KR20240009471A - Polishing pads with improved pore structure - Google Patents

Abstract

Embodiments herein relate generally to polishing pads and methods of forming polishing pads. A method of forming a polishing pad includes the steps of (a) dispensing droplets of a pre-polymer composition and droplets of a sacrificial material composition on the surface of a previously formed print layer according to a predetermined droplet distribution pattern; do. The method includes (b) at least partially curing the dispensed droplets of the prepolymer composition to form a print layer. The method includes sequentially repeating steps (a) and (b) to (c) form an abrasive layer having a plurality of pore-features formed therein. The prepolymer composition includes a multifunctional acrylate component. The curing rate of droplets of a dispensed prepolymer composition comprising a multifunctional acrylate component when exposed to a first dose of electromagnetic radiation is greater than or equal to that of the multifunctional acrylate component when exposed to the same first dose of electromagnetic radiation. It is greater than the cure rate of a prepolymer composition without an acrylate component.

Description

Polishing pads with improved pore structure

[0001] Embodiments of the present disclosure relate generally to polishing pads and methods of manufacturing polishing pads, and more specifically, to polishing pads used for chemical mechanical polishing (CMP) of a substrate in an electronic device fabrication process. It's about fields.

[0002] Chemical mechanical polishing (CMP) is commonly used in the fabrication of high-density integrated circuits to planarize or polish layers of material deposited on a substrate. A typical CMP process involves contacting a layer of material to be planarized with a polishing pad and, in the presence of a polishing fluid containing abrasive particles, moving the polishing pad, the substrate, or both, thereby creating a gap between the material layer surface and the polishing pad. Includes causing relative movement. One common application of CMP in semiconductor device manufacturing is planarization of bulk films, such as pre-metal dielectric (PMD) or interlayer dielectric (ILD) polishing, where underlying two- or three-dimensional features are planarized. Recesses and protrusions are created on the surface of the layer to be formed. Other common applications of CMP in semiconductor device manufacturing include shallow trench isolation (STI) and interlayer metal interconnect formation, where CMP creates vias from the exposed surface (field) of a layer within which the STI or metal interconnect features are disposed. , used to remove contact or trench fill material.

[0003] Often, polishing pads used in the CMP processes described above are selected based on the material properties of the polishing pad material and the suitability of those material properties for the desired CMP application. One example of material properties that can be adjusted to tune the performance of a polishing pad for a desired CMP application includes the porosity and related properties of the polymer material used to form the polishing pad, such as pore size and structure, and the material surface. These are aperities. Methods for introducing porosity into a polishing pad material include molding and curing a pre-polymer composition into individual polishing pads or a polymer cake before machining, such as skiving, the individual polishing pads therefrom. It may include blending the prepolymer composition with a pore-forming agent, such as a water-soluble material or air.

[0004] Polishing pads can also be manufactured using techniques other than molding, such as through additive manufacturing. In the creation of polishing pads using additive manufacturing techniques, such as 3D printing, droplets of a prepolymer composition and droplets of a pore-forming agent can be spatially selectively deposited on multiple print layers to form the polishing pads. Unfortunately, additive manufacturing techniques cannot provide precise placement of pores within formed pads, but, especially for polishing pads formed of relatively softer materials, the interaction between adjacent droplets of pore-forming agent and prepolymer composition is reduced. Mixing results in poor structure of the resulting pores, which hinders performance-tuning opportunities that might otherwise arise therefrom.

[0005] Accordingly, there is a need in the art for methods of improving the pore structure within polishing pads formed by additive manufacturing techniques.

[0006] Embodiments described herein generally relate to polishing pads that can be used in a chemical mechanical polishing (CMP) process, and methods for manufacturing polishing pads. More specifically, embodiments herein provide polishing pads with improved pore structure, and additive manufacturing methods for forming polishing pads.

[0007] In one embodiment, a method of forming a polishing pad includes the steps of (a) dispensing droplets of a prepolymer composition and droplets of a sacrificial material composition on the surface of a previously formed print layer according to a predetermined droplet distribution pattern; . The method includes (b) at least partially curing the dispensed droplets of the prepolymer composition to form a print layer. The method includes (c) sequentially repeating steps (a) and (b) to form a polishing layer having a plurality of pore-features formed therein. The prepolymer composition includes a multifunctional acrylate component. The curing rate of droplets of a dispensed prepolymer composition comprising a multifunctional acrylate component when exposed to a first dose of electromagnetic radiation is greater than or equal to that of the multifunctional acrylate component when exposed to the same first dose of electromagnetic radiation. It is greater than the cure rate of a prepolymer composition without an acrylate component. The plurality of pore-features include openings defined in the surface of the polishing layer, voids formed in the polishing layer below the surface, pore-forming features comprising a sacrificial material composition, or combinations thereof.

[0008] In another embodiment, a method of forming a polishing pad includes the steps of (a) dispensing droplets of a prepolymer composition and droplets of a sacrificial material composition on the surface of a previously formed print layer according to a predetermined droplet distribution pattern; . The method includes (b) at least partially curing the dispensed droplets of the prepolymer composition to form a print layer comprising a plurality of pore-features. The method includes (c) sequentially repeating steps (a) and (b) to form an abrasive layer. The prepolymer composition includes a surface active agent. The volume of the pore-feature space of an individual pore-feature among the plurality of pore-features comprises at least 50% of the volume of the sacrificial material composition distributed to form the corresponding pore-features. The plurality of pore-features include openings defined in the surface of the polishing layer, voids formed in the polishing layer below the surface, pore-forming features comprising a sacrificial material composition, or combinations thereof.

[0009] In another embodiment, the polishing pad includes a plurality of polishing elements. Each polishing element includes an individual surface forming a portion of the polishing surface of the polishing pad, and one or more side walls extending downwardly from the individual surface to define a plurality of channels disposed between the polishing elements. Each of the polishing elements has a plurality of pore-features formed therein. Each of the abrasive elements is formed from a prepolymer composition and a sacrificial material composition. The volume of the pore-feature space of an individual pore-feature among the plurality of pore-features comprises at least 50% of the volume of the sacrificial material composition distributed to form the corresponding pore-features. The plurality of pore-features include openings defined in the polishing surface, voids formed in the polishing elements below the polishing surface, pore-forming features comprising a sacrificial material composition, or combinations thereof.

[0010] In such a way that the above-mentioned features of the present disclosure can be understood in detail, a more detailed description of the present disclosure briefly summarized above may be made with reference to examples, some of which are appended to the present disclosure. Illustrated in the drawings. However, it should be noted that the accompanying drawings illustrate only exemplary embodiments of the present disclosure and should not be considered limiting the scope of the present disclosure, as the present disclosure may permit other equally effective embodiments. Because you can.
[0011] Figure 1A is a schematic cross-sectional view illustrating a portion of a polishing layer of an example polishing pad.
[0012] FIG. 1B is a schematic cross-sectional view illustrating a design layout for a to-be-printed polishing layer of a polishing pad, such as the polishing pad of FIG. 1A.
[0013] Figure 2 is a schematic cross-sectional view illustrating a portion of a polishing layer of a polishing pad according to embodiments described herein.
[0014] Figure 3 is a schematic side view of an example polishing system configured to use a polishing pad formed in accordance with embodiments described herein.
[0015] Figure 4 is a schematic isometric cross-sectional view of a polishing pad featuring selectively arranged pores, according to embodiments described herein.
[0016] Figures 5A-5F are schematic top views of various polishing pad designs that may be used in place of the pad design shown in Figure 4, according to embodiments described herein.
[0017] Figure 6A is a schematic cross-sectional view of an additive manufacturing system that may be used to form the polishing pads described herein.
[0018] Figure 6B is a close-up cross-sectional view schematically illustrating a droplet disposed on the surface of a previously formed print layer, according to embodiments described herein.
[0019] Figure 7 is a flow diagram presenting a method of forming a polishing pad, according to embodiments described herein.
[0020] Figure 8 is a graph illustrating conversion-exposure curves for prepolymer compositions with and without a multifunctional acrylate component.
[0021] To facilitate understanding, identical reference numbers have been used where possible to designate identical elements that are common to the drawings. It is contemplated that elements and features of one implementation may be beneficially incorporated into other implementations without further recitation.

