KR20080082128A - Wet station and method for controlling level of solution in the wet station - Google Patents

Abstract

A wet cleaning apparatus and a method for controlling a level of a solution in the wet cleaning apparatus are provided to prevent a cleaning bath from being flooded by the solution by automatically discharging the solution according to the level of the solution. A wet cleaning apparatus includes a cleaning bath(10), a solution spray unit(40), a level measuring unit(50), an ejector(70), and a controller(80). The cleaning solution is contained in the cleaning bath. The solution spray unit selectively supplies the solution to the cleaning bath according to a concentration variation of the cleaning solution. The level measuring unit measures a level of the cleaning solution. The ejector ejects the cleaning solution to outside. The controller controls the ejector according to a measurement signal from the level measuring unit, when the solution is supplied to the cleaning bath by the solution spray unit.

Description

WET STATION AND METHOD FOR CONTROLLING LEVEL OF SOLUTION IN THE WET STATION}

1 is a view for explaining a wet cleaning apparatus according to the present invention.

Figure 2 is a block diagram illustrating a method for adjusting the cleaning liquid level of the wet cleaning apparatus according to the present invention.

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

10: washing tank 20: inner tank

30: external tank 40: chemical liquid supply means

50: level measurement means 60: concentration detection means

70: discharge means 80: control unit

90: circulation means

The present invention relates to a wet cleaning apparatus, and more particularly, to a wet cleaning apparatus capable of stably controlling the level of the cleaning liquid and a method for adjusting the cleaning liquid level of the wet cleaning apparatus.

In general, in order to manufacture a semiconductor device, processes such as lithography, deposition, and etching are repeatedly performed. During these processes, various particles, metal impurities, organics, etc. remain on the substrate (eg, silicon wafer). Since such contaminants adversely affect the yield and reliability of the product, a cleaning process for removing contaminants remaining on the substrate should be performed in the semiconductor manufacturing process.

As such, the method of cleaning the substrate may be largely classified into a dry cleaning method and a wet cleaning method according to a processing method. Among them, the wet cleaning method refers to a method of cleaning a substrate by immersing the substrate for a predetermined time in a cleaning tank containing a cleaning liquid mixed with various chemical liquids at a predetermined ratio.

On the other hand, the concentration of the cleaning liquid used in the wet cleaning apparatus greatly affects the cleaning efficiency of the substrate. That is, when the concentration of the cleaning liquid is lowered below a certain level, since the cleaning effect of the substrate is also lowered, the concentration of the cleaning liquid should be kept constant during the cleaning process. However, when the cleaning process is continuously performed, the chemical liquid contained in the cleaning liquid is evaporated and the concentration of the cleaning liquid decreases. Therefore, additional supply of the chemical liquid should be made according to the concentration change of the cleaning liquid during the cleaning process.

However, conventionally, when the concentration of the cleaning liquid is lowered below a certain level without considering the level of the cleaning liquid, the additional supply of the chemical liquid is made. Thus, the level of the cleaning liquid is higher than the safety level by the additional supply of the chemical liquid for the concentration correction of the cleaning liquid. As a result, a problem arises in that the cleaning liquid overflows the cleaning tank in some cases.

That is, conventionally, even when the level of the cleaning liquid is close to the safety level, when the concentration of the cleaning liquid falls below a certain level, additional supply of the chemical liquid is made, so that the cleaning liquid overflows the cleaning tank and flows into other equipment around the cleaning tank. There is a problem. Since such a cleaning liquid has a very strong chemical property, there is a problem of causing corrosion and damage to the equipment when introduced into the peripheral equipment.

Accordingly, an object of the present invention is to provide a wet cleaning device capable of stably controlling the level of the cleaning liquid and a method for adjusting the cleaning liquid level of the wet cleaning device.

In particular, the present invention provides a wet cleaning apparatus and a method for adjusting the cleaning liquid level of the wet cleaning apparatus to selectively discharge the cleaning liquid according to the level of the cleaning liquid when the chemical liquid for the concentration correction of the cleaning liquid is additionally supplied during the cleaning process. There is a purpose.

In addition, an object of the present invention is to provide a wet cleaning apparatus and a method for adjusting the cleaning liquid level of the wet cleaning apparatus, which can automatically discharge the cleaning liquid according to the level of the cleaning liquid and prevent the overflow of the cleaning liquid. .

