KR20080024375A - Apparatus and method for maintaining wafer slot number and wafer indexer using the same - Google Patents

Abstract

An apparatus and a method for maintaining the wafer slot number and a wafer indexer using the same are provided to facilitate control of wafers with reduced failure rate by calculating the slot number of a wafer cassette and loading the same wafer into a slot with the same number. An apparatus for maintaining the wafer slot number(170) comprises a first controller(172) and a second controller(176). The first controller is connected to a send indexer(110) to calculate slot number of a wafer cassette located in the send indexer using a pulse signal pattern from a horseshoe sensor(113) of the send indexer, and detect if a wafer is loaded in each slot or not. The second controller is connected to a receive indexer(160) capable of data communication with the first controller, controls a motor(112) which drives a cassette elevator(111) of the receive indexer according to the data transmitted from the first controller to load the wafer with the same number with the slot between the send indexer and the receive indexer. The first and second controllers respectively have communication modules(174,178) for data communication.

Description

Apparatus and method for maintaining wafer slot number and wafer indexer using the same}

1 is a layout view showing an embodiment of a semiconductor manufacturing apparatus according to the present invention.

2 is a block diagram showing a control relationship of the semiconductor manufacturing equipment according to the present invention.

3 is a block diagram illustrating a control relationship between an apparatus for maintaining a wafer slot number and an indexer connected thereto according to the present invention.

4 is a side view showing an embodiment of a sand indexer according to the present invention.

5 is a perspective view showing one embodiment of a receive indexer according to the present invention.

6A to 6C are timing diagrams for explaining a method of maintaining a wafer slot number according to the present invention.

** Description of the symbols for the main parts of the drawings **

110: sand indexer

120: wafer aligner

130, 150: load lock chamber

140: process chamber

160: receive indexer

170: device for holding a wafer slot number

TECHNICAL FIELD The present invention relates to an apparatus and method used for manufacturing a semiconductor device, and more particularly, to an apparatus and method for maintaining a wafer slot number and a wafer indexer used therein.

Generally, a semiconductor device is manufactured by repeating a process of laminating a thin film or the like having a predetermined circuit pattern on a wafer made of pure silicon or the like in multiple layers.

Therefore, when a wafer made of pure silicon or the like is provided, the prepared wafer is transferred to a semiconductor manufacturing facility that performs each unit process in a predetermined order by an operator or a predetermined transfer means. Accordingly, the semiconductor manufacturing equipment manufactures a semiconductor device on the wafer by performing a predetermined unit process on the transferred wafer.

On the other hand, the wafer transfer to each semiconductor manufacturing equipment as described above is performed in the unit of wafer cassette in which approximately 25 wafers are loaded.

Therefore, when a wafer cassette loaded with about 25 wafers is transferred to a semiconductor manufacturing facility by an operator or a predetermined transfer means, the semiconductor manufacturing facility sequentially withdraws the wafers loaded in the wafer cassette and then proceeds the process. After proceeding, the process is carried out by storing the wafer in the cassette from which the wafer is taken out or storing the wafer in an empty cassette provided separately.

For example, in the case of the rainbow facility used for etching an oxide film as one of the semiconductor manufacturing facilities, when the wafer cassette is transferred to a sand indexer serving as a loader by an operator or a predetermined transfer means, the wafer cassette of the sand indexer is The wafers loaded on the wafers are sequentially taken out and then processed. After the process, the empty cassettes are separately provided in the receive indexer serving as the unloader, and the wafers are repeatedly stored in the separately provided empty cassettes. The process proceeds by performing.

However, the conventional rainbow facility draws the wafer of the sand indexer in order of descending from the upper side to the lower side of the wafer cassette, and the receiving indexer accommodates the wafer in the order of rising from the lower side to the upper side of the wafer cassette. Therefore, if a conventional rainbow facility processes about 25 wafers, that is, one lot of wafers or the like, the wafers loaded in the wafer cassette of the sand wafer are reversed when they are loaded into the wafer cassette of the receive indexer. Problems with loading occur. Therefore, according to the conventional rainbow facility, the management of the wafer becomes very difficult, which causes various problems such as process defect or quality deterioration.

