JP2005131772A - Polishing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polishing device capable of improving throughput by efficiently processing and carrying a polishing object. <P>SOLUTION: This polishing device has a plurality of polishing units 30-1 and 30-2 having respectively a plurality of polishing tables 60A and 60B having a polishing surface, and a plurality of top rings 61-1 to 61-3 for pressing the polishing object W to the polishing surface by moving between the plurality of polishing tables 60A and 60B while holding the polishing object W. The plurality of top rings 61-1 to 61-3 are respectively installed on a plurality of arms 16 arranged at an equal angle in the circumferential direction in a rotatable support part 14-1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a polishing apparatus for polishing a surface of an object to be polished such as a semiconductor wafer into a flat and mirror surface.

  In recent years, as semiconductor devices are highly integrated, circuit wiring is becoming finer and the distance between wirings is becoming narrower. In particular, in the case of photolithography having a line width of 0.5 μm or less, the depth of focus becomes shallow, so that the flatness of the imaging surface of the stepper is required. As one means for flattening the surface of such a semiconductor wafer, a polishing apparatus that performs chemical mechanical polishing (CMP) is known.

  This type of polishing apparatus includes a polishing table having a polishing pad such as a polishing cloth on the upper surface and a top ring. Then, the polishing object (wafer) is interposed between the polishing table and the top ring, and the polishing object (slurry) is supplied to the surface of the polishing pad, and the polishing object is pressed against the polishing table by the top ring. The surface of the object to be polished is polished flat and mirror-like.

  A polishing apparatus having four polishing tables is known as an example of a polishing apparatus that can increase the throughput (processing ability of an object to be polished per unit time). In this type of polishing apparatus, two of the four polishing tables are set as one set, and these are used as the first polishing table and the second polishing table. In addition, high throughput is realized by having two sets of these polishing tables.

  As another example of a polishing apparatus capable of improving throughput, a polishing apparatus having a carousel mechanism having four top rings fixed to a support shaft with respect to three polishing tables is known. In this type of polishing apparatus, each top ring is sequentially moved to the first polishing table, the second polishing table, and the third polishing table by rotating the support shaft by 90 °. As a result, high-throughput is realized by performing three-step polishing with the wafer held on one top ring.

  In the first conventional example described above, high throughput is achieved by providing four polishing tables. However, between the primary polishing at the first polishing table and the secondary polishing at the second polishing table, the wafer is detached from the top ring, the wafer is moved between the polishing tables, the wafer is held by the top ring, etc. The various processes were entered, and this caused a decrease in throughput.

  On the other hand, in the second conventional example described above, since three-step polishing is performed, wafer movement between the polishing tables occurs twice, resulting in a decrease in throughput. Furthermore, since there is only one carousel mechanism, the throughput could not be improved beyond a certain level.

  The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide a polishing apparatus that can efficiently process and convey an object to be polished to improve throughput.

In order to achieve the above-described object, according to one embodiment of the present invention, a polishing table having a polishing surface and a polishing object are moved to the polishing surface by moving between the plurality of polishing tables while holding the polishing object. A plurality of polishing units each having a plurality of top rings that press against the plurality of top rings, and the plurality of top rings are respectively provided on a plurality of arms provided at equal angles along a circumferential direction on a rotatable support portion. A polishing apparatus characterized by being attached.
A preferable aspect of the present invention includes a linear motion transport mechanism that transports a polishing object between a plurality of transport positions including a delivery position of the polishing object, and transport of the linear motion transport mechanism as the polishing object delivery position. A delivery mechanism for delivering an object to be polished between the linear motion transport mechanism and the top ring is provided at a position.
In a preferred aspect of the present invention, at least two of the support portions are arranged.
In a preferred aspect of the present invention, each of the plurality of polishing units performs a plurality of stages of polishing using the plurality of polishing tables.
In a preferred aspect of the present invention, a plurality of stages of polishing are performed by sequentially transferring wafers to the plurality of polishing tables of each of the polishing units.
The preferable aspect of this invention is further equipped with the washing | cleaning part which wash | cleans a grinding | polishing target object, The said washing | cleaning part has a temporary placing stand on which a grinding | polishing target object is mounted.
A preferable aspect of the present invention further includes a cleaning unit that cleans an object to be polished, and the cleaning unit includes a dryer that dries the object to be polished, a temporary table on which the object to be polished before cleaning is placed, and a drying unit. And a temporary table on which a subsequent polishing object is placed.
In a preferred aspect of the present invention, the linear motion transport mechanism includes a plurality of transport stages for transporting an object to be polished.

  According to the present invention, by using a plurality of polishing units each having a plurality of polishing tables and a plurality of top rings, a plurality of stages of polishing processes can be performed in parallel and in series on a plurality of objects to be polished. it can. Accordingly, it is possible to efficiently carry and polish the object to be polished between a plurality of polishing tables, and it is possible to improve the throughput (number of processed sheets per unit time) as compared with the conventional polishing apparatus.

Hereinafter, a polishing apparatus according to a first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view showing a polishing apparatus according to a first embodiment of the present invention.
As shown in FIG. 1, the polishing apparatus according to this embodiment includes a substantially rectangular housing 1, and the interior of the housing 1 includes a load / unload portion 2, a polishing portion 3, and partitions 1 a, 1 b, and 1 c. It is partitioned into a cleaning unit 4. The load / unload unit 2, the polishing unit 3, and the cleaning unit 4 are assembled independently and exhausted independently.

  The load / unload unit 2 includes two or more (three in this embodiment) front load units 20 on which wafer cassettes for stocking a plurality of wafers (substrates) are placed. These front load portions 20 are arranged adjacent to each other in the width direction (direction perpendicular to the longitudinal direction) of the polishing apparatus. The front load unit 20 can be equipped with an open cassette, a SMIF (Standard Manufacturing Interface) pod, or a FOUP (Front Opening Unified Pod). Here, SMIF and FOUP are sealed containers that can maintain an environment independent of the external space by accommodating a wafer cassette inside and covering with a partition wall.

