CN110744450B

CN110744450B - Dresser and dressing method for polishing pad

Info

Publication number: CN110744450B
Application number: CN201911002359.1A
Authority: CN
Inventors: 郭宇轩; 赵晟佑
Original assignee: Xian Eswin Silicon Wafer Technology Co Ltd; Xian Eswin Material Technology Co Ltd
Current assignee: Xian Eswin Silicon Wafer Technology Co Ltd; Xian Eswin Material Technology Co Ltd
Priority date: 2019-10-21
Filing date: 2019-10-21
Publication date: 2021-11-26
Anticipated expiration: 2039-10-21
Also published as: CN110744450A

Abstract

The present invention provides a dresser and a dressing method of a polishing pad, the dresser includes: the trimming arm comprises a fixed section and a trimming section, the fixed section is vertically arranged, one end of the trimming section is connected with the upper end part of the fixed section, the trimming section is in a first position perpendicular to the fixed section in a working state and in a second position collinear with the fixed section in a non-working state, and the trimming section can be switched between the first position and the second position; the supporting arm is used for supporting the trimming section, and the other end of the trimming section is supported at the upper end part of the supporting arm when the trimming section is at the first position; and the trimming body is fixed on the trimming section and is used for trimming the polishing pad. According to the dresser provided by the embodiment of the invention, the uniform load force on the dressing arm in the dressing process can be ensured, so that the dressing body is ensured to be parallel to the polishing pad, and the dressing effect is improved.

Description

Dresser and dressing method for polishing pad

Technical Field

The invention relates to the technical field of polishing, in particular to a trimmer and a trimming method for a polishing pad.

Background

The surface condition of a polishing pad is one of the important factors affecting the quality condition of silicon wafers, and in order to improve the surface properties of silicon wafers after polishing and maintain the batch production stability of silicon wafers, the polishing pad is usually dressed by a special dresser before the first polishing and after a plurality of times of polishing to restore the surface properties thereof.

At present, most of polishing pad dressers are cantilever beam structures, the dressing head is positioned at one end of the cantilever beam, and due to the influence of the gravity of the dressing head, the dressing arm is bent, so that the dressing head is not parallel to the polishing pad, and then the dressing effect of the dresser on the polishing pad is influenced.

Disclosure of Invention

Accordingly, the present invention provides a dresser and a dressing method for a polishing pad, which are used to solve the problem that the dressing head is not parallel to the polishing pad, which in turn affects the dressing effect of the dresser on the polishing pad.

In order to solve the technical problems, the invention adopts the following technical scheme:

an embodiment of an aspect of the present invention provides a dresser for a polishing pad, comprising:

the trimming arm comprises a fixed section and a trimming section, the fixed section is vertically arranged, one end of the trimming section is connected with the upper end part of the fixed section, the trimming section is in a first position perpendicular to the fixed section in a working state and in a second position collinear with the fixed section in a non-working state, and the trimming section can be switched between the first position and the second position;

the supporting arm is used for supporting the trimming section, and the other end of the trimming section is supported at the upper end part of the supporting arm when the trimming section is at the first position;

and the trimming body is fixed on the trimming section and is used for trimming the polishing pad.

Further, the finisher further includes:

the support plate is fixed at the upper end part of the support arm, a limit groove is formed in the support plate, and the other end of the trimming section is supported in the limit groove of the support plate when the trimming section is located at the first position.

Further, the finisher further includes:

and the driving motor is respectively connected with the fixed section and the supporting arm and is used for controlling the fixed section and the supporting arm to do synchronous lifting motion.

Further, the finisher further includes:

the fixing piece is used for fixedly connecting one end of the trimming section, which is not connected with the fixing section, to the supporting plate when the trimming section is in the first position.

Furthermore, the trimming body comprises a cylindrical main body and trimming brushes distributed on the side face of the cylindrical main body, and the trimming body can rotate around the central axis of the trimming body.

Furthermore, the material of the finishing brush is nylon 66, and the length of the bristles of the finishing brush is 5 mm-20 mm.

Another aspect of the present invention provides a dressing method of a polishing pad, applied to the dresser of any one of the above, the dressing method including:

adjusting a trimming section of the trimming arm to be vertically connected with a fixing section, and fixedly supporting one end, which is not connected with the fixing section, of the trimming section on a supporting plate of a supporting arm;

and controlling the polishing pad to rotate and synchronously descending the fixing section and the supporting arm at the same time, and finishing the polishing pad by utilizing the finishing body fixed on the finishing section.

Further, the polishing pad is controlled to rotate, and meanwhile, the repairing body is controlled to rotate around the central shaft.

