TW201341113A - Composite conditioner and method for manufacturing the same and CMP application thereof - Google Patents

Abstract

A composite conditioner includes: a base plate; a plurality of polishing units placed on the base plate and each polishing unit including a bonding layer and a plurality of polishing tips that are bonded in plane by the bonding layer; and an adhesive layer of which thickness is adjustable and used to secure the polishing units on the base plate, wherein a height difference between the first and second highest tips, between the first and tenth highest tips, and between the first and 100<SP>th</SP> highest tips based on a predetermined plane is respectively less than 10 &mgr; m, 20 &mgr; m, and 40 &mgr; m, and the protrusion height of the first highest tip above the bonding layer is greater than 50 &mgr; m. The present invention also relates to a method for manufacturing the conditioner and application thereof.

Description

Combined dresser and its manufacturing method and chemical mechanical flattening application

The present invention relates to a combined dresser, a method of fabricating the same, and a chemical-mechanical planarization (CMP) process using the same, and more particularly to a combined trimmer suitable for planarizing a surface of a semiconductor wafer, The manufacturing method thereof, and the chemical mechanical planarization process using the same.

For the fine copper circuit or the interlayer tungsten circuit on the surface of the germanium wafer, and even the oxide film dielectric layer of the insulating circuit, the planarization process must be planarized to flatten the surface for subsequent processing steps. At present, in the process of manufacturing integrated circuits (ICs) on semiconductor wafers, the most noticeable planarization technology is chemical-mechanical planarization (CMP), which presses the wafer against rotation. The polishing pad is ground to make the surface flat.

During the chemical mechanical planarization process, the slurry is stably and evenly transferred between the wafer and the polishing pad, so that the surface of the polishing pad is covered with a slurry (Slurry) containing chemicals (such as acid and oxidant). ) The film used to erode the surface of the wafer. The refining also contains numerous nano-ceramics (such as SiO ₂ , Al ₂ O ₃ , CeO ₂ ) abrasive particles, which can penetrate and scrape a small amount of film while chemical etching and Mechanical grinding removes the deposited layer on the wafer to polish the surface of the wafer for planarization.

The dresser is a consumable necessary for chemical mechanical planarization and functions as a conditioning polishing pad (Pad). The so-called trimming, including cutting the surface of the polishing pad, removes the accumulated debris on the surface of the polishing pad, thereby maintaining the roughness of the surface of the polishing pad. In addition, the refiner can also produce a slight amount of ridges and depressions on the surface, which is the so-called height of the Asperities, so that the area of the touch-polished pad can be greatly reduced. Once the contact area is smaller, the contact pressure is greater, and the contact is increased. The refining at the point can squeeze the protruding portion of the wafer, and the chemicals in the refining (such as H ₂ O ₂ ) will oxidize to soften or erode the wafer.

However, if the chemical mechanical planarization process, the generated waste, including wafer grinding debris, such as copper wire, tungsten hole filling, oxide film, refining, abrasive grains, polishing pad debris, etc., the grinding debris Usually it will accumulate on the surface of the polishing pad and be extruded into a hard layer. Once the hard layer is formed, the polishing pad becomes slippery and it is difficult to maintain the polishing force. Therefore, polishing each wafer often requires the use of a trimmer to achieve the process. Grinding efficiency (such as polishing speed) and flatness (such as thickness distribution of the wafer coating), thereby stabilizing wafer quality.

However, conventional diamond dressers usually fix the diamond particles on the surface of the metal plate with a bonding agent. Although it is suitable for refurbishing the polishing pad, for more precise chemical mechanical flattening processes, such as line width less than 45 nm. The following chemical mechanical planarization process, due to the roughness of the polishing pad, is liable to cause scratches, partial dishing, erosion, and non-uniformity of the wafer. As the linewidth requirements of integrated circuits are shrinking, the need for flatness of the wafer surface is increased, and the requirements for the trimmer are also increased, resulting in the conventional diamond dresser not meeting the chemical below 45 nm. Advanced requirements for mechanical flattening processes.

In view of the above, the patents laid-open publications TW 201038362 A1 and TW 201100198 respectively disclose a combined dresser and a method thereof, in which a sharp point of a sharp point of a grinding unit of various sizes, shapes and materials is pierced into a polishing pad. The other side of the subsequent press-grinding unit is filled with a resin to fix each of the grinding units so that the height difference of the apex of the grinding apex of the grinding unit is within 20 μm.

However, the sharpening point used in the above patent application requires the use of diamond abrasive grains having a relatively regular shape, and the crystal face coverage of the crystal form is very high (for example, a surface larger than 50% is a crystal growth surface), otherwise when used Sharp diamonds with low crystal face coverage can cause excessive height differences. In addition, the deepest diamond that penetrates the polishing pad, the so-called "killer diamond", is not standardized for the height of the top pad of other diamonds. In order to meet the process requirements of smaller line widths, it is necessary to continuously improve the dresser, and to maintain the flatness of the sharp point height (that is, the difference in the height of the sharp point of the sharp point) when using a sharper sharp point, the repairer A finer and more uniform score is formed on the polishing pad, and the removal rate of the polishing pad is improved, so that the hard layer can be effectively removed, and the fluff on the polishing pad can be restored to rapidly polish the coating on the wafer.

The main object of the present invention is to provide a combined dresser in which sharp sharp points are used, but the height distribution of the cusps is maintained, and the presence of "killer diamonds" is avoided, thereby increasing the proportion of effective working sharp points on the grinding unit. Increase wafer removal rate and trimper life.

