Abstract:
The present invention relates to a chemical mechanical polishing conditioner with optimal abrasive exposing rate, comprising a substrate; a bonding layer disposed on the substrate; and a plurality of abrasive particles placed on the bonding layer, and the abrasive particles are placed on the substrate by the bonding layer; wherein each abrasive particle has an abrasive exposing rate which is ¼ to ¾ of particle sizes of the abrasive particles and is measured by a height measuring device. Therefore, the chemical mechanical polishing conditioner with optimal abrasive exposing rate of the present invention can control the exposing rate of the abrasive particles to improve the cut rate of the conditioner.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefits of the Taiwan Patent Application Serial Number 103102128, filed on Jan. 21, 2014, the subject matter of which is incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a chemical mechanical polishing conditioner with optimal abrasive exposing rate, and more particularly to a chemical mechanical polishing conditioner with optimal cut rate. 
         [0004]    2. Description of Related Art 
         [0005]    Chemical mechanical polishing (CMP) is a common polishing process in various industries, which can be used to grind the surfaces of various articles, including ceramics, silicon, glass, quartz, or a metal chip. In addition, with the rapid development of integrated circuits, chemical mechanical polishing becomes one of the common techniques for wafer planarization because it can achieve an object of whole planarization. 
         [0006]    During the chemical mechanical polishing process of semiconductor, impurities or uneven structure on the surface of a wafer are removed by contacting the wafer (or the other semiconductor elements) with a polishing pad and using a polishing liquid if necessary, through the chemical reaction and mechanical force. When the polishing pad has been used for a certain period of time, the polishing performance and efficiency are reduced because the debris produced in the polishing process may accumulate on the surface of the polishing pad. Therefore, a conditioner can be used to condition the surface of the polishing pad, such that the surface of the polishing pad is re-roughened and maintained at an optimum condition for polishing. In the process for manufacturing a conditioner, it is necessary to dispose an abrasive layer by mixing abrasive particles and a binding layer on the substrate surface, and to fix the abrasive layer to the surface of the substrate by brazing or sintering methods. However, during the manufacturing process of the above conditioner, the exposing rate and cut rate of the chemical mechanical polishing conditioner have an important relationship. Therefore, when the exposing rates of the abrasive particles are large, an effect of the binding layer shielding the abrasive particles is worse, and a binding property between abrasive particles and the binding layer becomes bad, and thus the abrasive particles are easily fallen in the polishing process. Contrarily, when the exposing rate of the abrasive particles is small, the effect of the binding layer shielding the abrasive particles is overlarge, and then the cut rate of the abrasive particles to a polishing pad becomes bad, thereby reducing the polishing effects. 
         [0007]    In the known technology, such as China Patent Application No. 101320708, it discloses a polishing pad used in a CMP step in the manufacture of a semiconductor integrated circuit device is relatively expensive; thus, it is necessary to avoid a wasteful exchange of the pad. Accordingly, it is important to measure the abrasion amount of this pad precisely. However, in ordinary measurement thereof through light, the presence of a slurry hinders the measurement. In measurement thereof with a contact type sensor, a problem that pollutants elute out is caused. In a CMP step in the invention, the height position of a dresser is measured while the dresser operates, thereby detecting the abrasion amount or the thickness of a polishing pad indirectly. In this way, the time for exchanging the polishing pad is made appropriate. 
         [0008]    Besides, in the other known technology, such as Taiwan Patent Publication No. 200936316, it discloses a dressing method of dressing a polishing pad used in a polishing apparatus for polishing a substrate. This method includes repetitively moving the dresser on an upper surface of the polishing pad in a radial direction of the polishing pad so as to perform a dressing process on the polishing pad, during the dressing process, measuring a height of an upper surface of the polishing pad at a predetermined point in one of plural zones on the polishing surface, and repeating the repetitive moving of the dresser and the measuring of the height of the upper surface of the polishing pad so as to measure the height of the upper surface of the polishing pad in all of the plural zones. 
