JPS63164237A - Wafer positioning apparatus - Google Patents

Abstract

PURPOSE:To provide a positioning apparatus, which can position an orientation flat accurately with the center of a wafer being positioned accurately and can position wafers having different diameters accurately without removing and replacing mechanisms, by providing specified rotary chuck body, centering mechanism detecting mechanism and positioning mechanism. CONSTITUTION:A rotary chuck body 26 supports a wafer 28 and rotates the wafer. A centering mechanism comprises a pair of reference bodies 33, which have a plurality of reference surfaces 31 and 32 that are contacted with the outer periphery of the wafer 28 and can be moved back and forth and up and down with respect to the rotary chuck body 26. A detecting mechanism has a detecting part 48 that can handle a plurality of orientation flats and can be moved back and forth an up and down with respect to the rotary chuck 26. A positioning part comprises the following parts: a plurality of pushing bodies, which push the wafer 28 to the direction of the center of the rotary chuck body 26; pushing bodies 55, which can be moved back and forth and up and down with respect to the rotary chuck 26; and reference bodies 54, which are provided at the facing positions so as to hold the pushing body 55 and the rotary chuck body 26 and can be moved back and forth and up and down with respect to the rotary chuck 26.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Field of Application) The present invention relates to a positioning device for a disk-shaped wafer that has an orientation flat whose outer periphery is partially cut into a straight line.

(Prior Art) For example, in the production of semiconductor devices, semiconductors are often sliced into disk-shaped wafers and subjected to various processing. Many of these additions involve so-called fine machining, and high precision is required for positioning.

In order to position the wafer, it is most preferable to simultaneously position the center of the disk and simultaneously position the orientation flat (hereinafter referred to as orientation flat), which is a linear notch cut out in the circumference.

As positioning devices that take this requirement into consideration, there are recently devices shown in FIGS. 8 to 10.

The apparatus shown in FIG. 8 uses centering pins (3a
) (3b) (3c) (3d) (3e) Holds a concentric suction tube on a rotary chuck part (5) having a suction hole (4) and rotates the wafer (2) in the direction of the arrow (lot). Two optical detection bodies (G
a) (6b) detects that the light emitted from the detection objects (6a) (6b) no longer receives the reflected light from the back surface of the wafer (2), and rotates the wafer (2). A pressing body (1) that stops and presses the reference body (8) having the orientation flat reference surface (7) and the orientation flat (9) against the orientation flat reference surface (7).
This is a device that accurately positions by squeezing it with 0).

The apparatus shown in FIG. 9 includes a conveyor belt (11a) (1lb
) transporting the wafer (12) from the direction of the arrow (102) to the first transport belt (13a) (13b)
Rough positioning is achieved by stopping the conveyance at the stopper (I Ga) (1[ib) at the transfer section (15) between the first and second conveyor belts (14a) and (14b). Furthermore, as the transport of the wafer (12) is stopped, the transport belts (13a) (13b) (14a) (14b)
By the operation of the drive mechanism (not shown) of the arm (17), the proximal end is rotated upward with the other end as the fulcrum (18) (19).
(Figure 10). Thus, the optical detection section (20a)
Wafer guide (21a) with (20b) <21b
) is brought close to the wafer (12) to a position of about several m11. After this, the conveyor belt (13a) (14a
) in the direction of arrow (103) and conveyor belt (13b) (
14b) in the direction of arrow (104). As a result, the wafer (12) is transferred to the conveyor belt (13a) (14
a) Automatically rotates in the direction of arrow (105) under the inertial force of the system and the conveyor belt (13b) (14b) system. After that, the optical detection parts (20a) (20b) transmit the light emitted from the optical detection parts (20a) (20b) to the wafer (1).
2) When it detects that it no longer receives light reflected from the back surface of the conveyor belt (13a) (13
b) (14a) (+4b) stops rotating. Thereafter, the wafer guide (21a) (2lb) is further brought close to and in contact with the wafer (12).
) is a device for positioning.

