JP2001135700A - Underwater loader and substrate processor using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a underwater loader for effectively preventing any substrate from flipping out from a cassette, and for efficiently extracting the substrate and a substrate processor using the underwater loader. SOLUTION: A plurality of substrates W are housed in a cassette being laminated, and immersed in a water tank 12 in a waiting state. At the time of carrying the cassette by a carrying robot 20, the cassette is allowed to float. The water tank 12 is provided with a flip controlling member 70 for preventing the substrate W in each stage of the cassette from flipping out from the cassette in the elevating direction of the cassette. Thus, even when a water flow is generated in the water tank 12, the substrate can be prevented from flipping out from the cassette. At the time of elevating the cassette for extracting the arbitrary substrate W in the cassette, the cassette can be elevated while the substrate W is controlled in the cassette.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a semiconductor wafer,
A substrate processing apparatus for processing various substrates such as a glass substrate for a liquid crystal display device, a glass substrate for a plasma display, a substrate for a photomask, a substrate for an optical disk or a magneto-optical disk, and underwater used in such a substrate processing device. About loader.

[0002]

2. Description of the Related Art For example, in a manufacturing process of a semiconductor device,
A polishing step for polishing a surface of a semiconductor wafer (hereinafter, simply referred to as “wafer”) (a surface of the wafer itself or a surface of a thin film formed on the surface of the wafer) with an abrasive may be included. CMP (Chemical Mecha) for chemically and mechanically polishing a wafer surface using a chemical solution and a polishing cloth
nical Polishing) process is a typical example.

[0003] Since the polishing agent is present as a slurry on the surface of the wafer after polishing, cleaning of the wafer is essential after the polishing step. If the surface of the polished wafer dries before the cleaning process,
Removal of the slurry on the wafer surface becomes difficult. Therefore, a substrate cleaning apparatus used for cleaning a wafer after polishing is provided with a so-called underwater loader. The underwater loader includes a water tank for immersing a cassette containing a plurality of substrates (wafers) in water, and a stage for immersing / floating the cassette in the water tank. Above the water tank, a pure water shower nozzle for supplying pure water to the surface of the substrate in a floating state is provided.

[0004] The cassette has, for example, a 25-stage shelf formed on the inner wall surface, and is capable of accommodating 25 substrates at a time in a stacked state. However, the boards are not necessarily stored in all of the 25-stage shelves, and there may be no boards in the middle shelf, or there may be cases in which the boards are stored only in some upper shelves, for example. . The substrate is removed from the underwater loader by raising the stage by a required amount, inserting the hand into the cassette, holding the substrate, and retreating. The substrate transfer robot includes, for example, a suction unit for vacuum-sucking the center of the lower surface of the substrate at the tip of the hand. The removed substrate is carried into a cleaning processing unit for cleaning the substrate, and is transferred to the chuck. A pure water shower nozzle is provided above the substrate transfer robot, and is designed to prevent drying of the substrate even when the substrate is transferred.

If the control device of the substrate cleaning apparatus stores the number of the shelf where the substrate actually exists in the cassette, etc., the uppermost one of the plurality of substrates in the cassette can be stored in the cassette. It can be positioned just below the water surface, and in that state, the substrate unloading timing by the substrate transfer robot can be waited. In this case, the substrate can be unloaded by the substrate transfer robot after the stage is raised by the minimum necessary distance, so that the substrate unloading operation can be performed efficiently.

Incidentally, in the water tank, an irregular water flow is generated when the stage is moved up and down. Due to this water flow, the substrate in the cassette may be lifted or jump out of the cassette. If the substrate is protruded from the cassette, the holding position of the substrate transfer robot by the hand is shifted, so that a transfer failure occurs. That is, the substrate may fall out of balance on the hand and drop, or the delivery position of the hand from the hand to the chuck of the cleaning processing unit may be incorrect, resulting in chuck failure. As a result, problems such as stoppage of the operation of the substrate processing apparatus and damage of the substrate occur.

Therefore, in a typical prior art, a pure water nozzle is provided at a position directly below the water surface in a water tank, and pure water is discharged from the pure water nozzle, thereby causing a water flow in a direction of pushing the substrate into the cassette. It is formed just below the water surface. As a result, when taking out the substrate from the cassette,
Since it can be guaranteed that the substrate is located at the back of the cassette, it is possible to avoid a transfer failure. Substrates in a cassette are not always processed in order from the one located at the highest position, and there is a case where a substrate is unloaded in a so-called random access format by specifying a shelf number in an arbitrary order.
In this case, until the substrate to be processed is led to the surface of the water, the stages that are located above the substrate to be processed are stopped immediately at the timing when the respective substrates are positioned immediately below the surface of the water, and the substrates are pushed by the water flow. Will be done.