In order to achieve the above object, an example of the present invention provides a combined trimmer comprising: a bottom substrate; a plurality of polishing units disposed on a surface of the bottom substrate, each polishing unit including a plurality of polishing tips, and a a layer of bonding agent (which may be metal, ceramic or resin) for fixing the sharp points; and an adhesive layer of adjustable thickness for fixing the polishing units on the surface of the bottom substrate, wherein the polishing points The height difference between the first high point and the second high point of a predetermined plane is less than 10 micrometers, and the height difference between the first high point and the tenth high point is less than 20 micrometers, and the height of the first high point and the first hundred high point The difference is less than 40 microns and the first high point highlights the height of the bond layer by more than 50 microns.

Since chemical mechanical planarization is planar polishing, the distribution of contact between the high point of the wafer and the high point of the polishing pad determines the quality (eg, yield) and efficiency (eg, throughput) of chemical mechanical planarization. If the high point of the polishing pad is unevenly distributed, the grinding rate of different parts of the wafer is different, and the surface of the wafer is not flat. What's more, in some places, the polishing pad may be excessive, resulting in the same layer of Dishing or Erosion; or, in some places, insufficient polishing may cause residue. If the thickness of the wafer after polishing is uneven (Within Wafer Non-Uniformity or WIWUU), the effect of chemical mechanical flattening will be insignificant. In view of this, the present invention is based on data from a number of test experiments, an improved dresser, in particular by adjusting the height of the working burr by an adjustable thickness of the adhesive layer to compensate for the difference in thickness of the grinding unit to the highest point. Highly distributed, avoiding the production of killer diamonds and increasing the proportion of effective working sharp points on the grinding unit.

In the above-mentioned combined dresser of the present invention, the material of the thickness adjustable adhesive layer may be an organic adhesive. Each of the polishing units may further include a unit substrate, and the bonding agent layer is disposed between the surface of the unit substrate and the polishing cusps. The material of the bonding layer may be a solder layer, a plating layer, and a bonding layer. a sintered layer, or a resin layer. The above-mentioned grinding cusps refer to the end points of the abrasive particles contained in the plurality of grinding units that can reach the grinding effect, and the end points are exposed to the bonding agent layer, in other words, the height of the grinding cusps, that is, the grinding The cusps highlight the height of the surface of the bond layer.

For the height measurement of the grinding cusps, the height of the total grinding cusp (such as more than 10,000) of the dresser can be measured by an optical inspection system such as a surface detector manufactured by FRT (Fries Research & Technology GmbH). , that is, the polishing cusps protrude the height of the surface of the bonding agent layer, and the obtained height data is further calculated by a least square method to calculate a hypothesis plane composed of the sharp points of the grinding cusps, which is the above-mentioned Plan the plane. The first high point refers to the height of the grinding cusps which most protrudes the predetermined plane among the grinding cusps, and the second high point refers to the height of the grinding cusp of the second of the grinding cusps that protrudes the predetermined plane Other high points are analogous.

The polishing position of the wafer depends on the distribution of the apex of the polishing pad. This distribution is determined by the height of the burrs of the dresser. The dresser can be disc-shaped (for Appliced Materials machines) or ring-shaped (eg Suitable for Ebara machines). The diameter of the disc is generally about 100 mm, and the ring shape can be as large as 250 mm or more. Usually the trimmer is covered with tens of thousands of sharp points (such as diamond particles), such as 80/90 mesh, 100/120 mesh, 120/140 mesh sharp points, but even the same mesh The average size difference may also be higher than 30%. In addition, the same sharp points have different sizes from different directions. For example, the distance between the sharp points is 30% larger than the plane, and if the shape of the sharp points is irregular, the difference It will be even bigger.

Therefore, the present invention adjusts the abrasive particles used such that the height difference between the first high point and the second high point of the grinding cusp is less than 10 micrometers, and the height difference between the first high point and the tenth high point is less than 20 micrometers, first The height difference between the high point and the first hundred high point is less than 40 micrometers, and the first high point protrudes from the height of the bonding agent layer by more than 50 micrometers to ensure that the trimmer has a plurality of working cusps, thereby achieving an IC wafer surface film. Quick and even removal. In addition, it should be noted that the first high point and the second high point may be dispersed in different grinding units or in the same grinding unit, and the remaining high points are also the same; in other words, the distribution of the high points is not concentrated in a single Grinding unit.

In the above-mentioned combined dresser of the present invention, the material of the grinding cusps may be artificial or natural diamond, polycrystalline diamond (PCD), cubic boron nitride (CBN), polycrystalline cubic boron nitride ( PCBN) or a combination thereof, and the size of the abrasive cusps may range from 100 to 500 microns. The above diamonds may be chemically deposited diamonds, polycrystalline diamonds or combinations thereof. In addition, the material of the bottom substrate is not particularly limited, and examples thereof may be pure resin, metal, alloy, plastic, rubber, ceramic, glass, or a combination thereof (such as a mixture of resin and metal).

In addition, because diamonds are usually catalyzed by graphite under high pressure (such as 5 GPa), they contain molten iron and nickel inclusions. At high temperatures, the alloy catalyzes the conversion of diamonds back to graphite or carbon, where the volume increases dramatically and the diamond bursts. If the diamond is fixed on the diamond disc by brazing, many diamonds will rupture due to the high process temperature. In the chemical mechanical flattening process, the tip of the diamond that penetrates into the depth of the polishing pad may collapse along the micro-crack. These diamonds are broken. Chips can scratch expensive wafers. In view of this, diamonds often use magnetic separators to absorb the diamonds with more inclusions. Even so, the diamonds still contain some residual iron-nickel alloy. If the diamonds leave undetectable cracks inside, they will be in the chemical mechanical flattening process. It may break and disintegrate, causing scratches on the wafer. In view of this, high temperature brazing should select a solder with a lower melting point.

