JPH10144644A - Substrate cleaner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cause an effective flowing layer over the entire surface of substrates to be cleaned or avoid causing a vortex in a cleaning tank by injecting a fluid by injecting means in mutually approximately parallel but opposite directions in an upper and lower zones of the tank. SOLUTION: Approximately a uniform flow for water over the entire surface from above a cleaning tank 2 is fed and wound flow into a low-resistance space i.e., an inside face 2a of the tank 2 but is block by a control plate 51 from a biased flow, thus causing an effective flow layer over the entire surface of each of silicon wafers 3 at a feed rate enough to flow among the wafers 3. This ensures a good cleaning effect. The control plate 51 straighten the flow even between the inner side face 2a of the tank 2 and topmost wafer 3. Thus a vortex little occurs but pure water contg. particles is drained, without staying.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the cleaning of substrates such as silicon wafers or glass substrates for industrial use, for example.
In particular, the present invention relates to a substrate cleaning apparatus suitable for rinsing.

[0002]

2. Description of the Related Art FIG. 12 shows a conventional apparatus of this type.

[0003] As shown in the figure, the substrate cleaning apparatus includes a quartz cleaning tank 2 for storing pure water 1 as a cleaning fluid,
There is provided a transport means 5 for carrying in / out the silicon wafer 3 to be cleaned into / from the cleaning tank 2.

As shown in FIGS. 13 and 14, the cleaning tank 2 has a mounting table 7 at its bottom. This mounting table 7
Is a predetermined gap e (FIG. 1) in which a plurality of, for example, 25 silicon wafers 3 are arranged so that their main surfaces are parallel to each other.
4) are arranged and held. Specifically, receiving grooves (not shown) are provided side by side on the upper surface side of the mounting table 7,
Each silicon wafer 3 is held by its lower end engaging with these receiving grooves. Each silicon wafer 3
It is completely immersed in pure water 1 while being mounted on the mounting table 7.

[0005] As shown in FIG. 13, an injection section 9 for injecting pure water 1 into the cleaning tank 2 is provided above the cleaning tank 2. The injection section 9 is connected to a pure water tank 11 storing a large amount of pure water by a water supply pipe 12, and a water supply path formed by the water supply pipe 12 has a valve 14 for adjusting an opening degree of the water supply path. Is provided.

Further, a supply water amount control section 16 for controlling the operation of the valve 14 is provided to adjust the supply water amount.

As shown by an arrow A in FIG. 13, for example, new pure water is horizontally injected from the injection section 9 near the surface of the pure water 1 stored in the cleaning tank 2. This implantation direction is parallel to the main surface of each silicon wafer 3 to be cleaned.

[0008] The injection section 9, the pure water tank 11, the water supply pipe 1
2. The valve 14, the supply water amount control unit 16, and the like are collectively referred to as injection means.

An inclined water flow plate 18 is provided on the upper side of the washing tank 2 and on the side opposite to the injection section 9.

On the other hand, a drain box 20 is provided on the opposite side of the injection section 9, that is, below the washing tank 2. The drain box 20 and the cleaning tank 2 are communicated via a punching plate 22 having a large number of small-diameter communication lines 22a.

In the lower part of the drain box 20, a drain hole 2 is provided.
A drain 26 communicating with the drain hole 20 a is provided with a valve 26 for adjusting the degree of opening of the drain 24.

Further, a drainage control unit 28 for controlling the operation of the valve 26 to adjust the drainage is provided. The drainage amount control unit 28, the drainage box 20, the punching plate 22, and the valve 26 control the pure water 1 in the cleaning tank 2.
Discharging means for discharging the wastewater.

Next, the transfer means 5 will be described.

As shown in FIG. 12, the conveying means 5
A movable base 31 that is movable in a horizontal direction (indicated by an arrow H)
And a driving means (not shown) for moving the movable base 31. A movable pole 33 is provided on the movable base 31 so as to be movable up and down (indicated by an arrow Z).
It is moved up and down by driving means (not shown) provided in the movable base 31.

A base 35 is provided at the upper end of the movable pole 33.
Is provided. Two longitudinal support members 37 and 38 extending horizontally and parallel to each other are attached to the base portion 35 at one end thereof. These support members 3
The bearings 7 and 38 are rotatably supported around their axis by a bearing mechanism provided in the base 35 and are driven to rotate by driving means disposed in the base 35.

As shown in FIG. 13, a pair of hanger members 41, 42 are fixed in a hanging state to the respective distal end portions of the support members 37, 38 and the vicinity thereof. Between the lower ends of the hanger members 41 and 42, two substrate holding members 45 are attached in parallel. These substrate holding members 45 hold the respective silicon wafers 3 in a direction parallel to the main surface thereof, and the holding grooves 45a (see FIG. 12) with which the outer peripheral portions of the respective silicon wafers 3 are engaged have the same pitch. Are installed side by side.