In addition, an object of the present invention is to provide a wet cleaning apparatus capable of reducing the amount of chemical liquid used, and a method for adjusting the cleaning liquid level of the wet cleaning apparatus.

According to a preferred embodiment of the present invention for achieving the above object of the present invention, the wet cleaning device is a cleaning tank containing the cleaning liquid, the chemical liquid supply means for selectively supplying the chemical liquid to the cleaning tank according to the concentration change of the cleaning liquid, the cleaning liquid Level measurement means for measuring the level, the discharge means for discharging the cleaning liquid to the outside of the cleaning tank, the control unit for controlling the discharge means in accordance with the measurement signal of the level measurement means when the chemical liquid is supplied by the chemical liquid supply means.

The shape and structure of the cleaning bath can be varied in various ways depending on the required conditions and design specifications. As an example, the cleaning tank may include an inner tank and an outer tank. The inner tank contains the cleaning liquid and substantially the cleaning operation can be performed, and the outer tank contains the cleaning liquid overflowed from the inner tank. In addition, a circulation means for connecting the inner tank and the outer tank and circulating the washing liquid of the outer tank to the inner tank may be provided outside the washing tank.

The chemical liquid supply means is provided to selectively supply the chemical liquor to the cleaning tank according to the concentration change of the cleaning liquid. Whether the chemical liquid is supplied through the chemical liquid supply means and the supply amount may be controlled by a detection signal by a conventional concentration sensing means for detecting the concentration of the cleaning liquid. In addition, the chemical solution supply means may be configured to supply the chemical liquid to at least one side of the outer tank and the inner tank. However, when a high concentration chemical is directly supplied to the inner tank in which the substrate is accommodated, the substrate may be damaged by the high concentration chemical, so that the chemical is supplied to the outer tank first, and then mixed with the existing cleaning liquid through the circulation means. It is preferable to configure to flow into the inner tank.

The level measuring means is provided to measure the level change of the cleaning liquid, and the level measuring method of the level measuring means may be applied in various ways according to the required conditions.

The discharge means is provided to selectively discharge the washing liquid in the washing tank to the outside of the washing tank. As such discharge means, various methods for discharging the cleaning liquid in the cleaning tank to the outside may be employed.

The discharge means may be configured to be independently provided in the inner tank and the outer tank, respectively, to discharge the cleaning liquid contained in the inner tank and the outer tank to the outside, and in some cases, may be configured to discharge the cleaning liquid of any one of the inner tank and the outer tank to the outside. . Preferably, it can be configured to discharge the cleaning solution of the relatively low concentration tank to prevent unnecessary waste of the chemical liquid and to reduce the amount of the chemical liquid used.

Whether or not the discharge of the cleaning liquid by the discharge means and the discharge can be controlled according to the detection signal of the level measuring means through the control unit, such a control unit can be implemented by a conventional sequence program.

On the other hand, according to a preferred embodiment of the present invention, the cleaning liquid level control method of the wet cleaning device detects the change in the concentration of the cleaning liquid inside the cleaning tank, supplying the chemical liquid to the cleaning tank in accordance with the detected concentration change signal of the cleaning liquid, chemical liquid And measuring a change in the level of the cleaning liquid as supplied, and discharging a part of the cleaning liquid to the outside of the cleaning tank when the measured level of the cleaning liquid is higher than a preset reference level.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, but the present invention is not limited or limited by the embodiments. For reference, in the present description, the same numbers refer to substantially the same elements, and may be described by quoting the contents described in other drawings under the above rules, and the contents repeated or deemed apparent to those skilled in the art may be omitted.

1 is a view for explaining a wet cleaning apparatus according to the present invention.

As shown in FIG. 1, the wet cleaning apparatus according to the present invention includes a washing tank 10, a chemical liquid supply means 40, a level measuring means 50, a discharge means 70, and a controller 80.

The cleaning tank 10 is formed in a size that can accommodate a substrate for cleaning as a container in which the cleaning liquid is accommodated, and the shape and structure of the cleaning tank 10 may be variously changed according to required conditions and design specifications. In addition, the cleaning tank 10 is formed of a material that does not react with the cleaning liquid, the material of the cleaning tank 10 may be appropriately changed according to the required conditions. For example, the cleaning tank 10 may be formed of ordinary quartz, and other materials may be used.

In the present invention, the cleaning liquid may include a single or a plurality of chemical solutions as a chemical solution for cleaning contaminants remaining on the substrate.

Hereinafter, the washing tank 10 will be described with an example including the inner tank 20 and the outer tank 30. The cleaning solution is accommodated in the inner tank 20, and the cleaning operation is substantially performed in the inner tank 20. The outer tub 30 is formed along the circumference of the inner tub 20 to accommodate the washing liquid overflowed from the inner tub 20.

And, the outer side of the washing tank 10 may be provided with a circulation means 90 for connecting the inner tank 20 and the outer tank 30 and circulating the cleaning liquid of the outer tank 30 to the inner tank 20. The circulation means 90 may include a conventional circulation pump and a circulation passage, and the structure of the circulation means 90 may be variously changed according to required conditions and design specifications. In addition, various additional devices such as a filter and a heater may be provided on the circulation means 90, and the cleaning solution of the inner tank 20 and the outer tank 30 is circulated through the circulation means 90 through the additional device. Can be mixed, filtered and heated.

The chemical liquid supply means 40 is provided to selectively supply the chemical liquid (chemical liquor) to the cleaning tank 10 according to the concentration change of the cleaning liquid. That is, when the cleaning process is continuously performed, the chemical liquid contained in the cleaning liquid evaporates and the concentration of the cleaning liquid decreases. In this case, the chemical liquid supply means 40 additionally supplies the chemical liquid according to the change in the concentration of the cleaning liquid. The concentration of the cleaning liquid can be kept constant during the cleaning process.

The chemical liquid supply means 40 may include a conventional chemical liquid storage unit, a pump and a supply passage, and the structure of the chemical liquid supply means 40 may also be variously changed according to required conditions and design specifications. In addition, the chemical solution supply means 40 may be configured to supply only one chemical solution, and in some cases, may be configured to independently supply a plurality of chemical liquids having different chemical properties.

Whether or not the chemical solution is supplied through the chemical liquid supply means 40 may be controlled by a detection signal by the conventional concentration sensing means 60 for detecting the concentration of the cleaning liquid. That is, the concentration detecting means 60 detects the concentration of the cleaning liquid while the cleaning process is performed, and whether or not the additional supply of the chemical liquid and the amount of supply of the chemical liquid can be controlled according to the concentration change signal of the cleaning liquid detected by the concentration detecting means 60. have.

On the other hand, the chemical liquid supply means 40 may be configured to supply the chemical liquid to at least one side of the outer tank 30 and the inner tank (20). However, when the high concentration chemical liquid is directly supplied to the inner tank 20 in which the substrate is accommodated, since the substrate may be damaged by the high concentration chemical liquid, the chemical liquid is supplied to the outer tank 30 first, and then the circulation means 90 It is preferable to configure to flow into the inner tank 20 after being mixed with the existing washing liquid.

The level measuring means 50 is provided to measure the level change of the cleaning liquid. That is, the level measuring means 50 is provided to measure the level change of the cleaning liquid as the chemical liquid is additionally supplied, and the level measuring method of the level measuring means 50 may be applied in various ways according to the required conditions. . For example, the level measuring means 50 allows the non-reacted gas to be ejected through the tube from a position close to the inner bottom of the cleaning tank 10, and after measuring the back pressure applied when the non-reacted gas is ejected, the measured The back pressure may be compared with a preset reference value to measure the level of the cleaning liquid.

The discharge means 70 is provided to discharge the cleaning liquid in the cleaning tank 10 to the outside of the cleaning tank 10 selectively. That is, the discharge means 70 discharges the cleaning liquid in the cleaning tank 10 to the outside when the level of the cleaning liquid in the cleaning tank 10 rises above a certain level, and the cleaning liquid level in the cleaning tank 10 is kept constant. To be able. As the discharge means 70, various methods for discharging the cleaning liquid in the cleaning tank 10 to the outside may be employed. As an example, the discharge means 70 may include a discharge passage connected to the cleaning tank 10 and a valve for selectively opening and closing the discharge passage.

The discharge means 70 may be configured to be independently provided in the inner tank 20 and the outer tank 30 to discharge the cleaning liquid contained in the inner tank 20 and the outer tank 30 to the outside, respectively. It may be configured to discharge the cleaning liquid of any one of the inner tank 20 and the outer tank 30 to the outside.

Preferably, the discharge means 70 is configured to discharge the cleaning liquid contained in the inner tank 20 to the outside. That is, when the discharge means 70 is provided on the inner tank 20 and configured to discharge the cleaning liquid contained in the inner tank 20, the chemical liquid is additionally supplied so that the concentration is relatively lower than that of the high concentration tank 30. By allowing the cleaning liquid of the inner tank 20 to be discharged, it is possible to prevent unnecessary waste of the chemical liquid and to reduce the amount of chemical liquid used.

Whether the cleaning liquid is discharged by the discharge means 70 and the discharge amount may be controlled according to a detection signal of the level measuring means 50 through the controller 80. That is, the controller 80 controls whether the cleaning liquid is discharged or discharged according to the level change signal of the cleaning liquid measured by the level measuring means 50 when the chemical liquid is supplied to the cleaning tank 10 according to the concentration change of the cleaning liquid. As such, the controller 80 may be implemented by a general sequence program.

Hereinafter will be described a method for adjusting the cleaning liquid level of the wet cleaning apparatus according to the present invention. Figure 2 is a block diagram illustrating a method for adjusting the cleaning liquid level of the wet cleaning apparatus according to the present invention. In addition, the same or equivalent reference numerals are given to the same or equivalent components as those described above, and detailed description thereof will be omitted.

As shown in Figure 2, the cleaning liquid level control method of the wet cleaning apparatus according to the present invention comprises the steps of detecting the cleaning liquid concentration change in the cleaning tank 10, the cleaning tank 10 in accordance with the detected signal of the concentration change of the cleaning liquid ) Supplying the chemical liquid to the step, measuring a change in the level of the cleaning liquid as the chemical liquid is supplied, and discharges a part of the cleaning liquid to the outside of the cleaning tank 10 when the measured level of the cleaning liquid is higher than the predetermined reference level It includes a step.

In this case, the cleaning tank 10 may include an inner tank 20 for performing a cleaning operation and an outer tank 30 containing a cleaning liquid overflowed from the inner tank 20, and the cleaning liquid of the outer tank 30. May be circulated to the inner tank 20.

First, the cleaning liquid concentration change in the cleaning tank 10 is sensed while the cleaning process is in progress. Whether or not the additional supply of the chemical liquid may be determined according to the concentration change signal sensed at this stage. If the concentration of the cleaning liquid is constant, the cleaning process may be continuously performed without supplying the additional chemical liquid.

Thereafter, the chemical liquid is supplied to the cleaning tank 10 in accordance with the concentration conversion signal of the cleaning liquid. That is, in the step of supplying the chemical liquid, a certain amount of the chemical liquid is supplied according to the concentration change of the cleaning liquid. In this step, only one chemical liquid may be supplied. Alternatively, a plurality of chemical liquids having different chemical characteristics may be independently Can be supplied.

In addition, in the step of supplying the chemical liquid, when the high concentration chemical liquid is directly supplied to the inner tank 20 in which the substrate is accommodated, since the substrate may be damaged by the high concentration chemical liquid, the chemical liquid is supplied to the outer tank 30 first In addition, the chemical solution supplied to the outer tank 30 is preferably configured to be supplied to the inner tank 20 after being mixed with the existing washing liquid while passing through the circulating water stage 90.

Next, the change in the level of the cleaning liquid as the chemical liquid is supplied is measured. Whether the cleaning liquid is discharged or discharged may be determined according to the level change signal of the cleaning liquid detected in this step, and when the level of the cleaning liquid is lower than the preset reference level, the cleaning process may be continuously performed without discharging the cleaning liquid.

Next, a part of the cleaning liquid is discharged to the outside of the cleaning tank 10 in accordance with the measured level change signal of the cleaning liquid. In this step, when the level of the cleaning liquid according to the supply of the chemical liquid is higher than the predetermined reference level, a part of the cleaning liquid may be automatically discharged to the outside of the cleaning tank 10, and when the level of the cleaning liquid is lower than the preset reference level The cleaning process can be performed continuously without discharging the cleaning liquid.

