COMPOSITE POLISHING PAD

Abstract

An abrasive article referred to as composite polishing pad (CPP) includes a plurality of fixed abrasive elements or a plurality of chemical mechanical polishing (CMP) pads attached to a plurality of pressure pads suspended to flexible structures capable to follow the wafer topography. A plurality of stems with dimpled ends act on the pressure pads to generate desired pressure acting on the wafer. The stems are attached to a spring arrangement capable of substantial vertical deflection under a desired load. In one embodiment a plurality of pressure pads suspended to a plurality of stems by revolute joints. The stems are attached to a spring arrangement capable of substantial vertical deflection under a desired load. In another embodiment, a plurality of pressure pads are attached to a plurality of stems suspended to a series of springs capable of substantial vertical deflection under a desired load.

Description

FIELD OF THE INVENTION

The present invention is directed to an abrasive article including a plurality of abrasive element independently attached to gimbal structures.

BACKGROUND OF THE INVENTION

The invention relates to modifying the rigid substrate of a fixed abrasive article or a chemical mechanical pad used in semiconductor wafer polishing.

Chemical mechanical polishing (CMP) processes are used n semiconductor wafer fabrication to polish and planarize a semiconductor wafer. CMP processes involve placing an abrasive between a relatively stiff pad and a semi-conductor wafer and moving the pad and the semiconductor relatively to each of the to modify the surface of the wafer. The abrasives used in CMP process can in the form of a slurry or fixed abrasive particles, or a fixed abrasive element.

CMP processes attempt to remove material selectively from high location i.e. features having dimensions on the scale of those features commonly produced by photolithography, to planarize the wafer surface. CMP processes also attempt to remove material uniformly on the scale of the semiconductor wafer so that each die on the wafer is planarized to the same degree in an equivalent amount of time. The rate of planarization for each die is preferably constant over the entire wafer. It is difficult to achieve both these objective simultaneously because semiconductor wafers are often curved and warped. Semiconductor wafers present a topography with roughness, short and long range waviness in the radial and circumferential directions. At the microscopic level a semiconductor wafer is analogous to a potato ship. In addition some of the semiconductor wafers include numerous step height variations and protrusions, which are produced during the fabrication sequence of an integrated circuit on a wafer. These height variations and the wafer topography of the semiconductor wafer can interfere with the uniformity of the polishing process such that some regions of the wafer become over polished while other regions remain under polished.

In modern integrated circuit fabrication, layers of material are applied to embedded structures previously formed on semiconductor wafers. CMP is an abrasive process used to remove these layers and polish the surface of a wafer flat to achieve the desired structure. CMP may be performed on both oxides and metals and generally involves the use of chemical slurries applied via a polishing pad that is moved relative to the wafer (e.g., the pad may rotate circularly relative to the wafer). The resulting smooth, flat surface is necessary to maintain the photolithographic depth of focus for subsequent steps and to ensure that the metal interconnects are not deformed over contour steps.

The planarization/polishing performance of a pad/slurry combination is impacted by, among other things, the mechanical properties and slurry distribution ability of the polishing pad. Typically, hard (i.e., stiff) pads provide good planarization, but are associated with poor with-in wafer non-uniformity (WIWNU) film removal. Soft (i.e., flexible) pads, on the other hand, provide polishing with good WIWNU, but poor planarization. In conventional CMP systems, therefore, harder pads are often placed on top of softer pads to improve WIWNU. Nevertheless, this approach tends to degrade planarization performance when compared to use of a hard pad alone.

It is therefore the case that designing CMP polishing pads requires a trade-off between WIWNU and planarization characteristics of the pads. This trade-off has led to the development of polishing pads acceptable for processing dielectric layers (such as silicon dioxide) and metals such as tungsten (which is used for via interconnects in subtractive processing schemes). In copper processing, however, WIWNU directly impacts over-polishing (i.e., the time between complete removal of copper on any one area versus complete removal from across an entire wafer surface) and, hence, metal loss and, similarly, planarization as expressed by metal loss. This leads to variability in the metal remaining in the interconnect structures and impacts performance of the integrated circuit. It is therefore necessary that both planarity and WIWNU characteristics of a pad be optimized for best copper process performance.

