阅读说明：本技术 一种抛光垫的修整装置及修整方法 (Polishing pad dressing device and dressing method ) 是由 赵晟佑 于 2019-09-09 设计创作，主要内容包括：本发明提供一种抛光垫的修整装置及修整方法,修整装置包括：修整器,所述修整器包括呈圆柱状的修整器主体以及开设于所述修整器主体的修整面上的修整槽,所述修整槽包括圆环形槽和位于所述圆环形槽围合区域内的十字槽,所述十字槽的四端均与所述圆环形槽连通。根据本发明实施例的修整装置及修整方法,通过在修整器的修正面上开设修整槽,可有效将抛光垫上残留的颗粒杂质进行刮除并改善抛光垫表面的平坦度,从而防止硅片在抛光过程中发生划伤、造成硅片报废的现象,确保了硅片的抛光质量。(The invention provides a dressing device and a dressing method of a polishing pad, wherein the dressing device comprises: the trimmer, the trimmer is including being cylindric trimmer main part and seting up in trimming groove on the face of trimming of trimmer main part, trimming groove includes the annular groove and is located the annular groove encloses the cross recess in the closed area, four ends of cross recess all with the annular groove intercommunication. According to the trimming device and the trimming method provided by the embodiment of the invention, the trimming groove is formed on the correcting surface of the trimmer, so that residual particle impurities on the polishing pad can be effectively scraped, and the flatness of the surface of the polishing pad is improved, thereby preventing the silicon wafer from being scratched and scrapped in the polishing process, and ensuring the polishing quality of the silicon wafer.)

1. An apparatus for conditioning a polishing pad, comprising:

the trimmer, the trimmer is including being cylindric trimmer main part and seting up in trimming groove on the face of trimming of trimmer main part, trimming groove includes the annular groove and is located the annular groove encloses the cross recess in the closed area, four ends of cross recess all with the annular groove intercommunication.

2. A polishing pad dressing apparatus according to claim 1, further comprising:

the polishing brush, a side of the brush head of the polishing brush is provided with a bristle area, the bristle area is provided with bristles, and the dresser main body is opposite to the other side of the dressing surface, which is fixedly connected with the brush head of the polishing brush and the other side of the bristle area.

3. The dressing apparatus of claim 1, wherein said dresser body is made of alumina ceramic.

4. The dressing apparatus of claim 1, wherein the dresser body has a thickness of 15 to 20mm and a diameter of 100 to 150 mm.

5. The polishing pad dressing apparatus according to claim 1, wherein the width of the dressing groove is 1 to 5mm, and the depth thereof is 1 to 5 mm.

6. The polishing pad dressing apparatus according to claim 2, wherein said dresser main body is connected to a head of said polishing brush by a teflon bolt.

7. A dressing method of a polishing pad applied to the dressing apparatus according to any one of claims 1 to 6, wherein said dressing method comprises:

finishing: controlling the dressing surface of the dresser to be in contact with the polishing surface of the polishing pad, and controlling the dresser to move from the center of the polishing pad to the edge of the polishing pad while oscillating.

8. A method of conditioning a polishing pad as recited in claim 7, wherein in the conditioning step:

and controlling the dressing surface of the dresser to contact with the polishing surface of the polishing pad, and controlling the polishing pad to do autorotation motion and/or controlling the dresser to do autorotation motion.

9. A method of conditioning a polishing pad as recited in claim 7, wherein the conditioning device includes a polishing brush having a bristle field on one side of a head of the polishing brush, the bristle field having bristles, the other side of the conditioner body opposite the conditioning surface being fixedly attached to the other side of the head of the polishing brush opposite the bristle field, the method further comprising, prior to the conditioning step:

a cleaning step: and controlling the polishing pad to do autorotation motion, and controlling the bristles of the bristle field of the polishing brush to contact with the polishing surface of the polishing pad while enabling the brush head of the polishing brush to move from the center of the polishing pad to the edge of the polishing pad.

10. A method of conditioning a polishing pad as recited in claim 9, further comprising:

spraying deionized water to a contact area of the dresser and the polishing pad during the dressing step; and/or the presence of a gas in the gas,

and spraying deionized water to the contact area of the bristles of the polishing brush and the polishing pad during the cleaning step.

Technical Field

The invention relates to the technical field of silicon wafer processing, in particular to a polishing pad trimming device and a polishing pad trimming method.

