KR20110050168A - Exposure apparatus having cooling module of LED light source - Google Patents

Abstract

The present invention relates to an exposure apparatus including a cooling module of an LED light source, comprising: an LED light source unit generating light for irradiating a substrate positioned on a stage with light in a UV region, and converting light emitted from the LED light source unit into parallel light; Parallel light generating unit for switching to irradiate the substrate, a light amount control module for adjusting the light amount of the LED light source unit to maintain a constant intensity of the light emitted from the LED light source unit, the light amount control module to adjust the light amount of the LED light source unit While controlling the light amount of the LED light source unit from the signal of the cooling module and the light amount control module to prevent overheating of the LED light source unit in conjunction with the light amount control module, and overheating the LED light source unit corresponding to the adjusted light amount The main control unit for controlling the cooling module to prevent the Prepare a complimentary configuration.

By using the exposure apparatus including the cooling module of the LED light source as described above, it is possible to prevent overheating of the LED light source unit adopted in the exposure apparatus by controlling the operation of the cooling module in response to the light amount control module.

Light source, LED, exposure device, light quantity control module, UV sensor

Description

Exposure apparatus having cooling module of LED light source {Exposure apparatus having cooling system of UV LED light sources}

The present invention relates to an exposure apparatus including a cooling module of the LED light source, and in particular, by maintaining a constant temperature of the UV LED used as the light source to transfer the pattern of the mask to the substrate to improve the life of the UV LED, maintaining the exposure apparatus It relates to an exposure apparatus having a cooling module of the LED light source that can reduce the cost.

In general, semiconductor devices are manufactured through various processes such as an oxidation process, a diffusion process, an ion implantation process, a deposition process, and an exposure process. Among these, the exposure step is to form a pattern by depositing a photoresist on a wafer and irradiating the photoresist with light having a short wavelength emitted from a light source. In this case, the reason why the short wavelength of light is used as the light source is that the shorter the wavelength, the better the resolution characteristic.

Due to these characteristics, a mercury lamp or the like is mainly used as a light source of a conventional exposure apparatus in a UV region having a wavelength of about 360 nm. However, since the mercury lamp has a lifespan of about 800 h to 1,000 h, the mercury lamp had to be replaced regularly, thus increasing the maintenance cost of the exposure apparatus. In addition, the conventional exposure apparatus requires a high power in order to increase the illuminance of the lamp, so a heat generation countermeasure is required, and there is a risk of explosion due to inadvertent use of the lamp. During the explosion, mercury is present in the vapor phase, which can have a devastating effect on humans, allowing the process to be sealed after a certain period of time.

Therefore, recently, a light source of an exposure apparatus using a light emitting diode, which is a solid-state semiconductor device capable of reducing electric power due to a higher luminous efficiency than a mercury lamp and having a relatively high heat generation property and reducing maintenance costs, has been developed.

An example of a light source of the exposure apparatus using the light emitting diode is shown in FIG. 1.

As shown in FIG. 1, the exposure light source device rotates a UV-LED unit 1 having a plurality of ultraviolet light emitting diodes (UV-LEDs), a power supply unit 2 including a control circuit, and a mounted wafer 3. It comprises a rotating stage (4) having a drive for making. A photoresist 5 is coated on the wafer 3, and a mask 6 is positioned between the UV-LED unit 1 and the photoresist 5. The UV-LED unit 1 and the power supply unit 2 are connected by an electric cable 7.

However, the exposure apparatus using the UV-LED has a problem that it is difficult to irradiate light while maintaining a constant intensity of illumination by making parallel light on the mask and the substrate. In addition, the exposure apparatus has improved heat generation characteristics compared to the conventional mercury lamp, but also has a problem in that the temperature rise of the UV-LED is suppressed because the light efficiency characteristic is lowered when the temperature of the UV-LED rises.

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems described above, and provides an exposure apparatus including a cooling module of an LED light source capable of maintaining a constant illuminance of light irradiated from a light source to a substrate by using a light amount control module. It is.

Another object of the present invention is to provide an exposure apparatus including a cooling module of an LED light source capable of improving the light efficiency characteristics of the LED by lowering the temperature of the LED light source unit corresponding to the light amount controlled by the light amount control module.

According to an exposure apparatus including a cooling module of an LED light source according to an embodiment of the present invention to achieve the above object, an LED light source unit for generating light for irradiating a substrate located on the stage with the light of the UV region, the LED A parallel light generating unit for converting the light emitted from the light source unit into parallel light and irradiating the substrate, a light amount control module for adjusting the light amount of the LED light source unit to maintain a constant intensity of light emitted from the LED light source unit, the light amount control While controlling the amount of light from the LED light source unit from the module to control the amount of light from the LED light source unit from the signal of the cooling module and the light amount control module to prevent overheating of the LED light source unit in conjunction with the light amount control module, To prevent overheating of the LED light source unit corresponding to the amount of light It characterized in that it comprises a main control unit for controlling each module.

