Abstract:
The present invention relates to a method for manufacturing a chemical mechanical polishing conditioner, comprising: (A) providing a non-planar substrate; (B) providing a binding layer disposed on the surface of the non-planar substrate; (C) providing a plurality of abrasive particles embedded in a surface of the binding layer, and (D) heat curing the binding layer, such that the non-planar substrate is deformed into a planar substrate during curing the binding layer, and the abrasive particles are fixed to a surface of the planar substrate by the binding layer; wherein, after step (D), tips of the abrasive particles have a leveled height. Therefore, the present can effectively improve the problem of thermal deformation of the substrate of the chemical mechanical polishing conditioner during a heat curing process, and enhance surface flatness of the chemical mechanical polishing conditioner.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the benefits of the Taiwan Patent Application Serial Number 101141305, filed on Nov. 7, 2012, the subject matter of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a chemical mechanical polishing conditioner, and more particularly to a chemical mechanical polishing conditioner which may provide deformation compensation for a substrate. 
     2. Description of Related Art 
     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 due to its ability to achieve whole planarization. 
     During the chemical mechanical polishing process of semiconductor, impurities or uneven structure on the surface of a wafer is removed by a polishing pad in contact therewith (or semiconductor element) with optional use of slurry, 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 curing of the abrasive layer, the surface of the substrate may be deformed because of the difference in thermal expansion coefficient between the abrasive layer and the substrate, thus destroying flatness of the abrasive particles of the conditioner and thereby adversely affecting the polishing efficiency and service life of the conditioner. 
     Conventionally, the surface flatness of a chemical mechanical polishing conditioner is typically controlled by two ways. One way is to dispose the abrasive particles and the binding layer on the surface of the substrate, followed by pressing down the abrasive particles using a rigid plate to embed and fix the abrasive particles into the abrasive layer such that the surfaces of the abrasive particles and the rigid flat may have the same flatness. Another way is to dispose the abrasive particles into a recess of a mold, followed by covering the non-working surface of the abrasive particles with a binding layer and a substrate, and performing heat curing, and finally, flipping the mold upside down to separate the cured chemical mechanical polishing conditioner from the recess of the mold. However, in the above two methods for manufacturing the chemical mechanical polishing conditioner, during heat-curing the binding layer, the difference in thermal expansion coefficient between the binding layer and the substrate may result in deformation of the substrate of the chemical mechanical polishing conditioner after curing, which in turn results in deformation of the surface of the chemical mechanical polishing conditioner and destroys the flatness of the abrasive particles of the conditioner. 
     Therefore, what is needed is to develop a chemical mechanical polishing conditioner with surface flatness, which cannot only avoid the deformation of the substrate of the chemical mechanical polishing conditioner during curing, but also control the surface flatness of the chemical mechanical polishing conditioner. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a chemical mechanical polishing conditioner, to avoid the deformation of the substrate of the chemical mechanical polishing conditioner during curing, so as to achieve the surface flatness of the chemical mechanical polishing conditioner. 
     To achieve the above object, the present invention provides a chemical mechanical polishing conditioner, comprising: a planar substrate having a planar surface; a binding layer disposed on a surface of the planar substrate; and a plurality of abrasive particles embedded in a surface of the binding layer and fixed to the surface of the planar substrate by the binding layer, wherein, tips of the abrasive particles have a leveled height. 
     In the chemical mechanical polishing conditioner of the present invention, the planar substrate may be formed from a non-planar substrate which is deformed during curing the binding layer, wherein a surface of the non-planar substrate has a center surface and an outer edge surface, and a working surface is formed between the center surface and the outer edge surface. 
     In the chemical mechanical polishing conditioner of the present invention, the working surface may have a non-planar contour, wherein the non-planar contour may be spherical or non-spherical. 
     In the chemical mechanical polishing conditioner of the present invention, a height difference between the center surface and the outer edge surface may be 5-5000 μm. In a preferred aspect of the present invention, a height difference between the center surface and the outer edge surface may be 120 μm. 
     In the chemical mechanical polishing conditioner of the present invention, the planar substrate may be made of stainless steel, mold steel, metal alloy, or ceramic material, etc. In a preferred aspect of the present invention, the planar substrate may be made of type 316 stainless steel having a thermal expansion coefficient of about 16 ppm/° C. 
     In the chemical mechanical polishing conditioner of the present invention, the planar substrate may have a thickness of 3-50 mm and a diameter of 10-360 mm. In a preferred aspect of the present invention, the planar substrate may have a thickness of 6 mm and a diameter of 100 mm. 
     In the chemical mechanical polishing conditioner of the present invention, the binding layer may be a brazing layer, a resin layer, a electroplating layer, or a ceramic layer. In a preferred aspect of the present invention, the binding layer may be a brazing layer. The brazing layer may be at least one selected from the group consisting of iron, cobalt, nickel, chromium, manganese, silicon, aluminum, and combinations thereof, having a thermal expansion coefficient of about 14-15 ppm/° C. 
     In the chemical mechanical polishing conditioner of the present invention, the abrasive particles may be diamond or cubic boron nitride. In a preferred aspect of the present invention, the abrasive particles may be diamond. In addition, in the chemical mechanical polishing conditioner of the present invention, the abrasive particles may have a particle size of 20-450 μm. In a preferred aspect of the present invention, the abrasive particles may have a particle size of 200 μm. 
     Another object of the present invention is to provide a chemical mechanical polishing to provide a method for manufacturing a chemical mechanical polishing conditioner to obtain the above-described chemical mechanical polishing conditioner, and effectively avoid the deformation of the substrate of the chemical mechanical polishing conditioner during curing, so as to achieve the surface flatness of the chemical mechanical polishing conditioner. 
     To achieve the above object, the present invention provides a method for manufacturing a chemical mechanical polishing conditioner, comprising: (A) providing a non-planar substrate; (B) providing a binding layer disposed on the surface of the non-planar substrate; (C) providing a plurality of abrasive particles embedded in a surface of the binding layer, and (D) heat curing the binding layer, such that the non-planar substrate is deformed into a planar substrate during curing the binding layer, and the abrasive particles are fixed to a surface of the planar substrate by the binding layer; wherein, after step (D), tips of the abrasive particles have a leveled height. 
     In the method for manufacturing a chemical mechanical polishing conditioner of the present invention, the surface of the non-planar substrate has a center surface and an outer edge surface, and a working surface is formed between the center surface and the outer edge surface. 
     In the method for manufacturing a chemical mechanical polishing conditioner of the present invention, the working surface may have a non-planar contour, wherein the non-planar contour may be spherical or non-spherical. 
     In the method for manufacturing a chemical mechanical polishing conditioner of the present invention, a height difference between the center surface and the outer edge surface may be 5-5000 μm. In a preferred aspect of the present invention, a height difference between the center surface and the outer edge surface may be 120 μm. 
     In the method for manufacturing a chemical mechanical polishing conditioner of the present invention, the method for heat curing the binding layer may be brazing, heat-curing, ultraviolet radiation curing, electroplating, or sintering. In a preferred aspect of the present invention, the method for heat curing the binding layer may be brazing. 
     In the method for manufacturing a chemical mechanical polishing conditioner of the present invention, the abrasive particles may be diamond or cubic boron nitride. In a preferred aspect of the present invention, the abrasive particles may be diamond. In addition, in the method for manufacturing a chemical mechanical polishing conditioner of the present invention, the abrasive particles may have a particle size of 20-450 μm. In a preferred aspect of the present invention, the abrasive particles may have a particle size of 200 μm. 
     In the method for manufacturing a chemical mechanical polishing conditioner of the present invention, in the aforementioned step (C), the abrasive particles may be embedded in the surface of the binding layer by a template, a platen, or a temporary mold. 
     In summary, according to the method for manufacturing a chemical mechanical polishing conditioner of the present invention, the problem of the deformation of the substrate of the chemical mechanical polishing conditioner during curing may be effectively solved, and the surface flatness of the chemical mechanical polishing conditioner may be improved, thereby increasing the polishing efficiency and service life of the conditioner. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       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: 
         FIGS. 1A to 1D  show a conventional process flow for manufacturing a chemical mechanical polishing conditioner. 
         FIGS. 2A to 2E  show another conventional process flow for manufacturing a chemical mechanical polishing conditioner. 
       FIGS.  3 A to  3 C′ show a further conventional process flow for manufacturing a chemical mechanical polishing conditioner. 
         FIGS. 4A to 4C  show a process flow for manufacturing the chemical mechanical polishing conditioner of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Hereinafter, the actions and the effects of the present invention will be 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. 
     COMPARATIVE EXAMPLE 1 
     Refer to  FIGS. 1A to 1D , showing the conventional process flow for manufacturing a chemical mechanical polishing conditioner. 
     First, as shown in  FIGS. 1A and 1B , a binding layer  11  is formed on a working surface of a substrate  10  having a planar contour, and the abrasive particles  13  are employed, wherein the spacing and arrangement of the abrasive particles  13  are controlled by using template  12  while a rigid plate  14  is provided to press down the abrasive particles  13 . 
     Then, as shown in  FIG. 1C , after the abrasive particles  13  are pressed down by the rigid plate  14 , the abrasive particles  13  are embedded and fixed in the abrasive layer  11 , and the surfaces of the abrasive particles  13  and the rigid flat  14  may have the same flatness. 
