JP7374126B2 - Conditioners for chemical mechanical planarization pads and related methods - Google Patents

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims benefit under 35 USC 119, U.S. Provisional Patent Application No. 62/672,938, filed May 17, 2018, the disclosures of which are incorporated herein by reference for all purposes. is incorporated herein by reference in its entirety.

The following description describes polishing surfaces useful in pad conditioners for conditioning chemical mechanical planarization pads (CMP pads) used to fabricate microelectronic devices or memory substrates such as semiconductor or digital memory workpieces. METHODS, DEVICES, AND APPARATUS FOR PREPARING AN ABRASIVE SURFACE HAVING A GLOBAL SURFACE.

The electronics, microelectronics, and data storage industries rely on chemical mechanical planarization (CMP) techniques to prepare highly planarized or polished surfaces of process components for microelectronic and memory device products. Examples of these types of products are microprocessors and other integrated circuits that rely on silicon or another semiconductor material, digital memory devices (e.g., solid state and hard disks), optical materials and devices, and various other commercially available and modern electronic, microelectronic, magnetic, and optical devices, including consumer electronics products. Chemical-mechanical planarization, as is well known, is a process for planarizing or polishing workpiece surfaces that are to be processed for use as functional parts of any of these types of products. A workpiece (also known as a "substrate") can be a microelectronic, semiconductor, memory storage, or optical device or substrate in manufacturing, among others.

In a typical CMP process, the CMP pad surface that contacts the workpiece must be "conditioned" to prepare it for initial use. CMP pads are manufactured from polymeric materials that contain small voids or bubbles within them, but in their original, unused state, have a thin outer layer of substantially solid polymeric material on each of the two opposing major surfaces of the pad. It is included. When a CMP pad is first used, a thin layer of non-porous (solid) material on the surface must be removed to expose the internal (porous) portion of the pad that will be used during chemical mechanical planarization. To remove the thin solid outer layer, a pad conditioner (or "conditioner") is used to sand away the surface solid material and expose the interior polymeric material with air bubbles or voids.

After this initial conditioning step, the CMP pad can be used to process workpieces. Over the life of a CMP pad, surface wear and material buildup that occurs during chemical-mechanical processing can cause the CMP pad surface to become less effective, including deterioration of its surface quality, and must be periodically refreshed, or "conditioned." be. During use of a CMP pad to process a microelectronic device workpiece, the polishing pad is moved in contact with the workpiece in the presence of a slurry containing abrasive particles and chemicals. During use during chemical-mechanical planarization, the CMP pad surface can become abraded and exposed to abrasives and chemicals that can accumulate on the pad surface. As a result, "pad glazing" may occur, reducing the effectiveness of the CMP pad surface for removing material that planarizes or polishes the workpiece surface. Additionally, continued use can cause uneven wear on the CMP pad surface, resulting in undesirable surface irregularities. Therefore, in order to restore the used CMP pad surface to a useful form, it is necessary to condition the surface. The process of restoring the pad surface is called pad conditioning. Conditioning of a CMP pad can be performed before the first use of the pad (to remove the outer solid layer), during the polishing process (in-situ conditioning), or during the polishing process (ex-situ). conditioning). CMP pad conditioning is essential to prepare or restore the CMP pad surface to have properties, including frictional properties and surface texture, that enable the pad surface to function as designed and intended.

Many examples and types of CMP pad conditioners are known and commercially available. At a minimum, a pad conditioner (also known as a "conditioner") is capable of correcting and dressing the CMP pad surface when it comes into contact with the polishing surface while moving between the pad conditioner polishing surface and the CMP pad surface. and at least one abrasive surface that can be polished. Exemplary pad conditioners may include an abrasive surface on one side of the conditioner, and in other examples may include abrasive surfaces on two opposing sides. Preferred conditioners may be designed to be mounted within a support opening of a CMP tool such that the conditioner can be placed within the support (instead of the workpiece) during the process of conditioning the CMP pad surface. Consistent with these considerations, a wide variety of different types of pad conditioners are manufactured, sold, or used for conditioning CMP pads in connection with CMP processes applied to various types of workpieces.

