JP2004193344A - Substrate transport apparatus and substrate transfer method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate the need for installing an alignment mechanism apart from a transfer robot and to install a substrate rotating mechanism in a substrate holding part of the transfer robot. <P>SOLUTION: A substrate transport equipment is provided with a base mount 20 which is capable of moving in an X-axis direction in order to go to the front of a cassette or a treatment chamber; an arm which is elastic to R-axis direction to the base mount 20 and capable of pivoting in a θ-direction; a transfer robot having a substrate holding part G fixed to a tip of the arm; a luminescence device and a photodetector which are arranged upper and lower sides of a substrate entrance of the cassette and irradiate a light in the direction intersecting a pass of the substrate taken out from the cassette by the transfer robot; an operating means for calculating position deviation and rotation deviation from a reference point Og of the substrate holding part of the substrate, based on a light receiving signal; and control equipment for controlling an X-axis driving system, an R-axis driving system, and a θ-axis driving system by adding a correcting signal for correcting the calculated position deviation and rotation deviation, and making the substrate carry in a treatment chamber to a suitable position and a suitable direction. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a substrate transfer apparatus and a substrate transfer method for transferring a substrate such as a semiconductor wafer between a cassette and a processing chamber.
[0002]
[Prior art]
For example, in a semiconductor device manufacturing process, a cassette (for example, a storage container with a lid called a FOUP) containing many wafers in multiple stages in order to perform various kinds of processing on a semiconductor wafer (substrate) as an object to be processed. Etc.), it is essential to carry out a transport operation of taking out one wafer and carrying it into the processing chamber, or taking out a processed wafer from the processing chamber and transporting it again to the cassette. Articulated arm type transfer robots are widely used.
[0003]
In this type of processing system, the position and direction of the wafer carried into the processing chamber greatly affect the processing results, and therefore, it is necessary to carry the wafer at an appropriate position and angle (direction). Actually, since there is a load lock chamber in front of the processing chamber, it is important to optimize the loading into the load lock chamber.
[0004]
By the way, wafers are stored in a cassette in a horizontal state in multiple stages, and at that stage, each wafer is often stored with some positional deviation or rotational deviation. Therefore, even if the wafer is picked up by inserting the substrate holding unit of the transfer robot into the cassette as standard, the wafer is held by the substrate holding unit of the transfer robot with a shift, and the wafer is directly held in the processing chamber (or loaded). Loading the substrate into the lock chamber) can cause problems.
[0005]
Therefore, conventionally, a wafer positioning mechanism is provided separately from the transfer robot, and once the wafer is transferred to the positioning mechanism, the position is appropriately corrected, and then the wafer is again held by the transfer robot. It is carried into a processing chamber (for example, refer to JP-A-2002-26108).
[0006]
In addition, there is a type in which a substrate rotation mechanism is provided in a substrate holding unit of a transfer robot in order to particularly correct a rotational deviation of a wafer (for example, see Japanese Patent Application Laid-Open No. 2002-151576).
[0007]
[Patent Document 1]
JP-A-2002-26108
[Patent Document 2]
JP-A-2002-151576
[0008]
[Problems to be solved by the invention]
However, in the case where a positioning mechanism is provided separately from the transfer robot, an additional positioning mechanism must be provided, and there has been a problem that equipment costs are increased. Further, since the wafer must be transferred via the alignment mechanism every time the wafer is taken out of the cassette, there is a problem that the throughput is reduced.
[0009]
In addition, in the case where the substrate holding mechanism of the transfer robot is provided with a substrate rotation mechanism for correcting rotational displacement, an extra substrate rotation mechanism must be provided, which increases the weight of the tip of the arm and reduces equipment costs. There was a problem of up.
[0010]
The present invention has been made in view of the above circumstances, it is not necessary to provide a positioning mechanism separately from the transfer robot, or to provide a substrate rotation mechanism in the substrate holding unit of the transfer robot, to prevent a decrease in throughput. It is another object of the present invention to provide a substrate transfer apparatus and a substrate transfer method capable of preventing increase in the weight of a substrate holding section and reducing the cost of equipment.
[0011]
[Means for Solving the Problems]
The invention according to claim 1 of the present invention is directed to a substrate transfer apparatus for transferring substrates between a cassette containing a plurality of substrates in multiple stages and a processing chamber for performing predetermined processing on the substrates, A base that can move in the horizontal X-axis direction to go to the front of the chamber, an arm that can be extended and retracted in the R-axis direction with respect to the base, and that can pivot in the θ-direction, and a tip of the arm A transfer robot provided with a substrate holding portion for holding a substrate to be taken in and out of the cassette or the processing chamber; and a transfer robot provided above and below a substrate entrance of the cassette and taken out of the cassette by the transfer robot. A light-emitting device that irradiates light in a direction intersecting with the passing path, a light-receiving device that receives light from the light-emitting device, and the substrate that is taken out by the transport robot based on a light-receiving signal of the light-receiving device Calculating means for calculating the amount of displacement and rotation from the reference point of the holding unit; and an X-axis drive system for the transfer robot by adding a correction signal for correcting the amount of displacement and rotation calculated by the calculating means. A control device for controlling the R-axis drive system and the θ-axis drive system to carry the substrate into the processing chamber at a proper position in a proper direction.
[0012]
The invention according to claim 2 is characterized in that the light emitting unit and the light receiving unit can be integrally moved up and down according to the height of taking out the substrate from the cassette.
[0013]
According to a third aspect of the present invention, there is provided a substrate transfer method for transferring a substrate between a cassette containing a plurality of substrates in multiple stages and a processing chamber for performing a predetermined process on the substrate, wherein the transfer robot for transferring the substrate comprises Can move in the horizontal X-axis direction in order to go to the cassette or the processing chamber, and a substrate holding unit is provided in a horizontal direction perpendicular to the X-axis in order to take a substrate in and out of the cassette or the processing chamber. Using a multi-joint arm type transfer robot that can move in the Y-axis direction and that can rotate around the vertical θ axis where the substrate holding unit passes through the substrate holding reference point, A light-emitting device for irradiating light in a direction intersecting with a passage path of the substrate taken out by the transfer robot and a light-receiving device for receiving light from the light-emitting device. Based on the light receiving signal of the light receiving unit, a displacement amount and a rotation displacement amount of the substrate taken out by the transfer robot from a reference point are calculated, and a correction signal for correcting the calculated displacement amount and the rotation displacement amount is added. By controlling the X-axis drive system, the Y-axis drive system, and the θ-axis drive system of the transfer robot, the substrate is loaded into the processing chamber at an appropriate position.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a plan view showing an overall configuration of a first embodiment in which a substrate transfer apparatus of the present invention is applied to a substrate processing apparatus in a semiconductor manufacturing process.
[0015]
The substrate processing apparatus M has a load port A for mounting a plurality of cassettes E, a plurality of processing chambers B, and one transfer chamber C. In a cassette (transport container) E, a plurality of, for example, about 25 substrates (semiconductor wafers in this example) W are stored in multiple stages at a predetermined pitch in the vertical direction. The processing chamber B is a chamber for performing predetermined processing on the substrate W, and the transfer chamber C is a chamber for transferring the substrate W between the load port A (cassette E) and the processing chamber B. The transfer chamber C is provided with a transfer robot F for performing a transfer operation.
[0016]
The transfer chamber C is a rectangular chamber in a plan view. A rail 10 is provided along the longitudinal direction of the transfer chamber C, and the transfer robot F can move along the rail 10. Here, the moving direction of the transfer robot F along the rail 10 is defined as the X-axis direction, and the moving mechanism is called an X-axis drive system (not shown). A direction orthogonal to the X-axis direction is defined as a Y-axis direction.
[0017]
A plurality of load ports A are arranged on one side of the transfer chamber C along the longitudinal direction of the transfer chamber C. Each cassette E on each load port A is connected to the transfer chamber C via the door 11. The cassette E accommodated in the load port A is capable of accommodating the substrates W in multiple stages in a vertical state in a horizontal state, has a substrate entrance 13 with a lid on the front surface, and passes through the substrate entrance 13 on the front surface. The substrate W is taken in and out. The transfer chamber C and the cassette E are maintained at the atmospheric pressure.
[0018]
A plurality of processing chambers B are arranged on the other side of the transfer chamber C along the longitudinal direction of the transfer chamber C. Each processing chamber B is connected to the transfer chamber C via the load lock chamber D, and a gate valve is provided between the load lock chamber D and the transfer chamber C and between the load lock chamber D and the processing chamber B, respectively. 14 and 15 are provided. Although not shown, the load lock chamber D is equipped with a mounting table for the substrate W and a transfer arm for transferring the substrate W to and from the processing chamber B. The processing chamber B and the load lock chamber D can be evacuated and purged with nitrogen.
[0019]
The transfer robot F transfers the substrate W to the load lock chamber D when loading the substrate W into the processing chamber B, and receives the substrate W from the load lock chamber D when unloading the substrate W from the processing chamber B. Therefore, strictly speaking, the transfer robot F does not directly access the processing chamber B, but indirectly accesses it via the load lock chamber D. However, since the access is to the processing chamber B in the transport operation, the access to the load lock chamber D is regarded as a loading / unloading operation to the processing chamber B here.
[0020]
The transfer robot F can be moved in the X-axis direction by being mounted on a base 20 that moves on the rail 10, and by moving in the X-axis direction, each load port A or the processing chamber B ( It is positioned in front of the load lock chamber D). The transfer robot F is a multi-joint arm type robot, and has an arm portion T that can turn and expand and contract (bend and extend), and a lifting mechanism (not shown). Then, by driving the elevating mechanism or moving the arm portion T, the substrate holding portion (pic) G at the tip of the arm portion T is moved in the vertical Z-axis direction, The arm portion T can be turned around the turning center Of as a fulcrum, or the arm portion T can be expanded and contracted. Here, the turning direction of the arm portion T is referred to as the θ direction, and the extending / contracting direction is referred to as the R direction (radial direction). The substrate W is moved in and out of the cassette E or the processing chamber B (load lock chamber D) by the movement of the substrate holding unit G in the X-axis direction, the R direction, and the θ direction. Here, a drive system that performs drive control in the R-axis direction is called an R-axis drive system, and a drive system that performs drive control in the θ-axis direction is called a θ-axis drive system.
[0021]
In the substrate processing apparatus M, the position shift of the substrate W with respect to the normal substrate holding position (reference position) of the transfer robot F is located on the transfer chamber C side of the door 11 of the load port A, that is, outside the substrate entrance 13 of the cassette E. A sensor S for detection is provided. 2A and 2B are diagrams showing the relationship between the sensor S and the substrate entrance 13, wherein FIG. 2A is a front view and FIG. 2B is a side view. FIG. 3 is a plan view showing the relationship between the transfer robot F and the sensors S, the substrates W, and the cassette E.
[0022]
As shown in FIG. 2, the load port A is provided with an opening for taking in and out the substrate W and a door for opening and closing the opening. When the door is opened, the front cover (not shown) of the cassette E is opened. To open the substrate entrance 13. Thereby, the transfer robot F can move the substrate W in and out of the cassette E.
[0023]
The loading and unloading of the substrate W is performed in a horizontal posture. Therefore, the light emitting device 31 and the light receiving device 32 that constitute the sensor S are disposed at upper and lower positions sandwiching the passage of the substrate W. The light emitter 31 arranged on the upper side irradiates the light downward in a direction intersecting the passage path of the substrate W taken out of the cassette E by the substrate holding part G of the transfer robot F, and the light receiver 32 arranged on the lower side is The light from the light emitter 31 is received. In this case, the light emitter 31 is a line-type light emitter that irradiates the beam 30 in a continuous line in the width direction of the substrate W (the left-right direction orthogonal to the substrate take-out direction). That is, the beam 30 for detection is applied in a plane crossing the passage of the substrate W. The light receiver 32 includes an array-type light receiver 32 that can receive the beam 30 irradiated in a line.
[0024]
Here, the light-emitting device 31 is arranged at a level above the uppermost substrate W, and the light-receiving device 32 is arranged below the lowermost substrate W so that all the substrates W accommodated in the cassette E can be detected. Have been placed on the level. The length of the line for irradiating the beam 30 is naturally set to be longer than the diameter of the substrate W. Note that the light emitter 31 and the light receiver 32 may be mounted upside down.
[0025]
This substrate processing apparatus includes, in addition to the above configuration, an arithmetic unit (not shown) for calculating the amount of displacement and rotation of the substrate W based on the signal of the sensor S, and the calculated amount of displacement and rotation. A control device 50 for loading the substrate into the processing chamber at an appropriate position by controlling the X-axis drive system, the R-axis drive system, and the θ-axis drive system of the transfer robot by adding a correction signal for correcting the shift amount. Have.
