JPH11168080A - Device and method of washing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dry wafers at a high throughput by a method, wherein the speed at which a retaining part passes the liquid level of a cleaning solution is made slower than the speed at which a part other than retaining part passes through the liquid level. SOLUTION: When the contact part between a wafer 1 and a wafer lifter 3b comes close to the liquid level of a washing solution, having the wafer 1 brought up quickly is ended, and slow down of the rising speed is started. Then, slow down of the rising speed of the wafer 1 is ended, and the movement before the contact part between the wafer 1 and the wafer lifter 3b reaches the liquid level, and the wafer 1 is brought up at a slow speed at which the contact part can be dried up. Subsequently, when the wafer reaches the prescribed position in a drying vessel 5, the low speed rising of the wafer lifter 3b is made to stop, and the drying of the wafer 1 is made to finish. When the contact part of the wafer 1 and the wafer lifter 3b passes through the liquid level, the contact part, which is hardly dried up by the low rising speed and cleaning solution is likely to remain, can be dried up sufficiently. When a part other than the contact part passes through the liquid level, the washing efficiency is good because the wafer is brought up at high speed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cleaning apparatus and a cleaning method for cleaning a wafer. In particular, the present invention relates to a cleaning apparatus and a cleaning method capable of drying a wafer at a high throughput and efficiently cleaning the wafer.

[0002]

2. Description of the Related Art FIGS. 4A and 4B are schematic views of a cleaning apparatus for explaining a conventional method for drying a wafer. This cleaning apparatus has a cleaning tank 113, and a drying tank 115 is provided on the cleaning tank 113. The inside of the cleaning tank 113 is filled with a cleaning liquid 114 for cleaning the wafer 1. The inside of the drying tank 115 is filled with a drying gas 116 for drying the wafer 1. Further, the cleaning apparatus has a wafer lifter 112, and the wafer lifter 112 removes the wafer 1 from the cleaning tank 113 to the drying tank 115.
Is to be moved.

Next, an outline of a method for drying a wafer will be described. First, as shown in FIG. 4A, the wafer 1 placed on the wafer lifter 112 is placed in a cleaning tank 113, and the wafer 1 is cleaned with a cleaning liquid 114.

Next, after the cleaning of the wafer 1 is completed, the wafer 1 in the cleaning tank 113 is dried while being lifted by the wafer lifter 112 toward the drying tank 115 at a constant speed. That is, the drying of the wafer 1
This is performed at the moment when the wafer 1 passes over the surface (liquid level) of the cleaning liquid 114. For this reason, it is better to stabilize the liquid level,
Therefore, the rising speed of the wafer 1 is kept constant.

Then, as shown in FIG. 4B, when the wafer 1 reaches a predetermined position in the drying tank 115, the lifting of the wafer lifter 112 is stopped, and the drying is terminated.

[0006]

As described above, when the wafer 1 is dried while being raised at a constant speed, the contact portion 118 between the wafer 1 and the wafer lifter 112 is harder to dry than the other portions. Therefore, the cleaning liquid 114 easily remains on the contact portion 118. Therefore,
In order to dry such a part sufficiently, the wafer 1
It is necessary to slow the climb speed. This causes the throughput to not increase.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above circumstances, and has as its object to provide a cleaning apparatus and a cleaning method capable of drying a wafer at a high throughput and efficiently cleaning the wafer. Is to provide.

[0008]

In order to solve the above-mentioned problems, a cleaning apparatus according to the present invention comprises a cleaning unit having a cleaning liquid for cleaning a wafer, a drying unit for drying a cleaned wafer, and a cleaning unit. Moving means for holding and moving the wafer to the drying means; and moving the wafer by the moving means to dry the wafer, when the portion holding the wafer passes through the surface of the cleaning liquid. Means for lowering the speed of a portion other than the held portion when passing through.

Further, the cleaning method according to the present invention comprises a cleaning means having a cleaning liquid for cleaning the wafer, a drying means for drying the washed wafer, and the cleaning means holding and moving the wafer to the drying means. A moving means for cleaning the wafer using the cleaning method, wherein a cleaning step of cleaning the wafer with the cleaning liquid; and moving the wafer by the moving means to dry the wafer. Reducing the speed at which the portion holding the cleaning liquid passes through the liquid surface of the cleaning liquid to be lower than the speed at which the portion other than the held portion passes.
The washing step preferably includes a step of washing with a chemical solution, and a step of replacing the chemical solution with water and washing with water.

