 2

A preliminary composition including a urethane-based prepolymer was prepared by mixing the diisocyanate component and the polyol component in the composition ratio shown in Table 1 below, putting it in a four-necked flask, and reacting it at 80°C. 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.

Each of the polishing layers of Examples 1 to 4 and Comparative Examples 1 and 2 was processed to a thickness of 2 mm, and a concentric groove processing 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.

Item Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Preliminary composition diisocyanate 2,4-TDI 73 72 70 96 80 2,6-TDI 17 16 15 4 5 H ₁₂ MDI 10 12 15 - 15 Total 100 100 100 100 100 polyol PTMG (Mw 1000) 90.8 89.9 89.9 90.0 97.5 DEG (Mw 106) 9.2 10.1 10.1 10.0 2.5 Total 100 100 100 100 100 Pre-composition NCO group content (wt%) 9 9.2 9.5 6 8 amine curing agent Molar ratio of NH ₂ of curing agent to NCO in the preliminary composition 0.96 0.94 0.92 0.75 0.70 process conditions Prepolymer Preparation Reaction Temperature (℃) 80 80 80 80 80 Curing mold preheat temperature (℃) 90 95 100 90 100 Post-curing temperature (℃) 110 110 110 110 110

Experimental Example 1

About 1 g of the polishing layer of Examples and Comparative Examples was added to 15 ml of an aqueous KOH solution having a concentration of about 0.3 molar. Thereafter, the KOH solution mixed with the abrasive layer was placed in a sealed pressure vessel having a volume of about 48 ml, and depolymerized at a temperature of about 150° C. for about 48 hours at a pressure of about 3 atmospheres. Thereafter, the depolymerized composition was extracted with methylene chloride.

Mw (weight average molecular weight), Mn (number average molecular weight) and Mp (peak molecular weight) were measured for the extracted composition through a gel permeation chromatography (GPC) apparatus. As a control, Mw, Mn, and Mp values of the urethane-based prepolymer included in the preliminary composition of Example 1 were measured.

GPC equipment and measurement conditions are as follows.

Measuring device: Agilent 1260 Infinity GPC

Flow rate: 1ml/min in THF

Injection volume: 100ul

Column Temp: 40°C

Detector: RI

Column: TSKgel G1000HxL Molecular Weight Size 5060

Using the above GPC measurement value, a value according to the following formula (2) was calculated:

[Equation 1]

here,

Mw is the weight average molecular weight of the depolymerized composition of the polishing layer,

Mn is the number average molecular weight of the depolymerized composition of the polishing layer,

Mp is the peak molecular weight of the depolymerized composition of the polishing layer.

control Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Mn 3040 2725 2732 2745 2320 2163 Mp 4032 3229 3158 3160 2418 2359 Mw 4281 3331 3347 3357 2559 2560 value of expression 1 - 0.83 0.69 0.94 0.41 0.49

According to the measurement results, when the GPC measurement results of the urethane-based prepolymer are compared with the GPC measurement results of Examples and Comparative Examples, it can be confirmed that the position decomposed by depolymerization is different from that of the prepolymer.

Specifically, it will be said that the urethane-based prepolymer is prepared as an abrasive layer by curing, and the portion decomposed by depolymerization is different from the portion bonded during polymerization of the prepolymer.

In addition, it was confirmed that the polishing pads of Examples 1 to 3 were different from Comparative Examples 1 and 2 by confirming that, after depolymerization, the GPC measurement value, Mw (weight average molecular weight), was 2,600 or more, and Mn (number average molecular weight) was 2,500 or more. did

In addition, the value for Equation 1 also falls within the scope of the present invention for the polishing pad of the Example, but was found to be less than the numerical value for the Comparative Example.

Experimental Example 2

Hardness, average pore size, specific gravity (g/cc), tensile (N/mm ² ) and elongation (%) of the polishing layer in the polishing pad were measured. In addition, the polishing rate and the cutting rate of the polishing pad were measured.

(1) hardness

The Shore D hardness of the polishing pad prepared according to the Examples and Comparative Examples was measured, and the polishing pad was cut to a size of 2 cm Х 2 cm (thickness: 2 mm) in an environment with a temperature of 25° C. and a humidity of 50±5%. incubated for 16 hours. Thereafter, the hardness of the polishing pad was measured using a durometer (D-type durometer).

(2) seal

For each of the polishing pads manufactured according to the above Examples and Comparative Examples, the highest strength value just before fracture was obtained while testing at a speed of 500 mm/min using a universal testing machine (UTM), and then, through the obtained value, strain-Stress The slope in the region of 20 to 70% of the curve was calculated.

(3) elongation

For each of the polishing pads manufactured according to the above Examples and Comparative Examples, the maximum amount of deformation immediately before fracture was measured while testing at a speed of 500 mm/min using a universal testing machine (UTM), and then the ratio of the maximum amount of deformation to the initial length was expressed as a percentage (%).

(4) average pore size

The size of the diameter of the pores of the polishing layer was measured, and the method of measuring the size of the diameter of the pores was measured using a particle size analyzer, and the average pore means D50.

(5) specific gravity

The specific gravity of the window prepared according to the above Examples and Comparative Examples was measured, and the polishing pad was cut to a size of 2 cm Х 2 cm (thickness: 2 mm) and left at a temperature of 25° C. and a humidity of 50±5% for 16 hours. did After that, the density was calculated after measuring the initial weight and the weight when immersed in water using an electronic densimeter.

(6) Removal rate

Silicon oxide was deposited on a silicon wafer having a diameter of 300 mm by a chemical vapor deposition (CVD) process. The polishing pads of Examples and Comparative Examples were attached to the CMP equipment, and 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 on the polishing pad at a rate of 250 mL/min, the silicon oxide film was polished for 60 seconds under a load of 4.0 psi and a speed of 150 rpm. 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. 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.

