JP2023523022A - Chemical mechanical polishing pad with protruding structure - Google Patents

Abstract

The polishing pad includes a support layer and a raised pattern disposed on the support layer. The protruding pattern includes horizontal extending surfaces and vertical sides. Further, the support layer includes a first support layer and a second support layer, the first support layer disposed on the second support layer. In particular, the variation in horizontal cross-sectional area of the protruding pattern is less than 50% along the protruding direction. [Selection drawing] Fig. 1

Description

Cross-reference to related applications

This application claims priority to US Provisional Application No. 63/013,064, filed April 21, 2020, which is incorporated herein by reference in its entirety.

FIELD OF THE DISCLOSURE The present disclosure relates to chemical mechanical polishing and, more particularly, to chemical mechanical polishing pads having raised structures for improved thermal stability and improved roughness consistency of the polished surface.

In the semiconductor manufacturing process, chemical mechanical polishing (CMP) is used to smooth unevenness and undulations on the wafer surface. CMP is a process that uses the interaction of frictional and chemical energies to planarize the surface of a wafer or workpiece to the atomic level to minimize surface defects. While pressing the product against the polishing pad, relative motion is generated between the polishing pad and the product, and polishing is performed by supplying polishing slurry. The CMP process is used as an indispensable technique for smoothing interlayer insulating films of transistor elements and multi-layered wiring, and manufacturing tungsten wiring and copper wiring in the manufacture of ultra-large scale integrated circuits (ULSI).

As shown in FIG. 1, a typical CMP process includes mounting a polishing pad 1 on a platen 2, supplying a polishing slurry 3 onto the polishing pad 1, and pressing an article 4, such as a wafer, against the polishing pad 1. , to generate relative motion between the polishing pad 1 and the article of manufacture 4 . A polishing pad is a thin planar polishing tool and is mainly composed of a polymeric material. To control the polishing rate uniformly across the wafer, both the polishing pad and wafer are rotated while pressing against each other as shown in FIG. In particular, the polishing rate can be determined by the product of the polishing pressure and the relative velocity between the polishing pad and the wafer (ie, polishing pressure x relative velocity). Thus, for a given abrasive tool and article of manufacture, the polishing rate is determined by pressure and relative velocity. The CMP process is required to maintain polishing stability, ie, reproducibility. Factors that affect the stability of polishing include changes in frictional heat and changes in surface conditions.

Frictional heat due to friction has a great effect on polishing. For example, even if the polishing pressure and relative velocity are constant, the amount of frictional heat can vary with the chemical, mechanical, and/or thermal properties of the polishing slurry and pad. Therefore, frictional heat affects the polishing rate. Therefore, in general, polishing stability and reproducibility can be improved if the pressure and relative velocity can be strictly controlled. give. Therefore, precise control of the complicating factors in the CMP process is critical for a stable and reproducible polishing process.

However, as the polishing process progresses, frictional heat in the polishing process accumulates in the apparatus, causing variations in the process temperature and deteriorating the stability and reproducibility of polishing. Therefore, in order to maintain the stability of polishing, it is necessary to control frictional heat. Conventional polishing pads in the related art are constructed of polymer layers with poor heat transfer properties, and are therefore in need of improvement.

Furthermore, another factor that degrades polishing stability is the uniformity of the pad surface. Specifically, the polishing rate is proportional to the surface roughness of the pad. However, the roughness of the polished surface changes over time. To overcome this problem and restore surface roughness, the polishing pad is typically rubbed with a roughening tool such as a conditioning disc 5 (Fig. 1) that contains diamond particles coated thereon. It is difficult to maintain the surface condition of the polishing pad at all times because many factors affect the conditioning result, such as diamond particle size and distribution, pressure, conditioning method, and conditioning tool stability. As a result, the surface roughness of conventional polishing pads in the related art is unstable.

The present disclosure provides methods of designing and manufacturing polishing pads for use as polishing tools during, for example, chemical-mechanical, mechano-chemical, and tribo-chemical polishing processes in the manufacture of semiconductors or optical components. Polishing pads according to the present disclosure can provide improved thermal stability and more consistent surface roughness of the polishing surface.

One aspect of the present disclosure can provide a polishing pad that includes a support layer and a protruding pattern disposed on the support layer. The protruding pattern may include horizontal extending surfaces and vertical sides. The support layer may include a first support layer and a second support layer, and the first support layer may be disposed on the second support layer.

