CHEMICAL MECHANICAL POLISHING CONDITIONER
The present invention relates to a chemical mechanical polishing conditioner which comprises: a substrate; a bonding layer, disposed on the substrate; and an abrasive layer, having a thin metal sheet and a first layer of abrasive particles, wherein the first layer of abrasive particles is disposed on the thin metal sheet, and the abrasive layer is coupled to the substrate with the bonding layer; wherein the first layer of abrasive particles comprises a plurality of abrasive particles, of which protruding tips has a planar leveling surface, so that the plurality of abrasive particles do not have one or more protruding tips of the plurality of abrasive particles having particular significant difference in protrusion distance, and the plurality of abrasive particles have a patterning arrangement. Therefore, the present invention can reduce damage ratio of polished workpieces by a planar leveling surface of the chemical mechanical polishing conditioner, so that the chemical mechanical polishing conditioner has more excellent polishing efficiency and working life.
This application claims the benefits of the Taiwan Patent Application Serial no. 102206277, filed on Apr. 8, 2012, the subject matter of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION1. Field of the Invention
The present invention relates to a chemical mechanical polishing conditioner, more particularly, to a chemical mechanical polishing conditioner having a planar leveling surface.
2. Description of Related Art
Chemical mechanical polishing (CMP) process is a common polishing process for a variety of industries. Using the chemical mechanical polishing process can polish the surface of various kinds of materials, which comprises plane of integrated circuit, ceramic, silicon, glass, quartz or metal, or etc. In addition, with the rapid development of integrated circuit, the chemical mechanical polishing can achieve object of a large leveling area, and thus is commonly one of semiconductor wafer planarization techniques in the semiconductor processor. In particular, a number of processing times of the chemical mechanical polishing will increase with reducing the size of transistors, for example, in a 28 nm line-width process, the number of processing times of the chemical mechanical polishing may be up to 30 times.
The semiconductor industry currently spends in excess of one billion U.S. dollars each year manufacturing silicon wafers that must exhibit very flat and smooth surfaces. Known techniques to manufacture smooth and even-surfaced silicon wafers are plentiful. The most common of these involves the process known as Chemical Mechanical Polishing (CMP) which includes the use of a polishing pad in combination with an abrasive slurry. Of central importance in all CMP processes is the attainment of high performance levels in aspects such as uniformity of polished wafer, smoothness of the IC circuitry, removal rate for productivity, longevity of consumables for CMP economics, etc.
In CMP processes of semiconductors, the CMP pad is used to contact with wafers (or other semiconductor device) and is determined to the situation to be attached with slurry, so that the polishing pad removes impurity and unsmooth structure of the wafer surface by chemical reaction and physical mechanism; after the polishing pad is used for a certain time, the polished bits and small pieces producing during the polishing process stagnates on the surface of the polishing pad, so as to decrease the polishing effect and efficiency. Therefore, a conditioner can be used to recondition the surface of the polishing pad, so that the surface of the polishing pad is again to be roughened and is kept the best polishing state. However, in the manufacturing process of the conditioner, abrasive particles and a bonding layer are mixed to form an abrasive layer arranged on a surface of the substrate, wherein the abrasive layer is fixed and bonded on the surface of the substrate by brazing or sintering means; and in a hardening process of the abrasive layer, because of the difference of the thermal expansion coefficient between the bonding layer and the substrate, the conditioner usually has a problem distorted with the substrate surface. Therefore, the planarization of the surface of the conditioner is damaged, so as to affect polishing efficiency and working life.
In prior arts, Applicant proposed Taiwan patent application number No. TW 100133909, which comprise: a first monolayer of superabrasive particles disposed on and coupled to one side of a metal support layer; and a second monolayer of superabrasive particles disposed on and coupled to the metal support layer on an opposite side from the first monolayer. The superabrasive particles of the second monolayer are positioned to have substantially the same distribution as the superabrasive particles of the first monolayer. Therefore, in the above-mention patent, by distributing the warpage forces equally or substantially equally on both sides of the metal support layer through the arrangement of the superabrasive particles, these forces effectively cancel each other with respect to the degree of warping occurring in the metal support layer, thus also minimizing the relative height movement of the superabrasive particles relative to one another.
Furthermore, Applicant proposed Taiwan patent application number No. TW 101118288, which comprise: a matrix layer; and a monolayer of a plurality of superabrasive particles embedded in the matrix layer, wherein each superabrasive particle in the monolayer protrudes from the matrix layer, and the difference in protrusion distance between the highest protruding tip and the second highest protruding tip of the monolayer of superabrasive particles is less than or equal to about 20 microns and the difference in protrusion distance between the highest 1% of the protruding tips of the monolayer of superabrasive particles are within about 80 microns or less. The CMP pad dressers of the above-mentioned patent include a layer of superabrasive particles having substantially leveled tips across the working surface of the finished CMP pad dresser. The CMP pad dresser having such substantially leveled tip arrangements can have a low scratch rate because superabrasive particles are less likely to pull out of the matrix layer due to their more uniform protrusion distribution compared to traditional dressers. Additionally, the more uniform protrusion distributions of such a dressers allows the conditioning of CMP pads in such a manner as to facilitate good polishing rates while at the same time extending the effective working life of the dresser. These benefits can be affected by, for example, uniform asperity spacing and size distribution in the CMP pad.
