JP2012000692A - Suction device, vapor phase deposition apparatus with the same, and suction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a suction device preventing erroneous determination of a suction state, a vapor phase deposition apparatus with the suction device, and a suction method.SOLUTION: A flow rate sensor 66 is connected to each suction pad (not shown) constituting a suction part 16. Each flow rate sensor 66 measures a flow rate of air between each suction pad and a pump 82. An overall flow rate sensor 62 measure a flow rate of air between the suction part 16 and the pump 82. A control unit 54 changes a threshold of a measurement value of the flow rate sensor 66 in accordance with the measured values of respective flow rate sensors 66 and the overall flow rate sensor 62. By determining the suction state of the suction part 16 again based on the changed threshold, such an erroneous determination is prevented that the suction part 16 does not suck a substrate tray 32 despite the substrate tray 32 being actually sucked to the suction part 16.

Description

  The present invention relates to an adsorption device for adsorbing an adsorbate, a vapor phase growth apparatus including the adsorption device, and an adsorption method.

  Conventionally, vacuum suction devices have been used as means for automatically performing operations such as conveying, moving, and taking out articles in response to requests for automation of various operations. In the vacuum suction device, desired work such as transporting, moving, and taking out the article is achieved by sucking and holding the article with a suction pad. Specifically, the article is sucked and held by applying a negative pressure to the inside of the suction pad with a vacuum pump. At this time, if the adsorption pad adsorbs the adsorbed material, the negative pressure state in the adsorbing pad increases, so by detecting this with a sensor, it is determined whether or not the adsorbed material is adsorbed. Perform operations such as transport.

  Sensors for determining adsorption include a pressure sensor and a flow rate sensor. For example, when a pressure sensor is used, the pressure value in the suction pad before and after the suction is compared, and the suction state of the adsorbate is determined. However, when a plurality of suction pads are connected in communication with the vacuum pump, the suction capacity of one of the suction pads may vary depending on the suction capacity of one of the suction pads. That is, pressure fluctuation may be caused in the suction pad. Therefore, in general, when a pressure sensor is used, it is difficult to uniformly set a pressure value for confirming the suction of each suction pad (a pressure value for determining the suction state).

  Therefore, Patent Document 1 discloses a method for changing the pressure value for determining the adsorption state of the adsorbate in response to the pressure fluctuation in the adsorption pad. Specifically, the first pressure value V1 for determining the adsorption state is determined from the first flow rate Q1 of the air in the pressure pad and the first vacuum pressure P1 obtained by the first flow rate Q1. Here, when the flow rate of air in the suction pad changes from the first flow rate Q1 to the second flow rate Q2 due to the pressure fluctuation in the suction pad, the second vacuum pressure P2 obtained by the second flow rate Q2 is determined. Next, a second pressure value V2 for determining the adsorption state is determined based on a value obtained by dividing the first vacuum pressure P1 by the first pressure value V1.

  According to this, even when a pressure fluctuation occurs in the suction pad, it is easy to set a pressure value for determining whether or not each suction pad is sucked according to the pressure fluctuation.

  However, the technique described in Patent Document 1 has the following problems. In Patent Document 1, a pressure sensor is used. However, since the pressure sensor has a small change in pressure before and after adsorption, there is a drawback that accurate detection of the adsorption state is difficult and erroneous detection is easy. Therefore, instead of the pressure sensor, the adsorption state of the adsorbate was determined using a flow rate sensor. When using a flow sensor, the flow rate of air in the suction pad before and after the suction is compared to determine the suction state of the adsorbate. Generally, since the amount of change in the air flow rate in the suction pad before and after suction is large, there is little false detection of the suction state when a flow rate sensor is used.

JP 5-72067 A (published March 23, 1993)

  However, when the flow sensor is used, the following problems occur.

  For example, there are a vacuum generation source and a plurality of (for example, four) suction pads connected to the vacuum source. A flow rate sensor is connected to each suction pad, and the threshold value of the flow rate sensor is 23 L / min (below the threshold value is vacuum suctioned). State). When one transported object is lifted by vacuum suction with four suction pads, if the value of each flow rate sensor is about 20L / min, the value of each flow rate sensor is below the threshold value, so each suction pad holds the adsorbed material. Judged to be adsorbed. However, if any one of the suction pads is in a very good suction state, and the value of the flow sensor is almost 0 L / min, the flow sensors connected to the other suction pads are sucked as usual. However, the value of the flow sensor connected to the suction pad is about 25 L / min. This is because the suction state is influenced by the flow sensor. As a result, although the adsorbed material is actually adsorbed by the adsorbing pad, the value of the flow sensor is larger than the threshold value, so that the adsorbing pad does not adsorb the adsorbed material. There was a thing.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide an adsorption device that can prevent erroneous determination of the adsorption state, a vapor phase growth apparatus including the adsorption device, and an adsorption method. Is to provide.