In the present invention, when solder is used as the material of the bonding layer, the solder layer may contain at least one weight percent or more selected from the group consisting of Cr, B, P, Ti, and alloys thereof, and includes 50. The weight percentage or more is selected from at least one selected from the group consisting of Ni, Cu, and alloys thereof, or a combination thereof, wherein materials such as Cr, B, P, Ti, etc. are used to activate the solder layer. Specifically, the solder is usually Ni-Cr-B or Ni-Cr-P, or a Cu-Sn-Ti alloy, and the melting point (Solidus) is 800 ° C to 1000 ° C.

In addition, each of the polishing units may further include: a metal coating layer covering the surface of the bonding agent layer, and the material of the metal coating layer may be selected from Ni, Cr, palladium, Co, platinum, Au, Ti, At least one of the group of Cu, W and its alloys allows the polishing cusp to adhere more firmly to the unit substrate of the polishing unit. Furthermore, each of the polishing units may further comprise: a protective layer which is a thin layer of inert material covering the surface of the metal covering layer, and the protective layer may be made of a metal material such as palladium, platinum or non-metal. Materials such as ceramic films (such as tantalum carbide, tantalum nitride, aluminum nitride, aluminum oxide, zirconia), diamond-like carbon (DLC) films, organic films (such as Teflon) or combinations thereof to avoid soldering Grinding slurry erosion (such as tungsten process refining with pH=3).

In general, the apex height of a diamond determines the force that is pressed into the polishing pad, but its sharpness affects the depth of penetration. Generally, the more favorable the diamond, the smaller the amount of elastic and plastic deformation of the polishing pad, and the greater the depth of cutting. Since the diamond abrasive grains formed on the surface of the dresser are different in shape and in different directions, usually only the highest hundred are accessible to the polishing pad. If the shape of the diamond is regular and symmetrical, the angle will be obtuse and it will not penetrate into the polishing pad. Instead, it will push the surface of the polishing pad to form plastic deformation of the bulge on both sides. On the other hand, if the diamond has a rupture surface, that is, the shape is irregular. , it is possible to pierce the polishing pad, cut the surface of the polishing pad, and remove the waste.

Therefore, in the above-mentioned combined dresser of the present invention, among the one of the highest grinding points of the one hundred heights, more than 50% of the sharp points of the polishing point have a crystal face coverage of less than 80%, preferably a crystal face coverage. Less than 50%. When the coverage of the crystal face of the sharp point is lower, it means that the grinding sharp points have more crushing surfaces (ie, sharp surfaces), and also indicate the grinding sharp points of the working surface of the grinding unit, including sharp corners and ridge lines. Most of the ridge angles appear to be less than 45 degrees (ie, the angle between the two crystal faces that make up the ridgeline), or have a greater number of sharp angles less than 90 degrees, thus having a higher removal rate for the polishing pad. Referring to Figure 9, which is a schematic view of abrasive particles, wherein A, E and S represent sharp corners, ridges and surfaces, respectively, wherein S ₁ is a crystal plane, A ₁ is the angle of the crystal plane, S ₂ is the fracture surface, and A ₂ is at least There is an angle of broken face. It can be seen that A ₁ and A ₂ are two different sharp angles respectively, the angle of A ₁ is greater than 90 degrees (ie, obtuse angle), and the angle of A ₂ is less than 90 degrees (ie, acute angle), which means when using A ₂ When grinding sharp points, the removal efficiency will be greater than A ₁ .

The polishing cusps may be patterned on the unit substrate, or the polishing cusps may form a plurality of clusters, and the clusters are patterned and arranged on the unit substrate, wherein, for example, each cluster is from two to six It consists of a sharp point.

In addition, the polishing units may be arranged in a single turn, a double turn, a plurality of turns, a radial shape or a spiral shape on the bottom substrate, and may be in the shape of a disk, a blade or a polygon. If the grinding units are disc-shaped, the diameter is in the range of 5 to 30 mm, preferably not more than 20 mm, and the bottom substrate may also be disc-shaped and have a diameter of 80 to 120 mm. The range of the grinding unit can also be fixed on a circular substrate of 250 to 270 mm. In addition, if the disc-shaped polishing unit is located inside, the polishing pad is often blocked by the external polishing unit, making it difficult to function. Therefore, the polishing unit is preferably arranged on the outer periphery of the surface of the disc-shaped bottom substrate. The cliff effect of rim trimming occurs during chemical mechanical planarization, which increases the number of jobs and is suitable for chemical mechanical planarization processes applied to 18-inch wafers or 22 nm processes.

In the above-mentioned combined dresser of the present invention, the spacing between the grinding units is not narrower than 0.1 mm, preferably more than 0.5 mm, so as to ensure that the slurry can smoothly enter and exit the grinding in the chemical mechanical flattening process. The gap between the cells does not remain there and causes defects such as scratches on the wafer. In addition, the thickness of the adhesive layer on the bottom surface of the grinding unit ranges from 0.6 mm or less, so that the grinding cusps of the respective grinding units can be sufficiently adjusted to the same plane to effectively increase the number of working diamond particles.

Conventional differences in cusp height are too large. The number of cusps used by conventional dressers (and the number of cusps piercing the polishing pad) account for less than 1% of the total number of cusps, and the diamond coverage of traditional dressers exceeds 40. In contrast, in the above-mentioned combined dresser of the present invention, the polishing cusps for trimming a polishing pad may account for more than 1% of the total number of polishing cusps; in addition, the polishing unit covers the area of the bottom substrate. It accounts for less than 40% of the total surface area of the bottom substrate, so that the optimum removal rate can be achieved at a reduced cost.

