JPH0736396B2 - Multiple automatic wafer polishing apparatus and polishing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a polishing apparatus and a polishing method for mirror-finishing the surface of a wafer such as a semiconductor, and more particularly to a multi-type fully automatic wafer polishing apparatus and polishing method.

[0002]

2. Description of the Related Art As shown in FIG. 3 (a), a conventional polishing apparatus for mirror-finishing a wafer such as a silicon semiconductor adheres a plurality of wafers 1 to one surface of a flat plate 2 via wax, As shown in (b), after being placed on the polishing cloth 4 attached to the surface plate 3, the upper surface of the plate 2 is pressed against the polishing cloth 4 via the top ring 5, and the slurry 6 is placed in the center of the surface plate. The surface plate 3 was rotated while being supplied, and at the same time, the plate 2 was rotated together with the top ring 5 to mirror-finish the wafer.

[0003]

However, the above polishing apparatus requires a step of adhering the wafer 1 to the plate 2 with wax at the start of processing and a step of peeling the wafer 1 from the plate 2 after the processing is completed, and thus the entire polishing system is large-scaled. This makes it difficult to automate the device. Further, when the wafer 1 is bonded to the plate 2, if dust or air bubbles remain in the wax, it is impossible to perform mirror finishing with high precision. Furthermore, when batch processing is performed in which a large number of wafers 1 are bonded to one plate 2 and processed, it is very difficult to maintain uniform processing quality for each wafer 1.
In order to solve these problems, a single-wafer type apparatus that processes wafers one by one has been developed, but there is a problem in productivity because only one wafer can be processed.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a single-wafer processing type polishing apparatus capable of performing highly accurate and highly efficient mirror polishing of a wafer. The fully automatic wafer-polishing apparatus according to claim 1 and the fully-automatic wafer-polishing method according to claim 5 using the apparatus.
The top ring holding part is swingable at a surface plate position, the wafer storage mechanism is provided separately from the polishing apparatus main body, and further has a top ring surface cleaning means and a polishing cloth brushing mechanism for the surface plate. May be.

An embodiment of the present invention will be described below with reference to the drawings. As shown in FIGS. 1 (a) and 1 (b), the apparatus of the present invention includes a cassette mounting table 7, a wafer take-out mechanism 8, a wafer centering mechanism 9, a surface plate 3, and a wafer receiving section 10 which are sequentially arranged in series. The wafer storage mechanism 11 and the top ring 5 are suspended, and a saddle-shaped top ring holding portion 12 that runs between the wafer centering mechanism 9, the surface plate 3, and the wafer receiving portion 10 is provided.

An example of each of the units 3 and 7 to 12 will be described in detail below. a) Cassette mounting table 7 A wafer supply cassette 13 accommodating the wafer 1 can be mounted and moved up and down. b) Wafer take-out mechanism 8 The wafer 1 stored in the lowermost stage of the wafer supply cassette 13 placed on the cassette placing table 7 and lowered is taken out by the belt conveyor method and is conveyed to the next wafer centering mechanism 9. c) Wafer centering mechanism 9 A wafer 1 having an upper surface that is flush with the upper surface of the belt conveyor, is provided with a centering block 14, and is transferred.
Is stopped at a predetermined position. d) Surface plate 3 A polishing cloth 4 for processing is attached to the upper surface and rotated. Therefore, the polishing cloth brushing mechanism 15 for cleaning the polishing cloth 4 is provided near the surface plate 3, and the slurry supply nozzle 16 is provided at the center of the surface plate 3. e) Top ring lower surface cleaning mechanism 17 The lower surface of the top ring 5 for adsorbing the wafer is cleaned. f) The wafer receiving unit 10 is composed of the following a), b), and c). A) Wafer cleaning mechanism 18 The brush-implanted cylinder or sponge cylinder is moved onto the wafer 1 transferred to the next wet station 19 and rotated to clean the wafer 1. (B) Wet station 19 Pure water is supplied to the surface of the wafer 1 to clean the polishing surface and prevent scratches and the like. C) Wafer reversing arm 20 The wafer 1 in the wet station 19 is adsorbed and transferred to the wafer storage mechanism 11. g) Top ring 5 It has a wafer suction chuck 21 at the lower end and can move up and down and rotate. h) Top ring holding part 12 It is saddle-shaped, and the top ring 5 is hung and held, and the rail 22
It straddles the wafer centering mechanism 9, the surface plate, and the wafer receiving portion 10 along and runs between them, and can swing on the surface plate 3 during mirror surface processing. i) Wafer storage mechanism 11 The wafer 1 washed at the wet station 19
Water shooter 2 via wafer reversing arm 20
3, the wafer is transferred to the wafer storage cassette 24 and is stored therein. The apparatus of the present invention is, as shown in FIGS. 2A and 2B, a wafer transfer arm 25 between the wafer receiving portion 10 and the wafer storage mechanism 11 and a wafer processing station for performing etching of the wafer 1. 26 may be provided.

[0007]

Next, an example of the operating procedure of the polishing apparatus of the present invention will be described with reference to FIGS. 1 (a) and 1 (b). (1) The cassette mounting table 7 is attached to the wafer supply cassette 13
To the installation position of. (2) The wafer supply cassette 13 is attached to the cassette mounting table 7
Place on top. (3) The cassette mounting table 7 is lowered to bring the wafer 1 at the lowermost stage stored in the wafer supply cassette 13 into contact with the belt of the wafer takeout mechanism 8. (4) The belt is rotated and the wafer 1 in contact is taken out. (5) The wafer 1 is transferred onto the wafer centering mechanism 9, contacts the centering block 14, and stops at a predetermined position. (6) The top ring holder 12 moves on the rail 22 and moves onto the wafer centering mechanism 9, then lowers the top ring 5, and the wafer suction chuck 21 at the lower end sucks the wafer 1. (7) The top ring 5 is raised to move the top ring holding portion 12 onto the surface plate 3. (8) The top ring 5 is lowered and the wafer 1 is pressed against the polishing cloth 4 attached to the surface plate 3. (9) While the slurry is being supplied from the slurry supply nozzle 16 to the center of the surface plate 3, the surface plate 3 and the top ring 5 are rotated, and at the same time, the top ring holding portion 12 is swung along the rails 22 to move the wafer 1 Mirror finish. (10) The top ring 5 is lifted, the top ring holding part 12 is moved on the rail 22, and is moved onto the wet station 19 of the wafer receiving part 10. (11) The top ring 5 is lowered, and when the wafer 1 reaches near the water surface of the wet station 19, the lowering is stopped, the suction of the wafer suction chuck 21 is released, and the wafer is dropped onto the wet station 19. (12) The wafer cleaning mechanism 18 is moved onto the wet station 19 to clean the back surface of the wafer 1. (13) The wafer 1 which has been processed at the wet station 19 is transferred by the wafer reversing arm 20 to the wafer storage mechanism 1.
Transfer to 1. (14) The wafer 1 is transported on the water shooter 23 and stored in the lowermost stage of the wafer storage cassette 24. (15) The wafer storage cassette 24 descends by one step,
The next wafer is stored. (16) The top ring holding portion 12 is caused to travel on the top ring lower surface cleaning mechanism 17, and the top ring 5 is lowered to clean the suction chuck 21 at the lower end thereof. This completes one cycle of the wafer polishing operation. Of course, when the wafers in each stage are finished and sent to the next stage, a new wafer to be processed is immediately received from the previous stage, and the operations are performed without interruption in each stage. 1 and 2, the apparatus capable of processing two wafers at a time has been described. However, by connecting a series of mechanisms in parallel, more wafers can be processed simultaneously, and depending on the application, It is needless to say that a smaller number of wafers may be simultaneously processed in a double apparatus such as 1, 2 so that the wafers are processed one by one.

[0008]

According to the apparatus and method of the present invention, a plurality of wafers to be mirror-finished can be fully automatically taken out from the wafer supply cassette without touching human hands even once.
Since the wafer is stored in the wafer storage cassette after processing, there is little risk of damaging or contaminating the wafer, polishing can be done efficiently, and since each part has a cleaning mechanism, the device is stopped for cleaning as in the past. The present invention is extremely useful industrially because it can be operated continuously for a long period of time without doing so.

[Brief description of drawings]

1A is an explanatory view seen from above a polishing apparatus of the present invention, and FIG. 1B is an explanatory view seen from a side.

2A is an explanatory view seen from above a polishing apparatus of another embodiment of the present invention, and FIG. 2B is an explanatory view seen from a side.

3A is a perspective view of a plate to which a conventional wafer is attached, and FIG. 3B is a partial side view of a conventional polishing apparatus.

[Explanation of symbols]

1 Wafer 19 Wet Station 2 Plate 20 Wafer Inversion Arm 3 Surface Plate 21 Adsorption Chuck 4 Polishing Cross 22 Rail 5 Top Ring 23 Water Shooter 6 Slurry 24 Wafer Storage Cassette 7 Cassette Placement Table 25 Wafer Transfer Arm 8 Wafer Ejection Mechanism 26 Wafer Processing Station 9 Wafer centering mechanism 10 Wafer receiving unit 11 Wafer storing mechanism 12 Top ring holding unit 13 Wafer supply cassette 14 Centering block 15 Polishing cloth brushing mechanism 16 Slurry supply nozzle 17 Top ring cleaning mechanism 18 Wafer cleaning mechanism

Claims (5)

[Claims] 1. In a polishing apparatus for polishing a wafer surface by rubbing the surface of a wafer with a polishing cloth attached to a surface plate, a plurality of wafers are simultaneously taken out from a plurality of wafer supply cassettes by a wafer taking-out mechanism at predetermined positions. a plurality of wafers to be stopped - centering mechanism; -; Ken wafer base plate which is stuck a mirror-finished polishing cloth
A wafer receiving portion for receiving each polished wafer at the same time is sequentially arranged.
From the rails laid across the wafer receiving section
Top ring holder that runs on the linear motion mechanism; the top
It is vertically and rotatably suspended retaining the ring holding part, a wafer by suction chuck of the lower end surface - a plurality of top ring for pressing mirror finished the polishing cloth adsorbs; and bets
Wash the wafer that is adsorbed to the pulling plate and polished on the surface plate.
A multi-type fully automatic wafer polishing apparatus comprising: a cleaning mechanism provided in the receiving portion for cleaning . 2. The apparatus according to claim 1, wherein the top ring holder is swingable on a surface plate. 3. The apparatus according to claim 1, further comprising cleaning means for cleaning the lower surface of the top ring. 4. A polishing cloth is brushed near the surface plate.
Apparatus according to claim 1 having a brushing mechanism for. 5. A plurality of wafer-supply cassettes , respectively.
Each wafer taken out is sucked onto the lower end faces of a plurality of top rings suspended in the top ring holder.
Then , lower and rotate each top ring to set each wafer.
And pressed against the polishing cloth attached to the panel, the scan in the polishing cloth <br/> Lari - wafer while supplying - and rubbed to the polishing cloth mirror finished, after machining end, raising the respective top ring, the top Move the ring holder to receive the wafer
A multi-type fully automatic wafer polishing method characterized in that a wafer is cleaned by a cleaning mechanism of a part .