[0022] Embodiments described herein generally relate to polishing pads that can be used in a chemical mechanical polishing (CMP) process, and methods for manufacturing polishing pads. In particular, the polishing pads described herein feature improved pore structure compared to polishing pads formed using conventional methods.

[0023] The undesirable pore structure typically associated with polishing pads formed by conventional additive manufacturing techniques, particularly those formed using high-resolution printing and/or with relatively softer materials, is schematically illustrated in Figure 1A. do. 1A is a schematic cross-sectional view illustrating a portion of a polishing layer 102a of an example polishing pad. The abrasive material 104a of the abrasive layer 102a may include an insoluble polymer resulting from polymerization of droplets of the prepolymer composition. A plurality of pore-features 106a are formed in the abrasive material 104a by arranging droplets of the sacrificial material composition in combination with droplets of the prepolymer composition. Pore-features 106a may include openings defined in the polishing surface 108a of the polishing layer 102a. Here, the pore-features 106a are poorly defined, e.g., non-uniform diameter, non-uniform depth, non-uniform size distribution that varies across the pad, non-uniform shape, flat appearance in cross-section, e.g., parallel to the X-Y plane. or merging of abrasive material 104a across pore-features 106a in a vertical direction, discontinuities within each of pore-features 106a, and volumes of sacrificial material composition dispensed to form corresponding pore-features. has low pore-feature space as part of , and combinations thereof.

[0024] The polishing layer 102a may be formed according to the print design layout for the polishing layer 102b to be printed shown in FIG. 1B. In Figure 1B, each pore-feature to be printed 106b extends in the Z-direction through a number of print layers 110a-110k stacked one on top of the other. According to FIG. 1B, print layers 110a, 110c, 110e, and 110g have pores corresponding to droplets of sacrificial material composition 112 arranged adjacent to droplets of prepolymer composition comprising abrasive material 104b. Contains feature spaces. As shown, there is no pore-feature space in the Z-direction between print layers 110a, 110c, 110e, and 110g in an alternating arrangement, i.e., different print layers comprising only abrasive material 104b. (eg, 110b, 110d, and 110f) are interposed. Each pair of alternating print layers can have the same pattern so that droplets of prepolymer composition and sacrificial material composition are deposited at the same positions in each layer. Additional print layers (eg, 110h-110k) are disposed below print layer 110g. In some other embodiments, print layers 110a, 110c, 110e, and 110g containing pore-feature spaces are stacked in direct contact with each other, and print layers without pore-feature spaces (e.g., 110b, 110d, and 110f) is omitted. In such embodiments, droplets of sacrificial material composition 112 should be deposited at the same position in each layer such that the sacrificial material composition 112 is continuous within the individual pore-features 106b in the Z-direction. . The resulting pore-feature structure may be referred to as a “post”.

[0025] According to the design layout of FIG. 1B, the pore-features 106b may be distributed relative to each other (i.e., laterally) in one or both directions of the X-Y plane parallel to the polishing surface of the polishing pad. will be. Accordingly, at least some of the pore-features 106b should be spatially separated by at least some of the abrasive material 104b to be printed therebetween. That is, they must be spaced apart from each other. Pore-features 106b may be continuous with the polishing surface 108b to be printed.

[0026] Generally, the polishing layer 102b to be printed is designed to have well-defined pore-features, without any of the drawbacks apparent in the resulting polishing layer 102a described above. The poorly defined pore-features 106a shown in Figure 1A are believed to be the result of inter-mixing between adjacent droplets of the sacrificial material composition and the prepolymer composition prior to curing. Additionally, it is believed that inter-mixing may occur more easily during the fabrication of polishing pads using high-resolution printing and/or formed from relatively softer materials.

[0027] Advantageously, the embodiments described herein provide reduced inter-mixing between adjacent droplets of the prepolymer composition and the sacrificial material composition, thereby resulting in better defined pore-features compared to the example shown in Figure 1A. bring about In addition, reduced inter-mixing results in the formation of an abrasive layer 202, such as shown in FIG. 2, which more closely corresponds to the abrasive layer to be printed 102b shown in FIG. 1B.

[0028] 2 is a schematic cross-sectional view illustrating a portion of a polishing layer 202 of a polishing pad according to embodiments described herein. The abrasive material 204 of the abrasive layer 202 may include a hard or soft formulation, as described in more detail below. A plurality of pore-features 206 are formed in the abrasive material 204. Pore-features 206 include openings defined in the polishing surface 208 of the polishing layer 202, voids formed in the polishing material 204 below the polishing surface 208, and pores in the polishing surface 208. It may include disposed pore-forming features, pore-forming features disposed in the abrasive material 204 below the abrasive surface 208, and combinations thereof. Here, the pore-features 206 are well-defined, such as having a uniform diameter, uniform depth, uniform size distribution across the pad, uniform shape, rounded appearance in cross-section, and spacing between adjacent pore-features 206. Separation of the intervening abrasive material 204, continuity within each of the pore-features 206, high pore-feature spacing, pore-features as part of the volume of the sacrificial material composition dispensed to form the corresponding pore-features. less diffusion in the radial plane (e.g., in the X-Y plane) compared to pore-features 106a, reduced depth compared to pore-features 106a, and combinations thereof.

[0029] Embodiments described herein include the polarity of the components, the relative strength of the abrasive material (e.g., storage modulus or ultimate tensile strength), additives to adjust zeta potential, additives to tune water absorption, or mechanical properties. It provides a universal method for improving pore structure regardless of other aspects of the formulation, such as monomers to tune. Embodiments described herein improve pore structure even for high resolution printing, such as 300 dpi or 600 dpi. Embodiments described herein provide polishing pads with improved surface hardening that can reduce surface tack. Embodiments described herein provide polishing pads with reduced concentrations of potentially harmful residual monomers. Embodiments described herein provide polishing pads with reduced internal structural stress levels that can improve the flatness of polishing pads.

[0030] Embodiments described herein provide improved pore structure even for polishing pads formed using relatively soft material formulations. During a conventional pad fabrication process, due to the greater hydrophilicity of soft abrasive material formulations, the prepolymer droplets of soft abrasive material formulations are less likely to inter-mix with adjacent droplets of sacrificial material compared to hard material formulations. It is believed to be experiencing increasing problems. However, the embodiments described herein overcome the challenge of maintaining pore structure even with more hydrophilic formulations.

[0031] Embodiments described herein provide prepolymer compositions comprising a multifunctional acrylate component that increase the cure rate of droplets of the dispensed prepolymer composition when exposed to a dose of electromagnetic radiation. In other words, the cure rate of the prepolymer composition with the multifunctional acrylate component is greater than the cure rate of the prepolymer composition without the multifunctional acrylate component when exposed to the same dose of electromagnetic radiation. Advantageously, the accelerated curing of the prepolymer composition in the embodiments described herein results in inter-mixing between adjacent droplets of the sacrificial material composition and the prepolymer composition when compared to a prepolymer composition without the multifunctional acrylate component. reduce.

[0032] Advantageously, the embodiments described herein provide a prepolymer composition comprising a surface active agent that reduces inter-mixing between adjacent droplets of the sacrificial material composition and the prepolymer composition when compared to a prepolymer composition not comprising a surface active agent. provides.

[0033] Embodiments described herein provide sacrificial material compositions comprising a polyethylene glycol monoacrylate component that reduces the fluidity of the resulting pore-forming phase after curing. Advantageously, the reduced fluidity in the embodiments described herein improves the structure of the resulting pore-features when compared to polishing pads formed without a polyethylene glycol monoacrylate component.

