KR100718692B1 - Cold trap - Google Patents

Abstract

The present invention relates to a cold trap, which is installed on a discharge path of a residual gas after a manufacturing process, and collects a specific component of the residual gas, impurities contained in the residual gas, etc. A collecting tank through which a gas inlet and a gas outlet through which the injected residual gas is discharged are formed, and through which the residual gas passes; A cooling line provided in an inner space of the collection tank but having a cold air inlet through which cold air is injected and a cold air outlet through which cold air injected into the cold air inlet is circulated and discharged; In order to supply cold air to the cold air inlet of the cooling line, a valve is opened and closed to allow or block the compressor body from the outside, a regulator for regulating the pressure of the compressor body flowing through the valve, and the pressure is adjusted The compressed gas is separated into warm and cold air, and the warm air is exhausted to the outside, and the cold air is installed at the cold air inlet or the cold air outlet and passes through the vortex tube that supplies the cold air inlet of the cooling line. And a controller for controlling the regulator so that the pressure of the compressor body flowing into the vortex tube is increased when a temperature sensor detecting a temperature of the temperature sensor is higher than a predetermined reference temperature. Include,

According to the present invention configured as described above, the cooling efficiency is high, the collection effect of the specific components of the residual gas or impurities contained in the residual gas is excellent, and by providing a heat sink adjacent to the cooling line, the reaction gas can be contacted By enlarging the area, the collection effect can be further increased.

Semiconductor, LCD, Vacuum Pump, Scrubber, Cold Trap

Description

Cold trap

1 is a schematic view showing an example of a semiconductor manufacturing apparatus including a cold trap according to the prior art.

Figure 2 is a perspective view of the cold trap installed on the discharge path according to an embodiment of the present invention.

3 is a perspective view of a cold trap according to an embodiment of the present invention.

Figure 4 is a cross-sectional perspective view of the cold trap according to an embodiment of the present invention.

5 is an exploded perspective view of a cold trap according to an embodiment of the present invention.

Figure 6 is a cross-sectional view showing the residual gas flow in the trap of the cold trap according to an embodiment of the present invention.

7 is a block diagram showing the configuration of a cold trap supply device for cold traps according to an embodiment of the present invention.

8 is a view for explaining the principle of the vortex tube applied to the present invention.

<Explanation of symbols for the main parts of the drawings>

100: collection tank 110: gas inlet

120: gas outlet 150: collecting container

200: cooling line 210: cold air inlet

220: cold air outlet 300: cold air supply device

310: valve 320: regulator

330: vortex tube 340: temperature sensor

350: control unit 360: pressure sensor

370: air filter 400: heat sink

400h: hall

The present invention relates to a cold trap, and more particularly, to a cold trap installed on a discharge path of a residual gas that has been completed in a semiconductor or LCD manufacturing process, and collecting specific components of the residual gas or impurities contained in the residual gas. It is about.

In general, a cold trap means a device for placing a low temperature solid surface on a fluid path to trap and remove specific impurities due to a difference in vapor pressure or solubility between the solid surface and the fluid.

On the other hand, the residual gas or process products that have been processed in the equipment used for manufacturing the semiconductor is discharged to the outside through the vacuum exhaust device, the residual gas contains various impurities.

When such impurities are introduced into a vacuum pump or scrubber connected to the exhaust device, it is almost impossible to remove them and greatly shortens the life of the vacuum pump.

Therefore, a vacuum trap is protected by providing a cold trap to trap and remove these impurities contained in the gas.

1 illustrates an example of a semiconductor manufacturing apparatus including a cold trap according to the prior art, and is used in a process of forming a silicon nitride (Si ₃ N ₄ ) layer on a wafer W in a semiconductor manufacturing process. The silicon nitride layer is used as a mask for etching the silicon dioxide (SiO ₂ ) layer on the wafer (W).

Referring to FIG. 1, a reaction process of a conventional semiconductor manufacturing apparatus will be described. When the main valve 20 is opened and the vacuum pump 40 starts to operate, the pressure inside the diffusion path 10 is lowered. 10) When the pressure inside is sufficiently low, the injected reaction gas starts to react, and the silicon nitride layer is formed on the wafer W. When the silicon nitride layer is formed, the remaining gas is diffused through the exhaust line (10). ) It is discharged to the outside. At this time, the discharged residual gas passes through the cold trap 30.