Some of the above-described concepts can be illustrated graphically. FIG. 1 illustrates the surface of a post-CMP wafer 100 with copper interconnects 101 defined in a low-K dielectric layer 103. Stress induced cracking damage 102 is seen on the surface of the dielectric layer 103, as a result of using a conventional polishing pad. Dishing and erosion increase with over-polishing, hence there is a need to minimize over-polishing of copper wafers.

CMP processes that employ slurry have been modified in an effort to overcome the problem of non-uniform polishing as summarized above. As proposed by Goetz (2008) a composite polishing pad that includes a first elastic material carrying fixed abrasive tiles. The elastic side of the first elastic layer is attached to a second stiff layer. Fixed abrasive polishing do not rely on the transport of loose abrasive particles over the surface of the pad to effect polishing. The abrasive tiles include abrasive particles disposed in a binder and bonded to the backing, which forms a relatively high modulus fixed abrasive element. The proposed approach by Goetz suffers from a lack of ability to follow the topography of the semiconductor wafer to cause uniform cutting pressure during the polishing process.

Pressure sensing elements 300 are also connected to a pressure control mechanism to effect an appropriate pressure profile during polishing is shown in FIG. 3 by Baraj et al. (2009). Monitoring the pressures detected by the pressure sensing elements 301 and comparing that information to an established pressure model apply a predetermined pressure profile. Differences between the actual pressures and the pressure model may then be used to alter the polishing operations to affect the desired pressure profile. This approach is effective for long range waviness. The size of the sensing device is substantially larger than the die size leading to an average pressure detection not an instantaneous pressure detection as required to compensate for dishing and over polishing for small wafer features. In addition short range wavelength pressure fluctuations cannot be readily detected.

SUMMARY OF THE INVENTION

The proposed solution suspends each polishing element to comply with the semiconductor topography in a planar fashion while applying a desired load and pressure independently of the location on the wafer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates the surface of a post-CMP wafer.

FIG. 2 is a cross section view of a wafer is a schematic cross sectional view of a portion of an abrasive article reported in prior art.

FIG. 3 is a cross section view of a wafer is a schematic cross sectional view of a portion of an abrasive article reported in prior art.

FIG. 4 is a cross section view of an example embodiment of the present invention.

FIG. 5 is an exploded view a single component forming the composite universal polishing pad (CPP), according to an example embodiment.

FIG. 6 gives a view of an assembled CPP, according to an example embodiment.

FIG. 7 gives an exploded view of the layers forming a CPP, according to an example embodiment.

FIG. 8 gives a close up view of the preload structure and the gimaballing structure where a polishing pad attached, according to an example embodiment.

FIG. 9 gives a close up view of the out of plane (curvilinear) springs forming the gimbal structure, according to an example embodiment.

FIG. 10 gives a close up of the preload structure with the preload stem supported by a series of out of plane springs, according to an example embodiment.

FIG. 11 gives a concept of using a continuous polishing pad, according to an example embodiment.

FIG. 12 gives a view a single component forming a CPP with a continuous polishing pad, according to an example embodiment.

FIG. 13 gives a view of a single component forming a CPP with a continuous polishing pad, according to an example embodiment.

FIG. 14 gives an exploded view of a single component forming a CPP with a continuous polishing pad, according to an example embodiment.

FIG. 15 gives a cross section of a CPP with preload stems with a polishing pad attached to the end of the preload stems, according to an example embodiment.

FIG. 16 gives a 3-d view of the load layer with each stem connected to a preload spring, according to an example embodiment.

FIG. 17 gives a close up view of the preload stems supported by a series of springs to cause deflection under an externally applied load onto the carrier pad, according to an example embodiment.

FIG. 18 shows a polishing pad (with or without abrasives) attached to the stem ends spring loaded and attached to a carrier pad, according to an example embodiment.

