JP2010056184A - Chemical mechanical polishing pad and chemical mechanical polishing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chemical mechanical polishing pad being capable of suppressing the fluctuation of a polishing speed during a chemical mechanical polishing and having the long life of products and a chemical mechanical polishing method using the chemical mechanical polishing pad. <P>SOLUTION: The chemical mechanical polishing pad 10 includes a polishing layer containing a water-insoluble matrix material 14 and water-soluble particles 16 dispersed into the water-insoluble matrix material. The mean particle diameter of the water-soluble particles is 0.1 to 2 mm, and grooves are formed substantially to the surface of the polishing layer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

  In recent years, in the formation of semiconductor devices, etc., polishing that can form a surface having excellent flatness on a silicon substrate or a silicon substrate (hereinafter referred to as “wafer”) on which wirings, electrodes, and the like are formed. As a method, a chemical mechanical polishing method (Chemical Mechanical Polishing, generally abbreviated as “CMP”) is attracting attention.

  In the chemical mechanical polishing method, a chemical mechanical polishing aqueous dispersion (an aqueous dispersion in which abrasive grains are dispersed; slurry) is applied to the pad surface while sliding the chemical mechanical polishing pad and the surface to be polished. This is a technique for polishing by flowing down. In this chemical mechanical polishing method, it is known that the polishing result greatly depends on the properties and characteristics of the chemical mechanical polishing pad, and various chemical mechanical polishing pads have been proposed.

  For example, a polyurethane foam containing fine bubbles is used as a chemical mechanical polishing pad, and polishing is performed by holding a chemical mechanical polishing aqueous dispersion in a hole (hereinafter referred to as “pore”) opened on the surface of the pad. Chemical mechanical polishing pads are known. (For example, refer patent documents 1-3.).

  Further, a chemical mechanical polishing pad having a groove provided on the polishing surface of the pad has been developed. When chemical mechanical polishing is performed using this pad, the polishing rate and the surface condition of the object to be polished can be improved by holding the chemical mechanical polishing aqueous dispersion in the groove of the polishing surface. However, since the surface of the chemical mechanical polishing pad is usually sharpened with a kind of file called a diamond dresser, the groove depth changes depending on the use time, and the groove disappears eventually. At this time, since the amount of the chemical mechanical polishing aqueous dispersion is changed according to the depth of the groove, the polishing rate of the object changes with the usage time, so the usage time may be limited. is there. Therefore, a chemical mechanical polishing pad that can maintain the polishing rate for a long time is required.

On the other hand, by pre-dispersing water-soluble particles in the matrix, the water-soluble particles are dissolved in the aqueous dispersion during chemical mechanical polishing to form pores, and the chemical mechanical polishing aqueous dispersion is held in the pores. Studies have been made (see, for example, Patent Document 4). In this case, as in the pad described in the example of Patent Document 4, when the water-soluble particles have a small particle size, the recesses caused by the desorption or dissolution of the water-soluble particles are also small. Concave portions such as grooves created by machining or the like for distributing and holding the body are essential. Since the depth of such a recess becomes shallower as the pad wears, the polishing rate and the surface smoothness of the object to be polished cannot be kept constant, and it may be difficult to maintain the polishing performance. Further, in pad manufacturing, the productivity of pads has been reduced due to an increase in groove processing steps.
JP-A-11-70463 JP-A-8-216029 JP-A-8-39423 JP 2005-159340 A

  The present invention provides a chemical mechanical polishing pad that can suppress fluctuations in the polishing rate during chemical mechanical polishing and has a long product life, and a chemical mechanical polishing method using the chemical mechanical polishing pad.

The chemical mechanical polishing pad according to one embodiment of the present invention is as follows.
A polishing layer comprising a water-insoluble matrix material and water-soluble particles dispersed in the water-insoluble matrix material;
The water-soluble particles have an average particle size of 0.1 to 2 mm,
Grooves are not substantially provided on the surface of the polishing layer.

  In the present invention, “substantially no groove is provided on the surface of the polishing layer” means that no groove having a width of 100 μm or more or a depth of 100 μm or more is provided on the surface of the polishing layer. This is different from the concave portion generated by the desorption. In addition, the “surface of the polishing layer” refers to a polishing surface during chemical mechanical polishing (that is, a surface in contact with an object to be polished).

  In the chemical mechanical polishing pad, an average particle size of the water-soluble particles may be 0.03 to 0.95 with respect to a film thickness of the polishing layer.