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

For the polishing pads of Examples and Comparative Examples, the polishing rate was measured twice, respectively.

(7) pad cut-rate

The polishing pad was pre-conditioned with deionized water for 10 minutes, and then conditioned while spraying deionized water for 1 hour. The cutting rate of the polishing pad was calculated by measuring the thickness changed during the conditioning process. The equipment used for conditioning was CTS' AP-300HM, the conditioning pressure was 6 lbf, the rotation speed was 100 to 110 rpm, and the disk used for conditioning was Saesol LPX-DS2.

Evaluation　Items Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 thickness (mm) 2 2 2 2 2 Hardness (Shore D) 56.2 57.7 57.4 45 53.2 Average Pore size (um) 24.1 20.7 22.2 21 11.2 Specific gravity (g/cc) 0.8 0.8 0.8 0.8 0.8 Tensile (N/mm ² ) 22.2 22.3 21.5 22.9 19.82 Elongation (%) 107.5 103.7 100.5 170.6 81.3 Average removal rate (Å/min) 3724 3357 3253 1825 3458 Pad cutting rate (㎛/hr) 51.3 43.3 42.2 19.5 42.5 Polishing flatness (%) 3.2 3.6 3.9 5.6 5.8 number of defects 0.5 One 2 4 5

According to the experimental results, Examples 1 to 3 had a large hardness value, a tensile strength of 20N/mm ² or more, and an elongation of 100% or more.

As the physical property values within the above range were shown, an excellent effect was exhibited in the average polishing rate and the pad cutting rate.

In Comparative Example 1, it was confirmed that the average polishing rate and the pad cutting rate were low. On the other hand, Comparative Example 2 did not show a significant difference in the performance of the polishing pad compared to the Example, but it was confirmed that the average pore size of the polishing layer was small and the tensile and elongation values were low.

Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims are also provided. is within the scope of the

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
100, 200: polishing pad
110: polishing pad
120: surface plate
130: semiconductor substrate
140: nozzle
150: polishing slurry
160: abrasive head
170: conditioner

Claims (11)

The abrasive layer has a value of 1 to 2 according to Equation 1 below.
polishing pad.
[Equation 1]

here,
The 1 g of the abrasive layer was placed in 15 ml of an aqueous KOH solution having a concentration of 0.3 molar, and depolymerized at 150° C. for 48 hours in an airtight container, and the molecular weight of the depolymerized composition was measured by gel permeation chromatography (GPC),
wherein Mw is the weight average molecular weight of the depolymerized composition,
wherein Mn is the number average molecular weight of the depolymerized composition,
The Mp is the peak molecular weight of the depolymerized composition. According to claim 1,
The Mw (weight average molecular weight) is 2,600 to 4,000
polishing pad. According to claim 1,
The Mn (number average molecular weight) is 2,500 to 3,000
polishing pad. According to claim 1,
The tensile strength is 20 to 25N/mm ² and the elongation is 100 to 110%.
polishing pad. According to claim 1,
The polishing layer includes a cured product of a preliminary composition including a urethane-based prepolymer,
The preliminary composition has an isocyanate group (NCO) content of 5 to 11% by weight.
polishing pad. i) preparing a preliminary composition comprising a reactant of an isocyanate compound and a polyol compound;
ii) preparing a composition for preparing an abrasive layer comprising the preliminary composition, a foaming agent and a curing agent; and
iii) curing the composition for preparing an abrasive layer to prepare an abrasive layer;
The polishing layer has a value of 1 to 2 according to Equation 1 below.
Method of making a polishing pad:
[Equation 1]

here,
The 1 g of the abrasive layer was placed in 15 ml of an aqueous KOH solution having a concentration of 0.3 molar, and depolymerized at 150° C. for 48 hours in an airtight container, and the molecular weight of the depolymerized composition was measured by gel permeation chromatography (GPC),
wherein Mw is the weight average molecular weight of the depolymerized composition,
wherein Mn is the number average molecular weight of the depolymerized composition,
The Mp is the peak molecular weight of the depolymerized composition. 7. The method of claim 6,
The prepolymer composition is a urethane-based prepolymer, and the isocyanate (NCO) group of the urethane-based prepolymer comprises 5 to 10% by weight,
The composition for preparing an abrasive layer of step ii) includes a molar ratio of NH ₂ groups of the curing agent to the isocyanate (NCO) groups of the urethane-based prepolymer in a range of 0.8 to 1
A method of manufacturing a polishing pad. 1) providing a polishing pad including a polishing layer; and
2) polishing the semiconductor substrate while relatively rotating so that the polishing surface of the semiconductor substrate is in contact with the polishing surface of the polishing layer;
The polishing layer has a value of 1 to 2 according to Equation 1 below.
A method of manufacturing a semiconductor device:
[Equation 1]

here,
The 1 g of the abrasive layer was placed in 15 ml of an aqueous KOH solution having a concentration of 0.3 molar, and depolymerized at 150° C. for 48 hours in an airtight container, and the molecular weight of the depolymerized composition was measured by gel permeation chromatography (GPC),
wherein Mw is the weight average molecular weight of the depolymerized composition,
wherein Mn is the number average molecular weight of the depolymerized composition,
The Mp is the peak molecular weight of the depolymerized composition. 9. The method of claim 8,
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 silicon oxide film has an average polishing rate of 2,500 Å/min to 4,000 Å/min.
A method of manufacturing a semiconductor device. 9. The method of claim 8,
The rotation speed of the polishing object and the polishing pad is 10 rpm to 500 rpm, respectively
A method of manufacturing a semiconductor device. 9. The method of claim 8,
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 10ml/min to 800mL/min.
A method of manufacturing a semiconductor device.

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