KR20090013405A - Apparatus for grinding wafer - Google Patents

Abstract

A wafer polishing device is provided to reduce tact time by prevent polishing processing time from extending according to time interval among the processing. A wafer polishing device comprises a turn table(10), a rough polishing part(30), a fine polishing part(50) a polishing part(60), a polishing table(61), a polisher(62) and a buffer polishing part(40). The rough polishing part includes a roughing table(31) absorbing the wafer and a roughing wheel(32) progressing a rough process in one side of turn-table. The fine polishing part includes a fine table absorbing the wafer and a fine wheel progressing a fine process in the rear of the rough table.

Description

Wafer Grinding Equipment {Apparatus for grinding wafer}

The present invention relates to a wafer polishing apparatus, and more particularly, a wafer that can reduce the tact time by preventing the overall wafer backside polishing process time from being longer due to the time difference between the processes of the wafer backside polishing process. It relates to a polishing apparatus.

In the wafer fabrication process of forming a semiconductor integrated circuit on the active surface of the wafer, the wafers introduced into the wafer fabrication process in order to suppress damage of the wafer generated during movement or handling between the wafer fabrication apparatuses are substantially a semiconductor package. It is provided in a considerably thicker state than the wafers used in the manufacturing process.

Therefore, after the wafer fabrication process, a process of polishing one surface (rear surface) of the unnecessary wafer is involved before being provided to the semiconductor package fabrication process. Through the polishing of the back surface of the wafer, it is possible to reduce the volume of the semiconductor chip and to ensure good heat dissipation characteristics when packaged and used.

Conventional wafer polishing apparatus for polishing the back of the wafer is an apparatus for polishing the back of the wafer in the order of rough grinding, fine grinding and polishing processes.

This conventional wafer polishing apparatus includes a turntable that is rotatable, four chuck tables provided on the turntable, a wafer cassette for supply and a wafer cassette for storage provided on one side of the turntable. do. A polishing unit that performs a polishing process on the wafer adsorbed on the chuck table is installed on each of the three chuck tables.

As will be described in detail later, four chuck tables are provided for vacuum suction of wafers, and four chuck tables are provided at edge portions along the circumferential direction of the turntable, and rotate together with the turntable at predetermined angles as the turntable rotates.

At this time, the four chuck tables are divided into a standby table on which the wafer waits, a roughing table in which the roughing process is performed, a finishing table in which the finishing process is performed, and a polishing table in which the polishing process is performed.

The polishing unit is installed on the roughing table, the finishing table and the polishing table, except for the waiting table, which is a portion where the wafer is supplied or taken out. Briefly with respect to the polishing unit, the polishing unit is provided with a roughing wheel installed on the top of the roughing table to roughly polish the initial wafer rear surface, and a polishing wheel mounted on the top of the finishing table to precisely polish the back surface of the wafer where the roughing process is completed. And a polisher installed on the polishing table and polishing the back surface of the wafer, in which the finishing process is completed, by chemical mechanical polishing (CMP).

The supply wafer cassette and the storage wafer cassette are installed close to the waiting table. The supply wafer cassette provides a wafer to be subjected to the back polishing process to the waiting table, and the receiving wafer cassette is provided with a wafer on which the back polishing process is completed.

Meanwhile, as the thickness of the semiconductor package is accelerated, the back surface polishing amount of the wafer is gradually increased.

Increasing the amount of backside polishing of the wafer leads to an increase in roughing and finishing time. In order to proceed with the backside polishing process while minimizing time delay at each chuck table as the turntable rotates, Need to be increased. However, when the finishing amount exceeds 30 μm, wafer burning occurs and the quality of the wafer is degraded. Therefore, the finishing amount that can be increased is limited.

In view of such a problem, there is an example in which the back surface polishing process is performed by increasing only the roughing amount. However, when only the roughing amount is increased in this way, the overall wafer backside polishing time becomes longer as the roughing process time becomes relatively longer than other process times, resulting in a problem that the production yield of the wafer backside polishing apparatus decreases.

