JPH05275408A - Cleaning device for planar substrate - Google Patents

Abstract

PURPOSE:To clean the whole surface of a planar substrate such as wafer uniformly and efficiently at the time of cleaning the substrate by injecting a cleaning solvent while rotating the planar substrate such as wafer. CONSTITUTION:A wafer 1 is held and rotated by a spin chuck 12 and a cleaning solvent 4 is injected to the surface of the wafer 1 by an injection nozzle 20 while the injection nozzle 20 is caused to travel in the manner of scanning the radial direction of the wafer 1. The rotational speed of the wafer 1 and the travelling speed of the injection nozzle 20 are related to each other and controlled by a controller 40. Also, an ultrasonic vibration is given by an ultrasonic generator 34 to the cleaning solvent 4 to be supplied to the injection nozzle 20. Thus, the whole surface of the wafer 1 is cleaned uniformly and efficiently.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning device for spraying a cleaning liquid while rotating various types of flat substrates to clean the substrates, and for example, a cleaning device optimal for cleaning a wafer which is a semiconductor substrate. Regarding

[0002]

2. Description of the Related Art It is no exaggeration to say that the product yield of semiconductor devices depends on the adhesion of dust or the like to the wafer in each processing step. Therefore, it is necessary to sufficiently clean the wafer before and after each processing step with various chemicals or cleaning solutions such as pure water. As one of such wafer cleaning apparatuses, conventionally, a single wafer cleaning apparatus for cleaning wafers one by one has been known. This single-wafer cleaning apparatus cleans a wafer by immersing the wafers one by one in a cleaning tank filled with a cleaning liquid and dipping or rocking the wafer in the cleaning liquid. However, in the above-mentioned single-wafer cleaning apparatus, the cleaning effect is not always sufficient because the wafer is only immersed or swung in the cleaning liquid.

Therefore, a spin single-wafer cleaning device as shown in FIG. 3 has been proposed. That is, the wafer 1 is held and rotated by the spin chuck 2, and the cleaning liquid 4 is sprayed from the spray nozzle 3 toward the center of the surface of the wafer 1. According to this, since the surface of the wafer 1 is cleaned by the sprayed cleaning liquid 4, the cleaning is more effective than the general single-wafer cleaning in which the wafer 1 is immersed or swung in the cleaning liquid. It can be performed.

[0004]

However, in the conventional spin single-wafer cleaning apparatus as described above, the cleaning liquid 4 is sprayed only on the central portion of the surface of the wafer 1, and the cleaning liquid 4 is sprayed on the peripheral portion of the wafer 1. There is a problem that uneven cleaning is likely to occur at each position in the radial direction because it only flows due to the centrifugal force of the rotation. That is, as the wafer 1 rotates, the rotation speed increases toward the outer peripheral portion, so that the cleaning liquid 4 sprayed to the central portion is suddenly scattered outward. In addition, since the diameter of the wafer 1 tends to increase in recent years, the difference in rotational speed between the central portion and the outer peripheral portion increases, and the uneven cleaning becomes more noticeable.

If the cleaning liquid 4 is jetted for a long time so that the outer peripheral portion of the wafer 1 is also sufficiently washed, there arises a problem that the washing time becomes long and the working efficiency is significantly lowered. Further, in order to increase the injection pressure of the cleaning liquid 4, a high-pressure and large-sized injection pump is required, which causes a problem of increasing the size of the entire apparatus and increasing the cost.

In view of the above, the present invention has made it possible to uniformly and efficiently clean the entire surface of a substrate when the cleaning liquid is sprayed while rotating a planar substrate such as a wafer. An object of the present invention is to provide a cleaning device for a flat substrate.

[0007]

In order to achieve the above object, a flat substrate cleaning apparatus according to the present invention comprises a rotation driving means for rotating a flat substrate to be cleaned in its plane, and a surface of the substrate. An injection nozzle that injects cleaning liquid into the
A cleaning liquid supply unit that supplies a cleaning liquid to the spray nozzle at a predetermined pressure and a spray nozzle moving unit that moves the spray nozzle along the radial direction of the rotation of the substrate are provided.

[0008]

According to the present invention configured as described above, the flat substrate is rotated by the rotation driving means, and the jet nozzle moving means moves the jet nozzle in the radial direction by the rotation of the substrate, while the cleaning liquid supply means is used. The supplied cleaning liquid is sprayed from the spray nozzle onto the surface of the substrate. As a result, the cleaning liquid is sprayed so as to scan the rotating substrate in the radial direction, so that the entire surface of the substrate is uniformly and efficiently cleaned.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a wafer cleaning apparatus will be described below with reference to FIGS. FIG. 1 is a schematic configuration diagram of the entire apparatus, and FIG. 2 is a schematic perspective view of an injection nozzle moving means.