  In addition, a traveling mechanism 21 is laid along the arrangement direction of the front load unit 20 in the load / unload unit 2, and the traveling mechanism 21 is movable on the traveling mechanism 21 along the arrangement direction of the front load unit 20. One transfer robot 22 is installed. The first transfer robot 22 can access the wafer cassette mounted on the front load unit 20 by moving on the traveling mechanism 21. The first transfer robot 22 has two hands on the upper and lower sides. For example, the upper hand is used when returning the wafer to the wafer cassette, and the lower hand is used when transferring the unpolished wafer. The upper and lower hands can be used properly.

  Since the load / unload unit 2 is an area where the cleanest state needs to be maintained, the inside of the load / unload unit 2 is always at a higher pressure than any of the outside of the apparatus, the polishing unit 3 and the cleaning unit 4. Maintained. In addition, a filter fan unit (not shown) having a clean air filter such as a HEPA filter or a ULPA filter is provided above the traveling mechanism 21 of the first transfer robot 22. Clean air from which steam and gas have been removed is constantly blowing downward.

  The polishing unit 3 is a region where polishing of a semiconductor wafer, which is an object to be polished, is made up of a first polishing unit 30-1 and a second polishing unit 30-2. As shown in FIG. 1, the first polishing unit 30-1 and the second polishing unit 30-2 are arranged along the longitudinal direction of the polishing apparatus.

  The first polishing unit 30-1 polishes a plurality of (two in this embodiment) polishing tables 60A and 60B having a polishing surface, and holds the wafer and presses the wafer against the polishing tables 60A and 60B. A plurality of (three in this embodiment) top rings 61-1, 61-2, 61-3, and polishing liquid supply nozzles 62A, 62B for supplying the polishing liquid onto the polishing tables 60A, 60B, respectively. And dressers 63A and 63B for dressing the polishing table 60A.

  A rotatable support portion 14-1 is erected on the side of the polishing tables 60A and 60B. In the support portion 14-1, three arms 16 are provided radially at equal angles along the circumferential direction, that is, at an angle of 120 ° to each other. The above-mentioned three top rings 61-1, 61-2, 61-3 are fixed to the free ends of these arms 16, respectively. The support portion 14-1 is configured to perform an intermittent rotation operation that repeats rotation and stop, and temporarily stops after rotating 120 ° in accordance with the angle 120 ° between the arms 16. .

  The support portion 14-1, the arm 16, and the top rings 61-1, 61-2, 61-3 are moved in the vertical direction by a vertical movement mechanism (not shown), and the top rings 61-1, 61-2, 61-3 are moved. Is lowered so that the top rings 61-1, 61-2, 61-3 are pressed against the polishing surfaces of the polishing tables 60A, 60B. These top rings 61-1, 61-2, 61-3 are each rotationally driven independently by a driving source (not shown).

  Each of the top rings 61-1, 61-2, 61-3 includes a plurality of communication holes (not shown) opened at the lower portions thereof, and these communication holes are connected to a pressure generation source (not shown). ing. Then, by forming a negative pressure in the communication hole, the wafer (polishing object) is adsorbed and held under the top rings 61-1, 61-2, 61-3. Further, after the wafer is adsorbed, clean air such as clean air or nitrogen gas is supplied to the upper surface of the wafer from the communication hole, so that the wafer is pressed against the polishing surfaces of the polishing tables 60A and 60B. ing. Further, the wafer can be detached from the top rings 61-1, 61-2, 61-3 by blowing clean gas onto the wafer from the communication hole. In this case, it is possible to increase the force for removing the wafer by mixing pure water or the like with clean gas, and to reliably remove the wafer.

  The polishing tables 60A and 60B are disposed adjacent to each other, and the support portion 14-1 is disposed at a position where the distances from the polishing tables 60A and 60B are equal to each other. When the top rings 61-1, 61-2, 61-3 are intermittently rotated around the support portion 14-1 at intervals of 120 °, of the three top rings 61-1, 61-2, 61-3 The two are always positioned above the polishing tables 60A and 60B. In this way, a plurality of (three) top rings 61-1, 61-2, 61-3 are attached to one support portion 14-1, and these top rings 61-1, 61-2, 61-3 are attached. On the other hand, a plurality of (two) polishing tables 60A and 60B are arranged.

  A polishing pad (polishing cloth) or a grindstone or the like is affixed to the upper surfaces of the polishing tables 60A and 60B, and a polishing surface for polishing the wafer is constituted by the polishing pad or the grindstone. At the time of polishing, the polishing liquid is supplied to the polishing surfaces on the polishing tables 60A and 60B from the polishing liquid supply nozzles 62A and 62B, respectively, and the wafer that is the polishing target is the top ring 61-1 (or 61-2 or 61-3). ) Is pressed against the polishing surface for polishing. Note that a polishing belt may be used instead of the polishing table, or a combination of the polishing belt and the polishing table may be used.

  The dressers 63A and 63B are provided to recover the polishing performance of the polishing surfaces of the polishing tables 60A and 60B. Dressing members (not shown) in which diamond particles are electrodeposited are respectively attached to the lower surfaces of the dressers 63A and 63B, and the dressing of the polishing surfaces of the polishing tables 60A and 60B is performed by this dressing member. . As the dressing member, for example, a plurality of hard ceramic protrusions may be arranged. In this dressing process, the dresser 63A (or 63B) and the polishing table 60A (or 60B) are rotated while supplying a dressing liquid such as pure water to the polishing surface. Then, by pressing the dressing member against the polishing surface, the polishing liquid remaining on the polishing surface and the shavings of the object to be polished are removed, the polishing surface is flattened and sharpened, and the polishing surface is regenerated. This dressing is also called conditioning.

  Similar to the first polishing unit 30-1, the second polishing unit 30-2 includes polishing tables 60C, 60D, top rings 61-4, 61-5, 61-6, and polishing liquid supply nozzles 62C, 62D. , And dressers 63C and 63D. The support portion 14-2, the arm 16, and the top rings 61-4, 61-5, 61-6 of the second polishing unit 30-2 have the same configuration as that of the first polishing unit 30-1. Therefore, the overlapping description is omitted.

  Between the first polishing unit 30-1 and the cleaning unit 4, there are three transfer positions along the arrangement direction of the polishing tables 60A and 60B (the first transfer position TP1 and the first transfer position in order from the load / unload unit 2 side). The first linear transporter 5 is disposed as a linear motion transfer mechanism for transferring a wafer between the second transfer position TP2 and the third transfer position TP3. The first linear transporter 5 includes three transfer stages TS1, TS2, and TS3 that can linearly reciprocate along the direction in which the polishing tables 60A and 60B are arranged. It has become. That is, the first transfer stage TS1 and the second transfer stage TS2 are arranged in the lower stage, and the third transfer stage TS3 is arranged in the upper stage.