Therefore, it is necessary to improve the structure to reduce the tact time by preventing the overall wafer backside polishing time from lengthening according to the time difference between the processes of the wafer backside polishing process. However, when attempting to reduce the tact time by preventing the length of the wafer backside polishing process by simply increasing the size of the turntable or improving the number of chuck tables, the stiffness and vibration of the turntable may occur. As a result, the polishing quality of the wafer may be deteriorated, so countermeasures should be taken together.

It is an object of the present invention to provide a wafer polishing apparatus which can reduce the tact time by preventing the overall wafer backside polishing time from lengthening according to the time difference between the processes of the wafer backside polishing process.

Another object of the present invention is to provide a wafer polishing apparatus which can prevent the polishing quality on the wafer from being degraded due to the problems of the stiffness and vibration of the turntable.

The object is, according to the present invention, a turntable rotatable; A roughing polishing unit having a roughing table provided on one side of the turntable to adsorb a wafer, and a roughing wheel provided on the roughing table to perform a rough grinding process on the wafer; A finishing table provided on the turntable in the circumferential direction behind the roughing table and adsorbing the wafer; and a finishing table provided above the finishing table to perform a fine grinding process on the wafer where the roughing process is completed. Finishing polishing unit having a wheel; A polishing table provided on the turntable in a circumferential direction behind the finishing table to adsorb the wafer, and a polishing table provided on an upper portion of the polishing table to perform a polishing process on the wafer where the finishing process is completed. A polishing polishing unit having a polisher; And a buffer polishing unit disposed around the rough polishing unit and the finishing polishing unit to further perform at least one process selected from the roughing process and the finishing process.

The buffer polishing unit may include: a buffer table provided on the turntable; And a buffer wheel provided at an upper portion of the buffer table.

At least one buffer table may be provided in at least one region selected from an area between the roughing table and the finishing table and an area between the finishing table and the polishing table in the circumferential direction of the turntable.

The buffer polishing unit may be a secondary rough polishing unit provided between the rough polishing unit and the finishing polishing unit along the circumferential direction of the turntable.

The standby table may further include a standby table provided on one side of the turntable, and the standby table, the roughing table, the finishing table, the polishing table, and the buffer table are mutually along the circumferential direction of the table. It may be a chuck table for vacuum suction of the wafers arranged at intervals.

It may further include a table shaft to form a rotation axis of the turntable, the table shaft may be coupled to the cross roller bearing.

The cross roller bearing may be arranged in at least two stages at different positions on the table shaft.

Each of the roughing table, the buffer table, the finishing table and the polishing table includes: a table body having a vacuum line formed thereon; Porous chuck body having a plurality of pores in communication with the vacuum line, is provided on the table body; And a sludge inflow prevention part provided adjacent to the porosity chuck body in a state separated from the porosity chuck body to prevent sludge from flowing between the porosity chuck body and the wafer.

The sludge inflow prevention part may be a sludge inflow prevention ring having no pores formed therein, and the porosity chuck body may support the deposition section of the wafer from below, and the sludge inflow prevention part may support the non-deposition section of the wafer from below. The porosity chuck body may have an area smaller than an upper surface of the table body.

The sludge inflow prevention part may be an air injection hole formed in the table body to inject air for preventing sludge inflow into an edge region of the wafer.

The apparatus may further include a cleaning unit disposed in at least one region among the roughing table, the buffer table, the finishing table, and the polishing table to clean the wafer passing through the region.

The cleaning unit may include a cleaning body disposed at an upper region of the wafer; And an injection unit formed in the cleaning body to spray any one cleaning material selected from water and air toward the polishing surface of the wafer.

According to the present invention, it is possible to reduce the tact time by preventing the overall wafer backside polishing time from lengthening according to the time difference between the processes of the wafer backside polishing process.

In addition, according to the present invention, it is possible to prevent the polishing quality of the wafer from being degraded due to the rigidity and vibration problems of the turntable.

In order to fully understand the present invention, the operational advantages of the present invention, and the objects achieved by the practice of the present invention, reference should be made to the accompanying drawings which illustrate preferred embodiments of the present invention and the contents described in the accompanying drawings.

