KR20010096566A - Semiconductor wafer cleaning apparatus and method thereof using the same - Google Patents

Abstract

PURPOSE: An apparatus for cleaning a semiconductor wafer and a cleaning method using the same are provided to prevent the generation of watermark when a cleaning process is performed by using a marangoni dryer. CONSTITUTION: A loading portion(7) is formed at an upper portion of a body(1). The loading portion(7) is used for loading an empty cassette(5) or a cassette(5) filled with a plurality of semiconductor wafer(3). The first mobile portion(9a,9b) includes a pad(9a) to extract the semiconductor wafers(3). The first mobile portion(9a,9b) includes a rotary body(9b) to rotate the semiconductor wafers(3). The second mobile portion(11a-11c) includes a clutch(11a) for catching the semiconductor wafers(3) and the first rail(11b) and the second rail(11c) for shifting the semiconductor wafers(3) to a loader(13). An unloader(15) is used for the cleaned semiconductor wafers(3). The first and the second pushers(17,19) are installed at lower sides of the loader(13) and the unloader(15). An inner bath(19) performs a cleaning process by using pure water. A knife(21) and a supply line(28) are connected with at a lower portion of the inner bath(19). An outer bath(20) is installed by both sides of the inner bath(19). A recess portion(22) is formed at an upper portion of both sidewalls of the inner bath(19). A drain line(24) is connected with a bottom portion of the outer bath(20). An exhaust line(26) is connected with both back walls of the outer bath(20). A marangoni dryer(23) is used for drying the semiconductor wafers(3).

Description

Semiconductor wafer cleaning apparatus and method for cleaning semiconductor wafer using same

The present invention relates to a semiconductor wafer cleaning apparatus and a semiconductor wafer cleaning method using the same, and more particularly, to a semiconductor wafer cleaning apparatus employing a marangoni dryer and a semiconductor wafer cleaning method using the same.

When fabricating a semiconductor wafer into an integrated circuit, a cleaning process for cleaning the semiconductor wafer is required to remove residual chemicals, small particles, contaminants, and the like, which occur during various manufacturing processes. In particular, when manufacturing highly integrated integrated circuits, a cleaning process for removing fine contaminants adhering to the surface of a semiconductor wafer is very important.

The cleaning process of a semiconductor wafer can be divided into a chemical solution processing process (chemical liquid processing process), a water washing process, and a drying process. The chemical solution treating step is a step of treating the semiconductor wafer with a chemical solution, and the washing step is a step of washing the semiconductor wafer treated with the chemical solution with pure water, and the drying step is a step of drying the washed semiconductor wafer. In particular, since defects caused by a failure of the drying process are relatively large and are repeatedly generated on a pattern, a serious problem occurs that causes malfunction of an integrated circuit or does not function as an integrated circuit.

As integrated circuits become more complex, conventional centrifugal spin dryers in the drying process have reached the limit of performance, and IPA steam dryers using isopropyl alcohol ("IPA") have been proposed. However, the IPA steam dryer also has a problem that water marks or the like occur on the semiconductor wafer after drying.

In order to improve this, a marangoni dryer has been proposed in which the drying proceeds without being exposed to the atmosphere after the chemical liquid process and the water washing process. The marangoni dryer uses pure surface tension difference between IPA and pure water by lifting the semiconductor wafer located in the bath filled with de-ionized water or spraying IPA on the surface of the semiconductor wafer while slowly draining the pure water in the bath. To dry. Compared with the IPA steam dryer, the Marangoni dryer has a very small drying capacity of about 1/10 of the IPA usage. However, the Marangoni dryer has a problem in that it is easily affected by lamina flow of the semiconductor wafer cleaning apparatus or exhaust to the outside, resulting in water spots without uniform drying in the semiconductor wafer. In particular, when using a large diameter semiconductor wafer of 12 inches in diameter, the appearance of water spots is uneven.

Accordingly, an object of the present invention is to provide a semiconductor wafer cleaning apparatus capable of suppressing the generation of water spots without being affected by the ambient atmosphere when using a marangoni dryer.