Accordingly, the present invention has been made in view of the above problems, and the technical problem to be achieved by the present invention is that the slot number of the wafer loaded in the wafer cassette is maintained as it is, even after the process is progressed, and the slot is reversed. The present invention provides an apparatus and method for maintaining a wafer slot number, which can be prevented in advance, and a wafer indexer used therein.

According to a first aspect of the present invention for realizing such a technical problem, an apparatus for maintaining a wafer slot number is provided. The apparatus is connected to a sand indexer, and a first controller for calculating the slot number of the wafer cassette located in the sand indexer from the horseshoe sensor of the sand indexer and detecting the presence / absence of wafers for each slot, and connected to the receive indexer. In addition, the first controller is installed to enable data communication and controls a motor for driving the cassette elevator of the receive indexer according to the data transmitted from the first controller, so that the sand indexer and the receive indexer have the same number. And a second controller for loading the same wafer into the slot.

In another embodiment, the first controller and the second controller may be provided with a communication module to enable data communication between each other.

In another embodiment, the first controller calculates the slot number of the wafer cassette located in the sand indexer using the pattern of the pulse signal generated from the horseshoe sensor and detects the presence / absence of wafers for each slot. can do.

According to a second aspect of the present invention for implementing the above technical problem, a method for maintaining a wafer slot number is provided. The method comprises calculating and detecting the slot number of the wafer cassette located in the sand indexer and the presence / absence of wafers of each slot from the horseshoe sensor of the sand indexer using a first controller connected to the sand indexer, and connected to the receive indexer. In addition, the receive according to the data transmitted from the first controller so that the same wafer is loaded in the slot of the same number between the sand indexer and the receive indexer by using a second controller installed to enable data communication with the first controller. Controlling a motor that drives the cassette elevator of the indexer.

In another embodiment, the first controller and the second controller may communicate data with each other using a communication module provided.

In another embodiment, the first controller calculates the slot number of the wafer cassette located in the sand indexer using the pattern of the pulse signal generated from the horseshoe sensor and detects the presence / absence of wafers for each slot. can do.

On the other hand, according to the third aspect of the present invention for implementing the above technical problem, a wafer indexer is provided. The wafer indexer is installed on one side of the frame, a hollow case having an upper surface thereof opened, a frame disposed inside the case and in contact with the bottom and one side of the case, and on which the wafer cassette is seated. A cassette elevator for elevating the wafer cassette up and down a predetermined distance so that the wafer cassette enters the inside and the outside of the case; a motor connected to the cassette elevator and generating a rotational force to lift the cassette elevator; and the inside of the case. A wafer mapping sensor which is installed to face each other and scans whether a wafer is loaded in each slot of the wafer cassette, and an opposite surface of the inner surface of the case in the direction in which the wafer is withdrawn from the wafer cassette; Is installed on the wafer casein A wafer detachment detection sensor for detecting a wafer detached from the wafer cassette among wafers loaded on the wafer; and a wafer installed on an opposite surface of the case in which the wafer is stored in the wafer cassette among the inner surfaces of the case; And a wafer detector that detects whether the wafers are correctly loaded in the wafer cassette.

In another embodiment, the wafer mapping sensor, the wafer departure detection sensor, and the wafer detect sensor may both be optical sensors including a light receiving unit and a light emitting unit.

In another embodiment, the cassette elevator is installed in the frame in the vertical direction long and the ball screw shaft rotated in the forward or reverse direction in accordance with the rotation direction of the motor and the ball screw shaft to move up and down a predetermined distance in accordance with the rotation of the ball screw shaft It may include a cassette support coupled to the ball screw shaft and the wafer cassette is seated.

In another embodiment, the motor may be a step motor.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed subject matter is thorough and complete, and that the spirit of the invention will be fully conveyed to those skilled in the art. Like numbers refer to like elements throughout.

1 is a layout view showing an embodiment of a semiconductor manufacturing facility according to the present invention, Figure 2 is a block diagram showing a control relationship of the semiconductor manufacturing facility according to the present invention.