  In the chemical mechanical polishing pad, when the total amount of the water-insoluble matrix material and the water-soluble particles is 100% by volume, the water-soluble particles can be 1 to 50% by volume.

  In the chemical mechanical polishing pad, the water-soluble particles may be a saccharide.

A chemical mechanical polishing pad according to another aspect of the present invention is provided.
Chemical mechanical polishing of the object to be polished using the chemical mechanical polishing pad.

  According to the chemical mechanical polishing pad, even when the thickness of the chemical mechanical polishing pad changes due to wear of the diamond dresser during chemical mechanical polishing, the volume sufficient to hold the chemical mechanical polishing aqueous dispersion. Can be formed on the surface of the polishing layer, so that a stable polishing rate can be obtained and the product life is long.

  According to the chemical mechanical polishing method, high quality chemical mechanical polishing can be achieved over a long period of time by subjecting an object to be polished to chemical mechanical polishing using the chemical mechanical polishing pad.

  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 FIG. 1 is a cross-sectional view showing a chemical mechanical polishing pad according to an embodiment of the present invention, and FIG. 2 is a chemical mechanical polishing method using the chemical mechanical polishing pad according to an embodiment of the present invention. FIG.

  As shown in FIG. 1, the chemical mechanical polishing pad 10 according to this embodiment includes a water-insoluble matrix material (I) 12 and water-soluble particles (II) 16 dispersed in a water-insoluble matrix material 14. A polishing layer 12 is included.

1.1. Polishing layer 1.1.1. Water-insoluble matrix material (I)
The water-insoluble matrix material (I) is not particularly limited, but an organic material is preferably used because it can be easily molded into a predetermined shape and properties, and can be provided with appropriate hardness and appropriate elasticity. Examples of the organic material include thermoplastic resin, elastomer or raw rubber, and cured resin.

  Examples of the thermoplastic resin include olefin resins (for example, polyethylene and polypropylene), styrene resins (for example, polystyrene), acrylic resins (for example, (meth) acrylate resins), vinyl ester resins (however, (meth)). Examples thereof include those not corresponding to acrylate resins), polyester resins (excluding those corresponding to vinyl ester resins), polyamide resins, fluororesins, polycarbonate resins, polyacetal resins, and the like.

  Examples of the elastomer or raw rubber include diene elastomers (for example, 1,2-polybutadiene), olefin elastomers (for example, dynamically cross-linked ethylene-propylene rubber and polypropylene resin, etc.), urethane elastomers, urethane rubbers ( For example, urethane rubber, etc., styrene-based elastomers (for example, styrene-butadiene-styrene block copolymer (hereinafter sometimes referred to as “SBS”), hydrogenated products of styrene-butadiene-styrene block copolymer (hereinafter referred to as “ SEBS ”)), conjugated diene rubbers (for example, high cis butadiene rubber, low cis butadiene rubber, isoprene rubber, styrene-butadiene rubber, styrene-isoprene rubber, acrylonitrile-butadiene rubber, chloroprene rubber). ), Ethylene-α-olefin rubber (for example, ethylene-propylene rubber, ethylene-propylene-nonconjugated diene rubber, etc.), butyl rubber, and other rubbers (for example, silicone rubber, fluorine rubber, nitrile rubber, chlorosulfonated polyethylene, acrylic rubber, epichlorohydrin) Rubber, polysulfide rubber, etc.).

  Examples of the cured resin include a thermosetting resin, a photocuring resin, and the like. Specific examples thereof include, for example, a urethane resin, an epoxy resin, an unsaturated polyester resin, a polyurethane-urea resin, a urea resin, a silicon resin, and a phenol resin. Etc.

  These organic materials may be used alone or in combination of two or more.

  These organic materials may be modified so as to have an appropriate functional group. Examples of suitable functional groups include groups having an acid anhydride structure, carboxyl groups, hydroxyl groups, epoxy groups, and amino groups.

  These organic materials are preferably partially or wholly crosslinked. When the water-insoluble matrix material (I) contains a crosslinked organic material, an appropriate elastic recovery force is imparted to the water-insoluble matrix material (I), and shear stress applied to the chemical mechanical polishing pad during chemical mechanical polishing. The displacement due to can be suppressed. In addition, the water-insoluble matrix material (I) is excessively stretched and plastically deformed during the chemical mechanical polishing step and dressing (the “sharpening” treatment of the chemical mechanical polishing pad performed alternately or simultaneously with the chemical mechanical polishing). It is possible to effectively suppress the filling of the pores and the excessive fluffing of the surface of the chemical mechanical polishing pad. Therefore, a chemical mechanical polishing pad that can efficiently form pores at the time of dressing, can prevent deterioration of the retainability of the chemical mechanical polishing aqueous dispersion at the time of polishing, and can maintain polishing flatness for a long time with less fuzzing. Obtainable.