In addition, another technical problem to be achieved by the present invention is to provide a semiconductor wafer cleaning method that can suppress the generation of water spots by using the semiconductor wafer cleaning apparatus suitably.

1 is a perspective view schematically showing a semiconductor wafer cleaning apparatus including a marangoni dryer according to the present invention;

FIG. 2 is an enlarged view of the inner and outer baths of FIG. 1;

3 is an exploded perspective view of the Marangoni dryer of Figure 1,

4 to 10 are cross-sectional views schematically illustrating a process of cleaning a semiconductor wafer using the semiconductor wafer cleaning apparatus of FIG. 1.

FIG. 11 is a plan view at the time of cleaning the semiconductor wafer of FIG. 10;

12A and 12B are surface electron micrographs of the semiconductor wafer when and when the semiconductor wafer is cleaned with the cleaning apparatus including the marangoni dryer of the present invention.

In order to achieve the above technical problem, the semiconductor wafer cleaning apparatus of the present invention includes only one internal bath to perform chemical solution cleaning and pure water cleaning in one internal bath, and includes a marangoni dryer to clean the semiconductor wafer. Drying can be performed integrally. As shown in the configuration, a loading unit capable of loading a cassette on which a plurality of semiconductor wafers are loaded, a semiconductor wafer mounted on the cassette of the loading unit is extracted, and the extracted semiconductor wafer is moved to a loader spaced apart from the loading unit. And an internal bath spaced apart from the loader and capable of cleaning the plurality of semiconductor wafers with a chemical solution or pure water. Recess portions may be provided at both side walls of the inner bath, and outer baths may be further provided at both sides of the inner bath to cover the recess. Both rear walls of the outer bath may further be provided with an exhaust port for uniform exhaust.

In particular, the semiconductor wafer cleaning apparatus of the present invention includes a hood that can move the semiconductor wafer moved to the loader onto the inner bath and can move in the X, Y and Z axes with respect to the inner bath so that the semiconductor wafer cleaning apparatus can be in close contact with the inner bath. And a knife capable of supporting and moving the semiconductor wafer loaded in the inner bath under the inner bath and moving up and down at a constant speed. Specifically, the Marangoni dryer includes a hood for drying the wafer and a slot for mounting the semiconductor wafer mounted on the loader, and a hood for drying the wafer, and the IPA on the hood uniformly to the semiconductor wafer. It consists of an IPA supply plate having a plurality of holes to spread, and an IPA supply nozzle located on the IPA supply plate. Therefore, when the marangoni dryer and the internal bath which move in the X, Y and Z axes are brought into close contact with each other, and the semiconductor wafer after the cleaning process is dried, the lamina flow or exhaust of the semiconductor wafer cleaning apparatus is removed. The influence can be suppressed and the generation of water spots on the semiconductor wafer surface can be suppressed. In addition, when the semiconductor wafer is dried, when the exhaust port is provided in the external bath located at both sides of the inner bath, the exhaust air can be made uniform, further reducing the occurrence of water spots on the surface of the semiconductor wafer.

In order to achieve the above another technical problem, the cleaning method of the semiconductor wafer of the present invention loads a cassette on which a plurality of semiconductor wafers are loaded in a loading unit, and then extracts the semiconductor wafer mounted in the cassette of the loading unit and the loading unit; Move to the spaced loader. Subsequently, the semiconductor wafers moved by the loader are loaded into a marangoni dryer, and then the marangoni dryer on which the semiconductor wafer is mounted is moved onto an internal bath spaced apart from the loader. Next, the semiconductor wafers are moved into an internal bath in the Marangoni dryer to be cleaned with chemical solution and pure water. Subsequently, the marangoni dryer is moved downward to bring the internal bath and the marangoni dryer into close contact with each other, and the internal bath containing the pure water is injected while nitrogen and IPA fume are injected from the upper part of the marangoni dryer. The semiconductor wafer is raised at a constant speed or the pure water is slowly drained to dry the pure water using the surface tension difference between the IPA and the pure water. Drying the purely cleaned semiconductor wafer while the marangoni dryer and the internal bath are in close contact with each other prevents the influence of lamina flow or exhaust of the semiconductor wafer cleaning apparatus and thus suppresses the occurrence of water spots on the semiconductor wafer. When the pure water is dried, if the exhaust gas is made uniform through the exhaust ports provided in the outer baths located at both sides of the inner bath, it is possible to further suppress the generation of water spots.

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

1 is a perspective view schematically showing a semiconductor wafer cleaning apparatus including a marangoni dryer according to the present invention, FIG. 2 is an enlarged view of an inner bath and an outer bath of FIG. 1, and FIG. 3 is a marangoni dryer of FIG. 1. Is an exploded perspective view of the.

Specifically, the semiconductor wafer cleaning apparatus of the present invention may include only one inner bath to perform chemical solution cleaning and pure water cleaning in one inner bath. The cleaning of the semiconductor wafer does not use a cassette, and the semiconductor wafer is not exposed to the atmosphere. In addition, a marangoni dryer is included, so that the semiconductor wafer can be cleaned and dried.

In more detail, in the semiconductor wafer cleaning apparatus of the present invention, a plurality of semiconductor wafers 3, for example, 13 semiconductor wafers 3 having a diameter of 12 inches are mounted on one side of a body 1. A loading unit 7 for loading a cassette 5 or an empty cassette is included. Moreover, the 1st moving means 9a which can move to a Y-axis direction (front-back direction), extracts the several sheets of semiconductor wafer 3 mounted in the said cassette 5, and can rotate it to a Z-axis direction (upper direction). 9b). In other words, the first moving means moves the pad 9a through which the plurality of semiconductor wafers 3 can be extracted from the cassette 5, and the plurality of semiconductor wafers 3 mounted on the pads in the Z-axis direction. It includes the rotating body 9b which can be rotated (upward direction).

Then, the second moving means 11a to 11c capable of moving the semiconductor wafer 3 rotated upward by the first moving means 9a and 9b to the loader 13 or the unloader 15 are provided. Equipped. The second moving means 11a to 11c move in the X-axis, Y-axis, and Z-axis directions to hold the semiconductor wafer 3 rotated upward by the first moving means 9a, 9b. ), The first rail 11b and the second rail capable of moving in the X-axis, Y-axis, and Z-axis directions to move the semiconductor wafer 3 held by the clutch 11a to the loader 13. (11c). In FIG. 1, the movement of the first rail 11b in the Y-axis direction is not illustrated for convenience.

The loader 13 is a place where each semiconductor wafer waits before cleaning, and reference numeral 15 is an unloader where the semiconductor wafer 3 waits after cleaning. Therefore, the semiconductor wafer 3 located in the unloader 15 can be moved to the empty cassette of the loading section 7 by the second moving means and the first moving means, as opposed to the above. Under the loader 13 and the unloader 15, a first footer for moving the mounted semiconductor wafer 3 up and down (Z-axis) to allow the marangoni dryer 23 to hold the semiconductor wafer 3 well. (17, pusher) and the second footer (19).

In addition, there is an internal bath 19 spaced apart from the loader 13 and capable of cleaning with a chemical solution or pure water, and a semiconductor wafer 3 loaded in the internal bath 19 under the internal bath 19. ) Is connected to a knife 21 capable of supporting and moving up and down at a constant speed, and a supply line 28 for supplying pure water or chemical solution to the inner bath 19.

As shown in FIG. 2, an outer bath 20 is attached to both sides of the inner bath 19, and recess portions 22 are formed on upper portions of both side walls of the inner bath 19. Therefore, the pure water and the chemical solution in the inner bath 19 are overflowed. In other words, the outer bath 20 is formed to cover the recess 22 of the inner bath 19. A drain line 24 for draining pure water or a chemical solution is connected to the bottom portion of the external bath 20. Pure water or chemical solution overflowed from the internal bath 19 is sent to a storage tank (not shown) through the drain line 24. In addition, exhaust lines 26 are connected to both rear walls of the external Nas 20 to exhaust the chemical solution fumes and the IPA fumes to the outside of the semiconductor manufacturing plant. The exhaust line 26 is formed on the rear wall of the external bath 20 to uniformly exhaust the IPA fume or the like during drying.

