JP2004306220A - Chemical mechanical polishing conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a CMP conditioner having good sharpness. <P>SOLUTION: In this CMP conditioner 1, super-abrasives 3 are fixed to the surface 2a of a metallic support 2. The super-abrasives 3 include first super-abrasives 4 bringing about a grinding action and second super-abrasives 5 having a small mean particle diameter than the first super-abrasives 4. The first super-abrasives 4 contain blocky super-abrasives 6 and angular super-abrasives 7, and the angular super-abrasives 7 is 3 mass % or more of the super-abrasives 3 of the CMP conditioner 1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a CMP conditioner comprising a grindstone for conditioning a polishing material such as a polishing pad used when a surface of a material to be polished such as a semiconductor wafer is polished by a CMP device (chemical mechanical polishing machine). About.
[0002]
[Prior art]
Conventionally, in a CMP apparatus, a polishing pad is attached to a disk-shaped surface plate, and a semiconductor wafer is mounted on an upper surface of the polishing pad. In this CMP apparatus, while a semiconductor wafer is rotated by a carrier on a polishing pad, a polishing liquid containing abrasive particles is supplied between the polishing pad and the semiconductor wafer, and the surface of the semiconductor wafer is chemically and mechanically polished. CMP (Chemical and Mechanical Polishing) is performed (for example, see Patent Document 1).
In general, as a polishing pad, a polishing pad formed by providing a hard foamed polyurethane on a nonwoven fabric substrate is used.
As the abrasive particles, ferrite powder, alumina powder, barium carbonate, colloidal silica, or the like is used. As the polishing liquid, a potassium hydroxide solution, a hydrogen peroxide solution, an aqueous solution of iron nitrate, an acidic solution of dilute hydrochloric acid or dilute nitric acid, or the like is used.
[0003]
When such a semiconductor wafer is repeatedly polished, chips and abrasive particles of the material to be polished enter the fine holes of the polishing pad, causing clogging, and polishing by the chemical reaction heat between the abrasive particles and the semiconductor wafer. The polishing surface of the pad becomes mirror-finished, and polishing accuracy and polishing efficiency are reduced.
For this purpose, a pad conditioner is provided in the CMP apparatus, and conditioning of the surface of the polishing pad is periodically performed. For conditioning a polishing pad, a CMP conditioner having good sharpness and long life is required.
[0004]
As such a CMP conditioner, there is one described in Patent Document 1. Next, a CMP conditioner described in Patent Document 1 will be described with reference to FIGS.
FIG. 11 is a diagram showing a conventional CMP conditioner, and is an enlarged sectional view of a main part showing a CMP conditioner comprising two types of superabrasive grains having the same particle size (average particle size).
As shown in FIG. 11, this CMP conditioner 100 has, in addition to the ordinary artificial metal bond diamond abrasive grains 140 having a grain size of # 100 fixed on the metal base metal 120 by the plating film 130, It is composed of those containing 3% by weight or more in total of tetrahedral or octahedral diamond abrasive grains 110 of the same grain size of $ 100.
[0005]
FIG. 12 is a diagram showing a conventional CMP conditioner, and is an enlarged sectional view of a main part showing a CMP conditioner comprising two types of superabrasive grains having different particle sizes (average particle sizes).
As shown in FIG. 12, the CMP conditioner 200 includes a superabrasive 240 made of a normal artificial metal bond diamond abrasive having a grain size of # 100 fixed on a metal base 220 by a plating film 230. In addition, it is configured to contain a tetrahedral or octahedral diamond abrasive grain 210 having a grain size of # 80 in a total amount of 3% by weight or more.
[0006]
Here, superabrasive grains 140 and 240 are formed of so-called angular diamond abrasive grains having corners formed at acute angles. The superabrasive grains 110 and 210 having a tetrahedral or octahedral shape are formed of so-called blocky diamond abrasive grains whose corners are formed at obtuse angles, and are equivalent to the particle diameters of ordinary superabrasive grains 140 and 240. Or, it is larger than the particle diameters of normal superabrasive grains 140, 240.
[0007]
[Patent Document 1]
JP-A-2002-1270011 (pages 2 to 4, FIG. 1)
[0008]
[Problems to be solved by the invention]
However, in the CMP conditioners 100 and 200 of Patent Document 1, since the corners of the blocky super abrasive grains 110 and 210 are formed at obtuse angles, the angular super sharp abrasive grains 140 and 210 have sharp corners. The sharpness is inferior to 240.
The CMP conditioner 200 shown in FIG. 12 has a sharp, blocky superabrasive grain 210 that is larger than the particle diameter of the angularly shaped superabrasive grain 240. Since the polished material is polished with the superabrasives 210, there is a problem that the sharpness of the entire CMP conditioner is poor.
