JPH10321701A - Device for manufacturing semiconductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for manufacturing a semiconductor which does nor require a highly skilled operator and can reduce teaching man-hours by automatically compensate the hanging of a transfer unit when it is protruded and can always ensure constant compensation accuracy for the hanging. SOLUTION: After tweezers 5 have been protruded, they are lifted to a position where a substrate is sucked, and the suction of the substrate is detected by suction detection means 52. The height of the tweezers 5 where a suction detection signal is issued is detected by second detection means 53, and control means 11 determines the amount of hanging from the difference in the height of the tweezers 5 before the protrusion of the tweezers and the time of the suction of the substrate. Then, the control means 11 compensates the position data of a transfer unit 4 in a storing means 14, based, on the determined amount of hanging and performs an actual process based on the compensated position data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing apparatus, and more particularly to a semiconductor manufacturing apparatus capable of teaching the operation of a transfer machine for carrying a substrate to a substrate insertion position of a substrate storage.

[0002]

2. Description of the Related Art In a semiconductor manufacturing apparatus, a large number of wafers stored in a cassette (substrate storage unit) are loaded into a boat (substrate storage unit) by a transfer machine, and then loaded into a reaction furnace. Thus, these wafers are subjected to predetermined processing such as film formation and annealing. In addition, each wafer after processing,
From the boat discharged from the furnace, it is returned to the cassette by the transfer machine.

In the transfer processing by such a transfer machine, it is necessary to accurately insert a wafer into a wafer insertion groove of a cassette or a boat. That is, the tweezers, which are the wafer suction units of the transfer machine, move the wafer in the front-rear direction (X-axis direction), the left-right direction (Y-axis direction),
It is necessary to accurately position and insert in the vertical direction (Z-axis direction). Therefore, prior to the actual transport process (actual process), the operation of the transfer machine is taught. In the teaching of such a transfer machine, conventionally, for example, an operator manually operates the transfer machine to transfer a wafer, and counts a moving distance at this time by the number of pulses generated by a drive motor of the transfer machine. , The work was performed depending on the sense of the worker.

As shown in FIGS. 9 (a) and 9 (b), the transfer machine 4 reciprocating in the X direction on the base 4a is stroked, for example, toward the boat 2 to insert the board into the boat 2. When the wafer 1 inserted into the filling groove is sucked by the tweezers 5, the heavy transfer machine 4 moves to one side of the base 4a. Thereby, as shown in FIG. 6, the base 4a is inclined downward in the stroke direction by the weight of the transfer machine 4, and as a result, the height position h1 of the tip of the tweezer 5 before the stroke and the height position h1 after the stroke There is a shift ΔZ between the height position h2 of the tweezer tip. This shift is referred to as the sag (ΔZ is the sag amount) during the stroke of the transfer machine 4.

[0005] Due to the occurrence of the sag, the Z between the tweezers 5 inserted into the boat 2 and the wafer 1 to be sucked.
An axial displacement has occurred. Due to this, problems such as damage to the wafer 1 and the tweezers 5 are likely to occur when the wafer is taken in and out of each insertion groove in the actual process. Therefore, at the time of the above-described teaching, when the operator manually operates the transfer machine 4, the dripping amount is corrected with a visual sense.

[0006]

However, the correction of the amount of sagging of the transfer machine 4 during a stroke as described above is
Since the correction is sensuous based on the visual observation of the teaching operator, there is a problem that the operator requires a high level of skill and the number of steps of the teaching operation increases.
In addition, since this correction operation is performed manually, there is a problem in that it is not always possible to secure a constant precision sag correction.

The present invention has been made in view of the above-mentioned conventional circumstances, does not require a high level of skill of an operator, can reduce man-hours for teaching by automating sagging correction of a transfer machine at the time of a stroke, and is always constant. It is an object of the present invention to provide a semiconductor manufacturing apparatus capable of securing sag correction accuracy.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a transfer apparatus having a tweezer for sucking a substrate and reciprocating on a base that rotates and moves up and down. A first detecting means for detecting a height position of a substrate before a stroke of the transfer machine to the substrate storage body, wherein the tweezers include: Suction detecting means for detecting that the substrate has been sucked, second detecting means for detecting the height position of the tweezer when the substrate is sucked, and position data of the transfer machine with respect to the substrate insertion position of the substrate storage body. ,
Based on the height position data of the substrate before the stroke detected by the first detection means and the substrate suction signal from the suction detection means at the time of substrate suction detected by the second detection means. Storage means for storing the tweezer height position data, and obtaining the tweezer height position before the stroke from the substrate height position data stored in the storage means, and obtaining the obtained tweezer height before the stroke. The amount of sag due to the stroke of the transfer machine is determined from the difference between the position data and the height position data of the tweezer at the time of substrate suction stored in the storage means, and stored in the storage means based on the amount of sag. And control means for correcting the position data of the transfer machine and carrying out the transfer processing of the substrate to be processed in the actual process by the transfer machine. .

