JP2000124293A - Wafer detecting device for wafer washing vessel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the size of a washing vessel by providing an optical sensor on the outside of the side wall of the wafer washing vessel formed of a transparent material, and detecting a wafer in the wafer washing vessel with the optical sensor. SOLUTION: A wafer reception stage 12 is provided at the bottom part in a washing vessel 10 formed of a transparent material, while related to the washing vessel 10. A wafer detecting device 15 comprising a light-emitting optical fiber sensor 13 incorporating a light-emitting element and a light- receiving optical fiber sensor 14 incorporating a light-receiving element is provided outside the side walls 10a and 10b, facing each other, of the process vessel 10. Related to the wafer detecting device 15. The light from the light- emitting optical fiber sensor 13 transmits the side wall 10a of the washing vessel 10, and transmits the side wall 10b which is made incident on the light- receiving optical fiber sensor 14, for confirming a wafer W in the washing vessel 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer detecting apparatus for a wafer cleaning processing tank, and more particularly, to a wafer detecting apparatus for automatically transporting wafers by carrierless transport, sequentially immersing the wafers in a processing solution in each cleaning processing tank, and performing cleaning processing and water washing. The present invention relates to a wafer detection device of a wafer cleaning tank for performing a process.

[0002]

2. Description of the Related Art In wafer cleaning, a plurality of wafers are directly grasped by an arm of a transfer device (carrierless transfer device), immersed in a cleaning tank, and after cleaning, the wafer is taken out of the tank again by the arm. And a wafer cleaning method in which the wafer is transferred to the next cleaning tank.

In such a wafer cleaning method, since troubles in the transfer device immediately lead to damage to the wafer and damage to the cleaning processing tank, the sequencer uses the operation signals and sensors for traversing, raising and lowering the chuck, and opening and closing the chuck. Data is stored in an internal memory, and the presence or absence of a wafer in the cleaning tank is managed. FIG. 4 conceptually shows a conventional wafer detection apparatus for detecting whether or not a wafer exists in a cleaning tank. This wafer detection device has a wafer receiving arm 2 installed in a cleaning tank 1 so as to be vertically movable,
An end 2a of the arm 2 extends outward from the upper portion of the cleaning tank 1, and a proximity switch, a photoelectric switch 3 and the like 3 are installed in relation to the end 2a, and the wafer W is placed on the receiving arm 2. When the receiving arm 2 is
Is detected by a proximity switch, a photoelectric switch or the like 3 to confirm that the wafer W is present in the cleaning tank 1.

[0004]

In such a conventional wafer detecting apparatus for a wafer cleaning processing tank, since the receiving arm 2 is disposed in the cleaning processing tank 1, the space must be secured. As a result, not only does the cleaning tank 1 become large, but also the receiving arm 2 must be made of a material which is not corroded by the cleaning liquid, for example, Teflon (trade name), quartz or the like, and it becomes expensive. ing.

The present invention has been made in view of such circumstances, and provides a wafer detection apparatus for a wafer cleaning processing tank which does not require components to be disposed in the cleaning processing tank and thus can reduce the size of the cleaning processing tank. The purpose is to:

[0006]

According to the present invention, there is provided a wafer detecting apparatus for a wafer cleaning processing tank according to claim 1, wherein the wafer cleaning processing tank is formed of a transparent material. An optical sensor is installed outside the side wall of the wafer, and the optical sensor detects the presence of the wafer in the wafer cleaning tank.

According to a second aspect of the present invention, in the wafer detecting apparatus for a wafer cleaning processing tank, the optical sensor according to the first aspect is arranged such that the optical sensor is located outside one of the opposed side walls of the wafer cleaning processing tank. It is composed of a light emitting element installed and a light receiving element installed outside the other side wall. According to the first or second aspect of the present invention, since it is not necessary to dispose components in the cleaning tank, there is no need to secure a space for the cleaning tank, and the cleaning tank can be reduced accordingly.

Further, in the wafer detecting apparatus for a wafer cleaning tank according to the third aspect of the present invention,
In 2 or 3, above the end of the light sensor,
A waterproof cover is installed to cover the end of the optical sensor. According to the third aspect of the present invention, since the cleaning liquid overflowing from the cleaning tank is prevented from being applied to the optical sensor, the optical sensor is reliably protected.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a wafer detecting apparatus for a wafer cleaning tank according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 shows an embodiment of a wafer detecting apparatus for a wafer cleaning tank according to the present invention. FIG.
Is formed of quartz, has a gutter 11 on the upper periphery thereof, receives a cleaning liquid overflowing from the cleaning processing tank 10, and circulates the cleaning liquid again into the cleaning processing tank 10. This is a cleaning tank. A wafer receiving table 12 is provided at the bottom of the cleaning tank 10. On the other hand, the cleaning treatment tank 10 includes a light-emitting-side optical fiber sensor 13 with a built-in light-emitting element and a light-receiving-side optical fiber sensor 14 with a built-in light-receiving element outside the opposing side walls 10a and 10b of the processing tank 10. The wafer detection device 15 provided is provided. The light emitting side optical fiber sensor 13 and the light receiving side optical fiber sensor 1
4 are supported by supports 16 and 17, respectively.
The tip is arranged at an appropriate distance (1-2 mm) from the side walls 10a, 10b of the cleaning tank 10.

