CN214322989U

CN214322989U - Polishing pad

Info

Publication number: CN214322989U
Application number: CN202120177695.6U
Authority: CN
Inventors: 黄学良; 蔡长益; 罗乙杰; 桂辉辉; 刘敏; 杨佳佳; 邱瑞英; 张季平
Original assignee: Hubei Dinglong Co ltd; Hubei Dinghui Microelectronics Materials Co ltd
Current assignee: Hubei Dinghui Microelectronics Materials Co ltd; Hubei Dinglong Co ltd; Changxin Memory Technologies Inc
Priority date: 2021-01-22
Filing date: 2021-01-22
Publication date: 2021-10-01
Anticipated expiration: 2031-01-22

Abstract

The utility model discloses a polishing pad, including the polishing layer, the polishing layer includes polishing surface and the polishing unit that is located polishing surface, the polishing unit is one at least, and polishing unit constitutes polishing unit crowd, and the one end of polishing unit crowd forms the contact surface, and the contact surface directly contacts with the material ground, and every polishing unit is parallelogram in the projection of contact surface; the plurality of polishing units respectively form a first part and a second part, the first part extends along a first direction and is uniformly spaced, and the second part extends along a direction parallel to the first direction and is uniformly spaced; and the surface of the contact surface of the polishing unit is provided with a channel and comprises a first channel and a second channel; the utility model discloses polishing pad's structure and the polishing unit area ratio of injecing, effective area ratio, effective passageway volume ratio and effective passageway's width ratio isoparametric combine together, have excellent comprehensive properties.

Description

Polishing pad

Technical Field

The present invention relates to a polishing pad having a well-designed surface groove structure for chemical mechanical polishing of materials to be polished (e.g., thin films and devices on semiconductor wafers).

Background

In the fabrication of integrated circuits, other electronic devices, and optical materials, many processes involving polishing, thinning, or planarizing of the material are most commonly used chemical mechanical polishing. The action principle of chemical mechanical polishing is that on a fixed polishing machine, a grinding liquid acts on a polishing pad, the polishing pad is in contact with the surface of a ground material, chemical reaction can occur, meanwhile, the polishing pad and the ground material do rotary motion on the machine, mechanical action of shearing is generated, and the chemical action and the mechanical action polish the ground material together to form a desired pattern structure.

Therefore, the flow and distribution of the slurry, the distribution of the mechanical force generated by the grooves, and the like have a determining effect on the performance of the chemical mechanical polishing pad, and the effects of these factors have different requirements for different patterns and materials, and many attempts have been made to form the groove structure of the polishing pad.

EP0829328a2 of h.f. leinhardt et al discloses a surface structure of a polishing pad of concentric circles, grooves, spirals, rays, lattice to promote the flow of polishing liquid, but does not disclose the relation of specific parameters of the surface groove structure of the polishing pad to the polishing performance, or how to obtain a polishing effect having excellent overall performance.

US20060014477a1 of r.v. parrapabrus discloses a design with an oscillating structure in the radial direction, which has changed the residence time of the polishing liquid in different areas, but also does not disclose the relation of specific design parameters to the polishing performance.

JP2006167907A of g.p.malteni discloses a special structure having grooves spaced apart from each other in order to improve the flow rate of the slurry and thereby reduce the waste of slurry.

TW201904719A to j.v. raney et al discloses grooves of a non-isosceles trapezoid structure and illustrates that a concentric circular groove structure is the most popular groove pattern, and a polishing pad of a non-isosceles trapezoid structure is considered to have a better polishing effect.

The prior art discloses various groove structures, but the relation between a specific groove structure and polishing performance and how to optimize the groove structure are not deeply researched, and the research on the polishing performance as an experimental science has complicated influence relation among factors, and the theoretical research is not sufficient, so that the relation between the groove structure of the polishing pad and the polishing performance is urgently expected at present, and a polishing pad with excellent comprehensive polishing performance is designed.

The utility model discloses set up the polishing unit of range on the polishing pad to carry out the design of microchannel on the polishing unit, through a large amount of experimental studies, optimize out the polishing pad that has excellent comprehensive polishing performance.

SUMMERY OF THE UTILITY MODEL

The utility model provides a polishing pad, including the polishing layer, the polishing layer includes polishing surface and the polishing unit that is located polishing surface, the polishing unit is one at least, and the polishing unit has average height D1, and the polishing unit constitutes polishing unit crowd, and the one end of polishing unit crowd forms contact surface, and contact surface and the material direct contact that is ground, the projection of each polishing unit at contact surface is parallelogram;

a plurality of polishing elements constituting a first section, the polishing elements of the first section extending in a first direction and being uniformly spaced, the polishing elements of the second section extending in a direction parallel to the first direction and being uniformly spaced, the polishing elements of the first section being spaced at a distance W1 equal to the spacing of the polishing elements of the second section;

the polishing unit is composed of a plurality of first portions and second portions which are equally spaced from each other by a distance W2 in the second direction; the surface of the contact surface of the polishing unit is provided with a channel which is a straight line and comprises a plurality of first channels and a plurality of second channels, wherein the first channels are parallel to the first direction, and/or the second channels are parallel to the second direction;

the contact surface of the polishing unit has an area S1, the sides of a parallelogram projected on the contact surface of the polishing unit in a first direction and a second direction are respectively L1 and L2, and the included angle between the first direction and the second direction is theta, as follows:

S1＝L1*L2*sinθ

the projection of the channels on the contact surface of the polishing units has an area Sa, and on each polishing unit, the first channels are n in number, Waa in average width and L1 in length; the number of the second channels is m, the average width is Wab, the length is L2, the average depth of the channels is Da, where n and m are integers, m + n is greater than or equal to 1, and the number of intersections Nb is m × n, as follows:

Sa＝n*Waa*L1*sinθ+m*Wab*L2*sinθ-Nb*Waa*Wab*sinθ

the effective contact area Ss of the polishing unit is as follows:

Ss＝S1-Sa＝sinθ*(L1*L2-n*Waa*L1-m*Wab*L2+Nb*Waa*Wab)

the polishing layer effective contact area ratio RS3 is defined as follows:

RS3＝Ss/((L1+W1)*(L2+W2)*sinθ)

(L1 × L2-n × Waa × L1-m × Wab × L2+ Nb × Waa)/((L1 + W1) × (L2+ W2)), and RS3 is in the range of 50 to 85%;

the grinding surface sum ratio RS1 ═ L1L 2/((L1+ W1) ((L2 + W2)), the range of RS1 is 0.60 to 0.92;

the effective contact area ratio RS2 ═ Ss/S1 of the polishing unit, RS2 ranging from 0.5 to 0.97;

the effective channel width ratio RW4 (n × Waa + m × Wab)/(W1+ W2), the range of RW4 being 0.1-3.75;

effective channel volume ratio RV5 ═ Sa × Da)/(sin θ ((L1+ W1) × (L2+ W2) -L1 × L2) × D1; RV5 ranges from 0.03 to 3.4.

The utility model discloses an implementation mode, the scope of L1 and L2 of polishing unit is 10-20 mm.

The utility model discloses an implementation mode, effective area of contact ratio RS 3's scope is 60-70%.

The utility model discloses an implementation mode, a plurality of first passageway interval evenly distributed, and/or, a plurality of second passageway interval evenly distributed.

The utility model discloses an embodiment, polishing unit has the same or roughly the same height.

The utility model discloses an embodiment, the passageway has the same or roughly the same degree of depth.

The utility model discloses an implementation mode, average height D1 is 0.2-0.8 times the polishing layer thickness.

In one embodiment of the present disclosure, the average depth Da of the channel is 0.4 to 1 times the height D1 of the polishing unit.

The utility model discloses an implementation mode, Waa and Wab's scope is 0.15-0.6 mm.

The utility model discloses an implementation mode, Waa and Wab's scope is 0.15-0.4 mm.

The utility model discloses an implementation mode, the scope of the W1 of polishing unit and W2 is 0.5-5 mm.

The utility model discloses an implementation mode, the scope of the W1 of polishing unit and W2 is 0.8-3 mm.

The utility model discloses an implementation mode, the quantity of first passageway is any one in 2-5, and/or, the quantity of second passageway is any one in 2-5.

The utility model discloses an implementation mode, the quantity of first passageway is any one in 3-5, and/or, the quantity of second passageway is any one in 3-5.

The utility model discloses an implementation mode, wherein the projection of polishing unit at contact surface is the rectangle.

The utility model discloses an implementation mode, wherein the projection of polishing unit at the contact surface is the square.

The utility model discloses an implementation mode, wherein W1 is the same or roughly the same with W2.

The utility model discloses an implementation mode, wherein L1 is the same or roughly the same with L2.

The utility model discloses an implementation mode, wherein the projection of polishing unit at contact surface is the rhombus.

The utility model discloses an embodiment, polishing unit are arranged for the square matrix on polishing layer, and each adjacent polishing unit's interaxial distance equals.

The utility model discloses an implementation mode, RS 2's scope is 0.72-0.93.

In one embodiment of the present disclosure, the RW4 is in the range of 0.15-2.

The utility model discloses an implementation mode, RV 5's scope is 0.05-0.71.

In one embodiment of the present disclosure, the average depth Da of the channel is 0.4-0.8 times the height D1 of the polishing unit.

The utility model discloses an embodiment, the utility model discloses polishing pad's polishing layer still optionally includes the terminal point detection window, and preferred detection window is the wholeness window that combines to in the polishing layer.

The above-mentioned embodiments are merely some specific explanations made on the technical idea of the present invention, and should not be construed as limiting the present invention to these embodiments.

The beneficial effects of the utility model reside in that:

through a special groove design structure, the polishing pad with excellent comprehensive polishing performance is obtained.

Drawings

The above and other objects, features and advantages of the present invention will become more readily apparent as the following detailed description of the preferred embodiments of the invention proceeds with reference to the accompanying drawings, which are not intended to limit the invention to the scale and dimensions illustrated therein.

Fig. 1 schematically illustrates a perspective view of a polishing pad according to a preferred embodiment of the present invention.

Fig. 2 is a partially enlarged view of a group of polishing units of the polishing pad shown in fig. 1.

Fig. 3 is a partially enlarged view of a polishing unit of the polishing pad shown in fig. 2.

Fig. 4 schematically illustrates a plan view of a polishing pad according to another preferred embodiment of the present invention.

Fig. 5 schematically illustrates a plan view of a polishing pad according to another preferred embodiment of the present invention.

Fig. 6 schematically illustrates a plan view of a polishing pad according to another preferred embodiment of the present invention.

Fig. 7 schematically illustrates a plan view of a polishing pad according to another preferred embodiment of the present invention.

Detailed Description

The technical solution of the present invention will be described in detail with reference to the accompanying drawings.

As used herein, the term "substantially" is used to describe and illustrate small variations. For example, two numerical values are considered to be "substantially" the same or equal if the difference between the two numerical values is less than or equal to ± 5% (such as less than or equal to ± 5%, less than or equal to ± 4%, less than or equal to ± 3%, less than or equal to ± 2%, less than or equal to ± 1%, less than or equal to ± 0.5%, less than or equal to ± 0.1%, or less than or equal to ± 0.05%) of the mean of the values.