First of all, as shown in FIG.
0 is configured to spray the cleaning liquid 4 onto the surface of the wafer 1 for cleaning while rotating the wafer 1 in the cleaning cup 11. The cleaning cup 11 is formed in a flat circular shape, and the spin chuck 12 is arranged inside the cleaning cup 11. The spin chuck 12 holds the wafer 1 in a vacuum state or mechanically holds it horizontally, and is fixed to the upper end of a rotary shaft 13 that passes through the lower portion of the cleaning cup 11. Then, the rotation shaft 13, that is, the spin chuck 12 is rotationally driven by the motor 14 at, for example, about 200 to 300 rpm.

Next, a circular opening 15 for attaching and detaching the wafer is provided on the upper portion of the cleaning cup 11, and this opening 15 is formed.
An injection nozzle 20 is inserted therein, and is configured to be reciprocally movable in the directions of arrows a and b which are the radial direction of the wafer 1. As shown in FIG. 2, the injection nozzle 20 has a clamp 21.
Is vertically fixed to one end of the moving member 22, and the moving member 22 is supported by a guide portion 23 so as to be movable in the longitudinal direction (radial direction of the wafer 1). A rack 24 is formed on the upper surface of the moving member 22.
A pinion 26 that is rotationally driven by a motor 25 is meshed with the. Therefore, the forward / reverse rotation of the motor 25 causes the moving member 22, that is, the injection nozzle 20 to reciprocate along the radial direction of the wafer 1.

As shown in FIG. 1, the cleaning liquid supply means for supplying the cleaning liquid 4 to the jet nozzle 20 has a tank 31 for storing the cleaning liquid 4 and a pipe 3 for pressurizing the cleaning liquid 4.
Injection pump 33 which supplies the injection nozzle 20 via 2
And an ultrasonic generator 34 that applies (places) ultrasonic vibration to the cleaning liquid 4 in the middle of the pipe 32. The injection pump 33 supplies the cleaning liquid 4 to, for example, 1-2.
Pressurize to about kg / cm ² . Further, the ultrasonic generator 34 generates ultrasonic waves of 30 to 60 kHz, for example, and applies high frequency vibration to the cleaning liquid 4.

Further, a motor 14 for rotating the spin chuck 12 and a motor 25 for moving the jet nozzle 20.
And are configured to be controlled in relation to each other by the control unit 40. That is, since the rotation speed of the wafer 1 increases toward the outer peripheral portion, the moving speed of the ejection nozzle 20 decreases toward the outer peripheral portion. The control unit 40 may be a unit that integrally controls the entire apparatus, and includes the injection pump 33 and the ultrasonic generator 34.
The operation control of the above can also be performed by the control unit 40.

In the cleaning apparatus configured as described above, the wafer 1 is held by the holding means (not shown) and inserted into the cleaning cup 11 through the opening 15, and the wafer 1 is held on the spin chuck 12. .. At this time, the spray nozzle moving means is retracted above the cleaning cup 11 so as not to interfere with the wafer 1. The wafer 1 may be attached to and detached from the spin chuck 12 by dividing the cleaning cup 11 into upper and lower parts or left and right parts. In this case, a slit-shaped opening is provided on the upper part of the cleaning cup 11 to insert the injection nozzle 20. You should let me.

After the wafer 1 is held on the spin chuck 12, the motor 14 is rotated and the spin chuck 12 is rotated.
That is, the wafer 1 is rotationally driven. When the rotation becomes constant, the injection pump 33 and the ultrasonic generator 34 are operated to pressurize and the ultrasonic vibration is applied to the cleaning liquid 4.
Is supplied to the injection nozzle 20, the motor 25 is rotated, and the injection nozzle 20 is reciprocated in the directions of arrows a and b. As a result, while the jet nozzle 20 is reciprocatingly moved so as to scan the rotating wafer 1 in the radial direction, the cleaning liquid 4 to which ultrasonic vibration is applied is ejected to the jet nozzle 20.
Is sprayed toward the surface of the wafer 1 to clean the wafer 1. The cleaning liquid 4 after cleaning is the cleaning cup 11
It is discharged to the outside of the cleaning cup 11 through an appropriate number of discharge ports 16 provided in the lower part of the.