Next, the operation of the above-structured substrate cleaning apparatus will be described. However, the control of the operation described below is controlled by a control unit provided in the substrate cleaning apparatus.

At the time of cleaning, each silicon wafer 3 is carried into the cleaning tank 2. Specifically, in the previous step,
25 silicon wafers 3 are loaded on the substrate holding member 45 of FIG. ₁ , and the movable base 31 is horizontally moved in this state (indicated by an arrow H1 in FIG. 12). by this,
Each of the silicon wafers 3 is positioned above the cleaning tank 2, particularly, just above the mounting table 7. When this positioning is completed, the movable pole 33 is lowered, and each silicon wafer 3
The immersed in pure water 1 in the cleaning tank 2 together with the substrate holding member 45 which sandwiches this is placed on the stage 7 (indicated by an arrow Z ₁ in FIG. 12).

Thereafter, as shown in FIG. 13, the respective hanger members 41 are rotated by rotating the respective support members 37 and 38.
And 42 are opened, and the holding state of the silicon wafer 3 by the substrate holding member 45 is released.

After releasing the holding state, the movable pole 3
3 and leave only the silicon wafer 3 in the cleaning tank 2.

On the other hand, the following operation is performed on the cleaning tank 2 side.

That is, the valve 14 and the valve 26 are both opened, pure water is injected from the injection part 9 as shown by the arrow A, and drainage is made through the drain hole 20a of the drain box 20 as shown by the arrow B. As a result, a flow of the pure water 1 stored in the cleaning tank 2 from top to bottom and around each silicon wafer 3 is generated. In FIG. 13, this flow is indicated by arrows C and D. The water flow plate 18 provided on the upper part of the washing tank 2 promotes the generation of this flow.

At this time, the opening of both valves 14 and 26 is adjusted so that the amount of supplied water exceeds the amount of discharged water. Therefore, excess water flows outward from the edge of the cleaning tank 2. Thereby, light particles floating on the water surface are removed.

By the action of the water flow generated in the cleaning tank 2 as described above, particles adhering to each immersed silicon wafer 3 are removed.

When the cleaning of the silicon wafer 3 is completed, the silicon wafer 3 is unloaded by the transfer means 5. The carry-out operation is almost the same as the carry-in operation. That is, each hanger member 4
The movable pole 33 is lowered with the first and _second members 42 opened (indicated by an arrow Z2 in FIG. 12).
5 is brought to a position where the silicon wafer 3 can be held.
Thereafter, the support members 37 and 38 are rotated to close the hanger members 41 and 42, and the silicon wafer 3 is held by the substrate holding members 45. Then, the movable pole 33 is raised, and the silicon wafer 3 is pulled out above the cleaning tank 2. Subsequently, the movable base 31 is moved horizontally, (indicated by arrow H ₂ in FIG. 12) of the silicon wafer 3 after this washing is conveyed to the subsequent process.

[0026]

The above-mentioned conventional substrate cleaning apparatus has the following problems.

That is, as shown in FIG. 13, a relatively large gap d is provided between the silicon wafer 3 and the inner surface of the cleaning tank 2 in a direction parallel to the main surface of the silicon wafer 3. This is because the substrate holding member 45 and the hanger members 41 and 42 included in the transport unit 5 are inserted.

In the gap d, the frictional resistance of the flow is smaller than that between the silicon wafers 3. Therefore, FIG.
3, even when a substantially uniform water flow is applied from the upper portion of the cleaning tank 2 to the entire surface as shown by the arrow C, it is easy to flow into the smaller resistance, and the flow rate between the silicon wafers 3 is insufficient. An effective laminar flow is hardly generated, and disadvantages such as a difference in cleaning effect between the upper part and the lower part of the wafer occur.

In the above situation, the flow rate tends to increase as the distance from the center of the silicon wafer 3 to the inner surface of the cleaning tank increases. Therefore, a vortex is easily generated based on a difference in flow velocity between the inner surface side of the cleaning tank and the silicon wafer 3 side,
As a result, the pure water in this portion stays containing particles and is not completely discharged, and the cleaning effect is impaired.

Experiments have confirmed that the flow velocity increases as the inner surface of the cleaning tank 2 approaches, and the results are shown in FIG. FIG. 14 shows the distance X from the center of the silicon wafer 3 toward the inner surface of the cleaning tank on the horizontal axis,
The vertical axis is the flow velocity. Here, the flow velocity is displayed in algebraic form, and the scale is not made equal.
If a certain flow rate is S (algebraic, an arbitrary flow rate can be set), it is set to be an integral multiple of S per scale. Then, the flow velocity was measured at several points while appropriately changing the distance X at four levels extending from the vicinity of the water surface to the vicinity of the bottom, and the numerical values at each measurement point were plotted, and the plots were connected by line segments. In the reading of this drawing, the area surrounded by the 0-th straight line related to the flow velocity and these line segments represents the flow velocity at each part. From this figure, it can be seen that the flow velocity gradually increases from the vicinity of the water surface toward the bottom on the inner surface side of the cleaning tank 2, while the flow velocity gradually decreases on the center side of the silicon wafer 3.

