JP5450622B2 - Polishing pad with a floating element, method for producing and using the same - Google Patents

Description

(Cross-reference of related applications)
This application claims the benefit of US Provisional Patent Application No. 61 / 081,891, filed July 18, 2008, the entire disclosure of which is incorporated herein by reference.

  The present disclosure relates to a polishing pad having a floating polishing element, a method for manufacturing such a polishing pad, and a method for using such a polishing pad in a polishing process, such as a chemical mechanical planarization process.

  Silicon wafers are iteratively processed through a series of deposition and etching steps during the fabrication of semiconductor devices and integrated circuits to form overlying material layers and device structures. A polishing technique known as chemical mechanical planarization (CMP) is the goal of obtaining a smooth wafer surface with high uniformity across the wafer without scratches or depressions (known as dishing). Thus, it can be used to remove surface irregularities (such as bumps, non-uniform raised regions, grooves and trenches) remaining after the film formation and etching steps.

  In a typical CMP polishing process, a substrate, such as a wafer, is typically pressed against and relative to a polishing pad in the presence of a working fluid that is a slurry of abrasive grains in water and / or an etching action. Moved. Various CMP polishing pads for use with polishing slurries, such as US Pat. Nos. 5,257,478, 5,921,855, 6,126,532, 6 , 899, 598 (B2) specification and 7,267,610 specification are disclosed. A fixed abrasive polishing pad, as illustrated by US Pat. No. 6,908,366 (B2), is known, in which case abrasive grains often come from the pad surface. It is generally fixed to the surface of the pad in the form of a stretched finely shaped composite abrasive. Recently, a polishing pad having a very large number of polishing elements extending from a compressible underlayer and attached to the underlayer by a guide plate has been described in WO / 2006605714. Although a wide variety of polishing pads are known and used, the industry in particular requires a larger die aperture or requires a higher level of wafer surface flatness and polishing uniformity. There is a continuing effort to obtain new and improved polishing pads for CMP in the CMP process.

US Pat. No. 5,257,478 US Pat. No. 5,921,855 US Pat. No. 6,126,532 US Pat. No. 6,899,598 (B2) specification US Pat. No. 7,267,610 US Pat. No. 6,908,366 (B2) International Publication No. WO / 2006/057714 Pamphlet International Publication No. WO / 2006/055720 Pamphlet US Pat. No. 6,238,592 (B1) specification US Pat. No. 6,491,843 (B1) International Publication No. WO / 2002/33736 Pamphlet

  In one exemplary embodiment, the present disclosure is a polishing pad comprising a plurality of polishing elements, each polishing element having lateral movement of the polishing element relative to one or more other polishing elements. A polishing pad is described that is bonded to the support layer to limit the movement but remains movable on an axis perpendicular to the polishing surface of the polishing element. In some exemplary embodiments, the polishing pad is thermally bonded to the support layer. In some exemplary embodiments, at least a portion of the polishing element comprises a porous polishing element, and in additional embodiments, at least the surface of each porous polishing element has a plurality of pores. It comprises.

  In some specific embodiments of the porous abrasive element, the pores can be distributed substantially throughout the entire porous abrasive element. In other specific embodiments of the porous polishing element, the pores can be distributed substantially on the polishing surface of the element. In some exemplary embodiments, the pores substantially distributed on the polishing surface of the element have a cross-sectional shape selected from the group consisting of cylindrical, triangular, rectangular, trapezoidal, hemispherical and combinations thereof. A plurality of grooves having

  In another exemplary embodiment, the present disclosure provides a support layer having a first major surface and a second major surface opposite to the first major surface, and a first of the support layers. A polishing pad comprising a plurality of polishing elements attached to the major surface, wherein the polishing element has a first direction of the support layer along a first direction substantially perpendicular to the first major surface. A polishing pad extending from the main surface of 1 will be described. In some exemplary embodiments, the polishing element is thermally bonded to the support layer. In some exemplary embodiments, at least a portion of the polishing element comprises a porous polishing element, and in additional embodiments, at least the surface of each porous polishing element has a plurality of pores. It comprises.

  In some specific embodiments of the porous abrasive element, the pores can be distributed substantially throughout the entire porous abrasive element. In other specific embodiments, the pores can be substantially distributed on the polishing surface of the element. In some exemplary embodiments, the pores substantially distributed on the polishing surface of the element are cross-sections selected from the group consisting of cylindrical, triangular, rectangular, trapezoidal, hemispherical, and combinations thereof. A plurality of grooves having a shape are provided.

  In a further exemplary embodiment, a method of manufacturing a polishing pad is provided, the method comprising forming a plurality of polishing elements and bonding the polishing elements to a support layer. Bonding the abrasive element to the support layer includes thermal bonding, actinic radiation bonding, adhesive bonding, and combinations thereof.

  In some exemplary embodiments, the method further comprises arranging the plurality of polishing elements in a pattern prior to bonding the polishing elements to the support layer. In some exemplary embodiments, arranging the plurality of polishing elements in a pattern includes arranging the polishing elements in a template, arranging the polishing elements on the support layer, and Including a combination of In some embodiments, at least a portion of the polishing element comprises a porous polishing element. In some additional embodiments, at least a portion of the polishing element comprises a substantially non-porous polishing element.

  In some specific exemplary embodiments, the method includes injection molding of a gas saturated polymer melt, injection molding of a reaction mixture that releases gas during the reaction to produce a polymer, and dissolving the polymer in a supercritical gas. Porous abrasive elements by injection molding of the resulting mixture, injection molding of a mixture of polymers incompatible in the solvent, injection molding of porous thermosetting microparticles dispersed in the thermoplastic polymer, and combinations thereof Forming.

  In additional exemplary embodiments, the present disclosure focuses on a method of using a polishing pad as described above in a polishing process that includes a plurality of polishing elements thermally bonded to a surface of a substrate and a support layer. Contacting the polishing surface of the polishing pad provided, and moving the polishing pad relative to the substrate to wear the surface of the substrate. In some exemplary embodiments, at least a portion of the polishing element comprises a porous polishing element, and in some embodiments, at least the surface of each porous polishing element has a plurality of pores. It comprises. In other exemplary embodiments, the working fluid can be supplied to the boundary between the polishing pad surface and the substrate surface.

  Exemplary embodiments of a polishing pad having a porous polishing element according to the present disclosure have various features and characteristics that allow for use in various polishing applications. In some currently preferred embodiments, the polishing pads of the present disclosure may be particularly well suited for chemical mechanical planarization (CMP) of wafers used in the manufacture of integrated circuits and semiconductor devices. There is sex. In some exemplary embodiments, the polishing pad described in this disclosure can achieve some or all of the following effects.

  For example, in some exemplary embodiments, a polishing pad according to the present disclosure provides a working fluid used in a CMP process at the boundary between the polishing surface of the pad and the surface of the substrate being polished. It is possible to improve the effectiveness of the working fluid in increasing polishing. In other exemplary embodiments, a polishing pad according to the present disclosure can reduce or eliminate dishing and / or edge erosion of the wafer surface during polishing.

  The use of a polishing pad with a porous element according to the present disclosure allows the processing of larger diameter wafers while maintaining the required degree of surface uniformity to maintain a high chip yield, and a uniform polishing of the wafer surface. In order to maintain performance, it may be possible to process more wafers or reduce process time and pad conditioner wear before the pad surface needs to be adjusted. In some embodiments, a CMP pad with a porous polishing element can provide the benefits and effects of a conventional CMP pad with surface features such as grooves, but in a less costly and more reproducible manner. Can be manufactured. In additional embodiments, the bonding of the polishing element to the support layer can eliminate the need to use a guide plate to attach the element to the support layer.

  Thus far, various aspects and advantages of exemplary embodiments of the present disclosure have been summarized. The above summary is not intended to describe each illustrated embodiment or every implementation of some exemplary embodiments of the invention. The following drawings and detailed description illustrate some preferred embodiments more specifically using the principles disclosed herein.

  Exemplary embodiments of the present disclosure will be further described with reference to the accompanying drawings.

1 is a side view of a polishing pad having a floating polishing element coupled to a support layer, according to one exemplary embodiment of the present disclosure. FIG. FIG. 3 is a side view of a polishing pad having a floating polishing element coupled to a support layer and including a guide plate, according to another exemplary embodiment of the present disclosure. 1 is a perspective view of a template having polishing elements arranged in a pattern useful in manufacturing a polishing pad, according to one exemplary embodiment of the present disclosure. FIG. 1 is a plan view of a template having polishing elements arranged in a pattern useful in manufacturing a polishing pad, according to one exemplary embodiment of the present disclosure. FIG. FIG. 3 is a perspective view of a porous polishing element having a porous polishing surface according to another exemplary embodiment of the present disclosure. 1 is a side view of an exemplary coupling device useful in a method for bonding a large number of abrasive elements to a support layer, according to an exemplary embodiment of the present disclosure. FIG. In accordance with additional exemplary embodiments of the present disclosure, a template useful for arranging a large number of polishing elements in a pattern prior to bonding the polishing elements to a support layer and a highly arranged pattern FIG. 2 is an image showing a resulting support layer having a number of bonded abrasive elements. FIG. 7 is an image of the resulting support layer having a large number of bonded abrasive elements arranged in a pattern according to the embodiment of FIG. A polishing pad according to yet another exemplary embodiment of the present disclosure, comprising a large number of floating abrasive elements coupled to the support layer according to the embodiment of FIG. It is the image of the polishing pad adhering to the property base layer.

