JP2000343046A - Leaf type washer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform sorted recover in a leaf type spin washing machine almost without mixing of plural washing liquids successively used and also without being diluted. SOLUTION: This device has a holding means 4 for rotatably holding material to be washed, a nozzle 5 for feeding washing liquid to the rotating material to be washed, and a washing liquid recovery vessel 9 abutted on the rotating material to be washed to receive the washing liquid discharged to the periphery. In this case, the recovery vessel 9 is provided with plural recovery chambers 10-13 for receiving the discharged washing liquid in up and down directions, and the recovery vessel 9 and the holding means 4 are installed so as to be relatively movable up and down.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a single wafer cleaning apparatus. More specifically, the present invention relates to a single-wafer spin cleaning, in which a plurality of cleaning liquids used sequentially can be separated and collected without being substantially mixed with the preceding and following cleaning liquids and without being diluted. The present invention relates to a cleaning device.

[0002]

2. Description of the Related Art In an electronic material manufacturing plant, wet cleaning is performed to clean the surface of a semiconductor substrate or the like. In the conventional wet cleaning process, a batch-type cleaning has been mainly performed with an emphasis on a processing amount per time. On the other hand, in recent years, a single-wafer spin cleaning apparatus for cleaning substrates one by one has been used due to demands for improvement in cleaning effect and miniaturization of the apparatus. 2. Description of the Related Art A conventional single-wafer spin cleaning apparatus includes a turntable that holds and rotates a substrate, and a cup having a drain port and an exhaust port surrounding the turntable. The drainage port and the exhaust port are usually combined discharge ports, and are provided on the lower surface of the cup, and are separated into a drainage line and an exhaust line by a gas-liquid separator through a pipe. Even in the single-wafer type cleaning apparatus having such a structure, the cleaning liquid used earlier is discharged earlier, and the cleaning liquid used later is discharged later, but there is mixing during stagnation in the cup or the lower pipe, Each washing solution cannot be recovered alone. FIG. 1 is a schematic view of an example of a conventional single-wafer cleaning apparatus. The substrate 1 is rotated while being vacuum-adsorbed and held by a vacuum chuck type turntable 4 attached to an upper end of a rotating shaft 3 driven by a motor 2, and a cleaning liquid 6 is supplied from a nozzle 5 onto the substrate. The cleaning liquid in contact with the substrate is discharged outward by the centrifugal force of the substrate, and is discharged from the discharge port 8 along the inner wall of the cup 7. Single-wafer cleaning has many advantages, such as no risk of cross contamination from other substrates and high-precision cleaning with high in-plane uniformity. However, there is a practical problem in that a plurality of cleaning liquids used for cleaning are discharged in a mixed state, unlike the batch-type cleaning by the wet station method. In wet station batch cleaning, a large amount of cleaning solution is used, but only one type of cleaning solution is used in the dedicated tank for the cleaning solution. it can. In addition, since the cleaning liquid can be separated from other cleaning liquids at the time of discharge, it is easy to design the subsequent processing. On the other hand, in the case of single-wafer spin cleaning, a plurality of cleaning liquids are sequentially used for one substrate, so that wastewater is discharged in a state where these are mixed, making the subsequent processing difficult. ing. For example, if a cleaning step using hydrofluoric acid is included,
Since this hydrofluoric acid is mixed with the preceding and following cleaning liquids and discharged in a state of being extremely diluted as hydrofluoric acid, it is difficult to perform a recovery process. For this reason, there is a demand for a single-wafer cleaning apparatus capable of separating and recovering a plurality of cleaning liquids without causing mixing or dilution.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to separate and collect a plurality of cleaning liquids used successively in a single wafer spin cleaning without being mixed with the previous and next cleaning liquids and without being diluted. The object of the present invention is to provide a single-wafer cleaning apparatus capable of performing the above-described steps.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventor has found that a single-wafer spin cleaning uses a collecting container having a plurality of collecting chambers and a substrate holding means. The inventors have found that mixing the cleaning liquids can be prevented by relatively moving the cleaning liquids up and down to receive the plurality of cleaning liquids in the recovery chambers corresponding to the respective cleaning liquids, and based on this finding, the present invention has been completed. That is, the present invention provides: (1) holding means for rotatably holding an object to be cleaned;
In a single-wafer cleaning apparatus having a nozzle for supplying a cleaning liquid to a rotating object to be cleaned and a cleaning liquid collection container for receiving the cleaning liquid discharged to the periphery in contact with the rotating object to be cleaned, the recovery container is a discharged cleaning liquid. A plurality of collection chambers for receiving the collection container are provided in a vertical direction, and the collection container and the holding means are provided so as to be movable up and down relatively. Further, as a preferred embodiment of the present invention, (2) a single-wafer cleaning apparatus according to (1), wherein the number of recovery chambers is equal to or more than a plurality of cleaning liquids used for cleaning, (3) recovery The single-wafer cleaning apparatus according to (1), wherein the container moves up and down in response to the switching of the cleaning liquid, and receives a plurality of cleaning liquids in the recovery chambers corresponding to the respective cleaning liquids, and (4) an adjacent recovery chamber. (1) wherein the inner edge of the partition plate for partitioning the blade has a blade-like shape.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A single-wafer cleaning apparatus according to the present invention comprises a holding means for rotatably holding an object to be cleaned, a nozzle for supplying a cleaning liquid to the rotating object to be cleaned, and a rotating means for rotating the object to be cleaned. In a single-wafer cleaning apparatus having a cleaning liquid collecting container that receives a cleaning liquid discharged in contact with the periphery, a plurality of recovery chambers for receiving the cleaning liquid discharged are provided in a vertical direction. It is provided so as to be vertically movable. FIG. 2 is a schematic view of one embodiment of the single wafer cleaning apparatus of the present invention. A substrate 1 to be cleaned is a vacuum chuck type turntable 4 as a holding means attached to an upper end of a rotating shaft 3 driven by a motor 2.
The nozzle 5 is rotated while being held by suction under reduced pressure.
The cleaning liquid 6 is supplied. In the present embodiment, the cleaning liquid collection container 9 is provided in the first collection chamber 1 provided in the vertical direction.
0, a second collection chamber 11, a third collection chamber 12, and a fourth collection chamber 13. The collection container 9 and the turntable 4 as the holding means can be moved up and down relatively. In the state shown in FIG. 2, the substrate to be cleaned is present at the position of the first recovery chamber. When the first cleaning liquid is supplied to the substrate in this state, the cleaning liquid comes into contact with the substrate, and the substrate is rotated by centrifugal force. From the edge of the surface, it is emitted almost horizontally, so it is only received by the first collection chamber,
It does not enter the third and fourth collection chambers. The cleaning liquid received in the first collection chamber flows out of the first discharge port 14 and is stored in the first storage tank 16 also serving as a gas-liquid separation device via the first pipe 15. When the recovery container is moved up and down, it is preferable that the piping is made of a flexible tube or the like having flexibility. Next, at the same time when the cleaning liquid is switched to the second cleaning liquid, the holding unit that holds the object to be cleaned while rotating is moved to the position of the second collection chamber.
The second cleaning liquid is discharged almost horizontally from the edge of the substrate surface, received only by the second recovery chamber 11, flows out of the second discharge port 17, and flows through the second pipe 18 through the second pipe 18. 2 is stored in the storage tank 19. Hereinafter, similarly, the third cleaning liquid is received by the third recovery chamber 12 and stored in the third storage tank 20, and the rinsing water is stored in the fourth recovery chamber 1.
3 and is stored in the fourth storage tank 21. FIG.
In the embodiment shown in, each storage tank also serves as a gas-liquid separation device,
The exhaust gas discharged from each storage tank is discharged via a common exhaust pipe 22.