In the cleaning apparatus and the cleaning method, when the wafer is dried, the speed at which the portion holding the wafer passes through the surface of the cleaning liquid is reduced by the speed at which the portion other than the held portion passes. By making it slower, the held portion that is difficult to dry can be sufficiently dried. Moreover, when a portion other than the held portion passes through the liquid surface, the wafer is lifted at a higher speed than the held portion, so that drying can be performed at a high throughput, and as a result, Cleaning can be performed efficiently.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1A to 1D are schematic views of a cleaning apparatus illustrating a method for drying a wafer according to a first embodiment of the present invention.

The cleaning apparatus has a cleaning tank 4, and a drying tank 5 is provided on the cleaning tank 4. The inside of the cleaning tank 4 is filled with a cleaning liquid 6 for cleaning the wafer 1, and the cleaning liquid 6 is a chemical solution for removing organic contamination, metal contamination, particles and the like from the wafer 1, or pure water (water). The inside of the drying tank 5 is filled with a drying gas 5 a for drying the wafer 1. The cleaning apparatus has a wafer lifter 3b having a groove (not shown). The wafer lifter 3b supports the wafer 1 from below by hanging the wafer 1 on the groove, and moves the wafer 1 from the cleaning tank 4 to the drying tank 5. It is to let. Further, the wafer lifter 3b has a means for changing its moving speed as needed.

Next, an outline of a method for drying a wafer will be described. First, as shown in FIG. 1A, a wafer 1 placed on a wafer lifter 3b is put in a cleaning tank 4, and the wafer 1 is cleaned with a cleaning liquid 6.

Next, when the cleaning of the wafer 1 is completed, the wafer 1 in the cleaning tank 4 is raised at a high speed by the wafer lifter 3b, and drying is started. Since the drying is performed when the wafer 1 passes over the surface (liquid level) of the cleaning liquid 6, until the contact portion between the wafer 1 and the wafer lifter 3b comes close to the liquid level, the wafer 1 is dried at a high speed within a range where drying is possible. To rise. However, the speed is constant.

Thereafter, as shown in FIG. 1 (b), when the contact portion between the wafer 1 and the wafer lifter 3b comes close to the liquid surface, the raising of the wafer 1 at high speed is terminated, and the rising speed is reduced. Start deceleration.

Next, as shown in FIG. 1 (c), before the contact portion between the wafer 1 and the wafer lifter 3b reaches the liquid surface, the deceleration of the rising speed of the wafer 1 is terminated, and The wafer 1 is raised at a low speed in a range where drying is possible.
However, the speed is constant.

Thereafter, as shown in FIG. 1D, when the wafer 1 reaches a predetermined position in the drying tank 5, the low-speed rise of the wafer lifter 3b is stopped, and the drying is terminated.

According to the first embodiment, FIG.
As shown in (c), the wafer 1 and the wafer lifter 3b
When the contact portion with the liquid passes through the surface of the liquid, the contact portion is set at a low speed, so that the contact portion that is difficult to dry (that is, a portion where the liquid easily remains) can be sufficiently dried. Moreover, when the portion other than the contact portion passes through the liquid surface, the wafer 1 is raised at a high speed, so that the drying can be performed at a high throughput, and as a result, the wafer 1 can be efficiently cleaned. it can.

Further, as shown in FIG. 1B, the lifting speed of the wafer 1 is gradually reduced from a point shortly before the contact portion reaches the liquid level, and the contact portion shown in FIG. The final low-speed rise state is set before passing the liquid level. This is because if the contact portion reaches the liquid level and the rising speed of the wafer 1 is rapidly changed from a high speed to a low speed, particles tend to adhere to the wafer 1. By controlling the rising speed of the wafer 1 in this manner, the throughput can be increased without increasing the number of particles attached to the wafer 1.

FIGS. 2A to 2F are schematic views of a cleaning apparatus for explaining a method of drying a wafer according to a second embodiment of the present invention.

This cleaning apparatus has a wafer holder 2a which is often used in an actual apparatus and holds the wafer 1 from below with three grooves. Further, a holder lifter 3a for raising the wafer holder 2a is provided in the apparatus, and the holder lifter 3a vertically moves between the cleaning tank 4 and the drying tank 5. Further, the holder lifter 3a has means for changing its moving speed as needed. Further, the wafer 1 is placed on the cleaning tank 4.
A fall prevention tool 7b is provided to prevent the wafer 1 from falling when the wafer 1 is lifted by the wafer lifter 3b. The fall prevention tool 7b has means for changing the moving speed thereof as necessary, and prevents the fall from above by placing the upper portion of the wafer 1 in a groove. The configuration of the cleaning device other than these is the same as that of the first embodiment.

