KR100272317B1 - Observation apparatus for state of thermostat system - Google Patents

Abstract

PURPOSE: An apparatus for monitoring an operation state of a system for controlling hot water of a reduced projection lens is provided to performs an alarm operation if an abnormal state is generated in the system for controlling hot water, to maintain a constant state of the reduced projection lens. CONSTITUTION: The first sensing unit(30) senses the temperature of air supplied from an apparatus for controlling hot water. The second sensing unit(32) senses the temperature of the hot water of the apparatus for controlling hot water. A controller(34) determines whether the temperature values of the air and the hot water sensed from the first and second sensing units fall within upper and lower limits of a predetermined range. If the temperature values get out of the upper and lower limits, the controller outputs the first and second channel signals of a high or low level, respectively. A photocoupler(36,38,40,42) is so connected that the first, second, third and fourth channel signals are supplied, and outputs a signal of a level opposite to the channel signal. A switching unit performs a switching operation of a normal or abnormal state according to the output signal of the photocoupler. An alarm unit generates sound or light according to the level of a switching signal outputted from the switching unit.

Description

Operation state monitoring device of reduction projection lens temperature control system of exposure equipment

The present invention relates to an apparatus for monitoring an operating state of a reduction projection lens temperature control system of an exposure apparatus, and more particularly, by checking a temperature of air supplied circulating for heating a reduction projection lens and a temperature of hot water supplied for heating the reduction projection lens. The present invention relates to an apparatus for monitoring the operating state of a reduction projection lens temperature control system of an exposure apparatus that is improved to perform an alarm operation when out of a range.

The wafer for manufacturing a semiconductor device is repeatedly subjected to processes such as cleaning, diffusion, photography, etching, and ion implantation, and then manufactured into a finished product through a packaging process.

In the above-described process, a photo process is a process of forming a pattern on a wafer to form an image of a reticle or a mask on the wafer using a photosensitive material, and generally four steps such as photoresist coating, alignment and exposure, development and inspection. The photoresist coating may be performed by an apparatus such as a spin coater, alignment and exposure may be performed using a stepper, and inspection may be performed by an inspection apparatus.

Stepper is the light is projected through the reduction projection lens to form a pattern of the reticle on the wafer, the resolution or focus state must be maintained above a certain level for normal exposure. Therefore, the reduction projection lens should be prevented from varying in resolution or focus state due to thermal expansion or contraction due to changes in external temperature.

Normally, a pipe 14 is formed around the reduction projection lens 12 of the stepper 10 to maintain the constant temperature of the reduction projection lens, and the heater 16 is heated through the pipe 14. It is configured to supply the air so as to maintain the temperature of the reduced projection lens 12 at a constant temperature.

The temperature controller 16 is a device for maintaining a constant ambient temperature of the reduction projection lens 12 of the stepper 10 at all times to prevent distortion and contraction and expansion of the lens included in the reduction projection lens 12. It is configured to minimize misalignment and misalignment of the wafer.

The stepper 10 is configured to irradiate light from the light source 18 to the wafer 24 on the stage 22 via the reticle 20 and the reduction projection lens 22, and as described above, the reduction projection lens. (22) is comprised so that constant temperature may be maintained.

However, if the heater 16 is abnormally operated and the heating air is not properly supplied to the stepper 10, the reduction projection lens 22 of the stepper 10 is expanded or contracted under the influence of the external temperature. ) And the degree of focus was varied, the exposure process using the stepper 10 was abnormally performed. In addition, since the stepper exposure process was continued even when an abnormality of the temperature controller 16 occurred, there was a problem in that the exposure defect of the wafer was generated in large quantities.

An object of the present invention is to reduce the temperature of the exposure projection lens of the exposure equipment to perform an alarm operation and to provide an interlock operation of the stepper when an abnormality occurs in the temperature controller for supplying the heating air to maintain the constant temperature of the reduction projection lens The present invention provides a device for monitoring the operating state of a system.

1 is a view showing a reduced projection lens temperature control system of a conventional exposure equipment.

Fig. 2 is a block diagram showing a preferred embodiment of an operating state monitoring apparatus of a reduction projection lens temperature control system of an exposure apparatus according to the present invention.

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

10: stepper 12: reduction projection lens

14 piping 16: thermostat

18: light source 20: reticle

22: stage 24: wafer

30, 32: temperature sensor 34: controller

36-42 photocoupler 44 noah gate

46: relay 48: light emitting unit

50: stepper controller

In order to achieve the above object, an apparatus for monitoring an operating state of a reduction projection lens temperature control system of an exposure apparatus according to the present invention includes a constant temperature state of the reduction projection lens by circulating a reduction projection lens with air supplied by using hot water from a temperature controller. An apparatus for monitoring an operating state of a reduced projection lens temperature control system of an exposure apparatus, the first sensing means for sensing a temperature of air heated from the temperature controller, and the temperature sensed by the first sensing means is predetermined. A controller for determining whether the upper limit and the lower limit of the allowable range are included and outputting respective determination results as first and second channel signals, and performing a switching operation in a normal or abnormal state according to the determination result of the controller. Switching means and said switching Depending on the state of the switching signal outputted from the end is achieved by having an alarm means for performing an alarm operation.

The switching means outputs an alarm signal in conjunction with a noah gate configured to logically output the first channel signal and the second channel signal, a transistor switched by an output signal of the noah gate, and a switching of the transistor. It may be provided with a relay.

Here, the first and second channel signals may be configured to be applied to the noah gate through the photocoupler.

In addition, the alarm means may be configured as a sounding device for performing an alarm operation by the light emitting unit or the sound emitting operation that is extinguished and emitted according to the state of the switching signal output from the switching means.

In addition, the alarm means is preferably configured such that the interlock operation is performed by applying the switching signal output from the switching means to the stepper controller for controlling the exposure process.

On the other hand, it is determined by the second sensing means for sensing the temperature of the hot water in the temperature controller and the sensing signal input from the second sensing means whether the temperature of the hot water is within the upper limit and the lower limit of a predetermined allowable range and the respective determination results therefor. And a controller for outputting to the switching means as a third channel and a fourth channel signal.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2, an embodiment according to the present invention is a temperature sensor 30 for sensing the temperature of the heating air supplied to the stepper through the piping from the temperature controller and a temperature sensor for sensing the temperature of the hot water supplied for air heating 32 is connected to the controller 34 of the temperature controller.

In addition, the controller 34 of the temperature controller has a preset allowable range for the temperature of the heating air, so that the temperature of the current heating air, which is determined as the sensing signal input from the temperature sensor 30, exceeds the upper limit or falls below the lower limit. It is configured to make a judgment as to whether or not the signal is outputted as a 'CH1' and a 'CH2' signal. In addition, the controller 34 determines whether a temperature range of the current hot water, which is determined as a sensing signal input from the temperature sensor 32, is set in advance in an allowable range for the temperature of the hot water, exceeds or exceeds the lower limit. It is configured to output the 'CH3' and 'CH4' signals respectively.

It is configured to make an output from the controller 34 and to apply the respective 'CH1' to 'CH4' signals to the photocouplers 36 to 42, respectively, and the photocouplers 36 to 42 are noah gates. It is configured to apply an output signal to the input terminal of 44). The photocouplers 36 to 42 are constituted of ordinary photodiodes and phototransistors.

The output terminal of the NOA gate 44 is connected to the base of the transistor Q1, the driving side of the relay 46 is connected to the collector of the transistor Q1, and the first switching side of the relay 46 emits light. It is connected to the unit 48, and the second switching side of the relay 46 is connected to the stepper controller 50.

As described above, the light emitting unit 48 may be configured as a component for performing an alarm operation. In addition, a sounding device such as a buzzer may be configured, and the stepper controller 50 may perform an interlock operation as a switching signal is applied. To be connected.

The operation and effects of the embodiment according to the present invention configured as described above will be described.

When the temperature controller is operated, hot water heats the air supplied to the stepper through the pipe, and at this time, the temperature of the supplied air and the temperature of the hot water are sensed by the temperature sensors 30 and 32, respectively.

The temperature of the reduced projection lens is usually controlled at 23 ± 0.03 ℃. Based on this, the temperature controller must supply air heated by the above temperature standard with the reduced projection lens through the pipe, and in order to heat the air, The air must be heated to the temperature reference with hot water.

At this time, the temperature of the air supplied to the reduction projection lens and the temperature of the hot water for heating the air is sensed by the temperature sensor (30, 32), respectively, the controller 34 and the air sensed by the temperature sensor (30, 32) Determine the temperature of hot water respectively.

If the air temperature exceeds the upper limit of the bar, the 'CH1' signal is output at high level and if it is less than the lower limit, 'CH2' signal is output at high level. When the temperature of the hot water exceeds the upper limit of the bar set as the allowable range, the 'CH3' signal is output at a high level and when the temperature is below the lower limit, the 'CH4' signal is output at a high level.

Each photocoupler 36 to 42 outputs a low level signal when the 'CH1' to 'CH4' signals are applied at a high level, and outputs a high level when a low level is applied.

When the temperature of the heating supply air and the hot water of the temperature controller is within a predetermined allowable range, the photocouplers 36 to 42 output a low level signal, and accordingly, the transistor Q1 remains turned on. On the contrary, when the sensing temperature of the air and the sensing temperature of the hot water are outside the predetermined allowable range, a high level signal is output from any one of the photocouplers 36 to 42.

That is, when an abnormality occurs in the temperature of the air supplied from the water heater to the reduction projection lens or the temperature of the warm water of the heater, any one of the signals output from the photocouplers 36 to 42 is at a high level. Is switched to the low level, and thus the switching state of the transistor Q1 is switched to turn off.

When the transistor Q1 is turned off, the relay 46 is driven to output a switching signal having a level opposite to that of the first and second switching sides.

A high level signal is applied to the light emitting unit 48 connected to the first switching side, and thus the light emitting unit 48 emits light. As the light emitting unit 48 emits light, an abnormal state of the heater is recognized and Action can be taken.

Then, a low level signal is applied to the stepper controller 50 connected to the second switching side, so that the stepper controller 50 performs an interlock function to stop the current stepping process.

Therefore, the stepping process in the abnormal resolution and focus state as the reduction projection lens is set to an abnormal temperature is stopped, and thus poor exposure can be prevented. Therefore, mass defects in the wafer exposure process can be prevented, thereby improving productivity and maximizing reliability in the process equipment.

Therefore, according to the present invention, the yield change is improved because the resolution change or the focus abnormality caused by the temperature of the reduction projection lens installed inside the stepper becomes abnormal and the progress of the exposure process in the resolution change or the abnormal focus state is prevented. As a result, the reliability of the process equipment is maximized.

Although the present invention has been described in detail only with respect to the described embodiments, it will be apparent to those skilled in the art that various modifications and variations are possible within the technical scope of the present invention, and such modifications and modifications are within the scope of the appended claims.

Claims (3)

An apparatus for monitoring an operating state of a reduction projection lens temperature control system of an exposure apparatus configured to maintain a constant temperature state of the reduction projection lens by circulating the reduction projection lens by air supplied with hot water from a temperature controller, First sensing means for sensing a temperature of air heated by the temperature controller; Second sensing means for sensing a temperature of hot water in the temperature controller; When the temperature of the air sensed by the first sensing means and the second sensing means and the temperature of the hot water are included in the upper and lower limits of a predetermined allowable range, each determination result for the upper limit or lower than the lower limit A controller for outputting the first channel signal and the second channel signal in a high level or a low level form; A photocoupler connected to each of the first to fourth channel signals and outputting a signal having an opposite level to the input channel signal; Switching means for performing a normal or abnormal switching operation according to an output signal of the photocoupler; And Alarm means for performing an alarm operation such as sounding or emitting light according to the level of the switching signal output from the switching means; An apparatus for monitoring an operating state of a reduction projection lens temperature control system of an exposure facility, comprising: The method of claim 1, wherein the switching means; A noah gate for logically combining the output signal of the photocoupler with respect to the first channel signal, the second channel signal, the third channel signal, and the fourth channel signal; A transistor switched by an output signal of the noble gate; And A relay for outputting an alarm signal in conjunction with switching of the transistor; Operating state monitoring device of the reduced projection lens temperature control system of the exposure equipment characterized in that it comprises a. According to claim 1, The alarm means; And a switching signal output from the switching means is applied to a stepper controller that controls the exposure process so that the interlock operation is performed.

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