JPH09289185A - Semiconductor wafer cleaning equipment - Google Patents

Abstract

(57) [Summary] (Correction) [Problem] Cavitation is generated in water or in the air by a simple method, and foreign matter with a required degree of contamination is removed by using it to achieve a high degree of cleaning. There is provided a cleaning device and a method therefor. SOLUTION: In a water in a cleaning tank 4 for cleaning a semiconductor wafer 1 or a thin film substrate such as an LCD, a high pressure water jet accompanied by generation of cavitation bubbles is jetted from a jet nozzle 12 toward a semiconductor wafer or an LCD etc. In a cleaning device for cleaning foreign matter and dust adhering to the surface of a wafer, LCD, etc., a high-pressure water jet nozzle 12 and a drive mechanism for freely moving the nozzle in the cleaning tank, a high-pressure pump 10 for sending high-pressure water to the nozzle. A chuck for preventing vibration and movement of the substrate due to a jet flow during cleaning and a wafer fixing table 5, and a gripping device for exchanging the substrate before and after cleaning with the storage rack 14 and for mounting it on the transfer device 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning apparatus for removing foreign matter adhering to the surface of a member such as a semiconductor wafer or LCD by jetting a liquid jet onto the surface.

[0002]

2. Description of the Related Art Conventionally, in cleaning in the process of manufacturing a thin film substrate for semiconductor wafers, LCDs, etc., a method of spraying a water jet on the wafer in the atmosphere, a method utilizing ultrasonic waves, or a method utilizing cavitation is known. .

In recent years, high cleanliness is required for substrates, and it may not be possible to remove them by a method of jetting a water jet in the atmosphere or a method of using ultrasonic waves, depending on the degree of contamination of foreign matter. On the other hand, cleaning using cavitation can obtain a high degree of cleaning, but in order to generate cavitation, there is a need to seal the cleaning tank in a vacuum state such as JP-A-3-139832, a jet scrubber, and special features. Kaihei 6-208098, the wafer is placed near the surface of the water like a substrate cleaning device, and cavitation is generated by a water jet that entrains air, or an air injection nozzle is separately attached and air that is ejected from there is entrained. As a result, cavitation is generated, which makes the device complicated, which is a factor of increasing the difficulty and cost of handling.

[0004]

[Problems to be Solved by the Invention] Cavitation is generated by a simple method of injecting high-pressure water from a nozzle in water or in the atmosphere, and by utilizing it, foreign matter having a required degree of contamination is removed. It is an object of the present invention to provide a cleaning device and a method thereof capable of obtaining a high cleaning degree.

[0005]

To achieve the above object, the first means of the present invention is to face a semiconductor wafer or LCD in water in a washing tank for washing a thin film substrate such as a semiconductor wafer or LCD. A cleaning device that cleans foreign matter and dust adhering to the surface of the semiconductor wafer, LCD, etc. by spraying a high-pressure water jet accompanied by the generation of cavitation bubbles from the spray nozzle, and freely controlling the nozzle between the high-pressure water spray nozzle and the cleaning tank. Drive mechanism for moving, high pressure pump for sending high pressure water to the nozzle, chuck and wafer fixing table for preventing vibration and movement of substrate due to jet flow during cleaning, exchanging substrates before and after cleaning with storage shelf, transfer device It is a cleaning device characterized in that it is provided with a gripping device for mounting on.

The second means is the first means, and is a cleaning apparatus characterized in that a plurality of nozzles for injecting low-pressure water are provided around the nozzle for injecting high-pressure water so that cavitation can be easily generated even in the atmosphere. .

The third means is the first means, which is equipped with one or more nozzles for injecting low-pressure water in addition to the nozzles for injecting high-pressure water so that cavitation can easily occur in the atmosphere. The cleaning device is characterized in that the water injection nozzle and the substrate are surrounded by a water tank.