Implementation mode one

Fig. 1 is a perspective view schematically showing a polishing pad according to a preferred embodiment of the present invention, and for convenience of explanation, one direction in fig. 1 is referred to as an a direction, the other direction is referred to as a B direction, and a thickness direction of the polishing pad, i.e., a direction perpendicular to a surface of the polishing pad is referred to as a Z direction.

In the first embodiment, the a direction and the B direction are 90 degrees, i.e., sin θ is 1. Referring to FIG. 1, the polishing pad of the present invention is suitable for polishing or planarizing at least one of semiconductor, optical, and magnetic substrates. The polishing layer 110 has a polishing surface 10 and a polishing unit group 20, the polishing unit group 20 is distributed on the polishing surface 10, and the surface of the polishing unit group 20 forms a contact surface directly contacting the material to be ground. The projection of each polishing unit on the contact surface is a quadrangle, preferably a parallelogram such as a rectangle and a rhombus; specifically, the polishing unit group 20 includes a first portion 21 and a second portion 22, wherein the first portion 21 and the second portion 22 each include at least one polishing unit 23, and the arrangement of the polishing unit group 20 and the size of the polishing unit directly affect the grinding performance of the polishing pad.

Referring to fig. 2, the polishing elements 23 of the first section 21 are uniformly distributed in a direction parallel to the a direction, and define a length of the polishing elements 23 in the a direction as L1 and a length of the polishing elements 23 in the B direction as L2. The interval in the a direction between adjacent polishing elements 23 is defined as W1; the polishing elements 23 of the second portion 22 are also uniformly distributed in a direction parallel to the a direction, and the interval between adjacent polishing elements 23 in the a direction is also W1. As shown in fig. 2, the interval of the present invention refers to the interval between the adjacent surfaces of the adjacent polishing units, not the interval between the centers of the adjacent polishing units. The first portion 21 and the second portion 22 both extend along a direction parallel to the direction a and are uniformly distributed, and the distance between the second portion 22 and the first portion 21 in the direction B is defined as W2.

In view of the above size, the utility model preferably has L1 in the range of 10-20 mm; for example, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, or 20mm may be used. Preferably, L2 is in the range of 10-20mm, for example, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm may be mentioned. Preferably, W1 is in the range of 0.5-5mm, more preferably 0.8-3mm, for example, 0.8mm, 1mm, 1.5mm, 1.6mm, 2mm, 2.5mm, 3mm may be mentioned. Preferably, W2 is in the range of 0.5-5mm, more preferably 0.8-3mm, for example, 0.8mm, 1mm, 1.5mm, 1.6mm, 2mm, 2.5mm, 3mm may be mentioned.

With further reference to fig. 3, polishing element 23 further includes channels 23a, 23B, and a single polishing element 23 has n channels 23a parallel to direction a and m channels 23B parallel to direction B, where m and n are integers, where m + n is greater than or equal to 1, and the number of intersections between channels 23a and channels 23B is defined as Nb, then Nb is m × n. The width of the

channels

23a and 23b may be equal or different, and the average width of the channels 23a is defined as Waa, the average width of the channels 23b is defined as Wab, and the average width of the channels refers to the average of the widths of all the channels. Preferably Waa is in the range of 0.15 to 0.6mm, more preferably 0.15 to 0.4 mm. Preferably, the range of Wab is 0.15-0.6mm, more preferably 0.15-0.4 mm.

In the case where the size of the polishing unit 23 is defined as L1, and the interval between L2 and the adjacent polishing unit is defined as W1, and W2, the lapping area ratio RS1 is set to (L1 × L2)/((L1+ W1) ((L2 + W2)), which can approximately represent the ratio of the total area of the polishing units 23 to the area of the polishing layer. The above dimensions satisfy the relationship: 0.6 ≦ (L1 × L2)/((L1+ W1) (L2+ W2)) 0.92.

As shown in fig. 3, the effective contact area of the polishing element is lower than the area of the polishing element due to the presence of the channels, and in the polishing element 23, the length of the channel 23a is L1 equal to the length of the polishing element in the a direction, and the length of the channel 23B is L2 equal to the length of the polishing element in the B direction, Waa, Wab, Nb as defined above, and the channel area of the polishing element is calculated as follows: sa is n Waa L1+ m Wab L2-Nb Waa Wab. The invention thus further defines the effective contact area Ss of the polishing elements L1L 2- (n Waa L1+ m Wab L2-Nb Waa Wab).

The effective contact area ratio RS2 of the polishing unit 23 is Ss/S1, and the present invention defines the ratio in the range of 0.5 to 0.97, preferably in the range of 0.72 to 0.93.

The ratio of the total effective contact area of the polishing layer to the area of the polishing layer was characterized using the effective contact area ratio Ss/((L1+ W1) (L2+ W2) × sin θ). The effective contact area ratio of the polishing layer affects the cooperative action of mechanical polishing and chemical polishing, and is very important to the abrasive performance of the polishing pad. The utility model discloses it satisfies the relation to inject effective area of contact ratio RS 3: 50% or more (L1L 2- (n x Waa L1+ m x Wab L2-Nb x Waa Wab))/((L1+ W1) (L2+ W2))/(L1 + W1) or more than 85%. Further, the ratio ranges more preferably from 60% to 70%, for example, ratios such as 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69% and the like may be selected.

Referring to fig. 3, the average height D1 of the polishing elements 23 is defined as the average of the distances from the contact surfaces of the polishing elements 23 to the polishing surface 10 in the Z direction, the depth of the channels is defined as the distance from the channels to the contact surfaces of the polishing elements in the Z direction, and the average depth Da refers to the average depth of the

channels

23a and 23 b.