Ammonium chloride (NH ₄ Cl) gas is one of the gases generated from the reaction in the diffusion furnace 10. When the ammonium chloride gas flows into the vacuum pump 40 and the scrubber 50 and becomes solid, it is almost impossible to remove it. And the cold trap 30 is installed because it greatly reduces the performance of the vacuum pump 40 and the scrubber 50 and shortens the life of the vacuum pump.

On the other hand, ammonium chloride gas solidifies when the temperature is about 150 ° C. or lower when the pressure is 1 Torr. Therefore, when the pressure inside the cold trap is 1 Torr and the internal temperature is about 150 ° C. or lower, ammonium chloride gas solidifies to form a powder, which is adsorbed inside the cold trap.

Conventionally, in order to lower the internal temperature of the cold trap, a coolant tube through which a coolant such as low temperature cooling water flows is provided inside the cold trap. When the coolant tube is used in this way, the coolant may be heated according to heat exchange with the residual gas. Because of the increase, there is a problem in that the temperature of the coolant needs to be lowered and resupplyed again, and the cooling efficiency of the coolant is low, resulting in a low removal rate of residual gas.

In addition, the impurities adsorbed inside the cold trap should be periodically removed. In the conventional cold trap, since impurities are adsorbed in the refrigerant pipe, it takes a long time to remove the impurities, which leads to a problem in that productivity is lowered.

In addition, when the refrigerant leaks due to breakage of the refrigerant pipe, the discharge of the residual gas must be stopped, and the residual gas must be discharged again after repairing the leakage of the refrigerant, thereby reducing the productivity of the entire process. In this case, since a heater is required to increase the temperature, there is a problem in that manufacturing cost and maintenance cost are excessive.

The present invention has been made in view of the above problems, the cooling efficiency is high, and the trapping effect of the specific components of the residual gas or impurities contained in the residual gas, etc. excellent, easy to remove the impurities trapped inside the cold trap Its purpose is to provide.

The present invention for achieving the above object is provided on the discharge path of the residual gas after the manufacturing process, the cold trap for trapping the specific components of the residual gas, impurities contained in the residual gas, etc. A cold trap for collecting impurities and the like, comprising: a collecting tank through which a gas inlet through which the residual gas is introduced and a gas outlet through which the input residual gas is discharged are formed; A cooling line provided in an inner space of the collection tank but having a cold air inlet through which cold air is injected and a cold air outlet through which cold air injected into the cold air inlet is circulated and discharged; In order to supply cold air to the cold air inlet of the cooling line, a valve is opened and closed to allow or block the compressor body from the outside, a regulator for regulating the pressure of the compressor body flowing through the valve, and the pressure is adjusted The compressed gas is separated into warm and cold air, and the warm air is exhausted to the outside, and the cold air is installed at the cold air inlet or the cold air outlet and passes through the vortex tube that supplies the cold air inlet of the cooling line. And a controller for controlling the regulator so that the pressure of the compressor body flowing into the vortex tube is increased when a temperature sensor detecting a temperature of the temperature sensor is higher than a predetermined reference temperature. It can be made, including.

Here, a heat sink having a plurality of holes formed adjacent to the cooling line may be further provided, and the heat sink may be detachably configured.

In this case, an inner space of the collecting tank may further include a collecting container having an upper surface opened and a plurality of holes formed around the upper side, and configured to position the cooling line in the inner space of the collecting tank.

The controller may control the regulator to lower the pressure of the compressor body flowing into the vortex tube when the temperature value detected by the temperature sensor is lower than the reference temperature.

The pressure sensor may further include a pressure sensor configured to detect a pressure of the compressor body flowing into the regulator, wherein the controller is configured to adjust the regulator so that the pressure value detected by the pressure sensor is equal to a predetermined target pressure value. Can be controlled.

Here, the method may further include an air filter for dehumidifying the compressor body introduced through the valve and removing foreign substances.