In the above-mentioned patent of the CMP conditioner, the applicant uses the distributed position of the abrasive particles, so as to eliminate the distortion resulted in the manufacturing process of the CMP conditioner, or to further control protruding distances of the protruding tips of abrasive particles. Therefore, the chemical mechanical polishing conditioner forms a planar leveling surface and reduce damage ratio of polished workpieces, so that the chemical mechanical polishing conditioner has more excellent polishing efficiency and working life.
Therefore, it is necessary to develop a chemical mechanical polishing conditioner that has a planar leveling surface, which can improve the normal mechanical polishing conditioner limited due to manufacturing methods and avoid the inconsistency between protruding distances of the protruding tips of abrasive particles so as to damage the surface flatness of the chemical mechanical polishing conditioner.
SUMMARY OF THE INVENTIONThe primary objective of the present invention is to provide a chemical mechanical polishing conditioner, which can provide a design of a planar leveling surface of the chemical mechanical polishing conditioner to reduce the damage ratio of polished workpieces, so that the chemical mechanical polishing conditioner has more excellent polishing efficiency and working life.
To achieve the above-mentioned objective, the present invention provides a chemical mechanical polishing conditioner, which comprises: a substrate; a bonding layer, disposed on the substrate; and an abrasive layer, having a thin metal sheet and a first layer of abrasive particles, wherein the first layer of abrasive particles is disposed on the thin metal sheet, and the abrasive layer is coupled to the substrate with the bonding layer; wherein the first layer of abrasive particles comprises a plurality of abrasive particles, of which protruding tips have a planar leveling surface, so that the plurality of abrasive particles do not have one or more protruding tips, of which having particular significant difference in protrusion distance, and the plurality of abrasive particles have a patterning arrangement. In particular, the planer leveling surface can be configured of the protruding tips of the discontinuous abrasive particles, for example, the protruding tips of the 1,000 highest abrasive particles, which are not configured of the continued abrasive particles being all adjacent to each other, therefore, it can eliminate damage and scuff of the polishing pad by the protruding tips having particular significant height (i.e., Killer Diamond). In the above-mentioned chemical mechanical polishing conditioner of the present invention, which can further comprise a second layer of abrasive particles, wherein the second layer of abrasive particles is disposed under the thin metal sheet and is sandwiched between the thin metal sheet and the bonding layer. Therefore, the present invention can provide to reduce damage ratio of polished workpieces by a design of a planar leveling surface of the chemical mechanical polishing conditioner, so that the chemical mechanical polishing conditioner has more excellent polishing efficiency and working life. In addition, in the above-mentioned chemical mechanical polishing conditioner of the present invention, the protruding tips of the plurality of abrasive particles having the planar leveling surface are generally understood to indicate the protruding tips of the plurality of abrasive particles having the same height from the surface of the chemical mechanical polishing conditioner, so that the planar leveling surface can be formed from the protruding tips of the plurality of abrasive particles.
The present invention generally provides CMP pad conditioners and associated methods that can be utilized in conditioning (e.g., smoothing, polishing, dressing) a CMP pad. Pad dressers of the present invention can be advantageously utilized, for example, in dressing CMP pads that are used in polishing, finishing or otherwise affecting semiconductor materials. Specifically, the present disclosure concerns CMP pad dressers having abrasive particles with substantially leveled tips. Traditional CMP pad conditioner manufacturing methods, even many of those describing techniques for leveling abrasive particle tips prior to fixation, generally contain significant variation in tip height across the surface of the conditioner. Often, the abrasive particles are affixed to the CMP pad conditioner support (i.e., substrate) in a manner that disrupts any leveling that has occurred. On the other hand, fixation techniques that utilize high heat and/or pressure to fix abrasive particles on the surface of CMP pad conditioner, because of the difference of the thermal expansion coefficient between the bonding layer and the bottom of substrate, thus causing warping of the conditioner support as the conditioner cools. Thus, unless steps are taken to avoid such warpage, abrasive particles are not maintained in their leveled state following cooling of the conditioner. This can be particularly problematic with brazing techniques.
Accordingly, minimizing the warpage of the metal support layer can maintain a greater degree of leveling of abrasive particle tips in the finished workpiece. When heat and/or pressure are used to make a polished workpieces, warpage of the metal support layer can cause great variations in tip height level, even for those particles that were leveled prior to heating and/or applying pressure. By distributing the warpage forces equally or substantially equally on both sides of the metal support layer through the arrangement of the abrasive particles, these forces effectively cancel each other with respect to the degree of warping occurring in the metal support layer, thus also minimizing the relative height movement of the abrasive particles relative to one another.
In the chemical mechanical polishing conditioner of the present invention, the plurality of abrasive particles of the first layer of abrasive particles may have a monolayer arrangement, and the first layer of abrasive particles and the second layer of abrasive particles may have the same configuration and distribution of abrasive particles. Therefore, by distributing the warpage forces equally or substantially equally on both sides of the metal support layer through the arrangement of the abrasive particles, these forces effectively cancel each other with respect to the degree of warping occurring in the metal support layer, thus also minimizing the relative height movement of the abrasive particles relative to one another. In addition, in the above-mentioned chemical mechanical polishing conditioner of the present invention, the plurality of abrasive particles may be directly disposed on the thin metal sheet by heating or pressuring means according to the above-mention context. On the other hand, the plurality of abrasive particles may be coupled to the thin metal sheet with a bonding layer of abrasive particles, so as to have better bonding strength between the plurality of abrasive particles and the thin metal sheet.