Hereinafter, the present invention will be described in detail by explaining preferred embodiments of the present invention with reference to the accompanying drawings. Like reference numerals in the drawings denote like elements.

1 is a block diagram of a wafer polishing apparatus according to a first embodiment of the present invention, Figure 2 is a schematic longitudinal cross-sectional view of FIG.

As shown in these figures, the wafer polishing apparatus according to the present embodiment includes a turntable 10 that is rotatable, a rough polishing portion 30 that undergoes a first rough grinding process, and A buffer polishing unit 40 for performing a second roughing process, a finishing polishing unit 50 for performing a fine grinding process, and a polishing polishing unit 60 for performing a polishing process are provided.

The rough polishing unit 30, the buffer polishing unit 40, the finishing polishing unit 50, and the polishing polishing unit 60 are each provided along the circumferential direction on the turntable 10, and the wafer W, Polish the back side (one side or back side) of the wafer.

As described above, since the amount of abrasive machining in the roughing process is much larger than other processes, the time required for roughing naturally increases. If only the roughing amount is increased, the roughing process of the wafer (W) rear surface is performed. As the process time is relatively longer than other process times, the overall wafer W backside polishing process time is long, resulting in a decrease in production yield of the wafer W backside polishing apparatus.

Therefore, it is required to improve the structure to reduce the tact time by preventing the overall wafer W backside polishing time from lengthening according to the time difference between the processes of the backside polishing process of the wafer W. In the example, a separate buffer polishing unit 40 is further provided, and the buffer polishing unit 40 serves as a secondary rough polishing unit for the second roughing process. As described above, by performing the roughing process, which is the longest polishing process, in a plurality of processes, it is possible to prevent the tact time from being increased as a whole.

Five chuck tables (not shown) are provided on the turntables 10 of the wafer polishing apparatus according to the present embodiment so that the buffer polishing unit 40 can perform the second roughing process. Four polishing units (not shown) are provided above the four chuck tables except for the standby table 21.

For reference, the five chuck tables without reference numerals refer to the waiting table 21, the roughing table 31, the buffer table 41, the finishing table 51, and the polishing table 61. The four polishing units, which are not given reference numerals, refer to the roughing wheel 32, the buffer wheel 42, the finishing wheel 52 and the polisher 62.

At this time, the structures of the five chuck tables are all provided in the same manner, and are provided at equal intervals along the circumferential direction of the turntable 10. Since these five chuck tables are rotated by the turntable 10, substantially the five chuck tables have a waiting table 21, a roughing table 31, a buffer table 41, a finishing table 51 and a polishing table ( 61) to play all roles. However, in the present embodiment, for convenience of description, the chuck table at the moment located in the roughing wheel 32, the buffer wheel 42, the finishing wheel 52, and the polisher 62 is respectively roughed table 31, It is called the buffer table 41, the finishing table 51, and the polishing table 61. FIG.

By this logic, in the present embodiment, the rough table 31 and the rough wheel 32 are paired to form the rough polishing part 30, and the buffer table 41 and the buffer wheel 42 are paired. Polishing the buffer polishing part 40 by pairing the finishing table 51 and the finishing wheel 52 to the finishing polishing part 50 and the polishing table 61 and the polisher 62 as a pair. Polishing unit 60 is achieved. Each component is demonstrated sequentially.

The turntable 10 is a portion in which five chuck tables are supported along the circumferential direction on the upper surface thereof. The turntable 10 may be manufactured in a disk shape. The lower portion of the turntable 10 is coupled to the table shaft 12 to form the center of rotation of the turntable 10.

In the prior art, four chuck tables were provided on the turntable 10. In the present embodiment, as described above, a total of five chuck tables are provided. Therefore, the turntable 10 of the present embodiment, unlike the turntable (not shown) of the prior art, as the size increases, the load is increased due to the five chuck tables.