In the apparatus of the present invention, a plurality of outlets serving both as a drain port and an exhaust port can be provided for one recovery chamber. By setting the direction of the discharge port to the tangential direction of the outer periphery of the collection chamber, which is the same as the rotation direction of the object to be cleaned, it is possible to discharge the liquid without causing stagnation of the drainage liquid and exhaust gas. The plurality of drainage exhaust pipes are preferably connected to a drainage line and an exhaust line outside the apparatus via a gas-liquid separator so that all pipe resistances are the same. Alternatively, a plurality of piping systems can be combined into one system inside the apparatus. There is no limitation on the method of making the collection container and the holding means relatively vertically movable, for example, the collection container can be moved up and down with the holding means in a fixed position, and the holding means can be moved up and down with the collection container as a fixed position. Alternatively, both the collection container and the holding means can be moved up and down. There is no particular limitation on the method of moving the holding unit or the collection container up and down. For example, the holding unit or the collection container can be moved up and down by driving a motor, or can be moved up and down by driving air. FIG. 3 is a schematic view of one embodiment of the single wafer cleaning apparatus of the present invention. In this aspect, the cleaning liquid collection container that receives the discharged cleaning liquid is fixed, and the holding unit that rotatably holds the object to be cleaned is vertically moved by the lifting / lowering cylinder 23. FIG. 4 is a schematic view of another embodiment of the single wafer cleaning apparatus of the present invention. In this embodiment, the holding means for rotatably holding the object to be cleaned is fixed, and the cleaning liquid collecting container for receiving the discharged cleaning liquid is moved up and down by the hoisting machine 24.
In the device of the present invention, there is no particular limitation on the direction in which the holding means and the collection container are moved up and down relatively, and the first
From the fourth collection chamber to the fourth collection chamber or vice versa. When the same cleaning liquid is used twice or more for cleaning an object to be cleaned, the same cleaning liquid can be received in the same recovery chamber by moving the collection container upward and downward. Furthermore, if the collected water can be reused even if it is mixed and collected, as in the case where functional cleaning water containing no chemicals such as hydrogen gas-dissolved water and ozone-dissolved water is used as the cleaning liquid, the same applies. They can also be collectively collected using a collection chamber.

