US20110294406A1

US20110294406A1 - Wafer polishing apparatus

Info

Publication number: US20110294406A1
Application number: US13/151,233
Authority: US
Inventors: Sang-Min An
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-06-01
Filing date: 2011-06-01
Publication date: 2011-12-01
Also published as: JP2013527624A; WO2011152625A2; EP2577718A2; KR101089480B1; WO2011152625A3

Abstract

Provided is a wafer polishing apparatus. The wafer polishing apparatus comprises a first polishing part and a second polishing part. The first part is disposed at a position higher than a top surface of a wafer and configured to be rotated on a first rotation axis. The second polishing part is disposed at a position lower than a bottom surface of the wafer and configured to be rotated on a second rotation axis.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. 119 and 35 U.S.C. 365 to Korean Patent Application No. 10-2010-0051685(filed on Jun. 1, 2010), which is hereby incorporated by reference in its entirety.

BACKGROUND

The present disclosure relates to a wafer polishing apparatus.
Electronic components including integrated circuits (ICs), large-scale integration (LSI) circuits, or very large-scale integration (VLSI) circuits may be formed of a semiconductor material such as single crystal silicon through a process of slicing a single crystal ingot made of silicon or a semiconductor compound into thin disk-shaped wafers (as-cut-wafers), a process of forming fine electric circuits on the wafers, and a process of cutting the wafers into semiconductor chips. Processes such as lapping, etching, and polishing are performed on an as-cut-wafer sliced from an ingot to obtain a mirror surface wafer having a mirror surface on at least one side thereof. Thereafter, fine electric circuits are formed on the mirror surface of the wafer through device forming processes. However, until the wafer is divided into semiconductor chips, the wafer is processed with its original disk shape being maintained. Cleaning, drying, and carrying may be performed between processing processes of the wafer. If the edge of the wafer is in a sharply-cut state or non-machined rough state while the wafer is processed, the edge of the wafer may be broken into fine particles due to collision with a device or other objects, or fine contaminants may be absorbed in the rough edge of the wafer and released and scattered in a later process. In this case, a precisely processed surface of the wafer may be contaminated, which may reduce the process yield or product quality. To prevent this, the edge of the wafer may be beveled and finished into a mirror surface (edge polishing).
Generally, such an edge polishing process is performed as follows by using a polishing machine including a rotatable drum and an abrader formed of a material such as a synthetic resin, a nonwoven fabric, a nonwoven fabric treated with a resin, a synthetic leather, and a combination thereof. While rotating a beveled silicon wafer, the abrader is pressed against the edge of the beveled silicon wafer at a predetermined angle, and a polishing composition solution containing colloid silica as a main component is supplied to the edge of the beveled silicon wafer.

SUMMARY

Embodiments provide a wafer polishing apparatus for efficiently polishing an edge part of a wafer.
In one embodiment, a wafer polishing apparatus comprises: a first polishing part disposed at a position higher than a top surface of a wafer and configured to be rotated on a first rotation axis; and a second polishing part disposed at a position lower than a bottom surface of the wafer and configured to be rotated on a second rotation axis.
In another embodiment, a wafer edge polishing apparatus comprises: a first polishing part making direct contact with an edge part of a wafer and configured to be rotated on a first rotation axis; and a second polishing part making direct contact with the edge part of the wafer and configured to be rotated on a second rotation axis.
In further another embodiment, a wafer polishing part comprises: a first polishing part at a lateral side of a wafer; a first driving shaft connected to the first polishing part; and a first rotation driving part configured to rotate the first polishing part through the first driving shaft, wherein an outer surface of the first polishing part is brought into direct contact with an edge part of the wafer.
The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is view illustrating an apparatus for polishing an edge part of a wafer according to an embodiment.

FIG. 2 is a sectional view illustrating a wafer edge.

FIG. 3 is a plan view for explaining a wafer polishing process.

FIG. 4 is a sectional view taken along line A-C of FIG. 3.

