JP2001347452A - Wafer grinding device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet-type wafer automatic grinding device capable of shortening a throughput time. SOLUTION: A sheet-type wafer automatic grinding device 1 comprises a storage cassette 18 for loading, a storage cassette 18' for unloading, a first conveying robot 17, a second conveying robot 17', a first temporary table 16 capable of placing plural wafers, a second temporary table 16' capable of reciprocating in the horizontal direction of a position on the first temporary table and placing plural wafers, an index head 15 pivoted on a spindle shaft mounted separately from the first temporary table, m pieces (m=2-4) of wafer chuck mechanisms 5, 5, 5 mounted on the index head at equal intervals on a concentric circumference passing through a central point of the first temporary table while applying the spindle shaft as a shaft center, an elevating mechanism of the wafer chuck mechanisms, and (m-1) pieces of grinding platens 3 and 3 supported spindle shaft and mounted at equal intervals with the first temporary table on the circumference having the shaft center and the circumferential diameter same as the shaft center of the index head.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for polishing a single wafer having a short throughput time and a method for simultaneously polishing a plurality of wafers using the apparatus.

[0002]

2. Description of the Related Art A single wafer type polishing apparatus for simultaneously polishing a plurality of wafers is known (Japanese Patent Laid-Open No. Hei 7-130687,
JP-A-2000-24916, JP-A-2000-5223
No. 7). One example is shown in FIG. 6, FIG. 7 and FIG. In these figures, the single wafer type polishing apparatus 1 includes a loading cassette 18 for loading a wafer, a loading cassette 18 'for unloading a wafer, a first robot 17 for transporting a wafer, and a wafer 17 provided on a base Ba. The second robot for transport 17 ', the index head 15 mounted on the spindle shaft 15a, and the three spindle shafts 4a, 4b, 4c provided at equal intervals on the concentric circumference of the shaft are provided with heads 6a, 6b, 6c. The wafer chuck mechanisms 5, 5, 5, the temporary wafer table 16 installed below the index head 15, and the polishing platens 3, which are respectively supported by two spindle shafts 2, 2.
3 '(however, the spindle axis of the temporary mounting table and the spindle axes of the two polishing platens are present on a circumference having the same axis as the axis 15a of the index head), the pad conditioners 3a, 3a', and the wafer. It has thickness measuring devices 14 and 14.

The hollow shaft 15a of the index head 15, which rotatably supports the chuck mechanism 5, is connected to valves 8, 11, and 13, a pressure reducing pipe 9, and a pressurized air supply pipe 10 as shown in FIG. A tube 12 is provided so that the wafer w can be sucked and opened. 7 is a rotary joint.

The following steps are taken to simultaneously grind five wafers using the single wafer polishing apparatus 1. (1) Pre-position position transfer step: On a temporary table 16 on which n wafers can be placed by the first transfer robot 17 for each wafer stored in the load storage cassette 18. And then put the temporary table at 72 degrees (36
(0/5 degrees) After rotating horizontally, a new wafer is transported from the loading cassette to the temporary storage table by the first transfer robot, and thereafter, the temporary mounting table is rotated 72 degrees horizontally. The operation of transporting a new wafer is repeated, and five wafers are transported onto the temporary table 16.

(2) Wafer loading step: The chuck mechanism 5 on the temporary table is lowered or the temporary table is raised to bring the temporary table into contact with the chuck mechanism, and the vacuum pump connected to the chuck mechanism is operated to reduce the pressure. Then, five wafers are attracted to the chuck head 6 and the chuck mechanism 5 is raised to separate the temporary mounting table and the chuck mechanism.

(3) Polishing step: (3) -1 First polishing step: 12 index heads
The chuck mechanism, which is rotated 0 degrees (360/3 degrees) and sucks the five wafers, is moved onto the first polishing platen 3,
Next, the spindle shaft 4 of the chuck mechanism is lowered while being rotated, and the wafer is brought into contact with the rotating first polishing platen to be rubbed and rubbed roughly. During polishing, an abrasive slurry is provided on the first polishing platen. After the rough polishing, the chuck mechanism is moved up by the elevating mechanism and separated from the first polishing platen.

