KR20090131208A - Batch type cleaning apparatus for circumvolve wafer and method for cleaning - Google Patents

Abstract

PURPOSE: A batch type cleaning apparatus for a circumvolve wafer and a method for cleaning are provided to clean the surface of a wafer uniformly by maintaining a contact time of a wafer and a clean solution on the surface of wafer uniform. CONSTITUTION: In a device, a cleaning bath(20) accepts a washing solution. A plurality of slots respectively accepts a plurality of wafers in a vertical direction. A lift unit(100) transfers wafers to inside and outside of the cleaning bath. A wafer rotor is installed at the lift unit. The wafer rotor turns the wafer by spreading purge gas to the wafer. The wafer rotor includes a plurality of purge holes, a purge line, and a fuzzy gas supply unit(155). The purge hole spreads the purge gas to the wafer. A purge line supplies the purge gas to the purge hole, and the fuzzy gas supply unit selectively supplies the purge gas to the purge line.

Description

Batch type cleaning device capable of rotating wafers and cleaning method {BATCH TYPE CLEANING APPARATUS FOR CIRCUMVOLVE WAFER AND METHOD FOR CLEANING}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a batch type cleaning apparatus for a wafer and a cleaning method thereof, and more particularly, to a batch type cleaning apparatus having a uniform cleaning on the entire surface of a wafer and improved cleaning efficiency, and a batch type cleaning method using the same.

In general, a semiconductor device may be manufactured by repeatedly performing deposition, photography, and etching processes using a wafer, for example, a silicon wafer. Contaminants such as various particles, metal impurities, organic impurities, and the like may remain on the wafer during the processes. Since the contaminants adversely affect the yield and reliability of the semiconductor device, a cleaning process for removing contaminants remaining on the wafer is performed during semiconductor manufacturing.

The cleaning method for cleaning a semiconductor wafer can be largely classified into a dry cleaning method and a wet cleaning method. Among them, the wet cleaning method is a cleaning method using various chemical liquids, and a batch type for simultaneously cleaning a plurality of wafers. It is divided into batch type and single wafer type for cleaning wafers in sheet units.

The batch type cleaning apparatus removes contaminants by immersing a plurality of wafers at once in a container containing a cleaning liquid. However, the conventional batch type cleaning apparatus has a disadvantage in that it is not easy to cope with the trend of increasing the size of the wafer and uses a large amount of cleaning liquid. In addition, in the batch type cleaning apparatus, if any one wafer is broken during the cleaning process, the entire wafer in the same container may be damaged, and a large amount of wafer defects may occur.

The single wafer type cleaning device is a cleaning device that processes wafers in a single wafer unit. A spin type method removes contaminants by using a centrifugal force due to the rotation of the wafer and pressure caused by the injection of the cleaning liquid by spraying the cleaning liquid onto the wafer surface rotated at high speed. washing is performed by a spinning method.

A batch type cleaning apparatus, commonly referred to as a wet station, undergoes a series of processing steps as the wafer is transferred along the processing path of the cleaning process. In addition, the cleaning processing unit includes a plurality of cleaning units in which cleaning liquids containing various chemical liquids are mixed at a predetermined rate and a cleaning process is performed on the wafer, and using pure water to remove the chemical liquid from the wafer on which the chemical liquid cleaning process is completed. A rinse unit in which a rinse process is performed is provided.

On the other hand, the conventional batch type cleaning apparatus is immersed in the cleaning tank in a state in which a plurality of wafers of 25 sheets or 50 sheets are seated in the lift unit at the same time to perform the cleaning process.

Here, since the wafer is disposed in the direction perpendicular to the cleaning liquid, a difference occurs in the contact time with the cleaning liquid in the upper and lower portions of the wafer since the lower portion of the wafer is first obtained in the cleaning liquid and drawn out later than the upper portion. For this reason, the difference in the cleaning effect of the wafer occurs depending on the contact time with the cleaning liquid, and thus there is a problem that the cleaning is not uniformly performed on the entire surface of the wafer.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and to provide a batch type cleaning apparatus capable of uniformly cleaning the wafer surface and improving the cleaning efficiency by making the contact time between the wafer and the cleaning liquid uniform.

In addition, the present invention is to provide a cleaning method capable of maintaining a uniform contact time between the wafer and the cleaning liquid in the batch type cleaning apparatus described above.