  Above the first transfer position TP1 (first transfer stage TS1), a reversing machine 31 for inverting the wafer received from the first transfer robot 22 of the load / unload unit 2 is arranged, and below that is an upper and lower side. A lifter 32 that can be moved up and down is disposed. Further, a pusher (delivery mechanism) 33 that can be moved up and down below the second transfer position TP2 (second transfer stage TS2), and an up and down push below the third transfer position TP3 (third transfer stage TS3). Possible lifters 35 are respectively arranged. The positions of the lifter 32, the pusher 33, and the lifter 35 shown in FIG. 1 correspond to the first transport position TP1, the second transport position TP2, and the third transport position TP3, respectively.

  The lower transfer stages TS1 and TS2 and the upper transfer stage TS3 move on the same axis on the plan view of FIG. 1, but are installed at different heights. Therefore, the lower transfer stages TS1 and TS2 The upper transfer stage TS3 can freely move along the arrangement direction of the polishing tables 60A and 60B without interfering with each other. The first transfer stage TS1 and the second transfer stage TS2 are connected to each other by a shaft (not shown). The first transfer stage TS1 and the second transfer stage TS2 are integrated with the second transfer stage TS2 and simultaneously reciprocate linearly. Yes.

  In such a configuration, the first transport stage TS1 includes a first transport position TP1 where the reversing device 31 and the lifter 32 are disposed, and a second transport position TP2 where the pusher 33 is disposed (which is a wafer transfer position). The wafer is transported between. The second transfer stage TS2 transfers the wafer between the second transfer position TP2 (which is a wafer transfer position) and the third transfer position TP3 where the lifter 35 is disposed. The third transfer stage TS3 transfers the wafer between the first transfer position TP1 and the third transfer position TP3.

  Four pins (not shown) are fixed to each transfer stage TS1, TS2, TS3, and the outer peripheral edge of the wafer placed on the transfer stages TS1, TS2, TS3 is guided by these pins. The wafer is placed on the transfer stages TS1, TS2, TS3 in the positioned state. These pins are formed from a resin such as polychlorotrifluoroethylene (PCTFE) or polyetheretherketone (PEEK). Each transfer stage TS1, TS2, TS3 is provided with a sensor (not shown) for detecting the presence or absence of a wafer by a transmission type sensor or the like, and the wafer on each transfer stage TS1, TS2, TS3 by this sensor. The presence or absence of can be detected.

  The second polishing unit 30-2 is adjacent to the first linear transporter 5 and has three transfer positions along the arrangement direction of the polishing tables 60C and 60D (fourth transfer in order from the load / unload unit 2 side). A second linear transporter 6 is disposed as a linear motion transfer mechanism for transferring the wafer between the position TP4, the fifth transfer position TP5, and the sixth transfer position TP6. The second linear transporter 6 includes a fourth transfer stage TS4 and a fifth transfer stage TS5 that are linearly reciprocable along the arrangement direction of the polishing tables 60C and 60D. The transfer stages TS4 and TS5 are vertically moved. It has a two-stage configuration. That is, the fourth transfer stage TS4 is arranged on the upper stage, and the fifth transfer stage TS5 is arranged on the lower stage.

  Below the fourth transport position TP4 (fourth transport stage TS4), a lifter 36 that can be moved up and down is disposed, and below the fifth transport position TP5, a pusher (delivery mechanism) 37 that can be moved up and down is disposed. Yes. The upper fourth transport stage TS4 and the lower fifth transport stage TS5 move on the same axis on the plan view of FIG. 1, but are installed at different heights. The lower fifth transfer stage TS5 can freely move along the arrangement direction of the polishing tables 60C and 60D without interfering with each other. The positions of the lifter 36, the pusher 37, and the fifth transport stage TS5 shown in FIG. 1 correspond to the fourth transport position TP4, the fifth transport position TP5, and the sixth transport position TP6, respectively.

  In such a configuration, the fourth transport stage TS4 moves the wafer between the fourth transport position TP4 where the lifter 36 is disposed and the fifth transport position TP5 where the pusher 37 is disposed (wafer delivery position). Transport. The fifth transfer stage TS5 transfers the wafer between the fifth transfer position TP5 where the pusher 37 is disposed and the fourth transfer position TP4.

  Four pins (not shown) are fixed to each transfer stage TS5, TS6, and the outer peripheral edge of the wafer placed on the transfer stages TS5, TS6 is guided and positioned by these pins. Thus, the wafer is placed on the transfer stages TS5 and TS6. These pins are formed from a resin such as polychlorotrifluoroethylene (PCTFE) or polyetheretherketone (PEEK). Further, on each transfer stage TS5, TS6, a sensor (not shown) for detecting the presence / absence of a wafer is configured by a transmission type sensor or the like, and the presence / absence of a wafer on each transfer stage TS5, TS6 is detected by this sensor. It can be detected.

  The polishing portion 3 where the polishing liquid (slurry) is used is the most dirty (dirty) region. Therefore, in this embodiment, exhaust is performed from around each of the polishing tables 60A to 60D so that the particles in the polishing unit 3 are not scattered outside. As a result, the pressure inside the polishing unit 3 becomes lower than the pressure inside the polishing apparatus, inside the cleaning unit 4 and inside the load / unload unit 2, and particle scattering can be prevented. Further, an exhaust duct (not shown) is provided below the polishing tables 60A to 60D, and a filter (not shown) is provided above, and clean air is jetted through these exhaust duct and filter, A downflow is formed.

  The cleaning unit 4 is an area for cleaning the semiconductor wafer after polishing, and includes a second transfer robot 40, a reversing machine 41 for inverting the wafer received from the second transfer robot 40, and a cleaning for cleaning the polished semiconductor wafer. Machines 42 to 45, a temporary placement table (unload buffer stage) 46 on which the cleaned wafer is temporarily placed, and a transfer unit 50 that transfers the wafer between the reversing machine 41 and the cleaning machines 42 to 45. It has. The second transfer robot 40, the reversing machine 41, the washing machines 42 to 45, and the temporary placement table 46 are arranged in series along the longitudinal direction of the polishing apparatus. In addition, a filter fan unit (not shown) having a clean air filter is provided above the washing machines 42 to 45, and clean air from which particles have been removed by this filter fan unit is always directed downward. Is blowing. Further, the inside of the cleaning unit 4 is constantly maintained at a pressure higher than that of the polishing unit 3 in order to prevent inflow of particles from the polishing unit 3. A temporary placement table for temporarily placing the wafer before cleaning may be further provided between the reversing machine 41 and the first cleaning machine 42.

