JP2009272412A - Notched wafer aligning apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a notched wafer aligning apparatus that securely rotates and aligns each wafer, and to suppress production of wear powder. <P>SOLUTION: The notched wafer aligning apparatus aligns positions of notches of a plurality of notched wafers 1 contained in cassettes in a line and rotates the wafers to optional positions to align the positions of the notches in a line. According to the notched wafer aligning apparatus, driving rollers holding the respective wafers standing collaterally in a rotatable state are arranged in a plurality of aligns below the wafers, driving shafts 2 are held rotatably in the centers of the driving rollers, a driving mechanism transmitting the driving force of a motor 6 in the same direction synchronously is connected to respective rotary shaft, and a plurality of plungers, pressing positioning pins, sized to engage shapes of the notches in vertical directions, are fixed to a slider in a collaterally standing state. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a notched wafer alignment apparatus for aligning the positions of notches provided in the outer periphery of a wafer at an arbitrary position in a cassette containing a plurality of semiconductor wafers.

In the manufacture of semiconductor devices, a cassette for storing a plurality of semiconductor wafers is used as means for transporting the semiconductor wafers to each processing step. A part of the outer periphery of the wafer is provided with a notch (hereinafter referred to as a notch) for discriminating the crystal direction and for alignment.

The processing apparatus that executes each processing step is provided with a notched wafer alignment device that rotates the wafer in the cassette to align the notch positions in order to position the notches of the wafer. This aligning device includes a lifting device that comes in contact with the wafer by approaching from below the cassette, and a device that places a cassette containing a plurality of wafers on the aligning device by a transfer device such as a robot. .

As a process of the alignment apparatus, there are a process of aligning the positions of notches of a plurality of wafers in a line and a process of rotating all the aligned wafers to an arbitrary position.

The notch positions are aligned in a single line. The wafer is supported by a drive shaft that drives the wafer by transmitting a driving force such as a motor, and an idler shaft that supports the idler and idler that can rotate as the wafer rotates. Thus, when the drive shaft reaches the notch position of each wafer, the drive shaft and the notch of the wafer are not in contact with each other so that the positions of the notches of each wafer are aligned in a row.

As for the process of rotating all the aligned wafers to an arbitrary position at once, the drive shaft is released from the notch, and another drive shaft is rotated in contact with each wafer to rotate all the wafers. It is configured to rotate to any position at once.
JP-A-6-345208 Japanese Patent Laid-Open No. 10-4133 JP 2002-164418 A

Here, in order to reliably rotate each wafer in order to align the notch positions of the wafer, the material of the drive shaft is selected so that the contact resistance between the drive shaft and the wafer is increased, and the wafer is rotated by the drive shaft. The wafer cannot be rotated unless the rotational force is greater than the contact resistance between the idler and the idler shaft or the contact resistance of the wafer held in contact with the cassette.

However, in the conventional method, since the drive shaft for rotating each wafer needs to be large enough to fit into the notch, the thickness of the drive shaft cannot be increased, and the thin drive shaft is compared with the thick drive shaft. Since it is difficult to transmit the driving force transmitted from a motor etc. to the wafer, the contact resistance between the idler and idler shaft and the contact resistance with the cassette due to the tilt of the wafer may become larger, and the wafer rotates. There are things you can't do. In particular, after the re-fusion process in which the contact resistance is low in the wafer surface treatment process, the drive shaft and the wafer slide, and the wafer cannot be rotated well.

Furthermore, each wafer is stored side by side in the cassette, and because the wafers are arranged side by side by contacting a threshold plate provided in the cassette, the wafers are rotated. If the wafer is in contact with the threshold plate when aligning the notches, not only the contact resistance between the wafer and the cassette will increase, but also the wear powder of the wafer or threshold plate will be generated due to wear and adhere to the wafer. May end up.

Since the drive shaft is always rotating until it is determined that all the wafers are aligned, the drive shaft enters the notch of each wafer, and the drive shaft is not transmitted even after the driving force for rotating the wafer is transmitted. Rotating while making slight contact with the notch, the contact resistance of the drive shaft is lowered to make it slippery and the contact resistance is lowered, and wear powder may be generated and adhere to the wafer.

The present invention has been made based on the above circumstances, and an object of the present invention is to provide a notched wafer alignment apparatus capable of reliably rotating and aligning each wafer, and further generating wear powder. The purpose is to suppress.

As a means for solving the above-described problems, the present invention provides a notched wafer in which notch positions of a plurality of notched wafers housed in a cassette are aligned in a line and rotated to an arbitrary position to align the notch positions. In the alignment device, a plurality of rows of drive rollers that hold the wafers in parallel and rotatably are arranged below the wafers, and the drive shafts are rotatably held at the centers of the drive rollers. Of a wafer with a notch having a configuration in which a drive mechanism that transmits the same in the same direction is connected, and a plurality of positioning pins that engage with the shape of the notch are fixed to a slider that moves a plurality of plungers that move up and down. Configure the alignment device.