  In order to solve the above problems, an adsorption apparatus according to the present invention includes a vacuum generation source, a common pipe led out from the vacuum generation source, a plurality of individual pipes branched from the common pipe, and the individual individual An adsorbing portion made of an adsorbent connected to the end of the pipe, a plurality of first flow sensors that are provided in the individual pipes and that measure the air flow rate, and a common pipe that measures the air flow rate. To determine whether the measured value of each second flow sensor and each first flow sensor exceeds a predetermined first threshold, and the measured value of the second flow sensor exceeds a predetermined second threshold A determination unit that determines whether or not the adsorption unit is adsorbing an adsorbate by determining whether or not the adsorption unit adsorbs an adsorbate, wherein the first unit is based on a determination result of the determination unit. The threshold value is set to another first threshold value different from the first threshold value. It is characterized in that it comprises a changing unit for further.

  According to said structure, according to the comparison result of the measured value of a 1st flow sensor and a 1st threshold value, and the comparison result of the measured value of a 2nd flow sensor and a 2nd threshold value, an adsorption | suction part adsorb | sucks adsorbate. A determination unit for determining whether or not the determination has been made. The first flow sensor and the second flow sensor each measure the flow rate of air, and the change in the measured value before and after adsorbing the adsorbed material is larger than that of the conventional pressure sensor. Therefore, it is possible to more accurately determine the suction state of the suction portion.

  Furthermore, the control part which concerns on this invention changes the threshold value of the measured value of a 1st flow sensor based on the determination result of a determination part. By re-determining the adsorption state of the adsorption unit based on the changed threshold, it is erroneously determined that the adsorbed material is not adsorbed even though the adsorbed material is actually adsorbed. Can be prevented. As a result, it is not necessary to stop the adsorption device every time it is erroneously determined that the adsorbate is not adsorbed, and the operation rate of the adsorption device can be increased.

  In the adsorption device according to the present invention, when the determination unit determines that the measurement value of the second flow sensor is equal to or less than the second threshold value, the measurement value of the first flow sensor is the first value. When there is at least one of the first flow rate sensor determined to exceed one threshold and the first flow rate sensor determined that the measured value of the first flow rate sensor is equal to or less than the first threshold, The changing unit changes the first threshold value to the other first threshold value according to the number of the first flow rate sensors determined that the measured value exceeds the first threshold value, and sets each of the first threshold values. It is characterized by determining whether the said measured value of a flow sensor exceeds said other 1st threshold value.

  According to said structure, it changes into the other 1st threshold value according to the number of the 1st flow sensors from which the measured value was determined to exceed the 1st threshold value among several 1st flow sensors. That is, the threshold value of the measurement value of the first flow rate sensor is changed in accordance with the number of adsorbents that are determined not to adsorb adsorbents. According to this, it is possible to determine the adsorption state in consideration of the case where it is erroneously determined that the adsorbed material is not adsorbed even though the adsorbed material is actually adsorbed. More accurate determination is possible.

  Moreover, as for the adsorption | suction apparatus which concerns on this invention, it is preferable that each said 1st flow sensor is comprised by the some 3rd flow sensor, and the said some 3rd flow sensor is connected in series.

  According to the above configuration, even when a plurality of threshold values cannot be set for one first flow rate sensor, the threshold value for determining the adsorption state is changed by setting different threshold values for each third flow rate sensor. It becomes possible to do.

  In the adsorption device according to the present invention, when it is determined that the measurement value of the second flow rate sensor exceeds the second threshold value, or at least one of the plurality of first flow rate sensors has the measurement value. When it is determined that the other first threshold value is exceeded, it is preferable to further include a control unit that stops the operation of the suction unit and issues a warning.

  According to said structure, when an adsorption | suction part cannot adsorb | suck an adsorbate, while stopping operation | movement of an adsorption | suction part (adsorption apparatus), it issues a warning. By detecting the warning, the worker can recognize that there is some inconvenience that the adsorbing unit cannot adsorb the adsorbed material. Therefore, an appropriate treatment can be immediately applied to the adsorption device.

  In addition, a vapor phase growth apparatus according to the present invention includes any one of the adsorption apparatuses described above in order to solve the above-described problems.

  According to the above configuration, when the adsorbate is adsorbed and held and transported, it is possible to prevent erroneous determination of the adsorbed state of the adsorbate, and to perform a vapor phase growth that can make an accurate adsorbent determination. A device is realized.