  As the primary cleaning machine 42, the secondary cleaning machine 43, and the tertiary cleaning machine 44, for example, the front and back surfaces of the wafer are pressed by pressing the upper and lower roll sponges against the front and back surfaces of the wafer while rotating them. A roll type washing machine for washing can be used. As the tertiary cleaning machine 44, for example, a pencil-type cleaning machine that presses and cleans the wafer while rotating a hemispherical sponge may be used. As the quaternary cleaning machine 45, for example, a pencil-type cleaning machine that rinses and cleans the back surface of the wafer and presses and rotates the hemispherical sponge on the wafer surface can be used. The quaternary cleaning machine 45 has a function (spin dry function) of drying the wafer after cleaning by rotating the chucked wafer at a high speed, and also functions as a dryer. In addition, in each of the cleaning machines 42 to 45, in addition to the roll type cleaning machine and the pencil type cleaning machine described above, a megasonic type cleaning machine that performs cleaning by applying ultrasonic waves to the cleaning liquid may be additionally provided. .

  The transfer unit 50 has a plurality of chucking units (not shown) for holding wafers, and these chucking units move along the direction in which the cleaning machines 42 to 45 and the temporary placement table 46 are arranged. It is configured to be possible. In the present embodiment, the reversing machine 41 to the primary cleaning machine 42, the primary cleaning machine 42 to the secondary cleaning machine 43, the secondary cleaning machine 43 to the tertiary cleaning machine 44, and the tertiary cleaning machines 44 to 4. The wafers are configured to be transferred to the next cleaning machine 45 from the fourth cleaning machine 45 to the temporary placement table 46 at the same time. Further, the wafer can be transferred to the next cleaning machine inside the cleaning machine without taking out the wafer to the outside of the cleaning machine, and the wafer transfer time can be shortened.

Next, processing for polishing a wafer using the polishing apparatus having such a configuration will be described.
When serially processing a wafer, the wafer is transferred from the wafer cassette of the front load unit 20 → the first transfer robot 22 → the reversing device 31 → the lifter 32 → the first transfer stage TS1 → the pusher 33 → the top ring 61-1 (or 61). -2 or 61-3) → Polishing table 60A → Polishing table 60B → Pusher 33 → Second transport stage TS2 → Lifter 35 → Second transport robot 40 → Lifter 36 → Fourth transport stage TS4 → Pusher 37 → Top ring 61 -4 (or 61-5, or 61-6)-> polishing table 60C-> polishing table 60D-> pusher 37-> fifth transfer stage TS5-> lifter 36-> second transfer robot 40-> reversing machine 41-> primary cleaning machine 42-> Secondary cleaning machine 43 → tertiary cleaning machine 44 → quaternary cleaning machine 45 → temporary table 46 → first transfer robot 22 → It carried in the path of the wafer cassette of Ntorodo portion 20.

The serial processing described above will be described in more detail with reference to FIGS. 2 to 7, the top ring is not shown for easy understanding of the wafer flow.
First, the first transfer robot 22 takes out the wafer A from the wafer cassette on the front load unit 20 and transfers the wafer A to the reversing machine 31. The reversing machine 31 reverses the wafer A after chucking the wafer A. Then, the lifter 32 moves up to the height of the reversing machine 31 and the arm of the reversing machine 31 is opened, so that the wafer A is placed on the lifter 32. When the lifter 32 is lowered as it is, the wafer A is placed on the first transfer stage TS1 of the first linear transporter 5 (see FIG. 2A).

  Even after the wafer A is placed on the first transfer stage TS1 of the first linear transporter 5, the lifter 32 continues to descend to a position where it does not interfere with each other even if the first transfer stage TS1 moves. When the lifter 32 completes lowering, the lower transfer stages TS1 and TS2 move to the third transfer position TP3, and the upper transfer stage TS3 moves to the first transfer position TP1. As a result, the wafer A on the first transfer stage TS1 is moved to the wafer transfer position (second transfer position TP2) of the top ring 61-1 (see FIG. 2B).

  Here, the pusher 33 arranged at the second transfer position TP2 is raised, and the wafer A is delivered to the top ring 61-1. Wafer A is sucked and held at the bottom of top ring 61-1, and wafer A is transferred to polishing table 60A by rotating support portion 14-1 by 120 °. The wafer A held on the top ring 61-1 is primarily polished by a polishing surface made of a polishing pad or a grindstone attached on the polishing table 60A. Thereafter, the lower transfer stages TS1, TS2 move to the first transfer position TP1, and the upper transfer stage TS3 moves to the third transfer position TP3. With the polished wafer A held by the top ring 60-1, the next wafer B is placed on the first transfer stage TS1 in the same manner as described above (FIG. 2C).

  The transfer stages TS1, TS2 move to the third transfer position TP3 side, and the wafer B is moved to the wafer transfer position (second transfer position TP2) of the top ring 61-2. At the same time, the transport stage TS3 moves to the first transport position TP1 (FIG. 3 (a)). After the wafer B is held on the top ring 61-2, the support portion 14-1 is rotated by 120 °, whereby the wafer A is moved to the polishing table 60B and the wafer B is moved to the polishing table 60A (FIG. 3 ( b)). Then, the secondary polishing of the wafer A is performed on the polishing table 60B, and at the same time, the primary polishing of the wafer B is performed on the polishing table 60A. Thereafter, the lower transfer stages TS1, TS2 move to the first transfer position TP1, and the upper transfer stage TS3 moves to the third transfer position TP3. After the polishing of the wafers A and B is completed, the next wafer C is placed on the first transfer stage TS1.