(3) -2 Second polishing step: The index head is rotated by 120 degrees and the coarsely polished wafer 5 is rotated.
The chuck mechanism that has attracted the sheet is moved onto the second polishing platen 3 ′, and then the wafer is brought into contact with the rotating second polishing platen by lowering while rotating the spindle shaft 4 of the chuck mechanism, thereby rubbing the wafer. And finish polishing. During polishing,
An abrasive slurry is supplied on the second polishing platen.
After finishing polishing, the chuck mechanism is moved up by the elevating mechanism and separated from the second polishing platen.

(4) Wafer unloading step: The index head is rotated by 120 degrees or 240 degrees in the opposite direction to be positioned on the temporary mounting table, and then the chuck mechanism that has sucked the five polished wafers is lowered. Then, the valve 8 of the chuck mechanism is closed to release the reduced pressure, and the valve 11 of the pressurized gas supply building 10 is opened to close the valve 8 of the chuck mechanism.
The finish-polished wafers are placed on the temporary mounting table, and the valve 11 is closed. Subsequently, the chuck mechanism is raised, and then the transfer robot 5 ′ is moved to a position on the temporary table 16 using the second transfer robot 17 ′.
A storage cassette 18 'for unloading the finished polishing wafers.
Conveyed inside.

Next, five new wafers are transferred from the loading cassette 18 by the first transfer robot 17 and the pre-position position transfer step and the chuck mechanism 5 placed on the temporary table 16 are lowered. Then, a wafer loading process is performed in which the wafer placed on the temporary table is sucked and the chuck mechanism is raised.

Thereafter, the above-mentioned (3) polishing step and (4) wafer unloading step (including the pre-position position transfer step and the wafer loading step) are repeatedly performed, and continuous automatic operation is possible.

When two chuck mechanisms are used, one polishing platen is used and the rotation of the index head is 180 degrees. When three chuck mechanisms are used to perform rough polishing, medium finish polishing, and finish polishing, the polishing apparatus is assembled so that three polishing platens are used and the rotation of the index head is 90 degrees (Japanese Patent Laid-Open No. 2000-52237). ).

[0012]

In the above-mentioned single wafer type polishing apparatus, a plurality of wafer unloading steps, a wafer preposition position transfer step, and a wafer loading step on one temporary placing table are performed for four minutes to four minutes. Since the polishing is performed for 5 minutes, the polishing rate is determined as compared with the time of 1.5 to 3 minutes in the polishing step, and there is a drawback that the throughput time is long. The present invention
It is an object of the present invention to provide a single-wafer polishing apparatus capable of shortening a throughput time.

[0013]

According to a first aspect of the present invention, a wafer loading cassette, a wafer unloading cassette, a first wafer transfer robot, a wafer transfer second robot, A first temporary mounting table on which a plurality of wafers provided between the first robot for transferring a wafer and the second robot for transferring a wafer can be mounted, and is installed so as to be rotatable in a horizontal direction and vertically movable in a vertical direction. A first temporary mounting table, a second temporary mounting table capable of mounting a plurality of wafers rotatable in a horizontal direction and reciprocally movable in a horizontal direction at a position on the first temporary mounting table; An index head which is mounted on a spindle shaft provided at a distance from a center axis of the index head which is provided at equal intervals on a concentric circle passing over the center point of the first temporary mounting table with the spindle shaft as an axis. (M = 2-4) The e-chuck mechanism, the elevating mechanism of the wafer chuck mechanism, and the first temporary mounting table are provided at regular intervals on the circumference having the same axis as the axis of the index head and the circumference (m-1). An object of the present invention is to provide a polishing apparatus for a wafer, comprising a polishing platen supported on a base spindle shaft.

By providing the second temporary table, the time required for loading and unloading the wafer can be reduced to two minutes, and the time required for unloading and loading the wafer is substantially equal to the polishing time. It became possible to take time.

According to a second aspect of the present invention, there is provided a method for simultaneously polishing a plurality of wafers by using the above-mentioned single wafer type polishing apparatus, the method comprising the following steps. It is something to offer.

(1) Preposition position transfer step:
The wafers stored in the storage cassette are placed on the first temporary mounting table on which n wafers can be mounted one by one by the first transfer robot, and then the first temporary mounting table is moved to 360. / N degrees in the horizontal direction, the new wafer is carried from the loading cassette to the first temporary table by the first transfer robot, and then the first temporary table is rotated in the horizontal direction by 360 / n degrees. Operation and transporting a new wafer are repeated n
One wafer is transferred onto the first temporary table.

