A polishing pad and grinding equipment

Abstract

This invention discloses a polishing pad, comprising a polishing layer, which includes a plurality of concentric circular grooves, a plurality of first radial grooves, and a plurality of second radial grooves. The second radial grooves are disposed between two adjacent first radial grooves. The first radial grooves extend radially from the center of the polishing layer to its edge. The second radial grooves extend radially from any point on the polishing layer to any other point on the polishing layer. The lengths of the second radial grooves may be equal or unequal. The radius of the polishing layer is denoted as R. The inner end of each second radial groove is located at 0.15R to 0.35R, and the outer end is located at 0.68R to 0.92R. This invention combines first radial grooves of equal length with second radial grooves of unequal length to regulate the edge polishing rate, improve polishing uniformity, and solve the problem of edge effects.

Description

Technical Field

[0001] This invention relates to the field of chemical polishing. More specifically, this invention relates to a polishing pad and a grinding apparatus. Background Technology

[0002] Chemical mechanical polishing (CMP) is currently the most commonly used technique for polishing workpiece surfaces. CMP is a composite technique that combines chemical etching and mechanical removal, and it is also the most commonly used technique for planarization of semiconductor wafers and similar materials.

[0003] Currently, in a conventional CMP process, the wafer is mounted on a support assembly of the polishing equipment, and the contact position between the wafer and the polishing pad is set by adjusting relevant parameters. During polishing, the wafer is pressed against the polishing pad under controlled pressure, and an external driving force causes the polishing pad and wafer to rotate in the same or opposite directions. During this relative rotation, polishing slurry is continuously dripped onto the polishing pad, thereby planarizing and polishing the wafer surface through the mechanical action of the polishing pad surface and the chemical action of the polishing slurry.

[0004] However, chemical mechanical polishing (CMP) is often accompanied by the problem of "edge effect." The edge effect refers to the phenomenon that the polishing rate is uneven between the edge and the center of the wafer. Compared with the center of the wafer, the edge effect usually leads to the removal of too much material from the edge of the wafer. Therefore, it can result in an uneven edge polishing profile on the wafer, which can seriously affect the wafer yield and productivity. Summary of the Invention

[0005] One object of the present invention is to solve at least the above-mentioned problems and to provide at least the advantages that will be described later.

[0006] Another objective of this invention is to provide a polishing pad in which the polishing layer is combined with radial grooves of different lengths to improve polishing uniformity and solve the problem of edge effect.

[0007] To achieve these objectives and other advantages according to the invention, a first aspect of the invention provides a polishing pad comprising a polishing layer, the polishing layer including a plurality of concentric circular grooves, a plurality of first radial grooves, and a plurality of second radial grooves, the second radial grooves being disposed between two adjacent first radial grooves, the first radial grooves extending radially from the center of the polishing layer to the edge of the polishing layer, the second radial grooves extending radially from any point on the polishing layer to any other point on the polishing layer, the plurality of second radial grooves having equal or unequal lengths, the radius of the polishing layer being denoted as R, the inner end of the second radial groove being located at 0.15R~0.35R, and the outer end of the second radial groove being located at 0.68R~0.92R.

[0008] Specifically, the number of the second radial grooves is 2*K, where 2≤K≤16 and K is an integer; preferably, 4≤K≤8.

[0009] Preferably, the second radial groove includes at least three groove lengths: 0.320R~0.355R, 0.545R~0.590R, and 0.710R~0.730R.

[0010] Preferably, the length of the second radial groove gradually increases along the circumference, and the length L of the second radial groove... n =0.514R+A*n*(W+P), where n is an integer between 1 and 2*K, 2≤K≤16, W is the width of the concentric circular groove, P is the spacing between the concentric circular grooves, and A is a constant, with W ranging from 0.20mm to 0.50mm and P ranging from 1.47mm to 4.11mm.

[0011] Preferably, the ratio of the total volume of the second radial groove to the total volume of the first radial groove is in the range of 0.452 to 0.659, and more preferably 0.550 to 0.605.

[0012] Preferably, the width of the concentric circular grooves is denoted as W, the interval is denoted as P, and the range of W / R is 0.78*10. -3 ~1.33*10 -3 The P / W ratio ranges from 3.48 to 5.65.