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

As illustrated in FIG. 2, the cold trap of the present embodiment includes a collecting tank 100, a cooling line 200, and a cold air supply device 300.

The collection tank 100 is formed with a gas inlet 110 into which residual gas is introduced in a process, and a gas outlet 120 through which the remaining residual gas is discharged, thereby removing specific components of residual gas or impurities contained in the residual gas. To form a space for accommodating the residual gas.

Cooling line 200, the cold air inlet 210 and the cold air outlet 220 is formed in the inner space of the collection tank 100, the residual gas contained in the collection tank 100 is cold air to the cold air inlet 210 As heat is exchanged with the surface of the cooling line 200 supplied with a specific component of the residual gas or impurities contained in the residual gas (hereinafter referred to as "impurity of the residual gas") is collected.

The cold air supply device 300 is a device for supplying cold air to the cold air inlet 210 of the cooling line 200, and includes a valve 310, a regulator 320, a vortex tube 330, a temperature sensor ( 340 and the control unit 350 is included.

First, the collection tank 100 will be described.

The collecting tank 100 is a part for forming a space for collecting the residual gas impurities by adding the finished gas, and as shown in FIG. 2 and FIG. 3, at one side such that the remaining gas is injected. The gas inlet 110 is formed, and the gas outlet 120 is formed at the other side so that the remaining residual gas is discharged.

That is, the remaining gas is installed in the path of the exhaust line, the residual gas is introduced into the gas inlet 110 formed on one side, and the residual gas which is completed to be collected is discharged to the gas outlet 120 formed on the other side. The impurities of the remaining gas are collected while being fed into the 110 and discharged to the gas outlet 120.

On the other hand, the structure of the collecting tank 100, as shown in Figure 4, the cover 104, the gas inlet 110 protruding upward from the center portion of the circular panel, and the gas outlet (downward) from the cylindrical bottom center portion ( 120 includes a protruding body 102, and the cover 104 and the body 102 are coupled to each other by a coupling means 106 such as a bolt or the like.

Meanwhile, a collecting cylinder 150 is provided inside the body 102 of the collecting tank 100, and the collecting cylinder 150 has a plurality of holes 150h formed around the upper side thereof. Forming a plurality of holes (150h) around the upper side of the 150, a residual effect that can remain constant when the residual gas passes through the capture tank 100 occurs.

That is, as shown in FIG. 6, after the residual gas introduced into the gas inlet 110 circulates the bottom surface of the collecting container 150, a plurality of holes 150h are formed around the upper side of the collecting container 150. Since it is discharged to the gas outlet 120 through, the residual gas may stay in the collection tank 100 for a predetermined time. Thus, impurities in the residual gas can be collected sufficiently.

On the other hand, the structure in which the collecting container 150 is coupled to be positioned inside the body 102 of the collecting tank 100, as shown in Figure 5, the coupling is formed in the outer side of the upper edge of the collecting container 150 A plurality of flanges 152 are formed, and protruding pins 108 are formed at an inner edge of the body 102 of the collection tank 100 so that the holes of the coupling flanges 152 are fitted to the protruding pins 108, respectively. It is formed into a structure that can be removable.

As such, by combining the collecting container 150 to be detachable to the inside of the body 102 of the collecting tank 100, the cleaning container 150 can be easily separated when cleaning the cold trap, so that the cleaning is easy.

As described above, the collection tank 100 composed of the cover 104 and the body 102 forms a constant space through which the residual gas introduced into the gas inlet 110 passes, and the collecting container is formed inside the body 102. By detachably attaching the 150, the impurity collecting effect of the residual gas can be enhanced and the cleaning can be simplified.

Next, the cooling line 200 will be described.

The cooling line 200 is a portion for cooling the inside of the collection tank 100 by receiving cold air from the cold air supply device 300 which will be described later. As shown in FIGS. 4 and 5, the collection tank ( 100 is coupled to the cover 104 of the collection tank 100 so as to be located inside the collection tank 150 inside the collection tank 100, in detail, the cold air inlet on one side of the cover 104. 210 is formed and the cold air outlet 220 is formed on the other side of the cover 104.

