KR20020088233A - Marangoni type wafer cleaning equipment - Google Patents

Abstract

PURPOSE: A marangoni type wafer cleaning equipment is provided to prevent the leakage of solvent vapor flowing into a drying and washing unit so that the efficiency of cleaning process of a wafer is improved. CONSTITUTION: A marangoni type wafer cleaning equipment includes a storing part for solvent(B) and a drying part for a wafer(34) and a washing unit surrounded by the upper hood(206) and a housing(208) respectively. The upper hood is arranged without any separation with the housing in order to prevent the leakage of the solvent vapor inside the drying and washing room. A heater(201) in liquid tank(200) is installed to increase the vapor pressure of solvent. The third pipe is equipped to avoid overload of vapor pressure caused by heating and a control valve(205) is used to make the pressure constant.

Description

MARANGONNI TYPE WAFER CLEANING EQUIPMENT}

The present invention relates to a wafer cleaning apparatus, and more particularly, to a marangoni-type wafer cleaning apparatus capable of improving the cleaning efficiency of a wafer.

Semiconductor devices or semiconductor chips are generally manufactured by processing wafers formed of silicon using semiconductor equipment. Wafers are typically manufactured as semiconductor devices or semiconductor chips through a series of semiconductor device manufacturing processes such as photolithography, chemical or physical vapor deposition, and plasma etching.

During the process of manufacturing the semiconductor device, foreign substances such as compounds or particles remain on the surface of the wafer. In order to improve the quality of the semiconductor device, the wafer may be cleaned through a washing process such as washing and drying. Foreign matter remaining on the surface should be completely removed. In particular, when the wafer is cleaned using deionized water (DIW), hydration may occur due to the reaction of the deionized water with silicon. Therefore, the wafer must be completely dried after the cleaning process so that defects such as water marks on the silicon surface due to the hydration do not occur.

In the conventional method of drying the wafer, a spin rinse / dryer is mainly used. However, in the spin rinse / dryer, foreign matter may remain on the surface of the wafer due to the generation of static electricity while the rotational force is applied to the wafer. Further, as the line width of the pattern formed on the semiconductor substrate becomes smaller and the pattern becomes more complicated, there is a high possibility that the pattern collapses due to the frictional force between the deionized water and the pattern due to centrifugal force.

In order to improve the cleaning and drying efficiency of the wafer, a cleaning method utilizing the MARANGONNI EFFECT has recently been used. The Marangoni effect is a principle in which a liquid flows from a small surface tension region to a large surface tension region when two different surface tension regions exist in one liquid region. The marangoni-type wafer cleaning apparatus using the same is a method of removing deionized water from the surface of a wafer by applying isopropyl alcohol (IPA) vapor having a smaller surface tension than deionized water to the surface of the wafer. At this time, impurities on the wafer surface are removed together with the deionized water.

1 is a schematic cross-sectional view for explaining a conventional marangoni wafer cleaning apparatus.

Referring to FIG. 1, the marangoni wafer cleaning apparatus includes a storage unit A for storing a solvent, a drying unit surrounded by an upper hood 106, and a cleaning unit including a housing 108 filled with deionized water 14. . When the wafer is loaded into the cleaning apparatus, the solvent vapor 12 is injected into the drying unit surrounded by the upper hood 106 through the first pipe 104 connected to the upper hood 106. The solvent vapor 12 is a mixed gas of the solvent and the carrier gas 10.

Specifically, in order to generate the solvent vapor 12, the carrier gas 10 is injected into the liquid tank 100 in which the liquid solvent 11 is stored through the second pipe 102. At this time, the carrier gas 10 is injected into the liquid solvent 11 through the bubbler 107 provided in the second pipe 102 to generate bubbles. The liquid solvent 11 is vaporized by the injected carrier gas 10 to generate a solvent vapor 12 composed of a carrier gas and a solvent.

Subsequently, the injected solvent vapor 12 forms the solvent condensation layer 15 on the surface of the deionized water 14 filled in the housing 108. When the wafer 34 is immersed in the deionized water 14 and then rises to the drying unit in the upper hood 106, impurities are removed and dried by the marangoni effect while passing through the solvent condensation layer 15. .