In some embodiments, one or more of the following aspects may be included individually or in any combination. Variation in horizontal cross-sectional area of the protruding pattern may be equal to or less than 50% along the direction of protrusion. The area ratio of the extended surface to the polishing pad may be 1% or more and 80% or less. The protruding pattern may include a plurality of unit patterns arranged separately from each other, and/or the protruding pattern may include a plurality of unit patterns laterally connected to each other. The total peripheral length of the extending surfaces within a unit area of 1 cm ² of the polishing pad may be 24 cm or more and 2400 cm or less. The height of the projected pattern may be 10 μm or more and 1000 μm or less.

The support layer may include grooves that divide the support layer into sections. In some implementations, the support layer may include a first groove formed in the first support layer, the first groove dividing the support layer into multiple sections. A remaining thickness of the first support layer below the first groove may be 500 μm or less. The support layer may include a second groove formed within the first groove, and the width of the second groove may be narrower than the width of the first groove.

The thickness of the first support layer may be 1500 μm or less, and the thickness of the second support layer may be 100 μm or more and 3000 μm or less. The first support layer may comprise a first material and the second support layer may comprise a second material. The first material and the second material may be the same or different. The first hardness of the first material may be equal to or greater than the second hardness of the second material. In some implementations, the protruding pattern may comprise a first material and the support layer may comprise a second material. The first hardness of the first material may be equal to or greater than the second hardness of the second material. In some implementations, the second support layer may comprise a porous foam material. The porosity of the foamed material may be from 1% to 70%.

The first hardness may be Shore 30D or more and Shore 80D or less, and the second hardness may be Shore 20A or more and Shore 80A or less. For example, the first material may be polyurethane, polybutadiene, polycarbonate, polyoxymethylene, polyamide, epoxy, acrylonitrile butadiene styrene copolymer, polyacrylate, polyesterimide, acrylate, polyalkylene, polyethylene, polyester, natural rubber, polypropylene, polyisoprene, Polyalkylene oxide, polyethylene oxide, polystyrene, phenol resin, amine, urethane, silicone, acrylate, fluorene, phenylene, pyrene, azulene, naphthalene, acetylene, p-phenylene vinylene, pyrrole, carbazole, indole, azepine, aniline, thiophene, 3 , 4-ethylenediisoxibene and p-phenylene sulfide. The second material is polyurethane, polybutadiene, polycarbonate, polyoxymethylene, polyamide, epoxy, acrylonitrile butadiene styrene copolymer, polyacrylate, polyesterimide, acrylate, polyalkylene, polyethylene, polyester, natural rubber, polypropylene, polyisoprene, polyalkylene. Oxide, polyethylene oxide, polystyrene, phenol resin, amine, urethane, silicone, acrylate, fluorene, phenylene, pyrene, azulene, naphthalene, acetylene, p-phenylenevinylene, pyrrole, carbazole, indole, azepine, aniline, thiophene, 3,4 - may be selected from the group consisting of ethyldixibene and p-phenylene sulfide.

In particular, the present disclosure is not limited to combinations of elements as described above, but can be assembled with any combination of elements as described herein.
Other aspects of the disclosure are disclosed herein.

In order to better understand the drawings used in the detailed description of this disclosure, a brief description of each drawing is provided.

FIG. 1 shows a general set-up for a chemical-mechanical polishing process; FIG. 3 illustrates a polishing pad according to an exemplary embodiment of the present disclosure; [0014] FIG. 4 illustrates a raised pattern of a polishing pad according to an exemplary embodiment of the present disclosure; FIG. 4 shows parameters for a convective heat transfer model; FIG. 5 shows representative modeling results of the amount of heat transfer for various geometries of protruding patterns of a polishing pad according to exemplary embodiments of the present disclosure; [0014] Fig. 5 illustrates the shape of a protruding pattern according to an exemplary embodiment of the present disclosure; [0014] Fig. 5 illustrates the shape of a protruding pattern according to an exemplary embodiment of the present disclosure; [0014] Fig. 5 illustrates the shape of a protruding pattern according to an exemplary embodiment of the present disclosure; [0014] Fig. 5 illustrates the shape of a protruding pattern according to an exemplary embodiment of the present disclosure; 4 shows representative experimental results of removal rates for various designs of polishing pads according to exemplary embodiments of the present disclosure. 4 compares temperature rise during a polishing process using a conventional polishing pad in the related art and a polishing pad according to an exemplary embodiment of the present disclosure; 4 compares polishing efficiency between polishing pads according to exemplary embodiments of the present disclosure and conventional polishing pads in the related art.