If this operation is omitted, the state in which the substrate to be processed is pushed into the back of the cassette cannot be guaranteed, and another substrate above the substrate to be processed may jump out and come into contact with the substrate to be processed. . In this case, when the substrate to be processed is held and taken out by the hand, the contacting upper substrate is dragged out, and there is a possibility that a conveyance failure may occur. Therefore, it is not possible to omit the operation of stopping the elevation of the stage one by one at the timing when each substrate is located immediately below the water surface.

[0009]

However, in such an operation, it takes an extremely long time for the substrate transfer robot to take out the substrate to be processed from the underwater loader after receiving a request from the cleaning processing unit. There is a problem that the processing capacity of the cleaning device is significantly reduced. This problem may be avoided by previously holding the substrate to be processed immediately below the surface of the water, but when the substrate is taken out by the random access method as described above, the substrate above the substrate to be processed is removed. Since the substrate will be located above the water surface,
Their surfaces may dry out. Therefore, there is a possibility that cleaning failure occurs.

Accordingly, an object of the present invention is to solve the above-mentioned technical problems, and to provide an underwater loader capable of effectively preventing a substrate from jumping out of a cassette and efficiently removing a substrate. It is to be. Further, another object of the present invention is to provide a substrate processing apparatus having the above-described underwater loader to improve substrate processing efficiency.

[0011]

Means for Solving the Problems and Effects of the Invention According to the first aspect of the present invention, there is provided a multi-stage substrate housing capable of housing a plurality of substrates (W) in a stacked state. A water tank (12) capable of immersing a cassette (C) having a portion, and a cassette elevating mechanism (elevating the cassette in order to immerse the substrate in the cassette in the water tank or to float above the water surface of the water tank) 11, 13)
And a protrusion restricting member (70) disposed in the water tank along the direction of elevating the cassette by the cassette elevating mechanism, and restricting the substrates in the substrate accommodating portions of each stage of the cassette from jumping out of the cassette. An underwater loader (10) characterized by the following. It should be noted that the alphanumeric characters in parentheses represent corresponding components in the embodiments described later. Hereinafter, the same applies in this section.

The protrusion restricting member may be a columnar member extending in the elevating direction of the cassette, or may be a plate-like member. Further, only one protrusion regulating member may be provided, or a plurality of protrusion regulating members may be provided. According to the present invention, the protrusion restricting member is arranged in the water tank along the cassette elevating direction, whereby the substrate in the cassette is restricted so as not to protrude from the cassette in the water tank. . In addition, since the pop-out regulating member is provided along the cassette elevating direction,
When taking out the substrate, the cassette can be lifted while the substrate is regulated by the pop-out restricting member, and when taking out the substrate at an arbitrary position in the cassette, the cassette is stopped temporarily while being raised. You don't have to.

[0013] In this manner, the removal of the substrate can be effectively prevented, and compared with the above-described prior art in which the water flow is formed just below the water surface in the water tank, the substrate is particularly preferably accessed in a random access manner. In taking out the substrate, the substrate can be taken out efficiently. Moreover, the configuration can be significantly simplified as compared with the case of forming a water flow. It is preferable that the protrusion restricting member is provided so as to extend from a lowermost substrate position in the cassette lowered to a lowermost position by the cassette lifting mechanism to a water surface position in the water tank. More preferably, the upper end of the pop-out restricting member is positioned at a predetermined height above the water surface (however, below the lowermost substrate position in the cassette in a state where it is raised to the uppermost position by the cassette lifting mechanism).
Is preferably located at

Further, a substrate transfer height for receiving an access from the side by the hand (21) of the substrate transfer means (20) may be set above the water surface in the water tank. In this case, it is preferable that the upper end of the regulating member is positioned below the passage of the hand and the substrate so as to avoid interference with these. Claim 2
The described invention is characterized in that, in the process of lowering the cassette toward the water tank by the cassette elevating mechanism, whether the substrate in the cassette has protruded from the cassette to the extent that it collides with the upper end of the pop-out restricting member is determined by the pop-out restricting member. The underwater loader according to claim 1, further comprising a beam sensor (80) for detecting a position above an upper end of the underwater loader.

The beam sensor is a light emitting section (81)
Generates a light beam toward the light receiving unit (82), and detects the presence or absence of a light blocking object on the optical axis (L1) between the light emitting unit and the light receiving unit according to the magnitude of the received light amount in the light receiving unit. It is a sensor. According to the present invention, when the substrate is largely lowered from the cassette when the cassette is lowered and the substrate in the cassette is immersed in water, this is detected by the beam sensor. Therefore, in response to the detection of the substrate by the beam sensor, if the cassette descent by the cassette elevating mechanism is stopped, the ejected substrate may collide with the upper end of the regulating member, and the substrate may be damaged. Disappears.

The optical axis of the beam sensor is set so as to detect the substrate above the upper end of the protrusion restricting member and below the passage of the hand and the substrate. preferable. According to a third aspect of the present invention, the protrusion restricting member abuts on an end face of the substrate and guides the substrate to the inner part of the cassette.
The underwater loader according to claim 1 or 2, wherein a) is provided at an upper end.