[0013] Preferably, the W / R range is 0.94*10 -3 ~1.12*10 -3 The P / W ratio ranges from 3.48 to 4.65.

[0014] Specifically, the depth of the concentric grooves is 0.3 to 0.45 times the thickness of the polished layer.

[0015] A second aspect of the present invention provides a grinding apparatus having a polishing pad that contacts the workpiece being ground, wherein the polishing pad is the polishing pad described in the first aspect.

[0016] The present invention has at least the following beneficial effects:

[0017] This invention combines a first radial groove of the same length and a second radial groove of the same or different lengths to adjust the edge grinding rate, improve grinding uniformity, and solve the problem of edge effect.

[0018] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the trench structure design according to one embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of a trench structure design according to another embodiment of the present invention. Detailed Implementation

[0021] This invention provides polishing pads and grinding equipment, which will be described below with reference to specific embodiments. It should be noted that the terms "concentric circle," "radial," "edge," "inner end," "outer end," and "circumferential direction," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention. Other combinations and various modifications within the scope of the invention can be made without departing from the spirit or scope of the invention.

[0022] Polishing Pad

[0023] This invention provides a polishing pad, including a polishing layer, which is the polishing surface opposite to the wafer during polishing. In this invention, the thickness of the polishing layer is between 1.90 mm and 2.10 mm, for example, the thickness of the polishing layer can be 1.92 mm, 1.991 mm, 1.998 mm, 2.023 mm, 2.036 mm, 2.051 mm, or 2.072 mm. In this invention, the diameter of the polishing layer is 50-100 cm, preferably 50-90 cm; for example, it can be 77.47 cm or 74.168 cm. In this invention, to make the polishing rate more uniform and reduce edge effects, radial grooves of different lengths are provided. Some radial grooves have the same length as their radius, or if the center of the polishing layer is a blank area, the starting end of these radial grooves can also start from the end side of the blank area. Other radial grooves are set as grooves of equal or unequal length but shorter than the radius of the polishing layer. (See reference...) Figure 1 In this embodiment of the invention, the polishing layer includes a plurality of concentric circular grooves 1, a plurality of first radial grooves 2, and a plurality of second radial grooves 3. The second radial grooves 3 are disposed between two adjacent first radial grooves 2. One or more second radial grooves 3 may exist between two adjacent first radial grooves 2. When multiple second radial grooves 3 exist between two adjacent first radial grooves 2... Figure 2As shown. The first radial groove 2 of the present invention extends radially from the center of the polishing layer to the edge of the polishing layer, and a plurality of first radial grooves 2 are evenly distributed on the polishing layer. The second radial groove 3 of the present invention extends radially from any point on the polishing layer to any other point on the polishing layer. The lengths L of the plurality of second radial grooves 3 are equal or unequal. In the same polishing layer, there must exist second radial grooves of unequal lengths. The second radial grooves 3 are evenly distributed between two first radial grooves 2. The radius of the polishing layer is denoted as R. The inner end of the second radial groove 3 is located at 0.15R~0.35R, and the outer end of the second radial groove 3 is located at 0.68R~0.92R. The inner end of the second radial groove 3 can start at a concentric circular groove 1, or it can start in the blank space between two adjacent concentric circular grooves 1. The inner end of the second radial groove 3 can be located at a position with the same radius value on the polishing layer, or it can be located at a position with a different radius value on the polishing layer.

[0024] In this invention, the depth of the first radial groove 2 and the second radial groove 3 is 0.3 to 0.5 times the thickness of the polishing layer. In the embodiment described in this invention, the first radial groove 2, the second radial groove 3, and the concentric circular groove 1 are all kept in a connected state to facilitate the uniform distribution of polishing fluid on the polishing layer.

[0025] In this invention, the second radial grooves 3 on the polishing layer exist in an even number, and the number of second radial grooves 3 on the polishing layer is set according to the polishing rate and polishing effect. Specifically, the number of second radial grooves 3 is 2*K, 2≤K≤16, where K is an integer; preferably, 4≤K≤8. In this invention, the number of first radial grooves 2 can be 4, 8, 16, 32, or an even number within other ranges. One, two, three, or four second radial grooves 3 are uniformly arranged between two adjacent first radial grooves 2.