It should be appreciated that the above drawings are not necessarily to scale, but rather present somewhat simplified representations of various preferred features that illustrate the underlying principles of the present disclosure. Certain design features of the present disclosure, including, for example, specific dimensions, orientations, locations, and shapes are determined in part by the particular intended application and environment of use.

Advantages and features of the present disclosure, as well as methods of achieving the same, will become apparent by reference to the accompanying drawings and the exemplary embodiments described in detail below. This disclosure, however, is not limited to the exemplary embodiments set forth herein, but may be embodied in variations and modifications. Exemplary embodiments are provided merely to enable those skilled in the art to understand the scope of the present disclosure, which is to be defined by the claims. Thus, in some embodiments, well-known operations of processes, well-known structures, and well-known techniques have not been described in detail to avoid obscuring the disclosure. Like reference numerals refer to like elements throughout the specification.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure.
As used herein, the singular forms "a,""an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used herein, the terms "comprises" and/or "comprising" define the presence of the stated features, integers, steps, operations, elements and/or components, but one or more other It will further be understood that does not exclude the presence or addition of features, integers, steps, operations, elements, components, and/or groups thereof.
As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Unless stated otherwise, or clear from context, the term "about" as used herein is understood to be within normal tolerances in the art, e.g., within 2 standard deviations of the mean. "About" means 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, It can be understood to be within 0.05%, or 0.01%. All numerical values provided herein are modified by the term "about," unless otherwise clear from the context. As used herein, the terms “first,” “second,” etc. are used to distinguish between identical or similar elements and do not infer any order or plurality.

Aspects of the present disclosure provide methods of designing and manufacturing polishing pads for chemical-mechanical polishing (CMP) processes. In particular, polishing pads according to the present disclosure can exhibit improved thermal properties and maintain thermal stability during CMP processes. Furthermore, the polishing pad according to the present disclosure can minimize variations in surface roughness in the polishing pad with respect to polishing time, thus providing technical advantages such as improved reliability and repeatability for the polishing process. can. As a result, planarization of the wafer can be obtained more reliably. Additionally, because of the lower operating temperatures, polishing pads according to the present disclosure can last longer, require less frequent replacement, and provide economic advantages. Polishing pad defects can also be minimized. A conditioning tool, such as the conditioning disc 5 of FIG. 1, may be eliminated from the CMP configuration, thereby simplifying the process and CMP apparatus configuration. Moreover, since the polishing pad according to the present disclosure can maintain a more stable polishing temperature, fluctuations in the temperature of the polishing slurry can be prevented. Low temperature fluctuations in the polishing slurry are advantageous because temperature fluctuations in the polishing slurry can cause the pH of the polishing slurry to fluctuate, and the pH of the polishing slurry can affect the agglomeration of abrasive particles within the polishing slurry. be.

In order to keep the surface temperature of the polishing pad constant, the transfer rate of frictional heat generated in the pad to the polishing slurry may be increased. And, in order to more rapidly transfer frictional heat to the slurry dispensed onto the pad, the polishing pad surface geometry can be designed to increase convective heat transfer. Conventional polishing pads in the related art have polishing studs conically shaped for conditioning. Therefore, the space through which the slurry flows is more restricted and the distance between where frictional heat is generated in the pad and where the pad contacts the slurry is greater. As a result, the heat transfer efficiency decreases

ここで、Ｑは熱伝達量、ｈは対流熱伝達率、Ａは熱伝達面積、ΔＴは温度差、すなわち加工中の研磨温度（Ｔ）と背景温度（Ｔ_∞）との差である。背景温度（Ｔ_∞）は、研磨スラリーの温度を指す場合がある。動作温度とスラリー温度との温度差（ΔＴ）は、通常、１０～５０ケルビン（Ｋ）であるので、研磨パッドの設計対象は、所定の温度差（ΔＴ）に対する熱伝達量（Ｑ）の最大化となってもよい。例えば、対流熱伝達率（ｈ）を大きくしたり、パッド表面とスラリーの接触面積（Ａ）を大きくしたりすることが考えられる。 Newton's law of cooling is expressed as Equation 1 below.

where Q is the amount of heat transfer, h is the convective heat transfer coefficient, A is the heat transfer area, and ΔT is the temperature difference, ie, the difference between the polishing temperature (T) and the background temperature (T _∞ ) during processing. Background temperature (T _∞ ) may refer to the temperature of the polishing slurry. Since the temperature difference (ΔT) between the operating temperature and the slurry temperature is typically 10 to 50 Kelvin (K), the design objective of the polishing pad is the maximum amount of heat transfer (Q) for a given temperature difference (ΔT). It may become a change. For example, it is conceivable to increase the convective heat transfer coefficient (h) or increase the contact area (A) between the pad surface and the slurry.