[0034] Embodiments described herein generally relate to chemical mechanical polishing (CMP) pads used in semiconductor device manufacturing, but the polishing pads and methods of manufacturing the same include chemically active and chemically inert polishing fluids and/or abrasive particles. It is also applicable to other polishing processes using both polishing fluids. Additionally, embodiments described herein, alone or in combination, may be useful in at least the following industries: aerospace, ceramics, hard disk drive (HDD), MEMS and nano-technology, metal processing, optics and electro-optics, among others. It can be used in manufacturing, and semiconductor device manufacturing.

Exemplary Polishing System

[0035] 3 is a schematic side view of an example polishing system 300 configured to use a polishing pad 400 formed in accordance with embodiments described herein. Polishing pad 400 is further described in FIG. 4 .

[0036] Here, the polishing system 300 features a platen 304 to which a polishing pad 400 is secured using a pressure sensitive adhesive, and a substrate carrier 306. The substrate carrier 306 faces the platen 304 and the polishing pad 400 mounted on the platen 304. The substrate carrier 306 is used to press the material surface of the substrate 308 placed on the substrate carrier 306 against the polishing surface of the polishing pad 400 while rotating about the carrier axis 310. . Typically, the platen 304 rotates about the platen axis 312 while the rotating substrate carrier 306 sweeps back and forth from the inner diameter of the platen 304 to the outer diameter of the polishing pad 400. Partially reduces uneven wear.

[0037] Polishing system 300 further includes a fluid transfer arm 314 and a pad conditioner assembly 316. The fluid transfer arm 314 is positioned above the polishing pad 400 and is used to deliver a polishing fluid, such as a polishing slurry with abrasives suspended therein, to the surface of the polishing pad 400. Typically, the polishing fluid contains a pH adjuster and other chemically active ingredients, such as oxidizing agents, to enable chemical mechanical polishing of the material surface of the substrate 308. The pad conditioner assembly 316 applies a fixed abrasive conditioning disk 318 to the surface of the polishing pad 400 before polishing the substrate 308, after polishing the substrate 308, or during polishing of the substrate 308. It is used to condition the polishing pad 400 by applying pressure. Pressing the conditioning disk 318 against the polishing pad 400 includes rotating the conditioning disk 318 about the conditioner axis 320 and rotating the conditioning disk 318 from the inner diameter of the platen 304. It includes sweeping to the outer diameter of the platen (304). Conditioning disk 318 is used to polish and revitalize the polishing surface of polishing pad 400 and to remove polishing by-products or other debris from the polishing surface of polishing pad 400.

Polishing Pad Examples

[0038] Polishing pads described herein include a base layer and a polishing layer disposed on the base layer. The polishing layer forms the polishing surface of the polishing pad, and the foundation layer provides support for the polishing layer when the substrate to be polished is pressed against it. The base layer and the polishing layer are formed from different prepolymer compositions that, when cured, have different material properties. The base layer and polishing layer are formed integrally and sequentially using a continuous layer-by-layer additive manufacturing process. The additive manufacturing process provides a polishing pad body with a continuous polymer phase between the polishing layer and the foundation layer, thereby eliminating the need for an adhesive layer or other bonding method between the polishing layer and the foundation layer. In some embodiments, the polishing layer is formed of a plurality of polishing elements, the plurality of polishing elements being separated from each other across the polishing surface by recesses and/or channels disposed therebetween.

[0039] As used herein, the term “pore-features” refers to openings defined in the polishing surface, voids formed in the polishing material below the polishing surface, pore-forming features disposed on the polishing surface, pore-forming features disposed on the abrasive material, and combinations thereof. Pore-forming features typically include a water-soluble sacrificial material that dissolves upon exposure to the polishing fluid, forming corresponding openings in the polishing surface and/or voids in the polishing material beneath the polishing surface. In some embodiments, the water-soluble sacrificial material may swell upon exposure to the polishing fluid, deforming the surrounding polishing material and providing irregularities on the polishing pad material surface. The resulting pores and irregularities preferably allow transport of liquid and abrasives to the interface between the polishing pad and the material surface to be polished of the substrate, and to enable chemical and mechanical material removal from the substrate surface. Temporarily fixes such abrasives (abrasive capture).

[0040] As used herein, the term “pore-feature space” refers to the volume of each pore-feature. When multiple pore-features are merged together, the boundary lines defining the pore-feature space of each individual pore-feature can be determined according to the corresponding design layout for the abrasive layer to be printed. For example, when two pore-features are merged together, the average distance between the pore-features to be printed can be used as the boundary line between the merged pore-features.

[0041] As used herein, the term “pore-feature density” refers to the cumulative area comprising pore-features in the X-Y plane of a given sample, as a percentage of the total area of a given sample in the Pore-feature density within a surface or in the X-Y plane parallel to the polishing surface of the polishing pad refers to the cumulative area containing pore-features in micro-zones. As used herein, the term “porosity” refers to the volume of pore-feature space as a percentage of the total bulk volume within a given sample. In embodiments where the pore-feature as defined herein includes a pore-forming feature formed from a sacrificial material, the pore-feature density and porosity are measured after the sacrificial material forming the feature has dissolved therefrom.

[0042] Pore-feature density, pore-feature spacing, pore-feature structure, porosity, and pore size can be determined using any suitable method, such as those using scanning electron microscopy (SEM) or optical microscopy. . Techniques and systems for characterizing pore-feature density, porosity, and pore size are well known in the art. For example, a portion of the surface can be characterized by any suitable method (eg, electron microscopy image analysis, atomic force microscopy, 3D microscopy, etc.). In one embodiment, pore-feature density and pore size analysis is performed using a VK-X Series 3D UV Laser Scanning Confocal Microscope manufactured by KEYence Corporation of America, Elmwood Park, NJ, USA. It can be performed using a Scanning Confocal Microscope.

[0043] In some embodiments, the polishing material of the polishing pad may be formed of different prepolymer compositions, or different ratios of different prepolymer compositions, to provide unique material properties.

[0044] Generally, the methods described herein use an additive manufacturing system, such as a 2D or 3D inkjet printer system, to form (print) at least portions of the polishing pads in a layer-by-layer process. Typically, each print layer is formed (printed) by sequentially depositing and at least partially curing droplets of the desired prepolymer compositions and/or pore-forming sacrificial material precursor compositions on a fabrication support or previously formed print layer. . Advantageously, the additive manufacturing systems and methods described herein provide at least micron-scale droplet placement control (X-Y resolution) within each print layer, as well as micron-scale (0.1 μm to 200 μm) control over the thickness of each print layer ( Z resolution) is possible. The micron scale X-Y and Z resolutions provided by the additive manufacturing systems and methods presented herein enable the formation of desirable and repeatable patterns of pore-features described herein. Accordingly, in some embodiments, additive manufacturing methods used from polishing pads also impart one or more unique structural characteristics to polishing pads formed from the polishing pads.

[0045] As used herein, the term “high-resolution printing” refers to pore-features formed by up to four contiguous droplets, such as one to four contiguous droplets, of a sacrificial material composition. With high-resolution printing, negative changes in pore structure associated with inter-mixing between droplets of prepolymer composition and sacrificial material composition are more pronounced, as the dimensions of the pore-features are substantially reduced compared to low-resolution printing. Because.

[0046] 4 is a schematic isometric cross-sectional view of a polishing pad 400 featuring selectively arranged pore-features 410, according to embodiments described herein. Polishing pad 400 may be used as the polishing pad 400 of the example polishing system 300 illustrated in FIG. 3 . Here, the polishing pad 400 includes a plurality of polishing elements 404 , where the plurality of polishing elements 404 are disposed on and partially within the foundation layer 406 . The additive manufacturing process allows for the copolymerization of different prepolymer compositions used to form the base layer 406 and the abrasive layer comprising the abrasive elements 404, respectively, thereby creating an interfacial boundary between the abrasive layer and the base layer 406. It provides a continuous phase of polymer material across the zones.

