KR20060055775A - System and method for cleaning wafer - Google Patents

Abstract

Disclosed are a semiconductor wafer cleaning apparatus and a cleaning method using an apparatus for performing a multi-process in one bath. The cleaning apparatus according to the present invention includes a pure water spraying device which is installed at the upper end of the bath to inject pure water into the bath. In the cleaning method according to the present invention, after chemically treating a wafer in a bath with a chemical treatment liquid, at least a portion of the chemical treatment liquid in the bath is overflowed while pure water is supplied into the bath. The chemical treatment liquid and the pure water are completely discharged from the bath during the overflow, and the wafer is rinsed while the pure water is supplied into the bath through the piping.

Bath, Wafer, Pure Spray, Rinse

Description

Wafer cleaning apparatus and cleaning method {System and method for cleaning wafer}

1 is a view showing a schematic configuration of a conventional wafer cleaning apparatus.

2 is a diagram illustrating a main configuration of a wafer cleaning apparatus according to a preferred embodiment of the present invention.

3 is a side view showing a main configuration of a wafer cleaning apparatus according to a preferred embodiment of the present invention.

4 is a flowchart for explaining a wafer cleaning method according to a preferred embodiment of the present invention.

5 is a result of the TOC analysis when the wafer is cleaned by the wafer cleaning method according to the present invention.

6 is a result of TOC analysis when the wafer is cleaned by the wafer cleaning method according to the prior art.

<Explanation of symbols for the main parts of the drawings>

110: bath, 114: piping, 120: pure spray device, 122: pure water.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor wafer cleaning apparatus and a cleaning method, and more particularly, to a semiconductor wafer cleaning apparatus and a cleaning method using equipment for performing a multi-process in one bath.

In the semiconductor device manufacturing process, various films such as a conductive layer, a semiconductor layer, and an insulating layer are formed on a wafer using various processes such as photolithography, etching, ashing, diffusion, chemical vapor deposition, ion implantation, and metal deposition on the wafer. A series of processes for forming a back are performed. In addition, a cleaning process is performed between the unit processes to remove impurities including unnecessary substances, reaction by-products, and foreign substances remaining on the wafer.

As wafers have become larger in size, the construction and maintenance costs of clean rooms used for wafer cleaning have become a large part of the manufacturing cost. In an attempt to overcome such a problem, a facility structure having a function of performing a multi-process in one bath is mainly used. For example, in the case of the conventional 8-inch wafer cleaning apparatus, the bath for the HF cleaning liquid and the bath for the SC1 cleaning liquid were separately provided and used, but for the 300 mm wafer, the equipment for treating the HF and the SC1 in a single bath was used. have. The cleaning method using this facility was able to reduce the number of baths by more than 1/2 compared with the existing facility structure using a separate bath for each cleaning liquid.

FIG. 1 is a view showing a schematic configuration of a conventional wafer cleaning apparatus composed of a facility structure having a function of performing a multi-process in one bath.

Referring to FIG. 1, a bath 10 through which cleaning, rinsing, and drying processes are performed is installed, and a predetermined cleaning liquid is installed in the bath 10 through a pipe 14 connected to a lower portion of the bath 10. (12) The wafer W is introduced in an amount that is sufficiently locked.

When a predetermined time has elapsed while the wafers W are inserted to be immersed in the cleaning liquid 12 and the cleaning operation is completed by the cleaning liquid 12, deionized water is continuously supplied through the pipe 14. At the same time, the washing liquid 12 is diluted in the upper portion of the bath 10 until the washing liquid 12 in the bath 10 is completely replaced with pure water while overflowing the washing liquid in the bath 10. When the rinsing process is completed, the pure water in the bath 10 is completely discharged through the pipe 14 and the wafer W is dried.

In the conventional wafer cleaning apparatus having the above-described configuration, mixing defects with completely different properties in a single bath can cause unwanted defects on the wafer. In addition, a long time rinse cleaning time is required when the cleaning solution is replaced in order to use one cleaning solution and then switch to another cleaning solution. That is, since the rinse cleaning process is performed by diluting and removing the inside of the bath contaminated by chemical substances or contaminants remaining on the wafer by the pure water supplied from the lower part of the bath, the residue remaining on the wafer subjected to chemical treatment in the previous step is left. There is a problem in that it takes a long time to rinse the chemical to remove the chemicals. In practice, the time it takes to completely remove the contaminants in the bath by the conventional method using the conventional apparatus described above may vary depending on the type of chemical treatment solution, but it is usually about 300 seconds or more. The amount of pure water supplied to completely remove contaminants in the bath is about five times the capacity of the bath.

The present invention is to solve the above problems in the prior art, a wafer cleaning apparatus having a configuration that can shorten the replacement time of the chemical treatment liquid or cleaning liquid, or the rinse time of the wafer in the wafer cleaning apparatus using a single bath. To provide.

Another object of the present invention is to provide a wafer cleaning method capable of shortening the replacement time of the chemical treatment liquid or the cleaning liquid, or the rinse time of the wafer when the wafer is cleaned using the wafer cleaning apparatus using a single bath.

In order to achieve the above object, the wafer cleaning apparatus according to the present invention includes a bath for holding a wafer to be cleaned and a predetermined cleaning liquid, and a pipe connected to the bottom of the bath for supplying and discharging a predetermined cleaning liquid in the bath. And a pure water injecting device provided at an upper end of the bath to inject pure water into the bath.

Preferably, the pure water injection device is made in the form of a tube formed with a plurality of injection holes. Also preferably, the pure water injection device is installed in parallel to each other at two positions spaced apart from each other at the upper end of the bath.

In order to achieve the above another object, in the wafer cleaning method according to the present invention, the wafer is chemically treated with a chemical treatment liquid in a bath in which a pipe for discharging and supplying the treatment liquid is formed at the bottom thereof. At least a portion of the chemical treatment liquid in the bath is overflowed while pure water is supplied into the bath through the pipe. The chemical treatment liquid and the pure water are completely discharged from the bath. The wafer is rinsed while pure water is supplied into the bath through the pipe. The wafer is dried.

In a preferred embodiment, in the discharging step, pure water is continuously supplied from the top of the bath to the wafer while the chemical treatment liquid and the pure water are discharged. In order to continuously supply pure water to the wafer from the top of the bath, a pure water jetting device provided at the upper end of the bath can be used. Continuously supplying pure water to the wafer from the top of the bath preferably ensures that pure water is supplied to the wafer in at least two directions of the top of the wafer.

According to the present invention, the wafer rinse time can be greatly reduced and the rinse efficiency can be greatly improved.

Next, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 and 3 are each a view showing the main configuration of the wafer cleaning apparatus according to the preferred embodiment of the present invention, Figure 2 shows a side cross-sectional configuration, Figure 3 shows a side view.

2 and 3, the wafer cleaning apparatus according to the present invention includes a wafer W to be cleaned and a bath 110 containing a predetermined cleaning liquid (not shown). A pipe 114 is connected to the bottom of the bath 110 to supply and discharge a predetermined cleaning liquid in the bath 110. In addition, in order to inject the pure water 122 into the bath 110, the pure water injection device 120 is installed at the upper end of the bath 110.

As can be seen in the side view of Figure 3, the pure water injection device 120 is configured in the form of a long tube (tube), the pure water injection device 120 is formed with a plurality of injection holes for injecting the pure water 122 have.

2 and 3, the pure water injection device 120 is composed of two tubes installed in parallel to each other at two positions spaced apart from the upper end of the bath (110).

4 is a flowchart for explaining a wafer cleaning method according to a preferred embodiment of the present invention. The wafer cleaning method according to the present invention may be performed using the wafer cleaning apparatus according to the preferred embodiment of the present invention described with reference to FIGS. 2 and 3.

Referring to FIG. 4, first, in step 151, the wafer W is chemically treated with a chemical treatment liquid in the bath 110 in which a pipe 114 for discharging and supplying the treatment liquid is formed.

In step 152, at least a portion of the chemical treatment liquid in the bath 110 is overflowed while supplying pure water 122 into the bath 110 through the piping 114.

In step 153, the chemical treatment liquid and the pure water are completely discharged from the bath 110.

As described above, in the discharge of the chemical treatment liquid and the pure water completely in step 153, the wafer W is exposed to the air while the discharge is in progress, so that defects occur and grow on the wafer W or the chemical treatment liquid remains. Problems may occur due to the back-adsorption and natural drying of the wafer (W). In the present invention, in order to prevent the occurrence of such a problem, the wafer (W) from the top of the bath (110) in order to be able to maintain the wet processing state while the wafer (W) is completely discharged in step 153 W) is supplied with pure water. To this end, pure water may be continuously supplied to the wafer W from the pure water injection device 120 installed at the upper end of the bath 110 while discharging the chemical treatment liquid and the pure water. At least two directions of the upper portion of the wafer W so that the pure water can be evenly sprayed to all portions of the wafer W in continuously supplying the pure water to the wafer W from the top of the bath 110. It is desirable to allow pure water to be supplied to the wafers at As shown in FIG. 2, in the case where two pure spray devices 120 are installed on each of both sides of the upper end of the bath 110, pure water is supplied in two directions of the upper portion of the wafer W, respectively.

In step 154, the wafer W is rinsed while pure water is supplied into the bath 110 through the pipe 114.

In step 155, the wafer is dried. At this time, in order to dry the wafer W, the rinse liquid, that is, pure water, in the bath 110 is completely discharged through the pipe 114, and then a drying step is performed in the bath 110.

As described above, according to the wafer cleaning method according to the present invention, when the chemical treatment liquid and pure water are completely discharged in the bath during the overflow of the chemical treatment liquid, and the rinse process is performed while the pure water is overflowed, the rinse time is greatly reduced. And the rinse efficiency can be greatly improved.

FIG. 5 shows TOC (Total Oganic Carbon) analysis of the residual amount of chemicals in a bath when the wafer is cleaned according to the wafer cleaning method according to the present invention in rinsing with pure water after treating the wafer with an organic chemical treatment solution. It is a graph showing the result confirmed through. For the evaluation of FIG. 5, after processing the wafer with the organic chemical treatment liquid and during the overflow with pure water as described in step 152 of FIG. 4, the organic chemical treatment liquid from the bath and as described in step 153 of FIG. 4 and Pure water was drained completely and the wafer was rinsed as in step 154 of FIG. In this rinse step, 60 seconds (A) before discharge of organic chemical treatment liquid and pure water, 60 seconds after discharge (B), 120 seconds after discharge (C), 180 seconds after discharge (D), and 230 seconds after discharge (E) As time passed, the TOC analysis was performed.

6 is a graph showing a result of TOC analysis when the wafer is cleaned by the wafer cleaning method according to the prior art as a control example. For the evaluation of FIG. 6, the wafer was treated with an organic chemical treatment solution and then overflowed with pure water as described in step 152 of FIG. 4. Here, the difference from the case of FIG. 5 is that the organic chemical treatment liquid and the pure water discharge step described in step 153 of FIG. 4 are omitted, and when the organic chemical treatment liquid inside the bath is completely replaced with pure water in step 152 of FIG. Overflow continued until. In this rinse step, TOC analysis was performed according to the elapsed time of the rinse step.

As can be seen by comparing the results of Figs. 5 and 6, according to the wafer cleaning method according to the present invention, the rinse time is greatly reduced by about 1/10 compared to the conventional case.

In the wafer cleaning method according to the present invention, after treating the wafer with the organic chemical treatment liquid and then rinsing with pure water, the organic chemical treatment liquid and the pure water from the bath during the overflow with the pure water after processing the wafer with the organic chemical treatment liquid. After completely discharged, a wafer rinse step using pure water is performed. Therefore, according to the present invention, the wafer rinse time can be greatly reduced and the rinse efficiency can be greatly improved.

In the above, the present invention has been described in detail with reference to preferred embodiments, but the present invention is not limited to the above embodiments, and various modifications and changes by those skilled in the art within the spirit and scope of the present invention. This is possible.

Claims (7)

A bath accommodating a wafer to be cleaned and a predetermined cleaning liquid; Piping connected to the bottom of the bath for supplying and discharging a predetermined cleaning liquid in the bath; And a pure water injecting device provided at an upper end of the bath to inject pure water into the bath. The method of claim 1, The pure water jetting device is a wafer cleaning device, characterized in that made of a tubular shape formed with a plurality of injection holes. The method of claim 1, The pure water jetting device is a wafer cleaning device, characterized in that installed in parallel to the two positions spaced apart from each other at the upper end of the bath. Chemically treating the wafer with a chemical treatment liquid in a bath in which a pipe for discharging and supplying the treatment liquid is formed at a lower portion thereof; Overflowing at least a portion of the chemical treatment liquid in the bath while supplying pure water into the bath through the piping; Completely discharging the chemical treatment liquid and the pure water from the bath; Rinsing the wafer while supplying pure water into the bath through the piping; Wafer cleaning method comprising the step of drying the wafer. The method of claim 4, wherein And in the discharging step, pure water is continuously supplied from the top of the bath to the wafer while the chemical treatment liquid and the pure water are discharged. The method of claim 5, And a pure water jetting device provided at an upper end of the bath to continuously supply pure water from the top of the bath to the wafer. The method of claim 6, Continuously supplying pure water to the wafer from the top of the bath, wherein the pure water is supplied to the wafer in at least two directions of the top of the wafer, respectively.

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