The width ratio and the volume ratio of the channels formed between the channels of the polishing layer and the polishing units are also important parameters affecting the polishing performance of the polishing pad, and the width ratio of the effective channels is RW4 (n × Waa + m × Wab)/(W1+ W2), which is limited to 0.1-3.75, more preferably 0.15-2. The utility model discloses the preferred range of D1 is 0.2-0.8 times of polishing layer thickness, and the range of Da is 0.4D1-D1, and the more preferred range of Da is 0.4D1-0.8D 1. Defining the effective channel volume ratio as RV5 ═ Sa × Da/((L1 + W1) × (L2+ W2) -L1 × L2) × D1 × sin θ), the present invention limits this volume ratio to the range of 0.03 to 3.4, more preferably to the range of 0.05 to 0.71.

The number n and m of the channels of the utility model are preferably lower than 6, for example, n and m can be respectively and independently selected from 1,2,3,4 and 5; more preferably, each is independently any of 2,3,4,5, and most preferably, each is independently any of 3,4, 5.

In the above-mentioned RS1, RS2, RS3, RW4 and RV5 parameters, and the preferred size, the first channel and the second channel may be uniformly spaced and may also be non-uniformly spaced.

In the preferred embodiment of the present invention, the first channel and the second channel are uniformly distributed at equal intervals. Referring to fig. 3, the

channels

23a and 23b, which are uniformly spaced, may divide the polishing unit 23 into a plurality of sub-units having the same size. The length of the subunit along the B axis is defined as La, and similarly, the length of the subunit along the a axis is Lb, preferably La ranges from 2mm to 2mm, and preferably Lb ranges from 2mm to 2 mm.

FIG. 4 shows the polishing layer having the first and second channels spaced unevenly. Specifically, the first channel and the second channel divide the polishing unit 23 into a plurality of sub-units of different sizes, and under the condition that the sizes L1, L2, the intervals W1, W2, the widths and the numbers Waa, Wab, n, m, Da, D1 of the polishing units are the same as those in the example of fig. 3, the parameters RS1, RS2, RS3, RW4, RV5 are the same, and the polishing pad has good grinding performance.

In a preferred embodiment of the present invention, the polishing unit is a rectangular parallelepiped or a cube.

In a preferred embodiment of the present invention, the polishing unit is a cube.

In a preferred embodiment of the present invention, the intervals W1 between the polishing units are equal to W2.

As a preferred embodiment of the present invention, the polishing units are arranged in a matrix on the polishing layer, and the center-to-center distances of the polishing units are equal, i.e., L1 is equal to L2, and W1 is equal to W2.

Second embodiment

Similar to the first embodiment, the direction a and the direction B are 90 degrees in the second embodiment, i.e. sin θ is 1. Also, the polishing layer has a polishing surface and polishing unit groups distributed on the polishing surface, and the surfaces of the polishing unit groups are in direct contact with the semiconductor, as shown in fig. 1.

Arrangement pattern of polishing elements of polishing layer referring to fig. 5, the polishing elements 43 of the first and

second sections

41 and 42 are alternately arranged in the second embodiment. Preferably, the offset distance is half the side length of the grinding unit in the a direction.

This embodiment is one of the preferred embodiments of the present invention, and also, the polishing unit 43 includes a channel thereon, and the size of the polishing unit, the size of the channel and the number in different directions are as defined in the first embodiment.

Specifically, the polishing elements 43 of the first section 41 are uniformly distributed in parallel to the a direction, defining a length of the polishing elements 43 in the a direction of L1, a length of the polishing elements 43 in the B direction of L2, preferably L1 in the range of 10-20 mm; for example, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, or 20mm may be used. Preferably, L2 is in the range of 10-20mm, for example, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm may be mentioned. The interval of the adjacent polishing units 43 in the A direction is defined as W1, preferably W1 is in the range of 0.5-5mm, more preferably in the range of 0.8-3mm, and for example, 0.8mm, 1mm, 1.5mm, 1.6mm, 2mm, 2.5mm, 3mm may be preferred. Although the polishing elements 43 are arranged in a staggered manner, the polishing elements of the second portion 42 are also distributed at intervals along the direction a uniformly, i.e. the first portion 41 and the second portion 42 are parallel to each other, so that the interval between the second portion 42 and the first portion 41 in the direction B is defined as W2, preferably as W2, within the range of 0.5-5mm, more preferably within the range of 0.8-3mm, and for example, preferably 0.8mm, 1mm, 1.5mm, 1.6mm, 2mm, 2.5mm, 3 mm.

Similarly, the polishing unit includes a first channel and a second channel, the number m, n and the dimensions Waa, Wab of the channels are defined, and the range of the relevant parameters is as follows:

defining the lapping area ratio RS1 ═ L1L 2/((L1+ W1) (L2+ W2)), the ratio of the total area of the polishing elements 23 to the area of the polishing layer can be approximately characterized. The above dimensions satisfy the relationship: 0.6 ≦ (L1 × L2)/((L1+ W1) (L2+ W2)) 0.92.

The effective contact area ratio RS2 of the polishing unit is Ss/S1, which is defined as a range of 0.5 to 0.97, more preferably 0.72 to 0.93.

The polishing layer effective contact area ratio RS3 ═ Ss/((L1+ W1) (L2+ W2) × sin θ), and the effective contact area ratio RS3 satisfies the relationship: 50% or more (L1L 2- (n x Waa L1+ m x Wab L2-Nb x Waa Wab))/((L1+ W1) (L2+ W2))/(L1 + W1) or more than 85%. Further, the ratio ranges more preferably from 60% to 70%, for example, ratios such as 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69% and the like may be selected.