FIG. 19 gives an exploded view polishing pad (with or without abrasives) attached to the stem ends spring loaded and attached to a carrier pad, according to an example embodiment.

FIG. 20 gives a cross section of a CPP concept with individual pads or abrasives attached to the ends of load stems, according to an example embodiment.

FIG. 21 gives a close up view of the preload stems supporting polishing pads or abrasive elements, according to an example embodiment.

FIG. 22 gives a cross section of a CPP concept with individual polishing pads or abrasive elements supported by a revolute or cylindrical joint, according to an example embodiment.

FIG. 23 gives a cross section of a CPP concept with polishing pads supported by a revolute or cylindrical joint, according to an example embodiment.

FIG. 24 gives a close up view of the preload stems with an end revolute joint connected to a supporting pad, according to an example embodiment.

FIG. 25 gives a polishing pad arrangement with individual pad connected though a non-straight link, according to an example embodiment.

FIG. 26 gives an exploded view of the polishing pad arrangement shown in FIG. 25, according to an example embodiment.

DETAILED DESCRIPTION

Described herein is a pad suitable in a variety of CMP processes. A plurality of independently suspended polishing pads 401 are assembled into a polishing article 400 referred to as composite polishing pad (CPP). Each polishing pad is suspended to a pressure pad 402 attached to a flexure 403 and subject to a substantially constant preload. The preload is applied through a stem end 406 referred to as dimple acting on the opposite side of the flexure suspending the polishing pad. Each polishing pad applies a substantially constant pressure via the stem independently of its location on the semiconductor wafer. The suspended polishing pad follows the contour of the semiconductor wafer regardless of the waviness of the semiconductor wafer. The preload apparatus is formed of a stem 406 attached to a spring mechanism 407 allowing substantially constant load as a function of vertical displacement. The ability of each polishing pad to comply in the plane of the wafer and follow the wafer runnout causes substantially uniform material removal.

In one embodiment, a series of independent pressure pads 602 attached to independent stems 603 supported by preload flexures. In turn the polishing pads attached to the pressure allowing substantially constant load as a function of vertical displacement during polishing. The ability of each pressure pad to comply vertically with respect to plane of the wafer assures a constant pressure at each pressure pad 602.

In one embodiment, a series of independent pressure pads 802 attached via a spherical joints 803 to independent stems 804 supported to preload spring flexures 805. The flexures 805 deflect under a normal load to the pressure pads. In turn the polishing pads attached to the pressure pad allow substantially constant load as a function of vertical displacement during polishing. The ability of each polishing pad to comply in the vertical direction of the wafer and in the plane of wafer assures a constant pressure at each pressure pad independently of the wafer waviness and runnout.

In one embodiment of the present invention, the pressure applied by each polishing is made variable from inner diameter to outer diameter to cause uniform material removal throughout the semiconductor wafer as the travel contact length of each polishing pad is not constant from inner diameter to outer diameter. For example, the outer polishing pads can be envisioned to have a larger preload to apply a larger pressure in order to remove more material. The polishing pad may also include polishing fluid or slurry distribution layer.

The present invention recognizes the importance of tailored polishing pressure to maintain a uniform polishing action. Fragile low-K materials can be easily damaged by high stresses resulting from polishing operations. Nucleation of failure sites can occur at local high-pressure spots. A constant pressure pad configured according to the present invention provides the necessary information to develop polishing processes which do not exceed critical stress levels during processing operations. Designing the preload spring to yield a constant preload is a strategy to achieve uniform pressure to maintain a uniform polishing action.

In some embodiments of the present invention, the polishing pad may be configured to apply a higher pressure at a specific location or a variable pressure at various radii of the semiconductor wafer. For example, the polishing pads can be made of various materials such as polyurethane, polyester, polycarbonate, delrin, etc. In varying embodiments of the present invention, polishing elements are made of any suitable material such as polymer, metal, ceramic or combination thereof and capable of movement in the vertical axis and complying to the semiconductor wafer topography. Alternatively, or in addition, the polishing elements may be made in composite structures where a core is made of one material and the shell is made of another material (e.g., one of which is transparent or conductive). For example, a polishing element may contain a core made of a conductive material such as graphite or conductive polymer.