As used herein, abrasive slurry or slurry may refer to a colloid of suspended abrasive particles and/or corrosive chemicals in a liquid (eg, water). Cerium oxide powder can be used as the abrasive particles. Abrasive particles may have a nominal particle size of from about 1 nm to about 500 nm. However, the present disclosure does not limit the types or properties of slurries used in CMP processes, and any slurry used in the art may be used in combination with polishing pads according to the present disclosure.

Polishing pads according to exemplary embodiments of the present disclosure will now be described with reference to the accompanying drawings.

FIG. 2 shows a polishing pad according to an exemplary embodiment of the present disclosure, and FIG. 3 shows a protruding pattern of the polishing pad according to an exemplary embodiment of the present disclosure. 2 and 3, the polishing pad 10 may include a plurality of protruding patterns 100 and a support layer 200. As shown in FIG. Each of the plurality of protruding patterns 100 may include an extension surface 120 formed as a horizontal surface and side surfaces 180 substantially perpendicular to the extension surface 120 . To increase convective heat transfer, the contact area (A in Equation 1) may be increased, for example, by increasing the surface area of side 180 .

ここで、ｍは（ｈＰ／ｋＡ_ｃ）^１／２で定義されるフィンパラメータ、ｈは対流熱伝達率、Ｐは延長面１２０の周長、Ａ_ｃは延長面１２０の面積、ｋは突出パターン材料の伝導熱伝達率、Ｔ_ｂは延長面１２０の温度、Ｔ_∞はスラリーの温度である。対流熱伝達モデルのパラメータは、図４に示す通りである。 For each raised pattern 100, convective heat transfer can be calculated based on Equation 2 below.

Here, m is the fin parameter defined as (hP/kA _c ) ^1/2 , h is the convective heat transfer coefficient, P is the perimeter of the extension surface 120, A _c is the area of the extension surface 120, and k is the protrusion pattern. is the conductive heat transfer coefficient of the material, _Tb is the temperature of the extended surface 120, and _T∞ is the temperature of the slurry. The parameters of the convective heat transfer model are as shown in FIG.

According to an exemplary embodiment of the present disclosure, the protruding pattern 100 includes an extended surface 120 protruding from the support layer 200 such that the frictional heat generated at the extended surface 120 during the polishing process is transferred from the protruded pattern 100 to , can be more easily transferred to the slurry through the sides 180 of the protruding pattern 100 . Therefore, heat transfer efficiency can be improved.

FIG. 5 is a diagram showing representative modeling results of the amount of heat transfer for various geometries of a raised pattern of a polishing pad according to an exemplary embodiment of the present disclosure; More specifically, FIG. 5 shows that the convective heat transfer coefficient (h) of the slurry is 0.8 W/m ² K, the conductive heat transfer coefficient (k) of the protruding pattern 100 is 0.5 W/mK, and ΔT is It shows the modeling result of the amount of heat transfer (Q) performed at 50 K while changing the perimeter (P) and height (L) of the extension surface 120 . Referring to FIG. 5, as the perimeter (P) of the protruding pattern 100 increases and the height (L) of the protruding pattern 100 increases, the heat transfer amount (Q) increases. Therefore, in order to increase the amount of heat transfer for a given polishing pad area, the perimeter (P) and the height (L) of the protruded pattern 100 should be increased. As shown in FIG. 5, if the height (L) is greater than about 1000 μm, the effect is small, so the height (L) of the protruding pattern 100 may be about 1000 μm or less and about 10 μm or more.

As mentioned above, the convective heat resistance accounts for the majority of the overall thermal resistance, and the larger the surface area in contact with the slurry, the smaller the convective heat resistance. Q) can be considered. Therefore, the perimeter (P) may be increased with respect to the predetermined area (Ac) of the extension surface 120 . For example, the total perimeter of extended surface 120 within a unit area of 1 cm ² of polishing pad 10 may be greater than or equal to about 24 cm and less than or equal to about 2400 cm.

