KR100640141B1 - Chemical mechanical polishing pad, manufacturing process thereof and chemical mechanical polishing method - Google Patents

Abstract

The polished surface has an arithmetic surface roughness (R _a ) of 0.1 to 15 µm, a ten-point average height (R _z ) of 40 to 150 µm, a core roughness depth (R _k ) of 12 to 50 µm, and attenuated acid Provided are a chemical mechanical polishing pad, a manufacturing method thereof, and a chemical mechanical polishing method comprising a surface having a height R _pk of 7 to 40 μm. According to this pad, even if a large-diameter wafer is subjected to chemical mechanical polishing as a to-be-polished body, a to-be-polished surface excellent in in-plane uniformity and flatness can be formed.

Surface Roughness, Chemical Mechanical Polishing Pad, Polished Surface, Polished Surface, Wafer

Description

TECHNICAL MECHANICAL POLISHING PAD, MANUFACTURING PROCESS THEREOF AND CHEMICAL MECHANICAL POLISHING METHOD

BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing which shows the definition of 10-point average height R _z .

2 is an explanatory diagram showing the definition of a load curve;

3 is an explanatory diagram showing the definition of core roughness depth R _k .

4 is an explanatory diagram showing the definition of the damping peak height R _pk .

Document 1 JP 11-70463 A

[Document 2] JP 8-216029 A

Document 3 JP 2000-34416 A

Document 4 JP 2000-33552 A

Document 5 JP 2001-334455 A

The present invention relates to a chemical mechanical polishing pad, a method for producing the same, and a chemical mechanical polishing method.

More specifically, a chemical mechanical polishing pad capable of providing a polished surface having excellent in-plane uniformity and flatness when the surface to be polished is subjected to chemical mechanical polishing, a method for producing the same, and a chemical mechanical polishing performed using the chemical mechanical polishing pad. It is about a method.

In the semiconductor manufacturing process, chemical mechanical polishing (commonly abbreviated as "CMP") is employed as a technique for obtaining a wafer surface having high flatness. Chemical mechanical polishing is a chemical mechanical polishing slurry which is an aqueous dispersion in which abrasive grains are dispersed on a surface of a chemical mechanical polishing pad while sliding the surface to be pressed while the surface to be polished is pressed against the surface of the chemical mechanical polishing pad. It is a technique of performing chemical mechanical polishing while flowing down. In this chemical mechanical polishing, it is known that the properties and properties of the chemical mechanical polishing pad greatly influence the polishing result.

As chemical mechanical polishing pads, pads made of foamed resin such as polyurethane foam containing a large number of fine voids and pads in which a large number of fine water-soluble particles are dispersed in a non-foaming matrix are known. 11-70463 A and JP 8-216029 A. For the latter see JP 2000-34416 A, JP 2000-33552 A and JP 2001-334455 A).

By the way, in the semiconductor manufacturing process, productivity improvement is calculated | required in recent years, and there exists a tendency for the diameter of the wafer which requires chemical mechanical polishing to become large.

If such large-diameter wafers are subjected to chemical mechanical polishing by a method known in the art, in-plane uniformity and flatness of the to-be-polished surface after chemical mechanical polishing may be insufficient, which is a problem.

The present invention has been made in view of the above problems, and an object thereof is a chemical mechanical polishing pad capable of providing a polished surface having excellent in-plane uniformity and flatness even when chemical mechanical polishing is performed on a large-diameter wafer as an abrasive. And a chemical mechanical polishing method.

Still other objects and advantages of the present invention will become apparent from the following description.

According to the present invention, the above objects and advantages of the present invention are, firstly,

The polished surface and the non-polished surface, and the polished surface has arithmetic surface roughness (R _a ) of 0.1 to 15 μm, 10 point average height (R _z ) of 40 to 150 μm, and core roughness depth (R _k ) Is 12 to 50 µm and the damping height R _pk is 7 to 40 µm.

The objects and advantages of the present invention, secondly,

Forming a polishing layer and subsequently sanding at least the surface to be the polishing surface.

In addition, the above object and advantages of the present invention is third,

It is achieved by a chemical mechanical polishing method characterized by chemical mechanical polishing of a polished object using the chemical mechanical polishing pad.

In the chemical mechanical polishing pad of the present invention, the arithmetic surface roughness (R _a ) of the surface on the polishing surface is 0.1 to 15 µm, the 10-point average height (R _z ) is 40 to 150 µm, and the core roughness depth (R). _k ) is 12-50 micrometers, and the damping peak height _Rpk is _7-40 micrometers.

These values are defined as an average value of the following numerical values calculated from the roughness curves measured for each of the plurality of measurement lines set on the pad surface. For example, Mitani Shosha Co., Ltd. issued an "LM manual ( Analog version), Version 3.62 ".

Arithmetic surface roughness (R _a ) is the roughness curve of the measurement length (L), taking the x-axis in a direction parallel to the average line of the roughness curve, and taking the y-axis in the direction of the vertical magnification of the roughness curve, the measured roughness curve is the equation y When it is represented by f (x), it is the value represented by following formula (1).

The 10-point average height R _z is vertical from the average line when the x-axis is taken in the direction parallel to the average line of the roughness curve with respect to the roughness curve of the measurement length L, and the y-axis is taken in the direction of the vertical magnification of the roughness curve. The distance from the average line of the top of the mountain to the fifth peak from the highest peak measured in the direction of magnification is P ₁ to P ₅ , respectively, and the distance from the bottom of the valley of the bottom to the fifth valley of the lowest valley. Is a value represented by the following [Equation 2] when each is set to V ₁ to V ₅ (see FIG. 1).

The core roughness depth R _k and the damping height R _pk are defined by the load curve derived from the roughness curve of the measurement length L.