The present invention has been made in view of the above-mentioned disadvantages of the prior art, and has as its object to produce an effective laminar flow over the entire surface of a substrate to be cleaned.
An object of the present invention is to provide a substrate cleaning apparatus that prevents generation of a vortex in a tank and thereby improves a cleaning effect.

Further, the present invention provides a substrate cleaning apparatus which can exert other effects.

[0033]

In order to achieve the above object, the present invention provides a cleaning tank for storing a cleaning fluid, and a plurality of substrates arranged in the cleaning tank such that main surfaces thereof are substantially parallel to each other. And a mounting table for injecting the fluid into the cleaning tank substantially parallel to the main surface of the substrate, and discharging the fluid from the cleaning tank on a side substantially opposite to the injection means. In the first apparatus for cleaning a substrate, the injecting means is configured to inject fluids in substantially opposite directions in an upper part or a lower part of the cleaning tank in opposite directions.

In order to achieve the above object, the present invention provides a cleaning tank for storing a cleaning fluid, and a plurality of substrates arranged and held in the cleaning tank such that main surfaces thereof are substantially parallel to each other. A mounting table, transport means for carrying the substrates in and out of the mounting table while maintaining the arrangement of the substrates, and injection for injecting the fluid into the cleaning tank substantially parallel to a main surface of the substrates; And a discharge means for discharging the fluid from the cleaning tank on a side substantially opposite to the injection means.
In the above substrate cleaning apparatus, the injection means is configured to inject fluids in substantially opposite directions in an upper portion or a lower portion of the cleaning tank in opposite directions.

In order to achieve the above object, the present invention provides a cleaning tank for storing a cleaning fluid and a cassette holding a plurality of substrates arranged in such a manner that their main surfaces are substantially parallel to each other. Conveying means for carrying in and out of the tank, injecting means for injecting the fluid into the cleaning tank substantially parallel to the main surface of the substrate, and cleaning the fluid on a side substantially opposite to the injecting means. In a third substrate cleaning apparatus having a discharge means for discharging the liquid from the tank, the injection means is configured to inject fluids in substantially opposite directions in an upper part or a lower part of the cleaning tank.

In order to achieve the above object, the present invention provides a cleaning tank for storing a cleaning fluid and a plurality of substrates arranged and held so that their main surfaces are substantially parallel to each other. Transport means for carrying in and out, and an injection means for injecting the fluid into the cleaning tank substantially in parallel with the main surface of the substrate, and the fluid from the cleaning tank on a side substantially opposite to the injection means. In a fourth substrate cleaning apparatus having a discharge means for discharging, the injection means is configured to inject fluid in substantially opposite directions in an upper part or a lower part of the cleaning tank in opposite directions.

In addition, to obtain various other effects, the following configurations are employed.

That is, in each of the above substrate cleaning apparatuses,
The reciprocal injection by the injection means is performed at the same flow rate and the same pressure.

Further, in each of the substrate cleaning apparatuses, the cleaning tank has a guide means near the bottom thereof for guiding the flow of the fluid toward the center of the substrate.

[0040]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the accompanying drawings.

FIGS. 1 and 2 show a main part of a substrate cleaning apparatus according to a first embodiment of the present invention. However, the substrate cleaning apparatus is configured in the same manner as the above-described conventional substrate cleaning apparatus except for the parts described below, and the description of the configuration and operation of the entire apparatus is omitted because it is redundant, and only the main parts are omitted. Stop it for explanation.

In the following description, components that are the same as or correspond to those of the conventional example are denoted by the same reference numerals.

As shown in the figure, also in the substrate cleaning apparatus, for example, a substrate 2 is placed on a mounting table 7 fixed to the bottom of the cleaning tank 2.
Cleaning is performed with the five silicon wafers 3 arranged in an array. Therefore, as is apparent from FIG. 3, the end of the mounting table 7 protrudes, and the transfer means 5 (FIG. 12).
And Figure 13 the working space from the need to ensure the respective hanger members see) (41, 42), the distance a is a silicon wafer 3 of the inner surface 2a of the major surface and washing tank 2 of the silicon wafer 3 _-1 endmost It is considerably larger than the gap e between them (shown in the figure).

For this reason, each silicon wafer 3
The inner surface 2a of the cleaning tank 2 and the opposite end silicon wafer 3
The frictional resistance of the water stream to one side of _-1 is quite small.

Therefore, in the present embodiment, a control plate 51 is provided between the endmost silicon wafer 3 and the inner surface 2a of the cleaning tank 2. From FIG. 1, two control plates 51 are provided corresponding to both ends of the row of the silicon wafer 3 respectively. The control plate 51 controls a flow (described later) of pure water injected from above the cleaning tank 2.
In the present embodiment, it is formed in a rectangular plate shape and installed in a horizontally long state.