According to this configuration, since the taper surface is provided at the upper end of the pop-out restricting member, even if the substrate is slightly protruded from the cassette, such a substrate is lowered into the water tank by the cassette. Pushed into the cassette during the process. Therefore, the substrate can be regulated at a more accurate position in the water tank. In this case, the lower edge of the tapered surface is positioned at a height higher than the water surface in a state where the uppermost substrate in the cassette is located directly below the water surface (which can be displaced up and down by raising and lowering the cassette). It is preferred that For example, the lower edge of the tapered surface may be located at a height equal to or higher than the upper edge of the water tank.

In the case where the beam sensor is provided, when the substrate projects from the cassette beyond a position corresponding to the upper end of the tapered surface, the light of the beam sensor is detected so that such a substrate can be detected. Preferably, an axis is set. For example, when one column-shaped protrusion restricting member is provided in the water tank (for example, when the substrate is circular and the protrusion restricting member is provided at the center of the front of the substrate in the water tank in the direction of protrusion), the beam The optical axis of the sensor is preferably set closer to the cassette than the upper edge of the tapered surface.

Further, the beam sensor detects a substrate located deeper in the cassette than a substrate position when it comes into contact with a portion (for example, a lower edge of the tapered surface) of the protrusion restricting member which protrudes most toward the cassette. Therefore, it is preferable that the optical axis is set so that a substrate protruding from such a substrate position can be detected. More specifically, when one column-shaped protrusion restricting member having a tapered surface at the upper end is provided in the water tank, a range immediately above the tapered surface (preferably,
The optical axis of the beam sensor may be set so as to pass through (near the upper end of the tapered surface).

The invention described in claim 4 is the first to third aspects of the present invention.
And a substrate transport means (20) for unloading a substrate guided to a substrate transfer height by elevating the cassette by the cassette elevating mechanism.
And a substrate processing means (30) for receiving the substrate carried out by the substrate transfer means and performing predetermined processing on the substrate. According to the present invention, the substrate can be transferred from the underwater loader to the substrate transfer means by raising and lowering the cassette lifting mechanism to guide the substrate to be processed to the substrate transfer height. At this time, the substrate in the cassette raised from the water tank does not protrude due to the function of the protrusion restricting member provided in the water tank, so that the transfer of the substrate from the cassette to the substrate transfer means can be performed well. it can. Thereby, the transfer of the substrate from the substrate transporting unit to the substrate processing unit is also performed favorably. In this way, it is possible to prevent a transfer failure of the substrate.

As described above, even when the substrates in the cassette are taken out in a random access format, for example, the substrates to be processed can be quickly brought to the substrate delivery height. The substrate can be efficiently transported to the substrate, thereby contributing to an improvement in substrate processing efficiency. The substrate processing means may perform a cleaning process on the substrate. More specifically, the substrate processing means may perform cleaning of the substrate after the CMP processing.

Further, the substrate processing means may have a substrate holding portion (chuck) for receiving the substrate from the substrate transfer means.

[0023]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a simplified perspective view showing the appearance of a substrate processing apparatus according to an embodiment of the present invention. This substrate processing apparatus is a substrate cleaning apparatus for cleaning and removing an abrasive (slurry) on the surface of a substrate W such as a semiconductor wafer after a CMP process. This apparatus includes a cassette loading unit 2 for loading a cassette C capable of collectively storing a plurality of (for example, 25) substrates W after a CMP process, and a cassette (FIG. (Not shown). The cassette insertion section 2 is provided with a box-shaped cassette insertion door 5 rotatably mounted between a solid line position and a two-dot chain line position in FIG. 1 around a horizontal axis. The door 3 is provided with a door 6 which is mounted to be rotatable about a vertical axis. A handle 7 with a latch mechanism is provided at an upper portion (upper portion in the closed state) of the cassette loading door 5. An operator operates the handle 7 to open the cassette loading door 5, and the substrate after the CMP process is performed. The cassette C containing W is loaded into the substrate processing apparatus.

On the front side of the substrate processing apparatus, an operation panel 8 and a display device 9 are arranged above the cassette loading section 2 so that necessary processing conditions and the like can be inputted. It can be monitored.
FIG. 2 is a plan view showing the internal configuration near the cassette insertion section 2 of the above-described substrate processing apparatus. The cassette C loaded from the cassette loading section 2 is placed on the elevating stage 11 of the underwater loader 10. The underwater loader 10 is a cassette C
This is a device that provides a substrate transfer position for dispensing substrates W one by one immediately before processing, while waiting for substrates W in the substrate to be immersed in water.