Therefore, the rigidity and vibration problems of the turntable 10 may be caused, and when it is left, the polishing quality of the wafer W may be degraded. In order to solve this problem, the cross roller bearing 14 is coupled to the table shaft 12. As shown in FIG. 2, the cross roller bearings 14 are arranged in at least two stages at different positions on the table shaft 12 to solve the problems of rigidity and vibration of the turntable 10.

For reference, the cross roller bearing 14 is further described. Although not shown in detail, the structure and the features of the cross roller bearing 14 will be described. The cross roller bearing 14 has a cylindrical roller arranged at right angles between the spacer retainers on a rolling surface of a 90 degree V groove. It is possible to load loads in all directions, such as radial loads, axial loads, and moment loads. Since the inner and outer rings can be compactly compact and have high rigidity, in addition to the polishing apparatus of this embodiment, the joints or turning parts of industrial robots, turning tables of machining centers, rotating parts of menu plates, precision rotary tables, medical devices, measuring instruments, It is known that it is suitable for the use of IC manufacturing apparatus.

The cross roller bearing 14 can prevent the skew of a roller and the increase of the rotation torque by mutual friction of rollers by arrange | positioning the spacer retainer between the rollers orthogonally arranged. In addition, stable rotation is obtained even in a state where preload is applied without a single contact phenomenon or a lock phenomenon of the roller. In addition, since the inner ring or the outer ring is divided into two parts, the clearance of the bearing can be adjusted and the preload can be applied, thereby obtaining a highly accurate rotational motion.

The cross roller bearing 14 is easy to handle during assembly, and the roller retainer is always kept in the regular position by the spacer retainer, thereby preventing the roller skew (roller misalignment) and providing stable rotating performance because there is no mutual friction between the rollers. Lose. In particular, since the rollers are arranged orthogonally, the cross roller bearing 14 is known to have rigidity improved by three to four times or more even when a load is loaded in each direction with one bearing, compared to a thin angular ball bearing being used in a double row. ought. In this way, by applying the cross roller bearing 14 to the table shaft 12 while providing five chuck tables on the turntable 10, it is possible to appropriately solve the stiffness and vibration problems that may occur in the turntable 10. Will be.

On the other hand, as described above, the five chuck tables include a standby table 21 on which the wafer W waits, a roughing table 31 on which the first roughing process proceeds, and a buffer on which the second roughing process proceeds. It is divided into the table 41, the finishing table 51 which a finishing process advances, and the polishing table 61 which a polishing process advances.

Five chuck tables, the waiting table 21, the roughing table 31, the buffer table 41, the finishing table 51 and the polishing table 61 are radially installed at the edges along the circumferential direction on the turntable 10. do. At this time, the turntable 10 rotates the chuck tables collectively so that any chuck table can be positioned at the position of the neighboring chuck table by rotation, and at the same time, each step of the wafer W polishing process is performed. Allow it to proceed. That is, the five chuck tables serve as the standby table 21, the roughing table 31, the buffer table 41, the finishing table 51 and the polishing table 61 by the rotation of the turntable 10. Will be.

Looking at the chuck table by position, it is divided into a waiting table 21, a roughing table 31, a buffer table 41, a finishing table 51 and a polishing table 61 in a clockwise direction, which are centered on the turntable 10. Are positioned at 72 degrees to each other. The turntable 10 rotates 72 degrees every predetermined time, and the rotation period of the turntable 10 may be set based on the longest running time of the polishing process of the wafer (W).

On the other hand, the supply wafer cassette 15 and the storage wafer cassette 16 are provided on one side of the turntable 10 adjacent to the standby table 21. A conveyer 17 is provided between the standby table 21, the supply wafer cassette 15, and the storage wafer cassette 16. The wafer W to be polished can be transferred from the wafer cassette 15 for supply to the waiting table 21 by the transfer machine 17, and on the contrary, the polished wafer W is stored from the waiting table 21. Can be transferred to a wafer cassette 16 for use. For reference, when the wafer W to be polished is transferred from the wafer cassette 15 for supply to the waiting table 21 by the conveyer 17, the wafer W is aligned with an alignment means such as a camera (not shown). It may be desirable to transfer to the waiting table 21 after the process of aligning the position of the further progress.

