JP2009267187A - Chemical mechanical polishing pad and chemical mechanical polishing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chemical mechanical polishing pad which has a high polishing speed and is superior in flatness of a polished surface and causes less scratches, and to provide a chemical mechanical polishing method using the same. <P>SOLUTION: The chemical mechanical polishing pad has a polishing layer containing a component (A): 100 pts.vol. of ionomer resin and a component (B): 5 to 80 pts.vol. of water-soluble particles, wherein the component (A) contains a component (a1): 100 pts.mass of ethylene-(meth)acrylate copolymer and a component (a2): 1 to 20 pts.mass of a metal oxide or a metal hydroxide. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a chemical mechanical polishing pad and a chemical mechanical polishing method.

  In the manufacture of semiconductor devices and the like in recent years, a chemical mechanical polishing method (generally abbreviated as “CMP”) is widely used as a polishing method capable of forming a surface having excellent flatness. Yes. In this chemical mechanical polishing method, it is known that the polishing result varies greatly depending on the material of the chemical mechanical polishing pad, and chemical mechanical polishing pads having various compositions have been proposed.

  For example, JP-A-2002-134445 discloses a polishing pad made of a composition having a crosslinked elastomer and a polymer having a carboxyl group. Further, for example, JP 2004-343099 A discloses a polishing pad comprising a crosslinked diene elastomer and (B) a polymer having an acid anhydride structure. Furthermore, for example, Japanese Patent Application Laid-Open No. 2002-137160 discloses a polishing pad containing a hydrophilic and substantially water-insoluble filler. In addition, for example, JP-A-2001-239453 discloses a polishing pad containing a polymer polymerized from polyurethane and a vinyl compound.

However, with these polishing pads, it is difficult to achieve a uniform composition, and there are cases where it is impossible to ensure both the polishing rate and the flattening performance.
JP 2002-134445 A JP 2004-343099 A JP 2002-137160 A JP 2001-239453 A

  The present invention is a chemical mechanical polishing pad having a high polishing rate, excellent flatness of the surface to be polished (in-plane uniformity of the polishing amount on the surface to be polished), and having few scratches, and chemical mechanical polishing using the polishing pad Provide a method.

The chemical mechanical polishing pad according to one embodiment of the present invention is as follows.
(A) component; 100 parts by volume of ionomer resin;
(B) component; 5-80 volume parts of water-soluble particles;
Having a polishing layer comprising
The component (A) includes (a1) component; 100 parts by mass of an ethylene- (meth) acrylic acid copolymer, and (a2) component; 1 to 20 parts by mass of metal oxide or metal hydroxide.

  In the chemical mechanical polishing pad, the component (a2) may be a divalent metal oxide or a metal hydroxide. In this case, the component (a2) can be at least one selected from the group consisting of zinc oxide, magnesium oxide, zinc hydroxide, and magnesium hydroxide.

  In the chemical mechanical polishing pad, an average particle size of the component (B) may be 5 to 80 μm.

  In the chemical mechanical polishing pad, the (meth) acrylic acid content of the component (a1) may be 3 to 25% by mass.

  In the chemical mechanical polishing pad, the component (a1) may be a copolymer with at least one selected from the group consisting of acrylic acid, methacrylic acid, methyl acrylate, and ethyl acrylate.

  In the chemical mechanical polishing pad, the component (A) may be crosslinked with (C) an organic peroxide.

A chemical mechanical polishing method according to another embodiment of the present invention includes:
A step of chemically and mechanically polishing an object to be polished using the chemical mechanical polishing pad;

  In the chemical mechanical polishing method, the object to be polished may include silicon oxide.

  According to the chemical mechanical polishing pad and the chemical mechanical polishing method, in chemical mechanical polishing, it is possible to obtain a polished surface having a high polishing rate, excellent in-plane uniformity of the polishing amount, and few scratches.

  Hereinafter, a chemical mechanical polishing pad and a chemical mechanical polishing method according to an embodiment of the present invention will be specifically described.