[0026] In this invention, to achieve both increased polishing speed and reduced wafer defects, the length of the second radial trench 3 is further limited. The second radial trench 3 includes at least three lengths: 0.320R~0.355R, 0.545R~0.590R, and 0.710R~0.730R. In this embodiment of the invention, the inner ends of adjacent second radial trenches 3 can be located at the same radius value or at different radius values ​​on the polishing layer; on a polishing layer, the outer ends of the second radial trenches 3 are located at the same radius value or at different radius values ​​to meet the requirement of achieving different polishing rates at different locations.

[0027] In this invention, while improving the grinding rate, the grinding uniformity is also improved, making the second radial groove 3 more widely applicable to various types of polishing layers. In this embodiment of the invention, the length of the second radial groove 3 gradually increases along the circumference, L n Let L be the length of the nth second radial groove. n =0.514R+A*n*(W+P), where n is an integer between 1 and 2*K, W is the width of the concentric circular groove 1, P is the spacing between the concentric circular grooves 1, and A is a constant. The constant refers to a parameter designed based on the location of the area with excessively high grinding rate during the grinding process; A is generally 1~15, preferably 1~12. For example, in one embodiment, A can be 6.337. In this embodiment, the value of W ranges from 0.20mm to 0.50mm, and the value of P ranges from 1.47mm to 4.11mm.

[0028] In this invention, the ratio of the total volume of the first radial groove 2 to the total volume of the second radial groove 3 ranges from 0.452 to 0.659, and more preferably from 0.550 to 0.605. When the ratio of the total volume of all the first radial grooves 2 to the total volume of the second radial groove 3 is within this range, the grinding uniformity is further improved.

[0029] Specifically, the total volume of all the first radial grooves 2 is denoted as V. 总1 Let W1 be the width of the first radial groove 2, R be the length of the first radial groove 2, S1 = W1 * R be the surface area of ​​the first radial groove 2, D1 be the depth of the first radial groove 2, and V1 = S1 * D1 = W1 * R * D1 be the volume of a single first radial groove 2. Assume there are 2 * N first radial grooves 2, where 2 ≤ N ≤ 16, V 总1 =2*N*V1=2*N*W1*R*D1. When there is a blank area in the center of the polished layer, and the starting end of the first radial groove 2 is the end of the blank area, the total volume of all the first radial grooves 2 is denoted as V. 总1 = 2*N*V1= 2*N*W1*(R-R1)*D1, where R1 is the radius of the blank area of ​​the polished layer.

[0030] The total volume of all the second radial grooves 3 is denoted as V. 总2 The width of the second radial groove 3 is denoted as W2, and the length of the second radial groove 3 is denoted as L. n The surface area of ​​the second radial groove 3 is S2 = W2 * L n n is an integer between 1 and 2*K, where 2≤K≤16. The depth of the second radial groove 3 is denoted as D2, and the volume of a single second radial groove 3 is V2=S2*D2=W2*L. n*D2, Assuming there are 2*K first radial grooves 2, the total volume of all second radial grooves 3 is denoted as V. 总2 = V 21 + V 22 +···+V 2n = W2*(L1+L2+··+L n )*D2.

[0031] The ratio of the total volume of the second radial groove 3 to the total volume of the first radial groove 2 is denoted as V. 总2 / V 总1 V 总2 / V 总1 = W2*(L1+L2+··+L n )*D2 / 2*N*W1*R*D1. When the groove widths W1 and W2 of the first radial groove 2 and the second radial groove 3 are equal, and the groove depths D1 and D2 are equal, the volume ratio of the first radial groove 2 and the second radial groove 3 is related to the number of grooves and the groove length.

[0032] In this invention, to adjust the grinding rate and achieve a more uniform grinding effect, the width of the concentric circular grooves 1 is denoted as W, the interval as P, and the range of W / R is 0.78*10. -3 ~1.33*10 -3 The P / W ratio ranges from 3.48 to 5.65; preferably, the W / R ratio ranges from 0.94 to 10. -3 ~1.12*10 -3 The P / W ratio ranges from 3.48 to 4.65. The value of P ranges from 1.70 to 2.82 mm, and the value of W ranges from 0.28 mm to 0.50 mm.