According to embodiments of the present invention for achieving the above object of the present invention, a batch type cleaning apparatus capable of rotating a wafer includes a cleaning tank containing a cleaning liquid, and a plurality of slots each receiving a plurality of wafers in a vertical direction. And a lift unit configured to move up and down into the cleaning tank so as to move the plurality of wafers into and out of the cleaning tank, and a wafer rotating part provided in the lift unit to eject purge gas to the wafer to rotate the wafer.

In an embodiment, the wafer rotating part may be formed under the slots in the lift unit, a plurality of purge holes for injecting purge gas to the wafers, a purge line for providing purge gas to the plurality of purge holes, and the purge line. It comprises a purge gas supply for selectively supplying purge gas to the line. Here, the purge gas may be a cleaning gas and a stable gas that does not chemically react with the wafer. For example, the purge gas may be nitrogen gas.

In an embodiment, the slot is formed such that a portion of the wafer is in contact with the bottom surface of the slot, and the purge hole is formed in the slot portion in contact with the wafer.

In an embodiment, the lift unit includes a slot portion for supporting at least three points below each wafer accommodated in the vertical direction, and the purge hole is formed in any one of the slot portions. Of course, the purge hole may be formed in the entire slot portion.

In an embodiment, the purge hole injects the purge gas to be eccentric with the radial direction of the wafer so that the wafer can be rotated in the slot by the injection of the purge gas.

On the other hand, according to another embodiment of the present invention for achieving the above object of the present invention, the batch type cleaning method is obtained by obtaining a plurality of wafers to be cleaned in a vertical direction to the cleaning liquid, the plurality of wafers in the cleaning liquid A cleaning step is performed to remove contamination from the wafer surface by immersing for more than a predetermined time. Then, prior to withdrawing the cleaned wafer from the cleaning liquid, a purge gas is injected into the lower part of the wafer to rotate the wafer in a vertically standing state, thereby inverting the position of the wafer, and the wafer is obtained first. From the cleaning solution. Therefore, the surface of the wafer can be uniformly cleaned by making the time for contact between the wafer and the cleaning liquid relatively uniform.

In an embodiment, the wafer rotating step is performed for a predetermined time before cleaning of the wafer is completed and before the wafer is taken out. Here, the wafer rotating step rotates the wafer by 180 ° so that the positions of the first contacted portion of the wafer and the later contacted portion of the wafer can be reversed. Alternatively, the wafer is rotated a plurality of times, and when the wafer is withdrawn from the cleaning liquid, the wafer is rotated such that the positions of the first and last obtained portions of the wafer are reversed.

According to the present invention, first, by rotating the wafer, it is possible to change the position of the first potion first obtained in the cleaning liquid and the second potion obtained later, and to keep the time that the wafer contacts the cleaning liquid uniform with respect to the wafer surface. Can be.

In addition, since the cleaning liquid contact time is uniform, the wafer surface can be uniformly cleaned and the cleaning efficiency can be improved.

Although the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, the present invention is not limited or restricted by the embodiments.

1 is a perspective view for explaining a batch type batch type cleaning apparatus according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the lift unit along the line I-I in the cleaning apparatus of FIG. 1, and FIG. 3 is a side cross-sectional view of the lift unit along the line II-II in the cleaning apparatus of FIG. 4 and 5 are front views of a wafer for explaining an operation of a wafer rotating part according to embodiments of the present invention. 6A and 6B are front views of a wafer for describing an operation of a wafer rotating part according to an embodiment of the present invention.

Hereinafter, a batch type cleaning apparatus according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 6B.

Referring to the drawings, the batch type cleaning apparatus includes a cleaning tank 20, a lift unit 100, and a wafer rotating unit 150.

The cleaning tank 20 is provided with a space in which the cleaning liquid is accommodated so that the cleaning process for the wafer 10 is performed, and the cleaning tank 20 is formed to have a sufficient size so that the plurality of wafers 10 can be immersed in the cleaning liquid at the same time. In addition, the cleaning tank 20 is preferably formed of a material that does not chemically react with the cleaning liquid, for example, the cleaning tank 20 may be formed of quartz or synthetic resin material, in addition to the cleaning liquid Substantially various materials that do not react with may be used. However, the shape and structure of the cleaning tank 20 may be variously changed according to the conditions and design specifications required for cleaning the wafer 10.

In the present invention, the cleaning solution is a solution for cleaning contaminants remaining on the wafer 10. The cleaning solution is a chemical liquid and a pure or pure water and a chemical liquid which are determined according to the type of the wafer 10 and the type of material to be removed. These include mixed liquids mixed in a proportion. For example, the cleaning liquid may be an etchant for etching the thin film on the surface of the wafer 10 and may be an aqueous solution of hydrogen fluoride (HF), a sulfuric acid (H 2 SO 4) solution, a nitric acid (H 3 PO 4) solution, or an SC-1 ( standard clean-1) solution.