(2) Wafer loading step: The chuck mechanism on the first temporary mounting table is lowered or the first temporary mounting table is raised to bring the first temporary mounting table into contact with the chuck mechanism. The sheet is sucked and the chuck mechanism is raised or the first temporary mounting table is lowered to separate the first temporary mounting table and the chuck mechanism.

(3) Polishing step: The polishing step varies depending on the number of chuck mechanisms. In the case of one unit, it ends in the first polishing step. When two are used, the first polishing step (coarse polishing) and the second polishing step (finish polishing) are completed. In the case of three units, the first polishing step (coarse polishing), the second polishing step (medium finish polishing), and the third polishing step (finish polishing) are completed. (3) -1 First polishing step: 36 index heads
By rotating the chuck mechanism by sucking the n wafers by rotating 0 / m degrees onto the first polishing platen, the spindle mechanism of the chuck mechanism is lowered while rotating, and the first polishing platen is rotated. The wafer is brought into contact with and rubbed to polish. During polishing, an abrasive slurry is provided on the first polishing platen. After the polishing is completed, the chuck mechanism is moved up by the elevating mechanism and separated from the first polishing platen. (3) -2 Second polishing step: three chuck mechanisms (m =
In the case of 3), a second polishing step is further employed. That is, the index mechanism is rotated by 360 / m to move the chuck mechanism that has attracted the n polished wafers onto the second polishing platen, and then lowers while rotating the spindle shaft of the chuck mechanism. The wafer is brought into contact with the second polishing platen, and is rubbed and polished. During polishing, an abrasive slurry is provided on the second polishing platen. After the polishing is completed, the chuck mechanism is moved up by the elevating mechanism and separated from the second polishing platen. (3) -3 Third polishing step: 4 chuck mechanisms (m =
In the case of 4), a third polishing step is further employed. That is, the index mechanism is rotated by 360 / m to move the chuck mechanism holding the n polished wafers onto the third polishing platen, and then rotating the spindle shaft of the chuck mechanism by lowering while rotating. The wafer is brought into contact with the third polishing platen, which is being rubbed, and polished. During polishing, an abrasive slurry is provided on the third polishing platen. After the polishing, the chuck mechanism is moved up by the elevating mechanism and separated from the third polishing platen.

(4) Wafer unloading step: The second temporary table is moved in the horizontal direction to be positioned on the first temporary table, and the index head is rotated 360 / m degrees or 360 (m-1) / in the opposite direction. It is rotated by m degrees to be positioned on the moved second temporary table, and then the chuck mechanism that has sucked the n polished wafers is lowered and brought into contact with the second temporary table to release the decompression of the chuck mechanism. Then, the n polished wafers are mounted on the second temporary mounting table. Subsequently, the chuck mechanism is raised, and the second temporary mounting table on which the polishing wafer is mounted is retracted in the horizontal direction, and then the n number of polishing wafers on the second temporary mounting table are unlocked using the second transfer robot. Transported into the storage cassette for storage. During this time, n new wafers are transferred from the loading cassette by the first transfer robot, and the pre-position position transfer step and the chuck mechanism placed on the first temporary mounting table are lowered.
A wafer loading process is performed in which a wafer placed on the first temporary table is sucked and the chuck mechanism is raised.

By providing the first temporary table and the second temporary table between the wafer storage cassette and the chuck mechanism, rough polishing and finish polishing can be simultaneously performed in parallel by the index method, and the wafer is loaded into the polishing apparatus. After that, the throughput time of the wafer from polishing to storage in the unloading cassette is reduced.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a plan view of a single-wafer polishing apparatus showing an example used to carry out the present invention, FIG. 2 is a front view of the polishing apparatus, and a second temporary table is located on the first temporary table. This state is shown, and the storage cassette is omitted from the drawing. FIG.
Is a front view of the polishing apparatus, wherein the second temporary table is retracted from the first temporary table, the first temporary table is in contact with the chuck mechanism, and the storage cassette is omitted from the drawing. is there. FIG. 4 is a top view of the first temporary storage table, and FIG. 5 is a cross-sectional view of the first temporary storage table.

