TWI580523B - Chemical mechanical polishing conditioner with optimal abrasive exposing rate - Google Patents

Description

Chemical mechanical polishing dresser with optimum abrasive exposure rate

The present invention relates to a chemical mechanical polishing dresser having an optimum abrasive exposure rate, and more particularly to a chemical mechanical polishing dresser having an optimum cutting ability.

Chemical Mechanical Polishing (CMP) is a common grinding process in various industries. The surface of various articles can be ground using a chemical polishing process, including ceramic, tantalum, glass, quartz, or metal wafers. In addition, with the rapid development of integrated circuits, chemical mechanical polishing can achieve large-area planarization, so it is one of the common wafer planarization techniques in semiconductor manufacturing.

In the chemical mechanical polishing process of semiconductors, the wafer (or other semiconductor components) is contacted by a polishing pad (Pad), and the polishing liquid is used as needed to pass the chemical reaction and physical mechanical force to remove the wafer. Impurity or uneven structure of the surface; when the polishing pad is used for a certain period of time, the grinding debris generated by the grinding process is accumulated on the surface of the polishing pad to cause grinding The effect and efficiency are reduced. Therefore, the surface of the polishing pad can be ground by a conditioner to re-roughen the surface of the polishing pad and maintain the optimum grinding state. However, in the preparation process of the dresser, the polishing layer formed by mixing the abrasive particles and the bonding layer needs to be disposed on the surface of the substrate, and the polishing layer is fixedly bonded to the surface of the substrate by brazing or sintering. However, in the manufacturing process of the above-mentioned dresser, the exposure rate of the chemical mechanical polishing dresser has an important relationship with the cutting ability. Therefore, when the exposure rate of the abrasive particles is large, the bonding effect of the bonding layer on the abrasive particles is poor, and the abrasive particles and the abrasive particles are The bonding property of the bonding layer is poor, and thus, the abrasive particles are easily peeled off during the grinding process; conversely, the coating particle has a small exposure rate, and the bonding property of the bonding layer to the abrasive particles is too large, and therefore, the grinding ability of the polishing pad to the polishing pad is deteriorated. Therefore, the grinding effect is deteriorated.

In the known art, such as the Chinese Patent Application No. 101320708, the price of the polishing pad used in the CMP step in manufacturing the semiconductor integrated circuit device is relatively high, so it is necessary to avoid unnecessary replacement. Therefore, the focus is on accurately measuring the amount of wear of the mat. However, in the usual measurement using light, the presence of the slurry becomes an obstacle, and the elution of the contaminant causes a problem when measured by the contact type sensor. In the CMP step, during the operation of the dresser, the wear amount or thickness of the polishing pad can be indirectly detected by measuring the height position of the dresser, thereby rationalizing the replacement period of the polishing pad.

Further, as disclosed in the Republic of China Patent Publication No. 200936316, a dressing method for trimming a polishing pad for a polishing apparatus for polishing a substrate is provided. The method includes repeatedly moving the trimmer on the upper surface of the polishing pad along the radial direction of the polishing pad to perform a dressing process of the polishing pad; during the trimming process, Measuring the height of the upper surface of the polishing pad at a predetermined point of one of the plurality of regions on the polishing surface, and repeating the repeated movement of the dresser and measuring the height of the surface above the polishing pad to measure in all areas The height of the surface above the polishing pad.

However, the above detecting means utilizes the height position of the measuring dresser to indirectly detect the abrasion amount or thickness of the polishing pad, or repeatedly moves the dresser on the upper surface of the polishing pad to measure the height of the upper surface of the polishing pad. However, the exposure rate of the abrasive particles of the chemical mechanical polishing dresser cannot be effectively stabilized, so that a flat surface and stable polishing quality cannot be provided. Therefore, there is an urgent need to develop a chemical mechanical polishing dresser having an optimum abrasive exposure rate. Since the exposure rate of the abrasive particles has an important relationship with the cutting ability of the chemical mechanical polishing dresser, the present invention can control the exposure rate of the abrasive particles. A chemical mechanical polishing dresser that forms a flat surface, thereby improving the cutting ability of the abrasive particles to the polishing pad.

The main object of the present invention is to provide a CMP abrasive dresser having an optimum abrasive exposure rate, which has a flat surface with uniform exposure rates of abrasive particles, thereby improving the cutting ability of the chemical mechanical polishing dresser. To provide a stable grinding quality.