[0026]
Next, the principle of “position shift detection” performed based on the signal of the sensor S will be described. The calculating means detects a center position shift of the substrate W with respect to a reference point Og (a position corresponding to the center of the normal position of the substrate) of the substrate holding portion G based on a light receiving signal from the sensor S (light receiver 32) accompanying the operation of taking out the substrate W. The amount and the rotational deviation amount (deviation angle) of the substrate W with respect to the reference direction are calculated. That is, when the substrate holding unit G moves while holding the substrate W, the output of the sensor S changes because the substrate W crosses the detection surface (beam collecting surface) formed by the linear beams 30. . Therefore, the center position and the direction of the substrate W are calculated based on the change in the output of the sensor S and the coordinate data when the substrate holding unit G is moved, and are compared with the reference position and the data of the reference direction. Thus, the amount of positional deviation and the amount of rotational deviation of the substrate W are determined.
[0027]
FIG. 4A shows the relationship between the sensing position of the beam 30 (detection surface) and the substrate W, and FIG. 4B shows the sensor output at that time. Although the sensor S is fixed, the beam 30 is scanned because the substrate W moves. For example, if the sensing positions A, B, C, and D by the beam 30 are as shown in (a), the sensor output becomes as shown in (b). That is, the output is “L” in a place where the beam 30 is not blocked by the substrate W, but is “H” in a place where the beam 30 is blocked by the substrate W. Therefore, the position coordinates of the edge portion of the substrate W can be obtained from this data, and the center position of the substrate W can be geometrically determined by knowing the edge coordinates of three points separated from each other.
[0028]
Next, detection of the direction of the substrate W will be described. This type of substrate W is provided with a notch N (or orientation flat) for direction recognition at a specific portion of the outer peripheral edge portion. Therefore, the coordinates of the notch N are first determined. FIG. 5A shows the relationship between the sensing positions E, F, G, H, I, J of the beam 30 (detection surface) and the notch N, and FIG. 5B shows the sensor output at that time. The position of the notch N can be calculated from the sensor output as shown in (b) and the coordinates of the reference point Og of the substrate holding unit G at that time. When the position coordinates of the notch N are known, the shift angle θ1 of the substrate W can be calculated from the position coordinates of the notch N and the center coordinates of the substrate W. Note that the orientation and center coordinates of the substrate W are stored in a memory together with information on the coordinates of the reference point Og of the substrate holding unit G (a position corresponding to the center of the substrate at the normal position) at that time. After the acquisition, the signal is obtained by analyzing the signal.
[0029]
Next, the principle of position shift correction will be described. The robot control unit controls the X-axis drive system, the R-axis drive system, and the θ-axis drive system of the transfer robot F by adding a correction signal for correcting the position shift amount and the rotation shift amount calculated as described above, The substrate W is carried into the load lock chamber D by the transfer robot F at an appropriate position. For example, as shown in FIG. 6A, the center position Ow of the substrate W and the reference position Og of the substrate holding unit (pic) of the transfer robot F are shifted by X1 in the X-axis direction and Y1 in the Y-axis direction. When the substrate W is rotationally displaced by θ1 with respect to the substrate holding unit G, the amount of rotation θ and the amount of expansion and contraction when the substrate W is at the normal position (from the center of rotation Of the arm unit to the substrate holding unit G). The distance to the reference point Og and the radius of the arm portion are also referred to.) With respect to R and the horizontal movement amount X, the rotation correction amount Δθ, the expansion / contraction correction amount ΔR, and the horizontal movement correction amount ΔX are incorporated as correction values. Then, the transfer robot F is controlled.
[0030]
That is, in the X-axis direction and the Y-axis direction, the substrate W can be transferred to the load lock chamber D at an appropriate position by moving the substrate holding unit G by X1 and Y1 more than the reference position. Further, as shown in FIG. 6B, in order to correct the rotational deviation of θ1, the reference position Og of the substrate holding unit (pic) is added by θ1 about the turning center Of of the arm unit T on the base 20 as a center. , The substrate W can be delivered to the load lock chamber D at an appropriate position. Note that the substrate center Ow further shifts in the X-axis direction and the Y-axis direction with the rotation of θ1, and the shift amount can be eliminated by correcting the X-axis and Y-axis directions.