1, 2 and 3, 1 is a single-wafer polishing apparatus, 3 and 3 'are polishing platens supported on spindle shafts 2 and 3, 3a and 3a' are pad conditioners, and 5, Reference numerals 5 and 5 denote wafer chuck mechanisms. These chuck mechanisms are provided below three spindle shafts 4a, 4b and 4c provided at equal intervals on a concentric circle centered on a spindle shaft 15a of an index head 15 described later. 6
a, 6b, and 6c have a bearing structure. Reference numeral 15 denotes an index head, which is supported upward by a spindle shaft 15a. Reference numeral 16 denotes a first temporary mounting table, which is installed below the index head 15, and is provided at equal intervals on a concentric circle around the spindle shaft 15a together with the above-mentioned polishing platens 3, 3 '. Reference numeral 16 'denotes a second temporary table.

Reference numeral 17 denotes a first robot for transferring a wafer, 17 '
Is a second robot for transporting wafers; 18, 18, and 18 are cassettes for loading wafers provided on the base Ba;
Reference numerals 8 ', 18', 18 'denote storage cassettes for unloading wafers, 19 denotes a chuck cleaner, and w denotes a wafer.

In the first temporary table 16 shown in FIGS. 4 and 5, reference numeral 160 denotes an index table, and 161 denotes five wafer suction plate portions provided concentrically at equal intervals on the index table. , 161a is a chamber, 161a
b is a small hole, 162 is a cleaning liquid supply plate for supplying cleaning liquid to five wafers on the suction plate 161 provided at a position higher than the upper surface of the index table, 162a is a jet slit nozzle, 163a Is a hollow shaft bearing the center of the index table, 164 is a bearing, 165, 166
Is a gear, M is a motor, 167 is an air cylinder for raising and lowering the index table, 167a is a rod, 168 is a pipe and a chamber for supplying liquid to the suction plate chamber-161a, and the pressure in the chamber is reduced. Therefore, it is a decompression tube connected to a vacuum pump, and switching of supply of liquid, discharge of liquid, and decompression is performed by a valve (not shown). Reference numeral 169 denotes a cleaning liquid supply pipe.
The cleaning liquid is sprayed onto the wafer on the wafer suction part from the fan-shaped jet slit nozzle 162a.

A preposition position transfer step for placing n wafers on the first temporary table 16 using the first transfer robot, and a vacuum chuck mechanism for holding the n wafers on the first temporary table. The loading step for adsorbing and transferring to 5 is performed as follows. I) Preposition position transfer process: (1) Five wafer suction plates on the index table of the first temporary table 16 using the first robot 17 for transfer of the first wafer w from the cassette 18 The first suction plate is transported and placed on the first suction plate portion of the first suction plate.
Then, the wafer is suction-fixed by decompressing the wafer portion.

(2) The index table is moved to 72 degrees (3
60/5) Rotate clockwise to transfer a new second wafer from the cassette 18 by the arm 17a of the robot, place it on the second wafer suction plate section, and After the suction plate is depressurized and the wafer is suction-fixed, the index table is rotated in the positive direction by 72 degrees. Thereafter, new wafers are sequentially placed on the wafer suction plate in the same manner. Then, the five fixed wafers are mounted on the index table and the loading operation for fixing is completed.

(3) The vacuum chuck mechanism 5a of the index head 15 provided with the five wafer suction plates concentrically is lowered until it approaches the upper surface 1 to 3 mm of the wafer. (4) While supplying the cleaning liquid from the pipe 169 and injecting the cleaning liquid onto the wafer surface from the injection slit nozzle 161a of the supply board, the vacuum chuck mechanism decompresses the pipe of the pipe 5a to partially remove the cleaning liquid from the chuck mechanism 5a. To be discharged.

II) Loading process: (5) The air cylinder-167 is actuated to raise the first temporary table 16, and the wafer is brought into contact with the vacuum chuck mechanism 5a of the index head 15, and then each suction is performed. After the depressurization of the plate part 161 is stopped, a liquid is supplied to the suction plate part from the pipe 168 to facilitate separation of the wafer from the plate part of the temporary mounting table, and to vacuum five wafers. -Simultaneously chuck the memory chuck mechanism 5a. (6) Raise the vacuum chuck mechanism 5a.

In the above example, since the five wafers are placed on the temporary mounting table, the rotation of the temporary mounting table is 72 degrees at a time, but if the number of wafers is three, the rotation is 120 degrees or four. 90 degrees, 6
If it is a sheet, the index table rotates intermittently by 60 degrees.