The width ratio of the effective channel, RW4, (n × Waa + m × Wab)/(W1+ W2), is limited to a range of 0.1 to 3.75, more preferably 0.15 to 2.

The effective channel volume ratio is RV5 ═ Sa × Da/((L1 + W1) × (L2+ W2) -L1 × L2) × D1 × sin θ), the present invention limits this volume ratio to the range of 0.03 to 3.4, more preferably to the range of 0.05 to 0.71.

Other parameters, such as the number of channels: preferably less than 6, for example n, m may each independently be any of 1,2,3,4, 5; more preferably, each is independently any of 2,3,4, 5; most preferably, each is independently any of 3,4, 5; the height of the polishing element; the limiting range of parameters such as the depth of the channel is the same as that described in the first embodiment, and the polishing pad shown in fig. 5 has excellent polishing performance and service life within the limiting range.

In a preferred embodiment of the present invention, L1 of the polishing unit is equal to L2, and W1 is equal to W2.

Third embodiment

The direction a and the direction B may be perpendicular to each other, or may be at other angles, and in the third embodiment, the direction a and the direction B form an angle θ. In the first to second embodiments, the θ angle is 90 degrees; in the third embodiment, the θ angle may be any angle other than 90 degrees, for example, 10 degrees, 20 degrees, 30 degrees, 40 degrees, 45 degrees, 50 degrees, 60 degrees, 70 degrees, 80 degrees, 100 degrees, 110 degrees, 120 degrees, 130 degrees, 135 degrees, 140 degrees, 150 degrees, 160 degrees, 170 degrees, or the like.

Also, referring to fig. 1 in a perspective view, the polishing layer has a polishing surface and polishing unit groups distributed on the polishing surface, the surfaces of the polishing unit groups being in direct contact with the semiconductor.

Referring to fig. 6, the polishing element group includes a first portion 51 and a second portion 52, wherein each of the first portion 51 and the second portion 52 includes at least one polishing element 53. Fig. 6 shows an arrangement of polishing units 53 of the polishing layer.

The polishing unit includes a channel, and the dimensions of the polishing unit and the channel are defined in the same manner as in the first embodiment. Since the polishing unit is a parallelogram, the area thereof corresponds to:

with continued reference to FIG. 6, the polishing elements 53 are uniformly distributed parallel to the A direction and have a length L1 in the A direction, preferably L1 in the range of 10-20 mm; for example, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, or 20mm may be used. The length of the polishing unit 53 in the B direction is L2, preferably L2 is in the range of 10-20mm, for example, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm may be preferable. The interval between the adjacent polishing units 23 of the first section 51 and the second section 52 in the a direction is W1, preferably W1 is in the range of 0.5 to 5mm, more preferably in the range of 0.8mm to 3mm, and for example, 0.8mm, 1mm, 1.5mm, 1.6mm, 2mm, 2.5mm, 3mm may be preferred. The second portion 52 is spaced from the first portion 51 in the B direction by W2, and W2 is in the range of 0.5-5mm, more preferably 0.8-3mm, for example, 0.8mm, 1mm, 1.5mm, 1.6mm, 2mm, 2.5mm, 3 mm.

Since the polishing unit 53 is a parallelogram, the grinding area S1 of the polishing unit is L1L 2 sin θ; the lapping area ratio RS1 ═ L1 × (L2 × sin θ)/((L1+ W1) × (L2+ W2) × (sin θ) ═ L1 × L2)/((L1+ W1) ((L2 + W2)). The above dimensions satisfy the relationship: 0.6 ≦ (L1 × L2)/((L1+ W1) (L2+ W2)) 0.92.

The number and size of the channels are defined as in the first embodiment, and since the angle between the a direction and the B direction is θ, the channels are also parallelogram. On each polishing element, the first channels have a number n, a width Waa that is the width of the first channel in the B direction, and a length L1; the second channels have the number of m, the width Wab is the width of the second channels in the direction A, the length is L2, the average depth Da, wherein n and m are integers, m + n is more than or equal to 1, the number of intersection points Nb is m n, as mentioned above, the angle between the direction A and the direction B is theta, the channels are also parallelogram, and the area of a single channel is Waa L1 sin theta or Wab L2 sin theta; the intersection point of the channels is also a parallelogram, and the area of the intersection point is Waa Wab sin theta. Therefore, the total area Sa of the channel is n × Waa × L1 × sin θ + m × Wab × L2 × sin θ -Nb × Waa × sin θ.

The effective contact area Ss of the polishing unit is as follows:

Ss＝S1-Sa＝sinθ*(L1*L2-n*Waa*L1-m*Wab*L2+Nb*Waa*Wab)

the effective contact area ratio RS2 ═ Ss/(L1 × L2) × (L1 × L2-n × L1-m × Wab × L2+ Nb × Wab)/(L1 × L2) of the polishing unit 53 is defined by the present invention as being in the range of 0.5 to 0.97, more preferably 0.72 to 0.93.

The effective contact area ratio is defined as follows:

RS3＝Ss/((L1+W1)*(L2+W2)*sinθ)

＝sinθ*((L1*L2-n*Waa*L1-m*Wab*L2+Nb*Waa*Wab))/((L1+W1)*(L2+W2)*sinθ)

(L1 × L2-n × Waa × L1-m × Wab × L2+ Nb × Waa)/((L1 + W1) × (L2+ W2)). The utility model discloses it satisfies the relation to inject effective area of contact ratio RS 3: 50% or more (L1L 2- (n x Waa L1+ m x Wab L2-Nb x Waa Wab))/((L1+ W1) (L2+ W2))/(L1 + W1) or more than 85%. Further, the ratio ranges more preferably from 60% to 70%, for example, ratios such as 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69% and the like may be selected.

