JP3665717B2 - Optical substrate detection apparatus, and substrate processing apparatus and substrate processing method using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical substrate detection apparatus for optically detecting various substrates such as a semiconductor wafer, a glass substrate for a liquid crystal display device, a glass substrate for a plasma display, a photomask substrate, an optical disk or a magneto-optical disk substrate. And a substrate processing apparatus and a substrate processing method using the same.
[0002]
[Prior art]
In a substrate processing apparatus used in a semiconductor device manufacturing process, it is necessary to detect the presence and position of a semiconductor wafer (hereinafter simply referred to as “wafer”) that is a substrate to be processed in various situations. In this case, if a contact type sensor is used, damage to the wafer or generation of particles becomes a problem. Therefore, it is necessary to use a non-contact type sensor. Generally, a transmission type photo beam sensor is used. There are many cases.
[0003]
The transmissive photobeam sensor includes a light projecting unit and a light receiving unit, and the light beam is projected from the light projecting unit to the light receiving unit along an optical axis passing through the wafer detection position. If there is a wafer at the wafer detection position, the beam light is blocked. If there is no wafer at the wafer detection position, the beam light is incident on the light receiving unit. Therefore, the presence / absence of a wafer at the wafer detection position can be detected based on the amount of light received by the light receiving unit.
[0004]
[Problems to be solved by the invention]
Wafer detection may be required even in a humid environment where a large amount of water droplets or mist is present.
For example, after a CMP (Chemical Mechanical Polishing) process that chemically and mechanically polishes the surface of the wafer (the surface of the wafer itself or the surface of a thin film formed on the surface), a polishing agent (slurry) remaining on the wafer is removed. In the substrate cleaning apparatus for removing, a so-called underwater loader is used to prevent the slurry from drying. The underwater loader waits by dipping a cassette containing wafers in a water tank, and floats the cassettes on the water as needed to pay out the wafers immediately before the cleaning process. The underwater loader includes an elevating stage on which the cassette is placed, an elevating drive mechanism that moves the elevating stage up and down in the water tank, and a pure water shower nozzle that supplies pure water to the wafer in the cassette above the water tank. Yes.
[0005]
In such an underwater loader, it may be necessary to detect the position of the wafer in the process of lowering the elevating stage and immersing the wafer in water. That is, for example, the wafer in the cassette is not necessarily stored in a fixed position, and the wafer may protrude from the cassette. If the pop-out amount is large, the wafer may interfere with the upper end of the outer wall of the water tank and be damaged in the process of lowering the elevating stage. Therefore, it is preferable to detect the pop-out of the wafer at a position near the upper end of the outer wall of the water tank and stop the descent of the lift stage when the amount of the pop-out of the wafer is large.
[0006]
However, in a humid environment such as an underwater loader, even if the transmission type photo beam sensor having the above-described configuration is used, the wafer cannot always be detected satisfactorily. That is, when a water droplet adheres to the light projecting portion, the water droplet acts as a lens, the optical axis is diffused, and the amount of light incident on the light receiving portion is reduced. For this reason, the necessary sensitivity difference corresponding to the presence or absence of the wafer cannot be obtained, and even if the wafer is not shielded from light, it may be erroneously detected as a light-shielded state. Further, when the water droplet is decentered from the center of the light projecting portion, the optical axis direction is changed, so that even if there is no light shielding by the wafer, it may be erroneously detected as a light shielding state.
[0007]
  Similarly, when water droplets adhere to the light receiving unit, the water droplets act as a lens and the amount of incident light is reduced, so that the necessary sensitivity difference cannot be obtained, and the light shielding state is erroneous even though there is no light shielding by the wafer. May be detected. Further, when water droplets are attached eccentrically from the center of the light receiving unit, the light receiving direction is changed, so that even when there is no wafer, there is a possibility that the light shielding state is erroneously detected.
  Furthermore, in a processing unit that performs processing using a chemical solution, it may be necessary to detect the position of the wafer. In this case, in addition to the problem similar to the above-mentioned problem caused by water droplets, There is also an influence. In other words, the surface and the interior of the light projecting partDeparturePhotoelementChildTheIs receivedPhotoelementOf childThe construction material is eroded and the projector or receiver is damaged.LanoThe elution component of the constituent material may contaminate the processing target wafer.