Further, the drive roller has a V-shaped cross section, the edge portion of the outer peripheral surface of the wafer is held in contact with a plurality of rows of drive rollers, and each wafer and each drive roller are arranged at the same fixed interval as the cassette.

Furthermore, a positioning roller that engages with the notch is disposed at the tip of the positioning pin, and is configured to be rotatable with respect to the positioning pin.

As described above, since it is not necessary to make the drive shaft for rotating each wafer into the notch, the rotation shaft can be made thicker, a stable drive force can be transmitted, and a plurality of drive shafts can be transmitted. The driving roller holds the wafer side by side so that it can rotate freely, so that the rotation can be performed without contacting the cassette or the adjacent wafer.

In addition, a plurality of rows of rotating shafts for rotating each wafer and each driving roller are arranged, and each rotating shaft is connected to a driving mechanism that transmits the driving force of the motor in the same direction. Since the contact resistance generated between the idler and the idler shaft is not added, the rotation is not hindered.

For positioning of the notch, the plunger presses the positioning pin against the wafer from below, and when the tip of the positioning pin is inserted into the notch, the weight of the wafer and the shape of the notch are caught in the rotation direction and positioned at that location. Since it is configured, positioning is performed reliably. In this case, the rotation of the wafer is also positioned so that the driving roller in contact with the wafer also stops rotating, and the driving force transmitted by the driving shaft is driven by the driving roller. Since it is consumed by sliding between the shafts, no unnecessary force is applied to the wafer.

The driving roller that contacts the wafer has a V-shaped cross section, so that the edge portion of the outer peripheral surface of the wafer touches both of the V-shaped slopes of the driving roller. In addition to being able to reliably rotate the wafer, the wafer is held in contact with a plurality of rows of drive rollers, and each wafer and each of the drive rollers are arranged at the same fixed interval as the cassette, so that the wafer can be placed in addition to the drive rollers. Can be juxtaposed without contact.

Also, when the slider with the plunger fixed rises, the tip of the positioning pin of the plunger rises to a position where it engages with the notch of the wafer supported by the drive roller, positions the notch of each wafer, and the slider descends Sometimes it is possible to rotate all the aligned wafers to any position by lowering them to a position where they do not come into contact with the wafers. However, since the driving roller supports each wafer, another rotation is performed as in the past. An apparatus for aligning notched wafers can be configured with a simple configuration without providing an apparatus.

Furthermore, a positioning roller that engages with the notch is arranged at the tip of the positioning pin so that the location where the positioning pin contacts the wafer can be rotated to prevent dust generation when the wafer and the positioning pin contact. it can.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 and 3 show an apparatus configuration for supporting a wafer according to the first embodiment of the present invention. A total of three rotating shafts 2 are arranged at a substantially central portion below the wafer 1 and one below each end of the wafer 1, and the drive roller 3 is inserted into each rotating shaft 2 with the number of cassettes (not shown) inserted. The same number of rotations are inserted. (Partially omitted from the drawing)

5 and 6 show the cross-sectional shapes of the drive shaft 2 and the drive roller 3. The drive roller 3 has a substantially V-shaped cross-sectional shape, and the edge of the outer periphery of the wafer 1 and the slope of the drive roller 3 are in contact with each other. The wafer 1 is supported upright by the three drive shafts 2 and the drive rollers 3 below each wafer.

In the conventional example, the wafer 1 is supported by the single drive shaft 2 shown in FIG. 7 and the two idler shafts 14 and idlers 13 shown in FIG. Since the outer peripheral surface makes contact, the driving force for rotating the wafer is limited to one drive shaft 2 and one outer peripheral surface of the wafer 1, so that misalignment such as slip is likely to occur, and the idler 13 Since no driving force is generated, the load is in a direction that impedes the driving force of the drive shaft.

On the other hand, in this embodiment, since the three drive shafts 2 are driven in the same direction synchronously, at least two of the three drive forces can be transmitted to the wafer 1. Further, since the wafer 1 and the driving roller 3 are in contact with each other on a substantially V-shaped inclined surface, the load due to the weight of the wafer 1 acts as a concentrated load on the inclined surface of the driving roller 3, so that the wafer 1 and the driving roller 3 are in contact with each other on the flat portion of the outer peripheral surface of the wafer. It can act as a larger load and can transmit a larger driving force.

Next, the alignment positioning method will be described. For positioning, the number of plungers 7 arranged in a line equal to the number of cassettes inserted is fixed to the slider 8, and when the slider 8 is lifted, the positioning pins 9 of the plunger 7 are slightly compressed by the weight of the wafer 1, and the wafer. It arrange | positions in the position which touches 1 outer peripheral surface. At this time, the tip of the positioning pin 9 is shaped to engage with the notch of the wafer 1, and the positioning roller 10 that can rotate with respect to the positioning pin 9 is disposed at the tip, so that the wafer 1 and the positioning pin 9 slide. And prevent the generation of wear powder.