The control plate 51 is made of a metal such as quartz glass or duralumin or a synthetic resin, and has a length L.
(Shown in FIG. 1) is set to be equal to the width of the opening of the cleaning tank 2 and is set to, for example, 260 mm.

The width b (shown in FIG. 3) and the thickness t (same) of the control plate 51 are set to 66 mm and 5 mm, respectively.

As is clear from FIG. 1, the control plate 51
The silicon wafer 3 is installed so as to be immersed in the pure water 1 stored in the cleaning tank 2 and in parallel with the endmost silicon wafer 3. By providing such a control plate 51, the following effects can be obtained.

That is, as shown by an arrow G in FIG. 3, when a substantially uniform water flow is supplied from the upper portion of the cleaning tank 2 to the entire surface, the smaller one of the frictional resistance, that is, the cleaning tank 2
The control plate 51 suppresses this drift. Therefore, a sufficient flow rate is supplied between the silicon wafers 3 to generate an effective laminar flow over the entire surface of the silicon wafers, thereby obtaining a good cleaning effect.

[0050] Further, by the control plate 51, the rectifier also between the inner surface 2a and endmost silicon wafer 3 _-1 of the cleaning tank 2 is made, eddy hardly occurs, pure water residence containing particles Emitted without doing so. Therefore, the cleaning effect is further improved.

Here, how the width b of the control plate 51 is set will be described.

That is, if attention is paid only to the cleaning effect of the silicon wafer 3 in a short time, it is customary to first consider that the control plate 51 for adjusting the flow is made considerably large and extends to the vicinity of the lower end of the silicon wafer 3. is there. However, such a large control plate is inconvenient to handle, and as described later, it is also difficult to cause the transfer means 5 to transfer the control plate.

The length L of the control plate 51 is required to be equal to the opening width of the cleaning tank in view of its function.

Therefore, it was considered that the width b of the control plate 51 could not be reduced without impairing the function, and a plurality of control plates having different widths were manufactured, and an experiment was conducted to confirm the cleaning effect. Thus, relatively good results were obtained even when the width was considerably reduced. It was also found that the value of the width was opposite to the size of the silicon wafer to be cleaned.

The silicon wafer 3 to be cleaned in the substrate cleaning apparatus has a diameter of 8 inches (203.2).
mm). The value of the width b is a minimum value necessary for obtaining a good cleaning effect on a silicon wafer of this size.

The control plate 51 is provided with a transfer means (5: FIG. 12).
And FIG. 13), it is a hindrance when the silicon wafer is taken in and out of the cleaning tank 2, so that it is necessary to attach and detach it one by one. Here, the configuration of attaching and detaching the control plate 51 will be described with reference to FIG.

As shown, a receiving member 53 having a receiving groove 53a whose upper end is open is attached to the inner surface of the cleaning tank 2. The control plate 51 has one end thereof in the receiving groove 53.
a. Therefore, although not shown, the receiving member 53 is
Are provided corresponding to both ends. The receiving groove 53a
A taper 53b is formed on both sides of the open end of the receiving member 53, so that the receiving member 53 can be smoothly inserted into the receiving groove 53a.

The position of the receiving member 53 can be adjusted in the direction in which the silicon wafers 3 are arranged in the cleaning tank 2. Thereby, even if the number of processed silicon wafers is arbitrarily changed, it is possible to cope with it.

As shown in FIG. 4, in the vicinity of one end of the control plate 51, a groove 51a which is substantially vertical and has an open upper end is formed.
A continuous arc-shaped groove 51b is formed at the lower end of 1a.

On the other hand, a locking piece 55 protrudes from the side surface of the hanger member 42 provided in the conveying means (5: see FIGS. 12 and 13), and the locking piece 55 is formed by the grooves 51a, 51b.
Can be smoothly engaged. Specifically, the locking piece 55 is connected to the hanger member 42 at one end and
The small diameter portion 55a is slidably engaged with the small diameter portion 55a, and the large diameter portion 55b is connected to the other end of the small diameter portion 55a and acts as a stopper.

The radius of curvature of the arc-shaped groove 51b is set around the center of rotation of the hanger member 42.

Although not shown, a groove similar to the grooves 51a and 51b is provided on the other end side of the control plate 51, and another hanger member (41: FIG. 1) corresponding to the hanger member 42 is provided.
2, see FIG. 13) is provided with a locking piece that is engaged with this groove.

The above-mentioned grooves and locking pieces are collectively referred to as locking means. This locking means locks and releases the control plate 51 in accordance with the opening and closing operations of the hanger members 41 and 42.

That is, in FIG.
2 (when the hanger member 41 side is the same, the description will be omitted).
5a is located at the deepest part of the arc-shaped groove 51b. This allows
The control plate 51 is locked to the hanger member 42 and can be transported by the transporting means (5: described above).