Four polishing units are provided on the roughing table 31, the buffer table 41, the finishing table 51 and the polishing table 61, except for the waiting table 21. That is, the four polishing units are provided on the roughing table 31 and are provided on the roughing wheel 32 to roughly roughen the back surface of the initial wafer W first, and the buffer table 41 on the top of the wafer ( W) a buffer wheel 42 for roughly polishing the rear surface secondarily, a finishing wheel 52 for precisely polishing the back surface of the wafer W, which is installed on the upper part of the finishing table 51 and the roughing process is completed, and a polishing table ( And a polisher 62 installed on the upper portion 61 to polish the back surface of the wafer W, which has been finished, by a chemical mechanical method (CMP).

The roughing wheel 32 which forms the rough polishing part 30 together with the roughing table 31 has a particle size of 300 to 350 mesh, for example, 325 mesh, and thus the final wafer W is targeted. Roughly polish the back surface of the wafer (W) to be approximately 20 to 30㎛ thicker than the thickness.

The buffer wheel 42 forming the buffer polishing portion 40 together with the buffer table 41 is applied in the same manner as the roughing wheel 32 and secondly roughly polishes the back surface of the wafer W.

The finishing wheel 52 forming the finishing polishing part 50 together with the finishing table 51 has a particle size of 1500 to 2500 mesh, for example 2000 mesh, and precisely polishes the rear surface of the rough polished wafer W to a target thickness. do.

The polisher 62 forming the polishing polishing portion 60 together with the polishing table 61 may also be referred to as a polishing polishing pad. The polisher 62 may be covered with a cloth-like material on its underside. Has a conventional configuration in which a slurry feed is formed. The polisher 62 mirrors the back surface of the finely polished wafer W to the final thickness using the slurry.

The operation of the wafer polishing apparatus having such a configuration will be described below.

First, the conveyer 17 grips the wafer W from the supply wafer cassette 15 and transfers it to the waiting table 21. In this case, as described above, the process of aligning the position of the wafer W by an alignment means such as a camera (not shown) may be further performed.

When the wafer W is positioned on the standby table 21, the turntable 10 is rotated 72 degrees clockwise with the table axis 12 as the axis. When the wafer W is positioned on the roughing table 31 by the rotation of the turntable 10, the rear surface of the wafer W is roughly polished firstly by the roughing wheel 32 (primary roughing process), and at the same time The new wafer W is transferred to the waiting table 21 again.

After the back surface of the wafer W is roughly polished primarily by the roughing wheel 32, the turntable 10 is rotated 72 degrees again, so that the wafer W is positioned in the buffer table 41, and then the buffer wheel 42. ), The back surface of the wafer W is roughly polished secondarily (secondary roughing step).

Subsequently, after the finishing process by the finishing wheel 52 and the polishing process by the polisher 62 are performed by the continuous rotation of the turntable 10, the wafer W, which has been polished, is returned to the waiting table 21. Is located. The wafer W located on the waiting table 21 is finally transferred to the storage wafer cassette 16 through the conveyor 17.

As described above, in this embodiment, by dividing the roughing process having a relatively large amount of processing, the overall wafer W backside polishing time is lengthened according to the time difference between the processes of the backside polishing process of the wafer W. This can reduce the tact time.

In addition, according to the present embodiment, it is possible to prevent the polishing quality of the wafer W from deteriorating due to the rigidity and vibration problems of the turntable 10.

3 is a block diagram of a wafer polishing apparatus according to a second embodiment of the present invention.

In the first embodiment described above, by applying the buffer polishing portion 40 as the secondary roughing polishing portion, the initial roughing processing with a relatively large amount of processing is divided and processed.

However, the buffer polishing portion 40a may be applied as the secondary finishing polishing portion, as shown in FIG. 3.

As shown in FIG. 3, when the buffer polishing portion 40a is applied as the secondary finishing polishing portion, the wafer W positioned on the waiting table 21 is subjected to the roughing process and the primary finishing based on the rotation of the turntable 10. The back side is polished through a process, a secondary finishing process and a polishing process. In this case, it may be advantageous to increase the machining speed of the roughing wheel 32 to perform the roughing process in the form of a high speed machining, and then to perform the ultra-precise machining by finely finishing the finishing process than the conventional method.

4 is a block diagram of a wafer polishing apparatus according to a third embodiment of the present invention.

In the present embodiment, two buffer polishing parts 40 and 40a are provided. One is applied to the second rough polishing portion as in the first embodiment and the other is applied to the secondary rough polishing portion as in the second embodiment.

In the case of the present embodiment, the initial roughing process can be divided into a large amount of processing, there is an advantage that the fine machining can also be divided by performing fine machining than the conventional method.

3 and 4, the tact time can be reduced by preventing the entire wafer W backside polishing time from being longer depending on the time difference between the processes of the backside polishing process of the wafer W. It is enough to provide the effect.

5 is a configuration diagram of main parts of a wafer polishing apparatus according to a fourth embodiment of the present invention.

Referring to FIG. 1, the first roughing, the second roughing, the finishing and the polishing process are performed by the rough polishing unit 30, the dummy polishing unit 40, the finishing polishing unit 50, and the polishing polishing unit 60, respectively. In this process, sludge, which is an abrasive material for each process, is provided. However, if such sludge flows between the chuck table and the wafer W loaded thereon, it may cause contamination of the back grind tape (BG Tape) and the deposition surface of the wafer W, which may cause defects (die cracks). In addition, since the pores of the chuck table may be blocked, it is necessary to prevent this. This can be solved by the structure of FIG. 5 to be described below. For reference, the structure of FIG. 5 is applied to all the chuck tables of the waiting table 21, the roughing table 31, the dummy table 41, the finishing table 51, and the polishing table 61.

As shown in FIG. 5, the chuck table, which may be the waiting table 21, the roughing table 31, the dummy table 41, the finishing table 51, and the polishing table 61, has a large table body 71. ), A porous chuck body (73), and a sludge inflow prevention portion (75).

The table body 71 forms the lower region of the chuck table. For reference, instead of forming the table body 71, a portion of the turntable 10 may be used as the table body 71. The vacuum line 71a is formed in the center region of the table body 71. As the vacuum is formed in the direction of FIG. 5A through the vacuum line 71a, the wafer W may be adsorbed and supported on the upper surface of the POSOS chuck body 73.

The POROS chuck body 73 is provided in the upper region of the table body 71. Substantially, the wafer W is adsorbed and supported on the upper surface of the POROS chuck body 73. The wafer W is formed with a plurality of pores 73a communicating with the vacuum line 71a in the POROS chuck body 73 so as to be adsorbed and supported on the top surface of the POROS chuck body 73. Thus, a vacuum is formed in the direction of FIG. 5 (a) through the vacuum line 71a to inhale air through the plurality of pores 73a in the direction of (a), thereby loading the upper surface of the porosity chuck body 73. ) The wafer W may be adsorbed. At this time, the POROUS chuck body 73 is manufactured to have an area smaller than the upper surface of the table body 71.

On the other hand, the sludge inflow prevention part 75 is adjacent to the porosity chuck body 73 in a state separated from the porosity chuck body 73 to prevent sludge from flowing between the porosity chuck body 73 and the wafer W. To be prepared. While a plurality of pores 73a are formed in the POROS chuck body 73, the pores (not shown) are not formed in the sludge inflow prevention part 75. In the present embodiment, the sludge inflow prevention part 75 is applied to the sludge inflow prevention ring 75.

As such, the porous chuck body 73 in which the pores 73a are formed and the sludge inflow prevention part 75 in which no pores (not shown) are formed are supported to support the wafer W in a state in which the pores 73a are formed in a separated state. Sludge is introduced between the porosity chuck body 73 and the wafer (W) can be prevented.