The technical scheme of the invention has the following beneficial effects:

through set up the support at dressing section both ends, can guarantee that the dressing section receives the loading power of equipartition at the dressing in-process to guaranteed to repair wholly parallel with the polishing pad, improved the dressing effect.

Drawings

FIG. 1 is a schematic diagram of a trimmer in the prior art;

FIG. 2 is a schematic diagram illustrating a force analysis of a dresser in the prior art;

fig. 3 is a schematic structural diagram of a dresser in a first position according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a dresser in a second position according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram illustrating another trimmer according to the embodiment of the present invention in a first position;

FIG. 6 is a schematic structural diagram of a support plate according to an embodiment of the present invention;

FIG. 7 is a front view of a conditioning body in an embodiment of the invention;

FIG. 8 is a side view of a trim body in an embodiment of the present invention;

FIG. 9 is a schematic diagram illustrating a force analysis of a dresser in an embodiment of the present invention;

FIG. 10 is a flow chart illustrating a method for conditioning a polishing pad according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the drawings of the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the invention, are within the scope of the invention.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a trimmer in the prior art. As shown in fig. 1, the dresser is of a cantilever structure, and mainly includes a dressing arm 12 and a dressing pad 121 disposed at an extended end of the dressing arm 12, the dressing arm 12 is of an inverted L-shape, and is of an integrally formed structure, a polishing table 11 is disposed below the dressing pad 121, the polishing table 11 is used for placing a polishing pad, and a power output end of a motor group 13 is connected to the dressing arm 12 and is used for driving the dressing arm 12 to move downward, so that the dressing pad 121 on the dressing arm 12 contacts with and dresses the polishing pad on the polishing table 11, and the motor group 13 can also drive the dressing arm 12 to swing in a horizontal direction, so that the dressing pad 121 moves horizontally on the upper surface of the polishing pad.

Referring to fig. 2, fig. 2 is a schematic view illustrating a force analysis of a dresser in the prior art. As shown in fig. 2, the graph may represent the stress condition of the dresser in fig. 1, and in fig. 2, the dresser is simplified into a cantilever beam structure in material mechanics, according to the material mechanics formula:

and

wherein F is the gravity borne by the finishing pad 121, θ is the angle deviated from the horizontal plane, ω is the displacement deviated from the horizontal plane, l is the length of the cantilever beams A to B, and EI is the bending stiffness of the cantilever beams;

as can be seen from the above formula, the cantilever structure of the end of the arm 12 and the pad 121 thereon will be in a bending state under the action of gravity, and it is not guaranteed that the pad 121 is parallel to the polishing pad; when the arm length of the dressing arm 12 is longer and the weight of the dressing pad 121 is heavier, the bending degree of the dressing arm 12 is more obvious, thereby causing the dressing pad 121 to form an included angle with the polishing pad during dressing, and affecting the dressing effect; moreover, the precision of the dressing is also affected because the dressing arm 12 will have some degree of play during the dressing process. It should be noted that when the dresser is not operating, the dressing pad 121 fixed to the projecting end of the dressing arm 12 will irreversibly deform the dressing arm 12 under the influence of gravity for a long period of time, thereby further affecting the dressing effect of the dressing pad 121.

Accordingly, embodiments of the present invention provide a dresser for a polishing pad, which is used to solve the above-mentioned problems of the conventional cantilever-type dresser.

As shown in fig. 3, the finisher in the embodiment of the present invention includes: the trimming arm 32, the trimming body 33 and the supporting arm 34, wherein the trimming arm 32 is in an inverted L shape and comprises a fixing section 321 and a trimming section 322, the fixing section 321 is vertically arranged, and one end of the trimming section 322 is connected with the upper end of the fixing section 321. In the working state, the trimming section 322 is at the first position, i.e. the trimming section 322 is horizontally arranged, and the trimming section 322 is perpendicular to the fixing section 321 at this time, while in the non-working state, the trimming section 322 is at the second position, i.e. the trimming section 322 is vertically arranged, and the trimming section 322 and the fixing section 321 are arranged in a collinear way at this time; the finishing section 322 can be switched between the finishing section 322 and the fixing section 321, so that the connection between the finishing section 322 and the fixing section 321 can be in an articulated manner, and a locking buckle is arranged at the connection, under the condition that the locking buckle is controlled to be closed, the finishing section 322 and the fixing section 321 can be completely fixedly connected, torque can be transmitted between the finishing section 322 and the fixing section 321, and under the condition that the locking opening is opened, the finishing section 322 can be switched between a first position and a second position.