[0009]
In the CMP conditioner 100 shown in FIG. 11, the unsharp, blocky super abrasive grains 110 and the angular super abrasive grains 140 are randomly arranged, or substantially concentric with the dresser for the polishing cloth. Although the abrasive grains are arranged at relatively equal intervals, on the entire working surface of the dresser for polishing cloth, there are many super-abrasive grains 140 having an irregular shape in vertical and horizontal dimensions, so that the distance between the abrasive grains of the super-abrasive grains 110 and 140 is large. The intervals are not equal but non-uniform. Therefore, it is impossible to exhibit stable polishing performance and obtain a uniform polished surface. Further, even if the polishing rate is arbitrarily adjusted, it is impossible to obtain a uniform polished surface. For example, where the gap between the abrasive grains is small, chips and abrasive particles generated by the polishing are not ejected and adhere between the abrasive grains, and clogging occurs, and the polishing performance of the CMP conditioner 100 is reduced and the polishing is performed. There is a problem that the surface becomes semi-mirror and the polishing rate is reduced.
[0010]
Further, in the conventional CMP conditioner, since the power of discharging chips and abrasive particles is poor, the surface of a semiconductor wafer (not shown) is damaged, and the yield is reduced. The clogging of the CMP conditioner causes a concentrated stress to be applied to the clogged portion, and drops off from the plating film 130 holding the superabrasive grains 110 and 140, thereby causing the surface of the semiconductor wafer (not shown) to fall. Scratch occurs, causing fatal damage.
[0011]
An object of the present invention is to provide a CMP conditioner that has a long life, is sharp, and has a regular abrasive grain spacing.
[0012]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, a CMP conditioner according to claim 1 is a CMP conditioner in which superabrasive grains are fixed to a surface of a base metal, wherein the superabrasive grains have a first superabrasive effect. Abrasive grains, and second super-abrasive grains having an average particle size smaller than the first super-abrasive grains, wherein the first super-abrasive grains include blocky super-abrasive grains and angular super-abrasive grains The angular super-abrasive grains are 3% by mass or more with respect to the super-abrasive grains of the CMP conditioner.
[0013]
According to the first aspect of the present invention, the CMP conditioner is sharpened by containing a predetermined amount of angular superabrasive grains having a high EEC value (eccentricity) and a sharp corner. In addition, the polishing operation time can be reduced.
In addition, the CMP conditioner contains blocky super-abrasive grains having a low EEC value (eccentricity), consistency and impact resistance, so that the blocky super-abrasive grains are coated on the angular super-abrasive grains. Since the pressure of the polished material is prevented from being applied and the cutting edge of the angular superabrasive grains is prevented from being broken, the life is extended.
Furthermore, the CMP conditioner can hold the first superabrasive grains at a desired interval by the second superabrasive grains by containing the second superabrasive grains having an average particle size smaller than the first superabrasive grains. It becomes.
The CMP conditioner has a first super-abrasive made of blocky and angular super-abrasives and a second super-abrasive having an average particle diameter smaller than the first super-abrasive. The super-abrasive grains on the polished surface of the chip can be prepared in a well-balanced manner, and the second super-abrasive grains can prevent the first super-abrasive grains from falling off, thereby extending the life of the CMP conditioner.
[0014]
A CMP conditioner according to a second aspect is the CMP conditioner according to the first aspect, wherein the second superabrasive grains are made of blocky superabrasive grains.
[0015]
According to the invention as set forth in claim 2, the CMP conditioner is configured such that the second superabrasive grains having an average particle diameter smaller than the first superabrasive grains are made of blocky superabrasive grains, Since the first superabrasive grains having a large average particle diameter are formed in a highly consistent shape, the distance between the first superabrasive grains can be adjusted and the first superabrasive grains can be arranged in a stable state.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to FIGS.
In the description of the embodiment and each example, the same components will be denoted by the same reference symbols, without redundant description.
[0017]
First, the CMP conditioner will be described.
FIG. 1 is an enlarged sectional view of a main part showing a CMP conditioner according to an embodiment of the present invention. FIG. 2 is an enlarged plan view of a main part of the CMP conditioner according to the embodiment of the present invention.
[0018]
As shown in FIGS. 1 and 2, the CMP conditioner 1 has super abrasive grains 3 fixed to a surface 2 a of a base metal 2. The base metal 2 is a substrate made of metal such as stainless steel, and has, for example, a disk shape, a ring shape, or the like. The shape of the base 2 is not particularly limited.
[0019]
The superabrasive grains 3 include a first superabrasive grain 4 that provides a polishing action, and a second superabrasive grain 5 having an average particle diameter (hereinafter, simply referred to as “grain size”) smaller than the first superabrasive grain 4. are doing. The superabrasive grains 3 are, for example, abrasive grains made of artificial diamond, and are fixed to the surface 2a of the base metal 2 by a plating layer 9 electrodeposited or the like. The method of fixing the superabrasive grains 3 to the base metal 2 may be, for example, brazing or metal bonding, and is not particularly limited.