In order to increase the perimeter of the extended surface 120 per unit area of the polishing pad 10, the overall dimensions of the protruded pattern 100 may be reduced and/or the protruded pattern 100 may be formed in a particular geometric shape. may be formed. For example, the raised pattern 100 may include polygons such as triangles, squares, pentagons, hexagons, and the like. Also, the protruding pattern 100 may include a circle, an ellipse, or any free-form shape. Additionally, the raised pattern 100 may include features that are a combination of two or more features. In some embodiments, the protruding pattern 100 may include multiple unit patterns arranged separately from each other. Additionally or alternatively, the raised pattern 100 may include a plurality of unit patterns laterally linked together to form a network of unit patterns.

2, 6A, 6B, 7A, and 7B are diagrams showing protruding patterns 100 formed in various shapes. FIG. 2 shows a raised pattern 100 formed in squares, and FIG. 6A shows a cross pattern. Further, FIG. 6B shows a composite pattern of crosses and squares. As shown in FIG. 6B, the protruding pattern 100 may have non-uniform heights that vary locally within the unit pattern. In some embodiments, the perimeter (P) may be adjusted by increasing or decreasing the overall size of the same shape, as shown in Figures 7A and 7B. The shape of the protruding pattern 100 according to the present disclosure is not limited to the above examples, and may be variously determined to increase or decrease the perimeter (P) of the protruding pattern 100. FIG. The area ratio of the extension surface 120 to the polishing pad 10 may be about 1% or more and about 80% or less. For example, the area ratio of the extended surface 120 to the polishing pad 10 is about 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%. %, 60%, 65%, 70%, 75%, or 80%. Here, the area ratio of the extension surface 120 to the polishing pad 10 may mean the ratio of the total area of the extension surface 120 in the polishing pad 10 to the planar shape area of the polishing pad 10 . Similarly, the area ratio may be calculated as the total area of the extension surface 120 within the unit area of the polishing pad 10 .

According to an exemplary embodiment of the present disclosure, the support layer 200 may include a first support layer 210 and a second support layer 220, as shown in FIG. If the polishing pad 10 is uneven and the support layer 200 is rigid, the polishing pad 10 may exert uneven polishing pressure on an article of manufacture such as a wafer. The second support layer 220 may be made of a softer or more flexible material than the first support layer 210 to prevent the polishing pad 10 from exerting uneven polishing pressure on the article of manufacture. good. That is, the first support layer 210 may comprise a first material and the second support layer 220 may comprise a second material. The first material and the second material may be the same or different from each other, and the first hardness of the first material may be greater than or equal to the second hardness of the second material. For example, the second support layer 220 may comprise a foam material with porosity to provide the required range of hardness. The porosity of the foamed material may be from about 1% to about 80%. Alternatively, the foam material may have a porosity of greater than or equal to about 1% and less than or equal to about 70%. By forming the second support layer 220 with a material having a low hardness, it is possible to alleviate the discrepancy in the polishing pressure of the entire polishing pad 10 and improve the uniformity of the polishing process.

Alternatively, the first support layer 210 and the second support layer 220 may be made of the same material and configured to have different hardnesses. For example, the first support layer 210 and the second support layer 220 formed of the same material may include foam materials having different porosities. Alternatively or additionally, the first support layer 210 and the second support layer 220 may contain different additives to change the hardness of the material. The thickness of the first support layer 210 may be about 1500 μm or less. The thickness of the second support layer 220 may be greater than or equal to approximately 100 μm and less than or equal to approximately 3000 μm.

In some embodiments, support layer 200 may be formed as a single layer. In such embodiments, the protruding pattern 100 may comprise a first material and the support layer 200 may comprise a second material. The first material and the second material may be the same or different. In particular, the first hardness of the first material may be greater than the second hardness of the second material. In other words, the second hardness of the second material may be less than the first hardness of the first material so that the polishing pad 10 can apply more uniform pressure to the article of manufacture. . The first material of the protruding pattern 100 and the second material of the support layer 200 may be the same, while the support layer 200 may have a lower hardness due to different additives and/or structures.

Since the slurry contains about 90-99% water, the thermal properties of the slurry may be considered similar to those of water, which has a thermal conductivity of about 0.6 W/mK. As such, the thermal conductivity of the slurry may be relatively low and accordingly the convective heat transfer mode may dominate over the conductive heat transfer mode. Convective heat transfer may be affected by the type of flow (eg, laminar or turbulent regimes), and forced convection may enhance convective heat transfer more efficiently than natural convection. In the CMP process, the rotating polishing pad and the wafer move relative to each other while being maintained in a pressed state, which may force slurry to be supplied, discharged, mixed, and stirred. Such slurry movement can affect convective heat transfer.

