A discontinuous arc groove polishing pad

Abstract

The invention discloses an intermittent circular arc groove polishing pad, comprising a polishing pad body, a circular groove arranged at the center of the polishing pad body, a first short arc groove derived from the outside of the circular groove, a second short arc groove arranged between adjacent first short arc grooves, and an intermittent arc groove derived from the outside of the short arc groove area, which extends to any point on the polishing pad body in a divergent shape. The arc grooves in two adjacent intermittent arc groove areas of the device are intermittently distributed and not connected to each other, and the polishing liquid needs to change direction when it reaches the next intermittent arc groove area from one intermittent arc groove area, thereby increasing the time the polishing liquid stays in the intermittent arc groove area, so that the polishing liquid contacts the wafer more fully, and the polishing rate of the wafer is improved, and the arc grooves in adjacent intermittent arc groove areas are intermittently staggered and distributed more evenly on the polishing pad body, so that the flatness of the wafer surface can be significantly improved when the wafer is polished.

Description

Technical Field

[0001] The invention relates to the technical field of chemical mechanical polishing, and in particular to a discontinuous circular arc groove polishing pad. Background Art

[0002] Semiconductor chips are semiconductor devices that can achieve certain special functions and are made through steps such as deposition, etching, wiring and polishing on silicon wafers. From silicon wafers to a complete chip, multiple stringent processes are required, including depositing multiple layers of conductive materials, semiconductor materials and dielectric materials on the surface of the wafer, and etching away the multiple layers of conductive materials, semiconductor materials and dielectric materials from the surface of the wafer. In this process, the surface of the wafer will become uneven, affecting subsequent processes, so a polishing pad is needed to grind the surface of the wafer flat.

[0003] The existing publication number CN101234482A provides a polishing pad with grooves for reducing slurry consumption. The invention has radial or arc-shaped grooves on one side of the polishing pad, so that the consumption of polishing liquid can be reduced. Since the polishing pad rotates when grinding the wafer, the centrifugal force generated will accelerate the polishing liquid to separate from the polishing pad, reducing the contact time between the polishing liquid and the wafer, resulting in the polishing effect not meeting the expectations, and the polishing rate of the wafer is also relatively slow. Summary of the invention

[0004] In view of the above problems existing in the prior art, a discontinuous arc groove polishing pad is provided, which is used for polishing at least one wafer of magnetic, optical and semiconductor substrates, and comprises a polishing pad body;

[0005] a circular groove disposed at the center of the polishing pad body;

[0006] A first short arc groove is derived from the outside of the circular groove, the first short arc groove takes the edge of the circular groove as a starting point and extends in a divergent shape to any point on the polishing pad body, and a second short arc groove is arranged between adjacent first short arc grooves, and the area formed by the first short arc groove and the second short arc groove is defined as a short arc groove area;

[0007] Intermittent arc grooves are derived from the outside of the short arc groove zone and extend divergently to any point on the polishing pad body. According to the distance between the starting point of the intermittent arc groove and the center of the polishing pad body, the annular area composed of the intermittent arc grooves is defined as the intermittent arc groove zone. From the inside to the outer edge of the polishing pad body, the first-level...N-level intermittent arc groove zones are arranged in sequence. The arc grooves of the N-level intermittent arc groove zone are arranged in the polishing area formed by the extension lines of the arc grooves in the N-1-level intermittent arc groove zone.

[0008] As a further description of the above technical solution: the starting end of the arc groove inside the N-1th level discontinuous arc groove area is located on the circle where the end of the arc groove inside the N-2th level discontinuous arc groove area is located, and the end of the arc groove inside the N-1th level discontinuous arc groove area is located on the circle where the starting end of the arc groove inside the Nth level discontinuous arc groove area is located.

[0009] As a further description of the above technical solution: the cross-section of the circular groove can be rectangular, semicircular, a combination of rectangular and semicircular, trapezoidal and triangular.

[0010] As a further description of the above technical solution: the cross-sections of the first short arc groove, the second short arc groove and the intermittent arc groove can be rectangular, semicircular, a combination of rectangular and semicircular, trapezoidal and triangular.

[0011] As a further description of the above technical solution: in the first short arc groove, the second short arc groove and the intermittent arc groove, the distance between two adjacent grooves at any position ranges from 1mm to 50mm.

[0012] As a further description of the above technical solution: the diameter of the polishing pad body is 50-1000 mm, and the thickness of the polishing pad body is 0.5-5.0 mm.

[0013] As a further description of the above technical solution: the radius of the circular groove is 5-50 mm, preferably 10-25 mm.

[0014] As a further description of the above technical solution: referring to the polar coordinates of the coaxial center of the polishing pad, the orbital coordinates of the first short arc groove are (ρ, A), the polar angle of the center O2 of the first short arc groove is B, the polar angle of any point P on the first short arc groove is A, and the curvature radius of the first short arc groove is R, which can be expressed by the following polar coordinate equation:

[0015] ρ=2R cos(BA)

[0016] Wherein, R=0.5Rpad to 2Rpad, and Rpad is the radius of the polishing pad.

[0017] The arc angle of the first short arc groove track defined by the above equation is between 10° and 120°.

[0018] As a further description of the above technical solution: referring to the polar coordinates of the coaxial center of the polishing pad, the orbital coordinates of the second short arc groove and the discontinuous arc groove are (ρ', A'), according to the polar angle between the second short arc groove and the center O' of the discontinuous arc groove is B', the polar angle between the second short arc groove and any point P' on the discontinuous arc groove is A', and the curvature radius of the second short arc groove and the discontinuous arc groove is R', which can be expressed by the following polar coordinate equation:

[0019] p′=2R'cos(B'-A')

[0020] Wherein, R'=0.5Rpad to 2Rpad, Rpad is the radius of the polishing pad.

[0021] The curvature of the second short arc groove and the discontinuous arc groove track defined by the equation is between 10° and 120°.

[0022] As a further description of the above technical solution: the distance difference ΔL between the starting points of two adjacent levels of the discontinuous arc-shaped grooves and the center of the polishing pad body is in the range of 0.01Rpad-0.5Rpad.

[0023] The above technical solution has the following advantages or beneficial effects: the arc grooves in two adjacent intermittent arc groove areas are intermittently distributed and not connected to each other. When the polishing liquid reaches the next intermittent arc groove area from one intermittent arc groove area, it needs to change direction, thereby increasing the residence time of the polishing liquid in the intermittent arc groove area, so that the polishing liquid can contact the wafer more fully, thereby improving the polishing rate of the wafer. Since the arc grooves inside adjacent intermittent arc groove areas are intermittently staggered and distributed more evenly on the polishing pad body, the polishing pad can significantly improve the flatness of the wafer surface when polishing the wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The embodiments of the present invention are described more fully with reference to the attached drawings, however, the attached drawings are only used for illustration and description and do not constitute a limitation on the scope of the present invention.

[0025] Figure 1 This is a schematic structural diagram of a discontinuous circular arc groove polishing pad proposed in Embodiment 1 of the present invention;

[0026] Figure 2A schematic diagram of a first short arc groove of an intermittent circular arc groove polishing pad proposed by the present invention;

[0027] Figure 3 A schematic diagram of a second short arc groove and a discontinuous arc groove of an intermittent circular arc groove polishing pad proposed by the present invention;

[0028] Figure 4 A schematic diagram of a partial arc groove of an intermittent circular arc groove polishing pad proposed by the present invention;

[0029] Figure 5 Schematic diagram of the structure of a discontinuous arc groove polishing pad proposed in the third embodiment of the present invention

[0030] Figure 6 This is a schematic diagram of the structure of an intermittent arc groove polishing pad proposed in Example 4 of the present invention.

[0031] The above-mentioned figure marks indicate: 1. polishing pad body; 2. circular groove; 3. first short arc groove; 4. second short arc groove; 5. short arc groove area; 6. discontinuous arc groove area; 7. discontinuous arc groove. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the practical embodiment to clearly and completely describe the technical solution in the practical embodiment. Obviously, the described embodiment is only a part of the embodiment of the practical, not all of the embodiments. Based on the embodiment in the practical, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this practical.

[0033] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0034] The present invention is further described below with reference to the accompanying drawings and specific embodiments, but is not intended to be limiting of the present invention.

[0035] Reference Figure 1-Figure 4 , Embodiment 1 provided by the present invention: A discontinuous arc groove polishing pad, used for polishing at least one wafer of a magnetic, optical and semiconductor substrate, comprises a polishing pad body 1;

[0036] A circular groove 2 is provided at the center of the polishing pad body 1;

[0037] A first short arc groove 3 is derived from the outside of the circular groove 2. The first short arc groove 3 starts from the edge of the circular groove 2 and extends in a divergent shape to any point on the polishing pad body 1. A second short arc groove is arranged between adjacent first short arc grooves 3. The area formed by the first short arc groove and the second short arc groove is defined as a short arc groove area 5.

[0038] The short arc groove area 5 is externally provided with discontinuous arc grooves 7, which extend in a divergent manner to any point on the polishing pad body 1. According to the distance between the starting point of the discontinuous arc groove 7 and the center of the polishing pad body 1, the annular area formed by the discontinuous arc grooves 7 is defined as the discontinuous arc groove area 6. The first-level to the Nth-level discontinuous arc groove areas 6 are sequentially arranged from the inner outer edge of the polishing pad body 1. The arc grooves of the Nth-level discontinuous arc groove area 6 are arranged at the Nth-level discontinuous arc groove area 6. In the polishing area formed by the extension lines of the arc grooves in the -1 level intermittent arc groove area 6, the arc grooves in two adjacent intermittent arc groove areas 6 are intermittently distributed and not connected to each other, so that the polishing liquid needs to change direction when it reaches the next intermittent arc groove area from one intermittent arc groove area 6, thereby increasing the residence time of the polishing liquid in the intermittent arc groove area 6, so that the polishing liquid can contact the wafer more fully, thereby improving the polishing rate of the wafer.

[0039] The starting end of the arc groove inside the N-1th level intermittent arc groove area 6 is located on the circle where the end of the arc groove inside the N-2th level intermittent arc groove area 6 is located, and the end of the arc groove inside the N-1th level intermittent arc groove area 6 is located on the circle where the starting end of the arc groove inside the Nth level intermittent arc groove area 6 is located, and adjacent intermittent arc grooves 7 are staggered and distributed more evenly on the polishing pad body 1, so the polishing pad can significantly improve the flatness of the wafer surface when polishing the wafer.

[0040] Furthermore, the cross section of the circular groove 2 can be rectangular, semicircular, a combination of rectangular and semicircular, trapezoidal, and triangular.

[0041] Furthermore, the cross-sections of the first short arc groove 3 , the second short arc groove 4 and the discontinuous arc groove can be rectangular, semicircular, a combination of rectangular and semicircular, trapezoidal and triangular.

[0042] Furthermore, in the first short arc groove 3 , the second short arc groove 4 and the discontinuous arc groove, the distance between two adjacent grooves at any position ranges from 1 mm to 50 mm.

[0043] Further, the diameter of the polishing pad body is 50-1000 mm, and the thickness of the polishing pad body is 0.5-5.0 mm.

[0044] Furthermore, the radius of the circular groove 2 is 5-50 mm, preferably 10-25 mm.

[0045] Further, referring to the polar coordinates of the coaxial center of the polishing pad, the orbital coordinates of the first short arc groove 3 are (ρ, A), the polar angle of the center O2 of the first short arc groove 3 is B, the polar angle of any point P on the first short arc groove 3 is A, and the curvature radius of the first short arc groove 3 is R, which can be expressed by the following polar coordinate equation:

[0046] ρ=2R cos(BA)

[0047] Wherein, R=0.5Rpad to 2Rpad, and Rpad is the radius of the polishing pad.

[0048] The arc angle of the first short arc groove 3 track defined by the above equation is between 10° and 120°.

[0049] Further, referring to the polar coordinates of the coaxial center of the polishing pad, the orbital coordinates of the second short arc groove 4 and the discontinuous arc groove 7 are (ρ', A'), according to the polar angle between the second short arc groove 4 and the center O' of the discontinuous arc groove 7 is B', the polar angle between the second short arc groove 4 and any point P' on the discontinuous arc groove 7 is A', and the curvature radius of the second short arc groove 4 and the discontinuous arc groove 7 is R', which can be expressed by the following polar coordinate equation:

[0050] p'=2R'cos(B'-A')

[0051] Wherein, R'=0.5Rpad to 2Rpad, Rpad is the radius of the polishing pad.

[0052] The arc angles of the second short arc groove 4 and the discontinuous arc groove 7 tracks defined by the equation are between 10° and 120°.

[0053] Further, the arc length of the Nth level discontinuous arc-shaped groove is equal to or greater than the arc length of the N-1th level discontinuous arc-shaped groove.

[0054] Furthermore, the difference ΔL in distance between the starting points of the adjacent two-stage discontinuous arc-shaped grooves 7 and the center of the polishing pad body is in the range of 0.01Rpad-0.5Rpad.

[0055] Reference Figure 1, Embodiment 2 provided by the present invention: the radius of the polishing pad body 1 is 510 mm, the radius of the circular groove 2 is 15 mm, the thickness of the polishing pad 1 body is 2 mm, R=0.6Rpad, the curvature of the first short arc groove 3 is 30°, the curvature of the second short arc groove is 15°, the curvature of the first-level intermittent arc groove 7 is 30°, the curvature of the second-level intermittent arc groove 7 is 45°, the number of the first short arc grooves 3 is 32, the number of the second short arc grooves 4 is 32, the number of first-level intermittent arc grooves 7 is 128, the number of second-level intermittent arc grooves 7 is 256, among which the radius of the circle where the starting point of the first short arc groove 3 is located is 35mm, the radius of the circle where the starting point of the second short arc groove 4 is located is 110mm, the radius of the circle where the starting point of the first-level intermittent arc groove 7 is located is 240mm, the radius of the circle where the starting point of the second-level intermittent arc groove 7 is located is 480mm, and the fluctuation range of ΔP is 1-3mm.

[0056] Reference Figure 5 , Embodiment 3 provided by the present invention: the radius of the polishing pad body 1 is 510 mm, the radius of the circular groove 2 is 15 mm, the thickness of the polishing pad 1 body is 2 mm, R=0.8Rpad, the curvature of the first short arc groove 3 is 20°, the curvature of the second short arc groove is 10°, the curvature of the first-level intermittent arc groove 7 is 30°, the curvature of the second-level intermittent arc groove 7 is 45°, the number of the first short arc grooves 3 is 32, the number of the second short arc grooves 4 is There are 32 first-level intermittent arc grooves 7, 64 first-level intermittent arc grooves 7, and 128 second-level intermittent arc grooves 7. The radius of the circle where the starting point of the first short arc groove 3 is located is 35mm, the radius of the circle where the starting point of the second short arc groove 4 is located is 110mm, the radius of the circle where the starting point of the first-level intermittent arc groove 7 is located is 240mm, and the radius of the circle where the starting point of the second-level intermittent arc groove 7 is located is 480mm. The fluctuation range of ΔP is 1-3mm.

[0057] Reference Figure 6, Embodiment 4 provided by the present invention: the radius of the polishing pad body 1 is 510 mm, the radius of the circular groove 2 is 15 mm, the thickness of the polishing pad 1 body is 2.0 mm, R=0.5Rpad, the curvature of the first short arc groove 3 is 20°, the curvature of the second short arc groove is 10°, the curvature of the first-level intermittent arc groove 7 is 35°, the curvature of the second-level intermittent arc groove 7 is 45°, the number of the first short arc grooves 3 is 32, the number of the second short arc grooves 4 is There are 32 first-level intermittent arc grooves 7, 128 first-level intermittent arc grooves 7, and 256 second-level intermittent arc grooves 7. The radius of the circle where the starting point of the first short arc groove 3 is located is 35mm, the radius of the circle where the starting point of the second short arc groove 4 is located is 110mm, the radius of the circle where the starting point of the first-level intermittent arc groove 7 is located is 240mm, and the radius of the circle where the starting point of the second-level intermittent arc groove 7 is located is 480mm. The fluctuation range of ΔP is 1-3mm.

[0058] Working principle: When the device is used, the circular groove 2, the first short arc groove 3 and the intermittent arc groove 7 together form the short arc groove area 5 and the intermittent arc groove area 6 on the polishing pad body 1. The density of the first short arc groove 3 and the second short arc groove 4 in the short arc groove area 5 of the polishing pad body 1 is relatively sparse, while the density of the first-level to N-level intermittent arc groove areas 6 in the peripheral area of ​​the polishing pad body 1 is relatively gradually dense. When the polishing pad is in use, the polishing liquid diffuses from the circular groove 2 along the first short arc groove 3 and the second short arc groove 4 to the outside. Since the first-level to N-level intermittent arc groove areas 6 are outside the polishing pad body 1, the polishing liquid diffuses from the circular groove 2 along the first short arc groove 3 and the second short arc groove 4 to the outside. The distribution density of the arc grooves in the part is greater than that in the central area, and the arc grooves in the two adjacent intermittent arc groove areas 6 are intermittently distributed and not connected to each other, so that the polishing liquid needs to change direction when it reaches the next intermittent arc groove area from one intermittent arc groove area 6, thereby increasing the time the polishing liquid stays in the intermittent arc groove area 6, so that the polishing liquid can contact the wafer more fully, thereby improving the polishing rate of the wafer. At the same time, since the arc grooves inside the adjacent intermittent arc groove areas 6 are intermittently staggered, they are distributed more evenly on the polishing pad body 1, so the polishing pad can significantly improve the flatness of the wafer surface when polishing the wafer. The above description is only a preferred embodiment of the present utility, and does not limit the implementation method and protection scope of the present utility. For those skilled in the art, it should be realized that all solutions obtained by equivalent substitution and obvious changes made by using the present utility specification and the illustrated content should be included in the protection scope of the present utility.

Claims

1. A discontinuous arc groove polishing pad, characterized in that: including a polishing pad body; 1) a circular groove disposed at the center of the polishing pad body; 2) A first short arc groove is derived from the outside of the circular groove, the first short arc groove takes the edge of the circular groove as a starting point and extends in a divergent shape to any point on the polishing pad body, and a second short arc groove is arranged between adjacent first short arc grooves, and the area formed by the first short arc groove and the second short arc groove is defined as a short arc groove area; 3) Intermittent arc grooves are derived from the outside of the short arc groove area, extending in a divergent shape to any point on the polishing pad body. According to the distance between the starting point of the intermittent arc groove and the center of the polishing pad body, the annular area composed of the intermittent arc grooves is defined as the intermittent arc groove area. From the inside to the outer edge of the polishing pad body, the first-level ... N-level intermittent arc groove areas are arranged in sequence. The arc grooves of the N-level intermittent arc groove area are arranged in the polishing area formed by the extension lines of the arc grooves in the N-1-level intermittent arc groove area; 4) The starting end of the arc-shaped groove inside the N-1th level discontinuous arc-shaped groove area is located on the circle where the end of the arc-shaped groove inside the N-2th level discontinuous arc-shaped groove area is located, and the end of the arc-shaped groove inside the N-1th level discontinuous arc-shaped groove area is located on the circle where the starting end of the arc-shaped groove inside the Nth level discontinuous arc-shaped groove area is located; 5) The arc length of the Nth level of the discontinuous arc groove is equal to or greater than the arc length of the N-1th level of the discontinuous arc groove, and the distance difference ΔL between the starting points of the two adjacent levels of the discontinuous arc grooves and the center of the polishing pad body is in the range of 0.01Rpad-0.5Rpad; 6) The cross section of the circular groove is rectangular, semicircular, a combination of rectangular and semicircular, trapezoidal and triangular.

2. The intermittent arc groove polishing pad according to claim 1, characterized in that: The cross sections of the first short arc groove, the second short arc groove and the discontinuous arc groove are rectangular, semicircular, a combination of rectangular and semicircular, trapezoidal and triangular.

3. The intermittent arc groove polishing pad according to claim 1, characterized in that: In the first short arc groove, the second short arc groove and the intermittent arc groove, the distance between two adjacent grooves at any position ranges from 1 mm to 50 mm.

4. The intermittent arc groove polishing pad according to claim 1, characterized in that: The diameter of the polishing pad body is 50-1000 mm, and the thickness of the polishing pad body is 0.5-5.0 mm.

5. The intermittent arc groove polishing pad according to claim 1, characterized in that: The radius of the circular groove is 5-50 mm.

6. The intermittent arc groove polishing pad according to claim 1, characterized in that: Referring to the polar coordinates of the coaxial center of the polishing pad, the orbital coordinates of the first short arc groove are (ρ, A), the polar angle of the center O2 of the first short arc groove is B, the polar angle of any point P on the first short arc groove is A, and the curvature radius of the first short arc groove is R, which can be expressed by the following polar coordinate equation: ρ=2R cos(BA) Wherein, R = 0.5Rpad to 2Rpad, Rpad is the radius of the polishing pad; The arc angle of the first short arc groove track defined by the above equation is between 10° and 120°.

7. The intermittent arc groove polishing pad according to claim 1, characterized in that: Referring to the polar coordinates of the coaxial center of the polishing pad, the orbital coordinates of the second short arc groove and the discontinuous arc groove are (ρ', A'), according to the polar angle between the second short arc groove and the center O' of the discontinuous arc groove is B', the polar angle between the second short arc groove and any point P' on the discontinuous arc groove is A', and the curvature radius of the second short arc groove and the discontinuous arc groove is R', which is expressed by the following polar coordinate equation: p'=2R'cos(B'-A') Where, R' = 0.5Rpad to 2Rpad, Rpad is the radius of the polishing pad; The curvature of the second short arc groove and the discontinuous arc groove track defined by the above equation is between 10° and 120°.

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