TW201318766A - Polishing pad - Google Patents

Abstract

The present invention provides a polishing pad for chemical machinery polishing, which has at least a polishing layer. The polishing layer has the 1st groove and the 2nd groove on the polishing surface, wherein the 1st groove and the 2nd groove have side faces connecting to the polishing surface on each edge of width direction of the groove. On at least one edge of width direction of the 1st groove, the angle of the polishing surface and the side face connecting to the polishing surface is greater than 105 degrees and less than or equal to 150 degrees. On both edges of width direction of the 2nd groove, the angles of the polishing surface and the side faces connecting to the polishing surface are greater than or equal to 60 degrees and less than or equal to 105 degrees.

Description

Abrasive pad

The present invention relates to a polishing pad. More specifically, the present invention relates to a polishing pad which is suitably used for forming a flat surface in a semiconductor, a dielectric/metal composite, an integrated circuit or the like.

With the increase in the density of semiconductor devices, technologies such as multilayer wiring and the formation of interlayer insulating films, or electrode formation such as embedding and damascene are becoming more and more important. Along with this, the importance of the planarization process of the metal film of these interlayer insulating films or electrodes is also increasing. Regarding the technology for implementing this flattening process, a polishing technique called CMP (Chemical Mechanical Polishing) is becoming more and more popular.

In general, a CMP apparatus is composed of a polishing head that holds a semiconductor wafer of a workpiece, a polishing pad for polishing a workpiece, and a polishing pad that holds the polishing pad. Further, a polishing technique called CMP is a technique in which a polishing pad having an abrasive layer is used to supply a polishing slurry while polishing the material to be polished. Specifically, the CMP polishing of the semiconductor wafer refers to a protruding portion of the layer on the surface of the wafer by removing the semiconductor wafer (hereinafter simply referred to as a wafer) and the polishing pad by using the polishing slurry, so that the protruding portion of the layer on the surface of the wafer is removed. The layer on the surface of the wafer is flattened.

For CMP polishing, it is required to have characteristics such as ensuring local flatness of the wafer, overall flatness, prevention of occurrence of defects, and securing a high polishing rate. Therefore, in order to achieve these required characteristics, there have been documents One of the major factors affecting the polishing characteristics is the configuration of the groove of the polishing pad (the mode of the groove and the sectional shape of the groove, etc.).

For example, a cross-sectional shape of a groove formed on the surface of the polishing layer is V-shaped or U-shaped, and the mode of the groove is set to be a spiral shape or a mesh shape to stabilize the polishing property (see Patent Document 1). .

In this technique, a corner portion of the groove cross-sectional shape may scratch the surface of the wafer, or a scratch may be formed at a corner portion of the cross-sectional shape due to trimming or the like before and after polishing or polishing. In order to solve this problem, a technique is known in which an inclined surface is provided at a boundary portion between the polishing surface and the groove (see Patent Documents 2 and 3).

Prior technical literature Patent literature

Patent Document 1 Japanese Patent Laid-Open Publication No. 2001-212752

Patent Document 2 Japanese Patent Laid-Open Publication No. 2010-45306

Patent Document 3 Japanese Patent Laid-Open Publication No. 2004-186392

Here, the inventors of the present invention have found that by providing an inclined surface having a specific angle at a boundary portion between the polishing surface and the groove, the attraction force between the wafer and the polishing pad acts, the polishing rate becomes high, and the in-plane uniformity changes. Good. It is important to provide an inclined surface at the boundary between the polishing surface and the groove. Therefore, for example, a groove having a V-shaped cross-sectional shape is also suitable. Moreover, considering the manufacturing process, since the cross-sectional shape of a groove is a simple figure, it is suitable.

However, the present inventors have found that when the cross-sectional shape of the groove is V-shaped, the polishing pad wear occurs with the use of the polishing pad, and the polishing pad is supplied at the end of the polishing pad life at which the groove sectional area is reduced. There is a problem that the discharge function is insufficient and the grinding defects are increased.

The present invention has been made in view of the problems of the prior art, and it is an object of the invention to provide a polishing pad which maintains a high polishing rate and good in-plane uniformity, and which does not occur even if polishing pad wear occurs with the use of the polishing pad. Increased grinding defects caused by reduced supply and discharge functions.

The present inventors have considered a groove (for example, a V-shape) which is inclined at a specific angle between a polished surface and a groove at a boundary portion where the polishing rate is high and the in-plane uniformity is good, and even with the polishing pad. It is also possible to solve the problem by using the polishing pad to wear and maintain the supply of the slurry and the groove of the discharge function (for example, an I-shape or a trapezoid similar to the I-shaped groove).

Therefore, in order to solve the above problems, the present invention employs the following means. That is, the polishing pad of the present invention is a polishing pad for chemical mechanical polishing having at least a polishing layer, wherein the polishing surface of the polishing layer has a first groove and a second groove, and the first and second grooves are respectively The edge portion in the groove width direction has a side surface connected to the polishing surface, and an angle between the polishing surface and a side surface connected to the polishing surface is greater than 105 degrees in an edge portion of at least one groove width direction of the first groove. 150 degrees or less, the angle between the polishing surface and the side surface connected to the polishing surface is greater than 60 degrees and 105 degrees or less at two of the edge portions in the groove width direction of the second groove.

According to the present invention, it is possible to provide a polishing pad which can maintain a high polishing rate and good in-plane uniformity, and at the same time, even if the polishing pad wear occurs as the polishing pad is used, the supply and discharge functions of the polishing slurry are reduced, and the occurrence does not occur. Grinding defects increase.

The present embodiment will be described below.

The polishing pad of the present invention has a polishing pad having at least a polishing layer, wherein the polishing surface of the polishing layer has a groove A (first groove) and a groove B (second groove). The groove A and the groove B have side faces that are connected to the polishing surface in the edge portions in the groove width direction. In an edge portion of at least one groove width direction of the groove A, an angle between the polishing surface and a side surface connected to the polishing surface is greater than 105 degrees and 150 degrees. In the two edge portions of the groove B in the two groove width directions, the angle between the polishing surface and the side surface connected to the polishing surface is 60 degrees or more and 105 degrees or less.

It is considered that at least one groove width direction edge portion of the groove A, the angle between the polishing surface and the side surface connected to the polishing surface is more than 105 degrees and 150 degrees or less, whereby the attraction between the wafer and the polishing pad is exerted. As a result, the polishing rate will increase. It is also believed that by the attraction, the effect of uniform contact with the polishing pad in the wafer surface is accompanied by the high in-plane uniformity of the polishing rate of the wafer.