[0009] The term "substrate storage body" as used herein refers to a boat, cassette, or the like in which substrates are stored. As the detection means, for example, an optical sensor that transmits and receives laser light, infrared light, and the like, an ultrasonic sensor that emits an ultrasonic wave to an object, and detects a distance from a time until the reflected wave returns, and the like. , X-ray sensors for transmitting and receiving X-rays, and the like.

According to the semiconductor manufacturing apparatus of the present invention, at the time of teaching (including re-teaching) of the substrate transfer processing operation by the transfer machine, the substrate is first detected by the first detecting means at the initial position of the transfer machine. Processing for detecting the height position of. Then, the height position of the tweezer before the stroke is calculated based on the obtained height position data of the substrate. Next, the transfer machine is stroked on the base toward the substrate storage body (runs by a fixed distance). As a result, the base and the like are inclined, and the transfer machine at the time of the stroke may drop. This sagging amount is obtained as follows. That is, after the stroke, the tweezer is raised until the substrate is sucked. This substrate suction state is detected by the suction detection means. The height position of the tweezer at the time when the suction detection signal is transmitted from the suction detection means is detected by the second detection means. Thereafter, the controller calculates the amount of sag from the difference between the height position of the tweezer before the stroke and the height position of the tweezer at the time of substrate suction.

Next, the position data of the transfer machine stored in the storage means is corrected based on the sag amount. Thereafter, the transfer device performs an actual process by the control means based on the corrected position data. Therefore, this correction operation does not require a high skill of the operator. Further, the sag correction can be automated, and as a result, the number of teaching steps can be reduced. In addition, a constant sag correction accuracy can always be ensured.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a semiconductor manufacturing apparatus according to one embodiment of the present invention will be described with reference to the drawings. Here, an example is described in which automatic teaching is performed using a jig in which a cylindrical pin is provided upright at the center position of a disk portion having the same size and shape as the wafer. The same parts as those of the conventional means are denoted by the same reference numerals. As shown in FIGS. 1 and 2, the semiconductor manufacturing apparatus includes a boat 2 having a plurality of grooves 1 for inserting a plurality of wafers 1 for performing a predetermined process in a reaction chamber, and a multi-stage insertion groove. A cassette 3 for accommodating a plurality of processed or unprocessed wafers 1, a transfer machine 4 for transporting five wafers 1 between the boat 2 and the cassette 3,
A controller 7 for controlling a transfer process of the wafer 1 by the transfer machine 4.

The cassette 3 containing the wafers 1 is mounted on a cassette shelf 6 provided in a semiconductor manufacturing apparatus. The transfer machine 4 is provided with five tweezers 5 for sucking the wafer 1. A base 4a that can be turned and moved up and down by a base elevating and turning device 50 is disposed between the boat 2 and the cassette 3. The transfer machine 4 is mounted on the base 4a via an LM guide extending in the X direction. Rotary shaft 5 of base elevating and rotating device 50
While the base 4a is raised and lowered by protruding and retracting the base 1, the base 4a is horizontally turned by rotating the rotating shaft 51.

In this semiconductor manufacturing apparatus, the first detecting means 10 is provided on the front part of the transfer machine 4 (immediately below the tweezers 5), and the position data detected by the first detecting means 10 is analog data. Is input to an external terminal (PC) 12 via a digital / digital converter 11. The first detection means 10 is constituted by a sensor for optically detecting the position of the wafer 1 as described later, and this detection information is output to the external terminal 12 as position data. Further, on the rear surface portion of the transfer machine 4, suction detecting means 52 for detecting the suction state of the wafer 1 on each tweezer 5 is provided.

The suction detecting means 52 is a sensor for detecting that the tweezers 5 has suctioned the wafer 1, and outputs a suction detection signal indicating that the wafer 1 has been suctioned to the external terminal 12.
Output to Further, the base elevating and rotating device 50 has a second
The second detecting means 53 detects the height position of the tweezer 5 when the jig (wafer) is sucked from the vertical length of the rotating shaft 51. The second detecting means 53 is a sensor for detecting the amount of protrusion of the rotating shaft 51, and the detection information is output to the external terminal 12 as position data. The controller 7 and the external terminal 12 constitute control means of the semiconductor manufacturing apparatus.