  Like reference numerals in the drawings indicate like elements. The drawings herein are not drawn to scale, and in the drawings, the components of the polishing pad are sized to emphasize selected features.

  In a typical CMP slurry process for wafer polishing, a wafer to be processed with a specific topography is contacted with a polishing pad and a polishing liquid containing abrasive grains and an abrasive. If the polishing pad is flexible, the phenomenon of dishing and erosion can occur at the same rate as the raised area due to the soft pad polishing the lower area of the wafer. However, if the polishing pad is stiff, dishing and erosion can be greatly reduced, and a stiff polishing pad can advantageously provide good die planarization uniformity, but such a pad Can adversely effect poor wafer uniformity due to rebound effects that occur around the wafer. This rebound effect results in insufficient edge yield and a narrow CMP polishing process window. In addition, using a rigid polishing pad to develop a stable polishing process makes such a pad sensitive to different wafer topographies and retains its polishing liquid and is compatible with the wafer This can be difficult because it depends entirely on the use of a pad conditioner that produces optimal polishing characteristics.

  The present disclosure focuses on an improved polishing pad having a number of floating polishing elements coupled to a support layer, which, in various embodiments, is both a flexible polishing pad and a rigid polishing pad. Combining some of the advantageous properties and eliminating or reducing some of the disadvantageous properties of each pad. By expressing the abrasive element as a “floating” abrasive element coupled to a support layer, Applicants have determined that each of the abrasive elements has its own relative to one or more of the other abrasive elements. Although coupled to the support layer to limit the lateral movement of the polishing element, it is intended to remain movable on an axis that is generally perpendicular to the polishing surface of the polishing element.

  Various exemplary embodiments of the present disclosure will now be described with reference to the drawings. The exemplary embodiments of the present disclosure may employ various changes and substitutions without departing from the spirit and scope of the present disclosure. Accordingly, the embodiments of the present invention should not be limited to the exemplary embodiments described below, but should be controlled by the limitations set forth in the claims and any equivalents of the present invention. Should be understood.

  Referring to FIG. 1, an exemplary embodiment of a polishing pad 2 comprising a plurality of polishing elements 4-4 ′ is illustrated, each of the polishing elements 4-4 ′ including another polishing element 4-4 ′. Are coupled to the support layer 10 to limit the lateral movement of the polishing elements 4-4 ′ relative to one or more of the same, but in an axis perpendicular to the polishing surface 14 of each polishing element 4-4 ′. Remains movable. In the specific embodiment illustrated by FIG. 1, the polishing elements 4-4 ′ have a first support layer 10 first, for example, by direct thermal bonding to the support layer 10 or using an adhesive. It is shown in a state of being attached to the main surface.

  In the specific exemplary embodiment illustrated by FIG. 1, the support layer 10 is attached to a flexible layer 16 disposed on the opposite side of the plurality of polishing elements 4-4 '. In addition, an optional adhesive layer 12 is illustrated at the boundary between the flexible layer 16 and the support layer 10. Optional adhesive layer 12 can be used to attach the second major surface of support layer 10 to flexible layer 16. In addition, an optional pressure sensitive adhesive layer 18 attached to the flexible layer 16 opposite the plurality of polishing elements 4-4 'attaches the polishing pad 2 to the CMP polishing apparatus (not shown in FIG. 1). ) To a polishing platen (not shown in FIG. 1) for temporary (eg, detachable) use.

  Also shown in FIG. 1 is an optional polishing composition distribution layer 8 that also functions as a guide plate for polishing elements 4-4 '. During the polishing process, the optional polishing composition distribution layer 8 assists in the distribution of the working fluid and / or polishing slurry to the individual polishing elements 4-4 '. When used as a guide plate, the polishing composition distribution layer 8 (guide plate) can be arranged on the first main surface of the support layer 10 to facilitate the arrangement of a plurality of polishing elements 4-4 ′. As a result, the first major surface of the polishing composition distribution layer 8 (guide plate) is distal from the support layer 10, and the second major surface of the polishing composition distribution layer 8 (guide plate) is The polishing composition distribution layer 8 (guide plate) is opposite to the first main surface.

  The polishing elements 4 to 4 ′ extend from the first main surface of the polishing composition distribution layer 8 (guide plate) along a first direction substantially perpendicular to the first main surface of the support layer 10. Yes. When the polishing composition distribution layer 8 is also used as a guide plate, a plurality of openings 6 extending through the polishing composition distribution layer 8 (guide plate) are preferably provided. A part of each polishing element 4 extends into a corresponding opening 6. Thus, the plurality of openings 6 can act to guide the array of polishing elements 4 on the support layer 10.

  In one exemplary embodiment illustrated by FIG. 1, at least some of the polishing elements 4-4 ′ are porous polishing elements 4, and some polishing elements 4-4 ′ A substantially non-porous abrasive element 4 ′. However, in other exemplary embodiments not shown in FIG. 1, all polishing elements 4-4 ′ can be selected to be porous polishing elements 4, or all polishing elements It will be appreciated that elements 4-4 'can be selected to be substantially non-porous abrasive elements 4'.

  In the specific embodiment illustrated by FIG. 1, two porous polishing elements 4 are illustrated with one substantially non-porous polishing element 4 '. Further, the porous polishing element 4 is shown to include both a porous polishing surface 14 and pores 15 that are substantially dispersed throughout the polishing element 4. However, any number of polishing elements 4-4 ′ can be used, and so that any number of polishing elements 4-4 ′ are porous polishing elements 4 or substantially non-porous polishing elements 4 ′. It will be understood that it can be selected.

  Also, in some exemplary embodiments not shown in FIG. 1, a number of abrasive elements 4-4 ′ may be patterned, for example, on the support layer 10 or prior to attaching to the support layer. In addition, it can be arranged in a template or jig used to arrange the polishing elements. For example, FIGS. 3A and 3B show one exemplary arrangement of a plurality of polishing elements 4-4 ′ arranged in a template 30 with a generally circular two-dimensional arrangement pattern 32. After arranging the plurality of polishing elements 4 to 4 ′ in the pattern 30 on the template 30, the first main surface of the support layer 10 is thermally bonded directly to the support layer 10, for example, or an adhesive is used. It can be used or bonded with other bonding materials in contact with the polishing elements 4-4 ′.

  Furthermore, it will be appreciated that the polishing pad 2 need not comprise only substantially the same polishing element 4. Thus, for example, any combination or arrangement of porous and non-porous polishing elements can constitute a plurality of porous polishing elements 4. Any number, combination or arrangement of porous polishing elements 4 and substantially non-porous polishing elements 4 ′ may be formed to form a polishing pad having floating polishing elements 4-4 ′ coupled to the support layer 10. It will also be appreciated that can be advantageously used in some embodiments.

  In some additional exemplary embodiments illustrated by FIG. 1, at least the surface of the porous polishing element 4, in this case at least the polishing surface 14, has a plurality of pores (shown in FIG. 1). (Not shown, but shown in FIG. 4). In another exemplary embodiment, each of the porous polishing elements 4 is illustrated as having a plurality of pores 15 that are substantially distributed throughout the polishing element 4. In another exemplary embodiment (not illustrated in FIG. 1 but illustrated by FIG. 4), the pores are only on the polishing surface 14 of the porous polishing element 4 or the polishing thereof. It is substantially distributed in the vicinity of only the surface. However, the polishing element 4 having pores substantially distributed throughout the polishing element 4, having the pores substantially distributed only on the polishing surface of the polishing element 4 or in the vicinity of only the polishing surface. A polishing pad 2 having a combination or configuration consisting of the polishing element 4 and the polishing element 4 substantially free of pores is contemplated within the scope of this disclosure, and that the polishing pad can also be advantageously manufactured. Should be understood.

  Referring to FIG. 2, another exemplary embodiment of a polishing pad 2 ′ is illustrated, wherein the polishing pad 2 ′ includes a first major surface and a second opposite the first major surface. A support layer 10 having a main surface, a plurality of polishing elements 4-4 ′ coupled to the first main surface of the support layer 10, a first main surface, and a first main surface opposite to the first main surface And an optional guide plate 28 having a second major surface, the guide plate 28 having the first major surface of the optional guide plate 28 distal to the support layer 10. A plurality of polishing elements 4 to 4 ′ are arranged on the first main surface. In the specific embodiment illustrated by FIG. 1, the polishing elements 4-4 ′ have a first thickness of the support layer 10, for example by direct thermal bonding to the support layer 10 or using an adhesive. 1 is shown attached to one main surface.