[0020]
The first superabrasive grains 4 are abrasive grains which are polished in contact with a material to be polished (not shown). For example, the first superabrasive grains 4 are made of diamond abrasive grains having a grain size of $ 100. Preferably 37% by mass. And the remainder becomes the blocky second superabrasive grains 5. The first superabrasive grains 4 preferably contain 3 to 12.5% of angular superabrasive grains 7 with respect to the superabrasive grains 3 of the CMP conditioner 1.
In addition, 3 to 12.5 mass% with respect to the superabrasive grains 3 of the CMP conditioner 1 is referred to as “an angular superabrasive grain is 3 mass% or more with respect to the superabrasive grains of the CMP conditioner” in the claims. Corresponding to the content ratio.
[0021]
The blocky superabrasive grains 6 are composed of diamond grains having a cubic octahedral structure, the shapes of the abrasive grains are uniform, and the corners are formed at obtuse angles. The blocky superabrasive grains 6 are low in impurities in the crystal, lattice strain, and ECC value (eccentricity), and have high heat resistance, impact resistance, and shear resistance. The blocky superabrasives 6 correspond to, for example, superabrasives MBG (registered trademark; hereinafter abbreviated) -620T and MBG-640T manufactured by General Electric.
[0022]
The angular super abrasive grains 7 are formed of diamond abrasive grains having sharp corners. Compared with the blocky super-abrasive 6, the angular super-abrasive 7 has a high ECC value (eccentricity) and the shape of the abrasive is not uniform, but has a sharp cutting edge surface and a high friability. Abrasive grains. The angular super abrasive grains 7 correspond to super abrasive grains MBG-600T manufactured by General Electric.
[0023]
The second superabrasive grains 5 are small abrasive grains arranged between the first superabrasive grains 4, 4,..., For example, are made of diamond abrasive grains having a grain size of # 140. The second superabrasive grains 5 preferably contain, for example, 63% by mass of the blocky superabrasive grains 8 with respect to the superabrasive grains 3 of the CMP conditioner 1. The blocky super-abrasive grains 8 are made of diamond grains having a cubo-octahedral structure smaller than the blocky super-abrasive grains 6, and the corners are formed at an obtuse angle. The blocky super-abrasive grains 8 have a low ECC value (eccentricity) as described above, and therefore have high consistency.
[0024]
As described above, the CMP conditioner 1 according to the present invention includes an angular superabrasive grain 7 having a polishing action, a blocky superabrasive grain 6 having a grain size substantially the same as the angular superabrasive grain 7, and an angular superabrasive grain. It has superabrasive grains obtained by mixing with blocky superabrasive grains 8 having a smaller grain size than grains 7.
[0025]
Thus, when the object to be polished is polished, the object to be polished can be sharply polished by the sharp, angular super-abrasive grains 7 protruding most from the base metal 2. Since the blocky super-abrasive grains 6 have the same average diameter as the angular super-abrasive grains 7, when a large polishing load is applied to the object to be polished on the CMP conditioner 1, the blocky super-abrasive grains 6 have impact resistance. Since superabrasive grains 6 receive the polishing load, it is possible to prevent a large polishing load from being applied to angular superabrasive grains 7. The CMP conditioner 1 contains more blocky super-abrasive grains 6 than the angular super-abrasive grains 7 containing 3 to 12.5% by mass. Super abrasive grains 7 can be prevented from being worn. Therefore, the pad dressing rate (polishing ratio: polishing amount) of the CMP conditioner 1 can be stabilized for a long time.
[0026]
Further, between the angular super-abrasive grains 7 having a large grain size and the blocky super-abrasive grains 6, there is a blocky super-abrasive grain 8 having a small grain size. The gap between the super-abrasive 6 and the blocky super-abrasive grains 6 can be kept good, and the polished surface of the CMP conditioner 1 can be adjusted.
For this reason, in the polishing pad on which the CMP conditioning is performed by the CMP conditioner 1, the second super-abrasive grains 5 having a small grain size are made of the blocky super-abrasive grains 8, and the super-abrasive grains 8 are roughened. It is possible to adjust the surface of the polishing pad after the polishing is performed by the superabrasive grains 6 and 7 (the first superabrasive grains 4) having a large grain size while slightly polishing the surface.
As shown in FIG. 1, the super-abrasive grains 8 are contained at a ratio of 41 to 85% by mass with respect to the super-abrasive grains 3 of the CMP conditioner 1 so that the angular super-abrasive grains 7 and the blocky Since the spacing between the abrasive grains of the superabrasive grains 6 is widened, chips and abrasive particles generated by polishing can be easily discharged, and the occurrence of clogging due to adhesion between the abrasive grains can be reduced. Thereby, the superabrasives 8 can prevent the polishing performance of the CMP conditioner 1 from being reduced, the polishing surface being semi-mirrored, and the polishing speed from being reduced.