When the transfer means is operated in the above-mentioned locked state and each silicon wafer 3 is carried into the cleaning tank 2, the control plate 51 is fitted into the receiving groove 53 a of the receiving member 53. When each silicon wafer 3 is placed on the mounting table 7, the hanger member 42 (and 41) is rotated and opened (indicated by an arrow h in FIG. 4), and
Moves along the arc-shaped groove 51b to reach the lower end of the vertical groove 51a. Thereafter, the hanger member 42 rises,
The locking piece 55 comes out of the groove 51a (indicated by an arrow i in FIG. 4), and the control plate 51 is released from the locked state and stays in the cleaning tank 2.

When each of the cleaned silicon wafers is taken out of the cleaning tank by the transfer means, the operation is performed in a completely opposite manner to the above, and the control plate 51 is locked by the transfer means and taken out.

By providing the above-mentioned locking means, the control plate 51 can be automatically attached to and detached from the cleaning tank 2.
The attachment and detachment of the control plate 51 may be performed by the operator himself, but by automatically performing the operation in this manner, complicated operations are released.

The attachment / detachment means for automatically attaching / detaching the control plate 51 is not limited to the above-described locking means, and various means are applicable. However, the above-mentioned locking means has advantages such as a low cost and a low possibility of failure since the configuration is extremely simple.

Here, the control plate 51 will be described in more detail.

[0070] As already described with reference to FIG. 3, the control plate 51, gap e ₁ between the silicon wafer 3 _-1 endmost is substantially equal to the clearance e of each of the silicon wafer 3 together. According to this, the endmost silicon wafer 3 _-1
With respect to the above, the control plate 51 acts as if another silicon wafer is disposed, and the cleaning effect is effectively exerted even on the endmost silicon wafer.

In this case, it is particularly preferable to adopt the following configuration.

[0072] That is, the control plate 51, the roughness of the surface facing the silicon wafer 3 _-1 endmost is to substantially equal to the roughness of the surface of the silicon wafer. In this way, the action of the control plate 51 as a silicon wafer adjacent to the silicon wafer 3 _-1 endmost is ensured.

Next, an injection means for injecting pure water into the cleaning tank 2 from above will be described.

As shown in FIG. 2, the upper part of the cleaning tank 2
An injection section 9 is provided on one side, and another injection section 61 is provided on the other side. The injection section 61 is connected to the pure water tank 11 to which the injection section 9 is connected by a water supply pipe 62, and a water supply path formed by the water supply pipe 62 has a valve 64 for adjusting the opening degree of the water supply path. Is provided. The valve 64 is provided with a valve 14 provided corresponding to the injection section 9.
At the same time, the operation is controlled by the supplied water amount control unit 16.

From the injection section 9 and the injection section 61, new pure water is injected in directions opposite to each other near the surface of the pure water 1 stored in the cleaning tank 2. The directions of injection are indicated by arrows A and J. The injection in the opposite direction is performed at the same flow rate and the same pressure.

The pure water injected from the injection section 9 and the injection section 61 merge with each other as shown by arrows M and N to generate a downward flow P. Since the flows before the merging have vectors in the direction in which they are injected, that is, toward the center of the tank, the downward flow P after the merging is the silicon wafer 3
Flows into the center of the main surface. Thus, an effective laminar flow is supplied over the entire surface of the silicon wafer 3, and the cleaning effect is improved.

The reason for injecting water from the upper part of the washing tank as described above is as follows.

That is, as shown in FIG. 2, a relatively large gap d is provided between the silicon wafer 3 and the inner surface 2b of the cleaning tank 2 in a direction parallel to the main surface of the silicon wafer 3. This is because the substrate holding member 45 and the hanger members 41 and 42 included in the transfer means 5 shown in FIGS. 12 and 13 are inserted. This gap d
In this case, the frictional resistance of the flow is smaller than that between the silicon wafers 3. If water is uniformly injected from above the cleaning tank 2 over the entire surface of the cleaning tank 2, a drift is generated toward this part and the water tends to flow intensively. Then, a sufficient flow rate cannot be obtained between the silicon wafers 3, and the cleaning effect is lost.

Further, between the inner surface 2b of the cleaning tank 2 and the silicon wafer 3 separated by the gap d, the flow velocity tends to increase as approaching the inner surface 2b. Therefore, a vortex is likely to be generated based on a difference in flow velocity between the inner surface 2b side and the silicon wafer 3 side. As a result, the pure water in this portion stays containing particles and is not completely discharged, and the cleaning is not completed. The effect is impaired.

Therefore, in the substrate cleaning apparatus, in order to obtain a good cleaning effect, the above configuration is used, and a flow is generated along the center of the main surface of the silicon wafer 3. According to the configuration employed in the substrate cleaning apparatus, an effective laminar flow is obtained between the silicon wafers 3, and the generation of vortices in the gap d is prevented, and contaminated water is discharged without stagnation. .

In the substrate cleaning apparatus, the following configuration is added to the above configuration.