  In order to solve the above problems, an adsorption method according to the present invention includes a vacuum generation source, a common pipe led out from the vacuum generation source, a plurality of individual pipes branched from the common pipe, An adsorbing portion made of an adsorbent connected to an end of the individual pipe, a plurality of first flow sensors provided on the individual pipes for measuring the air flow rate, and an air flow rate provided on the common pipe. A second flow rate sensor for measuring the first flow rate sensor, and whether or not the measured value of each of the first flow rate sensors exceeds a predetermined first threshold value, and the measured value of the second flow rate sensor is a predetermined second threshold value. A determination unit that determines whether or not the adsorbing part is adsorbing an adsorbed material by determining whether or not the adsorbing part is adsorbed, wherein the vacuum generating source generates a vacuum; and The process of adsorbing the adsorbate by the adsorption unit Measuring the flow rate with each of the first flow rate sensors; measuring the flow rate with the second flow rate sensor; and determining the measured value of each of the first flow rate sensors with the first value. Determining whether the measured value of the second flow rate sensor exceeds the second threshold value, and determining the first threshold value based on the determination result of the determination unit. And a step of changing to another first threshold value different from the first threshold value.

  According to said method, the threshold value of the measured value of the 1st flow sensor previously determined in order to determine the adsorption | suction state of an adsorption | suction part according to the measured value of a 1st flow sensor and a 2nd flow sensor is changed. . By re-determining the adsorption state of the adsorption unit based on the changed threshold, it is erroneously determined that the adsorbed material is not adsorbed even though the adsorbed material is actually adsorbed. Can be prevented.

  The suction device according to the present invention changes a threshold value of the measurement value of the first flow sensor, which is predetermined to determine the suction state of the suction portion according to the measurement values of the first flow sensor and the second flow sensor. To do. Therefore, it is possible to cope with flow rate fluctuations that occur when a plurality of adsorbers are connected to one vacuum generation source. Furthermore, by performing the determination of the adsorption state of the adsorption unit again based on the changed threshold value, it is erroneously determined that the adsorbate is not adsorbed even though the adsorbate is actually adsorbed. Can be prevented. As a result, it is not necessary to stop the adsorption device every time it is erroneously determined that the adsorbate is not adsorbed, and the operation rate of the adsorption device can be increased.

(A) is sectional drawing which shows the structure of the vapor phase growth apparatus which concerns on one Embodiment of this invention, (b) is a top view of the vapor phase growth apparatus which concerns on one Embodiment of this invention. (A) is sectional drawing in the state in which the adsorption | suction part of the vapor phase growth apparatus which concerns on one Embodiment of this invention adsorb | sucked the substrate tray, (b) is a top view of a substrate tray. (A) is a graph which shows the mode of the change of the measured value of a flow sensor when adsorbed material is adsorbed, (b) is a setting example of the threshold value of the flow sensor according to an embodiment of the present invention. Yes, (c) is a setting example of the threshold of the overall flow sensor according to one embodiment of the present invention. It is a flowchart which shows the procedure of the adsorption | suction determination by the adsorption | suction determination apparatus which concerns on one Embodiment of this invention. It is sectional drawing which shows the structure of the vapor phase growth apparatus which concerns on one Embodiment of this invention.

  Several embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment]
(Configuration of the vapor phase growth apparatus 1)
First, the configuration of the vapor phase growth apparatus 1 according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1A is a cross-sectional view showing the configuration of the vapor phase growth apparatus 1. FIG. 1B is a top view of the vapor phase growth apparatus 1.

  As shown in FIG. 1A, the vapor phase growth apparatus 1 generally includes a transfer device 2 (adsorption device), a base portion 4, a chamber 34, and a substrate tray place 38. The conveyance device 2 further includes a conveyance unit 14 and an adsorption determination device 50 (determination unit, change unit, control unit).

  The base portion 4 includes a susceptor 6, a susceptor rotating means 8, a plurality of tray mounting tables 10, and a tray rotating means 12. As shown in FIG. 1B, the susceptor 6 has a disk shape, and a plurality of tray mounting tables 10 are mounted on one surface of the susceptor 6 along its own circumference. On each tray mounting table 10, one substrate tray 32 on which a substrate 30 to be deposited can be mounted.

  In the susceptor 6, a surface opposite to the surface on which the tray mounting table 10 is placed is provided with a susceptor rotating means 8 that rotates the susceptor 6 about the shaft portion 6 ′ of the susceptor 6 as a rotation axis. Yes. When the susceptor rotating means 8 rotates the susceptor 6, the tray mounting table 10 can be rotated together with the susceptor 6 (hereinafter also referred to as revolution). Further, a tray rotating means 12 is connected to each tray mounting table 10 with the susceptor 6 interposed therebetween. The tray mounting unit 10 can be rotated by the tray rotating unit 12 rotating about the shaft portion 10 ′ of the tray mounting table 10 as a rotation axis (hereinafter also referred to as “rotation”). The susceptor rotating means 8 and the tray rotating means 12 rotate independently of each other. Accordingly, the tray mounting table 10 placed on the susceptor 6 rotates and revolves due to the rotation of the susceptor rotating means 8 and the rotation of the tray rotating means 12.

  Further, the susceptor 6 and the tray mounting table 10 are sealed in the chamber 34 in a normal state. An openable / closable portion 36 is formed in the chamber 34, and by opening the open / close portion 36, the substrate tray 32 on which the substrate 30 is placed can be taken in and out of the chamber 34 via the open / close portion 36. A substrate tray place 38 for placing the substrate tray 32 is installed outside the chamber 34.

