JPH06105746B2 - Wafer counter and wafer counting method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a wafer counter and a wafer counting method used during a manufacturing process of a semiconductor device such as an IC or an LSI.

2. Description of the Related Art A wafer is stored in a carrier and transported, and the following work is performed during the transportation.

(1) Orientation flat alignment work for aligning the horizontal portion of each wafer in the carrier, that is, the orientation flat, on the same horizontal line.

(2) Counting work such as checking whether wafers are accommodated in each wafer groove of the carrier and calculating the number of wafers.

Conventionally, in this orientation flat alignment work, a facet aligner F as shown in FIG. 6 is used, a carrier C is placed on a stage S, a substrate 2 is moved up and down by a drive cylinder 1, and a roller 3 is mounted on a wafer W. After contacting the outer peripheral edge, the motor 4 is driven to rotate the roller 3 to align the orientation flats.

Further, for the counting work, a wafer counter K as shown in FIG. 7 is used. After the work is finished, the carrier C is carried to the stage S just above the wafer counter K, and the motor 6 is driven to push it up. After moving the table 7 upward to fit the outer peripheral edge of the wafer W into the wafer groove 8, the motor 9 is driven to move the reflection type optical sensor 11 and the central space portion 10 of the table 7.
Wafers are counted by moving the wafer along.

Problems to be Solved by the Invention In the conventional wafer counter, since the reflection type optical sensor 11 is moved to count the wafers, a lot of time is required for counting and the work efficiency is not good.

Further, the light of the reflection type optical sensor 11 hits the outer peripheral edge of the wafer W and is reflected. However, since the outer peripheral edge is formed extremely thin, the light of the sensor will be reflected on the outer peripheral edge of the wafer unless the wafer W is in the vertical state. If it does not hit, it may malfunction.

Further, since the facet aligner F and the wafer counter K are fixed at separate positions, the counting work cannot be performed unless the carrier is carried to the position of the wafer counter K after the completion of the orientation flat alignment work.

Therefore, it takes a considerable amount of time before the counting work is started, and the work efficiency is not good.

In view of the above circumstances, it is an object of the present invention to accurately and quickly count wafers and to improve work efficiency.

Means for Solving the Problems The present invention is directed to a wafer count portion formed on a vertically movable substrate and a plurality of wafer count portions formed in parallel to each other.
Further, a wafer counter means comprising a measurement groove of the wafer with which the orientation flat of the wafer abuts, and a transmissive optical sensor in which a light emitting portion and a light receiving portion are provided facing each other at ends on both side walls of each measurement groove. And a; a facet aligner that is integrally connected to the wafer counter means and that can be moved to directly below a carrier. Therefore, the above problem is solved.

After the carrier is carried to the predetermined position on the stage, the facet aligner is moved to bring the roller into contact with the lower end of the wafer in the carrier, and the roller is rotated to align the orientation flats of the wafers.

Next, the facet aligner is moved, the wafer counter is moved to the lower part of the carrier, and the lower end of the wafer is fitted into the measurement groove of each wafer.

At this time, the light of the light emitting portion of the optical sensor is radiated toward the wall portion of the facing measurement groove, but when the orientation flat (orientation flat) of the wafer comes into contact with the measurement groove and is housed in an aligned state, The light hits the surface of the wafer and is reflected and does not enter the light receiving portion. Conversely, when the wafer does not exist or the orientation flat of the wafer is located above and does not contact the measurement groove, the light of the optical sensor Is not shielded from light and crosses the measurement groove and enters the light receiving section.

Embodiment An embodiment of the present invention will be described with reference to the accompanying drawings.

In FIG. 1, reference numeral 11 denotes a facet aligner mounted on the second moving device 12, which comprises a cylindrical roller 13 and a motor 14 for driving the roller 13. The second moving device 12 includes a vertically moving cylinder 15, a left and right cylinder 16, and a front and rear cylinder 17, and moves the facet aligner 11 to an arbitrary position.

20 is a wafer counter mounted on the first moving device 21, which is a substrate
As shown in FIG. 2, a wafer support portion 23 is formed on both sides of the wafer 22, and a wafer counter portion 24 is formed at the center of the wafer support portion 23. The support portion 23 has support grooves 23 for a plurality of wafers.
a are formed in parallel with each other with a space.

In the counter portion 24 of the wafer, a plurality of measurement grooves 24a positioned on the same straight line as the support groove 23a are formed in parallel with each other. An optical sensor 25, for example, a photo sensor is arranged at an end portion of the wall portion 24b on both sides of each measurement groove 24a. The optical sensor 25 is formed of a light emitting portion 25a and a light receiving portion 25b, which are arranged so as to face the end portions 24b of the wall portions 24b on both sides of each measurement groove 24a.

The light emitting portion 25a of one set of optical sensors and the light receiving portion 25b of the other set of optical sensors are arranged on the same wall portion 24b, but since the width W of the wall portion is narrow, both of them are in the longitudinal direction of the measurement groove. Are arranged in a so-called zigzag pattern at intervals.

The optical sensor 25 is a transmissive type, but it goes without saying that it may be a so-called reflective type optical sensor in which a set of a light emitting portion 25a and a light receiving portion 25b are arranged on the same wall portion 24b.

The first moving device 21 includes a vertically moving cylinder 27 and a left and right cylinder.
It is composed of 16 and front and rear cylinders 17, and can move the wafer counter 20 to an arbitrary position. The wafer counter 20 is integrally connected to the facet aligner 11. The arrow indicates the moving direction.

Next, the operation of this embodiment will be described.
After the carrier 31 is conveyed to the predetermined position and locked, the facet aligner 11 is moved to just below the carrier 31 by the cylinders 16 and 17.

