JPH07169822A - Apparatus for detecting number of substrates - Google Patents

Abstract

PURPOSE:To detect the number of substrate at a low cost with the simple constitution by dipping a group of the substrate into a dipping tank, detecting the quantity of the liquid overflowed from the dipping tank, and computing the number of the substrate of the group of the substrates. CONSTITUTION:The upper part of one side surface of a dipping tank 20 is cut, and a weir 22 is formed. Pure water in the dipping tank 20 overflows through the weir 22. An overflow well 23 is provided so as to face the weir 22. A measuring pipe 24 is attached to the bottom surface of the well. The lower end of the pipe 24 is connected to a drain through a drain-liquid valve 25. A detecting part 26a of a pressure sensor 26 is inserted into the measuring pipe 24. The pressure sensor 26 measures the pressure of the pure water overflowed from the dipping tank 20 stored in the measuring pipe 24. The quantity of the water overflowed from the dipping tank 20 by the dipping of susbtrates 24 is computed based on the pressure measured with the pressure sensor 26. The number of the held substrates W is computed based on the volume per one substrate at the dipped part and the volume of a substrate holding chuck 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a board number detecting device for detecting the number of boards in a board group.

[0002]

2. Description of the Related Art In a manufacturing process of a semiconductor or a liquid crystal display device, a batch type substrate processing apparatus for collectively processing a plurality of substrates is used. In this type of substrate processing apparatus, as the size of the substrate is increased due to the increase in the degree of integration and resolution, high manufacturing quality is required. Therefore, a carrier for substrate transfer is not used in order to remove the adhesion of particles as much as possible. The carrierless method is adopted.

In general, a carrier-less type substrate processing apparatus includes a substrate transfer section for transferring a substrate to a carrier, a plurality of substrate processing sections for aligning a plurality of substrates one by one and collectively processing the substrates. A substrate transfer unit that transfers a substrate between the transfer unit and each substrate processing unit is provided. Each substrate processing unit has
A substrate holder that receives and holds the substrate transported by the substrate transport unit is provided.

In this substrate processing apparatus, the substrate stored in the carrier is taken out by the substrate transfer section, held by the substrate transfer section, and transferred to the first substrate processing section. The substrates collectively processed by the substrate processing unit are again received by the substrate transfer unit and transferred to the next substrate processing unit. After the substrate transfer and the substrate processing are performed one after another, the substrate is finally transferred to the substrate transfer unit by the substrate transfer unit and stored in the carrier.

In the carrierless system in which a plurality of substrates are aligned and held one by one, when the above-mentioned substrate transfer is performed, problems such as cracking of the substrate and damage of the substrate transfer section may occur, so that the substrates may be damaged. It is important to detect whether or not it has been delivered reliably. For this purpose, it is necessary to detect the number of substrates after receiving the substrates. As this type of substrate number detecting device, it is conceivable to use the wafer counter disclosed in JP-A-64-743. This wafer counter is a device that detects the number of substrates stored in a carrier, and a drive unit that raises and lowers the detection unit so that the substrate enters a groove of the detection unit and a detection unit that has a large number of grooves into which the substrate enters. And a substrate detection unit that detects whether or not the substrate has entered the groove of the detection unit.

By detecting the number of substrates held in the substrate transfer section by the wafer counter, it is possible to detect whether or not the substrates are delivered accurately. However, in this wafer counter, it is necessary to form a groove in the detection unit corresponding to the number of substrates and to arrange a substrate detection unit in each groove, which complicates the structure of the detection unit. Further, since many sensors are used as the substrate detecting means, the manufacturing cost becomes high.

An object of the present invention is to make it possible to inexpensively detect the number of substrates with a simple structure.

[0008]

A board number detecting device according to the present invention detects the number of boards in a board group.
It is provided with an overflow type immersion tank, an immersion means, a liquid amount detection means, and a substrate number calculation means. The immersion tank is a tank filled with a liquid. The immersion means immerses the substrate group in the liquid in the immersion tank. The liquid amount detecting means detects the amount of liquid overflowing from the dipping tank during the dipping operation by the dipping means. The substrate number calculating means calculates the number of substrates in the substrate group based on the detection result of the liquid amount detecting means.

[0009]

In the apparatus for detecting the number of substrates according to the present invention, the substrate group is immersed in the immersion tank filled with the liquid. as a result,
The liquid equivalent to the volume of the substrate group overflows from the immersion tank. The liquid amount detecting means detects the overflowed liquid amount, and the number-of-sheets calculating means calculates the number of substrates in the substrate group from the detected liquid amount.