In order to achieve the above object, the present invention provides a CMP polishing dresser having an optimum abrasive exposure rate, comprising: a substrate; a bonding layer disposed on the substrate; and a plurality of abrasive particles, the abrasive particles Buried in the bonding layer, and the abrasive particles are fixed by the bonding layer On the substrate; wherein each of the abrasive particles may have an abrasive exposure rate, the abrasive exposure rate may be 1/4 to 3/4 of the particle diameter of the abrasive particles, and the abrasive exposure rate may be via a height amount Measured by the measuring device; for example, when the particle size of the abrasive particles is 300 μm, the optimum abrasive exposure rate is 75 to 225 μm. In addition, if the abrasive exposure rate is greater than 3/4 of the particle diameter of the abrasive particles, the bonding layer may be poorly coated on the abrasive particles, thereby causing the dresser to easily cause the problem of dropping the diamond during the grinding process; On the other hand, if the abrasive exposure rate is less than 1/4 of the particle diameter of the abrasive particles, the bonding layer is excessively coated on the abrasive particles, thereby causing the abrasive particles to be applied to the workpiece (for example, a polishing pad). The cutting ability is deteriorated, resulting in poor grinding performance.

In the CMP polishing dresser having the optimum abrasive exposure rate of the present invention, the abrasive exposure rate may refer to the distance between the tips of the abrasive particles and the surface of the bonding layer. Since the spacing between each of the abrasive particles on the chemical mechanical polishing conditioner is extremely small, in the chemical mechanical polishing conditioner having the optimum abrasive exposure rate of the present invention, the height measuring device may include a height gauge and a An optical microscope, wherein the height gauge further comprises a height gauge needle (eg, a tungsten carbide tip), and the height gauge can be used to measure a height of a specific position, the specific position being the abrasive particle tip or the combination Layer surface. Furthermore, in the CMP polishing dresser having the optimum abrasive exposure rate of the present invention, the optical microscope can be used to determine the relative position of the height gauge, that is, the optical microscope can be used to determine the height gauge. The measured position is the surface of the abrasive particles or the surface of the bonding layer, and the distance between the tip of the abrasive particle and the surface of the bonding layer is calculated from the height of the tip of each abrasive particle and the height of the surface of the polishing layer, thereby calculating the abrasive. Exposure rate.

In the CMP polishing dresser having the optimum abrasive exposure rate of the present invention, the sampling amount of the height measuring device can be arbitrarily changed according to the user's demand or the quality of the trimmer required, wherein the height measuring device can be Measure 5 to 500 of the abrasive particles to obtain the measured abrasive exposure rate of the abrasive particles; in one aspect of the invention, the height measuring device can measure 20 of the abrasives Particles. Further, in the CMP polishing dresser having the optimum abrasive exposure rate of the present invention, the difference in the abrasive exposure rate of the abrasive particles measured may be less than 1/10 of the particle diameter of the abrasive particles, The abrasive particles have a uniform tip height and a flattened surface, thereby improving the abrasive performance of the chemical mechanical polishing dresser and reducing the occurrence of abrasive scratches; in one aspect of the invention, the abrasive particles are measured The difference in the abrasive exposure rate may be less than 1/20 of the particle size of the abrasive particles. In the CMP polishing dresser having the optimum abrasive exposure rate of the present invention, it is preferred that each of the abrasive particles has a fixed same exposure ratio to provide stable polishing quality. For example, in one aspect of the present invention, the height measuring device measures 20 abrasive particles having a particle size of 300 μm to obtain an abrasive exposure rate of 20 abrasive particles, and the abrasive exposure ratio of the abrasive particles is different. Within 30 micrometers, that is, the abrasive exposure rate (ie, 200 micrometers) is 2/3 of the particle diameter of the abrasive particles (ie, 300 micrometers), and the difference in the abrasive exposure ratio of the abrasive particles is smaller than the 1/10 of the particle size of the abrasive particles (ie, 300 micrometers), that is, the abrasive exposure of the abrasive particles is in the range of 185 micrometers to 215 micrometers; in another aspect of the invention, the same as described above Measuring the number and the same size of the abrasive particles, the abrasive particles have a difference in the abrasive exposure rate within 15 microns, that is, the abrasive exposure rate (ie, 200 microns) is the abrasive particles (ie, 300 microns) 2/3 of the particle size, And the difference in the abrasive exposure rate of the abrasive particles is less than 1/20 of the particle diameter of the abrasive particles (ie, 300 micrometers), that is, the abrasive exposure ratio of the abrasive particles is in the range of 192.5 micrometers to 207.5 micrometers.