Background

In the process of polishing the silicon wafer, the silicon wafer on the polishing head is in contact with the surface of the polishing pad attached to the rotating lower fixed disc, the polishing pad and the silicon wafer can be ground by polishing slurry, chemicals and the like used between the silicon wafer and the polishing pad, and the surface of the silicon wafer is polished under the combined action of chemical reaction of the polishing slurry and the chemicals and physical reaction caused by mechanical pressurization. At the same time, however, the surface morphology of the polishing pad gradually becomes uneven, and various particle impurities are more likely to accumulate on the surface of the polishing pad as the shape of the surface of the polishing pad changes, thereby causing deterioration of the flatness. Although the surface of the polishing pad is cleaned with deionized water before the next silicon wafer processing, the shape of the surface of the polishing pad cannot be restored to normal, and the particulate impurities deeply embedded therein cannot be completely removed.

Disclosure of Invention

In view of the above, the present invention provides a trimming device and a trimming method for a polishing pad, which are used to solve the problems that during the polishing process of a silicon wafer, the silicon wafer is easily scratched by particle impurities accumulated on the polishing pad, and the surface flatness of the silicon wafer is poor.

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

an embodiment of the present invention provides a dressing apparatus for a polishing pad, including:

the trimmer, the trimmer is including being cylindric trimmer main part and seting up in trimming groove on the face of trimming of trimmer main part, trimming groove includes the annular groove and is located the annular groove encloses the cross recess in the closed area, four ends of cross recess all with the annular groove intercommunication.

Further, the trimming apparatus further includes:

the polishing brush, a side of the brush head of the polishing brush is provided with a bristle area, the bristle area is provided with bristles, and the dresser main body is opposite to the other side of the dressing surface, which is fixedly connected with the brush head of the polishing brush and the other side of the bristle area.

Further, the dresser main body is made of alumina ceramics.

Further, the thickness of the dresser main body is 15-20mm, and the diameter is 100-150 mm.

Furthermore, the width of the groove body of the trimming groove is 1-5 mm, and the depth is 1-5 mm.

Further, the dresser main body is connected with the brush head of the polishing brush through a polytetrafluoroethylene bolt.

Another aspect of the present invention provides a method of dressing a polishing pad, applied to a dressing apparatus as described above, the method comprising:

finishing: controlling the dressing surface of the dresser to be in contact with the polishing surface of the polishing pad, and controlling the dresser to move from the center of the polishing pad to the edge of the polishing pad while oscillating.

Further, in the trimming step:

and controlling the dressing surface of the dresser to contact with the polishing surface of the polishing pad, and controlling the polishing pad to do autorotation motion and/or controlling the dresser to do autorotation motion.

Further, the trimming device includes a polishing brush, a brush head side of the polishing brush is provided with a bristle field, the bristle field is provided with bristles, the other side of the trimmer body opposite to the trimming surface is fixedly connected to the other side of the polishing brush head opposite to the bristle field, and before the trimming step, the trimming method further includes the following steps:

a cleaning step: and controlling the polishing pad to do autorotation motion, and controlling the bristles of the bristle field of the polishing brush to contact with the polishing surface of the polishing pad while enabling the brush head of the polishing brush to move from the center of the polishing pad to the edge of the polishing pad.

Further, the trimming method further includes:

spraying deionized water to a contact area of the dresser and the polishing pad during the dressing step; and/or the presence of a gas in the gas,

and spraying deionized water to the contact area of the bristles of the polishing brush and the polishing pad during the cleaning step.

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

according to the trimming device and the trimming method provided by the embodiment of the invention, the trimming groove is formed on the correcting surface of the trimmer, so that residual particle impurities on the polishing pad can be effectively scraped, and the flatness of the surface of the polishing pad is improved, thereby preventing the silicon wafer from being scratched and scrapped in the polishing process, and ensuring the polishing quality of the silicon wafer.

Drawings

FIG. 1 is a schematic illustration of a silicon wafer polishing process in an embodiment of the present invention;

FIG. 2 is a schematic illustration of the accumulation of particulate impurities on the surface of a polishing pad during polishing in an embodiment of the present invention;

FIG. 3 is a schematic representation of the change in surface flatness of the polishing pad before and after polishing in an embodiment of the present invention;

FIG. 4 is a schematic structural view of a dressing apparatus according to an embodiment of the present invention;

FIG. 5 is a front view of a dresser in an embodiment of the present invention;

fig. 6 is a schematic view of a dressing surface of a dresser in an embodiment of the present invention.