In the conventional example, positioning is performed by utilizing the fact that the driving force is not transmitted when the drive shaft 2 enters the notch of the wafer. However, the notch is cut out only a few millimeters relative to the size of the wafer. For this reason, a shaft having a diameter of about 4 mm is often used as the drive shaft 2. However, since the wafer is increased in size and the weight of the wafer in the cassette tends to increase, the drive shaft is sometimes used. Some of them are bent and cannot be positioned.

Further, in the conventional example, in the step of rotating all the aligned wafers to an arbitrary position, a method of rotating a rotating shaft 2 by disposing a driving shaft different from the rotating shaft 2, a method of rotating the rotating shaft 2, etc. However, in this embodiment, it is not necessary to provide a separate wafer rotation mechanism other than providing the slide 8 for removing the positioning pins 9.

Next, the operation will be described. A prescribed number of wafers 1 are arranged side by side in a cassette (not shown), the alignment device is raised from below the cassette, and each wafer 1 is pushed up and supported by a designated drive roller 3. Stop at a position where it does not touch.

Since the three drive shafts 2 are configured to rotate synchronously with the belt 5 and the pulley 4, the drive roller 3 inserted in the drive shaft 2 is rotated by rotating the motor to rotate the wafer 1. At this time, the slider 8 to which the plunger 7 is fixed is raised and is in contact with the positioning roller 10 that can rotate on the wafer 1 while being slightly pushed down by the weight of the wafer 1, but the wafer 1 rotates. As a result, the position of the notch rotates and approaches the positioning pin 9.

When the approaching notch reaches the position of the positioning pin 9, the positioning roller 10 at the tip of the positioning pin 9 enters the notch and acts as a stopper in the rotation direction. The driving roller 3 that has rotated the wafer 1 together with the driving shaft 2 is stopped together with the wafer when the wafer 1 is stopped, and the driving shaft 2 and the driving roller 3 having a small rotational resistance slide to cause the rotational force to escape and be positioned. .

The motor 6 is driven until the wafer 1 is rotated at least once, and stops when the wafer 1 is rotated one or more times. At this time, all the wafers supported by the aligning apparatus are positioned at the positions of the positioning pins 9, but the slide 8 is moved down to be positioned for easy rotation in the next step. The pins 9 are separated from the wafer 1.

Since the positioning pins are separated, there is no need to restrict the rotation of the wafer, so that the drive roller 3 can be rotated following the operation of the drive shaft 2 and all the wafers can be simultaneously rotated to an arbitrary position. it can. Thereafter, by lowering the aligning device, all the wafers 1 are supported by the cassette, and can be transferred to the next step with the notch positions aligned.

In the present embodiment, the drive unit has been described with the belt 5 and the pulley 4, but other mechanisms may be used as long as each drive shaft 2 rotates in the same direction synchronously. In the present embodiment, the configuration in which the alignment device is driven up and down has been described. However, the present invention can also be applied to a type of alignment device in which a cassette is transported and placed on the alignment device.

Explanatory drawing explaining the support method of Example 1. FIG. Explanatory drawing explaining the drive part of Example 1. FIG. Explanatory drawing explaining the structure of Example 1. FIG. Explanatory drawing explaining the positioning method Sectional drawing of the drive roller of Example 1 Explanatory drawing of the drive shaft of Example 1 Illustration of conventional drive shaft Cross section of conventional idler Explanatory drawing explaining the positioning operation | movement of the notch of Example 1. FIG. Explanatory drawing explaining the positioning operation | movement of the notch of Example 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wafer 2 Drive shaft 3 Drive roller 4 Pulley 5 Belt 6 Motor 7 Plunger 8 Slide 9 Positioning pin 10 Positioning roller 11 Spring 12 Tension unit 13 Idler 14 Idler shaft

Claims (3)

In a notched wafer alignment apparatus that aligns the positions of notches of a plurality of notched wafers stored in a cassette in a row and rotates them to arbitrary positions to align the positions of the notches, each wafer can be rotated side by side. Multiple rows of drive rollers are arranged below the wafer, each drive shaft is rotatably held at the center of the drive roller, and each drive shaft is connected to a drive mechanism that transmits the drive force of the motor in the same direction. And a notch-shaped wafer aligning device, wherein a plurality of plungers, which are pressed up and down by positioning pins that fit in the shape of the notch, are fixed to a slider that moves up and down. The driving roller has a V-shaped cross section, the edge portion of the outer peripheral surface of the wafer is held in contact with a plurality of driving rollers, and the interval between each wafer and each driving roller is the same as the cassette. 2. An apparatus for aligning notched wafers according to claim 1. 3. The notched wafer alignment apparatus according to claim 1, wherein a positioning roller engaging with the notch is disposed at a tip of the positioning pin and configured to be rotatable with respect to the positioning pin.