JPS62273748A - Automatic mask changer - Google Patents

Abstract

PURPOSE:To improve throughput and avoid input mistakes and obtain an automatic mask changer with high reliability by a method wherein a medium in which mask identification information is recorded is attached to a mask cassette and an information reading means which reads the identification information automatically when the mask cassette is inserted into a cassette carrier is provided. CONSTITUTION:A controller of an automatic mask changer judges whether a slot contains a mask cassette 2 or not by a signal from a switch 12 and drives the bar-code reader 11 of the slot which contains the mask casette 2 to read mask identification information on a bar-code card and inputs the information to a memory circuit of the controller. When a new mask cassette 2 is inserted into a cassette carrier 1 while the changer is being operated, the insertion operation of the mask cassette 2 is detected by signals from 1st and 2nd photosensors 9 and 10 and further the completion of the insertion is confirmed by the signal from the switch 12. After that, the bar-code reader 11 is driven and the identification information of the newly contained mask cassette 2 is read.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of the Invention] The present invention relates to an automatic mask exchange device for automatically exchanging a mask or a reticle and attaching it to a mask aligner in a semiconductor exposure apparatus.

Note that in this specification, the explanation using a mask as an example can be similarly applied to a reticle, and the term "mask" includes a "reticle."

[Background of the Invention] In the semiconductor photolithography process, in order to form a pattern on each chip of a wafer, a mask with an actual size pattern is brought into close contact with the surface of the sea urchin and exposed and baked, or a mask with a pattern of several times to 10 times the actual size is used. A reticle on which a pattern for one chip is formed is reduced through optical means and projected onto a wafer to print the pattern. To complete one semiconductor device, this pattern baking process is usually performed several to several 10 times on one wafer. Specifically, first, a reticle for a certain mask process is set in the exposure apparatus main body, and the pattern baking process is performed on a predetermined number of wafers (for example, 100 wafers). After the baking process has been completed, the reticle is processed as necessary by etching, impurity diffusion, formation of conductor layers, insulating layers, semiconductor layers, and even photoresist coating.Then, the reticle is used for the next mask process. The reticle pattern printing process is performed on all of these wafers. Thereafter, the baking process is repeated in the same manner to obtain a wafer with the desired pattern.

In this case, the pattern or mask (or reticle) used in each printing process is usually different. Therefore, it is necessary to set separate masks in the exposure apparatus main body (mask aligner) for each stage of exposure. An automatic mask exchange device is used to perform such mask exchange. Each mask is housed one by one in a mask cassette, and a plurality of mask cassettes are housed in each slot of the cassette carrier. The drive control circuit of the automatic mask exchange device has a memory circuit into which information regarding the masks in the mask cassettes stored in each slot of the cassette carrier, such as mask product number, pattern identification information, etc. Accordingly, the mask cassette to be used is selected based on the information in this memory circuit, and the drive is controlled so that it is automatically taken out from the cassette carrier and transported to the mask aligner.

[Prior Art] In a conventional automatic mask exchange device, information regarding the mask is manually input by an operator via a man-machine interface by operating a keyboard on a console. Therefore, each time a mask cassette is attached to a cassette carrier, it is necessary to input mask identification information, which requires time and effort to replace the cassette, reduces throughput, and prevents full automation of the exposure process. There was a problem with the occurrence.

[Object of the Invention] The present invention has been made in view of the drawbacks of the prior art, and aims to reduce operator operations and improve throughput by automatically inputting mask identification information associated with mask cassette exchange, and to reduce input errors. The purpose of the present invention is to provide a highly reliable automatic mask exchange device that prevents this.

[Example] FIG. 1 is a perspective view of an automatic mask exchange device according to the present invention. A plurality of mask cassettes 2 are housed in a cassette carrier 1. 3 is a fork unit for taking out a mask from a selected mask cassette 2; 4 is an elevator unit for moving the fork unit 3 up and down; 5 is a photo switch that detects the vertical position of the elevator unit 4; 6 is an elevator unit 4 7 is a hand unit that delivers the mask to the loading station of the mask aligner. The mask cassette 2 is inserted and stored in each slot 31 of the cassette carrier 1 as shown by arrow A, as shown in FIG. On the side of this mask cassette 2, there is a third
As shown in the figure, a barcode card 8 is attached so as to protrude.