[0008]
  In addition, light emission on the surface and inside of the projector or receiverelementOrLight receiving elementIn the case where at least a part of the wafer contains a metal material and these do not have corrosion resistance to pure water and chemicals for wafer processing, the wafer is cleaned as in the case of wafer cleaning processing after CMP processing. In a process environment where metal contamination is not allowed, metal contamination of the wafer and the substrate processing apparatus becomes a problem.
  SUMMARY OF THE INVENTION An object of the present invention is to solve the above technical problem and provide an optical substrate detection apparatus capable of reliably detecting a substrate even in a humid environment.
[0009]
Another object of the present invention is to provide a substrate processing apparatus and a substrate processing method that can detect a substrate satisfactorily even in a wet environment and perform processing on the substrate satisfactorily.
[0010]
[Means for Solving the Problems and Effects of the Invention]
  The invention according to claim 1 for achieving the above object is a substrate detection apparatus for optically detecting the presence or absence of a substrate at a substrate detection position, and contains a light emitting unit and the light emitting unit, A light projecting unit including a case in which an opening through which light emitted from the light emitting unit toward the substrate detection position is formed is inserted into the case of the light projecting unit from below, and the light emitting unit is coupled to one end of the light projecting unit. 1 optical fiber, a light emitting element optically coupled to the other end of the first optical fiber, a light detection unit, and the incident light traveling from the substrate detection position toward the light detection unit while accommodating the light detection unit A light receiving portion including a case in which an opening through which the light passes is formed; a second optical fiber inserted into the case of the light receiving portion from below and having the light detection portion coupled to one end thereof; Photoreceptor optically coupled to the edge If, containing the respective gas is supplied to the casing, the gas supply means for creating an air flow blown out through the respective opening from the inside of the casing of the light projecting section and a light receiving portionThus, a first gas flow passage is formed in the case of the light projecting unit to guide gas from behind the light emitting unit to the opening, and in the case of the light receiving unit, the light detecting unit A second gas flow passage for guiding gas from behind to the opening is formed, and the gas supply means supplies gas to the first and second gas flow passages.This is an optical substrate detection apparatus.
[0011]
  According to this configuration, the light emitting unitandThe light detectorRespectivelyThe contained case has an opening for light to pass through.RespectivelyThe air flow that is formed and blows out from the case through the opening is formed by the function of the gas supply means. Thereby, there is no possibility that a droplet or mist enters the case from the opening, and the droplet does not adhere to the vicinity of the light emitting unit or the light detection unit.
  Thereby, there is no possibility that the optical detection of the substrate is hindered even in a humid environment.
[0012]
  In addition, it is preferable that a gas supply means supplies clean air or inert gas (nitrogen gas etc.), for example..
[0013]
  A transmissive optical substrate detection device that projects light from the light projecting unit to the light receiving unit and detects the presence or absence of the substrate depending on whether or not the optical axis is blocked by the substrate may be configured, A reflection type optical substrate detection device that detects reflected light generated from the light projecting unit and reflected from the substrate by the light receiving unit may be configured..
[0014]
  Claim2The invention described in claim 1 is characterized in that the light projecting section generates a substantially linear beam light toward the light receiving section.1It is an optical board | substrate detection apparatus of description.
  According to this configuration, a light beam is generated from the light projecting unit toward the light receiving unit, and a transmission type sensor that detects the presence or absence of the substrate based on whether or not the beam light is shielded by the substrate is configured. In this case, the presence or absence of the substrate at the substrate detection position can be accurately detected by using the beam light. And since the droplet does not adhere to the vicinity of the light emitting unit or the light detecting unit, the optical axis does not change or the amount of received light in the light receiving unit does not decrease. The substrate can be detected reliably.
[0015]
  Claim3The invention described in claim 1 is characterized in that the case is made of a chemical resistant material.Or 2It is an optical board | substrate detection apparatus of description. According to this invention, since the case is made of a chemical resistant material, the substrate can be detected well even in an environment where an erodible chemical solution exists. In addition, since the light emission part and the light detection part are accommodated in a chemical-resistant case, and the outward airflow is blown out from the opening, there is no intrusion of the chemical liquid from the opening. For this reason, there is no problem even if a commercially available general-purpose unit that does not have chemical solution measures is used for the light emitting unit and the light detecting unit, the light emitting unit or the light receiving unit breaks down, or these constituent materials are eluted. There is no fear.
[0016]
  Claim4The invention according to any one of claims 1 to 3, wherein the case is made of a resin material containing no metal.3An optical substrate detection apparatus according to any one of the above.
