JP2002010530A - Interlock device and processing device - Google Patents

Abstract

(57) [Summary] To reduce wiring in an interlock device and a processing device provided with the interlock device. SOLUTION: A plurality of series circuits having a heater and a switch are connected in parallel with a power supply unit, and a series circuit (interlock monitoring means) having a bimetal and an oscillator is connected to both ends of the series circuit. A mixer is provided for each circuit to superimpose different frequency signals output from the oscillator on a power supply line. The bimetal is provided in the vicinity of the heater and is closed until the temperature exceeds a predetermined temperature, the frequency signal superimposed on the power supply line is separated by a separation unit, and a digital signal corresponding to each frequency signal is output to the control unit. ing. When the bimetal is opened due to an overheat state, the control unit recognizes the frequency signal that cannot be recognized, performs control to open the switch, and stops power supply to the heater.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an interlock device and a processing device to which the interlock device is applied, for example, for processing a semiconductor substrate.

[0002]

2. Description of the Related Art A coating and developing apparatus, which is one of semiconductor device manufacturing apparatuses, generally requires a large number of heating apparatuses.
For this reason, for example, the heating device is housed in a housing to form a unit, and the unit serving as the heating device is multi-tiered to form the shelf unit 1 to save space.

[0003] The shelf unit 1 has, for example, a structure as shown in FIG. 8. For example, a power supply unit 11 provided in a lowermost dummy unit 1 a is provided with a heating plate in each heating unit (heating device) 1 b. Provided heater 12
And a series circuit including a semiconductor switch 13 for controlling the duty ratio of the power output and a switch 14 for stopping the supply of power to the heater 12 are connected in parallel. A thermocouple 15 as a temperature detecting means is provided in the vicinity of each heater 12.
And a bimetal 16 serving as interlock monitoring means for detecting an abnormality of the power supply unit 1a, and each of them is connected to a control unit 17 in a control unit 1c provided on the power supply unit 1a, for example. The control unit 17 is configured to be able to open and close the switch 14 based on an interlock signal sent from the bimetal 16. For example, the switch 14 is closed when the heating plate has reached a predetermined temperature or higher,
The power supply to the heater 12 is stopped to prevent burnout due to overheating.

In the coating and developing apparatus, in addition to the above-described heating unit, for example, a multi-stage unit is provided. For example, each unit carries a rotatable and vertically movable semiconductor wafer (hereinafter referred to as a wafer). By arranging them close to each other so as to surround the mechanism, it is possible to transfer the wafers between the units and to make the configuration in which almost no empty space remains, thereby saving the space of the entire apparatus.

[0005]

As described above, each heating device has a power supply line, an interlock line connecting the bimetal 16 and the control unit 1c, a control signal line for sending a control signal to the thyristor 13, and detection of the thermocouple 15. Since sensor lines for transmitting signals and the like are wired, if these are considered in the entire shelf unit 1, the number of wires obtained by multiplying the number of wires by the number of heating devices to be stacked will be required. Further, in the above-described heating device, a plurality of thermocouples 15 and a plurality of bimetals 16 may be provided. When the number of wirings increases as described above, the units are extremely densely arranged in the coating and developing device. There is also a problem that it becomes difficult.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an interlock device for supplying power to a controlled object by reducing the number of wires by using both a power supply line and an interlock line. Is to do. Another object of the present invention is to provide a processing apparatus to which such an interlock device is applied to reduce the number of wires.

[0007]

According to the present invention, there is provided an interlock apparatus comprising: a power supply unit; a control target which is operated by power supplied from the power supply unit via a power supply line; Interlock monitoring means for monitoring whether or not there is, outputting an interlock monitoring signal corresponding to the monitoring result; superimposing means for superimposing the monitoring signal on the power supply line; and A separation unit that separates the monitoring signal, and a control unit that stops supply of power to the control target when the monitoring signal separated from the separation unit is a signal corresponding to information deviating from a predetermined state. And characterized in that:

[0008] According to such a configuration, the interlock monitoring signal output from the interlock monitoring means is superimposed on the power supply line, and then the control unit, based on the information of the separated monitoring signal, Since the power supply to the control target can be stopped, the power supply line and the interlock line for transmitting the interlock monitoring signal can be shared, and wiring can be reduced.