[0007] In the apparatus of the present invention, there is no particular limitation on the time of the vertical movement for switching the recovery chamber for receiving the cleaning liquid, but it is preferably within 1 second, more preferably within 0.5 second. When the object to be cleaned is an electronic material, it is not preferable that the surface of the object to be cleaned be dried during the cleaning process.
It can be switched continuously without interruption. For this reason, in the above-described example, a small amount of the second cleaning liquid is mixed in the discharged first cleaning liquid, and a small amount of the first cleaning liquid and the third cleaning liquid are mixed in the second cleaning liquid, There is a possibility that a slight amount of the second cleaning liquid is mixed into the third cleaning liquid and the third cleaning liquid is slightly diluted with the rinsing water. However, as long as the switching of the collection chamber is performed within one second, the effect is minimal. If absolutely no other cleaning liquid is to be mixed, the number of recovery chambers should be increased to increase the number of recovery chambers, such as the first cleaning liquid, rinsing water, second cleaning liquid, rinsing water, third cleaning liquid, and rinsing water. In addition, rinsing with rinsing water can be performed during the switching of the cleaning liquid. According to this method, the collected washing liquid may be slightly diluted by the rinsing water,
No contamination occurs between the two cleaning solutions. For this reason, the cleaning process is lengthened. However, when importance is attached to the separation and recovery of the cleaning liquid, it is preferable to perform rinsing between the cleaning with each cleaning liquid. FIG. 5A is a schematic side view of another embodiment of the single-wafer cleaning apparatus of the present invention, and FIG. 5B is a schematic plan view thereof. In the present embodiment, the substrate 1 to be cleaned is held and rotated by three chucks 25 as holding means. Further, a flow path of the cleaning liquid is provided inside the rotating shaft 3, and the cleaning liquid is supplied from the back nozzle 26 to the back surface of the object to be cleaned. The single-wafer cleaning apparatus of the embodiment shown in FIG. 5 also moves the collection container 9 and the holding unit relatively up and down similarly to the single-wafer cleaning apparatus of the embodiment shown in FIG.
0, the second recovery chamber 11, the third recovery chamber 12, and the fourth recovery chamber 13 collect the first cleaning liquid, the second cleaning liquid, the third cleaning liquid, and the rinsing water, respectively, and store each storage tank through a pipe. The cleaning liquid can be separated and collected with almost no mixing between different cleaning liquids.