1. Chemical mechanical polishing pad 1.1. Structure FIG. 1 is a cross-sectional view schematically showing an example of a chemical mechanical polishing pad according to an embodiment of the present invention. During chemical mechanical polishing, the surface (polishing surface) 10a of the polishing layer 10 of the chemical mechanical polishing pad 100 shown in FIG. 1 is in contact with an object to be polished (not shown).

  The chemical mechanical polishing pad according to this embodiment has a polishing layer containing (A) component; 100 parts by volume of ionomer resin, and (B) component; 5 to 80 parts by volume of water-soluble particles.

  Although the shape of the chemical mechanical polishing pad 100 is not limited, it can be, for example, a cylindrical shape, a polygonal column shape, etc., and is preferably a cylindrical shape.

  When the chemical mechanical polishing pad 100 is, for example, cylindrical, the diameter of the polishing surface (one bottom surface of the cylinder) is preferably 150 to 1,200 mm, and more preferably 500 to 820 mm. Moreover, the thickness of the chemical mechanical polishing pad 100 is, for example, preferably 0.5 to 5.0 mm, more preferably 1.0 to 3.0 mm, and 1.5 to 3.0 mm. Is more preferable.

  The Durro D hardness of the polishing layer 10 is preferably 50 to 85, and more preferably 55 to 80. When the Durro D hardness of the polishing layer 10 is less than 50, the polishing rate may not be sufficiently exhibited. On the other hand, when the Durro D hardness of the polishing layer 10 exceeds 85, scratches may occur.

  Further, the chemical mechanical polishing pad 100 can have an appropriate recess on the polishing surface 10a or the back surface (non-polishing surface) 10b of the polishing surface 10. Examples of the shape of the recess include concentric grooves, radial grooves, circular recesses, polygonal recesses, and combinations thereof.

  2 and 3 are cross-sectional views schematically showing another example of the chemical mechanical polishing pad according to one embodiment of the present invention. In the chemical mechanical polishing pad 200 shown in FIG. 2, the recess 12 is provided on the polishing surface 10a, and in the chemical mechanical polishing pad 300 shown in FIG. 3, the recess 14 is provided on the back surface (surface to be polished) 10b of the polishing surface 10a. It has been.

  FIG. 4 is a cross-sectional view schematically showing another example of a chemical mechanical polishing pad according to an embodiment of the present invention. A chemical mechanical polishing pad 400 shown in FIG. 4 is a multilayer pad provided with a support layer 16 on the non-polishing surface 10 b of the polishing layer 10.

  The support layer 16 supports the polishing layer 10 on the back side of the polishing surface 10a. The support layer 16 preferably has a lower hardness than the polishing layer 10. Since the chemical mechanical polishing pad 400 includes the support layer 16 having a hardness lower than that of the polishing layer 10, the pad 400 can be prevented from being lifted and the surface 10a of the polishing layer 10 from being curved during chemical mechanical polishing. Mechanical polishing can be performed stably. The hardness of the support layer 16 is preferably 90% or less of the Durro D hardness of the polishing layer 10, more preferably 50 to 90%, further preferably 50 to 80%, and particularly preferably 50 to 70%.

1.2. Composition 1.2.1. (A) component (A) component is (a1) component; 100 mass parts of ethylene- (meth) acrylic acid type copolymer, (a2) component; 1-20 mass parts of metal oxide or metal hydroxide, including.

Component (A): In order to produce an ionomer resin, the component (a1) and the component (a2) can be produced by a method such as kneading. Here, when the components (a1) and (a2) are mixed and kneaded, the carboxyl group (—CO ₂ H) contained in the component (a1) is neutralized by the metal ions in the component (a2). It becomes a carboxylate ion (—CO ₂ ⁻ ), and this carboxylate ion forms a salt with a metal ion. And the (meth) acrylic acid structural unit of (a1) component is pseudo-crosslinked by the some carboxylic acid ion in (a1) component associating with a metal ion, and it becomes ionomer resin. When the functional group contained in the component (a1) is an ester group (—CO ₂ R) (R represents an alkyl group), when the component (a1) and the component (a2) are kneaded (a2 ) It is easily hydrolyzed by components and moisture contained in the air to form carboxylate ions (—CO ₂ ⁻ ), and these carboxylate ions form salts with metal ions.