In addition, according to the exposure apparatus including a cooling module of the LED light source according to an embodiment of the present invention, the cooling module is located above the LED light source unit cooling jacket for preventing overheating of the LED light source unit, the control of the main control unit The cooler for circulating the refrigerant supplied to the cooling jacket and a cooling fan for circulating lowering the temperature of the coolant refrigerant is characterized in that it comprises.

In addition, according to the exposure apparatus including a cooling module of the LED light source according to an embodiment of the present invention, between the cooling jacket and the LED light source unit further comprises a heat sink for dissipating heat generated from the LED light source unit do.

In addition, according to the exposure apparatus including a cooling module of the LED light source according to an embodiment of the present invention, the light amount control module is a UV sensor for detecting the illumination of the light emitted from the LED light source unit, the light detected from the UV sensor An optical amplifier for amplifying, an A / D converter for converting light amplified by the optical amplifier into a digital value, and a PWM for adjusting the amount of light of the LED light source unit by receiving the digital value output from the A / D converter from the main controller. It characterized in that it comprises a control unit.

In addition, according to the exposure apparatus including a cooling module of the LED light source according to an embodiment of the present invention, the parallel light generating unit from the primary coherent lens, the primary coherent lens for forming the light emitted from the LED light source unit to direct light It comprises a fly-eye lens for passing through the direct light to form a bundle of light (flux) and a secondary aggregation lens for forming the bundle of light as a balanced light to irradiate the substrate.

As described above, according to the exposure apparatus including the cooling module of the LED light source according to the embodiment of the present invention, by using the light amount control module it is possible to maintain the constant illuminance of the light irradiated to the substrate located on the stage from the light source Effect is obtained.

In addition, according to the exposure apparatus including the cooling module of the LED light source according to the present invention, the effect that the light efficiency characteristics of the LED can be improved by lowering the temperature of the light source corresponding to the amount of light controlled by the light amount control module.

In addition, according to the exposure apparatus including the cooling module of the LED light source according to the present invention, the effect that the maintenance cost of the exposure apparatus can be reduced by using the LED having a relatively long life compared to the conventional mercury lamp.

These and other objects and novel features of the present invention will become more apparent from the description of the present specification and the accompanying drawings.

EMBODIMENT OF THE INVENTION Hereinafter, the structure of this invention is demonstrated in detail according to drawing.

In addition, in description of this invention, the same code | symbol is attached | subjected to the same part and the repeated description is abbreviate | omitted.

2 is a view schematically illustrating an exposure apparatus including a light amount control module and an LED cooling module according to an embodiment of the present invention, and FIG. 3 is a view illustrating a configuration of a light amount control module and an LED cooling module according to an embodiment of the present invention. A block diagram showing.

2 and 3, the exposure apparatus according to an embodiment of the present invention, the power supply unit 21, parallel light generating unit 23, LED light source unit 25, light amount control module 27, cooling module ( 29) and the main control part 31 is comprised.

The power supply unit 21 converts the supplied commercial power into direct current power to drive the LED light source unit 25. Although not shown, the power supply unit 21 may include a filter for filtering out noise of commercial power, a main power for driving the LED, and an auxiliary power for applying power to a circuit for controlling the power. The power supply unit 21 is connected to the LED light source unit 25 by an electric cable.

The parallel light generator 23 converts light emitted from the LED light source unit 25 into parallel light and irradiates a substrate on a stage (not shown). The parallel light generator 23 may include a primary coherent lens 33, a fly eye lens 35, and a secondary coherent lens 37. The primary coherent lens 33 is positioned below the LED light source unit 25 and serves to form light incident from the LED light source unit 25 into direct light. Preferably, the primary aggregation lens 33 is formed in plural. Light passing through the primary coherent lens 33 is incident to the fly's eye lens 35.

The fly's eye lens 35 plays a role of forming a bundle of light having uniform illuminance by passing light emitted from the primary aggregation lens 33. The secondary coherent lens 37 converts light of uniform illuminance passing through the fly's eye lens 35 into parallel light. The secondary coherent lens 37 is preferably formed of a hemispherical convex lens. Parallel light formed from the secondary coherent lens 37 passes through a pattern mask (not shown) positioned below the secondary coherent lens 37, and the light passing through the pattern mask passes through a substrate formed on the stage. Is investigated. The substrate is patterned after a photoresist is applied to perform a cleaning process to remove photoresist exposed or not exposed to light.

In the meantime, when the voltage is applied from the power source unit 21, the LED light source unit 25 generates light in a UV region for irradiating the substrate to which the photoresist is applied. The LED light source unit 25 may include a plurality of solid state light emitting devices, for example, a plurality of light emitting diodes (LEDs), formed in rows and columns on an aluminum substrate. Therefore, by replacing the conventional mercury lamp with the LED light source unit 25, it is possible to prevent the maintenance cost due to the life characteristics of the mercury lamp to increase, it is possible to prevent the risk of explosion accident. A portion of the light emitted from the LED light source unit 25 is incident on the light amount control module 27.

The light amount control module 27 adjusts the light amount of the LED light source unit 25 to maintain a constant intensity of the light emitted from the LED light source unit 25. The light amount control module includes a UV sensor 39, an optical amplifier 41, an A / D converter 43, and a PWM controller 45. The UV sensor 39 is positioned at a position that does not obstruct the path of light incident from the fly eye lens 35 to the secondary aggregation lens 37 between the fly eye lens 35 and the secondary aggregation lens 37. Is installed. For example, the UV sensor 39 may be installed on one wall of the exposure apparatus between the fly's eye lens 35 and the secondary coherent lens 37. The UV sensor 39 detects illuminance of light emitted from the LED light source 25.

The optical amplifier 41 amplifies the light sensed by the UV sensor 39 and transmits the amplified value to the A / D converter 43. The A / D converter 43 converts the amplified value into a digital value and transmits the converted value to the main controller 31. The main control unit 31 transmits the converted value to the PWM control unit 45, and the PWM control unit 45 controls the voltage difference by comparing the illumination intensity detected by the UV sensor 39 with a preset reference illumination value. The signal is output and transmitted to the LED light source unit 25. Therefore, the PWM control unit 45 may control the amount of light emitted from the LED light source unit 25.

Meanwhile, the cooling module 29 interlocks with the light amount control module 27 to prevent overheating of the LED light source unit 25 while adjusting the light amount of the LED light source unit 25 from the light amount control module 27. The cooling module 29 includes a cooling jacket 47, a cooler 49, and a cooling fan 51. The cooling jacket 47 may be positioned above the LED light source unit 25 using the refrigerant supplied from the cooler 49 to prevent overheating of the LED light source unit 25. The coolant is preferably a liquid coolant, for example water. A heat dissipation plate 53 may be further disposed between the cooling jacket 47 and the LED light source unit 25 to release heat generated from the LED light source unit 25. Therefore, the heat sink 53 may prevent overheating of the LED light source unit 25 even when the liquid refrigerant is not supplied to the cooling jacket 47.

The cooler 49 supplies the liquid refrigerant to the cooling jacket 47 under the control of the main controller 31. The cooler 49 is connected to the cooling jacket 47 by a liquid refrigerant supply inlet and an outlet. The cooling fan 51 serves to circulate by lowering the temperature of the cooler 49. In this case, the main control unit 31 controls the cooler 49 according to the digital value of the illuminance of the light input from the A / D converter 43 to supply the temperature or amount of the liquid refrigerant supplied to the cooling jacket 47. Can be controlled.

In addition, the main controller 31 controls the cooler 49 according to a temperature value sensed by a temperature sensor (not shown) mounted on the LED light source unit 25 to supply the temperature of the liquid refrigerant supplied to the cooling jacket 47. Alternatively, the amount may be controlled. As a result, the main control unit 31 controls to adjust the light amount of the LED light source unit 25 from the signals of the cooling module 29 and the light amount control module 27, the LED light source unit 25 corresponding to the adjusted light amount It can prevent overheating.

As mentioned above, although the invention made by the present inventor was demonstrated concretely according to the said Example, this invention is not limited to the said Example and can be variously changed in the range which does not deviate from the summary.

1 is a view schematically showing an exposure apparatus having an LED light source according to the prior art.

2 is a view schematically illustrating an exposure apparatus including a light amount control module and an LED cooling module according to an embodiment of the present invention.

3 is a block diagram showing the configuration of the light amount control module and the LED cooling module according to an embodiment of the present invention.

Claims (5)

An LED light source unit generating light for irradiating a substrate positioned on the stage with light in the UV region; A parallel light generator for converting the light emitted from the LED light source into parallel light and irradiating the light onto the substrate; A light amount control module configured to adjust a light amount of the LED light source unit to maintain a constant intensity of light emitted from the LED light source unit; A cooling module configured to prevent overheating of the LED light source unit in cooperation with the light amount control module while adjusting the light amount of the LED light source unit from the light amount control module; And And a main controller configured to control the amount of light of the LED light source unit from the signal of the light amount control module and to control the cooling module to prevent overheating of the LED light source unit in response to the adjusted light amount. An exposure apparatus having a cooling module of the. The method of claim 1, wherein the cooling module A cooling jacket positioned above the LED light source to prevent overheating of the LED light source; A cooler configured to circulate a coolant supplied to the cooling jacket under control of the main controller; And And a cooling fan for lowering and circulating the temperature of the coolant refrigerant. The method of claim 2, And a heat sink for dissipating heat generated from the LED light source unit between the cooling jacket and the LED light source unit. The method of claim 1, wherein the light amount control module UV sensor for detecting the illumination of the light emitted from the LED light source; An optical amplifier for amplifying the light sensed by the UV sensor; An A / D converter for converting light amplified by the optical amplifier into a digital value; And And a PWM control unit for receiving the digital value output from the A / D converter from the main control unit to adjust the amount of light of the LED light source unit. The method of claim 1, wherein the parallel light generating unit A primary aggregation lens for forming light emitted from the LED light source into direct light; A fly's eye lens that passes through the light direct from the primary aggregation lens to form a bundle of light; And And a secondary coherent lens for forming the bundle of light into balanced light to irradiate the substrate.

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