Aspects of the present disclosure provide a polishing pad structure that allows slurry to move in a turbulent flow due to the microstructure of the polishing surface. For example, polishing pad 10 may include structures that allow the slurry to move rapidly, thereby allowing the slurry to contact more micropatterns and transfer heat more efficiently. Accordingly, at least one groove may be formed in the polishing pad surface to more effectively control slurry flow.

Referring again to FIG. 2, polishing pad 10 according to exemplary embodiments of the present disclosure may include grooves in support layer 200 to enhance slurry flow. For example, support layer 200 may include first groove 230 and second groove 240 . A first groove 230 may be formed in the first support layer 210 to divide the support layer 200 into multiple sections. A second groove 240 may be formed within the first groove to enhance slurry supply and discharge. The width of the second groove 240 may be narrower than the width of the first groove 230 . For example, the width of the second groove 240 may be from about 0.1 mm to about 0.5 mm (inclusive), or from about 2 mm to about 5 mm (inclusive). The depth of second groove 240 may be between about 1% and about 99% of the thickness of second support layer 220 . Alternatively, if support layer 200 is formed as a single layer, the grooves may be contained in a single layer of support layer 200 .

As noted above, first support layer 210 may comprise a first material and second support layer 220 may comprise a second material. The first material and the second material may be the same or different. In particular, the first hardness of the first material may be the same as or greater than the second hardness of the second material. Because the second material of the second support layer 220 is less rigid or more flexible, the pressing force is more evenly distributed on the polishing pad surface even if the polishing pad has irregularities and/or thickness variations. , thereby allowing articles of manufacture, such as wafers, to be polished more smoothly (eg, with higher flatness or higher uniformity). In other words, the softer second support layer 220 allows the first support layer 210 and/or the protruding pattern 100 to more closely follow the surface topology or geometry of the article of manufacture when the polishing pad 10 and article of manufacture are pressed. can make it possible to

In some embodiments, first support layer 210 may be divided into multiple independent sections by first grooves 230 . The first grooves 230 may allow the first support layer 210 to move in a more flexible manner by providing smaller divided sections. The depth of the first groove 230 may be determined such that the remaining thickness of the first support layer 210 below the first groove 230 is about 500 μm or less. The remaining thickness of the first support layer 210 may be defined as the distance between the top of the second support layer 220 and the bottom of the first groove 230 . In some embodiments, the remaining thickness of the first support layer 210 below the first grooves 230 may be zero, which means that the first grooves 230 extend through the entire thickness of the first support layer 210. indicates that it is formed. In such cases, the first support layer 210 may be divided into completely independent sections.

In some embodiments, the thickness of the first support layer 210 may be zero or near zero. In this example, the protruding pattern 100 may be substantially disposed on the second support layer 220. FIG. The second support layer 220 (or the single layer support layer 200) may be formed of a material with a lower hardness than the protruding patterns 100, so that each of the protruding patterns 100 may be the same as the second support layer 220. Its more conformable nature allows it to follow the surface of the article of manufacture individually.

For example, materials for first support layer 210 and/or second support layer 220 include polyurethane, polybutadiene, polycarbonate, polyoxymethylene, polyamide, epoxy, acrylonitrile butadiene styrene copolymer, polyacrylate, polyesterimide, acrylate, polyalkylene, polyethylene. , polyester, natural rubber, polypropylene, polyisoprene, polyalkylene oxide, polyethylene oxide, polystyrene, phenol resin, amine, urethane, silicone, acrylate, fluorene, phenylene, pyrene, azulene, naphthalene, acetylene, p-phenylenevinylene, pyrrole, Carbazole, indole, azepine, aniline, thiophene, 3,4-ethylenedioxysaiphene and p-phenylene sulfide and the like.

The first hardness of the first support layer 210 may be between and including about 30D and about 80D in Shore hardness. The second hardness of the second support layer 220 may be between (and including) about 20A and about 80A in Shore hardness. As mentioned above, in some embodiments, the protruding pattern 100 may be made of the same first material as the first support layer 210 . In that case, the first material may be a composite material that includes additives to enhance abrasiveness and/or hardness. For example, additives may include Teflon (registered trademark), graphene, carbon nanoparticles, and the like. In brief, the protruding pattern 100, the first support layer 210 and the second support layer 220 may be made of different materials, or two or more components may be made of the same material.