The fourth means is the first means, in which the washing water tank is equipped with an ultrasonic wave generator, or the ultrasonic wave generator is inserted into the water from above the water surface above the washing tank in the same manner as the high pressure water jet nozzle.
A cleaning device characterized by being provided with a mechanism capable of freely driving the inside of the cleaning tank, wherein the fifth means is equipped with a device for mixing the chemical liquid into the high-pressure water sprayed from the nozzle by the first means. The sixth means is the first means, the cleaning water tank is equipped with a low-pressure water flow generator, and the low-pressure water injection device is inserted into the water from the water surface above the cleaning tank in the same manner as the high-pressure water injection nozzle. The cleaning device is provided with a mechanism that can freely drive the inside of the cleaning tank.

The seventh means is the first means, which is a cleaning device characterized by being equipped with a device for mixing carbon dioxide into high-pressure water.

The eighth means is a cleaning device characterized by being equipped with a transfer device using vacuum suction for transferring the wafer.

A ninth aspect of the present invention is a cleaning apparatus characterized in that the ninth means is provided with a fixing jig capable of setting a wafer in a wind-down state.

A tenth means is a cleaning apparatus including a table capable of inclining a wafer in an arbitrary direction.

[0013]

Embodiments of the present invention will be described below.

FIG. 1 shows an explanatory diagram of the configuration of an embodiment of the present invention.

The wafer 1 that has been mechanically polished or chemically polished before cleaning is stored in a storage rack 2. From here, one sheet or a plurality of sheets are transferred to the cleaning tank 4 by the manipulator 3 and chucked on the table 5 installed in the cleaning tank 4 in advance. The tip of the manipulator 3 may be a hand type for gripping the wafer 1 or a suction cup type for sucking the wafer as long as the wafer 1 can be transported. The cleaning tank 4 is equipped with a table 5 for chucking the wafer 1 and fixing it so as not to move during cleaning, and a dryer 6 for drying the wafer 1 after cleaning. The cleaning layer is constantly circulated between the tank 7 and the tank 7 in order to keep the ultrapure water in the tank. Further, the circulation system is provided with a waste liquid treatment tank 8 for removing dust in water and for post-treatment when a chemical liquid is used. The ultrapure water tank 7 is provided with an ultrapure water production device 9.

As shown in FIG. 1, the water jet injection device is attached to a jig which moves from the high pressure pump 10 through the high pressure hose 11 onto the water tank 4 in, for example, the x-, y-, and z-axis directions. A horn type nozzle 12 having a shape that actively causes cavitation is attached to the tip of the high-pressure hose 11 so that high-pressure water can be jetted onto the wafer 1 in the water tank 4.

When high-pressure water is jetted into the water tank, cavitation bubbles are generated due to a pressure difference between the surrounding water and the jetted water, a shearing action, etc., and the cavitation bubbles generate the wafer 1.
By the impact pressure generated when collapsing on the surface and in the vicinity thereof, it is possible to remove the deposits that cannot be removed by conventional ultrasonic cleaning or water jet cleaning in air.

After the cleaning is completed, the manipulator 3 pulls the wafer 1 above the water surface and the dryer 6 dries it.

Wafer 1 that has been dried to remove water droplets
Is handled by the manipulator 3 to the transport device 13. The transfer device 13 may have a structure capable of transferring the cleaned wafer 1 to the storage shelf 14, but it is preferable that the transfer device 13 be of a hermetic type and have a negative pressure inside in order to prevent reattachment of foreign matter. For this purpose, a compressor 15 is attached to the transport device 13.

The wafer 1 is transferred from the transfer device 13 to the storage rack 14 by the manipulator 3 and the series of cleaning steps is completed.

FIG. 2 shows an embodiment of claim 2. (a) is a cross-sectional view of a high-pressure water jet nozzle, showing an engaging portion 201 connected to a conduit for guiding high-pressure water, and a water chamber 2 following the engaging portion 201.
02, an orifice 203 following the water chamber 202, a throat 204 following the orifice 203, and a diffusion chamber 205 following the throat 204. When high-pressure water 206 is made to flow from this conduit to this nozzle, the pressure of the fluid flowing in the nozzle at the orifice 203 decreases, and cavitation nuclei are generated. Cavitation 26 is generated by a shearing action generated between the water around the jet 207 and the flow 208 sucked into the diffusion chamber when the jet is ejected from the diffusion chamber 205 through the throat 204. Therefore, by using the high-pressure water jet nozzle having the above-described characteristics in the water tank 4 as shown in (b), cavitation can be easily generated in water or in a water atmosphere, and the collapse pressure can be used to produce a wafer or substrate. It is possible to remove the above-mentioned foreign matter, flux, or dust attached to the LCD or the like.