FIG. 5 is a sectional view taken along line B-C of FIG. 3.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In the following description, it will be understood that when a part, a chuck, a wafer, or a pad is referred to as being ‘on’ another part, chuck, wafer, or pad, it can be directly on the other part, chuck, wafer or pad, or one or more intervening parts, chucks, wafers, or pads may also be present. Further, it will be understood that when a part, a chuck, a wafer, or a pad is referred to as being ‘under’ another part, chuck, wafer, or pad, it can be directly under the other part, chuck, wafer, or pad, or one or more intervening parts, chucks, wafers, or pads may also be present. In addition, it will also be understood that when a part, a chuck, a wafer, or a pad is referred to as being ‘between’ two parts, chucks, wafers, or pads, it can be the only the part, chuck, wafer, or pad between the two parts, chucks, wafers, or pads, or one or more intervening parts, chucks, wafers, or pads may also be present. Further, the reference about ‘on’ and ‘under’ each part, chuck, wafer, or pad will be made on the basis of drawings. Also, in the drawings, the sizes of elements may be exaggerated for clarity of illustration, and the size of each element does not entirely reflect an actual size.
FIG. 1 is view illustrating an apparatus for polishing an edge part of a wafer according to an embodiment. FIG. 2 is a sectional view illustrating a wafer edge. FIG. 3 is a plan view for explaining a wafer polishing process. FIG. 4 is a sectional view taken along line A-C of FIG. 3. FIG. 5 is a sectional view taken along line B-C of FIG. 3.
Referring to FIGS. 1 to 5, the polishing apparatus of the current embodiment includes a first polishing unit 100, a second polishing unit 200, a third polishing unit 300, a first gap adjustment unit 400, a second gap adjustment unit 500, a third gap adjustment unit 600, and a fourth gap adjustment unit 700.
As shown in FIG. 2, an edge part 13 of a wafer (W) is a peripheral part of the wafer (W). The edge part 13 may be a circumferential surface of the wafer (W). The edge part 13 may have a rounded shape. That is, the edge part 13 of the wafer (W) may be a rounded peripheral part of the wafer (W). The edge part 13 includes a chamfer 13A, a chamfer 13B, and a top 13C.
The chamfer 13A extends from a top surface 11 of the wafer (W). That is, the chamfer 13A is directly connected to the top surface 11 of the wafer (W). The chamfer 13A is located at an upper position of the edge part 13.
The chamfer 13B extends from a bottom surface 12 of the wafer (W). That is, the chamfer 13B is directly connected to the bottom surface 12 of the wafer (W). The chamfer 13B is located at a lower position of the edge part 13.
The top 13C is located between the chamfer 13A and the chamfer 13B. The top 13C is connected directly to the chamfer 13A and the chamfer 13B. The top 13C extends downward from the chamfer 13A and upward from the chamfer 13B. That is, the top 13C is located at a center portion of the edge part 13. In other words, the top 13C may be the outermost part of the wafer (W).
As shown in FIGS. 1, 3, and 4, the first polishing unit 100 is disposed at a lateral side of the wafer (W). In detail, the first polishing unit 100 may be disposed at an upper position of a lateral side of the wafer (W). The first polishing unit 100 may be used to polish an upper lateral side of the wafer (W). That is, the first polishing unit 100 may be mainly used to polish the chamfer 13A.
The first polishing unit 100 includes a first driving shaft 110, a first polishing part 120, and a first rotation driving part 130.
The first driving shaft 110 is disposed above the wafer (W). In detail, the first driving shaft 110 is disposed at an upper lateral side of the wafer (W). The first driving shaft 110 is disposed at a position higher than the top surface 11 of the wafer (W). That is, the first driving shaft 110 may be disposed at a lateral side of the wafer (W) and higher than the top surface 11 of the wafer (W).
The first driving shaft 110 extends in a first direction. The first direction may correspond to a direction in which the top surface 11 of the wafer (W) extends. In detail, the first direction may parallel with the top surface 11 of the wafer (W).
Torque is transmitted from the first rotation driving part 130 to the first polishing part 120 through the first driving shaft 110. The first driving shaft 110 is inserted in the first polishing part 120 and fixed to the first polishing part 120. Also, the first driving shaft 110 is fixed along a main axis of the first rotation driving part 130 for being rotated by the first rotation driving part 130.