That is, the cold air supplied from the cold air supply device 300 is injected into the cold air inlet 210, and the injected cold air cools the inside of the collection tank 100 while circulating the cooling line 200. It is discharged to the outlet 220.

As such, since the inside of the collection tank 100 is cooled by the cooling line 200 to create an environment in which impurities contained in the residual gas may be collected, the inside of the collection tank 100 may be mixed with the remaining gas. Impurities of the residual gas are collected on the contact surface, that is, the surfaces of the collecting container 150 and the cooling line 200.

At this time, the heat dissipation plate 400 may be provided adjacent to the cooling line 200. Thus, when the heat dissipation plate 400 is provided adjacent to the cooling line 200, the contact surface to which residual gas may contact may be increased. As a result, the effect of collecting impurities in the residual gas becomes larger.

At this time, by forming a plurality of holes (400h) in the heat sink 400, to smooth the flow of the exhaust gas to extend the life of the pump and improve the efficiency of cooling the entire heat sink 400 to collect impurities in the residual gas To improve the effect.

In addition, the heat sink 400 may be detachably configured. Thus, the heat sink 400 may be detachably configured so that the heat sink 400 may be easily separated and cleaned when the cold trap is cleaned.

As described above, the cooling line 200 receives cold air from the cold air supply device 300, which will be described later, to cool the inside of the collection tank 100, and thus, the remaining gas is inside the collection tank 100. The heat exchange is carried out to collect impurities in the residual gas, and the heat sink 400 may be detachably formed adjacent to the cooling line 200 to increase the impurities in the residual gas.

Finally, the cold air supply device 300 for supplying cold air to the cold air inlet 210 of the cooling line 200 will be described.

The cold air supply device 300 is a part for supplying cold air to the cold air inlet 210 of the cooling line 200 using the vortex tube 330 that separates the compressor body into hot and cold valves. The regulator 320, the vortex tube 330, the temperature sensor 340 and the control unit 350 is configured.

The valve 310 is a part which is opened and closed to allow or block the compressor body flowing from the compressor body providing means such as the compressor to be introduced into the cold air supply device 300. The compressor body includes compressed nitrogen gas (GN). ₂ ) compressed air, compressed dry air (CDA), etc. can be used.

On the other hand, the valve 310 described above is opened when the cold air supply device 300 is operated so that the compressor body is introduced into the cold air supply device 300, and when the cold air supply device 300 is not operated. It is closed to block the compressor body from flowing into the cold air supply device 300. That is, it is opened only when the cold air supply device 300 is operated so that the compressor body is introduced into the device.

As the valve 310 used in the cold air supply device 300, a valve that can be controlled by an electric signal, such as a solenoid valve, or a pneumatic valve that opens when a predetermined pressure or more is used. The electrical control of the solenoid valve to allow or block the compressor body flowing from the outside, or by providing the pressure of the compressor body flowing from the outside above or below a certain pressure to allow the pneumatic valve to open and close the external compressor body or You can block.

Meanwhile, as shown in FIG. 7, the air filter 370 may be installed before the compressor body passing through the valve 310 is introduced into the regulator 320.

The compressor body passing through the valve 310 contains foreign substances such as moisture, dust, dust, and the like, which are a cause of failure due to corrosion and accumulation of foreign substances in the machine of the pneumatic system. The air filter 370 is installed. As such, by filtering out foreign substances included in the compressor body flowing into the regulator 320, it is possible to prevent a failure of the device through which the regulator 320 and the compressor body pass.

The pressure of the compressor body flowing through the valve 310 described above is regulated by the regulator 320. In general, a regulator is a device for setting and regulating a gas pressure, for example, a gas of an external compressor body providing means. If the pressure is 8 kg / cm 2 and the gas pressure required by the cold air supply device 300 is 6 kg / cm 2, the regulator 320 is placed in a portion where the compressor body flows into the cold air supply device 300. The gas pressure supplied to the cold air supply device 300 is set to 6 kg / cm 2 by setting the set pressure to 6 kg / cm 2.

That is, the regulator 320 of the cold air supply device 300 is a part for adjusting the gas pressure of the compressor body flowing into the vortex tube 330 to be described later to appropriately adjust the temperature of the cold air. The pressure of the compressor body and the temperature of the cold air flowing into the 330 are included in the description of the vortex tube 330.