[0031]
FIG. 7 is a diagram for explaining the principle of correcting the rotational deviation θ1. When the substrate W is displaced by θ1 as in (a), the center of the transfer robot (the center of rotation of the arm) Of is moved by X in the X-axis direction by moving the base 20 as in (b). By adjusting the radius R of the arm portion T to R ′ while moving, the rotational deviation θ1 of the substrate W can be corrected while maintaining the position (R) in the Y-axis direction.
[0032]
When the correction is to be performed by the two connecting arms, as shown in FIGS. 8 (a) and 8 (b), the turning center Of of the arm portion T is moved by X in the X-axis direction by the movement of the base 20, so that the two The position (R) in the Y-axis direction is maintained by controlling the bending angle of the arm from α to β and adjusting the radius of the arm portion T (the distance from the turning center Of to the reference point Og) from R to R ′. Meanwhile, the rotational deviation θ1 of the substrate W can be corrected. In this case, since the lengths of the two arms are equal, X, R ', and B can be easily calculated mathematically.
[0033]
9A and 9B, the rotation center Of of the arm portion T is moved by X in the X-axis direction while the rotation deviation is corrected by the three connecting arms. By controlling the bending angle of the two arms from α to β and adjusting the radius of the arm portion T from R to R ′, the rotational deviation θ1 of the substrate W can be maintained while maintaining the position (R) in the Y-axis direction. Can be modified.
[0034]
Next, a method of transporting the substrate together with the operation will be briefly described. When taking out the substrate W from the cassette E, the transfer robot F moves before the corresponding load port A and stops. Then, the transfer robot F extends the substrate holding unit G to hold the substrate W in the cassette E, and then retracts the substrate holding unit G to take out the substrate W from the cassette E. At that time, the position information of the substrate W is collected by the substrate W passing between the light emitting unit 31 and the light receiving unit 32 of the sensor S. That is, the amount of positional deviation and the amount of rotational deviation of the substrate W from the reference point Og are calculated based on the signal of the light receiving unit 32 and the information on the movement position of the substrate holding unit G. Next, the transfer robot F moves and stops in front of the processing chamber B to be loaded. Then, the substrate W held in the load lock chamber D in front of the processing chamber B is carried in by operating an arm or the like.
[0035]
At this time, the substrate W is loaded by controlling the X-axis drive system, the R-axis drive system, and the θ-axis drive system of the transfer robot F by adding a correction signal for correcting the position shift amount and the rotation shift amount calculated previously. It is carried into the lock chamber D at an appropriate position. As described above, since the substrate W is carried into the processing chamber B while correcting the positional deviation directly by the transfer robot F, a positioning mechanism may be provided separately from the transfer robot as in the related art. There is no need to provide a rotating mechanism. Therefore, the cost can be reduced by simplifying the equipment, and the throughput can be improved.
[0036]
In the above-described embodiment, when the position of the notch N due to the rotational displacement of the substrate W is at a position that does not overlap with the substrate holding unit G, the beam of the sensor S can securely position the notch N without being disturbed by the substrate holding unit G. The notch N can be detected without any problem. However, when the position of the notch N is at a position overlapping the substrate holding portion G, the beam of the sensor S is obstructed by the substrate holding portion G. May not be possible. In order to prevent this, it is desirable that the substrate holding unit G is made of a transparent material such as quartz. Then, even if the notch N is hidden by the substrate holding part G, it can be detected. However, since the notch N is often located at 0 °, 90 °, 180 °, and 270 ° on the circumference of the substrate W, a problem actually occurs if the notch N can be detected in an angular range in the vicinity thereof. It can be said that there are few things. In addition, as shown in FIG. 10, if a window 41 is provided at a corresponding position of the substrate holding unit G in consideration of a possibility that the notch N exists at least at a position of 180 °, the notch N can be surely inserted through the window 41. Can be detected.
[0037]
Further, when the light emitting unit 31 and the light receiving unit 32 are arranged at intervals according to the total number of substrates mounted on the cassette E as in the above embodiment, the distance between the light emitting unit 31 and the light receiving unit 32 is too large, If the detection accuracy of the sensor S is likely to decrease, as shown in FIG. 11, the light emitting unit 31 and the light receiving unit 32 are arranged so as to be narrowed so that at least one substrate W can be taken in and out. The light-emitting unit 31 and the light-receiving unit 32 may be integrally moved up and down by an elevating mechanism (simply indicated by an arrow) 43 in accordance with the height at which the substrate W is taken out.
