KR20040097602A - The Wafer cleaning method and equipment, which is by spin scrubber - Google Patents

Abstract

PURPOSE: An apparatus and method for cleaning a semiconductor wafer using a spin scrubber are provided to improve cleaning effect and to reduce cleaning time by using the first injector and the second injector. CONSTITUTION: An apparatus for cleaning a semiconductor wafer includes the first injector, a brush, and the second injector. The first injector(15) is used for spraying deionized water on a wafer(22). The brush(20) is used for cleaning the wafer by moving to and fro. The second injector(19) is used for spraying chemicals on the wafer. Ozone water or diluted HF is used as the chemicals.

Description

Semiconductor wafer cleaning apparatus and cleaning method by spin scrubber {The Wafer cleaning method and equipment, which is by spin scrubber}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for cleaning a semiconductor wafer by a spin scrubber and a cleaning method using the same. In particular, the apparatus for cleaning and cleaning a semiconductor wafer can increase the cleaning effect on the wafer and at the same time shorten the cleaning time. It is about a method.

Recently, as semiconductor devices have been highly integrated, patterns of circuits to be implemented on wafers have also become smaller. Thus, the pattern on the wafer can cause defects in the semiconductor device even by very fine particles. Accordingly, the importance of the cleaning process is becoming more and more important. One of the methods generally used in such a cleaning process is a method of removing foreign matter on the wafer by using a spin scrubber.

The spin scrubber is mainly used to remove particles on the wafer before depositing the CVD film, or to remove particles by slurry that are not easily removed after a chemical mechanical polishing (CMP) process. It is mainly used in the late process of wafer manufacture.

On the other hand, the spin scrubber uses a method of cleaning the wafer by spraying DI water on the wafer by various physical transfer methods while rotating the wafer. Such a method of cleaning a wafer by a spin scrubber is a method of spraying and cleaning high-pressure pure water on a wafer at high speed, a method of spraying pure water on a wafer, and a method of cleaning the pure water by pushing a brush on the wafer, and spraying the wafer. There is a method of cleaning a wafer by applying ultrasonic waves to purified water.

This prior art wafer cleaning apparatus includes an ultrasonic oscillator for applying ultrasonic waves to the pure water injected by the high pressure injector. That is, the conventional apparatus for cleaning a semiconductor wafer by a spin scrubber uses ultrasonic waves to clean the wafer or the pure water sprayed by a high pressure injector by the pure water sprayed at a high speed or the brush horizontally moving on the wafer through the process described above. The wafer is cleaned by applying.

However, when the wafer is cleaned with pure water applied with high pressure or ultrasonic waves in this manner, particles that are simply attached to the surface of the wafer can be removed, but the particles are strongly bonded to the oxide film on the front or rear surface of the wafer, or the pattern is removed. If organic matter is strongly attached to the entire surface of the formed wafer, it cannot be effectively removed within a short time. These particles or organics may cause defects in the wafer, such as lowering the uniformity of the film quality in the subsequent process or causing film film feeling.

In accordance with the problems of the prior art, there is an urgent need for a semiconductor wafer cleaning apparatus and a method for cleaning the particles or organic matter strongly attached to the wafer in a short time.

The present invention is to solve the problems of the prior art as described above, an object of the present invention is to completely remove particles and organic matter strongly attached to the front and back of the wafer in a short time, thereby improving the cleaning efficiency for the wafer SUMMARY OF THE INVENTION An object of the present invention is to provide a cleaning device for a semiconductor wafer by a spin scrubber and a cleaning method using the same.

1 is a schematic block diagram showing an embodiment of a semiconductor wafer cleaning apparatus using a spin scrubber of the present invention.

-Explanation of symbols for the main parts of the drawing-

10: pure water source 11: chemical liquid source

16 filter 18 solenoid valve

15: first injector 17: driving source

19: second injector 20: brush

22: wafer

In order to achieve the above object, the present invention includes a first injector for spraying pure water on the wafer, a brush for cleaning the wafer by performing a horizontal motion on the wafer and a second injector for spraying the chemical liquid on the wafer A semiconductor wafer cleaning apparatus is provided.

The present invention also provides a method of cleaning a semiconductor wafer by a spin scrubber comprising a first cleaning step of cleaning the wafer by spraying a chemical solution on the wafer and a second cleaning step of cleaning the wafer by spraying pure water on the wafer. To provide.

According to such a wafer cleaning apparatus and a cleaning method of the present invention, by cleaning the wafer using a chemical solution together with the pure water used for the wafer cleaning in the prior art, even particles and organic matter strongly adhered to the surface of the wafer within a short time Effective removal can significantly reduce the cleaning time for the wafer and at the same time significantly increase the cleaning efficiency for the wafer.

