JP2000021953A - Method for semiconductor treatment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for semiconductor treatment automatically orienting an orientation flat of a wafer in a definite direction upon reaching the number of wafer transferring a predetermined number. SOLUTION: For transferring a wafer between a boat and a wafer cassette provided in a reaction chamber of a semiconductor manufacturing system, an orientation flat of the wafer prepared in the wafer cassette is automatically oriented (S6) each time the number of transferrings reaches a predetermined number (S1). Setting the allowable number of repeated transferrings of the wafer, corresponding to the number of allowable displacements of the orientation flat, will be able to automatically control an irregular orientation flat caused by the repeated transferrings within an allowable range and prevent in advance accident which results from the displaunt of orientation flat.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor processing method for transferring wafers between a boat disposed in a reactor of a semiconductor manufacturing apparatus and a wafer cassette.

[0002]

2. Description of the Related Art In a conventional semiconductor manufacturing apparatus, there is an operation of transferring a wafer stored in a wafer cassette to a wafer boat, or conversely, transferring a wafer mounted in the wafer boat to a wafer cassette. . This operation is repeatedly performed a plurality of times by forming a product wafer or using a test wafer or a dummy wafer. However, when this operation is repeatedly performed, the position of the orientation flat (orientation flat) of the wafer transferred to the wafer cassette may be slightly shifted.

[0003] When the transfer machine attempts to transfer the wafers stored in the wafer cassette to the wafer boat in a state where the displacement has occurred, the wafers do not accurately enter the slots of the boat due to the displacement. In addition to contacting the periphery of the slot and not being able to transfer the wafer, in a severe case, the wafer boat may be knocked down. Therefore, conventionally, in order to prevent these problems, when the transfer of the transfer machine reaches a predetermined number of times, the operator manually removes the cassette, realigns the wafer orientation flat, and returns the wafer to the apparatus again. To prevent accidents.

[0004]

In the above-mentioned conventional semiconductor manufacturing apparatus, if the transfer machine repeatedly transfers wafers, the wafer orientation flat of the wafer cassette is displaced. In order to prevent accidents that may occur, when the transfer machine reaches a predetermined number of times, the operator must manually align the wafer flattening. There is a problem that it takes time.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention is directed to a semiconductor manufacturing apparatus, in which a wafer cassette is moved by an orientation flat aligning apparatus when transfer by a transfer machine is repeated a predetermined number of times so that a wafer does not shift an orientation flat. It is an object of the present invention to provide a semiconductor processing method capable of automatically aligning a wafer stored in a wafer and automatically preventing an accident caused by misalignment of the wafer.

[0006]

In order to solve the above-mentioned problems, the present invention provides a semiconductor processing method for transferring wafers between a boat disposed in a reactor of a semiconductor manufacturing apparatus and a wafer cassette. Wherein, each time the number of times of the transfer reaches a predetermined number, the orientation flat of the wafer stored in the wafer cassette is automatically adjusted by the orientation flat alignment device arranged in the semiconductor device.

According to such a configuration, in the semiconductor manufacturing method of the present invention, the number of repetitions of wafer transfer can be set to a number within a range in which the displacement of the orientation flat can be tolerated. Deviations can be kept within acceptable limits.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a perspective view schematically showing a semiconductor manufacturing apparatus to which a semiconductor processing method according to the present invention is applied, FIG. 2 is a perspective view showing a structure of an orientation flat aligning apparatus used in the semiconductor processing method according to the present invention, FIG. 3 is an enlarged perspective view showing an orientation flat alignment unit used in the orientation flat alignment apparatus of FIG.
FIGS. 5 and 6 are views for explaining a positional relationship between a wafer accommodated in a wafer cassette, a driving roller, and a passive roller in the orientation flat aligning apparatus of FIG. 2, and FIGS.
7 for explaining the operation of the orientation flat aligner of FIG.
4 is a flowchart for explaining a semiconductor processing method of the present invention in which orientation flat alignment is performed by the orientation flat alignment apparatus of FIG. 2;

The semiconductor manufacturing apparatus 1 shown in FIG. 1 exchanges a wafer cassette 10 containing wafers with an external device via a cassette stage 11. For example, when a wafer cassette 10 containing a plurality of wafers CW having a disk shape and partially having an orientation flat (abbreviated as orientation flat) is supplied to the cassette stage 11, the cassette loader mechanism 12 supplies the wafer to the cassette stage 11. The loaded wafer cassette 10 is placed on the upper or lower cassette shelves 13 and 14, or
The wafer cassette 10 placed on the wafers 3 and 14 is moved to the cassette stage 11 for the purpose of delivering the wafer cassette 10 to the outside or performing orientation flat alignment.

The boat 15 has a boat elevator mechanism 16
Is raised or lowered as appropriate,
For example, it is arranged in a reaction furnace (not shown) for performing processing such as film formation on the wafer CW. The wafer transfer mechanism 17 is provided with the wafer cassette 10 mounted on the cassette shelves 13 and 14.
Is transferred to a slot at an appropriate position of the boat 15 lowered by the boat elevator mechanism 16, or a wafer CW such as a processed (or used) wafer CW is taken from the boat 15.
Transfer to 0.

The orientation flat alignment unit 20 includes, for example,
It is fixed below the cassette stage 11. The cassette loader mechanism 12 mounts the wafer cassette 10 on which a plurality of wafers CW are stored on the cassette stage 11 when aligning the orientation flat is required. In this case, as shown in FIG.
A plurality of stored wafers CW are placed in a vertically standing direction. The drive rollers 21 and 22 of the orientation flat aligning unit 20 shown in FIG.
The wafer cassette 10 is mounted so as to extend at right angles to the surface of the wafer of the wafer cassette 10 placed in 1 and in parallel along the same virtual horizontal plane.