Another object of the present invention is to provide a method for manufacturing a combined dresser in which a polishing unit having sharp sharpening points is used, and each polishing is adjusted by a reversal method with a maximum number of sharp points of each polishing unit as a plane reference. The thickness of the adhesive material under the unit is fixed on the substrate, so that the highest number of sharp points on the polishing unit are not particularly prominent and form a destructive "killer diamond". Using a coplanar force to force the highest point of each grinding unit to a common height also increases the proportion of effective working grinding cusps, thereby increasing the removal efficiency and service life of the dresser.

In order to achieve the above object, another example of the present invention provides a method of manufacturing a combined dresser, comprising the steps of: providing a second mold on a first mold, wherein the second mold has a plurality of holes; A grinding unit is disposed in each of the holes of the second mold, wherein each of the grinding units includes a plurality of grinding cusps, and a bonding agent layer for fixing the grinding cusps; forming an adhesive layer of adjustable thickness to Fixing the grinding units to a bottom substrate; and removing the first mold and the second mold to form a combined trimmer, wherein the first sharp points of the predetermined plane are protruded from the grinding sharp points The height difference between the two high points is less than 10 micrometers, and the height difference between the first high point and the tenth high point is less than 20 micrometers, and the height difference between the first high point and the first hundred high points is less than 40 micrometers, and the first high point protrudes The binder layer has a height greater than 50 microns.

A typical diamond dresser is manufactured by adding a flat diamond substrate (such as a matrix distribution) on a flat substrate (such as stainless steel No. 316). In the prior art, the height difference of the diamond apex on the surface of a single dresser usually exceeds 50 micrometers. The method of fixing the diamond abrasive grains can be fixed by electroplating (EDD) plus nickel or by brazing (BDD). The molten alloy is solidified and held. The diamond plane of the former is usually upward, while the sharp points or ridges of the latter are often prominent, and the diamonds in the plane direction are not easy to penetrate into the polishing pad, and the diamonds with sharp points or ridges are easier to cut the polishing pad. In contrast, the present invention firstly forms a polishing unit by a brazing method, and combines and compensates a plurality of polishing units by an organic elastic material to arrange the polishing units on the base substrate, so that in addition to the advantages of the brazing method, It can also avoid its shortcomings, so that the formed trimmer has the highest peak point of equal height, so when the diamond dresser is trimming the polishing pad, the protruding diamond apex can contact and penetrate the polishing pad, but there is no Excessively sharpening of the sharp points, so there is no such thing as the penetration of the polishing pad is too deep, so that the difference in the height of the pile is too large, so as to prevent the fluff of the "stand out of the chicken" from being excessively refined, resulting in excessive penetration of the nano-grain in the refining. The wafer surface is over-polished and even scratched.

In the manufacturing method of the above-mentioned combined dresser of the present invention, the thickness-adjustable adhesive layer can be formed after flattening the highest sharp point of the grinding units using another flat plate, or forming the thickness-adjustable adhesive layer. Thereafter, the bottom substrate is flattened to the highest sharp point of the polishing unit before the thickness-adjustable adhesive layer has not been cured.

The thickness adjustable adhesive layer may be composed of an organic adhesive, for example, a plastic material, a rubber material, a hot melt adhesive or a combination thereof; in addition, the holes of the second mold are arranged in the second The outer ring of the mold is used to set the positions of the grinding units to the outer ring of the bottom substrate. Specifically, the holes of the second mold are formed on the outer ring of the second mold to form, for example, 12 holes. In addition, in the combined dresser, the grinding unit can also be arranged in the inner and outer rings, and generally the smaller the area of the grinding unit, the more the number of working particles during grinding, but the manufacturing cost is high, so the appropriate amount of grinding unit A trimmer can be used to balance effects and costs.

In the manufacturing method of the above-mentioned combined dresser of the present invention, before the second mold is disposed on the first mold, the method further comprises the steps of: forming a temporary adhesive layer on the surface of the first mold, and setting the second mold to The temporary adhesive layer surface is such that the temporary adhesive layer is sandwiched between the second mold and the first mold, and after the second mold is removed, the method further includes the step of removing the temporary adhesive layer. In a preferred embodiment of the invention, the temporary adhesive layer is a double-sided tape.

In another preferred embodiment of the present invention, one side of the polishing unit has the polishing cusps, and the thickness adjustable adhesive layer is disposed on the opposite side of the side, and is disposed on the holes The grinding units contact the first mold with the polishing tips. In addition, after removing the second mold and the first mold, the method further comprises the steps of: forming a molding layer to fix the grinding units. As can be seen from the above, the polishing unit is evenly arranged on the same plane by the side of the press polishing unit having the sharp point.

The manufacturing method of the above-described combined dresser of the present invention may optionally further comprise the step of removing the second mold after removing the first mold. In other words, this means that the dresser can comprise a second mold.

Still another object of the present invention is to provide a chemical-mechanical planarization (CMP) process in which sharp sharp points are used, but the planarity of the working surface is maintained, thereby improving effective working grinding on the polishing unit. The ratio of sharp points increases the removal rate and service life.

In order to achieve the above object, still another example of the present invention provides a chemical mechanical planarization process comprising the steps of: providing a polishing pad; disposing a wafer on the surface of the polishing pad to grind it with the polishing pad; and using A trimmer disposed on the surface of the polishing pad to remove the ground debris of the wafer, wherein the trimmer is the above-described combined trimmer of the present invention.