In the wafer cleaning apparatus and the cleaning method according to the present invention, it is preferable to use ozone water or dilute hydrofluoric acid as the chemical liquid. Such materials can completely remove organic matter and particles attached to the surface of the wafer in a short time. In particular, when ozone water is used to clean the entire surface of the wafer on which the pattern is formed, the surface of the roughened oxide film may be regenerated and maintained uniformly by excessive etching, and in case of dilute hydrofluoric acid, the natural oxide film formed on the rear surface of the wafer may be removed. In this way, even particles strongly bound to the native oxide film can be completely removed.

Further, in the wafer cleaning method of the present invention, the first cleaning step of cleaning the wafer using pure water is a step of spraying and washing pure water on the wafer at high speed and the pure water injected onto the wafer on the wafer as in the prior art. And a step of cleaning by pushing with a brush formed in the brush and applying or washing ultrasonic waves to pure water sprayed on the wafer. That is, in the cleaning method of the present invention, the organic matter and the natural oxide film attached to the front and rear surfaces of the wafer are removed through the chemical solution, and then, as in the conventional art, pure water is sprayed at high speed, or pure water sprayed on the wafer is brushed. By cleaning the wafer using the method, it is possible to completely remove particles and organic matter strongly adhered to the native oxide film in a short time.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram which shows an example of the semiconductor wafer cleaning apparatus by the spin scrubber of this invention.

Referring to this, the apparatus for cleaning a semiconductor wafer according to the embodiment of the present invention includes a pure water source 10 for supplying pure water, a filter 12 for removing impurities by filtering pure water supplied by the pure water source 10 once more, and pure water. A solenoid valve 14 for adjusting the amount of water, a first injector 15 for spraying pure water on the wafer 22 at high speed, and a brush 20 for cleaning the wafer 22 by performing horizontal motion on the wafer 22. , A driving source 17 for controlling the horizontal movement of the brush 20, an ultrasonic oscillator (not shown) for applying ultrasonic waves to the pure water sprayed through the first injector 15, and a chemical liquid supply source 11 for supplying a chemical liquid. A filter 16 for filtering impurities contained in the chemical liquid supplied by the chemical liquid source 11, a solenoid valve 18 for adjusting the amount of the chemical liquid, and a second injector 19 for injecting the chemical liquid onto the wafer 22. And so on.

The operation of the semiconductor wafer cleaning apparatus according to the embodiment of the present invention will now be described.

First, pure water supplied from the pure water source 10 passes through the first filter 12. Subsequently, pure water passing through the first filter 12 is sequentially injected through the first solenoid valve 14 and the first injector 16, and is sprayed onto the cleaning wafer 22 having a specific pattern formed thereon.

In addition, the chemical liquid supplied from the chemical liquid source 11 passes through the second filter 16. Subsequently, the chemical liquid passing through the second filter 16 is sequentially injected through the second solenoid valve 18 and the second injector 19 and sprayed onto the cleaning wafer 22 having a specific pattern formed thereon.

In addition, on the wafer 22, a brush 20 which horizontally moves around the center and the periphery of the wafer 22 by the driving of the driving source 17 is positioned. The brush 20 and the wafer 22 are kept facing each other with a gap Gap of about 0.2 mm.

Referring to the process of cleaning the wafer according to this configuration, first, the foreign matter contained in the pure water is removed by passing the pure water supplied from the pure water source 10 through the first filter 12. Subsequently, the filtered pure water is passed through the first solenoid valve 14 to adjust the amount thereof and to spray the high speed water on the cleaning wafer 22 through the first injector 16. At this time, the brush 20 performs the movement on the wafer 22 by driving the drive source 17 to clean the wafer 22 rotating on the rotary chuck.

On the other hand, although not shown in Figure 1, it includes an ultrasonic oscillator for applying ultrasonic waves to the pure water. That is, through the process described above, the wafer is cleaned by washing the wafer with a high speed sprayed pure water or a brush moving horizontally on the wafer, or by applying ultrasonic waves to the pure water sprayed by the high pressure injector.

However, when the wafer is cleaned with pure water applied with high pressure or ultrasonic waves in this manner, particles that are simply attached to the surface of the wafer can be removed, but the particles are strongly bonded to the oxide film on the front or rear surface of the wafer, or the pattern is removed. If organic matter is strongly attached to the entire surface of the formed wafer, it cannot be effectively removed within a short time.

Thus, the chemical liquid is pre-cleaned by supplying the chemical liquid to the wafer 22 which has been cleaned with pure water in order to remove the organic matter strongly adhered to the entire surface of the wafer before the pure water is sprayed to clean the wafer.

The process of supplying the chemical liquid to the wafer is as follows.

The filter 16 filters the chemical liquid supplied as the chemical liquid source 11 to remove foreign substances contained in the chemical liquid, and adjusts the amount of the chemical liquid to be supplied by the solenoid valve 18. Thereafter, the second injector 19 sprays the chemical liquid passed through the solenoid valve 18 onto the wafer 22.

It is preferable to use ozone water or dilute hydrofluoric acid as the chemical liquid injected by the second injector 19.