A transfer robot 20 (substrate transfer means) is arranged adjacent to the underwater loader 10. The transfer robot 20 includes a hand 21 having a suction portion 21 a at a distal end for sucking substantially the center of the back surface of the substrate W, and a base portion 22 coupled to a base end of the hand 21. Then, the hand 21 is rotated by a double angle in a direction opposite to the rotation direction with the rotation of the base portion 22.
Can bend and stretch the hand 21 and the base portion 22 toward the underwater loader 10, and
The hand 21 and the base 22 can be bent and stretched with respect to the cleaning unit 30 (substrate processing means) arranged on the opposite side to the above. Along with such bending and stretching movements, the base portion 22 can move up and down. As a result, the transfer robot 20
One substrate W can be taken out from the cassette C and carried into the cleaning unit 30.

The cleaning unit 30 includes, for example, a substrate holding mechanism for holding and rotating the substrate W, and a processing liquid supply mechanism for supplying a processing liquid (chemical solution or pure water) to the substrate held by the substrate holding mechanism. And a scrub member for scrubbing the front or back surface of the substrate W held by the substrate holding mechanism. A substrate batch detection unit 40 (substrate detection device) is housed in the internal space of the cassette insertion door 5 of the cassette insertion section 2. The board batch detection unit 40
It includes a plurality of substrate detection probes P, a probe holding member 41 for holding the same, and an advance / retreat drive mechanism 42 for moving the probe holding member 41 toward and away from the cassette C held by the underwater loader 10. . This allows
The plurality of substrate detection probes P are collectively moved between a retracted position (the position indicated by the solid line) retracted into the cassette insertion door 5 and a detection position (the position indicated by the two-dot chain line) advanced to the position of the substrate W in the cassette C. You can move forward and backward.

In this embodiment, the accommodation position of the substrate W correctly accommodated in the cassette C placed on the elevating stage 11 at the elevating position corresponds to the substrate detection position. When viewed in a plan view looking down on the main surface (front surface), the position substantially coincides with the substrate transfer position for transferring the substrate W to the transfer robot 20. In this case, the accommodation position of the substrate W correctly accommodated in the cassette C is, for example, the substrate W on the inner wall surface at the back of the cassette C (on the cassette loading door 5 side).
(That is, the position of the substrate W indicated by a two-dot chain line in FIG. 2). Actually, not all the substrates W in the cassette C are necessarily at the correct substrate storage position, and some or all of the substrates W are protruding toward the open side (toward the transfer robot 20) in front of the cassette C. That is, the substrate W may be misaligned.

FIG. 3 is a simplified perspective view showing a configuration relating to the underwater loader 10. As shown in FIG. The underwater loader 10 includes an elevating stage 11 on which the cassette C can be placed while being positioned by the positioning member 15, a water tank 12 capable of submerging the cassette C mounted on the elevating stage 11, A lifting drive mechanism 13 (substrate moving mechanism) for raising and lowering the stage 11, and a pure water shower nozzle 14 (liquid supply means) for supplying pure water to the substrate W held in the cassette C from above the lifting stage 11 And In this case, the elevating stage 11 and the elevating drive mechanism 13 constitute a cassette elevating mechanism.

The water tank 12 is filled with pure water, and the substrate W in the cassette C can be immersed in pure water by lowering the elevating stage 11 by the elevating drive mechanism 13. In addition, by lifting the lifting stage 11 by the lifting drive mechanism 13, the lifting stage 11 can be guided to a raised position above the water surface in the water tank 12. The lifting drive mechanism 13 includes, for example, a ball screw mechanism 13a and a motor 13b for applying a driving force to the ball screw mechanism 13a.

When the transfer robot 20 takes out the substrate W, the lifting / lowering drive mechanism 13 moves the lifting / lowering stage 11
Is raised, and the substrate W to be processed is raised to a predetermined height. Thereafter, the substrate W is taken out by the hand 21 of the transfer robot 20. afterwards,
The elevating drive mechanism 13 lowers the elevating stage 11, and until the next substrate W is taken out, the substrate W in the cassette C is removed.
Is immersed in pure water in the water tank 12.

When the cassette C is loaded into the substrate processing apparatus, the elevating stage 11 is at a position above the water tank 12. The pure water shower nozzle 14 starts supplying the pure water immediately after closing the cassette input door 5, thereby drying the substrate W in the cassette C placed on the elevating stage 11. Is prevented. In this state, the substrate detection probe P accommodated in the cassette insertion door 5 enters the cassette C from behind the cassette C, and detects the presence or absence of the substrate W in each stage in the cassette C.

In the cassette C, a plurality of shelves (substrate accommodating portions) are formed at regular intervals on the inner wall surface, whereby a plurality of substrates W are stacked at regular intervals along the vertical direction. It can be held by. Behind the cassette C, a pair of vertically extending plate-shaped extensions Ca is formed, and between the pair of extensions Ca, an opening through which the substrate detection probe P can be inserted into the cassette C is formed. It is in a state.