Here, since the number of substrates is calculated based on the amount of liquid overflowing from the immersion tank, the number of substrates can be detected inexpensively with a simple structure.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a carrier-less type substrate processing apparatus 1 according to an embodiment of the present invention comprises a substrate transfer section 2 for loading and unloading a substrate W from a carrier C, and a chuck cleaning section 3. Three chemical solution processing units 4 arranged in a row
6, cleaning processing units 7 and 8 for cleaning the chemically processed substrate in two stages, a substrate drying unit 10 for drying the cleaned substrate W, and a space from the substrate transfer unit 2 to the substrate drying unit 10. And a substrate transfer robot 11 that aligns and holds a plurality of substrates W and transfers them. Substrate number detection devices 9 for detecting the number of substrates W held by the substrate transport robot 11 after the chemical treatment are arranged on the downstream side (the right side in FIG. 1) of the chemical treatment units 4 to 6 in the transport direction. ing.

The substrate transfer section 2 has an elevating mechanism (not shown) for holding and raising the substrates W housed in the carrier C all together. In addition, the chemical liquid processing units 4 to 6 and the cleaning processing units 7 and 8 include a processing tank (not shown) for immersing and processing the substrate, and a substrate holder (for holding the substrate W transferred by the substrate transfer robot 11). (Not shown). The cleaning processing unit 7 cleans the substrate W with pure water, and the cleaning processing unit 8 cleans the substrate W with ultrapure water.

The substrate transfer robot 11 has a substrate processing chuck 12 that opens and closes. Substrate transfer robot 11
1 moves the substrate holding chuck 12 up and down, and
It can be moved in the left and right directions. The board number detecting device 9
As shown in FIG. 2, it has an overflow type immersion tank 20. A pure water supply source 23 is connected to the bottom surface of the immersion tank 20 via a pure water supply valve 21. The upper part of one side surface of the immersion tank 20 is notched to form a weir 22,
Pure water in 0 overflows from the weir 22.

An overflow tank 23 is arranged facing the weir 22. A measurement pipe 24 is attached to the bottom surface of the overflow tank 23. The lower end of the measurement pipe 24 is connected to the drain via a drain valve 25. A detection unit 26a of the pressure sensor 26 is inserted in the measurement pipe 24. The pressure sensor 26 is for detecting the amount of pure water that has accumulated in the measurement pipe 24 and has overflowed from the immersion tank 20. Here, the change in the liquid amount is read based on the pressure detected by the detection unit 26a changing according to the liquid amount in the measurement pipe 24.

The processing tank of the cleaning processing section 8 is provided with the same structure as the overflow tank 23, the measuring pipe 24 and the pressure sensor 26 shown in FIG. Therefore,
In the cleaning processing unit 8, the number of substrates can be detected by the tank itself. The substrate processing apparatus 1, as shown in FIG.
It has a control unit 30 equipped with a microcomputer including PU, ROM, and RAM. The control unit 30 is connected to the pressure sensor 26, the substrate transfer robot 11, the pure water supply valve 21, the drainage valve 25, and other input / output units.

Next, the operation of the above embodiment will be described. When the two carriers C processed in the previous step are placed on the substrate transfer unit 2, the elevating mechanism in the substrate transfer unit 2 holds and raises the substrate W. At this time, the substrate transfer robot 11 is on standby on the substrate transfer unit 2. The lifted substrates W are collectively held by the substrate holding chuck 12 of the substrate transfer robot 11 in an aligned state. The held substrate W is transferred to the chemical processing unit 4 by the substrate transfer robot 11.

The chemical treatment unit 4 receives the substrates W from the substrate holding chuck 12 by the substrate holder in the treatment tank and collectively treats them. When the chemical treatment is completed, the substrate transfer robot 11 receives the substrate W from the substrate treatment section 4 and conveys the substrate W to the substrate number detecting device 9 arranged on the downstream side of the chemical treatment section 4. When the substrate W is conveyed to the substrate number detecting device 9, the control unit 30 executes the substrate number detecting process shown in FIG. 4 (described later).

When the detection of the number of substrates is completed, the substrate transport robot 11 transports the substrates W to the next chemical treatment unit 5. Subsequently, the substrate number detecting device 9 arranged on the downstream side executes the substrate number detecting process, and further conveys to the next chemical liquid processing section 6. When the chemical liquid processing in the chemical liquid processing unit 6 is completed, the substrate number detecting device 9 arranged on the downstream side similarly performs the substrate number detecting process. When these operations are completed, the substrate transfer robot 11 transfers the substrate to the cleaning processing unit 7. When the substrate cleaning process in the cleaning processing unit 7 is completed, the substrate transfer robot 11 transfers the substrate W to the cleaning processing unit 8.

As described above, the cleaning unit 8 is provided with the overflow tank 23, the measurement pipe 24, and the pressure sensor 26, which are similar to those shown in FIG. 2, and detect the number of substrates before the cleaning process. When the detection of the number of substrates is completed, the final substrate cleaning process is performed. After the final wash,
The substrate transport robot 11 transports the substrate W to the substrate drying unit 10. The dried substrate W is transferred onto the substrate transfer unit 2 by the substrate transfer robot 11 and stored in the carrier C.

Next, the above-mentioned substrate number detection processing will be described with reference to the flowchart of FIG. In the processing for detecting the number of substrates, first, in step S1 of FIG.
And the drain valve 25 is closed in step S2. In this state, the immersion tank 20 is filled with pure water, and the measurement pipe 2
The pure water in 4 has been discharged. This completes the preparation for detecting the number of substrates.

In step S3, the substrate transfer robot 11
The substrate holding chuck 12 is lowered until the center of the held substrate W reaches the liquid surface, and the lower half of the substrate W is immersed in the immersion tank 20. As a result, the pure water filled in the immersion tank 20 overflows from the weir 22 into the overflow tank 23 by the volume of the immersed substrate W and the substrate holding chuck 12. The water overflowing into the overflow tank 23 is measured by the measurement pipe 24.
Accumulate inside.

In step S4, the pressure of the pure water accumulated in the measuring pipe 24 is measured by the pressure sensor 26. In step S5, the amount of water overflowing from the immersion tank 20 due to the immersion of the substrate W is calculated from the pressure measured by the pressure sensor 26. In step S6, the number of substrates W held by the substrate holding chuck 12 is calculated from the calculated amount of water, the volume of the immersed portion per substrate and the volume of the substrate holding chuck 12. The reference volume is
It is preset according to the shape of the substrate W and the shape of the substrate holding chuck 12.

In step S7, it is determined whether or not the calculated number is equal to the preset number. This makes it possible to determine whether or not the substrate W has been delivered correctly. If the substrate is delivered correctly, the process proceeds to step S8.
In step S <b> 8, the substrate holding chuck 12 of the substrate robot 11 is raised and the substrate W is taken out of the immersion tank 20. Then, in step S9, the drain valve 25 is opened, and in step S9
Then, the pure water supply valve 21 is opened. This causes the dipping tank 20 to be refilled with water. Moreover, since water overflows from the dipping tank 20, after dipping the substrate W to which the chemical solution is attached,
The inside of the dipping tank 20 becomes clean again.

In step S7, if the calculated number is different from the preset number, the process proceeds to step S10.
In step S10, error processing is performed. In this error processing, for example, an alarm is issued or the held substrate is returned to the substrate transfer section 2 and stored in the carrier C. Here, since the number of substrates is detected by the amount of water that overflows when the substrate W is immersed, the number of substrates can be detected inexpensively with a simple configuration without contaminating the substrates. Further, unlike the conventional wafer counter, the sensor can be prevented from being corroded by the processing liquid adhering to the surface of the substrate, and the failure or malfunction of the sensor is unlikely to occur.

Other Embodiments (a) Instead of the configuration of FIG. 2, a three-way valve 27, a measuring container 28, and a weight measuring unit 29 may be adopted as shown in FIG. The three-way valve 27 switches the connection target of the measurement pipe 24 between the measurement container 28 and the drain. Measuring container 28
Are placed on the weight measuring unit 29.

Here, when the number of substrates is detected, the three-way valve 2
The measurement pipe 24 is connected to the measurement container 28 by 7. Then, the water overflowed by the substrate immersion is stored in the measuring container 28, and the amount of the stored liquid is measured by the weight measuring unit 29. The number of substrates is detected from the measured liquid amount. (B) The measurement pipe 24 may be made of glass, and photosensors or capacitance sensors may be arranged along the vertical direction corresponding to the number of substrates to measure the liquid amount. Alternatively, a float may be arranged inside the measurement pipe 24, and the liquid amount may be measured by the floating position of the float.

[0027]

In the substrate number detecting device according to the present invention, the number of substrates is detected from the amount of the liquid overflowing due to the immersion of the substrates. Therefore, the number of substrates can be detected inexpensively with a simple structure.

[Brief description of drawings]

FIG. 1 is a perspective view of a substrate processing apparatus in which an embodiment of the present invention is adopted.

FIG. 2 is a schematic vertical sectional view of a substrate number detecting device.

FIG. 3 is a block schematic diagram showing the configuration of a control system of the substrate processing apparatus.

FIG. 4 is a flowchart of a substrate number detection process.

FIG. 5 is a diagram corresponding to FIG. 2 of another embodiment.

[Explanation of symbols]

 9 Substrate Number Detector 20 Immersion Tank 21 Pure Water Supply Valve 24 Measuring Pipe 26 Pressure Sensor 30 Control Section

Claims (1)

[Claims] 1. An apparatus for detecting the number of substrates in a substrate group, comprising: an overflow type immersion tank filled with a liquid; an immersion means for immersing the substrate group in the liquid in the immersion tank; A liquid amount detecting means for detecting the amount of liquid overflowing from the immersion tank during the dipping operation by the dipping means, and a substrate number calculating means for calculating the number of substrates in the substrate group based on the detection result of the liquid amount detecting means, A board number detection device.