That is, as shown in FIGS. 1 and 2, guide plates 68 are provided on both sides near the bottom of the cleaning tank 2 at an angle. The guide plate 68 is provided with the downward flow P
And acts as guide means for guiding the diffusion toward the center of the silicon wafer 3. With this configuration, the flow P is maintained without being diffused, and the cleaning effect is further enhanced.

The substrate cleaning apparatus further includes the following configuration.

As shown in FIG. 5, an injection section 71 is provided above the cleaning tank 2 for injecting water into the surface layer of the stored pure water 1 in the arrangement direction of the silicon wafers 3.
The direction of water injection is indicated by arrow K. The injection section 71 is connected to the pure water tank 11 shown in FIG. 2 by a water supply pipe 72, and a water supply path formed by the water supply pipe 72 is provided with a valve 74 for adjusting the opening degree of the water supply path. ing.
The operation of the valve 74 is controlled by the supply water amount control unit 16 shown in FIG.

The supply water amount control section 16 stops the injection from the injection sections 9 and 61 shown in FIG. 2, and in this state, performs the injection only by the injection section 71. At the same time, the drainage control unit 28 shown in FIG. 2 closes the valve 26 to stop draining. Thereby, the pure water 1 in the cleaning tank 2 is gradually increased by the injection from the injection section 71 and overflows out of the tank. Thereby, light particles floating on the water surface are removed. However, in this operation, it is necessary that a flow occurs in the surface layer of the pure water 1 in the cleaning tank 2, so that the control plate 51 does not hinder the flow of this surface as shown in FIG.
It is arranged so that the upper end is located at a required depth g from the water surface.

As shown in FIGS. 1 and 5, an overflow guide 76 is provided as guide means for smoothly guiding the overflowing pure water to the outside of the washing tank 2 and flowing it down. The overflow guide 76 is arranged on the downstream side in the injection direction K by the injection unit 71. More specifically, the overflow guide 76 has a sharp projection 76a protruding outside the cleaning tank 2, and the provision of the projection 76a facilitates drainage.

The particles floating on the water surface are almost completely removed by the injection of water by the injection section 71 and the action of the overflow guide 76, and the particles are re-used when the cleaned silicon wafer 3 is drawn out of the cleaning tank. Adhesion is prevented.

The flow due to the water injection from the injection section 71 does not flow downward but flows through the water surface because the frictional resistance between the silicon wafers 3 present below is relatively large.

[0089]

Next, another embodiment which achieves the same cleaning effect as the substrate cleaning apparatus of the first embodiment will be described. In other words, a relatively large gap is provided in the cleaning tank as a space for not only the silicon wafer to be cleaned but also a cassette holding the silicon wafer and a transporting means, and a drift is generated toward the gap side, thereby deteriorating the cleaning effect. This problem has been solved by providing a control plate.

First, a substrate cleaning apparatus as a second embodiment will be described with reference to FIG. However, the substrate cleaning apparatus of the second embodiment has the same configuration as that of the above-described first embodiment except for the parts described below, and the description of the configuration and operation of the entire apparatus is omitted because it is redundant. Only the main part will be described.

In the following description, the same or corresponding components as those of the first embodiment are denoted by the same reference numerals. The same applies to the description of the third embodiment and thereafter, which will be described later.

In the first embodiment, the transport means 5 transports only the silicon wafer 3, whereas in the substrate cleaning apparatus of the second embodiment, the transport means 5 comprises the cassette 81 holding the silicon wafer 3. Is transported. The cassette 81 is a so-called full cassette, and holds, for example, 25 silicon wafers 3 with a predetermined gap therebetween so that the main surfaces thereof are parallel. This gap is set in the same manner as in the first embodiment (indicated by e in FIG. 3).

The cassette 81 has an overhang 81 at its upper end.
a is formed, and the transport means 5 is provided with a hook 41 formed at the lower end of the hanger members 41 and 42 provided therein.
The overhang portion 81a is suspended by the a and 42a.

A control plate 51 for controlling the flow in the washing tank 2 is detachably supported by support members 41b and 42b attached to the hanger members 41 and 42. The control plate 51 by the support members 41b and 42b
Is supported by the hanger member 4 in the first embodiment.
The control state is the same as that of the first and second embodiments, and the control plate 51 is attached to and detached from the cleaning tank 2 in the same manner as in the first embodiment. That is, the mounting is performed by the opening operation of the hanger members 41 and 42 when the cassette 81 is carried into the cleaning tank 2 and the subsequent ascent operation, and the control plate 51 is removed from the cleaning tank 2 by the reverse operation. .

[0095] position of the control plate 51, in relation to the distance between the 3 _-1 and the cassette 81 and the inner surface of the cleaning tank 2 having the highest edge of each of the silicon wafer 3 arranged as follows Selected.