  The transport unit 14 includes a suction unit 16, an elevating / lowering unit 24, a plane moving unit 26, and a pedestal unit 28. The configuration of the suction unit 16 will be described with reference to FIG. FIG. 2A is a cross-sectional view in a state where the adsorption unit 16 of the vapor phase growth apparatus 1 has adsorbed the substrate tray 32. FIG. 2B is a top view of the substrate tray 32.

  As shown in FIG. 2A, the suction part 16 includes a main body part 18, four leg parts 20, and a suction pad 22 (suction body). The suction pad 22 is a suction body that vacuum-sucks the upper surface of the substrate tray 32, and is attached to the tip portion of each leg portion 20. As shown in FIG. 2B, the suction pad 22 sucks a portion where the surface of the substrate tray 32 is exposed when sucking the substrate tray 32 on which the substrate 30 is placed. For this reason, the suction pad 22 does not directly contact the substrate 30 placed on the substrate tray 32. Therefore, the substrate 30 is not damaged or soiled. The substrate tray 32 has a disk shape and is configured to be larger than the substrate 30 in order to place the substrate 30 thereon. Moreover, in this embodiment, although the adsorption | suction part 16 is provided with the four leg parts 20, this invention is not limited to this. Moreover, although the board | substrate 30 is disk shape, it does not necessarily need to be disk shape. That is, the substrate 30 may be any shape and size that allows the suction pad 22 to contact the substrate tray 32 on which the substrate 30 is placed.

  The suction part 16 is attached to the tip part of the lifting / lowering moving part 24. By moving the elevating / lowering unit 24, the suction unit 16 can be moved in the vertical direction with respect to the mounting surface of the substrate tray 32 of the tray mounting table 10. The term “vertical” as used herein means complete vertical as well as substantially the case where it is within a range that provides substantially the same effect as complete vertical. The description below is also the same. Further, the up-and-down moving unit 24 is attached to a side surface of the planar moving unit 26 attached on the pedestal unit 28. By moving the plane moving unit 26 on the pedestal unit 28, the suction unit 16 can be moved in a parallel direction with respect to the mounting surface of the substrate tray 32 of the tray mounting table 10. “Parallel” as used herein means not only completely parallel, but also substantially means the case where it is within a range that exhibits substantially the same effect as perfect parallelism. The description below is also the same.

  The four suction pads 22 and each flow sensor 66 (first flow sensor) are connected by four pipes 64 (individual pipes). Each flow sensor 66 and the electromagnetic valve 72 are connected by four pipes 84, and the electromagnetic valve 72 is connected to the manifold 70. The manifold 70 and the overall flow sensor 62 (second flow sensor) are connected by an overall pipe 68 (common pipe). The overall flow sensor 62 and the pump 82 which is a vacuum generation source are connected by a pipe 86 (common pipe). That is, the pipe 86 is led out from the pump 82, and the pipe 68 connected to the pipe 86 via the overall flow sensor 62 is branched into four pipes 64. The suction pad 22 is connected to the end of each pipe 64 with the flow sensor 66 interposed therebetween. Each flow sensor 66 measures the flow rate of air in the pipe 64 connected to each suction pad 22. The overall flow sensor 62 measures the air flow rate in the pipe 68 connected to the overall flow sensor 62.

  The adsorption determination device 50 includes a base unit 52, a control unit 54, a control panel 56, a warning lamp 58, an overall flow sensor 62, a signal line 60 between the overall flow sensor 62 and the control unit 54, and a plurality of flow sensors 66. , And a signal line 74 between each flow sensor 66 and the control unit 54. A control unit 54, a control panel 56, and a warning lamp 58 are attached to the base unit 52. Also, one end of the signal line 60 and one end of the signal line 74 are connected to the control unit 54, the other end of the signal line 60 is connected to the overall flow sensor 62, and the other end of the signal line 74 is connected to each A flow sensor 66 is connected. A suction inspection method in the suction determination device 50 will be described later.

(Adsorption by vapor phase growth apparatus 1)
Next, processing including adsorption of the substrate tray 32 by the vapor phase growth apparatus 1 will be described.

  First, the opening / closing part 36 of the chamber 34 is opened. Next, the suction unit 16 is moved directly above the substrate tray storage place 38 by the movement of the plane moving unit 26. Here, “directly above” means not only completely above, but also substantially means a case where it is within a range in which an effect substantially equivalent to that directly above is achieved. The description below is also the same. In addition, a plurality of substrate trays 32 on which the substrates 30 before film formation that have been transported by a transport device (not shown) are placed one by one are placed in the substrate tray placement place 38.

  Next, as the elevating / lowering unit 24 moves, the suction unit 16 is approached from the upper surface side of the substrate tray 32, and the substrate tray 32 is suctioned to the suction pad 22. At this time, the four suction pads 22 suck a portion where the surface of the substrate tray 32 is exposed, as shown in FIG. Thereby, the substrate 30 is not soiled or damaged by the contact of the suction pad 22.

  When the suction pad 22 sucks the substrate tray 32, the lifting / lowering movement unit 24 moves to remove the substrate tray 32 from the substrate tray storage 38. Next, when the plane moving unit 26 moves, the substrate tray 32 is moved from the opening / closing unit 36 directly above the tray mounting table 10 located at a predetermined position on the susceptor 6 in the chamber 34. Then, the lifting / lowering movement unit 24 moves to bring the substrate tray 32 closer to the tray mounting table 10, and the suction unit 16 releases the suction of the suction pad 22, thereby placing the substrate tray 32 on the tray mounting table 10. Put. After the substrate tray 32 is placed on the tray mounting table 10, the up-and-down moving unit 24 and the plane moving unit 26 are moved to return the suction unit 16 to the position just above the substrate tray mounting place 38 outside the chamber 34. Here, a new substrate tray 32 is placed on the substrate tray place 38 by a transfer device (not shown). The transport unit 14 places the new substrate tray 32 placed on the substrate tray placement place 38 on the other tray placing table 10 on which the substrate tray 32 is not placed by the same procedure as described above. As described above, the transport unit 14 repeats the above-described procedure by the number of the substrate trays 32 placed on the susceptor 6.

  Further, every time one substrate tray 32 is placed on the tray placing table 10, the susceptor rotating means 8 of the base portion 4 rotates. As a result, the new tray mounting table 10 on which the substrate tray 32 is not yet mounted is moved to the position of the tray mounting table 10 on which the substrate tray 32 is mounted immediately before. That is, the new tray mounting table 10 is moved to the predetermined position. Therefore, the transport unit 14 may transport the new substrate tray 32 to the same position as the previous transport destination, that is, to a predetermined position on the susceptor 6 every time.

  After all the substrate trays 32 to be mounted on the susceptor 6 are mounted on the tray mounting table 10, the chamber 34 is sealed by closing the opening / closing part 36.

  Next, the vapor phase growth apparatus 1 forms a film on the surface of the substrate 30. Specifically, after the inside of the chamber 34 is replaced with nitrogen, the substrate 30 is heated to 800 degrees to 1400 degrees by a heating mechanism (not shown), and the process gas is supplied to the surface of the substrate 30. Thereby, a gas phase reaction is generated in the vicinity of the surface of the substrate 30 to form a film on the surface of the substrate 30. During the film formation, the tray mounting means 10 is rotated by the rotation of the tray rotating means 12. Furthermore, the susceptor 6 is rotated by rotating the susceptor rotating means 8. Thereby, the surface of the substrate 30 can be uniformly formed without unevenness.

  When the film formation on the surface of the substrate 30 is completed, the opening / closing part 36 is opened. Then, when the plane moving unit 26 moves, the suction unit 16 is moved from the opening / closing unit 36 to a position directly above the tray mounting table 10 located at the predetermined position in the chamber 34. Next, when the elevating / lowering unit 24 moves, the suction unit 16 is approached from the upper surface side of the substrate tray 32 on which the deposited substrate 30 is placed, and the substrate tray 32 is sucked to the suction pad 22. .

  When the suction pad 22 sucks the substrate tray 32, the up-and-down moving unit 24 moves to remove the substrate tray 32 from the tray mounting table 10 for the suction unit 16 that sucked the substrate tray 32. Next, when the plane moving unit 26 moves, the adsorbing unit 16 that has adsorbed the substrate tray 32 is moved directly above the substrate tray storage place 38 outside the chamber 34. Then, when the elevating / lowering unit 24 moves, the suction unit 16 is brought closer to the substrate tray placement place 38, and the suction unit 16 releases the suction of the suction pad 22, so that the substrate tray 32 is placed on the substrate tray placement place 38. To do.

  After the substrate tray 32 is placed on the substrate tray placement place 38, the up-and-down moving unit 24 and the planar moving unit 26 are moved to return the suction unit 16 to the position immediately above the tray mounting table 10 in the chamber 34. Here, the placed substrate tray 32 is removed from the substrate tray storage place 38 by a transfer device (not shown). The transport unit 14 places the substrate tray 32 placed on the new tray placement table 10 on the substrate tray placement place 38 by the same procedure as described above. As described above, the transport unit 14 repeats the above procedure by the number of the substrate trays 32 placed on the susceptor 6.

  Further, every time one substrate tray 32 is transported from the tray mounting table 10, the susceptor rotating means 8 of the base unit 4 rotates. As a result, the new tray mounting table 10 on which the substrate tray 32 is still mounted moves to the position of the tray mounting table 10 to which the substrate tray 32 has been transported immediately before. That is, the new tray mounting table 10 is moved to the predetermined position.

