JP2001077074A - Cleaning device for semiconductor wafer or the like - Google Patents

Abstract

PROBLEM TO BE SOLVED: To treat a plurality of bodies to be cleaned at the same time to enhance the productivity of the bodies to be cleaned. SOLUTION: This cleaning device is for cleaning bodies W to be cleaned, such as semiconductor wafers, with a cleaning fluid in a cleaning container 2 capable of flowing-in and letting-out this cleaning fluid. Here, a housing container 8 for housing a plurality of the bodies W to be cleaned is provided in the interior of the container 2. A plurality of inflow ports 11 for making the cleaning fluid flow in the interior of the container 8, and a plurality of outlet ports 12 for making the cleaning fluid let to the outside of the container 8, are provided in the container 8. The inflow ports 11 and the outlet ports 12 are formed in such a way that the areas of the respective apertures of the ports 11 and 12 and/or the numbers of the respective apertures of the ports 11 and 12 are different from each other in the mounting direction of the bodies W, so that the quantity of the cleaning fluid, which flows on the surface of each body W to be cleaned, is uniformly flowed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an apparatus for cleaning a component having an ultrafine structure such as a semiconductor or a micromachine with a cleaning fluid such as a supercritical gas or a subcritical gas.

[0002]

2. Description of the Related Art A cleaning apparatus using a supercritical fluid has been receiving attention in recent years. Supercritical fluids have a viscosity, diffusion coefficient, and density intermediate between those of gas and liquid, and when used as a cleaning medium, are easier to cope with miniaturization than conventional wet cleaning. It has many advantages, such as being unaffected by the shape and the need for a drying step. Therefore, the supercritical fluid is particularly effective for cleaning a semiconductor wafer in a manufacturing process of a highly integrated circuit in which a miniaturized structure is becoming more complicated.

[0003] The basic structure of a conventional cleaning apparatus using a supercritical fluid is a cleaning in which a wafer is placed in a high-pressure vessel and the temperature is raised to a supercritical point by a pressure pump and a heater so as to be in a supercritical state. The material is injected and contaminants on the surface of the wafer are extracted into the supercritical fluid.
Further, as an improved cleaning device, Japanese Patent Application Laid-Open No. 9-232
No. 271 discloses this. In this cleaning apparatus, a high-pressure container into which a wafer is placed and which has an inlet and an outlet for a cleaning substance, and a cleaning substance in a liquid state at a pressure higher than a supercritical pressure and lower than a supercritical temperature at an inlet of the high-pressure container. Cleaning material supply means for supplying the cleaning substance, cleaning substance discharge means for discharging the cleaning substance from the discharge port of the high-pressure container, discharge amount adjusting means for adjusting the discharge amount to maintain the pressure in the high-pressure container at a predetermined pressure, and heating the wafer. The wafer heating means is provided.

[0004] The high-pressure vessel is formed in a thin rectangular parallelepiped with its long sides oriented in the same direction as the surface of the wafer, and the injection port and the discharge port also have their long axes oriented in the same direction as the wafer surface and face each other. They are provided so as to be parallel.

[0005]

A conventional supercritical cleaning apparatus, particularly an apparatus for cleaning semiconductor wafers, is a so-called single wafer type in which a high pressure vessel can process only one wafer at a time. Was inferior. The present invention has been made in view of such a problem, and an object of the present invention is to provide a cleaning apparatus capable of performing processing with high productivity.

[0006]

Means for Solving the Problems The present inventors have noticed that in order to improve productivity, it is only necessary to simultaneously process a plurality of objects to be cleaned, and as an apparatus capable of cleaning a plurality of objects to be cleaned. Invented the following device. That is, a feature of the cleaning apparatus according to the present invention is an apparatus for cleaning an object to be cleaned such as a semiconductor wafer with the cleaning fluid in a cleaning vessel into which a cleaning fluid can flow, and wherein the cleaning vessel has A storage container for storing a plurality of cleaning bodies is provided, and the storage container has a plurality of inlets for allowing a cleaning fluid to flow into the storage container and a plurality of outlets for discharging the cleaning fluid to the outside of the storage container. The openings and / or the number of openings of each of the inlet and the outlet are different from each other in the mounting direction of the object to be cleaned so that the amount of the cleaning fluid flowing on the surface of each object to be cleaned is substantially uniform. It is in the point.