In some embodiments, the raised pattern 100 may include one or more additives to enhance hardness and/or wear resistance. Additionally, the protruding pattern 100 may be coated for increased wear resistance. As an example, one or more of Teflon, boron nitride, or carbon nanotubes may be included as additives and/or used as coating materials. The Teflon (registered trademark) coating can prevent or reduce deformation of the protruding pattern 100 due to heat during polishing by reducing thermal conductivity. Boron nitride can improve mechanical strength.

In the protruding pattern 100, wear can occur during the CMP process. Abrasion of the raised pattern 100 can lead to changes in the surface area of the raised pattern 100 that contacts the article of manufacture. To minimize contact area variation, the raised pattern 100 can be designed to minimize horizontal cross-sectional area variation. Here, the horizontal section of the protruding pattern 100 can be understood as a horizontal section perpendicular to the length direction or the protruding direction of the protruding pattern 100 . The longitudinal variation in horizontal cross-sectional area of the protruding pattern 100 may be equal to or less than about 50%. Further, the horizontal cross-sectional area of the protruding pattern 100 may vary by about 1% or less, about 5% or less, about 10% or less, or about 20% or less along the protrusion direction. Since the horizontal cross-sectional area of the protruded pattern 100 varies little, even if the length (L) of the protruded pattern 100 is gradually reduced due to wear of the protruded pattern 100, the effective distance between the polishing pad 10 and the article of manufacture is reduced. The contact area can be kept substantially constant.

FIG. 8 is representative experimental results of removal rates for various designs of polishing pads according to exemplary embodiments of the present disclosure. In these experiments, a cerium oxide slurry was used to polish the oxide layer of the wafer under various pressure and relative speed (represented by rotational speed) conditions. The horizontal axis of FIG. 8 represents the polishing rate (polishing
rate), and the vertical axis in FIG. 8 indicates the removal rate. Referring to FIG. 8, a polishing pad according to the present disclosure can exhibit a higher removal rate than conventional polishing pads in the related art under almost all conditions.

FIG. 9 compares temperature rise during a polishing process using a conventional pad in the related art and a polishing pad according to exemplary embodiments of the present disclosure. The horizontal axis of FIG. 9 represents polishing time, and the vertical axis of FIG. 9 represents temperature. Temperature data is presented in arbitrary units (AU), which correspond to voltage measurements from temperature sensors. AU can be interpreted as having a positive correlation with temperature. Referring to FIG. 9, a polishing pad according to an exemplary embodiment of the present disclosure exhibits a smaller temperature rise than conventional polishing pads in the related art for both silicon oxide polishing and silicon nitride (SiN) polishing. In particular, using a polishing pad according to an exemplary embodiment of the present disclosure reduced the temperature rise to about 17 AU (after 212 seconds), whereas using a conventional polishing pad in the related art had a temperature rise of about 23 AU (after 127 seconds). Experimental results show that polishing pads according to the present disclosure can provide higher polishing rates (see FIG. 8) and maintain lower temperatures for longer polishing times (see FIG. 9).

FIG. 10 is a diagram comparing polishing efficiency between a polishing pad according to an exemplary embodiment of the present disclosure and a conventional polishing pad in the related art. In FIG. 10, STI wafer with SKW3-2 pattern (HDP
CVD oxide) was used, and Dow Chemicals' polishing pad IC1010® was used as a conventional polishing pad in the related art. SP-20MD and SP-60MD represent polishing pads with raised patterns according to exemplary embodiments of the present disclosure. FIG. 10 shows that SP-20MD and SP-60MD polishing pads according to exemplary embodiments of the present disclosure can exhibit increased polishing efficiency over conventional IC1010 polishing pads. That is, the polishing rate of the top pattern is faster than the polishing rate of the bottom trench.

As described herein, the subject matter of the present disclosure provides designs and methods of manufacturing polishing pads with prominent patterns for CMP processes. Polishing pads according to the present disclosure can exhibit improved thermal stability during the CMP process while providing higher polishing rates. Further, a polishing pad according to the present disclosure can minimize changes in the surface roughness of the polishing pad over time. Accordingly, polishing pads according to the present disclosure can improve the reliability and reproducibility of polishing processes.