The lift unit 100 is a device capable of moving the wafer 10 in and out of the cleaning tank 20, and includes a guide part 110 and the guide part for accommodating the wafer 10 in a vertical direction. The wafer 10 is provided in the support part 115 supporting the 110 and the lifting movement axis, the elevating driver 130 and the guide part 110 for transmitting a driving force for the lifting movement of the lift unit 100. It includes the wafer rotating part 150 to rotate in a state supported by the guide portion 110.

The guide part 110 includes a plurality of slot parts 111 and 112. Each of the slots 111 and 112 may be provided with a plurality of slots 111a and 112a at a plurality of points below the wafer 10 accommodated in the vertical direction to the guide unit 110. A method of supporting the wafer 10 at the lower three points will be described as an example.

The slot portions 111 and 112 according to the embodiment of the present invention are spaced apart from the first slot portion 111 and the first slot portion 111 to support the lower portion of the wafer 10, and the first slot portions 111 and 112 are spaced apart from each other. The second slot portion 112 provided on both sides of the first slot portion 112 is included.

Here, the guide portion 110 is the second slot portion 112 to the first slot portion 111 so that the second slot portion 112 can stably support the side of the wafer (10). It is located in the upper part. In addition, the guide part 110 is formed such that the wafer 10 is accommodated in the vertical direction in a unit of sheet, but is accommodated at a predetermined interval apart from each wafer 10. In particular, as shown in FIGS. 2 and 3, the first and second slots 111a and 112a minimize contact area with the wafer 10, and the wafer 10 is connected to the first and second slots 111a and 112a. The wafer 10 has an inclined surface to prevent the wafer 10 from colliding with the first and second slots 111a and 112a while entering and exiting the second slots 111a and 112a. For reference, the second slot 112a is a portion shown by a dotted line in FIG. 2, and the second slot 112a is substantially the same as the first slot 111a shown in FIG. 3 when viewed from the side. The wafer 10 has a shape inclined downward toward the bottom so as to be spaced apart by a predetermined interval.

The wafer rotating unit 150 rotates the wafer 10 by injecting purge gas PG to the lower portion of the wafer 10. The wafer rotating unit 150 includes a purge line 152 and a purge line 152 for supplying purge gas PG to the purge hole 151 formed in the first and second slot parts 111 and 112 and the purge hole 151. And a gas supply unit 155.

Preferably, the purge gas PG may use a gas that does not chemically react with the wafer 10 and the cleaning liquid. For example, the purge gas PG may use nitrogen gas (N2). .

The purge holes 151 are formed in the first and second slots 111a and 112a, respectively, to spray the purge gas PG to the respective wafers 10, and the first and second slots 111a. , 112a is formed just below the position where the wafer 10 is seated. Here, the purge hole 151 may be formed in both the first and second slots 111 and 112 as shown in FIG. 4. Alternatively, as shown in FIG. 5, the purge hole 151 may be formed only in one of the first slot part 111 or the second slot part 112.

The purge line 152 communicates the purge hole 151 so as to supply the purge gas PG to the purge hole 151, and has a long pipe shape inside the first and second slots 111 and 112. It can be formed as. Here, the purge hole 151 may have various hole sizes in order to minimize the pneumatic pressure difference of the purge gas (PG) generated according to the distance away from where the purge gas is injected.

The wafer rotating part 150 injects the purge gas PG into the wafer 10 through the purge hole 151 to move the wafer 10 at a predetermined height in the first and second slots 111a and 112a. In addition, the wafer 10 is rotated by the airflow of the purge gas PG. In particular, the wafer 10 is rotated in a state accommodated in the first and second slots 111a and 112a.

Here, the direction in which the purge gas PG is injected from the purge hole 151 so that the wafer rotating unit 150 rotates the wafer 10 may be ejected eccentrically in a radial direction of the wafer 10. Can be. Alternatively, the purge hole 151 may spray the purge gas PG toward the circumference of the wafer 10 so that a force acts in the tangential direction of the wafer 10.

Hereinafter, the operation of the wafer rotating unit 150 according to an embodiment of the present invention will be described with reference to FIGS. 4 to 6B. 6A and 6B illustrate only the wafer 10 in order to explain the operation of the wafer rotating unit 150. The components of the wafer rotating unit 150 and the cleaning apparatus are already described with reference to FIGS. 1 to 3. Detailed description thereof will be omitted.