According to this cleaning apparatus, a plurality of objects to be cleaned can be stored in the high-pressure container by the storage container, and the plurality of objects to be cleaned can be processed simultaneously. Here, the flow rate of the cleaning fluid flowing into the high-pressure container is not constant in the space inside the high-pressure container. That is, the flow rate is high near the position where the cleaning fluid flows into the high-pressure vessel, and the flow rate is low near the position where the cleaning fluid flows. Further, the flow rate may not be uniform due to the shape of the internal space of the high-pressure vessel or the like, and a difference may occur depending on the position.

In the present invention, an inlet and an outlet are provided for inflow and discharge of a cleaning fluid into and from a storage container for storing a plurality of objects to be cleaned. The flow rate of the cleaning object may be different for each object to be cleaned. In other words, there is a possibility that a difference occurs in the amount of the cleaning fluid flowing into the inside of the storage container from each of the inlets, and that each of the objects to be cleaned is not uniformly cleaned. In the present invention, the opening area and / or the number of openings of each of the inflow port and the discharge port is formed so as to be different in the mounting direction of the cleaning object so that the amount of the cleaning fluid flowing on the surface of each cleaning object is substantially uniform. Therefore, the cleaning fluid flows almost uniformly on the surface of each object to be cleaned, and the plurality of objects to be cleaned can be evenly cleaned.

Further, the opening area and / or the number of openings is smaller at the inlet and the outlet closer to the position where the cleaning fluid flows into the cleaning container, and the inlet and the outlet farther from the position where the cleaning fluid flows into the cleaning container. It is preferable that the opening area and / or the number of openings be larger for the outlet. As described above, the closer to the position where the cleaning fluid flows into the cleaning container, the higher the flow rate of the fluid, and therefore, the easier the cleaning fluid flows from the inlet of the storage container. On the other hand, the flow rate of the fluid decreases as the distance to the position where the cleaning fluid flows into the cleaning container decreases. Therefore, the cleaning fluid hardly flows from the inlet of the storage container. In consideration of this, the opening area and / or the number of openings is smaller at the inlet and the outlet closer to the position where the cleaning fluid flows into the cleaning container, and the inlet and the drain farther from the position where the cleaning fluid flows into the cleaning container. By making the opening area and / or the number of openings larger toward the outlet, the amount of the cleaning fluid flowing on the surface of each object to be cleaned becomes uniform.

[0010] Preferably, in the cleaning container, a cleaning fluid flows in from an upper portion and is discharged from a lower portion, and the storage container can store a plurality of objects to be cleaned in a vertical direction.
The lower the inlet and the outlet, the opening area and / or
Alternatively, the number of openings may be large. Further, it is preferable that a guide portion for guiding the inflowing cleaning fluid to the inlet side of the storage container is provided inside the cleaning container. Thus, the cleaning fluid is efficiently supplied into the storage container.

The cleaning fluid flowing into the cleaning container flows into the storage container through the inflow port, is discharged out of the storage container through the discharge port, and is then discharged out of the cleaning container. Preferably, the directional flow path is formed inside the washing vessel. In this case, the cleaning fluid discharged from the storage container is directly discharged to the outside of the cleaning container, thereby preventing the contaminated cleaning fluid from re-circulating in the cleaning container. In addition, it is preferable that a projection for mounting and holding the object to be cleaned is provided on the inner surface of the storage container, and the projection can easily hold a plurality of objects to be cleaned.