(Problems to be Solved by the Invention) The device shown in FIG. 8 has centering pins (3a) (3b)
(3c) Hd) (3e) is fixed, so it can only be applied to wafers of one type of size, and each time the wafer size is changed, the dispensing pins (3a) (3b) (
3c) The arrangement of (3d) and (3e) must be changed, and the optical detector ((ia) (6b) can only be applied to one size of wafer, so if the wafer size is changed, Optical detector ([ia) (6b) in each case
There was a problem in that the arrangement of the parts had to be changed as well.

The device shown in FIG. 9 has a fixed stopper (tea)
IGb) and the wafer guide (21a) (
21b) can only accommodate wafers of one size, so when the size of the wafer is changed, the arrangement of the stoppers (16a) (18b) and the wafer guides (21a) (21t+ ) had to be changed in size.

The present invention has been made to eliminate such problems, and it is possible to accurately position the orientation flat while maintaining the 1u positioning accuracy of the center of the disk-shaped wafer, and furthermore, it is possible to accurately position the orientation flat for wafers with different radii. Another object of the present invention is to provide a wafer positioning device that can accurately position a wafer without removing and replacing the mechanism.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides a rotating chuck body that rotates while supporting a wafer provided with an orientation flat on its upper surface; A plurality of reference surfaces are provided at concentrically opposed positions and abut against the outer edge of the wafer.
1. Can it move forward and backward at the same time with respect to the rotating chuck body?
A centering mechanism consisting of a pair of base bodies that can be moved downward and a detection section for one or more types of orientation flats provided at opposing positions on the outer periphery of the rotary chuck body can move forward and backward with respect to the rotary chuck body. a detection mechanism that is large and movable up and down; and a plurality of detecting mechanisms provided on the outer circumference of the rotary chuck body at a position facing the detection mechanism and pushing the wafer supported on the upper surface of the rotary chuck body toward the center of the rotary chuck body. a pressing body having a set of pressing mechanisms and capable of moving forward and backward with respect to the rotary chuck body and movable up and down; and a plurality of reference surfaces provided at opposing positions inviting the pressing body and the rotary chuck body, and having a plurality of reference surfaces. A wafer positioning device is provided, characterized in that it is equipped with a positioning mechanism including a reference body that can move forward and backward with respect to a rotating chuck body and can move up and down.

(Function) According to the present invention, the semiconductor wafer to be positioned is placed on the rotating chuck body, and after centering by the centering mechanism is completed, it is rotated on the rotating chuck body, and the orientation flat surface is set at a predetermined position by the orientation flat detection mechanism. When it is detected that the
The rotary chuck body stops rotating and is finally positioned by the positioning mechanism. Furthermore, even if the size of the semiconductor wafer is changed, the centering mechanism, orientation flat detection mechanism, and positioning mechanism can accommodate wafers of various sizes by controlling the drive area of each mechanism. In other words, even if the size of the A conductor wafer is changed, the required positioning can be performed with high precision without requiring the removal and replacement of each mechanism.

(Example) An example of the present invention will be described below based on the drawings. This embodiment is a semiconductor wafer positioning device in which an orientation flat is formed.

This device is composed of a rotary chuck mechanism (1), a table, and a positioning mechanism (IV).

The rotary chuck mechanism (1) includes a drive motor (28) and an output shaft (2) of the drive motor (23) on a support base (22).
4) and a disc-shaped vacuum chuck part (2B) which is rotatably supported by the vacuum chuck part (2B) and has a suction hole (25) on the upper surface.

The vacuum chuck section (26) communicates with an external vacuum source (not shown). Wafer (2) with orientation flat (27)
8) is held by suction on the upper surface of the vacuum chuck part (2G) and is rotationally driven by the drive motor (23).

The centering mechanism (II) is connected to the vacuum chuck section (2B).
A reference surface C+ is provided at a position facing the table (29) across the wafer (28) held by suction on the upper surface, and abuts against the outer peripheral edge (30) of wafers of different sizes.
(3La), C2 (31b), C3 (31c)
.