A plurality of substrate detection probes P are held by a probe holding member 41. That is, each of the plurality of substrate detection probes P is formed in a plate shape, and is held by the probe holding member 41 in a posture parallel to each other. The plurality of substrate detection probes P are connected to the cassette C
The probe is held by the probe holding member 41 in a so-called staggered arrangement when viewed from the front. More specifically, in the closed state of the cassette insertion door 5, the substrate detection probes P are vertically adjacent to each other, and their positions are shifted along a horizontal direction perpendicular to the direction in which the substrate detection probes P move.
Every other substrate detection probe P is vertically opposed. Thereby, a sufficient interval is secured between the substrate detection probes P facing each other in the vertical direction.

The probe holding member 41 is formed in a box shape, and a rack 43 is attached to a side portion thereof. A pinion 44 meshes with the rack 43, and a rotational force from a rotary actuator 46 is applied to the pinion 44. With this configuration, by driving the rotary actuator 46, the plurality of substrate detection probes P held by the probe holding member 41 can be moved forward and backward toward the cassette C at a time. Thus, the rack 43, the pinion 4
The forward / backward drive mechanism 42 is constituted by the rotary actuator 4 and the rotary actuator 46.

More specifically, as shown in FIG. 2, in order to guide the probe holding member 41 forward and backward, a slide shaft 47 is provided in the internal space of the cassette loading door 5 in the forward and backward directions of the substrate detecting probe P. The probe holding member 41 is fixed via a bracket 49 to a slide bush 48 that slides on the slide shaft 47. The rack 43 is fixed to the bracket 49.

FIG. 4 shows a state where the substrates W
FIG. 7 is a simplified side view showing a state when detecting whether or not there is an image. Immediately after the cassette insertion door 5 is closed, a predetermined input operation from the operation panel 8 is performed in response to an output from a predetermined sensor (not shown) for detecting the closed state of the cassette insertion door 5. In response to the rack 43
The probe holding member 41 is advanced from the retracted position (the position indicated by the solid line) to the detection position (the position indicated by the two-dot chain line) by the operation of the advance / retreat drive mechanism 42 including the pinion 44 and the like. As a result, the plurality of substrate detection probes P stacked vertically in a staggered pattern as described above are inserted into the cassette C at a time.

At this time, each substrate detection probe P is located at an upper position apart from the position of the substrate W to be detected. That is, the uppermost substrate detection probe P
Represents the substrate W stored in the uppermost shelf in the cassette C.
Above, the uppermost substrate W is arranged to face downward. The remaining substrate detection probe P is
At a position between the substrates W stored in the plurality of shelves in the cassette C, the substrates W are arranged so as to face the respective lower substrates W.

FIG. 5 is a perspective view showing a configuration for preventing the board from jumping out of the cassette C. In the water tank 12, a substantially semi-cylindrical protrusion restricting member 70 is attached to a wall surface 12A on the transfer robot 20 side by an attaching member 75. This protrusion restricting member 70
Is a columnar portion 71 extending from a position facing the lowermost shelf in the cassette C when the elevating stage 11 is at the lowermost position to a position higher than the upper edge of the water tank 12 by a predetermined height.
And a tapered portion 72 connected to the columnar portion 71. In the columnar portion 71, the surface facing the inside of the water tank 12 is a substrate regulating surface that forms a substantially cylindrical surface, and the side facing the inside of the water tank 12 in the tapered portion 72 (moved up and down by the lifting stage 11). The surface facing the cassette C) has a conical tapered surface 72a that tapers upward.

The lower edge of the tapered surface 72a is
2 is located at a position higher than the upper edge by a predetermined height,
Further, the upper end (that is, the upper end of the pop-out restricting member 70) 70a is located below the moving path of the hand 21 of the transfer robot 20, as shown in FIG. With this configuration, the elevating stage 11 is lowered and the cassette C
When the wafer W is guided into the water tank 12, the end face of the substrate W jumped out of the cassette C is guided by the tapered surface 72a, and is pushed into a predetermined position at the back of the cassette C. Thereby, when all the substrates W accommodated in the cassette C are immersed in the water in the water tank 12, all the substrates W
The cassette C is pushed into the inner part. And
The protrusion of the substrate W from the cassette C in the water is regulated by the columnar portion 71 of the protrusion regulating member 70. Therefore, even if a water flow occurs in the water tank 12, the cassette C
There is no risk that any of the substrates W will jump out of the device.

In the process of raising the elevating stage 11 and guiding the substrate W to be processed to the substrate transfer height to be accessed by the hand 21 of the transfer robot 20,
The substrate W in the cassette C rises while the protrusion from the cassette C is regulated by the columnar portion 71 of the protrusion regulating member 70, and floats on the water surface. for that reason,
When the hand 21 of the transfer robot 20 accesses the substrate transfer height, there is a possibility that the substrate W located at the substrate transfer height and any one of the substrates W located above and below the substrate W may protrude excessively from the cassette C. There is no. Therefore, the transfer of the substrate from the cassette C by the transfer robot 20 can be performed favorably, and the hand 21
The substrate W can be reliably held at a predetermined position (that is, the center of the rear surface of the substrate W).