The load curve is a graph obtained by graphing the vertical axis as the cutting level and the horizontal axis as the load length ratio. Here, the cutting level means a specific value of y when the roughness curve is represented by the same equation V = f (x) as in the arithmetic surface roughness Ra _a . In addition, load length ratio is a percentage with respect to the measurement length L of the cutting part length when cutting a roughness curve at a constant cutting level. However, the load length ratio is set to 0% when the cutting level is at the top of the highest peak of the roughness curve and 100% when it is at the bottom of the lowest valley (see Fig. 2).

The core roughness depth R _k takes two points A and B where the difference in the value of the load length ratio is 40% on the load curve defined above, and the difference in the cutting level on the load curve is minimum, and is a straight line. When AB is extended in both directions, the cutting level of point C and point D when the intersection point with the line showing the load length ratio = 0% is set to point C and the intersection point with the line showing the load length ratio = 100% is set as D point. The difference of (see Fig. 3).

Damping height (R _pk ) is the intersection of the cutting level and the load curve passing through the point C in the definition of the core roughness depth (R _k ) as the H point, and the line showing the load curve and the load length ratio = 0%; The point C at the point where the point of intersection is the point I, and the area surrounded by the line segment CH, the line segment CI, and the curve HI is equal to the area of the triangle CHJ is taken on the straight line indicating the load length ratio = 0%. (See Fig. 4. In addition, in Fig. 4, "A1" is an area surrounded by line CH, line CI and curve HI, that is, area of triangle CHJ).

A plurality of measurement lines for measuring the arithmetic surface roughness (R _a ), the ten point average height (R _z ), the core roughness depth (R _k ), and the damping peak height (R _pk ) are set on the pad as follows. do.

First, the center points of the plurality of measurement lines are set as follows. The center point of the measurement line draws an imaginary straight line so that its length becomes maximum from any one point of the pad polishing surface end to the other point (when the pad polishing surface is circular, the virtual straight line forms a circle forming the pad surface). 10 to 50 on the imaginary straight line, except for the range of 5% of the imaginary straight line length on both sides from the center of the imaginary straight line, and the 5% of the imaginary straight line length from the both ends, respectively. The point is set. The number of center points of the measurement line is preferably 25 to 50 points.

Here, although the groove | channel may be formed in the grinding | polishing surface of the chemical mechanical polishing pad of this invention so that it may mention later, the center point of the measurement line in that case is so that all of the measurement lines set as mentioned later may become a part other than the groove | channel on a grinding | polishing surface. Should be set. Depending on the shape of the grooves formed on the polished surface, it may not be possible to set 10 to 50 measuring points at equal intervals on the electric virtual straight line, but at that time, a part of the measuring lines may be set to be approximately equal. It is sufficient to secure the number of points except for the point touching the groove. Subsequently, a straight line passing perpendicular to the hypothetical straight line assumed to set these points and passing through the "center point of the measuring line" can be assumed to be a measuring line. As a length of a measuring line, it can be about 1-15 mm centering on the center point of the said measuring line.

In addition, the roughness curve can be measured using a commercially available surface roughness machine.

For the chemical mechanical polishing pad of the present invention, the arithmetic mean roughness (R _a) of the abrasive face the surface to be measured in this manner is 0.1 to 15 ㎛. This value becomes like this. Preferably it is 0.1-12 micrometers. In addition, the 10 point average height R _z is 40-150 micrometers. It is preferable that it is 40-130 micrometers. Core roughness depth R _k is 12-50 μm. It is preferable that it is 12-45 micrometers. The damping peak height R _Pk is 7 to 40 μm. It is preferable that it is 7-30 micrometers.

When a chemical mechanical polishing process is performed by using a chemical mechanical polishing pad having these values set in this range, a to-be-polished surface excellent in in-plane uniformity and flatness can be obtained. This effect is remarkable especially when chemically polishing a large diameter wafer.

Preferably, the chemical mechanical polishing pad of this invention has a thickness distribution of 50 micrometers or less. By setting the thickness distribution of the chemical mechanical polishing pad to 50 µm or less, the effect of the present invention is more advantageously exerted. This value is more preferably 40 µm or less, and particularly preferably 30 µm or less. By setting the thickness distribution of the chemical mechanical polishing pad in this range, even if a large-diameter wafer is subjected to chemical mechanical polishing as an abrasive, a to-be-polished surface excellent in in-plane uniformity and flatness can be obtained.

Here, the thickness distribution can be calculated by the following formula by measuring the thickness of a plurality of measurement points set on the pad surface.

Thickness distribution = (maximum value of measured value of thickness)-(minimum value of measured value of thickness)

The measuring point draws an imaginary straight line from one point of the end of the pad polishing surface to the other point so that its length becomes the maximum (when the pad polishing surface is circular, the virtual straight line is formed of a circle forming the pad surface. Diameter), approximately 10 to 50 points on the imaginary straight line, except for the range of 5% of the imaginary straight line length on both sides from the center of the imaginary straight line, and the range of 5% of the imaginary straight line length from the both ends, respectively. Is set. The number of measurement points becomes like this. Preferably it is 25-50 points.

Here, although the groove | channel may be formed in the grinding | polishing surface of the chemical mechanical polishing pad of this invention as mentioned later, the measuring point in that case should be set in parts other than the groove | channel on a grinding | polishing surface. Depending on the shape of the grooves formed on the polished surface, it may not be possible to set 10 to 50 measuring points at equal intervals on the electric virtual straight line, but at that point, the points in the grooves are set to be approximately equal. It is sufficient to secure the above measurement points except.

The thickness at each measurement point can be known by placing the chemical mechanical polishing pad on the horizontal plane and measuring the distance between the measurement point and the horizontal plane. A contact type distance measuring apparatus can be used for measuring the distance between the measuring point and the horizontal plane. As this commercial item, "manual three-dimensional measuring machine" (made by Mitsutoyo Co., Ltd.) etc. are mentioned, for example.

The shape of the chemical mechanical polishing pad of the present invention is not particularly limited. For example, it can be set as disk shape, belt shape, roller shape, etc. It is preferable to select suitably according to a grinding | polishing apparatus. In addition, the size of the chemical mechanical polishing pad before use is not particularly limited. In disc shaped chemical mechanical polishing pads, the diameter is, for example, 0.5 to 500 cm, preferably 1.0 to 250 cm, more preferably 20 to 200 cm. The thickness may be, for example, more than 0.1 mm and 100 mm or less, preferably 1 to 10 mm.

The chemical mechanical polishing pad of the present invention may have grooves or recesses of any shape on the polishing surface. This groove or recess has a function of holding a chemical mechanical polishing aqueous dispersion supplied at the time of chemical mechanical polishing and evenly distributing it to the surface to be polished of the polished surface, It also serves as a path for temporarily holding waste such as polishing waste liquid and discharging the waste to the outside.

Although the shape of the said groove | channel is not specifically limited, Circular shape, a grid | lattice form, a radial shape, etc. are mentioned as an example. As a shape of the said recessed part, circular shape, a polygonal shape, etc. can be mentioned. In addition, the cross-sectional shape of a groove | channel or a recessed part is not specifically limited. For example, it may be rectangular, trapezoidal, U-shaped, V-shaped, or the like.

These grooves or recesses may be one, or may be a plurality.

The size of the grooves or recesses is not particularly limited. The width of the groove or the shortest diameter of the recess may be, for example, 0.1 mm or more, and may be 0.1 to 0.5 mm, and in particular, 0.2 to 3.0 mm. The depth of the groove or recess may be, for example, 0.1 mm or more, and may also be 0.1 to 2.5 mm, in particular 0.2 to 2.0 mm.

It is preferable that it is 20 micrometers or less, and, as for the surface roughness of the inner surface of the said groove | channel or recess, it is more preferable that it is 15 micrometers or less. By setting the surface roughness of the inner surface of the groove or the recessed portion to a value within this range, when chemical mechanical polishing is performed using the pad, it is possible to reduce the generation of clutches on the surface to be polished of the polished body and to reduce the polishing rate. It also contributes to the improvement and the life of the polishing pad. Here, it is inferred that the polishing rate is improved by making the surface roughness of the grooves or the inner surface of the recesses within the above range because the function of distributing the chemical mechanical polishing aqueous dispersion to the surface to be polished is performed better. In addition, it is inferred that the lifespan of the polishing pad is improved by making the surface roughness of the groove or recess inner surface within the above range because the discharge function of the waste generated during chemical mechanical polishing is performed more efficiently.

The said surface roughness can be measured using an optical surface roughness measuring apparatus, a contact surface roughness measuring apparatus, etc., for example. As said optical surface roughness measuring apparatus, a three-dimensional surface structure analysis microscope, a scanning laser microscope, an electron beam surface form analyzer, etc. are mentioned, for example. As said contact surface roughness measuring apparatus, a stylus type surface roughness machine etc. are mentioned, for example.

The chemical mechanical polishing pad of the present invention may further have a groove or a recessed portion on the non-abrasive surface side (back side of the pad).

The grooves or recesses contribute to suppression of surface defects on the surface to be polished in the chemical mechanical polishing step. The concave portion is provided with coarse particles that may exist in the chemical mechanical polishing aqueous dispersion between the polishing pad and the polished object, and foreign matter such as cutting chips derived from the manufacturing process of the chemical mechanical polishing pad. Even if it has a function of alleviating the excessively generated local pressure, it is inferred to act to reduce the surface defect of the to-be-polished surface.

The shape of the groove or the recess is not particularly limited. The shape of the grooves may be, for example, spiral, annular, lattice, or the like, and the shape of the recess may be, for example, circular, polygonal, or the like.

The size of the groove or the recess can be arbitrarily set. When the recess is circular, for example, it may be 1 to 300 mm in diameter, and may also be 5 to 200 mm, in particular 10 to 150 mm. The width when the groove is spiral, annular or lattice-shaped can be, for example, 0.1 to 20 mm, and can also be 0.1 to 10 mm. The depth of the groove or recess may be, for example, 0.01 to 2.0 mm, and may also be 0.1 to 1.5 mm, particularly 0.1 to 1.0 mm, regardless of its shape.

Only one of these grooves or recesses may be formed, or two or more of these grooves may be formed.

The chemical mechanical polishing pad of the present invention has a thickness distribution of 50 µm or less as described above, and optionally has grooves or recesses on the polishing surface and / or the non-polishing surface. Although the manufacturing method does not matter, it can manufacture by the method containing the following processes, for example.

(1) Process of preparing the composition for chemical mechanical polishing pads

(2) forming a polishing layer using the chemical mechanical polishing pad composition; and

(3) sanding the surface to be at least the polishing surface of the polishing layer;

Hereinafter, each process is explained in full detail.

(1) Process of preparing the composition for chemical mechanical polishing pads

The chemical mechanical polishing pad of the present invention may be made of any material as long as the object of the present invention can be achieved. Among the functions as a chemical mechanical polishing pad, it is preferable that a pore having a function such as holding a chemical mechanical polishing aqueous dispersion during chemical mechanical polishing and temporarily retaining a polishing chip is formed until polishing. For this reason, it is preferable to provide the raw material which consists of a water-insoluble matrix and the water-soluble particle which disperse | distributed, or the material which consists of a water-insoluble matrix material which disperse | distributed a cavity and a cavity, for example, foam.

Among these materials, the former material can dissolve or swell by desorbing in contact with the aqueous medium of the slurry containing the aqueous medium and the solid content when the water-soluble particles are polished, and retain the slurry in the pores formed by the detachment. On the other hand, the latter material can hold a slurry in a pore previously formed as a cavity.

