CN114043380B

CN114043380B - Grinding pad and grinding device with same

Info

Publication number: CN114043380B
Application number: CN202111372782.8A
Authority: CN
Inventors: 蒋锡兵; 唐强
Original assignee: Beijing Semicore Microelectronics Equipment Co Ltd
Current assignee: Beijing Jingyi Precision Technology Co ltd
Priority date: 2021-11-18
Filing date: 2021-11-18
Publication date: 2022-11-29
Anticipated expiration: 2041-11-18
Also published as: CN114043380A

Abstract

The invention relates to the technical field of wafer production, in particular to a grinding pad and a grinding device with the same. A polishing pad comprising: a base provided with a substrate; a plurality of abrasive blocks of different shapes are arranged on the substrate at intervals to form a plurality of storage troughs of different shapes. The invention solves the defects of unstable speed, easy unevenness, particle existence and low yield when the wafer is ground, and provides the grinding pad and the grinding device with the grinding pad.

Description

Grinding pad and grinding device with same

Technical Field

The invention relates to the technical field of wafer production, in particular to a grinding pad and a grinding device with the same.

Background

In wafer production, it is usually necessary to place the wafer on the surface of a polishing pad for polishing, and after a certain period of use, the center and the edge of the polishing pad are polished flat, and the edge loss is larger. For this reason, the center and the edge of the polishing pad are set to different heights in the prior art. However, since the wafer is uneven before rough grinding, and the conventional grinding pad is a concentric groove type grinding pad with uniformly distributed surface, the grinding fluid is dispersed to the periphery under the action of centrifugal force generated by high-speed rotation of the grinding turntable after being output, and since the shapes of all grooves on the grinding pad are the same, the grinding speed of the wafer during grinding is unstable, so that the defects of unevenness, particles and the like exist in the final product, and the yield of the product is reduced.

Disclosure of Invention

Therefore, the present invention is directed to overcome the defects in the prior art that the wafer polishing speed is not stable, the final product is uneven, particles exist, and the yield is low, so as to provide a polishing pad and a polishing apparatus having the same.

In order to overcome the problems, the invention provides a polishing pad and a polishing device with the same.

A base provided with a substrate;

and the abrasive blocks in different shapes are arranged on the substrate at intervals to form a plurality of stock chutes in different shapes.

Optionally, the plurality of abrasive blocks comprise at least two layers of first abrasive blocks arranged on the periphery of the substrate and a plurality of layers of second abrasive blocks arranged on the inner edge of the substrate, a first storage tank is formed between the at least two layers of first abrasive blocks, a plurality of second storage tanks are formed between the plurality of layers of second abrasive blocks, and the first storage tank and the second storage tanks are different in shape.

Optionally, a cross section of the first abrasive block perpendicular to the base is a regular trapezoid or an inverted trapezoid, and correspondingly, a cross section of the second abrasive block perpendicular to the base is an inverted trapezoid or a regular trapezoid.

Optionally, a third abrasive block is disposed between the adjacent first abrasive block and the second abrasive block, the first storage slot is formed between the third abrasive block and the first abrasive block, and the second storage slot is formed between the third abrasive block and the second abrasive block.

Optionally, a cross-section of the third abrasive block perpendicular to the base is a parallelogram.

Optionally, the section of the first storage tank perpendicular to the base is the trapezoid, the upper bottom of the trapezoid is 25 to 30mils in length, the lower bottom of the trapezoid is 12 to 16mils in length, and the height of the trapezoid is 20 to 25mils.

Optionally, the first accumulator tank is 2-5 circles, and the second accumulator tank is 43-58 circles.

Optionally, the section of the first stock vertical to the substrate is the inverted trapezoid, the length of the upper bottom of the inverted trapezoid is 22-28mils, the length of the lower bottom of the inverted trapezoid is 13-18mils, and the height of the inverted trapezoid is 22-28mils.

Optionally, the first storage tank is 2-5 circles, and the second storage tank is 45-50 circles.

Also provides a grinding device, which comprises the grinding pad, a conveying pipe and a regulator.

The technical scheme of the invention has the following advantages:

1. the invention provides a grinding pad.A substrate is provided with a substrate; a plurality of abrasive material blocks in different shapes are arranged on the substrate at intervals, and a plurality of material storage tanks in different shapes are formed among the abrasive material blocks. The combination of the first abrasive block and the second abrasive block with different shapes enables the grinding pad to have the shapes of a plurality of different material storage tanks, the material storage tanks are used for storing grinding fluid, and the quantity of the grinding fluid determines the grinding speed, so different grinding speeds can be obtained by storing different quantities of the grinding fluid, different speeds of the abrasive blocks during grinding of wafers are formed, the wafers with different heights can be subjected to targeted grinding at different grinding speeds, the grinding speed of the grinding pad at the later stage of the service life can be kept relatively stable, a flat wafer surface can be obtained in the ground wafers, and the advantages of strong pertinence and stable grinding speed are achieved.

2. The grinding pad provided by the invention is characterized in that the plurality of abrasive blocks comprise at least two layers of first abrasive blocks arranged on the periphery of the substrate and a plurality of layers of second abrasive blocks arranged on the inner edge of the substrate, a first storage tank is formed between the at least two layers of first abrasive blocks, a plurality of second storage tanks are formed between the plurality of layers of second abrasive blocks, and the first storage tanks and the second storage tanks are different in shape. The section of the first abrasive block vertical to the substrate is in a regular trapezoid shape or an inverted trapezoid shape, and correspondingly, the section of the second abrasive block vertical to the substrate is in an inverted trapezoid shape or a regular trapezoid shape. If the first abrasive material block is in a regular trapezoid shape, the second abrasive material block is in an inverted trapezoid shape, an inverted trapezoid storage tank is formed between the first abrasive material block and the first abrasive material block, an inverted trapezoid storage tank is formed between the second abrasive material block and the second abrasive material block, the grinding liquid loss speed of the edge storage tank in the inverted trapezoid shape is high, the grinding liquid loss speed of the middle storage tank in the regular trapezoid shape is low, and the wafer grinding device is suitable for wafers with high grinding speed at the edge and low grinding speed in the middle; if the first abrasive material block is in the inverted trapezoid shape, the second abrasive material block is in the regular trapezoid shape, a storage tank in the regular trapezoid shape is formed between the first abrasive material block and the first abrasive material block, a storage tank in the inverted trapezoid shape is formed between the second abrasive material block and the second abrasive material block, the grinding liquid in the storage tank in the edge in the regular trapezoid shape is slow in loss speed, the grinding liquid in the storage tank in the middle in the intermediate section in the inverted trapezoid shape is fast in loss speed, and the wafer grinding device is suitable for wafers with low grinding speed at the edge and high grinding speed in the middle. The combination of the first abrasive material block and the second abrasive material block with different shapes can enable the grinding pad to better adapt to the surface of the wafer according to different grinding requirements.

3. The grinding pad provided by the invention further comprises a third grinding material block arranged between the adjacent first grinding material block and the second grinding material block, a first material storage groove is formed between the third grinding material block and the first grinding material block, a second material storage groove is formed between the third grinding material block and the second grinding material block, and the cross section of the third grinding material block, which is vertical to the substrate, is a parallelogram. The third abrasive block forms a transition between the first abrasive block and the second abrasive block to form a first reservoir with the first abrasive block and a second reservoir with the second abrasive block, respectively. If the first abrasive material block is in a regular trapezoid shape and the second abrasive material block is in an inverted trapezoid shape, the first storage tank formed between the third abrasive material block and the first abrasive material block is in the inverted trapezoid shape, and the second storage tank formed between the third abrasive material block and the second abrasive material block is in the regular trapezoid shape; if the first abrasive material block is in a reverse trapezoid shape and the second abrasive material block is in a regular trapezoid shape, the second storage tank formed between the third abrasive material block and the first abrasive material block is in a regular trapezoid shape, and the second storage tank formed between the third abrasive material block and the second abrasive material block is in a reverse trapezoid shape. The third abrasive block plays a transition role between the first abrasive block and the second abrasive block, so that the first abrasive block and the second abrasive block of the grinding pad are more naturally jointed, and different grinding liquids can be stored conveniently.

4. According to the grinding pad provided by the invention, the section of a first storage tank vertical to a substrate is in a regular trapezoid shape, the length of the upper bottom of the regular trapezoid is 25-30mils, the length of the lower bottom of the regular trapezoid is 12-16mils, the height of the regular trapezoid is 20-25mils, the first storage tank is 2-5 circles, and the second storage tank is 43-58 circles; the section of the first storage tank, which is vertical to the substrate, is of an inverted trapezoid, the length of the upper bottom of the inverted trapezoid is 22-28mils, the length of the lower bottom of the inverted trapezoid is 13-14mils, the height of the inverted trapezoid is 22-28mils, the first storage tank is 2-5 circles, and the second storage tank is 45-50 circles. When the section of the first storage tank perpendicular to the substrate is in a regular trapezoid shape, the second storage tank is in an inverted trapezoid shape, the section of the first storage tank perpendicular to the substrate is in an inverted trapezoid shape, and the section of the second storage tank perpendicular to the substrate is in an inverted trapezoid shape, the grinding rates of the regular trapezoid shape and the inverted trapezoid shape are different, and different upper bottom lengths, lower bottom lengths, heights and turns are required to be designed to achieve the same grinding effect.

5. The grinding device provided by the invention comprises the grinding pad, a conveying pipe and a regulator, wherein the conveying pipe is used for conveying grinding liquid, and the regulator is used for regulating the inclination of the first grinding block and the second grinding block on the base of the grinding pad, so that the grinding effect is ensured.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a cross-sectional view of a polishing pad according to a first embodiment of the present invention;

FIG. 2 is a cross-sectional view of a polishing pad according to a second embodiment of the present invention;

FIG. 3 is a schematic perspective view of a polishing apparatus according to an embodiment of the present invention;

FIG. 4 is a graph showing the variation of the thickness of the wafer after polishing by the polishing pad before modification;

fig. 5 is a graph illustrating a variation trend of the wafer thickness after polishing by the polishing pad of the present embodiment.

Description of the reference numerals: 1. a delivery pipe; 2. a base; 3. an adjuster; 4. a substrate; 5. a first abrasive material block; 6. a third abrasive material block; 7. a second abrasive material block; 8. a second storage tank; 9. a first storage tank.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

One embodiment of the polishing pad shown in fig. 1 comprises a base 2 provided with a substrate 4 and a plurality of differently shaped abrasive segments spaced apart on the substrate 4.

As shown in fig. 1, the plurality of abrasive blocks includes a first abrasive block 5 disposed on the outer periphery of the substrate 4 and a second abrasive block 7 disposed on the inner periphery of the substrate, wherein the number of layers of the first abrasive block 5 is 2-5, preferably 2, and the number of layers of the second abrasive block 7 is 45-50, preferably 48, and a third abrasive block 6 is further disposed between the first abrasive block 5 and the second abrasive block 7. A first material storage groove 9 is formed between two adjacent layers of first abrasive blocks 5, a second material storage groove 8 is formed between two adjacent layers of second abrasive blocks 7, a first material storage groove 9 is formed between adjacent third abrasive blocks 6 and the first abrasive blocks 5, and a second material storage groove 8 is formed between adjacent third abrasive blocks 6 and the second abrasive blocks 7.

As shown in fig. 1, a cross section of the first abrasive block 5 perpendicular to the substrate 4 is a regular trapezoid, a cross section of the second abrasive block 7 perpendicular to the substrate 4 is an inverted trapezoid, a cross section of the third abrasive block 6 perpendicular to the substrate 4 is a parallelogram, a first stock chest 9 formed between the first abrasive block 5 and the first abrasive block 5 is an inverted trapezoid, a first stock chest 9 formed between the first abrasive block 5 and the third abrasive block 6 is an inverted trapezoid, a second stock chest 8 formed between the second abrasive block 7 and the third abrasive block 6 is a regular trapezoid, and a second stock chest 8 formed between the second abrasive block 7 and the second abrasive block 7 is a regular trapezoid. The first storage tank 9 is in the shape of an inverted trapezoid, the length of the upper bottom of the inverted trapezoid ranges from 22 to 28mils and preferably 26mils, and the length of the lower bottom ranges from 13 to 18mils and preferably 14mils; the shape of the second storage tank 8 is a regular trapezoid, the length range of the upper bottom of the regular trapezoid is 25-30mils, and the preferred length range is 28mils; the lower base length ranges from 12 to 16mils, preferably 14mils, and the height of each of the first and

second sumps

9 and 8 ranges from 22 to 28mils, preferably 26mils.

As shown in fig. 3, a polishing apparatus includes a polishing pad, a conditioner 3, and a feed pipe 1.

In order to verify the polishing effect of the polishing pad of the present example, the applicant polished wafers of the same specification using the polishing pad before modification and the polishing pad of the present example, and observed and compared the thickness of the polished wafers, and the results are shown in fig. 4 and 5. The cross sections of all grooves of the polishing pad before improvement, which are perpendicular to the substrate, are rectangular, H1, H2, H3 and H4 in fig. 4 and 5 are No. 1, no. 2, no. 3 and No. 4 polishing heads on the same polishing table respectively, each polishing head carries a wafer, the abscissa represents the positions of different points on the same wafer, and the ordinate represents the thickness of the polished wafer. Through comparison, the grinding pad adopting the grinding blocks with different shapes and combinations after the grinding is improved enables the thickness of the ground wafer to be more uniform compared with the grinding pad before the grinding, namely the thickness change range between each point of the ground same wafer is small, the fluctuation is small, and the surface of the obtained wafer is smoother.

As an alternative embodiment, as shown in fig. 2, the first abrasive material block 5 has 2 to 5 layers, preferably 2 layers, and the second abrasive material block 7 has 43 to 58 layers, preferably 52 layers. The section of the first abrasive block 5 perpendicular to the substrate 4 is an inverted trapezoid, the section of the second abrasive block 7 perpendicular to the substrate 4 is a regular trapezoid, the section of the third abrasive block 6 perpendicular to the substrate 4 is a parallelogram, the first storage tank 9 formed between the first abrasive block 5 and the first abrasive block 5 is a regular trapezoid, the first storage tank 9 formed between the first abrasive block 5 and the third abrasive block 6 is a regular trapezoid, the second storage tank 8 formed between the second abrasive block 7 and the third abrasive block 6 is an inverted trapezoid, and the second storage tank 8 formed between the second abrasive block 7 and the second abrasive block 7 is an inverted trapezoid. The first holding tank 9 is in the shape of an orthotrapezoidal shape having an upper base length in the range of 25 to 30mils, preferably 28mils, a lower base length in the range of 12 to 16mils, preferably 14mils, the second holding tank 8 is in the shape of an inverted trapezoidal shape having an upper base length in the range of 22 to 28mils, preferably 26mils, a lower base length in the range of 13 to 18mils, preferably 14mils, and the height of both the first holding tank 9 and the second holding tank 8 is in the range of 20 to 25mils, preferably 22mils.

Alternatively, the shape of the first abrasive material block 5 may be other shapes such as a regular triangle, an inverted triangle, a step shape, a circular arc shape, a parallelogram shape, a zigzag shape, and the like; accordingly, the shape of the second abrasive material block 7 may be other shapes such as an inverted triangle, a regular triangle, a step, a circular arc, a parallelogram, a zigzag, and the like, which are adapted to the shape of the first abrasive material block 5.

As an alternative embodiment, the abrasive blocks on the substrate may be shaped and arranged in the order of a first abrasive block, a third abrasive block, a second abrasive block, a third abrasive block, a first abrasive block from the outer edge; also can be a first abrasive material block, a second abrasive material block and a first abrasive material block; the grinding device can also be combined with a first grinding material block, a third grinding material block, a second grinding material block, a third grinding material block, a first grinding material block, a third grinding material block, a second grinding material block and other shapes.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications of the invention may be made without departing from the spirit or scope of the invention.

Claims

1. A polishing pad, comprising:

a base body (2) provided with a substrate (4);

the abrasive material storage tanks are arranged on the substrate (4) at intervals to form a plurality of storage tanks in different shapes, the abrasive material storage tanks comprise at least two layers of first abrasive material blocks (5) arranged on the periphery of the substrate (4) and a plurality of layers of second abrasive material blocks (7) arranged on the inner edge of the substrate (4), a first storage tank (9) is formed between the at least two layers of first abrasive material blocks (5), a plurality of second storage tanks (8) are formed between the plurality of layers of second abrasive material blocks (7), and the first storage tank (9) and the second storage tanks (8) are different in shape;

the section of the first abrasive block (5) perpendicular to the substrate (4) is in an inverted trapezoid shape, the section of the second abrasive block (7) perpendicular to the substrate (4) is in a regular trapezoid shape, the first storage tank (9) is in a regular trapezoid shape, the upper bottom length range of the regular trapezoid shape is 14-16mils, the lower bottom length range of the regular trapezoid shape is 25-28mils, the second storage tank (8) is in an inverted trapezoid shape, the upper bottom length range of the inverted trapezoid shape is 26-28mils, the lower bottom length range of the inverted trapezoid shape is 14-18mils, and the height ranges of the first storage tank (9) and the second storage tank (8) are both 20-25mils;

or;

first abrasive material piece (5) perpendicular to the cross-section of basement (4) is regular trapezoid, the cross-section of second abrasive material piece (7) perpendicular to basement (4) is for falling trapezoidal, the shape of first stock chest (9) is for falling trapezoidal, falls trapezoidal upper base length scope and is 26-28mils, and lower bottom length scope is 14-18mils, and the shape of second stock chest (8) is regular trapezoid, and regular trapezoidal upper base length scope is 14-16mils, and lower bottom length scope is 25-28mils, and the height scope of first stock chest (9) and second stock chest (8) is 22-28mils.

2. The polishing pad according to claim 1, further comprising a third abrasive block (6) disposed between the adjacent first abrasive block (5) and second abrasive block (7), the first accumulator groove (9) being formed between the third abrasive block (6) and the first abrasive block (5), and the second accumulator groove (8) being formed between the third abrasive block (6) and the second abrasive block (7).

3. The polishing pad according to claim 2, wherein a cross section of the third abrasive block (6) perpendicular to the substrate (4) is a parallelogram.

4. The polishing pad according to claim 1, wherein the first reservoir (9) has 2-5 turns and the second reservoir (8) has 43-58 turns.

5. The polishing pad according to claim 1, wherein the first reservoir (9) has 2-5 turns and the second reservoir (8) has 45-50 turns.

6. A grinding device, comprising the grinding pad of any one of claims 1 to 5, further comprising a delivery tube (1) and a conditioner (3).