The effective channel volume ratio is RV5 ═ Sa × Da)/((L1 + W1) × (L2+ W2) -L1 × L2) × D1 ═ n × Waa × (L1 × sin θ + m × Wab × L2 sin θ -Nb × Wab ×) Da)/(D1 × (L1+ W1) ((L2 + W2) -L1 × Wab × L2-Nb) × (n × L1+ m × (W86b) × (n × Wab)/(D36 1 ×) (1) — (360-1) is limited to the new practical range.

Other parameters, such as the number of channels: preferably less than 6, for example n, m may each independently be any of 1,2,3,4, 5; more preferably, each is independently any of 2,3,4, 5; most preferably, each is independently any of 3,4, 5; the height of the polishing element; the limitation range of parameters such as the depth of the channel is the same as that described in the first embodiment, and the polishing pad shown in fig. 6 has excellent polishing performance and service life within the limitation range.

In a preferred embodiment of the invention, the projection of the polishing elements onto the contact surface is a diamond.

In the preferred embodiment of the present invention, the a direction is 45 degrees to the B direction.

Embodiment IV

In the fourth embodiment, the a direction and the B direction are at θ degrees, similarly to the third embodiment. The angle θ can be any angle other than 90 degrees, such as 10 degrees, 20 degrees, 30 degrees, 40 degrees, 45 degrees, 50 degrees, 60 degrees, 70 degrees, 80 degrees, 100 degrees, 110 degrees, 120 degrees, 130 degrees, 135 degrees, 140 degrees, 150 degrees, 160 degrees, 170 degrees, and the like. Also, referring to fig. 1 in a perspective view, the polishing layer has a polishing surface and polishing unit groups distributed on the polishing surface, the surfaces of the polishing unit groups being in direct contact with the semiconductor.

Referring to fig. 7, the polishing element group includes a first portion 61 and a second portion 62, wherein each of the first portion 61 and the second portion 62 includes at least one polishing element 63. Fig. 7 shows an arrangement of polishing units 63 of the polishing layer. The utility model discloses the polishing unit of first portion and second portion can present parallel distribution, also can crisscross distribution. As shown in fig. 7, the polishing elements 63 of the first and

second sections

61 and 62 in the fourth embodiment are staggered. Preferably, the offset distance is half the side length of the diamond. This embodiment is one of the preferred embodiments of the present invention, and also, the polishing unit 43 includes a channel thereon, and the size of the polishing unit, the size of the channel and the number in different directions are as defined in the first embodiment.

Specifically, the polishing elements 63 of the first portion 61 are uniformly distributed in a direction parallel to the a direction, defining a length of the polishing elements 63 in the a direction of L1; the length of the polishing element 63 in the B direction is L2. The interval in the a direction between adjacent polishing elements 63 is defined as W1; although the polishing elements 63 are arranged in a staggered manner, the second portions 62 are also parallel to the a direction, and the polishing elements are uniformly spaced along the a direction, that is, the first portions 61 and the second portions 62 are parallel to each other, so that the spacing between the second portions 62 and the first portions 61 in the B direction is defined as W2. Preferred ranges of L1, L2, W1 and W2 are the same as in embodiment three.

The range of parameters such as the size, the interval, the size, the number, the area and the like of the polishing units is the same as that of the third embodiment. Therefore, the polishing unit has a polishing area S1 ═ L1 × L2 × sin θ, and a polishing area ratio RS1 ═ (L1 × L2 × sin θ)/((L1+ W1) × (L2+ W2)/((L1 × L2)/((L1+ W1) ((L2 + W2)). The above dimensions satisfy the relationship: 0.6 ≦ (L1 × L2)/((L1+ W1) (L2+ W2)) 0.92.

The effective contact area ratio RS2 ═ Ss/(L1 ═ L2) × (L1 × L2-n × L1-m × Wab × L2+ Nb × Wab)/(L1 × L2) of the polishing unit 63, and the present invention is limited to the range of this ratio from 0.5 to 0.97, and more preferably from 0.72 to 0.93.

Effective contact area ratio Ss/((L1+ W1) ((L2 + W2) × sin θ)

＝sinθ*((L1*L2-n*Waa*L1-m*Wab*L2+Nb*Waa*Wab))/((L1+W1)*(L2+W2)*sinθ)

＝(L1*L2-n*Waa*L1-m*Wab*L2+Nb*Waa*Wab)/((L1+W1)*(L2+W2))。

The utility model discloses it satisfies the relation to inject effective area of contact ratio RS 3:

50% or more (L1L 2- (n x Waa L1+ m x Wab L2-Nb x Waa Wab))/((L1+ W1) (L2+ W2))/(L1 + W1) or more than 85%. Further, the ratio ranges more preferably from 60% to 70%, for example, ratios such as 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69% and the like may be selected.

The width ratio of the effective channel, RW4, (n × Waa + m × Wab)/(W1+ W2), is limited to a range of 0.1 to 3.75, more preferably 0.15 to 2. RV5 ═ n × Waa × L1+ m × Wab × L2-Nb × Waa × Da)/(D1 ((L1+ W1) × (L2+ W2) -L1 × L2)), the present invention limits the volume ratio to the range of 0.03 to 3.4, more preferably to the range of 0.05 to 0.71.