However, as shown in FIG. 1, in the conventional marangoni wafer cleaning apparatus, an upper hood 106 surrounding the drying unit and a housing 108 filled with deionized water are provided at a distance from each other. As a result, the solvent vapor 13 injected into the drying part flows out into the space between the upper hood 106 and the housing 108. As a result, the concentration of the edge portion 16 of the solvent condensation layer 15 is lowered, resulting in a lower cleaning efficiency of the outer region of the wafer 34.

An object of the present invention is to provide a marangoni-type wafer cleaning apparatus having a high cleaning efficiency without the solvent vapor flowing into the drying unit and the cleaning unit in order to achieve the above-described problems.

1 is a schematic cross-sectional view for explaining a conventional marangoni wafer cleaning apparatus.

2 is a schematic cross-sectional view for explaining a marangoni wafer cleaning apparatus according to the present invention.

※ Explanation of code about main part of drawing ※

100, 200: liquid tank 104, 204: first pipe

106, 206: upper hood 108, 208: housing

102, 202: second pipe 203: third pipe

205: control valve 201: heating means

11, 21: liquid solvent 107, 207: bubbler

14: deionized water 15, 25: solvent condensation layer

In order to achieve the above object, the wafer cleaning apparatus of the present invention includes a housing filled with deionized water and an upper hood covering the upper portion of the housing and having a predetermined space therein, a storage portion for storing a solvent, and the storage portion. It includes a first pipe for delivering the solvent vapor to the upper hood. The upper hood and the housing are installed to be sealed without a separation distance during the cleaning and drying of the wafer to prevent the leakage of solvent vapor.

Specifically, the storage unit for storing the solvent includes a liquid tank in which the liquid solvent is stored and a second pipe for injecting a carrier gas into the liquid solvent. A bubbler is installed in the second pipe extending in the liquid solvent, through which the carrier gas is stored to generate bubbles in the liquid solvent to form solvent vapor.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the examples illustrated below. Rather, the embodiments illustrated herein are merely described to make the claims of the present invention clear and easy to understand. Accordingly, it is apparent that the present invention may be modified or further embodied by those skilled in the art within the technical spirit of the present invention.

2 is a schematic cross-sectional view of a marangoni wafer cleaning apparatus for explaining a preferred embodiment of the present invention.

Referring to FIG. 2, the marangoni-type wafer cleaning apparatus according to the present invention is surrounded by a storage unit B in which a solvent is stored, an upper hood 206, a drying unit in which a wafer 34 is dried, and the upper hood ( It includes a cleaning unit surrounded by a housing 208 installed at the bottom of the 206.

The first pipe 204 is connected to the upper hood 206 to transfer the solvent vapor 22 from the reservoir B. The deionized water 14 is filled in the washing section surrounded by the housing 208. In addition, the injection means 30 is installed in the upper hood 206 to inject the solvent vapor 22 received from the first pipe 204 into the drying unit. One of the features of the present invention is that the upper hood 206 and the housing 208 are arranged without a gap, unlike the conventional wafer cleaning apparatus shown in FIG. Therefore, since the outflow of the solvent vapor can be prevented and a uniform solvent condensation layer can be formed on the surface of the deionized water, the efficiency of cleaning and drying the wafer can be improved.

The storage unit B is in the liquid tank 200 in which the liquid solvent 21 is stored, the second pipe 202 for injecting the carrier gas 20 into the liquid solvent 21, and the liquid tank 200. The first pipe 204 extends. Another feature of the present invention is to install heating means 201 in the liquid tank 200. The heating means 201 may be used to increase the temperature inside the liquid tank 200. The purpose is to increase the vapor pressure of the solvent vapor 22 by increasing the temperature inside the liquid tank 200. A bubbler 207 is provided in the second pipe 202 extending in the liquid solvent 21. The bubbler 207 generates bubbles in the liquid solvent 21 to form the solvent vapor 22.

The solvent vapor 22 is formed to increase the pressure in the liquid tank 200 in the process of cleaning the wafer may be a heavy load on the device. In order to prevent this, a third pipe 203 capable of exhausting the solvent vapor 22 may be installed in the liquid tank 200. In addition, it is preferable to equip the third pipe 203 with a control valve 205 capable of controlling pressure so that the vapor pressure in the liquid tank 200 can be controlled constantly.