[0027]
In addition, the CMP conditioner 1 can control sharpness by controlling the number of angular super abrasive grains 7 and blocky super abrasive grains 6 having a large grain size acting on polishing.
[0028]
Next, the manufacturing method of the present invention will be described with reference to FIGS.
FIG. 3 is a view showing a state when the CMP conditioner according to the present invention is manufactured, and is a schematic view showing a state when a plating layer is formed on a base metal.
[0029]
First, the base metal 2 (see FIG. 3) having a substantially disk shape is prepared by machining stainless steel (for example, austenitic stainless steel SUS304).
Next, the surface 2a of the base metal 2 is insulated with a tape (not shown) and a masking paint (see FIG. 4), leaving an abrasive electrodeposited surface 2b for electrodepositing superabrasive particles (diamond abrasive particles) on the base metal 2. (Not shown) to perform a masking process.
[0030]
Then, the base metal 2 is brushed and washed with a neutral detergent, and an alkaline electrolytic degreasing process is performed.
Next, the base metal 2 was immersed in a pretreatment agent containing 220 g / L of nickel chloride and 100 g / L of hydrochloric acid, and the current density was 3 A / dm. ² At 40 ° C., the nickel plate 10 was set on the anode (+) side and the base metal 2 was set on the cathode (−) side, and strike plating was performed to improve the adhesion and covering power of the nickel plating. For 10 minutes.
Subsequently, as shown in FIG. 3, the nickel plate 10 is set on the anode (+) side, and the base metal 2 is set on the cathode (−) side, so that the nickel plate 10 is placed in a nickel sulfamate plating bath or a watt nickel plating bath 11. Immersion and current density 1A / dm ² For 5 minutes to form a base plating layer (not shown) of 3 μm.
[0031]
FIG. 4 is a view showing a state when the CMP conditioner according to the present invention is manufactured. A blocky super-abrasive grain having a grain size of $ 100 and an angular super-abrasive grain having a grain size of $ 100 are formed on the electrodeposited surface of the base metal. It is a principal part expanded schematic sectional view which shows the state at the time of dispersing | distributing the mixture of the abrasive grain and the blocky super-abrasive grain with a particle size of # 140. FIG. 5 is a diagram illustrating a state when the CMP conditioner according to the present invention is manufactured. FIG. 5 is an enlarged schematic cross-sectional view of a main part illustrating a state when the first plating layer is formed on the electrodeposited surface of the base metal. is there.
[0032]
Next, as shown in FIG. 3 and FIG. 4, 32% by mass of blocky superabrasive grains (diamond abrasive grains) 6 having a grain size of $ 100 are formed on the abrasive grain electrodeposition surface 2b of the base metal 2 to be electrodeposited. A mixture of 5% by mass of # 100 angular super-abrasive grains (diamond abrasive grains) 7 and 63% by mass of blocky super-abrasive grains (diamond abrasive grains) 8 of # 140 grain size are spread without gaps.
Then, it is immersed in a nickel sulfamate plating bath or a watt nickel plating bath 11 to which additives such as plating stress and hardness adjustment have been added, and the current density is 0.2 A / dm. ² Plating for 60 minutes. Then, superabrasive grains (diamond abrasive grains) 3 are embedded and temporarily fixed in first plating layer 91 formed of a single layer. The electrodeposition is a technique of generating a nickel thin film by applying electricity to the base metal 2, and a uniform thin film can be formed even with a complicated shape.
After that, when excess superabrasive grains (diamond abrasive grains) 3 are washed off, a state as shown in FIG. 5 is obtained.
[0033]
FIG. 6 is a diagram showing a state when the CMP conditioner according to the first embodiment of the present invention is manufactured, and is an enlarged schematic sectional view showing a state when the second plating layer is formed on the base metal.
[0034]
Further, the current density is 1 A / dm. ² Buried plating for 150 minutes. Then, a second plating layer 92 (see FIG. 6) is formed on the first plating layer 91 (see FIG. 5), and the thickness of the plating layer 9 is increased. The particles 3 are fixed to the abrasive electrodeposition surface 2 b of the base metal 2. Thereafter, the super-abrasive grains (diamond abrasive grains) 31 serving as floating stones are removed by brushing the electrodeposited abrasive grain surface 2b on which the super-abrasive grains (diamond abrasive grains) 3 are electrodeposited, as shown in FIG. State.
[0035]
Subsequently, an alkaline electrolytic degreasing treatment is performed (not shown).
Next, as shown in FIG. 3, the base metal 2 was immersed in a pretreatment agent containing 220 g / L of nickel chloride and 100 g / L of hydrochloric acid, and the current density was 3 A / dm. ² At 40 ° C., the base metal 2 is set on the cathode (−) side, the nickel plate 10 is set on the anode (+) side, and strike plating is performed for 5 minutes (not shown).
[0036]
Subsequently, it was immersed in a nickel sulfamate plating bath or a nickel plating bath 11 to obtain a current density of 1 A / dm. ² Buried plating for 180 minutes.
Then, as shown in FIG. 1, a third plating layer 93 is formed on the second plating layer 92, and the thickness of the plating layer 9 is further increased. Abrasive grains 6, angular superabrasive grains 7 having a grain size of $ 100, and blocky superabrasive grains 8 having a grain size of # 140 are embedded and completely fixed. At this time, the thickness of the plating layer 9 is about 90 μm in total.
[0037]
Next, all the masking is removed, and the base metal 2 on which the superabrasive grains (diamond abrasive grains) 3 have been electrodeposited is ultrasonically cleaned for 30 minutes, and the abrasive grain electrodeposited surface 2b is carefully brushed (not shown). .
Thereafter, ultrasonic cleaning is performed again for 30 minutes to completely remove the super-abrasive grains (diamond abrasive grains) 31 of the floating stone and the crushed super-abrasive grains (diamond abrasive grains), and then dry the CMP conditioner 1 (see FIG. 1). ) Can be obtained.
[0038]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples.
[First embodiment]
First, a first embodiment of the present invention will be described with reference to FIGS.
In the first embodiment, a CMP conditioning test was performed using the CMP conditioner 1.
The CMP conditioning test measures a pad dressing rate (abrasion amount of a polishing pad), and uses a polishing machine [ECOMET4, manufactured by Buehler Co., Ltd.] and a polishing pad [IC-1000, manufactured by Rodel-Nitta] to remove silica fine particles. The polishing load was 19.6 kPa and the polishing pad rotation speed was 100 min using the contained potassium hydroxide aqueous solution having a pH of 10.5 as a polishing liquid. ^-1 , Rotation speed of CMP conditioner 1 56min ^-1 And the conditioning time was 2 minutes.
[0039]
FIG. 7 is a table showing a pad dressing rate as a result of a conditioning test of the CMP conditioners manufactured in the first to fourth examples of the present invention and the comparative example 1. FIG. 8 is a bar graph showing a pad dressing rate as a result of a dressing test of the CMP conditioners manufactured in the first to fourth examples and the comparative example 1 of the present invention.
[0040]
As shown in FIGS. 7 and 8, the pad dressing rate (wear of the polishing pad) of the first embodiment of the CMP conditioner 1 containing 5% by mass of the angular super abrasive grains (diamond abrasive grains) 7 having a grain size of $ 100. Amount) was 221 μm / h.
[0041]
[Second embodiment]
In the second embodiment, the CMP conditioner 1 is manufactured by changing the mixing ratio of the superabrasive grains 3 by the same manufacturing method as in the first embodiment.
In the second embodiment, the ratio of the superabrasive grains 3 dispersed and mixed on the abrasive electrodeposited surface 2b was changed to 27% by mass of blocky superabrasive grains (diamond abrasive grains) 6 having a grain size of $ 100, The CMP conditioner 1 was made from a mixture of 10% by mass of angular super abrasive grains (diamond abrasive grains) 7 having a particle size of $ 100 and 63% by mass of blocky super abrasive grains (diamond abrasive particles) 8 having a particle size of # 140. .
This CMP conditioner 1 performed the same CMP conditioning test as in the first embodiment.
As shown in FIGS. 7 and 8, the pad dressing rate (wear of the polishing pad) of the second embodiment of the CMP conditioner 1 containing 10% by mass of angular super abrasive grains (diamond abrasive grains) 7 having a grain size of # 100. Amount) was 330 μm / h.
[0042]
[Third embodiment]
In the third embodiment, the CMP conditioner 1 is manufactured by changing the mixing ratio of the superabrasive grains 3 by the same manufacturing method as the first embodiment.
In the third embodiment, the ratio of the superabrasive grains 3 dispersed and mixed on the electrodeposition surface 2b of the abrasive grains was changed to 18.5% by mass of blocky superabrasive grains (diamond abrasive grains) 6 having a grain size of $ 100. CMP conditioner with a mixture of 18.5% by mass of angular super abrasive grains (diamond abrasive grains) 7 having a grain size of $ 100 and 63 mass% of blocky super abrasive grains (diamond abrasive grains) 8 having a grain size of # 140 1 was produced.
This CMP conditioner 1 performed the same CMP conditioning test as in the first embodiment.
As shown in FIGS. 7 and 8, the pad dressing rate (polishing pad) of the third embodiment of the CMP conditioner 1 containing 18.5% by mass of angular super abrasive grains (diamond abrasive grains) 7 having a grain size of $ 100. Was 370 μm / h.
[0043]
[Fourth embodiment]
In the fourth embodiment, the CMP conditioner 1 is manufactured by changing the mixing ratio of the superabrasive grains 3 by the same manufacturing method as the first embodiment.