Reference numerals:

a polishing table 100, a polishing pad 200, a polishing head 300, a silicon wafer 400, a catheter 500 and granular impurities 600;

a buffer brush 700, bristles 710, a buffer brush body 720;

dresser 800, circular ring groove 810, cross groove 820.

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.

As shown in fig. 1, the embodiment of the present invention relates to a single-side polishing process of a silicon wafer, in the polishing process, a polishing head 300 is arranged above, the number of the polishing heads may be one, or two or more, a polishing table 100 is arranged right below the polishing head 300, a polishing pad 200 is attached to the upper surface of the polishing table 100, and the silicon wafer 400 is clamped on the end face of the polishing head 300. The specific polishing process comprises the following steps: the lower polishing table 100 rotates around the rotation axis, and the polishing pad 200 attached thereon also rotates; the polishing head 300 and the silicon wafer 400 held on the end face thereof move downward while rotating, and come into contact with the rotating polishing pad 200, whereby the polishing pad 200 grinds and polishes the silicon wafer 400; while the polishing head 300 rotates, the liquid guide pipe 500 sprays grinding slurry and chemicals to the polishing area of the silicon wafer 400 to grind and polish the silicon wafer 400; the surface of the silicon wafer 400 is polished by the combined action of the chemical reaction of the polishing slurry and chemicals and the physical reaction caused by mechanical pressurization.

As shown in fig. 2 and 3, during the polishing process, some particulate impurities 600 will accumulate on the surface of the polishing pad 200, and as the polishing process progresses, the surface of the polishing pad 200 will be gradually worn to become uneven, and the deformation further aggravates the accumulation of particulate impurities 600 on the surface of the polishing pad 200, thereby causing the silicon wafer to be contaminated by the particulate impurities 600 during the polishing process, and simultaneously, the surface thereof will deteriorate in flatness, and the surface will be easily scratched, and in severe cases, even the whole silicon wafer will be scrapped.

Currently, the surface of the polishing pad 200 is cleaned with deionized water before the next silicon wafer processing, but this still fails to restore the surface of the polishing pad 200 to a normal shape and completely removes the particulate impurities 600 deeply embedded therein.

Thus, as shown in fig. 4 to 6, an embodiment of the present invention provides a dressing apparatus for a polishing pad, the dressing apparatus including a dresser 800 for repairing the surface flatness of the polishing pad 200, the dresser 800 including a dresser body having a cylindrical shape and dressing grooves on a dressing surface thereof. Specifically, one of the circular surfaces of the dresser body is used as a dressing surface, a dressing groove is formed in the dressing surface, the dressing groove includes an annular groove 810 and a cross groove 820, the cross groove 820 is located in an area surrounded by the annular groove 810, and four ends of the cross groove 820 are communicated with the annular groove 810. The trimming groove is formed on the trimming surface of the cylindrical trimmer main body, so that the damaged surface of the polishing pad 200 can be ground by using the trimming surface of the trimmer to recover the flatness of the surface of the polishing pad, the grinding effect can be effectively enhanced by the trimming groove, and the particle impurities 600 accumulated on the surface of the polishing pad 200 are deeply removed, so that the polishing quality of a silicon wafer is ensured.

Further, in some embodiments of the present invention, the trimming groove may be provided in other forms, for example, besides the circular groove 810, one or two or more straight grooves passing through the center of the circular groove are provided in the area enclosed by the trimming groove, and the included angle between the straight grooves is not particularly limited; or, an annular groove may be formed outside the annular groove 810; of course, the circular groove 810 may be eliminated by leaving only one or two or more straight grooves passing through the center of the circular dressing surface.

As shown in fig. 4, the dressing apparatus according to the embodiment of the present invention further includes a polishing brush 700, the polishing brush 700 includes a polishing brush main body 720, the polishing brush main body 720 is a bent rectangular parallelepiped, a bristle region is disposed on one side surface of one end portion (i.e., a brush head portion) of the polishing brush main body 720, a plurality of bristles 710 are disposed in the bristle region, the polishing brush 700 can clean the surface of the polishing pad 200, i.e., the bristles 710 at the end portion can be used to brush away the particulate impurities 600 accumulated on the surface of the polishing pad 200, and since the bristles 710 can penetrate into the recessed area of the surface of the polishing pad 200 and further cooperate with deionized water to wash the surface of the polishing pad 200, the polishing brush 700 can forcefully remove the particulate impurities 600 in the recessed area of the surface of the polishing pad 200.