Pressure control during polishing is critical especially for nanometer feature sizes. Table 1 shows the decrease in required pressure as a function of material type and die feature size.

FIG. 4 depicts a cross section of one embodiment of the present invention. A first adhesive layer 408 is applied to a backing element 409 supporting a preload flexure consisting of a stem protruding from the base 411 and in contact with a pivoting flexure supporting the polishing pad 403. An adhesive layer 404 holds the preload 411 and dimple structure 406 attached to the backing layer 409. An opening is made in the backing layer beneath the preload fixture to allow for the deformation of the preload flexure 411 without interference during the pressure generation during the polishing process. A series of protruding pillars 405 provide a fixed boundary condition supporting the outer edges of the pivoting flexure. Finally the abrasives 401 are attached to the pressure pads 402.

FIG. 5 is an exploded view of a single polishing pad assembly 420 contained in the CPP concept. A backing layer 409 with an opening 414 with an opening is assembled via an adhesive layer 408 to a preload flexure 407. The preload fixture has a preload stem 406 attached to a preload flexure design 407 capable of imparting a substantially constant preload for example. A series of protruding pillars 405 provide support to the pivoting flexures 403 supporting the pressure pads 401. The embodiment disclosed allows for the pressure pads 401 to follow the semiconductor wafer topography while allowing a locally stiff pad capable of planarazing the wafer.

FIG. 6 shows a series of individually suspended and preloaded polishing elements 401 assembled in a polishing pad referred to as CPP. A backing element 409 supports the preload flexure 411 applying a substantially constant load if desired. It is therefore the case that the proposed polishing pad design does not require a trade-off between WIWNU and planarization characteristics of the pads. This lack of required trade-off has led to the development of polishing pads (CPP) acceptable for processing dielectric layers (such as silicon dioxide) and metals such as tungsten (which is used for via interconnects in subtractive processing schemes). Avoiding over polishing in copper processing is achieved by CPP.

An exploded view is offered in FIG. 7 shows the various components involved in fabricating a composite universal polishing pad (CPP). It is foreseen that the backing layer 409 is attached to the preload flexure layer 411, followed by the attachment of the pivoting flexure layer 403 and finally the polishing pads 401 (CMP pads or abrasive pads) are finally added as the last step of the process.

A close up view in FIG. 8 offers a view of the assembly of each independent polishing structure 401. Note that the preload stem 406 is pressed against the pivoting flexure 407 allowing the polishing pad to move in the vertical direction while complying to the semiconductor wafer. Such strategy allows for the use of a hard polishing pad while providing compliance at the interface of the semiconductor wafer. This strategy of decoupling the pad characteristics from its ability to comply at the semiconductor interface leads to removing the traditional trade-off between WIWNU and planarization characteristics of the pads.

Detailed view of the pivoting flexure is provided in FIG. 9 includes a series of curvilinear springs 407 organized to allow compliant motion with respect to the semiconductor wafer of the attached polishing pad or polishing abrasive element 401. The springs 407 have a curvilinear shape designed to allow for out of plane motion while allowing for substantial pivoting to follow the plane defined by the semi-conductor wafer; note that straight springs do not flex out of plane causing tensile stresses in the spring beams and are inadequate. The spring members must allow for compliance out of plane under a normal load. Various examples of spring members can be listed such as L-shaped and Z-shaped.

The preload flexure layer is shown in details in FIG. 10. The preload stem 406 shows a spherical end to allow a dimple 413 like contact with the pivoting structure. A preload flexure 407 deforms under a preload applied by the stem 406. A series of protruding pillars provide 405 support to the ends of the pivoting flexure not shown herein. The preload stem can have many embodiments such as flat top, spherical and cylindrical structures.