  Here, the transport process in which the transport unit 14 transports the substrate tray 32 from the substrate tray storage 38 or the tray mounting table 10 includes a detection process for detecting whether or not the substrate tray 32 can be sucked. In the detection step, when it is determined that the suction unit 16 is sucking the substrate tray 32, the lifting / lowering moving unit 24 moves to remove the substrate tray 32 from the substrate tray storage place 38 or the tray mounting table 10. .

(Determination by the adsorption determination device 50)
As described above, the suction determination device 50 determines whether or not the suction unit 16 is sucking the substrate tray 32. Specifically, the suction determination device 50 is controlled based on the measurement results of the individual flow sensors 66 connected between the suction pads 22 and the pipes 64 and the measurement results of the overall flow sensor 62. The unit 54 determines.

  When the suction pad 22 is brought close to the substrate tray storage place 38 or the tray mounting table 10 and the substrate tray 32 is sucked, the individual flow rate sensors 66 measure the air flow rate in the pipes 64 connected to the suction pads 22. Is sent to the control unit 54 via the signal line 74. The overall flow sensor 62 sends the measurement result of the air flow rate in the pipe 68 connected to the overall flow sensor 62 to the control unit 54 via the signal line 60.

  The measurement result of the obtained flow rate is compared with a preset threshold value. The threshold value is a value at which the suction unit 16 (suction pad 22) is determined to be sucking the substrate tray 32 if the flow rate is equal to or lower than the threshold value. Therefore, if the flow rate of each flow sensor 66 or the overall flow sensor 62 is equal to or less than the threshold value, a signal indicating that the suction unit 16 (suction pad 22) is sucking the substrate tray 32 is output to the control unit 54.

  The threshold setting of the flow sensor 66 and the overall flow sensor 62 will be described with reference to FIG. FIG. 3A is a diagram illustrating a change in the measurement value of the flow sensor when the adsorbate is adsorbed. FIG. 3B is a setting example of the threshold value of each flow sensor 66. FIG. 3C is a setting example of the threshold value of the overall flow sensor 62. 3A to 3C, the vertical axis indicates the air flow rate, and the horizontal axis indicates the elapsed time.

  As shown in FIG. 3A, normally, if the adsorbate is adsorbed at the time P, the negative pressure state in the adsorbent increases, so the value of the flow sensor decreases. In the present embodiment, whether or not the suction unit 16 (suction pad 22) has sucked the substrate tray 32 is determined by determining whether the decreased value of the flow sensor 66 or the overall flow sensor 62 is equal to or less than the threshold value. to decide. As described above, if the value of the flow sensor 66 or the overall flow sensor 62 is equal to or less than the threshold value, it is determined that the suction unit 16 (suction pad 22) is sucking the substrate tray 32.

  FIG. 3B shows an example of setting the threshold value of the flow sensor 66. As shown in FIG. 3B, the flow rate sensor 66 is set with a plurality of threshold values (S0 to S3). Specifically, S0 is a threshold value for determining that the four suction pads 22 have performed normal suction. S1 is a threshold value for determining that the remaining three suction pads 22 are sucked when one suction pad 22 is sucked almost perfectly. S2 is a threshold value for determining that the remaining two suction pads 22 are sucked when the two suction pads 22 are sucked almost perfectly. S3 is a threshold value for determining that the remaining one suction pad 22 is sucked when the three suction pads 22 are sucked almost perfectly. The relationship between the threshold values is S0 <S1 <S2 <S3. The flow sensor 66 determines the suction state of the substrate tray 32 based on one of the threshold values S0 to S3.

  FIG. 3C shows an example of setting the threshold value of the overall flow sensor 62. As shown in FIG. 3C, a threshold value Sa is set for the overall flow sensor 62. Sa is set to 4 times S0 as a guide.

(Determination procedure by the adsorption determination device 50)
Next, the procedure of the suction determination by the suction determination device 50 is shown in the flowchart of FIG. Hereinafter, based on this flowchart, the adsorption determination and control method by the control unit 54 of the adsorption determination device 50 will be described in order. Note that the number of flow sensors 66 is m. In the present embodiment, there are four suction pads 22 and four flow rate sensors 66 are provided correspondingly, so m = 4.

  When the transfer process is started, as described above, after the suction unit 16 is moved to a position immediately above the substrate tray storage place 38 or the tray mounting table 10, the up-and-down moving unit 24 moves, so that suction is performed from the upper surface side of the substrate tray 32. The substrate tray 32 is sucked onto the suction pad 22 by approaching the portion 16 (step 1, hereinafter abbreviated as ST1).

  The suction of the substrate tray 32 is performed by the operation of an electromagnetic valve 72 provided for each suction pad 22. It waits for the vacuum pressure of the pipe 64 connected to the suction pad 22 to be stabilized due to the suction of the substrate tray 32, and at a stable stage, it is determined whether or not the measured value of the overall flow sensor 62 is less than or equal to the threshold value Sa (first threshold value). Check (ST2). Either a signal that the flow rate value of the overall flow sensor 62 is equal to or less than the threshold value Sa or a signal that is larger than the threshold value Sa is output to the control unit 54.