6A and 6B, when the wafer 10 is obtained in the cleaning liquid for cleaning the wafer 10, a portion of the wafer 10 that first comes into contact with the cleaning liquid is referred to as a lower portion 10b. And the last contacted portion is referred to as the upper portion (10a).

The wafer rotating part 150 changes the positions of the upper portion 10a and the lower portion 10b of the wafer 10 to uniform the time for which the wafer 10 is in contact with the cleaning liquid. That is, the wafer rotating part 150 rotates while the wafer 10 is vertically received in the lift unit 100 so that the positions of the upper portion 10a and the lower portion 10b are reversed. Therefore, when the wafer 10 is obtained in the cleaning liquid, the upper portion 10a contacts the cleaning liquid first, but when the wafer 10 is withdrawn, the upper portion 10a is drawn out first, so that the wafer 10 is in contact with the cleaning liquid. Since this becomes approximately the same, there is an advantage that the cleaning effect due to the time when the surface of the wafer 10 is in contact with the cleaning liquid is kept uniform.

In detail, the wafer rotating unit 150 does not operate during the cleaning of the wafer 10, and rotates the wafer 10 before the wafer 10 is cleaned and pulled out of the cleaning tank 20. . Alternatively, the wafer rotating unit 150 may selectively rotate the wafer 10 only when the wafer 10 is obtained from the cleaning liquid and withdrawn from the cleaning liquid.

The wafer rotation unit 150 rotates the wafer 10 a plurality of times, but when the wafer 10 is withdrawn from the cleaning liquid, the wafer rotation unit 150 rotates the positions of the upper portion 10a and the lower portion 10b to be reversed. . Alternatively, the wafer rotating part 150 may be rotated gradually until the positions of the upper portion 10a and the lower portion 10b are reversed.

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.

1 is a perspective view for explaining a cleaning apparatus and a wafer lift unit according to an embodiment of the present invention;

2 is a cross-sectional view showing a cross section of the lift unit cut along the line I-I in FIG. 1;

3 is a side cross-sectional view showing a cross section of the lift unit cut along the line II-II in FIG. 1;

4 is a front view of a wafer for explaining a wafer rotating part according to an embodiment of the present invention;

4 is a front view of a wafer for explaining a wafer rotating part according to another embodiment of the present invention;

6A and 6B are diagrams for describing an operation of a wafer rotating part according to an exemplary embodiment of the present invention.

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

10: wafer 10a: first portion

10b: second potion 20: washing tank

100: lift unit 110: guide portion

111: first slot portion 111a, 112a: slot

112: second slot portion 115: support portion

130: lifting drive unit 150: wafer rotating unit

151: purge hole 152: purge line

155: purge gas supply unit

G: gap PG: purge gas

Claims (8)

A cleaning tank containing a cleaning liquid; A lift unit including a plurality of slots each receiving a plurality of wafers in a vertical direction, the lift unit lifting up and down to move the plurality of wafers into and out of the cleaning tank; And A wafer rotating unit provided in the lift unit to rotate the wafer by injecting purge gas to the wafer; Batch type cleaning apparatus comprising a. The method of claim 1, The wafer rotating unit, A plurality of purge holes formed under the slots in the lift unit to inject purge gas into the wafer; A purge line providing a purge gas to the purge hole; And A purge gas supply unit selectively supplying purge gas to the purge line; Batch type cleaning apparatus comprising a. The method of claim 2, The slot is formed so that a portion of the wafer is in contact, And the purge hole is formed in the slot portion in contact with the wafer. The method of claim 2, The lift unit has a slot portion for supporting at least three points below each wafer accommodated in the vertical direction, And the purge hole is formed in at least one of the slots. The method of claim 2, The purge hole is a batch rotation type wafer cleaning apparatus, characterized in that for spraying the purge gas eccentrically and the radial direction of the wafer. Obtaining a plurality of wafers in a direction perpendicular to the cleaning liquid; Cleaning the wafer by immersing the wafer for a predetermined time; Injecting purge gas into the lower portion of the wafer to rotate the wafer in a vertical position; And Withdrawing the wafer from the cleaning liquid; Batch type cleaning method comprising a. The method of claim 6, The wafer rotating step is a batch type cleaning method, characterized in that is performed for a predetermined time before withdrawing the wafer. The method of claim 6, The rotating step of the wafer is batch type cleaning method, characterized in that when the withdrawal of the wafer in the cleaning liquid, the wafer is rotated so as to reverse the position of the first and later obtained parts of the cleaning liquid.

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