  Examples of the crosslinked organic material include a crosslinked thermoplastic resin and a crosslinked elastomer or a crosslinked rubber (herein, the “crosslinked rubber” means a crosslinked product of the “raw rubber”). It is more preferable to contain at least one selected from the group consisting of a cross-linked diene elastomer, a cross-linked styrene elastomer, and a cross-linked conjugated diene rubber. Contains at least one selected from crosslinked 1,2-polybutadiene, crosslinked SBS, crosslinked SEBS, crosslinked styrene butadiene rubber, crosslinked styrene-isoprene rubber, and crosslinked acrylonitrile-butadiene rubber It is particularly preferred that the crosslinked 1,2-polybutadiene, And most preferably contains at least one selected from been SBS, and crosslinked SEBS.

  When a part of the organic material is cross-linked and the other part is non-cross-linked, the non-cross-linked organic material includes non-cross-linked thermoplastic resin, non-cross-linked elastomer and raw rubber. It is preferable to contain at least one selected from the group consisting of non-crosslinked olefin resin, non-crosslinked styrene resin, non-crosslinked diene elastomer, non-crosslinked styrene elastomer, non-crosslinked conjugated diene rubber and non-crosslinked It is more preferable to contain at least one selected from butyl rubber, non-crosslinked polystyrene, non-crosslinked 1,2-polybutadiene, non-crosslinked SBS, non-crosslinked SEBS, non-crosslinked styrene-butadiene rubber, At least one selected from non-crosslinked styrene-isoprene rubber and non-crosslinked acrylonitrile-butadiene rubber. More preferably to, the non-crosslinked polystyrene, non-crosslinked 1,2-polybutadiene, it is particularly preferred to contain at least one selected from non-crosslinked SBS and non-cross-linked SEBS.

  When a part of the organic material is cross-linked and the other part is non-cross-linked, the proportion of the cross-linked organic material in the water-insoluble matrix material (I) is 30% by mass. Preferably, it is 50% by mass or more, and more preferably 70% by mass or more.

  When the organic material is partially or wholly crosslinked, the crosslinking method is not particularly limited, and for example, a chemical crosslinking method, a radiation crosslinking method, a photocrosslinking method, or the like can be used. The chemical crosslinking method can be performed using, for example, an organic peroxide, sulfur, a sulfur compound, or the like as a crosslinking agent. The radiation crosslinking method can be performed by a method such as electron beam irradiation. The photocrosslinking method can be performed by a method such as ultraviolet irradiation.

  Among these, it is preferable to use a chemical cross-linking method, and it is more preferable to use an organic peroxide because it has good handling properties and does not contaminate an object to be polished in chemical mechanical polishing. Examples of the organic peroxide include dicumyl peroxide, diethyl peroxide, di-t-butyl peroxide, diacetyl peroxide, and diacyl peroxide.

  When the crosslinking is performed by a chemical crosslinking method, the amount of the crosslinking agent used is preferably 0.01 to 0.6 parts by mass with respect to 100 parts by mass of the total amount of the water-insoluble matrix material (I) used for the crosslinking reaction. By setting the amount used within this range, it is possible to obtain a chemical mechanical polishing pad in which the generation of scratches is suppressed in the chemical mechanical polishing step.

  The cross-linking may be performed collectively for all the materials constituting the water-insoluble matrix material (I), and the remainder after the cross-linking is performed on a part of the material constituting the water-insoluble matrix material (I). May be mixed with. Moreover, you may mix several types of crosslinked material which performed each bridge | crosslinking.

  Further, when the cross-linking is based on a chemical cross-linking method, the amount of cross-linking agent used and the cross-linking conditions are adjusted. By the operation, it is possible to easily obtain a mixture of organic materials partially cross-linked and other parts non-cross-linked.

  The water-insoluble matrix material (I) is suitable for controlling the affinity with the water-soluble particles (II) described later and the dispersibility of the water-soluble particles (II) in the water-insoluble matrix material (I). A solubilizer can be included. Here, examples of the compatibilizer include nonionic surfactants and coupling agents.

1.1.2. Water-soluble particles (II)
The average particle size of the water-soluble particles (II) is 0.1 to 2 mm, preferably 0.3 to 1.5 mm, and more preferably 0.4 to 1.0 mm. In the chemical mechanical polishing pad according to the present embodiment, the water-soluble particles (II) have an average particle size of 0.1 to 2 mm, so that the chemical mechanical polishing aqueous dispersion retention capacity and polishing rate are improved in chemical mechanical polishing. Since it can be held for a long time, it can be a long-life pad. Here, when the average particle diameter of the water-soluble particles (II) is less than 0.1 mm, the volume of the pores formed on the surface of the polishing layer by dissolving the water-soluble particles in the aqueous dispersion during chemical mechanical polishing, It may not be large enough to hold the chemical mechanical polishing aqueous dispersion. On the other hand, if it exceeds 2 mm, pores formed by dissolving the water-soluble particles in the aqueous dispersion during chemical mechanical polishing may penetrate the polishing layer, and the aqueous dispersion may ooze out to the back of the polishing layer.

  When the water-soluble particles (II) are brought into contact with water, the water-soluble particles (II) are desorbed and concave portions are formed on the surface of the polishing layer. The recess has a function of holding the chemical mechanical polishing aqueous dispersion. The width of the recess is a size according to the average particle diameter of the water-soluble particles (II). The desorption is caused by dissolution, swelling or the like due to contact with water or an aqueous medium contained in the chemical mechanical polishing aqueous dispersion.

  As shown in FIG. 2, when the workpiece 20 is subjected to chemical mechanical polishing using the chemical mechanical polishing pad 10 according to this embodiment, water-insoluble particles (II) are contained in the water-insoluble matrix material (I) of the pad 10. ) Are uniformly dispersed, the new water-soluble particles (II) 18 are exposed on the surface of the polishing layer 12 as the chemical mechanical polishing proceeds, and the water-soluble particles (II) 12 are desorbed and newly added. A recess 18 is created. For this reason, even if chemical mechanical polishing proceeds and cutting of the polishing layer 12 proceeds, even if the depth of the hole of the concave portion 18 on the surface (polishing surface) 13 of the polishing layer 12 becomes shallow, polishing is performed by cutting the polishing layer 12. A new concave portion 18 is formed on the surface 13, and the chemical mechanical polishing aqueous dispersion 22 can be held in the new concave portion 18. Thereby, the polishing rate of the workpiece 20 can be kept constant, and the life of the pad can be extended.

  The average particle diameter of the water-soluble particles (II) is preferably 0.03 to 0.95, and more preferably 0.10 to 0.50 with respect to the film thickness of the polishing layer. When the average particle diameter of the water-soluble particles (II) is less than 0.03 with respect to the film thickness of the polishing layer, the water-soluble particles are dissolved in the aqueous dispersion during chemical mechanical polishing and are formed on the surface of the polishing layer. The pore volume may not be large enough to hold the chemical mechanical polishing aqueous dispersion. On the other hand, if it exceeds 0.95, the pores formed by dissolving the water-soluble particles in the aqueous dispersion during chemical mechanical polishing may penetrate the polishing layer, and the aqueous dispersion may ooze out to the back of the polishing layer. is there.

  The water-soluble particles (II) are preferably solid in order to ensure the indentation hardness of the polishing layer. Therefore, the water-soluble particles (II) are particularly preferably solid bodies that can ensure sufficient indentation hardness in the chemical mechanical polishing pad.

  Although the material which comprises water-soluble particle | grains (II) is not specifically limited, Organic water-soluble particle | grains and inorganic water-soluble particle | grains are mentioned. Examples of the organic water-soluble particles include saccharides (polysaccharides (eg, starch, dextrin, cyclodextrin, etc.), lactose, mannitol, sucrose, etc.), celluloses (hydroxypropylcellulose, methylcellulose, etc.), proteins, polyvinyl alcohol, polyvinyl Examples include pyrrolidone, polyacrylic acid, polyethylene oxide, water-soluble photosensitive resin, sulfonated polyisoprene, and sulfonated polyisoprene copolymer. Examples of the inorganic water-soluble particles include potassium acetate, potassium nitrate, potassium carbonate, potassium hydrogen carbonate, potassium chloride, potassium bromide, potassium phosphate, and magnesium nitrate. Among these, organic water-soluble particles are preferable, saccharides are more preferable, and at least one selected from β-cyclodextrin and sucrose is more preferable.

