JPH0334216B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a wafer centering device for aligning the centers of semiconductor wafers and the like having orientation flats to the same position.

[Technical background of the invention and its problems]

There are various methods for aligning the centers of wafers, but the following methods are typical. That is, in the system shown in FIG. 3, a plurality of rotating rollers 2 are provided on one side of a wafer centering position 1, and the wafer 3 is rotated by pressing the wafer 3 against the rotating rollers 2 using air or tilting. In addition, 3 of the rotating rollers 2...
The rotation rollers 2a, 2a at both ends are arranged along the circumferential surface of the wafer 3, and the interval between the rotating rollers 2a, 2a at both ends is set to the length of the orientation flat 3a (hereinafter referred to as orientation flat) of the wafer 3. And rotating roller 2...
When the orientation flat 3a of the wafer 3 that is being rotated is located between the rotating rollers 2a, the wafer 3 falls in the direction of arrow a and stops rotating. At this time, the orientation flat 3a of the wafer 3 is in a non-contact state with the intermediate rotating roller 2b, and by detecting this state with, for example, a photodetector, the position of the orientation flat 3a and the center of the wafer 3 are aligned.

In addition, in the case shown in FIG. 4, when the wafer 3 is rotated while being attracted by a chuck (not shown) and the orientation flat 3a faces in a direction parallel to the rollers 4a and 4a, this is detected by a photodetector or the like. , the rotation is stopped, the vacuum chuck is released, and the wafer 3 is pushed toward the roller 4b using a cylinder or the like, and the wafer is centered at position 1.
The wafer 3 is brought into contact with a plurality of rotatable rollers 4 provided on one side of the wafer 3 to align the position of the orientation flat 3a and the center of the wafer 3.

However, in any of the above centering devices, the rollers are arranged along the outer circumferential surface of the wafer, so if there are variations in the outer diameter of the wafer, the outer circumferential surface of the wafer will not come into contact with all the rollers. This causes a shift in the center position of the wafer, and there is also variation in the length of the orientation flat, so there is a problem that the orientation flat position cannot be accurately determined.

Also, in order to solve the problem as mentioned above,
Devices configured as shown in FIGS. 5 and 6 are also known. In the system shown in FIG. 5, a drive belt 6 is wound around the outside of a plurality of rollers 5 arranged so as to surround a wafer centering position 1, and this drive belt 6 is driven by a pair of drive rollers 7. Run in the direction of the arrow. Furthermore, a contactor 8 is attached to an eccentric position of each of the rollers 5, and the roller 5 is
By displacing the contacts 8 toward the center of the wafer 3 by the rotation of the wafer 3, the outer circumferential surface of the wafer 3 is pressed toward the center for centering. In the device shown in FIG. 6, a plurality of swinging arms 9 arranged to surround the wafer centering position 1 are urged outward, and contacts 10 are provided at the tips of the swinging arms 9, and these swinging arms are By moving the arms 9 upward and pushing the ring 11 upward, the contacts 10 press the outer peripheral surface of the wafer 3 toward the center, thereby aligning the center.

With this configuration, even if the outer diameter of the wafer varies, it is possible to center the wafer, but in the case of FIG. 5, the drive belt 6 is run by the drive roller 7. As a result, the drive belt 6 is partially bent, causing a slip phenomenon in the drive belt 6, and a mechanism for correcting this is required. Further, in the case of FIG. 6, there are problems in that it is difficult to horizontally move the push ring 11 up and down, and it is also difficult to adjust the positions of the contacts 10.

[Purpose of the invention]

This invention was made in view of the above-mentioned circumstances, and its purpose is to accurately maintain the center of the wafer no matter where the orientation flat position of the wafer is or even if there are variations in the outer diameter of the wafer. An object of the present invention is to provide a wafer centering device that can center a wafer.