As shown in fig. 3, when the trimming arm 32 is in a working state, that is, when the trimming section 322 is in the first position, one end of the trimming section 322, which is far away from the fixing section 321, is supported at the upper end of the supporting arm 34, the supporting arm 34 is vertically arranged, and the height of the supporting arm is consistent with the height of the fixing section 321, that is, two ends of the trimming section 322 are respectively supported by the fixing section 321 and the supporting arm 34, so that the load on the trimming arm 32 is changed into a uniform load, and under the condition of uniform load, the bending deformation of the trimming arm 32 is reduced, thereby ensuring the trimming precision.

As shown in fig. 3, the trimming body 33 is fixedly arranged on the trimming section 322, when the trimming section 322 is in a working state, the trimming body 33 is positioned under the trimming section 322, and because the two ends of the trimming section 322 are both provided with the supporting structures, even if the trimming body 33 is subjected to the action of gravity, the amount of bending deformation generated by the trimming section 322 is in a small range, the parallel arrangement relationship between the trimming body 33 and the polishing pad cannot be influenced, and under the action of uniform load, the trimming precision of the trimming body 33 is high, and the trimming effect is good; in addition, during the trimming process, because both ends of the trimming section 322 are effectively supported, the shaking amplitude of the trimming section 322 is limited, and the influence on the trimming precision is further reduced.

In the embodiment of the present invention, as shown in fig. 3 and 4, when the dresser is in the working state, the dressing section 322 of the dressing arm 32 is lowered to the horizontal position, and the extended end thereof is supported on the support arm 34; when the dresser is in a non-working state, the dressing section 322 in the dressing arm 32 is lifted and arranged in line with the fixing section 321, so that the dressing section 322 is prevented from bending and deforming under the action of gravity for a long time.

As shown in fig. 3 and 6, in order to support the trimming section 322 more effectively, a supporting plate 35 is further disposed at the upper end of the supporting arm 34, the supporting plate 35 and the supporting arm 34 are fixedly disposed, a limiting groove is disposed on the supporting plate 35, when the trimming section 322 is located at the first position, the extending end of the trimming section 322 is supported in the limiting groove of the supporting plate 35, and the limiting groove can limit horizontal shaking and vertical shaking of the trimming section 322, so as to reduce influence on the trimming process. In some embodiments, the supporting plate 35 is U-shaped, and the U-shaped groove of the supporting plate 35 is a limiting groove, and in order to match with the limiting groove, a spherical body may be disposed at the end of the protruding end of the trimming section 322, and the spherical body has a shape matched with the shape of the U-shaped groove to reduce the impact generated during trimming of the trimming section 322.

As shown in fig. 3, in the embodiment of the present invention, the dresser further includes a motor unit 36, the fixing section 321 of the dresser arm 32 is connected to the power output end of the motor unit 36, and the dresser arm 32 can perform vertical lifting movement under the driving of the motor unit 36; further, the power output end of the motor unit 36 is connected to the support arm 34, and the support arm 34 can perform synchronous lifting movement with the trimming arm 32 under the driving of the motor unit 36. That is, when the polishing pad on the polishing table 31 needs to be dressed, the dressing section 322 is supported on the supporting plate 35 fixed to the upper end of the supporting arm 34, and the motor unit 36 controls the dressing arm 32 and the supporting arm 34 to vertically descend simultaneously, so that the dressing arm 32 and the supporting arm 34 descend synchronously until the dressing body 33 and the polishing pad are in contact dressing, thereby ensuring the parallelism between the dressing body 33 and the polishing pad, and the dressing section 322 is also in a uniformly loaded state, so that the dressing effect is better.

As shown in fig. 7 and 8, in the embodiment of the present invention, the conditioning body 33 includes a cylindrical main body 331 and conditioning brushes 332, the conditioning brushes 332 are uniformly distributed on the side surface of the cylindrical main body 331, and the conditioning body 33 can perform a rotation motion around its central axis, so as to condition the polishing pad by the conditioning brushes 332 fixed on the side surface. Specifically, the fixed relationship between the trimming body 33 and the trimming section 322 may be: a rotating shaft is arranged on the central axis of the cylindrical main body 331, and two ends of the rotating shaft are fixedly connected with the trimming section 322 through a fixed shaft, so that the trimming body 33 can rotate around the central axis thereof and can also be driven by the trimming section 322 to move up and down.

In some embodiments of the present invention, the brush 332 is made of nylon 66, the nylon 66 is wear resistant and does not contaminate the polishing pad, and the length of the bristles of the brush 332 is between 5mm and 20 mm.