If the angle between the polishing surface and the side surface connected 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. Therefore, excessive polishing mud is discharged, resulting in a decrease in polishing rate. On the other hand, if it is too small, the suction effect on the side of the inclined groove does not show Come. Therefore, the angle between the polishing surface and the side surface connected to the polishing surface needs to be more than 105 degrees and 150 degrees or less, more preferably 110 degrees or more, more preferably 115 degrees or more, and still more preferably 120 degrees or more.

The groove A may also have a bottom surface. The bottom surface refers to a surface that is connected to the side opposite to the polishing surface and that is connected to the other side surface that faces the polishing surface. Further, the shape of the bottom surface portion is not particularly limited.

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

The groove A101 shown in Fig. 1A has a V-shaped cross-sectional shape. The groove A101 has two side faces 2 connected to the polishing surface 1 at the edge portions in the groove width direction. In the case shown in Fig. 1A, the angle θ _A between the polishing surface and the side surface connected to the polishing surface is equal to each other at both edge portions in the groove width direction, and the value is greater than 105 degrees and 150 degrees or less as described above. .

The groove A102 shown in Fig. 1B has a substantially U-shaped bottom surface 3 between the two side faces 2.

The groove A103 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 faces 2.

The groove A104 shown in Fig. 1D has a concave portion 5 recessed in a direction perpendicular to the polishing surface 1 between the two side faces 2, and this bottom surface is parallel to the polishing surface 1.

Further, in the side surface connected to the polishing surface in the groove A, even if the polishing pad is worn, the angle between the edge portion and the polishing surface can be maintained not only as a straight line but also as a curve as long as it can be maintained at more than 105 degrees and 150 degrees or less. , polylines, wavy lines, or a combination of these lines.

Here, the groove A constituting the polishing pad is not necessarily one type. For example, at least one of the angles between the polishing surface and the side surface connected to the polishing surface may have a plurality of different sections greater than 105 degrees and 150 degrees or less in the edge portion having at least one groove width direction. The grooves of the shape are combined to form a polishing pad. Further, from the viewpoint of in-plane uniformity, it is preferable to form the polishing pad from one type of groove A.

When the polishing pad is ground, it must be trimmed by adjusting it with a diamond-mounted adjuster on a metal or ceramic pedestal. By adjusting, the surface of the polishing pad can maintain a concave-convex shape suitable for polishing, and the polishing can be performed stably. However, the polishing layer is ground due to the adjustment, and the groove is reduced as the polishing progresses. When the cross-sectional area of the groove is lowered, the balance between the supply and discharge of the slurry is deteriorated, and the polishing rate may be lowered or the defect may be adversely affected.

For example, when the cross-sectional shape of the groove is only V-shaped, the supply and discharge functions of the polishing slurry are sufficient in the initial stage of polishing. However, the polishing can not be surely performed at the end of the life of the polishing pad as the cross-sectional area of the groove decreases. The supply and discharge of the mud may cause defects such as an increase in defects or adsorption of the wafer to the polishing pad.

When only the groove A having the above-described side surface is disposed on the entire surface of the pad surface, there is a problem that the cross-sectional area at the end of the life of the polishing pad is lowered, the polishing rate is lowered, or the defect is increased. However, it is considered that the supply of the slurry is provided. The discharged groove B can maintain a high polishing rate and in-plane uniformity, and can be stably ground until the end of the polishing pad life.

Therefore, in order to stabilize the shape of the groove, the groove B must have any angle between the polishing surface and the side surface connected to the polishing surface of the groove B. It is preferably 60 degrees or more and 105 degrees or less, and more preferably 80 degrees or more, and more preferably 85 degrees or more. Further, 100 degrees or less is preferable, and 95 degrees or less is more preferable.

The groove B is preferably provided with a bottom surface. Further, the shape of the bottom surface of the groove B is also not particularly limited.

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

The groove B201 shown in Fig. 2A has a rectangular cross-sectional shape. The groove B201 has two side faces 2 that are respectively connected to the polishing surface 1 at the edge portion in the groove width direction. In the case shown in Fig. 2A, the angle θ _B between the polishing surface and the side surface connected to the polishing surface is equal to each other at both edge portions in the groove width direction, and the value is 90 degrees. In this manner, the groove B201 has a rectangular cross-sectional shape, and the bottom surface 6 is parallel to the polishing surface 1.

The groove B202 shown in Fig. 2B has a substantially U-shaped bottom surface 7 between the two side faces 2.

The groove B203 shown in Fig. 2C has a concave portion 8 which is slightly narrower than the width between the two side faces 2, and this bottom surface is parallel to the polishing surface 1.

The groove B204 shown in Fig. 2D has a tapered inclined surface 9 which is formed by being connected to the two side faces 2, and is inclined toward the inner peripheral side, and a bottom surface 10 which is formed between the two inclined faces 9 and has a substantially U-shape.

The groove B205 shown in Fig. 2E has a tapered inclined surface 11 which is formed by being connected to the two side faces 2, and is inclined toward the inner peripheral side, and a V-shaped bottom surface 12 formed between the two inclined faces 11.

The groove B206 shown in Fig. 2F has a bottom surface 14 parallel to the polishing surface 1 between the two side faces 13. In the groove B206, the angle θ _B ' between the polishing surface 1 and the side surface 2 connected to the polishing surface 1 is an acute angle.

Further, in the side surface of the groove B connected to the polishing surface, even if the polishing pad is worn, the angle between the edge portion and the polishing surface can be maintained not less than 60 degrees and 105 degrees or less, but not only a straight line but also A curve, a polyline, a line with multiple bend points, a wave line, or a combination of these lines.

Here, the groove B constituting the polishing pad is not necessarily one type of groove, and the polishing pad may be configured by combining grooves having a plurality of different cross-sectional shapes. Further, from the viewpoint of in-plane uniformity, it is preferable to use one type of groove.

The groove formed on the polishing surface is set by the ratio of the area occupied by the groove formed in each area of the polishing surface. The groove area formed on the polishing surface preferably has a groove area ratio per unit structure of 5% or more and 50% or less. In particular, the lower limit of the groove area ratio per unit structure is preferably 10% or more, and more preferably 15% or more. Further, the upper limit of the groove area ratio per unit structure is preferably 45% or less, more preferably 40% or less.

The unit structure refers to a unit formed by a combination of a groove A and a groove B which are arranged in parallel with each other, and since the unit structure is repeatedly formed on the polishing surface, the groove is formed on the entire surface of the polishing surface.

3A to 3I are views showing a configuration example of a unit structure represented by the groove A and the groove B.

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

The unit structure 302 shown in Fig. 3B is composed of a combination of one groove A and two adjacent grooves B (arrangement mode: ABB).

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

The unit structure 304 shown in Fig. 3D is composed of one groove A and one groove B (array pattern: AB) adjacent to each other.

The unit structure 305 shown in Fig. 3E is composed of a combination of two adjacent grooves A and two adjacent grooves B (arrangement mode: AABB).

The unit structure 306 shown in Fig. 3F is composed of a combination of three adjacent grooves A and three adjacent grooves B (arrangement mode: AAABBB).

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

The unit structure 308 shown in Fig. 3H is composed of a combination of two adjacent grooves A and one groove B (arrangement mode: AAB).

The unit structure 309 shown in Fig. 3I is composed of a combination of three adjacent grooves A and one groove B (arrangement mode: AAAB).

On the other hand, the area occupation ratio of the groove A in the area of each groove means the ratio of the area of the groove A in the area of the groove formed on the polishing surface, and the area of the groove A in each of the grooves formed in the polishing surface. The area occupancy rate is preferably 30% or more and 90% or less, more preferably 40% or more, and more preferably 50% or more. Further, the area occupation ratio of the groove A in the area of each groove is preferably 80% or less, and more preferably 70% or less.

In order to suppress the water-slip phenomenon or to prevent the adsorption of the wafer and the pad on the surface of the polishing layer of the polishing pad, a groove which can be used in a normal polishing pad such as a lattice shape, a spiral shape, a spiral shape or a concentric shape may be provided. It is also suitable to use a combination of these shapes, and in particular, a lattice shape is preferred. A lattice shape refers to a shape in which lines are combined at right angles into a checkerboard. Love in the shape of a lattice In the case where the grooves in the longitudinal direction and the lateral direction are equal intervals, the interval between the grooves in the longitudinal direction is narrower than the interval between the grooves in the lateral direction, and the interval between the grooves in the lateral direction is narrower than the interval between the grooves in the vertical direction. And so on.

The groove A formed on the surface of the polishing surface of the polishing pad can impart a high polishing rate and good in-plane uniformity as described above. However, as the cross-sectional area at the end of life decreases, the balance of supply and discharge of the slurry deteriorates, resulting in deterioration. The increase in defects. Therefore, the groove length formed in the groove of the polishing surface is preferably 10% or more and 90% or less of the total groove length of the groove formed in the polishing surface, and 20% or more is preferable. Good, more than 25% is better, more than 30% is better, and more than 35% is especially good. Further, the total length of the groove of the groove A formed in the groove of the polishing surface is 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 groove length of the groove A formed on the polishing surface to the total of the groove lengths of all the grooves is within the above range, the attraction force between the wafer and the polishing pad acts to exhibit the polishing rate. The effect of the rise. Further, in the method of forming the groove formed on the surface of the polishing surface of the polishing pad, the groove A may be concentrated in the center of the polishing pad, and the groove B may be formed in the remaining portion. In the case where the polishing surface has a circular polishing pad, the groove A is preferably formed in a region including two straight lines passing through the center of the polishing pad and perpendicular to each other, wherein at least one of the two straight lines is calculated The distance is 70% or less of the radius of the polishing pad, preferably in the region of 60% or less, more preferably in the region of 50% or less, and in the region of 40% or less. It is especially good.

Fig. 4 is a schematic view showing an arrangement example of the groove A in the polishing surface of the polishing pad. In the polishing pad 401 shown in FIG. 4, in the circular polishing surface 402, the groove A403 (described by a thick line) is formed in a region including two straight lines L1 passing through the center O of the polishing surface 402. The region of L2, wherein the minimum value of the distance calculated by at least one of the two straight lines is 1/3 (about 33%) or less of the radius r. Further, the broken line shown in Fig. 4 indicates the groove B404. In such a manner, when the shape of the groove is in the shape of an XY lattice, it is preferable to disperse the groove A403 in only two directions and to disperse the groove A403 in two perpendicular directions (X direction and Y direction). .

When the groove A and the groove B are formed in a regular arrangement, the polishing pad can be configured based on, for example, a unit structure as shown in any of FIGS. 3A to 3H. However, in terms of the combination of the grooves, the ratio of the number of the grooves A to the total number of the entire grooves is not limited by the illustration.

Since it is necessary to have a cross-sectional area in which the slurry can be supplied and discharged, the groove width of the groove A and the groove B is preferably 0.1 mm or more and 10 mm or less, more preferably 0.3 mm or more, and still more preferably 0.5 mm or more. Further, the groove width of the groove A and the groove B is preferably 8 mm or less, more preferably 5 mm or less.

The groove depth of the groove A and the groove B is 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 ensure the supply and discharge of the slurry and the sufficient life. Further, the groove depth of the groove A and the groove B is preferably 3 mm or less, and more preferably 2 mm or less.

The thickness of the polishing layer may be less than the distance from the upper surface of the fixing plate of the polishing apparatus to the lower surface of the polishing head. Therefore, it is preferably 4.0 mm or less, preferably 3.5 mm or less, more preferably 3.0 mm or less, and particularly preferably 2.5 mm or less. .

In the present invention, the polishing layer constituting the polishing pad has a structure in which the micro-rubber A has a hardness of 70 degrees or more and has closed cells, and since it forms a flat surface in a semiconductor, a dielectric/metal composite, and an integrated circuit, To be suitable. It is not particularly limited, and examples of the material forming the structure include polyethylene, polypropylene, polyester, polyurethane, polyurea, polyamine, polyvinyl chloride, polyacetal, polycarbonate, and poly. Methyl methacrylate, polytetrafluoroethylene, epoxy resin, ABS resin, AS resin, phenol resin, melamine resin, "Neoprene (registered trademark)" rubber, butadiene rubber, styrene butadiene rubber, ethylene propylene Rubber, silicone rubber, fluororubber, and resins containing these as main components. These may also be used in two or more types. From the viewpoint that the particle diameter of the closed cells can be easily controlled, a material containing a polyurethane as a main component among these resins is preferable.

Polyurethane refers to a polymer synthesized by addition polymerization or polymerization of polyisocyanate. Examples of the polyisocyanate include toluene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate. However, these are not limited thereto, and two or more of them may be used. The compound to be used as a reaction object of the polyisocyanate is an active hydrogen-containing compound, that is, a compound containing two or more polyhydroxy or amine groups. The polyhydroxy group-containing compound is represented by a polyhydric alcohol, and examples thereof include a polyether polyol, a polytetramethylene ether di-alcohol, a cycloolefin resin denatured polyol, a polyester polyol, an acrylic polyol, and a polybutadiene polyol. , polyoxyl polyol, etc., these can also be used in two on. The combination or optimum amount of the polyisocyanate and the polyol, and the catalyst, the foaming agent, and the foam stabilizer are preferably determined in accordance with the hardness, the particle diameter, and the expansion ratio.

The method of forming the closed cells in these polyurethanes is generally a chemical foaming method in which various foaming agents are blended in the resin at the time of manufacture of the polyurethane, and is also suitable for mechanical stirring. A method of foaming a resin and then hardening it.

From the viewpoint of holding the slurry on the surface of the mat, the average bubble diameter of the closed cells is preferably 20 μm or more, and more preferably 30 μm or more. On the other hand, from the viewpoint of ensuring the flatness of the local unevenness of the semiconductor substrate, the average bubble diameter of the closed cells is preferably 150 μm or less, more preferably 140 μm or less, and still more preferably 130 μm or less. In addition, the average bubble particle diameter can be observed in a field of view by using a VK-8500 ultra-deep microscope manufactured by Keyence Corporation and observing the sample profile at a magnification of 400 times. It was observed that a circular bubble other than the bubble having a defective circle was obtained by measuring the circle equivalent diameter from the cross-sectional area by the image processing apparatus, and calculating the number average value.

One suitable embodiment of the polishing pad of the present invention is a pad having a closed cell of a polymer containing a vinyl compound and a polyurethane. If only a polymer produced from a vinyl compound is used, although the toughness and hardness can be improved, it is difficult to obtain a homogeneous polishing pad having closed cells. In addition, if the hardness of the polyurethane is increased, it becomes brittle. By impregnating the vinyl compound into the polyurethane, a polishing pad containing closed cells and high toughness and hardness can be obtained.

The vinyl compound is a compound having a polymerizable carbon-carbon double bond. Specific examples thereof include methacrylate, 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, methyl Dimethylamine ethyl acrylate, diethylamine ethyl methacrylate, glycidyl methacrylate, ethylene glycol dimethacrylate, acrylic acid, methacrylic acid, fumaric acid, dimethyl fumarate , diethyl fumarate, dipropyl fumarate, maleic acid, dimethyl maleate, diethyl maleate, dipropyl maleate, phenyl maleimide, cyclohexyl Maleic imine, isopropyl maleimide, acrylonitrile, acrylamide, vinyl chloride, vinylidene chloride, styrene, α-methylstyrene, divinylbenzene, ethylene glycol Acrylate, diethylene glycol dimethacrylate, and the like. Further, two or more of these may be used as the vinyl compound.

Among the above vinyl compounds, CH ₂ =CR ¹ COOR ² (R ¹ :methyl or ethyl, R ² :methyl, ethyl, propyl or butyl) is preferred. The hardness of a foamed structure of a polymer and a polyurethane which is easy to form a closed cell in a polyurethane, has a good impregnation property of a monomer, is easily polymer-hardened, and contains a vinyl compound after polymerization hardening. High, flattening characteristics are good. Among them, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, and isobutyl methacrylate are preferred.

Examples of the polymerization initiator which is suitably used for obtaining a polymer of these vinyl compounds include azobisisobutyronitrile, azobis(2,4-dimethylvaleronitrile), azobiscyclohexanecarbonitrile, and benzene. Formyl peroxide, laurel A free radical initiator such as a peroxide or isopropylperoxydicarbonate. These may also be used in two or more types. Further, a redox system polymerization initiator such as a combination of a peroxide and an amine can also be used.

The method of impregnating the vinyl compound into the polyurethane may, for example, be a method of immersing the polyurethane in a container in which the vinyl compound is placed. Further, at this time, in order to accelerate the impregnation speed, it is also suitable to perform treatment such as heating, pressurization, decompression, stirring, oscillation, and ultrasonic vibration.

The impregnation amount of the vinyl compound impregnated into the polyurethane should be determined according to the type of the vinyl compound and the polyurethane used, or the characteristics of the polishing pad to be produced, and cannot be generalized, for example, for example. In the polymerized and cured foamed structure, the content ratio of the polymer obtained from the vinyl compound to 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. Further, when the content ratio is 80/20 or less, the elasticity of the polishing layer can be made sufficiently high.

Further, in the polyurethane, the content of the polymer and the polyurethane obtained by the polymerization-hardened vinyl compound can be measured by thermal decomposition gas chromatography/mass spectrometry. For the apparatus that can be used in this method, the thermal decomposition apparatus may be a double-click pyrolysis apparatus (PY-2010D) (manufactured by Frontier Lab), and a gas chromatography ‧ mass analysis apparatus may be referred to as "TRIO". -1" (made by VG company).

In the present invention, the polymer obtained from the vinyl compound is contained from the viewpoint of the flatness of the local unevenness of the semiconductor substrate. It is preferred that the phase is in phase with the polyurethane to prevent phase separation. When this phenomenon is quantitatively explained, it is "the infrared spectrum when the polishing pad is observed by a micro-infrared spectroscopic device having a spot size of 50 μm, and has an infrared absorption peak of a polymer obtained by polymerizing a vinyl compound. The infrared absorption peak of the polyurethane and the infrared spectrum of each place are substantially the same." The micro-infrared spectroscopic device used herein includes IR μs manufactured by SPECTRA-TEC.

In order to improve the characteristics, the polishing pad may contain various additives such as an abrasive, an antistatic agent, a lubricant, a stabilizer, a dye, and the like.

In the present invention, the micro-rubber A hardness of the polishing layer is a value obtained by evaluation by a micro rubber hardness meter MD-1 manufactured by Kobunshi Corporation. The micro rubber A hardness tester MD-1 can measure the hardness of a thin object or a small object which is difficult to measure by a conventional hardness tester. The micro rubber A hardness meter MD-1 is designed and manufactured by a reduction model of a spring type rubber durometer type A of about 1/5, so that a measured value consistent with the hardness of the spring type hardness meter type A can be obtained. A typical polishing pad is cut into an abrasive layer or a hard layer having a thickness of 5 mm, so that it cannot be evaluated by a spring type rubber hardness meter type A. Thus, in the present invention, the micro rubber A hardness of the polishing layer was evaluated by the aforementioned micro rubber MD-1.

In the present invention, the hardness of the polishing layer is preferably such that the hardness of the polishing layer is 70 degrees or more, and preferably 80 degrees or more, from the viewpoint of flatness of a part of the unevenness of the semiconductor substrate.

In the present invention, from the viewpoint of reducing local flatness defects or overall height difference, the density of the polishing layer is preferably 0.3 g/cm ³ or more, more preferably 0.6 g/cm ³ or more, and 0.65 g/cm. ³ or more is better. On the other hand, from the viewpoint of reducing scratches, the density of the polishing layer is preferably 1.1 g/cm ³ or less, more preferably 0.9 g/cm ³ or less, and still more preferably 0.85 g/cm ³ or less. Further, the density of the abrasive layer in the present invention is a value measured using a Hubbard type pycnometer (based on JIS R-3503) and using water as a medium.

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

The volume modulus of elasticity in the present invention is measured by the following method. A sample piece and water at 23 ° C were placed in a stainless steel measuring cell having an internal volume of about 40 mL, and a suction tube (0.55 mL of a minimum scale of 0.5 mL) containing a capacity of 0.5 mL of borosilicate glass was attached. Further, the pressure vessel was made of a tube made of polyvinyl chloride resin (inner diameter: 90 mm Φ × 2000 mm, thickness: 5 mm), and a measurement tank in which the sample piece was placed was placed therein, and nitrogen pressure was applied to the pressure P to measure the volume change V1. Next, the sample piece was placed in the measurement tank, and nitrogen pressure was applied to the pressure P to measure the volume change V0. The pressure P was divided by ΔV/Vi = (V1 - V0) / Vi, and the calculated value was defined as the volume modulus of the sample.

In the present invention, the volume elastic modulus of the buffer layer is preferably 40 MPa or more. By setting the bulk modulus to 40 MPa or more, the in-plane uniformity of the entire surface of the semiconductor substrate can be improved. In addition, flow through grinding The slurry or water of the holes on the surface of the pad and the back is not easily impregnated into the buffer layer to maintain the cushioning properties.

The tensile modulus in the present invention is a dumbbell shape and a tensile stress is applied, and the tensile stress is measured in a range of tensile strain (=length of change in stretch/original length) of 0.01 to 0.03, based on the measurement result, The calculation was carried out from the tensile modulus = ((tensile stress at a tensile strain of 0.03) - (tensile stress at a tensile strain of 0.01)) / 0.02. The apparatus for measuring the tensile stress includes a Tensilon universal testing machine RTM-100 manufactured by Orientec. The tensile stress was measured at a test speed of 5 cm/min, and the shape of the test piece was a dumbbell shape having a width of 5 mm and a sample length of 50 mm.

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

Examples of such a buffer layer include natural rubber, nitrile rubber, "Neoprene (registered trademark)" rubber, polybutadiene rubber, thermosetting polyurethane rubber, thermoplastic polyurethane rubber, and enamel rubber. The foamed elastomer, however, is not limited by these. The thickness of the buffer layer is preferably in the range of 0.1 to 2 mm. The thickness of the buffer layer is preferably 0.2 mm or more and 0.3 mm or more from the viewpoint of in-plane uniformity of the entire surface of the semiconductor substrate. Further, from the viewpoint of local flatness, the thickness of the buffer layer is preferably 2 mm or less, and preferably 1.75 mm or less.

The means for bonding the polishing layer to the buffer layer may, for example, be a double-sided tape or an adhesive.

The double-sided tape has a general configuration in which an adhesive layer is provided on both surfaces of a substrate such as a nonwoven fabric or a film. Further, the polishing pad of the present invention may be provided with a double-sided tape on the surface of the cushion sheet and the platform. Such a double-sided tape can be used in the same manner as described above, and has a tape having a general structure in which an adhesive layer is provided on both surfaces of the substrate. The base material may, for example, be a nonwoven fabric or a film. If it is considered to peel the polishing pad from the platform after use, the substrate is preferably a film.

Further, examples of the composition of the adhesive layer include a rubber-based adhesive or an acrylic adhesive. When the content of the metal ion is considered, the acrylic adhesive is suitable because the metal ion content is small. Further, there are many cases in which the buffer sheet and the composition of the stage are different, and the respective layers of the double-sided tape may be set to have different compositions, and the adhesion to the cushion sheet and the stage may be appropriate.

The material to be polished which is polished in the present invention may, for example, be a surface of an insulating layer or a metal wiring formed on a semiconductor wafer. The insulating layer may be an interlayer insulating film of a metal wiring or a lower insulating film of a metal wiring or a shallow trench isolation used for element isolation. Examples of the metal wiring include aluminum, tungsten, copper, etc., and the structure may be inlaid, double damascene, plug, or the like. In the case where copper is used as the metal wiring, the barrier metal such as tantalum nitride may be the object of polishing. The insulating film is now dominated by yttrium oxide, but a low dielectric insulating film can also be used. The material to be polished can be used for polishing of a magnetic head, a hard disk, sapphire or the like in addition to a semiconductor wafer.

The polishing method of the present invention is suitably used for forming a flat surface in a glass, a semiconductor, a dielectric/metal composite, an integrated circuit, or the like.

[Examples]

The details of the invention are illustrated by the following examples. However, the present invention is not limited by the definition of the embodiment. Further, the measurement was carried out as follows.

<Measurement of the tilt angle>

A polishing pad having a groove formed on the surface of the polishing layer was sliced in the depth direction of the groove, and a section of the groove was observed by a VK-8500 ultra-deep microscope manufactured by Keyence, and the angle between the polishing surface and the side surface connected to the polishing surface was measured. When the polishing pad is circular, the groove closest to the position is measured at a position of 50 mm, 150 mm, and 250 mm from the center of the polishing pad, and the average of the three points is determined as an inclination angle. In addition, in the case where the polishing pad is not circular, the positions of 50 mm, 150 mm, and 250 mm are calculated from the intersection of the diagonal lines of the sheet to one edge, and the ditch closest to the positions is measured, and the average of the three points is measured. Set to the angle of inclination.

<Measurement of average polishing rate and in-plane uniformity>

The Mirra 3400 manufactured by Applied Materials Co., Ltd. was used to perform end point detection under predetermined polishing conditions while performing grinding. The average polishing rate of the polishing characteristics was a polishing rate (nm/min) except for the outermost circumference of 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 is defined as in-plane uniformity.

<Defect Evaluation>

In the strengthening treatment, the polished wafer was immersed in 0.5% by weight of hydrofluoric acid for 10 minutes, washed with water, and washed with a mixed solution of 1.0% by weight of an ammonia solution and 1.0% by weight of hydrogen peroxide water, and washed with water. Correct The number of defects of 0.155 μm or more was counted on the cleaned wafer using SP-1 manufactured by KLA-Tencor Co., Ltd.

<Pad grinding speed>

The depth of the groove before and after the grinding was measured using a depth gauge (digital type) manufactured by Mitutoyo Co., Ltd., and the value of the groove was divided by the time of use of the disk under evaluation, and the obtained value was determined as the pad polishing speed.

<Proportion of the number of grooves A>

A polishing pad having a groove formed on the surface of the polishing surface was sliced in a direction parallel to the groove, and the number of the groove A and the groove B was measured. Further, the arrangement of the groove A and the groove B (cross-sectional view: FIG. 3) and the arrangement example of the groove A and the groove B (schematic diagram: FIG. 4) divide the number of the groove A by the sum of the number of the groove A and the groove B, and The ratio of the number of grooves A. The formula is described below.

Proportion of the number of grooves A = number of grooves A / (number of grooves A + number of grooves B) × 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 parts by weight of water and 0.3 parts by weight of triethylamine, 1.7 parts by weight of a polyoxygenated foaming agent, and 0.09 parts by weight of tin octylate were mixed by a RIM molding machine. , spouted to a metal mold and subjected to press molding to produce a foamed polyurethane sheet having a thickness of 2.6 mm (micro rubber A hardness: 42 degrees, density: 0.76 g/cm ³ , average of independent bubbles) Bubble particle size: 34 μm).

The foamed polyurethane sheet was immersed in 0.2 part by weight of methyl methacrylate added with azobisisobutyronitrile for 60 minutes. Next, will The foamed polyurethane sheet was immersed in 15 parts by weight of polyvinyl alcohol "CP" (degree of polymerization: about 500, manufactured by Nacalai Tesque Co., Ltd.), and ethyl alcohol (test grade, manufactured by Katayama Chemical Co., Ltd.). The solution of 35 parts by weight and 50 parts by weight of water is then dried to cover the surface layer of the foamed polyurethane sheet with polyvinyl alcohol.

Next, the foamed polyurethane sheet was sandwiched between two glass plates via a gasket made of vinyl chloride, and heated at 65 ° C for 6 hours and at 120 ° C for 3 hours to cure the polymer. . After demolding between glass plates, after water washing, vacuum drying was carried out at 50 °C. The hard foamed sheet obtained in this manner was sliced to have a thickness of 2.00 mm, whereby an abrasive layer was produced. The methyl methacrylate content in the polishing layer was 66% by weight. Further, the polishing layer had a D hardness of 54 degrees, a density of 0.81 g/cm ³ , and an average bubble diameter of the closed cells of 45 μm.

Both sides of the obtained rigid foamed sheet were polished to prepare a polishing layer having a thickness of 2 mm.

Using a roll coater, a micro-rubber A of a thermoplastic polyurethane made by Japan Matai Co., Ltd. as a buffer layer has a hardness of 90 mm of 0.3 mm (volume modulus = 65 MPa, tensile modulus = 4 MPa) A double-sided tape made of Sekisui Chemical Co., Ltd., which is laminated on the back side and laminated on the back side, is a layer of MA-6203 made of Mitsui Chemicals Polyurethane Co., Ltd., laminated with the polishing layer obtained by the above method. 5604TDM.

_A rectangular cross section having a groove width of 3.0 mm, a groove pitch of 15 mm, a slope angle θ _A of 135 degrees, a groove shape of a groove depth of 1.5 mm, a groove width of 1.5 mm, a groove pitch of 15 mm, and a groove depth of 1.5 mm ( The groove B alternating repetition (hereinafter referred to as mode A) of the inclination angle θ _B = 90 degrees) is formed into an XY lattice shape to form a polishing pad. The groove area ratio per unit structure of the groove A was 24.9%, and the area occupation ratio of the groove A in each groove area was 73.7%.

The polishing pad obtained by the above method was attached to a fixing plate of a grinder ("Mirra 3400" manufactured by Applied Materials Co., Ltd.). Set to fixed ring pressure = 41 kPa (6 psi), inner tube pressure = 28 kPa (4 psi), membrane pressure = 28 kPa (4 psi), platform speed = 76 rpm, grinding head speed = 75 rpm, grinding mud at a flow rate of 150 mL / minute (Cabot Company system, SS-25) flowed, load 17.6N (4lbf), grinding time 1 minute, 30 seconds from grinding, in-situ trimming with Saesol dresser, grinding 100 pieces of oxide film 8 inches Wafer. The 100th oxide film had an average polishing rate of 202 nm/min and an in-plane uniformity of 11.8%.

The number of defects of 0.155 μm or more was counted by the aforementioned defect evaluation method for the polished wafer, and as a result, the number of defects was 331, which was very good. Further, the pad polishing rate at the time of polishing was 1.01 μm/min.

(Example 2)

A groove having a groove width of 3.0 mm, a groove pitch of 15 mm, a V-shaped cross section having an inclination angle θ _A of 135 degrees, a groove A having a groove depth of 1.5 mm, a groove width of 1.5 mm, a groove pitch of 15 mm, and a groove depth of 1.5 mm. B is a groove constituting the polishing surface, and a combination of one groove A and two grooves B (hereinafter referred to as mode B) is repeated, and the center of the polishing surface of the polishing pad is formed in an XY lattice shape over the entire area of the pad radius, and It was ground in the same manner as in Example 1. The groove area ratio per unit structure of the groove A was 20.7%, and the area occupation ratio of the groove A in the area of each groove was 60.9%. The average polishing rate was 197 nm/min and the in-plane uniformity was 9.0%.

The number of defects of 0.155 μm or more was counted by the aforementioned defect evaluation method for the polished wafer, and as a result, the number of defects was 211, which was good. Further, the pad polishing rate at the time of polishing was 1.21 μm/min.

(Example 3)

On the surface of the polishing layer, a groove A having a groove width of 3.0 mm, a groove pitch of 15 mm, a V-shaped cross section having an inclination angle θ _A of 135 degrees, and a groove depth of 1.5 mm was provided with two straight lines perpendicular to each other passing through the center of the polishing surface and perpendicular to each other. The area, and the distance calculated by at least one straight line is 32% or less of the radius of the grinding surface to form an XY grid shape, and the groove B of the rectangular section having a groove width of 1.5 mm, a groove pitch of 15 mm, and a groove depth of 1.5 mm is in diameter. The calculated distance was a XY grid shape in a region exceeding 32% of the radius, and was polished in the same manner as in Example 1 except that a polishing pad (hereinafter referred to as mode C) was prepared. The groove area ratio per unit structure of the groove A was 23.1%, and the area occupation ratio of the groove A in the area of each groove was 67.7%. The layout of the groove is shown in Fig. 4. The average polishing rate was 196 nm/min and the in-plane uniformity was 10.9%.

The number of defects of 0.155 μm or more was counted by the aforementioned defect evaluation method for the polished wafer, and as a result, the defect was 142, which was very good. Further, the pad polishing rate at the time of polishing was 1.34 μm/min.

(Example 4)

The polishing was carried out in the same manner as in Example 1 except that the groove A on the surface of the polishing layer was set to have a trapezoidal cross section with an inclination angle θ _A of 120 degrees. The groove area ratio per unit structure of the groove A was 16.5%, and the area occupation ratio of the groove A in the area of each groove was 54.8%. The average polishing rate was 199 nm/min and the in-plane uniformity was 6.0%.

The number of defects of 0.155 μm or more was counted by the aforementioned defect evaluation method for the polished wafer, and as a result, the number of defects was 155, which was very good. Further, the pad polishing rate at the time of polishing was 1.14 μm/min.

(Example 5)

The groove A was polished in the same manner as in Example 4 except that the groove A on the surface of the polishing layer was set to have a trapezoidal cross section with an inclination angle θ _A of 123 degrees. The groove area ratio per unit structure of the groove A was 28.3%, and the area occupation ratio of the groove A in each groove area was 73.6%. The average polishing rate was 203 nm/min and the in-plane uniformity was 8.4%.

The number of defects of 0.155 μm or more was counted by the aforementioned defect evaluation method for the polished wafer, and as a result, the defect was 141, which was very good. Further, the pad polishing rate at the time of polishing was 1.32 μm/min.

(Example 6)

The polishing was carried out in the same manner as in Example 4 except that the groove B on the surface of the polishing layer was set to have a trapezoidal cross section in which the inclination angle θ _B was 85 degrees. The groove area ratio per unit structure of the groove A was 30.2%, and the area occupation ratio of the groove A in the area of each groove was 68.9%. The average polishing rate was 201 nm/min and the in-plane uniformity was 9.1%.

The number of defects of 0.155 μm or more was counted by the aforementioned defect evaluation method for the polished wafer, and as a result, the defect was 139, which was very good. Further, the pad polishing rate at the time of polishing was 1.11 μm/min.

(Example 7)

The groove A on the surface of the polishing layer was set to a V-shaped cross section having an inclination angle θ _A of 120 degrees, and the groove B was set to have a trapezoidal cross section having an inclination angle θ _B of 85 degrees, and was polished in the same manner as in Example 3. The groove area ratio per unit structure of the groove A was 16.5%, and the area occupation ratio of the groove A in the area of each groove was 54.8%. The average polishing rate was 200 nm/min and the in-plane uniformity was 9.8%.

The number of defects of 0.155 μm or more was counted by the aforementioned defect evaluation method for the polished wafer, and as a result, the number of defects was 211, which was very good. Further, the pad polishing rate at the time of polishing was 1.33 μm/min.

(Example 8)

The groove A on the surface of the polishing layer was set to a V-shaped cross section having an inclination angle θ _A of 120 degrees, and the groove B was set to have a trapezoidal cross section having an inclination angle θ _B of 95 degrees, and was polished in the same manner as in Example 3. The groove area ratio per unit structure of the groove A was 18.4%, and the area occupation ratio of the groove A in the area of each groove was 49.0%. The average polishing rate was 209 nm/min, and the in-plane uniformity was 10.1%.

The number of defects of 0.155 μm or more was counted by the aforementioned defect evaluation method for the polished wafer, and as a result, the number of defects was 109, which was very good. Further, the pad polishing rate at the time of polishing was 1.30 μm/min.

(Example 9)

The polishing was performed in the same manner as in Example 3 except that the groove A on the surface of the polishing layer was set to a V-shaped cross section having an inclination angle θ _A of 150 degrees. The groove area ratio per unit structure of the groove A was 34.6%, and the area occupation ratio of the groove A in the area of each groove was 78.4%. The average polishing rate was 200 nm/min and the in-plane uniformity was 9.9%.

The number of defects of 0.155 μm or more was counted by the aforementioned defect evaluation method for the polished wafer, and as a result, the number of defects was 111, which was very good. Further, the pad polishing rate at the time of polishing was 1.41 μm/min.

(Embodiment 10)

The groove A on the surface of the polishing layer was set to a V-shaped cross section having an inclination angle θ _A of 150 degrees, and the groove B was set to have a trapezoidal cross section having an inclination angle θ _B of 85 degrees, and was polished in the same manner as in Example 3. The groove area ratio per unit structure of the groove A was 34.6%, and the area occupation ratio of the groove A in the area of each groove was 78.4%. The average polishing rate was 206 nm/min and the in-plane uniformity was 10.0%.

The number of defects of 0.155 μm or more was counted by the aforementioned defect evaluation method for the polished wafer, and as a result, the number of defects was 153, which was very good. Further, the pad polishing rate at the time of polishing was 1.44 μm/min.

(Example 11)

The groove A on the surface of the polishing layer was set to a V-shaped cross section having an inclination angle θ _A of 150 degrees, and the groove B was set to have a trapezoidal cross section having an inclination angle θ _B of 95 degrees, and was polished in the same manner as in Example 3. The groove area ratio per unit structure of the groove A was 36.5%, and the area occupation ratio of the groove A in each groove area was 74.3%. The average polishing rate was 200 nm/min, and the in-plane uniformity was 10.1%.

The number of defects of 0.155 μm or more was counted by the aforementioned defect evaluation method for the polished wafer, and as a result, the number of defects was 134, which was very good. Further, the pad polishing rate at the time of polishing was 1.40 μm/min.

(Comparative Example 1)

The polishing was performed in the same manner as in Example 1 except that the groove on the surface of the polishing layer was set to have a rectangular cross section of 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 number of defects of 0.155 μm or more was counted by the aforementioned defect evaluation method for the polished wafer, and as a result, the number of defects was 583, which was good. Further, the pad polishing rate at the time of polishing was 1.13 μm/min.