[0009] To give a specific configuration of the above-mentioned device, for example, a plurality of control targets and a power supply unit are connected in parallel by a power supply line, and the interlock monitoring means includes an oscillator and a switch unit. When the target is a monitoring target and the monitoring target is in a predetermined state, the switch unit is closed and a frequency signal from the oscillator is superimposed on the power supply line, and when the monitoring target is out of the predetermined state, the switch unit is closed. Can be opened to stop superimposing the frequency signal on the power supply line.

In such a configuration, the frequency signal plays the role of an interlock monitoring signal, and power is supplied to all interlock lines in an interlock device in which a plurality of control objects are expected to increase the number of wires. Since they are combined into one line, further reduction in wiring can be achieved, and maintainability is also improved.

Here, for example, when the control target is a heating means, for example, a heater, and this heating means is a monitoring target, the interlock monitoring means outputs different frequency signals from each other, for example, so that it is in an overheating state. It is also possible to specify a heater and cut off only the power supply of the heater. Note that a bimetal can be used for the switch unit, for example.

Further, the processing apparatus according to the present invention includes a plurality of heat processing units for performing heat processing on the object to be processed, and heating means used for each of the heat processing units is connected to a power supply line from a power supply unit. In the processing devices connected in parallel with each other, a frequency signal is output when the heating temperature of the heating unit is equal to or lower than a predetermined temperature, and the output of the frequency signal is output when the heating temperature exceeds a predetermined temperature. Interlock monitoring means to be stopped, superimposing means for superimposing the frequency signal on the power supply line, separation means for separating the frequency signal from the power supply line, and the frequency signal separated from the separation means A control unit for stopping supply of power to the heating means when the power is lost.

In such a processing apparatus, the interlock monitoring means includes an oscillator and a switch section, and when the heating temperature is lower than a predetermined temperature, the switch section is closed and a frequency signal from the oscillator is supplied to the power supply line. When the heating temperature exceeds a predetermined temperature, a switch may be opened to stop superimposing the frequency signal on the power supply line.

[0014]

FIG. 1 is a plan view showing an embodiment of a processing apparatus according to the present invention, and FIG. 2 is a perspective view of the same.
Hereinafter, a wafer W as a substrate to be processed according to this embodiment will be described.
A description will be given of an example of a pattern forming apparatus for forming a predetermined resist pattern.

In FIG. 1, reference numeral 21 denotes a cassette station for loading and unloading a cassette C containing, for example, 25 wafers W. The cassette station 21 has a mounting portion 21a for mounting the cassette C, Delivery means 22 for taking out the wafer W from the cassette C is provided. On the back side of the cassette station 21 (on the right side in FIG. 1), for example, on the right side when viewed from the cassette station 21, for example, a coating / developing system unit U1 is provided.
On the left, front and back sides, shelf units U2, U3 and U4 in which heating / cooling units and the like are stacked in multiple stages are arranged, respectively, and a coating / developing system unit U1 and shelf units U2, U3 and U4 are arranged. The main transfer means 23 for transferring the wafer W between the main transfer means and the transfer means is provided. However, the transfer means 22 and the main transport means 23 are not shown in FIG. 2 for convenience.

In the coating / developing system unit U1,
For example, an upper unit is provided with a developing unit 24 having two developing devices described above, and a lower unit is provided with a coating unit 25 having two coating devices. Shelf units U2, U3, U4
In the above, in addition to the heating unit and the cooling unit, a wafer transfer unit, a hydrophobizing unit, and the like are assigned vertically.

A portion provided with the main transport means 23 and the coating / developing system unit U1 is called a processing block. The processing block is connected to an exposure block 27 via an interface unit 26. . The interface unit 26 transfers wafers W between the processing block and the exposure block 27 by means of a wafer W transfer means 28 which is configured to be movable up and down, movable left and right, back and forth, and rotatable about a vertical axis. Is what you do.