  In the specific exemplary embodiment illustrated by FIG. 2, the support layer 10 is opposite to the plurality of abrasive elements 4-4 ′ attached to the first major surface of the support layer 10. Is attached to the flexible layer 16 located on the second major surface of the first layer. Furthermore, an optional adhesive layer 12 is illustrated at the boundary between the flexible layer 16 and the support layer 10. Optional adhesive layer 12 can be used to attach the second major surface of support layer 10 to flexible layer 16. In addition, an optional pressure-sensitive adhesive layer 18 attached to the flexible layer 16 opposite the plurality of polishing elements 4-4 'attaches the polishing pad 2' to the CMP polishing apparatus (not shown in FIG. 2). Can be used to temporarily (eg, detachably) fix to a polishing platen (not shown in FIG. 2).

  Optional guide plate 28 is also illustrated in the exemplary embodiment of FIG. An optional guide plate 28 that also serves as an alignment template for aligning the plurality of polishing elements 4-4 ′ on the first major surface of the support layer 10 is suitable for manufacturing the polishing pad 2 ′ according to the present disclosure. In general, not necessary. In some exemplary embodiments, the optional guide plate 28 can be completely removed from the polishing pad, as illustrated by the polishing pad 2 of FIG. Such an embodiment can be advantageously manufactured more easily and at a lower cost than other known polishing pads with multiple polishing elements.

  An optional polishing composition distribution layer 8 'that also serves as a guide plate for the polishing elements 4-4' is also illustrated in FIG. During the polishing process, the optional polishing composition distribution layer 8 'assists in the distribution of the working fluid and / or polishing slurry to the individual polishing elements 4-4'. When used as a guide plate, the polishing composition distribution layer 8 can be disposed on the first major surface of the support layer 10 to facilitate the arrangement of the plurality of polishing elements 4-4 ′, and as a result, The first major surface of the polishing composition distribution layer 8 ′ is distal from the support layer 10, and the second major surface of the polishing composition distribution layer 8 ′ is the first surface of the polishing composition distribution layer 8 ′. It is on the opposite side of the main surface. Also, as shown in FIG. 2, a plurality of openings 6 extending through at least an arbitrary guide plate 28 (if present) and / or an optional polishing composition distribution layer 8 ′ (if present) may be provided. Good.

  As shown in FIG. 2, each polishing element 4-4 ′ has a first main surface substantially perpendicular to the first main surface of the support layer 10 from the first main surface of any guide plate 28. It extends along the direction. In some embodiments shown in FIG. 2, each polishing element 4-4 ′ has a mounting flange, and each polishing element 4-4 ′ is, and optionally, the first major surface of the support layer 10. Accordingly, it is bonded to the first major surface of the support layer 10 by engagement of a corresponding flange with the second major surface of any polishing composition distribution layer 8 ′. As a result, during the polishing process, the polishing elements 4-4 ′ can be freely and independently displaced in a direction substantially perpendicular to the first major surface of the support layer 10, but are bonded to the support layer 10. And optionally attached to the support layer 10 by an optional polishing composition distribution layer 8 '.

  In such an embodiment, at least a portion of each polishing element 4-4 ′ extends into the corresponding opening 6, and each polishing element 4-4 ′ passes through the corresponding opening 6, An arbitrary guide plate 28 extends from the first main surface to the outside. Accordingly, the plurality of openings 6 and / or the optional polishing composition distribution layer 8 ′ of any guide plate 28 guide the lateral arrangement of the polishing elements 4-4 ′ on the first major surface of the support layer 10. It can also be useful as a template to do. In other words, the optional guide plate 28 and / or the optional polishing composition distribution layer 8 ′ arranges a plurality of polishing elements 4-4 ′ on the first major surface of the support layer 10 during the polishing pad manufacturing process. Can be used as a template or guide.

  In the specific embodiment illustrated by FIG. 2, the optional guide plate 28 has an adhesive (not shown) provided at the interface between the support layer 10 and the polishing composition distribution layer 8 ′. You may have. Thus, the optional guide plate 28 can be used to attach the optional polishing composition distribution layer 8 ′ to the support layer 10, whereby a plurality of polishing elements 4-4 ′ can be attached to the first of the support layer 10. It is securely attached to the main surface of the. However, other bonding methods may be used including, for example, direct bonding of the polishing elements 4-4 'to the support layer 10 using heat or pressure.

  In the related exemplary embodiment shown in FIG. 2, a plurality of openings can be arranged as an array of openings, in which case at least a portion of the openings 6 are provided with any polishing composition distribution layer 8. And an undercut region formed by an optional guide plate 28, and the undercut region forms a shoulder that engages a corresponding abrasive element flange, thereby The polishing elements 4-4 ′ are securely attached to the support layer 10 without the need for direct bonding of the polishing elements 4-4 ′ to the support layer 10. In addition, in some exemplary embodiments not illustrated by FIG. 2, a number of polishing elements 4-4 ′ are arranged in a two-dimensional array, for example consisting of elements arranged on the major surface of the support layer 10. Or in a template or jig used to align the polishing elements prior to bonding to the support layer.

  In an additional exemplary embodiment illustrated by FIG. 2, at least the surface of the porous polishing element 4, in this case at least the polishing surface 14, has a plurality of pores (not shown in FIG. 4). In another exemplary embodiment, each of the porous polishing elements 4 is illustrated such that a plurality of pores 15 are distributed substantially throughout the polishing element 4. In another exemplary embodiment (not illustrated in FIG. 2 but illustrated by FIG. 4), the pores are substantially only on the polishing surface 14 of the porous polishing element 4, Alternatively, it is dispersed only in the vicinity of the polished surface. However, the polishing element 4 having pores substantially distributed throughout the polishing element 4, having the pores substantially distributed only on the polishing surface of the polishing element 4 or in the vicinity of only the polishing surface. A polishing pad 2 ′ having a combination or configuration consisting of the polishing element 4 and the polishing element 4 substantially free of pores is contemplated within the scope of this disclosure, and the polishing pad can also be advantageously manufactured. Should be understood.

  Referring now to FIG. 4, a porous polishing element 4 having a porous polishing surface 14 with a plurality of pores 15 can be used in a polishing pad according to another exemplary embodiment of the present disclosure. . Also, the porous abrasive element 4 of FIG. 4 is illustrated with a flange 25 that can be used, for example, to facilitate bonding to a support layer (not shown in FIG. 4) as shown in FIG. Yes. The porous polishing element shown in FIG. 4 comprises a plurality of pores 15 provided substantially in the polishing surface 14. However, it is understood that in other embodiments, such as the embodiment shown in FIGS. 1 and 2, a plurality of pores 15 can be distributed throughout the porous polishing element 4 and on the polishing surface 14. Will. Furthermore, it will be appreciated that in other embodiments, the plurality of pores 15 can be distributed throughout the porous polishing element 4 but not necessarily on the polishing surface.

  FIG. 4 shows one specific shape of the porous polishing element 4. It will be appreciated that the same shape may be used to make a polishing element 4 'that is not substantially porous. Furthermore, the polishing elements 4-4 ′ can be formed in virtually any shape, and a plurality of polishing elements 4-4 ′ having two or more different shapes can be advantageously used, And if necessary, can be arranged in a pattern prior to bonding to a support layer (not shown in FIG. 4) used to form a polishing pad (not shown in FIG. 4) Will be understood.

  In some exemplary embodiments, the polishing elements 4-4 'can be characterized by height (H) and width (W), as shown in FIG. In addition, the cross-sectional shape of the polishing elements 4-4 'depicted through the polishing elements 4-4' in a direction generally parallel to the polishing surface 14 can vary widely depending on the intended application. Although FIG. 4 shows a generally cylindrical abrasive element 4 having a generally circular cross section, in some embodiments other cross-sectional shapes are possible and may be preferred. For example, circular, elliptical, triangular, square, rectangular and trapezoidal cross-sectional shapes may be useful.

  For a generally cylindrical polishing element 4 having a circular cross-section as shown in FIG. 4, the cross-sectional diameter of the polishing element 4 in a direction generally parallel to the polishing surface 14 is, in some embodiments, at least about 50 micrometers ( μm), more preferably at least about 1 mm, and even more preferably at least about 5 mm. The cross-sectional diameter of the polishing element 4 in a direction generally parallel to the polishing surface 14 is at most about 20 mm, more preferably at most about 15 mm, and even more preferably at most about 12 mm. The diameter of the polishing element depicted by the polishing surface 14 and corresponding to the width (W) as shown in FIG. 4 can be from about 50 μm to about 20 μm, in some embodiments, The diameter is from about 1 mm to about 15 mm, and in other embodiments, the cross-sectional diameter is from about 5 mm to about 12 mm.

  In the case of a non-cylindrical abrasive element having a non-circular cross section, the unique dimensions can be used to characterize the size of the abrasive element with respect to height, width and / or length. In some exemplary embodiments, the characteristic dimension can be selected to be at least about 50 μm, more preferably at least about 1 mm, and even more preferably at least about 5 mm. In some embodiments, the cross-sectional diameter of the polishing element 4 in a direction generally parallel to the polishing surface 14 is at most about 20 mm, more preferably at most about 15 mm, and even more preferably at most about 12 mm.