The second temporary table 16 'is provided on the side of the first temporary table provided between the first robot for transferring a wafer and the second robot for transferring a wafer. The second temporary table is the air-cylinder section 16 of the first temporary table shown in FIG.
7, a moving mechanism including a rail 16'a and an air cylinder 16'b is provided so as to be able to reciprocate horizontally in the position on the first temporary table (see FIG. 1).

The unloading step of placing the polished wafer on the second temporary table 16 'by the chuck mechanism and transporting it to the storage cassette 18' using the second transport robot 17 'is as follows. Done in (1) The second temporary table 16 'is moved in the horizontal direction to be positioned on the first temporary table 16 and the index head 15
Is rotated by 120 degrees or 240 degrees in the opposite direction to be positioned on the moved second temporary table, and then the chuck mechanism that has sucked the five polished wafers is lowered to contact the second temporary table. Then, the pressure in the chuck mechanism is released, and the five polished wafers are placed on the second temporary table, and the wafers are vacuum-adsorbed.

(2) Subsequently, the chuck mechanism is raised, and the second temporary mounting table 16 'on which the polished wafer is mounted is retracted in the horizontal direction. Then, the second temporary mounting table 16' is moved using the second transfer robot 17 '. The upper five polishing wafers are sequentially transferred into the unloading storage cassette 18 'as follows. (A) 5 on the index table of the second temporary table 16 '
First suction plate of two wafer suction plate units 161
Then, the wafer on the suction plate is transferred into the storage cassette 18 'by using the transfer second robot 17'. (B) The index table is rotated clockwise by 72 degrees to release the decompression of the second suction plate portion, and the wafer on the suction plate is moved using the second transfer robot 17 '. It is transported into the storage cassette 18 '. (C) Thereafter, the index table is rotated clockwise by 72 degrees, the pressure of the n-th suction plate is released, and the wafer on the suction plate is stored using the second transfer robot 17 '. The operation of transferring the wafers into the cassette 18 'is repeated to perform an unloading step of loading all five polished wafers into the cassette.

The process of polishing n wafers using the single wafer polishing apparatus having the m chuck mechanisms of the present invention is performed as follows. (1) Preposition position transfer step: the first robot 17 for transferring n wafers stored in the load storage cassette 18 one by one by the first transfer robot 17 After placing on the temporary mounting table 16 and then rotating the first temporary mounting table in the horizontal direction by 360 / n degrees, a new wafer is transferred from the loading cassette 18 to the first temporary mounting table by the first transfer robot. Carrying, the operation of rotating the first temporary placement table in the horizontal direction by 360 / n degrees and the operation of transporting a new wafer are repeated, and n wafers are transported onto the first temporary placement table.

(2) Wafer loading step: The chuck mechanism 5 on the first temporary table 106 is lowered or the first temporary table is raised to bring the first temporary table into contact with the chuck mechanism, and the pressure of the chuck mechanism is reduced. The n wafers are simultaneously sucked and the chuck mechanism is raised or the first temporary mounting table is lowered to separate the first temporary mounting table and the chuck mechanism.

(3) Polishing step: The polishing step depends on the number of chuck mechanisms. In the case of one unit, it ends in the first polishing step. When two are used, the first polishing step (coarse polishing) and the second polishing step (finish polishing) are completed. In the case of three units, the first polishing step (coarse polishing), the second polishing step (medium finish polishing), and the third polishing step (finish polishing) are completed.

(3) -1 First polishing step: The index mechanism 15 is rotated by 360 / m to move the chuck mechanism 5 holding the n wafers onto the first polishing platen 3, and then the chuck mechanism is rotated. The wafer is brought into contact with the rotating first polishing platen 3 while rotating the spindle shaft 4 while rotating the spindle shaft 4, and the wafer is rubbed and polished. During polishing, an abrasive slurry is provided on the first polishing platen (not shown). After the polishing is completed, the chuck mechanism is moved up by the elevating mechanism and separated from the first polishing platen.

(3) -2 Second polishing step: When the number of chuck mechanisms 5 is three (m = 3), a second polishing step is further employed. That is, the index mechanism is rotated by 360 / m to move the chuck mechanism that has attracted the n polished wafers onto the second polishing platen, and then lowers while rotating the spindle shaft of the chuck mechanism. The wafer is brought into contact with the second polishing platen, and is rubbed and polished. During polishing, an abrasive slurry is provided on the second polishing platen. After the polishing is completed, the chuck mechanism is moved up by the elevating mechanism and separated from the second polishing platen.