  According to the present invention, the case is made of a resin material that does not contain metal, so that metal contamination does not occur. And claims3As in the case of the invention, even if the constituent material of the light emitting part or the light detecting part contained in the case contains a metal, these are not affected by the external atmosphere, so the metal in the constituent material There is no risk of elution. Therefore, the degree of freedom in selecting the constituent material of the light emitting unit or the light detecting unit is increased.
[0017]
  Claim5The invention described in claim 1 detects a substrate placed in a humid environment.4The optical substrate detection device according to any one of the above, a substrate transfer means for transferring a substrate detected by the substrate detection device, and a substrate to be processed is delivered by the substrate transfer means. A substrate processing apparatus including substrate processing means for performing a predetermined process.
  Claims6According to the present invention, a substrate placed in a wet environment is defined in claims 1 to 4.4A substrate detection step of detecting using the optical substrate detection device according to any one of the above, a substrate transfer step of transferring the substrate detected in this substrate detection step to the substrate processing means, and a substrate processing means by this substrate transfer step And a substrate processing step for performing a predetermined process on the substrate carried into the substrate.
[0018]
  theseofAccording to the invention, since the presence or absence of the substrate can be reliably detected in a non-contact state even in a humid environment, the subsequent substrate processing can be performed satisfactorily.
  The wet environment is, for example, an environment in which the liquid from the liquid supply unit is supplied to the substrate, or the substrate is placed in a predetermined position in a state where the substrate is immersed in the liquid. Means the environment. In this case, the optical substrate detection device is arranged at a position where the liquid can be supplied to the substrate, or at a position where the droplets of the liquid supplied to the substrate or the liquid splashing from the surface of the substrate can reach. Detection may be performed.
[0019]
Further, the optical substrate detection apparatus may be used for detecting the positional deviation of the substrate at the substrate transfer position for transferring the substrate to the substrate transfer means. In this case, specifically, the optical substrate detection device may be arranged so as to be able to detect only a substrate in which a large positional deviation has occurred so as to cause a defect in the substrate transport by the substrate transport unit.
Further, the substrate processing means may specifically perform a substrate cleaning process. More specifically, the substrate processing unit may clean the substrate after the CMP process.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a perspective view showing a simplified 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 CMP processing. This apparatus includes a cassette loading unit 2 for loading a cassette C that can collectively accommodate a plurality of (for example, 25) substrates W after CMP processing, and a cassette (FIG. And a cassette takeout unit 3 for taking out (not shown). The cassette loading unit 2 is provided with an open / close box 5 that is rotatably mounted between a solid line position and a two-dot chain line position in FIG. 1 around a horizontal axis. A door 6 is provided that is pivotably mounted about a vertical axis. A handle 7 with a latch mechanism is provided at the upper part (the upper part in the closed state) of the open / close box 5. The operator operates the handle 7 to open the open / close box 5, and the substrate W after the CMP process is opened. The accommodated cassette C is put into the substrate processing apparatus.
[0021]
On the front surface of the substrate processing apparatus, an operation panel 8 and a display device 9 are disposed above the cassette loading unit 2 so that necessary processing conditions can be input and the progress of substrate processing can be monitored. It has become.
FIG. 2 is a plan view showing an internal configuration in the vicinity of the cassette loading portion 2 of the substrate processing apparatus. The cassette C loaded from the cassette loading unit 2 is placed on the lift stage 11 of the underwater loader 10. The underwater loader 10 is a device that stands by in a state where the substrates W in the cassette C are immersed in water, and provides a substrate delivery position for discharging the substrates W one by one immediately before processing.
[0022]
A transfer robot 20 (substrate transfer means) is disposed adjacent to the underwater loader 10. The transfer robot 20 includes a hand 21 having a suction part 21 a at the tip for sucking the substantially center of the back surface of the substrate W, and a base part 22 coupled to the base end part of the hand 21. As the base portion 22 is rotated, the hand 21 is rotated by an angle twice as large as the direction opposite to the rotation direction, whereby the transfer robot 20 moves toward the underwater loader 10. The hand 21 and the base portion 22 can be bent and stretched, and the hand 21 and the base portion 22 can be bent and stretched with respect to the cleaning unit 30 (substrate processing means) disposed on the side opposite to the underwater loader 10. Along with such bending and stretching movements, the base portion 22 can move up and down. Thereby, the transfer robot 20 can take out one substrate W from the cassette C of the underwater loader 10 and carry it into the cleaning unit 30.