FIG. 11 gives a cross section of a CPP concept with a continuous flexible polishing pad 501 attached to the contact pads 502 of each pivoting flexure 503. Upon bringing the CPP in contact with wafer a preload is generated from the preload flexure 507 to the contacting pads 503 by deflecting the supporting springs 507. The dimple end of the stems 515 contacts the back end of the pivoting flexure 503. The preload flexure 508 applies a constant load onto the contact pads 502.

FIG. 12 gives an exploded view of a polishing pad assembly contained in the CPP. A backing plate 509 is assembled via an adhesive layer 508 to a preload flexure 507. The preload fixture has a preload stem attached to a spring flexure design capable of imparting a substantially constant preload for example. A series of protruding pillars provide support to the pivoting flexures. A final layer of continuous polishing pad 501 is assembled to the individual contacting pads 502 to provide constant preload at each contacting pad during the polishing process. The embodiment disclosed allows the continuous polishing pad to follow the semiconductor wafer topography while allowing a locally stiff pad capable of planarazing the wafer.

The preload flexure layer is shown in details in FIG. 13. The preload stem shows dimple structure like in contact with the gimballing structure. A preload flexure deforms under a preload applied by the contacting pad 502 contacting the polishing pad 501. A series of protruding pillars provide supports to the ends of the pivoting springs 503. The preload stem can have many embodiments such as flat top, spherical and cylindrical shapes. The contact pad presses against the continuous polishing pad to provide a substantially uniform pressure.

FIG. 14 gives an exploded view of the assembly shown in FIG. 13. A polishing pad 501 is in direct contact with a pressure pad 502 supported by a pivoting flexure 504. The pivoting flexure 504 is preloaded via the dimple 503 attached to the spring loaded stem 503.

FIG. 15 gives a cross section of a CPP concept with a continuous polishing pad 601 at the end of the contacting pads 602. Upon bringing the CPP in contact with wafer a preload is applied to the polishing pad 601 by deflecting the supporting springs 604. The preload springs apply a constant load onto the polishing pad 601.

FIG. 16 shows a series of pressure pads 602 organized to form a circular pad 605. Each pressure pad 602 is attached to spring structure 604 allowing for compliance in the vertical direction. The preload fixture 604 has a preload stem attached to a spring flexure design capable of imparting a substantially constant preload for example. The embodiment disclosed allows the continuous polishing pad to apply a substantially constant load on the semiconductor wafer while allowing a locally stiff pad capable of planarazing the wafer.

The preload flexure layer 605 is shown in details in FIG. 17. The end of the preload stem 603 holds a pressure pad 602. A preload flexure 604 deforms under a load applied by the pressure pads 602. The pressure pad pushes against the continuous polishing pad to provide a substantially uniform pressure.

FIG. 19 gives an exploded view of the assembly shown in FIG. 18. A polishing pad 601 is in direct contact with a multitude of pressure pads 602 supported by a backing layer 605.

FIG. 20 gives a cross section of a polishing pad with a series of independent flexible pressure pads 703 at the end of the load stems 705. The end of each pressure pad 702 is equipped with abrasive pads 701 or a polishing pads 701. Each individual polishing pad or abrasive pad deflects under an externally applied load to provide a substantially constant pressure upon contact with the wafer. The preload springs 703 apply a constant load onto the polishing pad.

FIG. 21 shows a series of pressure pads 702 organized to form a circular pad 700. Each pressure pad 702 is attached to spring structure 703 allowing for compliance in the vertical direction with respect to the wafer. The preload fixture 703 is equipped with a preload stem 705 attached to a spring flexure design 703 capable of imparting a substantially constant preload for example. The embodiment disclosed allows the continuous polishing pad to apply a substantially constant load on the semiconductor wafer while allowing a locally stiff pad capable of planarazing the wafer.

FIG. 22 shows a concept of a polishing pad 800 where the pressure pad 802 is suspended by a revolute joint 803 to the load stem 804. The load stem 804 is supported by a series of springs 805 design to deflect under a normal load. The pressure pad 804 is equipped with an abrasive or polishing pad 801. The configuration shown herein allows for the polishing pad or abrasive pad to follow the wafer topography with 3 dimensional rotational freedoms. The rotary joint allows the polishing pad to pivot with respect to the wafer.

