JP3174452B2 - Substrate detection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate detecting method for detecting a displacement of a substrate such as a wafer and a glass substrate to be processed in semiconductor manufacturing.

[0002]

2. Description of the Related Art First, an outline of a semiconductor manufacturing apparatus will be described with reference to FIG.

In the figure, reference numeral 1 denotes a cassette transfer unit, 2 denotes a cassette stocker, 3 denotes a wafer transfer machine, 4 denotes a boat elevator, and 5 denotes a reaction furnace.

The wafer 6 is transferred between the semiconductor manufacturing apparatus and an external device while being loaded in the wafer cassette 7.

The wafer cassette 7 is placed on the cassette holder 8 of the cassette transfer unit 1, and is stored in the cassette stocker 2 by elevating the elevating stage 9 and inverting and moving the cassette holder 8 forward and backward. Similarly, the payout of the wafer cassette 7 from the cassette stocker 2 is also performed via the cassette transfer unit 1.

The boat elevator 4 loads and unloads a boat 11 mounted via a boat cap 10 into and from the reaction furnace 5, and the boat 11 is pulled out. The transfer of the wafer 6 is performed between the wafer cassette 7 and the wafer cassette 7 stored in the cassette stocker 2.

The wafer transfer device 3 has a chucking head 12 which moves up and down, rotates, moves forward and backward, and further has a plurality of chuck plates 13 which will be described later. Each of them holds the wafer 6. The transfer of the wafer 6 described above is performed by holding the wafer 6 on the chucking head 12 and moving the chucking head 12 up and down, rotated,
The transfer between the boat 11 and the wafer cassette 7 is performed by the reciprocation.

In order to reliably transfer the wafer 6 by the wafer transfer device 3, it is necessary to detect whether the wafer 6 is securely held on each chuck plate 13. Conventionally, this wafer detection has been performed by pressure detection by vacuum suction. The above wafer holding is performed for the wafer 6
Was received on the chuck plate 13 and was adsorbed by vacuum suction.

[0009]

The conventional wafer detection can be performed only while the wafer is held on the chuck plate 13. For this reason, when the wafer was transferred to the boat, it was not possible to detect whether the wafer was displaced or whether the transfer was properly performed. A separate detector must be provided to check whether the wafers are properly loaded in the boat.However, it is structurally difficult to provide a wafer detector on the boat side. Even so, the structure becomes complicated, causing an increase in cost. Further, there is a lapse of time until the position of the wafer with respect to the boat is detected after the transfer of the wafer, which causes a problem of causing a loss time.

The present invention seeks to provide such a view of the circumstances, <br/> substrate detection method that can detect the displacement of the substrate when the substrate transfer by the substrate transfer machine such as a wafer.

[0011]

According to the present invention, a boat is provided with a substrate.
A plate that holds the substrate is installed on the substrate transfer machine that
Vignetting, a detector for detecting an edge portion of the substrate holding state in the plate to the plate, a predetermined amount by relatively moving the plates relative to the substrate placed on the substrate platform of the boat, the detector by Ri engages the substrate detection method for detecting a displacement of the substrate relative to the substrate platform by detecting the edge portion of the substrate placement state, and the substrate boat transfer the
A plurality of plates to hold the substrate
The edge of the board held in each plate
Providing a detector for detection and placing it on the substrate platform of the boat
A predetermined amount of plates on multiple substrates
Move the pair and the edge of the substrate placed by the detector
By detecting the position of the substrate with respect to the substrate mounting portion.
The present invention relates to a substrate detection method for detecting the above.

[0012]

The relative displacement between the substrate and the chuck plate by a predetermined amount and the detection of the edge of the substrate make it possible to detect whether the displacement of the substrate is within a predetermined amount.

[0013]

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

The chucking head 12 of the wafer transfer machine 3 and the substrate detecting device will be described with reference to FIGS.

A rotary stage 14 is rotatably provided on an elevator (not shown), and the rotary stage 14 includes a slider 1.
The slider 15 is provided with a required number of chuck plates 13 (five in this embodiment), and each of the chuck plates 13 has a strip shape. A suction hole 16 for suction is formed, and the suction hole 16 is connected to a vacuum source (not shown). Further, a concave portion 17 is formed in the mounting portion of the chuck plate 13 on which the wafer 6 is placed, and a step portion 18 is formed at an edge portion of the concave portion 17, and the peripheral edge of the wafer 6 is supported by the step portion 18. It is like.

An L-shaped wafer detector 20 is provided on one side of the base of the chuck plate 13. The wafer detector 20 is disposed such that an L-shaped long side portion 20a is parallel to the wafer 6 below the wafer 6 and a short side portion 20b faces the peripheral end surface of the wafer 6.

A light receiver 21 is provided at the tip of the long side 20a, and a light projector 22 is provided at a tip of the short side 20b, and the optical axis of the light receiver 21 and the optical axis O of the light projector 22 are matched. The light receiving device 21 can receive the detection light from the light emitting device 22. Further, the light receiver 21 and the light projector 22 are arranged such that the optical axis O crosses the periphery of the wafer 6 in a state where the wafer 6 is properly placed on the chuck plate 13.