1 and 2, a semiconductor manufacturing apparatus 100 according to an embodiment of the present invention may include a process chamber 140 in which a process such as an oxide film etch is directly performed, and a wafer (or wafer) into the process chamber 140. The sand indexer 110 for supplying the 80, the wafer aligner 120 for pre-aligning the wafer 80 supplied to the process chamber 140, and the aligned wafer 80 include the process chamber ( The first load lock chamber 130, which is intermediately passed before being supplied to the 140, a receive indexer 160 for accommodating the wafer 80 processed in the process chamber 140, and the process chamber 140. In the process, the wafer 90 is processed between the second load lock chamber 150 before being transferred to the receiving indexer 160, and the wafer (between the sand indexer 110 and the receiving indexer 160). Wafer slot to prevent slot change of 80) And a device 170 and a central control device for the overall control of the semiconductor manufacturing facility 100, 180 to maintain the arc.

Specifically, the process chamber 140 is disposed between the first load lock chamber 130 and the second load lock chamber 150, and processes the wafers 80 one by one. In this case, the internal pressure of the process chamber 140 may be maintained at a low or very low pressure to process the wafer 80 as described above, and the internal temperature may also be maintained at a high temperature.

The sand indexer 110 serves as a loader. That is, the sand indexer 110 is loaded with a wafer 80 to be processed such as an etching process, and the sand indexer 110 may be supplied to the process chamber 140 so that the loaded wafer 80 may be well supplied. It plays a role. On the other hand, the sand indexer 110 is not loaded in the unit of a single wafer 80, but instead of about 25 sheets of wafer 80 in a wafer cassette unit. Therefore, the sand indexer 110 lifts the wafer cassette 90 so that about 25 wafers 80 loaded on the wafer cassette 90 can be sequentially supplied to the process chamber 140. Do it. A detailed configuration of the sand indexer 110 will be described later.

The wafer aligner 120 is disposed between the sand indexer 110 and the process chamber 140 to pre-align the wafer 80 supplied to the process chamber 140, and a wafer 90 therein. There is provided a robot arm 125 for transferring. Therefore, the robot arm 125 takes out the wafers 80 one by one from the sand indexer 110 and aligns them. After the alignment, the robot arms 125 transfer the aligned wafers 80 toward the process chamber 140. .

The first load lock chamber 130 is disposed between the wafer aligner 120 and the process chamber 140 such that the aligned wafer 80 is intermediately passed before being supplied to the process chamber 140. . The robot arm 136 is provided inside the first load lock chamber 130. Thus, the robot arm 136 receives the aligned wafer 80 from the wafer aligner 120 and transfers it to the process chamber 140.

The receive indexer 160 serves as an unloader. That is, the receive indexer 160 is provided with a wafer cassette 90 which is empty inside to accommodate the wafer 80 processed by etching, and the receive indexer 160 is such an empty wafer cassette 90. ) Serves to elevate the wafer cassette 90 so that about 25 wafers 80 may be sequentially stored and loaded. A detailed configuration of the receive indexer 160 will also be described later.

The second load lock chamber 150 is disposed between the process chamber 140 and the receive indexer 160 such that the wafer 80 subjected to the process is intermediately passed before being transferred to the receive indexer 160. . The robot arm 154 is provided inside the second load lock chamber 150. Therefore, the robot arm 154 receives the wafer 80 processed in the process chamber 140 and transfers it to the receive indexer 160.

The apparatus 170 for maintaining the wafer slot number may include the sand indexer 110 and the receive indexer such that the slot change of the wafer 80 does not occur between the sand indexer 110 and the receive indexer 160. 160, respectively, and transmits a predetermined control signal to the receive indexer 160. A detailed configuration of the apparatus 170 for holding the wafer slot number will be described later.

The central controller 180 controls the semiconductor manufacturing equipment 100 according to the present invention from the sand indexer 110 to the receive indexer 160 so that a process such as etching proceeds well.

3 is a block diagram illustrating a control relationship between an apparatus for maintaining a wafer slot number and an indexer connected thereto according to the present invention, and FIG. 4 is a side view illustrating an embodiment of a sand indexer according to the present invention. 5 is a perspective view showing an embodiment of a receive indexer (receive indexer) according to the present invention.

Therefore, hereinafter, the apparatus for maintaining the wafer slot number and the indexers connected thereto will be described in more detail with reference to FIGS. 3 to 5.