FIG. 23 shows a concept where the pressure pad is suspended by a revolute joint to the load stem. The load stem is supported by a series of springs design to deflect under a normal load. The pressure pads support a continuous polishing pad. The configuration shown herein allows for the polishing pad to follow the wafer topography with 3 dimensional rotational freedoms at each pressure pad.

FIG. 24 gives a detailed view of a single pressure pad 802. A revolute joint 803 between the load stem 804 and the pressure pad 802 supports the pressure pad. The load stem is supported by a series of vertically compliant springs 805 allowing the pressure pad 802 to freely pivot with respect to the surface of the wafer while keeping the ability to follow the runnout produced by the wafer.

FIG. 25 gives a detailed view of a polishing pad 900 used in conjunction with the present invention. The polishing pad assembly 910 is fabricated via an S-shaped link 920 to each others. The S-shaped links are arranged to connect each polishing pad with minimal out of plane resistance and contributes to decoupling the motion of each polishing pad from each other. Cross talk between polishing pads is minimized for example if polishing pad 910 is deflected in the z plane perpendicular to the polishing pad assembly 910, the displacement experienced by the surrounding pads 911, 912, 913, and 914 will be minimum. FIG. 26 gives a detailed view of a polishing pad 900 used in conjunction with the present invention showing the S-structure of the links and the polishing pads. The S-shape feature 920 has a low bending stiffness due to S shape allowing minimum cross talk between the pads when subjected to an in-plane or out of plane deflection. Non-straight shaped links such as Z, L, etc. can be arranged to further reduce the bending moment. In contrast, a straight connector generates tension on the adjacent polishing pads during a vertical or in-plane motion. Displacement due to in plane stretching of a straight connector requires very large forces to be produced thus limiting the amount of vertical displacement or in-plane displacement achieved by traditional configurations as shown in continuous polishing pad (601). So instead of fabricating a continuous polishing pad a discontinuous sheet with S shape connector attaching adjacent independent pads is desirable for ease of assembly and for providing a low coupling between individual polishing pads. Such pad can be used to accept CMP polishing pads, abrasive charged polishing pads, etc.

Useful adhesives include, e.g., pressure sensitive adhesives, hot melt adhesives and glue. Suitable pressure sensitive adhesives include a wide variety of pressure sensitive adhesives including, e.g., natural rubber-based adhesives, (meth)acrylate polymers and copolymers, AB or ABA block copolymers of thermoplastic rubbers, e.g., styrene/butadiene or styrene/isoprene block copolymers available under the trade designation KRATON (Shell Chemical Co., Houston, Tex.) or polyolefins. Suitable hot melt adhesives include, e.g., polyester, ethylene vinyl acetate (EVA), polyamides, epoxies, and combinations thereof. The adhesive preferably has sufficient cohesive strength and peel resistance to maintain the components of the fixed abrasive article in fixed relation to each other during use and is resistant to chemical degradation under conditions of use.

Examples of useful commercially available backing, materials include poly(ethylene-co-vinyl acetate) foams available under the trade designations 3M SCOTCH brand CUSHIONMOUNT Plate Mounting Tape 949 double-coated high density elastomeric foam tape (Minnesota Mining and Manufacturing Company, St. Paul, Minn.), EO EVA foam (Voltek, Lawrence, Mass.), EMR 1025 polyethylene foam (Sentinel Products, Hyannis, N.J.), HD200 polyurethane foam (Illbruck, Inc. Minneapolis, Minn.), MC8000 and MC8000EVA foams (Sentinel Products), SUBA IV Impregnated Nonwoven (Rodel, Inc., Newark, Del.).

Thus, an improved fixed abrasive or CMP polishing pad and process for polishing semiconductor wafers and structures layered thereon has been described. Although the present polishing pad and processes for using it have been discussed with reference to certain illustrated examples, it should be remembered that the scope of the present invention should not be limited by such examples.