Due to the fact the chemical-mechanical planarization is directed to planar polishing, the contact distribution between the high point of the wafer and the polishing pad lead to confirm the quality (ex. yield rate) and the efficiency (ex. production capacity) of the chemical-mechanical planarization. If the distribution of the high point of the asperities is uneven, the abrasion rate of the wafer in different part would be different in speed and the wafer surface would be uneven. Furthermore, it is possible that some areas would be over-polished to result in subjecting the same layer to dishing or more layers to erosion; or result in subjecting some places under-polished to produce residuals. If within wafer non-uniformity (WIWNU), the effect of the chemical-mechanical planarization would be not desired. Accordingly, the present invention improves the conditioner based on extensive data from testing and experiment, especially adjusts the height of the working polishing tips by controlling an arrangement of the abrasive particles to achieve aforesaid height distribution of the highest tip, so as to avoid producing the killer diamond and enhance the ratio of the effective working polishing tips on the polishing units. Wherein, the aforesaid killer diamond is generally understood to indicate abrasive particles (i.e., diamond particles) having higher tip height corresponding to tip height of the other abrasive particles on the surface of the chemical mechanical polishing conditioner.
Accordingly, the present invention provides a chemical mechanical polishing conditioner, which is using the shape polishing tips but maintaining the distribution of the tips height to avoid the existence of the killer diamond so as to enhance the ratio of the working polishing tips on the polishing unit and increase the removal ratio on the wafer and the durability of the conditioner. In the chemical mechanical polishing conditioner of the present invention, the protruding tips of the plurality of abrasive particle have a planar leveling surface, which performs the protruding tips of the plurality of abrasive particles having the same height (or protruding distance) from the surface of the chemical mechanical polishing conditioner. Wherein, the crucial concept of the planar leveling surface of the abrasive particles is to avoid damage of the polished workpieces (i.e., Polishing Pad) resulted by the killer diamond, in this case, because of the tip height of the killer diamond being relatively higher than the tip height of the other of abrasive particles, the killer diamond will penetrate and permeate over the polished workpiece and then result to damage scratch of the polished workpiece in the CMP manufacturing process.
In order to illustrate further the tip leveling of the abrasives particle, the present invention can define the protruding tips of the plurality of abrasive particles being a planar leveling surface by a variety of ways, which include: using FRT (Germany FRT (Fries Research & Technology GmbH)) to measure all of protruding tips of the abrasive particles on the substrate (i.e., backward substrate) of the chemical mechanical polishing conditioner, for example, to measure the chemical mechanical polishing conditioner manufactured by brazing means, wherein the surface of the chemical mechanical polishing conditioner has over 30,000 protruding tips of the abrasive particles. The total of height of the protruding tips of the chemical mechanical polishing conditioner, which protruding tips protrude the surface of the bonding layer, is measured. Using the least square method with the height data, a hypothetical plane may be calculated by those protruding tips top, and the hypothetical plane is the aforesaid predetermined plane, which may be defined the protruding distance of the predetermined plane being 0. The first highest tip is the heights of the protruding tip which protrude over the predestine plane the most in those protruding tips, the second highest tip is the heights of the protruding tip which protrude over the predestine plane the second most in those protruding tips, and the other highest tip are the like.
However, by use of the normal chemical mechanical polishing conditioner, it is only measured about protruding tips of 300 abrasive particles producing wear and tear during the scaling value of 50 multiplying power after polishing. That is, the about 30% abrasive particles produce wear and tear in the polishing process, so that the present protruding distance of the protruding tip of these abrasive particles is lower than the initial protruding distance of the protruding tip of these abrasive particles, and thus the hypothetical plane extrapolated by all of protruding tips is not preformed effectiveness; therefore, according to the practical experience of the applicant of the present invention, the 1,000 highest protruding tips of all of abrasive particles are regarded as a planar leveling surface, so that protruding tips of about 1,200 abrasive particles producing wear and tear in the composite chemical mechanical polishing conditioner after polishing are measured during the scaling value of 50 multiplying power.
In another more logical measuring method of the planar leveling surface, that is to use the conditioner to apply about 3 kg of downward force, so as to implement scratch testing, wherein the maximum penetration depth (about 50 microns) is formed in the conditioner, which corresponds the protruding tip of the conditioner regarded as killer diamond. However, the protruding distances of the abrasive particles or spacing between the abrasive particles are very small, so that it is difficult to make actual measurements.
In the other measuring method of the planar leveling surface, that is, an abrasive surface of the conditioner distributed abrasive particles is set in contact with a carbon paper arranged on a planar leveling surface (e.g., grantie surface), and then three highest protruding tips is remarked by carbon powder, and a planar leveling surface is defined by the three points. However, the measuring method still has a problem. That is, when the three highest protruding tips by measurement are all located in the same side of the conditioner, the three points will connect to form an incline surface, which is not actual the required planar leveling surface.
On another case, if spacing between the killer diamond and other abrasive particles is further far, the killer diamond will be easily produced damages. In addition, because the killer diamond lacking to go along with the neighboring higher abrasive particles supports to be the abrasive surface, so that the polishing pad will be produced greater than usual scratches.