FIG. 3 shows an embodiment of claim 3. The multi-nozzle of this example has a ring-shaped second sub-injection port 23 and a third sub-injection port 2 surrounding the main injection port 22 for injecting the high-pressure water 21.
4, ... Are provided in multiple numbers, and the high-pressure water 21 is jetted from the main jet port 22, and the jet water 25 having a lower pressure than the high-pressure water 21 jetted from the main jet port 22 is jetted from the sub jet ports 23 and 24.
Shear occurs due to the speed difference between the high pressure water 21 and the low pressure water 25,
Cavitation occurs. This method makes it possible to clean the wafer surface using the collapse pressure of cavitation even in the atmosphere.

FIG. 4 shows an embodiment of claim 3. Cleaning tank 4
By providing the ultrasonic generator 31 in the
The cavitation 32 generated by the jet flow from the nozzle 12 is generated more actively than usual due to the rise in the water temperature due to. The collapse pressure causes the wafer 1 to be cleaned with a high cleaning degree. Further, fine vibrations due to the ultrasonic waves 33 are further superimposed to remove the deposits on the wafer surface.

FIG. 5 shows another embodiment of claim 3. Without installing the general-purpose ultrasonic generator 41 in the water tank 4, the nozzle 1
As in the case of 2, the method is to insert it into the water from the water surface. Cavitation 32 generated by the jet by this method
And the vibration caused by the ultrasonic wave 33 are superposed on each other to remove the deposits on the surface of the wafer 1.

In FIG. 1, the chemical liquid is mixed with pure water from the chemical liquid tank 16 and sprayed into the water tank 4 by the high pressure pump 10. With this method, the wafer 1 is produced by the synergistic effect of chemical cleaning with a chemical solution and mechanical cleaning with the collapse pressure of cavitation.
Can remove the deposits on the surface. In FIG. 1, carbon dioxide gas is mixed with pure water in the chemical tank 16 and the water tank 4 is driven by the high pressure pump 10.
Spray inside. By this method, the conductivity of the water in the cleaning tank is lowered and it is possible to prevent the generation of static electricity.

FIG. 6 shows an embodiment of claim 5.

The cleaning tank 4 is provided with a jet port 51 for low-pressure water flow,
The pure water in the cleaning tank 4 is agitated. Further, like the high-pressure water jet nozzle 12, the low-pressure water jet nozzle 52 is inserted into the water from above the water surface to jet high-pressure water and low-pressure water onto the surface of the wafer 1. Foreign substances on the surface of the wafer 1 can be removed by the synergistic action of the axial guiding pressure of the low-pressure water flow, the cavitation, and the water flow in the water tank.

FIG. 7 shows another embodiment of the wafer grip portion of the manipulator. The wafer 1 is sandwiched by the upper and lower suction covers 61 and 62, and is sucked by the compressor 15 to convey the wafer 1. Negative pressure due to suction can prevent foreign matter from adhering during transportation. Further, it is possible to remove water droplets during transportation without performing drying by the dryer 6 after washing, and it is possible to shorten the construction time.

FIG. 8 shows another embodiment of the carrying device.

The transfer path is sealed with a cover 71, and clean air 73 is jetted from the belt or roller 72 of the feeding mechanism so that the wafer 1 and the transfer device 13 do not come into direct contact with each other, and foreign matter attached to the transfer device 13 To prevent reattachment to the wafer 1. Alternatively, the air is drawn from the belt or the roller 72 of the feed mechanism of the transfer path 13 by the compressor 15 to transfer the wafer 1 while sucking the wafer 1 with a negative pressure. By this method, it is possible to prevent foreign matter from adhering to the wafer 1 during transportation.

FIG. 9 shows an embodiment of the wafer chuck mechanism.