In one aspect, the invention features an abrasive article including a) a fixed abrasive element including a plurality of abrasive particles, b) the fixed abrasives are affixed to a gimballing flexure, (c) a gimbal structure formed around the fixed abrasive elements hold the abrasive element, (d) a stem supported by a preload flexures applies a load through a dimple to back of the gimballing flexure, (e) a plurality of pillars affixed to the preload flexure layer provide fixed boundary conditions for the edges of gimbal flexure, and (f) an opening made in the carrier allows for the preload flexure to move vertically with no interference.

In some embodiment, the invention features an abrasive article including (a) a fixed abrasive element including a plurality of abrasive particles, (b) the fixed abrasives are affixed to a pressure pad, and (c) a stem supported by a preload flexure applies a load to the pressure pad under normal deflection.

In some embodiment, the invention features an abrasive article including (a) a polishing pad, (b) the polishing pad is affixed to a pressure pad, and (c) a stem supported by a preload flexure applies a load to the pressure pad under normal deflection.

In some embodiment, the invention features an abrasive article including (a) a fixed abrasive element including a plurality of abrasive particles, (b) the fixed abrasives are affixed to a pressure pad, (c) the pressure pads are supported by a revolute joint to (d) a stem supported by a preload flexure applies a load to the pressure pad under normal deflection.

In some embodiment, the invention features a polishing pad (a) a polishing pad, (b) the polishing pad is supported by a spherical joint to (c) a stem supported by a preload flexure applies a load to the pressure pad under normal deflection.

In some embodiments polishing pads replace the abrasive articles. The pads interact with slurries to provide a CMP operation as described previously. The pad geometry is typically flat of shaped to enhance interaction with the slurry.

In other embodiments fluid bearing structures are formed on the fixed abrasive structures or the soft pad structures to allow for a lift between the lubricant present during polishing and the semiconductor wafer. Such fluid bearing forms during the relative motion of the composite polishing pad and the semiconductor wafer due to the shearing of the lubricant.

In other embodiments the gimbal flexure allows the fixed abrasive element of the pads to follow the semiconductor wafer topography and exerts a uniform pressure. The gimbal flexure is fabricated from a polymer or stainless steel material. The gimbal structure allows uniform planar stiffness of the abrasive element or the pads to enable following the contour of the semiconductor wafer.

In other embodiments the preload stem dimple structure applies a given preload onto each abrasive element or pad. The geometry of the load dimple structure is designed such that the end of the load dimple structure is spherical and allows for contact against resilient element.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which these inventions belong. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present inventions, the preferred methods and materials are now described. All patents and publications mentioned herein, including those cited in the Background of the application, are hereby incorporated by reference to disclose and described the methods and/or materials in connection with which the publications are cited.

The publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present inventions are not entitled to antedate such publication by virtue of prior invention. Further, the dates of publication provided may be different from the actual publication dates which may need to be independently confirmed.

Other embodiments of the invention are possible. Although the description above contains much specificity, these should not be construed as limiting the scope of the invention, but as merely providing illustrations of some of the presently preferred embodiments of this invention. It is also contemplated that various combinations or sub-combinations of the specific features and aspects of the embodiments may be made and still fall within the scope of the inventions. It should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the disclosed inventions. Thus, it is intended that the scope of at least some of the present inventions herein disclosed should not be limited by the particular disclosed embodiments described above.

Thus the scope of this invention should be determined by the appended claims and their legal equivalents. Therefore, it will be appreciated that the scope of the present invention fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the present invention is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” All structural, chemical, and functional equivalents to the elements of the above-described preferred embodiment that are known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the present claims. Moreover, it is not necessary for a device or method to address each and every problem ought to be solved by the present invention, for it to be encompassed by the present claims. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims.