Therefore, the substrate does not fall out of balance on the hand 21 and does not fall.
Therefore, the delivery of the substrate to the chuck of the substrate holding mechanism of the cleaning unit 30 does not become defective. When the cassette C is at the uppermost position, the substrate transfer height of the substrate stored in the lowermost shelf of the cassette C is set so that all the substrates W in the cassette C can be unloaded. It is determined to be less than the height.

The cassette C carried into the substrate processing apparatus
When immersing in the pure water stored in the water tank 12 for the first time, there is a possibility that the substrate W jumps out of the cassette C. The amount of protrusion of the substrate W is large, and a part of the protrusion W
In the case of overlapping with a, the end face of the substrate W cannot be guided by the tapered surface 72a, and the substrate W may collide with the protrusion restricting member 70, and the substrate W may be damaged.

Therefore, in this embodiment, a beam sensor 80 (see FIGS. 2 and 3) for detecting an excessive protrusion of the substrate W is provided. This beam sensor 8
0, the beam sensor 80 shown in FIG.
A sensor that detects the presence of a light blocking object on the optical axis L1 between the light emitting unit 81 and the light receiving unit 82 by detecting light from the light emitting unit 81 with the light receiving unit 82. The light projecting unit 81 and the light receiving unit 82 are connected to the sensor amplifier 83 by the optical fiber 8.
4,855. Sensor amplifier 83
A light emitting element (not shown) optically coupled to an end of an optical fiber 84 coupled to the light projecting section 81;
And a light-receiving element (not shown) optically coupled to an optical fiber 85 coupled to the optical fiber 85. When detecting the substrate W, the light emitting element emits light and the output signal of the light receiving element is monitored. If the amount of light received by the light receiving element decreases and the output signal decreases, it means that the optical axis L1 has been shielded by the substrate W.

The light projecting portion 81 and the light receiving portion 82 are further supplied with clean air (or an inert gas such as nitrogen gas) from an air pump 86 (gas supply means) via air supply pipes 87, 88, 89. Good.) Is supplied. As shown in FIG. 6, the optical axis L1 is set at a position above the upper end 70a of the protrusion regulating member 70 and below the movement path of the hand 21 of the transfer robot 20. Further, the optical axis L1 can detect the substrate W that has protruded so as to interfere with the upper end of the protruding restriction member 70, and has a small protruding substrate that can guide the end surface by the tapered surface 72a. W
Is set so that it is not detected. Specifically, the optical axis L1 is set at a position slightly closer to the cassette C than the upper end edge of the tapered surface 72a.

FIG. 8 is a block diagram showing an electrical configuration of a main part of the substrate processing apparatus of this embodiment. The control device 201 including the microcomputer and the memory M,
In response to signals from the substrate collective detection unit 40, the operation panel 8, and the beam sensor 80, the operation of the lifting drive mechanism 13 and the transfer robot 20 is controlled. Control device 201
Further receives a substrate transfer request from the cleaning unit 30, and displays an error message or the like on the display device 9 as necessary.

Immediately after the cassette C is loaded into the substrate processing apparatus, the substrate collective detection unit 40 is operated.
Based on the detection result, the control device 201 stores in the memory M data on the presence or absence of the substrate W on each shelf in the cassette C on the elevating stage 11. Thereafter, the control device 201 controls the lifting / lowering driving mechanism 13 to control the lifting / lowering stage 1.
1 is lowered to guide the cassette C into the water tank 12. In this process, the control device 201 monitors a detection signal from the beam sensor 80. When the beam sensor 80 detects the substrate W earlier than when the lifting stage 11 reaches the lowermost position (when the optical axis L1 is blocked by the substrate W), the control device 201 stops the lifting drive mechanism 13. With
The display device 9 displays a message or the like for notifying that the protrusion of the substrate from the cassette has been detected. In this case, the operator operates the operation panel 8 to raise the elevating stage 11, push the substrate W into the cassette C, and restart the operation of the apparatus.

When the stage 11 reaches the lowermost position without the substrate W being detected by the beam sensor 80, all the substrates W in the cassette C are at the predetermined positions pushed into the back of the cassette C. The control device 201 controls the lifting / lowering drive mechanism 13 based on the data stored in the memory M so that the uppermost substrate W in the cassette C is located directly below the water surface in the water tank 12, and controls the lifting / lowering stage 11 To control the height. Of course, when the cassette C is lowered into the water tank 12, the lowering of the stage 11 may be stopped at such a height. Even in this case, all the substrates W in the cassette C can be pushed into the cassette C.