On the barcode card 8, mask identification information such as the name, product number, pattern type, etc. of the mask (not shown) housed in the mask cassette 2 is encoded and recorded in barcode format. The information on this barcode card 8 is read by a barcode reader 11 provided inside the cassette carrier 1 and movable as indicated by arrow B (FIG. 4). As shown in FIG. 5, a first photo sensor 9, a second photo sensor IO, and the barcode reader 11 are provided on the side surface of each slot in the cassette carrier 1 in order in the insertion direction of the mask cassette 2 (six arrow directions). It will be done. Also, at the end position in the insertion direction, a stopper 13 for stopping the insertion of the mask cassette 2 is provided. ．． 14 and a switch 12 for detecting that the mask cassette 2 has come into contact with the stopper 13, 14 and the insertion operation has been completed. Rows of each sensor and switch, (b) is the arrangement seen from the front. 1st. Second photosensor9. IO is a photocoupler consisting of a light emitting element and a phototransistor, and is activated by the passage of the barcode card 8 of the mask cassette 2. The switch 12 is a mechanical contact switch that operates when the mask cassette 2 comes into contact with it and presses it. Each photosensor9. IO and switch 12 are connected to a control circuit (not shown) and control the barcode reading operation based on each detection signal.

Next, mask identification information (
The barcode) reading operation will be explained. When using a semiconductor exposure device and an automatic mask exchange device, it is necessary to initialize each device and input identification information for each mask to be used. In this case, the control circuit of the automatic mask exchange device determines whether a mask cassette is stored in each slot of the cassette carrier based on the signal from the switch 12, and drives the barcode reader 11 of the slot in which the mask cassette is stored. The mask identification information is read from the barcode card attached to the mask cassette and input into the storage circuit in the control circuit.

When a new mask cassette is inserted into the cassette carrier while the device is in operation, the first mask cassette is inserted into the cassette carrier. 2nd photosensor 9.10
The insertion operation of the mask cassette is detected by a signal from the switch 12, and completion of insertion is confirmed by a signal from the switch 12. Thereafter, the barcode reader 11 is driven to read the identification information of the newly stored mask cassette. In order to detect the insertion operation of the mask cassette, for example, it is possible to detect that the signal of the first photo sensor 9 is output before the signal of the second photo sensor 10, and to identify that the mask cassette is moving in the insertion direction. The detection circuit may be configured as follows.

1st. FIG. 7 shows an example of an interface circuit for inputting the detection signals of the second photosensor 9, 10 and the switch 12 to the control circuit. 1st. Second photosensor 9
．． lO is a light emitting diode 9a, t.

a and phototransistors 9b and 10b,
Each sensor9. lO is the first. Second. 3rd NAND
Connected to circuit 15.18.22. 1st. 2nd, 3rd
NAND circuits 15, 18, and 22 are differentiating circuits 16 and 1, respectively.
9.20 to the set and reset sides of flip-flop 17 and to the reset side of flip-flop 21. Each flip-flop 17, 21 is connected to a control circuit (
CPU) 24. A switch 12 for detecting completion of cassette insertion is connected to the set side of the flip-flop 21. The control 24 further includes a barcode reader control section 30 for driving and controlling the barcode reader 11.
are concatenated. 29 is a barcode reader driving motor. The barcode reader 11 is connected to the barcode detection control circuit 2 via a signal conversion circuit 25 consisting of a serial/parallel conversion circuit, etc.
6. Barcode detection control circuit 26 is connected to motor 29 via buffer circuit 27 .

The operation of the circuit with the above configuration will be explained. When inserting the cassette, the mask cassette is the first. In the middle of insertion before reaching the position of the second photo sensor and reaching the end stopper 13.14, the first. Second photosensor9. IO is covered with the barcode card 8 and the switch 12 is not operating, so the first NAND circuit 15 is connected to the first NAND circuit 15. The second photosensors 9 and 10 both input "H" level signals, and the flip-flop 21 outputs "L" level signals, which are sent to the first NAND circuit 15 at "H" level via an inverter.
is input. Therefore, all the input side signals are at the "°H" level, and the first NAND circuit 15 operates. 1st
The output of the NAND circuit 15 is shaped into a waveform by a differentiating circuit 16, and a flip-flop 17 is set. As a result, the flip-flop 17 issues a cassette insertion signal a. This cassette insertion signal a is input to the control circuit 24 via the interface 23, and the insertion operation of the cassette is detected. When the cassette comes into contact with the stoppers 13 and 14 at the end of the slot and the insertion operation is completed, the cassette causes the switch 12 to
is pressed to operate. Therefore, the flip-flop 21 is set and outputs an "H" level output. This "H" level output is input to the control circuit 24 via the interface 23 as an insertion completion signal, and the completion of the cassette insertion operation is detected. This insertion completion signal is further input to the second NAND circuit 18 and resets the flip-flop 17. When the mask cassette is pulled out and the barcode card 8 is separated from the second photo sensor 10 and covers only the first photo sensor 9, all input terminals of the third NAND circuit 22 become H'' level and the flip-flop 21 is reset. When the insertion completion signal is sent to the control circuit 24 and it is confirmed that the mask cassette has been stored in the slot of the cassette carrier, the barcode reader drive motor 29 is actuated via the barcode detection control circuit 26 and the barcode reader drive motor 29 is activated. Start reading the code.The read signal sent serially from the barcode is converted into parallel signals by the register of the signal conversion circuit 25, and then converted into parallel signals by the barcode detection control circuit 26.
The mask identification information is sent to the control circuit 24 via the mask identification information and registered in the storage circuit.