     Finally, as shown in  FIG. 1D , the abrasive particles  13  are fixed to the surface of the substrate  10  by a heat-curing process through the binding layer  11 . However, the substrate  10  of the chemical mechanical polishing conditioner may be deformed after curing because of the difference in thermal expansion coefficient between the binding layer  11  and the substrate  10 , and thus the binding layer  11  and the abrasive particles  13  on the surface of the substrate are also deformed thereby deteriorating the flatness of the abrasive particles of the conditioner, wherein tips of the center abrasive particles  131  are relatively high, while the tips of the outer edge abrasive particles  132  are relatively low, resulting in a height difference H 1  between the center abrasive particles  131  and the outer edge abrasive particles  132 . 
     In Comparative Example 1, the binding layer  11  is made of common nickel-based metal brazing and the substrate  10  is made of stainless steel. 
     COMPARATIVE EXAMPLE 2 
     Please refer to  FIGS. 2A to 2E , showing another conventional process flow for manufacturing a chemical mechanical polishing conditioner. 
     First, as shown in  FIGS. 2A and 2B , a mold  25  is provided, wherein the mold  25  has a recess structure, and a binding agent  27  is disposed in the mold  25 . Then, abrasive particles  23  and a binding layer  21  are provided and fixed on a soft substrate  26 , and after that, the soft substrate  26  is disposed on the surface of the binding agent  27  in the mold  25 , and the abrasive particles  23  are attached to the surface of the recess in the mold  25  by the binding agent  27 , such that the abrasive particles  23  may be provided have the same flatness with the surface of the recess in the mold  25 . 
     Subsequently, as shown in  FIG. 2C , an adhesive layer  28  and a substrate  20  are provided and attached onto the soft substrate  26 , such that the abrasive particles  23  on the surface of the soft substrate  26  and the binding layer  21  can be combined to the substrate  20  by the adhesive layer  28 , wherein the surface of the substrate  20  has a planar contour. 
     Then, as shown in  FIG. 2D , the abrasive particles  23  are fixed to the substrate  20  by the binding layer  21 , the soft substrate  26  and the adhesive layer  28  through a heat curing process. However, the substrate  20  of the chemical mechanical polishing conditioner may be deformed after curing, because of the difference in thermal expansion coefficient between the binding layer  21  and the substrate  20 , resulting in deformation of the binding layer  21  on the surface of the substrate  20  and the abrasive particles  23 , thus destroying the flatness of the abrasive particles  23  of the conditioner, wherein the center abrasive particles  231  and the outer edge abrasive particles  232  have different tip heights. 
     Finally, as shown in  FIG. 2E , the aforementioned cured chemical mechanical polishing conditioner is removed from the recess in the mold  25 , and the binding layer  21  on the surface of the substrate  20  and the abrasive particles  23  have been deformed, thereby destroying the flatness of the abrasive particles  23  on the surface of the chemical mechanical polishing conditioner, wherein tips of the center abrasive particles  231  are relatively high, while the tips of the outer edge abrasive particles  232  are relative low, such that a height difference  112  between the center abrasive particles  231  and the outer edge abrasive particles  232  is formed. 
     In Comparative Example 2, the binding layer  21  is made of common nickel-based metal brazing, the substrate  20  is made of stainless steel, the binding agent  27  is wax, and the soft substrate  26  is a metal foil. 
     COMPARATIVE EXAMPLE 3 
     Refer to FIGS.  3 A to  3 C′, showing a further conventional process flow for manufacturing a chemical mechanical polishing conditioner. The manufacturing process of Comparative Example 3 is substantially the same as the above Comparative Example 1, except that the substrate in Comparative Example 1 or Comparative Example 2 is selected to have a planar contour, while the substrate in Comparative Example 3 is selected to have a non-planar contour. 
     First, as shown in  FIG. 3A , a substrate  30  having a non-planar contour is provided, wherein a working surface  303  having a linear surface is formed between the center surface  301  and the outer edge surface  302 , and the height of the substrate is gradually increased from the center surface  301  to the outer edge surface  302 . In addition, the height of the center surface  301  is lower and the outer edge height of the surface  302  is higher, such that a height difference H 3  between the center surface  301  and the outer edge surface  302  is formed. 
     Next, as shown in  FIG. 3B , a binding layer  31  and the abrasive particles  33  are disposed on the working surface  303  of the substrate  30 , wherein the binding layer  31  and the abrasive particles  33  may be optionally disposed by the method disclosed in Comparative Example 1 or Comparative Example 2 to control the arrangement or surface flatness of the abrasive particles  33 . 