Although the material which comprises said "water-insoluble matrix" is not specifically limited, The organic material is used preferably because it is easy to shape | mold to a predetermined shape and a characteristic, and can provide an appropriate hardness, an appropriate elasticity, etc. As the organic material, for example, thermoplastic resins, elastomers, rubbers, for example, crosslinked rubbers and cured resins, for example, resins cured by heat and light such as thermosetting resins and photocurable resins, etc. may be used alone or in combination. .

Among these, as the thermoplastic resin, for example, 1, 2-polybutadiene resin, polyolefin resin such as polyethylene, polystyrene resin, polyacrylic resin, for example, (meth) acrylate resin, vinyl ester resin (except acrylic resin) ), Polyester resins, polyamide resins, fluorine resins such as polyvinylidene fluoride, polycarbonate resins, polyacetal resins, and the like.

As the elastomer, for example, a diene elastomer such as 1,2-polybutadiene, a polyolefin elastomer (TPO), a styrene-butadiene-styrene block copolymer (SBS), a styrene elastomer such as a hydrogenated block copolymer (SEBS), Thermoplastic elastomers such as thermoplastic polyurethane elastomers (TPU), thermoplastic polyester elastomers (TPEE), polyamide elastomers (TPAE), silicone resin elastomers, fluororesin elastomers, and the like. Examples of the rubber include butadiene rubber, for example, high cis butadiene rubber and low cis butadiene rubber, such as isoprene rubber, styrene butadiene rubber, conjugated diene rubber such as styrene-isoprene rubber, and acrylonitrile butadiene. Nitrile rubbers such as rubber, acrylic rubbers, ethylene propylene rubbers, ethylene-?-Olefin rubbers and butyl rubbers such as ethylene-propylene-diene rubbers, and other rubbers such as silicone rubbers and fluorine rubbers.

Examples of the cured resins include urethane resins, epoxy resins, acrylic resins, unsaturated polyester resins, polyurethane-urea resins, urea resins, silicon resins, phenol resins, and vinyl ester resins.

In addition, these organic materials may be modified with an acid anhydride group, a carboxyl group, a hydroxyl group, an epoxy group, an amino group, or the like. By modification, affinity with the water-soluble particle mentioned later and a slurry can be adjusted.

Only one type may be used for these organic materials and they may use two or more types together.

In addition, these organic materials may be a crosslinked polymer in which part or all of them are crosslinked, or may be a non-crosslinked polymer. Therefore, the water-insoluble matrix may consist only of a crosslinked polymer, may be a mixture of a crosslinked polymer and a noncrosslinked polymer, or may consist only of a noncrosslinked polymer. However, it is preferable to consist only of a crosslinked polymer, or a mixture of a crosslinked polymer and a noncrosslinked polymer. By containing a crosslinked polymer, elastic recovery force is provided to a water-insoluble matrix, and the displacement according to the sliding stress applied to a chemical mechanical polishing pad at the time of polishing can be suppressed small. In addition, the water-insoluble matrix may be excessively stretched during polishing and dressing to plastically deform to fill the pores, or excessively fluff on the surface of the chemical mechanical polishing pad may be effectively suppressed. Therefore, even when dressing, a pore is formed efficiently, and the fall of the holding property of the slurry at the time of grinding | polishing can be prevented, or a low fluff does not occur and does not impair polishing flatness. Moreover, the method of performing the said crosslinking is not specifically limited, For example, it can carry out by chemical crosslinking using organic peroxide, sulfur, a sulfur compound, etc., radiation crosslinking by electron beam irradiation, etc.

As this crosslinked polymer, a crosslinked rubber, a cured resin, a crosslinked thermoplastic resin, a crosslinked elastomer and the like can be used among the organic materials. Among these, crosslinked thermoplastic resins and / or crosslinked elastomers are preferable because they are stable to strong acids and strong alkalis contained in many slurries and have little softening due to absorption. Among the crosslinked thermoplastic resins and crosslinked elastomers, those crosslinked using an organic peroxide are particularly preferable, or crosslinked 1, 2-polybutadiene is more preferable.

Although content of these crosslinked polymers is not specifically limited, Preferably it is 30 volume% or more of the whole water-insoluble matrix, More preferably, it is 50 volume% or more, More preferably, it is 70 volume% or more and 100 volume% may be sufficient. When content of the crosslinked polymer in a water-insoluble matrix is less than 30 volume%, the effect containing a crosslinked polymer may not fully be exhibited.

The water-insoluble matrix containing the crosslinked polymer has a residual amount (hereinafter, simply referred to as "breakage residual excess") remaining after fracture when the test member made of the water-insoluble matrix is broken at 80 ° C in accordance with JIS K 6251. It can be set as volume% or less. That is, the total distance between the marking lines after breaking becomes less than twice the distance between the marking lines before breaking. This break residual excess becomes like this. Preferably it is 30% or less, More preferably, it is 10% or less, Especially preferably, it is 5% or less, It is more preferable that it is 0% or more normally. If the residual residual excess exceeds 100%, fine pieces scratched or elongated from the surface of the chemical mechanical polishing pad at the time of polishing and surface renewal tend to easily prevent pores. According to JIS K 6251 "Tensile force test method of vulcanized rubber", this "break residual excess" fractures a test piece in the tensile force test at the test piece shape dumbbell shape No. 3 type | shaft, a tensile speed of 500 mm / min, and a test temperature of 80 degreeC. In this case, it is the elongation obtained by subtracting the distance between the marking lines before the test from the total distance from the marking lines of each of the test pieces broken and divided to the breaking portion. In addition, in actual grinding | polishing, since it generate | occur | produces by sliding, it is a test in the temperature of 80 degreeC.