Next, an outline of a method for drying a wafer will be described. First, as shown in FIG. 2A, the wafer 1 is held vertically in the wafer holder 2a with respect to the bottom surface of the cleaning tank 4 (holding the wafer 1 upright). The wafer 1 is placed in the cleaning tank 4 and the wafer 1 is cleaned with the cleaning liquid 6.

Next, when the cleaning of the wafer 1 is completed, the wafer 1 in the cleaning tank 4 is raised together with the wafer holder 2a at a predetermined high speed by the holder lifter 3a.
Start drying. This high-speed rise is performed at a high speed (however, a constant speed) within a range in which drying can be performed when the wafer 1 passes over the liquid surface, and the falling prevention device 7b waiting in the drying tank 5 transfers the wafer 1 to the falling prevention device 7b. Continue until the top contacts. At this time, the wafer lifter 3b is
Raise as in a.

Thereafter, as shown in FIG. 2 (b), when the contact portion comes close to the liquid level, the rising speed of the wafer lifter 3b is made faster than the predetermined high speed. This speed is set such that the upper end of the wafer 1 comes into contact with the fall prevention tool 7b and the wafer lifter 3b comes into contact with the lower end of the wafer 1 at the same time.

Next, the upper end of the wafer 1 is placed on the fall prevention device 7b.
Touching (operation of the fall prevention device). Then, the wafer 1 is supported by the preventing member 7b so as not to fall down. At the same time, a wafer lifter 3b is
Contact. Then, the wafer 1 is held by the wafer lifter 3b. At this time, the fall prevention device 7b is raised at a predetermined high speed in the same manner as the wafer lifter 3b, the lifting speed of the wafer lifter 3b is returned to the predetermined high speed, and the lifting speed of the holder lifter 3a is further reduced. Slower than a predetermined high speed. As a result, the wafer 1 is held between the wafer lifter 3b and the fall prevention device 7b. Then, as shown in FIG. 2C, the wafer 1 is separated from the wafer holder 2a and is brought into a non-contact state with the wafer holder 2a. At this time, the lifting speed of the holder lifter 3a is returned to the predetermined high speed.

The reason why the support of the wafer 1 is transferred from the wafer holder 2a to the wafer lifter 3b is to facilitate drying of the contact portion with the wafer 1. That is, both the wafer holder 2a and the wafer lifter 3b have a groove-shaped contact portion with the wafer 1. However, the groove of the wafer holder 2a is narrower than the groove of the wafer lifter 3b because the groove also serves to prevent the wafer 1 from falling down. Therefore, the wafer 1 is placed on the wafer holder 2a.
Holding the wafer 1 on the wafer lifter 3b.
Holds the wafer 1 more easily.

Thereafter, as shown in FIG. 2D, before the contact portion between the wafer 1 and the wafer lifter 3b reaches the liquid level, the raising of the wafer 1 at a predetermined high speed is completed. The deceleration of the rising speed of the wafer lifter 3b, the holder lifter 3a, and the fall prevention tool 7b is started. On this occasion,
Each of the lifters 3b, 3a and the preventer 7b has the same ascending speed.

Next, as shown in FIG. 2E, when the contact portion between the wafer 1 and the wafer lifter 3b reaches the liquid surface, the wafer 1 is lifted as in the first embodiment. The speed reduction is ended, and the wafer 1 is raised at a low speed within a range where the contact portion can be dried. However, the speed is constant.

Thereafter, as shown in FIG. 2 (f), when the wafer 1 reaches a predetermined position in the drying tank 5, the low-speed rise of the wafer lifter 3b is stopped, and the drying is terminated.

The same effects as in the first embodiment can be obtained in the second embodiment.

In the second embodiment, the holder lifter 3a for raising the wafer holder 2a is provided separately from the wafer lifter 3b. However, in order to simplify the structure of the apparatus, the wafer lifter 3b is used. And fall prevention device 7b
It is also possible to adopt a configuration in which the wafer holder 2a is raised only by the holder lifter 3a without using the above. However, as described above, since the groove of the wafer holder 2a is poorly drained, the rising speed when the groove (that is, the contact portion between the wafer 1 and the wafer holder 2a) passes through the liquid surface uses the wafer lifter 3b. It must be slower than in this case, in which case the throughput is slightly reduced. If the contact portion has a distance to the lower end of the wafer after passing through the liquid surface, it is preferable to increase the speed again in order to increase the throughput.

[0032]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 3 is a perspective view illustrating a cleaning apparatus according to an embodiment of the present invention.