The semiconductor manufacturing apparatus is provided with communication control means 13 for controlling communication between the external terminal 12 and the controller 7. An operation command from the external terminal 12 is input to the controller 7 via the communication control means 13, and a status signal and an encoder value obtained by the controller 7 are input to the external terminal 12. The encoder value is the number of pulses generated by the drive motor of the transfer machine 4, and the operation can be controlled while detecting the movement distance of the transfer machine 4 (ie, the movement distance of the tweezers 5).

The external terminal 12 is provided with a memory 14 for storing position data and detection signals input from the first and second detection means 10 and 53 and the suction detection means 52 and encoder values input from the controller 7. This memory 14
(Storage means). Further, the position data of the transfer machine is stored in the memory 14. The position data, the position data, and the encoder value are data for controlling the operation of the transfer machine 4 as described later. In the transfer process of the wafer 1 in the actual process, the external terminal 12 and the controller 7 The transfer machine 4 is operated based on the stored data. In order to obtain this position data, in a teaching operation performed prior to the actual process, a jig 21 shown in FIG. 3 is used instead of the wafer 1 to be processed. This jig 21
Is composed of a disk portion 21a made of quartz having the same shape and the same size as the wafer 1, and a cylindrical pin 21b made of quartz welded to the center position of the disk portion 21a.

In the semiconductor manufacturing apparatus having the above structure, an automatic teaching operation is performed as described below, and thereafter, a transport process of an actual process is performed. First, as shown in FIG.
In the teaching operation, an operator inserts the jig 21 into, for example, the boat 2 (the same applies to the case of the cassette 3), and
1, clearance between the left and right insertion grooves (clearance),
The clearance (clearance) in the vertical direction with respect to the insertion groove of the jig 21 and the clearance (clearance) with respect to the insertion groove in the back of the jig 21 are adjusted to be a predetermined interval.
Then, with the transfer machine 4 fixed at the home position serving as a reference position for operation, the position of the jig 21 loaded into the boat 2 with a predetermined clearance is determined by the first detecting means 10.
And the position data obtained in this detection processing is stored in the memory 14.

That is, as shown in FIG.
The laser beam R from the detecting means 10 in the Y-axis direction (left-right direction)
Then, the left and right ends of the pin 21b are detected from the presence or absence of the reflected light, and the bisected position (that is, the center of the jig 21) is detected as the position of the jig 21 in the Y-axis direction. Further, as shown in FIG. 3B, the first detector 10 irradiates the laser beam R up and down in the Z-axis direction (vertical direction) to detect the edge of the disk portion 21a from the presence or absence of reflected light. The position is detected as the position of the jig 21 in the Z-axis direction. Further, as shown in FIG. 3C, the first detecting means 10 determines the position of the pin 21b (that is, the center of the jig 21) in the X-axis direction (front-back direction) based on the reflected light from the pin 21b (that is, , The distance between the center of the jig 21 and the transfer machine 4).

In the above detection processing, an optical displacement sensor is used as the first detecting means 10, and this optical displacement sensor is constituted by combining a light emitting element and a light position detecting element (PSD). . In particular, the distance in the X-axis direction is detected by a method using triangulation. The detection processing by this sensor will be described in more detail. Light from a light emitting element such as a light emitting diode or a semiconductor laser is condensed by a light projecting lens and irradiated to a jig 21. A part of the light diffusely reflected from the jig 21 is condensed on the light position detecting element through the light receiving lens. The Y-axis position and the Z-axis position are detected based on the presence or absence of the collected light. At the same time, the distance in the X-axis direction is detected based on the spot position of the collected light.

That is, the light position detecting element is the sensor 10
A voltage corresponding to the distance between the tool and the jig 21 or the position of the formed spot is output, and the distance in the X-axis direction is detected based on the output voltage value. Thus, the sensor 10 as a whole has three functions of detecting the position in the Y-axis direction, the position in the Z-axis direction, and the distance in the X-axis direction. The above detection processing is performed by the transfer machine 4 and the tweezers 5.
In the home position. Also,
Even if the positional relationship between the sensor 10 and the tip of the tweezer 5 is detected and measured in advance and the operation is controlled based on the position data obtained by the sensor 10, the position of the tweezer 5 can be accurately controlled in an actual process.

