This application claims the benefits of the Taiwan Patent Application Serial Number 102146375, filed on Dec. 16, 2013, the subject matter of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to a chemical mechanical polishing conditioner with high quality abrasive particles, and more particularly to a chemical mechanical polishing conditioner with high quality abrasive particles which is applied to remove risk diamonds.
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 because it can achieve an object of whole planarization.
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, or when the conditioner conditions a polishing pad, the diamond particles on the conditioner may be broken to form risk diamonds, such that the conditioner may become a defective one. Therefore, it is necessary to implement a detection process to ensure an expected polishing effect in the subsequent steps. It is a known method to use an optical microscope (OM) to perform a visual observation whether a pad conditioner has any risk diamond or not. When risk diamonds are observed, the positions would be marked by a marked method (such as oil pen) and taken a photograph. Finally, the photos are taken before and after the grinding process which would be compared by a person, and the risk diamonds are removed by a person or a mechanical method to avoid the risk diamonds residue on the conditioner.
In the known technology, such as Taiwan Patent Publication No. 201102215, it discloses that methods and systems for removing dirt and/or debris from a CMP pad surface during CMP pad processing are provided. In one aspect, a method for removing debris from a CMP pad surface during CMP processing can include rotating a CMP pad having a polishing surface, and pressing a CMP pad dresser into the polishing surface of the CMP pad, the CMP pad dresser having a plurality of superabrasive particles coupled thereto and oriented toward the CMP pad. The method can further include spraying a jet of liquid onto the polishing surface of the CMP pad with sufficient force to dislodge debris from the polishing surface of the CMP pad.
Besides, in the other known technology, such as Taiwan Patent Issue No. 438650, it discloses that a method for recycling a diamond wheel in chemical mechanical polishing (CMP) comprises using a water jet at a high pressure of 1500 to 6000 psi to spray a deionized (DI) water on the surface of a diamond wheel with accumulated SiO2 thereby removing most of the powder scraps; mounting the diamond wheel on a heating platform at 40° C. and using a high-pressure CO2 gas at 0° C. and a pressure of 800 to 6000 psi, followed by a clean dry air, to flush the surface of the diamond wheel thereby removing the residual SiO2; and mounting the diamond wheel in an ultrasonic water tank to wash off the remaining impurities by vibrating the DI water. The use of the above mentioned three steps can remove most of the SiO2 on the surface of the diamond wheel and recycle the diamond wheel.
However, the above-mentioned chemical mechanical polishing conditioner with a water jet is used to remove debris on the surfaces of a conditioner or a polishing pad to maintain polishing performance between the conditioner and the polishing pad during polishing process. But, the above-mentioned chemical mechanical polishing conditioner cannot improve a problem of risk diamonds residue on the conditioner during manufacturing process. Therefore, there is an urgent need for a chemical mechanical polishing conditioner with high quality abrasive particles, which is used to remove risk diamonds on the surface of the conditioner, thereby avoiding scratches and breakages produced on the polishing pad due to the risk diamonds during a chemical mechanical polishing process.
An object of the present invention is to provide a chemical mechanical polishing conditioner with high quality abrasive particles, which is used to remove risk diamonds on the chemical mechanical polishing conditioner by a water jet, thereby avoiding scratches and breakages produced on the polishing pad due to the risk diamonds during a chemical mechanical polishing process.
During a manufacturing process of the general chemical mechanical polishing conditioner, the brazing powder comprising a metal alloy and the diamond particles are disposed on a surface of a substrate made of stainless steel and performed a heat brazing process, such that the diamond particles are fixed on the surface of the substrate by the brazing ally to complete the chemical mechanical polishing conditioner. However, during an actual process for manufacturing the chemical mechanical polishing conditioner, a part of diamond particles include risk diamonds having twin crystal structures, internal crack structures or diamonds embedded in the binding layer with low encapsulation, wherein the risk diamonds may be come from the source of materials of the diamonds themselves, or the diamond particles in the brazing process or the conditioner in the post-processing procedure result in diamond particles having defects. The risk diamond is different from general diamond particles with perfect crystal forms which can provide excellent and stable polishing performance; therefore, the risk diamonds on the chemical mechanical polishing conditioner are removed by the water jet and the high pressure fluid of the present invention, thereby avoiding scratches and breakages produced on the polishing pad due to the risk diamonds during a chemical mechanical polishing process. Besides, the chemical mechanical polishing conditioner of the present invention cannot only remove risk diamonds on the chemical mechanical polishing conditioner by the water jet and the high pressure fluid, but also supply diamond particles with perfect crystal forms for leaving positions after removing risk diamonds to remain numbers and arrangement patterns of diamond particles positioned on the surface of original conditioner.
