KR20140062095A - Polishing pad - Google Patents

Abstract

A polishing pad for chemical mechanical polishing having at least an abrasive layer, wherein the abrasive pad has a first groove and a second groove on the polishing surface of the abrasive layer, the first and second grooves are formed in the groove- And an angle formed between the polishing surface and a side surface continuous with the polishing surface is at least 105 degrees and less than or equal to 150 degrees at the edge portion of at least one groove width direction, The angle formed between the polishing surface and the side surface continuous to the polishing surface is 60 degrees or more and 105 degrees or less at both of the two edge portions in the groove width direction.

Description

Polishing pad {POLISHING PAD}

The present invention relates to a polishing pad. More particularly, the present invention relates to a polishing pad that is preferably used to form a flat surface in a semiconductor, a dielectric / metal complex, and an integrated circuit.

As the density of semiconductor devices becomes higher, the importance of technologies such as multilayer wiring, the formation of an interlayer insulating film thereon and the formation of electrodes such as plugs and damascene are increasing. Accordingly, the importance of the planarization process of the interlayer insulating film and the metal film of the electrode is also increasing. As an efficient technique for this planarization process, a polishing technique called CMP (Chemical Mechanical Polishing) is spreading.

Generally, a CMP apparatus is composed of a polishing head for holding a semiconductor wafer to be processed, a polishing pad for polishing the object to be processed, and an abrasive plate for holding the polishing pad. A polishing technique called CMP is a technique of polishing a material to be polished while supplying a slurry by using a polishing pad having a polishing layer. CMP polishing of a semiconductor wafer refers specifically to a method in which a semiconductor wafer (hereinafter simply referred to as a wafer) and a polishing pad are relatively moved using a slurry to remove a protruded portion of the wafer surface, .

CMP polishing has required characteristics such as securing the local flatness of the wafer, global flatness, preventing occurrence of defects, and securing a high polishing rate. Therefore, in order to achieve these required characteristics, various studies have been conducted on the configuration of the grooves of the polishing pad (groove pattern, groove cross-sectional shape, etc.), which is one of the factors affecting the polishing characteristics.

For example, there has been known a technique of stabilizing the polishing characteristics by forming the grooves formed on the surface of the polishing layer in a V-shaped or U-shaped cross-sectional shape and forming a groove pattern in a spiral shape or a knitting nose shape 1).

In this technique, a burr is formed in a corner portion due to a scratch on the surface of the wafer at the corner portion in the cross-sectional shape of the groove, dressing performed before or after polishing in the cross-sectional shape, or the like, . As a technique for solving the problem, there is known a technique of forming an inclined surface at a boundary between a polishing surface and a groove (see Patent Documents 2 and 3).

Japanese Patent Application Laid-Open No. 2001-212752 Japanese Patent Application Laid-Open No. 2010-45306 Japanese Patent Application Laid-Open No. 2004-186392

Here, the present inventors have found that, by forming a sloped surface at a specific angle in the boundary between the polishing surface and the groove, a suction force acts between the wafer and the polishing pad, the polishing rate is increased, and the in-plane uniformity is improved. It is important to form a sloped surface at the boundary between the polishing surface and the groove. Therefore, it is suitable, for example, for a groove having a V-shaped sectional shape. Further, considering the manufacturing process, the cross-sectional shape of the groove is preferable because it is a simple figure.

However, the inventors of the present invention found that when the cross-sectional shape of the groove is a V-shape, the polishing pad wears due to the use of the polishing pad and the slurry supply and discharge functions are not sufficient at the polishing pad end of life It is found that the polishing defects caused by the abrasion are increased.

SUMMARY OF THE INVENTION In view of the problems of the prior art, it is an object of the present invention to provide an abrasive pad which has a high polishing rate and good in-plane uniformity while increasing abrasive defects The present invention provides a polishing pad that does not require a polishing pad.

The present inventors have found that a groove (for example, a V-shape) having an inclined surface at a specific angle to a boundary between a polishing surface and a groove for increasing a polishing rate and improving in-plane uniformity and a polishing pad (For example, a trapezoid close to an I-shaped or I-shaped groove) for maintaining the supply and discharge functions of the slurry.

Therefore, the present invention employs the following means to solve the above problems. That is, the polishing pad of the present invention is a polishing pad for chemical mechanical polishing having at least a polishing layer, and has a first groove and a second groove on the polishing surface of the polishing layer, Wherein the first groove has a side surface continuous with the polishing surface at a rim end portion in the groove width direction and the side surface of the first groove has a side surface extending from the polishing surface to the polishing surface, Wherein an angle between the polishing surface and a side surface continuous to the polishing surface is equal to or greater than 60 degrees and equal to or less than 105 degrees at both sides of two edge portions in the groove width direction, do.

According to the present invention, it is possible to provide a polishing pad which, while maintaining a high polishing rate and good in-plane uniformity, wears the polishing pad as the use of the polishing pad and does not increase polishing defects even when the feeding and discharging functions of the slurry are reduced have.

1A is a diagram showing a cross-sectional shape (first example) of a first groove of a polishing pad according to an embodiment of the present invention.
1B is a view showing a cross-sectional shape (second example) of the first groove of the polishing pad according to one embodiment of the present invention.
1C is a diagram showing a cross-sectional shape (third example) of the first groove of the polishing pad according to one embodiment of the present invention.
FIG. 1D is a view showing a cross-sectional shape (fourth example) of the first groove of the polishing pad according to one embodiment of the present invention. FIG.
2A is a diagram showing a cross-sectional shape (first example) of a second groove of a polishing pad according to an embodiment of the present invention.
Fig. 2B is a view showing a sectional shape (second example) of the second groove of the polishing pad according to one embodiment of the present invention. Fig.
2C is a diagram showing a cross-sectional shape (third example) of the second groove of the polishing pad according to one embodiment of the present invention.
FIG. 2D is a view showing a cross-sectional shape (fourth example) of the second groove of the polishing pad according to one embodiment of the present invention. FIG.
Fig. 2E is a view showing a cross-sectional shape (fifth example) of the second groove of the polishing pad according to one embodiment of the present invention. Fig.
FIG. 2F is a view showing a sectional shape (sixth example) of the second groove of the polishing pad according to one embodiment of the present invention. FIG.
3A is a cross-sectional view showing a configuration example (first example) of a unit unit including first and second grooves.
3B is a cross-sectional view showing a configuration example (second example) of the unit unit including the first and second grooves.
3C is a sectional view showing a configuration example (third example) of the unit unit including the first and second grooves.
FIG. 3D is a sectional view showing a structural example (fourth example) of the unit unit including the first and second grooves.
3E is a cross-sectional view showing a configuration example (fifth example) of the unit unit including the first and second grooves.
FIG. 3F is a sectional view showing a configuration example (sixth example) of the unit unit including the first and second grooves. FIG.
3G is a cross-sectional view showing a configuration example (seventh example) of the unit unit including the first and second grooves.
3H is a sectional view showing a configuration example (eighth example) of the unit unit including the first and second grooves.
Fig. 3I is a sectional view showing a configuration example (ninth example) of the unit unit including the first and second grooves. Fig.
4 is a diagram schematically showing an example of the arrangement of the first grooves on the polishing surface of the polishing pad according to one embodiment of the present invention.