[Summary of the invention]

In order to achieve the above object, the present invention includes a plurality of rotating arms disposed at equal intervals around the periphery of a sliding ring that is rotatably supported in a horizontal plane and surrounding a wafer installation part, and these rotating arms are arranged at equal intervals. A contact element is provided at one end of the arm to press the outer circumferential surface of the wafer toward the center as the rotating arm rotates, and each of the rotating arms is displaced in the same manner to move the contact element forward and backward with respect to the center of the wafer. The reason is that the wafer is configured to align the center of the wafer.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 shows the wafer centering device as seen from above, and FIG. 2 is a partially sectional side view thereof. In the figure, reference numeral 21 denotes a ring-shaped fixed base, and a sliding ring 23 is rotatably supported on the upper surface of the fixed base 21 via a bearing 22 in a horizontal plane. And this sliding ring 2
3 surrounds the wafer installation part 24,
The wafer installation section 24 has a vacuum chuck 26 that vacuum-chucks the wafer 25 carried in through a wafer conveyance path (not shown) from its lower surface.
is provided. Furthermore, the sliding ring 23
A plurality of lever-type contact mechanisms 27, six in this embodiment, are provided on the front surface of the lever-type contact mechanisms 27 at equal intervals in the circumferential direction. Since these lever type contact mechanisms 27... have the same structure, one of them will be explained as follows.
is a rotating arm, and the intermediate portion of this rotating arm 28 is rotatably supported on the upper surface of the sliding ring 23 by a pivot pin 29. A pinch roller 30 is rotatably supported at one end of the rotating arm 28, and a cylindrical contact 31 is fixed at an eccentric position on the upper surface of the pinch roller 30. That is, by rotating the pinch roller 30, the contactor 31 revolves and moves forward and backward relative to the outer peripheral surface of the wafer 25. Further, a sliding plate 32 is integrally fixed to the side surface of the other end of the rotating arm 28, and a sliding pin 33 is protruded from the upper surface of the fixed base 21 facing the sliding plate 32. Furthermore, a tension spring 35 is stretched between the end of the rotating arm 28 and a post 34 protruding from the outer circumferential surface of the sliding ring 23 to press the sliding plate 32 and the sliding pin 33. This constitutes a rotating means 28a for rotating the rotating arm 28. Then, when the sliding ring 23 rotates clockwise, the sliding plate 32 slides on the sliding pin 33, and the rotating arm 28 rotates counterclockwise about the pivot pin 29, and the contactor 31 moves forward toward the outer peripheral surface of the wafer 25, and conversely, when the sliding ring 23 rotates counterclockwise, the rotating arm 28 rotates clockwise and the contactor 31 retreats from the outer peripheral surface of the wafer 25. It's becoming like that. Moreover, the pivot arms 28 of the lever-type contact mechanisms 27 are configured to be displaced simultaneously and in the same manner.

A part of the outer peripheral surface of the sliding ring 23 configured as described above is provided with an actuating rod 36 projecting outward, and the tip of the actuating rod 36 is connected to an actuator installed perpendicularly thereto. It is connected to 37. The sliding ring 23 is rotated by an operating rod 36 which is rotated by an actuator 37. In addition, 38 is the sliding ring 23
This is a manual operation arm that protrudes from a part of the outer peripheral surface of the slide ring 23, and rotates the sliding ring 23 during adjustment. Further, 39 is a fixing jig for fixing the sliding ring 23 to the fixed base 21 when adjusting the contactor 31.

Therefore, the contact 3 of each lever type contact mechanism 27...
1... form the same inscribed circle, the manual operation arm 38 is operated to rotate the sliding ring 23, and each rotating arm 28...
to the adjustment position. And fixing jig 3
9 fixes the sliding ring 23. In this state, a master disk (not shown) is attracted to the vacuum chuck 26 of the wafer installation section 24. And the pinch roller 30 of each lever type contact mechanism 27...
is rotated to bring the contactor 31 into contact with the outer peripheral surface of the master disk.