It is preferable that the storage container is composed of a plurality of divided bodies divided in the mounting direction of the object to be cleaned. In this case, storage and removal of the object to be cleaned into and from the storage container can be easily performed. Furthermore, if the divided body is connected by a hinge and the storage container is made openable and closable by the hinge, the storage object can be more easily stored and taken out of the storage container by opening and closing the storage container by the hinge. It can be carried out.

It is preferable that the washing container is provided with a main fluid discharge passage located outside the storage container and a sub-fluid discharge passage located inside the storage container. By providing not only the main fluid discharge path but also the auxiliary fluid discharge path located inside the storage container, it is possible to prevent fine dirt (particles) from accumulating in the storage container. Furthermore, between the washing container and the storage container,
Preferably, a partition chamber is provided. By providing the partition chamber, fine dirt generated from the cleaning container is prevented from flowing into the storage container.

Further, the features of the present invention from another viewpoint are as follows.
An apparatus for cleaning an object to be cleaned such as a semiconductor wafer with the cleaning fluid in a cleaning container into which a cleaning fluid can flow in and out, wherein a storage container for storing a plurality of objects to be cleaned is provided inside the cleaning container, The storage container is provided with an inlet for allowing the cleaning fluid to flow into the storage container, and an outlet for discharging the cleaning fluid to the outside of the storage container. A first guide passage that guides to the inlet and a second guide passage that guides the cleaning fluid discharged from the discharge port to the outside of the cleaning container are formed in the cleaning container.

In this configuration, a plurality of objects to be cleaned can be stored in the high-pressure container by the storage container, and the plurality of objects to be cleaned can be processed simultaneously. A storage container for storing a plurality of objects to be cleaned is provided, and in a structure in which the storage container has an inlet and an outlet, a first guide for guiding the cleaning fluid flowing into the cleaning container to the inlet. A guide passage and a second guide passage for guiding the cleaning fluid discharged from the discharge port to the outside of the cleaning container are formed in the cleaning container, so that the cleaning fluid discharged from the discharge port and contaminated is formed. Recirculation in the washing container is prevented.

More specifically, a partition chamber is provided between the cleaning container and the storage container, and the partition chamber has a space serving as the first guide passage and a space serving as the second guide passage. It is preferable that the space is partitioned into a space. In this case, the first guide passage and the second guide passage can be configured with a simple configuration, and the partition chamber prevents fine dirt of the cleaning container from flowing into the storage container.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a cleaning apparatus 1 according to the present invention.
2 shows the cross-sectional structure of the device. The cleaning apparatus 1 is for cleaning a plurality of semiconductor wafers W, and has a cleaning vessel (pressure vessel) 2 having a cleaning processing space inside. The cleaning container 2 includes a container cylinder 3, an upper lid 4 for closing an upper part of the container cylinder 3, and a lower lid 5 for closing a lower part of the container cylinder 3.

The cleaning vessel 2 is kept in a high-pressure atmosphere for supercritical processing. In order to maintain the container internal pressure,
The lower lid 5 is used while being fixed to the container cylinder 3.
Note that a sealing member 6 is provided on the upper lid 4 and the lower lid 5 in order to seal the container internal pressure. Storage of semiconductor wafers
When taking out, the lower lid 5 is moved up and down by an elevating means (not shown) with the upper lid 4 and the integral cylinder of the container cylinder 3 fixed, or with the lower lid 5 fixed. The integral cylinder of the upper lid 4 and the container cylinder 3 may be moved up and down by an elevating means (not shown).

A partition chamber 7 is mounted on the upper surface of the lower lid 5. The partition chamber 7 has a cylindrical shape, and an opening through which a cleaning fluid flows is provided in an upper ceiling portion. A cylindrical storage container 8 is provided inside the partition chamber 7, and the storage container 8 is attached to the upper surface of the lower lid 5 similarly to the partition chamber 7. The storage container is formed in an inverted cup shape, and on the inside, a plurality of protrusions 9 protruding inward are provided in the height direction,
Further, a plurality of projections 9 are provided in the circumferential direction even at the same height position. By mounting the wafers W on the projections 9 at each height position, a plurality of wafers W are set one by one in the up-down direction. I can do it.