Of these, ozone water is preferable for cleaning the entire surface of the wafer. Conventionally, not only pure water but also an organic solvent has been used to clean the entire surface of the wafer. However, when the cleaning using the organic solvent is performed, organic matter remains on the wafer due to the limitation of the cleaning ability. In the process, defects in the uniformity of the oxide film are caused, or peeling of the oxide film is caused. In contrast, ozone water can completely remove the organic matter remaining on the wafer, and regenerate the surface of the oxide film roughened by excessive etching, thereby maintaining the surface of the wafer on which the oxide film is formed uniformly. Moreover, ozone water is a small amount of ozone dissolved in water, and unlike organic solvents, there is no fear of causing environmental pollution.

On the other hand, a large amount of particles generated during the previous process can be attached to the back of the wafer, these particles are strongly adhered by the natural oxide film over time is not removed by the physical force of pure water. Therefore, it is preferable to use dilute hydrofluoric acid in cleaning the back side of the wafer. These particles can be completely removed by completely removing the native oxide film using hydrofluoric acid and then cleaning the wafer backside with pure water.

In addition, the cleaning of the entire surface of the wafer may cause damage to other metal materials or oxide films. Therefore, it is not easy to apply other chemicals other than pure water or ozone water, but the back surface of the wafer may be damaged. Therefore, other cleaning liquids such as SC1 and the like may be used.

That is, the semiconductor wafer cleaning apparatus of the present invention has a second injector for injecting such a chemical liquid onto the wafer. Hereinafter, the wafer cleaning method of the present invention for cleaning the wafer through the wafer cleaning apparatus of the present invention. An example of the will be described in detail.

As described above, in the wafer cleaning method of the present invention, first, a first cleaning step of cleaning the wafer by spraying a chemical liquid on the wafer is performed. In the first cleaning step, ozone water or dilute hydrofluoric acid is used as the chemical liquid. In particular, it is preferable to use ozonated water for cleaning the entire surface of the wafer and dilute hydrofluoric acid for cleaning the rear surface.

Such a chemical liquid is first supplied from the chemical liquid supply source 11 and undergoes a filtering process for removing foreign substances contained in the chemical liquid. The filtered chemical liquid is passed through the second solenoid valve 18 to adjust the amount thereof, and then injected onto the wafer 22 through the second injector 19. In this way, the chemical liquid is injected onto the wafer 22 to clean the wafer 22.

Subsequently, a second cleaning step of the wafer using pure water is performed. Such pure water is supplied from the pure water source 10 and undergoes a filtering process for removing foreign matters contained in the pure water. The filtered pure water is passed through the first solenoid valve 14 to adjust the amount thereof and to spray the high speed water on the cleaning wafer 22 through the second injector 16. At this time, the brush 20 performs the movement on the wafer 22 by driving the drive source 17 to clean the wafer 22 rotating on the rotary chuck.

In addition, the wafer 22 is cleaned by washing the wafer 22 or applying ultrasonic waves to the pure water injected by the first injector by the brush 20 moving horizontally on the wafer 22 or the pure water jetted at a high speed.

The semiconductor wafer cleaning apparatus and the cleaning method according to the embodiment of the present invention having the above configuration are mainly used in the latter process of wafer fabrication, and the front and rear surfaces of the wafer are cleaned after the CVD process, the CMP process, or the etching process. It can be used to

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

According to the present invention, particles and organic substances strongly attached to the front and rear surfaces of the wafer can be completely removed within a short time, thereby improving the cleaning efficiency of the wafer, and by using a spin scrubber that can significantly shorten the cleaning time. A cleaning apparatus for a semiconductor wafer and a cleaning method using the same can be provided.

Therefore, the particles or organics are not completely removed, thereby preventing the uniformity of the semiconductor device from being lowered, and the cost of the semiconductor manufacturing process can be reduced by shortening the cleaning time, while at the same time improving the reliability of the semiconductor device manufactured. Can be improved.

Claims (7)

A first injector for spraying pure water on the wafer at high speed, A brush for cleaning the wafer by performing horizontal motion on the wafer and A second injector for injecting a chemical into the wafer Semiconductor wafer cleaning apparatus comprising a. The semiconductor wafer cleaning apparatus of claim 1, wherein ozone water or dilute hydrofluoric acid is used as the chemical liquid. The method of claim 1 or 2, And an ultrasonic oscillator for applying ultrasonic waves to the pure water sprayed through the first injector. A first cleaning step of cleaning the wafer by spraying a chemical solution on the wafer and And a second scrubbing step of cleaning the wafer by spraying pure water on the wafer. 5. The method of claim 4, wherein the first cleaning step comprises spraying and washing pure water on the wafer at a high speed, cleaning the pure water sprayed on the wafer with a brush formed on the wafer, and applying ultrasonic waves to the pure water sprayed on the wafer. A semiconductor wafer cleaning method comprising any one or more steps selected from cleaning steps. The semiconductor wafer cleaning method according to claim 4 or 5, wherein ozone water or dilute hydrofluoric acid is used as the chemical liquid. The method of claim 4, wherein the CVD process, the CMP process, or the etching process is performed before the first cleaning step.