In the fourth embodiment, the ratio of the superabrasive grains 3 dispersed and mixed on the electrodeposition surface 2b of the abrasive grains was set to 10% by mass of the blocky superabrasive grains (diamond abrasive grains) 6 having a grain size of $ 100. The CMP conditioner 1 was made of a mixture of 27% by mass of an angular super abrasive (diamond abrasive) 7 having a particle size of $ 100 and 63% by mass of a blocky super abrasive (diamond abrasive) 8 having a particle size of # 140. .
This CMP conditioner 1 performed the same CMP conditioning test as in the first embodiment.
As shown in FIGS. 7 and 8, the pad dressing rate (wear of the polishing pad) of the fourth embodiment of the CMP conditioner 1 including 27% by mass of the angular super abrasive grains (diamond abrasive grains) 7 having a grain size of # 100. Amount) was 550 μm / h.
[0044]
[Comparative Example 1]
Comparative Example 1 is the same manufacturing method as in the first embodiment, except that the mixing ratio of the superabrasive grains 3 is changed and the CMP conditioner 1 does not include the angular superabrasive grains (diamond abrasive grains) 7 having a grain size of $ 100. Was produced.
In Comparative Example 1, the ratio of the superabrasive grains 3 dispersed and mixed on the abrasive electrodeposited surface 2b was set to 37 mass% of the blocky superabrasive grains (diamond abrasive grains) 6 having a grain size of $ 100, A CMP conditioner 1 was prepared using a mixture of 0% by mass of # 100 angular super abrasive grains (diamond abrasive grains) 7 and 63% by mass of blocky super abrasive grains (diamond abrasive grains) 8 of # 140 grain size.
This CMP conditioner 1 performed the same CMP conditioning test as in the first embodiment.
As shown in FIG. 7 and FIG. 8, the pad dressing rate (the polishing pad of the polishing pad) of Comparative Example 1 of the CMP conditioner 1 which does not contain 0% by mass of the angular super-abrasive grains (diamond abrasive grains) having a grain size of $ 100. Wear amount) was 187 μm / h.
[0045]
As shown in FIG. 7, the CMP conditioner 1 containing the angular super abrasive grains (diamond abrasive grains) 7 having a grain size of # 100 of the first to fourth embodiments is different from the angular super abrasive grains (diamond abrasive grains). Compared with Comparative Example 1 containing no diamond abrasive particles 7, the sharpness of the polishing pad was good and the pad dressing rate was high.
Further, in the CMP conditioners 1 manufactured in the first to fourth examples and the comparative example 1, wear of the tips of the superabrasive grains 3 was not observed within the test ranges respectively performed, and the wear resistance was low. It was expensive and had a long life.
The angular super-abrasive grains 7 contained in the CMP conditioner 1 of the present invention have many portions where the crystal morphology is sharp, and therefore are compared with the case where only the blocky super-abrasive grains (diamond abrasive grains) 6 are used. It is sharp. The CMP conditioner 1 contains the blocky super-abrasive grains (diamond abrasive grains) 6 so that the polishing load applied to the angular super-abrasive grains (diamond abrasive grains) 7 is reduced by the blocky super-abrasive grains (diamond abrasive grains). ) 6 to reduce the polishing load, so that the life can be extended. Therefore, the pad dressing rate can be stabilized for a long time.
Further, as shown in FIG. 8, the CMP conditioner 1 adjusts the content ratio of the angular super abrasive grains (diamond abrasive grains) 7 so that the sharpness (patting dressing rate) of the polishing pad varies depending on the polishing conditions. Can be controlled.
[0046]
[Comparative Example 2]
Next, Comparative Example 2 will be described with reference to FIG.
FIG. 9 is an enlarged sectional view of a principal part showing a comparative example 2 of the CMP conditioner.
Comparative Example 2 is the same manufacturing method as that of the first embodiment, except that the mixing ratio of the superabrasive grains 3 is changed, and the angular second superabrasive grains (diamond abrasive grains) are used as the small second superabrasive grains 5 having a grain size of $ 140. 12), and a CMP conditioner 1 containing no small blocky superabrasive grains (diamond abrasive grains) 8 having a grain size of # 140.
In Comparative Example 2, the ratio of the superabrasive grains 3 dispersed and mixed on the abrasive grain electrodeposition surface 2b was changed to 27% by mass of the blocky # 100 superabrasive grains (diamond abrasive grains) 6 and the angular # 100 The CMP conditioner 1 was produced from a mixture in which 10% by mass of superabrasive particles (diamond abrasive particles) 7 and 63% by mass of angular # 140 superabrasive particles (diamond abrasive particles) 12 were prepared.
[0047]
[Fifth embodiment]
Next, a fifth embodiment will be described with reference to FIG.
In the fifth example, the surface condition of the polishing pad after the CMP conditioning was observed with a stereoscopic microscope using the CMP conditioners 1 manufactured in the second example and the comparative example 2, respectively.
