JPH09162152A - Versatile cleaner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a rotary versatile cleaner where the problem of dust generation from a rotary sliding part is eliminated and cleaning and drying can be carried out while shutting off the outer air perfectly. SOLUTION: In a cleaner where a member 104 for holding a matter 105 to be treated is disposed, while being coupled with a rotary shaft 107, in a cleaning bath 101 having parts 103, 106 for feeding and discharging cleaning liquid and the matter 105 is cleaned and/or dried while turning, the rotary shaft 107 penetrates the discharging part 106. The cleaner further comprises means for controlling the flow rate of cleaning liquid discharged through the discharging part 106, and means for shutting the outer air off from the cleaning bath 101 by means of the cleaning liquid itself being discharged through the discharging part 106.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary type universal cleaning device, and more particularly to a cleaning device which prevents dust from entering a cleaning tank from a sliding portion.

[0002]

2. Description of the Related Art In recent years, with the higher integration of semiconductor integrated circuits, the circuit patterns formed on the surface of a semiconductor wafer have become finer and more complicated. Therefore, even if a minute foreign substance or a small amount of impurities is attached to the semiconductor wafer, the characteristics of the semiconductor circuit are deteriorated and the manufacturing yield is lowered. Therefore, the cleaning process is extremely important in the semiconductor manufacturing process.

As a method for cleaning a semiconductor wafer, there is used a cleaning method in which a semiconductor substrate is rotated in a cleaning tank while a cleaning liquid or an inert gas is sprayed to clean and dry the semiconductor substrate. In the rotary cleaning device for this purpose, the rotating shaft of the substrate holding member penetrates the device and is supported by a bearing, but since this bearing is exposed inside the cleaning tank, dust generated by sliding is generated in the cleaning tank. There is a problem of polluting the atmosphere. In addition, there is also a problem that outside air is mixed in through the penetrating portion or the like and contaminates the inside of the cleaning tank and thus the object to be cleaned.

[0004]

SUMMARY OF THE INVENTION In view of the above situation, an object of the present invention is to provide a rotary type universal cleaning apparatus which eliminates the problem of dust generation from the rotary sliding portion. And Furthermore, it aims at providing the washing | cleaning apparatus which can perform a washing | cleaning and drying process in the state shielded from the open air.

[0005]

According to the universal cleaning apparatus of the present invention, a holding member for an object to be cleaned is arranged inside a cleaning tank having a cleaning liquid supply section and a cleaning solution connection, A cleaning device for cleaning and / or drying an object to be cleaned while rotating the object, wherein the rotating shaft penetrates the discharge part.

It is characterized in that it has flow rate control means for adjusting the flow rate of the cleaning liquid discharged from the discharge part.

The flow rate control means adjusts the discharge flow rate by changing the gap between the rotary shaft and the discharge part. In particular, the rotary shaft having at least two different outer diameters and the discharge shaft. It is preferable that it is configured by a displacement unit that displaces the relative position in the axial direction between the portion and the rotating shaft. Further, the rotating shaft having at least two different outer diameters has one or more portions whose outer diameters change at a predetermined angle, and the discharging portion has a portion whose inner diameter changes at a predetermined angle. It is preferable to have a configuration having 1 or 2 or more.

Further, the flow rate control means is characterized in that unevenness, fins or grooves are provided on the rotary shaft or the discharge part, and the flow rate is adjusted by the rotation direction and / or the rotation speed of the rotary shaft.

Further, it is preferable that a container for receiving the cleaning liquid discharged from the discharging portion is disposed on the rotary shaft, and the cleaning liquid accumulated in the container is passed through the rotary shaft and discharged from a lower portion thereof. It is preferable that at least a part of the shaft is hollow.

The universal cleaning apparatus of the present invention is characterized in that it is provided with an outside air blocking means for blocking the inside of the cleaning tank from the outside air by the cleaning liquid itself discharged from the discharge part.

In the universal cleaning apparatus of the present invention, the holding member is a holding member for the substrate storage cassette, and cleaning is performed at low speed or medium speed rotation, and drying is performed by centrifugal force at high speed rotation. Is possible.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An example of a semiconductor wafer cleaning / drying apparatus according to the present invention is shown in FIGS. 1 and 2, and the present invention will be described with reference to FIG.