(3) -3 Third polishing step: When the number of chuck mechanisms 5 is four (m = 4), a third polishing step is further employed. That is, the index mechanism is rotated by 360 / m to move the chuck mechanism holding the n polished wafers onto the third polishing platen, and then rotating the spindle shaft of the chuck mechanism by lowering while rotating. The wafer is brought into contact with the third polishing platen, which is being rubbed, and polished. During polishing, an abrasive slurry is provided on the third polishing platen. After the polishing, the chuck mechanism is moved up by the elevating mechanism and separated from the third polishing platen.

(4) Wafer unloading step: The second temporary table 16 'is moved in the horizontal direction to be positioned on the first temporary table 16, and the index head 15 is moved to 360 /
It is rotated by 360 degrees (m-1) / m degrees in the opposite direction by m degrees and positioned on the moved second temporary table, and then the chuck mechanism 5 that has sucked the n polished wafers is moved down to The chucking mechanism is brought into contact with the second temporary mounting table 16 ′, and the pressure of the chuck mechanism is released, and the n polished wafers are mounted on the second temporary mounting table.

Subsequently, the chuck mechanism 5 is raised, and the second temporary table 16 'on which the polished wafer is placed is retracted in the horizontal direction, and then the second temporary robot 17' is used to move the second temporary table 16 'on the second temporary table. The n wafers are transported into the unloading cassette 18 '. During this time, n new wafers are transferred from the loading storage cassette 18 by the first transfer robot 17 and the preposition position transfer step mounted on the first temporary mounting table, and the chuck mechanism is lowered. Then, a wafer loading process is performed in which the wafer placed on the first temporary table is sucked and the chuck mechanism is raised.

In order to easily separate the wafer from the chuck mechanism 5 at the time of wafer unloading, pressurized air is supplied from the tube 10. The connection pipe 12 is washed by opening the valve 13 and supplying a cleaning liquid to the connection pipe 12.

Each time the polishing of the wafer is completed, the pad conditioner-3 is used so that the pad (polishing cloth) of the polishing platen is worn out during the polishing and the polishing amount of the wafer is not reduced.
In a and 3b, the pad surface is shaved thinly and repaired (conditioned) so as to be close to the original porosity and surface texture of the polishing pad. Further, the surface of the chuck mechanism 5 is cleaned by the chuck cleaner 19.

In the polishing step, the number of rotations of the rotating shafts 2 and 4 is 10 to 200 rpm, and the wafer is
The pressure applied to 3 ′ is 0.1 to ² kg / cm ² . Rotating shaft 2 of polishing platen and rotating shaft 4 of chuck mechanism
May be both forward directions or forward and reverse directions.

[0044]

The single wafer type automatic polishing apparatus of the present invention for simultaneously polishing multiple wafers can reduce the throughput time by using two temporary mounting tables.

[Brief description of the drawings]

FIG. 1 is a plan view of a single wafer type automatic polishing apparatus according to the present invention.

FIG. 2 is a front view of a single wafer type automatic polishing apparatus.

FIG. 3 is a front view of the single wafer type automatic polishing apparatus.

FIG. 4 is a plan view of a wafer temporary mounting table.

FIG. 5 is a cross-sectional view of a first wafer temporary mounting table.

FIG. 6 is a plan view of a known single-wafer type automatic polishing apparatus.

FIG. 7 is a sectional view of an index head of the single wafer type automatic polishing apparatus.

FIG. 8 is a perspective view of an index head of the single wafer type automatic polishing apparatus.

[Explanation of symbols]

 Reference Signs List 1 single-wafer type automatic polishing apparatus w wafer 2 spindle shaft 3 polishing platen 4 shaft 5 chuck mechanism 15 index head 16 first temporary mounting table 16 'second temporary mounting table 17 first transfer robot 17' second transfer robot 18 Wafer storage cassette for loading 18 'Wafer storage cassette for unloading Ba Base

Claims (2)