[0023]
The cleaning unit 30 includes, for example, a substrate holding mechanism that holds and rotates the substrate W, a processing liquid supply mechanism that supplies a processing liquid (chemical solution or pure water) to the substrate held by the substrate holding mechanism, and a substrate And a scrub member for scrubbing the front surface or the back surface of the substrate W held by the holding mechanism.
A substrate detection unit 40 is accommodated in the internal space of the open / close box 5 of the cassette loading unit 2. The board detection unit 40 includes a plurality of board detection probes P, a probe holding member 41 that holds the board detection probes P, and an advance / retreat drive mechanism for moving the probe holding member 41 forward and backward toward the cassette C held by the underwater loader 10. 42. Thus, the position between the retreat position (solid line position) where the plurality of substrate detection probes P are retreated in the open / close box 5 and the detection position (position of the two-dot chain line) advanced to the position of the substrate W in the cassette C. You can move forward and backward at once.
[0024]
For example, the plane position where the end surface of the substrate W is in contact with the inner wall surface of the back of the cassette C (on the open / close box 5 side) (that is, the position of the substrate W indicated by the two-dot chain line in FIG. 2) is the correct accommodation of the substrate W. In actuality, not all the substrates W in the cassette C are necessarily in the correct substrate accommodation positions. That is, some or all of the substrates W may protrude to the open side (the transfer robot 20 side) in front of the cassette C, that is, the substrate W may be misaligned.
[0025]
FIG. 3 is a perspective view showing a configuration related to the underwater loader 10 in a simplified manner. The underwater loader 10 includes an elevating stage 11 that can be placed with the cassette C positioned by the positioning member 15, a water tank 12 that can submerge the cassette C placed on the elevating stage 11, A lift drive mechanism 13 (substrate movement mechanism) for moving the stage 11 up and down, 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 lift stage 11. And.
[0026]
The water tank 12 is filled with pure water, and the substrate W in the cassette C can be immersed in the pure water by lowering the elevating stage 11 by the elevating drive mechanism 13. Further, by raising and lowering the elevating stage 11 by the elevating drive mechanism 13, the elevating stage 11 can be guided to a raised position above the water surface in the water tank 12.
The elevating drive mechanism 13 includes, for example, a ball screw mechanism 13a and a motor 13b that applies a driving force thereto.
[0027]
When the substrate W is taken out by the transfer robot 20, the elevating drive mechanism 13 raises the elevating stage 11 and raises the substrate W to be taken out to a predetermined height. Thereafter, the substrate W is taken out by the hand 21 of the transfer robot 20. Thereafter, the elevating drive mechanism 13 lowers the elevating stage 11 and immerses the substrate W in the cassette C in pure water in the water tank 12 until the next substrate W is taken out.
[0028]
When the cassette C is loaded into the substrate processing apparatus, the lifting / lowering stage 11 is in a raised position above the water tank 12. The pure water shower nozzle 14 starts supplying pure water promptly after closing the open / close box 5, thereby drying the substrate W in the cassette C placed on the elevating stage 11. It is prevented. In this state, the substrate detection probe P accommodated in the open / close box 5 enters the cassette C from behind the cassette C, and detects the presence or absence of the substrate W at each stage in the cassette C.
[0029]
The cassette C has a plurality of stages of shelves formed on the inner wall surface at regular intervals, so that a plurality of substrates W can be held in a stacked state at regular intervals along the vertical direction. It has become. A pair of plate-like extensions Ca extending in the vertical direction is formed behind the cassette C, and the substrate detection probe P can be inserted into the cassette C between the pair of extensions Ca. It is in a state.
A plurality of substrate detection probes P are held by the 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 held by the probe holding member 41 in a so-called zigzag arrangement state when viewed from the cassette C. More specifically, in the closed state of the open / close box 5, the substrate detection probes P adjacent to each other in the vertical direction are shifted in the horizontal direction perpendicular to the advancing / retreating direction, and every other one. The substrate detection probe P is opposed to the vertical direction. Thereby, a sufficient space is secured between the substrate detection probes P opposed to each other in the vertical direction.
[0030]
The probe holding member 41 is formed in a box shape, and a rack 43 is attached to the side portion thereof. A pinion 44 meshes with the rack 43, and a rotational force from the 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 advanced and retracted collectively toward the cassette C. Thus, the advance / retreat drive mechanism 42 is configured by the rack 43, the pinion 44, the rotary actuator 46, and the like.