The first polishing part 120 is connected to the first driving shaft 110. In detail, the first polishing part 120 may surround the first driving shaft 110. The first polishing part 120 is rotated by torque transmitted through the first driving shaft 110.
The first polishing part 120 may be shaped like a roller. Alternatively, the first polishing part 120 may have a cylindrical shape or a disk shape. A hole is formed in the first polishing part 120 to receive the first driving shaft 110.
The first polishing part 120 is brought into direct contact with the edge part 13 of the wafer (W). In detail, the outer surface of the first polishing part 120 may be brought into direct contact with the chamfer 13A. The first polishing part 120 may be rotated centered on the first driving shaft 110 by torque transmitted through the first driving shaft 110.
That is, the first polishing part 120 is rotated on a first rotation axis Al. The first rotation axis Al corresponds to the first driving shaft 110. The first rotation axis Al is higher than the top surface 11 of the wafer (W) and may be parallel with the top surface 11 of the wafer (W).
Alternatively, the first rotation axis Al may cross a plane extending from the top surface 11 of the wafer (W).
The edge part 13 of the wafer (W) can be polished using the first polishing part 120. In detail, as the first polishing part 120 rotates, the first polishing part 120 may mainly polish the chamfer 13A of the wafer (W).
The first polishing part 120 includes a first polishing head 121 and a first polishing pad 122.
The first polishing head 121 is connected to the first driving shaft 110. The first polishing head 121 is rotated on the first rotation axis Al. The first polishing head 121 and the first driving shaft 110 may be formed in one piece. The first polishing head 121 may have a cylindrical shape.
The first polishing pad 122 is disposed around the first polishing head 121. The first polishing pad 122 may surround the first polishing head 121. The first polishing pad 122 may be brought into direct contact with the edge part 13 of the wafer (W). The first polishing pad 122 may include a nonwoven fabric and a polyurethane resin.
The first rotation driving part 130 applies torque to the first polishing part 120 through the first driving shaft 110. The first rotation driving part 130 may include a device such as a motor to produce torque.
As shown in FIGS. 1, 3, and 5, the second polishing unit 200 is disposed at another lateral side of the wafer (W). In detail, the second polishing unit 200 may be disposed at a lower position of a lateral side of the wafer (W). The second polishing unit 200 may be used to polish a lower lateral side of the wafer (W). That is, the second polishing unit 200 may be mainly used to polish the chamfer 13B.
The second polishing unit 200 includes a second driving shaft 210, a second polishing part 220, and a second rotation driving part 230.
The second driving shaft 210 is disposed below the wafer (W). In detail, the second driving shaft 210 is disposed at a lower lateral side of the wafer (W). The second driving shaft 210 is disposed at a position lower than the bottom surface 12 of the wafer (W). That is, the second driving shaft 210 may be disposed at a lateral side of the wafer (W) and lower than the bottom surface 12 of the wafer (W).
The second driving shaft 210 extends in a second direction. The second direction may correspond to a direction in which the bottom surface 12 of the wafer (W) extends. In detail, the second direction may parallel with the bottom surface 12 of the wafer (W).
Torque is transmitted from the second rotation driving part 230 to the second polishing part 220 through the second driving shaft 210. The second driving shaft 210 is inserted in the second polishing part 220 and fixed to the second polishing part 220. Also, the second driving shaft 210 is fixed along a main axis of the second rotation driving part 230 for being rotated by the second rotation driving part 230.
The second polishing part 220 is connected to the second driving shaft 210. In detail, the second polishing part 220 may surround the second driving shaft 210. The second polishing part 220 is rotated by torque transmitted through the second driving shaft 210.