         [0009]    However, a measurement of height positions of the conditioner is used in the above-mentioned measure devices to detect indirectly an abrasion value or a thickness of the polishing pad. Alternatively, the conditioner is moved repeatedly over a top surface of the polishing pad to measure the height of the top surface of the polishing pad; however, the exposing rate of the abrasive particles on the chemical mechanical polishing conditioner still cannot steady effectively, so that a flat surface and a stable polishing quality of the chemical mechanical polishing conditioner cannot be provided. Therefore, there is an urgent need for a chemical mechanical polishing conditioner with optimal abrasive exposing rate. Further, the exposing rate of the abrasive particles and the cut rate of the chemical mechanical polishing conditioner have an important relationship; therefore, the exposing rate of the abrasive particles of the present invention can be controlled to form a plate surface of the chemical mechanical polishing conditioner, thereby improving an ability of abrasive particles cutting the polishing pad. 
       SUMMARY OF THE INVENTION 
       [0010]    An object of the present invention is to provide a chemical mechanical polishing conditioner with optimal abrasive exposing rate, which has a flat surface with the exposing rate of the abrasive particles to he uniform, thereby improving the cut rate of the chemical mechanical polishing conditioner to provide a stable polishing quality. 
         [0011]    To achieve the above object, the present invention provides a chemical mechanical polishing conditioner with optimal abrasive exposing rate, comprising; a substrate; a binding layer disposed on a surface of the substrate; and a plurality of abrasive particles embedded in a. surface of the binding layer and fixed to the surface of the substrate by the binding layer; wherein every abrasive particle can has an abrasive exposing rate which can be ¼ to ¾ of particle sizes of these abrasive particles, and the abrasive exposing rate can be measured by a height measurement device, for example, when the particle sizes of the abrasive particles are 300 μm, the optimal abrasive exposing rate is 75 to 225 μm. Besides, when the abrasive exposing rate is more than ¾ of the particle sizes of these abrasive particles, the effect of the binding layer shielding these abrasive particles is worse, so that the diamonds on the conditioner are easily fallen during polishing process. On the other hands, when the abrasive exposing rate is less than ¼ of the particle sizes of these abrasive particles, the binding layer shields excessively these abrasive particles, so that the ability of these abrasive particles cutting a workpiece(such as the polishing pad) becomes bad, which results to the polishing performance becomes bad. 
         [0012]    In above-mentioned the chemical mechanical polishing conditioner with optimal abrasive exposing rate, the abrasive exposing rate may mean a distance between tips of these abrasive particles and the binding layer. 
         [0013]    The spaces between every abrasive particle on the chemical mechanical polishing conditioner are too small; therefore, in the chemical mechanical polishing conditioner with optimal abrasive exposing rate of the present invention, the height measurement device may has a height gauge and an optical microscope; wherein the height gauge may further a height gauge probe (such as a tungsten carbide probe) and the height gauge may be used to measure the height of a specific position which the tips of these abrasive particles or the surface of the binding layer. Further, in above-mentioned the chemical mechanical polishing conditioner with optimal abrasive exposing rate of the present invention, the optical microscope may be used to determine a relative position measured by the height gauge, namely, the optical microscope may be used to determine the positions which are the tips of theses abrasive particles or the surface of the binding layer and are measured by the height gauge, and the distance between tips of these abrasive particles and the surface of the binding layer are calculated by the heights of the tips of every abrasive particle and the height of the surface of an abrasive layer, thereby calculating the abrasive exposing rate. 