Comparing the polishing pad surface after the CMP conditioning with the CMP conditioner 1 manufactured in the second example and the CMP conditioner 1 manufactured in the comparative example 2, respectively, the conditioner 1 manufactured in the second example is However, the scratches on the surface of the polishing pad were small and shallow, and in the conditioner 1 prepared in Comparative Example 2, many large and deep scratches were observed on the surface of the polishing pad.
This is because, in comparison with the second embodiment in which the second superabrasive grains 5 having a small particle size were changed to blocky superabrasive grains 8 (see FIG. 1), Comparative Example 2 This is due to the fact that the abrasive grains 12 were used.
In CMP conditioning, polishing is substantially performed by superabrasive grains 6, 7 (first superabrasive grains 4) having a large grain size, and polishing pad is formed by superabrasive grains 8, 12 (second superabrasive grains 5) having a small grain size. The rough surface is adjusted. Since the angular super abrasive grains 12 have sharp corners, they have a high polishing power and do not contribute much to the roughness adjustment.
On the other hand, since the blocky superabrasive particles 8 only slightly polish the rough surface of the polishing pad due to the obtuse angle and the small polishing force, the surface of the polishing pad does not generate new scratches, The large super-abrasive grains 6 and 7 (the first super-abrasive grains 4) can adjust the rough surface of the polishing pad that has been substantially polished. Therefore, in the present invention, the second superabrasive grains 5 having a small particle size used for the CMP conditioner 1 have only a blocky shape.
[0048]
Next, the abrasive grains used in the first to fourth embodiments will be described with reference to FIG.
FIG. 10 is a graph in which the data of FIG. 8 is represented by a line graph, and an upper limit, a target value, and a lower limit are given.
In FIG. 10, the solid line a represents the pad dressing rate μm / h of the data tested in the first to fourth embodiments. A broken line b is an approximate value graph (line) of the solid line a. An alternate long and short dash line c is the maximum value (pass upper limit) of the pad dressing rate μm / h desired to be provided as the CMP conditioner 1. The two-dot chain line d is the minimum value (lower limit) of the pad dressing rate μm / h desired to be provided as the CMP conditioner 1. A broken line e is a target value of the pad dressing rate μm / h desired to be provided as the CMP conditioner 1.
The pad dressing rate μm / h indicates the removal amount of the polishing pad by polishing.
[0049]
As shown in FIG. 10, the test result of the pad dressing rate (Comparative Example 1) when the mixing ratio of the angular superabrasive grains MGB-600T is 0% by mass is 187 μm / h.
The test result of the pad dressing rate μm / h (first example) when the mixing ratio of the angular superabrasive grains MGB-600T is 5% by mass is 221 μm / h.
The test result (second example) of the pad dressing rate μm / h when the mixing ratio of the angular superabrasive grains MGB-600T is 10% by mass is 330 μm / h.
The test result of the pad dressing rate μm / h (third example) when the mixing ratio of the angular superabrasive grains MGB-600T is 18.5% by mass is 370 μm / h.
The test result of the pad dressing rate μm / h (fourth example) when the mixing ratio of the angular superabrasive grains MGB-600T is 27% by mass is 550 μm / h.
[0050]
As described above, the value of the pad dressing rate increases in proportion to an increase in the mixing ratio% of the angular superabrasive grains MGB-600T. The superabrasive grains MGB-600T are made of angular diamond grains having sharp corners and sharp cutting edges.
For this reason, in the CMP conditioner 1, the value of the pad dressing rate μm / h increases and the sharpness increases by increasing the content of the angular superabrasive grains MGB-600T.
[0051]
Angular diamond abrasives use coarse abrasives for higher pad dressing rates. If the value of the pad dressing rate μm / h exceeds the maximum value (c: upper limit of acceptance), the surface roughness of the polished surface of the material to be polished becomes rough, and the surface property is sacrificed. Conversely, when determining the surface properties of the polished surface, the pad dressing rate is sacrificed. Therefore, the pad dressing rate μm / h is optimally not less than 220 μm / h (d: lower limit of acceptance) and not more than 331 μm / h maximum (c: upper limit of acceptance) shown in FIG. Good surface properties can be obtained.
At the pad dressing rate μm / h of the approximation line b in FIG. 10, the mixing ratio of the superabrasive grains MGB-600T from the minimum value (d: lower limit of acceptance) to the maximum value (c: upper limit of acceptance) is determined according to the experimental data. , And about 3 to 12.5% by mass, and this about 3 to 12.5% by mass is the range f of the optimum mixing ratio of the angular diamond abrasive grains.
[0052]
As shown in FIG. 2, the second superabrasive grains 5 contain the second superabrasive grains 5 having a smaller particle size than the first superabrasive grains 4 in the first superabrasive grains 4 having the above-described mixing ratio. Accordingly, the first superabrasive grains 4 can be arranged in a well-balanced manner, so that the polishing surface of the CMP conditioner 1 can be adjusted.