That is, the second polishing part 220 is rotated on a second rotation axis A2. The second rotation axis A2 corresponds to the second driving shaft 210. The second rotation axis A2 is lower than the bottom surface 12 of the wafer (W) and may be parallel with the bottom surface 12 of the wafer (W).
Alternatively, the second rotation axis A2 may cross a plane extending from the bottom surface 12 of the wafer (W).
The second polishing part 220 may be shaped like a roller. Alternatively, the second polishing part 220 may have a cylindrical shape or a disk shape. A hole may be formed in the second polishing part 220 to receive the second driving shaft 210.
The second polishing part 220 is brought into direct contact with the edge part 13 of the wafer (W). In detail, the outer surface of the second polishing part 220 may be brought into direct contact with the chamfer 13B. The second polishing part 220 may be rotated centered on the second driving shaft 210 by torque transmitted through the second driving shaft 210.
That is, the second polishing part 220 is rotated on the second rotation axis A2. The second rotation axis A2 corresponds to the second driving shaft 210. The second rotation axis A2 is lower than the bottom surface 12 of the wafer (W) and may be parallel with the bottom surface 12 of the wafer (W).
Alternatively, the second rotation axis A2 may cross a plane extending from the bottom surface 12 of the wafer (W).
The first polishing part 120 and the second polishing part 220 may be rotated in the same direction or in different directions. The first polishing part 120 and the second polishing part 220 may be rotated clockwise or counterclockwise.
In this way, the edge part 13 of the wafer (W) can be polished using the second polishing part 220. In detail, as the second polishing part 220 rotates, the second polishing part 220 may mainly polish the chamfer 13B of the wafer (W).
The second polishing part 220 includes a second polishing head 221 and a second polishing pad 222.
The second polishing head 221 is connected to the second driving shaft 210. The second polishing head 221 is rotated on the second rotation axis A2. The second polishing head 221 and the second driving shaft 210 may be formed in one piece. The second polishing head 221 may have a cylindrical shape.
The second polishing pad 222 is disposed around the second polishing head 221. The second polishing pad 222 may surround the second polishing head 221. The second polishing pad 222 may be brought into direct contact with the edge part 13 of the wafer (W). The second polishing pad 222 may include a nonwoven fabric and a polyurethane resin.
Torque is transmitted from the second rotation driving part 230 to the second polishing part 220 through the second driving shaft 210. The second rotation driving part 230 may include a device such as a motor to produce torque.
As shown in FIGS. 1, 3, and 5, the third polishing unit 300 is disposed at a side of the wafer (W). In detail, the third polishing unit 300 may be disposed at a lateral side of the wafer (W). The third polishing unit 300 may be used to polish a center portion of the edge part 13 of the wafer (W). That is, the third polishing unit 300 may be mainly used to polish the top 13C.
The third polishing unit 300 includes a third driving shaft 310, a third polishing part 320, and a third rotation driving part 330.
The third driving shaft 310 is disposed at a side of the wafer (W). In detail, the first driving shaft 310 is disposed at a lateral side of the wafer (W). For example, the third driving shaft 310 may be disposed between the top surface 11 and the bottom surface 12 of the wafer (W). That is, the third driving shaft 310 may be disposed at a lateral side of the wafer (W) on the same level as the wafer (W). For example, the axis of the third driving shaft 310 may be disposed between the top surface 11 and the bottom surface 12 of the wafer (W).
The third driving shaft 310 extends in a third direction. The third direction may correspond to a direction in which the top surface 11 and the bottom surface 12 of the wafer (W) extend. In detail, the third direction may parallel with the top surface 11 and the bottom surface 12 of the wafer (W).
Torque is transmitted from the third rotation driving part 330 to the third polishing part 320 through the third driving shaft 310. The third driving shaft 310 is inserted in the third polishing part 320 and fixed to the third polishing part 320. Also, the third driving shaft 310 is fixed along a main axis of the third rotation driving part 330 for being rotated by the third rotation driving part 330.