Further, as shown in FIG. 4, the drive rollers 21 and 22 sandwich the position directly below the center CC of the wafer CW which is housed in the wafer cassette 10 and stands upright.
They are arranged to face each other. The passive roller 23 extends adjacent to and parallel to one of the drive rollers 21 and 22. However, the uppermost part of the passive roller 23 is attached to be slightly higher than the uppermost parts of the drive rollers 21 and 22. In addition, the passive roller 23 horizontally moves the wafer C from the center or the top of the passive roller 23.
The length of the W to a position immediately below the center CC is smaller than half the length of the orientation flat. In the above example, the orientation flat alignment unit 20
Is fixed to the lower side of the cassette stage 11, but may be raised to a position where the orientation flat can be adjusted only at the time of orientation flat alignment, and may be lowered at other times.

Next, control of a control unit (not shown) of the semiconductor manufacturing apparatus 1 for controlling the orientation flat aligning apparatus of FIG. 2 will be described with reference to FIGS. Cassette shelf 13,
The wafer CW stored in the wafer cassette 10 mounted on the wafer 14 is transferred by the wafer transfer mechanism 17 so as to reciprocate with the boat 15. This transfer operation is performed a plurality of times, for example, for film formation of a product wafer, use of a dummy wafer or a test wafer, and the like. The control unit counts the number of times of transfer, and determines whether or not the count reaches a parameter which is a prescribed number of times of transfer stored in the memory in advance (step S1). If the parameter has not been reached, the next count is performed (step S
From 2), the process returns to step S1. If the parameters have been reached, the corresponding wafer cassette 10 is moved from the cassette shelves 13, 14 to the cassette loader mechanism 12 (step S3).

The cassette loader mechanism 12 is moved to the cassette stage 11 (Step S4), and the wafer cassette 1 is moved.
0 from the cassette loader mechanism 12 to the cassette stage 11
(Step S5). Next, drive roller 2
5 are driven in the direction of arrow RP in FIG. 5 to rotate the wafer CW in the direction of arrow RR by the contact frictional force against the peripheral edge of the wafer CW stored in the wafer cassette 10. At this time, the passive roller 23
Of the wafer CW is not in contact with the peripheral edge of the wafer CW.

When the orientation flat of the wafer CW comes over the rollers 21, 22, 23 as shown in FIG. 6, the uppermost part of the passive roller 23 is slightly higher than the uppermost parts of the other driving rollers 21, 22. When the wafer CW advances slightly in the state shown in FIG. 6, the orientation flat separates from the drive rollers 21 and 22 and stops in the wafer cassette 10 while being supported by the passive roller 23. The drive rollers 21 and 22 continue idling. Thus, all the wafers C in the wafer cassette 10 are
The orientation flats of W are aligned in a fixed direction (step S).
6). Then, the aligned wafer cassettes 10 are moved from the cassette stage 11 onto the cassette loader mechanism 12 (step S7). Cassette loader mechanism 1
2 is moved from the cassette stage 11 to the cassette shelves 13 and 14 (step S8), and the wafer cassette 10 is placed on the cassette shelves 13 and 14 (step S9). Thereafter, the wafer CW of the wafer cassette 10 is repeatedly transferred (used) between the wafer cassette 10 and the boat 15 by the wafer transfer mechanism 17 as necessary.
At the same time, the counting of the number of times of transfer is newly started.

[0016]

As described in detail above, the semiconductor processing method according to the present invention can be used to transfer wafers between a boat disposed in a reactor of a semiconductor manufacturing apparatus and a wafer cassette. Each time the number of times of transfer reaches a predetermined number of times, the wafer is transferred by automatically aligning the wafer stored in the wafer cassette by the orientation flat aligning device arranged in the semiconductor device. The number of repetitions is set to the number of times that the displacement of the orientation flat is within an allowable range, and the displacement of the orientation flat generated during the repetition of the transfer is automatically corrected within the allowable range, and the displacement of the orientation flat is adjusted. It is possible to prevent an accident caused by the above.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing a semiconductor manufacturing apparatus to which a semiconductor processing method according to the present invention is applied.

FIG. 2 is a perspective view showing a relationship between an orientation flat alignment unit and a wafer cassette accommodating wafers in the orientation flat alignment apparatus used by the semiconductor processing method according to the present invention.

FIG. 3 is an enlarged perspective view showing the orientation flat aligning unit shown in FIG. 2;

FIG. 4 is a view for explaining a positional relationship between a wafer housed in a wafer cassette of FIG. 2, a driving roller of an orientation flat aligning unit, and a passive roller.

FIG. 5 is a diagram for explaining the operation of the orientation flat aligning device of FIG. 2;

FIG. 6 is a diagram for explaining the operation of the orientation flat aligning apparatus.

FIG. 7 is a flowchart showing a control process of the semiconductor processing method according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 semiconductor manufacturing apparatus 10 wafer cassette 11 cassette stage 12 cassette loader mechanism 13, 14 cassette shelf 15 boat 16 boat elevator mechanism 17 wafer transfer mechanism 20 orientation flat aligning unit 21, 22 drive roller 23 passive roller CW wafer S1 to S10 Step

Claims (1)

[Claims] 1. A semiconductor processing method for transferring wafers between a boat disposed in a reaction furnace of a semiconductor manufacturing apparatus and a wafer cassette, wherein each time the number of transfers reaches a predetermined number. The orientation flat alignment device arranged in the semiconductor device,
A semiconductor processing method, wherein the orientation flat of wafers stored in the wafer cassette is automatically adjusted.