The wafer chucking device on the table 5 has a structure in which the wafer 1 is pressed from both sides and the upper surface of the wafer 1 at the same time so as to prevent the wafer 1 from vibrating or moving during cleaning. The chuck 81 is driven by a motor 82 and a ball screw 83 when the wafer 1 is attached or released. The combination of the motor and the ball screw may be another combination as long as it has the same drive mechanism.

FIG. 10 shows another embodiment of the wafer chuck mechanism.

FIG. 10A shows an example of a mechanism using a chuck 81 and vacuum suction for fixing the wafer 1. Lateral vibration of the wafer 1 during cleaning is suppressed by chucking from the cleaning surface side of the wafer 1, and vibration in the ejection direction is suppressed by vacuum suction from the back surface by a suction plate 91. Further, by this mechanism, it is not necessary to repeat chucking of the wafer 1 from the storage shelf 2 to the cleaning tank 4 and the transfer device 13, and it is possible to reduce foreign matter adhesion at the time of wafer chucking.

FIG. 10B shows an example of a mechanism using the chuck 81 and air jet for fixing the wafer 1. Lateral vibration of the wafer 1 during cleaning is suppressed by chucking from the cleaning surface side of the wafer 1, and clean air is blown from the back surface through an air tube 92 to form slits 93 having a large number of micro holes.
Vibration from the injection direction is suppressed by injecting from. Further, by this mechanism, it is not necessary to repeat chucking of the wafer 1 from the storage shelf 2 to the cleaning tank 4 and the transfer device 13, and it is possible to reduce foreign matter adhesion at the time of wafer chucking.

FIG. 11 shows another embodiment of the wafer fixing table 5 in the cleaning tank 4.

A top view is shown in a and a side view is shown in b. Wafer 1
It is possible to install a plurality of wafer surfaces in a direction parallel to the jet stream by a structure in which the chuck 101 is gripped from both sides only.

Further, by installing the wafer 1 in parallel with the jet flow, it is possible to utilize only the active cavitation 26 without directly applying the water pressure to the wafer surface. In addition, since a plurality of thin wafers 1 can be arranged side by side in parallel, the construction time can be shortened.

FIG. 12 shows another embodiment of the fixing table in the cleaning tank.

A top view is shown in (a) and a side view is shown in (b).
A chuck 8 for fixing the wafer 1 on the table 5
1 is equipped. The table 5 is supported by the support base 111 so that the table 5 can be rotated and tilted in any direction around the support base 111. Further, in order to move the table 5 in an arbitrary direction, the table 5 is connected to the floor surface to which the support base 111 is fixed by a plurality of legs or rollers, balls 112, and the like.

When the jet flow 113 containing the cavitation 26 is jetted from the nozzle 12 onto the wafer 1, the legs connecting the table 5 and the floor surface, or the rollers, balls, etc. 11
2 is moved to change the angle of the jet flow hitting the wafer, the cavitation 26 contained in the jet flow is changed to the table 5
The cavitational cleaning effect can be obtained over a wider area than the area where the jet normally hits, as it flows over a wide range along the slope of.

[0042]

According to the present invention, the foreign matter on the wafer surface can be removed by the collapse pressure of cavitation in water or in the water atmosphere of air.
Foreign matter on the wafer that could not be removed by a water jet directly in the atmosphere or a cleaning method using ultrasonic waves in water can be removed in water or air.

Further, according to the present invention, the effect that cavitation is easily generated only by injecting high-pressure water from the nozzle in water or in a water atmosphere can be used to directly inject a water jet in the atmosphere or in water. Foreign matter on the wafer that could not be removed by the ultrasonic cleaning method can be removed in water or air.

According to the third aspect of the present invention, the low-pressure jet nozzle is arranged around the high-pressure jet nozzle to generate a water atmosphere with the low-pressure water flow, and the collapse pressure of the cavitation generated by the pressure difference from the high-pressure water flow and the shearing action. This has the effect of removing foreign matter on the wafer surface. Even in the air, foreign matter on the wafer that could not be removed by directly spraying a water jet in the air or cleaning by ultrasonic waves in water can be removed in water. It can be removed regardless of the inside.

