JP2013251383A - Wafer cleaning device and cleaning method for cleaning tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a wafer cleaning device that allows a contaminated cleaning liquid retained in a lower portion of a cleaning tank to overflow outside the cleaning tank, and further to obtain a cleaning method for the cleaning tank.SOLUTION: The wafer cleaning device comprises: bubbler plates 5 that have bubbling holes for cleaning provided on front surfaces, bubbling holes for agitation having diameters larger than those of the bubbling holes for cleaning provided on rear surfaces and partition walls for separating front surface sides and rear surface sides from one another and forming chambers different from one another and are installed with the rear surfaces directed toward a bottom surface side of a cleaning tank 3; gas supply stop means for switching whether or not an inert gas is supplied to respective chambers of the front surface sides and the rear surface sides of the bubbler plates 5; a cassette detection sensor 6 for detecting whether or not a cassette is disposed inside the cleaning tank 3; and a controller 7 that supplies the inert gas to the gas supply stop means corresponding to the chambers of the front surface sides of the bubbler plates 5 when the cassette is disposed inside the cleaning tank 3, and supplies the inert gas to the gas supply stop means corresponding to the chambers of the rear surface sides of the bubbler plates 5 when the cassette is not disposed inside the cleaning tank 3.

Description

  The present invention uses a wafer cleaning apparatus of a wafer etching apparatus and a wafer cleaning apparatus for automatically cleaning a cassette containing a plurality of wafers to be processed by sequentially immersing them in a plurality of processing tanks arranged in a row by a transfer means. The present invention relates to a cleaning method for a cleaning tank.

  In a wafer etching apparatus that automatically cleans a cassette containing a plurality of wafers to be processed in a plurality of processing tanks arranged in a row by using a transfer means, the surface is treated with a chemical solution, and then pure water is used. Wash with. If this cleaning is insufficient, impurities such as a chemical solution remain on the wafer surface, resulting in deterioration of product performance and appearance defects.

  However, simply injecting pure water from the pure water supply pipe installed at the bottom of the cleaning tank of the wafer etching apparatus and causing it to overflow outside the cleaning tank may result in insufficient cleaning due to insufficient replacement of pure water. is there. If the cleaning time is simply extended in order to enhance cleaning with pure water, the production tact will be affected, resulting in poor productivity and an increase in the amount of pure water used.

  As a measure for solving this problem, a pure water supply pipe for supplying pure water and an inert gas supply pipe for supplying an inert gas into the cleaning tank from under the cassette are provided, and the pure water is supplied into the cleaning tank. Patent Document 1 discloses a cleaning apparatus that cleans a wafer while bubbling an inert gas in pure water. Since a forced cleaning action by bubbling of inert gas is added, deposits such as a chemical solution can be more effectively removed from the wafer surface than in the case of pure water overflow alone.

JP-A 61-007633

  As in Patent Document 1, it is possible to effectively clean the wafer surface by bubbling an inert gas from under the cassette containing the wafer. However, in the bubbling from the bottom to the top of the cassette, the contaminated water collected at the bottom of the washing tank is not scraped out of the washing tank, but stays in the lower part of the washing tank and is contaminated in the washing tank. There was a problem that liquid gradually deposited.

  The present invention has been made in view of the above, and it is possible to obtain a wafer cleaning apparatus and a cleaning tank cleaning method capable of causing the contaminated cleaning liquid staying in the lower part of the cleaning tank to overflow outside the cleaning tank. Objective.

  In order to solve the above-described problems and achieve the object, the present invention provides a wafer cleaning apparatus for cleaning a wafer by immersing a cassette containing a plurality of wafers to be processed in a cleaning tank, and a plurality of wafer cleaning apparatuses are provided on the surface. A cleaning bubbling hole, a plurality of stirring bubbling holes having a larger diameter than the cleaning bubbling hole on the back surface, and a partition wall that separates the front side and the back side to form separate chambers, Is the bubbler plate installed in the cleaning tank with the back side facing the bottom surface of the cleaning tank and whether the inert gas is supplied to the corresponding room? Gas supply / stop means for switching whether or not, cassette detection sensor for detecting whether or not the cassette is placed in the cleaning tank, and when the cassette detection sensor detects that the cassette is placed in the cleaning tank In When the inert gas is supplied to the gas supply / stop means corresponding to the room on the surface side of the bubbler plate and the cassette detection sensor does not detect that the cassette is placed in the cleaning tank, the bubbler plate And a controller for supplying the inert gas to the gas supply / stop unit corresponding to the room on the back surface side.

