JP2002110606A - Cleaning apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning device, with which the throughput of obtained semiconductor devices can be improved or the reliability of functions can be improved by suppressing the adhesion of impurities, such as particles to objects to be cleaned like semiconductor wafers and the like, in the cleaning process. SOLUTION: The cleaning device cleans semiconductor wafers W as objects to be cleaned, by immersing them in a cleaning liquid 11. It has a cleaning bath 12, which contains a first cleaning liquid 11 for cleaning the semiconductor wafers W and a cleaning liquid spraying device 40, which is mounted on the cleaning bath 12 and sprays a second cleaning liquid 45 on the surface of the semiconductor wafers W, which are immersed in the first cleaning liquid 11 and are raised for removing the first cleaning liquid 11 adhered to their surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning apparatus and a cleaning method for cleaning a body to be cleaned by immersing the body in a liquid. The present invention relates to a cleaning apparatus and a cleaning method for immersing in pure water or the like to clean the surface.

[0002]

2. Description of the Related Art With the demand for high-density integration and miniaturization in the technical field of semiconductor devices and the like, it is important to remove impurities attached to the surface of a semiconductor wafer in a manufacturing process. Is a factor that greatly affects the yield or reliability. Therefore, in order to remove impurities adhering to the surface of the semiconductor wafer, a multi-tank dipping process employing a plurality of cleaning steps such as chemical cleaning or pure water cleaning is generally performed.

[0003]

In such a multi-tank dipping process, for example, a semiconductor wafer is immersed in an etching chemical bath to perform a cleaning process, and then the etching chemical is washed away. When the semiconductor wafer is immersed in a washing bath and washed with water, particles (fine particles) are generated and adhere to the surface of the semiconductor wafer in a vertical stripe shape as shown in FIGS. 3 (a) and 3 (b). There is. This phenomenon is due to the fact that the residue of the substance etched by the etching chemical is brought to the washing tank while being attached to the surface of the semiconductor wafer, and when the semiconductor wafer is immersed in the washing tank, it is pulled upward. It is caused by The particles attached to the surface of the semiconductor wafer are difficult to remove by another chemical cleaning treatment, and the semiconductor device is manufactured in a state where the particles are attached to the surface of the semiconductor wafer. This is a factor that leads to a decrease in sex and the like. On the other hand, when cleaning a semiconductor wafer, a plurality of semiconductor wafers are collectively chucked, and these semiconductor wafers are simultaneously immersed in a chemical solution for cleaning. Although the wafers are arranged at predetermined intervals, the front surface of one wafer and the back surface of the adjacent wafer face each other, so if there is dust on the back surface even if the front surface of each wafer is clean, dust There is a possibility that the surface opposite to the back surface where is present is contaminated.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to cause impurities such as particles to adhere to an object to be cleaned such as a semiconductor wafer in a cleaning process. It is an object of the present invention to provide a cleaning apparatus capable of improving the yield of the obtained semiconductor device or the like or improving the functional reliability.

[0005]

According to a first aspect of the present invention, there is provided a cleaning apparatus for cleaning an object to be cleaned by immersing the object in a cleaning liquid. A cleaning tank containing a cleaning liquid, and a cleaning liquid spraying means for spraying a second cleaning liquid onto a surface of the object to be cleaned which is dipped in the first cleaning liquid and pulled up to remove the first cleaning liquid attached to the surface of the object to be cleaned. And

Preferably, the second cleaning liquid is pure water.

A cleaning apparatus according to a second aspect of the present invention is a cleaning apparatus for immersing a body to be cleaned in a cleaning liquid for cleaning, and is aligned with a cleaning tank containing a cleaning liquid for cleaning the body to be cleaned. A transport mechanism for holding a plurality of objects to be cleaned collectively, immersing them in the cleaning liquid in the cleaning tank, and then lifting up the cleaning tank, wherein the cleaning tank is provided with a cleaning liquid in which each of the cleaning objects is immersed. It is characterized in that a separation partition for separating the object to be cleaned is provided.