  As described above, the (meth) acrylic acid structural units of the component (a1) are pseudo-crosslinked with each other by the association of the plurality of carboxylate ions in the component (a1) with the metal ions, whereby an ionomer resin is obtained.

  For example, component (A); an ionomer resin can be obtained by uniformly dispersing component (a1) and component (a2) by melt-kneading. More specifically, the components (a1) and (a2) are previously dry blended and uniformly dispersed, and then kneaded using a kneader such as an extruder, roll, brabender, kneader, or banbury. The ionomer resin can be produced by a method or a method in which the components (a1) and (a2) are separately supplied to a continuous extruder and melt-kneaded.

  By using the component (A) in the polishing layer, it becomes possible to melt and knead during the production of the polishing layer, so that the manufacturing process can be simplified, and an appropriate hardness and elastic modulus are exhibited near room temperature. A polishing pad having good polishing characteristics can be obtained.

  Component (A): The ionomer resin is a resin in which a carboxyl group present in the resin is pseudo-crosslinked with a metal ion such as zinc ion, potassium ion, sodium ion, or magnesium ion. As a metal ion, it is preferable that it is a bivalent metal ion, and a zinc ion and a magnesium ion are especially preferable.

  Component (A): The degree of pseudo-crosslinking of the ionomer resin can be determined by the following method. Total amount (I) of carboxyl groups in component (a1) before crosslinking (before addition of component (a2)) and total amount of carboxyl groups in component (a1) after crosslinking (after addition of component (a2) (II) Are confirmed by infrared absorption spectrum (IR) measurement. (II) / (I) is the proportion of the carboxyl groups in component (a1) that are ionized and converted into carboxylate ions, that is, component (A); the degree of pseudo-crosslinking of the ionomer resin.

The carboxyl group (—CO ₂ H) has a C═O stretch absorption peak near 1700 cm ⁻¹ . When the carboxyl group pseudo-crosslinked with the metal ion is converted to a carboxylate ion (—CO ₂ ^— ), the peak of the carboxyl group disappears. When a carboxylate ion that is pseudo-crosslinked with a metal ion is treated with a strong acid such as hydrochloric acid, the metal ion is released and returns to the original carboxyl group, and the C═O stretching absorption peak is restored.

1.2-1. (A1) Component The (a1) component ethylene- (meth) acrylic acid copolymer is a copolymer having a carboxyl group in the molecule. The component (a1) is at least one selected from the group consisting of an ethylene-acrylic acid copolymer, an ethylene-methacrylic acid polymer, an ethylene-methyl acrylate copolymer, and an ethylene-ethyl acrylate copolymer. Preferably there is.

  Examples thereof include a copolymer of ethylene with a (meth) acrylic monomer having a carboxyl group such as acrylic acid and methacrylic acid, and a copolymer of ethylene with an acid anhydride monomer such as maleic anhydride. In the component (a1), the preferred range of the carboxyl group content is 0.5 to 30 mol%, more preferably 1 to 20 mol%. If it is less than 0.5 mol%, an ionomer resin may not be obtained. On the other hand, if it exceeds 30 mol%, the mechanical strength is extremely lowered.

  Moreover, it is preferable that the (meth) acrylic acid content rate in (a1) component is 3-25 mass%, It is more preferable that it is 5-20 mass%, It is further more preferable that it is 10-18 mass%. In this case, if the (meth) acrylic acid content is less than 3% by mass, the effect of the ionomerization reaction may be insufficient, while the (meth) acrylic acid content exceeds 25% by mass. And the hardness of the chemical mechanical polishing pad obtained tends to be too low.

  As the component (a1), for example, commercially available products include “Nucrel” (trade name) manufactured by Mitsui DuPont Polychemical Co., Ltd. and “REXPEARL” (trade name) manufactured by Nippon Polyethylene Co., Ltd.