  When the flow rate value of the overall flow sensor 62 is larger than the threshold value Sa (ST 2, NO), the single or plural suction pads 22 have not sucked the substrate tray 32, and air leaks from the suction pads 22. The control unit 54 determines that there is a possibility. In that case, the control unit 54 determines that the suction of the substrate tray 32 has failed, and performs a suction error process (ST9).

  When the flow rate value of the overall flow sensor 62 is equal to or less than the threshold value Sa (ST2, YES), the suction status of each suction pad 22 is examined. Specifically, the flow rate value of each flow rate sensor 66 is compared with the threshold value S0, and a signal that the flow rate value of each flow rate sensor 66 is equal to or less than the threshold value S0 (second threshold value) and a signal that is greater than the threshold value S0. Is output to the control unit 54. The control unit 54 obtains the number of flow sensors 66 that satisfy “individual flow value ≦ threshold value S0”, and sets the number to n1 (ST3).

  The n1 and m (number of flow sensors 66) are compared (ST4). If n1 and m match (ST4, YES), it is determined that all the suction pads 22 have sucked the substrate tray 32 and the suction has been successful (ST8).

  Here, although the substrate tray 32 is actually sucked, n1 and m may not match (ST4, NO). This is a case where the flow rate value of the flow rate sensor 66 connected to the suction pad 22 is extremely smaller than the threshold value S0 when the suction state of the suction pad 22 or the plurality of suction pads 22 is very good. In this case, the flow rate value of the flow rate sensor 66 connected to the suction pad 22 is influenced by the suction pad 22 having a very good suction state even if the suction pads 22 are sucked in the same manner as usual. Thus, the threshold value S0 may be exceeded. As described above, when the plurality of suction pads 22 are connected to one pump 82, the flow rate may vary.

  Therefore, in this embodiment, the threshold value of the flow rate sensor 66 exceeding the threshold value S0 is changed according to the number (m−n1) of the flow rate sensors 66 exceeding the threshold value S0 (ST5). Specifically, when n1 = 1, the threshold value S1 is changed, when n1 = 2, the threshold value S2 is changed, and when n1 = 3, the threshold value S3 is changed.

  Again, the flow value of each flow sensor 66 is compared with the new threshold value (S1, S2 or S3) (third threshold value), and the flow value of each flow sensor 66 is greater than the threshold value and the signal below the threshold value. Is output to the control unit 54. The control unit 54 obtains the number of flow sensors 66 that satisfy “individual flow value ≦ new threshold value”, and sets the number to n2 (ST6).

  The n2 and m (number of flow sensors 66) are compared (ST7). If n2 and m match (ST7, YES), it is determined that all the suction pads 22 have sucked the substrate tray 32 and the suction has been successful (ST8). If n2 and m do not match (ST7, NO), the control unit 54 determines that the suction of the substrate tray 32 has failed, and performs a suction error process (ST9).

  When an adsorption error occurs, the control unit 54 emits a warning sound. By hearing this warning sound, the worker can recognize that there is some inconvenience that the substrate tray 32 cannot be sucked. Therefore, when the worker hears a warning sound, it is possible to immediately take an appropriate measure for the transport device 2. The warning for the worker to recognize may be performed by turning on the warning lamp 58 or may be displayed on a monitor such as the control panel 56 via a communication medium.

  As described above, in the present embodiment, the threshold value of the measurement value of the flow sensor 66 is changed according to the measurement values of the individual flow sensors 66 and the overall flow sensor 62. Therefore, it is possible to cope with flow rate fluctuations that occur when a plurality of suction pads 22 are connected to one pump 82. Furthermore, by performing the determination of the suction state of the suction unit 16 again based on the changed threshold value, it is erroneously determined that the substrate tray 32 is not sucked even though the substrate tray 32 is actually sucked. Can be prevented. As a result, it is not necessary to stop the operation of the adsorption unit 16 every time it is erroneously determined that the substrate tray 32 is not adsorbed, and the operating rate of the vapor phase growth apparatus 1 can be increased.

[Second Embodiment]
A vapor phase growth apparatus according to a second embodiment of the present invention will be described with reference to FIG. FIG. 5 is a cross-sectional view showing the configuration of the vapor phase growth apparatus 11.

  In the first embodiment described above, the number of flow sensors 66 connected to one suction pad 22 is one, but the present invention is not necessarily limited to this. For example, a plurality of flow rate sensors can be connected to one suction pad 22 as in this embodiment.