According to the invention of claim 4, the generation of cavitation is activated by the generation of bubbles by ultrasonic waves and the heat generation phenomenon caused by the collapse thereof, and the collapse pressure of the generated cavitation makes it possible to remove foreign matter on the wafer surface. Thus, even in the atmosphere, foreign matters on the wafer which cannot be removed by a direct water jet in the atmosphere or a cleaning method using ultrasonic waves in water can be removed in water or in air. According to the invention of claim 5, the foreign matter on the wafer surface can be removed by the chemical reaction by the chemical liquid such as acid and alkali and the collapse pressure of the cavitation, and the water jet is directly jetted in the atmosphere even in the atmosphere. The foreign matter on the wafer that could not be removed by the ultrasonic cleaning method in water can be removed in water or in the air.

According to the invention of claim 6, the generated cavitation is diffused by the agitation of the low-pressure water flow in the water tank and the axial guiding pressure of the jet, and the foreign matter on the wafer surface can be removed by the collapse pressure of the cavitation generated over a wide range. In this way, even in the atmosphere, foreign matter on the wafer that cannot be removed by directly spraying a water jet in the atmosphere or by the ultrasonic cleaning method in water,
It can be removed regardless of the air.

According to the invention of claim 7, it is possible to prevent generation of static electricity by mixing carbon dioxide gas in pure water to reduce the conductivity.

According to the invention of claim 8, the wafer does not move due to an external force by vacuum-adsorbing the wafer, and
A vacuum is constantly applied to obtain an effect that foreign matter does not adhere to the wafer, which suppresses movement of the wafer during cleaning and prevents foreign matter from being adhered during wafer transfer.

According to the ninth aspect of the present invention, by inclining the object to be cleaned in an arbitrary direction, cavitation can be diffused over a wide range, and the wide range can be efficiently cleaned in a short time.

According to the tenth aspect of the present invention, the wafer is fixed in the shape of a windsock, and is set in parallel with the jet flow.
With the jet flow, cavitation spreads evenly on the front and back surfaces of the wafer, allowing a wide area in a short time.
A large number of objects can be washed efficiently.

According to the eleventh aspect of the present invention, by vacuum-adsorbing the cleaned wafer from both sides, the foreign matter and water droplets can be removed, and the wafer can be transported without re-adhesion.

According to the twelfth aspect of the invention, the action of causing plastic strain in the wafer due to the collapse pressure of the cavitation is provided, and the heavy metal element existing on the cleaned surface is moved away from the vicinity of the surface.

[Brief description of drawings]

FIG. 1 is a block diagram of a semiconductor wafer cleaning apparatus using cavitation according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a nozzle for generating cavitation in the air or air, which is one embodiment of the present invention, and an explanatory diagram of a cleaning device provided with the nozzle.

FIG. 3 is a cross-sectional view of a nozzle that generates cavitation in the atmosphere, which is an embodiment of the present invention.

FIG. 4 is an explanatory diagram of a cleaning device that is a combination of cavitation and ultrasonic waves according to an embodiment of the present invention.

FIG. 5 is an explanatory diagram of another embodiment of a cleaning apparatus that is a combination of cavitation and ultrasonic waves, which is an embodiment of the present invention.

FIG. 6 is an explanatory diagram of a cleaning device that is a combination of cavitation, axial guiding pressure, and low-pressure water flow according to an embodiment of the present invention.

FIG. 7 is an explanatory view of a wafer gripping portion by vacuum suction of a manipulator according to an embodiment of the present invention.

FIG. 8 is an explanatory diagram of a carrying device that is an embodiment of the present invention.

FIG. 9 is an explanatory diagram of a wafer chucking device that is an embodiment of the present invention.

FIG. 10 is an explanatory diagram of a wafer chucking device by vacuum suction or air jetting, which is an embodiment of the present invention.

FIG. 11 is an explanatory diagram of a blow-off type wafer fixing device that is an embodiment of the present invention.

FIG. 12 is an explanatory diagram of a multi-tilt table device according to an embodiment of the present invention.