  The water-soluble particles (II) can be used alone or in combination of two or more. That is, it may be one type of water-soluble particles (II) made of a predetermined material, or two or more types of water-soluble particles (II) made of different materials.

  The content of the water-soluble particles (II) is preferably 1 to 50% by volume when the total of the water-insoluble matrix material (I) and the water-soluble particles (II) is 100% by volume. Preferably it is 2-40 volume%, More preferably, it is 5-30 volume%. In this case, if the content of the water-soluble particles (II) is less than 1% by volume, the total volume of pores formed on the surface of the polishing layer by dissolving the water-soluble particles in the aqueous dispersion during chemical mechanical polishing, It may not be sufficient to hold the chemical mechanical polishing aqueous dispersion. On the other hand, if it exceeds 50% by volume, the water-soluble particles (II) are not uniformly dispersed in the water-insoluble matrix material (I). Therefore, in this case, when the content of the water-soluble particles (II) is 1 to 50% by volume, a chemical mechanical polishing pad having an excellent balance between mechanical strength and polishing rate can be obtained.

1.1.3. Surface of polishing layer (polishing surface)
In the chemical mechanical polishing pad according to this embodiment, grooves are not substantially provided on the surface of the polishing layer.

  For example, an embodiment of Japanese Patent Application Laid-Open No. 2005-159340 discloses a chemical mechanical polishing pad in which concentric grooves are provided on the polishing surface. Thus, in the chemical mechanical polishing pad having a groove on the polishing surface, the depth of the groove of the pad becomes shallow as the chemical mechanical polishing proceeds, so the ability of the groove to hold the chemical mechanical polishing aqueous dispersion decreases, It is usually difficult to maintain a constant polishing rate for a long time.

  In contrast, in the chemical mechanical polishing pad according to the present embodiment, grooves are not substantially provided on the surface of the polishing layer, and the water-insoluble matrix material (I) and the water-insoluble matrix material ( It has a polishing layer containing water-soluble particles (II) having an average particle diameter of 0.1 to 2 mm dispersed in I). Therefore, as shown in FIG. 2, during chemical mechanical polishing, the water-soluble particles (II) 16 having an average particle diameter of 0.1 to 2 mm are detached, and the recesses 18 having a predetermined volume become the polishing surface of the polishing layer 12. 13, the new recesses 18 are formed as the polishing of the polishing layer 12 proceeds. Therefore, the chemical mechanical polishing aqueous dispersion 22 is always held in a certain number of recesses 18. As a result, a constant polishing rate can be maintained for a long time, so that the life of the pad 10 can be extended.

  In the chemical mechanical polishing pad according to the present embodiment, it is desirable that the polishing surface of the polishing layer is finished smoothly, and the surface roughness (Ra) on the polishing surface side is 10 μm or less, preferably 7 μm or less, Preferably it is 5 micrometers. If this Ra exceeds 10 μm, it may be impossible to achieve planarization of the object to be polished.

  In addition, the chemical mechanical polishing pad according to the present embodiment can include a portion having another function in the polishing layer for polishing. Examples of the part having other functions include a window part for detecting an end point using an optical end point detection device. As the window portion, for example, at a thickness of 2 mm, the transmittance of light of any wavelength between 100 nm and 300 nm is 0.1% or more (preferably 2% or more), or the wavelength is 100 nm to A material having an integrated transmittance of 0.1% or more (preferably 2% or more) in any wavelength region between 3000 nm can be used. The material of the window portion is not particularly limited as long as it satisfies the optical characteristics described above. For example, the same composition as that of the polishing layer can be used.

1.1.4. Production of Polishing Layer The method for forming the polishing layer of the chemical mechanical polishing pad according to this embodiment is not particularly limited. For example, a composition obtained by kneading a necessary material such as a predetermined organic material with a kneader or the like is used. A polishing layer can be formed by using. A conventionally known kneading machine can be used. Examples thereof include kneaders such as rolls, kneaders, Banbury mixers, and extruders (single screw and multi screw).

  More specifically, for example, the present embodiment is obtained by extruding a composition obtained by kneading the water-insoluble matrix material (I), the water-soluble particles (II) and other additives into a mold. A polishing layer of the chemical mechanical polishing pad according to the above can be obtained.

  However, it is usually kneaded by heating so as to be easily processed during kneading, but the water-soluble particles (II) are preferably solid at the kneading temperature. In this case, since the water-soluble particles (II) are solid, the water-soluble particles (II) having an average particle diameter of 0.1 to 2 mm regardless of the compatibility with the water-insoluble matrix material (I). ) Can be uniformly dispersed in the water-insoluble matrix material (I).

1.2. Other Configurations The chemical mechanical polishing pad according to this embodiment may further include a cushion layer. This cushion layer can be provided on the opposite side of the polishing surface of the polishing layer. As long as the cushion layer is made of a material whose hardness is lower than that of the polishing layer, the material is not particularly limited, and may be a porous body (foam) or a non-porous body. Can be. The thickness of the cushion layer is preferably, for example, 0.1 mm to 5.0 mm, and more preferably 0.5 mm to 2.0 mm.

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

Examples of the object to be polished by the chemical mechanical polishing method according to the present embodiment include a metal, a barrier metal, and an insulating film that are wiring materials. Examples of the metal include tungsten, aluminum, copper, and alloys containing these. Examples of the barrier metal include tantalum, tantalum nitride, titanium, titanium nitride, and tungsten nitride. As the insulating film, a silicon oxide film (PETOS film (Plasma Enhanced-TEOS film), HDP film (High Density Plasma Enhanced-TEOS film)) formed by a vacuum process such as chemical vapor deposition, or an oxidation obtained by a thermal CVD method is used. silicon film, etc.), a small amount of boron and phosphorus added boron phosphorus silicate film (BPSG film SiO _2), FSG fluorine-doped _{SiO 2 (fluorine-doped silicate glass} ) and an insulating film called, SiON (silicon oxynitride) An insulating film called silicon nitride, a low dielectric constant insulating film, and the like.

As the low dielectric constant insulating film, for example, in the presence of oxygen, carbon monoxide, carbon dioxide, nitrogen, argon, H ₂ O, ozone, ammonia, alkoxysilane, silane, alkylsilane, arylsilane, siloxane, Insulating film made of polymer obtained by plasma polymerization of silicon-containing compounds such as alkylsiloxane, insulating film made of polysiloxane, polysilazane, polyarylene ether, polybenzoxazole, polyimide, silsesquioxane, etc., low dielectric constant And a silicon oxide insulating film.

  As described above, the chemical mechanical polishing pad according to the present embodiment can be used in a wide range of chemical mechanical polishing processes, but can be particularly suitably used in a damascene wiring forming process using copper as a wiring material. .

  For example, a damascene wiring forming process using copper as a wiring material is performed by, for example, forming a barrier metal layer in a groove portion and a portion other than the groove portion of an insulating film in which a groove is formed in a portion to be a wiring, and then depositing copper as a wiring material. A process for removing the excess copper (first polishing process), a process for removing the barrier metal other than the groove (second polishing process), and a process for slightly polishing the insulating film portion (first process) A flat damascene wiring is obtained by (3 polishing process step). The school machine polishing pad according to the present embodiment can be used in any of the first to third polishing treatment steps.

  In addition, it should be understood that the above "copper" is an alloy of copper and aluminum, silicon or the like other than pure copper, and includes a copper content of 95% by mass or more. .

3. EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. The present invention is not limited to the following examples. In the examples and comparative examples, “%” and “parts” indicate “% by mass” and “parts by mass”, respectively, unless otherwise specified.

  The chemical mechanical polishing pad according to the present example and the chemical mechanical polishing pad according to the comparative example were manufactured, and chemical mechanical polishing was performed.

3.1. Production Example 1 (Production of chemical mechanical polishing pads A-1 and A-2)
1,2-polybutadiene (manufactured by JSR Corporation, trade name “JSR RB830”) in 72.8 parts by mass (corresponding to 73.9 parts by volume) and sucrose (manufactured by Nissin Sugar Co., Ltd., trade name “Granu Sugar”) , G grade ”, average particle size 0.6 mm) 27.2 parts by mass (corresponding to 26.1 parts by volume) was kneaded for 3 minutes with a rudder adjusted to 130 ° C. Next, 0.55 parts by mass (dicumyl peroxide per 100 parts by mass of 1,2-polybutadiene) “Park Mill D40” (trade name, manufactured by NOF Corporation, containing 40% by mass of dicumyl peroxide) In terms of amount, it corresponds to 0.30 parts by mass.) Was further kneaded at 120 pm at 60 pm for 2 minutes to obtain chemical mechanical polishing pad composition pellets. 1500 grams of the pellets were molded by heating at 170 ° C. for 18 minutes in a mold having a gap of 2.5 mm to obtain a circular flat plate having a diameter of 762 mm and a thickness of 2.5 mm. Furthermore, a double-sided tape manufactured by Sekisui Chemical Co., Ltd., trade name # 5673JX as an adhesive layer was attached to the non-polishing surface side of the flat plate to obtain a chemical mechanical polishing pad A-1.