Hereinafter, the present invention will be described in detail.

The polishing pad of the present invention is a polishing pad having at least a polishing layer and has a groove A (first groove) and a groove B (second groove) on the polishing surface of the polishing layer. The groove A and the groove B each have a side surface continuous with the polishing surface at the edge portion in the groove width direction. In the grooves A, the angle formed between the polishing surface and the side surface continuous to the polishing surface in the at least one grooved edge portion is greater than 105 degrees and equal to or less than 150 degrees. The groove B has an angle formed by both the polishing surface and the side surface continuous to the polishing surface at 60 degrees or more and 105 degrees or less at both sides of the edge portion in the groove width direction.

The angle formed by the polishing surface and the side surface continuous to the polishing surface in the grooved edge portion of at least one of the grooves A is greater than 105 degrees but less than 150 degrees so that a suction force acts between the wafer and the polishing pad, Is expected to rise. In addition, it is thought that the polishing pad is uniformly brought into contact with the wafer surface by the action of the suction force, thereby imparting a high in-plane uniformity to the polishing rate of the wafer.

If the angle formed by the polishing surface and the side surface continuous to the polishing surface is too large, the surface area of the polishing pad is reduced and the cross-sectional area of the groove is excessively large, so that the slurry is excessively discharged and the polishing rate is lowered. On the other hand, if it is too small, the effect of suction on the sloped groove side surface is not exhibited. Therefore, the angle formed by the polished surface and the side surface continuous to the polishing surface needs to be more than 105 degrees but not more than 150 degrees, preferably 110 degrees or more, more preferably 115 degrees or more, and more preferably 120 degrees or more.

The groove A may have a bottom surface. The bottom surface is a surface continuous to the side opposite to the polishing surface with respect to the side surface continuous to the polishing surface, and is a surface connected to the other side surface facing the polishing surface. The shape of the bottom surface is not particularly limited.

Figs. 1A to 1D are views showing specific examples of the cross-sectional shape of the groove A. Fig.

The groove A 101 shown in Fig. 1A has a V-shaped cross-sectional shape. The groove A (101) has two side surfaces (2) continuous to the polishing surface (1) at the edge portion in the groove width direction. In the case shown in Fig. 1A, the angle &thetas; _A between the polished surface and the side surface continuous to the polished surface is equal to each other at the two edge portions in the groove width direction, and the value is more than 105 degrees and less than 150 degrees, as described above.

The groove A 102 shown in Fig. 1B has a substantially U-shaped bottom surface 3 between two side surfaces 2.

The groove A 103 shown in Fig. 1C has a trapezoidal cross-sectional shape and has a bottom surface 4 parallel to the polishing surface 1 between the two side surfaces 2.

The groove A 104 shown in Fig. 1D has a concave portion 5 formed between two side surfaces 2 in a direction orthogonal to the polishing surface 1, It is parallel.

As for the side surface continuous to the polishing surface in the groove A, if the angle between the polishing surface and the polishing surface at the edge portion can be maintained at more than 105 DEG C but not more than 150 DEG C even if the polishing pad is worn, the curved line, Or a combination thereof.

Here, the grooves A constituting the polishing pad need not be one kind. For example, by combining grooves having a plurality of different cross-sectional shapes with at least one of the angle formed by the polishing surface and the side surface continuous to the polishing surface being greater than or equal to 105 degrees and less than or equal to 150 degrees, As shown in Fig. Further, from the viewpoint of in-plane uniformity, it is more preferable to constitute the polishing pad by one kind of groove A.

The polishing pad is conditioned by conditioning the dressing of the pad surface by using a conditioner in which diamond is placed on a metal or ceramic pedestal during polishing. By carrying out the conditioning, the surface of the polishing pad maintains the shape of irregularities suitable for polishing, and stable polishing can be performed. However, by conditioning, the abrasive layer is ground, and the grooves are reduced as the polishing proceeds. When the cross-sectional area of the grooves is reduced, the balance of the supply and discharge of the slurry is deteriorated, and adverse influences such as a decrease in the polishing rate and an increase in defects may occur.

For example, when the cross-sectional shape of the groove is only the V-shape, sufficient slurry supply and discharge functions are provided at the initial stage of polishing. However, in the case of the end of the life of the polishing pad in which the cross- There is a case that problems such as an increase in defects and adsorption of the wafer on the polishing pad occur.

If only the grooves A having the above-mentioned side surfaces are disposed on the entire surface of the pad surface, the cross-sectional area may be reduced at the end of the life of the polishing pad and the polishing rate may be decreased or defects may increase. However, It is considered that a high polishing rate and in-plane uniformity can be maintained by providing the groove B for discharging, and stable polishing can be performed until the end of the life of the polishing pad.

Therefore, in order to stabilize the shape of the groove in the groove B, the angle between the polished surface and the "continuous side surface of the groove B" must be 60 degrees or more and 105 degrees or less, more preferably 80 degrees or more, More preferably 85 degrees or more. It is more preferably 100 degrees or less, and further preferably 95 degrees or less.

The groove B preferably has a bottom surface. The shape of the bottom surface of the groove B is not particularly limited.

Figs. 2A to 2F are diagrams showing specific examples of the cross-sectional shape of the groove B. Fig.

The groove B 201 shown in Fig. 2A has a rectangular cross-sectional shape. The groove B 201 has two side faces 2 which are continuous to the polishing face 1 at the edge portion in the groove width direction. In the case shown in Fig. 2A, the angle &thetas; _B between the polished surface and the side surface continuous to the polishing surface is equal to each other at two edge portions in the groove width direction, and the value is 90 DEG. Thus, the groove B 201 has a rectangular cross-sectional shape, and the bottom surface 6 is parallel to the polishing surface 1.