1.2.1-2. (A2) Component (a2) The metal constituting the component metal oxide or metal hydroxide forms a pseudo-crosslinked structure between the molecules of the (a1) component ethylene- (meth) acrylic acid copolymer. A metal that can be used is preferable. That is, the component (a2) can contribute to the pseudo-crosslinked structure in the polishing layer, and the metal can exist as metal ions in the polishing layer.

  The metal oxide or metal hydroxide as component (a2) is at least one selected from zinc oxide, magnesium oxide, zinc hydroxide, and magnesium hydroxide in that it tends to maintain pseudo-crosslinking even at high temperatures. Preferably it is a seed. These can be used alone or in admixture of two or more.

  The component (a2) is preferably used in an amount of 1 to 20 parts by mass, more preferably 1 to 15 parts by mass with respect to 100 parts by mass of the component (a1). In this case, when the amount of the component (a2) used is less than 1 part by mass, there may be insufficient crosslinking with the component (a1) when the pad is molded and manufactured. On the other hand, when the amount of the component (a2) used is larger than 20 parts by mass, when the pad is molded and manufactured, the crosslinking with the component (a1) becomes excessive, the hardness of the polished surface is increased, and scratching during polishing is performed. May occur more often.

  The component (a2) may have a surface modified with a compound having at least one functional group selected from an acid anhydride group, a carboxyl group, a hydroxyl group, an epoxy group, and an amino group.

1.2.2. Component (B) The water-soluble particles as component (B) are separated from the polishing surface of the polishing pad by contacting with the chemical mechanical polishing aqueous dispersion supplied during chemical mechanical polishing, and the chemical mechanical polishing aqueous system. It has a function of forming pores that can hold the dispersion. In the present invention, the “water-soluble particles” include not only a mode of dissolving in water upon detachment from the polishing surface, but also a mode of swelling or forming a sol upon contact with water.

  Component (B) may be either an organic water-soluble substance or an inorganic water-soluble substance.

  Examples of organic water-soluble substances include saccharides (polysaccharides such as starch, dextrin and cyclodextrin, lactose, mannitol, etc.), celluloses (hydroxypropylcellulose, methylcellulose, etc.), proteins, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic. Examples include acid, polyethylene oxide, water-soluble photosensitive resin, sulfonated polyisoprene, and sulfonated isoprene copolymer.

  Examples of the inorganic water-soluble substance include potassium acetate, potassium nitrate, potassium carbonate, potassium hydrogen carbonate, potassium bromide, potassium phosphate, potassium sulfate, magnesium sulfate, and calcium nitrate.

  As the component (B), one of the above may be used, or two or more may be mixed and used.

  The component (B) is preferably solid from the viewpoint that the hardness of the polishing surface of the chemical mechanical polishing pad can be set to an appropriate value.

  Moreover, the average particle diameter of (B) component becomes like this. Preferably it is 0.1-500 micrometers, More preferably, it is 0.5-100 micrometers. When the average particle diameter of the component (B) is 0.1 to 500 μm, a chemical mechanical polishing pad that exhibits a high polishing rate and is excellent in mechanical strength can be obtained.

  In addition, it is preferable that (B) component melt | dissolves or swells in water etc. only when exposed to the surface layer in the polishing layer of the chemical mechanical polishing pad, absorbs moisture inside the polishing layer, and does not swell. For this reason, (B) component may be provided with the outer shell which suppresses moisture absorption in at least one part of the outermost part. The outer shell may be (B) physically adsorbed on the water-soluble particles, (B) chemically bonded to the water-soluble particles, or may be in contact with the water-soluble particles (B). Good. Examples of the material for forming such an outer shell include epoxy resin, polyimide, polyamide, polysilicate, silane coupling agent, and the like. In this case, (B) the water-soluble particles may be composed of a water-soluble substance having an outer shell and a water-soluble substance not having an outer shell. Even if the shell is not covered, the above effect can be sufficiently obtained.