In other exemplary embodiments, the cross-sectional area of each polishing element 4 in a direction generally parallel to the polishing surface 14 is at least about 1 mm ² , in other embodiments at least about 10 mm ² , and still other embodiments. Can be at least about 20 mm ² . In other exemplary embodiments, the cross-sectional area of each polishing element 4 in a direction generally parallel to the polishing surface 14 is at most about 1,000 mm ² , in other embodiments at most about 500 mm ² , and further In other embodiments, it can be up to about 250 mm ² .

  The polishing element (reference numerals 4 to 4 ′ in FIGS. 1 and 2) is distributed on the main surface of the support layer (reference numeral 10 in FIGS. 1 and 2) in a wide variety of patterns depending on the intended use. And the pattern may be regular or irregular. The abrasive element can be on substantially the entire surface of the support layer, or there can be regions of the support layer that do not include the abrasive element. In some embodiments, the abrasive element has an average surface coverage of the support layer of at least 30%, at least 40%, or at least 50%. In an additional embodiment, the polishing element has a maximum total area of about 80 of the major surface of the support layer, as determined by the number of polishing elements, the cross-sectional area of each polishing element, and the cross-sectional area of the polishing pad. %, Up to about 70%, or up to about 60% of the average surface coverage of the support layer.

Sectional area of the polishing pad in a direction generally parallel to the main surface of the polishing pad, in some exemplary embodiments, from about 100 cm ² ~ about 300,000 ^2, in another embodiment, about 1, 000cm ² ~ about 100,000 ^2, and in yet another embodiment is from about 2,000 cm ² ~ about 50,000 cm ^2.

  Prior to the first use of the polishing pad (reference numeral 2 in FIG. 1, reference numeral 2 ′ in FIG. 2) in the polishing process, in some exemplary embodiments, each polishing element (in FIGS. 1 and 2) 4-4 ') extends along a first direction substantially perpendicular to the first major surface of the support layer (10 in FIGS. 1 and 2). In some exemplary embodiments, the polishing element comprises, along its first direction, any polishing composition distribution layer (8 in FIG. 1, 8 ′ in FIG. 2) and / or any It extends at least about 0 mm, 0.25 mm, at least about 0.3 mm, or at least about 0.5 mm above the plane containing the guide plate (28 in FIG. 2).

  In other exemplary embodiments, the polishing surface of the polishing element can be coplanar with the exposed major surface of the optional polishing composition distribution layer. In another exemplary embodiment, the polishing surface of the polishing element is formed to be recessed from the exposed major surface of the optional polishing composition distribution layer, and then, for example, the optional polishing composition By removing a part of the distribution layer, the polishing composition can be formed so as to extend in the same plane as the exposed main surface of the optional polishing composition distribution layer or to extend beyond the exposed main surface. Such embodiments are selected to be worn or eroded during the polishing process or in any conditioning process applied to the polishing pad before, during or after contact with the workpiece. It can be advantageously used with a polishing composition distribution layer.

  In an additional exemplary embodiment, each polishing element 4-4 ′ has, along its first direction, at least about 0. 0 above the plane containing its support layer (reference numeral 10 in FIGS. 1 and 2). It extends to 25 mm, at least about 0.3 mm, or at least about 0.5 mm. In an additional exemplary embodiment, the height of the polishing surface (14 in FIGS. 1 and 2) above the base or bottom of the polishing element, ie the height of the polishing element as shown in FIG. H) is 0.25 mm, 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm, depending on the polishing composition used and the material selected for the polishing element It can be 5.0 mm, 10 mm or more.

  Referring again to FIGS. 1 and 2, any polishing composition distribution layer (8 in FIG. 1, 8 ′ in FIG. 2) and / or an opening over the entire surface of any guide plate 28 (FIGS. 1 and 2). The depth and spacing of 6) may be varied for a particular CMP process, if desired. In some embodiments, the polishing elements (reference numerals 4-4 ′ of FIGS. 1 and 2) are respectively in contact with each other and its polishing composition distribution layer (reference numeral 8 of FIG. 1, reference numeral 28 of FIG. 2) and Maintained in a substantially planar direction relative to the guide plate 31 and on the surface of the optional polishing composition distribution layer (reference numeral 8 in FIG. 1, reference numeral 8 ′ in FIG. 2) and / or the guide plate 28 Protruding.

  In some exemplary embodiments, the polishing element on any arbitrary guide plate (reference numeral 28 in FIG. 2) and any arbitrary polishing composition distribution layer (reference numeral 8 in FIG. 1, reference numeral 8 ′ in FIG. 2). The void volume formed by the 4-4 ′ elongated portions provides a space for the distribution of the polishing composition on the surface of an arbitrary polishing composition distribution layer (reference numeral 8 in FIG. 1, reference numeral 8 ′ in FIG. 2). Can be provided. The polishing elements 4 to 4 ′ are made of the polishing composition (working fluid and / or coating material) covering the material properties of the polishing element and the surface of the polishing composition distribution layer (reference numeral 8 in FIG. 1, reference numeral 8 ′ in FIG. 2). Or over the polishing composition distribution layer (8 in FIG. 1, 8 ′ in FIG. 2) by an amount that depends at least in part on the desired flow of the polishing slurry.

  As illustrated by FIGS. 1 and 2, in some exemplary embodiments, at least a portion of the polishing elements 4-4 ′, in some embodiments, is at least a porous polishing surface (FIG. 1, a porous polishing element 4 having the reference numeral 14) in FIG. 2, which can make sliding or rotating contact with a substrate to be polished (not shown in FIG. 1). In other embodiments, the porous polishing element may not have a porous polishing surface 14, but has pores 15 distributed over substantially the entire porous polishing element 4. be able to. Such porous polishing elements may be useful as flexible polishing elements that exhibit some of the advantageous features of flexible polishing pads. A suitable porous polishing element is “POLISHING PAD WITH POROUS ELEMENTS AND METHOD OF MAKING AND USING THE”, filed on June 26, 2008, “Polishing Pad with POROUS ELEMENTS AND METHOD OF MAKING AND USING THE”. SAME ") is disclosed in co-pending US Provisional Patent Application No. 61/075970.

  One or more of the porous abrasive elements 4 can comprise a plurality of pores 15 distributed in the form of a porous foam and substantially throughout the abrasive element. The foam can be a closed cell foam or an open cell foam. Closed cell foam may be suitable in some embodiments. Preferably, the plurality of pores 15 in the foam exhibits a unimodal distribution of pore sizes, eg, pore diameter. In some exemplary embodiments, the plurality of pores exhibits an average pore size of at least about 1 nanometer (nm), at least about 100 nm, at least about 500 nm, or at least about 1 μm. In other exemplary embodiments, the plurality of pores exhibits an average pore size of up to about 100 μm, up to about 50 μm, up to about 10 μm, or up to about 1 μm. In some currently preferred embodiments, the plurality of pores exhibits an average pore size of about 1 μm to about 50 μm.

  1 and 2, the polishing surface 14 of the polishing elements 4-4 'can be a substantially flat surface or can be a rough surface. In some currently preferred embodiments, at least the polishing surface of each porous polishing element can take the form of an orifice, a passage, a groove, a channel, etc., for example, a fine surface opening or pore 15. Is formed to be porous. Such pores 15 in the polishing surface are present at the interface between the substrate (not shown) and the corresponding porous polishing element at the polishing composition (e.g., not shown, working fluid and / or polishing slurry). ) To be distributed and maintained.

  In some exemplary embodiments illustrated by FIG. 4, the polishing surface 14 comprises pores that are generally cylindrical capillaries. The pores 15 can extend from the polishing surface 14 into the polishing element 4. In a related embodiment, the polishing surface comprises pores 15 that are generally cylindrical capillaries extending from the polishing surface 14 into the porous polishing element 4. The pores need not be cylindrical, but can be other shapes such as conical, rectangular, pyramidal, and the like. The characteristic dimensions of the pores can generally be specified as depth along with width (or diameter) and length. Its characteristic pore dimensions can range from about 25 μm to about 6,500 μm in depth, from about 5 μm to about 1000 μm in width (or diameter), and from about 10 μm to about 2,000 μm in length. .

  In another exemplary embodiment (not shown), the polishing surface comprises pores in the form of a plurality of grooves, and each channel is preferably in a direction generally parallel to the polishing surface. , Extending over at least a portion of the polishing surface of the corresponding polishing element. Preferably, each groove extends across the entire polishing surface of the corresponding polishing element in a direction generally parallel to the polishing surface. In other exemplary embodiments (not shown), the pores can take the form of a two-dimensional array of grooves, each groove extending only over a portion of the polishing surface. .

In additional exemplary embodiments (not shown), the grooves can have virtually any shape, for example, cylindrical, triangular, rectangular, trapezoidal, hemispherical, and combinations thereof. It is. In some exemplary embodiments, the depth of each groove in a direction substantially perpendicular to the polishing surface of the polishing element is selected to be at least in the range of about 100 μm to about 7500 μm. In other exemplary embodiments, the cross-sectional area of each groove in a direction substantially perpendicular to the polishing surface of the polishing element ranges from about 75 square micrometers (μm ² ) to about 3 × 10 ⁶ μm ² . Selected to be.