     Then, as shown in  FIG. 3C , the abrasive particles  33  are fixed to the substrate  30  by the binding layer  31  through a heat curing process. However, the substrate  30  of the chemical mechanical polishing conditioner may be deformed after curing, because of the difference in thermal expansion coefficient between the binding layer  31  and the substrate  30 , resulting in deformation of the binding layer  31  on the surface of the substrate  30  and the abrasive particles  33 , thus destroying the flatness of the abrasive particles  33  of the chemical mechanical polishing conditioner. 
     In Comparative Example 3, the binding layer  31  is made of common nickel-based metal brazing, and the substrate  30  is made of stainless steel. In Comparative Example 3, since the thermal expansion coefficient of the substrate  30  is selected to be higher than that of the binding layer  31 , the working surface  303  of the substrate  30  after heat-curing will present a upward-protruding curved surface, wherein tips of the center abrasive particles  331  and the tips of the outer edge abrasive particles  332  are relatively low, while tips of the therebetween abrasive particles  333  are relatively high. 
     Further, FIG.  3 C′ shows another aspect of Comparative Example 3. If the thermal expansion coefficient of the selected substrate  30  is lower than that of the binding layer  31 ′, the substrate  30  of the chemical mechanical polishing conditioner may be deformed after curing, because of the difference in thermal expansion coefficient between the binding layer  31 ′ and the substrate  30 , resulting in deformation of the binding layer  31 ′ on the surface of the substrate  30  and the abrasive particles  33 , and destroying the flatness of the abrasive particles  33 ′ of the chemical mechanical polishing conditioner, the working surface  303 ′ of the substrate  30  after heat-curing will present a downward-protruding curved surface, wherein tips of the center abrasive particles  331  and the tips of the outer edge abrasive particles  332 ′ are relatively high, while tips of the therebetween abrasive particles  333 ′ are relatively low. 
     EXAMPLE 
     Please refer to  FIGS. 4A to 4C , showing the process flow for manufacturing the chemical mechanical polishing conditioner of the present invention. The manufacturing process of this Example is substantially the same as the above Comparative Example 3, except that the working surface of substrate in this Example is selected to have a non-planar contour, while the working surface of the substrate in Comparative Example 3 is selected to have a linear contour. 
     First, as shown in  FIG. 4A , a substrate  40  having a non-planar contour is provided, wherein a working surface  403  having a non-planar surface is formed between the center surface  401  at and the outer edge surface  402 , and the non-planar surface may comprise a spherical contour or a non-spherical contour. In this Example, the working surface  403  has a non-spherical curved contour. In addition, the height of the center surface  401  is relative low and the height of the outer edge surface  402  is relatively high, such that a height difference H 4  between the center surface  401  and the outer edge surface  402  is formed. In this Example, the substrate  40  is a type 316 stainless steel having a thermal expansion coefficient of about 16 ppm/° C., and the substrate  40  has a diameter of 100 mm and a thickness of 6 mm. The height difference H 4  formed between the center surface  401  and the outer edge surface  402  is 120 μm. That is, the height difference H 4  formed between the center surface  401  and the outer edge surface  402  is 2% of the thickness of the substrate  40 . 
     Then, as shown in  FIG. 4B , a binding layer  41  and abrasive particles  43  are disposed on the working surface  403  of the substrate  40 , wherein the binding layer  41  and the abrasive particles  43  may be optionally disposed by the method disclosed in Comparative Example 1 or Comparative Example 2 to control the arrangement or surface flatness of the abrasive particles  43 . In this Example, the abrasive particles  43  are diamond having a particle size of 200 μm. 
     After that, as shown in  FIG. 4C , the abrasive particles  43  are fixed to the substrate  40  by the binding layer  41  through a heat curing process. However, the substrate  40  of the chemical mechanical polishing conditioner may be deformed after curing, because of the difference in thermal expansion coefficient between the binding layer  41  and the substrate  40 , resulting in deformation of the binding layer  41  on the surface of the substrate  40  and the abrasive particles  43 . However, in this Example, the binding layer  41  is a brazing made of nickel, chromium, silicon, and boron, having a thermal expansion coefficient of about 14-15 ppm/° C., and since the thermal expansion coefficient of the substrate  40  is selected to be higher than the binding layer  41 , the working surface  403  of the substrate  40  after heat-curing will present a upward-protruding curved surface. Referring back to  FIG. 4A , however, since the working surface  403  of the substrate  40  in this Example has a non-spherical curved contour, and the working surface  403  is trimmed to have a recessed contour before heat-curing, the substrate  40  will be deformed to compensate the recessed surface of the working surface  403 . Finally, the cured substrate  40  and the surface of the abrasive particles  43  show a high degree of flatness, and as a result, the tips of all the abrasive particles  43  (including the center abrasive particles  431  and the outer edge abrasive particles  432 ) have a leveled height. 
     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.