Furthermore, in the above-mentioned context, a variety of techniques are contemplated to facilitate the protruding tips of the abrasive particles to be defined as a planar leveling surface, and are considered to be within the present scope, but not limited to. In one aspect of the present invention, the above chemical mechanical polishing conditioner can use FRT to measure the protruding tips of all of the highest abrasive particles, and then can use least square method to extrapolate a hypothetical plane made of the protruding tips and be defined the height deviation between the abrasive particles and the hypothetical plane as the planar leveling surface of the protruding tips. Therefore, after the chemical mechanical polishing conditioner is used, the chemical mechanical polishing conditioner may have 300 or more abrasive particles producing wear and tear during the scaling value of 50 multiplying power
The present CMP pad dressers include a layer of abrasive particles having substantially leveled tips across the working surface of the finished CMP pad dresser. A variety of techniques can be utilized to maintain tip leveling, and any such technique is considered to be within the present scope. In the chemical mechanical polishing conditioner of the present invention, the planar leveling surface may be made by a hypothetical plane as a level, so that the planar leveling surface may be formed the protruding tips of the plurality of abrasive particles relative to the hypothetical plane; wherein the planar leveling surface may be configured of the protruding tips of the discontinuous abrasive particles extrapolated by FRT measurement, and not configured of the continued abrasive particles being all adjacent to each other; wherein the number of the protruding tips of the plurality of abrasive particles may be from 1000 to 30,000 or more, and preferably, the number of the protruding tips of the plurality of abrasive particles may be 1000. In one aspect of the present invention, the hypothetical plane can measure the protruding tips of all of abrasive particles (e.g., over 30,000 protruding tips of the abrasive particles) on the conditioner by using FRT, and then use least square method to extrapolate a hypothetical plane made of the protruding tips of all of abrasive particles. Or, in another aspect of the present invention, it may be to use FRT to measure the protruding tips of the 1,000 highest abrasive particles, and then use least square method to extrapolate a hypothetical plane made of the 1,000 highest protruding tips of all of abrasive particles, and be defined the height deviation between the abrasive particles and the hypothetical plane as the planar leveling surface of the protruding tips, wherein in the above-mentioned two extrapolated methods of the hypothetical plane is compared with the hypothetical plane extrapolated by protruding tips of all of abrasive particles, the hypothetical plane defined by protruding tips of the 1,000 highest abrasive particles will make the protruding tips to have the better function; In addition, the height of protruding tips of the abrasive particles may be compared and defined with the height of the hypothetical plane, wherein, the height of protruding tips of the abrasive particles will be compared with the height of the hypothetical plane and have the most difference distance regarded as the highest protruding tip, compared with the height of the hypothetical plane and have the 2nd most difference distance regarded as the 2nd highest protruding tip, compared with the height of the hypothetical plane and have the 10nd most difference distance regarded as the 10nd highest protruding tip, compared with the height of the hypothetical plane and have the 100nd most difference distance regarded as the 100nd highest protruding tip, compared with the height of the hypothetical plane and have the most difference 1% distance regarded as the 1% highest protruding tip. Therefore, the difference in protrusion distance between the highest protruding tip and the 2nd highest protruding tip is the difference that the highest protruding tip and the 2nd highest protruding tip is relative to the plane of the differences in the hypothetical plane; the difference in protrusion distance between the highest protruding tip and the 10nd highest protruding tip is the difference that the highest protruding tip and the 10nd highest protruding tip is relative to the plane of the differences in the hypothetical plane; the difference in protrusion distance between the highest protruding tip and the 100nd highest protruding tip is the difference that the highest protruding tip and the 100nd highest protruding tip is relative to the plane of the differences in the hypothetical plane; the difference in protrusion distance between the highest protruding tip and the highest 1% protruding tip is the difference that the highest protruding tip and the highest 1% protruding tip is relative to the plane of the differences in the hypothetical plane; and the difference in protrusion distance between the other protruding tips can be all derivate by principle.
In the chemical mechanical polishing conditioner of the present invention, protruding tips of the plurality of abrasive particles may be regarded as a planar leveling surface according to the above-mention context, wherein, in one aspect of the present invention, the difference in protrusion distance between the highest protruding tip and the 2nd highest protruding tip of the first layer of abrasive particles may be less than or equal to about 20 microns. In another aspect of the present invention, the difference in protrusion distance between the highest protruding tip and the 2nd highest protruding tip of the first layer of abrasive particles may be less than or equal to about 10 microns. Furthermore, in one aspect of the present invention, the difference in protrusion distance between the highest protruding tip and the 10th highest protruding tip of the first layer of abrasive particles may be less than or equal to about 20 microns. In another aspect of the present invention, the difference in protrusion distance between the highest protruding tip and the 100th highest protruding tip of the first layer of abrasive particles may be less than or equal to about 40 microns. Additionally, in another aspect of the present invention, the difference in protrusion distance between the highest 1% of the protruding tips of the first layer of abrasive particles may be less than or equal to about 80 microns.
It is noted that the above-mentioned context defining the planar leveling surface of the protruding tips can be referenced, which the protruding distance may be the difference in protrusion distance between the protruding tips and the hypothetical plane extrapolated by FRT measurement, and the recited protrusion distances can include a distribution across the entire monolayer surface or a discrete area of the monolayer. For example, the highest 1% of protruding tips can be located around the periphery of the monolayer. In one embodiment, discrete regions of leveled abrasive particle tips can be located within a larger area of abrasive particles having a lower protrusion distance than the leveled portion. It is also contemplated that the monolayer can include multiple regions of abrasive particles that are leveled as described, within a larger area of abrasive particles having a lower protrusion distance.