  The usage ratio of the component (B) in the polishing layer is preferably 5 to 80 parts by volume, more preferably 10 to 60 parts by volume, with respect to 100 parts by volume of the component (A). More preferably, it is a volume part.

  Chemical mechanical polishing which shows a high polishing rate and has appropriate hardness and mechanical strength by setting the content of component (B) to 5 to 80 parts by volume with respect to 100 parts by volume of component (A). It can be a pad.

1.2.3. Component (C) In the polishing layer of the chemical mechanical polishing pad according to the present embodiment, the component (A) is preferably crosslinked with the component (C): an organic peroxide.

  When the polishing layer of the chemical mechanical polishing pad according to this embodiment contains the component (C), the component (C) functions as a cross-linking agent, and the ethylene- (meth) acrylic acid-based copolymer (a1). The crosslinked structure of the coalescence can be formed stably. Thereby, mechanical strength can be raised.

  Examples of the component (C) include 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane, di-t-butyl peroxide, dicumyl peroxide, t-butylcumyl peroxide, 2,5 -Di-methyl-2,5-di (t-butylperoxy) hexane, 2,5-di-methyl-2,5-di (t-butylperoxy) hexyne, 1,3-bis (t-butylperoxy- And isopropyl) benzene. Of these, dicumyl peroxide, 2,5-di-methyl-2,5-di (t-butylperoxy) hexane, 2,5-di-methyl-2,5-di (t-butylperoxy) hexyne More preferred. These can be used alone or in admixture of two or more.

  (C) 0.5-15 mass parts is preferable with respect to 100 mass parts of (a1) component, and, as for the usage-amount of a component, 1-10 mass parts is more preferable. By using 0.5 to 15 parts by mass of component (C) with respect to 100 parts by mass of component (a1), a chemical mechanical polishing pad is obtained in which the generation of scratches is suppressed in the chemical mechanical polishing step and the polishing rate is high. be able to.

  The component (C) can be used in combination with at least one compound selected from sulfur compounds, polyfunctional monomers, and oxime compounds. In this case, with respect to 100 parts by mass of component (C), at least one compound selected from sulfur compounds, polyfunctional monomers, and oxime compounds is 15 parts by mass or less with respect to 100 parts by mass of component (C). It is preferable that it is 0.3-8 mass parts.

1.2.4. Additives The chemical mechanical polishing pad according to this embodiment may further contain other additives as long as the characteristics of the present invention are not impaired. Examples of such other additives include softeners, plasticizers, lubricants, and the like.

  Examples of the softening agent include process oil such as aromatic oil, naphthenic oil, and paraffin oil, vegetable oil such as palm oil, and synthetic oil such as alkylbenzene oil. Of these, process oil is preferred. The above softeners can be used alone or in admixture of two or more.

  Examples of the plasticizer include phthalate, adipate, sebacate, polyether, and polyester.

  Examples of the lubricant include paraffin and hydrocarbon resin, fatty acid amide, fatty acid ester, fatty alcohol, and the like.

1.2.5. Method for Preparing Composition for Forming Polishing Layer A method for preparing a composition (a composition for forming a polishing layer) for forming a polishing layer of the chemical mechanical polishing pad according to the present embodiment is not particularly limited. For example, each of the above components constituting the polishing layer of the chemical mechanical polishing pad according to this embodiment can be obtained by kneading by a known method using a kneader or the like. A well-known thing can be used as a kneading machine. Examples thereof include kneaders such as rolls, kneaders, Banbury mixers, and extruders (single screw and multi screw). The temperature at the time of kneading should be appropriately set according to the type of components to be used, but is preferably 100 to 120 ° C., for example.

1.2.6. Formation method of polishing layer The polishing layer of the chemical mechanical polishing pad according to the present embodiment can be produced from the composition for forming a polishing layer containing the components (A) to (C).