Moore's law mentions that the number of transistors that are housed on the same wafer of a single size is multiplied every eighteen months due to process technology improvements, which in turn increases the speed at which wafers perform operations. As the Moore's Law continues to improve, the line width of the integrated circuit (IC) gradually exceeds the limit of 32 nm. However, it is difficult to enter the chemical mechanical flattening process beyond the bottleneck. The process of small line width and line spacing. In contrast, since the improved trimmer is used in the above chemical mechanical planarization process of the present invention, the chemical mechanical planarization process of the present invention can use a wafer having a diameter of 200 mm, 300 mm or 450 mm, and the wafer surface The IC line width can be less than or equal to 45 nm, 28 nm or 22 nm. Therefore, if the technique of the present invention is employed in the related art, for example, the chemical mechanical planarization process of the present invention is applied to a logic device, a dynamic random access memory (DRAM), a flash memory, or The production of a hard drive will increase the execution speed of each of the above devices as described in Moore's Law.

In general, due to the different sizes of diamonds, different shapes, different directions, and high distances, the plough and cutting methods of polishing pads are varied, resulting in uneven heights of the polished polishing pads. Furthermore, the high-point position of the wafer contact, the area and pressure of each contact point are difficult to control, so that the polishing rate and uniformity variability of the chemical mechanical planarization process are extremely high. When the wafer changes greatly (such as 8吋 to 12吋 or even 18未来 in the future), the polishing rate and uniformity variability will be enlarged, and the quality and efficiency of the chemical mechanical flattening process will be reduced. Not only that, but when the wire width is getting narrower (such as 45 nm to 32 nm or even 22 nm in the future), the high point of the polishing pad is more likely to cause damage. When the circuit is narrowed, the dielectric material must be hollower to avoid de-energization, but the hollow dielectric layer becomes weak, so the contact pressure of the chemical mechanical planarization process needs to be weakened, but after the contact pressure is reduced, This will result in a lower rate of polishing the wafer, resulting in poor productivity.

Current diamond dressers are usually manufactured by adding diamonds in a plane, so the height of the apex is difficult to control. In addition, under high temperature manufacturing (such as brazing), the substrate is distorted, causing the diamond's apex height to be more uneven, and the number of working particles is greatly reduced, resulting in tens of thousands of diamonds on the dresser, but the working particles. There are only a few hundred.

Due to the diamond dresser (made by the top of the diamond abrasive grain), the size and shape of the diamond are difficult to control, and the number, position and penetration depth of the diamond on the working surface are also elusive, resulting in chemical mechanical flatness. The predictability of the process results is greatly reduced. Although the industry continues to strictly control the flatness of the substrate of the dresser, the shape of the diamond, etc., the improvement effect is limited.

In view of the difficulty in aligning the apex of the diamond, the present invention adopts the method of inverting and combining, firstly forming a diamond grinding unit, and the diamond grinding unit is placed on the plane to make the grinding sharp points flush. At this time, an adjustable thickness of the adhesive layer is placed on the opposite side of the sharp point of the grinding, and finally a mold layer (such as a resin) is poured to fix all the grinding units. This reversed manufacturing method can avoid the "Killer Diamond" that is common on diamond discs - the prominent diamonds that stand out from the crowd. If the "Diamond Killer" is too sharp, it is easy to pull the polishing pad too deep and pull and break, and then form "Killer Asperities" on the surface of the polishing pad, causing damage to the wafer scratch.

The embodiments of the present invention are described by way of specific examples, and those skilled in the art can readily appreciate the other advantages and advantages of the present invention. The present invention may be embodied or applied in various other specific embodiments, and various modifications and changes can be made without departing from the spirit and scope of the invention.

The drawings in the embodiments of the present invention are simplified schematic diagrams. However, the drawings show only the components related to the present invention, and the components shown therein are not examples in actual implementation, and the actual number of components, the shape, and the like are designed in an optional manner, and the component layout type thereof. The state may be more complicated.

Preparation Example 1

Referring to Figures 1A through 1G, a schematic flow diagram of a combined trimmer is made.

First, as shown in FIG. 1A, a first mold 10 is provided, the first mold 10 having an opening 101. Next, as shown in FIG. 1B, a temporary adhesive layer 11 is formed on the surface of the opening 101 of the first mold 10, and then a second mold 12 is disposed on the surface of the temporary adhesive layer 11, so that the second mold 12 is placed on the surface. The temporary adhesive layer 11 is interposed between the second mold 12 and the first mold 10, wherein the second mold 12 has a plurality of holes 121. In the present preparation example, the temporary adhesive layer 11 is a double-sided tape.

As shown in FIG. 1C and FIG. 1G, a grinding unit 20 is disposed in each of the holes 121 of the second mold 12, wherein each of the grinding units 20 includes a plurality of abrasive particles 22 (each abrasive particle 22 has at least one grinding) A sharp point 221), a unit substrate 21, and a bonding agent layer 213 disposed between the surface of the unit substrate 21 and the polishing sharp points 221. The polishing units 20 are manufactured by a general brazing method, and the manufacturing method thereof is briefly described below. The soldering piece (BNi ₂ ) is spot-welded on the unit substrate 21 having a diameter of 20 mm and a thickness of 4 mm, and then about 150 μm of abrasive particles (such as diamond particles) are arranged on the adhesive-coated soldering piece by a template, and then placed. The vacuum is evacuated to a vacuum of about 5 to 10 torr, heated to a maximum of 1020 ° C for 12 minutes (during which the volatilized volatilized), and the solder of the solder is melted into a liquid-welded diamond particle.

Since the diamond is originally placed on the fixed solder, when the solder melts to form a liquid, the carbide elements (such as Cr) therein diffuse to the surface of the diamond. The solder will thus sink the diamond with capillary hair, and the capillary force will also climb the surface of the diamond to form a slope. The diamond originally adhered to the surface of the soldering piece in a plane, and now the sharp angle is often caused by the rotation in the liquid.