The groove B 202 shown in Fig. 2B has a substantially U-shaped bottom face 7 between the two side faces 2.

The groove B 203 shown in Fig. 2C has a concave portion 8 formed by bending the width between the two side surfaces 2, and the bottom surface thereof is parallel to the polishing surface 1. Fig.

The groove B 204 shown in Fig. 2D is a tapered inclined surface 9 continuously formed on the two side surfaces 2 and inclined to the inner circumferential side and a substantially U-shaped inclined surface 9 formed between the two inclined surfaces 9 Shaped bottom surface 10 as shown in Fig.

The groove B 205 shown in FIG. 2E has a tapered inclined surface 11 continuously formed on the two side surfaces 2 and inclined to the inner side, and a V-shaped (Not shown).

The groove B 206 shown in FIG. 2F has a bottom surface 14 parallel to the polishing surface 1 between the two side surfaces 13. In the groove B 206, the angle? _B 'between the polishing surface 1 and the side surface 2 continuous to the polishing surface 1 is an acute angle.

As far as the side surface continuous to the polishing surface in the groove B is capable of maintaining the angle between the polishing surface and the polishing surface at 60 degrees or more and 105 degrees or less even if the polishing pad is worn, the curved surface, the bent line, A broken line, or a combination thereof.

Here, the grooves B constituting the polishing pad are not necessarily one type of grooves, and it is also possible to constitute the polishing pad by combining grooves having a plurality of different cross-sectional shapes. In addition, from the viewpoint of in-plane uniformity, it is preferable to use one kind of groove.

The grooves formed on the polishing surface are defined by the area ratio of the grooves formed per area of the polishing surface. It is preferable that the grooves formed in the polishing surface have a groove area ratio per unit unit of 5% or more and 50% or less. In particular, the lower limit of the groove area ratio per unit unit is preferably 10% or more, more preferably 15% or more. The upper limit of the groove area ratio per unit unit is more preferably 45% or less, and further preferably 40% or less.

The unit unit is a unit formed by a combination of the grooves A and the grooves B arranged in parallel with each other, and the unit unit is repeatedly formed on the polishing surface, whereby grooves are formed on the entire surface of the polishing surface.

Figs. 3A to 3I are diagrams showing a configuration example of a representative unit unit including a groove A and a groove B. Fig.

The unit unit 301 shown in Fig. 3A includes a combination of one groove A and three adjacent grooves B (arrangement pattern: ABBB).

The unit unit 302 shown in Fig. 3B includes a combination of one groove A and two adjacent grooves B (arrangement pattern ABB).

The unit unit 303 shown in Fig. 3C includes a combination of two adjacent grooves A and three adjacent grooves B (arrangement pattern: AABBB).

The unit unit 304 shown in Fig. 3D includes one groove A and one groove B (arrangement pattern AB) which are adjacent to each other.

The unit unit 305 shown in Fig. 3E includes a combination of two adjacent grooves A and two adjacent grooves B (arrangement pattern: AABB).

The unit unit 306 shown in Fig. 3F includes a combination of three adjacent grooves A and three adjacent grooves B (arrangement pattern: AAABBB).

The unit unit 307 shown in Fig. 3G includes a combination of three adjacent grooves A and two adjacent grooves B (arrangement pattern: AAABB).

The unit unit 308 shown in FIG. 3H includes a combination of two adjacent grooves A and one groove B (arrangement pattern AAB).

The unit unit 309 shown in Fig. 3 (i) includes a combination of three adjacent grooves A and one groove B (arrangement pattern: AAAB).

On the other hand, the area occupancy rate of the groove A per groove area is the ratio of the area of the groove A per area of the groove formed on the polishing surface, and the area occupancy rate of the groove A per groove area formed on the polishing surface is 30% Or less, more preferably 40% or more, and still more preferably 50% or more. Further, the area occupancy rate of the groove A per groove area is more preferably 80% or less, and further preferably 70% or less.

The surface of the polishing layer of the polishing pad is provided with grooves (grooves) such as a lattice shape, a dimple shape, a spiral shape and a concentric circle shape which can be taken by a normal polishing pad in order to suppress the hydroplane phenomenon or adsorption of the wafer and the pad. Or a combination thereof is preferably used, but a lattice shape is particularly preferable. The lattice shape is a shape obtained by combining lines at right angles with a checkerboard eye. In the lattice shape, when the grooves in the longitudinal direction and the transverse direction are equidistant, when the grooves in the longitudinal direction are narrower than the grooves in the transverse direction, when the grooves in the transverse direction are narrower than the grooves in the longitudinal direction , A plurality of cases may be considered.

The grooves A formed on the polishing surface of the polishing pad give a high polishing rate and good in-plane uniformity as described above, but the balance of supplying and discharging of the slurry with the decrease in the cross-sectional area at the end of life becomes worse, . Therefore, of the grooves formed in the polishing surface, the total groove length of the grooves A formed on the entire polishing surface is preferably 10% or more and 90% or less of the total groove length of grooves formed on the polishing surface, , More preferably 25% or more, still more preferably 30% or more, and particularly preferably 35% or more. The total length of the groove A in the groove formed in the polishing surface is more preferably 80% or less, more preferably 70% or less, still more preferably 60% or less, and particularly preferably 55% or less.

When the ratio of the total groove length of the groove A formed on the polishing surface to the total groove length of all the grooves is within the above range, an attractive force acts between the wafer and the polishing pad, do. In the method of forming the grooves formed on the polishing surface of the polishing pad, it is also possible to form the grooves A so as to be concentrated at the center of the polishing pad and form the grooves B in the remaining portion. In the case where the polishing surface is a circular polishing pad, the groove A is an area including two straight lines passing through the center of the polishing pad and orthogonal to each other. The distance from at least one of the two straight lines is 70% Or less, more preferably 60% or less, more preferably 50% or less, and particularly preferably 40% or less.