First, the sand indexer 110 will be described. The sand indexer 110 may include a hollow case 114 having an upper surface thereof opened and formed in a rectangular box shape, disposed inside the case 114, and the case ( The frame 117 formed to contact the bottom and one side of the 114 and the wafer cassette 90 are installed on one side of the frame 117 so that the wafer cassette 90 is seated, and the wafer cassette 90 to be seated is lifted by a predetermined distance up and down. A cassette elevator 111 to allow the wafer cassette 90 to enter and exit the case 114, and a motor connected to the cassette elevator 111 to generate a rotational force so that the cassette elevator 111 is elevated; And a top limit sensor 116a and a bottom limit sensor 116b to limit the entire lifting section of the cassette elevator 111 and to control driving of the sand indexer 110. 116, a support 119 fixed in a vertical direction to the bottom surface of the frame 117 to support the circuit board 116, and an upper surface of the support 119 and provided on the upper surface of the support 119. A wafer detection sensor 119a for detecting the wafer 80 lowered adjacent to the upper surface of the cassette elevator 111 and detecting whether the wafer cassette 90 is seated on the upper surface of the cassette elevator 111. It includes a cassette detecting sensor 111d.

At this time, the cassette elevator 111 is installed in the frame 117 long in the vertical direction and is rotated in the forward or reverse direction according to the rotation direction of the motor 112 and the ball screw shaft (111a), the ball screw shaft ( Shanghai support body (111b) coupled to the ball screw shaft (111a) to move up and down a predetermined distance in accordance with the rotation of the 111a, and cassette supporter coupled to the upper surface of the Shanghai body (111b) so that the wafer cassette 90 is seated ( 111c). In this case, the sand indexer 110 is provided with a plurality of gears therein to appropriately adjust the rotational speed of the motor 112 and the like, between the motor 112 and the ball screw shaft 111a. Gear box 118 is installed and is connected to one end of the ball screw shaft (111a) or one end of the gear box 118 in order to detect the rotation of the ball screw shaft (111a) and rotating projection 115a on one surface thereof. ) And a horseshoe sensor 113 for sensing the rotation of the ball screw shaft 111a by detecting the gears 115 and the rotary protrusion 115a.

Accordingly, when the wafer cassette 90 on which the wafers 80 are loaded is seated on the cassette elevator 111, the cassette detection sensor 111d detects this and transmits the detected value to the central controller 180. Will be sent. Accordingly, the central controller 180 transmits a driving signal to the motor 112, and the motor 112 rotates in one direction according to the transmitted signal, so that the wafer cassette 90 is lowered. The elevator 111 starts to descend. Thereafter, the wafer sensor 119a detects the wafer 80 from the descending wafer cassette 90 and transmits the detected value to the central controller 180. Accordingly, the central control unit 180 transmits a predetermined control signal to the motor 112, and the motor 112 stops rotation in any one direction according to the control signal and again is the opposite direction of the one direction. It is rotated only by a predetermined angle in the other direction. Accordingly, the wafer 80 of the detected wafer cassette 90 is stopped for a while at the detected position and then raised again by a predetermined height, and the sand indexer 110 moves the wafer 80 to the central controller 180. ) Will send a signal indicating that the preparation for supply is complete.

The receiver indexer 160 has a hollow case 164 having an upper surface thereof opened and formed in a rectangular box shape, disposed inside the case 164, and in contact with a bottom surface and one side of the case 164. The frame 167 and the wafer cassette 90 are installed on one side of the frame 167 so that the wafer cassette 90 can be seated thereon. Cassette elevator 161 for entering and exiting the inside and outside of the 164, a motor 162 connected to the cassette elevator 161 and generating a rotational force to raise and lower the cassette elevator 161, and the case 164 A wafer mapping sensor 164b which is installed to face each other at both sides of the inside of the wafer cassette 90 and scans whether the wafer 80 is loaded in each slot of the wafer cassette 90 and the inner surfaces of the case 164. Wafers which are installed on opposite sides of the wafer cassette 90 from the wafer cassette 90 and are separated from the wafer cassette 90 among the wafers 80 loaded on the wafer cassette 90 ( A wafer detachment detection sensor 164a for detecting 80 and an opposite surface in a direction in which the wafer 80 is accommodated in the wafer cassette 90 among the inner surfaces of the case 164. It includes a wafer detector sensor 164c that detects whether the field 80 is correctly loaded in the wafer cassette 90.