Said "water-soluble particle" is particle | grains which detach | desorb from a water-insoluble matrix by contacting with the slurry which is an aqueous dispersion in a chemical mechanical polishing pad. The desorption may be generated by dissolving by contact with water or the like contained in the slurry, or may be generated by swelling and containing the water or the like to form a gel. The dissolution or swelling may be not only by water but also by contact with an aqueous mixed medium containing an alcohol solvent such as methanol.

In addition to the effect of forming pores, the water-soluble particles have an effect of increasing the indentation hardness of the chemical mechanical polishing pad in the chemical mechanical polishing pad. For example, by containing water-soluble particles, the Shore D hardness of the chemical mechanical polishing pad of the present invention is preferably 35% or more, more preferably 50 to 90, still more preferably 60 to 85, and usually 100% or less. You can do If the Shore D hardness exceeds 35, the pressure that can be loaded onto the polished object can be increased, and the polishing rate can be improved with this. In addition, high polishing flatness can be obtained. Therefore, it is especially preferable that this water-soluble particle is a solid body which can ensure sufficient indentation hardness in a chemical mechanical polishing pad.

The material which comprises this water-soluble particle is not specifically limited. For example, organic water-soluble particle | grains and inorganic water-soluble particle | grains are mentioned. Examples of the material of the organic water-soluble particles include sugars, for example, polysaccharides such as starch, dextrin and cyclodextrin, lactose and mannitol, celluloses such as hydroxypropyl cellulose and methyl cellulose, proteins and polyvinyl alcohol. And polyvinylpyrrolidone, polyacrylic acid, polyethylene oxide, water-soluble photosensitive resin, sulfonated polyisoprene, sulfonated polyisoprene copolymer and the like. Moreover, as a raw material of inorganic water-soluble particle | grains, potassium acetate, potassium nitrate, potassium carbonate, potassium hydrogen carbonate, potassium chloride, potassium bromide, potassium phosphate, magnesium nitrate, etc. are mentioned, for example. These water-soluble particles can be used alone or in combination of two or more of the above materials. Moreover, one type of water-soluble particle which consists of a predetermined raw material may be sufficient, and two or more types of water-soluble particle which consists of another raw material may be sufficient.

The average particle diameter of the water-soluble particles is preferably 0.1 to 500 µm, more preferably 0.5 to 100 µm. The size of the pore is preferably 0.1 to 500 m, more preferably 0.5 to 100 m. If the average particle diameter of the water-soluble particles is less than 0.1 µm, the size of the formed pores becomes smaller than the abrasive grains to be used, so it is difficult to obtain a chemical mechanical polishing pad capable of sufficiently holding the slurry. On the other hand, if it exceeds 500 µm, the mechanical strength and polishing rate of the chemical mechanical polishing pad, which may increase the size of the formed pores, tends to decrease.

The content of the water-soluble particles is preferably 1 to 90% by volume, more preferably 1 to 60% by volume, and even more preferably when the total amount of the water-insoluble matrix and the water-soluble particles is 100% by volume. Is 2 to 40% by volume. If the content of the water-soluble particles is less than 1% by volume, the pores are not sufficiently formed in the resulting chemical mechanical polishing pad, and the polishing rate tends to be lowered. On the other hand, when it contains water-soluble particles exceeding 90% by volume, it is difficult to sufficiently prevent the water-soluble particles existing inside the chemical mechanical polishing pad from swelling or dissolving in the chemical mechanical polishing pad to be obtained. It is difficult to maintain the hardness and mechanical strength of the polishing pad at an appropriate value.

Furthermore, it is preferable that the water-soluble particles dissolve in water only when exposed to the surface layer in the chemical mechanical polishing pad, and do not absorb or swell within the chemical mechanical polishing pad. For this reason, the water-soluble particle can be provided with the outer edge which suppresses moisture absorption in at least one part of outermost part. This outer edge may be physically adsorbed to the water-soluble particles, may be chemically bonded to the water-soluble particles, or may be in contact with the water-soluble particles by both. As a material which forms such an outline, an epoxy resin, polyimide, polyamide, polysilicate, etc. are mentioned, for example. Moreover, even if this outer edge is formed only in a part of water-soluble particle, the said effect can fully be acquired.

The water-insoluble matrix may contain a compatibilizer to control affinity with the water-soluble particles and dispersibility of the water-soluble particles in the water-insoluble matrix. As the compatibilizer, for example, polymers, block copolymers and random copolymers modified with acid anhydride groups, carboxyl groups, hydroxyl groups, epoxy groups, oxazoline groups and amino groups, and various nonionic surfactants, coupling agents, etc. Can be mentioned.

On the other hand, as a water-insoluble matrix material which comprises the chemical-mechanical polishing pad provided with the water-insoluble matrix material (foam etc.) which the latter cavity disperse | distributed, polyurethane, melamine resin, polyester, polysulfone, poly Vinyl acetate and the like.

The size of the cavity dispersed in such a water-insoluble matrix material is an average value, Preferably it is 0.1-500 micrometers, More preferably, it is 0.5-100 micrometers.

In addition, a chemical mechanical polishing pad having a water-insoluble matrix material formed by dispersing a cavity, for example, a foam or the like, may be used for arithmetic of a surface of a pad, which is a preferable requirement for the chemical mechanical polishing pad of the present invention, depending on the size of the cavity. The chemical mechanical polishing pad of the present invention may not be able to meet the requirements of surface roughness (R _a ), 10-point average height (R _z ), core roughness depth (R _k ), and damping height (R _pk ). It is preferable to provide a polishing layer formed of a material composed of a water-soluble particle and a water-insoluble matrix in which the water-soluble particles are dispersed.

The method of obtaining the composition for chemical mechanical polishing pads from the above materials is not specifically limited. For example, necessary materials, such as a predetermined organic material, can be kneaded with a kneader or the like. As a kneader, a conventionally well-known thing can be used. For example, kneaders, such as a roll, a kneader, a Banbury mixer, and an extruder (single-axis, multi-axis), are mentioned.