The third polishing part 320 is connected to the third driving shaft 310. In detail, the third polishing part 320 may surround the third driving shaft 310. The third polishing part 320 is rotated by torque transmitted through the third driving shaft 310. A rotation axis of the third polishing part 320 is disposed between the top surface 11 and the bottom surface 12 of the wafer (W).
The third polishing part 320 may be shaped like a roller. Alternatively, the third polishing part 320 may have a cylindrical shape or a disk shape. A hole is formed in the third polishing part 320 to receive the third driving shaft 310.
The third polishing part 320 is brought into direct contact with the edge part 13 of the wafer (W). In detail, the outer surface of the third polishing part 320 may be brought into direct contact with the top 13C. The third polishing part 320 may be rotated centered on the third driving shaft 310 by torque transmitted through the third driving shaft 310.
That is, the third polishing part 320 is rotated on a third rotation axis A3. The third rotation axis A3 corresponds to the third driving shaft 310. The third rotation axis A3 may be disposed between the top surface 11 and the bottom surface 12 of the wafer (W). The third rotation axis A3 may be parallel with the top surface 11 and the bottom surface 12 of the wafer (W).
Alternatively, the third rotation axis A3 may cross planes extending from the top surface 11 and the bottom surface 12 of the wafer (W).
The edge part 13 of the wafer (W) can be polished using the third polishing part 320. In detail, as the third polishing part 320 rotates, the third polishing part 320 may mainly polish the top 13C of the wafer (W).
The third polishing part 320 includes a third polishing head 321 and a third polishing pad 322.
The third polishing head 321 is connected to the third driving shaft 310. The third polishing head 321 is rotated on the third rotation axis A3. The third polishing head 321 and the third driving shaft 310 may be formed in one piece. The third polishing head 321 may have a cylindrical shape.
The third polishing pad 322 is disposed around the third polishing head 321. The third polishing pad 322 may surround the third polishing head 321. The third polishing pad 322 may be brought into direct contact with the edge part 13 of the wafer (W). The third polishing pad 322 may include a nonwoven fabric and a polyurethane resin.
Torque is transmitted from the third rotation driving part 330 to the third polishing part 320 through the third driving shaft 310. The third rotation driving part 330 includes a device such as a motor to produce torque.
The first gap adjustment unit 400 moves the first polishing unit 100 upward and downward. That is, the vertical position of the first polishing unit 100 can be varied using the first gap adjustment unit 400. The first gap adjustment unit 400 is fixed to a support plate 800. The first gap adjustment unit 400 includes a fourth electric motor 410 and a first screw 420.
The fourth electric motor 410 is fixed to the support plate 800 to rotate the first screw 420. The fourth electric motor 410 may be a stepping motor. In this case, rotation of the first screw 420 can be precisely controlled.
The first screw 420 moves the first polishing unit 100 upward and downward by using torque received from the fourth electric motor 410. For example, the first screw 420 may be inserted in a nut 401 connected to the first rotation driving part 130 so as to move the first polishing unit 100 upward and downward by using torque transmitted from the fourth electric motor 410.
In some embodiments, the polishing apparatus may further include a first guide part 402 such as a guide rod or a guide rail so as to guide the first polishing unit 100 when the first polishing unit 100 is moved upward or downward by the first gap adjustment unit 400. The first guide part 402 may be fixed to the support plate 800.
The second gap adjustment unit 500 moves the second polishing unit 200 upward and downward. That is, the vertical position of the second polishing unit 200 can be varied using the second gap adjustment unit 500. The second gap adjustment unit 500 is fixed to a support plate 800. The second gap adjustment unit 500 includes a fifth electric motor 510 and a second screw 520.
The fifth electric motor 510 is fixed to the support plate 800 to rotate the second screw 520. The fifth electric motor 510 may be a stepping motor. In this case, rotation of the second screw 520 can be precisely controlled.
The second screw 520 moves the second polishing unit 200 upward and downward by using torque transmitted from the fifth electric motor 510. For example, the second screw 520 may be inserted in a nut 501 connected to the second rotation driving part 230 so as to move the second polishing unit 200 upward and downward by using torque transmitted from the fifth electric motor 510.
In some embodiments, the polishing apparatus may further include a second guide part 502 such as a guide rod or a guide rail so as to guide the second polishing unit 200 when the second polishing unit 200 is moved upward or downward by the second gap adjustment unit 500. The second guide part 502 may be fixed to the support plate 800.
The third gap adjustment unit 600 moves the third polishing unit 300 horizontally. That is, the horizontal position of the third polishing unit 300 can be varied using the third gap adjustment unit 600. That is, the horizontal distance between the third polishing unit 300 and the wafer (W) can be adjusted using the third gap adjustment unit 600. The third gap adjustment unit 600 includes a sixth electric motor 610 and a third screw 620.
The sixth electric motor 610 rotates the third screw 620. The sixth electric motor 610 may be a stepping motor. In this case, rotation of the third screw 620 can be precisely controlled.
The third screw 620 moves the third polishing unit 300 upward and downward by using torque transmitted from the sixth electric motor 610. For example, the third screw 620 may be inserted in a nut 601 connected to the third rotation driving part 330 so as to move the third polishing unit 300 upward and downward by using torque transmitted from the sixth electric motor 610.
In some embodiments, the polishing apparatus may further include a third guide part 602 such as a guide rod or a guide rail so as to guide the third polishing unit 300 when the third polishing unit 300 is horizontally moved by the third gap adjustment unit 600.
Furthermore, In some embodiments, the polishing apparatus may further include a frame to support and fix the third gap adjustment unit 600.
The fourth gap adjustment unit 700 moves the support plate 800 horizontally. That is, the horizontal position of the support plate 800 can be varied using the fourth gap adjustment unit 700. As a result, the first polishing unit 100 and the second polishing unit 200 can be horizontal moved using the fourth gap adjustment unit 700. That is, the horizontal distance between the first polishing unit 100 and the wafer (W) and the horizontal distance between the second polishing unit 200 and the wafer (W) can be adjusted using the fourth gap adjustment unit 700. The fourth gap adjustment unit 700 includes a seventh electric motor 710 and a fourth screw 720.
The seventh electric motor 710 rotates the fourth screw 720. The seventh electric motor 710 may be a stepping motor. In this case, rotation of the fourth screw 720 can be precisely controlled.
The fourth screw 720 moves the support plate 800 horizontally by using torque transmitted from the seventh electric motor 710. For example, the fourth screw 720 is inserted in a nut connected to the support plate 800 so as to horizontally move the support plate 800 by using torque transmitted from the seventh electric motor 710.
In some embodiments, the polishing apparatus may further include a fourth guide part (not shown) so as to guide the support plate 800 when the support plate 800 is horizontally moved by the fourth gap adjustment unit 700.
Furthermore, in some embodiments, the polishing apparatus may further include a frame (not shown) to support and fix the fourth gap adjustment unit 700.
Furthermore, in some embodiments, the polishing apparatus may further include a wafer rotating unit (not shown) to support and rotate the wafer (W). The wafer rotating unit may hold the wafer (W) by creating a vacuum and rotate the wafer (W) on a fourth rotation axis.
The first rotation axis A1 crosses the fourth rotation axis. In detail, the first rotation axis A1 may cross the fourth rotation axis substantially at right angle. The second rotation axis A2 crosses the fourth rotation axis. In detail, the second rotation axis A2 may cross the fourth rotation axis substantially at right angle. The third rotation axis A3 crosses the fourth rotation axis. In detail, the third rotation axis A3 may cross the fourth rotation axis substantially at right angle.