The cleaning device 20 has a substantially rectangular parallelepiped cleaning tank 4 having a substantially rectangular parallelepiped shape as a whole and located below the center of the device. The cleaning tank 4 is fixed, and the inside of the cleaning tank 4 is filled with a cleaning liquid 6 for cleaning the wafer 1 during cleaning. This cleaning liquid 6 is applied to the wafer 1
Is a chemical solution for removing organic contamination, metal contamination, particles and the like from water, or pure water (water).

A drying tank 5 for drying the wafer 1 is provided on the cleaning tank 4, and the inside of the drying tank 5 is filled with a dry gas 5a for drying the wafer 1 during drying. A cylinder 14 is attached to the drying tank 5, and the drying tank 5 is separated from the cleaning tank 4 by the cylinder 14.
Can be slid upward. A vertical cylinder 15 is attached to the drying tank 5, and the vertical cylinder 15 allows the drying tank 5 to move up and down.

The cleaning apparatus 20 has a wafer lifter 3b having two grooves (not shown). The wafer lifter 3b is attached to one end of a rod 9b, and the other end of the rod 9b is attached to one end of a member 10b. The other end of the member 10b is attached to one end of a ball screw 12b, and the other end of the ball screw 12b is attached to a pulse motor 11b.

The wafer lifter 3b supports the wafer 1 from below by hanging the wafer 1 in the groove, and the ball screw 1 between the cleaning tank 4 and the drying tank 5 is driven by a pulse motor 11b.
2b, the member 10b, and the rod 9b are moved up and down. Further, the wafer lifter 3b has a means (not shown) that can change the moving speed as needed.

The cleaning apparatus 20 has two rod-shaped holder lifters 3a on which the wafer holder 2a is placed. The holder lifter 3a is attached to one end of a rod 9a, and the other end of the rod 9a is attached to one end of a member 10a. The other end of the member 10a is attached to one end of the ball screw 12a.
Is attached to the pulse motor 11a.

The holder lifter 3a is connected between the washing tank 4 and the drying tank 5 by a ball motor 12a by a pulse motor 11a.
a, up and down through the member 10a and the rod 9a. Further, the holder lifter 3a has means (not shown) capable of changing the moving speed thereof as required.

The cleaning device 20 has a fall prevention device 7b for preventing the wafer 1 supported by the wafer lifter 3b from falling. This fall prevention device 7b is a rod 9
The other end of the rod 9c is attached to one end of the member 10c. The other end of the member 10c is attached to the cylinder 13. Therefore, the fall prevention device 7b can be moved in the direction parallel to the liquid level on the washing tank 4 by the cylinder 13 through the rod 9c and the member 10c.

An operation panel 8 is mounted outside the cleaning device 20. The operation panel 8 is for inputting an operation command of the apparatus from an operator.

Next, the operation of the cleaning device 20 will be described with reference to FIG. This figure shows a state in which the operator has mounted the wafer holder 2a on which the wafer 1 is mounted on the holder lifter 3a. Further, the fall prevention device 7b and the drying tank 5 are on standby beside the cleaning tank 4, and the cleaning liquid 6 is supplied into the cleaning tank 4.

Here, when the operator gives a command to perform the cleaning operation of the wafer 1 by the operation panel 8, the ball screw 12a is driven by the pulse motor 11a, and the rod 9a is driven.
Then, the holder lifter 3a on which the wafer lifter 3b is placed is lowered through the member 10a. Then, the cleaning of the wafer 1 is started. Next, the cylinder 13 is driven, and the fall prevention device 7b moves above the wafer 1 through the rod 9c and the member 10c. In addition, the drying tank 5 is moved above the cleaning tank 4 by driving the cylinder 14, and thereafter, the drying tank 5 is lowered by driving the vertical cylinder 15. Thereby, a room in which the washing tank 4 and the drying tank 5 are vertically connected as shown in FIG. 2 is formed.

Thereafter, the wafer 1 is cleaned by changing the cleaning liquid 6 several times. Next, the drying of the wafer 1 is started in the same manner as in the second embodiment. And FIG.
The pulse motors 11a and 11b are operated so that the holder lifter 3a and the wafer lifter 3b operate along (a) to (f).
11b is controlled to dry the wafer 1.

Here, the interlocking of the fall prevention tool 7b and the wafer lifter 3b (as shown in FIG.
Is interposed between the wafer lifter 3b and the fall prevention device 7b, and thereafter, when the fall prevention device 7b is raised at a predetermined high speed in the same manner as the wafer lifter 3b), the following is performed. That is, at the moment when the wafer lifter 3b rises and the lifter 3b contacts the wafer 1,
A configuration is such that a not-shown hooked portion of the member 10b is hooked on the member 10c, and the member 10b lifts the member 10c.
This makes it possible to raise the fall prevention device 7b at the same predetermined high speed as the wafer lifter 3b.