C' (32a), C' (32b), C'
(32c) arranged in steps
A pair of reference bodies (3
3a) (33b) and the above pair of reference bodies (33a)
(33b>) and the air cylinder (35) attached to the fixture (34), and the pair of reference bodies (33a) (
33b) to the guide rail (87a) (67b) (8
7c) Guide table (38a) (36b) (36c) (30c) movably supported along (87d)
) (30d) and the air cylinder (35) are formed by a four-bar link that transmits the driving force of the air cylinder (35) to the pair of reference bodies (33a) (a3b), /, and two opposing apexes thereof are pins (08a) ( 68b) and the pair of reference bodies (33a
) (33b) connecting rod (37a) (37b)
) (37c) (37d) and the above connecting rod (37a)
(37b) (37c) Stoppers that limit the movement range of (37d) (38a) (38b) (38e)
(38d) and the connecting rods (37a) (37b) (3
7c) The connecting rod (39) and the connecting plate (40) that transmit the drive of the air cylinder (35) to (37d) and the pair of reference bodies (33a) and (33b) move in the opposite direction (when The above connecting rods (37a) (37b) (3
7c) (37d) to the reference body (33a) (
33b) and an elastic body (41) that applies a driving force. The elastic body (41) is attached to a pin (42) and a screw (43).

The pair of reference bodies (33a) and (33b) are simultaneously driven forward and backward relative to the suction-held wafer by transmitting the drive of the air cylinder (35) by the above-mentioned transmission means.

The orientation flat detection mechanism (nI) detects a wafer (2B) held by suction on a guide rail (44) provided at a position orthogonal to the moving direction of the reference bodies (33a) (33b) on the table (29). A reference body (45) is cantilevered so as to be movable forward and backward, and an air cylinder (45) attached to a fixture (not shown) drives the reference body (45).
), the air cylinder, and the reference body (45)
and a connecting rod (47) passing through a guide groove (46) connecting the two. Furthermore, on the upper surface of the reference body (45) -)C
I) Maintenance of wafers with different sizes; Detector for detecting W (48a) (48b) (48c), (49a)
(49b) (49c) , (50a) (50b)
(50c), and as shown in FIG.
(49b) (49c).

(50a) (50b) (50c) are box bodies (
51) (52) It is stored inside, and the box body (51
) (52) is attached to a long hole (not shown) provided on the top surface of the reference body (45) by a long screw (not shown). As a result, the box bodies (51) and (52) are installed at their mounting positions on the top surface of the reference body (45) as indicated by the arrows (100).
Can be adjusted in direction. Furthermore, each of the above detection bodies (48
a) (48b) (48c).

(49a) (49b) (49c) , (50a)
(50b) and (50c) are optical sensors, which have a function of detecting the light emitted from the internal light emitting element reflected on the back surface of the wafer (28) using the internal light receiving element. When the oriflano reaches the upper part of a predetermined detection object due to the rotation of the rotary chuck mechanism, this is detected and a signal is sent to an external control device (not shown) to stop the rotation. Furthermore, the above detection bodies (411a) (48b) (4
8C), (49a) (49b) (49c),
The arrangement of each detection object in each set (50a), (50b), and (50c) is determined according to the size of the wafer to which each set corresponds. Further, each of the detection bodies is collected into one bundle and connected to an external control device through the hole ( ) i ) of the reference body (45).