  According to the present invention, there is an effect that the cleaning liquid staying at the bottom of the cleaning tank is pushed up to the upper part of the cleaning tank to be overflowed, and contamination of the cleaning liquid can be reduced.

FIG. 1 is a diagram showing a configuration of an embodiment of a wafer cleaning apparatus according to the present invention. FIG. 2 is a cross-sectional view showing the configuration of the bubbler plate. FIG. 3 is a diagram showing a bubbling method in a state where a cassette containing wafers is not arranged in the cleaning tank. FIG. 4 is a diagram illustrating a bubbling method in a state where a cassette containing wafers is arranged in a cleaning tank.

  Embodiments of a wafer cleaning apparatus and a cleaning tank cleaning method according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment.
FIG. 1 is a diagram showing a configuration of an embodiment of a wafer cleaning apparatus according to the present invention. The wafer cleaning apparatus according to the embodiment includes a cleaning tank 3, a pure water supply pipe 4, a bubbler plate 5, a cassette detection sensor 6, and a controller 7. The pure water supply pipe 4 supplies pure water into the cleaning tank 3, and the cleaning liquid overflows (overflows) from the cleaning tank 3 to replace a part of the cleaning liquid with pure water. The cassette detection sensor 6 is a sensor that detects that a cassette containing a wafer, which will be described later, is disposed in the cleaning tank 3. The bubbler plate 5 is a device that generates bubbles in the cleaning tank 3 in order to replace the cleaning liquid in the cleaning tank 3 and to clean the wafers contained in the cassette. The controller 7 is a control device that switches whether or not the bubble for cleaning liquid replacement and the bubble for cleaning the wafer are generated from the bubbler plate 5.

  FIG. 2 is a cross-sectional view showing the configuration of the bubbler plate. The bubbler plate 5 has a two-layer structure in which a front surface side and a back surface side are separated by a partition wall 55 and include a front surface side room 51 and a back surface side room 52. On the surface of the bubbler plate 5, fine cleaning bubbling holes 5b for wafer cleaning are formed. On the other hand, a rough bubbling hole 5a (having a larger diameter than the cleaning bubbling hole 5b) for cleaning liquid replacement is opened on the back surface of the bubbler plate 5. Gas supply pipes 53 and 54 for supplying an inert gas are connected to the chambers 51 and 52 of the bubbler plate 5, respectively, and the controller 7 opens and closes the air valves 5c and 5d as gas supply / stop means. You can switch between bubbling from the room.

  FIG. 3 is a diagram showing a bubbling method in a state where a cassette containing wafers is not arranged in the cleaning tank. When the cassette containing the wafer is not in the cleaning tank 3 (when the cassette detection sensor 6 has not detected the cassette), the controller 7 opens the air valve 5d and supplies gas to the room 52 from the gas supply pipe 54. Then, bubbling is performed by jetting gas from the stirring bubbling hole 5a, and the cleaning liquid staying at the bottom of the cleaning tank 3 is pushed up to the upper side of the cleaning tank 3 to overflow. At this time, the bubbler plate 5 is installed in a state where the back surface of the bubbler plate 5 is inclined so as to face the peripheral edge side of the bottom surface 31 of the cleaning tank 3, and the flow of the cleaning liquid along the bottom surface 31 and the side wall surface 32 of the cleaning tank 3. By forming 33, the cleaning liquid staying at the bottom of the cleaning tank 3 can be efficiently pushed up to the upper side of the cleaning tank 3.