In addition, the step of discharging the cleaning liquid is preferably configured to discharge the cleaning liquid of the inner tank 20 having a relatively lower concentration than the cleaning liquid of the outer tank 30 to prevent unnecessary waste of the chemical liquid and to reduce the amount of the chemical liquid used. .

In the discharging of the cleaning liquid, the cleaning liquid may be discharged when the level change signal of the cleaning liquid lasts for a predetermined time or more. Of course, the cleaning liquid may be discharged immediately when the change of the cleaning liquid is measured. However, since the cleaning liquid may be temporarily changed during the cleaning process, unnecessary cleaning liquid may be prevented and the cleaning liquid may be stably maintained. In the discharging of the cleaning liquid, the cleaning liquid may be discharged if the level change signal of the cleaning liquid lasts for a predetermined time or more.

In addition, in the discharging of the cleaning liquid, the cleaning liquid may be uniformly discharged by a predetermined amount, and in some cases, only the amount corresponding to the supply amount of the chemical liquid may be discharged.

On the other hand, in the above-described embodiment of the present invention has been described with an example configured to discharge the cleaning liquid in accordance with the change in the level of the cleaning liquid as the supply of the chemical liquid, otherwise the cleaning liquid is supplied at the same time according to the concentration and level of the cleaning liquid Can be configured to be discharged.

As described above, the cleaning liquid level adjusting method of the wet cleaning device and the wet cleaning device according to the present invention has the effect of stably controlling the level of the cleaning liquid.

In particular, the present invention allows the cleaning liquid to be selectively discharged according to the level of the cleaning liquid when the chemical liquid for the concentration correction of the cleaning liquid is additionally supplied during the cleaning process. Therefore, the concentration of the cleaning liquid can be kept constant during the cleaning process, as well as the level of the cleaning liquid can be stably maintained.

In addition, the present invention allows the cleaning liquid to be discharged automatically according to the level of the cleaning liquid and prevents the phenomenon that the level of the cleaning liquid rises above the safety level or the cleaning liquid overflows the cleaning tank.

In addition, according to the present invention there is an effect that can prevent unnecessary waste of the chemical liquid and reduce the amount of the chemical liquid used.

As described above, although described with reference to the preferred embodiment of the present invention, those skilled in the art various modifications and variations of the present invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

Claims (9)

A washing tank in which a washing liquid is accommodated; Chemical liquid supply means for selectively supplying the chemical liquid to the cleaning tank according to the concentration change of the cleaning liquid; Level measuring means for measuring the level of the cleaning liquid; Discharge means for discharging the cleaning liquid to the outside of the cleaning tank; And A control unit controlling the discharge means according to a measurement signal of the level measuring means when the chemical liquid is supplied by the chemical liquid supply means; Wet cleaning device comprising a. The method of claim 1, The cleaning tank includes an inner tank for performing a cleaning operation and an outer tank containing a cleaning liquid overflowed from the inner tank, Wet cleaning apparatus further comprises a circulation means for circulating the cleaning solution of the outer tank to the inner tank. The method of claim 2, The chemical liquid supply means is a wet cleaning device, characterized in that for supplying the chemical liquid to the outer tank. The method of claim 2, The discharge means is a wet cleaning apparatus, characterized in that installed on at least one side of the inner tank and the outer tank. Detecting a change in the concentration of the cleaning liquid in the cleaning tank; Supplying a chemical liquid to the cleaning tank according to the detected concentration change signal of the cleaning liquid; Measuring a level change of the cleaning liquid as the chemical liquid is supplied; And Discharging a portion of the cleaning liquid to the outside of the cleaning tank when the measured level of the cleaning liquid is higher than a predetermined reference level; Cleaning liquid level control method of the wet cleaning device comprising a. The method of claim 5, In the discharging of the cleaning liquid, the cleaning liquid level control method, characterized in that the cleaning liquid is discharged when the level change signal of the cleaning liquid lasts for more than a predetermined time. The method of claim 5, The cleaning tank includes an inner tank for performing a cleaning operation and an outer tank for receiving a washing liquid overflowed from the inner tank, wherein the washing liquid of the outer tank is circulated to the inner tank. The method of claim 7, wherein The cleaning liquid level control method, characterized in that the chemical liquid is supplied to the outer tank in the step of supplying the chemical liquid. The method of claim 7, wherein And discharging the cleaning liquid, wherein the cleaning liquid contained in the inner tank is discharged.

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