At this time, the cassette elevator 161 is installed in the frame 167 long in the vertical direction and is rotated in the forward or reverse direction according to the rotation direction of the motor 162 and the ball screw shaft (161b) and the ball screw shaft ( The frame support (161a) coupled to the ball screw shaft (161b) so as to move up and down a predetermined distance according to the rotation of the 161b and the wafer cassette 90 is seated, and the lifting and lowering of the cassette support (161a). It may be composed of the LM guide 161c installed in the vertical direction in the 167. The wafer mapping sensor 164b, the wafer departure detection sensor 164a, and the wafer detector sensor 164c may both be optical sensors having a light receiving unit and a light emitting unit. In this case, the wafer departure detection sensor 164a is preferably installed such that the light receiving unit and the light emitting unit are immediately adjacent to each other, and the wafer detector sensor 164c has an arc shape formed so that one side edge of the wafer 80 is sandwiched therebetween. The sensor support bar 164d is preferably installed on one surface of the case 164. In this case, the light receiving portion and the light emitting portion of the wafer detector sensor 164 is preferably installed at both ends of the sensor support bar (164d) to face each other. In addition, the motor 162 is preferably implemented as a step motor. In addition, when the cassette elevator 161 is configured as described above, the receive indexer 160 is provided with a plurality of gears therein to appropriately adjust the rotation speed of the motor 162 and the like (the motor ( It may further include a gear box 165 installed between the 162 and the ball screw shaft (161b). Reference numeral 163 denotes a display unit for displaying the current state of the receive indexer 160 to the outside.

On the other hand, the device for maintaining the wafer slot number 170 is connected to the sand indexer 110 and from the horseshoe sensor 113 of the sand indexer 110 of the wafer cassette 90 located in the sand indexer 110 The first controller 172 which calculates a slot number and detects the presence / absence of wafers for each slot, and is connected to the receive indexer 160 and installed to enable data communication with the first controller 172. Control the motor 162 for driving the cassette elevator 161 of the receive indexer 160 in accordance with the data transmitted from the first controller 172 between the sand indexer 110 and the receive indexer 160. It includes a second controller 176 to load the same wafer 80 in the slot of the same number. In this case, the first controller 172 and the second controller 176 may be provided with a communication module (174, 178) to enable data communication between each other. Thus, the first controller 172 and the second controller 176 are communicated with each other through these communication modules (174, 178). On the other hand, the first controller 172 calculates the slot number of the wafer cassette 90 located in the sand indexer 110 using the pattern of the pulse signal generated from the horseshoe sensor 113 and each slot The presence / absence of each wafer is detected.

Hereinafter, a method of maintaining a wafer slot number according to the present invention will be described in detail with reference to FIGS. 6A to 6C.

6A to 6C are timing diagrams for explaining a method of maintaining a wafer slot number according to the present invention.

First, referring to FIG. 6A, FIG. 6A illustrates pulse signal patterns for loading a wafer cassette 90 loaded with a wafer into a sand indexer 110, and then sensing the wafer 80 from the loaded wafer cassette 90. One of them is a pulse signal pattern showing a case where the first wafer is loaded in the first slot.

That is, when the wafer cassette 90 in which the first wafer is loaded in the slot 1 is seated on the cassette elevator 111 of the sand indexer 110, the cassette detection sensor 111d detects this, and the motor 112 In accordance with this detected value, the cassette elevator 111 is started to descend so that the wafer cassette 90 is lowered by rotating in one direction. At this time, the horseshoe sensor 113 is in a low state.

Thereafter, when the wafer cassette 90 is continuously lowered by the cassette elevator 111, the wafer detection sensor 119a detects the wafer 80 in the wafer cassette 90 which is lowered, and the detected value is centered. The control unit 180 is to be transmitted. At this time, when the wafer detection sensor 119a detects the wafer 80, the horseshoe sensor 113 also detects the rotation protrusion 115a that can detect the rotation of the ball screw shaft 111a. The horseshoe sensor 113 also transmits the detection value of the rotary protrusion 115a to the central controller 180.