Furthermore, In some embodiments, the polishing apparatus may further include a slurry injection unit (not shown) to inject a polishing liquid such as slurry to the wafer (W). The slurry injection unit may inject slurry to the top surface 11 of the wafer (W). Alternatively, the slurry injection unit may inject slurry to a contact region between the first polishing part 120 and the edge part 13 of the wafer (W), a contact region between the second polishing part 220 and the edge part 13 of the wafer (W), and a contact region between the third polishing part 320 and the edge part 13 of the wafer (W).
During a polishing process, the wafer (W) may be rotated, and the first polishing part 120, the second polishing part 220, and the third polishing part 320 may rotated while making direct contact with the wafer (W).
In this way, the edge part 13 of the wafer (W) may be polished by the first polishing unit 100, the second polishing unit 200, and the third polishing unit 300. In detail, the chamfer 13A may be polished by the first polishing part 120, the chamfer 13B may be polished by the first rotation driving part 130, and the top 13C may be polished by the third polishing part 320.
Therefore, all the chamfer 13A, the chamfer 13B, and the top 13C can be polished through a single process by using the polishing apparatus of the current embodiment. That is, the edge part 13 of the wafer (W) can be efficiently polished using the polishing apparatus to reduce process time and cost.
The first polishing unit 100 can be freely moved in vertical and horizontal directions by the first gap adjustment unit 400 and the fourth gap adjustment unit 700. Therefore, the chamfer 13A of the wafer (W) can be polished into a desired shape by using the first polishing unit 100.
Like the first polishing unit 100, the second polishing unit 200 can be freely moved in vertical and horizontal directions by the second gap adjustment unit 500 and the fourth gap adjustment unit 700. Therefore, the chamfer 13B of the wafer (W) can be polished into a desired shape by using the second polishing unit 200.
The third polishing unit 300 can be freely moved by the third gap adjustment unit 600 in a horizontal direction. Therefore, the top 13C of the wafer (W) can be polished into a desired shape by using the third polishing unit 300.
That is, the edge part 13 of the wafer (W) can be polished into a desired shape by using the polishing apparatus of the current embodiment.
As described above, polishing of the edge part 13 of the wafer (W) can be efficiently carried out, and the shape of the edge part 13 can be controlled as desired by using the polishing apparatus of the current embodiment. Therefore, high-quality wafers can be produced with reduced process time and cost by using the polishing apparatus of the embodiment.
The polishing apparatus of the embodiments can be used in the semiconductor industry.
According to the embodiments, an edge part of a wafer can be polished by using the first and second polishing parts of the wafer polishing apparatus. Particularly, since the first rotation axis is higher than the top surface of the wafer, a first chamfer of the edge part of the wafer can be polished using the first polishing part. In addition, since the second rotation axis is lower than the bottom surface of the wafer, a second chamfer of the edge part of the wafer can be polished using the second polishing part.
That is, both the first and second chambers can be polished using the wafer polishing apparatus of the embodiments. Furthermore, in some embodiments, the wafer polishing apparatus may include a third polishing part configured to be rotated on a third rotation axis. In this case, a top of the edge part of the wafer can be polished using the third polishing part. Therefore, all the first and second chambers and the top of the edge part of the wafer can be polished using the wafer polishing apparatus of the embodiments.
Furthermore, in some embodiments, the wafer polishing apparatus may further include gap adjustment units configured to move the first polishing part, the second polishing part, and the third polishing part. Since the first polishing part, the second polishing part, and the third polishing part can be moved, the shape of the edge part of the wafer can be controlled as desired.
Therefore, the first and second chambers and top of the edge part of the wafer can be polished to desired shapes by using the wafer polishing apparatus of the embodiments.
Any reference in this specification to “one embodiment,” “an embodiment,” “example embodiment,” etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to effect such feature, structure, or characteristic in connection with other ones of the embodiments.
Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.