[0053]
It should be noted that the CMP conditioner 1 according to the present invention is not limited to the above embodiment and the first to fourth examples, and various modifications and changes are possible within the scope of the technical idea. The invention naturally extends to these modified and modified inventions.
[0054]
【The invention's effect】
As described above, according to the CMP conditioner according to claim 1 of the present invention, the CMP conditioner has a sharpness by containing a predetermined amount of angular superabrasive grains having a high EEC value (eccentricity). And the polishing operation time can be shortened.
In addition, the CMP conditioner contains blocky super-abrasive grains having a low EEC value (eccentricity), consistency and impact resistance, so that the blocky super-abrasive grains are coated on the angular super-abrasive grains. A CMP conditioner having a long life and a stable pad dressing rate for a long period of time can be provided in order to prevent pressure of the polished object from being applied and to prevent breakage of the angular superabrasive cutting edge.
Furthermore, the CMP conditioner can hold the first superabrasive grains at a desired interval by the second superabrasive grains by including the second superabrasive grains having a smaller particle size than the first superabrasive grains. .
The CMP conditioner has a first superabrasive grain composed of blocky and angular superabrasive grains, and a second superabrasive grain having a smaller grain size than the first superabrasive grain. The super-abrasive grains on the polished surface can be prepared in a well-balanced manner, and the second super-abrasive grains can prevent the first super-abrasive grains from falling off, thereby extending the life of the CMP conditioner.
[0055]
According to the CMP conditioner of claim 2, the CMP conditioner is configured such that the second superabrasive grains having a smaller particle size than the first superabrasive grains are made of blocky superabrasive grains, Since the first super-abrasive grains having a large grain size are formed, the intervals between the first super-abrasive grains having a large grain size can be adjusted and the first super-abrasive grains can be arranged in a stable state.
[Brief description of the drawings]
FIG. 1 is an enlarged sectional view of a main part showing a CMP conditioner according to an embodiment of the present invention.
FIG. 2 is an enlarged plan view showing a main part of the CMP conditioner according to the embodiment of the present invention.
FIG. 3 is a view showing a state when a CMP conditioner according to the present invention is manufactured, and is a schematic view showing a state when a plating layer is formed on a base metal.
FIG. 4 is a view showing a state when a CMP conditioner according to the present invention is manufactured, wherein a blocky super-abrasive grain having a grain size of $ 100 and an angular super-abrasive grain having a grain size of $ 100 are formed on the electrodeposited surface of the base metal. It is a principal part expanded schematic sectional view which shows the state at the time of dispersing | distributing the mixture of the abrasive grain and the blocky super-abrasive grain with a particle size of # 140.
FIG. 5 is a diagram showing a state when the CMP conditioner according to the present invention is manufactured, and is an enlarged schematic cross-sectional view of a main part showing a state when a first plating layer is formed on an electrodeposited abrasive grain surface of a base metal. is there.
FIG. 6 is an enlarged schematic cross-sectional view showing a state when the CMP conditioner according to the first embodiment of the present invention is manufactured, and showing a state when a second plating layer is formed on a base metal.
FIG. 7 is a table showing a pad dressing rate as a result of a conditioning test of the CMP conditioners manufactured in the first to fourth examples and the comparative example 1 of the present invention.
FIG. 8 is a bar graph showing a pad dressing rate as a result of a dressing test of the CMP conditioners manufactured in the first to fourth examples and the comparative example 1 of the present invention.
FIG. 9 is an enlarged sectional view of a main part showing a comparative example 2 of the CMP conditioner.
FIG. 10 is a graph in which the data of FIG. 8 is represented by a line graph, and an upper limit value, a target value, and a lower limit value are added.
FIG. 11 is a diagram showing a conventional CMP conditioner, and is an enlarged sectional view of a main part showing a CMP conditioner comprising two types of superabrasive grains having the same particle size (average particle size).
FIG. 12 is a diagram showing a conventional CMP conditioner, and is an enlarged sectional view of a main part showing a CMP conditioner comprising two types of superabrasive grains having different particle sizes (average particle sizes).
[Explanation of symbols]
1 CMP conditioner
2 gold
2a surface
2b Abrasive electrodeposited surface
3 super abrasive
4 First super abrasive
5 Second super abrasive
6,8 Blocky super abrasive
7,12 Angular super abrasive

Claims (2)

A CMP conditioner in which superabrasive grains are fixed to the surface of a base metal,
The super-abrasive has a first super-abrasive that provides a polishing action, and a second super-abrasive having an average particle diameter smaller than the first super-abrasive,
The first superabrasive contains a blocky superabrasive and an angular superabrasive, and the angular superabrasive is 3% by mass or more based on the superabrasive of the CMP conditioner. A CMP conditioner characterized by the following. The CMP conditioner according to claim 1, wherein the second superabrasive grains are made of blocky superabrasive grains.

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