In this way, the position data that allows the jig 21 (ie, the wafer 1) to be inserted into the boat 2 in an appropriate state with a predetermined clearance is stored in the memory 14
Is stored in Thereafter, in the actual process, the position data stored in the memory 14 is output to the controller 7 and the transfer device 4 is operated.
The boat 2 is inserted into the insertion groove 2b of the boat 2 with an appropriate clearance in the horizontal direction and the vertical direction. In this embodiment, the five tweezers 5 of the transfer machine 4 transport the wafers one by one and insert them into the boat 2 with a predetermined clearance.

As described above, when the transfer machine 4 is stroked on the base 4a toward the boat 2, the relatively heavy transfer machine 4 moves to one side of the base 4a.
The base 4a is inclined downward in this stroke direction, and the transfer machine 4
At the time of the stroke. This dripping phenomenon may cause inconveniences such as damaging the wafer 1 and the tweezers 5 when the wafer is taken in and out of each of the insertion grooves in the actual process. Therefore, by performing the following operation, the sagging of the transfer machine 4 is automatically corrected.

That is, at the time of teaching the operation of the transfer machine 4, first, the height position of the jig 21 is detected by the sensor 10 while the rotating shaft 51 of the base lifting / lowering device 50 is projected (FIG. 4A). )reference). Next, the obtained jig height position data is stored in the memory 14, and based on the stored jig height position data, the external terminal 12
In, the height position of the tweezers 5 before the stroke is calculated. After that, the rotating shaft 5 of the
1 is lowered by a predetermined length, and the disc portion 21a of the jig 21 is lowered.
A predetermined tweezer 5 is arranged at the height position of FIG.
(B)). Then, when the transfer machine 4 is stroked toward the boat 2 on the base 4a, the tweezers 5 are inserted obliquely below the disk portion 21a while causing the transfer machine 4 to sag during the stroke (FIG. 5, See FIG. 6).

The sagging amount at this time is obtained as follows. That is, after the stroke, the tweezers 5 are connected to the jig 2
The first disk portion 21a is raised until it is sucked. The suction state of the jig 21 is detected by the suction detection means 52. At this time, the second detecting means 53 detects the protruding length of the rotating shaft 51 of the base lifting / lowering / turning device 50. Then, based on the protrusion length, the external terminal 12 calculates the height position of the tweezers 5. Then, external terminal 1
In step 2, the sag amount ΔZ is calculated from the difference between the height position of the tweezers before the stroke and the height position of the tweezers 5 at the time of chucking the jig. As shown in FIGS. 7A and 7B, the sag amount ΔZ is divided into a horizontal descending component ΔZ1 and a vertical downward rotating component ΔZ2 due to the downward rotation of the tweezer 5 by the angle θ. . Therefore, ΔZ1 and ΔZ1
By adding Z2, the sag amount ΔZ is obtained.

Next, based on the sag amount ΔZ, the memory 1
4 to correct the position data of the transfer machine 4. Then, based on the corrected position data,
Since the actual process is performed by the external terminal 12 and the controller 7, a high level of skill of the operator is not required, the man-hour for teaching can be reduced by automating sag correction, and a constant sag correction accuracy can always be ensured.

It should be noted that the present invention is not limited to this embodiment, and any changes in design without departing from the gist of the present invention are included in the present invention. For example, in the embodiment, the case where the automatic teaching is performed using a jig in which a cylindrical pin is erected at the center position of the disk portion having the same size and shape as the wafer is taken as an example, but is not limited thereto. This can be applied to, for example, manual teaching by an operator. In this case, what is absorbed by the tweezers is not a jig but a wafer (substrate).

In the embodiment, quartz is used as the material of the jig. However, the present invention is not limited to this. For example, an opaque material such as alumina (preferably a material having a high light reflectance) is used.
May be adopted. According to this configuration, the laser light (including the sensor light of another type) emitted from the first detection unit
Without penetrating the target jig, for example, a pin,
Good reflection. Thereby, erroneous detection of the jig by the first detection means can be reduced, and the detection accuracy can be improved.

Further, if the jig material is made of an opaque material and the pins are screwed to the disk portion, the problem of corrosion and contamination of the joint portion during cleaning of the jig can be solved. That is, since the cleaning of the jig usually uses a cleaning process of a semiconductor manufacturing line, there is a concern that there is a possibility of corrosion or contamination of the joint depending on the chemical used.
However, if the connection between the pin and the disk portion is screwed in this way, those problems can be solved.