  The transfer stages TS1, TS2 move to the third transfer position TP3 side, and the wafer C is moved to the wafer transfer position (second transfer position TP2) of the top ring 61-3. At this time, the transfer stage TS3 moves to the first transfer position TP1 (FIG. 3C). After the wafer C is held by the top ring 61-3, the support portion 14-1 is rotated by 120 °, whereby the wafer A is polished to the second transfer position TP2, the wafer B is polished to the polishing table 60B, and the wafer C is polished. It is moved to the table 60A (FIG. 4 (a)). Then, the secondary polishing of the wafer B is performed on the polishing table 60B, and at the same time, the primary polishing of the wafer C is performed on the polishing table 60A. Thereafter, the lower transfer stages TS1, TS2 move to the first transfer position TP1, and the upper transfer stage TS3 moves to the third transfer position TP3. After the polishing of the wafers B and C is completed, the next wafer D is placed on the first transfer stage TS1.

  At this time, the pusher 33 rises and the wafer A is transferred from the top ring 61-1 to the pusher 33. When the pusher 33 is lowered as it is, the wafer A is placed on the second transfer stage TS2 (FIG. 4A). The second transfer stage TS2 moves to the third transfer position TP3 side together with the first transfer stage TS1, the wafer A on the second transfer stage TS2 is at the third transfer position TP3, and the wafer D on the first transfer stage TS1 is the second transfer position TS1. 2 is moved to the transport position TP2 (FIG. 4B). The wafer A is lifted upward by the lifter 35 disposed at the third transfer position TP3. At this time, the wafer D is sucked and held by the top ring 61-1, and is polished as described above.

  The wafer A is transferred from the lifter 35 at the third transfer position TP3 of the first linear transporter 5 to the lifter 36 at the fourth transfer position TP4 of the second linear transporter 6 by the second transfer robot 40. When the lifter 36 is lowered, the wafer A is placed on the fourth transfer stage TS4 (FIG. 5 (a)), and then the upper fourth transfer stage TS4 is positioned at the wafer transfer position where the top ring 61-4 is located ( It is moved to the fifth transport position TP5) (FIG. 5B). Here, the pusher 37 disposed at the fifth transfer position TP5 is raised, and the wafer A is sucked and held on the top ring 61-4. The support portion 14-2 rotates 120 °, whereby the wafer A is transferred to the polishing table 60C (FIG. 5C). Then, the wafer A held on the top ring 61-4 is tertiary polished by the polishing table 60C. Thereafter, the fourth transfer stage TS4 moves to the fourth transfer position TP4. After the third polishing of the wafer A is completed, the wafer B is placed on the fourth transfer stage TS4 via the second transfer robot 40 and the lifters 35 and 36 in the same manner as described above.

  The wafer B on the fourth transfer stage TS4 is moved to the fifth transfer position TP5 and held on the top ring 61-5 (FIG. 6A). With the top rings 61-4 and 61-5 holding the wafers A and B, the support portion 14-2 rotates 120 °, whereby the wafers A and B are transferred to the polishing tables 60C and 60D, respectively (see FIG. 6 (b)). Then, the fourth polishing of the wafer A is performed by the polishing table 60D, and the third polishing of the wafer B is performed by the polishing table 60C. Thereafter, the fourth transfer stage TS4 is moved to the fourth transfer position TP4. After the polishing of the wafers A and B is completed, the wafer C is transferred onto the fourth transfer stage TS4 in the same manner as described above.

  The wafer C is moved to the fifth transfer position TP5 together with the fourth transfer stage TS4 and is held on the top ring 61-6 (FIG. 6C). With the top rings 61-4, 61-5, and 61-6 holding the wafers A, B, and C, the support portion 14-2 is rotated by 120 °, whereby the wafer A is moved to the fifth transfer position TP5. B is transferred to the polishing table 60D, and the wafer C is transferred to the polishing table 60C (FIG. 7A). Then, the fourth polishing of the wafer B is performed by the polishing table 60D, and the third polishing of the wafer C is performed by the polishing table 60C. Thereafter, the upper fourth transport stage TS4 is moved to the fourth transport position TP4, and the lower fifth transport stage TS5 is moved to the fifth transport position TP5. After the polishing of the wafers B and C is completed, the wafer D is transferred onto the fourth transfer stage TS4 in the same manner as described above. At this time, the pusher 37 rises and the wafer A is transferred from the top ring 61-4 to the pusher 37. When the pusher 37 is lowered as it is, the wafer A is placed on the fifth transfer stage TS5. The wafer A on the fifth transfer stage TS5 moves to the fourth transfer position TP4, and at the same time, the wafer D on the fourth transfer stage TS4 moves to the fifth transfer position TP5 (FIG. 7B). Then, the wafer A on the fifth transfer stage TS5 is lifted upward by the lifter 36 and transferred to the reversing machine 41 by the second transfer robot 40. Thereafter, the fifth transfer stage TS5 moves to the fifth transfer position TP5 and receives the wafer B after the polishing process (FIG. 7C). At the same time, the fourth transfer stage TS4 moves to the fourth transfer position TP4, and the wafer E is transferred to the fourth transfer stage TS4. Thereafter, operations similar to those shown in FIGS. 7B and 7C are repeated. In this manner, a plurality of wafers are sequentially transferred in series to the polishing units 30-1 and 30-2, and four-step polishing using the polishing tables 60A and 60B and the polishing tables 60C and 60D is performed.

  The process after the reversing machine 41 will be described with reference to FIG. In FIG. 1, a reversing machine 41 chucks a polished wafer and reverses the wafer to change from face-down to face-up. The wafer is transferred by the transfer unit 50 in the order of the cleaning device 42, the cleaning device 43, the cleaning device 44, and the cleaning device 45, and a cleaning process and a drying process corresponding to the process are performed. The wafer subjected to the cleaning process and the drying process is transferred to a temporary table (unload buffer stage) 46 and returned to the wafer cassette of the front load unit 20 by the first transfer robot 22.

  Next, a case where the wafer is processed in parallel will be described. In the first polishing unit 30-1, the wafer is stored in the wafer cassette of the front load unit 20, the first transfer robot 22, the reversing machine 31, the lifter 32, the first transfer stage TS1, the pusher 33, the top ring 61-1, or the like. 61-2 or 61-3) → Polishing table 60A → Polishing table 60B → Pusher 33 → Second transport stage TS2 → Lifter 35 → Second transport robot 40 → Reversing machine 41 → Primary cleaning machine 42 → Secondary cleaning machine 43 → tertiary cleaning machine 44 → quaternary cleaning machine 45 → temporary placing table 46 → first transfer robot 22 → was transferred along the path of the wafer cassette of the front load unit 20.