In other embodiments of the present invention, as shown in fig. 5, the dresser further includes a fixing member 37, the fixing member 37 is used for fixedly connecting one end of the dressing section 322 supported on the supporting plate 35 to the supporting plate 35 when the dressing section 322 is in the first position, that is, when the fixing member 37 is not present, the dressing section 322 is only supported on the supporting plate 35 but not completely fixed to the dressing section 322, and the fixing member 37 is added to completely fixedly connect the two, so that when the motor set 36 drives the dressing arm 32 and the supporting arm 34 to synchronously descend, the dressing body 33 contacts the polishing pad to apply pressure to the polishing pad to perform dressing, and the polishing pad applies a reaction force to the dressing body 33, so that the dressing section 322 tends to move upwards, and by completely fixing the protruding end of the dressing section 322 to the supporting arm 34, the supporting arm 34 descends under the driving of the motor set 36, a downward force is applied to the dressing section 322 to counteract the force applied by the polishing pad to the dressing body 33, so that sufficient pressure is maintained between the dressing body 33 and the polishing pad, and the parallelism between the two is good, thereby improving the dressing accuracy and increasing the dressing rate.

In some embodiments, the fixing member 37 may be a U-shaped member, i.e., a U-shaped member is inserted through the supporting plate 35, and the end of the finishing section 322 is fastened by bolts or the like.

Referring to fig. 9, fig. 9 is a schematic view illustrating a stress analysis of a dresser according to an embodiment of the present invention, as shown in fig. 9, which may show a stress condition of the dresser in fig. 5, in fig. 9, the dresser is simplified to a cantilever beam structure in material mechanics, where, according to a material mechanics formula:

and

wherein q is uniform load, theta is an angle deviating from a horizontal plane, omega is a displacement deviating from the horizontal plane, l is the length from A to B of the cantilever beam, and EI is the bending rigidity of the cantilever beam;

as can be seen from the above formula, compared with the dresser in the prior art, the dresser provided by the embodiment of the present invention has a greatly reduced deviation angle and a greatly reduced displacement from the horizontal plane, so that the parallelism between the dresser body 33 and the polishing pad is ensured, and the dressing effect of the dresser is optimized.

Another aspect of the present invention provides a method of dressing a polishing pad, applied to the dresser of any one of the above, the method comprising:

step 101: adjusting the trimming section to be vertically connected with the fixing section, and enabling one end of the trimming section, which is not connected with the fixing section, to be fixedly supported on a supporting plate of a supporting arm;

step 102: and controlling the polishing pad to rotate and synchronously descending the fixed section and the supporting section at the same time, and finishing the polishing pad by utilizing the finishing body fixed on the finishing section.

In the embodiment of the present invention, first, the trimming section 322 is horizontally disposed, in which the trimming section 322 is vertically connected to the fixing section, the other end of the trimming section 322 is supported on the supporting plate 35, and the end of the trimming section 322 can be further completely fixed to the supporting plate 35 by the fixing member 37;

then, a polishing pad is placed on the polishing table 31, the polishing pad performs a rotation motion around its central axis, the fixing section 321 and the supporting arm 34 are synchronously driven by the motor unit 36 to descend synchronously, when the polishing pad descends to a certain position, the dressing brush 332 of the dressing body 33 is based on the polishing pad to start dressing the polishing pad, and since both ends of the dressing section 322 are stably supported, the dressing body 33 fixed thereon and the polishing pad can maintain good parallelism, thereby ensuring dressing accuracy.

Further, during the dressing process, the dressing body 33 can be controlled to perform a rotation motion around its central axis to accelerate the dressing of the polishing pad and increase the dressing rate.

After finishing the trimming operation, the fixing member 37 can be unfastened, and the trimming section 322 is lifted to be arranged in a collinear manner with the fixing section 321, so that the bending deformation of the trimming section 322 caused by the long-term gravity action is avoided.

While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A dresser for a polishing pad, comprising:

the trimming arm comprises a fixed section and a trimming section, the fixed section is vertically arranged, one end of the trimming section is connected with the upper end part of the fixed section, the trimming section is located at a first position which is perpendicular to the fixed section in a working state and at a second position which is collinear with the fixed section in a non-working state so as to prevent the trimming section from bending deformation under the action of gravity, and the trimming section can be switched between the first position and the second position;

a dressing body fixed to the dressing section for dressing a polishing pad;

2. The dresser of the polishing pad of claim 1, further comprising:

3. The dresser of the polishing pad of claim 2, further comprising:

4. The dresser of claim 1, wherein the dresser includes a cylindrical body and dressing brushes disposed on sides of the cylindrical body, the dresser being capable of spinning about a central axis of the dresser.

5. The dresser of claim 4, wherein the dresser brush is made of nylon 66, and the length of the bristles of the dresser brush is 5mm to 20 mm.

6. A dressing method for a polishing pad, applied to the dresser of any one of claims 1 to 5, comprising:

7. A method of conditioning a polishing pad as recited in claim 6, wherein the conditioning body is controlled to rotate about its central axis while the polishing pad is controlled to rotate.