In particular, in the wafer W, the deposition section W1, which is a portion where the deposition film is to be formed, is supported on the upper surface of the porosity chuck body 73, and the non-deposition section W2 is disposed on the upper surface of the sludge inflow prevention portion 75. Since it is supported, even if the sludge penetrates into the lower part of the wafer W, it falls between the separated porosity chuck body 73 and the sludge inflow prevention part 75. Therefore, the phenomenon in which sludge flows between the porosity chuck body 73 and the wafer W can be prevented, so that a defective wafer can be mass-produced or the pores 73a of the porosity chuck body 73 are blocked. .

On the other hand, as described above, even if the porosity chuck body 73 in which the pores 73a are formed and the sludge inflow prevention portion 75 in which no pores (not shown) are formed are separated from each other, sludge is produced. Phenomenon that flows between the porous chuck body 73 and the wafer W can be prevented.

However, in addition to the above structure, when the air injection hole 72 is further provided in the table body 71, it may be more advantageous to prevent the sludge from flowing between the porosity chuck body 73 and the wafer W. .

That is, as shown in Figure 5, after the air injection hole 72 is provided in the table body 71 at the position corresponding to the edge (edge) region of the wafer (W), the polishing operation of Figure 5 (b) When the air is injected in the direction, the sludge is more difficult to flow between the porosity chuck body 73 and the wafer (W) due to the air injected.

For reference, in this embodiment, the porosity chuck body 73 in which the pores 73a are formed, and the sludge inflow prevention part 75 in which the pores (not shown) are not formed are separated from each other, and the air spray hole 72 is formed. Is applied together. However, since the scope of the present invention is not limited thereto, the porosity chuck body 73 in which the pores 73a are formed, and the sludge inflow prevention part 75 in which the pores (not shown) are not formed are separated from each other. , The air injection hole 72 may be applied to each individually.

6 is a configuration diagram of main parts of a wafer polishing apparatus according to a fifth embodiment of the present invention.

Referring to FIG. 1, in the present embodiment, a cleaning unit 80 is further provided to clean the surface of the wafer W during the first roughing, the second roughing, the finishing, and the polishing process, and then move to the next step. Doing.

The cleaning unit 80 serves to remove foreign matter that may remain on the wafer W after finishing the polishing process and proceeding to the next polishing process. Therefore, the cleaning unit 80 may be provided in at least one region among the waiting table 21, the roughing table 31, the buffer table 51, the finishing table 51, and the polishing table 61.

As shown in FIG. 6, the cleaning unit 80 is formed on the cleaning body portion 81 disposed on the upper region of the wafer W and the cleaning body portion 81 to clean the polishing surface of the wafer W. As shown in FIG. And a sprayer 82 for spraying the cleaning material toward. In this case, the cleaning material injected through the injection unit 82 may be any one selected from water and air.

For reference, since the wafer W has a disc shape, it may be preferable that the cleaning material injected through the injection unit 82 is also sprayed on all the regions of the disc wafer. Therefore, although not shown in detail, it will be preferable that the cleaning unit 80 also has the same disk shape as the wafer W. FIG.

However, the scope of the present invention is not limited thereto. For example, the spraying unit 82 of the cleaning unit 80 may be disposed in a rod shape between the chuck tables, and the cleaning material sprayed through the spraying unit 82 may be sprayed in an air curtain manner. Even with such a structure, the wafer W can be cleaned while passing through the injection portion 82.

In addition, briefly referring to the installation position of the cleaning unit 80, the cleaning unit 80 has to spray the cleaning material downward from the top of the wafer (W). Therefore, the cleaning unit 80 is the waiting table 21, the roughing table 31, the finishing table 51 and the range that does not interfere with the roughing wheel 32, the finishing wheel 52 and the polisher 62, and It would be desirable to be provided between the polishing tables 61. In addition, if the cleaning unit 80 is to be approached and spaced apart from the wafer W in order to increase the cleaning efficiency, it may provide a better cleaning effect.

As described above, the present invention is not limited to the described embodiments, and various modifications and changes can be made without departing from the spirit and scope of the present invention, which will be apparent to those skilled in the art. Therefore, such modifications or variations will have to be belong to the claims of the present invention.