As described above, since the cleaning liquid 4 is sprayed so as to scan the rotating wafer 1 in the radial direction, the cleaning liquid 4 can be directly applied to each position of the wafer 1 in the radial direction, and the surface of the wafer 1 is exposed. The whole can be washed extremely uniformly and efficiently. The movement of the spray nozzle 20 may be repeated by one-way movement, reciprocating movement, and reciprocating movement, depending on the type of the wafer 1 and cleaning. Then, as in the case of spraying the cleaning liquid 4 only on the central portion of the wafer 1,
Since it is not necessary to lengthen the injection time or increase the injection pressure, the cleaning time can be greatly shortened and the injection pump 33 can be a low pressure and small one.

Further, since the rotation speed of the wafer 1 increases toward the outer peripheral portion, if the moving speed of the spray nozzle 20 is constant, the irradiation amount of the cleaning liquid 4 per unit area decreases toward the outer peripheral portion. .. Therefore, the control unit 40 slows the moving speed of the spray nozzle 20 in relation to the rotation speed of the wafer 1 toward the outer peripheral portion, so that the cleaning liquid 4 is sprayed per unit area at each position in the radial direction of the wafer 1. The amount can be constant.

Further, since ultrasonic vibration is applied to the cleaning liquid 4 to be sprayed, the high frequency vibration can remove fine particles which cannot be removed by merely spraying the cleaning liquid 4, and the cleaning liquid 4 can be removed. Occurrence of cavitation can also be prevented. Therefore, extremely effective cleaning can be performed without accidentally damaging the wafer 1.

When the jet nozzle 20 is moved in the radial direction of the wafer 1, the jet nozzle 20 may be swung about the upper end portion or the central portion thereof, but the jet nozzle 20 may be moved as in the above embodiment. When moved in the vertical state, the distance between the spray nozzle 20 and the wafer 1 and the spray angle with respect to the wafer 1 are always constant, so that the cleaning liquid 4 can be constantly applied to the wafer 1 at a constant pressure and amount. Uniform cleaning can be performed.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various effective modifications and applications are possible based on the technical idea of the present invention. .. For example, various structures can be used as the structure of the ejection nozzle moving means other than the embodiment. Further, the present invention can be applied to various types of planar substrate cleaning apparatuses other than the wafer cleaning apparatus, and the shape of the substrate can be rectangular as well as circular. The term "cleaning" as used in the present invention is not limited to removing dust and the like adhering to the substrate, but also includes various chemical cleaning such as etching.

[0021]

As described above, according to the present invention,
When cleaning the substrate by spraying the cleaning liquid from the spray nozzle while rotating the flat substrate, the spray nozzle is moved so as to scan in the radial direction due to the rotation of the substrate, so that the entire surface of the substrate is extremely uniform. It can be cleaned efficiently and efficiently. In addition, the cleaning time can be significantly shortened, and a low-pressure and small-sized cleaning liquid injection pump can be used. Therefore, the cleaning efficiency can be significantly improved, and the overall size and cost of the apparatus can be reduced. be able to.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an entire apparatus in an embodiment in which the present invention is applied to a wafer cleaning apparatus.

FIG. 2 is a schematic perspective view of an injection nozzle moving means in the above embodiment.

FIG. 3 is a schematic view of a conventional spin single wafer type wafer cleaning apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wafer 4 Cleaning liquid 10 Cleaning device 11 Cleaning cup 12 Spin chuck 14 Wafer rotating motor 15 Opening 20 Injection nozzle 22 Moving member 25 Nozzle moving motor 33 Injection pump 34 Ultrasonic generator 40 Control unit

Claims (3)

[Claims] 1. A rotary drive means for rotating a planar substrate to be cleaned in its plane, an injection nozzle for injecting a cleaning liquid onto the surface of the substrate, and a cleaning liquid supply for supplying the cleaning liquid to the injection nozzle at a predetermined pressure. An apparatus for cleaning a planar substrate, comprising: means and an ejection nozzle moving means for moving the ejection nozzle in a radial direction by rotation of the substrate. 2. A control means for controlling the rotational speed of the substrate by the rotary drive means and the moving speed of the jet nozzle by the jet nozzle moving means in association with each other. 1. The flat substrate cleaning apparatus according to 1. 3. The planar substrate cleaning apparatus according to claim 1, wherein the cleaning liquid supply unit has an ultrasonic generator for applying ultrasonic vibration to the cleaning liquid.