  On the other hand, in the second polishing unit 30-2, the wafer is transferred from the wafer cassette of the front load unit 20 to the first transfer robot 22, the reversing device 31, the lifter 32, the third transfer stage TS3, the lifter 35, and the second transfer robot 40. → lifter 36 → fourth transfer stage TS4 → pusher 37 → top ring 61-4 (or 61-5 or 61-6) → polishing table 60C → polishing table 60D → pusher 37 → fifth transfer stage TS5 → lifter 36 → Second transfer robot 40 → reversing machine 41 → primary cleaning machine 42 → secondary cleaning machine 43 → third cleaning machine 44 → quaternary cleaning machine 45 → temporary placement table 46 → first transfer robot 22 → front load unit 20 It is conveyed by a route called a wafer cassette.

The parallel processing described above will be described in detail with reference to FIGS. 1 and 8A to 13B. In FIGS. 8A to 11B, the polishing units 30-1 and 30-2 are shown in parallel.
First, the first transfer robot 22 takes out the wafer A from the wafer cassette on the front load unit 20 and transfers the wafer A to the reversing machine 31. The reversing machine 31 reverses the wafer A after chucking the wafer A. Then, the lifter 32 moves up to the height of the reversing machine 31 and the arm of the reversing machine 31 is opened, so that the wafer A is placed on the lifter 32. When the lifter 32 is lowered as it is, the wafer A is placed on the first transfer stage TS1 of the first linear transporter 5 (FIG. 8A).

  When the lifter 32 completes lowering, the lower transfer stages TS1 and TS2 move to the third transfer position TP3, and the upper transfer stage TS3 moves to the first transfer position TP1. As a result, the wafer A on the first transfer stage TS1 is moved to the wafer transfer position (second transfer position TP2) of the top ring 61-1 (FIG. 8B). Here, the pusher 33 arranged at the second transfer position TP2 is raised, and the wafer A is delivered to the top ring 61-1. At this time, the next wafer B is placed on the third transfer stage TS3.

  The wafer A is sucked and held at the lower part of the top ring 61-1, and the wafer A is conveyed to the polishing table 60A by rotating the support portion 14-1 by 120 ° (FIG. 9A). Then, the wafer A held on the top ring 61-1 is primarily polished by the polishing table 60A. Thereafter, the lower transfer stages TS1, TS2 move to the first transfer position TP1, and the upper transfer stage TS3 moves to the third transfer position TP3. Here, the next wafer C is placed on the first transfer stage TS1. The lifter 35 disposed at the third transfer position TP3 is raised, and the wafer B is placed on the lifter 35. The wafer B on the lifter 35 is transferred to the lifter 36 of the second linear transporter 6 by the second transfer robot 40. Then, when the lifter 36 is lowered, the wafer B is placed on the fourth transfer stage TS4.

  The lower transfer stages TS1, TS2 move to the third transfer position TP3 side, and the wafer C is moved to the wafer transfer position (second transfer position TP2) of the top ring 61-2. At this time, the third transfer stage TS3 moves to the first transfer position TP1, and the next wafer D is placed on the third transfer stage TS3 (FIG. 9B). After the wafer C is held by the top ring 61-2, the support portion 14-1 is rotated by 120 °, whereby the wafer A is moved to the polishing table 60B and the wafer C is moved to the polishing table 60A (FIG. 10 ( a)). Then, secondary polishing of the wafer A is performed on the polishing table 60B, and at the same time, primary polishing of the wafer C is performed on the polishing table 60A. Thereafter, the lower transfer stages TS1 and TS2 move to the first transfer position TP1, the upper transfer stage TS3 moves to the third transfer position TP3, and the wafer D moves to the third transfer position TP3. After the polishing of the wafers A and C is completed, the next wafer E is placed on the first transfer stage TS1. On the other hand, in the second polishing unit 30-2, the fourth transfer stage TS4 moves to the delivery position (fifth transfer position TP5) of the top ring 61-4, whereby the wafer B has the first pusher 37 disposed thereon. 5 is moved to the transport position TP5. Here, the pusher 37 is raised and the wafer B is held by the top ring 61-4.

  The transfer stages TS1 and TS2 move to the third transfer position TP3 side, and the wafer E is moved to the wafer transfer position (second transfer position TP2) of the top ring 61-3 (FIG. 10B). At this time, the third transfer stage TS3 moves to the first transfer position TP1, and the next wafer F is placed on the third transfer stage TS3. At the same time, the fourth transfer stage TS4 moves to the fourth transfer position TP4, and the wafer D is transferred from the third transfer stage TS3 to the fourth transfer stage TS4 via the lifters 35 and 36 and the second transfer robot 40.

  After the wafer E is held by the top ring 61-3, the support portion 14-1 is rotated by 120 °, whereby the wafer A is polished to the second transfer position TP2, the wafer C is polished to the polishing table 60B, and the wafer E is polished. It is moved to the table 60A (FIG. 11 (a)). Then, the secondary polishing of the wafer C is performed on the polishing table 60B, and at the same time, the primary polishing of the wafer E is performed on the polishing table 60A. Thereafter, the lower transfer stages TS1, TS2 move to the first transfer position TP1, and the next wafer G is placed on the first transfer stage TS1. At the same time, the upper transfer stage TS3 moves to the third transfer position TP3, and the wafer F moves to the third transfer position TP3.

  Next, the pusher 33 at the second transfer position TP2 is raised, and the polished wafer A is transferred from the top ring 61-1 to the second transfer stage TS2. The pusher 33 is lowered as it is, so that the wafer A is placed on the second transfer stage TS2. On the other hand, in the second polishing unit 30-2, the fourth transfer stage TS4 moves together with the wafer D to the delivery position (fifth transfer position TP5) of the top ring 61-5. Thereafter, the pusher 37 is raised and the wafer D is held by the top ring 61-5.