Claims

1. A polishing pad comprising: an abrasive element;a pivoting flexure formed around the abrasive element and attached to the abrasive element, the abrasive element including a plurality of abrasive particles, the pivoting flexure including a dimple to allow pivoting of the abrasive element;(d) a stem supported by a preload flexure, the stem positioned to apply a load through the dimple of the pivoting flexure,(e) a plurality of pillars affixed to a plurality of preload flexures arranged in a layer to provide fixed boundary conditions for the edges of pivoting flexure, and(f) an opening made in the carrier that allows for the preload flexure to move vertically.

2. The polishing pad of claim 1, wherein the fixed abrasive elements are in a rectangular shape.

3. The polishing pad of claim 1, wherein the fixed abrasive elements are in a circular shape

4. A polishing pad comprising: a polishing pad,a pivoting flexure formed around the polishing pads hold the polishing pads, the polishing pad affixed to pivoting flexure,a stem supported by a preload flexure, the stem applying a load through a dimple pn the pivoting flexure,a plurality of pillars affixed to a preload flexure layer to provide fixed boundary conditions for the edges of pivoting flexure, andan opening made in the carrier allows for the preload flexure to move vertically with substantially no interference.

5. The polishing pad of claim 4, wherein the polishing pad is one of a plurality of polishing pads arranged in a rectangular shape.

6. The polishing pad of claim 4, wherein the polishing pad is one of a plurality of polishing pads arranged in a circular shape.

7. A polishing comprising a) a polishing pad element, b) the polishing pad elements are affixed to a pivoting flexure, (c) a pivoting flexure formed around the fixed abrasive elements hold the abrasive element, (d) a stem supported by a preload flexure to apply a load through a dimple on the pivoting flexure, (e) a plurality of pillars affixed to the preload flexure layer provide fixed boundary conditions for the edges of pivoting flexure, and (f) an opening made in the carrier allows for the preload flexure to move vertically with substantially no interference.

8. The polishing pad of claim 7, wherein the polishing pad is one of a plurality of polishing pads arranged in a rectangular shape.

9. The polishing pad of claim 7, wherein the polishing pad is one of a plurality of polishing pads arranged in a circular shape.

10. The polishing pad of claim 7, wherein the polishing pad is one of a plurality of polishing pads arranged in a rectangular shape.

11. The polishing pad of claim 7, wherein the polishing pad is one of a plurality of polishing pads arranged in a circular shape.

12. The polishing pad of claim 7, wherein at least one of the polishing pads is fabricated for chemical mechanical polishing (CMP) applications.

13. The polishing pad of claim 7, wherein at least on of the polishing pads contains abrasive particles.

14. A polishing pad, comprising: a plurality of flexible flexures with flexibility in a direction transverse to the plane defined by the polishing plane, anda plurality of polishing elements each attached via stems to a the flexible flexures applying a desired pressure in the transverse direction with respect to the polishing pad in order to contact and polish the workpiece.

15. The pad of claim 17, wherein at least one of the polishing elements has a circular cross sections.

16. The pad of claim 17, wherein at least one of the polishing elements has a rectangular cross sections.

17. A polishing pad, comprising: a plurality of flexible flexures with flexibility in a substantially vertical direction to the plane defined by the polishing plane, anda plurality of pressure pads each connected via spherical joints to the stems attached to the pivoting flexures applying a desired pressure in a vertical direction with respect to the polishing pad in order to contact and polish the workpiece.

18. The polishing pad of claim 17, wherein at least one of the polishing elements has circular cross sections.

19. The polishing pad of claim 17, wherein at least one of the polishing elements has rectangular cross sections.

20. A polishing pad comprising: a plurality of individual polishing pads, andat least one in-plane non straight links connecting adjacent polishing pads.

21. The polishing pad of claim 20, wherein the polishing pads are in a rectangular shape.

22. The polishing pad of claim 20, wherein the polishing pads are in a circular shape.

23. The polishing pad of claim 20, wherein at least on of the polishing pads is fabricated for CMP applications.

24. The polishing pad of claim 20, wherein at least on of the polishing pads contains abrasive particles.

25. The polishing pad of claim 20, wherein at least on of the polishing pads is textured and substantially covered with a deposited film, such as diamond like carbon (DLC).