In the embodiment, the installation position of the first detecting means in the transfer machine is directly below the tweezers in the front of the transfer machine. However, the present invention is not limited to this.
In the case of a type in which the tweezers 5 are lifted and lowered, such as the scooping and transferring machine 4A shown in FIG. 1, the first detecting means 10A may be provided on one side of the transferring machine 4A. Thus, the sensor 10
A is provided on the side of the transfer machine 4A so that the transfer machine 4A
Is horizontally rotated, the pin 21b of the jig 21 can always be accurately detected obliquely regardless of whether the tweezers 5 are raised or lowered. In addition, in FIG. 8, 2a is a boat pillar.

In this embodiment, the sag correction at the time of teaching the operation of the transfer machine is automated. However, for example, during operation of the semiconductor manufacturing apparatus, a boat or a cassette serving as a substrate storage body may be changed for some reason (hereinafter, the case of a boat will be described as an example). In such a case, it is generally considered that the boat has a set position deviation. Therefore, it is necessary to re-teaching of the operation of the transfer machine. At this time, the position data of the old board must be compared with the position data of the new board, and only the positional deviation must be corrected. In order to implement this, the control means of the semiconductor manufacturing apparatus may be provided with a memory for storing the position data of the exchanged new and old substrate storage bodies. This makes it possible to automate the re-teaching that can reduce the number of steps of the re-teaching operation of the operation of the transfer machine and the variation in the operation.

[0032]

As described above, according to the present invention, at the time of teaching the operation of the transfer machine, the tweezer is raised until the substrate is sucked after the stroke of the transfer machine, and the height of the tweezer at this time is raised. Position, and then
The sagging amount of the transfer machine is calculated from the difference between the height positions of the respective tweezers before the stroke and during the suction of the substrate. Then, the position data of the transfer machine stored in the storage means is corrected based on the amount of dripping, and the actual process is performed based on the corrected position data. This makes it possible to automate the sag correction, thereby reducing the number of teaching steps and also ensuring a constant sag correction accuracy.

[Brief description of the drawings]

FIG. 1 is an overall perspective view of a semiconductor manufacturing apparatus according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a semiconductor manufacturing apparatus according to one embodiment of the present invention.

FIG. 3 is a conceptual diagram illustrating a method of detecting a jig position by a detecting unit according to one embodiment of the present invention.

FIG. 4 is a conceptual diagram illustrating a method for detecting the amount of sag of a transfer machine during a stroke by a semiconductor manufacturing apparatus according to an embodiment of the present invention.

FIG. 5 is a conceptual diagram illustrating a method of detecting the amount of sag of the transfer machine during a stroke by the semiconductor manufacturing apparatus according to one embodiment of the present invention.

FIG. 6 is a conceptual diagram illustrating the amount of sagging of a transfer machine before and after a stroke.

FIG. 7 is a conceptual diagram illustrating various components of a sagging amount.

FIG. 8 is a conceptual diagram illustrating a method for detecting a jig position by a semiconductor manufacturing apparatus according to another embodiment of the present invention.

FIG. 9 is a conceptual diagram illustrating a method of detecting the amount of sag of a transfer machine during a stroke by a semiconductor manufacturing apparatus according to a conventional example.

[Explanation of symbols]

 Reference Signs List 1 wafer, 2 boat (substrate storage body), 3 cassette (substrate storage body), 4 transfer machine, 4a base, 5 tweezer, 7 controller (control means), 10 sensor (first detection means), 12 external Terminal (control means), 14 memory (storage means), 52 suction detection means, 53 second detection means, ΔZ sag amount.

Claims (1)

[Claims] 1. A semiconductor manufacturing apparatus comprising: a transfer device that has a tweezer for sucking a substrate and reciprocates on a base that rotates and moves up and down to transfer a substrate to be processed to a substrate insertion position of a substrate storage body. In the apparatus, first detecting means for detecting a height position of the substrate before a stroke of the transfer machine to the substrate storage body; suction detecting means for detecting that the substrate is sucked by the tweezers; Second detecting means for detecting the height position of the tweezer at the time of suction, position data of the transfer machine with respect to the substrate insertion position of the substrate storage body, before the stroke detected by the first detecting means, The substrate height position data and the tweezer height position data at the time of substrate suction detected by the second detection means based on the substrate suction signal from the suction detection means are stored. Means and the height position of the tweezer before the stroke is obtained from the height position data of the substrate stored in the storage means, and the obtained height position data of the tweezer before the obtained stroke is stored in the storage means. The amount of sag due to the stroke of the transfer machine is obtained from the difference from the height position data of the tweezer at the time of substrate suction,
After correcting the position data of the transfer machine stored in the storage means based on the sagging amount, the transfer means transports the substrate to be processed in the actual process by the transfer machine. Semiconductor manufacturing equipment.