As shown in FIG. 2, a plurality of inlets 11 through which the cleaning fluid flows and a plurality of outlets 12 through which the cleaning fluid is discharged are provided on the side surface of the storage container 8 so as to face each other. Fluid flows on the surface of each wafer placed in the wafer 8. Further, as shown in FIG. 3, the opening areas of the inflow port 11 and the discharge port 12 are set in the up-down direction (storage direction) where the wafers W are placed in the storage container 8 so that the amount of fluid flowing on the surface of each wafer W is uniform. (In the container axis direction). Here, the opening heights of the inlet 11 and the outlet 12 are H1, H2, H3, H4, H
5 and H6, and the height of the opening of the inflow port 11 provided below is increased.

The cleaning fluid is introduced into the cleaning vessel 2 through the fluid introduction path 14 and discharged out of the cleaning vessel 2 through the fluid discharge path 15. A heater 19 is provided in the middle of the fluid introduction passage 14, and heats the fluid to a supercritical temperature or higher. Further, the fluid introduction path 14 is attached to the upper lid 4, and a fluid flows from the upper portion of the cleaning container 2 through the upper lid 4. The fluid discharge path 15 is attached to the lower lid 5, and the fluid is discharged from the lower portion of the cleaning container 2 through the lower lid 5. The introduction path 14 is connected to the upper opening of the partition chamber 7 via the flange 20 in the cleaning container 2 so that fluid flows into the partition chamber. In addition,
The flange 20 and the upper opening of the chamber 7 are not airtight, and a fluid flows to the outside of the flange 20 to some extent so that the pressure difference between the inside and the outside of the partition chamber 7 does not damage the partition chamber 7. That is, most of the fluid that has flowed into the cleaning vessel 2 flows into the partition chamber 7, and part of the fluid flows outside the partition chamber 7.

The upper inside surface of the partition chamber 7 is partitioned between the fluid flowing into the partition chamber 7 and the upper surface of the storage container 8 so that the fluid flows in one direction from the inlet 11 on the side surface of the storage container 8 to the discharge port 12. A plate 22 is provided. The partition plate 22 communicates the space between the partition chamber 7 and the storage container 8 with the introduction path 14, the first guide path leading to the inflow port 11, and the second guide path leading from the discharge port 12 to the discharge path 15. It is divided into. That is, the partition plate 22 is also a guide portion for exclusively guiding the fluid flowing into the storage container 8 to the inflow port 11 side. One direction in which the wafer W is washed through each of the inlets 11 through each of the inlet ports 11 to wash the wafer W, discharged from each of the outlets 12 to the outside of the storage container 8, and then discharged to the outside of the cleaning container 2. Distribution channel is formed.

As described above, since the fluid flows in one direction,
Recirculation of the fluid contaminated by fine dirt and the like is prevented. Note that the partition plate 22 does not need to completely partition the first and second guide passages.
It is sufficient if most of the flow of the fluid flowing into the inside can be guided to the first guide passage side, and the fluid may slightly flow toward the second guide passage. The fluid that has reached each inflow port 11 from the first guide passage enters the storage container 8 from each inflow port 11. At this time, in the chamber 7, the fluid tends to enter the storage container 8 because the flow rate is higher near the fluid introduction path 14 because the flow rate is higher, and the fluid enters the storage vessel 8 because the flow rate is lower toward the lower side from the fluid introduction path 14. Hateful.

According to the flow rate difference in the chamber, the opening height of the inflow port 11 and the outlet port 12 of the storage container 8 are larger toward the lower side as described above, and accordingly, the opening area is larger. . By making the opening areas different in this way, the fluid amount in the storage container 8 becomes substantially uniform in the vertical direction, and the plurality of semiconductor wafers W placed in the vertical direction
Are uniformly washed. The inlet 11 and the outlet 12
Flows on the surface of the wafer W placed on the protrusion 9,
It is provided above each projection 9.