Preferably, the cleaning liquid is supplied to each space separated by the separation partition from a bottom and / or a side of the cleaning tank, and is discharged from an upper part of the cleaning tank by overflow. .

A cleaning apparatus according to a third aspect of the present invention is a cleaning apparatus for immersing a body to be cleaned in a cleaning liquid to clean the body, and a cleaning tank containing a first cleaning liquid for cleaning the body to be cleaned. Holding a plurality of objects to be cleaned arranged in a lump, immersing them in a first cleaning solution in the cleaning tank, and then pulling up the same; and a transport mechanism for immersing in the first cleaning solution and lifting the objects to be cleaned. Cleaning liquid spraying means for spraying a second cleaning liquid onto the surface to remove the first cleaning liquid attached to the surface of the object to be cleaned; and It is characterized by comprising a separation partition for separating one cleaning liquid for each of the objects to be cleaned.

In the cleaning apparatus according to the first aspect of the present invention,
When the object to be cleaned is pulled up from the first cleaning liquid, the first cleaning liquid is removed from the object to be cleaned by spraying a second cleaning liquid onto the surface of the object to be cleaned. Thus, the contaminated first cleaning liquid does not remain on the surface of the object to be cleaned.

In the cleaning apparatus according to the second aspect of the present invention,
When the object to be cleaned is immersed in the cleaning liquid, the cleaning liquid is separated by the partition wall. Therefore, even if one cleaning target is contaminated with dust or the like, the cleaning target adjacent thereto is not further contaminated.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. First Embodiment FIG. 1 is a schematic configuration diagram of a cleaning system according to a first embodiment of the present invention. This cleaning system includes a first cleaning device 10 for cleaning with an etching chemical, a second cleaning device 20 for performing a water washing process as a post-process, a transfer arm 30, and a cleaning solution provided for the first cleaning device 10. A cleaning liquid spraying device 40 as spraying means is provided.

The first cleaning apparatus 10 includes a cleaning tank 12 filled with an etching chemical 11 as a cleaning liquid and formed so that the etching chemical 11 can flow out (overflow) from an upper opening 12a. A supply pipe 13 is connected to the bottom of the cleaning tank 12 to supply the etching chemical solution 11 to the cleaning tank 12, and a filter 14 and a pump 15 are connected to the supply pipe 13.

An outer peripheral tank 16 for receiving the etching chemical solution 11 flowing out of the opening 12 a is arranged on the outer periphery of the cleaning tank 12. The etching chemical solution 11 flowing into the outer peripheral tank 16 is pumped by a return pipe 17. 15, and is supplied to the cleaning tank 12 via the supply pipe 13 again via the filter 14. A support member 18 for supporting the immersed semiconductor wafer W at a predetermined position is disposed inside the cleaning tank 12.

The second cleaning device 20 is provided with a cleaning tank 22 filled with pure water 21 as a cleaning liquid and formed so that the pure water 21 can overflow (overflow) from an upper opening 22a. A supply pipe 23 communicated with a bottom surface of the cleaning tank 22 to supply pure water 21 to the cleaning tank 22;
A pump 25 and the like connected to the supply pipe 23 are provided.

An outer peripheral tank 26 for receiving the pure water 21 flowing out of the opening 22a is disposed on the outer periphery of the washing tank 22. The pure water 21 flowing into the outer peripheral tank 26 is discharged by a discharge pipe 27 into a drain tank. (Not shown) for post-processing. In addition, this drain pipe 27
Can be configured to be supplied to the cleaning tank 22 via the supply pipe 23 again through a supply pipe 23 via a filter or the like. In addition, a support member 28 that supports the immersed semiconductor wafer W at a predetermined position is disposed inside the cleaning tank 22.