In the chemical mechanical polishing conditioner of the present invention, various methods can be utilized to measure abrasive particle tip height to determine the difference in protrusion distance between tips. As such, any method for making such a determination is considered to be within the present scope. It should be noted that for the purposes of the present disclosure, the term “protrusion” refers to the height of a particle relative to some reference point. Techniques for such measurements can include direct measurements of the tip heights relative to a reference point such as, for example, the highest particle tip, a surface of a rigid support, the bottom surface of the matrix, etc. Measurements of particle height from the surface of the matrix material can be problematic, however, due to the irregular nature of such materials due to wicking around the abrasive particles. In those cases whereby the matrix material is uniform, such a surface may be used to determine particle height. Additionally, a relative protrusion or height difference between two particles would be the difference in the heights between these particles measured from a common reference point. Furthermore, in some cases the abrasive particles may lie along a slope, curvature, or some other arrangement that is not parallel to the metal support layer. In these cases, the protrusion height would be normalized against the slope, curvature, or other arrangement that is not parallel to the metal support layer so that the relative protrusion height difference between particles can be measured in the absence of the slope, curvature, etc. It should be noted that the abrasive particle tip height leveling can, in some cases, be independent from the positioning or patterning of the abrasive particles across the surface of the conditioner.
One example of a direct measurement technique can include an optical scanning process to evaluate abrasive particle tip positions. In one such process, an optical scanner can scan the surface of the CMP pad conditioner to determine the height of the abrasive particle tips relative to a fixed point. For example, the scanner can scan downward in space toward the conditioner until the highest tip is located. The highest tip can then be set to the reference point, and the scanner can continue scanning in a direction toward the conditioner measuring the distance from the reference point to each abrasive particle tip across the surface of the conditioner. Accordingly, the difference in protrusion distance between all of the abrasive particles across the conditioner can be directly measured. Furthermore, measurement techniques can also include indirect measurements, such as, for example, applying the diamond monolayer to a deformable substrate that deforms relative to the protrusion distance of the particle tips. The diamond monolayer can be pressed into the deformable substrate and/or moved across the deformable substrate to form a scratch pattern therein. Tip height can thus be extrapolated from such indirect measurements.
In the chemical mechanical polishing conditioner of the present invention, arrangement or orientation of the abrasive particles may be any varied according to conditions or requirement of a polishing process, but no limited to. In the above-mentioned chemical mechanical polishing conditioner of the present invention, the patterning arrangement of the abrasive particles can be an array pattern, a annular ring pattern, a concentric annular ring pattern, or a spiral ring pattern. On the other hand, the abrasive particles are oriented in a specific attitude, and the abrasive particles is formed a tip-grinding surface, a plane-grinding surface, a ridge-grinding surface or a combination thereof, but not limited to. In addition, the above-mentioned tip-grinding surface is generally understood to indicate that the protruding tips of the abrasive particles facing towards the polished workpieces (e.g. polishing pad), so that the surface of the chemical mechanical polishing conditioner is the tip-grinding surface consisted of the protruding tips of the abrasive particles; the above-mentioned plane-grinding surface is generally understood to indicate that the protruding tips of the abrasive particles facing towards the leveling parallel to the conditioner, so that the surface of the chemical mechanical polishing conditioner is the plane-grinding surface consisted of the protruding plane of the abrasive particles; the above-mentioned plane-grinding surface is generally understood to indicate that the protruding tips of the abrasive particles form a incline degree with the conditioner, so that the surface of the chemical mechanical polishing conditioner is the ridge-grinding surface consisted of the protruding incline plane of the abrasive particles.
In the chemical mechanical polishing conditioner of the present invention, the abrasive particles can be arranged into a predetermined pattern. Such a pattern can be a uniformly distributed pattern or a non-uniformly distributed pattern. Additionally, a variety of techniques are contemplated to facilitate the arrangement of abrasive particles into a predetermined pattern, and are considered to be within the present scope. Predetermined is understood to mean a non-random pattern that has been determined prior to arranging the abrasive particles. In one aspect of the present invention, a predetermined pattern can also apply to a predetermined spacing between particles. Non-limiting examples of such techniques include arrangement by a template, arrangement using spots of adhesives, arrangement on a first substrate followed by a pattern specific transfer from the first substrate to the metal support layer, and the like, including combinations thereof. The abrasive particles from either of the monolayers can be temporarily held in position in the predetermined pattern using a variety of techniques, including, without limitation, adhesives, dimpled locations on the metal support matrix, a supporting compound such as, for example, a wax, and the like, including combinations thereof. In another aspect of the present invention, the abrasive particles can be temporarily coupled to the metal support layer using an adhesive that then volatilizes away and is eliminated during construction of the conditioner.
In the chemical mechanical polishing conditioner of the present invention, a CMP pad conditioner having such substantially leveled tip arrangements can have a low scratch rate because abrasive particles of the present invention are less likely to pull out of the matrix layer due to their more uniform protrusion distribution compared to traditional conditioners. Additionally, the more uniform protrusion distributions of such a dressers allows the conditioning of CMP pads in such a manner as to facilitate good polishing rates while at the same time extending the effective working life of the conditioner. These benefits can be affected by. Additionally, uniform asperity spacing and size distribution in the CMP pad.