In addition, the composition for chemical-mechanical polishing pads containing water-soluble particles for obtaining a chemical-mechanical polishing pad containing water-soluble particles can be obtained by, for example, kneading a water-insoluble matrix, water-soluble particles, other additives, and the like. However, at the time of kneading | mixing, it heats and knead | mixes so that it may be easily processed, but it is preferable that water-soluble particle is solid at this time. By being solid, the water-soluble particles can be dispersed to the above-described preferred average particle diameter regardless of the size of compatibility with the water-insoluble matrix. Therefore, in this case, it is preferable to select the kind of water-soluble particle according to the processing temperature of the water-insoluble matrix to be used.

(2) forming a polishing layer using the chemical mechanical polishing pad composition

The manufacturing method of the polishing layer which should become the chemical mechanical polishing pad of this invention is not specifically limited. For example, a polishing layer can be manufactured by preparing the composition for chemical-mechanical polishing pads used as a polishing layer beforehand, and shape | molding this composition into the shape of a desired shape. At this time, by forming the composition for chemical mechanical polishing pads by using a mold having a pattern to be grooves and / or recesses formed on the surface and / or the rear surface of the polishing layer, the grooves and / or The recess can be formed at the same time. Forming the grooves and / or recesses by mold molding has the advantage of simplifying the process and facilitating the surface roughness of the inner surface of the grooves and / or recesses to be 20 µm or less.

In addition, the grooves and / or recesses on the surface and / or the rear surface of the polishing layer may be formed by cutting, spot facing, or the like after producing the polishing layer having no these. In the case where the grooves and / or recesses are formed by cutting, spot facing, or the like, the step of forming the grooves and / or recesses may be performed before (3) the sander treatment step described later, and (3) after the sander treatment step. You may carry out.

(3) sanding the surface to be at least the polishing surface of the polishing layer;

Next, at least the surface which should be the polishing surface of the polishing layer formed as described above is sanded.

Here, sander processing means the grinding | polishing process by sand paper. Sandpaper refers to a string in which abrasive grains are planted by an adhesive on a base member made of sheet, strip or belt-shaped paper or cloth. As a material which comprises an abrasive grain, the fine crystal of a natural mineral and fine grain of an artificial inorganic compound are mentioned, for example. As a natural mineral, an emery, a garnet, etc. are mentioned, for example, As an artificial inorganic compound, aluminum oxide, silicon carbide, etc. are mentioned, respectively.

It is preferable that it is 20-200 micrometers, and, as for the abrasive grain size used for the said sander process, it is more preferable that it is 25-150 micrometers. It is preferable that it is # 80- # 600, and, as for the particle size mesh of sand paper, it is more preferable that it is # 120- # 400.

In the sander process, it is preferable to use sand paper having a width larger than that of the polishing surface of the polishing layer.

In the sander treatment, the polishing layer is fixed on a horizontal surface with the surface to be the polishing surface facing up, and the entire surface of the polishing surface is in contact with the sand paper so that the relative speed between the polishing surface and the sand paper is preferably 0.1 to 100. It can be carried out by moving the sand paper to m / min, more preferably 0.5 to 50 m / min. This motion may be a rotational motion or a linear motion on the basis of the contact portion between the polishing surface of the polishing layer and the sand paper.

It is preferable that it is 0.05-3.0 mm, and, as for the quantity crushed by sander process, ie, the thickness of the abrasive | polishing layer removed, it is more preferable that it is 0.1-2.0 mm.

The sander process may be performed using only one type of sand paper of one type of particle size mesh, or may be performed in multiple stages using sand papers of different particle size meshes, respectively. Among these, the sander process performed in multiple steps using the sand paper of a different particle size mesh is respectively preferable. As the number of steps, it is preferable that they are 2-10 steps, and it is more preferable that they are 3-6 steps. The amount to be crushed in each step, that is, the thickness of the abrasive layer to be removed is preferably 0.01 to 1.5 mm, more preferably 0.1 to 1.0 mm. In the case where the sander treatment is performed in multiple steps using sand papers of different particle size meshes, it is preferable to proceed to the step of using sand papers of fine particle size mesh in the step of using sand papers of coarse particle size mesh.

The sander treatment can be performed using, for example, a sand blasting apparatus, a belt polishing apparatus, a barrel polishing machine, a puff polishing machine, a ring polishing machine, an electrolytic polishing apparatus, an electrolytic and particle polishing apparatus, or the like. Among these, it is preferable to use a belt polishing apparatus. As a commercial item of a belt grinding | polishing apparatus, for example, TS130D type | mold grinder made by Amitech Corporation, T-142DG type wide belt sander made by Kikugawa Co., Ltd., and Meinan Machinery Works, Ltd. Inc.) wide belt sander etc. are mentioned.

By performing such a grinding process, and the thickness distribution of not more than 50 ㎛, the arithmetic mean roughness (R _a) of 0.1 to 15 ㎛ of the surface of the polished surface, 10-point height (R _z) of 40 to 150 ㎛ and It is possible to easily obtain a chemical mechanical polishing pad having a core roughness depth R _k of 12 to 50 µm and a damping height R _pk of 7 to 40 µm.

Next, the chemical mechanical polishing method of the present invention will be described.

The chemical mechanical polishing method of the present invention can be carried out by a known chemical mechanical polishing method, except that the chemical mechanical polishing pad of the present invention is attached to a commercially available polishing apparatus and used.

Although the kind of to-be-polished surface in that case does not matter, a metal film, a barrier metal film, an insulating film, etc. which are wiring materials are mentioned, for example. As a material which comprises the said metal film, tungsten, aluminum, copper, the alloy containing at least 1 type of these metals, etc. are mentioned, for example. As said barrier metal film, tantalum, titanium, tantalum nitride, titanium nitride, etc. are mentioned, for example. As a material which comprises an insulating layer, silicon oxide etc. are mentioned, for example. The type of chemical mechanical polishing aqueous dispersion to be used should be appropriately selected depending on the type of surface to be polished, the purpose of chemical mechanical polishing, and the like.

As the to-be-polished material of the chemical mechanical polishing method of this invention, it is especially preferable that it is a semiconductor wafer which has at least 1 sort (s) of the above-mentioned material in a to-be-polished surface. Although the size of a semiconductor wafer does not matter, when the chemical-mechanical polishing of a large diameter semiconductor wafer is carried out, the advantage of the chemical mechanical polishing method of this invention appears remarkably. Here, a large-diameter semiconductor wafer means a semiconductor wafer having a diameter of more than 8 inches, and preferably a semiconductor wafer having a diameter of 10 inches or more.

As described above, the chemical mechanical polishing pad of the present invention has an advantage of increasing stability at the time of wafer polishing by making the surface roughness within a certain range. That is, in the conventionally known polishing pads, break-in dressing is required before the new pads are attached to the polishing apparatus and the wafer polishing is performed, but the initial surface dressing is not performed by the surface roughness, or By the initial dressing of a shorter time than before, stable polishing performance is exhibited from the first wafer after mounting.

According to the present invention, there is provided a chemical mechanical polishing pad capable of providing a polished surface having excellent in-plane uniformity and flatness even when chemical mechanical polishing is performed on a large diameter wafer as an abrasive, and a manufacturing method thereof and a chemical mechanical polishing method.

(First embodiment)

1, 2-polybutadiene (JSR RB830), 98 vol%, and β-cyclodextrin (Koshiki Kokusai Biogenkyu Sho Co., Ltd. ) 2% by volume was kneaded with a rudder heated to 155 ° C. Thereafter, 1.0 parts by mass of Park Mill D40 (trade name, manufactured by Nippon Yushi Kabushiki Co., Ltd., containing 40% by mass of dicumyl peroxide) in terms of 100 parts by mass of 1,2-polybutadiene (pure) Converted into dicumyl peroxide, equivalent to 0.4 parts by mass], and kneaded again, and then crosslinked for 18 minutes at 170 ° C. in a press die to obtain a disk-shaped molded body having a diameter of 810 cm and a thickness of 3.3 mm. Sand paper (Novatech) of grain size mesh # 120, # 150, # 220, # 320 while setting this molding to insertion slot of wide belt sander machine (product made by Meinan Seisakusho), and moving at a speed of 0.1m / s Co., Ltd.) for, while the rollers used in turn rotated by 500 rpm subjected to grinding treatment by grinding the molded article surface by 0.04 ㎜ for each mesh, average thickness 2.5 ㎜, thickness distribution of 20 ㎛, arithmetic mean roughness (R _a) is 4.4 ㎛ And a molded body having a 10-point average height R _z of 125 μm, a core roughness depth R _k of 16 μm, and a damping peak height R _pk of 14 μm.

Moreover, in the said sander process, the relative speed of the molded object and sand paper in the contact surface of a molded object and sand paper was 5 m / min.

The thickness distribution is defined as "manual three-dimensional measuring instrument" for 33 points taken uniformly in the radial direction of the surface to be the polished surface of the molded body, except for the range of 40 mm from the center to both sides and the range of 40 mm from each end. (From Mitsutoyo Co., Ltd.) was calculated by the following formula.

Thickness distribution = (maximum value of measured value of thickness)-(minimum value of measured value of thickness)

In addition, arithmetic surface roughness (R _a ), 10-point average height (R _z ), core roughness depth (R _k ), and damping peak height (R _pk ) are from both ends in the radial direction of the surface to be the polishing surface of the molded body. 10 points taken evenly except the range of 40 mm, respectively, about 10 measuring lines (measurement length 10mm) orthogonal to the radial direction of a pad, respectively, by "1LM21P" (made by Lasertech) It is the average value of what was computed from the measured roughness curve.

Subsequently, a concentric groove having a width of 0.5 mm, a pitch of 2 mm, and a depth of 1.0 mm was formed by using a cutting machine (manufactured by Kato Kioka Co., Ltd.) on the surface of the molded body subjected to the sander treatment. Mechanical polishing pads were prepared. In addition, the surface roughness of the inner surface of the groove | channel formed here was 6 micrometers.

This chemical mechanical polishing pad was attached to a chemical mechanical polishing apparatus "Applied Reflexion" made by Applied Material, and initial dressing was performed while supplying deionized water on condition of the following.

Surface rotation speed: 120 rpm

Deionized Water Supply: 100 mL / min

Polishing time: 600 seconds

Subsequently, the wafer with a 12-inch PETEOS film was subjected to chemical mechanical polishing under the following conditions as an object to be polished. In addition, PETEOS film | membrane is a silicon oxide film formed by the chemical vapor deposition method using the tetraethyl silicate (TEOS) as a raw material and using plasma as an acceleration condition.

Surface rotation speed: 120 rpm

Polishing head rotation speed: 36 rpm

Polishing Pressure:

Retainer Ring Pressure = 7.5 psi

Pressure in Zone 1 = 6.0 psi

Pressure in Zone 2 = 3.0 psi

Pressure in Zone 3 = 3.5 psi

Aqueous Dispersion Supply: 300 mL / min

Polishing time: 60 seconds

Aqueous dispersion for chemical mechanical polishing: CMS1101 (manufactured by JSR Corporation)

The thickness of the PETEOS film before and after chemical mechanical polishing was measured for 33 points equally taken except the range of 5 mm from each end in the radial direction on the wafer with the 12-inch PETEOS film, which is the polishing object. From this measurement result, the polishing rate and in-plane uniformity were calculated by the following formula.