  A method of forming the composition into a desired shape under an appropriate pressure while heating the composition to about 150 to 190 ° C, or a desired shape after forming the composition into a sheet shape while heating to about 150 to 190 ° C. By cutting, a polishing layer in which the water-soluble particles (B) are dispersed in the ionomer resin (A) can be obtained.

  The polishing layer of the chemical mechanical polishing pad according to this embodiment preferably has a crosslinked structure. Because the polishing layer of the polishing pad has a crosslinked structure, the ionomer resin as the component (A) has an appropriate elastic recovery force, so that the displacement due to the shear stress generated in the chemical mechanical polishing pad during polishing can be suppressed to a low level. In addition, it is possible to effectively suppress the component (A) from being excessively stretched during plasticizing and dressing to be plastically deformed and filling the pores, and the surface of the polishing layer from becoming excessively fuzzy. That is, in the polishing layer, the (A) component is cross-linked by the (C) component, so that pores can be efficiently formed even during dressing, the retention of the slurry during polishing can be prevented from decreasing, and fuzzing can occur. Less and excellent polishing flatness can be realized.

  In addition, the formation method of a crosslinked structure is not specifically limited. For example, in the chemical mechanical polishing pad according to this embodiment, when the polishing layer does not contain (C) an organic oxide, a crosslinked structure may be formed by radiation crosslinking by electron beam irradiation, or crosslinking may be performed by heating. May be.

2. Chemical mechanical polishing method A chemical mechanical polishing method according to an embodiment of the present invention includes a step of chemically mechanically polishing an object to be polished using the chemical mechanical polishing pad.

  The chemical mechanical polishing method according to the present embodiment can be used for polishing an insulating film or a protective film, for example, in manufacturing a semiconductor device or the like.

  In the chemical mechanical polishing method according to the present embodiment, an object to be polished is not particularly limited. For example, the object to be polished preferably contains silicon oxide. As an object to be polished containing silicon oxide, for example, an insulating film containing silicon oxide having an STI structure can be given.

  According to the chemical mechanical polishing method according to the present embodiment, it is possible to obtain a surface to be polished having a high polishing rate, excellent in-plane uniformity of the polishing amount, and less scratching.

3. Example 3.1. Example 1
3.1.1. Preparation of Composition for Forming Polishing Layer In a twin-screw extruder adjusted to 130 to 170 ° C., Rexpearl EMAA Nukurel N1560 (trade name, manufactured by Mitsui DuPont Chemical Co., Ltd., ethylene-methacrylic) as component (a1) Acid copolymer) 100 parts by weight, (a2) Component (a2) and (a2) are each fed using a gravimetric feeder so that magnesium hydroxide powder is 5 parts by weight, and extrusion kneading is performed. went. Furthermore, as component (B), Dixie Pearl 100 (trade name, Yokohama International Bio Co., Ltd.) in an amount corresponding to 70 parts by volume with respect to 100 parts by volume of component (A) (component (a1) + component (a2)) R & D Co., Ltd., β-cyclodextrin, average particle size 15 μm) was charged into a twin screw extruder using a weight type feeder and kneaded. Next, as component (C), Park Mill D-40 (trade name, manufactured by NOF Corporation) 7.0 parts by mass and TAIC-M60 (trade name, manufactured by Nippon Kasei Co., Ltd.) 4.0 parts by mass. Was added and kneaded to obtain a polishing layer forming composition of Example 1.

3.1.2. Production of Chemical Mechanical Polishing Pad The polishing layer forming composition of Example 1 was set in a pad molding die and heated at 175 ° C. for 12 minutes to obtain a molded body having a diameter of 60 cm and a thickness of 2.8 mm. Next, a concentric groove having a groove width of 0.5 mm, a groove depth of 1.4 mm, and a pitch of 4.0 mm is formed on the surface to be a polished surface of the molded body using a cutting machine manufactured by Kato Machine Co., Ltd. To obtain a chemical mechanical polishing pad of Example 1 comprising a polishing layer.