[0047] The polishing pad 400 has a first thickness T(1) of about 5 mm to about 30 mm. The abrasive elements 404 polish the pad 400 by a portion of the base layer 406 having a second thickness T(2) that is about one-third to about two-thirds the first thickness T(1). ) is supported in the thickness direction. Abrasive elements 404 have a third thickness T(3) that is about one-third to about two-thirds of the first thickness T(1). As shown, at least portions of the polishing elements are disposed below the surface of base layer 406, with remaining portions extending upwardly therefrom by a height H. In some embodiments, the height H is less than or equal to about 1/2 the first thickness T(1).

[0048] Here, the plurality of abrasive elements 404 are disposed around the post 405 and include a plurality of discontinuous (segmented) concentric rings 407 extending radially outward from the post 405 . Here, the post 405 is disposed at the center of the polishing pad 400. In other embodiments, the center of the post 405 and thus the center of the concentric rings 407 may be positioned to achieve a relative wiping type between the polishing pad surface and the substrate as the polishing pad 400 rotates relative to the polishing platen. It may be offset from the center of the polishing pad 400 to provide motion. The side walls of the plurality of polishing elements 404 and the upward surface of the foundation layer 406 are between the surface of the foundation layer 406 and the plane of the polishing surface 401 of the polishing pad 400 and the polishing elements 404 ) defines a plurality of channels 418 disposed on the polishing pad 400 between each. The plurality of channels 418 enable distribution of polishing fluids across the polishing pad 400 and to the interface between the polishing pad 400 and the material surface of the substrate to be polished on the polishing pad 400. Here, the abrasive elements 404 have a top surface parallel to the X-Y plane and side walls that are substantially perpendicular, such as within about 20° of vertical (perpendicular to the The width W(1) of the abrasive element(s) 404 is between about 250 microns and about 10 millimeters, such as between about 250 microns and about 5 millimeters, or between about 1 mm and about 5 mm. The pitch (P) between the abrasive element(s) 404 is about 0.5 millimeters to about 5 millimeters. In some embodiments, one or both of width W(1) and pitch P vary across the radius of polishing pad 400 to define zones of pad material properties.

[0049] The polishing elements 404 include a plurality of pore-features 410 disposed on the polishing elements 404 . The plurality of pore-features 410 may be arranged in any desired vertical arrangement when viewed in cross-section. For example, in Figure 4, a plurality of pore-features 410 are arranged vertically in columnar arrangements (two columns are shown), wherein each of the columns pore-features 410 is substantially vertically aligned. In some other examples, individual rows or groups of rows of pore-features 410 in the depth direction of abrasive elements 404 are offset in one or both of the X-Y directions, above and/or above. Corresponding pore-features 410 may be provided below the polishing surface 401 , staggered perpendicularly to the pore-features 410 disposed below. The orientation of the pore-features 410 can advantageously be used to adjust the compliance of the polishing material with respect to the direction of the load applied by the substrate being polished on top. Accordingly, in one example, staggered pore-features 410 may be advantageously used to adjust and/or control the polishing planarization performance of a polishing pad formed therefrom.

[0050] In some embodiments, individual pore-features 410 are about 600 μm or less, such as about 500 μm or less, about 400 μm or less, about 300 μm or less, about 200 μm or less, about 100 μm or less, about 50 μm or less. Hereinafter, it may have a height of about 40 μm or less, about 30 μm or less, about 20 μm or less, or about 10 μm or less. The height of the individual pore-features 410 is typically a multiple of the thickness of each of the print layers, such as 1X or greater. For example, the thickness of the pore-features in the print layer can be equal to the thickness of the continuous polymer phase of the abrasive material disposed adjacent to the print layer. Accordingly, if the laterally disposed pore-features in at least two sequentially deposited print layers are aligned or at least partially overlap in the Z-direction, the resulting thickness of the pore-features will be at least equal to that of at least two sequentially deposited print layers. It is the combined thickness of the printed layers. In some embodiments, one or more of the pore-features do not overlap the pore-features of an adjacent layer disposed above or below it, and thus have the thickness of a single printed layer.

[0051] In some embodiments, individual pore-features 410 are about 600 μm or less, such as about 500 μm or less, about 400 μm or less, about 300 μm or less, about 200 μm or less, about 100 μm or less, about 50 μm or less. , about 40 μm or less, about 30 μm or less, about 20 μm or less, or about 10 μm or less to about 5 μm or more, such as about 10 μm or more, about 25 μm or more, or about 50 μm or more in diameter (D) (X-Y measured in a plane). In some embodiments, the average diameter (D) of individual pore-features 410 is between about 50 μm and about 600 μm. In some embodiments, pore-features 410 are formed relatively narrow in the X-Y plane compared to the height of pore-features 410, such as, in some embodiments, the diameter (D ) is less than about 2/3, such as less than about 1/2, or less than about 1/3, than the height of the individual pore-features.

[0052] Here, individual pore-features of the plurality of pore-features 410 are vertically spaced apart by one or more printed layers of polymer material 412 formed therebetween. In some examples, the spacing between vertical pore-features 410 may be less than or equal to about 100 μm, such as less than or equal to about 40 μm, such as less than or equal to about 10 μm, or between about 10 μm and about 40 μm. Pore-features 410 may form a substantially closed-cell structure once the sacrificial material used to form the pore-features is removed from the pore-features. In one example, the spacing between pore-features 410 may be approximately 40 μm in the vertical direction. A 40 μm gap can be formed by placing four 10 μm printed layers of polymer material 412 between the printed layers containing pore-features 410. In another example, the spacing between pore-features 410 may be about 10 μm in the vertical direction. A 10 μm gap can be formed by placing four 2.5 μm printed layers of polymer material 412 between the printed layers containing pore-features 410.

[0053] In other embodiments, one or more of the pore-features 410, or portions thereof, are not spaced apart from one or more of the pore-features 410 adjacent thereto, such that once the sacrificial material is in the pore-features When removed from 410, it forms a more open cell structure. The thickness of one or more printed layers may be at least about 5 μm, such as at least about 10 μm, at least 20 μm, at least 30 μm, at least 40 μm, or at least 50 μm. The individual pore-features 410 may be formed within a corresponding single print layer and thus have a height corresponding to the thickness of the print layer, or may be formed within two or more adjacent print layers to provide an accumulation of print layers. Pore height corresponding to thickness can be provided.

[0054] Abrasive elements 404 are formed from a continuous polymer phase of polymer material 412. Polymeric material 412 may have a relatively low storage modulus (E') (i.e., a soft pad material), a relatively high storage modulus (E') (i.e., a hard pad material), or a relatively low storage modulus (E'). It may have a relatively intermediate storage modulus (E') between that modulus and a relatively high storage modulus (i.e., an intermediate pad material). In some examples, polymeric material 412 may have a generally homogeneous material composition. In some other examples, polymeric material 412 may include at least two prepolymer compositions, thereby providing a combination of low, medium, or high storage modulus (E') materials that differ from each other in one or more material properties. It can be included. Characterizations of low, medium and high storage modulus (E') (E'30) materials at a temperature of about 30° C. are summarized in Table 1.

Table 1

[0055] FIGS. 5A-5F are schematic top views of various polishing element 504a-504f shapes that may be used in conjunction with or instead of polishing elements 404 of polishing pad 400 described in FIG. 4. 5A-5F each are pixel charts with white regions (regions of white pixels) representing polishing elements 504a-504f and black regions (regions of black pixels) representing base layer 406. Includes.

[0056] In Figure 5A, polishing elements 500a include a plurality of concentric annular rings. 5B, polishing elements 500b include a plurality of segments of concentric annular rings. In FIG. 5C , polishing elements 504c form a plurality of spirals (four are shown) extending from the center of polishing pad 500c to or near the edge of polishing pad 500c. 5D, a plurality of discontinuous polishing elements 504d are arranged in a spiral pattern on the foundation layer 406 of the polishing pad 500d.