Claims

1. A wafer polishing apparatus comprising:

a first polishing part disposed at a position higher than a top surface of a wafer and configured to be rotated on a first rotation axis; and

a second polishing part disposed at a position lower than a bottom surface of the wafer and configured to be rotated on a second rotation axis.

2. The wafer polishing approximately according to claim 1, further comprising a third polishing part disposed at a lateral side of the wafer and configured to be rotated on a third rotation axis.

3. The wafer polishing approximately according to claim 2, wherein the first polishing part, the second polishing part, and the third polishing part are brought into direct contact with an edge part of the wafer.

4. The wafer polishing approximately according to claim 3, wherein the edge part comprises:

a first chamfer extending from the top surface of the wafer;

a second chamfer extending from the bottom surface of the wafer; and

a top between the first and second chambers,

wherein the first polishing part is brought into direct contact with the first chamfer, the second polishing part is brought into direct contact with the second chamfer, and the third polishing part is brought into direct contact with the top.

5. The wafer polishing approximately according to claim 2, wherein the first to third polishing parts are shaped like a roller, a disk, or a cylinder.

6. The wafer polishing approximately according to claim 2, wherein the third rotation axis is between the top and bottom surfaces of the wafer.

7. The wafer polishing approximately according to claim 1, further comprising a first gap adjustment unit configured to adjust a gap between the first polishing part and the wafer.

8. The wafer polishing approximately according to claim 1, further comprising a second gap adjustment unit configured to adjust a gap between the second polishing part and the wafer.

9. The wafer polishing approximately according to claim 1, wherein the wafer is rotated on a fourth rotation axis perpendicular to the top surface of the wafer;

the first rotation axis extends in a direction crossing the fourth rotation axis; and

the second rotation axis extends in a direction crossing the fourth rotation axis.

10. A wafer edge polishing apparatus comprising:

a first polishing part making direct contact with an edge part of a wafer and configured to be rotated on a first rotation axis; and

a second polishing part making direct contact with the edge part of the wafer and configured to be rotated on a second rotation axis.

11. The wafer edge polishing apparatus according to claim 10, further comprising a third polishing part making direct contact with the edge part of the wafer and configured to be rotated on a third rotation axis.

12. The wafer edge polishing apparatus according to claim 11, wherein the first rotation axis is higher than a top surface of the wafer, the second rotation axis is lower than a bottom surface of the wafer, and the third rotation axis is between the top and bottom surfaces of the wafers.

13. The wafer edge polishing apparatus according to claim 10, wherein the first rotation axis is parallel with a top surface of the wafer, and the second rotation axis is parallel with a bottom surface of the wafer.

14. The wafer edge polishing apparatus according to claim 10, wherein the first polishing part is disposed at an upper lateral side of the wafer, and the second polishing part is disposed at a lower lateral side of the wafer.

15. The wafer edge polishing apparatus according to claim 11, wherein the third polishing part is disposed at a lateral side of the wafer.

16. The wafer edge polishing apparatus according to claim 10, wherein the first polishing part comprises:

a first polishing head configured to be rotated on the first rotation axis; and

a first polishing pad disposed around the first polishing head.

17. A wafer polishing part comprising:

a first polishing part at a lateral side of a wafer;

a first driving shaft connected to the first polishing part; and

a first rotation driving part configured to rotate the first polishing part through the first driving shaft,

wherein an outer surface of the first polishing part is brought into direct contact with an edge part of the wafer.

18. The wafer polishing apparatus according to claim 17, further comprising:

a second polishing part at another lateral side of the wafer;

a second driving shaft connected to the second polishing part; and

a second rotation driving part configured to rotate the second polishing part through the second driving shaft,

wherein an outer surface of the second polishing part is brought into direct contact with the edge part of the wafer.

19. The wafer polishing apparatus according to claim 17, further comprising a first gap adjustment unit configured to adjust a gap between the first polishing part and the edge part of the wafer by moving the first positive pressure and the first rotation driving part.

20. The wafer polishing apparatus according to claim 19, further comprising a second gap adjustment unit configured to move the first positive pressure, the first rotation driving part, and the first gap adjustment unit.