  The transfer stages TS1 and TS2 move to the third transfer position TP3 side, the wafer A is moved to the third transfer position TP3, and the wafer G is moved to the wafer transfer position (second transfer position TP2) of the top ring 61-1. FIG. 11B). At this time, the third transfer stage TS3 moves to the first transfer position TP1, and the next wafer H is placed on the third transfer stage TS3. When the lifter 35 disposed at the third transfer position TP3 is raised, the wafer A is placed on the lifter 35, and the wafer A is transferred from the lifter 35 to the reversing machine 41 by the second transfer robot 40. On the other hand, in the second polishing unit 30-2, the wafer F is transferred from the third transfer stage TS3 to the fourth transfer stage TS4 via the lifters 35 and 36 and the second transfer robot 40. The steps after the reversing machine 41 are the same as those in the serial processing described above. Moreover, since the process similar to FIG.11 (a) and FIG.11 (b) is repeated after the process shown in FIG.11 (b) in the 1st grinding | polishing unit 30-1, the description is abbreviate | omitted.

  In the second polishing unit 30-2, after the wafer D is held by the top ring 61-5, the support portion 14-2 is rotated by 120 °, whereby the wafer B becomes the polishing table 60D and the wafer D becomes the polishing table. It is moved to 60C (FIG. 12 (a)). Then, the secondary polishing of the wafer B is performed by the polishing table 60D, and the primary polishing of the wafer D is performed by the polishing table 60C. Thereafter, the fourth transfer stage TS4 moves to the fifth transfer position TP5, whereby the wafer F is moved to the delivery position of the top ring 61-6. Then, the pusher 37 is raised and the wafer F is held by the top ring 61-6. Thereafter, the fourth transfer stage TS4 moves to the fourth transfer position TP4, and the wafer H is transferred from the third transfer stage TS3 to the fourth transfer stage TS4 via the lifters 35 and 36 and the second transfer robot 40 (FIG. 12 (b)).

  With the wafers B, D, and F being held by the top rings 61-4, 61-5, and 61-6, the support portion 14-2 is rotated by 120 °, whereby the wafer B is moved to the fifth transfer position TP5. The wafer D is moved to the polishing table 60D, and the wafer F is moved to the polishing table 60C. Then, the secondary polishing of the wafer D is performed by the polishing table 60D, and the primary polishing of the wafer F is performed by the polishing table 60C. Thereafter, the fifth transfer stage TS5 moves to the fifth transfer position TP5, and the wafer B is transferred from the top ring 61-4 to the fifth transfer stage TS5 via the pusher 37 (FIG. 13A).

  The fifth transfer stage TS5 moves to the fourth transfer position TP4, and at the same time, the fourth transfer stage TS4 moves to the fifth transfer position TP5. Thereby, the wafer B is moved to the fourth transfer position TP4, and the wafer H is moved to the delivery position (fifth transfer position TP5) of the top ring 61-4 (FIG. 13B). As the lifter 36 disposed at the fourth transfer position TP4 moves up, the wafer B on the fifth transfer stage TS5 is placed on the lifter 36. Then, the wafer B is transferred from the lifter 36 to the reversing machine 41 by the second transfer robot 40. The processes after the reversing machine 41 are the same as those in the serial processing described above. Thus, a plurality of wafers are sequentially transferred in parallel to the polishing units 30-1 and 30-2, and the polishing tables 60A and 60B and the polishing tables 60C and 60D are used in the respective polishing units 30-1 and 30-2. 2-step polishing is performed.

Next, a second embodiment of the present invention will be described with reference to FIG.
FIG. 14 is a plan view showing a polishing apparatus according to the second embodiment of the present invention. Note that the configuration of the second embodiment that is not particularly described is the same as that of the first embodiment, and therefore, redundant description thereof is omitted.

  As shown in FIG. 14, each of the first polishing unit 30-1 and the second polishing unit 30-2 includes four top rings 61-1 to 4 and 61-5 to 8. Since the first polishing unit 30-1 and the second polishing unit 30-2 have the same configuration, only the first polishing unit 30-1 will be described below. A rotatable support portion 14-1 is erected on the side of the polishing tables 60A and 60B. In the support portion 14-1, four arms 16 are provided radially at equal angles along the circumferential direction, that is, at an angle of 90 ° to each other. The above-described four top rings 61-1 to 6-4 are attached to the free ends of these arms 16, respectively. The support portion 14-1 is configured to perform an intermittent rotation operation that repeats rotation and stop, and temporarily stops after rotating 90 ° according to the angle 90 ° between the arms 16. .

  Between the first polishing unit 30-1 and the cleaning unit 4, there are four transfer positions along the arrangement direction of the polishing tables 60A and 60B (the first transfer position TP1 and the first transfer position in order from the load / unload unit 2 side). The first linear transporter 5 is disposed as a linear motion transfer mechanism for transferring a wafer between the second transfer position TP2, the third transfer position TP3, and the fourth transfer position TP4. The first linear transporter 5 includes three transfer stages TS1, TS2, and TS3 that can linearly reciprocate along the direction in which the polishing tables 60A and 60B are arranged. It has become. That is, the first transfer stage TS1 and the second transfer stage TS2 are arranged in the lower stage, and the third transfer stage TS3 is arranged in the upper stage. The first transport stage TS1 is integrated with the second transport stage TS2 to reciprocate linearly.

  Above the first transfer position TP1 (first transfer stage TS1), a reversing machine 31 for inverting the wafer received from the first transfer robot 22 of the load / unload unit 2 is arranged, and below that is an upper and lower side. A lifter 32 that can be moved up and down is disposed. Further, a pusher (delivery mechanism) 33 that can be moved up and down is provided below the second transfer position TP2, and a pusher (a transfer mechanism) that can be raised and lowered up and down below the third transfer position TP3 (second transfer stage TS2). 34 are respectively arranged below the fourth transfer position TP4 (third transfer stage TS3) and can be lifted up and down. The positions of the lifter 32, the pusher 33, the pusher 34, and the lifter 35 shown in FIG. 14 correspond to the first transport position TP1, the second transport position TP2, the third transport position TP3, and the fourth transport position TP4, respectively. Yes.

  In such a configuration, the first transport stage TS1 includes a first transport position TP1 where the reversing device 31 and the lifter 32 are disposed, and a second transport position TP2 where the pusher 33 is disposed (which is a wafer transfer position). The wafer is transported between. The second transfer stage TS2 transfers the wafer between the third transfer position TP3 (which is a wafer transfer position) and the fourth transfer position T43 where the lifter 35 is disposed. The third transfer stage TS3 transfers the wafer between the first transfer position TP1 and the fourth transfer position TP4.