The transfer arm 30 holds the semiconductor wafer W in the first cleaning apparatus 10, immerses the semiconductor wafer W in the cleaning tank 12, and conveys the semiconductor wafer W up and down so as to be taken out of the cleaning tank 12. The semiconductor wafer W having been subjected to the cleaning process at 10 is gripped and transported in the horizontal direction so as to be positioned in the second cleaning device 20, and further, the semiconductor wafer W is gripped by the second cleaning device 20 and is transferred to the cleaning tank 22. It is immersed and transported up and down so as to be taken out of the washing tank 22. The transfer arm 30 has a driving mechanism (not shown).
Driven by

The cleaning liquid spraying device 40 includes a nozzle 41 provided at the upper end of the cleaning tank 12, a supply pipe 43 connected to the nozzle 41, and a pump 42 connected to the supply pipe 43. I have.

The nozzle section 41 applies pure water 45 as a cleaning liquid to the surface of the semiconductor wafer W which is pulled up from the cleaning tank 11 by the transfer arm 30 along the surface of the etching chemical solution 11 contained in the cleaning tank 12. It is installed so that it can be sprayed. Specifically, the spray direction of the nozzle portion 41 is substantially parallel to the surface of the semiconductor wafer W, and the pure water 45 sprayed from the nozzle portion 41
On both sides of the semiconductor wafer W lifted by the above. The pure water 45 sprayed from the nozzle 41 is pressurized by the pump 42 and acts to remove the etching chemical solution 11 attached to both surfaces of the semiconductor wafer W.

Next, the operation of cleaning the semiconductor wafer W by the cleaning system having the above configuration will be described. First, the first
In the cleaning apparatus 10, the semiconductor wafer W cleaned by the etching chemical solution 11 in the cleaning tank 12 for a predetermined time.
Is gripped by the transfer arm 30 and pulled up. At this time, the etching chemical solution 11 stored in the cleaning tank 12 is used.
Pure water 45 is sequentially sprayed from the upper end to the lower end on both surfaces of the semiconductor wafer W rising from the liquid level.

By spraying the pure water 45, the etching chemical solution 11 adhered to both surfaces of the semiconductor wafer W becomes
Removed reliably.

After the semiconductor wafer W is gripped and taken out by the transfer arm 30 and then washed with water,
The transfer arm 30 transfers the semiconductor wafer W to the second cleaning device 20.

At this time, the pure water 21 is supplied to the cleaning tank 22 of the second cleaning device 20 at a predetermined flow rate by the drive of the pump 25, and is adjusted to overflow from the opening 22a. This overflow state is maintained in order to drive out impurities such as particles existing in the cleaning tank 22 before washing the semiconductor wafer W with water.

Subsequently, the transfer arm 30 is lowered (transferred downward), and the semiconductor wafer W is immersed in the cleaning tank 22. The semiconductor wafer W is supported by the support member 28 in a state where the semiconductor wafer W is entirely below the water surface 21a. Thereafter, this state is maintained for a predetermined time, and washing with pure water 21 is performed.

By driving the transfer arm 30 again, the semiconductor wafer W is transferred and taken out, and the surface of the semiconductor wafer W is dried by a drying means (not shown) in the next step.

By the above-mentioned cleaning, particles adhering to the surface of the semiconductor wafer W in the form of vertical stripes can be suppressed, and the amount of particles adhering to both surfaces of the semiconductor wafer W can be significantly reduced. . As a result, the yield of semiconductor devices using the semiconductor wafer W is improved, functional reliability such as quality is improved, and high-density integration or miniaturization becomes possible.

Second Embodiment FIG. 2 is a view showing a schematic configuration of a cleaning apparatus according to a second embodiment of the present invention. FIG. 2A shows a cleaning device along a semiconductor wafer W as an object to be cleaned. It is sectional drawing of a direction, and (b) is sectional drawing of the direction orthogonal to (a). As shown in FIG. 2, the cleaning device 50 includes a cleaning tank 52 that contains an etching chemical 51 as a cleaning liquid and is formed so that the etching chemical 51 can flow out (overflow) from an upper opening 52a. A transfer arm 7 serving as a transfer mechanism for holding the semiconductor wafer W as the object to be cleaned, dipping the semiconductor wafer W in the etching chemical solution 51 of the cleaning tank 52, and then pulling up the semiconductor wafer W.
0.

The washing tank 52 includes, as shown in FIG.
The semiconductor wafer W is provided with a plurality of separation partitions 60 arranged at equal intervals for separating the etching chemical 51 into which the semiconductor wafer W is immersed. These separation partitions 6
Numerals 0 are arranged in parallel with each other, and the interval between the adjacent separation partitions 60 is set to a size that allows two semiconductor wafers W to be inserted, for example. Furthermore, the separation partition 60 is
The height is slightly lower than the upper end of the opening 52 a of the cleaning tank 52. Further, the width of the separation partition wall 60 is large enough not to interfere with the transfer arm 70 that holds the semiconductor wafer W, specifically, slightly smaller than the diameter of the semiconductor wafer W. A support member 58 that supports the immersed semiconductor wafer W at a predetermined position is disposed between the separation partitions 60.

An outer peripheral tank 56 for receiving the etching chemical 51 flowing out of the opening 52a is disposed on the outer periphery of the cleaning tank 52. The etching chemical 51 flowing into the outer peripheral tank 56 is collected and returned (not shown). The cleaning tank 52 is supplied again via a pipe, a pump, a filter, and the like. At this time, the etched etching chemical solution 51 is
As shown in FIG. 2, the water is supplied from the bottom 52b of the cleaning tank 52 and both side walls 52c in the direction along the separation partition wall 60. That is, a large number of etching chemicals 51 (not shown) are provided on the bottom 52b and the side walls 52c.
Supply port is provided.

The transfer arm 70 collectively holds a plurality of, for example, 25 semiconductor wafers W arranged at predetermined intervals, and immerses them in the etching chemical solution 51 of the cleaning tank 52 and then pulls them up. The transfer arm 7
0 is driven by a drive mechanism (not shown).

Next, the operation of cleaning the semiconductor wafer W by the cleaning apparatus 50 having the above-described configuration will be described. First, the plurality of semiconductor wafers W are gripped by the transfer arm 70,
By lowering the transfer arm 70, the semiconductor wafer W is immersed in the cleaning tank 52. The semiconductor wafer W immersed in the cleaning tank 52 is inserted between the separation partitions 60 and supported by the support members 58, respectively.

The cleaning tank 52 is constantly supplied with a clean etching chemical 51 from a number of supply ports (not shown) formed in the bottom 52b and the side wall 52c. The etching chemical solution 51 is formed on the side wall 52c and the bottom 5c.
By being supplied from 2b, after convection between the partition walls 60 in the upward direction, it overflows from the opening 52a above the cleaning tank 52. Therefore, a clean etching chemical solution 51 is always supplied between the separation partitions 60.

The semiconductor wafer W disposed between the separation partitions 60 is cleaned by the etching chemical 51. By this cleaning, the contaminated etching chemical 51
After the convection of the adjacent semiconductor wafers W toward the upper side of the cleaning tank 52 without secondary contamination by the presence of the separation partition wall 60, the opening 52a above the cleaning tank 52
Overflows from For this reason, the cleanliness of the etching chemical solution 51 in the cleaning tank 52 is always kept high, and secondary contamination of the semiconductor wafer W by the contaminated etching chemical solution 51 can be prevented as much as possible.

In this embodiment, only the cleaning device 50 using the etching chemical solution 51 has been described. However, similar to the above-described embodiment, after cleaning with the etching chemical solution 51, cleaning with pure water is performed. The cleaning tank used for cleaning with pure water can have the same configuration as the cleaning device 50 according to the present embodiment.

Further, in the present embodiment, the structure is such that the clean etching chemical solution 51 is supplied from the side wall portion 52c and the bottom portion 52b of the cleaning tank 52, but the present invention is not limited to this. Even in a configuration in which the clean etching chemical solution 51 is supplied only from the bottom 52b of the cleaning tank 52, this bottom 52b
Since the convection of the etching chemical 51 toward the opening 52a of the cleaning tank 52 occurs and overflows, the semiconductor wafer W can always be cleaned with the clean etching chemical 51.

The present invention is not limited to the first and second embodiments described above. For example, a configuration is also possible in which the cleaning liquid spraying device 40 described in the first embodiment is provided for the cleaning tank 52 according to the second embodiment. With such a configuration, secondary contamination between the adjacent semiconductor wafers W can be prevented, and
Particles adhering to the surface of the semiconductor wafer W in the form of vertical stripes can be suppressed.

[0037]

According to the present invention, in a cleaning process, impurities such as particles are prevented from adhering to an object to be cleaned such as a semiconductor wafer, so that the yield of semiconductor devices and the like obtained can be improved or functional reliability can be improved. Performance can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a cleaning system according to a first embodiment of the present invention.

FIG. 2 is a view showing a schematic configuration of a cleaning apparatus according to a second embodiment of the present invention, in which (a) is a cross-sectional view along a semiconductor wafer W as an object to be cleaned; (b) is a sectional view in a direction orthogonal to (a).

FIG. 3 is a diagram showing a state where particles are attached in a vertical stripe shape on the surface of a semiconductor wafer.

[Explanation of symbols]

10 first cleaning device, 11 cleaning solution, 12 cleaning tank, 1
6 outer peripheral tank, 18 support member, 20 second cleaning device, 2
DESCRIPTION OF SYMBOLS 1 ... Cleaning liquid, 22 ... Cleaning tank, 30 ... Transfer arm, 40 ...
Cleaning liquid spraying device, W: wafer.

Claims (5)

[Claims] 1. A cleaning apparatus for immersing a body to be cleaned in a cleaning liquid for cleaning, comprising: a cleaning tank containing a first cleaning liquid for cleaning the body to be cleaned; A cleaning liquid spraying means for spraying a second cleaning liquid onto the surface of the object to be cleaned to remove the first cleaning liquid attached to the surface of the object to be cleaned. 2. The method according to claim 1, wherein said second cleaning liquid is pure water.
The cleaning device according to item 1. 3. A cleaning apparatus for immersing a body to be cleaned in a cleaning liquid for cleaning, wherein a cleaning tank containing a cleaning liquid for cleaning the body to be cleaned and a plurality of aligned bodies to be cleaned are collectively held. And a transport mechanism for immersing them in the cleaning liquid in the cleaning tank and then pulling up the cleaning tank, wherein the cleaning tank separates the cleaning liquid in which each of the cleaning objects is immersed for each of the cleaning objects. A cleaning device comprising: 4. The cleaning liquid is supplied to each space separated by the separation partition from a bottom and / or a side of the cleaning tank, and is discharged from an upper part of the cleaning tank by overflow. 4. The cleaning device according to 3. 5. A cleaning apparatus for immersing a body to be cleaned in a cleaning liquid for cleaning, wherein a cleaning tank containing a first cleaning liquid for cleaning the body to be cleaned and a plurality of aligned bodies to be cleaned are collectively provided. After immersing them in the first cleaning liquid in the cleaning tank, the transport mechanism pulls them up, and sprays the second cleaning liquid onto the surface of the object to be cleaned immersed in the first cleaning liquid and pulled up. Cleaning liquid spraying means for removing the first cleaning liquid attached to the surface of the object to be cleaned, wherein the cleaning tank separates the first cleaning liquid into which each of the objects to be cleaned is immersed for each of the objects to be cleaned. A cleaning device, comprising: