KR20070009850A - Wafer dryer having ipa sensor - Google Patents

Abstract

A wafer drying apparatus including an IPA(isopropyl alcohol) detecting unit is provided to more effectively control an IPA drying process based upon a detected IPA gas density by detecting the IPA density of IPA gas acting upon a drying process in real time such that the IPA gas is substantially supplied to a dry bath. A wafer(200) is dried by a supply of a cleaning solution and IPA gas in a process bath. An IPA density detecting unit(400) extracts the IPA gas supplied to the inside of the process bath to extract the IPA density. The process bath includes an inner bath(110) and an outer bath(130). The wafer is installed in the inner bath to which the cleaning solution and the IPA gas are supplied. The inner bath is surrounded by the outer bath so that the cleaning solution overflowing the inner bath flows to the outer bath. The detecting unit includes an extraction port(401) and an exhaust unit. The extraction port is installed in the inner wall of the outer bath to extract the IPA gas, connected to the outside. The exhaust unit exhausts the IPA gas whose density is detected by the detecting unit.

Description

Wafer drying apparatus with isopropyl alcohol detector {Wafer dryer having IPA sensor}

1 is a view schematically illustrating a wafer drying apparatus having an IPA detector according to an embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to semiconductor manufacturing equipment, and more particularly, to a wafer drying apparatus having an isopropyl alcohol (IPA) detector.

The fabrication of semiconductor devices inevitably involves the cleaning of the wafer. After the cleaning of the wafer, a process of drying the wafer while preventing occurrence of water spots on the wafer is performed. The drying process of the wafer is performed using an IPA gas, in which an IPA drying apparatus is used.

The IPA drying apparatus can be understood as an apparatus for drying a wafer using the Marangoni effect at the interface between IPA and pure water. That is, when there are regions with different surface tensions such as IPA region and DI water region, the pure water is removed from the wafer surface by the effect of liquid flowing from the region having a small surface tension to the region having a high surface tension. It is being removed.

The concentration of IPA gas supplied from the IPA drying apparatus is recognized as a factor that greatly affects the drying effect. By the way, the currently proposed IPA drying apparatus is mostly used as a means for controlling the IPA concentration, a method of simply controlling the IPA gas pressure or flow rate when supplying the IPA gas.

The IPA gas is supplied using an IPA gas generator such as a bubbler, wherein the pressure of the bubbling gas supplied for IPA gas bubbling, for example, nitrogen gas N ₂ , Or control the flow rate and / or pressure of the generated IPA gas, i.e., the mixed gas of the gaseous IPA and the nitrogen gas which is the carrier gas, thereby substantially supplying the IPA concentration to the drying bath of the IPA drying apparatus. Is indirectly controlled.

By the way, since this method cannot detect the density | concentration of the IPA gas supplied in the liquid tank substantially dried, it cannot control the density | concentration of the IPA gas supplied correctly. In order to improve the drying efficiency in the IPA drying apparatus, it is advantageous to relatively increase the concentration of the supplied IPA gas. In the general IPA drying apparatus, since the concentration of the supplied IPA gas cannot be detected accurately, it is difficult to effectively control the IPA drying process. Practically difficult.

The technical problem to be achieved by the present invention is to provide a wafer drying apparatus using IPA capable of detecting the concentration of the IPA gas supplied to the drying liquid tank of the IPA drying apparatus and controlling the IPA drying process according to the IPA gas concentration. There is.

One aspect of the present invention for achieving the above technical problem is a processing bath in which a wafer is dried by supplying a cleaning liquid and isopropyl alcohol (IPA) gas, and the isopropyl alcohol gas supplied in the processing liquid tank. The present invention provides a wafer drying apparatus including an isopropyl alcohol concentration detector for extracting isopropyl alcohol concentration.

In this case, the processing liquid tank may include an inner tank in which the wafer is mounted and the cleaning liquid and the isopropyl alcohol (IPA) gas are supplied, and an outer tank in which the cleaning liquid overflows the inner tank and flows in the inner tank. The detector is connected to the outside on the inner wall of the outer tank is an extraction port for extracting the isopropyl alcohol gas, and exhaust means for exhausting the isopropyl alcohol gas detected in the concentration to the outside to the outside It may include.