Accordingly, the central controller 180 recognizes where the detected wafer 80 is located according to the detected values, and transmits a predetermined signal to the motor 112 to transfer the predetermined signal to the motor 112. Stop the rotation Thus, the motor 112 is stopped and the wafer 80 is located (stopped) at a position slightly lower than its sensed position. At this time, the position of the sensed wafer 80, that is, the height of the sensed wafer 80, is introduced into the wafer cassette 90 by the robot arm 125 of the wafer aligner 120 to pull out the wafer 80. The central controller 180 is at a position that is about one pitch higher than the detected position to allow the robot arm 125 of the wafer aligner 120 to withdraw the detected wafer 80. Will be moved to the location. Here, since the pitch 1 rise and the pitch 1 fall of the wafer 80 is equal to one rotation of the rotation protrusion 115a sensed by the horseshoe sensor 113, the central controller 180 is predetermined to the motor 112. By transmitting a signal, the rotary protrusion 115a is reversely rotated by one revolution to a position immediately before being detected by the horseshoe sensor 113.

On the other hand, the detected wafer 80 is moved upward from the detected position by the reverse rotation of the motor 112, the wafer 80 loaded on the wafer cassette 90 is a wafer cassette 90 Since the wafer is loaded in the slot 1 located at the lowermost side of the upper side), the above upward movement is forcibly interrupted in the middle by the top limit sensor 116a which defines the moving section of the cassette elevator 111. . As a result, the wafer 80 that has been raised is stopped at a position that is slightly lower than the position to be raised without being raised by one pitch from the detected position. Accordingly, the horseshoe sensor 113 and the wafer detection sensor 119a are both turned off, and the pulse signal detected by the horseshoe sensor 113 when detecting the case where the first wafer is loaded in the first slot as described above. The pattern of is as shown in Figure 6a. Therefore, the first controller 172 connected to the horseshoe sensor 113 presets the pattern of the pulse signal as described above and compares the set pattern with subsequent patterns, so that the first controller 172 is connected to the first slot of the wafer cassette 90. The case where the first wafer is loaded is recognized. Accordingly, the second controller 176 is configured such that the wafer 80 of the slot 1 loaded on the wafer cassette 90 of the sand indexer 110 is positioned at the receiver indexer 160. The motor 162 driving the cassette elevator 161 of the receive indexer 160 is controlled to be stored and stored in the second slot. Therefore, the wafer 80 of the slot 1 loaded on the wafer cassette 90 of the sand indexer 110 is stored and loaded into the slot 1 of the wafer cassette 90 located on the receive indexer 160.

Referring to FIG. 6B, FIG. 6B shows a pulse signal pattern for detecting the wafer 80 from the loaded wafer cassette 90 after loading the wafer cassette 90 with the wafer 80 loaded on the sand indexer 110. One of them is a pulse signal pattern showing a case where the first wafer is loaded in the second slot. The pulse signal pattern described above differs only in the number of triggers from the high value to the low value, but the first wafer is loaded in slot 2 and the first wafer is loaded in slot 26. The first controller 172 connected to the sensor 113 counts the number of times triggered from the high value to the low value to recognize how many slots the first wafer is loaded.

In detail, when the wafer cassette 90 in which the first wafer is loaded in the slot 2 of the cassette elevator 111 of the sand indexer 110 is seated, the cassette detection sensor 111d detects this, and the motor 112 starts lowering the cassette elevator 111 so that the wafer cassette 90 is lowered by rotating in one direction according to this detected value. At this time, the horseshoe sensor 113 is in a low state.

Next, when the wafer cassette 90 continues to be lowered by the cassette elevator 111, the wafer sensor 119a detects the wafer 80 in the wafer cassette 90 which is lowered, and the detected value is centered. The control unit 180 is to be transmitted. At this time, when the wafer detection sensor 119a detects the wafer 80, the horseshoe sensor 113 also detects the rotation protrusion 115a that can detect the rotation of the ball screw shaft 111a. The horseshoe sensor 113 also transmits the detection value of the rotary protrusion 115a to the central controller 180.

Accordingly, the central controller 180 recognizes where the detected wafer 80 is located according to the detected values, and transmits a predetermined signal to the motor 112 to rotate the motor 112. To stop. Thus, the motor 112 is stopped and the wafer 80 is located at a position slightly lower than its sensed position. At this time, the position of the sensed wafer 80, that is, the height of the sensed wafer 80, is introduced into the wafer cassette 90 by the robot arm 125 of the wafer aligner 120 to pull out the wafer 80. The central controller 180 is at a position that is about one pitch higher than the detected position to allow the robot arm 125 of the wafer aligner 120 to withdraw the detected wafer 80. Will be moved to the location. Here, since the pitch of the wafer 80 is equal to one rotation of the rotation protrusion 115a sensed by the horseshoe sensor 113, the central controller 180 transmits a predetermined signal to the motor 112. The rotary protrusion 115a is reversely rotated by one rotation to a position immediately before being detected by the horseshoe sensor 113.