[0096] First, with respect to the present embodiment, as shown in FIG. 7, the distance j ₁ between the inner surface 81a of the silicon wafer 3 _-1 endmost cassette 81 is substantially equal to the clearance e of each of the silicon wafer 3 together Shall be done. in this case,
End silicon wafer _3-1 and inner surface 8 of cassette 81
It is considered that an effective laminar flow is obtained between the laminar flow and la. In this case, the control plate 51 is connected to the cassette 81 as shown in FIG.
It is arranged in a large gap generated between the cleaning tank 2 and the inner side surface 2a. As a result, the control plate 51 effectively performs a rectifying action in this gap.

On the other hand, the case shown in FIG. 8 can be considered. That is, the endmost silicon wafer _3-1 and the cassette 8
In this case, the distance j ₂ between the first silicon wafer 3 and the inner side surface 81 a is considerably larger than the gap e between the silicon wafers 3. in this case,
Control plate 51 is disposed between the inner surface 81a of the silicon wafer 3 _-1 and the cassette 81 of the outermost end. Thus, the cleaning effect on the outer surface of the silicon wafer 3 _-1 outermost edge is obtained, rectifying effect in large gap on the opposite side to this is also achieved.

In the second embodiment described above, a full cassette is used. However, a half cassette whose height is about half that of the full cassette is frequently used. Even in such a case, the position of the control plate 51 is selected in the same manner as described above. It is effective.

Next, a substrate cleaning apparatus as a third embodiment will be described with reference to FIG.

In this substrate cleaning apparatus, a cassette 83 having a height lower than that of the half cassette is used. Specifically, the height of the cassette 83 is set to about １ ／ of the diameter of the silicon wafer 3. Such a cassette is called a boat cassette. The detailed configuration of the boat cassette is not shown here, but is shown only schematically. In the cassette 83, a projection 83 a is formed at an end of the silicon wafer 3 in the arrangement direction, and the hanger member 4
The projections 83a are supported by hooks 41a and 42a formed on the first and second 42.

In the substrate cleaning apparatus, similarly to the first embodiment, the control plate 51 is detachably attached to the hanger members 41 and 42, and the opening and closing operation of the hanger members 41 and 42 causes the cleaning tank 2 to be opened and closed. Removal is performed.

Next, a substrate cleaning apparatus according to a fourth embodiment will be described with reference to FIG.

In the substrate cleaning apparatus, cleaning is performed while each silicon wafer 3 is held by the transfer means 5. Therefore, the mounting table (7) shown in the first embodiment and the cassette shown in the other embodiments are not present in the cleaning tank 2. Also in this type of cleaning apparatus, since the hanger members 41 and 42 of the transport means 5 and the substrate holding member 45 enter the cleaning tank 2, a relatively large gap is provided in the cleaning tank 2, and the control plate 51 It is necessary to make rectification effectively by the action.

In each of the embodiments described above, for example, 25 silicon wafers 3 are subjected to cleaning as one lot. However, for example, as shown in FIG. 11, two lots, ie, 50 lots (more than 50 (It is also possible to handle the silicon wafer 3) at once. In this case, from the viewpoint of handling in the steps before and after the washing step, it is conceivable to arrange them on the cassette 85 in lots one by one. At this time, a gap n is provided between each lot. Therefore, the control plate 51, the inner surface 2a of the cleaning tank 2 and the silicon wafer 3 _-1 on one side of each lot
Not only between, there is also a need to provide between the silicon wafer 3 _-1 between the outermost ends of the opposing side of each lot.

In each of the above embodiments, the cleaning tank 2
However, the present invention can be applied to an apparatus having a configuration in which water is injected from the lower part and drained from the upper part.

Further, in each embodiment, after the cleaning step of the silicon wafer 3 is completed, the injection portion 71 shown in FIG.
Particles floating on the water surface are removed by more water injection, and the order of the cleaning step and the overflow step, the number of times these steps are performed, and the like are arbitrarily set. However, if the overflow step is performed after the completion of the cleaning step as in the embodiment, particles floating in the cleaning step can be efficiently removed.

[0107]

As described above, in the substrate cleaning apparatus according to the present invention, the injection means is provided so that the fluid is injected substantially horizontally in the upper or lower part of the cleaning tank in opposite directions. I have.

According to such a configuration, fluids injected in opposite directions merge with each other to generate a downward or upward flow. Since the flows before the merge have a vector toward the direction in which they are injected, that is, toward the center of the tank, the downward or upward flow after the merge flows into the central portion of the main surface of the substrate. As a result, a sufficient flow rate is supplied between the substrates to generate an effective laminar flow over the entire surface of the substrates, and a good cleaning effect is obtained.

Further, even between the inner surface of the cleaning tank having a large gap and the substrate, the difference in the flow velocity between the inner surface and the substrate is suppressed to a small value, vortices are less likely to occur, and particles are contained. The cleaning fluid is discharged without stagnation. Therefore, the cleaning effect is further improved.

[Brief description of the drawings]

FIG. 1 is a perspective view including a partial cross section showing a cleaning tank as a main part of a substrate cleaning apparatus as a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view showing a part of the substrate cleaning apparatus as a first embodiment of the present invention in a block form.