[0031]
Specifically, as shown in FIG. 2, in order to guide the advancement and retraction of the probe holding member 41, a slide shaft 47 is arranged in the inner space of the open / close box 5 along the advance / retreat direction of the substrate detection probe P. The probe holding member 41 is fixed to a slide bush 48 that slides on the slide shaft 47 via a bracket 49. The rack 43 is fixed to the bracket 49.
[0032]
FIG. 4 is a block diagram for explaining the substrate detection probe P and the electrical configuration related thereto. The substrate detection probe P includes a probe case 55 (non-conductive partition wall) made of a resin that is a non-conductive material (for example, FEP (tetrafluoroethylene / hexafluoropropylene copolymer resin)), and the probe case 55. A detection electrode 51 embedded therein and a ring-shaped guard electrode 52 disposed so as to surround the detection electrode 51 are provided. The detection electrode 51 is formed in a rectangular shape, for example, and the guard electrode 52 is formed in a rectangular ring shape, for example. The detection electrode 51 and the guard electrode 52 are opposed to the substrate detection position via the probe case 55 that functions as a non-conductive partition wall.
[0033]
A rectangular wave voltage is applied to the detection electrode 51 from the rectangular wave generating circuit 61 via a resistor R. If a dielectric to be detected (substrate W in this embodiment) grounded in a high-frequency circuit exists in the vicinity of the detection electrode 51, the capacitance between the detection electrode 51 and the ground is increased, and the detection target is in the vicinity of the detection electrode 51. If there is no dielectric, the capacitance between the detection electrode 51 and the ground is negligibly small. Therefore, the time constant of the RC circuit formed by the resistance R and the capacitance between the detection electrode 51 and the ground is increased when a detected dielectric exists in the vicinity of the detection electrode 51. The appearing rectangular wave voltage has a delay time at the rise and fall. This delay time is detected by a delay time detection circuit 62. The magnitude of the delay time is determined by the comparison circuit 63, and when the large delay time is detected, a signal indicating the presence of the detected object is output via the output circuit 64. 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 the substrate W.
[0034]
On the other hand, a rectangular wave voltage created 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. The rectangular wave voltage generated by the guard electrode pulse generating circuit 65 is a voltage signal having the same phase (same frequency) and the same potential as the rectangular wave voltage applied to the detection electrode 51. Therefore, the potential of the guard electrode 52 is equal to that of the detection electrode 51 at any time, and no significant potential difference occurs between them.
[0035]
Therefore, since an electric field component in a direction along the surface of the detection electrode 51 does not occur, even if a water droplet adheres to the surface of the substrate detection probe P, no charge movement occurs 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 only has the same effect as the thickness of the detection electrode 51 is increased. Therefore, even when water droplets are attached, the distance between the ground and the ground can be considered infinite, so that a large capacitance is not generated and a correct signal indicating “no substrate” is output.
[0036]
On the other hand, as shown in FIGS. 2 and 3, the substrate W protrudes from the opening in front of the cassette C (substrate misalignment) near the upper end of the outer wall 12 </ b> A of the water tank 12 on the transfer robot 20 side. Beam sensors 80 and 90 for detection are arranged. The beam sensors 80 and 90 have light projecting portions 81 and 91 and light receiving portions 82 and 92, respectively, and the optical axes L1 and L2 of the beam light directed from the light projecting portions 81 and 91 to the light receiving portions 82 and 92 are substrates. It is configured to detect the presence or absence of the substrate W in a state where each predetermined amount protrudes depending on whether or not W shields light.
[0037]
As shown in FIG. 5, the optical axis L1 of the beam sensor 80 is set slightly above the outer wall 12A of the water tank 12 so as to pass through a position inside the water tank 12 relative to the inner surface of the outer wall 12A. Further, the optical axis L2 of the beam sensor 90 is set so as to be located inward of the substrate W (on the open / close box 5 side) with respect to the optical axis L1 of the beam sensor 80.
That is, when the substrate W has greatly jumped out of the cassette C and the substrate W may interfere with the outer wall 12A when descending to the water tank 12, the beam sensor 80 detects the substrate W that has jumped out in this way. .
[0038]
On the other hand, even when the substrate W does not protrude so much as to interfere with the outer wall 12A, the substrate W has protruded to a position where it may not be detected by the substrate detection probe P (the substrate in plan view). When the detection electrode 51 of the detection probe P and any part of the substrate W are not likely to overlap each other), the beam sensor 90 detects such a substrate W.