According to this specification, applicants have identified a precision polishing surface made from high density silicon carbide. The polished surface can be used as a pad conditioner surface, optionally and preferably coated with a CVD diamond coating. Preferred precision abrasive surfaces used as pad conditioner surfaces include commercially advantageous levels of control over the abrasive properties of the pad conditioner, such as beneficial levels of control over the abrasive cutting rate of the pad conditioner. , can exhibit useful or desired abrasive properties. An improved level of control over the cutting speed of pads of the present invention that are manufactured to have the same physical characteristics of the abrasive surface, such as, for example, the same size, shape, and morphology of the protrusions, and the same spacing of the protrusions. This can be expressed as a reduction in pad-to-pad variation. Improved control of polishing properties can be achieved by controlling the physical properties of the polishing surface, such as the size, shape, and morphology (e.g., angle) of the protrusions formed, as well as the precise spacing of the protrusions in the pattern of protrusions on the polishing surface. This is due to its high level of precision.

A measure of a pad conditioner is its level of "aggressiveness" in removing material from a CMP pad. The level of aggressiveness of a pad conditioner can be quantified as the "pad cutting rate" (PCR), ie, the rate at which material is removed from the CMP pad during the conditioning process. Conventional pad conditioners made with shaped or abrasive coated surfaces can generally have a wide range of aggressiveness as measured by pad cutting speed. Pad cutting speed has proven difficult to control even with commercially available pad conditioners, as pad cutting speeds vary even between pad conditioners prepared from the same material and using the same method. This means that it can vary between pad conditioners.

Applicants believe that abrasive surfaces manufactured from high-density silicon carbide have well-controlled levels of abrasive aggressiveness, e.g., predictably controlled pad cutting speeds with low pad-to-pad variations; It is concluded that highly polished surfaces can be formed that exhibit desirable or beneficial polishing properties. High-density silicon carbide has shaped protrusions with highly precise shapes, precise spacing between protrusions, optionally and preferably highly precise (e.g., low roughness) land surfaces, or polished surfaces with a combination of these. Dense silicon carbide can be effective in increasing the controllability of the cutting speed of the conditioning pad.

The precision polished surface may be manufactured using any suitable technique, such as any machining, etching, or cutting technique that provides the desired level of precision of the polished surface (e.g., physical features of the protrusions and land surfaces). It can be formed from high density silicon carbide. The currently preferred technique for forming highly accurate shapes and land surfaces is through the use of laser cutting, a precise and repeatable laser machining process.

In one aspect, the present invention relates to a polishing surface that includes a flat land surface and a plurality of dense silicon carbide protrusions extending from the flat land surface, the protrusions having a highly precise shape.

In another aspect, the invention relates to a method of forming an abrasive surface on a silicon carbide body. The method includes, from a block of silicon carbide having a dense silicon carbide surface, removing dense silicon carbide from the surface to produce a plurality of dense silicon carbide protrusions extending from a flat land surface; has a highly accurate shape

In yet another aspect, the invention relates to a method of conditioning a CMP pad surface using a CMP tool. The CMP tool includes a rotating platen holding a CMP pad having a top CMP pad surface and at least one support having at least one opening. The method includes disposing one or more pad conditioners in the at least one opening, each of the one or more pad conditioners comprising an abrasive surface as described herein. . The method also includes providing contact and motion between the polishing surface and the CMP pad surface.

FIG. 2 is a top schematic view of a polishing surface as described herein. FIG. 1B is an enlarged perspective view of the polished surface of FIG. 1A. FIG. 2 is a side view of a polishing surface as described herein. FIG. 2A is a side view (enlarged view of FIG. 2A) of a polishing surface as described herein. FIG. 3 is an individual protrusion cross-section of a polished surface as described prepared by laser profilometry; FIG. 3 is an individual protrusion cross-section of a polished surface as described prepared by laser profilometry; FIG. 3 is a cross-section of an individual protrusion of a non-inventive polished surface produced by laser profilometry; FIG. 1 illustrates an example of a pad conditioner as described.

1A, 1B, 2A, 2B, and 4 are schematic and not necessarily to scale.

According to this specification, applicants have identified a precision polishing surface made from high density silicon carbide. The polished surface can be used as a pad conditioner surface, optionally and preferably coated with a CVD diamond coating. Preferred precision polishing surfaces used as pad conditioner surfaces include a commercially advantageous level of control of the pad conditioner's polishing properties, such as, for example, a beneficial level of control of the pad conditioner's polishing cutting rate. Can exhibit useful or desired abrasive properties. Improved control of polishing properties such as cutting speed means polishing properties that exhibit reduced variation, e.g., polishing that exhibits reduced variation in cutting speed between pad conditioners prepared to exhibit a particular cutting speed. means a characteristic. Improved control of polishing properties is achieved through, for example, the precise size, shape, and form (e.g. angle) of the protrusions, the precise spacing of the protrusions in the protrusion pattern on the polishing surface, and the precise level of the land surface on the polishing surface. flatness, or a combination thereof, due to a high level of precision in the physical characteristics of one or more of the polished surfaces.