In the cleaning process of the marangoni wafer cleaning apparatus of the present invention, first, the liquid solvent 21 is stored in the liquid tank 200. The liquid solvent 21 is a material having a lower surface tension than deionized water, for example, isopropyl alcohol 21. The carrier gas 20 is supplied into the liquid tank 200 through the second pipe 202. The carrier gas 20 is preferably one selected from oxygen, nitrogen and argon, for example. When the carrier gas 20 is supplied, bubbles are generated by the bubbler 207 provided in the liquid solvent 21, thereby promoting vaporization of the liquid solvent 21 to be a mixed gas of the carrier gas and the solvent. Solvent vapor 22 is formed. As described above, since the heating means 201 is installed in the liquid tank 200, the formation of the solvent vapor 22 is further promoted, so that the solvent vapor 22 having a higher vapor pressure can be obtained as compared with the conventional art. have. The solvent vapor 22, for example, a mixture of nitrogen and isopropyl alcohol, is delivered to the drying unit in the upper hood 206 through the first pipe 204. When the solvent vapor 22 is injected into the deionized water 14 filled in the drying unit and the housing 208 by the injection means (not shown) provided in the upper hood 206, the deionized water 14 The solvent condensation layer 25 is formed on the surface. When the wafer 34 to be cleaned is immersed in the deionized water 14 and then slowly moved upward, the solvent condensation layer 25 is partially drawn along the surface of the wafer 34. At this time, the surface tension is inclined between the wafer 34, the solvent condensation layer 25 and the deionized water 14, and the surface of the wafer 34 is dried at the same time by the marangoni effect. 34) Foreign substances on the surface are removed together. In addition, the surface of the wafer 34 is completely dried by the solvent gas 22 injected into the drying part in the upper hood 206.

As described above, unlike the conventional cleaning apparatus, the wafer cleaning apparatus of the present invention is sealed between the upper hood 206 and the housing 208. Therefore, the solvent condensation layer 25 is uniformly formed on the surface of the deionized water 14 because the solvent gas 22 in the drying unit does not leak to the outside between the upper hood 206 and the housing 208. do.

As described above, the marangoni-type wafer cleaning apparatus according to the present invention is provided with a sealed upper lid covering the drying portion and a housing filled with deionized water without a separation distance, thereby preventing the outflow of the solvent vapor used for cleaning to prevent deionized water. A uniform solvent condensation layer can be formed on the surface of the. As a result, the entire surface of the wafer can be cleaned evenly.

In addition, by providing a heating means in the solvent storage, it is possible to increase the vapor pressure of the solvent vapor used in the cleaning process for cleaning and drying the wafer to increase the efficiency of the wafer cleaning process.

Claims (7)

In the wafer cleaning apparatus for cleaning and drying the substrate using the vaporization of the solvent, A housing having an upper opening filled with deionized water; An upper hood covering an upper portion of the housing and having a predetermined space therein; A first tubing connected to the upper hood for delivering solvent vapor into the upper hood; and Including a storage unit for storing the solvent connected to the first pipe, When cleaning and drying the wafer, the upper hood and the housing is sealed without separation distance Maranoni wafer cleaning apparatus, characterized in that the leakage of solvent vapor is prevented. According to claim 1, The solvent is Marangoni wafer cleaning apparatus, characterized in that the isopropyl alcohol (IPA; iosopropyl alcohol). According to claim 1, The upper hood is mounted, the marangoni-type wafer cleaning apparatus characterized in that it further comprises a spray means for receiving the solvent through the first pipe to inject the solvent vapor on the upper and both sides of the wafer. According to claim 1, The storage unit for storing the solvent, A liquid tank in which a liquid solvent is stored; A second pipe for injecting a carrier gas into the liquid solvent; and And a bubbler for storing carrier gas through the second pipe to generate bubbles in the liquid solvent to form solvent vapor. The method of claim 4, wherein The carrier gas is a marangoni wafer cleaning apparatus, characterized in that selected one of oxygen, argon and nitrogen gas. The method of claim 4, wherein And a heating means for increasing the internal temperature of the liquid tank in the storage unit. The method of claim 4, wherein And a third pipe for adjusting an internal pressure of the liquid tank in the storage unit, and further comprising a control valve for controlling pressure in the third pipe.