Then, as shown in FIG. 1D and FIG. 1E, the polishing units 20 are leveled by a bottom substrate 24, and an adhesive layer 23 of adjustable thickness is filled in, and the polishing units 20 are fixed. Next, as shown in FIG. 1F, the first mold 10, the temporary adhesive layer 11, and the second mold 12 are removed to form a combined dresser 2.

The combined dresser 2 includes: a bottom substrate 24; a plurality of polishing units 20 disposed on the surface of the bottom substrate 24, each of the polishing units 20 including a plurality of polishing sharp points 221; and an adjustable thickness adhesion The coating layer 23 is configured to fix the polishing unit 20 on the surface of the bottom substrate 24, wherein the height difference between the first high point and the second high point protruding from a predetermined plane in the grinding sharp points 221 is less than 10 micrometers. The height difference between the high point and the tenth high point is less than 20 micrometers, the height difference between the first high point and the first hundred high point is less than 40 micrometers, and the first high point protrudes from the height of the bonding agent layer 213 by more than 50 micrometers.

Referring to Figure 1G, it is an enlarged schematic view of the polishing unit of the present invention. Each of the polishing units 20 includes a plurality of abrasive particles 22 (each polishing particle has at least one polishing cusp 221), a unit substrate 21, and a bonding agent disposed between the surface of the unit substrate 21 and the polishing cusps 221 The layer 213, a metal cover layer 212 covering the surface of the bond layer 213, and a protective layer 211 covering the surface of the metal cover layer 212.

The bonding agent layer 213 can be a solder layer, a plating layer, a sintered layer, or a resin layer. If the solder layer is more than 1% by weight, it is selected from the group consisting of Cr, B, P, Ti, and alloys thereof. At least one of the groups, comprising more than 50% by weight, is selected from at least one of the group consisting of Ni, Cu, and alloys thereof, or a combination thereof.

The metal cap layer 212 may be formed by electroplating, and the material thereof may be at least one selected from the group consisting of Ni, Cr, palladium, Co, platinum, Au, Ti, Cu, W, and alloys thereof; It may be palladium, platinum, ruthenium carbide, aluminum nitride, aluminum oxide, zirconium oxide, diamond-like carbon (DLC) or a combination thereof.

Preparation Example 2

Referring to Figures 2A through 2G, a schematic flow diagram of a combined trimmer is made.

First, as shown in FIG. 2A, a second mold 12 is provided. The second mold 12 has 12 holes 121, and the holes are arranged in the outer ring of the second mold 12. Next, as shown in FIG. 2B, the second mold 12 is placed on the surface of a first mold 10.

As shown in FIG. 2C, in each of the holes 121 of the second mold 12, a grinding unit 20 is disposed, wherein the working surface of the grinding unit 20 (the surface having the sharp points) faces the surface of the first mold 10. In the present preparation example, the grinding units 20 are similar to those described in Preparation 1. Then, as shown in Fig. 2D, the opposite side of the grinding cusp of each of the grinding units 20 is dispensed to form an adhesive layer 23 of adjustable thickness. Next, as shown in FIG. 2E, a bottom substrate 24 is pressed against the thickness-adjustable adhesive layer 23, wherein the bottom substrate 24 has a recess, so that the bottom substrate 24 has a U-shape, and the crucible is The base substrate 24 of the glyph is pressed by the groove to the thickness-adjustable adhesive layer 23.

As shown in FIG. 2F, the first mold 10 is removed. Next, as shown in FIG. 2G, the structure of FIG. 2F is reversed, the second mold 12 is removed and a mold sealing layer 25 is formed, and the grinding unit 20 is strengthened to be fixed to the bottom substrate 24 to form a combined trimming. Device.

Although the grinding unit produced by the brazing method may have a killer diamond, the above-described method of the present invention can be used in combination with different grinding units having similar high-killing diamonds, and the grinding tips are flush, so the "killer diamond" has been combined with other grinding. The protruding tip of the diamond on the unit is close in height.

Test case

Referring to Fig. 3, there is shown a combined dresser prepared in the above Preparation Example 2 (Example 1 wherein the diamond particles used have a crystal face coverage of about 60% to 80%, which is a PDA 878 manufactured by Element Six. The trimmer height difference and the number of working particles are compared between the trimmer prepared by the conventional ceramic sintering method (Comparative Example 1) and the trimmer prepared by the brazing method (Comparative Example 2). As can be seen from Fig. 3, there are 60 to 70 working particles on the dresser of the first embodiment of the present invention at a height difference of 10 μm at the time of grinding; in comparison, Comparative Example 1 and Comparative Example 2 require a large tip height. The difference can provide more working particles. Even in the case of the trimmer of Comparative Example 1, it is required that the height difference of the abrasive particles exceeds 40 μm to reach more than 100 working particles. It can be seen that the dresser of the present invention is much higher than the conventional dresser for the number of abrasive particles actually working in the same height difference.

Referring to FIG. 4 and FIG. 5, respectively, the combined dresser prepared in the above Preparation Example 2 is shown (Example 1 wherein the diamond particles used have a crystal face coverage of about 60% to 80%, which is Element Six. Manufactured PDA 878; Example 2, wherein the diamond particles used have a crystal face coverage of 40% to 60%, which is a PDA 657 manufactured by Element Six, and a dresser made by a brazing method (Comparative Example 2) Wait for the three, the difference between the height difference (micron) of the first high point and the second high point and the number of scratches, and the comparison of the number of scratches and the removal rate.