The precision silicon carbide polishing surface includes a plane extending in the xy plane, commonly referred to as a "land surface," and a plurality of dense silicon carbide protrusions extending from the land surface. The protrusions are made of high-density silicon carbide, and due to the high density of silicon carbide, they can be formed into high-precision shapes. These protrusions may be referred to herein using terms such as "high precision protrusions." The land surface may also preferably be made of high density silicon carbide and is preferably integral with high density silicon carbide protrusions. The individual precisely formed protrusions extend from the land surface in a direction perpendicular to the plane of the land surface, the protrusions optionally being regular (advantageously A high-precision pattern with precise spacing can be placed on the land surface.

As described, Applicant claims that high-density silicon carbide can be used for high-precision land surfaces, high-precision three-dimensional projections extending from the land surfaces, and high-precision placement of the projections on the land surfaces (e.g., projection spacing). ), or combinations thereof, have been found to be useful or advantageous in that they can be formed into highly precisely formed polished surfaces. The protrusions and preferably land surfaces formed are made of high density silicon carbide, which is a carbide having low or very low porosity, e.g. less than 5, 2, or 1% porosity. means silicon. Dense silicon carbide may also be characterized as having a density of at least 2.5 grams per cubic centimeter. Dense silicon carbide, and dense silicon carbide bodies suitable for use in abrasive surface formation as described, are commercially available, including ceramic and It can be prepared by methods well understood by those skilled in the silicon carbide art.

A silicon carbide body (e.g., a silicon carbide "pad" or " The remaining material of the "segments") may be made of dense silicon carbide, or alternatively may be made of non-dense (e.g., porous) silicon carbide. For example, a portion of the thickness of the silicon carbide body in the face containing the abrasive surface may be made of dense silicon carbide, and the remainder of the body (i.e., the remainder of the body thickness) may be made of non-dense silicon carbide. May be made of silicon. The non-dense silicon carbide material may have a porosity in the range of 10-80%, for example.

Applicants believe that the polished surface of the protrusions extending from the land surface and formed of high-density silicon carbide will depend on the shape, size, morphology (e.g., angle), and placement (distance of spacing) of the protrusions on the land surface. We conclude that various physical characteristics of the polished surface, such as its flatness, can be formed to exhibit very high precision. A high level of accuracy of these physical features of the polishing surface can be particularly useful and advantageous when included as a feature of the polishing surface, such as in a CMP pad conditioner.

The precision polishing surface may include precision physical characteristics of each formed protrusion, as measured by one or more dimensional or shape features of the polishing surface. Examples of highly accurate physical characteristics of protrusions include the height of each protrusion from the land surface, the width of each protrusion at its base, the shape of the tip of each protrusion, e.g. angle, or the width of the tip, the angle of the sidewall relative to the land surface, the shape of the sidewall of the protrusion, e.g. the shape of the sidewall is strongly related to the line compared to curved, jagged, or not closely correlated may include, but are not limited to, one or more of the following:

Optionally and preferably, the precision-formed polished surface also includes a precision-patterned arrangement of protrusions on the land surface, such that the arrangement pattern of the protrusions and the spacing between the protrusions is precisely patterned. It means something.

Optionally, the high-precision polished surface is also a high-precision land surface, i.e. a land surface with low variation in height, e.g. a very precise roughness, e.g. in the range of 2-10 μm when measured by laser profilometry. and a flatness measuring less than 50 micrometers.

An exemplary polishing surface as described includes a plurality of individual three-dimensional structures (eg, protrusions) extending from a land surface of a silicon carbide body. The three-dimensional protrusion may be integral with the land surface and the silicon carbide body. The protrusion extends from the land surface in a direction perpendicular to the xy plane of the land surface. The three-dimensional structures may be placed on the land surface in a repeating, patterned, unpatterned (eg, apparently random), or clustered arrangement. A particularly preferred three-dimensional structure may be a patterned repeat, for example in the form of a set of similar repeating three-dimensional geometric shapes.