3.1.3. Evaluation of polishing performance The chemical mechanical polishing pad of Example 1 was attached to a chemical mechanical polishing apparatus (manufactured by Ebara Manufacturing Co., Ltd., model “EPO112”), and a PETEOS film (tetraethylorthosilicate as a raw material on the surface) was used as an acceleration condition. 300 wafers having a diameter of 8 inches on which a silicon oxide film (PETEOS film) formed by chemical vapor deposition using plasma is prepared and used as an object to be polished are subjected to chemical mechanical polishing under the following conditions. Was performed continuously.

Chemical mechanical polishing aqueous dispersion: SS-25 (manufactured by Cabot Microelectronics) diluted twice with ion-exchanged water Aqueous dispersion supply speed: 150 mL / min Head pressing pressure: 250 hPa
Plate rotation speed: 70 rpm
Head rotation speed: 70rpm
Polishing time: 60 seconds / sheet

3.1-1. Evaluation of Polishing Rate For the wafer with PETEOS film as the object to be polished, the film thickness of the PETEOS film is measured using an optical interference film thickness meter, and the difference in film thickness before and after polishing, that is, chemical mechanical polishing The film thickness decreased by the following procedure was obtained.

  For the wafer with PETEOS film, 21 specific points are set evenly in the diameter direction except for the outer circumference of 5 mm, and the polishing rate at each point is calculated from the difference in thickness of the PETEOS film before and after polishing and the polishing time for these specific points. The average value was used as the polishing rate.

  The polishing rate was evaluated for every 50th wafer polished continuously, and the average of 6 evaluations was taken as the polishing rate, and the value was 282 nm / min. It can be said that the polishing rate is good when this value is 400 nm / min or more, and particularly good when the value is 500 nm / min or more.

3.1.3-2. Evaluation of in-plane uniformity of polishing rate Using the difference in thickness of the PETEOS film before and after polishing at the 21 specific points (this value is referred to as “polishing amount”) In-plane uniformity was calculated.

In-plane uniformity of polishing amount (%) = (standard deviation of polishing amount ÷ average value of polishing amount) × 100
The in-plane uniformity of the polishing rate was evaluated for every 50th wafer polished continuously, and the average of 6 evaluations was taken. The value was 4.8%. It can be said that the in-plane uniformity is good when this value is within 7%, and particularly good when it is 6% or less.

3.1.3-3. Scratch Evaluation The surface to be polished of the PETEOS film-coated wafer after chemical mechanical polishing was subjected to a defect inspection as follows using a defect inspection apparatus (manufactured by KLA-TENCOR, model “KLA2351”).

  First, the number of defects counted by the defect inspection apparatus was measured for the entire range of the wafer surface under the conditions of a pixel size of 0.62 μm and a threshold of 30. Next, 100 of these defects are extracted at random, displayed on the display of the apparatus and observed, and the defects are scratches or adhered foreign matter (such as abrasive grains contained in the chemical mechanical polishing aqueous dispersion). The ratio of scratches with a major axis of 0.20 μm or more in the total number of defects was calculated, and the number of scratches per wafer was calculated from this.

  The scratch was evaluated for every 50th wafer polished continuously, and the average of 6 evaluations was 1 piece / surface. It can be said that the scratch is good when this value is within 3 pieces / surface, and is particularly good when the value is 2 pieces / surface or less.

3.2. Examples 2-8 and Comparative Examples 1-5
A chemical mechanical polishing pad was produced in the same manner as in Example 1 except that the types and amounts of the components (A) to (D) were changed as shown in Table 1, and the chemical mechanical polishing performance was evaluated. The results are shown in Table 1.

  In addition, the abbreviation of each component in Table 1 is shown below.

(A) Polymer (a1) Ethylene- (meth) acrylic acid copolymer “A210K”: trade name “Rex Pearl EAA A210K”, manufactured by Nippon Polyethylene Co., Ltd., ethylene-acrylic acid copolymer “N1560” —commodity Name “Nucleel N1560”, manufactured by Mitsui DuPont Chemical Co., Ltd., ethylene-acrylic acid copolymer (control) “LE520H” ... Product name “Novatech LD LE520H”, manufactured by Nippon Polyethylene Co., Ltd., low density polyethylene (a2) Metal oxide or metal hydroxide “ZnO”: Trade name “No. 1 Zinc Hana”, Sakai Chemical Industry Co., Ltd., Zinc Oxide (Zinc Hana)
“Mg (OH) ₂ ” ... trade name “Kyowa Mag 150”, Kyowa Chemical Industry Co., Ltd., magnesium hydroxide “MgO” ... trade name “Kisuma 5”, Kyowa Chemical Industry Co., Ltd., magnesium oxide “Zn (OH)” ₂ "... Trade name" Zinc hydroxide ", manufactured by MP Biomedicals, Inc., Zinc hydroxide

(B) Water-soluble particles “WSP”: trade name “Dexy Pearl β-100”, manufactured by Yokohama International Bio-Laboratory Co., Ltd., β-cyclodextrin (average particle size 15 μm)
In Table 1, the amount of (B) water-soluble particles used is shown as a volume part relative to 100 parts by volume of the component (A).

(C) Organic peroxide “Park mill D-40”: trade name “Park mill D-40”, manufactured by NOF Corporation and containing 40% by mass of dicumyl peroxide.

(D) Crosslinking assistant “TAIC-M60”: trade name “TAIC-M60”, manufactured by Nippon Kasei Co., Ltd., containing 60% by mass of triallyl isocyanurate.

  According to the chemical mechanical polishing pads of Examples 1 to 10, it has a polishing layer containing 100 parts by volume of the (A) component and 5 to 80 parts by volume of the (B) component, and the (A) component is the (a1) component 100. By containing 1 part by mass and 1 to 20 parts by mass of component (a2), it is possible to obtain a polished surface with high polishing rate, excellent in-plane uniformity of the amount of polishing and less scratches in chemical mechanical polishing. Can understand.

FIG. 1 is a cross-sectional view schematically showing an example of a chemical mechanical polishing pad according to an embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing another example of a chemical mechanical polishing pad according to an embodiment of the present invention. FIG. 3 is a cross-sectional view schematically showing another example of a chemical mechanical polishing pad according to an embodiment of the present invention. FIG. 4 is a cross-sectional view schematically showing another example of a chemical mechanical polishing pad according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Polishing layer, 10a ... Polishing surface, 10b ... Non-polishing surface, 12, 14 ... Recess, 16 ... Support layer, 100, 200, 300, 400 ... Chemical mechanical polishing pad

Claims (9)

(A) component; 100 parts by volume of ionomer resin;
(B) component; 5-80 volume parts of water-soluble particles;
Having a polishing layer comprising
The (A) component includes (a1) component; 100 parts by mass of an ethylene- (meth) acrylic acid copolymer, and (a2) component; 1 to 20 parts by mass of metal oxide or metal hydroxide, Chemical mechanical polishing pad.   The chemical mechanical polishing pad according to claim 1, wherein the component (a2) is a divalent metal oxide or metal hydroxide.   The chemical mechanical polishing pad according to claim 2, wherein the component (a2) is at least one selected from the group consisting of zinc oxide, magnesium oxide, zinc hydroxide, and magnesium hydroxide.   The chemical mechanical polishing pad according to claim 1, wherein the component (B) has an average particle size of 5 to 80 μm.   The chemical mechanical polishing pad according to any one of claims 1 to 4, wherein the (meth) acrylic acid content of the component (a1) is 3 to 25% by mass.   The component (a1) is a copolymer of ethylene and at least one selected from the group consisting of acrylic acid, methacrylic acid, methyl acrylate, and ethyl acrylate. The chemical mechanical polishing pad described in 1.   The chemical mechanical polishing pad according to any one of claims 1 to 5, wherein the component (A) is crosslinked with an organic peroxide (C).   A chemical mechanical polishing method comprising a step of chemically mechanically polishing an object to be polished using the chemical mechanical polishing pad according to claim 1.   The chemical mechanical polishing method according to claim 7, wherein the object to be polished contains silicon oxide.

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