  In additional exemplary embodiments, the support layer may be substantially incompressible, such as a hard film or other hard substrate, but preferably has a positive pressure directed toward its polishing surface. Give compressibility. In some exemplary embodiments, the support layer comprises a soft and flexible material such as a flexible rubber or polymer. In other exemplary embodiments, the support layer is preferably formed of a compressible polymeric material, with a foamed polymeric material being preferred. In some embodiments, closed cell foam may be suitable, but in other embodiments, open cell foam may be used. In additional exemplary embodiments, the abrasive element is provided with its support layer as a single sheet of abrasive elements attached to a support layer that can be a compressible or flexible support layer. be able to.

  The support layer is preferably liquid impervious to prevent penetration or permeation of the processing fluid into or through the support layer. However, in some embodiments, the support layer may comprise a liquid permeable material, alone or with any barrier that acts to prevent or inhibit liquid penetration or permeation through the support layer. it can. Further, for example, a porous support layer can be advantageously used to hold a working fluid (eg, polishing slurry) at the interface between the polishing pad and the workpiece being polished.

  In some exemplary embodiments, the support layer can include a polymeric material selected from silicone, natural rubber, styrene butadiene rubber, neoprene, polyurethane, polyester, polyethylene, and combinations thereof. The support layer can further include a wide variety of additional materials such as fillers, particulates, fibers, reinforcements and the like.

  Polyurethanes have been found to be particularly useful support layer materials, and thermoplastic polyurethanes (TPUs) are particularly suitable. In some presently preferred embodiments, the support layer is from one or more TPUs, such as (Lubrizol Advanced Materials, Inc., Cleveland, OH). Texin or Desmopan Tee (available from ESTANE TPU), Bayer Materials Science, Pittsburgh, PA (available) (TEXIN or DESMOPAN TPU), PELLETHANE TPU (available from Dow Chemical Company, Midland, MI) and the like.

  The abrasive element can include a wide variety of materials, with polymeric materials being preferred. Suitable polymeric materials are, for example, polyurethane, polyacrylate, polyvinyl alcohol polyester, polycarbonate, and (EIDuPont de Nemours, EIDuPont de Nemours, Inc., Wilmington, DE), including acetals available under the trade name DELRIN. In some exemplary embodiments, at least some of the abrasive elements include thermoplastic polyurethane, polyacrylate, polyvinyl alcohol, or combinations thereof.

  The abrasive element can also include a reinforced polymer or other composite material including, for example, metal particulates, ceramic particulates, polymeric particulates, fibers and combinations thereof. In some embodiments, the polishing element can be made conductive and / or thermally conductive by including therein a filler such as carbon, graphite, metal, or combinations thereof. In other embodiments, for example, polyaniline (PANI) sold under the trade name ORMECOM (available from Ormecon Chemie, Ammersbek, Germany), etc. The conductive polymer can be used with or without the conductive or thermal conductive fillers described above.

  In some exemplary embodiments, the polishing pad further comprises a flexible layer attached to a support layer opposite the polishing element. The flexible layer can be attached to the support layer using any bonding surface, but preferably an adhesive layer located at the interface between the flexible layer and the support layer is provided on the abrasive element. Used to attach the support layer to the opposite flexible layer.

  In some embodiments, the flexible layer is preferably compressible to provide a positive pressure that directs the polishing surface of the polishing element toward the workpiece being polished. In some exemplary embodiments, the support layer can include a soft and flexible material such as a flexible rubber or polymer. In other exemplary embodiments, the support layer is preferably formed of a compressible polymeric material, with a foamed polymeric material being preferred. In some embodiments, closed cell foam may be suitable, but in other embodiments, open cell foam may be used.

  In some specific embodiments, the flexible layer can include a polymeric material selected from silicone, natural rubber, styrene butadiene rubber, neoprene, polyurethane, polyethylene, and combinations thereof. The flexible layer can further include a wide variety of additional materials such as fillers, particulates, fibers, reinforcements and the like. The flexible layer is preferably liquid impervious (although permeable material can be used with any barrier that prevents or inhibits liquid penetration into the flexible layer).

  A preferred polymeric material for use in the flexible layer is polyurethane, with T.P.U (TPU) being particularly preferred. Suitable polyurethanes include, for example, polyurethanes available under the trade name PORON of Rogers Corporation, Rogers, Connecticut, and Dow Chemical, Midland, Michigan. , MI) under the trade name PELLETHANE, in particular polyurethanes available as PELLETHANE 2102-65D. Other suitable materials are, for example, polyethylene terepthalate (PET), such as biaxially oriented PET, widely available under the trade name MYLAR, and bonded rubber sheets (eg, , Revelte Cypress Sponge Rubber Products, Inc., Santa Ana, Calif. (BONDTEX), available from Rubberite Cypress Sponge Rubber Products, Inc., Santa Ana, Calif.).

  In some exemplary embodiments, a polishing pad according to the present disclosure has several advantages when used in a CMP process, such as improved in-plane polishing uniformity, a more evenly polished wafer surface. Increased edge die yield from the wafer, and improved CMP process operating tolerance and consistency. While not wishing to be bound by any particular theory, these effects separate the polishing surface of the polishing element from the flexible layer underneath the support layer, so that during the polishing process, This is provided by allowing the polishing element to “float” in a direction substantially perpendicular to the polishing surface of the element when the polishing pad is brought into contact with the workpiece.

  In some embodiments, separation of the polishing surface of the polishing element from the flexible underlayer includes a plurality of apertures extending from the first major surface, through the guide plate, to the second major surface. Can be augmented by incorporating the abrasive into any guide plate, including at least a portion of each polishing element extending into the corresponding opening, and each polishing element including the first of the guide plates. 2 extends from the main surface to the outside. Any guide plate that preferably comprises a hard or inflexible material can be used to maintain the spatial adaptation of the polishing surface and to maintain lateral movement of the element on the polishing pad. . However, in other embodiments, the spatial adaptation of the polishing element is maintained by bonding the element to the support layer, preferably by directly bonding the polishing element to the support layer, And since the lateral movement is prevented, the optional guide plate is not necessary.

  The optional guide plate can be formed of a wide variety of materials such as polymers, copolymers, polymer blends, polymer composites, or combinations thereof. Hard, non-flexible, non-conductive and liquid-impermeable polymeric materials are generally suitable and polycarbonate has been found to be particularly useful.

  In additional embodiments, the polishing pad of the present disclosure optionally covers at least a portion of the first major surface of the support layer and the first major surface of the optional guide plate (if present). The polishing composition distribution layer may be further provided. The arbitrary polishing composition distribution layer can be formed of a wide variety of polymer materials. The optional polishing composition distribution layer may include at least one hydrophilic polymer in some embodiments. Suitable hydrophilic polymers include polyurethanes, polyacrylates, polyvinyl alcohol, polyoxymethylene and combinations thereof. In one specific embodiment, the polishing composition layer preferably has a hydrogel material capable of absorbing from about 5 to about 60% by weight moisture to provide a smooth surface during the polishing process. For example, hydrophilic polyurethane or polyacrylate can be included.

  In additional exemplary embodiments, the optional polishing composition distribution layer is flexible to provide a positive pressure directed to the substrate during the polishing process when the polishing composition distribution layer is pressed. Material, such as porous polymers or foams. In some exemplary embodiments, the flexibility of the polishing composition distribution layer is selected to be less than the flexibility of the optional flexible layer. A porous or foam material having open or closed cells may be a suitable flexible material for use in any polishing composition distribution layer in some embodiments. In some specific embodiments, the optional polishing composition distribution layer has a porosity of about 10 to about 90%.

  In some exemplary embodiments, the polishing surface of the polishing element is formed flush with or indented from the exposed major surface of the optional polishing composition distribution layer. Can do. Such an embodiment can be advantageously used to hold a working fluid, such as an abrasive slurry, at the interface between the exposed abrasive surface of the abrasive element and the workpiece. In such embodiments, the polishing composition distribution is determined during any polishing process or in any conditioning process applied to the polishing surface of the polishing pad before, during or after contact with the workpiece. It can be advantageously chosen to include materials that are worn or eroded.

  In additional exemplary embodiments, the polishing composition distribution layer can act to distribute the polishing composition substantially uniformly across the surface of the substrate being polished, thereby making it more uniform. Polishing can be realized. The polishing composition distribution layer can optionally include anti-flow elements such as baffles, grooves (not shown), pores, etc. to adjust the flow rate of the polishing composition during polishing. In additional exemplary embodiments, the polishing composition distribution layer includes various layers of different materials to achieve a desired polishing composition flow rate at various depths from the polishing surface. Can do.