Each projection can be characterized by having a measured height in the z-direction, where the height is measured as the vertical distance from the land surface to the top surface of the projection. Each projection also includes a width dimension measured at the location where the projection contacts the land surface, ie, at the horizontal base of the projection. Each projection can also include a length dimension that is perpendicular to the width and in the plane of the land surface.

The shape of the protrusion can be any shape that is useful for a polishing surface, such as any shape that is useful as part of a polishing surface of a pad conditioner for performing a conditioning process as described herein. can. The specific shape of the protrusions can be any useful or desired three-dimensional shape, based on preference and the desired use for the polishing surface (e.g., as a pad conditioner). and the desired level of aggressiveness of the abrasive surface. The projections may be formed to include any one or more of the following shapes: rounded, curved, symmetrical, asymmetrical, angular, angular, or straight. Exemplary shapes are pyramidal (having a base of any shape e.g. triangular, square, rectangular, pentagonal, hexagonal, octagonal, etc.), conical (having a circular or oval base), prismatic (e.g. with geometric cross-section and elongated length), ribbed, trapezoidal, hemispherical, flat-topped, triangular, hexagonal, octagonal, star-shaped, zigzag, square, rectangular, elongated (straight) or a combination of two or more thereof.

The dimensions or morphology of the protrusions (eg, angle, flatness, line correspondence, etc.) can be measured by any suitable measurement technique, such as known laser profilometry techniques. As shown herein, the dimensions and morphology (e.g., angles) of polishing surfaces fabricated from high-density silicon carbide provide high accuracy and can be manufactured with precision and reproducibility, e.g. achieved by forming equivalent structures in silicon carbide with lower density and higher porosity, e.g. >20% porosity. In comparison, it can be manufactured with improved precision and reproducibility. Various techniques are useful for measuring these dimensions and morphology, and various known assays can be used to compare the accuracy of the polished surfaces described herein with the accuracy of polished surfaces not of the present invention. Statistical and statistical methods are available.

Improving the accuracy of the polished surface described herein refers to the size (dimensions), morphology (angle, flatness, correspondence with lines, etc.) of the polished surface, or the arrangement of physical features (protrusions or land surfaces). It means improved accuracy. Accuracy in this regard can be assessed in terms of variations in size, shape, or placement of physical features on the polished surface. Examples of physical characteristics of the polishing surface that may be evaluated to determine the accuracy of formation and placement of the polishing surface features include (but are not limited to) any one or more of the following: protrusion dimensions; For example, the height or width of the protrusion, the shape or morphology of the protrusion, e.g. the angle of the sidewall relative to the land surface, the "width" of the tip of a conical or pyramidal protrusion (this means that the tip is (on the micrometer scale) meaning a degree of rounding as opposed to completely sharpened), the straight (desired) sidewalls of the protrusion are curved or lack strong correlation. In contrast, the extent to which straight lines correlate, the distances (in the x-y plane) between similar features of the polished surface, e.g. distance between similar base locations,

When measuring the dimensions of the protrusions or the distance between the protrusions in order to evaluate the dimensional accuracy between a plurality of protrusions on the polishing surface, the dimensions to be measured must be similar dimensions for each protrusion. To measure the spacing, the spacing (distance) between identical locations of a pair of protrusions may be measured, and the protrusions should be similarly located as part of the pattern of protrusions on the polishing surface. In any measurement, the specific dimension or interval measured to assess accuracy is not a critical feature of the measurement, but the endpoint of each measurement of the measurement sample must be consistent from measurement to measurement. .

As a general matter, the protrusions can have height, width, and length dimensions effective to achieve the desired abrasive properties of the abrasive surface. The scale of the dimensions of the protrusions may be on the scale of micrometers, for example tens or hundreds of micrometers. Exemplary heights of protrusions of various shapes and forms may range from 20 to 100 micrometers, such as from 25 to 75 micrometers. Exemplary widths of the bases of protrusions (eg, circular or rounded base diameters) can range from 10 to 200 micrometers, such as from 20 to 150 micrometers. (The width of a protrusion with a circular base may be the diameter of the base. Other width dimensions may also be useful in assessing the accuracy of the polished surface, such as the diagonal dimension of a square or rectangular base. ) Exemplary lengths may vary depending on the type of polishing surface desired, e.g., for elongated protrusions, the length may be equal to or greater than the width or less than the width. It may be of substantially large size. Generally, for individual, non-elongated protrusions, the length will generally be in a range similar to the width of the protrusion at the base, such as from 20 to 1000 micrometers, such as from 25 to 75 micrometers. It may be. In a patterned arrangement of protrusions on an abrasive surface, the spacing between two adjacent or adjacent pairs of protrusions may vary depending on the type of abrasive surface desired, and the spacing between adjacent protrusions may vary depending on the type of abrasive surface desired. Examples of spacings include, for example, between 1,000 and 10,000 micrometers, such as between 1,500 and 7,000 micrometers, or between 2,000 and 6,000 micrometers. Good too.