To achieve the above object, the present invention provides a chemical mechanical polishing conditioner, 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 the chemical mechanical polishing conditioner with high quality abrasive particles is moved to pass through a water jet and a high pressure fluid by a conveying device, and the high pressure fluid is applied to the abrasive particles through the water jet to remove one or more than one risk diamonds included in the abrasive particles.
In above-mentioned the chemical mechanical polishing conditioner with high quality abrasive particles of the present invention, the risk diamonds can have twin crystal structures, internal crack structures or diamonds embedded in the binding layer with low encapsulation; wherein the risk diamonds may be come from the source of materials of the diamonds themselves, or the diamond particles in the brazing process or the conditioner in the post-processing procedure result in diamond particles having defects. The risk diamond is different from general diamond particles which can provide excellent and stable polishing performance. These risk particles have twin crystal structures, internal crack structures or diamonds embedded in the binding layer with low encapsulation present in the inside or surface of the diamond particles; therefore, the intensity and crystal forms of diamond particles can be destroyed, and the polishing performance of these risk diamonds become worse.
In above-mentioned the chemical mechanical polishing conditioner with high quality abrasive particles of the present invention, the water jet can include one or a plurality of nozzles, and the number of the nozzles included in the water jet may be randomly varied based on the user's requirements or quality requirements of these diamond particles; wherein in an aspect of the present invention, the water jet can include two to ten nozzles, and in another aspect of the present invention, the water jet can include three to five nozzles. Besides, in above-mentioned the chemical mechanical polishing conditioner with high quality abrasive particles of the present invention, pore sizes of the nozzles of these water jets may be randomly varied based on the user's requirements or quality requirements of these diamond particles; wherein in an aspect of the present invention, these water jets can have the same pore sizes of the nozzles; and in another aspect of the present invention, these water jets can have different pore sizes of the nozzles, but the present invention is not limited thereto.
In above-mentioned the chemical mechanical polishing conditioner with high quality abrasive particles of the present invention, the different spray angles can be formed by these nozzles of the present invention, which is different from a traditional water jet limited to a washing function through a single nozzle and a single angle. The water jet of the present invention may be randomly varied based on the user's requirements or quality requirements of these diamond particles to form various spray angles toward these abrasive particles on the surface of the conditioner. Besides, in above-mentioned the chemical mechanical polishing conditioner with high quality abrasive particles of the present invention, the water jet can be a fixing mechanism, such as a fixing water jet, such that the high pressure fluid is applied to fixing positions of these abrasive particles by the fixing water jet or the nozzles to remove the risk diamonds included in these abrasive particles. Alternatively, the water jet is a rotating mechanism, such as a rotating water jet, such that the high pressure fluid is applied to non-fixing positions of these abrasive particles by a continuous rotating water jet or the nozzles.
In above-mentioned the chemical mechanical polishing conditioner with high quality abrasive particles of the present invention, a rotating speed of the rotating mechanism may be randomly varied based on the user's requirements or quality requirements of these diamond particles; wherein the rotating speed of the rotating mechanism can be 5 rpm to 2,000 rpm, and in an aspect of the present invention, the rotating speed of the rotating mechanism can be 10 rpm to 1,050 rpm. Besides, in above-mentioned the chemical mechanical polishing conditioner with high quality abrasive particles of the present invention, a pressure of the high pressure fluid applied to these abrasive particles may be randomly varied based on the user's requirements or quality requirements of these diamond particles; wherein the pressure of the high pressure fluid applied to these abrasive particles can be 300 psi (lbf/in2) to 40,000 psi, and in an aspect of the present invention, the pressure of the high pressure fluid applied to these abrasive particles can be 1,000 psi to 32,000 psi.