Polishing amount = film thickness before polishing-film thickness after polishing

Polishing speed = ∑ (polishing amount) / polishing time

In-plane uniformity = (standard deviation of polishing amount ÷ average value of polishing amount) × 100 (%)

The results are shown in Table 1. When in-plane uniformity is 3 or less, it can be said that in-plane uniformity is favorable.

(2nd Example)

In the first embodiment, the amount of 1, 2-polybutadiene is 80% by volume, the amount of β-cyclodextrin is 20% by volume, and the amount of parkmill D40 is 1, 2-polybutadiene Is 0.8 mass parts (corresponding to pure dicumyl peroxide, equivalent to 0.32 parts by mass) in terms of 100 parts by mass, and the average thickness of 2.5 mm, thickness distribution of 20 µm, and arithmetic surface roughness in the same manner as in the first embodiment. A molded article having _a (R _a ) of 3.4 μm, a 10-point average height (R _z ) of 108 μm, a core roughness depth (R _k ) of 18 μm, and a damping peak height (R _pk ) of 16 μm was obtained.

Subsequently, similarly to the first embodiment, concentric grooves having a width of 0.5 mm, a pitch of 2 mm, a depth of 1.0 mm, and an inner surface roughness of 5 μm were formed on the surface of the molded body subjected to the sander treatment. A polishing pad was prepared.

It evaluated like this 1st Example using this chemical mechanical polishing pad. The results are shown in Table 1.

(Third Embodiment)

In the first embodiment, the amount of 1,2-polybutadiene is 64% by volume, 16% by volume of styrene-butadiene block polymer (manufactured by JSR, Inc., TR2827) is used, and the amount of? -Cyclodextrin is used. in the same manner as the first embodiment except that a 20% by volume, an average thickness of 2.5 ㎜, thickness distribution of 25 ㎛, arithmetic mean roughness (R _a) 3.8 ㎛, 10-point height (R _z) is 115 ㎛, core roughness A molded article having a depth R _k of 15 μm and a damped peak height R _pk of 14 μm was obtained.

Subsequently, on the surface of the molded body subjected to the sander treatment, in the same manner as in the first embodiment, concentric grooves having a width of 0.5 mm, a pitch of 2 mm, a depth of 1.0 mm, and an inner surface roughness of 4.5 µm were formed and chemically formed. Mechanical polishing pads were prepared.

It evaluated like this 1st Example using this chemical mechanical polishing pad. The results are shown in Table 1.

(First Comparative Example)

In the first embodiment, molding was carried out using a mold having an average thickness of 2.5 mm, and was carried out in the same manner as in the first embodiment except that the sander treatment was performed, and the average thickness was 2.5 mm, the thickness distribution was 70 µm, and the arithmetic surface. A molded article having _a roughness (R _a ) of 1.5 µm, a 10-point average height (R _z ) of 25 µm, a core roughness depth (R _k ) of 8 µm, and a damping peak height (R _pk ) of 6 µm was obtained.

Subsequently, in the surface to be used as the polished surface of the molded body, in the same manner as in the first embodiment, concentric grooves having a width of 0.5 mm, a pitch of 2 mm, a depth of 1.0 mm, and an inner surface roughness of 5.5 µm were formed to chemically polish them. The pad was prepared.

It evaluated like this 1st Example using this chemical mechanical polishing pad. The results are shown in Table 1.

Polishing Speed (Å / min) In-plane uniformity (%) First embodiment 2850 1.0 Second embodiment 2700 2.0 Third embodiment 2750 1.5 Comparative Example 1 2800 8.0

(Example 4)

In the first embodiment, the chemical mechanical polishing of the wafer with the 12-inch PETEOS film was performed in the same manner as in the first embodiment except that no initial dressing was performed. Subsequently, the chemical mechanical polishing of the wafer with the 12-inch PETEOS film was sequentially performed, and the chemical mechanical polishing of 10 wafers in total was performed continuously. The polishing rate of each wafer is shown in Table 2.

(2nd comparative example)

In Example 4, chemical mechanical polishing of 10 wafers was performed continuously in the same manner as in Example 4, except that the chemical mechanical polishing pad manufactured in the same manner as the first comparative example was used as the chemical mechanical polishing pad. . The polishing rate of each wafer is shown in Table 2.

Wafer polishing sequence Polishing Speed (Å / min) Fourth embodiment 2nd comparative example One 2830 1830 2 2850 1850 3 2870 1910 4 2820 2100 5 2840 2510 6 2850 2840 7 2880 2860 8 2870 2870 9 2850 2840 10 2840 2830

According to the present invention, even when a large diameter wafer is subjected to chemical mechanical polishing as an object to be polished, a chemical mechanical polishing pad capable of providing a polished surface having excellent in-plane uniformity and flatness, a manufacturing method thereof, and a chemical mechanical polishing method are provided.

Claims (5)

The polished surface and the non-polished surface, and the polished surface has arithmetic surface roughness (R _a ) of 0.1 to 15 μm, 10 point average height (R _z ) of 40 to 150 μm, and core roughness depth (R _k ) A chemical mechanical polishing pad comprising 12 to 50 µm and a damping height R _pk of 7 to 40 µm. The chemical mechanical polishing pad of claim 1, wherein the thickness distribution is 50 μm or less. A method for producing the chemical mechanical polishing pad according to claim 1 or 2, comprising the step of molding the polishing layer and subsequently sanding at least the surface to be the polishing surface. A chemical mechanical polishing method of subjecting a polishing object to chemical mechanical polishing using the chemical mechanical polishing pad according to claim 1. The chemical mechanical polishing pad according to claim 1, wherein the chemical mechanical polishing pad is made of a material composed of water-soluble particles and water-insoluble particles in which the water-soluble particles are dispersed.

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