In addition, it includes a marangoni dryer 23 capable of holding the semiconductor wafer 3 moved to the loader 13 and moving it onto the inner bath 19 and drying the cleaned semiconductor wafer 3. As shown in FIG. 3, the marangoni dryer 23 includes a slot (inside the hatching in FIG. 1) and a locking portion (as shown in FIGS. 4 to 10) on which the semiconductor wafer 3 mounted on the loader 13 can be mounted. A reference numeral 27, which includes a locking unit and includes a hood 23a for drying the semiconductor wafer 3, and a plurality of holes on the hood 23a for uniformly spreading the IPA over the semiconductor wafer. It consists of an IPA supply plate 23b and a supply nozzle 23c located on the IPA supply plate 23b.

In particular, in the marangoni dryer 23 of the semiconductor wafer cleaning apparatus of the present invention, since the IPA nozzles 23c are positioned at the center and left and right sides, and the IPA fume is evenly spread throughout the hood 23a, the drying uniformity in the semiconductor wafer 3 is improved. Can be improved. In addition, the marangoni dryer 23 includes third moving means 25a and 25b that can move in the X, Y, and Z axes. That is, the third moving means 25a and 25b include a third rail 25a capable of moving the marangoni dryer in the Z axis and a fourth rail 25b capable of moving in the X axis. 1, the movement of the marangoni dryer in the Y-axis direction is not shown for convenience.

Moreover, the marangoni dryer 23 of the semiconductor wafer cleaning apparatus of this invention can also move to Z-axis (up-down direction). If the marangoni dryer 23 can be moved along the Z-axis, the inner bath 19 and the marangoni dryer 23 are brought into close contact with each other during the drying of the semiconductor wafer. Due to this, it is possible to suppress the effect of the vortex and loss of the IPA gas supplied into the Marangoni dryer. Thereby, drying uniformity can be improved in the semiconductor wafer 3, and generation | occurrence | production of a water spot can be suppressed. In addition, when the semiconductor wafer is dried, it is possible to make the exhaust gas more uniform through the exhaust port provided in the external bath, thereby further reducing the occurrence of water spots on the semiconductor wafer surface.

1 and 2, the IPA supplied to the hood 23a is supplied in a bubbling manner, but is not shown for convenience. 1 and 2, only one inner bath 19 is illustrated for convenience, but a plurality of inner baths 19 may be provided, and the washing and drying may be performed in one inner bath as described above.

4 to 10 are cross-sectional views schematically illustrating a process of cleaning a semiconductor wafer using the semiconductor wafer cleaning apparatus of FIG. 1, and FIG. 11 is a plan view of the semiconductor wafer cleaning process of FIG. 10. In Figs. 4 to 11, the same reference numerals as Figs. 1 to 3 denote the same members.

First, as shown in FIG. 4, after extracting the semiconductor wafer 3 from the cassette of the loading part 7, it moves and places the semiconductor wafer 3 on the loader 13. As shown in FIG. Subsequently, the semiconductor wafer 3 placed on the loader 13 is lifted up to the hood side 23a of the marangoni dryer 23 located above the loader 13 by using the first pusher 17. At this time, the locking portion 27 of the hood 23a is released (up and down) to allow the semiconductor wafer 3 to be moved into the hood 23a.

Next, as shown in FIG. 5, when the semiconductor wafer 3 is loaded into the hood 23a, the locking part 27 is locked (horizontally) to prevent the semiconductor wafer 3 from moving downward. . Thereafter, the marangoni dryer 23 loaded with the semiconductor wafer 3 is moved to the upper portion of the inner bath 19 filled with the pure water 29a using the fourth rail 25b.

Subsequently, the marangoni dryer 23 moved to the inner bath 19 as shown in FIG. 6 releases the locking portion 27 in the hood 23a to fill the semiconductor wafer 3 with pure water 29a. It descends to the internal bath 19 and wash | cleans with pure water 29a. At this time, nitrogen gas is injected from the upper part of the marangoni dryer 23.