[Claims] 1. A wafer loading cassette, a wafer unloading cassette, a wafer transfer first robot, a wafer transfer second robot, the wafer transfer first robot, and a wafer transfer second robot. A first temporary mounting table provided between the robots, on which a plurality of wafers can be placed, the first temporary mounting table being rotatable in a horizontal direction and vertically movable up and down, and rotatable in a horizontal direction. A second temporary table on which a plurality of wafers reciprocally movable in a horizontal direction at a position on the first temporary table can be mounted, and the second temporary table is supported by a spindle shaft provided separately on the first temporary table. Index heads, m (m = 2 to 4) wafer chuck mechanisms provided at equal intervals on concentric circles passing through the center point of the first temporary mounting table with the spindle shaft as the axis center, The wafer chuck A lifting / lowering mechanism of the mechanism, and a (m-1) base spindle provided at regular intervals together with the first temporary mounting table on a circumference having the same axis as the axis of the index head and the same circumference. An apparatus for polishing a wafer, comprising: a polishing platen which is provided. 2. A method for simultaneously polishing a plurality of wafers using the polishing apparatus according to claim 1, wherein the method includes the following steps. (1) Preposition position transfer step: On the first temporary mounting table on which n wafers can be placed by the first transfer robot for each wafer stored in the loading cassette. After the first temporary table is horizontally rotated by 360 / n degrees, a new wafer is transported from the loading cassette to the first temporary table by the first transfer robot. The operation of rotating the temporary mounting table in the horizontal direction by 360 / n degrees and the operation of transporting a new wafer are repeated to transport n wafers onto the first temporary mounting table. (2) Wafer loading step: The chuck mechanism on the first temporary table is lowered or the first temporary table is raised to bring the first temporary table into contact with the chuck mechanism, and the chuck mechanism is depressurized to suck n wafers. Then, the chuck mechanism is raised or the first temporary mounting table is lowered to separate the first temporary mounting table and the chuck mechanism. (3) Polishing step: The polishing step differs depending on the radix of the chuck mechanism. In the case of one unit, it ends in the first polishing step. In the case of two units, the first polishing step (coarse polishing) and the second polishing step (finish polishing)
Ends with In the case of three units, the first polishing step (coarse polishing), the second polishing step (medium finish polishing), and the third polishing step (finish polishing) are completed. (3) -1 First polishing step: 36 index heads
By rotating the chuck mechanism by sucking the n wafers by rotating 0 / m degrees onto the first polishing platen, the spindle mechanism of the chuck mechanism is lowered while rotating, and the first polishing platen is rotated. The wafer is brought into contact with and rubbed to polish. During polishing, an abrasive slurry is provided on the first polishing platen. After the polishing is completed, the chuck mechanism is moved up by the elevating mechanism and separated from the first polishing platen. (3) -2 Second polishing step: three chuck mechanisms (m =
In the case of 3), a second polishing step is further employed. That is, the index mechanism is rotated by 360 / m to move the chuck mechanism that has attracted the n polished wafers onto the second polishing platen, and then lowers while rotating the spindle shaft of the chuck mechanism. The wafer is brought into contact with the second polishing platen, and is rubbed and polished. During polishing, an abrasive slurry is provided on the second polishing platen. After the polishing is completed, the chuck mechanism is moved up by the elevating mechanism and separated from the second polishing platen. (3) -3 Third polishing step: 4 chuck mechanisms (m =
In the case of 4), a third polishing step is further employed. That is, the index mechanism is rotated by 360 / m to move the chuck mechanism holding the n polished wafers onto the third polishing platen, and then rotating the spindle shaft of the chuck mechanism by lowering while rotating. The wafer is brought into contact with the third polishing platen, which is being rubbed, and polished. During polishing, an abrasive slurry is provided on the third polishing platen. After the polishing, the chuck mechanism is moved up by the elevating mechanism and separated from the third polishing platen. (4) Wafer unloading step: the second temporary table is moved in the horizontal direction to be positioned on the first temporary table, and the index head is rotated 360 / m degrees or 360 degrees in the reverse direction.
(M-1) / m degree of rotation and positioned on the moved second temporary mounting table, and then lower the chuck mechanism that has attracted the n polished wafers to contact the second temporary mounting table; The pressure in the chuck mechanism is released, and the n polished wafers are placed on the second temporary table. Subsequently, the chuck mechanism is raised and the second temporary mounting table on which the polishing wafer is mounted is retracted in the horizontal direction, and then the n number of polishing wafers on the second temporary mounting table are unlocked using the second transfer robot. Transported into the storage cassette for storage. During this time, n new wafers are transferred from the loading cassette by the first transfer robot, and the pre-position position transfer step and the chuck mechanism placed on the first temporary mounting table are lowered. A wafer loading process is performed in which the wafer placed on the temporary table is sucked and the chuck mechanism is raised.