In the chemical mechanical polishing conditioner of the present invention, the plurality of abrasive particles may be consisted of all kind of configuration of abrasive particles; in one aspect of the present invention, the plurality of abrasive particles may be synthetic diamond, natural diamond, Poly-crystalline diamond, CBN (cubic Boron Nitride), PCBN (Poly-crystalline cubic Boron Nitride); in another aspect of the present invention, the plurality of abrasive particles may be synthetic diamond; and, in the other aspect of the present invention, the plurality of abrasive particles may be synthetic polycrystalline diamond, but not limited to. Additionally, in the chemical mechanical polishing conditioner of the present invention, a particle size may be dependent on the particle type, or crystal form of particles, or surface roughness that a polishing process requires; in one aspect of the present invention, the particle size of the plurality of abrasive particles may be from 100 microns to 600 microns; and, in another aspect of the present invention, the particle size of the plurality of abrasive particles may be from 500 microns, but not limited to. Furthermore, in the chemical mechanical polishing conditioner of the present invention, the thin metal sheet may be selected any flexible and thin sheet so as to easily attach the abrasive layer with the substrate and fix the plurality of abrasive particles, or the thin metal sheet can be a flexible and thin sheet to fix the plurality of abrasive particles, and the above-mentioned thin metal sheets are considered to be within the present scope, for example copper metal sheet, thin plastic sheet, or thin braze alloy sheet.
In the chemical mechanical polishing conditioner of the present invention, constituents of the bond layer or the bond layer of abrasive particles may be any varied according to conditions or requirement of a polishing process, wherein, the bonding layer or the bonding layer of abrasive particles may be a solder layer, a plating layer, a sinter layer, or a resin layer. In one aspect of the present invention, the bonding layer or the bonding layer of abrasive particles may be a solder layer, wherein, the solder layer may be at least one selected from the group consisting of copper (Cu), ferrous (Fe), stannum (Sn), cobalt (Co), nickel (Ni), chromium (Cr), manganese (Mn), silicon (Si), aluminum (Al), titanium (Ti), boron (B), phosphorus (P), or combinations thereof. In another aspect of the present invention, the solder layer may be nickel-based braze material or Ni—Co braze alloy material. Furthermore, in the other aspect of the present invention, the solder layer may be Cu—Sn—Ti braze alloy material. In addition, in the chemical mechanical polishing conditioner of the present invention, the substrate may be a stainless steel layer, but not limited to. Furthermore, in the above-mentioned chemical mechanical polishing conditioner of the present invention, the above-mentioned chemical mechanical polishing conditioner may further comprise a protective layer disposed on the surface of the abrasive layer, wherein the protective layer may cover the first layer of abrasive particles and the thin metal sheet, or the protective layer may cover the first layer of abrasive particles and the abrasive layer, wherein, the protective layer may be a Ni-metal layer, a Pd-metal layer, a DLC layer, a layer of diamond thin film or likes, so that the chemical mechanical polishing conditioner can provide with more excellent corrosion resistance and work life by the protective layer
Consequently, the chemical mechanical polishing conditioner of the present invention can control the protruding distance of the protruding tips of abrasive particles, so as to decrease to damage ratio of polished workpieces, and thus the chemical mechanical polishing conditioner has more excellent polishing efficiency and working life.
Hereafter, examples will be provided to illustrate the embodiments of the present invention. Other advantages and effects of the invention will become more apparent from the disclosure of the present invention. Other various aspects also may be practiced or applied in the invention, and various modifications and variations can be made without departing from the spirit of the invention based on various concepts and applications.
Comparative Example 1Please refer to
The primary objective of the present invention is to control the protruding distance of the protruding tips of abrasive particles, so as to decrease to damage ratio of polished workpieces, and thus the chemical mechanical polishing conditioner has more excellent polishing efficiency and working life.
Next, as shown in
Accordingly, the chemical mechanical polishing conditioner of the embodiment 1 of the present invention comprises: a substrate 20; a bonding layer 21, disposed on the substrate 20; and an abrasive layer 22, having a thin metal sheet 222 and a first layer of abrasive particles 221a, wherein the first layer of abrasive particles 221a is disposed on the thin metal sheet 222, and the abrasive layer 22 is coupled to the substrate 20 with the bonding layer 21; wherein the first layer of abrasive particles 221a comprises a plurality of abrasive particles, of which protruding tips have a planar leveling surface, so that the plurality of abrasive particles do not have one or more protruding tips of the plurality of abrasive particles having particular significant difference in protrusion distance, and the plurality of abrasive particles have a patterning arrangement. In addition, the chemical mechanical polishing conditioner of the embodiment 1 further comprises a second layer of abrasive particles 221b, wherein the second layer of abrasive particles 221b is disposed under the thin metal sheet 222 and is sandwiched between the thin metal sheet 222 and the bonding layer 21. Furthermore, the plurality of abrasive particles of the first layer 221a of abrasive particles have a monolayer arrangement, and the first layer of abrasive particles 221a and the second layer of abrasive particles 221b have the same configuration and distribution of abrasive particles.
In particular, the above chemical mechanical polishing conditioner can use FRT to measure the protruding tips of the 1,000 highest abrasive particles, and then can use least square method to extrapolate a hypothetical plane made of the protruding tips and be defined the height deviation between the abrasive particles and the hypothetical plane as the planar leveling surface of the protruding tips. In the embodiment 1, the protruding tips of the plurality of abrasive particles have a planar leveling surface, wherein the difference in protrusion distance between the highest protruding tip and the 2nd highest protruding tip of the first layer of abrasive particles is less than or equal to about 20 microns, the difference in protrusion distance between the highest protruding tip and the 10th highest protruding tip of the first layer of abrasive particles is less than or equal to about 20 microns, the difference in protrusion distance between the highest protruding tip and the 100th highest protruding tip of the first layer of abrasive particles is less than or equal to about 40 microns, and the difference in protrusion distance between the highest 1% of the protruding tips of the first layer of abrasive particles is less than or equal to about 80 microns.