Next, as shown in FIG. 7, the pure water 29a is drained, and the chemical solution 31 is filled in the internal bath 19 to treat the semiconductor wafer 3 with the chemical solution 31. That is, the semiconductor wafer 3 is cleaned with the chemical solution 31.

Subsequently, after the chemical solution 31 is drained, as shown in FIG. 8, the pure water 29b is refilled into the internal bath 19 loaded with the semiconductor wafer 3 cleaned with the chemical solution 31. Let's do it. Subsequently, chemicals on the surface of the semiconductor wafer 3 cleaned with the chemical solution 31 are removed by using a mechanonic apparatus in the internal bath 19 filled with the pure water 29b. In Fig. 8, reference numeral 33 denotes water droplets generated when using the mechanic apparatus.

Next, as shown in FIG. 9, the pure water 29b is quickly drained from the internal bath 19 loaded with the cleaned semiconductor wafer 3, and the chemicals in the surface of the semiconductor wafer 3 or in the internal bath 19 are removed. Remove them quickly.

Next, the pure water 29c is filled again into the internal bath 19 in which the pure water 29b is drained. Next, the marangoni dryer 23 is moved in the Z-axis direction (downward direction) to bring the internal bath 19 and the marangoni dryer 23 into close contact with each other. In other words, the marangoni dryer 23 and the inner bath 19 as shown in FIG. 2 are brought into close contact with each other. When the inner bath 19 and the marangoni dryer 23 are brought into close contact with each other, the influence of lamina flow or exhaust of the semiconductor wafer cleaning apparatus during drying can be reduced as described below.

Subsequently, as shown in FIG. 10 and FIG. 11, while the small amount of nitrogen and IPA fume are being injected from the upper side of the marangoni dryer 23, the locking part 27 of the marangoni dryer is released and the semiconductor wafer 3 is removed. The pure water is dried by using the surface tension difference between the IPA and the pure water while slowly moving from the inner bath 19 to the marangoni dryer 23 with the knife 21.

At this time, the present invention is in close contact with the internal bath (19) and the marangoni dryer 23, the vortex and the loss of the IPA gas supplied into the marangoni dryer due to the lamina flow (laminar flow) or exhaust of the semiconductor wafer cleaning apparatus It is possible to eliminate the effect, so that generation of water spots on the semiconductor wafer 3 can be suppressed. In addition, the present invention can further reduce the occurrence of water spots on the semiconductor wafer 3 by eliminating the effects of lamina flow or exhaust since the exhaust becomes uniform on both sides of the internal bath as described above. In the present embodiment, the semiconductor wafer 3 is gradually moved from the internal bath 19 to the marangoni dryer 23, and dried. However, the pure water 29c may be dried while gradually draining.

The marangoni dryer 23 including the semiconductor wafer 3 thus dried is moved upward and unloaded to the unloader 15 using a fourth rail. The unloaded semiconductor wafer 3 is loaded into the empty cassette using the second moving means 11a to 11c and the first moving means 9a and 9b to complete cleaning and drying.

12A and 12B are surface electron micrographs of the semiconductor wafer when and when the semiconductor wafer is cleaned with the cleaning apparatus including the marangoni dryer of the present invention.

Specifically, FIG. 12A illustrates a case where drying is performed in a state in which the marangoni dryer and the internal bath are in close contact after pure water cleaning, and FIG. 12B illustrates a case where drying is performed without closely contacting the marangoni dryer and the internal bath after pure water cleaning. As shown in FIG. 12A, when the marangoni dryer comes into close contact with the inner bath, water spots do not occur. However, as shown in FIG. 12B, when the marangoni dryer is not brought into close contact with the internal bath, it is understood that water spots occur on the surface of the semiconductor wafer.

As mentioned above, although this invention was demonstrated concretely through the Example, this invention is not limited to this, A deformation | transformation and improvement are possible with the conventional knowledge in the art within the technical idea of this invention.