  The second polishing unit 30-2 is adjacent to the first linear transporter 5 and has three transfer positions along the arrangement direction of the polishing tables 60C and 60D (the fifth transfer in order from the load / unload unit 2 side). A second linear transporter 6 is disposed as a linear motion transfer mechanism for transferring a wafer between position TP5, sixth transfer position TP6, and seventh transfer position TP7). The second linear transporter 6 includes a fourth transfer stage TS4 and a fifth transfer stage TS5 that are linearly reciprocable along the arrangement direction of the polishing tables 60C and 60D. The transfer stages TS4 and TS5 are vertically moved. It has a two-stage configuration. That is, the fourth transfer stage TS4 is arranged on the upper stage, and the fifth transfer stage TS5 is arranged on the lower stage.

  Below the fifth transfer position TP5 (fourth transfer stage TS4) is a lifter 36 that can be moved up and down, and below the fifth transfer position TP5 is a pusher (delivery mechanism) 37 that can be moved up and down. Pushers 38 are arranged below the position TP7 (fifth transfer stage TS5) if they can be moved up and down. The positions of the lifter 36, the pusher 37, and the pusher 38 shown in FIG. 14 correspond to the fifth transport position TP5, the sixth transport position TP6, and the seventh transport position TP7, respectively.

  In such a configuration, the fourth transport stage TS4 moves the wafer between the fifth transport position TP5 where the lifter 36 is disposed and the sixth transport position TP6 where the pusher 37 is disposed (which is a wafer transfer position). Transport. The fifth transfer stage TS5 transfers the wafer between the seventh transfer position TP7 and the fourth transfer position TP4 where the pusher 38 is disposed (which is a wafer transfer position).

  Also in this embodiment, a plurality of wafers are conveyed in series or in parallel to the polishing units 30-1 and 30-2, and a plurality of stages of polishing using the polishing tables 60A and 60B and the polishing tables 60C and 60D are performed. . As described above, also in the present embodiment, similar to the first embodiment, serial processing and parallel processing of the wafer are performed, and thereby high throughput is realized.

It is a top view which shows the whole structure of the polishing apparatus in the 1st Embodiment of this invention. FIGS. 2A to 2C are schematic diagrams for explaining the operations of the first linear transporter and the top ring when the wafers are processed in series. FIGS. 3A to 3C are schematic diagrams for explaining the operations of the first linear transporter and the top ring when the wafers are processed in series. FIGS. 4A and 4B are schematic diagrams for explaining the operation of the first linear transporter and the top ring when the wafers are processed in series. FIGS. 5A to 5C are schematic diagrams for explaining the operations of the second linear transporter and the top ring when the wafers are processed in series. FIGS. 6A to 6C are schematic diagrams for explaining the operations of the second linear transporter and the top ring when the wafers are processed in series. FIGS. 7A to 7C are schematic views for explaining the operations of the second linear transporter and the top ring when the wafers are processed in series. FIGS. 8A and 8B are schematic diagrams for explaining the operations of the first and second linear transporters and the top ring when the wafer is processed in parallel. FIGS. 9A and 9B are schematic diagrams for explaining the operations of the first and second linear transporters and the top ring when the wafer is processed in parallel. FIGS. 10A and 10B are schematic diagrams for explaining the operations of the first and second linear transporters and the top ring when the wafer is processed in parallel. FIGS. 11A and 11B are schematic diagrams for explaining the operations of the first and second linear transporters and the top ring when the wafer is processed in parallel. FIGS. 12A and 12B are schematic diagrams for explaining the operations of the second linear transporter and the top ring when the wafer is processed in parallel. FIGS. 13A and 13B are schematic diagrams for explaining the operations of the second linear transporter and the top ring when the wafer is processed in parallel. It is a top view which shows the whole structure of the polishing apparatus in the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Housing 2 Load / unload part 3 Polishing part 4 Washing part 5,6 Linear transporter 14-1, 14-2 Support part 16 Arm 20 Front load part 21 Traveling mechanism 22 1st conveyance robot 30-1, 30-2 Polishing unit 31, 41 Inverter 32, 35, 36 Lifter 33, 34, 37, 38 Pusher 40 Second transfer robot 42, 43, 44, 45 Washing machine 46 Temporary table 50 Transfer unit 60A, 60B, 60C, 60D Polishing Tables 61-1 to 61-8 Top rings 62A, 62B, 62C, 62D Polishing liquid supply nozzles 63A, 63B, 63C, 63D Dressers TS1 to TS5 Transport stages TP1 to TP7 Transport positions

Claims (8)

A plurality of polishings each having a plurality of polishing tables having a polishing surface and a plurality of top rings that move between the plurality of polishing tables while holding the polishing object and press the polishing object against the polishing surface. With units,
The polishing apparatus, wherein the plurality of top rings are respectively attached to a plurality of arms provided at equal angles along a circumferential direction on a rotatable support portion. A linear motion transport mechanism that transports a polishing object between a plurality of transport positions including a delivery position of the polishing object,
2. A delivery mechanism for delivering a polishing object between the linear motion transport mechanism and the top ring is provided at a transport position of the linear motion transport mechanism as a delivery position of an object to be polished. The polishing apparatus according to 1.   The polishing apparatus according to claim 1, wherein at least two of the support portions are arranged.   The polishing apparatus according to claim 2, wherein each of the plurality of polishing units performs a plurality of stages of polishing using the plurality of polishing tables.   4. The polishing apparatus according to claim 2, wherein a plurality of stages of polishing are performed by sequentially transporting wafers to the plurality of polishing tables of each of the polishing units. 5. It further includes a cleaning unit for cleaning the object to be polished,
The polishing apparatus according to claim 2, wherein the cleaning unit includes a temporary table on which an object to be polished is placed. It further includes a cleaning unit for cleaning the object to be polished,
The cleaning unit includes a dryer for drying an object to be polished, a temporary table on which an object to be polished before cleaning is placed, and a temporary table on which an object to be polished after drying is placed. The polishing apparatus according to claim 2 or 3.   The polishing apparatus according to claim 2, wherein the linear motion transport mechanism includes a plurality of transport stages that transport an object to be polished.

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