As can be seen from FIG. 4, in the trimmers of Embodiments 1 and 2, when the height difference between the first high point and the second high point is about 0 micrometers, the number of scratches after polishing is between 100 and 150, which means that the embodiment The quality of the trimmers of 1 and 2 is good, and the quality stability during grinding is good. On the other hand, in the dresser of Comparative Example 2, the difference in the height of the abrasive particles is different, and the number of scratches is only less than 50 When the number is less than 100, this indicates that the quality of the dresser of Comparative Example 2 is different, and the quality stability during polishing is poor. On the other hand, as can be seen from FIG. 5, the dresser removal rate of the embodiment of the present invention is about 250 to 300 micrometers per hour, and the number of scratches is about 100 to 150, and the dresser of the embodiment 1 of the present invention is ground. The removal rate is about 150 to 200 micrometers per hour, and the number of scratches is about 125 to 150. This indicates that the trimmer of the first embodiment and the second embodiment of the present invention has high stability and easy product quality; in contrast, the comparative example 2 The dresser has a polishing removal rate of about 125 to 225 μm per hour and a scratch number of about 50 to 75, which means that the dresser of Comparative Example 2 has not only a small number of scratches but also an unstable quality.

Referring to Fig. 6, there is shown a combination dresser prepared in the above Preparation Example 2 (Example 1 and Example 2), a conventionally prepared solder trimmer (Comparative Example 2), and a conventional plating method. (Comparative Example 3) and other four, the comparison of the use time and removal rate of the dresser. It can be seen from FIG. 6 that the dressing rate of the trimmers of Embodiments 1 and 2 of the present invention is gradually decreased with the use time, which means that the trimmer of the present invention has the fastest dressing rate and the longest due to good flatness control. On the other hand, the dresser removal rate of Comparative Example 2 was unstable in the up and down, which caused a problem in quality control, and the dresser removal rate of Comparative Example 3 was not good, and the time and cost of the polishing process could not be saved.

Referring to Fig. 7, there is shown a comparison between the number of polished wafers and the removal rate of the combined trimmer prepared in the above Preparation Example 2 (Example 2) and the trimmer prepared by the brazing method (Comparative Example 2). Figure. As can be seen from Fig. 7, the trimmer of the second embodiment of the present invention can be used for the chemical mechanical planarization process to achieve a higher number of wafers than the comparative example 2.

Application example

Referring to Figure 8, it is a schematic diagram of a chemical-mechanical planarization (CMP) process. As shown in FIG. 8, a wafer 4 is generally disposed on the surface of the polishing pad 6, and the slurry is supplied by the pipeline 8 to be ground with the polishing pad 6, and another blank surface of the polishing pad 6 is blank. In part, a trimmer 2 is provided to remove the ground debris of the wafer, wherein the trimmer used herein can use the trimmer prepared by the above preparation example of the invention.

In summary, because the current maximum polished apex of the entire piece of brazed diamond dresser is often more than 20 microns above the next highest, and the top 10 highest abrasive particles have a protruding range of only 50 microns; The method of manufacturing the combined dresser by the inversion method can reduce the difference between the highest grinding apex and the next highest to less than 10 micrometers, thereby increasing the proportion of effective working grinding cusps on the grinding unit, increasing the removal rate and using life.

The above-mentioned embodiments are merely examples for convenience of description, and the scope of the claims is intended to be limited to the above embodiments.

10. . . First mold

101. . . Opening

11. . . Temporary adhesive layer

12. . . Second mold

121. . . Hole

20. . . Grinding unit

221. . . Grinding cusps

twenty one. . . Unit substrate

213. . . Bond layer

twenty four. . . Bottom substrate

twenty three. . . Adjustable thickness of adhesive layer

2. . . Combined dresser

212. . . Metal cover

211. . . The protective layer

25. . . Mold sealant

4. . . Wafer

6. . . Polishing pad

8. . . Pipeline

1A to 1G are schematic views showing the flow of manufacturing a combined dresser in Preparation Example 1 of the present invention.

2A to 2G are schematic views showing the flow of manufacturing a combined dresser in Preparation Example 2 of the present invention.

Figure 3 is a graph comparing the height difference between the tip of the present invention and the conventional dresser and the number of working particles.

Figure 4 is a graph comparing the height difference (micrometers) and the number of scratches between the first high point and the second high point of the present invention and the conventional finisher.

Figure 5 is a graph comparing the number of scratches and the removal rate caused by the present invention and a conventional finisher.

Figure 6 is a graph comparing the use time and removal rate of the dresser of the present invention with a conventional finisher.

Figure 7 is a graph comparing the number of polished wafers and the removal rate of the present invention with conventional trimmers.

Figure 8 is a schematic illustration of the chemical mechanical planarization process of the present invention.

Figure 9 is a schematic illustration of abrasive particles.

Claims (38)