The positioning mechanism (IV) is supported by a cantilever as shown in FIG. The wafer (28) held by suction on the upper surface of the vacuum chuck part (26) is sandwiched between the base body (54) and the wafer (28) held by suction on the upper surface of the vacuum chuck part (26). It consists of a pressing body (55) which is provided at a position and is provided to move in the same direction as the moving direction of the reference body (54). The reference body (54) is attached to the fixture (58) by a connecting rod (57) passing through the guide groove (56) and has reference peaks jD + (6Qa), D 2 (GO
b), D 3 (GOc) is arranged in steps. The pressing body (55) has a guide groove (81a) (
81b) and is connected to an air cylinder (63) attached to a fixture (62) as shown in FIG. Further, the pressing body (55) has the reference plane D + (60a) - D 2 (Bob), D 3
([10c)] It is possible to press the wafer (28) by coming into contact with the outer peripheral edge of the wafer (28), and also to prevent the movement of the wafer (28) in a direction perpendicular to the direction of suppression, and when the wafer (28) is suppressed. Elastic body (64a) that buffers and absorbs impact
(64b) (Ili4c) (84d) (84e
) (84f) (85a) (85b)
) (65c) (85d) (85e) (851'
) as the reference plane D + (60a), D 2 <GOb
), D 3 (60c) and are arranged in a step-like shape at positions facing each other. Further, the reference body (54) and the pressing body (55) can be driven forward and backward relative to the wafer (28) simultaneously or individually.

The table (29) also has an air cylinder (86a
) (GGb), whereby each mechanism provided on the table (29) can be adjusted to any height.

Next, the operation of the above embodiment will be explained.

Initially, the rotating chuck mechanism (1) does not rotate and is stopped.

A pair of reference bodies (33a) (Jb), a reference body (45),
The reference body (54) and the pressing body (55) are placed on the table (29) by a rotary chuck machine? g (1) and the table (29) is in a lowered state. First, a wafer (28) having an orientation flat (27) is placed on the vacuum chuck section (26) and held by suction. At this time, the suction power is a pair of reference bodies (33a) (33b),
In response to the force applied to the wafer (28) held by suction on the vacuum chuck part (26) by the reference body (54) and the pressing body (55), the wafer (28) moves to the vacuum chuck part (26).
26) It is sufficient to be able to move it on the top. In addition, wafer (28
) is arranged so that it is roughly centered when placed on the vacuum chuck part (26). Subsequently, the table (29) is raised by a predetermined upward drive distance for the size of the wafer (28) held by suction, and then a pair of reference bodies (33a) (3
3b) moves forward at the same time to pinch and center the wafer (28). At this time, since the upward drive distance is determined for each wafer size, the wafer (28)
The forward drive distance relative to the wafer may remain constant as the wafer size changes.

After centering, a pair of reference bodies <33a) (33b)
moves backward relative to the wafer (28), and the table (29) descends by a certain distance.The downward driving distance at this time is the distance from the back surface of the wafer (28) near the outer periphery after the centering of the reference body (45). The detection object (48a) (48
b) (48c) , (49a) (49b) (49
c) , (50a) (50b) (50c) may be a distance that allows detection of the orientation flat (27) of the wafer (28).

Thereafter, the reference body (45) moves forward with respect to the wafer (28) by a driving distance predetermined based on the size of the wafer (28), and enters under the back surface near the outer peripheral edge of the wafer (28). As a result, a detection body suitable for the size of the held wafer (28) is placed at the optimal orientation flat detection position near the outer peripheral edge and under the back surface of the wafer (28). After that, drive the drive motor (28) to move the vacuum chuck part (2B),
When the wafer (28) is rotated and the state shown in FIG. 7 (2) is reached, the drive motor (23) is temporarily stopped and then driven again at low speed until the state shown in FIG. 7 (3) is reached. When this happens, a signal is sent from the detection object and the drive motor (23)
stops.

After the orientation flat is detected, the reference body (45) retreats, and then the table (29) rises by an upward drive distance predetermined for the size of the wafer (28) held by suction. At this time, the vacuum chuck section (2B) stops suction by the external vacuum source.