The compressor body adjusted to the proper pressure through the regulator 320 is passed through the vortex tube 330, at which time, the compressor body is separated into warm and cold, the warm air is exhausted to the outside, the cold air cooling line 200 It is supplied to the cold air inlet 210.

Here, the vortex tube 330, as shown in Figure 8, the first flow pipe 332 is formed on one side of the case 331 into which the compressor body is introduced, the second flow pipe 333 is formed on the other side, An end of the second flow pipe 333 is a tube in which the control valve 334 is installed, and the principle thereof will be described below.

The gas rotating at high speed causes spontaneous thermal separation, and the hot air flow at this time causes a temperature difference between the outer circumference and the center due to the scroll of the vortex tube 330, and separates the generated warm and cold air from the cooler. Will be functioning.

That is, the compressor body flowing into the case 331 flows while strongly turning the second flow pipe 333 having a large diameter. At this time, the periphery of the outer periphery is high in pressure and the center of the swirling air flow becomes low in pressure, whereby throttling occurs. A portion of the compressor body flows to the first flow pipe 332 while losing heat and cooling while passing through the center of the swirling air stream.

The number of rotations of the gas flow near the outer circumference of the vortex tube 330 and the center gas flow are the same, but the movement speed is higher than the center of the circumference, and the difference in the kinetic energy is converted to heat, so the gas temperature increases and the center gas increases. The temperature drops.

By operating in the same principle as described above, the vortex tube 330 turns the inside of the compressor body into which the cooled air is supplied to the cold air inlet 210 of the cooling line 200, and the warmed temperature is exhausted.

Table 1 below shows the temperature values dropping with respect to the input temperature according to the pressure and cold air ratio when using compressed air as the compressor body.

Supply air pressure unit (kg / cm2) Ratio of cold 20% 30% 40% 50% 60% 70% 80% 1.4 34.4 33.3 31.1 28.3 24.4 20.0 15.6 2 40.9 39.6 37.1 33.8 29.2 24.0 18.1 3 50.4 48.7 45.7 41.6 36.0 29.7 21.9 4 56.9 54.7 50.9 46.1 40.0 32.9 25.1 5 61.6 59.0 54.8 49.4 43.0 35.4 26.9 6 65.4 62.7 58.2 52.7 45.6 37.6 28.6 7 68.6 65.8 61.4 55.7 48.0 39.6 30.0 8 71.1 68.2 63.8 57.3 50.0 40.8 30.4

For example, when the temperature of the air flowing into the vortex tube 330 is 25 ° C. and the pressure is 3 kg / cm 2 and the ratio of the cold air is 80%, the temperature drop is 21.9 ° C., so that the vortex tube 330 is removed. The temperature of the cold air supplied to the cold air inlet 210 of the cooling line 200 is 43.6 ° C.

Ex) 25 ℃-21.9 ℃ = 3.1 ℃

On the other hand, a pressure sensor for detecting the pressure of the compressor body flowing into the regulator 320 is installed, the pressure sensor is a portion for detecting the pressure of the compressor body flowing from the regulator 320, the control unit 350 is a pressure sensor The pressure value of the compressor body sensed from the control unit 350 is compared with the target pressure value of the control unit 350 to control the pressure of the compressor body flowing out of the regulator 320 to be equal to the target pressure value.

For example, the control unit 350 controls the pressure of the compressor body to be 3 kg / cm ² in a state where the ratio of cold air is 80% in order to maintain 3.1 ° C. as described above.

In addition, a temperature sensor 340 is installed at the cold air inlet 210 or the cold air outlet 220, and when the temperature value detected by the temperature sensor 340 is higher than a preset reference temperature, the vortex tube 330 flows into the vortex tube 330. The regulator 320 may be controlled to increase the pressure of the compressor body.

That is, when the temperature value detected by the temperature sensor 340 is higher than the reference temperature of the controller 350, the controller 350 controls the regulator 320 to increase the pressure of the compressor body flowing into the vortex tube 330. In this way, by increasing the pressure of the compressor body flowing into the vortex tube 330, the temperature drop value of the compressor body increases, thereby supplying the cold air supplied to the cold air inlet 210 at a lower temperature. It is to control to the desired temperature.

In addition, when the temperature value detected by the temperature sensor 340 is lower than the reference temperature, the controller 350 controls the regulator 320 to lower the pressure of the compressor body flowing into the vortex tube 330, Therefore, the temperature drop value of the compressor body is reduced, thereby controlling the temperature of the cold air supplied to the cold air inlet 210.

As described above, the cold air generated from the cold air supply device 300 including the valve 310, the regulator 320, the vortex tube 330, the temperature sensor 340, and the controller 350 is cooled to the cooling line 200. It is supplied to the cold air inlet 210 of the), the cooling line 200 is supplied with cold air to cool the inside of the collection tank (100).

As a result, as the inside of the collecting tank 100 is cooled, the residual gas is heat-exchanged while passing through the collecting tank 100, whereby impurities of the residual gas are collected.

The present invention described above can be embodied in many other forms without departing from the spirit or main features thereof. Therefore, the above embodiments are merely examples in all respects and should not be interpreted limitedly.

According to the present invention configured as described above, it is possible to prevent the environmental damage by using the compressor body in place of the existing refrigerant or cooling material, and the cooling efficiency is high, and the effect of collecting specific components of the residual gas or impurities of the residual gas is excellent. .

In addition, since no heater is required to increase the temperature during supercooling, manufacturing cost and maintenance cost are reduced.

In addition, as the collection effect of the specific components of the residual gas or impurities contained in the residual gas is excellent, it is possible to prevent the specific components of the residual gas or the impurities contained in the residual gas from sticking to an auxiliary device such as a vacuum pump or a scrubber. This prevents the breakdown of the accessory device and extends the device life.

On the other hand, by providing a heat sink adjacent to the cooling line, the collection effect can be further increased by increasing the area where the reaction gas can contact.

In addition, since the heat sink is detachably configured, cleaning of the collection is easy.

In addition, by providing a collecting container in the collecting tank, and increasing the residual time of the residual gas, the collecting effect is excellent.

Claims (8)

In the cold trap that is installed on the discharge path of the residual gas after the manufacturing process, and collects the specific components of the residual gas, impurities contained in the residual gas, etc. A collection tank through which a gas inlet through which the residual gas is introduced and a gas outlet through which the injected residual gas is discharged are formed, and through which the residual gas passes; A cooling line provided in an inner space of the collection tank but having a cold air inlet through which cold air is injected and a cold air outlet through which cold air injected into the cold air inlet is circulated and discharged; In order to supply cold air to the cold air inlet of the cooling line, a valve is opened and closed to allow or block the compressor body from the outside, a regulator for regulating the pressure of the compressor body flowing through the valve, and the pressure is adjusted The compressed gas is separated into warm and cold air, and the warm air is exhausted to the outside, and the cold air is installed at the cold air inlet or the cold air outlet and passes through the vortex tube that supplies the cold air inlet of the cooling line. And a controller for controlling the regulator so that the pressure of the compressor body flowing into the vortex tube is increased when a temperature sensor detecting a temperature of the temperature sensor is higher than a predetermined reference temperature. Cold trap, characterized in that consisting of. The method of claim 1, And a heat sink having a plurality of holes formed adjacent to the cooling line. The method of claim 2,  Cold trap characterized in that the heat sink is removable. The method of claim 1, Cold traps, characterized in that the inner space of the collecting tank, the upper surface is opened and a plurality of holes are formed around the upper side, the cooling line is located in the inner space of the collecting tank. The method of claim 1, The control unit, Cold regulator, characterized in that for controlling the regulator to lower the pressure of the compressor body flowing into the vortex tube when the temperature value detected by the temperature sensor is lower than the reference temperature. The method of claim 1, Cold trap further comprises a pressure sensor for detecting the pressure of the compressor body flowing into the regulator. The method of claim 6, The control unit, And the regulator is controlled such that the pressure value sensed by the pressure sensor is equal to a predetermined target pressure value. The method of claim 1, Cold trap further comprises an air filter for dehumidifying the compressor body flowing through the valve and to remove foreign substances.

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