Thereafter, the control device 201 controls the elevation drive mechanism 13 in response to a request from the cleaning unit 30 so that the substrate W to be processed is positioned at the substrate transfer height. Is operated to take out the substrate W at the substrate transfer height from the cassette C,
Further, the substrate is carried into the cleaning unit 30. FIG. 9 is a block diagram for explaining the substrate detection probe P and an electrical configuration related thereto. The substrate detection probe P is made of a non-conductive resin (for example, FEP).
(Ethylene tetrafluoride / propylene hexafluoride copolymer resin)
Etc.) (non-conductive partition)
And the detection electrode 5 embedded in the probe case 55.
1 and a ring-shaped guard electrode 52 disposed so as to surround the detection electrode 51. Detection electrode 51
Is formed in a rectangular shape, for example, and accordingly, guard electrode 52 is formed in a rectangular ring shape, for example. These detection electrode 51 and guard electrode 52
Will face the substrate detection position via the probe case 55 functioning as a non-conductive partition.

A rectangular wave voltage is applied to the detection electrode 51 from a rectangular wave generating circuit 61 via a resistor R. In the vicinity of the detection electrode 51, a detected dielectric (substrate W in this embodiment) which can be regarded as being grounded in a high-frequency circuit due to energization on the surface of the cassette C or the apparatus or aerial discharge of the substrate W
Is present, the capacitance between the detection electrode 51 and the ground increases, and if the dielectric to be detected does not exist near the detection electrode 51, the capacitance between the detection electrode 51 and the ground becomes negligibly small. Therefore, the time constant of the RC circuit formed by the resistor R and the capacitance between the detection electrode 51 and the ground increases when the dielectric to be detected exists near the detection electrode 51, The appearing rectangular wave voltage has a delay time at rising and falling. This delay time is detected by the delay time detection circuit 62. The magnitude of the delay time is determined by the comparison circuit 63.
When a large delay time is detected, a signal indicating that an object is present is output to the output circuit 64.
Is output via. As described above, the rectangular wave generation circuit 61, the delay time detection circuit 62, the comparison circuit 63, and the like form a substrate detection circuit for detecting the presence or absence of a substrate.

On the other hand, a rectangular wave voltage generated by a guard electrode pulse generating circuit 65 (guard electrode rectangular wave applying circuit) based on the rectangular wave voltage from the rectangular wave generating circuit 61 is applied to the guard electrode 52. I have. The rectangular wave voltage generated by the guard electrode pulse generation circuit 65 has the same phase (same frequency) as the rectangular wave voltage applied to the detection electrode 51, and
The voltage signals have the same potential. Therefore, the guard electrode 5
The potential of No. 2 is equal to that of the detection electrode 51 at any time, and there is no significant potential difference between them.

Therefore, since no electric field component is generated in the direction along the surface of the detection electrode 51, even if a water droplet adheres to the surface of the substrate detection probe P, no charge moves in the water droplet. Therefore, there is no potential difference between the detection electrode 51 and the surface of the water droplet, and the water droplet has only the same effect as increasing the thickness of the detection electrode 51. Therefore, even when water droplets are attached, the distance between the ground and the ground can be regarded as infinite, so that a large capacitance does not occur,
A correct signal representing "no substrate" will be output.

FIGS. 10A and 10B are a perspective view and a sectional view, respectively, showing a common internal structure of the light projecting section 81 and the light receiving section 82. The light projecting unit 81 and the light receiving unit 82 include a cylindrical outer case 100. The outer case 100 has a gas flow passage 101 into which air supply pipes 88 and 89 are inserted from below, and optical fibers 84 and 8 also from below.
5 is formed therein. An optical component 103 as a light emitting unit (in the case of the light projecting unit 81) or a light detecting unit (in the case of the light receiving unit 82) is attached to the distal ends of the optical fibers 84 and 85. Optical component 1
03 is, for example, a cylindrical inner case 1 made of stainless steel.
04 and a lens 105 housed in the inner case 104 and for inputting and outputting light to and from the optical fibers 84 and 85.
And a reflecting mirror 106 for changing the traveling direction of light. In the inner case 104, an opening 107 for inputting and outputting light is formed at a position near the reflecting mirror 106.

On the other hand, the opening 1
10 are formed. Inner case 10 of optical component 103
4 is attached to the outer case 100 with the opening 107 facing the opening 110. And outer case 1
The gas flow passage 101 in the hole 00 communicates with the opening 110. With this configuration, the clean air is supplied from the air supply pipes 88 and 89 into the outer case 100, thereby generating a clean air flow blown out of the opening 110 through the gas flow passage 101. Therefore, even in a humid atmosphere near the underwater loader 10, water droplets and mist do not reach the optical component 103.

Therefore, the optical component 103 is
The incident light from zero can be satisfactorily guided to the optical fiber 84, and the emitted light from the optical fiber 85 can be satisfactorily guided to the opening 110. Since water droplets do not adhere to any part of the optical component 103, there is no possibility that the emitted light is refracted or diffused, and the light generated from the light projecting unit 81 is not blocked by the substrate W. , Make sure the light receiving section 8
2 is incident. Therefore, in the light receiving section 82, the optical axis L1
Depending on the presence or absence of the substrate W that blocks light, a sufficient difference in the amount of received light can be secured.