[0057] In FIG. 5E , each of the plurality of polishing elements 504e includes a cylindrical post extending upwardly from the base layer 406 . In other embodiments, the abrasive elements 504e may be of any suitable cross-sectional shape, such as toroidal, partially toroidal (e.g., arc) in a section cut generally parallel to the underside surface of pad 500e. , have columns having oval, square, rectangular, triangular, polygonal, irregular shapes, or combinations thereof. FIG. 5F illustrates a polishing pad 500f having a plurality of distinct polishing elements 504f extending upwardly from the base layer 406. Polishing pad 500f of FIG. 5F is similar to polishing pad 500e except that some of the polishing elements 504f are connected to form one or more closed circles. One or more closed circles create dams to retain the polishing fluid during the CMP process.

Additive Manufacturing Systems and Process Examples

[0058] 6A is a schematic cross-sectional view of an additive manufacturing system that may be used to form polishing pads described herein, according to some embodiments. Here, the additive manufacturing system 600 features a movable manufacturing support 602, a plurality of dispensing heads 604 and 606 disposed on the manufacturing support 602, a curing source 608, and a system controller 610. do. In some embodiments, the dispense heads 604 and 606 move independently of each other and independently of the manufacturing support 602 during the polishing pad manufacturing process. Here, the first and second dispensing heads 604 and 606 dispense, respectively, a first prepolymer composition 612 used to form the polymer material 412 and pore-features 410 described in FIG. 4 above. ) Source and sacrificial material 614 is fluidly coupled to the source. Typically, the additive manufacturing system 600 includes at least one dispensing head (e.g., a third dispensing head not shown) fluidly coupled to the second prepolymer composition source used to form the base layer 406 described above. ) is characterized. In some embodiments, additive manufacturing system 600 includes as many dispensing heads as desired to each dispense a different prepolymer composition or sacrificial material precursor composition. In some embodiments, the additive manufacturing system 600 further includes a plurality of dispensing heads, where two or more dispensing heads are configured to dispense identical prepolymer compositions or sacrificial material precursor compositions.

[0059] Here, the dispensing heads 604, 606 each have droplet ejection nozzles configured to eject droplets 630, 632 of the respective prepolymer composition 612 and sacrificial material composition 614 to be delivered to the dispensing head reservoirs. It features an array of (616). Here, droplets 630 , 632 are ejected toward the manufacturing support and thus onto the manufacturing support 602 or onto a previously formed print layer 618 disposed on the manufacturing support 602 . Typically, each of the dispensing heads 604, 606 is a separate geometric array or It is configured to fire the droplets 630 and 632 in a pattern (control the ejection of the droplets 630 and 632). Herein, the nozzles 616 independently follow a droplet distribution pattern for the print layer to be formed, such as print layer 624, as the distribution heads 604, 606 move relative to the fabrication support 602. It fires. Once dispensed, droplets 630 of prepolymer composition 612 and/or droplets 632 of sacrificial material composition 614 are applied to a curing source 608, e.g., a print layer, such as a partially formed print layer 624. It is at least partially cured by exposure to electromagnetic radiation, such as UV radiation 626, provided by an electromagnetic radiation source, such as a UV radiation source, to form the layer.

[0060] In some embodiments, dispensed droplets of prepolymer compositions, such as dispensed droplets 630 of prepolymer composition 612, are physically separated from the droplets before they spread to an equilibrium size, as shown in the illustration of FIG. 6B. It is exposed to electromagnetic radiation to fix it. Typically, dispensed droplets are dispensed within one second or less of droplet contact with a surface, such as a previously formed print layer 618 disposed on fabrication support 602, or with the surface of fabrication support 602. The droplets are exposed to electromagnetic radiation to at least partially cure the prepolymer compositions.

[0061] FIG. 6B is an enlarged cross-sectional view schematically illustrating a droplet 630 disposed on a surface 618a of a previously formed layer, such as the previously formed layer 618 described in FIG. 6A , according to some embodiments. In a typical additive manufacturing process, a droplet of prepolymer composition, such as droplet 630a, spreads within about one second from the moment in time the droplet 630a contacts the surface 618a of a previously formed layer to form a surface. (618a) and reaches the equilibrium contact angle (α). The equilibrium contact angle (α) is, at least, a function of the material properties of the prepolymer composition and the energy (surface energy) at the surface 618a of a previously formed layer, such as previously formed layer 618. In some embodiments, it is desirable to at least partially cure the dispensed droplet before it reaches equilibrium size in order to fix the contact angle of the droplet with the surface 618a of the previously formed layer. In such embodiments, the contact angle θ of a stationary droplet 630b is greater than the equilibrium contact angle α of a droplet 630a of the same prepolymer composition allowed to spread to its equilibrium size.

[0062] Herein, at least partially curing a dispensed droplet causes at least partial polymerization, such as crosslinking, of the prepolymer composition(s) within the droplets and with adjacently placed droplets of the same or different prepolymer composition, Forms a continuous polymer phase. In some embodiments, the prepolymer compositions are dispensed and at least partially cured to form a well around the desired pore before the sacrificial material composition is dispensed into the desired pore.

Formulation and Ingredient Examples

[0063] The prepolymer compositions used to form the polymer material 412 and base layer 406 of the abrasive elements described above include functional polymers, functional oligomers, functional monomers, reactive diluents, and photoinitiators, respectively. Contains a mixture of one or more of the following:

[0064] Examples of suitable functional polymers that can be used to form one or both of the at least two prepolymer compositions include multifunctional acrylates, including di, tri, tetra and higher functional acrylates, such as 1, Includes 3,5-triacryloylhexahydro-1,3,5-triazine or trimethylolpropane triacrylate.

[0065] Examples of suitable functional oligomers that can be used to form one or both of the at least two prepolymer compositions include mono- and multi-functional oligomers, acrylate oligomers such as aliphatic urethane acrylate oligomers, aliphatic hexa-functional Polyurethane acrylate oligomers, diacrylates, aliphatic hexa-functional acrylate oligomers, multifunctional urethane acrylate oligomers, aliphatic urethane diacrylate oligomers, aliphatic urethane acrylate oligomers, aliphatic diacrylate oligomers Aliphatic polyester urethane diacrylate blends, or combinations thereof, such as bisphenol-A ethoxylate diacrylate or polybutadiene diacrylate, tetrafunctional acrylated polyester oligomers, aliphatic polyester based urethane diacrylates Includes oligomers and aliphatic polyester based acrylates and diacrylates.

[0066] Examples of suitable monomers that can be used to form one or both of the at least two prepolymer compositions include both monofunctional and multifunctional monomers. Suitable monofunctional monomers include tetrahydrofurfuryl acrylate (e.g., SR285 from ^Sartomer® ), tetrahydrofurfuryl methacrylate, vinyl caprolactam, isobornyl acrylate, isobornyl methacrylate, 2-phenoxy Ethyl acrylate, 2-phenoxyethyl methacrylate, 2-(2-ethoxyethoxy)ethyl acrylate, isooctyl acrylate, isodecyl acrylate, isodecyl methacrylate, lauryl acrylate, lauryl Methacrylates, stearyl acrylate, stearyl methacrylate, cyclic trimethylolpropane formal acrylate, 2-[[(butylamino) carbonyl]oxy]ethyl acrylate (e.g., Genomer 1122 from RAHN USA Corporation) ), 3,3,5-trimethylcyclohexane acrylate, or monofunctional methoxylated PEG (350) acrylate. Suitable multifunctional monomers are diacrylates or dimethacrylates of diols and polyether diols, such as propoxylated neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol. Dimethacrylate, 1,3-butylene glycol diacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, alkoxylated aliphatic Diacrylates (e.g. SR9209A from Sartomer ^® ), diethylene glycol diacrylate, diethylene glycol dimethacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, triethylene glycol dimethacrylate, Alkoxylated hexanediol diacrylates, or combinations thereof, such as SR562, SR563, SR564 from ^Sartomer® .