[Explanation of Codes] 1 ... Wafer, 2 ... Pre-cleaning wafer storage shelf, 3 ... Manipulator, 4 ... Cleaning tank, 5 ... Table, 6 ... Dryer, 7
... Ultrapure water tank, 8 ... Waste liquid treatment tank, 9 ... Ultrapure water production apparatus, 10 ... High pressure pump, 11 ... High pressure hose, 12 ... Nozzle, 13 ... Wafer transfer device, 14 ... Wafer storage shelf after cleaning, 15 ... Compressor, 16 ... Chemical tank.

Front Page Continuation (72) Inventor Hideo Miura 502 Jinritsucho, Tsuchiura-shi, Ibaraki Machinery Research Laboratory, Hiritsu Seisakusho Co., Ltd. Hitachi Semiconductor Division

Claims (12)

[Claims] 1. A cavitation collapse pressure generated when high-pressure water is sprayed in water or in a water atmosphere is used to remove foreign matter or flux on a wafer or substrate, dust adhering to an LCD, and the like. Semiconductor wafer cleaning device. 2. A high-pressure water jet equipped with an engagement part connected to a conduit for guiding high-pressure water, a water chamber following the engagement part, an orifice following the water chamber, a throat following the orifice, and a diffusion chamber following the throat. Equipped with a nozzle, a high-pressure pump, and a high-pressure water injection device for a high-pressure hose, cavitation is generated in water or in a water atmosphere, and the collapse pressure is used to collect foreign matter or flux on the wafer or substrate, or dust attached to the LCD. A semiconductor wafer cleaning device characterized by removing the. 3. A low-pressure jet nozzle is arranged around the high-pressure jet nozzle to create a water atmosphere even in the air, and by injecting high-pressure water therein, cavitation is generated in the same manner as underwater, and a cavitation on a wafer or substrate is produced. A semiconductor wafer cleaning apparatus, which removes foreign matter, flux, and dust adhering to an LCD. 4. The semiconductor wafer cleaning apparatus according to claim 1, wherein cavitation and ultrasonic waves are combined to remove foreign matters and the like, and the foreign matters are removed by a synergistic effect thereof. 5. The semiconductor wafer cleaning apparatus according to claim 1, wherein cavitation and a chemical reaction with a chemical solution are combined with the removal of foreign matters and the like, and the foreign matters are removed by a synergistic effect thereof. 6. The semiconductor wafer cleaning apparatus according to claim 1, wherein cavitation, axial guiding pressure and water flow are combined to remove foreign matter and the like, and the foreign matter is removed by a synergistic effect thereof. 7. The semiconductor according to claim 1, wherein carbon dioxide gas is inserted into a pure water tank or a water tank to reduce conductivity, thereby preventing static electricity from being generated and utilizing cavitation collapse pressure to remove foreign matters. Wafer cleaning equipment. 8. A semiconductor wafer cleaning apparatus according to claim 1, 2, 3, 4, 5, 6 or 7, wherein the cleaned wafer is transferred from both sides by vacuum suction so that it can be dried at the same time as being transferred. 9. The vacuum suction device according to claim 1, 2, 3, 4, 5, 6 or 7, wherein the object to be cleaned on the wafer is not deformed, does not move during cleaning, and can reduce adhesion of foreign matter during transportation. Wafer fixing device during cleaning using. 10. Claims 1, 2, 3, 4, 5, 6 or 7
In order to effectively use the wraparound effect of cavitation in order to clean a wider range of target surfaces of multiple objects in a short time, a wafer fixing device that can set several objects such as wafers in a streamwise manner. 11. A method according to claim 1, 2, 3, 4, 5, 6 or 7.
In the above, a wafer fixing device during cleaning, in which an object to be cleaned such as a wafer can be tilted in an arbitrary direction so that the wraparound effect of cavitation can be effectively used to clean a wider area of the object surface in a short time. 12. A surface opposite to the cleaning surface by aggregating heavy elements in the wafer or substrate on the cleaning surface by utilizing the collapse pressure of cavitation generated when high-pressure water is sprayed in water or water atmosphere. Semiconductor wafer cleaning equipment that keeps the heavy elements of the device away from the surface vicinity.