A combined dresser comprising: a bottom substrate; a plurality of grinding units disposed on a surface of the bottom substrate, each grinding unit comprising a plurality of grinding sharp points, and a bonding agent layer fixing the grinding sharp points; And an adjustable thickness of the adhesive layer for fixing the polishing unit to the surface of the bottom substrate, wherein a difference in height between the first high point and the second high point of the predetermined one of the grinding sharp points is less than 10 Micrometer, the height difference between the first high point and the tenth high point is less than 20 micrometers, the height difference between the first high point and the first hundred high point is less than 40 micrometers, and the first high point protrudes from the bonding layer to a height greater than 50 micrometers . The combination dresser of claim 1, wherein the polishing cusps for trimming a polishing pad account for more than 1% of the total number of polishing cusps. The combined dresser of claim 1, wherein the area of the polishing unit covering the bottom substrate accounts for less than 40% of the total surface area of the bottom substrate. The combination dresser of claim 1, wherein the polishing units are arranged in a single turn, a double turn, a plurality of turns, a radial or a spiral on the base substrate. The combination dresser of claim 1, wherein at least one or more of the polishing cusps are in contact with a polishing pad during trimming. The combination dresser of claim 1, wherein the material of the grinding cusps is diamond, cubic boron nitride (CBN) or a combination thereof. The combination dresser of claim 6, wherein the diamond is a chemically deposited diamond, a polycrystalline diamond, or a combination thereof. The combination dresser of claim 1, wherein among the one hundred of the highest grinding points, more than 50% of the grinding cusps have a crystal face coverage of less than 80%. The combination dresser of claim 8, wherein among the one hundred of the highest grinding points, more than 50% of the grinding cusps have a crystal face coverage of less than 50%. The combination dresser of claim 1, wherein each of the polishing units further comprises a unit substrate, and the bonding agent layer is disposed between the surface of the unit substrate and the polishing cusps. The combination dresser of claim 1, wherein the bonding agent layer is a solder layer, a plating layer, a sintered layer, or a resin layer. The combined dresser of claim 11, wherein each of the grinding units further comprises: a metal coating layer covering the surface of the bonding agent layer, and the material of the metal coating layer is selected from the group consisting of Ni At least one of the group consisting of Cr, palladium, Co, platinum, Au, Ti, Cu, W, and alloys thereof. The combined dresser of claim 12, wherein each of the polishing units further comprises: a protective layer covering the surface of the metal covering layer, and the material of the protective layer is palladium, platinum, Tantalum carbide, aluminum nitride, aluminum oxide, zirconium oxide, diamond-like carbon (DLC) or a combination thereof. The combination dresser of claim 11, wherein the solder layer comprises at least one weight percent or more selected from the group consisting of Cr, B, P, Ti, and alloys thereof, and comprises 50 weight percent The above is selected from at least one of the group consisting of Ni, Cu, and alloys thereof, or a combination thereof. The combination dresser of claim 1, wherein the grinding units are disc-shaped, radial or polygonal. The combination dresser of claim 15, wherein the disc-shaped diameter is in the range of 5 to 30 mm. The combination dresser of claim 1, wherein the bottom substrate is disc-shaped and has a diameter ranging from 80 to 120 mm. The combination dresser of claim 1, wherein the grinding cusps have a particle size ranging from 100 to 500 microns. The combination dresser of claim 1, wherein the thickness of the adhesive layer is an organic adhesive. The combination dresser of claim 1, wherein the polishing cusps are patterned on the unit substrate, or the plurality of clusters are formed by the grinding cusps, and the clusters are patterned. Arranged in the unit substrate, wherein each cluster is composed of two to six grinding cusps. The combination dresser of claim 1, wherein the spacing between the grinding units is not narrower than 0.1 mm. The combination dresser of claim 21, wherein the spacing is greater than 0.5 mm. The combination dresser of claim 1, wherein the thickness of the adhesive layer on the bottom surface of the grinding unit ranges from 0.6 mm or less. The combination dresser of claim 23, wherein the top surface of the polishing unit is higher than the surface of the adhesive layer having an adjustable thickness of 1 mm or more. A manufacturing method of a combined dresser, comprising the steps of: providing a second mold on a first mold, wherein the second mold has a plurality of holes; and a grinding unit is disposed in each hole of the second mold Each of the polishing units includes a plurality of polishing cusps and a bonding agent layer for fixing the polishing cusps; forming an adjustable thickness of the adhesive layer to fix the polishing units to a bottom substrate; Dividing the first mold and the second mold to form a combined dresser, wherein a difference in height between the first high point and the second high point of a predetermined plane protruding from a predetermined point is less than 10 micrometers, first The height difference between the high point and the tenth high point is less than 20 microns, the height difference between the first high point and the first high point is less than 40 microns, and the first high point protrudes from the bonding layer by a height greater than 50 microns. The method of manufacturing the combined dresser of claim 25, before the second mold is disposed on the first mold, further comprising the steps of: forming a temporary adhesive layer on the surface of the first mold, and setting The second mold is on the surface of the temporary adhesive layer, and the temporary adhesive layer is sandwiched between the second mold and the first mold. The method for manufacturing a combined dresser according to claim 26, after removing the second mold, further comprising the step of removing the temporary adhesive layer. The method of manufacturing a combined dresser according to claim 25, wherein the one side of the grinding unit has the grinding sharp points, and the thickness adjustable adhesive layer is disposed on the side Opposite side. The method of manufacturing a combination dresser according to claim 28, wherein the polishing units disposed in the holes contact the first mold with the polishing tips. The method of manufacturing the combined dresser of claim 29, after removing the second mold and the first mold, further comprising the steps of: forming a mold seal layer to fix the grinding units . The method of manufacturing a combined dresser according to claim 25, wherein the holes of the second mold are arranged in an outer ring of the second mold. The method of manufacturing a combined dresser according to claim 31, wherein the holes of the second mold are formed in the outer ring of the second mold to form 12 holes. A chemical-mechanical planarization (CMP) process comprising the steps of: providing a polishing pad; disposing a wafer on the surface of the polishing pad to grind it with the polishing pad; and using a trimmer, And being disposed on the surface of the polishing pad to remove the ground debris of the wafer, wherein the trimmer is the combined dresser described in claim 1 of the patent application. The chemical mechanical planarization process described in claim 33, which can be applied to a logic device, a dynamic random access memory (DRAM), a flash memory or a hard disk ( Hard drive). The chemical mechanical planarization process of claim 33, wherein the wafer has a diameter of 200 mm, 300 mm or 450 mm. The chemical mechanical planarization process of claim 33, wherein the wafer surface has an IC line width of less than or equal to 45 nanometers. The chemical mechanical planarization process of claim 36, wherein the wafer surface has an IC line width of less than or equal to 28 nm. The chemical mechanical planarization process of claim 37, wherein the wafer surface has an IC line width of less than or equal to 22 nm.