         [0014]    In above-mentioned the chemical mechanical polishing conditioner with optimal abrasive exposing rate of the present invention, the numbers of samples sampling from the height measurement device may be randomly varied based on the user&#39;s requirements or quality of the required conditioner; wherein the height measurement device may measure 5 to 500 abrasive particles to obtain the abrasive exposing rate of these measured abrasive particles. In an aspect of the present invention, the height measurement device may measure 20 abrasive particles. Besides, in above-mentioned the chemical mechanical polishing conditioner with optimal abrasive exposing rate of the present invention, the abrasive exposing rate of the measured abrasive particles may be less than 1/10 of the particle sizes of these abrasive particles, so that these abrasive particles have a uniform tip height and a flatness surface, thereby improving the polishing performance of the chemical mechanical polishing conditioner and avoiding scratches produced on the polishing pad. In an aspect of the present invention, the abrasive exposing rate of the measured abrasive particles may be less than 1/20 of the particle sizes of these abrasive particles. In above-mentioned the chemical mechanical polishing conditioner with optimal abrasive exposing rate of the present invention, every abrasive particle has preferably the same exposing rate to provide a stable polishing quality. For example, in an aspect of the present invention, 20 abrasive particles having the particle sizes of 300 μmare are measured by the high measurement device to obtain the abrasive exposing rate of 20 abrasive particles. The differences of the abrasive exposing rate of these abrasive particles are within 30 μm, namely, the abrasive exposing rate (the particle size to be 200 μm) is ⅔ of the particle size of these abrasive particles (the particle size to be 300 μm), and the differences of the abrasive exposing rate of these abrasive particles are less than 1/10 of the particle sizes of these abrasive particles (the particle size to be 300 μm), in other words, the abrasive exposing rate of these abrasive particles is in a range of 185 μm to 215 μm. In another aspect of the present invention, when the same numbers and the same particles sizes of these abrasive particles mentioned above are used, the differences of the abrasive exposing rate of these abrasive particles are within 15 μm, namely, the abrasive exposing rate (the particle size to be 200 μm) is ⅔ of the particle size of these abrasive particles (the particle size to be 300 μm), and the differences of the abrasive exposing rate of theses abrasive particles (the particle size to be 300 μm) are less than 1/20 of particle size of theses abrasive particles, in other words, the abrasive exposing rate of theses abrasive particles is in a range of 192.5 μm to 207.5 μm. 
         [0015]    In above-mentioned the chemical mechanical polishing conditioner with optimal abrasive exposing rate of the present invention, the abrasive particles may be artificial diamond, nature diamond, polycrystalline diamond or cubic boron nitride. In a preferred aspect of the present invention, the abrasive particles may be artificial diamond. Furthermore, in above-mentioned the chemical mechanical polishing conditioner with optimal abrasive exposing rate of the present invention, the abrasive particles may have a particle size of 30 to 600 μm. In a preferred aspect of the present invention, the abrasive particles may have a particle size of 300 μm. 
         [0016]    In above-mentioned the chemical mechanical polishing conditioner with optimal abrasive exposing rate of the present invention, the compositions of the binding layer or the abrasive particles may be varied based on the polishing conditions or the user&#39;s requirements, which includes: a ceramic material, a brazing material, an electroplating material, a metallic material, or a polymer material, but the present invention is not limited thereto. In an aspect of the present invention, the binding layer can be made of a brazing material, wherein the brazing material can be at least one selected from the group consisting of iron, cobalt, nickel, chromium, manganese, silicon, aluminum, and combinations thereof. In another aspect of the present invention, the polymer material can be epoxy resin, polyester resin, polyacrylic resin, or phenolic resin. Besides, in above-mentioned the chemical mechanical polishing conditioner with optimal abrasive exposing rate of the present invention, the materials and sizes of the substrate may be varied based on the polishing conditions or the user&#39;s requirements; wherein the materials of the substrate can be stainless steel, mold steel, metal alloy, ceramic material or polymer material etc., but the present invention is not be limited thereto. In a preferred aspect of the present invention, the material of the substrate may be a stainless steel substrate. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
           [0018]      FIG. 1  shows a schematic diagram of the chemical mechanical polishing conditioner with optimal abrasive exposing rate according to Example 1 of the present invention. 
           [0019]      FIG. 2  shows a spatial diagram of the high measurement device of the present invention. 