The lower lid 5 is provided with a second
A main fluid discharge passage 16 communicating with the guide passage, a first sub-fluid discharge passage 17 communicating with the inside of the storage container 8, and a chamber 7
And a second fluid sub-discharge passage 18 communicating with the outside of the fluid. The first fluid sub-discharge path 17 can prevent the accumulation of fine dirt or the like inside the storage container 8 by directly exhausting air from the lower part of the storage container 8. Also,
The second fluid sub-discharge passage allows the fluid to be discharged from the outside of the chamber 7 due to the flow of the fluid outside the chamber 7.

As shown in FIG. 4, the storage container 8 is composed of two divided bodies 25a and 25b obtained by dividing a cylindrical body in the vertical direction (the direction in which the wafer W is placed), and each divided body 25 is not shown. The storage container 8 is connected by a hinge, and the storage container 8 can be brought into an open state as shown in FIG. 4 and a closed state as shown in FIGS. When the wafer W is stored and unloaded in the storage container 8, it may be performed in an open state as shown in FIG. Note that the present invention is not limited to the above embodiment. For example, each of the inlets 11 and the outlets 12 may have different numbers of openings instead of different opening areas. That is, in the above embodiment, the number of openings can be reduced above the storage container 8 and increased below the storage container 8.

Further, in the above embodiment, the cleaning fluid is supplied from above the cleaning container 2, but may be supplied from below the cleaning container 2. In this case, the inlet 11 and the outlet 12 reduce the opening area below the storage container 8,
The opening area above the storage container 8 may be increased. Further, the fluid inflow position into the cleaning container 2 may be another position, and the opening area and the like may be made smaller as the position is closer to the inflow position. The mounting direction of the semiconductor wafers W is not particularly limited. For example, the semiconductor wafers W may be arranged side by side in addition to the vertical direction.

Further, in the above-described embodiment, the opening area is made different in view of the distance from the fluid inflow position into the cleaning container 2 in particular. However, depending on the shape of the cleaning container 2 or the like, the opening area is different. In some cases, a difference in the flow rate of the fluid may occur due to another factor. In such a case, the flow rate of the fluid flowing on the surface of each wafer W is substantially uniform according to the difference in the flow rate. The opening areas of the inlet and the outlet can be made different. The object to be cleaned by the cleaning apparatus 1 is not limited to a semiconductor wafer, but may be a micromachine or the like.

In the above embodiment, the storage container 8 is
Although the two divided bodies 25a and 25b are joined by a hinge, the divided bodies 25a and 25b are completely divided without being joined by a hinge, and the two divided bodies 25a and 25b are separately divided by a fixing means.
a and 25b may be combined. The number of divided bodies is not limited to two, and may be three or more.

[0030]

As described above, according to the cleaning apparatus of the present invention,
Since a plurality of objects to be cleaned can be processed at the same time, productivity can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional structural view of a cleaning apparatus according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is an external view of a storage container.

FIG. 4 is an external view showing a state where the storage container is opened.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cleaning device 2 Cleaning container (pressure container) 3 Container cylinder 4 Upper lid 5 Lower lid 7 Partition chamber 8 Storage container 9 Projection 11 Inflow port 12 Drain port 14 Fluid introduction path 15 Fluid discharge path 16 Main fluid discharge path 17 First sub fluid Discharge path 18 Second fluid sub-discharge path 20 Flange 22 Partition plate (guide portion) 25 Divided body W Semiconductor wafer (object to be cleaned)

Claims (12)