  In addition, using a commercially available groove processing machine, concentric grooves having a pitch of 2.0 mm, a groove width of 0.25 mm, and a depth (d) of 1.4 mm are formed on the polishing surface side of the previously prepared flat plate to obtain a polishing layer. Got. Furthermore, a double-sided tape manufactured by Sekisui Chemical Co., Ltd., product name # 5673JX as an adhesive layer was attached to the non-polished surface side of this polishing layer to obtain a chemical mechanical polishing pad A-2.

3.2. Production Example 2 (Production of chemical mechanical polishing pads B-1, B-2, C-1, C-2, D-1, and D-2)
Chemical mechanical polishing pads B-1 and C in which concentric grooves are not formed on the polishing surface are the same as in Production Example 1 except that the types and amounts used of the respective raw materials in Production Example 1 are as shown in Table 1. -1, and D-1 and chemical mechanical polishing pads B-2, C-2, and D-2 having concentric grooves formed on the polishing surface were obtained. However, the abbreviations used in Table 1 are shown below.

RB830: 1,2-polybutadiene (manufactured by JSR Corporation, trade name “JSR RB830”)
HF55: Polystyrene (manufactured by PS Japan Ltd., trade name “HF55”)
Granulated sugar G: Nissin Sugar Co., Ltd., trade name “Granulated sugar, G grade”, average particle size 0.6 mm
D40: Nippon Oil & Fat Co., Ltd., trade name “Park Mill D40”, containing 40% by mass of dicumyl peroxide.

Granulated sugar L: manufactured by Nissin Sugar Co., Ltd., trade name “Granulated sugar, L grade”, average particle size 0.4 mm
White coarse sugar F3: manufactured by Nissin Sugar Co., Ltd., trade name “white coarse sugar, F3 grade”, average particle size 1.0 mm

3.3. Production Example 3 (Production of chemical mechanical polishing pads E-1 and E-2)
Further, as Production Example 3, the following chemical mechanical polishing pads E-2 and F-2 were prepared.

  1,2-polybutadiene (trade name “JSR RB830”, manufactured by JSR Corporation) 72.8 parts by mass (corresponding to 73.9 parts by volume) and β-cyclodextrin (β-CD) (Yokohama International Co., Ltd.) 27.2 parts by mass (corresponding to 26.1 parts by volume) manufactured by Bio-Laboratory, trade name “Dexy Pearl β-100”, average particle diameter 20 μm) were kneaded for 2 minutes with a rudder adjusted to 160 ° C. Next, 0.55 parts by mass (dicumyl peroxide per 100 parts by mass of 1,2-polybutadiene) “Park Mill D40” (trade name, manufactured by NOF Corporation, containing 40% by mass of dicumyl peroxide) In terms of amount, it corresponds to 0.30 parts by mass.) Was further kneaded at 120 pm at 60 pm for 2 minutes to obtain chemical mechanical polishing pad composition pellets. 1500 grams of the pellets were molded by heating at 170 ° C. for 18 minutes in a mold having a gap of 2.5 mm to obtain a circular flat plate having a diameter of 762 mm and a thickness of 2.5 mm. Furthermore, a double-sided tape manufactured by Sekisui Chemical Co., Ltd., product name # 5673JX as an adhesive layer was attached to the non-polished surface side of this flat plate to obtain a chemical mechanical polishing pad E-1.

  In addition, using a commercially available groove processing machine, concentric grooves having a pitch of 2.0 mm, a groove width of 0.25 mm, and a depth (d) of 1.4 mm are formed on the polishing surface side of the previously prepared flat plate to obtain a polishing layer. Got. Furthermore, a double-sided tape manufactured by Sekisui Chemical Co., Ltd., product name # 5673JX as an adhesive layer was attached to the non-polishing surface side of this polishing layer to obtain a chemical mechanical polishing pad E-2.