According to the semiconductor wafer cleaning apparatus of the present invention, the marangoni dryer may move on the X, Y and Z axes from the upper part of the inner bath to perform drying in a state in which the inner bath and the marangoni dry are in close contact with each other, and the exhaust gas is dried during drying The exhaust port of the external bath located on both sides of the gas can be exhausted uniformly. Accordingly, the semiconductor wafer cleaning apparatus of the present invention can perform drying while making the exhaust gas uniform without being affected by self exhaust or lamina flow, thereby preventing generation of water spots on the semiconductor wafer after drying. In addition, the Maragoni dryer of the semiconductor cleaning device of the present invention can uniformly inject the IPA vapor to the top, it is possible to improve the drying uniformity.

Claims (11)

A loading unit capable of loading a cassette on which a plurality of semiconductor wafers are mounted; Moving means for extracting the semiconductor wafer mounted on the cassette of the loading unit and moving the extracted semiconductor wafer to the loader spaced apart from the loading unit; An internal bath spaced apart from the loader and capable of cleaning a plurality of semiconductor wafers with a chemical solution or pure water; A marangoni dryer including a hood for moving the semiconductor wafer moved to the loader onto an inner bath and moving in the X, Y, and Z axes based on the inner bath to be in close contact with the inner bath; And And a knife capable of supporting the semiconductor wafer loaded in the inner bath under the inner bath and moving the upper and lower portions at a constant speed. The method of claim 1, wherein the moving means comprises: a first moving means including a pad capable of extracting the semiconductor wafer from the cassette, and a rotating body capable of rotating the semiconductor wafer extracted on the pad upwardly; And second moving means capable of moving the semiconductor wafer rotated upward by the first moving means to a loader. 3. The method of claim 2, wherein the second moving means comprises: a clutch capable of moving in the X-axis, Y-axis, and Z-axis directions to hold the semiconductor wafer rotated upward by the first moving means; And a rail for moving the semiconductor wafer held by the clutch to the loader by moving in the axial direction. The wafer cleaning apparatus according to claim 1, wherein the loader includes a pusher for moving the mounted semiconductor wafer up and down (Z-axis) so that the marangoni dryer can hold the semiconductor wafer well. The semiconductor device of claim 1, wherein the marangoni dryer includes a hood and a locking part for mounting the semiconductor wafer mounted on the loader, the hood for drying the wafer, and the IPA on the hood uniformly to the semiconductor wafer. A semiconductor wafer cleaning apparatus comprising: an IPA supply plate having a plurality of holes to be spread, and an IPA supply nozzle located on the IPA supply plate. The semiconductor wafer cleaning apparatus according to claim 1, wherein both side walls of the inner bath have recesses and further include outer baths on both sides of the inner bath to cover the recesses. 7. The semiconductor wafer cleaning apparatus according to claim 6, wherein exhaust ports for uniform exhausting are provided on both rear walls of the external bath. Loading a cassette loaded with a plurality of semiconductor wafers into a loading unit; Extracting the semiconductor wafer mounted on the cassette of the loading unit and moving the semiconductor wafer to the loader spaced apart from the loading unit; Mounting the semiconductor wafers transferred to the loader into a marangoni dryer; Moving the marangoni dryer on which the semiconductor wafer is mounted onto an internal bath spaced apart from the loader; Moving the semiconductor wafers into an internal bath in the marangoni dryer to clean them with chemical solution and pure water; Moving the marangoni drier downward to closely contact the inner bath and the marangoni drier; And While injecting nitrogen and IPA fume from the upper part of the Marangoni dryer, the semiconductor wafer is raised at a constant speed in the internal bath containing pure water, or the pure water is slowly drained to use the surface tension difference between IPA and pure water. Method of cleaning a semiconductor wafer comprising the step of drying the pure water. The semiconductor wafer cleaning method according to claim 8, wherein the semiconductor wafers moved to the loader are carried out using a pusher located under the loader when the semiconductor wafers are loaded into the marangoni dryer. The method of claim 8, wherein the semiconductor wafers are lifted into a marangoni dryer and dried by using a knife located under the inner bath. The semiconductor wafer cleaning method according to claim 8, wherein in the drying of the pure water, exhaust is uniformly provided through exhaust ports provided in external baths located at both sides of the inner bath.