FIG. 1 is a conceptual diagram showing the basic concept of the cleaning apparatus of the present invention.

In FIG. 1, 101 is a cleaning tank, 102 is a lid, 103 is a cleaning liquid supply pipe, and 104 is a semiconductor substrate 105.
It is a rotation holding member. Reference numeral 106 denotes a discharge part, and in the example shown in the figure, a pipe arranged at the center of the bottom surface of the cleaning tank 101 and having a taper whose opening diameter decreases as it goes downward is used. A rotating shaft 107 penetrates through the discharging portion 106, one of which is connected to the holding member 104 and the other of which is connected to a driving motor 109. The rotating shaft 107 has a large diameter portion 110 having a taper portion at the same angle as the taper of the discharge portion.
And a cleaning liquid receiving container 108 that rotates together with the rotating shaft.

As shown in FIG. 1, the cleaning apparatus of the present invention is
Since the bearing that supports the rotating shaft has been removed from the cleaning tank,
It is possible to avoid the problem of dust generation at the sliding portion between the rotating shaft and the bearing, which is a problem in the conventional device. Further, the cleaning liquid flowing between the rotary shaft and the discharge portion can prevent foreign matters such as dust from entering from the outside.

The liquid accumulated in the receiving container 108 is, for example, as shown in FIG.
As shown in, the drain pipe 302 may be attached to the receiving container 108, and the drainage may be drained to the annular drainage receiving groove 303. In this case, it is preferable to provide a plurality of discharge pipes 302 in consideration of the balance during rotation. Alternatively, it may be annular like the receiving groove 303.

Further, the liquid accumulated in the receiving container 108 may be further provided with a container 402 for receiving the cleaning liquid overflowing the receiving container 108, for example, as illustrated in FIG.

Further, as shown in FIG.
The inside of 7 may be hollow at the lower part from the receiving container 108, and the cleaning liquid accumulated in the container 108 may be discharged from the lower part of the rotating shaft 107 through the discharge port 601 and the hollow portion 602. Further, the discharge amount can be adjusted by providing a valve 603 at the lower end of the rotary shaft 107, for example.

FIG. 2 is a conceptual diagram showing a preferred example of the cleaning apparatus of the present invention.

In FIG. 2, 201 is a cleaning tank, 202 is a lid, 203 is a plurality of cleaning liquid supply pipes, and 204 is an inert gas supply pipe. 205 is a megasonic ultrasonic transducer,
Reference numeral 206 is an infrared lamp for heating the semiconductor substrate, and 207 is a rotation holding member for the semiconductor substrate 208. Also, the cleaning tank 2
A semiconductor substrate transfer device (not shown) is connected to 01, and has a structure capable of carrying out and carrying in the semiconductor substrate without contacting the atmosphere.

Reference numeral 209 is a cleaning liquid discharge portion, and 210 is a rotary shaft having a large diameter portion 211 having the same structure as in FIG. The rotating shaft 210 is connected to the rotation holding member 207 and a driving motor 217, and is supported by a bearing 220.

Reference numeral 212 denotes an outside air blocking means for blocking the inside of the discharge part 209 and the inside of the cleaning tank 201 from the outside air. The drainage pipe 216 for use.
Further, 214 and 219 are a drain valve and a pipe for discharging the cleaning liquid in the liquid reservoir 215 when the cleaning liquid is exchanged. The cleaning device shown in FIG.
Although 20 is provided, dust and the like generated in the bearing 220 is blocked by the cleaning liquid itself accumulated in the liquid reservoir 215, and is completely prevented from entering the cleaning tank 201.

Reference numeral 218 is a displacement means for displacing the relative position of the discharge pipe 209 and the rotary shaft in the axial direction, 221 is a motor support member, and these are housed in the housing 222. In addition, in order to prevent the cleaning liquid from being contaminated by steam or mist, a dry N ₂ gas, clean air, an inert gas, or the like is caused to flow through the housing 222.