3.4. Production Example 4 (Production of chemical mechanical polishing pads F-1 and F-2)
Further, the chemical mechanical polishing pads F-1 and F-2 were prepared in the same manner as in Production Example 3 except that the types and amounts used of the respective raw materials in the production of the chemical mechanical polishing pads E-1 and E-2 were as shown in Table 2. -2 was obtained.

3.4. Chemical mechanical polishing process 3.1. To 3.3. The chemical mechanical polishing pad manufactured in 1 was mounted on a surface plate of a chemical mechanical polishing apparatus “Reflexion LK” (manufactured by Applied Materials), and the P-TEOS blanket wafer was subjected to chemical mechanical polishing. The conditions for chemical mechanical polishing are as follows.

Aqueous dispersion for chemical mechanical polishing: Silica abrasive-containing slurry manufactured by JSR Corporation, CMS-1101
Aqueous dispersion supply amount: 300 mL / min Plate rotation speed: 63 rpm
Head rotation speed: 60rpm
Head pressing pressure Retainer ring pressure: 8 psi
Membrane pressure: 4.0 psi
Polishing time: 60 seconds Further, before chemical mechanical polishing of the wafer, a diamond dresser manufactured by Mitsubishi Materials (model number MEC-200) was pressed against the pad surface at 5 psi for 20 minutes in advance to sharpen the surface.

  Further, each time one wafer was polished, the diamond dresser was pressed against the pad surface at 5 psi for 20 seconds, and the wafer was continuously polished.

3.5. Evaluation Table 3 shows changes in the polishing rate, the film thickness, and the groove depth when the polishing object (P-TEOS blanket wafer) was chemically mechanically polished using the pads A-1 to F-2. That is, pads A-1, B-1, C-1, D-1, E-1, and F-1 are pads having no grooves on the polishing surface.

  As shown in Table 3, in Comparative Examples 1 to 4, 6, and 8, as the number of wafers polished increases, the groove depth gradually becomes shallow due to wear by the diamond dresser, and the polishing rate depends on the groove depth. A decrease was observed. That is, in this case, it is considered that the retention ability of the chemical mechanical polishing aqueous dispersion in the groove was reduced due to the shallow depth of the groove. Moreover, in Comparative Examples 5-8, since the average particle diameter of water-soluble particle | grains is less than 0.1 micrometer, polishing rate was not enough.

  On the other hand, in Examples 1 to 4, as the number of wafers to be polished increases, the chemical mechanical polishing pad is thinned by being worn by the diamond dresser, but is caused by water-soluble particles having an average particle diameter of 0.1 to 2 mm. It can be understood that a constant polishing rate was maintained because the chemical mechanical polishing aqueous dispersion was stably held in the predetermined volume of the recess. This shows that the chemical mechanical polishing pad of the present invention has a long product life.

  This is the end of the description of the present embodiment. The present invention is not limited to the above-described embodiments, and various modifications can be made. The present invention also includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations that have the same functions, methods, and results, or configurations that have the same purposes and results). In addition, the present invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that achieves the same effect as the configuration described in the embodiment or a configuration that can achieve the same object. Further, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

FIG. 1 is a cross-sectional view schematically showing a chemical mechanical polishing pad according to an embodiment of the present invention. FIG. 2 is a cross-sectional view schematically illustrating a chemical mechanical polishing method using a chemical mechanical polishing pad according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Chemical mechanical polishing pad, 12 ... Polishing layer, 13 ... Polishing surface, 14 ... Water-insoluble matrix material, 16 ... Water-soluble particle | grains, 18 ... Recessed part, 20 ... To-be-polished object, 22 ... Chemical mechanical polishing aqueous dispersion

Claims (5)

A polishing layer comprising a water-insoluble matrix material and water-soluble particles dispersed in the water-insoluble matrix material;
The water-soluble particles have an average particle size of 0.1 to 2 mm,
A chemical mechanical polishing pad, wherein a groove is not substantially provided on a surface of the polishing layer.   The chemical mechanical polishing pad according to claim 1, wherein an average particle diameter of the water-soluble particles is 0.03 to 0.95 with respect to a film thickness of the polishing layer.   The chemical mechanical polishing pad according to claim 1 or 2, wherein the water-soluble particles are 1 to 50% by volume when the total of the water-insoluble matrix material and the water-soluble particles is 100% by volume.   The chemical mechanical polishing pad according to claim 1, wherein the water-soluble particles are sugars.   A chemical mechanical polishing method comprising chemically mechanically polishing an object to be polished using the chemical mechanical polishing pad according to claim 1.

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