Then, the thus configured wafer detecting device 1
In 5, light is constantly emitted from the light emitting side optical fiber sensor 13, the light is transmitted through the side wall 10 a of quartz, further transmitted through the side wall 10 b, and is incident on the light receiving side optical fiber sensor 14. Here, when the wafer W is dropped into the cleaning tank 10, the light is blocked by the wafer W, so that the light from the light emitting side optical fiber sensor 13 does not enter the light receiving side optical fiber sensor 14. Therefore, it is confirmed that the wafer W exists in the cleaning tank 10.

FIGS. 2 and 3 show another embodiment of the wafer detecting device for a wafer cleaning tank according to the present invention. The cleaning tank 10 is also formed of quartz.
Not equipped. Therefore, the cleaning liquid overflowing from the cleaning tank 10 falls along the side walls 10a, 10b and the like. Therefore, the wafer detection device 15 of the present embodiment
In the embodiment, an outer tank 16 is formed outside the cleaning tank 10, and a light-emitting-side optical fiber sensor 13 and a light-receiving-side optical fiber sensor 14 are installed on side walls 16 a and 16 b of the outer tank 16. 1
A waterproof cover 17 is installed so as to cover the tip of the fourth. The waterproof cover 17 is made of a corrosion-resistant material,
As shown in FIG. 3A and FIG. 3B, the cross section has an arc shape and covers the upper end of the optical fiber sensors 13 and 14 from the side walls 10 a and 10 b of the cleaning tank 10.

Then, the wafer detection device 15 confirms the presence or absence of the wafer W in the cleaning tank 10 in the same manner as described above. However, in the case of this wafer detection device 15,
The cleaning liquid overflowing from the cleaning tank 10 is directly applied to the side walls 10a,
Although it falls along 10b and the like, the waterproof cover 17 prevents the optical fiber sensors 13 and 14 from hitting. Therefore, the reliability of detection can be improved.

In the above embodiment, the cleaning tank 1
Although 0 is formed of quartz, it may be formed of a transparent synthetic resin or the like in the case of a water washing treatment tank or the like where there is no risk of corrosion. Further, in the above embodiment, the optical fiber sensor is employed as the sensor. However, the light emitting element and the light receiving element may be used as the sensor without incorporating the fiber.

In the above-described embodiment, the light-emitting-side optical fiber sensor and the light-receiving-side optical fiber sensor are installed so as to face each other. However, if a reflection-type optical sensor can be used, both sensors should be installed in one place. Can be.

[0015]

As described above, according to the wafer detecting apparatus for a wafer cleaning processing tank according to the first and second aspects of the present invention, it is not necessary to dispose components in the cleaning processing tank. There is no need to secure space for this in the tank, so the cleaning tank can be made smaller accordingly.

In the wafer detecting apparatus for a wafer cleaning processing tank according to the third aspect of the present invention, the cleaning liquid overflowing from the cleaning processing tank is prevented from being applied to the optical sensor. Protected.

[Brief description of the drawings]

FIG. 1 is a conceptual configuration diagram showing one embodiment of a wafer detection device for a wafer cleaning tank according to the present invention.

FIG. 2 is a conceptual configuration diagram showing another embodiment of the wafer detecting device of the wafer cleaning tank according to the present invention.

3 is an enlarged view of a main part A in FIG. 2, FIG. 3 (a) is a side view thereof, and FIG. 3 (b) is a cross-sectional view perpendicular to the axis of FIG. 3 (a). .

FIG. 4 is a conceptual configuration diagram showing a conventional wafer detection device in a wafer cleaning tank.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Wafer cleaning tank 10a, 10b ... Side wall 11 ... Gutter 12 ... Wafer holder 13 ... Light emitting side optical fiber 14 ... Light receiving side optical fiber 15 ... Wafer detection device 16 ... Outer tank 16a, 16b ... Side wall 17 ... Waterproof cover W ... Wafer

Claims (3)

[Claims] 1. A wafer cleaning process, wherein an optical sensor is provided outside a side wall of a wafer cleaning processing tank formed of a transparent material, and the presence of a wafer in the wafer cleaning processing tank is detected by the optical sensor. Tank wafer detector. 2. The light sensor according to claim 1, wherein the light sensor is disposed outside one of the opposite side walls of the wafer cleaning processing tank.
2. The wafer detecting apparatus according to claim 1, further comprising a light receiving element provided outside the other side wall. 3. The wafer detecting apparatus according to claim 1, wherein a waterproof cover for covering the end of the optical sensor is provided above the end of the optical sensor.