Therefore, the rotation protrusion 115a is reversely rotated by one rotation to a position immediately before being detected by the horseshoe sensor 113 by the reverse rotation of the motor 112, and stopped in the reversely rotated state. Thus, the wafer detection sensor 119a is turned off, the horseshoe sensor 113 is turned on, and the horseshoe sensor 113 when detecting the case where the first wafer is loaded in slot 2 as described above. The pattern of the pulse signal detected at is shown in Figure 6b. Therefore, the first controller 172 connected to the horseshoe sensor 113 presets the pattern of the pulse signal as described above and compares the set pattern with the subsequent patterns, so that the slot 2 of the wafer cassette 90 is inserted into the horseshoe sensor 113. The case where the first wafer is loaded is recognized. Accordingly, the second controller 176 has two slots of the wafer cassette 90 in which the wafer 80 of the second slot loaded on the wafer cassette 90 of the sand indexer 110 is located in the receive indexer 160. The motor 162 driving the cassette elevator 161 of the receive indexer 160 is controlled to be stored and stored in the second slot. Thus, the wafer 80 of the second slot loaded on the wafer cassette 90 of the sand indexer 110 is stored and loaded into the second slot of the wafer cassette 90 located on the receive indexer 160.

Referring to FIG. 6C, FIG. 6C is a timing diagram illustrating a method of determining whether a wafer is present in each slot. If slot number of the previous wafer is 2, slots 3, 4, and 5 are empty. A pulse signal pattern showing that the wafer of slot 6 is loaded onto the robot arm of the wafer aligner 120.

Specifically, when the previous supply wafer, for example, the wafer 80 of the slot 2 is supplied to the robot arm 125 of the wafer aligner 120, the sand indexer 110 is removed from the central controller 180. The device waits until it receives a signal to supply the wafer 80 again.

Subsequently, if another wafer 80 is required to be supplied to the robot arm 125 of the wafer aligner 120, the central controller 180 may send the robot arm 125 and the sand indexer of the wafer aligner 120 to each other. The wafer supply signal is transmitted to the motor 112 of the 110.

Accordingly, the motor 112 of the sand indexer 110 starts to lower the cassette elevator 111 so that the wafer cassette 80 is lowered by rotating in one direction according to the transmitted signal. At this time, the horseshoe sensor 113 detects the rotary protrusion 115a until the wafer 80 is detected in the wafer cassette 90 in which the wafer detection sensor 119a is lowered, and then turns on again after the rotary protrusion 115a passes. It keeps counting the number of times it goes off, that is, the number of triggers from high to low. In the case of FIG. 6C, the number of triggers is 4 times, and since the wafer 80 of the slot 2 is already supplied to the robot arm 125 of the wafer aligner 120 in the previous step, the slot number by this counting Is 3, 4, 5 and 6.

Next, after the horseshoe sensor 113 is triggered for the fourth time, the wafer sensor 119a detects the wafer 80 from the lowered wafer cassette 90. Accordingly, the wafer detection sensor 119a transmits the detected value to the central controller 180, and the central controller 180 transmits a predetermined signal to the motor 112 according to the detected value. Stop the rotation of 112. Accordingly, the motor 112 is stopped, and the wafer 80 is located at a position slightly lower than the detected position, and the pulse signal pattern detected by the horseshoe sensor 113 until this time is as shown in FIG. 6C. Therefore, the first controller 172 connected to the horseshoe sensor 113 presets the pattern of the pulse signal as described above, and compares the set pattern with the subsequent patterns, so that the wafer cassette 90 of the sand indexer 110 is formed. ), Slots 3, 4, and 5 are empty, and the wafer is loaded in slot 6. Accordingly, the second controller 176 is configured such that the wafer 80 of the sixth slot loaded on the wafer cassette 90 of the sand indexer 110 is positioned at the receiver indexer 160. The motor 162 driving the cassette elevator 161 of the receive indexer 160 is controlled to be stored and stored in the second slot. Accordingly, the wafer 80 of the sixth slot loaded on the wafer cassette 90 of the sand indexer 110 is stored and loaded into the sixth slot of the wafer cassette 90 located on the receive indexer 160.