A method of cleaning a semiconductor substrate including hydrofluoric acid, ultrapure water rinsing, isopropyl alcohol (IPA) cleaning, and a drying step will be described using the apparatus shown in FIG.

(A) Hydrofluoric Acid Cleaning First, the silicon wafer 208 is set on the holding member 207 by a transfer device (not shown).

When the hydrofluoric acid is poured into the cleaning tank 201 from the first cleaning liquid supply pipe 203 and the silicon wafer is sufficiently covered, the holding member 207 is rotated at a low to medium speed (for example, 30).
˜500 rpm), a voltage is applied to the ultrasonic transducer 205, and a megasonic ultrasonic wave of 1 to 5 MHz is applied to the wafer to clean the wafer. By applying megasonic ultrasonic waves, the cleaning effect is further improved, and especially dust and impurities in the grooves such as trenches can be completely removed.

The hydrofluoric acid flows downward through the gap between the large diameter portion 211 of the rotary shaft 210 and the discharge portion 209, and the liquid pool portion 21.
5 through the liquid level holding pipe 216 and is discharged to a drainage tank (not shown). Therefore, inside the cleaning tank 201,
The gap between the large-diameter portion 211 of 0 and the discharge portion 209 and the cleaning liquid itself accumulated in the liquid reservoir 215 completely block dust and the like generated from bearings and the like.

In the above cleaning, impurities, dust and the like adhering to the silicon wafer are extremely effectively removed from the wafer surface by the rotational movement of the wafer, the supply of a fresh cleaning liquid, and the action of megasonic ultrasonic waves. It is discharged to the outside through the above gap.

The size of the gap between the large-diameter portion 211 of the rotary shaft 210 and the discharge pipe 209 determines the flow rate of the liquid discharged through this gap, but is 1 to 10% of the supply amount.
It is preferred that Normally, this gap is set to 1 to 10 mm, but it is appropriately determined depending on the viscosity of the liquid.

After the hydrofluoric acid cleaning is completed, N ₂ gas is supplied into the tank and the displacement means 218 moves the rotary shaft 210 upward to increase the gap between the discharge portion 209 and the large diameter portion 211 of the rotary shaft. Then, the hydrofluoric acid is dropped and released to the outside. Even in this case, since hydrofluoric acid accumulates in the liquid pool 215,
Dust and the like do not enter the inside of the cleaning tank 201 and the discharge pipe 209.

(B) Ultrapure water rinsing cleaning Next, ultrapure water is supplied from the ultrapure water supply pipe into the bath, and ultrapure water rinsing cleaning is performed in the same manner as hydrofluoric acid cleaning.

(C) IPA Cleaning and Drying IPA is supplied from the IPA supply pipe into the tank and cleaning is carried out in the same manner as the hydrofluoric acid cleaning. Then, the wafer 208 is heated by the infrared lamp 206 while supplying N ₂ gas and rotated at a high speed (1000 to 3600 rpm) to remove IPA adhering to the wafer and dry it. Also in this step, dust is prevented from entering from the outside, so the wafer is always kept in a clean atmosphere. Therefore, a highly clean wafer surface can be maintained, and a high manufacturing yield can be stably obtained.

When the inorganic drainage such as hydrofluoric acid and the organic drainage such as IPA are discharged to separate drainage tanks, after connection with the ultrapure water rinse, the drainage pipe 216 is connected. The inorganic drainage tank may be replaced with an organic drainage tank. Also,
In order to completely separate each cleaning liquid, the cleaning liquid accumulated in the liquid reservoir 215 may be discharged from the drain pipe 219.

Depending on the cleaning liquid, the cleaning liquid may be returned to the supply pipe from the drain pipe 216 and the drain pipe 219 via a filter or the like.

(Embodiment example) In the above, an example in which hydrofluoric acid cleaning, ultrapure water rinsing, and IPA cleaning / drying steps are continuously performed by the apparatus of FIG. 2 has been described. Not limited to the case, it is possible to add a step using another cleaning liquid. Alternatively, a method is adopted in which one device is provided for each process, such as a device for hydrofluoric acid cleaning / rinsing with ultrapure water and a device for IPA cleaning / drying, and the substrate is transferred between these devices. Is also good.

In the cleaning apparatus of the present invention, for example, by inserting an O-ring or the like at the angled portion of the rotary shaft or the discharge part in FIG. 2 and bringing the rotary shaft into pressure contact with the O-ring, the drainage can be completely discharged. It can be omitted and can be used as a general cleaning tank.

The cleaning apparatus of the present invention is not limited to the method of immersing a substrate in a cleaning solution for cleaning, and can be similarly applied to the case of spraying a cleaning solution on the surface of a substrate by spraying. In this case as well, the cleaning liquid in the gap between the rotary shaft and the discharge part and / or the cleaning liquid itself stored in the liquid pool also prevents dust from entering from the sliding part, and also can block the inside of the cleaning tank from the outside air. As a result, cleaning can be performed in a highly clean atmosphere.

Further, in the present invention, when the substrate is not immersed in the cleaning liquid, the cleaning can be effectively performed by spraying a jet stream of the cleaning liquid containing megasonic ultrasonic waves on the substrate surface. Further, by providing an ultraviolet lamp in the cleaning tank and irradiating the surface of the substrate with ultraviolet rays to radically activate the cleaning liquid, the cleaning effect can be further enhanced.

The main constituent elements of the present invention will be described in more detail below.

Flow Rate Control Means The flow rate control means shown in FIG. 2 comprises a rotary shaft having a large diameter portion whose outer diameter changes at a predetermined angle, and displacement means for axially displacing the rotary shaft. The flow rate control means is not limited to this, and the rotary shaft may have at least two different outer diameters, and the discharge part may be a straight pipe instead of a tapered shape. However, by changing the outer diameter of the rotating shaft in multiple stages, and further by continuously changing it, it can be applied to various cleaning liquids having a wide range of viscosity, and the degree of freedom in selecting the cleaning liquid increases. Controllability is also improved.

Further, the displacement means may move the cleaning tank and the discharge part instead of moving the rotating shaft itself. The displacement means for moving the rotary shaft or the cleaning tank may be those that move them mechanically, or a permanent magnet may be arranged on a part of the rotary shaft and a current may be applied to a coil arranged around the permanent magnet. , May be moved by interaction of magnetic fields.

In addition to the above, the flow rate control means of the present invention may be of any type as long as the flow rate can be adjusted. For example, the inner diameter can be changed continuously or stepwise like the diaphragm of a camera. A member may be used and this may be provided at the discharge part or the bottom opening of the cleaning tank.

As one mode of a preferable flow rate control means,
As shown in FIG. 3, the spiral fin 30 is attached to the rotary shaft 107.
1 may be used. Thus, the amount of drainage can be controlled by changing the rotation speed of the rotary shaft, and the drainage can be forcibly discharged by rotating in the opposite direction. Although the example in which the spiral fin is provided is shown in the example of FIG. 3, the present invention is not limited to this, and irregularities, grooves, or the like may be provided on the rotary shaft or the discharge portion, and the flow rate can be adjusted by the rotation speed or the rotation direction. If it is a thing, it does not need to be limited to a spiral shape.

Further, if the method of FIG. 3 is used, the above-mentioned displacement means and the like are unnecessary, but it goes without saying that they may be used in combination. In FIG. 3, the liquid accumulated in the receiving container 108 is discharged to the annular drain receiving groove 303 through the drain pipe 302 as described above, but the structure of FIGS. Not to mention good things.

Outside air shut-off means The structure shown in FIG. 2 can shut off the inside of the cleaning tank from the outside air around the bearing. In addition to this, for example, as shown in FIG. 4, the cylindrical body 213 in FIG. It is arranged upside down, and the inner diameter of this cylindrical body 401 is set to the discharge portion (discharge pipe) 209.
Larger than the outside diameter of the discharge pipe 2
09 may be overlapped. With this configuration, the cleaning liquid accumulated in the cylindrical body 401 can always shut off the inside of the cleaning tank 201 from the outside air.

The cleaning liquid overflowing from the cylindrical body 401 is received by a container 402 fixed to a cleaning tank or the like, and is discharged to the outside by a pipe 403. In this case, it is preferable to further provide the second cylindrical body 404 on the bottom surface in order to prevent the cleaning liquid from traveling along the bottom surface of the cylindrical body 401 and dropping to the bearing 220 side.

Further, as shown in FIG. 6, the inside of the rotating shaft is made hollow without letting the cleaning liquid accumulated in the cylindrical body 401 overflow, and the cleaning liquid accumulated in the cylindrical body is discharged from the lower part of the rotating shaft through this hollow portion. Alternatively, a valve may be provided below the rotating shaft to adjust the flow rate of the discharged gas.

Cleaning Tank In the present invention, the holding member 207 is provided in the cleaning tank 201.
It is preferable to provide a partition plate whose lower end is fixed to the bottom surface of the cleaning tank so as to surround the. By providing a partition plate and overflowing a part of the supplied cleaning liquid to the outside of the cleaning tank, relatively heavy dust is discharged to the outside together with the cleaning liquid flowing downward through the gap between the discharge unit 209 and the rotating shaft 211 described above. The light dust discharged to the outside can be discharged to the outside together with the cleaning liquid overflowing the partition plate, and the dust removing effect is further improved. Further, the cleaning liquid overflowing from the partition plate is passed through a filter and then returned to the cleaning liquid supply pipe again, whereby the amount of the cleaning liquid used can be reduced.

Further, it is preferable that the bottom surface of the cleaning tank is inclined downward toward the discharge opening. As a result, dust and the like quickly flow to the opening of the discharge portion, and the discharge becomes more efficient.

Holding Member In FIG. 2, a single-wafer cleaning / drying apparatus has been described, but the universal cleaning apparatus of the present invention can also clean a large number of sheets at once. An example is shown in FIG. FIG. 5 is (a) a schematic plan view and (b) a schematic sectional view of a holding member in which six wafer cassettes are arranged.

The holding member is a wafer cassette 50 containing a disk 502 fixed to a rotary shaft 501 and a wafer 504.
5 holding portions 503.

As shown in FIG. 4, the wafer storage cassette 5
05 is attached to the holding portion 503 by fitting or the like, and the cleaning liquid is supplied in the same manner as in the single-wafer type, and rotation cleaning is performed. Since the wafer surface is arranged horizontally, a high cleaning effect can be obtained by the centrifugal force of rotation.

It should be noted that the cassette is preferably mounted and unloaded by the transport mechanism and mounted / removed in / from the holding portion as in the case of the single-wafer type.

Heating means As the heating means, in addition to heating the substrate with an infrared lamp or the like, an electric heater or the like may be provided on the holding member to directly heat it, or a heated inert gas or the like may be blown onto the substrate. .

As the material of the members such as the rotating shaft, the inner wall of the tank, and the holding member that come into contact with the cleaning liquid, those which are not corroded by the cleaning liquid and generate no impurities or the like are used. For example, quartz or stainless steel coated with silicon rubber or polyethylene and further coated with Teflon is preferably used. By using these, hydrofluoric _{acid, H 2 SO 4 -H 2 O} 2, NH 4 OH
It is possible to perform cleaning with highly corrosive cleaning solution, such as -H ₂ O _2.

The rotary shaft may be directly fixed to a rotary drive source such as a motor to rotate, or may be rotated via a gear or belt.

[0057]

According to the invention of claim 1, it is possible to avoid the problem of dust generation from the rotary sliding portion. Further, according to the inventions of claims 2 to 6, the effect of preventing dust and impurities from being mixed in from the outside during the cleaning step is further improved, and higher integration and higher performance of the integrated circuit can be achieved, and the manufacturing yield is improved. It is possible to improve.

According to the seventh and eighth aspects of the present invention, the cleaning liquid discharged can be easily managed, and the apparatus can be downsized.

According to the ninth aspect of the present invention, the surface of the object to be cleaned can be kept clean without being affected by the outside air during the cleaning step. As a result, higher performance of the integrated circuit can be achieved.

Further, according to the invention of claim 10, it becomes possible to process a large number of substrates and the like at a time.
It is possible to reduce the manufacturing cost by reducing the amount of cleaning liquid used.

The present invention is applicable not only to semiconductor substrates, photomasks and the like, but also to any precision cleaning, and for example, it is also suitable for cleaning metals that are oxidized when contacted with the atmosphere.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram illustrating the concept of a cleaning device of the present invention.

FIG. 2 is a conceptual diagram showing an example of a cleaning device of the present invention.

FIG. 3 is a conceptual diagram showing another example of the cleaning apparatus of the present invention.

FIG. 4 is a conceptual diagram showing another example of the outside air blocking means of the present invention.

FIG. 5 is a conceptual diagram showing an example of a holding member of the present invention.

FIG. 6 is a conceptual diagram showing another example of the cleaning device of the present invention.

[Explanation of symbols]

 101 cleaning tank, 102 lid, 103 cleaning liquid supply pipe, 104 rotation holding member, 105 semiconductor substrate, 106 discharge part (discharge pipe), 107 rotating shaft, 108 discharge liquid receiving container, 109 motor, 110 large diameter part of rotating shaft , 201 cleaning tank, 202 lid, 203 plural cleaning liquid supply pipes, 204 inert gas supply pipe, 205 megasonic ultrasonic vibrator, 206 infrared lamp for heating semiconductor substrate, 207 rotation holding member, 208 semiconductor substrate, 209 Discharge part, 210 rotary shaft, 211 large diameter part, 212 outside air shutoff means, 213 cylindrical body, 214 drain valve, 215 liquid pool part, 216 liquid level holding pipe, 217 motor, 218 displacement means, 219 drain pipe, 220 Bearing, 221 motor support, 222 housing, 301 spiral fin, 02 drain pipe, 303 annular drainage receiving groove, 401 cylindrical body, 402 container, 403 piping, 404 spill-preventing cylindrical body, 501 rotating shaft, 502 disc, 503 cassette holding part, 504 wafer, 505 wafer cassette 601 outlet, 602 Hollow part, 603 valve.

Claims (10)

[Claims] 1. A holding member for an object to be cleaned is disposed inside a cleaning tank having a supply part and a discharge part for the cleaning liquid, the member being connected to a rotating shaft, and the cleaning target is cleaned and / or dried while rotating. A cleaning device, wherein the rotating shaft penetrates the discharge part. 2. The universal cleaning apparatus according to claim 1, further comprising flow rate control means for adjusting a flow rate of the cleaning liquid discharged from the discharge part. 3. The universal cleaning apparatus according to claim 2, wherein the flow rate control means adjusts the discharge flow rate by changing the gap between the rotary shaft and the discharge part. 4. The flow rate control means comprises: the rotary shaft having at least two different outer diameters; and a displacement means for displacing the relative position in the axial direction between the discharge part and the rotary shaft. The universal cleaning device according to claim 3. 5. The rotating shaft having at least two different outer diameters has at least one portion whose outer diameter changes at a predetermined angle, and the discharge portion has an inner diameter changing at a predetermined angle. The universal cleaning apparatus according to claim 4, wherein the universal cleaning apparatus has one or more parts. 6. The flow rate control means is characterized in that unevenness, fins, or grooves are provided on the rotary shaft or the discharge part, and the flow rate is adjusted by the rotation direction and / or the rotation speed of the rotary shaft. The universal cleaning apparatus according to any one of claims 2 to 5. 7. The universal cleaning apparatus according to claim 1, wherein a container for receiving the cleaning liquid discharged from the discharging portion is arranged on the rotary shaft. 8. The universal cleaning apparatus according to claim 7, wherein at least a part of the rotary shaft is hollow so that the cleaning liquid accumulated in the container is passed through the rotary shaft and discharged from a lower portion thereof. 9. The universal type according to claim 1, further comprising an outside air shutoff means for shutting off the inside of the washing tank from the outside air by the washing liquid itself discharged from the discharge part. Cleaning device. 10. The holding member is a holding member for a substrate storage cassette, and is characterized in that cleaning can be performed at low or medium speed rotation and drying can be performed using centrifugal force at high speed rotation. The universal cleaning apparatus according to any one of claims 1 to 9.