FIG. 3 is an enlarged longitudinal sectional view showing a main part in a cleaning tank of the substrate cleaning apparatus shown in FIGS. 1 and 2;

FIG. 4 is a perspective view, including a partial cross section, showing a control plate provided in the substrate cleaning apparatus shown in FIGS. 1 and 2 and members around the control plate;

FIG. 5 is a longitudinal sectional view of a main part of a cleaning tank included in the substrate cleaning apparatus shown in FIGS. 1 and 2.

FIG. 6 is a perspective view including a partial cross section of a main part of a substrate cleaning apparatus as a second embodiment of the present invention.

FIG. 7 is a longitudinal sectional view of a main part of a cleaning tank included in the substrate cleaning apparatus shown in FIG.

FIG. 8 is a longitudinal sectional view showing a modification of a main part of a cleaning tank included in the substrate cleaning apparatus shown in FIG.

FIG. 9 is a perspective view including a partial cross section of a main part of a substrate cleaning apparatus as a third embodiment of the present invention.

FIG. 10 is a perspective view including a partial cross section of a main part of a substrate cleaning apparatus according to a fourth embodiment of the present invention.

FIG. 11 is a longitudinal sectional view showing a modified example of a main part of the substrate cleaning apparatus according to the present invention.

FIG. 12 is a perspective view including a partial cross section of a main part of a conventional substrate cleaning apparatus.

FIG. 13 is a vertical sectional view showing a part of the substrate cleaning apparatus shown in FIG. 12 in a block form;

FIG. 14 is a view showing a result of measuring a flow rate of each part in a tank in the substrate cleaning apparatus shown in FIGS. 12 and 13. .

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Pure water (cleaning fluid) 2 Cleaning tank 3 Silicon wafer (substrate) 5 Transport means 7 Mounting table 9, 61, 71 Injection part 11 Pure water tank 14, 26, 64 74 Valve 16 Supply water amount control part 20 Drainage box 28 Drainage amount Controllers 41, 42 Hanger member 45 (of conveying means 5) 45 Substrate holding member (of conveying means 5) 51 Control plate 68 Rectifying plate 76 Overflow guide (guide means) 81, 83, 85 Cassette

Claims (6)

[Claims] A cleaning tank for storing a cleaning fluid; a mounting table for holding a plurality of substrates arranged in the cleaning tank such that main surfaces thereof are substantially parallel to each other; A substrate cleaning apparatus comprising: an injecting unit that injects the fluid into the cleaning tank substantially parallel to a main surface; and a discharging unit that discharges the fluid from the cleaning tank on a side substantially opposite to the injecting unit. Is a substrate cleaning apparatus characterized in that fluids are injected in substantially opposite directions in an upper portion or a lower portion of the cleaning tank. 2. A cleaning tank for storing a cleaning fluid; a mounting table for holding a plurality of substrates arranged in the cleaning tank such that main surfaces thereof are substantially parallel to each other; Transport means for carrying in and out of the mounting table while maintaining the above, an injection means for injecting the fluid into the cleaning tank substantially parallel to a main surface of the substrate, and substantially opposite to the injection means. And a discharge means for discharging the fluid from the cleaning tank on the side, wherein the injecting means injects fluids in substantially opposite directions in an upper part or a lower part of the cleaning tank. A substrate cleaning apparatus characterized by the above-mentioned. 3. A cleaning means for storing a cleaning fluid, and a transport means for loading and unloading a cassette holding a plurality of substrates arranged in such a manner that main surfaces thereof are substantially parallel to each other and into and out of the cleaning tank. Substrate cleaning, comprising: an injection means for injecting the fluid into the cleaning tank substantially parallel to a main surface of the substrate; and a discharge means for discharging the fluid from the cleaning tank on a side substantially opposite to the injection means. The substrate cleaning apparatus, wherein the injection means injects fluids in substantially opposite directions in an upper part or a lower part of the cleaning tank in opposite directions. 4. A cleaning tank for storing a cleaning fluid, and transport means for holding and arranging a plurality of substrates such that main surfaces thereof are substantially parallel to each other, and carrying in and out of the cleaning tank. A substrate cleaning apparatus comprising: an injection unit configured to inject the fluid into the cleaning tank substantially parallel to a main surface of the substrate; and a discharge unit configured to discharge the fluid from the cleaning tank on a side substantially opposite to the injection unit. The substrate cleaning apparatus, wherein the injection means injects fluids in substantially opposite directions in an upper part or a lower part of the cleaning tank in opposite directions. 5. The injection in the opposite direction by said injection means,
2. The method according to claim 1, wherein the pressure and the pressure are the same.
The substrate cleaning apparatus according to claim 1. 6. The cleaning tank according to claim 1, further comprising a guide near the bottom thereof for guiding the flow of the fluid toward the center of the substrate. A substrate cleaning apparatus as described in the above.