Other parameters, such as the number of channels: preferably less than 6, for example n, m may each independently be any of 1,2,3,4, 5; more preferably, each is independently any of 2,3,4, 5; most preferably, each is independently any of 3,4, 5; the height of the polishing element; the limitation range of parameters such as the depth of the channel is the same as that described in the first embodiment, and the polishing pad shown in fig. 7 has excellent polishing performance and service life within the limitation range.

For the above embodiments one to four, if the L1 or L2 value is less than 10mm, the contact area of the polishing unit is reduced, and the polishing rate is reduced, and if the L1 or L2 value is greater than 20mm, the contact area of the polishing unit is too large, which affects the distribution speed of the polishing liquid in the grooves, and causes scratches. A W1 or W2 value of more than 5mm may cause too fast a flow rate of a polishing liquid or decrease wettability of a polishing pad, and a W1 or W2 value of less than 0.5mm may cause removal of abraded residues inefficiently.

If Waa or Wab is less than 0.15mm, there may be a serious quality problem in the processing of the polishing pad, even scratching the wafer, and if Waa or Wab is more than 0.6mm, the flow rate of the polishing liquid may be too fast to adversely affect the defectivity and the polishing rate.

If the range of RS1 is not in the range of [0.60-0.92], defectivity is adversely affected.

If the RS2 range is not in the [0.5-0.97] range, defectivity and polishing non-uniformity may be adversely affected.

If RS3 is less than 50%, the grinding rate is so severely lost that it cannot be used well for production, and if RS3 is more than 85%, the grinding rate can satisfy the basic requirements, but the scratch problem is remarkably prominent.

The RW4 in the range of [0.1-3.75] can well balance the flow velocity of the large and small channels, thereby improving the distribution of the polishing liquid and the removal efficiency of the waste residue.

n or m is more than 5, which affects the processing quality of the groove and the rigidity of the groove and reduces the utilization capacity of the polishing solution, thereby reducing the grinding quality.

The RV5 is in the range of 0.03-3.4, the whole transport capacity of the polishing solution in the groove and the whole slag discharge capacity of the waste liquid can be reasonably balanced, and the polishing pad has excellent grinding performance.

Examples

(1) Preparation of polishing layer

The polyurethane polishing layer can be prepared by adopting the methods such as the known prepolymer method, the one-step method, the utility model discloses the method that the technical staff selected as required does not influence the utility model discloses a design and protection scope as long as can make the utility model relates to a polishing pad all can. The polishing layer prepared by the utility model uses 23.0 parts by mass of TDI (toluene diisocyanate), 46.3 parts by mass of PTMEG (polytetramethylene ether glycol) (molecular weight 701.0) and 30.7 parts by mass of MOCA (3, 3 '-dichloro-4, 4' -diaminodiphenylmethane); the microspheres were manufactured by Akzo Nobel under the trade name Expancel551DE40D42, the mass of the microspheres accounted for 1.2% of the total mass of the polishing layer, the above materials were put into a casting head, rapidly mixed at a mixing rate of 5000rpm, cast into a mold to form a cylinder, the cylinder was sliced to obtain a sheet, finally, grooving process was performed on the sheet to obtain a polishing layer having a groove pattern, and the obtained polishing layer was about 2mm, had a hardness of 56D, and had a density of 0.84g/cm³(ii) a The storage modulus E' of the polishing layer is 210MPa, the tan delta is 0.083 and the KEL is 364.9Pa under the conditions of 40 ℃ and 1HZ by using a dynamic mechanical analyzer^-1。

(2) Preparation of polishing pad

The polishing pad of the present invention may also be the polishing layer described above; may further comprise a bottom layer; or a bottom layer and one or more intermediate layers disposed between the polishing layer and the bottom layer. The chemical mechanical polishing of the semiconductor substrate is carried out by a polishing layer, and the bottom layer or the middle layer is not limited by the structure of the utility model.

It is noted that the polishing layer of the polishing pad of the present invention optionally further comprises an endpoint detection window, preferably the detection window is an integrity window incorporated into the polishing layer.

The utility model discloses used buffer layer of pasting of polishing pad is polyurethane flooding non-woven fabrics, hardness 74A, compressionThe rate is 7%, and the density is 0.3g/cm³。

Code number explanation:

w1: interval length in the a-axis direction between polishing elements (parallelograms), unit: mm;

w2: interval length in the B-axis direction between polishing elements (parallelograms), unit: mm;

l1: length of polishing element (parallelogram) in a-axis direction, unit: mm;

l2: length of polishing element (parallelogram) in B-axis direction, unit: mm;

waa, Wab: the average widths of the first channel and the second channel in the B-axis direction and the A-axis direction respectively are in mm;

n, m: the number of channels in the polishing unit along the A-axis direction and the B-axis direction respectively;

nb: the number of intersections of the channels;

d1: average height of polishing elements in mm;

da: average depth of channels of polishing elements in mm;

RS1：L1*L2/((L1+W1)*(L2+W2))

RS2：(L1*L2-n*Waa*L1-m*Wab*L2+Nb*Waa*Wab)/L1*L2

RS3：100％*(L1*L2-n*Waa*L1-m*Wab*L2+Nb*Waa*Wab)/((L1+W1)*(L2+W2))

RW4：(n*Waa+m*Wab)/(W1+W2)

RV5：((n*Waa*L1+m*Wab*L2-Nb*Waa*Wab)*Da)/(((L1+W1)*(L2+W2)-L1*L2)*D1)

grinding parameters and evaluation methods:

the polished wafer was a Cu 10K wafer and the slurry was a diluted (10 fold) solution of ANJI U3061A plus 1% wt H₂O₂The flow rate was 230ml/min, the dresser was a Saesol AK53 diamond disk, the pressure was 6lbf, the polishing head pressure was 2.7psi, the platen speed was 77rpm, the carrier speed was 71rpm, and the polishing time was 30 s.