Next, the wafer detecting operation will be described with reference to FIGS.

When the chucking head 12 grips the wafer 6 from the wafer cassette 7, all the wafer detectors 20 on the chuck plate 13 are held in this state.
Is used to detect the presence or absence of a wafer. The presence or absence of the wafer 6 is determined based on whether the detection light from the light projector 22 is blocked by the wafer 6. That is, if the detection light is not detected by the light receiver 21, it is determined that the wafer 6 is present, and if the detection light is detected by the light receiver 21, it is determined that there is no wafer. In the case of the determination that there is no wafer, the transfer operation is stopped.

When the wafer 6 is normally gripped by the chuck plates 13, the slider 15 advances toward the boat 11 and stops at the position where the wafer 6 is inserted into the wafer holding groove 23 of the boat 11 (FIG. 5, (Fig. 6). The slider 15 is lowered by ΔZ ₁ to a position where the wafer 6 and the projection forming the wafer holding groove 23 substantially contact each other, and the vacuum suction of the chuck plate 13 is cut off. Further, the slider 1
5 is lowered by ΔZ _2, and the wafer 6 is completely held in the wafer holding groove 23 (FIGS. 6 and 7).

In order to detect whether or not the wafer 6 has been normally inserted into the boat 11, the slider 15 retreats by ΔX. This ΔX is assumed to be slightly larger than the allowable shift amount between the wafer 6 and the boat 11 (FIG. 8).

The wafer 6 is detected by the wafer detector 20.
The deviation of is detected. That is, the wafers 6 are
When properly inserted into the chucking head 1
The detection light from 2 is detected by the light receiver 21 without being blocked by the wafer 6. However, if the wafer 6 'is displaced by more than the allowable displacement amount, the detection light from the light projector 22 is blocked by the wafer 6, and the light receiver 21 does not receive the detection light. Thus, the deviation of the wafer can be detected based on the presence or absence of the detection light of the light receiver 21.

If there is no deviation of the wafer 6, the transfer of the wafer 6 is further continued, and if there is a deviation of the wafer 6,
Immediately, the transfer operation is stopped, or the transfer operation is stopped with the slider 15 returned to the home position.
The stop of the transfer operation is notified to the worker by issuing an alarm.

Thus, the deviation of the wafer can be detected in real time.

In the above embodiment, the wafer detector 2
Although light is used as the zero detection medium, ultrasonic waves may be used, and a detection type may be a reflection type instead of a transmission type.
Needless to say, various changes are possible, such as a light receiver and a light projector may be provided separately on the upper and lower chuck plates 13, and the detection target substrate is not limited to a wafer but can be implemented on various substrates such as glass. Of course.

[0026]

As described above, according to the present invention, the presence / absence detection of a wafer and the displacement detection can be performed by the same substrate detection apparatus, so that the cost can be reduced and the detection can be performed in a series of transfer operations. Since it is possible, various excellent effects are exhibited, such as no time loss and no influence on throughput.

[Brief description of the drawings]

FIG. 1 is a perspective view of a chucking head for gripping a substrate in which the present invention is implemented.

FIG. 2 is a side view showing one embodiment of the present invention.

FIG. 3 is a plan view of the same.

FIG. 4 is a flowchart showing the operation of the embodiment.

FIG. 5 is an explanatory diagram showing the operation of the embodiment.

FIG. 6 is an explanatory diagram showing the operation of the embodiment.

FIG. 7 is an explanatory diagram showing the operation of the embodiment.

FIGS. 8A and 8B are explanatory views showing the operation of the embodiment.

FIG. 9 is an explanatory diagram showing the operation of the embodiment.

FIG. 10 is a schematic perspective view of a semiconductor manufacturing apparatus.

[Explanation of symbols]

 Reference Signs List 6 wafer 11 boat 12 chucking head 13 chuck plate 15 slider 20 wafer detector 21 light receiver 22 light projector

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A 63-162536 (JP, U) JP-A 5-28041 (JP, U) (58) Fields surveyed (Int. Cl. ⁷ , DB name) H01L 21/68

Claims (2)

(57) [Claims] 1. A substrate transfer machine for transferring a substrate to a boat is provided with a plate for holding the substrate , and the plate is held on the plate.
A detector for detecting the edge portion of the substrate in the state provided <br/> to the plate, the substrate placed on the substrate platform of the boat
On the other hand, the plate is relatively moved by a predetermined amount.
<br/> substrate detection method characterized by detecting a shift of the substrate relative to the substrate platform by detecting the edge portion of the substrate placement state. 2. A substrate transfer machine for transferring substrates to a boat, wherein a plurality of plates for holding the substrates are provided, and each of the plates is provided with a detector for detecting an edge of the substrate in the held state. The plurality of plates are relatively moved relative to the plurality of substrates mounted on the substrate mounting portion of the boat by a predetermined amount, and the detector detects an edge of the mounted substrate to detect the substrate mounting portion. A substrate detection method comprising: detecting a displacement of a substrate with respect to a substrate.