Then, as shown in FIG. 5, the roller 13 is moved by the vertically moving cylinder 15 from the position indicated by the chain line to the position indicated by the solid line to bring it into contact with the lower end of the wafer 32 in the carrier. When the motor 14 is driven, the roller 13 is rotated. The position of each wafer 32 is adjusted so that the orientation flats 32a are aligned.

Next, using the vertical movement cylinder 15, the facet aligner 11
After moving down, the wafer counter 20 is positioned directly below the carrier 31 by the cylinders 16 and 17, and the vertical moving cylinder 27 moves the substrate 22 from the position indicated by the chain line to the position indicated by the solid line as shown in FIG. Then, the lower end of the wafer 32 in the carrier is fitted into each measurement groove 24a.

At this time, the light from the light emitting unit 25a crosses the measurement groove 24a and is received by the light receiving unit
Although directed toward 25b, when the wafer 32 exists in the measurement groove 24a, the light impinges on the surface of the wafer and is reflected.
Never enter 25b.

On the contrary, if the wafer 32 does not exist in the measurement groove 24a, the light crosses the measurement groove 24a and enters the light receiving section 25b.

In this way, the presence / absence of wafers and the number of wafers are measured based on the presence / absence of light reception by the light receiving unit 25b. Also, wafer
Even if 32 is present in the measurement groove 24a, if the orientation flat of the wafer is not aligned, that is, if the orientation flat is positioned above or to the left or right, the wafer 32 is positioned in the measurement groove 24a at the arc-shaped peripheral edge. Since it abuts, the wafer 32
The lower part of does not exist. Therefore, the light of the optical sensor is not shielded by the lower portion of the wafer and enters the light receiving portion, so that it is understood that the orientation flat is not aligned.

EFFECTS OF THE INVENTION As described above, according to the present invention, the measurement grooves of a plurality of parallel wafers formed in the counting portion of the wafer and the optical sensor arranged on the wall of each measurement groove are provided. If the wafer is present in the wafer, the light from the light emitting portion of the photosensor will surely strike the surface of the wafer.

Therefore, even if the wafer is not in the vertical state, the light can be surely shielded, so that the wafer can be accurately counted.

Further, since the optical sensor is provided on the wall portion of each measuring groove, the lower end of the wafer can be accommodated in the measuring groove and at the same time the counting of each wafer can be performed.

Therefore, the counting time is extremely shortened as compared with the conventional example.

Further, since the wafer counter is integrally connected to the movable facet aligner, if the carrier is placed at a predetermined position on the stage, it is possible to move the facet aligner and the wafer counter without moving the carrier. It is possible to align orientation flats and count wafers.

Therefore, the work time can be shortened and the work efficiency is improved. Further, since the transmission type optical sensor in which the light emitting portion and the light receiving portion are provided so as to face each other is provided at the end portions of the wall portions on both sides of each measurement groove, the orientation flat of the wafer is present even if the wafer exists in the measurement groove. When located on the upper side, the arcuate peripheral edge of the wafer comes into contact with the central portion of the measurement groove, but since the lower portion of the wafer is not located at both ends of the measurement groove, the light from the optical sensor is at the lower portion of the wafer. It enters the light receiving part without being shielded from light. Therefore, it is possible to know that the orientation flats of the wafer are not aligned. Further, since the transmissive optical sensor is used, the state of the wafer surface and the influence of external light are not affected as compared with the reflective optical sensor, so that accurate detection can be performed.

[Brief description of drawings]

1 to 5 are views showing an embodiment of the present invention.
The figure is a perspective view, FIG. 2 is a plan view of the wafer counter, FIG. 3 is a vertical cross-sectional view showing the usage state of the wafer counter, and FIG. 4 is a part of an enlarged view taken along line IV-IV of FIG. FIG. 5 is a vertical cross-sectional view showing the facet aligner in use, FIGS. 6 and 7 are views showing a conventional example, FIG. 6 is a perspective view showing the facet aligner, and FIG. 7 is a perspective view showing a wafer counter. Is. 11 …… Facet aligner 20 …… Wafer counter 22 …… Substrate 23 …… Wafer support 23a …… Wafer support groove 24 …… Wafer counter 24a …… Wafer measurement groove 25 …… Optical sensor

Claims (3)

[Claims] 1. A counting part of a wafer formed on a vertically movable substrate; a plurality of counting parts are formed in parallel with each other on the counting part.
A wafer counter comprising: a measurement groove of the wafer with which the orientation flat of the wafer abuts; and a transmissive optical sensor in which a light emitting portion and a light receiving portion are provided to face each other at ends of walls on both sides of the measurement groove. 2. A counting part of a wafer formed on a vertically movable substrate: a plurality of counting parts are formed in parallel with each other on the counting part.
Also, a wafer counter means comprising: a measurement groove of the wafer with which the orientation flat of the wafer abuts; and a transmissive optical sensor in which a light emitting portion and a light receiving portion are provided facing each other at ends of walls on both sides of each measurement groove. A wafer counter comprising: a facet aligner that is integrally connected to the wafer counter means and that can be moved to directly below a carrier. 3. A step of placing a carrier containing a plurality of wafers on an adjusting section of a stage, a step of moving a facet aligner just below the adjusting section to adjust an orientation flat of the wafer, and a step of adjusting the facet aligner. After moving to the standby position, a step of moving a substrate having measurement grooves of a plurality of wafers, which are in contact with the orientation flats of the wafers, directly below the adjusting part, and raising the substrates to move the wafers in the carrier to the measurement grooves. The step of housing the lower part: Counting the wafer and aligning the orientation flat depending on the presence / absence of light reception by the light receiving part of the transmissive optical sensor in which the light emitting part and the light receiving part are provided facing each other at the ends of the walls on both sides of each measurement groove And a step of detecting the state.