[0033] In this invention, the depth of the concentric circular groove 1 is 0.3 to 0.45 times the thickness of the polished layer. For example, it can be 0.70 mm, 0.71 mm, 0.72 mm, 0.74 mm, 0.76 mm, 0.77 mm, 0.79 mm, 0.81 mm, 0.82 mm, 0.83 mm, 0.85 mm, 0.86 mm, or 0.88 mm.

[0034] <Preparation of Polishing Pads>

[0035] The polishing pad of the present invention includes a polishing layer and may also include a buffer layer. The polishing layer and buffer layer can be made in-house using the methods described below, or commercially available products can be purchased directly. There are no particular limitations on the method for bonding the polishing layer and buffer layer to prepare the polishing pad; examples include: laminating an adhesive layer made of a polyester hot-melt adhesive onto the buffer layer, heating and melting the adhesive layer with a heater, and then laminating the polishing layer onto the molten adhesive layer and pressing it.

[0036] As a polishing layer, the polishing layer of the present invention can be prepared by known methods such as the prepolymer method and the one-step method. The method selected by the technical personnel of the present invention as needed does not affect the concept and scope of protection of the present invention, as long as the polishing layer involved in the present invention can be produced.

[0037] The polishing layer is made of materials conventionally used in the art, such as polyurethane. Polyurethane refers to a product derived from difunctional or polyfunctional isocyanates. For example, the polyurethane can be one or more of polyether urea, polyisocyanurate, polyurethane, polyurea, and polyurethane urea. The polyurethane can also be a copolymer formed from two or more of polyether urea, polyisocyanurate, polyurethane, polyurea, and polyurethane urea. Preferably, the polyurethane is prepared by reacting an isocyanate-terminated prepolymer obtained from the reaction of isocyanate and polyol with a curing agent, or by reacting an isocyanate-terminated prepolymer obtained from the reaction of isocyanate and polyol with a mixture of a curing agent and hollow microspheres.

[0038] Unless otherwise specified, the isocyanate may be a compound known in the polyurethane field, such as an aromatic isocyanate and / or an aliphatic isocyanate. The isocyanate may be one or more of aromatic diisocyanate compounds, aliphatic diisocyanate compounds, and alicyclic diisocyanate compounds. Preferably, the aromatic diisocyanate compound is one or more of 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, terephthalic diisocyanate, isophthalic diisocyanate, terephthalimide diisocyanate, and isophthalimide diisocyanate. Preferably, the aliphatic diisocyanate compound is one or more of ethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and 1,6-hexamethylene diisocyanate. The alicyclic diisocyanate compound is preferably one or more of 1,4-cyclohexane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate, and norbornene diisocyanate.

[0039] Unless otherwise specified, the polyol may be a compound known in the polyurethane field, such as a polyether polyol and / or a polyester polyol. Preferably, the polyol is one or more of polytetramethylene ether glycol, polyethylene glycol, polypropylene glycol, polybutylene glycol, ethylene adipate, and butyl adipate, or the polyol is a copolymer formed from two or more of the above six substances.

[0040] The prepolymer is preferably one or more of Adiprene® L325, Adiprene® LF750, and Adiprene® LF700D.

[0041] Unless otherwise specified, the curing agent may be a compound known in the polyurethane industry, such as one or more of polyols, polyamines, and alkanolamines, wherein the polyamine is a diamine and other polyfunctional amines. Preferably, the curing agent is one or more of 4,4'-methylenebis(o-chloroaniline), 4,4'-methylenebis(3-chloro-2,6-diethylaniline), dimethylthiotoluenediamine, 1,3-propanediol diaminobenzoate, diethyltoluenediamine, 5-tert-pentyl-2,4- and 3-tert-pentyl-2,6-toluenediamine, and chlorotoluenediamine. More preferably, the curing agent is MOCA and / or MCDEA, wherein MOCA is 3,3-dichloro-4,4-diaminodiphenylmethane, and MCDEA is 4,4-methylenebis(3-chloro-2,6-diethylaniline).