           [0020]      FIG. 3  shows a schematic diagram of the chemical mechanical polishing conditioner with optimal abrasive exposing rate according to Example 2 of the present invention, 
           [0021]      FIGS. 4  shows a schematic diagram of the chemical mechanical polishing conditioner with optimal abrasive exposing rate according to Example 3 of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0022]    Hereinafter, the actions and the effects of the present invention will he explained in more detail via specific examples of the invention. However, these examples are merely illustrative of the present invention and the scope of the invention should not be construed to be defined thereby. 
       Example 1 
       [0023]    Please refer to  FIG. 1 ,  FIG. 1  shows a schematic diagram of a device of the chemical mechanical polishing conditioner with optimal abrasive exposing rate of the present invention. As shown in  FIG. 1 , first, provided is a substrate  10  made of stainless steel material; a binding layer  11  made of a nickel-based metallic brazing material; and a plurality of abrasive particles  12  embedded in the binding layer by a heat-brazing method, and these abrasive particles  12  fixed to the surface of the substrate  10  by the binding layer  11  to obtain a chemical mechanical polishing conditioner  1 ; wherein these abrasive particles  12  are formed of artificial diamonds having particle sizes of 300 μm, and the abrasive particles  12  are disposed by using a known diamond distribution technique (for example, template distribution), and the spacing and arrangement of the abrasive particles  12  are controlled by the template (not shown). Further, tips of these abrasive particles  12  are all directed up to form the directivity of the polishing surface of tips. Alternatively, tips of these abrasive particles  12  may be varied based on the polishing conditions or the user&#39;s requirements, and these abrasive particle  12  have the same or different directivity of tips; wherein every abrasive particle  12  has an abrasive exposing rate which means a distance between tips of these abrasive particles  12  and the surface of the binding layer  11 . The abrasive exposing rate applied in the chemical mechanical polishing conditioner with optimal abrasive exposing rate of the present invention is ¼ to ¾ of the particle sizes of these abrasive particles  12 , so that abrasive particles have the optimal shielding and the optimal polishing property simultaneously. In Example 1, these abrasive particles  12  are artificial diamond having particle size of 300 μm; therefore, the abrasive exposing is in a range of 75 μm to 225 μm. Then, please refer to  FIG. 2 ,  FIG. 2  shows a spatial diagram of the high measurement device of the present invention; wherein tips of  20  abrasive particles  22  and the surface of the binding layer  21  are measured by a height gauge  23  and an optical microscope  24 . The tips of these abrasive particles  22  are measured and then measured the surface of the binding layer  21 ; wherein a relative position measured by the height gauge  23  are decided by the optical microscope  24 . The differences of both heights are the abrasive exposing rates to obtain the abrasive exposing rates of the measured abrasive particles  22 . Please refer to  FIGS. 1 and 2 , the abrasive exposing rates of these abrasive particles  22  are D1, D2, D3, D4, D5, D6 to D20 (not shown in figures); wherein D1 is obtained by the optical microscope  24  and the height gauge  23 . First, the height of surface of the chemical mechanical polishing conditioner  2  is measured by the height gauge  23  and the optical microscope  24  is used to decide the measured positions to be tips of these abrasive particles  22  or the surface of the binding layer  21 . Alternatively, the tip of the abrasive particle  12  corresponding to D1 is located by the optical microscope  24 , and then a tip height of these abrasive particles  12  is measured by the height gauge  23 . Furthermore, the surface of the binding layer  21  is located by the optical microscope  24 , and the height of the surface of the binding layer  21  is measured by the height gauge  23 . Subsequently, the obtained heights are both subtracted to obtain a value of D1, and the values of D2, D3, D4, D5, D6 to D20 can be obtained by analogy. Finally, the results of the abrasive exposing rates measured from the abrasive particles  22  are shown in a display device  25  to decide these abrasive particles  22  capable of providing to as the chemical mechanical polishing conditioner  2  with optimal abrasive exposing rate. 