It is preferable that the liquid level during the drying operation is maintained at a constant level and the liquid is supplied by overflow. The overflow supply means that a discharge port (not shown) for discharging the cleaning liquid at the same height as the liquid level is provided in the cleaning tank 4, and the cleaning liquid is continuously supplied to the cleaning tank 4 and the cleaning liquid is discharged from the discharge port. This keeps the liquid level constant. Since the particles on the liquid surface are discharged from the outlet together with the cleaning liquid by the overflow supply, the overflow supply has an effect of preventing the particles from adhering to the wafer 1.

The washing and drying operations of the wafer are completed at this point, and the operation of taking out the wafer 1 and the wafer holder 2a is performed as follows.

After the cleaning liquid 6 is drained from the cleaning tank 4, the holder lifter 3a holding the wafer holder 2a, the wafer lifter 3b holding the wafer 1, and the fall prevention member 7b are lowered at the same speed. Next, when the holder lifter 3a is lowered to the position shown in FIG.
Only a is stopped. Then, the wafer 1 is transferred from the wafer lifter 3b to the holder lifter 3a.
Thereafter, the holder lifter 3a is lowered again at the same speed as the wafer lifter 3b. At this time, since the fall prevention device 7b has already reached the lower end, it is left behind. The falling end of the fall prevention device 7b is the position of the fall prevention device 7b shown in FIG. 2A, and the prevention device 7b does not move below the lower end. Thereafter, each of the wafer lifter 3b and the holder lifter 3a also descends to the lower end and stops.

Next, after the drying tank 5 is raised by the vertical cylinder 15, the drying tank 5 is moved by the cylinder 14 to the cleaning tank 4.
To the initial state shown in FIG. Also, the fall prevention device 7b is returned to the initial state shown in FIG.

After returning to the state shown in FIG. 3 in this way, the operator operates the cleaned wafer 1 and the wafer holder 2.
is removed, and the washing operation is completed.

[0050]

As described above, according to the present invention, the speed at which the portion holding the wafer passes through the liquid surface of the cleaning liquid is set to be higher than the speed at which the portion other than the portion held passes. I'm late. Therefore, it is possible to provide a cleaning apparatus and a cleaning method capable of drying a wafer with high throughput and efficiently cleaning the wafer.

[Brief description of the drawings]

FIGS. 1A to 1D are schematic views of a cleaning apparatus for explaining a method of drying a wafer according to a first embodiment of the present invention.

FIGS. 2A to 2F are schematic views of a cleaning apparatus for explaining a wafer drying method according to a second embodiment of the present invention.

FIG. 3 is a perspective view illustrating a cleaning apparatus according to an embodiment of the present invention.

FIGS. 4A and 4B are schematic views of a cleaning apparatus for explaining a conventional wafer drying method.

[Description of Signs] 1 wafer, 2a wafer holder, 3a holder lifter, 3b wafer lifter, 4 cleaning tank, 5 drying tank, 5a dry gas, 6 cleaning liquid, 7b fall prevention tool , 8 ... operation panel, 9a-9c ... rod, 10a-10c
... members, 11a, 11b ... pulse motors, 12a, 12
b: Ball screw, 13, 14: Cylinder, 15: Vertical cylinder, 20: Cleaning device, 112: Wafer lifter,
113 cleaning tank, 114 cleaning liquid, 115 drying tank, 1
16 ... Dry gas.

Claims (3)

[Claims] A cleaning unit having a cleaning liquid for cleaning the wafer; a drying unit for drying the cleaned wafer; a moving unit for holding and moving the wafer from the cleaning unit to the drying unit; By moving the wafer, when drying the wafer, the speed at which the portion where the wafer is held passes through the liquid surface of the cleaning liquid is slower than the speed at which the portion other than the held portion passes. A cleaning device, comprising: 2. A cleaning device having a cleaning solution for cleaning a wafer, a drying device for drying a wafer after cleaning, and a moving device for holding and moving the wafer from the cleaning device to the drying device. A cleaning method for cleaning the wafer, comprising: a cleaning step of cleaning the wafer with the cleaning liquid; and moving the wafer by the moving unit and drying the wafer. A step of lowering the speed at the time of passing through the liquid surface from the speed at the time of passing through a portion other than the held portion. 3. The cleaning method according to claim 2, wherein the cleaning step includes a step of cleaning with a chemical solution, and a step of replacing the chemical solution with water and cleaning with water.