For the 10 th and 100 th wafers, the polishing rate, polishing non-uniformity and defectivity were measured.

The lapping rate was calculated by measuring the lapping removal at various locations on the wafer over a polishing time using a Nano SpecII tool.

The polishing rate heterogeneity (Nu) was also calculated from the Nano SpecII.

The defectivity is a count of defects on the wafer measured using a KLA-Tencor SP2 analyzer.

TABLE 1 Trench sample set

Note: the polishing layers used in examples 1 to 15 and comparative examples 1 to 10 each had a thickness of 2 mm.

The projected surfaces of the contact surfaces of the polishing units of examples 1-13 and example 15 were rectangular; the projection surface of the contact surface of the polishing unit of example 13 is rectangular, and is arranged as shown in fig. 5, and the polishing units in the same direction are staggered with the polishing units in another parallel direction; the projected surface of the contact surface of the polishing unit of example 14 was diamond shaped with an included angle of 45 °; example 15 the channels of the polishing elements are shown in figure 4 and are not evenly spaced.

TABLE 2 groove sample geometry parameters

TABLE 3 evaluation of polishing Properties

Table 1 shows the dimensional parameters of the grooves of the examples and comparative examples of the present invention, table 2 shows RS1, RS2, RS3, RW4, RV5, and table 3 shows the grinding evaluation results of the examples and comparative examples of the present invention, which are calculated from the groove dimensions.

As can be seen from examples 1 to 13 and 15, the polishing pad had a rectangular projected surface and had a preferable polishing rate (greater than that of the polishing pad) in the range of 0.60 to 0.92 for RS1, 0.5 to 0.97 for RS2, 50 to 85% for RS3, 0.1 to 3.75 for RW4, and 0.03 to 3.4 for RV5

Min), lower defectivity (less than 100) and lower polishing rate non-uniformity (less than 6%). The polishing effect of example 14 was also excellent.

Comparative examples 1,2, 6, 10 had RS3 below 50%, the reduction in grinding rate was significant, down to around 5000 and below; comparative example 3 has RS1 of 0.93, greater than the appropriate range of 0.6-0.92, and the defectivity increased to 154(10 pieces) and 201(100 pieces). Comparative example 4 had RV5 of 3.9 and RW4 of 4.29, exceeding 0.03-3.4 for RV5 and 0.1-3.75 for RW4, respectively, with defect levels rising to 232(10 tablets) and 200(100 tablets). RS3 of comparative example 7 is higher than 85%, resulting in excessively high defect level, which rises to 503(10 pieces) and 492(100 pieces). Comparative example 9 has no small channels, a defect degree of nearly 300 and above, and poor uniformity (9%).

The utility model discloses through a lot of experimental research and creative work, the comprehensive consideration various factors, the polishing pad that accords with parameter range who obtains has the best polishing performance.

Claims

1. A polishing pad is characterized by comprising a polishing layer, wherein the polishing layer comprises a polishing surface and polishing units arranged on the polishing surface, the number of the polishing units is at least one, the polishing units have an average height D1, the polishing units form a polishing unit group, one end of the polishing unit group forms a contact surface, the contact surface is directly contacted with a material to be ground, and the projection of each polishing unit on the contact surface is a parallelogram;

a plurality of polishing elements constituting a first section, the polishing elements of the first section extending in a first direction and being uniformly spaced,

a plurality of polishing elements constituting a second section, the polishing elements of the second section extending in a direction parallel to the first direction and being uniformly spaced, the polishing elements of the first section being spaced at a spacing equal to the spacing of the polishing elements of the second section, the spacing distance in the first direction being W1;

S1＝L1*L2*sinθ

Sa＝n*Waa*L1*sinθ+m*Wab*L2*sinθ-Nb*Waa*Wab*sinθ

the effective contact area Ss of the polishing unit is as follows:

Ss＝S1-Sa＝sinθ*(L1*L2-n*Waa*L1-m*Wab*L2+Nb*Waa*Wab)

the polishing layer effective contact area ratio RS3 is defined as follows:

RS3＝Ss/((L1+W1)*(L2+W2)*sinθ)

the grinding area ratio is defined as follows:

RS1 ═ L1 × L2/((L1+ W1) × (L2+ W2)), RS1 ranges from 0.60 to 0.92;

the effective contact area ratio RS2 of the polishing elements is defined as follows:

RS2 ═ Ss/S1, RS2 ranging from 0.5 to 0.97;

2. The polishing pad of claim 1, wherein the polishing elements have an L1 and L2 range from 10-20 mm.

3. The polishing pad of claim 1, wherein the effective contact area ratio RS3 is in the range of 60-70%.

4. The polishing pad of claim 1, wherein the first plurality of channels are evenly spaced and/or the second plurality of channels are evenly spaced.

5. The polishing pad of claim 1, wherein the polishing elements have the same or substantially the same height and the channels have the same or substantially the same depth.

6. The polishing pad of claim 1, wherein the average height D1 is 0.2-0.8 times the thickness of the polishing layer.

7. The polishing pad of claim 1, wherein the channels have an average depth Da of 0.4-1 times the polishing element height D1.

8. The polishing pad of claim 1, wherein Waa and Wab range from 0.15 to 0.6 mm.

9. The polishing pad of claim 1, wherein the polishing elements have a W1 and W2 in the range of 0.5-5 mm.

10. The polishing pad of claim 1, wherein the number of first channels is any one of 2-5, and/or the number of second channels is any one of 2-5.

11. The polishing pad of claim 1, wherein the polishing elements have a rectangular, square, or diamond shape in projection on the contact surface.