[0042] A polishing layer containing hollow microspheres, wherein the hollow microspheres are uniformly dispersed within the polishing layer. The hollow microspheres have a capsule-like structure with a polyacrylonitrile or polyacrylonitrile copolymer outer wall. More preferably, the hollow microspheres are Expancel series hollow microspheres or Matsumoto microspheres F series. Even more preferably, the hollow microspheres are Expancel® 551DE20d42. The dispersion of the hollow microsphere polymer in the polishing layer allows the polishing layer to ultimately have a porosity of 10–40% and a pore size of <120 μm; more preferably, a porosity of 15–35% and a pore size of <50 μm.

[0043] Different hardness, density, compressibility, and other physical properties of the polished layer are controlled by varying the content of prepolymers, curing agents, and microspheres. The composition is poured into a mold to form a cylinder, which is then sliced ​​to obtain thin sheets. Finally, grooves are engraved on the thin sheets to obtain a polished layer with a grooved pattern.

[0044] As a buffer layer, examples include fiber nonwoven fabrics such as polyester nonwoven fabric, nylon nonwoven fabric, and acrylic nonwoven fabric; resin-impregnated nonwoven fabrics such as polyester nonwoven fabric impregnated with polyurethane; polymer resin foams such as polyurethane foam and polyethylene foam; rubbery resins such as butadiene rubber and isoprene rubber; and photosensitive resins.

[0045] The density, hardness, and compressibility of the buffer layer can be adjusted by using different nonwoven fabrics and polyurethane DMF solutions of varying viscosities. After impregnation for a period of time, the TPU is molded and adhered to the nonwoven fabric through a coagulation tank with a low concentration of DMF, via solution exchange. The fabric is then placed in a water washing tank to remove the solvent, dried in a tunnel oven at 150°C, and finally sanded to the required thickness.

[0046] Grinding Equipment

[0047] A second aspect of the present invention provides a grinding apparatus having a polishing pad that contacts the workpiece being ground, wherein the polishing pad is the same as the polishing pad provided in the first aspect of the present invention.

[0048] The present invention will be further described in detail below with reference to embodiments, so that those skilled in the art can implement it based on the description.

[0049] It should be noted that, unless otherwise specified, the experimental methods described in the following implementation plan are all conventional methods, and the reagents and materials described are all commercially available unless otherwise specified.

[0050] In the following examples, the polishing layer of the polishing pad has a diameter of 74.168 cm, a radius of 37.084 cm, and a thickness of 2.072 mm.

[0051] In Examples 1-5, a second radial groove is provided between two adjacent first radial grooves.

[0052] In the polishing layer of the polishing pads used in Examples 1-4 and Comparative Examples 1-5, the width W of the concentric circular grooves is 0.30 mm, the spacing P between the concentric circular grooves is 1.57 mm, the depth of the concentric circular grooves is 0.7112 mm, the width W1 of the first radial groove and the width W2 of the second radial groove are equal, W1=W2=0.7239 mm, the depth D1 of the first radial groove and the depth D2 of the second radial groove are equal, D1=D2=0.7112 mm.

[0053] In Example 5, the width W of the concentric circular groove is 0.3937 mm, the spacing P is 1.7272 mm, and the depth of the concentric circular groove, the width and depth of the first radial groove and the second radial groove are the same as in Examples 1 to 4.

[0054] The parameter designs for Examples 1-5 and Comparative Examples 1-5 are shown in Table 1. In Table 1, OT refers to the first radial groove, TT refers to the second radial groove, and TT sorting refers to the clockwise circumferential order of the second radial grooves. The numbers recorded in the TT sorting column indicate the specific sorting order of the second radial grooves; for example, "1" indicates the first second radial groove, and "2 / 3" indicates the second and third second radial grooves in a clockwise order. Ratio 1 refers to the ratio of the value at the inner end of the second radial groove to the radius of the polished layer; ratio 2 refers to the ratio of the value at the outer end of the second radial groove to the radius of the polished layer; ratio 3 refers to the ratio of the length of the second radial groove to the radius of the polished layer; and ratio 4 is V. 总2 / V 总1 V 总2 V is the sum of the volumes of all the second radial trenches on the polished layer. 总1 This represents the total volume of all the first radial trenches on the polished layer.

[0055] The implementation effects of Examples 1-5 and Comparative Examples 1-5 are shown in Table 2.

[0056] Table 1

[0057]

[0058]

[0059] In Example 4, the lengths of the eight second radial grooves gradually increase along the circumference, with A taking the value of 4.0153, corresponding to formula L. n =0.514R+4.0153*n*(W+P), where n is an integer from 1 to 8, and the inner ends of the 8 second radial grooves increase by 2 (W+P) in the circumferential direction.

[0060] Table 2

[0061]

[0062] Evaluation methods for polishing pads:

[0063] The polished wafers were Oxide 7.5K and 6.0K wafers. The polishing slurry was Ceria Abrasive CES333F with a flow rate of 200cc. The dresser was a Saesol DS8051 diamond disk with a pressure of 4lbf. The polishing head pressures were 1.0psi and 2.0psi. The stage speed was 93rpm and the carrier speed was 87rpm.

[0064] Average polishing rate: Under the above conditions, a non-metallic oxide film with a thickness of 1 μm will be deposited on the test wafer for polishing. The average polishing rate will be calculated from the wear reduction and the unit is (Å / min).

[0065] Defect count testing method: Defect count is the number of defects on the wafer. The instrument used is a KLA-Tencor SP2 analyzer, which records the average number of defects in 10 wafers.

[0066] Grinding rate non-uniformity: The thickness of the polished object was measured before and after the polishing experiment. Forty-nine locations were pre-selected on the surface of the polished object for measurement, and the grinding rate non-uniformity of the polished wafer was recorded after 1 hour and 10 hours of polishing. Grinding rate non-uniformity can be calculated using the maximum (Max) and minimum (Min) differences in thickness measured at the 49 locations before and after the experiment, and the average of these values. The formula is: Grinding rate non-uniformity = 100 * (Max - Min) / average value.

[0067] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and embodiments shown and described herein.

Claims

1. A polishing pad, characterized in that, The system includes a polishing layer comprising a plurality of concentric circular grooves, a plurality of first radial grooves, and a plurality of second radial grooves. The second radial grooves are disposed between two adjacent first radial grooves. The first radial grooves extend radially from the center of the polishing layer to its edge. The second radial grooves extend radially from any point on the polishing layer to any other point on the polishing layer. The radius of the polishing layer is denoted as R. The inner end of the second radial groove is located at 0.15R~0.35R, and the outer end is located at 0.68R~0.92R. The length of the second radial groove gradually increases circumferentially, L. n Let L be the length of the nth second radial groove. n =0.514R+A*n*(W+P), where n is an integer between 1 and 2*K, 2≤K≤16, W is the width of the concentric circular groove, P is the spacing between the concentric circular grooves, and A is a constant, with W ranging from 0.20mm to 0.50mm and P ranging from 1.47mm to 4.11mm.

2. The polishing pad as described in claim 1, characterized in that, The number of the second radial grooves is 2*K, where 2≤K≤16, and K is an integer.

3. The polishing pad as described in claim 1 or 2, characterized in that, 4≤K≤8。 4. The polishing pad as described in claim 1, characterized in that, The second radial groove includes at least three groove lengths: 0.320R~0.355R, 0.545R~0.590R, and 0.710R~0.730R.

5. The polishing pad as described in claim 1, characterized in that, The ratio of the total volume of the second radial groove to the total volume of the first radial groove ranges from 0.452 to 0.

659.

6. The polishing pad as described in claim 1, characterized in that, The ratio of the total volume of the second radial groove to the total volume of the first radial groove is in the range of 0.550 to 0.

605.

7. The polishing pad as described in claim 1, characterized in that, The range of W / R is 0.78*10 -3 ~1.33*10 -3 The P / W ratio ranges from 3.48 to 5.

65.

8. The polishing pad as described in claim 7, characterized in that, The range of W / R is 0.94*10 -3 ~1.12*10 -3 The P / W ratio ranges from 3.48 to 4.

65.

9. The polishing pad as described in claim 1, characterized in that, The depth of the concentric grooves is 0.3 to 0.45 times the thickness of the polished layer.

10. A grinding apparatus, characterized in that, A polishing pad having contact with the workpiece being polished, wherein the polishing pad is the polishing pad according to any one of claims 1 to 9.

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