The outer case 100 to be exposed to the atmosphere in the underwater loader 10 is made of a resin material containing no metal (for example, tetrafluoroethylene resin (PTFE) or ethylene tetrafluoride / perfluoroalkoxy ethylene). It is preferably made of a polymer resin (PFA). Thereby, it is possible to prevent the metal substance from attaching to the substrate W after the CMP processing. As mentioned above, although one Embodiment of this invention was described, this invention can be implemented also in another form. For example, in the above-described embodiment, an example in which one column-shaped protrusion restricting member 70 is disposed in the water tank 12 has been described. It may be arranged along the elevating direction. In this case, for example,
The two pop-out restricting members may be arranged on both the left and right sides of the hand 21 (the state of FIG. 5) extending toward the underwater loader 12 so as to restrict the end surface of the circular substrate W. At this time, the pop-out restricting member is slightly larger than the position of the pop-out restricting member 70 shown in FIG.
It will have a board | substrate control surface in a near position. However,
The position of the optical axis L1 of the beam sensor 80 may remain at the position shown in FIG. In this case, the optical axis L1 of the beam sensor 80 is positioned closer to the transfer robot 20 (opposite to the cassette C) than the tip of the protrusion restricting member.

Further, in the above-described embodiment, the case where the processing is performed on a semiconductor wafer which is a substantially circular substrate has been described. However, the present invention is not limited to a general rectangular substrate such as a glass substrate for a liquid crystal display device and other arbitrary substrates. It can also be applied to the case of processing a substrate having the shape shown in FIG. In addition to these modifications, various design changes can be made within the scope of the matters described in the claims.

[Brief description of the drawings]

FIG. 1 is a simplified perspective view showing the appearance of a substrate processing apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view showing an internal configuration near a cassette insertion portion of the substrate processing apparatus.

FIG. 3 is a simplified perspective view showing a configuration related to an underwater loader of the substrate processing apparatus.

FIG. 4 is a simplified side view showing a state when detecting whether a substrate is present on each shelf in a cassette.

FIG. 5 is a perspective view for explaining a configuration for restricting the protrusion of the substrate.

FIG. 6 is an illustrative sectional view for explaining the arrangement of an optical axis of a protrusion restricting member and a beam sensor.

FIG. 7 is a perspective view for explaining the configuration of the beam sensor.

FIG. 8 is a block diagram illustrating an electrical configuration of a main part of the substrate processing apparatus.

FIG. 9 is a block diagram for explaining a substrate detection probe and an electrical configuration related thereto.

FIG. 10 is a perspective view and a cross-sectional view showing a common internal structure of a light projecting unit and a light receiving unit of the beam sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Underwater loader 11 Elevating stage 12 Water tank 13 Elevating drive mechanism 20 Transfer robot 21 Hand 30 Washing unit 40 Substrate batch detection unit 70 Protrusion control member 71 Columnar part 72 Tapered part 72a Tapered surface 80 Beam sensor C Cassette P Substrate detecting probe W Substrate

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Asahi sentence 4 chome, Horikawa-dori Teranouchi, Kamigyo-ku, Kyoto-shi, Kyoto, Japan BB31 GG18 GG28 5F031 CA02 CA05 CA07 DA01 EA09 FA01 FA03 FA09 FA11 GA47 HA72 JA05 JA23 MA16 MA22 MA23 MA33

Claims (4)

[Claims] 1. A water tank capable of immersing a cassette having a plurality of stages of substrate accommodating portions capable of accommodating a plurality of substrates in a stacked state, a substrate in the cassette being immersed in the water tank, or a water surface of the water tank. A cassette elevating mechanism for elevating and lowering the cassette so that it floats above the cassette; and a substrate disposed in the above-mentioned water tank along the elevating direction of the cassette by the cassette elevating mechanism. An underwater loader, comprising: a protrusion restricting member for restricting the protrusion. 2. In the process of lowering the cassette toward the water tank by the cassette elevating mechanism, it is determined whether the substrate in the cassette has protruded from the cassette to such an extent that the substrate collides with the upper end of the pop-out restricting member. The underwater loader according to claim 1, further comprising a beam sensor for detecting a position above an upper end of the underwater loader. 3. The underwater underwater according to claim 1, wherein the protrusion restricting member has a tapered surface at an upper end which comes into contact with an end surface of the substrate and guides the substrate to a deep portion of the cassette. loader. 4. A submersible loader according to claim 1, wherein said substrate elevating mechanism lifts and lowers the cassette to transport a substrate guided to a substrate transfer height. A substrate processing means for receiving the substrate carried out by the apparatus and performing predetermined processing on the substrate.