(Comparative Example 2)

The polishing was performed in the same manner as in Example 1 except that the groove on the surface of the polishing layer was set to 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 an inclination angle of 135 degrees. The average polishing rate was 217 nm/min and the in-plane uniformity was 21.1%.

The number of defects of 0.155 μm or more was counted by the aforementioned defect evaluation method for the polished wafer, and as a result, the defect was 297, which was very good. Further, the pad polishing rate at the time of polishing was 1.73 μm/min.

(Comparative Example 3)

The polishing was performed in the same manner as in Example 1 except that the polishing layer was set to 1.0 mm, and the groove of the surface was set to 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%.

For the polished wafer, the defects of 0.155 μm or more were counted by the aforementioned defect evaluation method, and as a result, there were as many as 1,521 defects. Further, the pad polishing rate at the time of polishing was 1.68 μm/min.

The results obtained in Examples 1 to 11 and Comparative Examples 1 to 3 described above are disclosed in Table 1.

1, 402‧‧‧ polished surface

2, 13‧‧‧ side

3, 4, 6, 7, 8, 10, 12, 14‧‧‧ bottom

5‧‧‧ recess

9,11,13‧‧‧Slope

101, 102, 103, 104, 403‧‧‧ Ditch A

201, 202, 203, 204, 205, 206, 404‧‧‧ Ditch B

301, 302, 303, 304, 305, 306, 307, 308, 309‧‧‧ unit structure

401‧‧‧ polishing pad

Fig. 1A is a view showing a cross-sectional shape (first example) of a first groove of a polishing pad to which the embodiment of the present invention is associated.

Fig. 1B is a view showing a cross-sectional shape (second example) of a first groove included in a polishing pad to which one embodiment of the present invention is concerned.

Fig. 1C is a view showing a cross-sectional shape (third example) of a first groove of the polishing pad to which the embodiment of the present invention is associated.

Fig. 1D is a view showing a cross-sectional shape (fourth example) of a first groove of a polishing pad to which the embodiment of the present invention is associated.

Fig. 2A is a view showing a cross-sectional shape (first example) of a second groove of the polishing pad to which the embodiment of the present invention is associated.

Fig. 2B is a view showing a cross-sectional shape (second example) of the second groove of the polishing pad to which the embodiment of the present invention is associated.

Fig. 2C is a view showing a cross-sectional shape (third example) of the second groove of the polishing pad to which the embodiment of the present invention is associated.

Fig. 2D is a view showing a cross-sectional shape (fourth example) of the second groove of the polishing pad to which the embodiment of the present invention is associated.

Fig. 2E is a view showing a cross-sectional shape (fifth example) of the second groove of the polishing pad to which the embodiment of the present invention is associated.

Fig. 2F is a view showing a cross-sectional shape (sixth example) of the second groove of the polishing pad to which the embodiment of the present invention is associated.

3A is a cross-sectional view showing a configuration example (first example) of a unit structure composed of the first and second grooves.

Fig. 3B is a cross-sectional view showing a configuration example (second example) of a unit structure composed of the first and second grooves.

3C is a cross-sectional view showing a configuration example (third example) of a unit structure composed of the first and second grooves.

3D is a cross-sectional view showing a configuration example (fourth example) of a unit structure composed of the first and second grooves.

3E is a cross-sectional view showing a configuration example (fifth example) of a unit structure composed of the first and second grooves.

3F is a cross-sectional view showing a configuration example (sixth example) of a unit structure composed of the first and second grooves.

3G is a cross-sectional view showing a configuration example (seventh example) of a unit structure composed of the first and second grooves.

3H is a cross-sectional view showing a configuration example (eighth example) of a unit structure composed of the first and second grooves.

Fig. 3I is a cross-sectional view showing a configuration example (ninth example) of a unit structure composed of the first and second grooves.

Fig. 4 is a schematic view showing an arrangement example of a first groove in a polishing surface of a polishing pad to which one embodiment of the present invention is concerned.

Claims (11)

A polishing pad for a chemical mechanical polishing polishing pad having at least a polishing layer, wherein the polishing surface of the polishing layer has a first groove and a second groove, and the first groove and the second groove have respective groove widths The edge portion of the direction has a side surface connected to the polishing surface, and an angle between the polishing surface and a side surface connected to the polishing surface is at least 105 degrees 150 degrees or less at an edge portion of the first groove in at least one groove width direction. In the two edge portions of the second groove in the groove width direction, the angle between the polishing surface and the side surface connected to the polishing surface is 60 degrees or more and 105 degrees or less. The polishing pad of claim 1, wherein the second groove has a bottom surface. The polishing pad according to claim 2, wherein a groove area ratio per unit structure is 5% or more and 50% or less, and an area occupation ratio of the first groove in each 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. The polishing pad according to the fourth aspect of the invention, wherein the groove length of the first groove formed on the polishing surface is 10% or more and 90% or less of the total groove length of the groove formed on the polishing surface. The polishing pad of claim 4, wherein the polishing surface has a circular shape, and the first groove formed on the polishing surface is formed in a region containing two strips passing through the center of the polishing surface and perpendicular to each other Straight The region, and the distance calculated by at least one of the two straight lines is a region of 70% or less of the radius of the polished surface. The polishing pad of claim 5, wherein the polishing surface has a circular shape, and the first groove formed on the polishing surface is formed in a region containing two strips passing through a center of the polishing surface and perpendicular to each other The area of the straight line, and the distance calculated by at least one of the two straight lines is a region of 70% or less of the radius of the polished surface. The polishing pad of claim 4, wherein an angle between the polishing surface and a side surface connected to the polishing surface is greater than 105 degrees at two of the two edge portions in the groove width direction of the first groove. Below 150 degrees. The polishing pad according to claim 5, wherein an angle between the polishing surface and a side surface connected to the polishing surface is greater than 105 degrees at two of the two edge portions in the groove width direction of the first groove. Below 150 degrees. The polishing pad of claim 6, wherein the angle between the polishing surface and the side surface connected to the polishing surface is greater than 105 degrees at two of the two edge portions in the groove width direction of the first groove. Below 150 degrees. The polishing pad of claim 7, wherein the angle between the polishing surface and the side surface connected to the polishing surface is greater than 105 degrees at two of the two edge portions in the groove width direction of the first groove. Below 150 degrees.