4 is a diagram schematically showing an example of the arrangement of the grooves A on the polishing surface of the polishing pad. In the polishing pad 401 shown in Fig. 4, a groove A 403 (described by a bold line) is formed on a circular polishing surface 402 in such a manner that two straight lines L passing through the center O of the polishing surface 402 ₁ , and L _2, and the minimum value of the distance from at least one of the two straight lines is 1/3 (about 33%) or less of the radius r. Note that the broken line in Fig. 4 represents groove B (404). As described above, when the XY grid shape is applied as the groove shape, the groove A 403 is dispersed in two orthogonal directions (X direction and Y direction), rather than concentrating the groove A 403 in only one direction. .

 When the grooves A and the grooves B are regularly arranged, the polishing pad can be formed on the basis of a unit unit as shown in any one of Figs. 3A to 3H, for example. However, the ratio of the number of grooves A to the total number of grooves as a combination of grooves is not limited to the illustrated example.

The groove widths of the grooves A and the grooves B are preferably 0.1 mm or more and 10 mm or less, more preferably 0.3 mm or more, and even more preferably 0.5 mm or more, since it is necessary to have a cross sectional area capable of supplying and discharging the slurry. Further, the groove widths of the groove A and the groove B are more preferably 8 mm or less, and more preferably 5 mm or less.

The groove depths of the grooves A and the grooves B are preferably 0.2 mm or more and 4 mm or less, more preferably 0.3 mm or more, and more preferably 0.4 mm or more since it is necessary to secure the supply and discharge of the slurry and sufficient lifetime. Further, the groove depths of the groove A and the groove B are more preferably 3 mm or less, and more preferably 2 mm or less.

Since the thickness of the polishing layer is preferably smaller than the distance from the upper surface of the polishing head to the lower surface of the polishing head, it is preferably 4.0 mm or less, more preferably 3.5 mm or less, still more preferably 3.0 mm or less, mm or less.

The polishing layer constituting the polishing pad in the present invention is preferably a structure having a micro-rubber A hardness of 70 degrees or more and having independent bubbles because it forms a flat surface in a semiconductor, a dielectric / metal composite and an integrated circuit. Although not particularly limited, examples of the material for forming such a structure include polyethylene, polypropylene, polyester, polyurethane, polyurea, polyamide, polyvinyl chloride, polyacetal, polycarbonate, polymethyl methacrylate, polytetrafluoro A thermoplastic resin such as ethylene, epoxy resin, ABS resin, AS resin, phenol resin, melamine resin, "Neoprene (registered trademark) rubber, butadiene rubber, styrene butadiene rubber, ethylene propylene rubber, silicone rubber, fluorine rubber, . Two or more of these may be used. Also in these resins, a material containing polyurethane as a main component is more preferable in that the independent bubble diameter can be controlled relatively easily.

Polyurethane is a polymer which is synthesized by the reaction of a polyisocyanate or by polymerization reaction. Examples of the polyisocyanate include tolylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate, but are not limited thereto, and two or more of them may be used. The compound used as the reaction partner of the polyisocyanate is an active-containing hydrogen compound, that is, two or more polyhydroxy groups or an amino group-containing compound. Examples of the polyhydroxy group-containing compound include polyols such as polyether polyol, polytetramethylene ether glycol, epoxy resin-modified polyol, polyester polyol, acrylic polyol, polybutadiene polyol and silicone polyol. have. It is preferable to determine the combination or optimal amount of the polyisocyanate and the polyol and the catalyst, the foaming agent and the foam stabilizer depending on the hardness, the cell diameter and the expansion ratio.

As a method of forming the independent bubbles in these polyurethanes, a chemical foaming method by mixing various foaming agents into resins in the production of polyurethane is generally used, but a method of foaming the resin by mechanical stirring and then curing is also preferable Can be used.

The average cell diameter of the closed cells is preferably 20 占 퐉 or more and more preferably 30 占 퐉 or more from the viewpoint of holding the slurry on the pad surface. On the other hand, the average cell diameter of the closed cells is preferably 150 占 퐉 or smaller, more preferably 140 占 퐉 or smaller, and even more preferably 130 占 퐉 or smaller, from the viewpoint of securing the flatness of local unevenness of the semiconductor substrate. The average bubble diameter was obtained by measuring the average diameter of the bubbles in the bubbles observed in one field of view at a magnification of 400 times using an ultracentrifuge microscope manufactured by Keyence VK-8500 except for the bubbles observed in a circular shape, By measuring the circle-equivalent diameter from the cross-sectional area with the image processing apparatus, and calculating the number average value.

Preferred as one embodiment of the polishing pad in the present invention is a pad containing a polymer of a vinyl compound and a polyurethane and having a closed cell. Although it is possible to increase toughness and hardness with only a polymer from a vinyl compound, it is difficult to obtain a homogeneous polishing pad having closed cells. Further, the polyurethane becomes brittle when the hardness is increased. By impregnating a polyurethane with a vinyl compound, a polishing pad containing closed cells and having high toughness and high hardness can be obtained.

The vinyl compound is a compound having a polymerizable carbon-carbon double bond. Specific examples include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-butyl acrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, isodecyl methacrylate, isobutyl Methacrylate, n-lauryl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl Acrylates such as methacrylate, glycidyl methacrylate, ethylene glycol dimethacrylate, acrylic acid, methacrylic acid, fumaric acid, dimethyl fumarate, diethyl fumarate, dipropyl fumarate, maleic acid, dimethyl maleate, diethyl maleate, Propylmaleimide, cyclohexylmaleimide, isopropylmaleimide, acrylonitrile, acrylamide, vinyl chloride, vinylidene chloride, styrene, ? -methylstyrene, divinylbenzene, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, and the like. Two or more kinds of vinyl compounds may be used.

Among the above-mentioned vinyl compounds, CH ₂ ═CR ¹ COOR ² (R ¹ : a methyl group or an ethyl group, and R ² : a methyl group, an ethyl group, a propyl group or a butyl group) are preferable. Of these, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate and isobutyl methacrylate are preferred because of the ease of formation of independent bubbles into polyurethane, the good impregnation of monomers, And that the foamed structure containing the polymer of the polymerized cured vinyl compound and the polyurethane is preferable in that the hardness is high and the planarization property is good.

Examples of the polymerization initiator preferably used for obtaining the polymer of these vinyl compounds include azobisisobutyronitrile, azobis (2,4-dimethylvaleronitrile), azobiscyclohexanecarbonitrile, benzoyl peroxide, lauroyl And radical initiators such as peroxide, isopropyl peroxydicarbonate, and the like. Two or more of these may be used. Also, a redox system polymerization initiator, for example, a combination of peroxide and amines may be used.

As a method of impregnating the vinyl compound into the polyurethane, there is a method of immersing the polyurethane in a container containing the vinyl compound. It is also preferable to carry out treatment such as heating, pressurization, decompression, stirring, shaking, ultrasonic vibration for the purpose of accelerating the impregnation speed.

The amount of the vinyl compound to be impregnated into the polyurethane should be determined depending on the kind of the vinyl compound and the polyurethane to be used and the characteristics of the polishing pad to be produced and can not be uniformly determined. For example, The content ratio of the polymer obtained from the vinyl compound and the polyurethane is preferably 30/70 to 80/20 by weight. When the content ratio of the polymer obtained from the vinyl compound is 30/70 or more by weight, the hardness of the polishing pad can be made sufficiently high. When the content ratio is 80/20 or less, the elasticity of the polishing layer can be sufficiently increased.

The content of the polymer and the polyurethane obtained from the polymerization-cured vinyl compound in the polyurethane can be measured by pyrolysis gas chromatography / mass spectrometry. As a device usable in the present method, a double shot pyrolizer "PY-2010D" (manufactured by Frontier Labs) and a "TRIO-1" (manufactured by VG) as a gas chromatograph and mass spectrometer have.

In the present invention, from the viewpoint of the flatness of local unevenness of the semiconductor substrate, it is preferable that the phase of the polymer obtained from the vinyl compound and the phase of the polyurethane are contained without being separated. Quantitatively, this means that the infrared spectrum when the polishing pad is observed with a brown infrared infrared spectroscope having a spot size of 50 占 퐉 has an infrared absorption peak of a polymer polymerized from a vinyl compound and an infrared absorption peak of a polyurethane, The infrared spectra of various portions are almost the same ". As the brown and infrared infrared spectroscopic apparatus used herein, IR 占 s manufactured by SPECTRA-TEC can be mentioned.

The polishing pad may contain various additives such as an abrasive, an antistatic agent, a lubricant, a stabilizer, and a dye for the purpose of improving properties.

In the present invention, the micro-rubber A hardness of the abrasive layer refers to a value evaluated by a micro-rubber hardness meter MD-1 manufactured by Kobunshi Kagaku Co., Ltd. The micro-rubber A hardness meter MD-1 enables hardness measurement of a thin or small one, which was difficult to measure in a conventional hardness meter. The micro-rubber A hardness meter MD-1 was designed and manufactured as a 1/5 shrinkage model of a spring type rubber durometer (durometer) type A, and thus a measurement value consistent with the hardness of the spring hardness meter type A was obtained . A conventional polishing pad can not be evaluated as a spring type rubber durometer type A because the thickness of the abrasive layer or the hard layer is less than 5 mm. Therefore, in the present invention, the micro rubber A hardness of the abrasive layer is evaluated by the micro rubber MD-1.

In the present invention, the hardness of the polishing layer is preferably 70 degrees or more, more preferably 80 degrees or more, in view of the flatness of local unevenness of the semiconductor substrate.

In the present invention, the density of the polishing layer is a local flatness defects and perspective 0.3g / cm ³ or higher to reduce the global level difference is preferable, 0.6g / cm ³ or more is more preferable, 0.65g / cm ³ or more More preferable. On the other hand, the density of the polishing layer is not more than 1.1g / cm ³ preferably from the viewpoint of reducing scratches, and 0.9g / cm ³ or less is more preferable, and below, more preferably 0.85g / cm ^3. The density of the abrasive layer in the present invention is a value measured with a water medium using a Harvard type pycnometer (JIS R-3503 standard).

The polishing pad of the present invention preferably has a cushion layer having a bulk elastic modulus of 40 MPa or more and a tensile elastic modulus of 1 MPa or more and 20 MPa or less from the viewpoint of improving in-plane uniformity. The volumetric modulus of elasticity is calculated by applying an isotropic applied pressure to an object to be measured in advance and measuring the change in volume thereof and calculating the volume modulus based on the measurement result by the applied elastic modulus = applied pressure / (volume change / original volume) . In the present invention, it refers to a bulk modulus when a pressure of 0.04 to 0.14 MPa is applied to a sample at 23 占 폚.

The volume modulus of elasticity in the present invention is measured by the following method. A sample piece and water at 23 ° C are placed in a measuring cell made of stainless steel having a volume of about 40 mL, and a measuring pipette (minimum scale: 0.005 mL) of 0.5 mL in capacity is mounted. Separately, as a pressure vessel, a tube made of polyvinyl chloride resin (inner diameter: 90 mm? 占 2000 mm, thickness: 5 mm) was used, and a measuring cell containing the sample piece was placed therein. Subsequently, the sample piece is not put in the measuring cell but is pressurized with nitrogen at the pressure P, and the volume change V0 is measured. The value obtained by dividing the pressure P by? V / Vi = (V1-V0) / Vi is calculated as the bulk modulus of the sample.

In the present invention, the volume modulus of elasticity of the cushion layer is preferably 40 MPa or more. By setting the volume modulus of elasticity to 40 MPa or more, the in-plane uniformity of the entire surface of the semiconductor substrate can be improved. Further, it is difficult for the slurry or water flowing into the holes penetrating the front and back surfaces of the polishing pad to hardly impregnate the cushion layer, and the cushioning property can be maintained.

The tensile elastic modulus in the present invention is determined by applying a tensile stress in the form of a dumbbell, measuring tensile stress in a range of tensile strain (= tensile length change / original length) of 0.01 to 0.03, Elastic modulus = ((tensile stress when tensile strain is 0.03) - (tensile stress when tensile strain is 0.01)) / 0.02. As a tensile stress measuring apparatus, Tensilon universal testing machine RTM-100 manufactured by Orientech can be mentioned. The measurement conditions of the tensile stress are a dumbbell shape with a test speed of 5 cm / min, a test piece shape of 5 mm in width, and a sample length of 50 mm.

In the present invention, the tensile modulus of elasticity of the cushion layer is preferably 1 MPa or more, more preferably 1.2 MPa or more, from the viewpoint of the in-plane uniformity of the entire surface of the semiconductor substrate. The tensile modulus of elasticity of the cushion layer is preferably 20 MPa or less, more preferably 10 MPa or less.

Examples of the cushion layer include non-expanded elastomers such as natural rubber, nitrile rubber, "neoprene (registered trademark)" rubber, polybutadiene rubber, thermosetting polyurethane rubber, thermoplastic polyurethane rubber and silicone rubber. But is not limited thereto. The thickness of the cushion layer is preferably in the range of 0.1 to 2 mm. The thickness of the cushion layer is preferably 0.2 mm or more from the viewpoint of the in-plane uniformity of the entire surface of the semiconductor substrate, and more preferably 0.3 mm or more. The thickness of the cushion layer is preferably 2 mm or less, more preferably 1.75 mm or less from the viewpoint of local flatness.

As means for bonding the abrasive layer and the cushion layer, for example, a double-sided tape or an adhesive may be used.

The double-sided tape has a general structure in which an adhesive layer is formed on both surfaces of a substrate such as a nonwoven fabric or a film. Further, the polishing pad of the present invention may have a double-sided tape formed on the surface of the polishing pad adhered to the platen of the cushioning sheet. As such a double-sided tape, those having a general structure in which an adhesive layer is formed on both surfaces of the substrate as described above can be used. Examples of the substrate include nonwoven fabrics and films. Considering peeling from the platen after use of the polishing pad, it is preferable to use a film for the substrate.

Examples of the composition of the adhesive layer include a rubber-based adhesive and an acrylic-based adhesive. Considering the content of the metal ion, the acrylic adhesive is preferable because the content of the metal ion is small. In addition, the cushion sheet and the platen often have different compositions, and it is also possible to make the adhesive force of the cushion sheet and the platen to be appropriate by making the composition of each adhesive layer of the double-sided tape different.

The abrasive to be polished in the present invention includes, for example, an insulating layer formed on a semiconductor wafer or a surface of a metal wiring. Examples of the insulating layer include interlayer insulating films of metal wirings, lower insulating films of metal wirings, and shallow trench isolation used for device isolation. Examples of the metal wiring include aluminum, tungsten, copper, and the like. Structurally, there are a damascene, a dual damascene, a plug, and the like. When copper is used as a metal wiring, a barrier metal such as silicon nitride is also to be polished. The insulating film is currently the mainstream of silicon oxide, but a low dielectric constant insulating film is also used. The abrasive to be polished may be used for polishing a magnetic head, a hard disk, sapphire, etc. in addition to a semiconductor wafer.

The polishing method of the present invention is suitably used for forming a flat surface on glass, semiconductor, dielectric / metal complex and integrated circuit.

Example

Hereinafter, the details of the present invention will be described by way of examples. However, the present invention is not limited to this embodiment. The measurement was carried out as follows.

≪ Measurement of inclination angle &

The polishing pad having grooves formed on the surface of the polishing layer was sliced in the groove depth direction and the cross-section of the grooves was observed with an ultracentrifuge microscope of VK-8500 manufactured by Keith Corporation to measure the angle between the polishing surface and the continuous surface side with the polishing surface . When the polishing pad is circular, the grooves nearest to the positions of 50 mm, 150 mm, and 250 mm from the center of the polishing pad were measured, and the average of the three points was determined as the inclination angle. When the polishing pad is not circular, the grooves nearest to the positions of 50 mm, 150 mm and 250 mm from the intersection of the diagonal lines of the sheet toward one end are measured, and the average of the three points is determined as the inclination angle.

≪ Average polishing rate measurement and in-plane uniformity >

Polishing was carried out using Mirra 3400 manufactured by Applied Materials Co., Ltd. while performing end point detection under predetermined polishing conditions. The average polishing rate as the polishing characteristic was the polishing rate (nm / minute) excluding the outermost circumference 10 mm of the 8-inch wafer. The value obtained by dividing the standard deviation of the polishing rate by the difference between the maximum value and the minimum value of the polishing rate was defined as in-plane uniformity.

<Defect Evaluation>

As the enhanced treatment, the polished wafer was immersed in 0.5 wt% of hydrofluoric acid for 10 minutes, washed with water, and then washed with a mixed solution of 1.0 wt% of ammonia solution and 1.0 wt% of hydrogen peroxide solution, followed by washing with water. For the washed wafer, the number of defects of 0.155 mu m or more was counted using SP-1 manufactured by KLA-Tencor Corporation.

<Pad grinding speed>

The groove depth before and after polishing was measured using a dip gauge (Digimatic type) manufactured by Mitsutoyo Co., and a value obtained by dividing the reduced value of the groove by the disk use time during evaluation was regarded as the pad grinding speed.

<Percentage of Number of Home A's>

A polishing pad having grooves formed on the surface of the polishing surface was sliced in parallel with the grooves, and the number of grooves A and grooves B was measured. The number of grooves A is divided by the sum of the number of grooves A and the number of grooves B from the arrangement of groove A and groove B (sectional view: FIG. 3) A ratio. The calculation formula is described below.

The ratio of the number of grooves A = the number of grooves A / (the number of grooves A + the number of grooves B) x 100 (%)

Examples 1 to 11 and Comparative Examples 1 to 3 will be described below.

(Example 1)

30 parts by weight of polypropylene glycol, 40 parts by weight of diphenylmethane diisocyanate, 0.5 part by weight of water, 0.3 part by weight of triethylamine, 1.7 parts by weight of silicone foam stabilizer and 0.09 part by weight of tin octylate were mixed by an RIM molding machine , And a molded polyurethane sheet (micro-rubber A hardness: 42 degrees, density: 0.76 g / cm &lt; ³ &gt;, average cell diameter of closed cells: 34 mu m) Respectively.

The foamed polyurethane sheet was immersed in methyl methacrylate to which 0.2 part by weight of azobisisobutyronitrile had been added for 60 minutes. Next, 15 parts by weight of polyvinyl alcohol "CP" (polymerization degree: about 500, manufactured by Nacalai Tesque KK), 35 parts by weight of ethyl alcohol (reagent grade, manufactured by Katayama Chemical Industry Co., Ltd.) And 50 parts by weight of water, followed by drying, whereby the surface layer of the foamed polyurethane sheet was coated with polyvinyl alcohol.

Subsequently, the foamed polyurethane sheet was sandwiched between two glass plates through a gasket made of vinyl chloride, and the mixture was polymerized by heating at 65 DEG C for 6 hours and at 120 DEG C for 3 hours. After releasing from the glass plate and rinsed with water, vacuum drying was performed at 50 캜. The hard foam sheet thus obtained was sliced to a thickness of 2.00 mm to prepare a polishing layer. The content of methyl methacrylate in the polishing layer was 66% by weight. Further D hardness of the polishing layer is 54 degrees, and the density was 0.81g / cm ^3, a mean cell diameter of the closed cells is 45㎛.

The resulting rigid foam sheet was polished on both sides to prepare a polishing layer having a thickness of 2 mm.

As a cushion layer, a micro-rubber A of a thermoplastic polyurethane manufactured by Nippon Mata Co., Ltd. A 0.3-mm article having a hardness of 90 degrees (volume elastic modulus = 65 MPa, tensile elastic modulus = 4 MPa) was applied to the abrasive layer obtained by the above- MA-6203 adhesive layer manufactured by Kagaku Polyurethane Co., Ltd., and a double-sided tape 5604TDM made by Sekisui Chemical Co., Ltd. as a backing tape was bonded to the backside.

3.0mm groove width, groove pitch 15mm, the tilt angle θ _A is 135 degrees V-sectional shape, and the groove depth A of groove 1.5mm, 1.5mm groove width, groove pitch 15mm, the rectangular cross section of the groove depth of 1.5mm (the inclination angle θ _B = 90 degrees) were alternately repeated (hereinafter, referred to as a pattern A) to form a polishing pad in the form of an XY lattice. The groove area ratio per unit unit of groove A was 24.9%, and the area occupancy rate of groove A per groove area was 73.7%.

The polishing pad obtained by the above method was attached to the surface of a polishing machine ("Mirra 3400" manufactured by Applied Materials, Inc.). The 8-inch wafer of the oxide film was set at a pressure of 41 kPa (6 psi), an inner tube pressure of 28 kPa (4 psi), a membrane pressure of 28 kPa (4 psi), a platen revolution number of 76 rpm and a polishing head revolution speed of 75 rpm. (SS-25) was flowed at a flow rate of 150 mL / min, and 100 sheets were polished by a Saesol preparation dresser with a load of 17.6 N (4 lbf), a polishing time of 1 minute, and a time of 30 seconds from the start of polishing . The average polishing rate of the 100th oxide film was 202 nm / min and the in-plane uniformity was 11.8%.

For the polished wafers, defects of 0.155 mu m or more were counted by the above defect evaluation method, and the defects were very good at 331 pieces. The pad grinding speed during polishing was 1.01 탆 / min.

(Example 2)

_A groove A having a groove width of 1.5 mm, a groove pitch of 15 mm, and a groove depth of 1.5 mm was formed in a groove A having a groove width of 3.0 mm, a groove pitch of 15 mm, an inclination angle? B, and the combination of the groove A 1 and the groove B 2 was repeated (hereinafter referred to as pattern B), and the wafer was formed in an XY lattice pattern from the center of the polishing surface of the polishing pad to the entire area of the pad radius Polishing was carried out in the same manner as in Example 1. The groove area ratio per unit unit of groove A was 20.7% and the area occupancy rate of groove A per groove area was 60.9%. The average polishing rate was 197 nm / min, and the in-plane uniformity was 9.0%.

The polished wafers were counted for defects of 0.155 탆 or more by the defect evaluation method, and the defects were good at 211 pieces. The pad grinding speed during polishing was 1.21 탆 / min.

(Example 3)

_A V-shaped section having a groove width of 3.0 mm, a groove pitch of 15 mm, a tilting angle? _A of 135 degrees, and a groove A having a groove depth of 1.5 mm was formed on the surface of the polishing layer as a region including two straight lines passing through the center of the polishing surface and perpendicular to each other , A groove B having a rectangular cross section with a groove width of 1.5 mm, a groove pitch of 15 mm and a groove depth of 1.5 mm is formed in an XY grid pattern in a region where the distance from at least one straight line is 32% or less of the radius of the polishing surface. Was polished in the same manner as in Example 1 except that it was formed as an XY lattice in an area exceeding 32% of the radius and made into a polishing pad (hereinafter referred to as pattern C). The groove area ratio per unit unit of groove A was 23.1%, and the area occupancy rate of groove A per groove area was 67.7%. The arrangement of the grooves is shown in Fig. The average polishing rate was 196 nm / min, and the in-plane uniformity was 10.9%.

Defects of 0.155 mu m or more were counted for the polished wafers by the defect evaluation method described above, and the defects were very good at 142 pieces. The pad grinding speed during polishing was 1.34 탆 / min.

(Example 4)

The polishing was performed in the same manner as in Example 1 except that the groove A on the surface of the polishing layer had a trapezoidal cross section with an inclination angle &amp;thetas; _A of 120 degrees. The groove area ratio per unit unit of groove A was 16.5%, and the area occupancy rate of groove A per groove area was 54.8%. The average polishing rate was 199 nm / min, and the in-plane uniformity was 6.0%.

The polished wafers were counted for defects of 0.155 탆 or more by the above defect evaluation method, and the defects were very good at 155 pieces. The pad grinding speed during polishing was 1.14 占 퐉 / min.

(Example 5)

Polishing was performed in the same manner as in Example 4 except that the groove A on the surface of the polishing layer had a trapezoidal cross section with an inclination angle &amp;thetas; _A of 123 degrees. The groove area ratio per unit unit of groove A was 28.3%, and the area occupancy rate of groove A per groove area was 73.6%. The average polishing rate was 203 nm / min, and the in-plane uniformity was 8.4%.

The polished wafers were counted for defects of 0.155 탆 or more by the above defect evaluation method, and the defects were very good at 141 pieces. The pad grinding speed during polishing was 1.32 탆 / min.

(Example 6)

And the inclination angle? _B of the groove B on the surface of the polishing layer was 85 degrees. The groove area ratio per unit unit of the groove A was 30.2% and the area occupancy rate of the groove A per groove area was 68.9%. The average polishing rate was 201 nm / min, and the in-plane uniformity was 9.1%.

The polished wafers were counted for defects of 0.155 탆 or more by the above defect evaluation method, and the defects were very good at 139. The pad grinding speed during polishing was 1.11 탆 / min.

(Example 7)

Degrees, the home A tilt angle θ _A of the abrasive layer surface 120 V-shaped cross-section, the groove B being a trapezoidal cross section with the inclination angle θ _B is other than 85 degrees was polished in the same manner as in Example 3. The groove area ratio per unit unit of groove A was 16.5%, and the area occupancy rate of groove A per groove area was 54.8%. The average polishing rate was 200 nm / min, and the in-plane uniformity was 9.8%.

The polished wafers were counted for defects of 0.155 탆 or more by the defect evaluation method, and the defects were 211, which was very good. The pad grinding speed during polishing was 1.33 탆 / min.

(Example 8)

A groove A on the surface of the abrasive layer was polished in the same manner as in Example 3, except that the V-shaped section having the inclination angle? _A of 120 degrees and the groove B had the trapezoidal section having the inclination angle? _B of 95 degrees. The groove area ratio per unit unit of the groove A was 18.4% and the area occupancy rate of the groove A per groove area was 49.0%. The average polishing rate was 209 nm / min, and the in-plane uniformity was 10.1%.

The polished wafers were counted for defects of 0.155 탆 or more by the above defect evaluation method, and the defects were 109, which was very good. The pad grinding speed during polishing was 1.30 탆 / min.

(Example 9)

Polishing was carried out in the same manner as in Example 3 except that the groove A on the surface of the polishing layer had a V-shaped section with an inclination angle &amp;thetas; _A of 150 degrees. The groove area ratio per unit unit of groove A was 34.6% and the area occupancy rate of groove A per groove area was 78.4%. The average polishing rate was 200 nm / min and the in-plane uniformity was 9.9%.

The polished wafers were counted for defects of 0.155 탆 or more by the defect evaluation method, and the defects were 111, which was very good. The pad grinding speed during polishing was 1.41 탆 / min.

(Example 10)

A polishing layer surface groove inclination angle θ _A is 150 degrees of the V-shaped cross-section, the groove B being a trapezoidal cross section with the inclination angle θ _B is other than 85 degrees was polished in the same manner as in Example 3. The groove area ratio per unit unit of groove A was 34.6% and the area occupancy rate of groove A per groove area was 78.4%. The average polishing rate was 206 nm / min, and the in-plane uniformity was 10.0%.

Defects of 0.155 mu m or more were counted for the polished wafers by the defect evaluation method described above, and the defects were extremely good at 153 pieces. The pad grinding speed during polishing was 1.44 탆 / min.

(Example 11)

A polishing layer surface groove inclination angle θ _A is 150 degrees of the V-shaped cross-section, the groove B being a trapezoidal cross section with the inclination angle θ _B is other than 95 degrees was polished in the same manner as in Example 3. The groove area ratio per unit unit of groove A was 36.5% and the area occupancy rate of groove A per groove area was 74.3%. The average polishing rate was 200 nm / min and the in-plane uniformity was 10.1%.

The polished wafers were counted for defects of 0.155 탆 or more by the above defect evaluation method, and the defects were very good at 134 pieces. The pad grinding speed during polishing was 1.40 탆 / min.

(Comparative Example 1)

The grooves on the surface of the abrasive layer were polished in the same manner as in Example 1 except that the grooves on the surface of the abrasive layer had a rectangular cross section having a groove width of 1.5 mm, a groove pitch of 15 mm, and a groove depth of 1.5 mm. The average polishing rate was 180 nm / min and the in-plane uniformity was 12.2%.

The polished wafers were counted for defects of 0.155 탆 or more by the above defect evaluation method, and the defects were good at 583 pieces. The pad grinding speed during polishing was 1.13 탆 / min.

(Comparative Example 2)

A groove on the surface of the polishing layer was polished in the same manner as in Example 1 except that the groove had a V-shaped cross section having a groove width of 3.0 mm, a groove pitch of 15 mm, a groove depth of 1.5 mm and a tilt angle of 135 degrees. The average polishing rate was 217 nm / min, and the in-plane uniformity was 21.1%.

The polished wafers were counted for defects of 0.155 mu m or more by the above defect evaluation method, and the defects were very good with 297 defects. The pad grinding speed during polishing was 1.73 탆 / min.

(Comparative Example 3)

The polishing was carried out in the same manner as in Example 1 except that the abrasive layer was 1.0 mm and the groove on the surface was a V-shaped cross section having a groove width of 1.0 mm, a groove pitch of 15 mm, a groove depth of 0.5 mm, and an inclination angle of 135 degrees. The average polishing rate was 205 nm / min and the in-plane uniformity was 18.3%.

The polished wafers were counted for defects of 0.155 탆 or more by the defect evaluation method, and the defects were as many as 1521 pieces. In addition, the pad grinding speed during polishing was 1.68 탆 / min.

Table 1 shows the results obtained in Examples 1 to 11 and Comparative Examples 1 to 3 described above.

1, 402 polishing surface
2, 13 side
3, 4, 6, 7, 8, 10, 12, 14 Bottom
5 concave portion
9, 11, and 13 slopes
101, 102, 103, 104, 403 Home A
201, 202, 203, 204, 205, 206, 404 Home B
301, 302, 303, 304, 305, 306, 307, 308, 309 unit units
401 Polishing Pads

Claims (7)

A polishing pad for chemical mechanical polishing having at least a polishing layer,
A first groove and a second groove formed on the polishing surface of the polishing layer,
Wherein the first and second grooves each have a side surface continuous with the polishing surface on a rim of each groove width direction,
Wherein the first groove has an angle formed by the polishing surface and the side surface continuous to the polishing surface at an edge portion in at least one groove width direction of more than 105 degrees but not more than 150 degrees,
Wherein the second groove has an angle formed by both the polishing surface and the side surface continuous to the polishing surface at not less than 60 degrees and not more than 105 degrees on both sides of the two edge portions in the groove width direction. The polishing pad according to claim 1, wherein the second groove has a bottom surface. The polishing pad according to claim 2, wherein the groove area ratio per unit unit is 5% or more and 50% or less, and the area occupancy rate of the first groove per groove area is 30% or more and 90% or less. The polishing pad according to any one of claims 1 to 3, wherein the first and second grooves are formed in a lattice shape. 5. The polishing pad according to claim 4, wherein the total length of grooves of the first grooves formed on the polishing surface is 10% or more and 90% or less of the total length of grooves formed in the polishing surface. The polishing apparatus according to claim 4 or 5, wherein the polishing surface has a circular shape, and the first groove formed on the polishing surface is a region including two straight lines passing through the center of the polishing surface and orthogonal to each other, Wherein a distance from at least one of the two straight lines is formed in an area of 70% or less of a radius of the polishing surface. The polishing apparatus according to any one of claims 4 to 6, wherein the first groove has an angle formed by the polishing surface and the side surface continuous to the polishing surface at both sides of two edge portions in the groove width direction of more than 105 degrees Of the polishing pad.

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