1 is a block diagram of a wafer polishing apparatus according to a first embodiment of the present invention.

2 is a schematic longitudinal cross-sectional view of FIG. 1.

3 is a block diagram of a wafer polishing apparatus according to a second embodiment of the present invention.

4 is a block diagram of a wafer polishing apparatus according to a third embodiment of the present invention.

5 is a configuration diagram of main parts of a wafer polishing apparatus according to a fourth embodiment of the present invention.

6 is a configuration diagram of main parts of a wafer polishing apparatus according to a fifth embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

10: turntable 12: table axis

14 cross roller bearing 15 wafer cassette for supply

16: storage wafer cassette 17: transfer machine

21: waiting table 30: rough grinding

31: roughing table 32: roughing wheel

40: buffer polishing unit 41: buffer table

42: buffer wheel 50: finishing polishing unit

51: finishing table 52: finishing wheel

60: polishing polishing portion 61: polishing table

62: polisher 71: table body

73: poros chuck body 75: sludge inflow prevention

80: cleaning unit

Claims (12)

Rotatable turntables; A roughing polishing unit having a roughing table provided on one side of the turntable to adsorb a wafer, and a roughing wheel provided on the roughing table to perform a rough grinding process on the wafer; A finishing table provided on the turntable in the circumferential direction behind the roughing table and adsorbing the wafer; and a finishing table provided above the finishing table to perform a fine grinding process on the wafer where the roughing process is completed. Finishing polishing unit having a wheel; A polishing table provided on the turntable in a circumferential direction behind the finishing table to adsorb the wafer, and a polisher provided on the polishing table to perform a polishing process on the wafer where the finishing process is completed. Polishing polishing unit having a; And And a buffer polishing unit disposed around the rough polishing unit and the finishing polishing unit to further perform at least one process selected from the roughing process and the finishing process. The method of claim 1, The buffer grinding unit, A buffer table provided on the turntable; And And a buffer wheel provided on an upper portion of the buffer table. The method of claim 2, At least one buffer table is provided in at least one region selected from an area between the roughing table and the finishing table and an area between the finishing table and the polishing table in the circumferential direction of the turntable. Wafer polishing apparatus. The method of claim 3, And the buffer polishing unit is a secondary rough polishing unit provided between the rough polishing unit and the finishing polishing unit along the circumferential direction of the turntable. The method of claim 2, A standby table provided on one side of the turntable to wait for the wafer; And the waiting table, the roughing table, the finishing table, the polishing table and the buffer table are chuck tables for vacuum suction of the wafers arranged at equal intervals along the circumferential direction of the table. The method of claim 1, It further comprises a table axis for forming the axis of rotation of the turntable, And a cross roller bearing coupled to the table shaft. The method of claim 6, And the cross roller bearings are arranged in at least two stages at different positions on the table axis. The method of claim 2, The roughing table, the buffer table, the finishing table and the polishing table, respectively, Table body formed with a vacuum line; Porous chuck body having a plurality of pores in communication with the vacuum line, is provided on the table body; And And a sludge inflow preventing portion which is adjacent to the porosity chuck body in a state separated from the porosity chuck body to prevent sludge from flowing between the porosity chuck body and the wafer. The method of claim 8, The sludge inflow prevention portion is a sludge inflow prevention ring is not formed pores, The porosity chuck body supports the deposition section of the wafer from the bottom, the sludge inflow prevention portion supports the non-deposition section of the wafer from the bottom, And the porosity chuck body has an area smaller than an upper surface of the table body. The method of claim 8, The sludge inflow prevention unit is a wafer polishing device, characterized in that the air injection hole formed in the table body to inject air for preventing sludge inflow to the edge (edge) area of the wafer. The method of claim 2, And a cleaning unit provided in at least one region among the roughing table, the buffer table, the finishing table and the polishing table to clean the wafer passing through the region. The method of claim 11, The cleaning unit, A cleaning body disposed in an upper region of the wafer; And And an injection unit formed in the cleaning body to spray any one cleaning material selected from water and air toward the polishing surface of the wafer.

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