Although the present disclosure has been described in terms of specific matters such as specific components, the exemplary embodiments and drawings are provided merely to assist in the overall understanding of the present disclosure. Accordingly, the disclosure is not limited to the exemplary embodiments described herein. Various modifications and alterations may occur to those of ordinary skill in the art to which this disclosure pertains. The essence of this disclosure should not be limited to the exemplary embodiments described above, but rather the following claims and all equivalents or equivalents of the technical should be construed to be contained in

Claims (19)

a support layer;
a protruding pattern disposed on the support layer;
the protruding pattern comprises a horizontal extending surface and a vertical side surface;
the support layer comprises a first support layer and a second support layer, the first support layer disposed on the second support layer; and
A polishing pad in which the hardness of the first support layer and the hardness of the second support layer are different from each other. 2. The polishing pad according to claim 1, wherein the variation in horizontal cross-sectional area of said protruding pattern is 50% or less along the direction of protrusion. 2. The polishing pad according to claim 1, wherein the area ratio of said extension surface to said polishing pad is 1% or more and 80% or less. 2. The polishing pad according to claim 1, wherein said protruding pattern comprises a plurality of unit patterns arranged separately from each other. 2. The polishing pad of claim 1, wherein the protruding pattern comprises a plurality of unit patterns laterally connected to each other. 2. The polishing pad according to claim 1, wherein the total peripheral length of said extension surface within a unit area of 1 cm ^<2> of said polishing pad is 24 cm or more and 2400 cm or less. 2. The polishing pad according to claim 1, wherein the protruding pattern has a height of 10 [mu]m or more and 1000 [mu]m or less. 2. The polishing pad of claim 1, wherein the support layer comprises first grooves formed in the first support layer, the first grooves dividing the support layer into a plurality of sections. 9. The polishing pad of claim 8, wherein the remaining thickness of the first support layer below the first grooves is 500 [mu]m or less. The thickness of the first support layer is 1500 μm or less,
2. The polishing pad according to claim 1, wherein the second support layer has a thickness of 100 [mu]m or more and 3000 [mu]m or less. a support layer comprising a second groove formed within the first groove;
9. The polishing pad according to claim 8, wherein the width of the second groove is narrower than the width of the first groove. 2. The polishing pad of claim 1, wherein the support layer comprises grooves dividing the support layer into a plurality of sections. said first support layer comprising a first material and said second support layer comprising a second material;
2. The polishing pad according to claim 1, wherein the hardness of said first support layer is greater than or equal to the hardness of said second support layer. wherein the protruding pattern comprises a first material and the support layer comprises a second material;
2. The polishing pad according to claim 1, wherein the hardness of said first material is greater than or equal to the hardness of said second material. 2. The polishing pad of claim 1, wherein the second support layer comprises a porous foam material. The first hardness is Shore hardness 30D or more and Shore hardness 80D or less,
14. The polishing pad according to claim 13, wherein the second hardness is Shore hardness 20A or more and Shore hardness 80A or less. At least one of said first material or said second material is polyurethane, polybutadiene, polycarbonate, polyoxymethylene, polyamide, epoxy, acrylonitrile butadiene styrene copolymer, polyacrylate, polyetherimide, acrylate, polyalkylene, polyethylene, polyester , natural rubber, polypropylene, polyisoprene, polyalkylene oxide, polyethylene oxide, polystyrene, phenol resin, amine, urethane, silicone, acrylate, fluorene, phenylene, pyrene, azulene, naphthalene, acetylene, p-phenylene vinylene, pyrrole, carbazole, 17. The polishing pad of claim 16 selected from the group consisting of indole, azepine, aniline, thiophene, 3,4-ethylenedioxydiphene and p-phenylene sulfide. The first hardness is Shore hardness 30D or more and Shore hardness 80D or less,
15. The polishing pad according to claim 14, wherein the second hardness is Shore hardness 20A or more and Shore hardness 80A or less. At least one of said first material or said second material is polyurethane, polybutadiene, polycarbonate, polyoxymethylene, polyamide, epoxy, acrylonitrile butadiene styrene copolymer, polyacrylate, polyetherimide, acrylate, polyalkylene, polyethylene, polyester , natural rubber, polypropylene, polyisoprene, polyalkylene oxide, polyethylene oxide, polystyrene, phenol resin, amine, urethane, silicone, acrylate, fluorene, phenylene, pyrene, azulene, naphthalene, acetylene, p-phenylenevinylene, pyrrole, carbazole, 19. The polishing pad of claim 18 selected from the group consisting of indole, azepine, aniline, thiophene, 3,4-ethylenedioxydiphene and p-phenylene sulfide.

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