  FIG. 4 is a diagram illustrating a bubbling method in a state where a cassette containing wafers is arranged in a cleaning tank. When the cassette 1 containing the wafer 2 is in the cleaning tank 3 (when the cassette detection sensor 6 detects the cassette 1), the controller 7 opens the air valve 5c and supplies gas from the gas supply pipe 53 to the room 51. Then, gas is injected from the cleaning bubbling hole 5b to overflow, and the flow rate of the cleaning liquid flow 34 passing through the surface of the wafer 2 is increased to increase the cleaning efficiency.

  During maintenance (cleaning) of the cleaning tank 3 and the bubbler plate 5, the controller 7 may open the air valves 5c and 5d at the same time regardless of the detection result of the cassette detection sensor 6. If it does in this way, it will become easy to discharge the dirt inside bubbler board 5 outside by air pressure.

  In the wafer cleaning apparatus according to the present embodiment, the cleaning liquid staying at the bottom of the cleaning tank can be pushed up and overflowed to the upper part of the cleaning tank, and contamination of the cleaning liquid can be reduced. As a result, a decrease in yield due to insufficient cleaning can be suppressed, and the wafer cleaning apparatus can be used for a long time. In addition, the cleaning time can be shortened, and the wafer can be strongly cleaned without reducing productivity. Furthermore, since it is not necessary to increase the supply amount of pure water to the cleaning tank, energy consumption in a pump or the like for supplying pure water can be reduced.

  As described above, the wafer cleaning device and the cleaning method for the cleaning tank according to the present invention are useful in that the cleaning liquid staying at the bottom of the cleaning tank can be pushed up to the upper part of the cleaning tank and overflowed. It is suitable for application to a wafer etching apparatus in which a cassette containing a plurality of wafers to be processed is automatically immersed in a plurality of processing tanks arranged in a row by a transfer means and washed automatically.

DESCRIPTION OF SYMBOLS 1 Cassette 2 Wafer 3 Cleaning tank 4 Pure water supply piping 5 Bubbler plate 5a Stirring bubbling hole 5b Cleaning bubbling hole 5c, 5d Air valve 6 Cassette detection sensor 7 Controller 31 Bottom surface 32 Side wall surface 51, 52 Room 53, 54 Gas supply piping 55 Bulkhead

Claims (3)

A wafer cleaning apparatus for cleaning the wafer by immersing a cassette containing a plurality of wafers to be processed in a cleaning tank,
A plurality of cleaning bubbling holes provided on the front surface, a plurality of stirring bubbling holes provided on the back surface having a larger diameter than the cleaning bubbling holes, and a partition that separates the front side and the back side to form separate chambers And a bubbler plate installed in the cleaning tank with the back surface facing the bottom surface of the cleaning tank,
Gas supply / stop means for switching whether or not to supply an inert gas to the corresponding room, provided corresponding to each room on the front and back sides of the bubbler plate,
A cassette detection sensor for detecting whether or not the cassette is disposed in the cleaning tank;
When the cassette detection sensor detects that the cassette is disposed in the cleaning tank, the inert gas is supplied to the gas supply / stop means corresponding to the room on the surface side of the bubbler plate. When the cassette detection sensor does not detect that the cassette is disposed in the cleaning tank, the inert gas is supplied to the gas supply / stop unit corresponding to the room on the back side of the bubbler plate. And a controller for supplying the wafer.   2. The wafer cleaning apparatus according to claim 1, wherein the bubbler plate is installed in the cleaning tank in a state where the back surface of the bubbler plate is inclined so as to face the peripheral edge side of the bottom surface of the cleaning tank. A cleaning method for a cleaning tank using the wafer cleaning apparatus according to claim 1,
In the state where the cassette is arranged in the cleaning tank, the inert gas is supplied to the chamber on the surface side of the bubbler plate, and bubbling by the inert gas sent into the cleaning tank from the cleaning bubbling hole Cleaning the wafer with:
In a state where the cassette is not disposed in the cleaning tank, the inert gas is supplied to the backside chamber of the bubbler plate, and the cleaning liquid staying on the bottom surface of the cleaning tank is passed through the stirring bubbling hole. And a step of pushing up to the upper part of the cleaning tank by bubbling with the inert gas fed into the cleaning tank.

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