The improved level of accuracy achieved with the polishing surfaces described herein compared to other comparable polishing surfaces made of non-dense silicon carbide is known to those skilled in the art of analytical and statistical methods. It can be demonstrated by available measurement and statistical methods. The increased level of accuracy achieved by the polishing structure as described is dependent on the physical characteristics of the polishing surface, e.g. the dimensions, angles, or morphology of the protrusions, between similar positions of two independent protrusions within the pattern. Demonstrable by demonstrating a statistically significant improvement (reduction) in variation in one or more of the following: spacing, land surface flatness (e.g., roughness), or other measurable physical characteristics It is.

As an example to demonstrate the useful or improved level of accuracy that can be achieved by the methods or structures described herein, the variation in the physical characteristics of a sample of protrusions on a single polished surface is It can be stated in terms of the standard deviation of measured values. As used herein, the term standard deviation refers to a group of measurements (i.e., "sample standard deviation" as opposed to "population standard deviation") ("SD", Greek letter sigma σ or Latin letter s given its usual meaning in the field of statistics, i.e. the amount of variation in a set of data values (measured values) based on the values in the sample and the total number of values in the sample or a calculated value used to quantify the amount of dispersion.

With reference to the example values referenced herein for protrusion width (base width), protrusion height, and protrusion spacing, an exemplary or preferred standard deviation may be as follows. A preferred standard deviation of the width of the protrusion base (base width) may be less than 7 μm, such as less than 6 μm, or less than 5 μm. A preferred standard deviation of the height of the protrusions may be less than 5.0 μm, such as less than 1.2 μm, or less than 1.0 μm. A preferred standard deviation of the spacing between the positions of a pair of protrusions may be less than 10 μm, such as less than 4 μm, or less than 1 μm.

Referring to FIG. 1A (top view) and FIG. 1B (side enlarged view of FIG. 1A), an exemplary polishing surface 10 of a silicon carbon body 20 (e.g., a silicon carbide "pad" or "segment" of a pad conditioner) is shown. It is shown. Polishing surface 10 includes a flat land surface 24 extending in the x and y directions (in the "xy plane"). The silicon carbide body 20 also has a depth or thickness in the z-direction (not shown in FIG. 1A) and a substantially parallel x- and a second surface (not shown) in the y-plane. Three-dimensional shaped protrusions 22 extend from the flat land surface 24 in the z direction and are arranged in a regular repeating pattern separated by intervals (eg, 26, 28) in the x and y directions. As shown, protrusion 22 is conical with a circular base, but other shapes are also useful.

As an example of certain precise physical features of the polishing surface, FIGS. 2A and 2B (enlarged view of FIG. 2A) schematically show a side view of a silicon carbide body 52, which has a land surface 56. It includes a polishing surface 50 that includes conical protrusions 54 arranged in a repeating pattern thereon. For each protrusion that is conical (or pyramidal) shaped, the protrusion has a height (h, z direction) dimension from the base 58 (located at the connection between the protrusion 54 and the land surface 56) to the tip 60. , and the tip 60 is considered to be the upper surface structure of each protrusion 54, as opposed to the position of the apex of the angle formed by the intersection of the lines corresponding to the two side walls of the conical protrusion. The angle (α) formed by the intersection of the lines corresponding to the two side walls (62) of the conical projection 54 can be measured as the angle between the side walls. Another angle (β) may be the angle between the sidewall and the land surface 56. The base width (Wb) of the conical protrusion is the width of the base 58 at the diameter of the base. The tip width (Wt) of a conical (or pyramidal) protrusion is precisely the width of the tip that is not sharp when viewed at a sufficiently high magnification. Those skilled in the art will be aware of techniques for making stable measurements of tip width between different protrusions of a sample of protrusions on a polished surface, for example by determining the standard deviation, for the purpose of evaluating tip width variations. you will understand.

The distance (d) or spacing between projections of an arrangement can be assessed by measuring the distance between any two positions of any two projections, e.g., the distance between the ends of the bases on the same side of two conical projections. It is. Comparison of distance measurements to assess variability, such as identifying standard deviation, can be performed by making multiple measurements between the same two locations across a pair of protrusion samples. As shown, the exemplary polishing surface 50 distance d can range from 1,000 to 10,000 angstroms, and the polishing surface sample spacing is less than 0.5 angstroms, 0.4 have a standard deviation of less than angstroms, or less than 0.3 angstroms.

An example height (h) of the conical protrusion 54 of the polishing surface 50 may range from 20 to 100 micrometers, such as from 25 to 75 micrometers, and a sample of the measured height of the polishing surface is It has a standard deviation of less than 1.5 micrometers, such as less than 1.2 micrometers, or less than 1.0 micrometers.

An example base width (Wb) of the conical protrusion 54 of the polishing surface 50 may range from 10 to 200 micrometers, such as from 50 to 150 micrometers, and a sample of the measured base width of the polishing surface is It has a standard deviation of less than 7 micrometers, such as less than 6 micrometers, or less than 5 micrometers.

An example of the angle (α) formed by the intersection of the lines corresponding to the two side walls (62) of the conical projection 54 may be in the range 30 to 70 degrees, for example in the range 40 to 60 degrees; A sample of the measured base angles of the surfaces have a standard deviation of less than 5 degrees, such as less than 1 degree.

An example of the angle (β) between the sidewall 62 and the land surface 56 may be in the range 30 to 70 degrees, such as 40 to 60 degrees, and a sample of the measured angles of the polished surface may be 1 have a standard deviation of less than, such as less than 0.5 degrees, 0.4 degrees, or 0.3 degrees.

An example tip width (Wt) of the conical protrusion 54 of the polishing surface 50 may range from 10 to 30 micrometers, and a sample of the measured tip width of the polishing surface may be less than 5 μm, such as less than 2 μm, or have a standard deviation of less than 1 μm.

2A and 2B, which are schematic illustrations that do not show imperfections and contours of the projection surface, FIGS. 3A and 3B show the conical (or pyramidal) projections described herein, such as FIGS. 2A and 2B. An example of a cross-sectional form (created by laser profilometry) of a protrusion 54 is shown. Compared to the schematic diagram of the protrusion 54 in FIGS. 2A and 2B, the cross section of the protrusion 54 in FIGS. 3A and 3B shows a side wall that is not a perfect line but has a strong correlation with the line between the land surface and the protrusion tip. It shows. The tip of protrusion 54 in FIG. 3A is not a single acute angle, but has a good correlation with the apex of the angle formed by the line through the sidewall. The tip of protrusion 54 is somewhat rounded and includes a flat top with a discernible tip width. Therefore, each protrusion 54 in FIGS. 3A and 3B is considered to have a highly accurate configuration corresponding to the cross-sectional shape of a conical or pyramidal protrusion with an arbitrary flat top (FIG. 3B).

In contrast, FIG. 3C shows an example in which the comparative protrusion cross-sectional morphology is not made of high-density silicon carbide. The protrusion of FIG. 3C includes a less precisely formed surface, including a rounded top and sidewalls with an indiscernible tip and substantially non-linear (curved) sidewalls.

Various manufacturing methods are available for processing a ceramic material such as silicon carbide to form a ceramic polished surface that includes protrusions extending from the land surface. Examples include conventional milling, such as wire electrical discharge machining (EDM), masking polishing, water jet machining, photopolishing, laser machining, and machining, or etching techniques. Any of these techniques can be useful for forming three-dimensional surfaces in silicon carbide, including forming highly precise structured polished surfaces from dense silicon carbide. A preferred technique for forming precision polished surfaces in silicon carbide as described herein is a technique that produces polished surfaces and protrusions with precise physical characteristics as described herein. , and one example of a preferred technique is laser cutting.

A preferred example of a silicon carbide polished surface as described can be further processed to place a coating of chemical vapor deposited diamond (i.e., "CVD diamond") on the precision silicon carbide polished surface. A CVD diamond coating placed on an abrasive surface can be effective in improving the performance and service life of the abrasive surface. Methods of depositing CVD diamond coatings on surfaces are known. One exemplary method ionizes carbon gas at very high temperatures using microwave and/or electrical power, hot filaments, lasers, electron beams, etc., and the ionized carbon is preferably continuously as a diamond coating on a substrate (e.g., a three-dimensional structured surface of silicon carbide segments as described). During this process, the substrate can reach temperatures of approximately 800°C, so the ceramic material of the ceramic segment must be of a type that can withstand this high temperature.