In the apparatus of the present invention, it is preferable that the clearance between the edge of the substrate to be cleaned and the inner edge of the partition plate of the collection chamber is narrow. By reducing the clearance, the width of the recovery chamber in the vertical direction can be reduced, so that the amount of exhaust for preventing rebound can be reduced, and the apparatus can be downsized. For example, in order to clean a so-called 8-inch wafer having a diameter of 200 mm, it is preferable that the inner edge of the partition plate of the collection chamber has a diameter of 205 to 300 mm. In the apparatus of the present invention, the interval between the upper and lower partition plates of the recovery chamber is preferably as small as possible in order to reduce the displacement, but if it is too narrow, the cleaning liquid discharged will not fit in one recovery chamber. It is preferable to appropriately select the clearance in consideration of the clearance between the edge of the object to be cleaned and the inner edge of the partition plate, the rotation speed of the object to be cleaned, the flow rate of the cleaning liquid, and the like. Clearance 10mm, rotation speed 500rpm
If you do not use a chuck that will cause liquid splash,
It is sufficient to have an interval of about 20 mm each above and below the surface of the substrate. If the chuck holding the substrate causes liquid splashing, it is preferable to set the interval between the upper and lower partition plates even wider in consideration of this. In the apparatus of the present invention, it is preferable that the inner edge of the partition plate for partitioning the adjacent recovery chamber has a blade-like shape. FIG. 6 is a partial schematic view showing the shape of the inner edge of the partition plate. In the embodiment shown in this figure, the inner edge portion 28 of the partition plate 27 has a single-edged blade shape. It is preferable that the partition plates that partition the upper and lower recovery chambers be thin in order to prevent the cleaning liquid from splashing toward the object to be cleaned. However, since there is a limit in maintaining the strength of thinning, it is preferable to make the shape thinner as it approaches the end like a blade. The cleaning liquid 6 supplied to the rotating substrate 1 to be cleaned is splashed 29
Released as When a plurality of cleaning liquids are continuously switched and supplied without interruption, since the recovery container is moved up and down while supplying the cleaning liquid, the inner edge portion of the partition plate may traverse the flow of the cleaning liquid discharged as droplets. At this time, if the inner edge of the partition plate has a blade-like shape, it is difficult for the cleaning liquid to rebound toward the object to be cleaned, and the amount of exhaust for preventing the rebound can be reduced. FIG. 7 is a schematic view of another embodiment of the collection container of the apparatus of the present invention. In this embodiment, the pipe 30 for discharging the drainage and the exhaust is
It is provided in the collection container 9. FIG. 8 is a schematic view of another embodiment of the gas-liquid separation device and the storage tank used in the device of the present invention. In this embodiment, a gas-liquid separation device 32 is provided between the collection container and the storage tank 31. After the gas-liquid separation device exhausts the waste liquid, the waste liquid is sent to the storage tank and stored.

[0009]

According to the single-wafer cleaning apparatus of the present invention, in a single-wafer spin cleaning, a plurality of cleaning liquids used in sequence are hardly mixed with the preceding and following cleaning liquids and are not diluted. , And can be separated and collected. In addition, by taking a smaller amount of exhaust gas than in the conventional apparatus, it is possible to perform high-precision single-wafer spin cleaning without causing rebound of drainage, and to reduce the size of the cleaning apparatus.

[Brief description of the drawings]

FIG. 1 is a schematic view of an example of a conventional single-wafer cleaning apparatus.

FIG. 2 is a schematic view of one embodiment of a single wafer cleaning apparatus of the present invention.

FIG. 3 is a schematic view of one embodiment of the single wafer cleaning apparatus of the present invention.

FIG. 4 is a schematic view of another embodiment of the single wafer cleaning apparatus of the present invention.

FIG. 5 is a schematic view of another embodiment of the single wafer cleaning apparatus of the present invention.

FIG. 6 is a partial schematic view showing the shape of the inner edge of the partition plate.

FIG. 7 is a schematic view of another embodiment of the collection container of the apparatus of the present invention.

FIG. 8 is a schematic view of another embodiment of the gas-liquid separation device and the storage tank used in the device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Motor 3 Rotating shaft 4 Turntable 5 Nozzle 6 Cleaning liquid 7 Cup 8 Discharge port 9 Cleaning liquid recovery container 10 First recovery chamber 11 Second recovery chamber 12 Third recovery chamber 13 Fourth recovery chamber 14 First Outlet 15 first pipe 16 first storage tank 17 second discharge port 18 second pipe 19 second storage tank 20 third storage tank 21 fourth storage tank 22 exhaust pipe 23 elevating cylinder 24 hoisting machine 25 chuck 26 Back Nozzle 27 Partition Plate 28 Inner Edge 29 Splash 30 Piping 31 Storage Tank 32 Gas-Liquid Separator

Claims (1)

[Claims] 1. A holding means for rotatably holding an object to be cleaned, a nozzle for supplying a cleaning liquid to the rotating object to be cleaned, and a cleaning liquid recovery for receiving a cleaning liquid discharged to the periphery in contact with the rotating object to be cleaned. In the single-wafer cleaning apparatus having the container, the collection container is configured such that a plurality of collection chambers for receiving the cleaning liquid to be discharged are provided in a vertical direction, and the collection container and the holding means are provided so as to be movable up and down relatively. Characteristic single-wafer cleaning equipment.