As mentioned above, although the present invention has been described with reference to the illustrated embodiments, it is only an example, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the scope of the present invention should be defined by the appended claims and their equivalents.

As described above, the present invention calculates the slot number of the wafer cassette located in the sand indexer using a horseshoe sensor for detecting rotation of the ball screw shaft and a first controller connected to the horseshoe sensor, Since it detects nothing, the current wafer being processed or the wafer being processed has the advantage of knowing exactly how many slots the wafer is.

Further, since the present invention controls the motor for driving the cassette elevator of the receiving indexer using the data relating to the slot number as described above, according to the present invention, the same wafer is provided in the slot of the same number between the sand indexer and the receiving indexer. Can be loaded. As a result, according to the present invention, it is very easy to manage the wafer, and there is an effect of preventing various problems such as process defects and quality deterioration due to this wafer management error.

Claims (10)

A first controller connected to a sand indexer and calculating a slot number of a wafer cassette located in the sand indexer from a horseshoe sensor of the sand indexer and detecting the presence / absence of wafers in each slot; It is connected to a receive indexer and is capable of data communication with the first controller, and controls a motor for driving a cassette elevator of the receive indexer according to the data transmitted from the first controller to control the sand indexer and the receive indexer. And a second controller for loading the same wafer into slots of the same number therebetween. The method of claim 1, The first controller and the second controller is a device for maintaining a wafer slot number, characterized in that each communication module is provided to enable data communication between each other. The method of claim 1, The first controller calculates the slot number of the wafer cassette located in the sand indexer using the pattern of the pulse signal generated from the horseshoe sensor and detects the presence / absence of wafers for each slot. The device that keeps the number. Calculating and detecting the slot number of the wafer cassette located in the sand indexer and the presence / absence of wafer for each slot from the horseshoe sensor of the sand indexer using a first controller connected to the sand indexer; A second controller connected to a receive indexer and capable of data communication with the first controller is transmitted from the first controller so that the same wafer is loaded in the slot of the same number between the sand indexer and the receive indexer. And controlling a motor for driving a cassette elevator of the receive indexer according to the data. The method of claim 4, wherein And the first controller and the second controller communicate data with each other using a communication module provided. The method of claim 4, wherein The first controller calculates the slot number of the wafer cassette located in the sand indexer using the pattern of the pulse signal generated from the horseshoe sensor and detects the presence / absence of wafers for each slot. How to keep the number. A hollow case whose top surface is opened; A frame disposed inside the case and formed to be in contact with the bottom and one side of the case; A cassette elevator installed at one side of the frame such that a wafer cassette is seated, and moving the seated wafer cassette up and down a predetermined distance to allow the wafer cassette to enter and exit the case; A motor connected to the cassette elevator and generating a rotational force to raise and lower the cassette elevator; A wafer mapping sensor installed on both sides of the case to face each other and scanning whether a wafer is loaded in each slot of the wafer cassette; A wafer departure detection sensor installed on an opposite surface of the inner surface of the case in a direction in which the wafer is withdrawn from the wafer cassette and detecting a wafer separated from the wafer cassette among wafers loaded on the wafer cassette; And, And a wafer detector installed on an opposite side of the inner surface of the case in a direction in which the wafer is stored in the wafer cassette and detecting whether the wafers to be stored are correctly loaded in the wafer cassette. The method of claim 7, wherein And the wafer mapping sensor, the wafer departure detection sensor, and the wafer detector sensor are all optical sensors including a light receiving unit and a light emitting unit. The method of claim 7, wherein The cassette elevator is installed in the frame in the vertical direction long and coupled to the ball screw shaft to be rotated in the forward or reverse direction according to the rotation direction of the motor, and the ball screw shaft to be elevated by a predetermined distance in accordance with the rotation of the ball screw shaft and A wafer indexer comprising a cassette support on which a wafer cassette is seated. The method of claim 7, wherein And the motor is a step motor.

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