         [0024]    Please refer to  FIGS. 1 and 2 , in Example 1 of the present invention, these abrasive particles  12  have particle sizes of 300 μm, and the abrasive exposing rates are ¼ to ¾ of particle sizes of these abrasive particles; therefore, the optimal abrasive exposing rate is 75 to 225 μm. Please refer to  FIG. 1 , when the abrasive exposing rate of these abrasive particles  121  is more than 225 μm, the effect of the binding layer shielding these abrasive particles  121  is worse, so that the binding effect of these abrasive particles  121  becomes bad and results in these abrasive particles  121  easily fallen during polishing process. When the abrasive exposing rate of these abrasive particles  122  is less than 75 μm, the effect of the binding layer shielding these abrasive particles  122  is excessive, so that the ability of these abrasive particles  122  cutting the polishing becomes bad and results in the polishing effect become bad. 
       Example 2 
       [0025]    The chemical mechanical polishing conditioner with optimal abrasive exposing rate of Example 2 is substantially the same as the above Example 1, but the differences are that the abrasive exposing rate of Example 1 is ¼ to ¾ of particle sizes of these abrasive particles, and the abrasive exposing rate of Example 2 is ⅔ of particle sizes of these abrasive particles. Further, the differences between the abrasive exposing rate of these abrasive particles are less than 1/10 of particle sizes of these abrasive particles. As shown in  FIG. 3 , these abrasive particles of Example 2 of the present invention are artificial diamonds having particle sizes of 300 μm. The differences of the abrasive exposing rate is less than 30 μm, and the optimal abrasive exposing rate of these abrasive particles is in a range of 185 μm to 215 μm, for example, please refer to  FIG. 3 , the values of D2, D3, D4, D5, D6 to D20 (no shown in figure) are preferably 185 μm to 215 μm. Besides, the differences among values of D1 to D20 of abrasive exposing rate are 30 μm. When the difference of the abrasive exposing rate is less than 30 μm, a surface of the chemical mechanical polishing conditioner  3  is more similar to a flat surface to provide an ability of the abrasive particles  32  cutting the polishing pad (no shown in figure). 
         [0026]    Contrarily, when the differences of the abrasive exposing rate are more than 30 μm, the polishing is focused on few abrasive particles having large abrasive exposing rate during polishing process, so that the polishing performance of the conditioner becomes bad and service life of the conditioner are shortened. 
       Example 3 
       [0027]    The chemical mechanical polishing conditioner with optimal abrasive exposing rate of Example 3 is substantially the same as the above Example 2, but the differences are that the differences of the abrasive exposing rate of these abrasive particles of Example 2 are less than 1/10 of particle sizes of these abrasive particles, and the differences of the abrasive exposing rate of these abrasive particles of Example 3 are less than 1/20 of particle sizes of these abrasive particles. As shown in  FIG. 4 , the measured exposing rate of these abrasive particles  42  is less than 1/20 of the particle sizes of these abrasive particles  42 ; therefore, the differences of the abrasive exposing rate is less than 15 μm, and the optimal abrasive exposing rate of these abrasive particles  42  is in a range of 192.5 μm to 207.5 μm. Thus the chemical mechanical polishing conditioner  4  having a surface more similar to a flat surface can be obtained, and the ability of these abrasive particles  42  cutting the polishing pad can be improved to stabilize the polishing performance and quality of the chemical mechanical polishing conditioner  4 . 
         [0028]    The above-mentioned results show that when the abrasive exposing rate is ¼ to ¾ of the particles of these abrasive particles, the effect of the binding layer shielding these abrasive particles is preferably to avoid problems that these abrasive particles are fallen and the ability of cutting becomes bad. Besides, when the differences of the abrasive exposing rate is small, a flat surface with uniform abrasive exposing rate can be obtained; therefore, the ability of these abrasive particles cutting the polishing pad is excellent to stabilize the polishing performance and quality of the chemical mechanical polishing conditioner during polishing process. 
         [0029]    It should be understood that these examples are merely illustrative of the present invention and the scope of the invention should not be construed to be defined thereby, and the scope of the present invention will be limited only by the appended claims.