Once formed, a silicon carbide body containing an abrasive surface as described herein is attached to a flat, rigid base plate as an abrasive silicon carbide "pad," "segment," or "insert." Can be incorporated into conditioner. An exemplary pad conditioner structure includes a rigid disc-shaped plate (or base) that supports one or more silicon carbide bodies with precision silicon carbide polishing surfaces. The rigid plate includes a top plate surface, a bottom plate surface, and a plate thickness extending between the top plate surface and the bottom plate surface. One or more silicon carbide segments are attached to the plate to provide a polishing surface.

Preferred conditioners include a flat, rigid plate (e.g., disk, support, substrate, etc.) to which one or preferably multiple abrasive segments (or "pads" or "conditioning segments") are attached, each with a The abrasive segment of includes an abrasive surface as described herein that includes dense silicon carbide protrusions. An example is shown in FIG. Pad conditioner 26 includes a rigid base plate 24 having silicon carbide segments 20 attached to one side of plate 24 . Each silicon carbide segment 20 includes an abrasive surface as described herein. Base plate 24 is substantially planar, stiff, strong, and of substantially uniform thickness, and pad conditioner 26 can be used to condition the pad surface of the CMP tool for effective results. As such, it is effective in supporting the abrasive segment 20. Examples of materials useful as plates include metallic and ceramic materials. Specific examples of materials that may be useful as flat, rigid plates include stainless steel, molybdenum, aluminum, and ceramics such as alumina, steatite or zirconia, or other similar metals (including alloys) and ceramics. Materials include, but are not limited to: For the purpose of providing an abrasive surface for the pad conditioner, the abrasive segments may be secured to the plate in any manner, such as adhesively bonded to the surface of the plate.

In use, a pad conditioner of the present invention, such as pad conditioner 26 of FIG. 4, can be used with a CMP tool to condition the surface of a chemical mechanical planarization pad (CMP pad). An example of a useful CMP tool is a rotating platen that holds a CMP pad with an exposed surface. The support is typically positioned adjacent to the exposed pad surface (eg, on top of the pad surface). The opening in the support is adapted to accommodate a pad conditioner. When the pad conditioner is placed in the opening with the polishing surface of the pad conditioner facing the CMP pad surface, contact and movement is provided between the polishing surface and the CMP pad surface. The contact and motion creates friction between the polishing surface and the CMP pad surface, causing the polishing surface to polish material from the CMP pad surface.

Pad conditioners such as those described can exhibit useful abrasive performance or, preferably, otherwise equivalent, include a precision silicon carbide abrasive surface such as those described herein. The pad conditioner may exhibit improved polishing performance as indicated by more precisely controlled (eg, reduced variation) cutting speeds compared to pad conditioners without pad conditioners. Based on this specification, high precision silicon carbide polishing surfaces can be prepared to achieve desired and well-controlled (compared to other pad conditioners) levels of polishing surface aggressiveness with respect to cutting speed. I found out. In a comparison of cutting speed with similar CMP pads (pads of similar composition, surface wear, etc.) using similar equipment and conditions (time, temperature, speed, etc.) of the conditioning process, the described conditioning pads: Pads made with abrasive surfaces that can be prepared to have a desired cutting speed, and the individual cutting speeds (i.e., variations between pads) of multiple such pad conditioners are not of the present invention. shows less variation compared to

Claims (1)

A method of forming a polishing surface of a pad conditioner for conditioning a chemical mechanical processing (CMP) pad on a silicon carbide body, the method comprising: forming a polishing surface of a pad conditioner on a silicon carbide body with a porosity of less than 5 percent; removing dense silicon carbide from a block of silicon carbide having a flat surface to produce a plurality of protrusions of dense silicon carbide extending from a flat land surface;
Each protrusion has a height extending vertically between the land surface and the furthest surface of the protrusion, the height of the protrusion is in the range of 25-75 micrometers, and the height of the protrusion is in the range of 25 to 75 micrometers; the standard deviation of the height of the protrusion is less than 5 micrometers,
Each protrusion has a base width in the range of 20 to 150 micrometers, and the standard deviation of the base width of the protrusion on the polishing surface is less than 7 micrometers.

Images