[0038]
As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the present invention is not limited to the above embodiments, and various design changes and the like can be made without departing from the gist of the present invention. is there. For example, in the above embodiment, a semiconductor wafer is assumed as a substrate, but another circular substrate may be used. Further, in the above embodiment, the case where the present invention is applied to the scalar type transfer robot has been described. However, the present invention is directed to a parallel link type, a flock leg type, and a linear motion type in which the substrate holding unit moves on a rail. As described above, it can be extended, retracted, and turned, and can be applied to a transfer robot that moves on the X axis.
[0039]
【The invention's effect】
In short, according to the present invention, the following effects can be obtained.
[0040]
(1) According to the invention of claim 1, in the substrate transfer apparatus for transferring a substrate between a cassette accommodating a plurality of substrates in multiple stages and a processing chamber for performing predetermined processing on the substrate, A base that can move in the horizontal X-axis direction to go to the front of the chamber, an arm that can be extended and retracted in the R-axis direction with respect to the base, and that can pivot in the θ-direction, and a tip of the arm A transfer robot provided with a substrate holding portion for holding a substrate to be taken in and out of the cassette or the processing chamber; and a transfer robot provided above and below a substrate entrance of the cassette and taken out of the cassette by the transfer robot. A light-emitting device that irradiates light in a direction intersecting with the passing path, a light-receiving device that receives light from the light-emitting device, and a substrate holder of a substrate taken out by the transport robot based on a light-receiving signal of the light-receiving device. Calculating means for calculating the amount of displacement and rotation from the reference point of the unit, and an X-axis drive system of the transport robot by adding a correction signal for correcting the amount of displacement and rotation calculated by the calculating means; The control unit controls the R-axis drive system and the θ-axis drive system to carry the substrate to the processing chamber in the proper position and in the proper direction. It is not necessary to provide a positioning mechanism separately from the transfer robot and to provide a substrate rotating mechanism in the substrate holding unit as in the related art. Therefore, the weight of the substrate holding portion and the cost can be reduced by simplifying the equipment, and the throughput can be improved.
[0041]
(2) According to the second aspect of the present invention, since the light emitting section and the light receiving section can be integrally moved up and down in accordance with the height of taking out the substrate from the cassette, the distance between the light emitting section and the light receiving section is reduced. It can be narrowed, and the displacement detection accuracy of the substrate can be improved.
[0042]
(3) According to the third aspect of the present invention, in a substrate transfer method for transferring a substrate between a cassette accommodating a plurality of substrates and a processing chamber for performing predetermined processing on the substrate, the transfer for substrate transfer is performed. As a robot, a base that can move in the horizontal X-axis direction to go to the cassette or the processing chamber, and an arm portion that can be extended and contracted in the R-axis direction and pivotable in the θ direction with respect to the base. And a substrate holding unit attached to the tip of the arm unit and holding a substrate to be taken in and out of the cassette or the processing chamber, using the transfer robot above and below a substrate entrance of the cassette. A light-emitting device for irradiating light in a direction intersecting with a passage path of the substrate taken out by the light-emitting device and a light-receiving device for receiving light from the light-emitting device; The transfer robot calculates a positional shift amount and a rotational shift amount of the substrate taken out by the transfer robot from a reference point of the substrate holding unit, and adds a correction signal for correcting the calculated position shift amount and the rotational shift amount, thereby performing the transfer. By controlling the X-axis drive system, R-axis drive system, and θ-axis drive system of the robot, the substrate is loaded into the processing chamber in the proper position and in the proper direction. It is not necessary to provide a positioning mechanism separately from the transfer robot and to provide a substrate rotating mechanism in the substrate holding unit as in the related art. Therefore, the weight of the substrate holding portion and the cost can be reduced by simplifying the equipment, and the throughput can be improved.
[Brief description of the drawings]
FIG. 1 is a plan view showing a configuration of an embodiment in which the present invention is applied to a substrate processing apparatus.
FIGS. 2A and 2B are diagrams showing a relationship between a substrate displacement detecting sensor, a cassette, and a substrate in the same apparatus, wherein FIG. 2A is a front view and FIG. 2B is a side view.
FIG. 3 is a plan view showing a relationship among a transfer robot, the sensor, a cassette, and a substrate in the apparatus.
4A and 4B are explanatory diagrams of the principle of detecting the center of the substrate by the sensor, wherein FIG. 4A is a plan view showing the relationship between the position of a beam emitted by the sensor and the substrate, and FIG. 4B is a diagram showing the output of the sensor. .