After that, the reference body (54) and the pressing body (55) are attached to the wafer (28).
) direction by a certain distance. Here, the reference body (
54) and the pressing body (55) have the upper y7 driving distance determined in advance for each wafer size, so the wafer (
The forward drive distance for 28) may remain constant as the wafer size changes. Thereafter, the reference body (54) and the pressing body (55) are driven forward, and the orientation flat (27) is moved forward by the reference body (55).
54) Reference plane DI (80a) D 2 (Bob)
Place the pressing tool (6) on the corresponding reference surface in D3 (60c).
5a) (85b) (85c) (65d) (θ5e)
The wafer (28) is pressed by the abutting suppressor in (θ51'), thereby positioning the wafer (28). At this time, the reference body (54) and the pressing body (55) are attached to the orientation flat (27
) may be pinched from both sides without being parallel to the corresponding reference plane, but since the wafer is not attracted, it is positioned with a slight pinching force. After this, the reference body (
54) and the pressing body (55) retreat. This completes the final positioning of the wafer.

Note that this series of operations is controlled by an external control device.

In this embodiment, a semiconductor wafer has been described, but the present invention is not limited to this and has an orientation flat. Wafers are fine. Also, a pair of reference bodies (33a) (33b), a reference body (5
4) Although the pressing body (55) is configured in a step-like manner, it may be configured in another way, and the orientation flat detection section may be attached to the reference body (45) in other ways, and furthermore, in a non-contact manner, it may be configured in another way. The following detection method may also be used. Further, the drive motor may be a DC motor or another motor.

Further, in this embodiment, each mechanism was moved up and down by the table (29), but it is also possible to move it up and down by providing each mechanism with its own drive device.

[Effects of the Invention] According to the present invention, it is possible to handle the positioning of several types of wafers of different sizes without changing the setup of the apparatus. Further, when the detection section detects a predetermined position (orientation flat surface) of the semiconductor wafer rotated by the rotary chuck body, the rotation is stopped and predetermined positioning is performed, so that no complicated calculation means is required. Furthermore, since the wafer is rotated while being held by the rotary chuck body, centering accuracy can be maintained as is.

Furthermore, the ability to handle several types of wafers of different sizes without having to change the equipment setup reduces the number of equipment setup changes, and also eliminates the problem of dust generation during setup changes. It is also useful for use in clean rooms.

[Brief explanation of the drawing]

1 to 6 are detailed explanatory diagrams of the present invention, in which FIG. 1 is a plan view of an embodiment of the present invention, and FIG. 2 is similar to FIG. 1A.
3 is a cross-sectional view of the main part as seen from the A' direction on the line B-B' in FIG. 1, and FIG. FIG. 5 is an enlarged view of the upper part of FIG. 4, FIG. 6 is a front view of the main portion seen from direction C, FIG. 7 is a positional relationship between the detection object and the wafer. FIG. 8 is a plan view of the conventional example, FIG. 9 is a plan view of another embodiment, FIG. 10 is a front view of the main part seen from direction E in FIG. 9, and FIG. The operating states of the detection body and the drive motor in each state of the figure are shown. (22)...Support stand (23)...Drive motor (2B)...Rotary chuck body (28)...Wafer (29)...Table (33a), (Hb
) ---Reference body (36a), (36b), (36c)
, (3Gd) - Guide table (44)...Guide rail (48a) (48b) (48c), (49a)
(49b) (49c). (50a) (50b) (50c) - Detector (53)
・・・Guide rail

Claims (1)

[Scope of Claims] A rotary chuck body that rotates while supporting a wafer on its upper surface provided with an orientation flat, and a plurality of references that are provided at positions concentrically facing the rotary chuck body and abut against the outer peripheral edge of the wafer. A centering mechanism consisting of a pair of reference bodies each having a surface and capable of moving forward and backward with respect to the rotary chuck body simultaneously and movable up and down; a detection mechanism that has a corresponding detection section and is capable of moving forward and backward relative to the rotary chuck body and can move up and down; a pressing body having a plurality of pressing mechanisms for pushing the supported wafer toward the center of the rotating chuck body, and capable of moving forward and backward with respect to the rotating chuck body, and movable up and down; the pressing body and the rotating chuck body; 1. A wafer positioning device comprising: a reference body which has a plurality of reference surfaces and is movable up and down as well as forward and backward relative to the rotating chuck body.