More specifically, the detection electrode 51 of the substrate detection probe P is located on the inner side of the substrates W1 and W2 that are projected to a degree slightly larger than the degree of conveyance failure by the conveyance robot 20 during substrate detection. It is inserted into the cassette C so as to be located in the region (inner region in plan view). In FIG. 5, the symbol W <b> 1 represents the substrate W that has not jumped out of the cassette C, and the symbol W <b> 2 represents the substrate W that has jumped to the detection limit position by the substrate detection probe P.
[0039]
Further, the optical axis L2 of the beam sensor 90 is set so as to be able to detect the substrate W2 on which a jumping amount slightly larger than the jumping amount that is a limit amount that can be detected by the substrate detection probe P has occurred.
Therefore, if the optical axis L2 of the beam sensor 90 is shielded from light by the substrate W, the substrate W on any shelf in the cassette C has a conveyance failure, or the substrate detection probe P can accurately detect the presence or absence of the substrate W. Thus, it is detected that an undesired pop-out has occurred that has not been performed. In this case, the conveyance failure means that the hand 21 of the conveyance robot 20 damages the substrate W, conversely, the hand 21 is damaged, or the suction portion 21 of the hand 21 is greatly displaced from the center of the back surface of the substrate W. This includes a situation in which the position W is attracted and the substrate W falls out of balance on the hand 21 and the delivery from the hand 21 to the substrate holding mechanism of the cleaning unit 30 fails.
[0040]
If the optical axis L1 of the beam sensor 80 is shielded by the substrate W, it is detected that there is a substrate W3 that may interfere with the outer wall 12A.
As shown in FIG. 6, the optical axis L1 of the beam sensor 80 is set so as to be inclined with respect to a plane including the main surface of the substrate W to be arranged horizontally, whereby the optical axis L1 is Since the main surface of the substrate W in the protruded state is shielded from light, the protrusion of the substrate W can be reliably detected. Similarly, the optical axis L2 of the beam sensor 90 is set to be inclined with respect to a plane including the main surface of the substrate W.
[0041]
After the detection operation of the presence / absence of the substrate W at each stage is completed by the substrate detection probe P and the substrate detection probe P is retracted into the internal space of the open / close box 5, the elevation stage 11 is lowered by the action of the elevation drive mechanism 13. The cassette C is guided into the water tank 12. In this process, the beam sensors 80 and 90 perform a substrate detection operation. That is, as the cassette C descends with respect to the fixedly arranged beam sensors 80 and 90, the position of the substrate W on the shelf of each stage of the cassette C is scanned in sequence, and the substrate W at each stage jumps out. Detected.
[0042]
If the beam sensor 80 detects the jumping out of the substrate W while the lifting stage 11 is being lowered, the substrate W may be damaged if the lifting stage 11 is further lowered. Therefore, the lifting drive mechanism 13 stops the lifting stage 11 in response to the beam sensor 80 detecting the substrate W. Along with this, a message for notifying that the substrate W is popping out is displayed on the display device 9. In this case, the operator pushes the protruding substrate W into the cassette C and gives an instruction for resuming processing from the operation panel 8.
[0043]
On the other hand, when only the beam sensor 90 detects the jumping of the substrate W while the lifting stage 11 is being lowered, the lifting of the lifting stage 11 is continued because there is no possibility of the substrate W being damaged. Then, the display device 9 displays a message for notifying that the substrate W has jumped out. In this case, the substrate W is immersed in the pure water stored in the water tank 12 until the lifting / lowering stage 11 is raised and the operator pushes the protruding substrate W into the cassette C. Thus, drying of the substrate W is prevented. After the substrate W is returned to the normal position, the substrate W can be reliably detected by the substrate detection probe P, and the substrate transfer by the transfer robot 20 does not become defective.
[0044]
With reference to FIGS. 6 and 7, the configuration of the beam sensor 80 will be described in more detail. Since the configuration of the beam sensor 90 is the same, description thereof is omitted.
The light projecting unit 81 and the light receiving unit 82 of the beam sensor 80 are coupled to the sensor amplifier 83 via optical fibers 84 and 85. The sensor amplifier 83 is optically coupled to a light emitting element (not shown) optically coupled to the end of the optical fiber 84 coupled to the light projecting unit 81 and an optical fiber 85 coupled to the light receiving unit 82. Light receiving element (not shown). When detecting the substrate W, the light emitting element is caused to emit 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 becomes smaller, it means that the optical axis L1 is shielded by the substrate W.
[0045]
The light projecting section 81 and the light receiving section 82 are further supplied with clean air (or an inert gas such as nitrogen gas) from the air pump 86 (gas supply means) through the air supply pipes 87, 88, 89. Is supplied.
7A and 7B are a perspective view and a cross-sectional view showing a common internal structure of the light projecting unit 81 and the light receiving unit 82, respectively. The light projecting unit 81 and the light receiving unit 82 include a cylindrical outer case 100 (corresponding to a “case” in the claims). The outer case 100 is formed with a gas flow passage 101 into which the air supply pipes 88 and 89 are inserted from below and a fiber insertion hole 102 into which the optical fibers 84 and 85 are similarly inserted from below. An optical component 103 serving 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 tips of the optical fibers 84 and 85. The optical component 103 is, for example, a cylindrical inner case 104 made of stainless steel, the lens 105 for receiving light into and out of the optical fibers 84 and 85, and changing the light traveling direction. And a reflecting mirror 106. In the inner case 104, an opening 107 for entering and exiting light is formed at a position near the reflecting mirror 106.
[0046]
On the other hand, an opening 110 is formed in the side wall of the outer case 100. The inner case 104 of the optical component 103 is attached to the outer case 100 with the opening 107 facing the opening 110. The gas flow passage 101 in the outer case 100 communicates with the opening 110.
With this configuration, clean air is supplied from the air supply pipes 88 and 89 into the outer case 100, thereby generating an air flow of clean air that blows out from the opening 110 through the gas flow passage 101. Accordingly, water droplets and mist do not reach the optical component 103 even in a humid atmosphere near the underwater loader 10.
[0047]
Therefore, the optical component 103 can guide the incident light from the opening 110 to the optical fiber 84 and can guide the outgoing light from the optical fiber 85 to the opening 110. Since no water droplets adhere to any part of the optical component 103, there is no possibility that the optical axis is shifted or undesired diffusion of light occurs, and the light generated from the light projecting unit 81 As long as it is not obstructed, the light is surely incident on the light receiving portion 82. Therefore, the light receiving unit 82 can ensure a sufficient difference in the amount of received light depending on the presence or absence of the substrate W that blocks the optical axis L1.
[0048]
The outer case 100 to be exposed to the atmosphere in the underwater loader 10 is made of a resin material not containing metal (for example, tetrafluoroethylene resin (PTFE) or tetrafluoroethylene / perfluoroalkoxyethylene copolymer resin ( PFA) and the like. Thereby, it is possible to prevent the metal material from adhering to the substrate W after the CMP process. Since water droplets or the like do not enter the outer case 100, there is no problem even if the inner case 104 accommodated in the outer case 100 is made of a material containing a metal substance.
[0049]
Further, the beam sensor having the above-described configuration can be used for the purpose of detecting the position of the substrate W and the presence / absence of the substrate W in the substrate processing unit (for example, the cleaning unit 30) using a chemical solution. In this case, the outer case 100 is preferably made of a chemical resistant material (for example, PTFE or PFA). In this case, each component housed in the outer case 100 is not exposed to a chemical atmosphere due to the blowing of clean air from the opening 110. Therefore, the component needs to be made of a particularly chemical-resistant material. There is no.
[0050]
  As mentioned above, although one Embodiment of this invention was described, this invention can be implemented also with another form. For example, in the above-described embodiment, the light projecting portions 81 and 92 of the beam sensors 80 and 90 are replaced with the different outer cases 100.Consists ofSimilarly, the light receiving portions 82 and 92 are respectively connected to different outer cases 100.Consists ofHowever, the projectors 81 and 92 are in one case.Consists ofThe light receiving parts 82 and 92 in another case.Consists ofYou may make it do.
[0051]
In the above-described embodiment, the optical path of light entering and exiting the optical fibers 84 and 85 is bent at a right angle using the reflecting mirror 106, but the end faces of the optical fibers 84 and 85 are opposed to the outer case 100. In this case, it is not necessary to deflect the optical path by the reflecting mirror 106. In this case, the shape of the outer case 100 may be changed as necessary.
Furthermore, in the above-described embodiment, a so-called transmission type sensor that detects the presence or absence of the substrate W according to whether or not the substrate W shields the optical axis from the light projecting unit to the light receiving unit has been described. The present invention may be applied to a reflection type sensor in which reflected light emitted from the substrate and reflected by the substrate W is detected by a light receiving unit.
[0052]
In the above-described embodiment, the substrate detection unit 40 detects the presence / absence of the substrate W at each stage of the cassette C on the elevation stage 11 at the elevated position, and then lowers the elevation stage 11 to remove the substrate W from the cassette C. However, the order may be reversed.
Furthermore, in the above-described embodiment, the case where processing is performed on a semiconductor wafer that is a substantially circular substrate has been described. However, the present invention can be applied to a general rectangular substrate or other arbitrary shape in a glass substrate for a liquid crystal display device. The present invention can also be applied when processing a substrate.
[0053]
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 perspective view showing a simplified appearance of a substrate processing apparatus according to an embodiment of the present invention.
FIG. 2 is a plan view showing an internal configuration in the vicinity of a cassette loading portion of the substrate processing apparatus.
FIG. 3 is a perspective view schematically showing a configuration related to an underwater loader of the substrate processing apparatus.
FIG. 4 is a block diagram for explaining a substrate detection probe and an electrical configuration related thereto.
FIG. 5 is an illustrative view for explaining the principle of detection of jumping out of a substrate.
FIG. 6 is a perspective view for explaining the configuration of a beam sensor that detects the jumping out of a substrate.
FIG. 7 is a diagram for explaining a configuration of a light projecting unit and a light receiving unit constituting the beam sensor.
[Explanation of symbols]
2 Cassette loading part
5 Open / close box
10 Underwater loader
11 Lifting stage
12 Aquarium
13 Elevating drive mechanism
14 Pure water shower nozzle
20 Transport robot
21 hands
30 Cleaning unit
40 Substrate detection unit
41 Probe holding member
42 Advancing and retracting drive mechanism
43 racks
44 Pinion
46 Rotary actuator
51 Detection electrode
52 Guard electrode
55 Probe case
61 Square wave generator
62 Delay time detection circuit
63 Comparison circuit
64 output circuit
65 Guard electrode pulse generation circuit
80 Beam sensor
81 Emitter
82 Receiver
83 Sensor amplifier
84 Optical fiber
85 optical fiber
86 Air Pump
87 Air supply pipe
88 Air supply pipe
89 Air supply pipe
90 Beam sensor
90 optical axis
91 Projector
92 Light receiver
100 outer case
101 Gas flow passage
102 Fiber insertion hole
103 Optical components
110 opening
C cassette
L1 optical axis
L2 optical axis
P substrate detection probe
R resistance
W substrate

Claims (6)

A substrate detection device for optically detecting the presence or absence of a substrate at a substrate detection position,
A light projecting unit including a light emitting unit and a case in which the light emitting unit is accommodated and an opening through which emitted light from the light emitting unit toward the substrate detection position is formed;
A first optical fiber inserted into the case of the light projecting unit from below and having the light emitting unit coupled to one end thereof;
A light emitting element optically coupled to the other end of the first optical fiber;
A light receiving unit that includes a light detection unit and a case in which the light detection unit is accommodated and an opening through which incident light from the substrate detection position toward the light detection unit is formed;
A second optical fiber inserted into the case of the light receiving unit from below and having the light detection unit coupled to one end thereof;
A light receiving element optically coupled to the other end of the second optical fiber;
The light projecting unit and the gas is supplied to each of the case of the light receiving portion, seen including a gas supply means for creating an air flow blown out through the respective opening from the inside of the case,
In the case of the light projecting portion, a first gas flow passage for guiding gas from behind the light emitting portion to the opening is formed,
In the case of the light receiving part, a second gas flow path for guiding gas from behind the light detection part to the opening is formed,
The optical substrate detection apparatus , wherein the gas supply means supplies gas to the first and second gas flow passages . The light projecting unit, optical substrate detection apparatus according to claim 1 Symbol mounting, characterized in that toward the light receiving portion is for generating a substantially linear light beam. 3. The optical substrate detection apparatus according to claim 1, wherein the case is made of a chemical resistant material. Wherein the case, the optical substrate detection apparatus according to any one of claims 1, characterized by being composed of a resin material containing no metal 3. The optical substrate detection device according to any one of claims 1 to 4 , which detects a substrate placed in a wet environment;
Substrate transport means for transporting a substrate detected by the substrate detection device;
A substrate processing apparatus comprising: a substrate processing means for delivering a substrate to be processed by the substrate transport means and performing a predetermined process on the substrate. A substrate detection step of detecting a substrate placed in a humid environment using the optical substrate detection device according to any one of claims 1 to 4 ;
A substrate transfer step of transferring the substrate detected in this substrate detection step to the substrate processing means;
And a substrate processing step of performing a predetermined process on the substrate carried into the substrate processing means by the substrate transporting step.

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