Further, in order to simplify the structure of the dressing apparatus, facilitate the integration and facilitate the use, the dresser 800 of the embodiment of the present invention is mounted on the polishing brush 700, and specifically, the other circular surface of the dresser 800 opposite to the dressing surface is fixedly attached to the other side surface of the brush head of the polishing brush 700 opposite to the bristle field, that is, when the bristles 710 are facing upward, the dressing surface of the dresser 800 is facing downward, and when the bristles 710 are facing downward, the dressing surface of the dresser 800 is facing upward, so that the surface of the polishing pad 200 can be cleaned and repaired at different positions of the dressing apparatus by turning the polishing brush 700.

In some embodiments of the present invention, the dresser 800 is made of alumina ceramic, which has a strong structural strength and is not easily worn, thereby preventing particle debris generated during the repairing process from further aggravating the unevenness of the surface of the polishing pad 200; moreover, even if a small amount of fine particles are generated, the silicon wafer is not contaminated.

Further, the thickness of the main body of the dresser 800 in the embodiment of the invention is 15-20mm, the diameter is 100-150 mm, and the diameter is moderate, so that the dresser can conveniently grind and repair the surface of the polishing pad 200 according to regions.

Further, the width of the groove body of the trimming groove in the embodiment of the invention is 1-5 mm, and the depth is 1-5 mm, and the groove depth and the groove width in the range can scrape the protrusions on the surface of the polishing pad 200 to recover the flatness of the surface.

Further, the trimmer 800 is connected with the brush head of the polishing brush through a polytetrafluoroethylene bolt, and the adopted polytetrafluoroethylene bolt does not pollute the silicon wafer.

Another aspect of the present invention provides a trimming method applied to the trimming apparatus described above, the trimming method including:

finishing: the dressing surface of the dresser 800 is controlled to be in contact with the polishing surface of the polishing pad 200, and the dresser 800 is controlled to move from the center of the polishing pad 200 toward the edge of the polishing pad 200 while oscillating.

That is, the dresser 800 is driven to oscillate left and right, and the polishing surface of the polishing pad 200 is dressed by the dressing surface and the dressing grooves formed therein, so that the left and right oscillations of the dresser 800 accelerate the dressing of the polishing surface of the polishing pad 200 and enhance the dressing force of the dressing surface.

Further, while the dresser 800 is in contact with the polishing surface of the polishing pad 200, the polishing pad 200 is controlled to perform a rotation motion and/or the dresser 800 is controlled to perform a rotation motion, and by further controlling the polishing pad 200 to perform a rotation motion and/or the dresser 800 to perform a rotation motion, the surface of the polishing pad 200 can be uniformly dressed step by step, and the dressing speed and dressing accuracy can be further improved.

In some embodiments of the present invention, before the trimming step, the method further comprises:

a cleaning step: the polishing pad is controlled to rotate, and the brush head of the polishing brush 700 is moved from the center of the polishing pad 200 to the edge of the polishing pad 200 while the brush head 710 of the polishing brush 700 is controlled to contact the polishing surface of the polishing pad 200.

That is, before the dressing process using the dresser 800, the bristles 710 of the brush head of the polishing brush 700 are used to penetrate into the recessed area of the surface of the polishing pad 200 to remove the particulate impurities 600, so as to avoid the reduction of the dressing effect caused by too many particulate impurities 600 existing in the dressing process. Since the dresser 800 is mounted on the brush head of the polishing brush 700, after the polishing brush 700 is cleaned, the dressing surface of the dresser 800 can be opposite to the polishing surface of the polishing pad 200 by directly turning over the polishing brush 700, thereby simplifying the whole dressing process.

Further, the repairing efficiency is improved by spraying deionized water to the contact area of the dresser 800 and the polishing pad 200 to wash away the generated debris during the dressing step.

Further, in the cleaning process, deionized water is sprayed to the contact area between the bristles 710 of the polishing brush 700 and the polishing pad 200 to assist the bristles in brushing away the particulate impurities 600, thereby improving the cleaning efficiency and cleaning effect.

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.