After setting the contacts 31 of each lever-type contact mechanism 27 in this way, the fixing jig 3
After releasing the fixation of the sliding ring 23 by 9 and removing the master disk, the center of the wafer 25 is aligned. In this case, the wafer 25 carried in via the wafer transport path is attracted by the vacuum chuck 26 and set in the wafer setting section 24. Next, when the actuator 37 operates and the operating rod 36 rotates in the direction of the arrow, the sliding ring 2
3 rotates clockwise (actually a rotation angle of several degrees). Therefore, the sliding pin 33 and the sliding plate 32 of each lever type contact mechanism 27 slide, and the rotating arm 2
8 rotates counterclockwise around a pivot pin 29. Therefore, the contacts 31 move toward the center of the wafer installation section 24 and press the outer peripheral surface of the wafer 25 from six directions toward the center. Therefore, the wafer 25 moves to the center position, and in this state, the vacuum chuck 26 sucks the wafer 25, thereby making it possible to center the wafer 25. At this time, the rotating arm 28
When the contactor 31 provided on one of the rotating arms 28 is at the orientation flat 25a of the wafer 25, the other rotating arm 28
The wafer 25 is disposed at a position where the wafer 25 can be held by a contactor 31 provided thereon. Therefore, the fixed amount of displacement of the rotating arm 28 is such that the contactor 31 provided on the rotating arm 28 contacts the outer peripheral portion of the wafer 25 and does not contact the orientation flat 25a. It is set. Therefore, in this embodiment, due to the presence of the orientation flat 25a of the wafer 25, one contactor 31 out of the six lever-type contact mechanisms 27 faces the orientation flat 25a and is in a non-contact state. Centering of the wafer 25 is possible using the remaining five contacts 31, and no matter where the orientation flat 25a is located, the centering is not affected; however, the number of contacts 31 is It is desirable that the number is 5 or more. After centering the wafer 25 through these series of operations, the orientation flat 25a can also be detected in a non-contact manner using the fixed image pickup device and the rotation of the wafer itself.

Note that, according to the embodiment, the sliding ring 23
Although an actuating rod rotated by an actuator is used as a means for rotating the rotary arm, the present invention is not limited to this, and other rotary drive means may be used, and a sliding plate and a sliding pin can be used as a means for rotating each rotary arm. was used, but this structure is not limited.

The wafer centering device of this invention is
It can be used in any semiconductor manufacturing process such as a wafer inspection process, exposure process, and various processing processes that requires centering of a wafer.

〔Effect of the invention〕

As explained above, according to the present invention, even if there are variations in the outer diameter of the wafer, regardless of the position of the orientation flat, a plurality of contacts that are simultaneously displaced from the outer circumference of the wafer in the same manner By pressing toward the center with the child, the center can be accurately aligned.

[Brief explanation of drawings]

FIG. 1 is a plan view of a wafer centering device showing an embodiment of the present invention, FIG. 2 is a partially longitudinal side view of the same, and FIGS. 3 to 6 are different views of conventional wafer centering devices. It is an explanatory diagram showing an example. 21...Fixed base, 23...Sliding ring, 2
4...Wafer installation part, 25...Wafer, 28
a... Rotating means, 28... Rotating arm, 31...
contact child.

Claims (1)

[Claims] 1. A wafer centering device for positioning the center of a wafer at a predetermined position, which has an orientation flat on a part of the peripheral edge, and a wafer installation part that removably holds the wafer, and a wafer installation part that is fixed. a fixed base, a sliding ring rotatably supported by the fixed base in a horizontal plane and surrounding the wafer installation section, a sliding ring rotating means for rotationally driving the sliding ring, and a sliding ring rotatably supported by the fixed base in a horizontal plane; at least five rotating arms disposed along the circumferential direction of the sliding ring and rotatably supported in a horizontal plane with respect to the sliding ring; A contact element that comes into contact with the outer peripheral surface of the wafer as the arm rotates, and a contact that contacts the outer peripheral surface of the wafer each time as the sliding ring rotates by the sliding ring rotation means provided between the fixed base and the sliding ring. biasing means for positioning the center of the wafer at a predetermined position by displacing the movable arm by a predetermined amount relative to the wafer and elastically pressing the contactor against the wafer; The pivoting arms of the pivoting arms of the wafer are arranged such that when the contactors provided on one of the pivoting arms are in the orientation flat position of the wafer, the contactors provided on the other pivoting arm cause the wafer to be is placed in a position where it can hold, and
The fixed amount of displacement of the rotating arm is set such that a contact provided on the rotating arm contacts the outer circumference of the wafer and does not contact the orientation flat. A wafer centering device featuring: