KR100875831B1 - Wet Cleaner for Semiconductor Devices - Google Patents

Abstract

Provided is a wet cleaning apparatus capable of improving the efficiency of a semiconductor wafer cleaning process.

The wet cleaning device provided rotates the wafer guide clockwise or counterclockwise to react the wafer seated or mounted on the wafer guide with a compound material or the like filled inside the cleaning bath.

The wet cleaning apparatus for a semiconductor process provided includes a wafer guide on which a wafer is mounted, a container for accommodating the wafer guide, and a motor having a rotating shaft, the rotating shaft being coupled to one side of the wafer guide to rotate the wafer guide.

The disclosed wet cleaning apparatus for semiconductor processing has the advantage of controlling the reaction process with the chemical reacting with the wafer according to the process content by controlling the rotational speed of the wafer guide using a motor.

Description

Wet cleaning device for semiconductor devices {Wet station for semiconductor device}

1 is a schematic structural cross-sectional view of a reaction tank or a cleaning tank that is an essential component of a wet cleaning equipment generally used.

2 is a schematic structural cross-sectional view of a reaction tank or a cleaning tank that is an essential component of the wet cleaning equipment proposed in the present invention.

3 and 4 are diagrams illustrating a motor-controlled wafer guide and a wafer mounting structure on the wafer guide proposed in the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer cleaning apparatus for use in semiconductor processes, and more particularly to wet stations for semiconductor processes.

The cleaning process of the semiconductor manufacturing process is a very important process, which is the first and the last of the semiconductor manufacturing process.

The cleaning process is classified into a wet cleaning method and a dry cleaning method, but the wet cleaning method will be described in the present invention.

First, the possible processes of the semiconductor wet process are listed below.

1. Wafer cleaning process

2. wet etching process (metal, dielectric, silicon, etc)

3. PR removing process (polymer removing)

These processes are carried out in a wet station.

On the other hand, in order to prevent contamination of the wet cleaning device, it is common to use different wet cleaning devices depending on the type of chemicals used in the processes (1, 2, and 3).

First of all, the wafer cleaning process is based on the process announced by RCA in 1970, and is still based on this, and many other options are used. For this reason, the wafer cleaning process is sometimes called the RCA process.

As a simple RCA process, a combination of Piraha solution (Surfuric acid peroxide mixture (SPM) / Diluted HF (DHF) solution / rinse is often used. Additional processes may be added depending on the application. For reference, the CMOS class process is much more complicated and many processes are used.

Below, the types and names of chemical complexes commonly used in the wafer cleaning process are briefly listed.

Ammonia peroxide mixture (APM) NH4OH / H2O2 / H2O (DI) complex for removing particles

Surfuric acid peroxide mixture (SPM) H2SO4 / H2O2 / H2O (DI) complex for removing organics

Hydrochloric acid and peroxide mixture (HPM) HCl / H2O2 / H2O (DI) complex for removing metal particles

Diluted HF (DHF) HF / H2O (DI) complex for removing natural oxide and light metal

Piranha solution is used to remove organic matter and large dust on the wafer surface by mixing sulfuric acid (H2SO4) and hydrogen peroxide (H2O2) in an appropriate ratio.

DHF solution is diluted with hydrofluoric acid (HF) with DI water. Usually 1:10 to 1: 100. The DHF solution is used to remove the native oxide film and various metals on the wafer.

Subsequently, the next cleaning process is distilled water (DI water only), which consists of a DI shower (down flow) and a DI supply (up flow). In this way, particles on the wafer surface are removed.

Second, in the wet etching process, the chemicals used and the conditions vary depending on the material to be etched. In particular, in the case of metals used in most semiconductor processes, there is a specialized wet etching solution.

Finally, the PR removing process is a process of removing the photoresist (PR) used in the semiconductor process.

In general, PR can be easily removed with acetone, but PR is not easy to remove after plasma process. Therefore, depending on the purpose of use and the material to be used, it is possible to remove PR using Piranha or plasma ashing process.

The wet station in which this process is performed is largely composed of a reaction bath and a quick drain and rinse (QDR).

Reactors should be changed according to the type of chemical used, and quartz, teflon, stainless steel 316 (SUS 316), etc. are used.

The size of the bath is determined by the type of the process wafer, and a heating line, a drain line, and the like are mounted on the reactor. In addition, a temperature sensor and a capacitive sensor are essentially provided.

Meanwhile, most of the cleaning tanks are made of clean PVC, and are equipped with a DI nozzle and a snug plate large capacity drain valve.

Hereinafter, with reference to Figure 1 will be briefly described the principle of a conventional general wet cleaning equipment.

1 is a schematic cross-sectional view of a reaction tank or a cleaning tank, which is an essential component of a commonly used wet cleaning equipment.

In Fig. 1, the number "111" means a reaction tank or a cleaning tank (hereinafter, referred to as a cleaning tank for convenience of description) constituting the wet cleaning apparatus, the number "13" represents a wafer, and the number "121" represents a wafer. The wafer guide on which (13) is seated is shown. The cleaning tank 111 is filled with a predetermined compound quality according to the process step.

In relation to the cleaning process, conventionally, the wafer guide 121 seated inside the cleaning tank 111 is shaken up, down, front, back, left, or right to cause the wafer 13 to react with the compound in the cleaning tank 111. .

However, the conventional cleaning method of shaking the wafer 13 has a problem that the type of wafer that can be cleaned is limited depending on the size of the cleaning tank and the size of the wafer guide.

In addition, conventionally, a plate (not shown) on which the wafer guide 121 is mounted is constantly shaken up, down, front, rear, left, or right by using a mechanical device (not shown) such as a hydraulic cylinder.

For this reason, there was a problem that the agitation condition cannot be changed immediately due to the change in the type of the compound and the reaction condition in the cleaning tank 111 that reacts with the wafer 13 under the predetermined process conditions.

The present invention has been proposed in order to solve the conventional problems, to provide a wet cleaning apparatus that can improve the efficiency of the cleaning process.

To this end, an object of the present invention is to rotate the wafer guide in a clockwise or counterclockwise direction so that the wafer seated or mounted on the wafer guide reacts with a compound material filled in the cleaning tank.

In addition, the present invention aims to control the reaction speed between the wafer and the compound by controlling the rotational speed of the wafer guide.

A first embodiment of a wet cleaning apparatus for a semiconductor process according to the present invention includes a wafer guide on which a wafer is mounted, a container for accommodating the wafer guide, and a motor having a rotating shaft, wherein the rotating shaft is one side of the wafer guide. It is combined with, characterized in that for rotating the wafer guide.

In the first embodiment of the present invention, the vessel is characterized in that the reaction tank for reacting the wafer with a predetermined compound or a cleaning tank for cleaning the wafer with distilled water.

In the first embodiment of the present invention, the revolutions per minute of the motor is characterized in that it is adjustable.

A second embodiment of the wet cleaning apparatus for a semiconductor process according to the present invention includes a wafer guide, a cassette detachably mounted to the wafer guide, a cassette into which a wafer is inserted, a container for accommodating the wafer guide and the cassette; And a motor having a rotating shaft, wherein the rotating shaft is coupled to one side of the wafer guide to rotate the wafer guide.

In the second embodiment of the present invention, the vessel is characterized in that the reaction tank for reacting the wafer with a predetermined compound or a cleaning tank for cleaning the wafer with distilled water.

In a second embodiment of the present invention, the revolutions per minute of the motor is characterized in that it is adjustable.

In the second embodiment of the present invention, the cassette body is characterized in that a plurality of holes are formed for introducing the compound or distilled water in the container into the cassette.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 2 shows a first embodiment of the wet cleaning apparatus for semiconductor process proposed in the present invention.

In FIG. 2, the numeral "111" means a reaction tank or a cleaning tank (hereinafter, referred to as a cleaning tank for convenience of description) constituting the wet cleaning apparatus.

The number "13" represents a wafer, and the number "311" represents a wafer guide on which the wafer 13 is seated.

The wafer 13 is mounted to the fixing portions 20a and 20b formed on both sides of the wafer guide 311. That is, the wafer 13 is attached to the wafer guide 311 by the fixing parts 20a and 20b so that attachment and detachment are possible.

The wafer guide 311 equipped with the wafer 130 is accommodated in the cleaning tank 111 filled with a predetermined compound according to the process step.

On the other hand, one side of the top plate of the wafer guide 311 is coupled to the motor rotation shaft 223, the motor rotation shaft 223 is rotatable by the motor 221.

In operation, when the motor 221 is operated at a predetermined rotation speed (rotation per minute), the wafer guide 311 coupled with the motor rotation shaft 223 is clockwise or counterclockwise at a corresponding rotation speed. Rotate

Thus, the wafer 13 rotates and reacts with the chemicals in the cleaning tank 111.

In the case of the present invention, it is possible to adjust the rotation speed of the motor 221 to adjust the contact time, the number of times of contact with the compound material reacting with the wafer 13. As a result, there is an advantage that the optimum rotation speed can be selected according to the type of compound that reacts with the wafer.

FIG. 3 is a schematic diagram illustrating an external appearance of the wafer guide 311 described in FIG. 2 and the wafer mounted thereto.

However, when the wafer guide 311 having the structure shown in FIG. 3 is used, a disadvantage may occur in that the number of wafers that can be processed in one process is limited.

To this end, the present invention proposes a method of using a cassette which is a wafer receiving device having the structure as shown in FIG.

As shown in FIG. 4, the basic structures of the motor 221, the motor rotation shaft 223, and the wafer guide 311 are not significantly different from those described with reference to FIGS. 2 and 3.

The biggest difference is that it is not the wafer but the cassette 41 in which the wafer is accommodated, which is mounted on the fixing portions 20a and 20b formed on both sides of the wafer guide 311.

The cassette 41 is formed with a plurality of grooves for seating a plurality of wafers. Preferably, the plurality of wafers in the cassette 41 are preferably seated in the horizontal direction. For this purpose, the grooves in the cassette 41 are preferably formed to be aligned in the vertical direction. This is to reduce the resistance during rotation (in this case, the elastic material may be filled in the upper or lower portion of the cassette 41 to stably fix the wafer to prevent the wafer from leaving during the rotational movement). . On the other hand, as another embodiment, it may be possible to insert the wafer in the longitudinal direction to be seated.

In this manner, the user may mount the plurality of wafers on the cassette 41 and then attach the plurality of wafers to the fixing portions 20a and 20b.

In this regard, the structure shown in FIG. 4 may be referred to as a batch type. In contrast, the structure shown in FIG. 3 may be referred to as a single type. Both of them implement the technical idea of the present invention that the rotation is possible by using a motor, and a process facilitator may select and use a structure of a required type according to the contents of a semiconductor process.

On the other hand, a plurality of holes are formed in the outer circumferential surface of the cassette 41 body, which allows chemicals in the cleaning tank 111 to flow into the cassette 41 to react with the wafer.

For reference, the size of the plurality of holes is preferably designed in an optimal size according to a wafer cleaning process, a wet etching process, and a PR removing process. This is because the size of the cleaning tank 111 and the size of the cassette 41 and the number of wafers inserted into the cassette 41 may be related.

As described above, the present invention provides a technical idea of an apparatus for rotating a wafer guide accommodated in a cleaning tank using a motor.

In the case of the present invention, by controlling the rotational speed of the wafer guide by using a motor there is an advantage that can control the reaction process with the chemical reacting with the wafer according to the process content.

In the present specification and drawings, preferred embodiments of the present invention have been disclosed, and although specific terms have been used, these are merely used in a general sense to easily explain the technical contents of the present invention and to help the understanding of the present invention. It is not intended to limit the scope. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention can be carried out in addition to the embodiments disclosed herein.

Claims (7)

delete delete delete Wafer guides; A cassette detachably mounted to the wafer guide, wherein the cassette is inserted and seated in a plurality of wafers; A container filled with the wafer guide and the cassette and filled with a chemical reacting with the wafers or a cleaning liquid for cleaning the wafers; And A motor having a rotation axis, The rotating shaft is coupled to one side of the wafer guide to rotate the wafer guide, The cassette is rotated while immersed in the chemical or the cleaning liquid, And the wafers are disposed inside the cassette in a longitudinal direction parallel to the axis of rotation. delete The method of claim 4, wherein Wet cleaning apparatus for a semiconductor process, characterized in that the rotational speed per minute of the motor is adjustable. The method of claim 4, wherein Wet cleaning device for a semiconductor process, characterized in that the body of the cassette is formed with a plurality of holes for introducing the compound or cleaning liquid into the cassette.

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