  In the present embodiment, as shown in FIG. 5, a plurality of flow rate sensors 75, 76, 78, and 80 (third flow rate sensors) are arranged in series and connected between one suction pad 22 and the electromagnetic valve 72. Yes. A threshold value S0 is set for the flow rate sensor 75, a threshold value S1 is set for the flow rate sensor 76, a threshold value S2 is set for the flow rate sensor 78, and a threshold value S3 is set for the flow rate sensor 80. According to this, even when a plurality of threshold values cannot be set for one flow rate sensor, by using the flow rate sensors 75, 76, 78, and 80 having different threshold values, the determination of the adsorption state is performed. The determination can be made based on the threshold value. That is, for example, when it is determined that the flow rate sensor 75 connected to two of the four suction pads 22 exceeds the threshold value S0, the determination of the suction status of each suction pad 22 is performed for each flow rate. This is performed based on the flow rate value of the sensor 78 and the threshold value S2.

  In the present embodiment, the configuration other than the provision of the plurality of flow rate sensors 75, 76, 78, and 80 is the same as that of the first embodiment described above, and thus will not be described here. Further, the specific procedure for determining the suction state of the substrate tray 32 is the same as that in the first embodiment, and a description thereof will be omitted.

  The present invention can be applied to an adsorption device that changes the threshold value of the flow rate sensor according to the status of each adsorption pad when adsorbing an adsorbate using an adsorption pad that is an adsorbent, for example, adsorption of a substrate tray It can be used in a vapor phase growth apparatus or the like that performs the above.

DESCRIPTION OF SYMBOLS 1,11 Vapor growth apparatus 2 Conveyance apparatus 4 Base part 6 Susceptor 6 'Shaft part 8 Susceptor rotation means 10 Tray mounting base 10' Shaft part 12 Tray rotation means 14 Conveyance part 16 Adsorption part 22 Adsorption pad 24 Elevation moving part 26 Moving unit 28 Pedestal unit 30 Substrate 32 Substrate tray 34 Chamber 38 Substrate tray place 50 Adsorption determination device 52 Base unit 54 Control unit 56 Control panel 58 Warning light 60, 74, 84 Signal line 62 Overall flow sensor 64, 68 Tube 66, 75, 76, 78, 80 Flow sensor 70 Manifold 72 Solenoid valve 82 Pump

Claims (6)

A vacuum source;
A common tube derived from the vacuum source;
A plurality of individual pipes branched from the common pipe;
An adsorbing portion comprising an adsorbent connected to the end of each individual pipe;
A plurality of first flow sensors provided in each of the individual pipes to measure the flow rate of air;
A second flow rate sensor provided in the common pipe for measuring the flow rate of air;
Determining whether the measured value of each first flow sensor exceeds a predetermined first threshold, and determining whether the measured value of the second flow sensor exceeds a predetermined second threshold And a determination unit that determines whether or not the adsorption unit is adsorbing an adsorbate,
An adsorption apparatus comprising: a changing unit that changes the first threshold value to another first threshold value different from the first threshold value based on a determination result of the determination unit.   When the determination unit determines that the measurement value of the second flow sensor is equal to or less than the second threshold value, the first value determined that the measurement value of the first flow sensor exceeds the first threshold value When there is at least one 1 flow rate sensor and at least one first flow rate sensor determined that the measured value of the first flow rate sensor is less than or equal to the first threshold value, the changing unit is configured so that the measured value is In accordance with the number of the first flow rate sensors determined to exceed the first threshold value, the first threshold value is changed to the other first threshold value, and the measured value of each of the first flow rate sensors is the other It is determined whether it exceeds a 1st threshold value, The adsorption | suction apparatus of Claim 1 characterized by the above-mentioned.   Each of said 1st flow sensors is comprised by the some 3rd flow sensor, The said some 3rd flow sensor is connected in series, The adsorption | suction of Claim 1 or 2 characterized by the above-mentioned. apparatus.   When it is determined that the measurement value of the second flow rate sensor has exceeded the second threshold value, or at least one of the plurality of first flow rate sensors has been determined to have exceeded the other first threshold value. 4. The suction device according to claim 2, further comprising a control unit that stops the operation of the suction unit and issues a warning when the operation is performed. 5.   A vapor phase growth apparatus comprising the adsorption apparatus according to claim 1. A vacuum source;
A common tube derived from the vacuum source;
A plurality of individual pipes branched from the common pipe;
An adsorbing portion comprising an adsorbent connected to the end of each individual pipe;
A plurality of first flow sensors provided in each of the individual pipes to measure the flow rate of air;
A second flow rate sensor provided in the common pipe for measuring the flow rate of air;
Determining whether the measured value of each first flow sensor exceeds a predetermined first threshold, and determining whether the measured value of the second flow sensor exceeds a predetermined second threshold And a determination unit that determines whether or not the adsorption unit is adsorbing an adsorbate,
Generating a vacuum by the vacuum source;
Adsorbing an adsorbate by the adsorbing part;
Measuring the flow rate by each of the first flow sensors;
Measuring the flow rate by the second flow sensor;
The determination unit determines whether or not the measured value of each first flow sensor exceeds the first threshold, and determines whether or not the measured value of the second flow sensor exceeds the second threshold. Process,
And a step of changing the first threshold value to another first threshold value different from the first threshold value based on a determination result of the determination unit.

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