In the CMP polishing dresser having the optimum abrasive exposure rate of the present invention, the abrasive particles may be synthetic diamond, natural diamond, polycrystalline diamond, or cubic boron nitride; in a preferred aspect of the present invention The abrasive particles are synthetic diamonds. In another aspect, in the CMP polishing dresser having the optimum abrasive exposure rate of the present invention, the abrasive particles may have a particle diameter of 30 micrometers to 600 micrometers; in one aspect of the invention, the abrasive particles The particle size is 300 microns.

In the CMP polishing dresser having the optimum abrasive exposure rate of the present invention, the composition of the bonding layer can be arbitrarily changed according to the conditions of the grinding process and the user's requirements, and the composition of the bonding layer can be ceramic material, brazing. The material, the plating material, the metal material, or the polymer material, the present invention is not limited thereto. In one aspect of the invention, the bonding layer may be composed of a solder material, and the solder material may be at least one selected from the group consisting of iron, cobalt, nickel, chromium, manganese, lanthanum, aluminum, and combinations thereof. . In another aspect of the invention, the composition of the bonding layer may be a polymer material, and the polymer material may be an epoxy resin, a polyester resin, a polyacrylic resin, or a phenolic resin. In addition, in the CMP polishing dresser having the optimum abrasive exposure rate of the present invention, the material and size of the substrate may be arbitrarily changed according to the conditions of the polishing process and the user's needs, wherein the substrate may be made of stainless steel or The mold steel, the metal alloy, or the ceramic material, the polymer material, or a combination thereof, is not limited thereto. In a preferred aspect of the invention, the substrate may be made of a stainless steel substrate.

1,2,3,4‧‧‧Chemical mechanical polishing dresser

10,30,40‧‧‧substrate

11,21,31,41‧‧‧bonding layer

12,121,122,22,32,42‧‧‧Abrasive particles

23‧‧‧ height gauge

24‧‧‧Light microscope

25‧‧‧ display device

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic illustration of a CMP polishing dresser having an optimum abrasive exposure rate in accordance with Example 1 of the present invention.

Figure 2 is a perspective view of the height measuring device of the present invention.

Figure 3 is a schematic illustration of a CMP polishing dresser having an optimum abrasive exposure rate in accordance with Example 2 of the present invention.

Figure 4 is a schematic illustration of a CMP polishing dresser having an optimum abrasive exposure rate in accordance with Example 3 of the present invention.

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

Example 1

Referring to Figure 1, there is shown a schematic view of a CMP polishing dresser having an optimum abrasive exposure rate. As shown in FIG. 1 , a substrate 10 made of stainless steel, a bonding layer 11 of a nickel-based metal solder, and a plurality of abrasive particles 12 are first provided, and then the abrasive particles 12 are buried and fixed by means of heat brazing. In the bonding layer 11, and the abrasive particles 12 are fixed on the substrate 10 by the bonding layer 11 to form a chemical mechanical polishing conditioner 1; The abrasive particles 12 are synthetic diamond particles having a particle size of 300 micrometers, and the abrasive particles 12 can be arranged in a conventional cloth drilling technique (for example, a template drill), and can be formed by a template (not shown). Controlling the pitch and arrangement of the abrasive particles 12, and the abrasive particles 12 are all directed upward to form a tip-grinding surface, or arbitrarily changed according to user requirements or processing conditions, the abrasive particles 12 Having the same or different tip orientation; wherein each of the abrasive particles 12 has an abrasive exposure rate, and the abrasive exposure rate is defined as the distance between the tips of the abrasive particles 12 and the surface of the bonding layer 11, which is suitable for the present invention. The abrasive exposure rate of the CMP mechanical polishing dresser is 1/4 to 3/4 of the particle diameter of the abrasive particles 12, so that the abrasive particles have both good coating properties and better grinding. Performance, in the embodiment 1, the abrasive particles 12 are artificial diamond particles having a particle diameter of 300 μm, and therefore, the abrasive exposure rate is between 75 μm and 225 μm; and then, referring to FIG. 2 , A perspective view of the height measuring device of the invention measures 20 tips of the abrasive particles 22 and the surface of the bonding layer 21 via a height gauge 23 and an optical microscope 24, and measures the tip of the abrasive particles 22 before measuring and then measures the surface of the bonding layer 21. (The optical microscope 24 determines the relative position measured by the height gauge 23), and the height difference between the two is the abrasive exposure rate to obtain the measured abrasive exposure rate of the abrasive particles 22, Referring to FIG. 1 and FIG. 2, the abrasive exposure rates of the abrasive particles 12 are D1, D2, D3, D4, D5, D6 to D20 (not shown), wherein D1 is matched by an optical microscope 24 and height. Obtained by the gauge 23, first, the height of the surface of the chemical mechanical polishing conditioner 2 is measured using the height gauge 23, and the optical microscope 24 is used in combination to determine the measurement position as the tip of the abrasive particles 22 or the surface of the bonding layer 21. Or, use this The optical microscope 24 positions the tip of the abrasive particle 12 corresponding to D1, and then measures the tip height of the abrasive particle 12 using the height gauge 23, and then uses the optical microscope 24 to position the surface of the bonding layer 21, and then uses the height. The gauge 23 measures the height of the surface of the bonding layer 21, and subtracts the obtained two heights to obtain a D1 value, and so on, to obtain D2, D3, D4, D5, D6 to D20 values; The results of the abrasive exposure measured by the abrasive particles 22 are displayed on the display device 25 to determine that the abrasive particles 22 can be provided as a chemical mechanical polishing conditioner 2 having an optimum abrasive exposure rate.

Referring to FIG. 1 and FIG. 2, in the first embodiment of the present invention, the abrasive particles 12 have a particle diameter of 300 micrometers, and the abrasive exposure rate is 1/4 to 3/4 of the particle diameter of the abrasive particles. The optimum abrasive exposure rate is 75 to 225 micrometers. Referring to FIG. 1, if the abrasive exposure rate of the abrasive particles 121 is greater than 225 micrometers, the adhesion of the bonding layer 11 to the abrasive particles 121 is poor, and the abrasive particles 121 are combined. The property is deteriorated, causing the abrasive particles 121 to be easily dropped during the grinding process; if the abrasive exposure rate of the abrasive particles 122 is less than 75 micrometers, the bonding layer 11 over-coats the abrasive particles 122 to make the abrasive particles 122 to the polishing pad. The cutting ability is deteriorated, resulting in poor grinding performance.

Example 2

Embodiment 2 is substantially the same as the CMP polishing dresser of the preferred abrasive exposure rate described in the foregoing Embodiment 1, except that Example 1 is that the abrasive exposure rate is 1/1 of the particle diameter of the abrasive particles. 4 to 3/4, and in Example 2, the abrasive exposure rate is 2/3 of the particle diameter of the abrasive particles, and the difference in the abrasive exposure rate of the abrasive particles is smaller than the particle diameter of the abrasive particles. 1/10. As shown in FIG. 3, the abrasive particles in the second embodiment of the present invention are artificial diamond particles having a particle diameter of 300 μm, the difference in the exposure rate of the abrasive is less than 30 μm, and the optimum abrasive exposure ratio of the abrasive particles is 185. In the range of micrometers to 215 micrometers, for example, referring to FIG. 3, values of D1, D2, D3, D4, D5, D6 to D20 (not shown) are preferably 185 micrometers to 215 micrometers, and in addition, values of D1 to D20 are mutually The difference in the exposure rate of the abrasive is less than 30 microns. When the difference in abrasive exposure ratio is less than 30 microns, the surface of the chemical mechanical polishing conditioner 3 is closer to a flat surface to provide the cutting ability of the abrasive particles 32 to the polishing pad (not shown) such that the abrasive particles 32 The polishing effect on the polishing pad is more stable. Conversely, if the difference in the exposure rate of the abrasive is greater than 30 μm, the grinding is concentrated on a small amount of the abrasive particles having a large exposure rate of the abrasive during the grinding process, so that the polishing performance of the dresser is deteriorated and the use of the dresser is shortened. life.