[Claims] 1. An apparatus for cleaning an object to be cleaned (W) such as a semiconductor wafer with a cleaning fluid in a cleaning vessel (2) into which a cleaning fluid can flow in and out. A storage container (8) for storing a plurality of objects to be cleaned (W), wherein the storage container (8) has an inlet (11) for flowing a cleaning fluid into the storage container (8); An outlet (1) for discharging the cleaning fluid to the outside of the storage container (8).
2), and the inlet (11) and the outlet (12) such that the amount of the cleaning fluid flowing on the surface of each object to be cleaned (W) is substantially uniform.
An apparatus for cleaning a semiconductor wafer or the like, wherein each opening area and / or the number of openings are formed so as to be different in a mounting direction of a body to be cleaned. 2. The opening area and / or the number of openings are smaller in the inflow port (11) and the discharge port (12) closer to the position where the cleaning fluid flows into the cleaning vessel (2). 2. The apparatus for cleaning a semiconductor wafer or the like according to claim 1, wherein the opening area and / or the number of openings are larger at an inlet (11) and an outlet (12) farther from a position where the cleaning fluid flows. 3. The cleaning container (2) receives a cleaning fluid from an upper portion and discharges the cleaning fluid from a lower portion. The storage container (8) can store a plurality of cleaning objects (W) in a vertical direction. 3. The apparatus for cleaning a semiconductor wafer or the like according to claim 1, wherein the opening area and / or the number of openings of the inflow port (11) and the discharge port (12) are larger as they are lower. . 4. A guide portion (22) is provided inside the cleaning container (2) for guiding the inflowing cleaning fluid to the inlet (11) side of the storage container (8). The apparatus for cleaning a semiconductor wafer or the like according to claim 1. 5. The cleaning fluid flowing into the cleaning container (2) flows into the storage container (8) from the inflow port (11) and flows out of the storage container (8) through the discharge port (12). Is discharged to the outside of the washing container (2).
The apparatus for cleaning a semiconductor wafer or the like according to any one of claims 1 to 4, wherein the directional flow path is formed inside the cleaning container (2). 6. The storage container (8) has an inner surface provided with a projection (9) for placing and holding the object to be cleaned (W). 3. A cleaning device for a semiconductor wafer or the like according to 1. 7. The storage container (8) includes an object to be cleaned (W).
Divided bodies (25a, 25a) divided in the mounting direction of
7. The method according to claim 1, wherein the method comprises: b).
The cleaning device for a semiconductor wafer or the like according to any one of the above. 8. The divided body (25a, 25b) is connected by a hinge, and the storage container (8) is connected by the hinge.
Is openable and closable.
The cleaning device for a semiconductor wafer or the like according to any one of the above. 9. The cleaning container (2) has a main fluid discharge path (16) located outside the storage container (8) and a sub-fluid discharge path (16) located inside the storage container (8). 17)
The cleaning device for a semiconductor wafer or the like according to any one of claims 1 to 8, further comprising: 10. The method according to claim 1, wherein a partition chamber (7) is provided between the cleaning container (2) and the storage container (8). Cleaning equipment for semiconductor wafers. 11. An apparatus for cleaning an object to be cleaned (W) such as a semiconductor wafer with a cleaning fluid in a cleaning vessel (2) through which a cleaning fluid can flow in and out, wherein the cleaning vessel (2) has: A storage container (8) for storing a plurality of objects to be cleaned (W), wherein the storage container (8) has an inlet (11) for flowing a cleaning fluid into the storage container (8); An outlet (1) for discharging the cleaning fluid to the outside of the storage container (8).
2) is provided, and the cleaning fluid flowing into the cleaning vessel (2) is supplied to the inflow port (1).
A first guide passage for guiding to 1) and the outlet (12);
A second guide passage for guiding the cleaning fluid discharged from the cleaning container to the outside of the cleaning container (2) is formed in the cleaning container (2). 12. A partition chamber (7) is provided between the washing container (2) and the storage container (8),
The apparatus for cleaning a semiconductor wafer or the like according to claim 11, wherein the inside of the partition chamber (7) is partitioned into a space serving as the first guide passage and a space serving as the second guide passage.