JPH06291102A - Cleaning equipment for substrate - Google Patents

Abstract

PURPOSE:To provide a cleaning equipment for substrate in which a wafer can be subjected to different cleaning processing on the surface and rear thereof while eliminating the need for discharging the cleaning liquid from a cleaning bath at the time of mounting or demounting a wafer. CONSTITUTION:A cleaning bath 10 is partitioned by a barrier 13 into two independent cleaning baths 11, 12 where the barrier 13 is provided with an opening 14 for holding a wafer 1 and movable shutters 18, 19 for opening/closing the opening 14 is also provided. Cleaning liquid supply means 25, 26 feed cleaning liquid 27, 28 through nozzles 21, 22. After the opening 14 is closed by means of the shutters 18, 19 and the wafer 1 is held at the opening 14, the opening 14 is opened by means of the shutters 18, 19 and the wafer 1 is cleaned, on the surface 1a and the rear 1b thereof, with the cleaning liquids 27, 28. Since the wafer 1 is cleaned separately on the surface and rear thereof, the cleaning liquids 27, 28 are prevented from mixing at the time of mounting/demounting of the wafer 1.

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 cleaning a substrate such as a wafer in a semiconductor device manufacturing process.

[0002]

2. Description of the Related Art In the process of manufacturing a semiconductor device, it is necessary to keep the surface of a semiconductor substrate such as a wafer clean. For example, contaminants such as foreign matter adhering to the surface of the wafer during photoetching may cause wiring short-circuiting or disconnection, and if the wafer is heated with foreign matter containing metal adhering to the surface, That portion causes alloying and short-circuiting of the pn junction. Therefore, in order to improve the performance and reliability of the product, it is necessary to reduce contaminants on the surface of the wafer as much as possible.

Therefore, conventionally, in the process of manufacturing a semiconductor device, the wafer is cleaned with various cleaning solutions such as a chemical solution and pure water, such as pre-cleaning before forming an oxide film on the wafer and post-cleaning after photo-etching. ing. Then, the conventional general cleaning apparatus cleans the wafers by immersing each wafer carrier containing a plurality of wafers or one wafer at a time in a cleaning tank filled with a cleaning liquid. .

[0004]

However, as described above, in the conventional cleaning apparatus, the foreign matter adhering to the wafer is removed by immersing the wafer in the cleaning liquid in the cleaning tank. Therefore, the same cleaning process is always performed on the front surface and the back surface of the wafer, and different cleaning processes cannot be performed on the front surface and the back surface.

By the way, the types and sizes of foreign substances adhering to the wafer are different on the front and back sides, and the allowable range of foreign substance sizes to be managed is different on the front and back sides. That is, the front surface of the wafer is mirror-finished to form a semiconductor element, but the back surface of the wafer is not as mirror-finished as the front surface. Further, the back surface of the wafer is held at the time of other process processing by various devices.
Therefore, in general, more foreign matter is attached to the back surface than the front surface of the wafer.

When such a wafer is cleaned in the same cleaning solution, even if an attempt is made to perform a processing with a strong cleaning solution corresponding to the back surface, the surface for forming the semiconductor element is adversely affected, so a strong cleaning processing is performed. Could not be done. Also,
If the wafer is cleaned in the same cleaning liquid, foreign matter that had adhered to the back surface may re-adhere to the front surface even if the cleaning is carried out. Therefore, in the conventional cleaning apparatus, the foreign matter removal rate is low, and there is a risk that foreign matter may be brought into the next process due to insufficient cleaning. In order to increase the foreign matter removal rate, it is necessary to perform at least two types of sequences (treatments) or to perform cleaning with a weak cleaning liquid for a long time, which is a problem of inefficient cleaning processing. was there.

Therefore, the present invention provides a substrate cleaning apparatus that can perform different cleaning processes on the front and back surfaces of a substrate and that does not require a cleaning liquid to be discharged from the cleaning tank when the substrate is attached and detached. With the goal.

[0008]

In order to achieve the above object, a substrate cleaning apparatus according to the present invention comprises a cleaning tank, a partition partitioning the cleaning tank into two independent cleaning tanks, and each of the independent cleaning tanks. Cleaning liquid supply means for supplying cleaning liquid to
An opening provided in the partition wall corresponding to the outer shape of the substrate, a substrate holding unit that holds the outer peripheral portion of the substrate around the opening, and a shutter that opens and closes the opening in a liquid-tight state. Then, after the substrate is held in the opening by the substrate holding means in a state where the opening is closed by the shutter, the opening is opened by the shutter and the both sides of the substrate are individually cleaned. It is configured to be washed with the washing liquid in the tank.

Further, in the substrate cleaning apparatus according to the present invention, a shutter is not provided on the partition wall, and an opening / closing position at which the opening of the partition wall comes out of each of the independent cleaning tanks and a cleaning position at which the opening of each partition enters the independent cleaning tank. So that the partition wall is movable in a liquid-tight state so that the partition wall is moved to the attachment / detachment position, and the substrate is held in the opening by the substrate holding means, The partition is moved to a cleaning position, and both surfaces of the substrate are cleaned with the cleaning liquid in each of the independent cleaning tanks.

Further, the substrate cleaning apparatus according to the present invention is
Of the respective independent cleaning tanks, a cleaning liquid supply means for supplying a cleaning liquid is provided in one independent cleaning tank, and a non-liquid cleaning means is provided in the other independent cleaning tank so that both sides of the substrate are individually cleaned. The cleaning liquid in the tank and the non-liquid cleaning means are used for cleaning.

[0011]

According to the present invention configured as described above, since the substrate is held by the substrate holding means in the partition having the opening, the partition of the partition is completely separated from the front surface and the back surface of the substrate. It is exposed in the independent cleaning tanks on both sides. Then, different cleaning treatments are optimally performed on the front surface and the back surface of the substrate by a cleaning liquid such as a chemical liquid or pure water in each independent cleaning tank or a non-liquid cleaning means such as a rotating brush.

Further, according to the present invention, the front surface and the back surface of the substrate are separated and cleaned, but when the substrate is attached to and detached from the opening of the partition wall, the opening is closed by the shutter. The openings are exposed to the outside of each independent cleaning tank by the movement of the partition wall itself, so that the mixing of the cleaning liquid in each independent cleaning tank or the outflow from one to the other is completely prevented. Therefore, it is not necessary to discharge the cleaning liquid from the independent cleaning tank when the substrate is attached or detached.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment in which the present invention is applied to a wafer cleaning apparatus will be described below with reference to the drawings.

First, FIGS. 1 to 3 show a first embodiment, and FIG. 1 is a sectional view of the entire apparatus when a wafer is attached and detached, and FIG.
3 is a sectional view of the entire apparatus during wafer cleaning, and FIG. 3 is an enlarged sectional view of a partition wall portion of the apparatus.

As shown in FIGS. 1 and 2, a partition wall 13 is provided vertically at approximately the center of the cleaning tank 10 whose upper side is open, and the partition wall 13 causes the cleaning tank 10 to have two independent cleaning tanks 11 on the left and right. It is divided into 12. The partition wall 13
Also extends above the cleaning tank 10.

A circular opening 14 having a diameter slightly smaller than the outer diameter of the wafer 1 is formed substantially at the center of the partition wall 13 in the cleaning tank 10. Further, a slit-shaped wafer insertion portion 15 opened from above is formed in the partition wall 13. Then, as shown in FIG. 3, a plurality of small holes 16 for vacuum suction are formed around the opening 14 in the wafer insertion part 15, and these small holes 16 pass through the communication passage 17 in the partition wall 13. It is connected to a vacuum suction device (not shown). An annular groove may be provided instead of the plurality of small holes 16.

As shown in FIGS. 1 and 2, a pair of shutters 18 and 19 are provided on both sides of the opening 14 of the partition wall 13. These shutters 18 and 1
Reference numeral 9 is configured to be movable in a liquid-tight state by the drive mechanism 20 between a closed position for closing the opening 14 as shown in FIG. 1 and an open position for opening the opening 14 as shown in FIG. Has been done.

In the independent cleaning tanks 11 and 12 partitioned by the partition wall 13, a pair of jet nozzles 21 and 2 are provided.
2 are opposed to each other with the opening 14 of the partition wall 13 interposed therebetween. The injection nozzles 21 and 22 are provided at the tips of the supply pipes 23 and 24, and these supply pipes 23 and 24 are connected to the cleaning liquid supply devices 25 and 26. The cleaning liquid supply devices 25 and 26 supply the same or different cleaning liquids 27 and 28 into the independent cleaning tanks 11 and 12, respectively.
The supply time of these is also adjustable.

Discharge pipes 29 and 30 are provided on the bottoms of the independent cleaning tanks 11 and 12, and are closed during normal cleaning. In addition, the independent cleaning tanks 11 and 12,
The partition wall 13, the shutters 18 and 19 and the like require a material for maintaining the characteristics of a predetermined chemical solution or ultrapure water, and for example, Teflon resin or high-purity quartz glass is used.

In the cleaning device constructed as described above, first, as shown in FIG.
Is moved to the closed position and the opening 14 of the partition wall 13 is closed, the independent cleaning tanks 11 and 12 are filled with the cleaning liquids 27 and 28. That is, the independent cleaning tanks 11 and 1
2 is partitioned by a partition wall 13 and the opening 1 of the partition wall 13
Since 4 is closed in a liquid-tight state by shutters 18 and 19, the cleaning liquids 27 and 28 in the independent cleaning tanks 11 and 12 are completely separated and never mixed.

In this state, wafer transfer means (not shown)
The wafer insertion portion 15 of the partition wall 13
The outer peripheral portion of the wafer 1 is sucked and held by the suction action of the small holes 16 around the opening 14.

Next, as shown in FIG.
And 19 are moved to the open position and the opening 1 of the partition wall 13 is
4 is open. As a result, the front surface 1a and the back surface 1b of the wafer 1 are brought into contact with the cleaning liquids 27 and 28 in the independent cleaning tanks 11 and 12 in a state where they are completely separated. The front surface 1a and the back surface 1b of the wafer 1 are separately cleaned by the jets of the cleaning liquids 27 and 28 from the spray nozzles 21 and 22, respectively.

The independent cleaning tanks 11 and 12 are of the overflow type, and the overflowing cleaning liquids 27 and 28 are discharged from the upper edge. Furthermore, in order to quickly discharge the removed foreign matter from the independent cleaning tanks 11 and 12, appropriate cutouts 11a and 12a are formed at the upper edges of the independent cleaning tanks 11 and 12.
Is provided, and the flow rates of the overflowing cleaning liquids 27 and 28 are increased.

Next, when the predetermined cleaning process is completed, as shown in FIG.
As shown in, the shutters 18 and 19 are again moved to the closed position, and the opening 14 of the partition wall 13 is closed. In this state, the wafer 1 is transferred to the partition wall 13 by the wafer transfer means.
Then, the next uncleaned wafer 1 is newly mounted.

As described above, the wafers 1 can be efficiently cleaned by the cleaning liquids 27 and 28 which have a high effect of removing foreign matters attached to the front surface 1a and the rear surface 1b of the wafer 1, respectively. For example, the back surface 1b containing more foreign matter than the front surface 1a can be treated with the strong cleaning liquid 28, and the foreign matter can be removed in a short time without adversely affecting the front surface 1a forming the semiconductor element.

Moreover, when the wafer 1 is attached to or detached from the opening 14 of the partition wall 13, the opening 14 is closed by the shutters 18 and 19, so that mixing of the cleaning liquids 27 and 28 can be completely prevented. Therefore, it is not necessary to discharge the cleaning liquids 27 and 28 when the wafer 1 is attached and detached, and the continuous cleaning process of the plurality of wafers 1 can be rapidly performed.

In this embodiment, since the shutters 18 and 19 are provided on both sides of the opening 14, the shutter 18 or 19 is moved to the closed position during the cleaning so that the front surface 1a or the back surface 1b of the wafer 1 can be removed. It is possible to adjust the cleaning time. In addition, the injection nozzles 21 and 22
It is also possible to adjust the cleaning time by stopping the spraying of the cleaning liquids 27 and 28 by. Although the different cleaning liquids 27 and 28 are used in the above-mentioned example, when the same cleaning liquid is used, the adjustment of the cleaning time is particularly effective.

Next, FIGS. 4 and 5 show a second embodiment. FIG. 4 is a sectional view of the entire apparatus when the wafer is attached and detached, and FIG. 5 is a sectional view of the entire apparatus when the wafer is cleaned.

In the second embodiment, the partition wall 13 'itself for partitioning the cleaning tank 10 into two independent cleaning tanks 11 and 12 is movable. That is, as for the partition wall 13 ′, as shown in FIG. 4, the opening 14 is attached / detached to the outside of the independent cleaning tanks 11 and 12, and the opening 14 is inserted into the independent cleaning tanks 11 and 12 as shown in FIG. A drive mechanism 20 'is configured to be movable between the position and the position in a liquid-tight state.

According to this example, as shown in FIG.
The wafer 1 is held in the opening 14 with 3'moved to the attachment / detachment position. At this time, since the independent cleaning tanks 11 and 12 are separated by the partition wall 13 ', the cleaning liquids 27 and 28 are used. Is completely prevented. And
As shown in FIG. 5, when the partition wall 13 ′ is moved to the cleaning position, the front surface 1 a and the back surface 1 b of the wafer 1 come into contact with the cleaning liquid 27 and the cleaning liquid 28, respectively.

Next, FIG. 6 is a sectional view of the entire apparatus during wafer cleaning in the third embodiment.

In the third embodiment, one independent cleaning tank 11 partitioned by the partition wall 13 similar to that of the first embodiment is filled with the cleaning liquid 27 and the other independent cleaning tank 1 is used.
A non-liquid cleaning means is provided in 2 '. This non-liquid cleaning means is composed of a rotating brush 32 which is rotationally driven by a motor 31, and foreign matter is removed when the rotating brush 32 contacts the back surface 1b of the wafer 1.
In this example, the shutter 18 is provided only on the independent cleaning tank 11 side of the opening 14 of the partition wall 13,
The shutter 18 prevents the cleaning liquid 27 from flowing out.

Next, FIG. 7 is a sectional view of the entire apparatus during wafer cleaning in the fourth embodiment.

In the fourth embodiment, a non-liquid cleaning means using a rotary brush 32 similar to that of the third embodiment is provided in the construction using the movable partition wall 13 'similar to that of the second embodiment. It is a thing.

When the rotating brush 32 is used as in the third and fourth embodiments, the other independent cleaning tank 12 'is used.
As a closed chamber, and the gas supply device 33 to the supply pipe 3
It is preferable to supply an inert gas or the like into the independent cleaning tank 12 ′ via 4 to discharge the foreign matter removed by the rotating brush 32 together with the gas from the discharge pipe 35. Further, the non-liquid cleaning means is not limited to mechanical cleaning such as the rotary brush 32, but may be gas cleaning using chemical gas or clean air supplied into the independent cleaning tank 12 '.

The embodiments of the present invention have been described above.
The present invention is not limited to the above embodiments, and various effective modifications and applications are possible based on the technical idea of the present invention. Although the cleaning process for removing foreign matter has been described in the present embodiment, it is needless to say that the wet etching process can be performed by using various etching solutions or pure water as the cleaning solution. Further, although the cleaning target is the wafer in this embodiment, it goes without saying that various substrates such as a mask for exposure and a reticle can be cleaned.

[0037]

As described above, according to the present invention,
By cleaning with the front and back surfaces of the substrate completely separated, it is possible to perform optimum cleaning that has a high removal effect for foreign substances adhering to each of the front and back surfaces, and also to adhere to the back surface. It is also possible to prevent the foreign matter that had been attached to the surface from reattaching. Therefore, it is possible to perform efficient cleaning with a very high foreign matter removal rate, and it is possible to improve the yield.

Moreover, according to the present invention, both the front and back surfaces of the substrate can be separated and cleaned as described above,
Mixing or outflow of the cleaning liquid in the independent cleaning tank can be completely prevented when the substrate is attached to or detached from the opening of the partition. Therefore, the cleaning process can be continuously performed without discharging the cleaning liquid from the independent cleaning tank when the substrate is attached or detached,
It is possible to significantly improve the throughput and significantly reduce the cost.

[Brief description of drawings]

FIG. 1 is a sectional view of the entire apparatus when a wafer is attached and detached in a first embodiment in which the present invention is applied to a wafer cleaning apparatus.

FIG. 2 is a sectional view of the entire apparatus when cleaning a wafer in the first embodiment.

FIG. 3 is an enlarged cross-sectional view of a partition wall portion of the device according to the first embodiment.

FIG. 4 is a cross-sectional view of the entire apparatus when a wafer is attached and detached in the second embodiment of the present invention.

FIG. 5 is a cross-sectional view of the entire apparatus during wafer cleaning in the second embodiment.

FIG. 6 is a cross-sectional view of the entire apparatus when cleaning a wafer according to a third embodiment of the present invention.

FIG. 7 is a cross-sectional view of the entire apparatus when cleaning a wafer according to a fourth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wafer 1a Front surface 1b Back surface 10 Cleaning tank 11, 12, 12 'Independent cleaning tank 13, 13' Partition wall 14 Opening portion 15 Wafer inserting portion 16 Small hole for vacuum suction 17 Communication path 18, 19 Shutter 20, 20 'Drive mechanism 21, 22 Injection nozzle 23, 24, 34 Supply pipe 25, 26 Cleaning liquid supply device 27, 28 Cleaning liquid 29, 30, 35 Discharge pipe 31 Motor 32 Rotating brush 33 Gas supply device

Claims (6)

[Claims] 1. A cleaning tank, partition walls for partitioning the cleaning tank into two independent cleaning tanks, cleaning liquid supply means for supplying a cleaning liquid into each of the independent cleaning tanks, and partition walls corresponding to the outer shape of the substrate. An opening portion provided, a substrate holding means for holding the outer peripheral portion of the substrate around the opening portion, and a shutter for opening and closing the opening portion in a liquid-tight state are provided, and the opening portion is closed by the shutter. In such a state, the substrate is held in the opening by the substrate holding means, and then the opening is opened by the shutter to clean both surfaces of the substrate with the cleaning liquid in each of the independent cleaning tanks. Substrate cleaning equipment. 2. A cleaning tank, partition walls for partitioning the cleaning tank into two independent cleaning tanks, cleaning liquid supply means for supplying a cleaning liquid into each of the independent cleaning tanks, and the partition walls corresponding to the outer shape of the substrate. An opening provided and a substrate holding means for holding the outer peripheral portion of the substrate around the opening, and the opening / closing position of the partition opening outside the independent cleaning tank and the independent cleaning. The partition is configured so as to be movable in a liquid-tight state so as to move between the partition and the cleaning position that enters the tank, and the substrate is held by the substrate holding means while the partition is moved to the attachment / detachment position. The substrate cleaning apparatus is configured to move the partition wall to a cleaning position and then clean both surfaces of the substrate with the cleaning liquid in each of the independent cleaning tanks. 3. A cleaning tank, a partition for partitioning the cleaning tank into two independent cleaning tanks, a cleaning liquid supply means for supplying a cleaning liquid into the one independent cleaning tank, and a cleaning liquid supply means provided in the other independent cleaning tank. Non-liquid cleaning means, an opening provided in the partition wall corresponding to the outer shape of the substrate, a substrate holding means for holding the outer peripheral portion of the substrate around the opening, and the opening being liquid-tight. A shutter that opens and closes in a state, wherein the substrate is held by the substrate holding means in the opening while the opening is closed by the shutter, and then the opening is opened by the shutter. A substrate cleaning apparatus configured to clean both surfaces of the substrate with the cleaning liquid in each of the independent cleaning tanks and the non-liquid cleaning means. 4. A cleaning tank, a partition for partitioning the cleaning tank into two independent cleaning tanks, a cleaning liquid supply means for supplying a cleaning liquid into the one independent cleaning tank, and a cleaning liquid supply means provided in the other independent cleaning tank. A non-liquid cleaning means, an opening provided in the partition wall corresponding to the outer shape of the substrate, and a substrate holding means for holding the outer peripheral portion of the substrate around the opening, The partition is configured to be movable in a liquid-tight state so that the opening moves between a detaching position that goes out of each of the independent cleaning tanks and a washing position that goes into each of the independent cleaning tanks. After the substrate is held in the opening by the substrate holding means in the state of being moved to the position, the partition walls are moved to the cleaning position so that both surfaces of the substrate are respectively the cleaning liquid and the non-liquid in each of the independent cleaning tanks. Cleaning solution Cleaning device for the substrate. 5. The substrate cleaning apparatus according to claim 1, wherein the cleaning liquid supply unit has a spray nozzle for spraying the cleaning liquid onto the surface of the substrate. 6. The substrate cleaning apparatus according to claim 3, wherein the non-liquid cleaning means is a rotating brush that contacts the surface of the substrate.