[0067] Typically, the reactive diluents used to form one or more of the prepolymer compositions are minimally monofunctional and undergo polymerization when exposed to free radicals, Lewis acids and/or electromagnetic radiation. Examples of suitable reactive diluents include monoacrylates, 2-ethylhexyl acrylate, octyldecyl acrylate, cyclic trimethylolpropane formal acrylate, caprolactone acrylate, isobornyl acrylate (IBOA), or alkoxylated lauryl. Contains methacrylates.

[0068] Examples of suitable photoinitiators used to form one or more of the at least two different prepolymer compositions include polymeric photoinitiators and/or oligomeric photoinitiators, such as benzoin ethers, benzyl ketals, acetyl phenones, alkyl phenones, phosphatase pin oxides, thioxanthone compounds including amine synergists, and benzophenone compounds, or combinations thereof.

[0069] Examples of polishing pad materials formed from the prepolymer compositions described above typically include polyamides, polycarbonates, polyesters, polyether ketones, polyethers, polyoxymethylenes, polyether sulfone, polyetherimide. , polyimides, polyolefins, polysiloxanes, polysulfones, polyphenylenes, polyphenylene sulfides, polyurethanes, polystyrene, polyacrylonitriles, polyacrylates, polymethylmethacrylates , polyurethane acrylates, polyester acrylates, polyether acrylates, epoxy acrylates, polycarbonates, polyesters, melamines, polysulfones, polyvinyl materials, acrylonitrile butadiene styrene ( ABS), halogenated polymers, block copolymers, and random copolymers thereof, and combinations thereof. do.

[0070] Sacrificial material composition(s) that can be used to form the pore-features 410 described above include water-soluble materials such as glycols (e.g., polyethylene glycols), glycol-ethers, and amines. Examples of suitable sacrificial material precursors that can be used to form the pore forming features described herein include ethylene glycol, butanediol, dimer diol, propylene glycol-(1,2) and propylene glycol-(1,3), octane-1. ,8-diol, neopentyl glycol, cyclohexane dimethanol (1,4-bis-hydroxymethylcyclohexane), 2-methyl-1,3-propane diol, glycerin, trimethylolpropane, hexanediol-(1, 6), hexanetriol-(1,2,6) butane triol-(1,2,4), trimethylolethane, pentaerythritol, quinitol, mannitol and sorbitol, methyl glycoside, also diethylene glycol, Triethylene glycol, tetraethylene glycol, polyethylene glycols, dibutylene glycol, polybutylene glycols, ethylene glycol, ethylene glycol monobutyl ether (EGMBE), diethylene glycol monoethyl ether, ethanolamine, diethanolamine (DEA) ), triethanolamine (TEA), and combinations thereof.

[0071] In some embodiments, the sacrificial material precursor is a water-soluble polymer, such as 1-vinyl-2-pyrrolidone, vinylimidazole, polyethylene glycol diacrylate, acrylic acid, sodium styrenesulfonate, Hitenol BC10 ^® , Maxemul 6106 ^® , hydroxyethyl acrylate and [2-(methacryloyloxy)ethyltrimethylammonium chloride, sodium 3-allyloxy-2-hydroxy-1-propanesulfonate, sodium 4-vinylbenzenesulfonate, [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide, 2-acrylamido-2-methyl-1-propanesulfonic acid, vinylphosphonic acid, allyltriphenylphosphonium Chloride, (vinylbenzyl)trimethylammonium chloride, allyltriphenylphosphonium chloride, (vinylbenzyl)trimethylammonium chloride, E-SPERSE RS-1618, E-SPERSE RS-1596, methoxy polyethylene glycol monoacrylate, methoxy polyethylene Glycol diacrylate, methoxy polyethylene glycol triacrylate, or combinations thereof.

Exemplary Prepolymer Compositions - Multifunctional Acrylate Component

[0072] In some examples, prepolymer composition 612 may contain a multifunctional acrylate component, such as tripropylene glycol diacrylate, poly(propylene glycol) diacrylate (e.g., in the range of about 350 g/mol to about 2000 g/mol). having a molecular weight), trimethylol triacrylate, neopentyl glycol diacrylate, ethoxylated neopentyl glycol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, or combinations thereof. In some examples, the multifunctional acrylate component is at least one having a molecular weight of at least about 200 g/mol, at least about 350 g/mol, or at least about 600 g/mol, such as from about 350 g/mol to about 2000 g/mol. It may include diacrylate or triacrylate. In some examples, the concentration of the multifunctional acrylate component in the prepolymer composition 612 may be about 20 wt% or less, such as about 10 wt% or less, or about 10 wt% to about 20 wt%. In some examples, prepolymer composition 612 further includes at least one of phenoxyethyl acrylate, tetrahydrofurfuryl acrylate, butylcarbamatetoethyl acrylate, isobornyl acrylate, or combinations thereof.

[0073] In some examples, the cure rate of droplets 630 of dispensed prepolymer composition 612 comprising a multifunctional acrylate component when exposed to a first dose of electromagnetic radiation is When exposed, the cure rate is greater than that of the prepolymer composition 612 without the multifunctional acrylate component. In some examples, the prepolymer composition 612, when cured, has a density of less than 100, less than 90, less than 80, less than 70, less than 60, less than 50, less than 40, less than 30, less than 20, or less than 10, or 0 to about 20. , can form a polymer having a Shore A hardness of about 20 to about 40, about 40 to about 60, about 60 to about 80, or about 80 to about 100.

[0074] In some examples, at least partial curing of the dispensed droplets 630 of the prepolymer composition 612 comprises exposing the dispensed droplets 630 to electromagnetic radiation for a first period of time from about 2 seconds to about 4 seconds. wherein the cure rate of the prepolymer composition 612 having the multifunctional acrylate component corresponds to about 50% to about 70% conversion of the multifunctional acrylate component during the first period of time.

[0075] In some examples, the pore-feature space volume of an individual pore-feature among the plurality of pore-features 410 is at least 50% greater than the volume of the sacrificial material composition 614 dispensed to form the corresponding pore-features 410. %, at least 60%, at least 70%, at least 80%, or at least 90%, or about 50% to about 60%, about 60% to about 70%, about 70% to about 80%, about 80% to about 90% %, or about 90% to about 100%.

[0076] In some examples, the cure rate of the prepolymer composition 612 with the multifunctional acrylate component is greater than the curing rate of the prepolymer composition 612 and the sacrificial material composition (612) when compared to the cure rate of the prepolymer composition 612 without the multifunctional acrylate component. Reduces inter-mixing between adjacent droplets 630 and 632 of 614).

[0077] In some examples, the cure rate of the prepolymer composition 612 with a multifunctional acrylate component is a critical condition for inter-mixing between adjacent droplets 630, 632 of the prepolymer composition 612 and the sacrificial material composition 614. satisfies. In some examples, the critical condition for inter-mixing is at least 50%, at least 60%, at least 70%, at least 80% of the volume of sacrificial material composition 614 dispensed to form corresponding pore-features 410. %, or at least 90%, or about 50% to about 60%, about 60% to about 70%, about 70% to about 80%, about 80% to about 90%, or about 90% to about 100%. Among the pore-features 410, the individual pore-features correspond to the volume of the pore-feature space.

[0078] In some examples, when the cure rate of the prepolymer composition 612 with the multifunctional acrylate component meets or exceeds the critical cure rate, at least 5%, at least 10%, at least 20%, at least 30% of the plurality of pore-features %, at least 40%, or at least 50% of the plurality of pore-features is isolated from other pore-features within the polishing layer.

[0079] In some examples, the multifunctional acrylate component reduces swelling of the polishing pad 400 when exposed to an aqueous polishing fluid compared to a polishing pad formed using the prepolymer composition 612 without the multifunctional acrylate component. .

[0080] In some examples, the multifunctional acrylate component increases the surface contact angle of a water droplet disposed on an abrasive layer compared to an abrasive layer formed using the prepolymer composition 612 without the multifunctional acrylate component.