In the above-mentioned context, the chemical mechanical polishing conditioner disclosed by the comparative example 1 is by the conventional manufacturing manner, which disposes abrasive particles and a bonding layer is in advance disposed on a substrate in advance and the carries out on heating, so that the abrasive particles is fixed on the substrate by a brazing reaction of the bonding layer. However, because of the difference of the thermal expansion coefficient between the bonding layer and the substrate, the chemical mechanical polishing conditioner will be distorted in the cooling process after hardening the chemical mechanical polishing conditioner, and thus the bonding layer and the abrasive particles of the surface of the substrate will be distorted. Accordingly, the height of the bonding layer and the abrasive particles in the central region of the chemical mechanical polishing conditioner is higher than the height of the bonding layer and the abrasive particles in the outside annular region of the chemical mechanical polishing conditioner, so as to form a distorted surface in which the height of the outside region is higher than the height of the central region. Therefore, the leveling of the chemical mechanical polishing conditioner is damaged to increase damage ratio of polished workpieces, and thus the polishing efficiency and the working life of the chemical mechanical polishing conditioner become to decrease. It is different to the manufacturing manner and the configuration of the conventional chemical mechanical polishing conditioner, in the embodiment 1 of the present invention, a plurality of abrasive particles are bonded to and fixed on a substrate in advance so as to form an abrasive layer, and then the abrasive layer is disposed on the substrate and the bonding layer and carried out on heating, so that the abrasive layer is fixed on the substrate by a brazing reaction of the bonding layer. Therefore, the chemical mechanical polishing conditioner of the present invention can avoid a problem that is easily resulted to distort and drift in a cooling process after a hardening process or in a hardening process. On the other hand, the chemical mechanical polishing conditioner of the present invention can further have a planar leveling surface by controlling the protruding distance of protruding tips of the plurality of abrasive particles, or the chemical mechanical polishing conditioner of the present invention can form to distribute the distorted forces equally on both sides of the thin metal sheet by the plurality of abrasive particles that have the same configuration and distribution to dispose on both side of the thin metal sheet respectively, so as to offset effectively the distorted degree resulted from cooling the abrasive layer after brazing.
Embodiment 2Next, as shown in
Accordingly, the chemical mechanical polishing conditioner of the embodiment 2 of the present invention comprises: a substrate 30; a bonding layer 31, disposed on the substrate 30; and an abrasive layer 32, having a thin metal sheet 322 and a first layer of abrasive particles 321, wherein the first layer of abrasive particles 321 is disposed on the thin metal sheet 322, and the abrasive layer 32 is coupled to the substrate 30 with the bonding layer 31; wherein the first layer of abrasive particles 321 comprises a plurality of abrasive particles, of which protruding tips have a planar leveling surface, so that the plurality of abrasive particles do not have one or more protruding tips of the plurality of abrasive particles having particular significant difference in protrusion distance, and the plurality of abrasive particles have a patterning arrangement, and the plurality of abrasive particles of the first layer 321 of abrasive particles have a monolayer arrangement.
Furthermore, In the above-mentioned chemical mechanical polishing conditioner, the protruding tips of the plurality of abrasive particles have a planar leveling surface, wherein the difference in protrusion distance between the highest protruding tip and the 2nd highest protruding tip of the first layer of abrasive particles is less than or equal to about 20 microns, the difference in protrusion distance between the highest protruding tip and the 10th highest protruding tip of the first layer of abrasive particles is less than or equal to about 20 microns, the difference in protrusion distance between the highest protruding tip and the 100th highest protruding tip of the first layer of abrasive particles is less than or equal to about 40 microns, and the difference in protrusion distance between the highest 1% of the protruding tips of the first layer of abrasive particles is less than or equal to about 80 microns.
It is different to the manufacturing manner and the configuration of the conventional chemical mechanical polishing conditioner, in the embodiment 2 of the present invention, a plurality of abrasive particles are bonded to and fixed on a substrate in advance so as to form an abrasive layer, and then the abrasive layer is disposed on the substrate and the bonding layer and carried out on heating, so that the abrasive layer is fixed on the substrate by a brazing reaction of the bonding layer. Therefore, the chemical mechanical polishing conditioner of the present invention can avoid a problem that is easily resulted to distort and drift in a cooling process after a hardening process or in a hardening process. On the other hand, the chemical mechanical polishing conditioner of the present invention can further have a planar leveling surface by controlling the protruding distance of protruding tips of the plurality of abrasive particles, so as to decrease to damage ratio of polished workpieces, and thus the chemical mechanical polishing conditioner has more excellent polishing efficiency and working life.
Embodiment 3The embodiments described above are only to exemplify the present invention but not to limit the scope of the present invention. Any equivalent modification or variation according to the spirit of the present invention is to be also included within the scope of the present invention.