Example 3

Embodiment 3 is substantially the same as the CMP polishing dresser of the preferred abrasive exposure rate described in the foregoing Embodiment 2, except that the difference in the abrasive exposure ratio of the abrasive particles of Example 2 is smaller than the abrasive particles. The particle size is 1/10, and in Example 3, the difference in the abrasive exposure rate of the abrasive particles is less than 1/20 of the particle diameter of the abrasive particles. As shown in FIG. 4, the difference in the exposure rate measured by the abrasive particles 42 is less than 1/20 of the particle diameter of the abrasive particles 42. Therefore, the difference in the abrasive exposure rate is less than 15 micrometers, and the abrasive particles 42 The optimum abrasive exposure rate is in the range of 192.5 micrometers to 207.5 micrometers, so that a more flat chemical mechanical polishing dresser 4 can be obtained. The cutting ability of the abrasive particles 42 to the polishing pad is improved to stabilize the polishing performance and quality of the chemical mechanical polishing conditioner 4.

It can be seen from the above results that when the abrasive exposure rate is 1/4 to 3/4 of the particle diameter of the abrasive particles, the bonding layer is better for coating the abrasive particles, preventing the abrasive particles from falling off and the cutting ability being deteriorated. In addition, the smaller the difference in the exposure rate of the abrasive, the flat surface with uniform exposure rate of the abrasive particles can be obtained. Therefore, the abrasive particles have good cutting ability to the polishing pad to stabilize the chemical mechanical polishing dresser during the grinding process. Grinding performance and quality.

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.

1‧‧‧Chemical mechanical polishing dresser

10‧‧‧Substrate

11‧‧‧Combination layer

12,121,122‧‧‧Abrasive particles

Claims (12)

A CMP polishing dresser having an optimum abrasive exposure rate, comprising: a substrate; a bonding layer disposed on the substrate; and a plurality of abrasive particles embedded in the bonding layer And the abrasive particles are fixed on the substrate by the bonding layer; wherein each of the abrasive particles has an abrasive exposure rate, and the abrasive exposure rate is 1/4 to 3/ of the particle diameter of the abrasive particles. 4, and the abrasive exposure rate is measured by a height measuring device; the height measuring device comprises a height gauge and an optical microscope; the height gauge is used for measuring the height of a specific position, the specific position For these abrasive particle tips or the surface of the bonding layer. A CMP abrasive dresser having an optimum abrasive exposure rate as described in claim 1, wherein the abrasive exposure rate refers to a distance between the tip of the abrasive particle and the surface of the bonding layer. A CMP polishing dresser having an optimum abrasive exposure rate as described in claim 1, wherein the optical microscope is used to determine the relative position measured by the height gauge. A chemical mechanical polishing dresser having an optimum abrasive exposure rate as described in claim 1, wherein the height measuring device measures 5 to 500 of the abrasive particles to obtain the measured The abrasive exposure rate of some of the abrasive particles. The CMP polishing dresser having an optimum abrasive exposure rate as described in claim 4, wherein the difference in the abrasive exposure rate of the abrasive particles measured is less than 1 of the particle diameter of the abrasive particles. /10. The CMP polishing dresser having an optimum abrasive exposure rate as described in claim 4, wherein the difference in the abrasive exposure rate of the abrasive particles measured is less than 1 of the particle diameter of the abrasive particles. /20. A CMP abrasive dresser having an optimum abrasive exposure rate as described in claim 1, wherein the abrasive particles are synthetic diamonds, natural diamonds, polycrystalline diamonds, or cubic boron nitride. A CMP abrasive dresser having an optimum abrasive exposure rate as described in claim 1, wherein the abrasive particles have a particle size of from 30 micrometers to 600 micrometers. A chemical mechanical polishing dresser having an optimum abrasive exposure rate as described in claim 1, wherein the bonding layer is composed of a ceramic material, a brazing material, a plating material, a metal material, or a polymer material. A CMP abrasive dresser having an optimum abrasive exposure rate as described in claim 9, wherein the brazing material is at least one selected from the group consisting of iron, cobalt, nickel, chromium, manganese, lanthanum, aluminum, and A group of combinations. A CMP polishing dresser having an optimum abrasive exposure rate as described in claim 9 wherein the polymer material is an epoxy resin, a polyester resin, a polyacrylic resin, or a phenol resin. A CMP polishing dresser having an optimum abrasive exposure rate as described in claim 1, wherein the substrate is a stainless steel substrate, a mold steel substrate, a metal alloy substrate, a ceramic substrate, a polymer substrate, or a combination thereof.