In the above embodiment, the mask identification information was recorded on the recording medium (barcode card) using a barcode, but the identification information may be recorded on a magnetic tape or the like using a magnetic recording means. In this case, a reading magnetic head is used instead of the barcode reader to perform the information reading operation.

Further, the mounting position of the recording medium is not limited to the side surface of the mask cassette, but may be mounted at an appropriate position such as the back surface, top surface, bottom surface, etc., and a reading means may be provided correspondingly. Further, the cassette insertion detection means and the insertion completion detection means are the photosensor 9 of the above-mentioned embodiment. In addition to IO and switch 12, other optical sensors, magnetic sensors, mechanical switches, etc. may be used.

[Effects of the Invention] As explained above, in the automatic mask exchange device according to the present invention, when a medium recording mask identification information is attached to a mask cassette, the mask cassette is automatically identified when inserted into the cassette carrier. It is equipped with an information reading means for reading information, and automatically registers information as the cassette is inserted. This eliminates the need for operators to manually enter mask identification information using a keyboard when inserting or replacing mask cassettes, reducing the effort required to install cassettes, fully automating the exposure process, and improving throughput. A highly reliable semiconductor exposure apparatus in which mistakes are prevented can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an automatic mask exchange device according to the present invention, FIG. 2 is a partial detailed view of the cassette carrier section of the automatic mask exchange device of FIG. 1, and FIG. 3 is a perspective view of a mask cassette used in the present invention. 4 is a perspective view of the information reading state of the mask cassette shown in FIG. 3, FIG. 5 is a perspective view showing the arrangement of the detection means of the mask cassette according to the present invention, and FIG. 6 is a perspective view of each detection shown in FIG. 5. FIG. 7 is a circuit diagram of the automatic mask exchange device according to the present invention. 1: Cassette carrier, 2: Mask cassette, 8: Barcode card, 9.10: Photo sensor, 11: Barcode reader, 12: Switch, 24: Control circuit.

Claims (1)

[Scope of Claims] 1. An automatic mask exchange device for a semiconductor exposure apparatus in which a plurality of mask cassettes are stored in a cassette carrier and a mask cassette to be used is automatically and selectively taken out from the cassette carrier. 1. An automatic mask exchange device, comprising: a recording medium on which information regarding masks stored in a cassette is recorded in advance; and an information reading means for reading information on the recording medium. 2. The automatic mask changing device according to claim 1, wherein the information reading device is connected to a drive control device of the automatic mask changing device. 3. The information reading means is provided on the cassette carrier and reads the information during mask cassette storage operation;
3. The automatic mask changing device according to claim 2, wherein the information is input to a storage circuit within the drive control means. 4. The automatic mask changing device according to claim 1, wherein the information is recorded in the form of a barcode, and the information reading means comprises a barcode reader. 5. The automatic mask exchange apparatus according to claim 1, wherein the information is recorded by a magnetic recording means, and the information reading means comprises a reading magnetic head. 6. The automatic mask exchange device according to claim 3, wherein the information reading means includes cassette detection means for detecting that a mask cassette is stored in the cassette carrier. 7. The automatic mask exchange device according to claim 6, wherein the cassette detection means comprises an insertion sensor that detects the insertion operation of the cassette and an insertion completion sensor that detects the completion of the insertion operation. 8. The recording medium is a card and is attached to protrude from the side surface of the mask cassette, the insertion sensor is composed of two photosensors arranged in parallel in the insertion direction for detecting the card, and the insertion completion sensor is 8. The automatic mask changing device according to claim 7, comprising a switch that is pressed and operated by the mask cassette in the storage position.