As an embodiment to which the interlock device according to the present invention is applied, the shelf unit U2 and the heating device 30 incorporated in the shelf unit U2 will be described as an example. The circuit configuration of the interlock device will be described. First, the shelf unit U2 and the heating device 30 will be briefly described. As shown in FIG. 3, the shelf unit U2 has, for example, a configuration in which units surrounded by a housing are stacked in nine stages, and two lower stages include a power supply unit PU that supplies power to the entire shelf unit U2. A control unit CU that monitors the temperature of a heater 4 (not shown) in the heating device 30 to be controlled, for example, and controls the heating temperature,
The heating unit 3 having the heating device 30 therein is provided on the seven stages stacked thereon.

A power supply line L1 from a power supply unit PU is connected in parallel to the heater 4 in each heating unit 3, and a detection signal line L2 for transmitting a temperature detection value near the heater 4 from the control unit CU. And a control line L3 necessary for stopping the power supply to the heater 4. An opening E is formed on the side of the housing forming the heating unit 3, and a wafer W can be loaded and unloaded through the opening E.

Next, the heating device 30 will be described with reference to FIG. In the drawing, reference numeral 31 denotes a cylindrical heating plate made of, for example, aluminum nitride (AlN), and a plurality of ring-shaped heaters 4 arranged concentrically are embedded near the surface thereof. This corresponds to the control target in the range. Further, in the heating plate 31, for example, a bimetal 5 corresponding to a switch unit of an interlock monitoring unit for monitoring whether or not the heater 4 has exceeded a predetermined temperature, and a plurality of temperature detection units (not shown) such as thermocouples Is buried and this bimetal 5
The heater 4 is connected to a power supply line L1, and a thermocouple (not shown) is connected to a detection signal line L2 via an electrical unit 30a. The electrical unit 30a is provided with a thyristor for controlling the output of the heater 4, a switch for stopping the power supply connected to the control line L3, and the like.

A recess 32 is formed on the outer edge of the heating plate 31 over the entire circumference, and the lower side is supported by a leg 33. The surface of the heating plate 31 is provided with, for example, three projections 34 having a height of 0.1 mm, whereby the wafer W as a substrate is horizontally supported while slightly floating from the surface of the heating plate. . Below the position where the wafer W is supported, a lift pin 36 whose lower end is supported by an elevating mechanism 35 and penetrates the heating plate 31 is provided. Wafer W between transfer arm
Is delivered.

On the upper side of the heating plate 31, a lid 3 is provided.
7 is provided so as to be able to move up and down by a raising and lowering member 37a connected to a driving mechanism (not shown).
It is configured to form a processing container. A gas supply pipe 38 and an exhaust pipe 39 are connected to the lid 37. A purge gas is supplied from the gas supply pipe 38 through the gas holes 38a and 38b, and exhaust gas is exhausted from the exhaust pipe 39 through the exhaust port 39a. In this case, an airflow is formed inside the processing container.

Next, the circuit configuration of the interlock device in the shelf unit U2 and the heating device 30 will be described with reference to FIG. Reference numeral 41 denotes a power supply unit that supplies power to the heating device 30. The power supply unit 41 is provided for each heating unit 3 (3a to 3g), and includes a switch 42 (42a) that switches between power supply and cutoff. ~ 42g),
A heater 4 (4a to 4g) and a semiconductor switch 43 composed of, for example, a thyristor for adjusting the output of the heater 4
(43a to 43g) is connected to the power supply line L
1 are connected in parallel. Semiconductor switch 43
(43a to 43g) are based on the detected temperature value of the heating plate 31 transmitted from the temperature detecting means (not shown) described above.
The duty ratio is controlled by a control unit 8, which will be described later, whereby the heating temperature (processing temperature of the wafer W) of the heater 4 (4a to 4g) is controlled. Although one bimetal 5 is shown in the figure, when the bimetal 5 is provided at a plurality of locations on the heating plate, the bimetals 5 may be connected in series.

A bimetal 5 (5a to 5g) which is the above-described switch unit is provided at both ends of each series circuit.
In order to identify which heating unit 3 (3a to 3g) has passed through the bimetal 5 (5a to 5g) the current flowing through the bimetal 5 (5a to 5g) can be identified.
An oscillator 51 (51a) that outputs different frequency signals
To the interlock monitoring means 52 (52a to 52g).
a to 53g), and a mixer 6 (6a to 6g) as a superimposing means for superimposing the frequency signal on the power supply voltage of the power supply line L1 is provided at a connection portion on one end side. . Here, the above-mentioned frequency signal corresponds to the interlock monitoring signal in the claims.

The power supply line L1 is provided with a separating means 7 for separating the frequency signal superimposed by the mixer 6 (6a to 6g) from the current.
Represents a detector 71 for detecting the frequency signal group, and a corresponding heating unit 3 (3a to 3a) from the frequency signal group.
g) Frequency classifier 7 for classifying frequency signals
2 is constituted. As the frequency classifier, for example, an FM demodulator, a band-pass filter, a high-pass filter, or the like can be used.

The frequency classifier 72 is connected to the control unit 8,
The control unit 8 also controls the switch 42 by the control line L3 described above.
(42a-42g), and the switch 42 (42a-42g) is connected when the separated frequency signal disappears.
42g) is closed to shut off the power supply. The sorting means 7 and the control unit 8 are provided, for example, in the control unit CU of the shelf unit U2 in FIG.

Next, the operation of the above embodiment will be described. First, by closing the switches 42 (42a to 42g), the heater 4 (4a to 4g) is energized through the power supply line L1, and the temperature of the heater 4 (4a to 4g) rises to a predetermined temperature. Is performed. At this time, the bimetal 5 (5a to 5g) is closed, and the oscillator 51 (51a to 51g) outputs the bimetal 5 (5a to 5g) as described above.
a to 5 g) are provided in the heating unit 3 (3a to 3g).
For example, the oscillator 51a is set to 100
kHz, the oscillator 51b is 200 kHz. . . Oscillator 51
The frequency is shifted by, for example, 100 kHz so that g becomes 700 kHz, and different frequency signals are output.

These frequency signals are supplied to mixers 6 (6a to 6a).
g) is superimposed on the power supply voltage of the power supply line L1;
The superposed seven frequency signals can be confirmed by the detector 71. This will be described with reference to FIG. 6 taking the heating unit 3a as an example. At time t1 in the figure, the heating plate is at a normal temperature, and at this time, the bimetal 5a is closed and the switch 42a is also closed. It has become. Therefore, a 100 kHz frequency signal from the oscillator 51 a is superimposed on the power supply line, detected by the detector 71, and transmitted to the control unit 8 via the frequency separator 72.

At time t2, for example, when the heater 4a is overheated, the corresponding bimetal 5a opens,
The frequency signal from the oscillator 51a disappears. Therefore, the signal for identifying the heating unit 3a, which has been continuously transmitted from the frequency separator 72, is no longer transmitted.
In the power supply line L1, for example, excluding 100 kHz
Information that only six frequency signals from 00 kHz to 700 kHz are included is transmitted.

Based on this information, the control unit 8 recognizes that the heater 4a has overheated, and opens the switch 42a to stop the power supply (interlock) independently of the temperature control of the heater 4a. . Further, the power supply to the entire shelf unit U2 may be set to be stopped when the frequency signal is no longer output from any one of the heating units 3, and in this case, the control unit 8 performs the control based on the information. Control to open all switches 42 (42a to 42g). Similarly, when the heating plate of another heating unit 3 is overheated, the corresponding frequency signal disappears from the power supply line, the corresponding switch 42 is opened, and the power supply of the heater 4 is stopped. Stopped.

According to the present invention, there is provided an interlock device having a control target to be supplied with electric power and a monitoring means therefor.
It focuses on superimposing the interlock line on the original power supply line itself, which finally handles interlock, and in the above-described embodiment, the interlock that monitors the state of the heater 4 that is the control target is used. Since a frequency signal is used as a lock monitoring signal, and this frequency signal is superimposed on the power supply voltage and detected to determine whether or not to apply an interlock, an "interlock line" is connected to the power supply line L1. Can also be used. For this reason,
There is no need to provide an interlock line for each monitoring means provided on the control target, and wiring can be reduced.

Further, as described above, since the control unit 8 can recognize which interlock monitoring means 52 (52a to 52g) has stopped transmitting the frequency signal,
For example, maintenance is easy when performing repair or the like after performing the interlock.

Further, for example, unplugged power supply line L1 (not shown) in one or more heating units 3a,
Alternatively, even when the power supply line L1 is broken or the like, the control unit 8 cannot recognize the frequency signal (interlock monitoring signal), so that the abnormality can be detected.

The separating means 7 is, for example, shown in FIG.
As shown in FIG. 7, a number, for example, seven detectors 71 (71a to 71g) corresponding to the type of the frequency signal superimposed on the power supply voltage
May be provided.

Further, the present embodiment can be applied to other than monitoring the abnormal heating of the heater. For example, the motor control circuit monitors the number of rotations of the motor. The present invention can also be applied to a circuit in which a signal is superimposed on a power supply line of a motor, and when the rotation speed becomes abnormal, the frequency signal disappears and the motor is stopped.

[0036]

As described above, according to the present invention, a power supply line and an interlock line can be used in an interlock device in which power is supplied to a controlled object and its monitoring means. Further, it is possible to reduce wiring in a processing apparatus to which the interlock device is applied.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of a processing apparatus according to the present invention.

FIG. 2 is a perspective view showing an embodiment of a processing apparatus according to the present invention.

FIG. 3 is a schematic perspective view showing a shelf unit in the processing apparatus.

FIG. 4 is a longitudinal sectional view illustrating a heating device included in the shelf unit.

FIG. 5 is an explanatory diagram showing an embodiment of an interlock device according to the present invention.

FIG. 6 is an explanatory diagram illustrating the operation of the embodiment according to the present invention.

FIG. 7 is a schematic explanatory view showing a sorting unit according to another embodiment of the interlock device.

FIG. 8 is an explanatory view of an interlock device according to a conventional invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 3 Heating unit 4 Heater 41 Power supply part 42 Switch 5 Bimetal 51 Oscillator 6 Mixer 7 Classification means 71 Detector 72 Frequency classifier 8 Controller

Claims (9)

[Claims] 1. A power supply unit, a control object operated by electric power supplied from the power supply unit via a power supply line, and whether or not the monitoring target is in a predetermined state is monitored, and a monitoring result is determined. Interlock monitoring means for outputting an interlock monitoring signal; superimposing means for superimposing the monitoring signal on the power supply line; separating means for separating the monitoring signal from the power supply line; A control unit for stopping the supply of power to the control target when the monitoring signal separated from the control signal is a signal corresponding to information deviating from a predetermined state. . 2. The interlock device according to claim 1, wherein a monitoring target is the control target. 3. The interlock monitoring means includes an oscillator and a switch. When the object to be monitored is in a predetermined state, the switch is closed and a frequency signal from the oscillator is superimposed on a power supply line. 3. The interlock device according to claim 1, wherein the switch is opened to stop superimposing the frequency signal on the power supply line when the power supply is out of the predetermined state. 4. The interlock device according to claim 1, wherein a plurality of control objects are connected in parallel by a power supply line. 5. The interlock device according to claim 4, wherein the interlock monitoring signals corresponding to the plurality of control targets are frequency signals having different frequencies from each other. 6. A control object is a heating means for heating the object to be processed, and the interlock monitoring means monitors whether or not the heating temperature of the heating means exceeds a predetermined temperature. The interlock device according to any one of claims 1 to 5, wherein: 7. A plurality of heat treatment units for performing heat treatment on an object to be processed, wherein heating means used in each of the heat treatment units are connected in parallel by a power supply line from a power supply unit. An apparatus for outputting a frequency signal when a heating temperature of the heating means is equal to or lower than a predetermined temperature, and for stopping an output of the frequency signal when the heating temperature exceeds a predetermined temperature.
Lock monitoring means, superimposing means for superimposing the frequency signal on the power supply line, separating means for separating the frequency signal from the power supply line, and when the frequency signal separated from the separating means disappears. A control unit for stopping supply of electric power to the heating unit. 8. The interlock monitoring means includes an oscillator and a switch. When the heating temperature is lower than a predetermined temperature, the switch is closed to superimpose a frequency signal from the oscillator on a power supply line, and 8. The processing apparatus according to claim 7, wherein when the temperature exceeds a predetermined temperature, the switch unit is opened to stop superimposing the frequency signal on the power supply line. 9. The processing apparatus according to claim 6, wherein the switch unit is a bimetal switch.