Exemplary Prepolymer Compositions - Surface Active Agent

[0081] In some examples, prepolymer composition 612 may be added with a surface active agent, such as polybutylated phenol, nonylphenol, 2-methyl-4-t-octylphenol, 4,6-di-t-butyl-2-methylphenol, or Includes combinations of these. In some examples, the concentration of surface active agent in the prepolymer composition 612 may be about 1 wt% or less, such as about 0.1 wt% or less, or about 0.1 wt% to about 1 wt%.

[0082] In some examples, the surface active agent increases the hydrophobicity of the dispensed droplets 630 of the prepolymer composition 612. In some examples, the pore-feature space volume of an individual pore-feature among the plurality of pore-features 410 is at least 50% greater than the volume of the sacrificial material composition 614 dispensed to form the corresponding pore-features 410. %, at least 60%, at least 70%, at least 80%, or at least 90%, or about 50% to about 60%, about 60% to about 70%, about 70% to about 80%, about 80% to about 90% %, or about 90% to about 100%.

Exemplary Sacrificial Material Compositions - Polyethylene Glycol Monoacrylate Component

[0083] In some examples, sacrificial material composition 614 includes a polyethylene glycol monoacrylate component. The concentration of the polyethylene glycol monoacrylate component in the sacrificial material composition 614 may be at least about 30 wt%, at least about 40 wt%, or at least about 50 wt%. In some examples, the molecular weight of the polyethylene glycol monoacrylate component may be from about 400 g/mol to about 1200 g/mol, such as from about 400 g/mol to about 750 g/mol.

[0084] In some examples, sacrificial material composition 614 may further include a polyethylene glycol diacrylate component, a polyethylene glycol component, or combinations thereof. In some examples, the concentration of the polyethylene glycol diacrylate component in the sacrificial material composition may be about 30 wt% or less, about 20 wt% or less, or about 10 wt% or less. In some examples, the concentration of the polyethylene glycol component in the sacrificial material composition may be about 40 wt% or less, about 30 wt% or less, or about 20 wt% or less. In one example, the concentration of the polyethylene glycol monoacrylate component in the sacrificial material composition can be about 30 wt% or more, the concentration of the polyethylene glycol diacrylate component in the sacrificial material composition can be about 10 wt% or less, and the concentration of the polyethylene glycol diacrylate component in the sacrificial material composition can be about 10 wt% or less. The concentration of the polyethylene glycol component may be about 40 wt% or less. In some examples, the sacrificial material composition 614, when cured, may form a polymer having a Shore A hardness of greater than 1, greater than 5, or greater than 10, such as from 10 to 100, at room temperature.

[0085] In some instances, the polymer is water-soluble, and exposing the polymer to an aqueous solution forms a plurality of pores in the polishing layer. In some examples, when the sacrificial material composition 614 cures, it forms a linear polymer matrix. In some examples, prepolymer composition 612 may include at least one of phenoxyethyl acrylate, tetrahydrofurfuryl acrylate, butylcarbamatetoethyl acrylate, isobornyl acrylate, or combinations thereof.

[0086] In some examples, the pore-feature space volume of an individual pore-feature among the plurality of pore-features 410 is a sacrificial material comprising a polyethylene glycol monoacrylate component distributed to form the corresponding pore-features 410. at least 50%, at least 60%, at least 70%, at least 80%, or at least 90%, or about 50% to about 60%, about 60% to about 70%, or about 70% of the volume of material composition 614 about 80%, about 80% to about 90%, or about 90% to about 100%.

[0087] Here, the additive manufacturing system 600 shown in FIG. 6A further includes a system controller 610 for directing the operation of the additive manufacturing system 600. System controller 610 includes a programmable central processing unit (CPU) 634 operable with memory 635 (e.g., non-volatile memory) and support circuits 636. Support circuits 636 are typically coupled to a CPU 634, a cache coupled to various components of the additive manufacturing system 600 to enable control of the various components of the additive manufacturing system 600; clock circuits, input/output subsystems, power supplies, etc., and combinations thereof. The CPU 634 is one of any type of general-purpose computer processors used in industrial settings, such as a programmable logic controller (PLC), to control various components and sub-processors of the additive manufacturing system 600. Memory 635 coupled to CPU 634 is non-transitory and typically includes readily available memories, such as random access memory (RAM), read only memory (ROM), floppy disk drives, and hard disks. , or any other form of local or remote digital storage.

[0088] Typically, memory 635 is in the form of a computer-readable storage medium (e.g., non-volatile memory) that contains instructions that, when executed by CPU 634, modify the operation of manufacturing system 600. Make it possible. The instructions in memory 635 are in the form of a program product, such as a program that implements the methods of the present disclosure.

[0089] Program code may follow any one of a number of different programming languages. In one example, the present disclosure may be implemented as a program product stored on a computer-readable storage medium for use with a computer system. The program(s) of the program product define the functionality of the embodiments (including the methods described herein).

[0090] Exemplary computer-readable storage media include (i) non-recordable storage media on which information is permanently stored (e.g., read-only memory devices within a computer, such as CD-ROM disks readable by a CD-ROM drive) , flash memory, ROM chips, or any type of solid-state non-volatile semiconductor memory); and (ii) a recordable storage medium on which the changeable information is stored (e.g., floppy disks in a hard-disk drive or diskette drive, or any type of solid-state random access semiconductor memory), including (but not limited to) does not work). Such computer-readable storage media are embodiments of the disclosure when they carry computer-readable instructions directing the functions of the methods described herein. In some embodiments, the methods presented herein, or portions of such methods, are performed by one or more application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other types of hardware implementations. . In some other embodiments, the polishing pad manufacturing methods presented herein are performed by a combination of software routines, ASIC(s), FPGAs and/or other types of hardware implementations.

[0091] Here, the system controller 610 controls the motion of the manufacturing support 602, the motion of the dispensing heads 604 and 606, the firing of nozzles 616 for ejecting droplets of prepolymer compositions therefrom, and the UV radiation source ( Indicates the degree and timing of hardening of the dispensed droplets, provided by 608). In some embodiments, the instructions used by the system controller to direct the operation of manufacturing system 600 include droplet distribution patterns for each of the print layers to be formed. In some embodiments, droplet distribution patterns are collectively stored in memory 635 as CAD compatible digital printing instructions.

[0092] FIG. 7 is a flow diagram illustrating a method of forming a print layer of a polishing pad, according to embodiments described herein. Embodiments of method 700 may be used in combination with one or more of the systems and system operations described herein, such as the additive manufacturing system 600 of FIG. 6A and the stationary droplets of FIG. 6B. Additionally, embodiments of method 700 may be used to form any one or combination of the embodiments of polishing pads shown and described herein.

[0093] At activity 710, method 700 includes dispensing droplets of a prepolymer composition and droplets of a sacrificial material composition onto the surface of a previously formed print layer, according to a predetermined droplet distribution pattern.

[0094] At operation 720, method 700 includes at least partially curing the dispensed droplets of prepolymer composition to form a print layer comprising a plurality of pore-features.

[0095] In some embodiments, method 700 includes activities ( It further includes sequential repetitions of 710 and 720). The predetermined droplet distribution pattern used to form each print layer may be the same or different from the predetermined droplet distribution pattern used to form the previous print layer disposed beneath each such print layer. In some embodiments, the plurality of print layers includes an abrasive layer with a plurality of pore-features formed therein. In some embodiments, the plurality of print layers includes an abrasive layer with a plurality of pore-forming features formed therein, and the plurality of pore-forming features include a sacrificial material composition.

[0096] Preferably, as illustrated in the conversion-exposure curves shown in Figure 8, the prepolymer composition embodiments described herein comprising a multifunctional acrylate component exhibit accelerated cure when compared to conventional prepolymer compositions. to provide.

[0097] Figure 8 shows conversion-exposure curves 802a-802b for prepolymer compositions without multifunctional acrylate component, and for corresponding prepolymer compositions with multifunctional acrylate component at a concentration of about 10 wt%. -Graph 800 illustrating exposure curves 804a-804b. In the example illustrated in FIG. 8 , droplets of prepolymer composition and sacrificial material composition may be dispensed and cured, such as according to method 700. In this example, the sacrificial material composition may form about 16% of the total volume of dispensed droplets.

[0098] In the example of Figure 8, dispensed droplets are exposed to a sequence of pulses of electromagnetic radiation (eg, UV radiation), each pulse having a fixed energy (dose). Thus, the exposure time (x-axis) corresponds to the cumulative dose of electromagnetic radiation applied to the dispensed droplets, and the conversion of the multifunctional acrylate component (y-axis) is measured as a function of the cumulative dose. In this example, conversion may refer to the degree of chemical crosslinking of a UV curable composition as measured by optical differential scanning calorimetry (DSC).

[0099] As shown in Figure 8, the conversion-exposure curves for the prepolymer compositions with the multifunctional acrylate component are the corresponding conversion-exposure curves 802a-802b for the prepolymer composition without the multifunctional acrylate component. When compared there is a beneficial shift towards increased conversion at the same exposure time (cumulative dose). In some examples, the initial cure rate (corresponding to the initial slope of the conversion-exposure curve) is increased by at least about 2X, or from about 1X to about 2X, such as about 1.6X to about 1.95X. In one example, the ratio of the cure rate of the prepolymer composition with the multifunctional acrylate component to the cure rate of the prepolymer composition without the multifunctional acrylate component can be at least about 1.6, such as about 1.6 to about 1.95.

[00100] Table 2 presents the hardness and pore-feature spacing (%) for polishing pads formed using the prepolymer compositions of FIG. 8 (i.e., a plurality of These are the values of the volume of the pore-feature space of individual pore-features among the pore-features.

Table 2

[00101] Although the foregoing relates to embodiments of the disclosure, other and additional embodiments of the disclosure may be devised without departing from the basic scope of the disclosure, and the scope of the disclosure is defined in the following claims. is determined by

Claims (20)

A method of forming a polishing pad, comprising:
(a) distributing droplets of a pre-polymer composition and droplets of a sacrificial material composition on the surface of a previously formed print layer according to a predetermined droplet distribution pattern; and
(b) curing the dispensed droplets of the prepolymer composition at least partially to form a print layer; and
(c) sequentially repeating steps (a) and (b) to form a polishing layer having a plurality of pore-features formed therein,
The prepolymer composition includes a multifunctional acrylate component,
The curing rate of the dispensed droplets of the prepolymer composition comprising the multifunctional acrylate component when exposed to a first dose of electromagnetic radiation is when exposed to the same first dose of electromagnetic radiation. , is greater than the cure rate of the prepolymer composition without the multifunctional acrylate component,
The plurality of pore-features include openings defined in the surface of the polishing layer, voids formed in the polishing layer below the surface, pore-forming features comprising the sacrificial material composition, or combinations thereof. How to. 2. The method of claim 1, wherein the concentration of the multifunctional acrylate component in the prepolymer composition is less than or equal to about 20 wt%. The method of claim 1, wherein the multifunctional acrylate component comprises at least one diacrylate or triacrylate having a molecular weight of at least about 200 g/mol. The method of claim 1, wherein the multifunctional acrylate component is tripropylene glycol diacrylate, poly(propylene glycol) diacrylate, trimethylol triacrylate, neopentyl glycol diacrylate, ethoxylated neopentyl glycol diacrylate. , pentaerythritol triacrylate, pentaerythritol tetraacrylate, or combinations thereof. The method of claim 1 , wherein the ratio of the cure rate of the prepolymer composition with the multifunctional acrylate component to the cure rate of the prepolymer composition without the multifunctional acrylate component is at least about 1.6. 2. The method of claim 1, wherein the volume of pore-feature space of an individual pore-feature among the plurality of pore-features comprises at least 50% of the volume of the sacrificial material composition distributed to form corresponding pore-features. method. 2. The method of claim 1, wherein the cure rate of the prepolymer composition having the multifunctional acrylate component is compared to the cure rate of the prepolymer composition without the multifunctional acrylate component. A method for reducing inter-mixing between droplets. According to paragraph 1,
The cure rate of the prepolymer composition with the multifunctional acrylate component satisfies a critical condition for inter-mixing between adjacent droplets of the prepolymer composition and the sacrificial material composition,
The critical condition for inter-mixing is a pore-feature of individual pore-features of the plurality of pore-features comprising at least 50% of the volume of the sacrificial material composition distributed to form corresponding pore-features. A method that corresponds to the volume of space. The method of claim 1, wherein when the cure rate of the prepolymer composition having the multifunctional acrylate component meets or exceeds a critical cure rate, at least 5% of the plurality of pore-features are A method in which one of the pore-features is isolated from other pore-features. The method of claim 1, wherein the prepolymer composition further comprises at least one of phenoxyethyl acrylate, tetrahydrofurfuryl acrylate, butylcarbamatetoethyl acrylate, isobornyl acrylate, or combinations thereof. method. The method of claim 1, wherein the multifunctional acrylate component reduces swelling of the polishing pad when exposed to an aqueous polishing fluid compared to a polishing pad formed using the prepolymer composition without the multifunctional acrylate component. , method. The method of claim 1, wherein the multifunctional acrylate component increases the surface contact angle of water droplets disposed on the polishing layer compared to an polishing layer formed using the prepolymer composition without the multifunctional acrylate component. , method. A method of forming a polishing pad, comprising:
(a) dispensing droplets of a prepolymer composition and droplets of a sacrificial material composition on the surface of a previously formed print layer according to a predetermined droplet distribution pattern; and
(b) at least partially curing the dispensed droplets of the prepolymer composition to form a print layer comprising a plurality of pore-features; and
(c) sequentially repeating steps (a) and (b) to form a polishing layer,
The prepolymer composition includes a surface active agent,
The volume of the pore-feature space of an individual pore-feature of the plurality of pore-features comprises at least 50% of the volume of the sacrificial material composition distributed to form the corresponding pore-features,
The plurality of pore-features include openings defined in the surface of the polishing layer, voids formed in the polishing layer below the surface, pore-forming features comprising the sacrificial material composition, or combinations thereof. How to. The method of claim 13, wherein the surfactant is polybutylated phenol, nonylphenol, 2-methyl-4-t-octylphenol, 4,6-di-t-butyl-2-methylphenol, or combinations thereof. Containing at least one method. 14. The method of claim 13, wherein the concentration of the surface active agent in the prepolymer composition is about 1 wt% or less. 14. The method of claim 13, wherein the surface active agent increases the hydrophobicity of dispensed droplets of the prepolymer composition. As a polishing pad,
Comprising a plurality of polishing elements, each of the plurality of polishing elements:
an individual surface forming part of the polishing surface of the polishing pad; and
comprising one or more sidewalls extending downwardly from the individual surfaces to define a plurality of channels disposed between the polishing elements;
Each of the polishing elements has a plurality of pore-features formed therein,
Each of the polishing elements is formed from a prepolymer composition and a sacrificial material composition,
The volume of the pore-feature space of an individual pore-feature of the plurality of pore-features comprises at least 50% of the volume of the sacrificial material composition distributed to form the corresponding pore-features,
The plurality of pore-features include openings defined in the polishing surface, voids formed in the polishing elements below the polishing surface, pore-forming features comprising the sacrificial material composition, or combinations thereof. , polishing pad. 18. The polishing pad of claim 17, wherein the prepolymer composition includes a multifunctional acrylate component. 18. The polishing pad of claim 17, wherein the prepolymer composition includes a surface active agent. According to clause 17,
The concentration of the polyethylene glycol monoacrylate component in the sacrificial material composition is about 30% by weight or more,
The concentration of the polyethylene glycol diacrylate component in the sacrificial material composition is about 10 wt% or less,
A polishing pad, wherein the concentration of the polyethylene glycol component in the sacrificial material composition is about 40 wt% or less.