Claims
1. A chemical mechanical polishing conditioner, which comprises:
- a substrate;
- a bonding layer, disposed on the substrate; and
- an abrasive layer, having a thin metal sheet and a first layer of abrasive particles, wherein the first layer of abrasive particles is disposed on the thin metal sheet, and the abrasive layer is coupled to the substrate with the bonding layer;
- wherein the first layer of abrasive particles comprises a plurality of abrasive particles, of which protruding tips have a planar leveling surface, so that the plurality of abrasive particles do not have one or more protruding tips of the plurality of abrasive particles having particular significant difference in protrusion distance, and the plurality of abrasive particles have a patterning arrangement.
2. The chemical mechanical polishing conditioner as claimed in claim 1, further comprising a second layer of abrasive particles, wherein the second layer of abrasive particles is disposed under the thin metal sheet and is sandwiched between the thin metal sheet and the bonding layer.
3. The chemical mechanical polishing conditioner as claimed in claim 1, wherein the plurality of abrasive particles of the first layer of abrasive particles have a monolayer arrangement.
4. The chemical mechanical polishing conditioner as claimed in claim 1, wherein the first layer of abrasive particles and the second layer of abrasive particles have the same configuration and distribution of abrasive particles.
5. The chemical mechanical polishing conditioner as claimed in claim 1, wherein the plurality of abrasive particles are coupled to the thin metal sheet with the bonding layer of abrasive particles.
6. The chemical mechanical polishing conditioner as claimed in claim 1, wherein the difference in protrusion distance between the highest protruding tip and the 2nd highest protruding tip of the first layer of abrasive particles is less than or equal to about 20 microns.
7. The chemical mechanical polishing conditioner as claimed in claim 6, wherein the difference in protrusion distance between the highest protruding tip and the 2nd highest protruding tip of the first layer of abrasive particles is less than or equal to about 10 microns.
8. The chemical mechanical polishing conditioner as claimed in claim 1, wherein the difference in protrusion distance between the highest protruding tip and the 10th highest protruding tip of the first layer of abrasive particles is less than or equal to about 20 microns.
9. The chemical mechanical polishing conditioner as claimed in claim 1, wherein the difference in protrusion distance between the highest protruding tip and the 100th highest protruding tip of the first layer of abrasive particles is less than or equal to about 40 microns.
10. The chemical mechanical polishing conditioner as claimed in claim 1, wherein the difference in protrusion distance between the highest 1% of the protruding tips of the first layer of abrasive particles is less than or equal to about 80 microns.
11. The chemical mechanical polishing conditioner as claimed in claim 1, wherein the planar leveling surface is made by a hypothetical plane as a level, so that the planar leveling surface is formed the protruding tips of the plurality of abrasive particles relative to the hypothetical plane.
12. The chemical mechanical polishing conditioner as claimed in claim 11, wherein the planar leveling surface is configured of the protruding tips of the discontinuous abrasive particles extrapolated by FRT measurement.
13. The chemical mechanical polishing conditioner as claimed in claim 12, wherein the number of the protruding tips of the plurality of abrasive particles are from 1000 to 30,000 or more.
14. The chemical mechanical polishing conditioner as claimed in claim 13, wherein the number of the protruding tips of the plurality of abrasive particles is 1000.
15. The chemical mechanical polishing conditioner as claimed in claim 1, wherein, after the chemical mechanical polishing conditioner is used, the chemical mechanical polishing conditioner has 300 or more abrasive particles producing wear and tear during the scaling value of 50 multiplying power.
16. The chemical mechanical polishing conditioner as claimed in claim 1, wherein the patterning arrangement is an array pattern, a annular ring pattern, a concentric annular ring pattern, or a spiral ring pattern.
17. The chemical mechanical polishing conditioner as claimed in claim 1, wherein the plurality of abrasive particles are oriented in a specific attitude, and the plurality of abrasive particles is formed a tip-grinding surface, a plane-grinding surface, a ridge-grinding surface or a combination thereof.
18. The chemical mechanical polishing conditioner as claimed in claim 1, wherein the plurality of abrasive particles are synthetic diamond, natural diamond, Poly-crystalline diamond, CBN (cubic Boron Nitride), or PCBN (Poly-crystalline cubic Boron Nitride).
19. The chemical mechanical polishing conditioner as claimed in claim 1, the particle size of the plurality of abrasive particles is from 100 microns to 600 microns.
20. The chemical mechanical polishing conditioner as claimed in claim 1, wherein the bonding layer or the bonding layer of abrasive particles is a solder layer, a plating layer, a sinter layer, or a resin layer.
21. The chemical mechanical polishing conditioner as claimed in claim 20, wherein the bonding layer or the bonding layer of abrasive particles is a solder layer.
22. The chemical mechanical polishing conditioner as claimed in claim 21, wherein the solder layer is at least one selected from the group consisting of copper (Cu), ferrous (Fe), stannum (Sn), cobalt (Co), nickel (Ni), chromium (Cr), manganese (Mn), silicon (Si), aluminum (Al), titanium (Ti), boron (B), phosphorus (P), or combinations thereof.
23. The chemical mechanical polishing conditioner as claimed in claim 1, wherein the substrate is a stainless steel layer.
24. The chemical mechanical polishing conditioner as claimed in claim 1, further comprising a protective layer disposed on the surface of the abrasive layer.
25. The chemical mechanical polishing conditioner as claimed in claim 24, wherein the protective layer is a Ni-metal layer, a Pd-metal layer, a DLC layer, or a layer of diamond thin film.
Type: Application
Filed: Apr 8, 2014
Publication Date: Oct 16, 2014
Inventors: Chien-Min Sung (Tansui), Wen-Ting Yeh (Taipei)
Application Number: 14/248,163