  In some exemplary embodiments, one or more of the polishing elements may include an open core region or cavity defined within the polishing element, although such a configuration is not necessary. Absent. In some embodiments, the core of the polishing element includes a sensor that detects pressure, conductivity, capacitance, eddy currents, etc., as described in WO / 2006/055720. Can be included. In another embodiment, the polishing pad may include a window extending through the pad in a direction perpendicular to the polishing surface, or an “endpoint” filed on May 15, 2008. POLISHING PAD WITH ENDPOINT WINDOW AND SYSTEM AND METHOD OF USING THE SAME ", co-pending US Provisional Patent Application No. 61 / 053,429 A transparent layer and / or a transparent polishing element can be used to enable optical endpoint detection of the polishing process as described in.

  The term “transparent layer” described above is intended to include a layer with a transparent region that can be formed of the same or different material as the rest of the layer. In some exemplary embodiments, the element, layer or region can be transparent, or formed transparent by applying heat and / or pressure to the material, or A transparent material can be introduced into the openings properly positioned in the layer to form a transparent region. In an alternative embodiment, the entire support layer is transparent to, or can be formed transparent to, the energy of the wavelength range of interest used by the endpoint detector. Can be formed. Suitable transparent materials for the transparent elements, layers or regions include, for example, transparent polyurethane.

  Furthermore, the term “transparent” as described above is intended to include elements, layers and / or regions that are substantially transparent to the energy of the wavelength range of interest used by the endpoint detector. Yes. In some exemplary embodiments, the endpoint detector takes the form of ultraviolet light, visible light, infrared light, microwaves, radio waves, combinations thereof, etc., using one or more electromagnetic energy sources. Give off radiation. In some embodiments, the term “transparent” means at least about 25% (eg, at least about 35%, at least about 50%, at least about at least about 25% of the energy of the wavelength of interest that hits the transparent element, layer or region. About 60%, at least about 70%, at least about 80%, at least about 90%, at least about 95%) is transmitted through the element, layer or region.

  In some exemplary embodiments, the support layer is transparent. In some exemplary embodiments, at least one polishing element is transparent. In additional exemplary embodiments, the at least one abrasive element is transparent, and its adhesive layer and support layer are also transparent. In a further exemplary embodiment, the support layer, guide plate, polishing composition distribution layer, at least one polishing element, or a combination thereof is transparent.

  The present disclosure further focuses on a method of using a polishing pad as described above in a polishing process, the method comprising contacting a surface of a substrate with a polishing surface of a polishing pad comprising a plurality of polishing elements, the method comprising: Some polishing elements include being porous and moving the polishing pad relative to the substrate to wear the surface of the substrate. In some exemplary embodiments, a working fluid can be supplied to the boundary between the surface of the polishing pad and the surface of the substrate. Suitable working fluids are known, for example, US Pat. No. 6,238,592 (B1), 6,491,843 (B1), and International Publication No. WO / 2002/33736. Can be found in brochures.

  The polishing pads described herein may be relatively easy and inexpensive to manufacture in some embodiments. The following briefly discusses some exemplary methods for forming a polishing pad according to the present disclosure, but the discussion is not intended to be exhaustive or vice versa. . Accordingly, in an additional exemplary embodiment, a method is provided for forming a polishing pad, the method comprising forming a plurality of polishing elements and attaching the polishing elements to a support layer to form a polishing pad. It comprises. Attaching the abrasive element to the support layer may include, in some embodiments, the use of a bonding material that performs thermal bonding or adhesive bonding, actinic radiation bonding, or combinations thereof.

  In some embodiments, the abrasive element is thermally bonded to the support layer. Thermal bonding, for example, brings the major surface of the support layer into contact with the surface of each abrasive element to form a bonded interface, and the abrasive element and support layer are softened and melted by the abrasive element and support layer, Alternatively, it can be realized by heating together to a temperature that flows together and forms an adhesive state at the bonding interface. Ultrasonic welding can also be used to perform thermal bonding of the abrasive element to the support layer. In some presently preferred embodiments, pressure is applied to the bonding interface and the polishing element and support layer are heated. In an additional presently preferred embodiment, the support layer is heated to a temperature above that at which the polishing element is heated.

  In another exemplary embodiment, bonding the polishing element to the support layer is a bond that forms a physical and / or chemical bond at the boundary between the polishing element and the major surface of the support layer. Including using the material. Such physical and / or chemical bonds may be formed in some embodiments using an adhesive disposed at the bonding interface between each abrasive element and the major surface of its support layer. it can. In other embodiments, the binding material is cured, for example, using thermal radiation, radiation curing (eg, actinic radiation such as ultraviolet light, visible light, infrared light, electron beam or other radiation source). By curing), a material that forms a bonded state can be obtained.

  In some embodiments, at least some of the abrasive elements are substantially non-porous abrasive elements. In some presently preferred embodiments, at least a portion of the polishing element can be a porous polishing element. Thus, in some exemplary embodiments, the method includes injection molding of a gas saturated polymer melt, injection molding of a reaction mixture that releases gas during the reaction to produce a polymer, and dissolving the polymer in a supercritical gas. Porous abrasive elements by injection molding of the resulting mixture, injection molding of a mixture of polymers incompatible in the solvent, injection molding of porous thermosetting microparticles dispersed in the thermoplastic polymer, and combinations thereof Forming.

  In some exemplary embodiments, the porous polishing element has pores distributed substantially throughout the polishing element. In other embodiments, the pores can be distributed substantially on the polishing surface of the porous polishing element. In some additional embodiments, the porosity imparted to the polishing surface of the porous abrasive element may be, for example, injection molding, crimping, mechanical drilling, laser drilling, needle punching, gas dispersion foaming, chemical processing and these Can be given by combination.

  It will be appreciated that the polishing pad need not comprise only substantially identical polishing elements. Thus, for example, any combination or arrangement of porous and non-porous abrasive elements can create a plurality of porous abrasive elements. Also, any number, combination or arrangement of porous polishing elements and substantially non-porous polishing elements, in some embodiments, form a polishing pad having a floating polishing element coupled to a support layer. However, it will also be understood that it can be used advantageously.

  In additional exemplary embodiments, the polishing elements can be arranged to form a pattern. Any pattern can be advantageously employed. For example, the polishing elements can be arranged to form a two-dimensional array, eg, a rectangular, triangular or circular array of polishing elements. In additional exemplary embodiments, the polishing element can include both a porous polishing element and a substantially non-porous polishing element arranged in a pattern on the support layer. In some exemplary embodiments, the porous polishing element is advantageously arranged with respect to several substantially non-porous polishing elements so that the major surface of the support layer has a porous polishing element. And an array of non-porous abrasive elements can be formed. In such embodiments, the number and arrangement of porous abrasive elements relative to the substantially non-porous abrasive element can be advantageously selected to obtain the desired polishing capability.

  For example, in some exemplary embodiments, the porous polishing element can be arranged substantially near the center of the major surface of the polishing pad, and the substantially non-porous polishing element is , Substantially can be arranged near the periphery of the main surface of the polishing pad. Such exemplary embodiments desirably and more effectively hold a working fluid, such as a polishing slurry, in the contact zone between the polishing pad and the wafer surface, thereby improving wafer surface polishing uniformity. (E.g., reduced dishing at the wafer surface) and the amount of waste slurry generated by the CMP process can be reduced. Such exemplary embodiments can also desirably perform more aggressive polishing at the edge of the die, thereby reducing or eliminating the formation of edge ridges, and yield and Die polishing uniformity can be improved.

  In other exemplary embodiments, the porous polishing elements can be arranged substantially near the edges of the major surface of the polishing pad, and the substantially non-porous polishing elements are The main surface of the pad can be arranged substantially near the center. Other arrangements and / or patterns of abrasive elements are also contemplated within the scope of this disclosure.

  In certain embodiments, the abrasive elements can be arranged in a pattern by placement on the major surface of the support layer. In other exemplary embodiments, the polishing elements can be arranged in a pattern using a template of the desired pattern, and the support layer is at the bonding interface such that the major surface of the support layer is , In contact with each abrasive element, and can be placed on or under the abrasive element and template prior to bonding.

  Exemplary embodiments of polishing pads having polishing elements according to the present disclosure can have a variety of configurations and features that allow their use in a wide range of polishing applications. In some presently preferred embodiments, the disclosed polishing pads may be particularly well suited for chemical mechanical planarization (CMP) of wafers used in the manufacture of integrated circuits and semiconductor devices. is there. In some exemplary embodiments, the polishing pads described in this disclosure can provide an advantage over known polishing pads.

  For example, in some exemplary embodiments, a polishing pad according to the present disclosure maintains a good working fluid used in the CMP process at the boundary between the polishing surface of the pad and the substrate surface being polished. Acting thereby, it can improve the effectiveness of the working fluid in increasing polishing. In other exemplary embodiments, a polishing pad according to the present disclosure can reduce or eliminate dishing and / or edge erosion on the wafer surface during polishing. In some exemplary embodiments, the use of a polishing pad according to the present disclosure in a CMP process improves wafer in-plane polishing uniformity, a more evenly polished wafer surface, increased edge die yield from the wafer, and Improved CMP process operating latitude and consistency can be provided.

  In additional exemplary embodiments, the use of a polishing pad having a porous element according to the present disclosure can process larger diameter wafers while maintaining the required degree of surface uniformity and obtaining high chip yields. Can process more wafers or reduce process time and wear of the pad conditioner before the pad surface needs to be adjusted to maintain polishing uniformity on the wafer surface .

An exemplary polishing pad according to the present disclosure will now be described with reference to the following non-limiting examples.
(Example)

The following non-limiting examples are for making both porous and non-porous polishing elements that can be used to make a polishing pad comprising a plurality of polishing elements attached to a support layer. Various methods will be described.
Example 1

  This example describes the fabrication of both a non-porous abrasive element (Example 1A) and a porous abrasive element (Example 1B) in which pores are distributed substantially throughout the abrasive element. The porous abrasive element was made by injection molding a mixture of polymer dissolved in supercritical gas.

  Thermoplastic polyurethane with a melt index of 5 at 210 ° C and a force of 3800 g (Esthein ET 60 DT 3 NA 002 B, Lubrisol Advanced Materials Inc. , Cleveland, Ohio (ESTANE ETE 60DT3 NAT 022P, Lubrizol Advanced Materials, INC., Cleveland, OH)). 80 ton MT Arburg injection molding machine (Alberg, equipped with a single screw 30 mm in diameter (L / D = 24: 1) at high temperature and pressure to produce polymer melt • Thermoplastic polyurethane pellets were fed to GM B. Her, Rossburg, Germany (Arburg GmbH, Lossburg, Germany).

  In Example 1A, the polymer melt was injection molded in a 32 cavity cold runner mold (solid injection weight 9.2 grams), having a hollow internal cylindrical cavity and a metering of 0.15 grams / element. A non-porous abrasive element was formed.

  In Example 1B, a Trexel S.I. equipped with a Mass Pulse Dosing delivery system (available from Trexel, INC., Woburn, MA).・ Nitrogen gas was injected into the polymer melt under high temperature and high pressure using Trexel SII-TR10, 0.6% w / w supercritical nitrogen and polymer melt Resulted in the production of a blend of The blend of supercritical nitrogen and polymer melt was injection molded in a 32 cavity cold runner mold (solid injection weight 9.2 grams), and had a hollow internal cylindrical cavity and a weigh of 0.135 grams A fine abrasive element, in which the pores were distributed substantially throughout the abrasive element.

  The temperature, mold temperature, screw, injection, pack pressure, molding time and clamp tonnage of each zone of the extruder are summarized in Table 1 of Comparative Example 1A and Example 1B.

（実施例２）

(Example 2)

  This example demonstrates the creation of a porous abrasive element having pores distributed substantially only on the abrasive surface of the abrasive element.

  First, a thermoplastic polyurethane with a melt index of 5 at 210 ° C and a force of 3800g (Esthein ET 60 DT 3 NA 002 P, Lubrizol Advanced Material Incorporated, Cleveland, Ohio (ESTANE ETE 60DT3 NAT 022P, Lubrizol Advanced Materials, INC., Cleveland, OH)) is injection molded to form a non-porous abrasive element, ie as described in Example 1A, A generally cylindrical abrasive element having a diameter of about 15 mm was made.

Then, nanosecond pulse rate, 15 kHz repetition rate, 60-80% power setting (0.8-1.1 watts), and 100 mm / second to 300 mm / second (total run time 29.8 seconds to 13.2 The abrasive surface of the injection molded abrasive element was laser drilled to form a porous abrasive element using an AVIA 355 nm ultraviolet laser (Coherent, Inc., Santa Clara, Calif.) Operating at a scan rate of seconds.
(Example 3)

  This example shows a non-porous polishing element in which pores in the form of a plurality of grooves formed on the polishing surface are substantially dispersed only on the polishing surface of the polishing element (Example 3A). And the preparation of both porous abrasive elements (Example 3B).

  A thermoplastic polyurethane having a melt index of 5 at 210 ° C. and a force of 3800 g (available from Lubrizol Advanced Materials, Inc., Cleveland, Ohio) A porous abrasive element was produced by injection molding of E60, DTE3, NTA2, 022, P (ESTANE ETE 60DT3 NAT 022P). The pellets made of the thermoplastic polyurethane were heated at a high temperature and a high pressure at an Engel 100 ton injection molding machine (Angel Machinery Inc., York, equipped with a single screw 25 mm in diameter (L / D = 24.6: 1), York, It was fed to Pennsylvania (Engel Machinery, Inc., York, PA) to produce a polymer melt.

  The thermoplastic polyurethane melt was injection molded in a two-cavity cold runner mold (injection weight 34.01 grams) with a ribbed mold insert in one cavity and a blank mold insert in the other cavity. . The injection molding conditions are summarized in Table 2.

  FIG. 5 illustrates one exemplary apparatus useful in a method for thermal bonding of an abrasive element to a support layer. A number of non-porous polishing elements 4 ′ can be arranged in a two-dimensional arrangement pattern on a template 30 (see FIG. 3A) disposed on the release layer 34. The support layer 10 can be placed over the exposed surface of the polishing element 4 '. The release layer 34 ′ can be placed over the exposed surface of the support layer 10, and the entire assembly can be placed between the upper platen 36 and the lower platen 38 of the hot press. .

It will be understood that the relative order and arrangement of elements in this exemplary apparatus can be varied without departing from the scope of the present disclosure. Thus, for example, the support layer 10 is arranged on the release layer 34 before non-porous abrasive elements are arranged in a two-dimensional array pattern on the template, and the arrayed elements are covered with the release layer 34 '. Then, it can be covered with the template 30. Furthermore, the porous polishing element 4 can be replaced by a non-porous polishing element in any number, arrangement or combination.
Example 4

  Example 4 shows a method for thermally bonding an injection molded thermoplastic polyurethane abrasive element made according to Example 1 to a support layer membrane comprising a thermoplastic polyurethane.

  Abrasive elements (15 mm diameter) are available from Thermoplastic Polyurethane (TPU) according to Example 1, ie, (Lubrizol Advanced Materials, Inc., Cleveland, OH) ) Estane 58144 was formed by injection molding. The abrasive elements are arranged in a generally circular two-dimensional array pattern using a template as shown in FIG. 6, and at 182 ° C., thermoplastic polyurethane (TPU), ie (Lubrisol Advanced Material Incorporated, 26 μm thick support layer formed by extrusion of CESTBRAN, Ohio (available from Lubrizol Advanced Materials, INC., Cleveland, OH) Estein 58887 NTA 02 (ESTANE 58887-NAT02) To form a membrane structure.

Thermal bonding was performed on a heated platen press (Pasadena Hydraulics Press Company, EI Monte, Calif.) Substantially as shown in FIG. The upper platen was maintained at about 143.3 ° C and the lower platen was maintained at about 26.7 ° C. Sufficient pressure was applied to effect contact between the TPU abrasive element and the TPU support layer positioned between the paper release liners as shown in FIG. Bonding was substantially complete and uniform after 30 seconds. After the TPU support layer is thermally bonded to the TPU abrasive element, the paper liner is removed to obtain a transparent integrated sheet of thermally bonded TPU abrasive element and TPU support layer as shown in FIG. It was.
(Example 5)

  Example 5 illustrates a method of thermally bonding an injection molded thermoplastic polyurethane abrasive element made according to Example 1 to a support layer membrane comprising a different thermoplastic polyurethane.

  Abrasive elements (6mm diameter), Estein 58212 (ESTANE) available from TPU (Lubricol Advanced Materials, Inc., Cleveland, Ohio) 58212)) by injection molding. After the polishing elements were arranged in a generally circular two-dimensional array pattern using a polycarbonate template (FIG. 6), a 122 μm thick TPU membrane support layer (Stevens Ulsein ST 1522 CEL, Heat-bonded to Easthampton, Mass. (Stevens Urethane ST-1522CL, Easthampton, MA).

Thermal bonding was performed on a heated platen press (HIX N-800 single platen press, Pittsburgh, KS) substantially as shown in FIG. The upper platen was maintained at about 149 ° C and the lower platen was maintained at about 26.7 ° C. A pressure of 40 psi (about 275,790 Pa) was applied to the TPU abrasive element and the TPU support layer disposed between the paper release liners as shown in FIG. Bonding was substantially complete and uniform after 15 seconds. After the TPU support layer was thermally bonded to the TPU abrasive element, the paper liner was removed to obtain a transparent integral sheet comprising the TPU support layer and the thermally bonded TPU abrasive element.
(Example 6)

  Example 6 shows an alternative method of thermally bonding an injection molded thermoplastic polyurethane abrasive element made according to Example 1 to a support layer membrane comprising polyester.

  By injection molding a TP U (TPU) according to Example 1 (ESTANE 58144 available from Lubrizol Advanced Materials, Inc., Cleveland, Ohio). A polishing element (diameter 15 mm) was formed. The abrasive element is divided into a support layer, ie, a 102 μm thick polyester film (3M Thermo-Bond 615 Film, 3M Company, St Paul, MN)) directly arranged on the main surface and thermally bonded to the support layer.

Thermal bonding was performed on a heated platen press (Pasadena Hydraulics Press, EI Monte, Calif.). The upper platen was maintained at about 121 ° C and the lower platen was maintained at about 26.7 ° C. Sufficient pressure was applied to effect contact between the TPU abrasive element positioned between the paper release liner and its support layer. Bonding was substantially complete and uniform after 20 seconds. After the support layer was thermally bonded to the TPU abrasive element, the paper liner was removed to obtain a transparent monolithic sheet consisting of the support layer and the thermally bonded TPU abrasive element.
(Example 7)

  Example 7 shows a method for thermally bonding a thermoplastic polyurethane abrasive element made according to Example 1 to a support layer comprising a different polyester membrane.

  T.P.U (TPU) according to Example 1 (ESTANE 58144 available from Lubrizol Advanced Materials, INC., Cleveland, OH) A polishing element (15 mm in diameter) was formed by injection molding. The abrasive element was directly aligned to the main surface of the support layer, ie, a 102 μm thick polyester film (3M Thermo-Bond 668 Film, 3M Company, St. Paul, Minn.) And thermally bonded to the support layer.

Thermal bonding was performed on a heated platen press (HIX N-800 single platen press, Pittsburgh, KS). The upper platen was maintained at about 149 ° C and the lower platen was maintained at about 26.7 ° C. A pressure of 40 psi (about 275,790 Pa) was applied to the TPU polishing element and the TPU support layer disposed between the paper release liners. Bonding was substantially complete and uniform after 15 seconds.
(Example 8)

  Example 8 illustrates a method of thermally bonding an integral membrane comprising an abrasive element bonded to a support layer to a flexible layer to form a polishing pad having a floating element.

  As described in Example 4, after the TPU support layer was thermally bonded to the TPU polishing element, the main surface of the support layer opposite the polishing element was bonded to a 127 μm thick adhesive layer (Three M.9672). • 1.59mm thick polyurethane foam flexible layer (3M 9672 Transfer Adhesive, 3M Company, St. Paul, Minn.) By manual lamination to Transfer Adhesive, 3M Company, St. Paul, MN Attached to Rogers PORON urethane foam, part number 4701-50-20062-04, obtained from American Flexible, Chaska, Minn. The polishing pad is a pressure-sensitive adhesive (3M 442DL Transfer Tape, 3M Company, St. Paul, MN), 3M Company, St. Paul, MN Was completed by manually laminating the polyurethane foam flexible layer on the opposite side of the abrasive element.

FIG. 8 is a photograph of a polishing pad comprising a floating polishing element bonded to a support layer, which according to yet another exemplary embodiment of the present disclosure, the support layer is bonded to a flexible sublayer by an adhesive. A pressure sensitive adhesive is applied to the flexible sublayer on the major surface opposite the abrasive element.
Example 9

  The polishing pad of Example 8 was attached to an aluminum polishing platen using a transfer tape pressure sensitive adhesive on the bottom surface of the flexible foam sublayer. The polishing platen with the polishing pad is placed in contact with a diamond pad dresser (3M Sintered Abrasive Conditioner A3800). (CETR) Placed in Polisher (CP-4, Center for Tribology, Inc., Cambell, CA) under various conditions (See Table 1) and stressed in deionized water for 5 minutes.

  After each test condition, the pad was inspected for element debonding. To determine whether the pad can withstand continuous conditioning or wear, the top of the pad is 8 lbf (about 3,632 gf), a 60 rpm table and platen speed, and 10 mm vibration (4 Cycle / min) until wear. During the test, the pad was periodically checked for delamination of the polishing element, but nothing was detected. The test conditions are summarized in Table 3.

  Individual porous abrasive elements, and optionally non-porous abrasive elements, can be attached to the support layer using the teachings set forth in the detailed description and examples above, to provide various additional features of the invention. A polishing pad according to any of the embodiments can be formed. It will be appreciated that a polishing pad according to an exemplary embodiment of the present invention need not comprise only substantially identical polishing elements. Thus, for example, any combination or arrangement of porous and non-porous abrasive elements can form a plurality of porous abrasive elements. Also, any number, combination or arrangement of porous polishing elements and substantially non-porous polishing elements, in some embodiments, includes a polishing pad having a floating polishing element coupled to a support layer. It can be advantageously used to form.

  In one particularly advantageous embodiment describing a single polishing pad, the multicavity mold may be provided with a backfill chamber, where each cavity corresponds to one polishing element. A plurality of polishing elements, which can include a porous polishing element and a non-porous polishing element, can be formed by injection molding a suitable polymer melt into the multi-cavity mold and the backfill chamber can be the same polymer melt or separate It can be formed by backfilling with a polymer melt of to form a support layer. The abrasive element remains attached to the support layer when the mold is cooled, thereby forming a plurality of abrasive elements as a single sheet comprising the abrasive element and the support layer.

  Throughout this specification the phrase “one embodiment”, “some embodiments”, “one or more embodiments” or “embodiments” precedes the term “embodiments” and “examples”. The specific configuration, structure, material, or feature described in connection with that embodiment, regardless of whether or not it includes the term “a”, is out of the several exemplary embodiments of the present invention. In at least one embodiment. Thus, the appearances of phrases such as “in one or more embodiments”, “in some embodiments”, “in one embodiment”, or “in an embodiment” in various places in the specification are not necessarily It is not intended to refer to the same of several exemplary embodiments of the invention. Furthermore, the particular shapes, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments.

  Although the present specification has been described in detail in several exemplary embodiments, those skilled in the art may readily make alternatives, modifications and equivalents to these embodiments in order to realize an understanding of the above. It will be recognized correctly that we can come up with. Accordingly, it is to be understood that this disclosure should not be unnecessarily limited to the exemplary embodiments described above. Specifically, a description relating to a range of numbers by endpoint includes all numbers included in the range as used herein (eg, 1 to 5 is 1, 1.5, 2, 2 .75, 3, 3.80, 4 and 5). In addition, all numbers used herein are intended to be modified by the term “about”. Further, all publications and patents referred to herein are to the same extent as if each individual publication or patent was specifically and individually indicated to be incorporated by reference. Which is incorporated herein by reference in its entirety.

  Various exemplary embodiments have been described. These and other embodiments are also within the scope of the following claims.

Claims (19)

A support layer having a first main surface and a second main surface opposite to the first main surface;
A polishing composition distribution layer having a second main surface on the first main surface of the support layer and comprising a plurality of openings;
A plurality of abrasive elements bonded to the first major surface of the support layer without using an adhesive ;
With
The polishing element includes an extending portion extending along a first direction substantially perpendicular to a plane including the first and second main surfaces of the support layer, and the first main surface of the support layer. And a mounting flange attached to the
The extending portion of the polishing element extends along the first direction through the opening of the polishing composition distribution layer,
Each polishing element having a polishing surface exposed, Migaku Ken pad. Further comprising a flexible layer attached to the second major surface of the support layer, the polishing pad of claim 1.   The polishing pad of claim 1, wherein each polishing element extends along the first direction at least about 0.25 mm above a plane that includes the support layer. At least one of the polishing elements comprises a porous polishing element;
The polishing pad of claim 1, wherein each porous polishing element comprises a plurality of pores.   The polishing pad of claim 1, wherein each polishing element is bonded to the support layer using only heat and pressure.   The at least some of the polishing elements are selected to have a cross-sectional area taken in the first direction, selected from circular, elliptical, triangular, square, rectangular and trapezoidal. The polishing pad as described.   The polishing pad according to claim 1, wherein the plurality of polishing elements are formed as a single sheet comprising the polishing element and a support layer.   The polishing pad of claim 1, wherein at least a portion of the polishing element comprises thermoplastic polyurethane, polyacrylate, polyvinyl alcohol, or a combination thereof.   The polishing pad of claim 1, wherein the polishing element has at least one dimension of about 0.1 mm to about 30 mm.   The polishing pad according to claim 1, wherein the support layer is made of thermoplastic polyurethane.   The polishing pad of claim 1, wherein at least a portion of the polishing element comprises abrasive particulates.   The polishing pad according to claim 1, wherein the polishing elements are arranged in a two-dimensional arrangement pattern on a main surface of the support layer.   The polishing pad of claim 1, wherein at least one polishing element is transparent.   The polishing pad according to claim 1, wherein the support layer is transparent. A method of using a polishing pad,
Contacting the surface of the substrate with the polishing surface of the polishing pad of claim 1;
Moving the polishing pad relative to the substrate to wear the surface of the substrate. A method of making a polishing pad,
Forming a plurality of abrasive elements;
Bonding the polishing element to a support layer to form a polishing pad according to claim 1. The method of claim 16 , further comprising arranging the plurality of polishing elements in a predetermined pattern prior to thermally bonding the polishing elements to the support layer. The method of claim 16 , wherein bonding the polishing element to the support layer includes thermal bonding, actinic radiation bonding, adhesive bonding, and combinations thereof. The polishing pad according to claim 1, further comprising a guide plate between the first main surface of the support layer and the second main surface of the polishing composition distribution layer.

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