In above-mentioned the chemical mechanical polishing conditioner with high quality abrasive particles of the present invention, the chemical mechanical polishing conditioner with high quality abrasive particles can be moved to pass through a water jet and a high pressure fluid by a conveying device, such that the high pressure fluid is applied to the abrasive particles through the water jet to remove one or more than one risk diamonds included in the abrasive particles. Furthermore, a moving speed of the conveying device may be randomly varied based on the user's requirements or quality requirements of these diamond particles; wherein the moving speed of the conveying device can be 10 mm/min to 1,000 mm/min.
In above-mentioned the chemical mechanical polishing conditioner with high quality abrasive particles of the present invention, the water jet can has a cage lifter for adjusting a spacing between the water jet and the chemical mechanical polishing conditioner with high quality abrasive particles, and adjusting the pressure of the high pressure fluid applied to these abrasive particles by varying the spacing while the pressure of the high pressure fluid is a constant. Besides, the spacing between the water jet and the conditioner with high quality abrasive particles may be randomly varied based on the user's requirements or quality requirements of these diamond particles, but the present invention is not be limited thereto.
In above-mentioned the chemical mechanical polishing conditioner with high quality abrasive particles of the present invention, the high pressure fluid can be any fluid capable of removing risk diamonds, such as pure water, ultra-pure water, non-corrosive fluid, and the like or combinations thereof, but the present invention is not be limited thereto. The above-mentioned ultra-pure water means the water in which main impurities are removed through an ion exchange resin method, an activated carbon method and a filter membrane method under a resistivity reached 18.2 MΩ·cm at a temperature of 25° C., and corrosion or destruction produced on the binding layer of the conditioner due to the high pressure fluid can be reduced.
In above-mentioned the chemical mechanical polishing conditioner with high quality abrasive particles of the present invention, these abrasive particles may be artificial diamonds, nature diamonds, polycrystalline diamonds or cubic boron nitride. In a preferred aspect of the present invention, the abrasive particles may be artificial diamonds. Furthermore, in above-mentioned the chemical mechanical polishing conditioner with high quality abrasive particles 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 200 μm.
In above-mentioned the chemical mechanical polishing conditioner with high quality abrasive particles of the present invention, the compositions of the binding layer or the abrasive particles may be varied based on the polishing conditions and 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 high quality abrasive particles of the present invention, the materials and sizes of the substrate may be varied based on the polishing conditions and 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.
In summary, according to the chemical mechanical polishing conditioner with high quality abrasive particles of the present invention, the risk diamonds included in the abrasive particles can be removed, thereby avoiding scratches and breakages produced on the polishing pad due to the risk diamonds during a chemical mechanical polishing process.
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:
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.
The chemical mechanical polishing conditioner with high quality abrasive particles of the present invention can be used to remove the risk diamonds on the chemical mechanical polishing conditioner, thereby avoiding scratches and breakages produced on the polishing pad due to the risk diamonds during a chemical mechanical polishing process. Please refer to
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In above-mentioned the chemical mechanical polishing conditioner with high quality abrasive particles of the present invention, the water jet may be varied based on the polishing conditions or the user's requirements, such as the number of the nozzles, pore sizes of the nozzles, the angles of the high pressure toward these abrasive particles, the designs of the fixing mechanism or the rotating mechanism, and adjusting the spacing between the water jet and the chemical mechanical polishing conditioner by the cage lifter. Further, various parameters of the rotating speed of rotating mechanism, the pressure of the high pressure fluid applied to these abrasive particles and the moving speed of the conveying device are adjusted to accomplish the user's requirements or quality requirements of these abrasive particles. Therefore, the risk diamonds in the abrasive particles can be removed effectively by the chemical mechanical polishing conditioner with high quality abrasive particles of the present invention to avoid scratches and breakages produced on the polishing pad during a chemical mechanical polishing process.
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.
Number | Date | Country | Kind |
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102146375 | Dec 2013 | TW | national |