5A and 5B are explanatory diagrams of a principle of detecting a rotational displacement of a substrate by the sensor, wherein FIG. 5A is a plan view showing a relationship between a position of a beam emitted by the sensor and the substrate, and FIG. 5B is a diagram showing an output of the sensor. It is.
FIGS. 6A and 6B are explanatory diagrams of the principle of positional deviation correction by the transfer robot, wherein FIG. 6A is a plan view showing the relationship between positional deviation between the substrate holding unit and the substrate, and FIG. 6B is a plan view for explaining rotational deviation correction; It is.
FIGS. 7A and 7B are explanatory diagrams illustrating the principle of the rotation shift correction, in which FIG. 7A illustrates a state before correction, and FIG. 7B illustrates a state after correction.
FIGS. 8A and 8B are explanatory diagrams illustrating the principle of the case where the rotational displacement is corrected using two connecting arms, wherein FIG. 8A illustrates a state before correction and FIG. 8B illustrates a state after correction.
9A and 9B are explanatory diagrams illustrating the principle of the case where the rotational displacement is corrected using the three connecting arms, wherein FIG. 9A illustrates a state before correction, and FIG. 9B illustrates a state after correction.
FIG. 10 is a plan view showing a main part configuration of another embodiment of the present invention.
FIG. 11 is a front view showing a configuration of a main part of still another embodiment of the present invention.
[Explanation of symbols]
M substrate processing equipment
A load port
B processing room
C transfer room
D Load lock room
E cassette
F Transfer robot
G board holder
S sensor
T arm
W substrate
Og reference point
10 rails
13 Substrate doorway
20 bases
30 beams
31 Light emitting unit
32 Receiver
50 Control device

Claims (3)

In a substrate transfer apparatus for transferring substrates between a cassette accommodating a plurality of substrates in multiple stages and a processing chamber for performing predetermined processing on the substrates, a horizontal X-axis direction is required to go to the cassette or the processing chamber. A base that can be moved to and from the base, an arm that can be extended and retracted in the R-axis direction with respect to the base, and that can be turned in the θ direction, attached to the tip of the arm, and put in and out of the cassette or the processing chamber. A transfer robot provided with a substrate holding unit for holding a substrate to be processed, and light emission provided above and below a substrate entrance of the cassette and irradiating light in a direction intersecting a passage path of a substrate taken out of the cassette by the transfer robot. And a light-receiving device for receiving light from the light-emitting device; and a displacement amount of a substrate taken out by the transport robot based on a light-receiving signal of the light-receiving device from a reference point of the substrate holding portion. Calculating means for calculating the amount of rotational deviation, and adding a correction signal for correcting the amount of positional deviation and the amount of rotational deviation calculated by the calculating means to add an X-axis drive system, an R-axis drive system, and a θ-axis drive system of the transfer robot. A control device for controlling the substrate to be carried into a processing chamber in a proper position in a proper direction by controlling the substrate transfer apparatus. 2. The substrate transport apparatus according to claim 1, wherein the light emitting unit and the light receiving unit can be integrally moved up and down in accordance with the height of taking out the substrate from the cassette. In a substrate transfer method for transferring a substrate between a cassette accommodating a plurality of substrates and a processing chamber for performing a predetermined process on the substrate, a substrate is transferred to the cassette or the processing chamber as a transfer robot for transferring the substrate. A base that can be moved in the horizontal X-axis direction, an arm that can be extended and contracted in the R-axis direction with respect to the base, and that can pivot in the θ direction, Using a transfer robot provided with a substrate holding section for holding a substrate to be taken in and out of a cassette or a processing chamber, in a direction intersecting a passage path of a substrate taken out by the transfer robot above and below a substrate entrance of the cassette. A light emitting unit for irradiating light and a light receiving unit for receiving light from the light emitting unit are provided, and the light is picked up by the transport robot based on a light receiving signal of the light receiving unit when the substrate is taken out from the cassette. X-axis drive system of the transfer robot by calculating a displacement amount and a rotation displacement amount of the obtained substrate from the reference point of the substrate holding unit, and adding a correction signal for correcting the calculated displacement amount and the rotation displacement amount. A substrate transfer method for controlling the R-axis drive system and the θ-axis drive system to load a substrate into a processing chamber at a proper position in a proper direction.

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