In addition, an inner tank supplied with a cleaning liquid and an isopropyl alcohol (IPA) gas, an outer tank installed to surround the inner tank so that the cleaning liquid supplied to the inner tank overflows, and wafers to be dried in the inner tank are mounted and a Marangoni effect A wafer support portion for raising the wafers into the isopropyl alcohol gas in the cleaning liquid so that the wafers are dried, and an extraction port for extracting the isopropyl alcohol gas installed on the inner wall of the outer tank. And a detector for detecting isopropyl alcohol concentration of the isopropyl alcohol gas extracted from the extraction port, and exhaust means for exhausting the isopropyl alcohol gas detected at the concentration to the outside. Can be.

According to the present invention, the concentration of the IPA gas which is substantially supplied to the drying liquid tank of the IPA drying apparatus and participates in the drying operation can be detected, and the IPA drying process can be effectively controlled based on the detected IPA gas concentration.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, embodiments of the present invention may be modified in many different forms, and the scope of the present invention should not be construed as being limited by the embodiments described below. Embodiments of the invention are preferably to be interpreted as being provided to those skilled in the art to more fully describe the invention.

In the embodiment of the present invention, in order to directly detect the concentration of the IPA gas substantially participating in the drying process in the wafer drying apparatus using the IPA gas, sampling the concentration of the IPA gas supplied to the liquid tank in which the drying apparatus is dried. Or to introduce an IPA concentration detector to detect by extraction.

It is possible to confirm the concentration of IPA in the IPA gas substantially participating in the drying process in the IPA drying apparatus, so that it is possible to confirm in real time the IPA condition of the wafer drying apparatus.

Conventionally, in the wafer drying apparatus using the IPA gas, the IPA concentration cannot be confirmed, and the IPA flow meter or the pressure gauge is visually checked to indirectly estimate the IPA concentration. Thus, it is virtually impossible to monitor IPA concentration conditions that would otherwise cause problems with the drying process. In addition, when the IPA gas flows out from the IPA drying apparatus, it relies solely on the smell caused by the IPA, and thus cannot detect the IPA gas state.

In the embodiment of the present invention, these conventional problems can be solved, and since the IPA concentration of the IPA gas that is substantially supplied to the drying liquid tank of the IPA drying apparatus and participates in the drying operation can be detected in real time, the detected IPA gas concentration Based on this, IPA drying process can be controlled more effectively. In addition, it is possible to prevent the occurrence of a process accident due to the IPA gas leakage in advance.

1 is a view schematically illustrating a wafer drying apparatus having an IPA detector according to an embodiment of the present invention.

Referring to FIG. 1, a wafer drying apparatus according to an exemplary embodiment of the present invention includes an inner bath 110, an outer bath 130, a wafer support unit 250, an IPA feeder 301, and an IPA concentration detector 400. do. Such a wafer drying apparatus can be understood that the basic configuration is composed of a Marangoni dryer.

The wafer 200 is substantially supported by the wafer support 250 and mounted in the inner bath 110 of the liquid baths 110 and 130 of the drying apparatus. In the inner tank 110, a cleaning liquid, for example, pure water, is supplied by the cleaning liquid supplying means 115, for example, a pure net supply nozzle, and the wafer 200 is supplied so as to be locked. Then, after the inner tank 110 is filled with pure water, isopropyl alcohol (IPA) gas is supplied from the IPA supplier 301 in the inner tank 110.

The IPA supply 301 may be configured in the form of a bubbler, and the IPA gas ie, by supplying a bubbling gas, for example, nitrogen gas, for conversion into the gas phase, that is, bubbling, in the IPA liquid phase 302. It produces a mixture of IPA gas and nitrogen gas. The generated IPA gas is supplied onto the inner tank 110 of the drying apparatus by the supply pressure of the carrier gas, for example, nitrogen gas.

Hoods 150 are placed on the liquid baths 110 and 130 of the wafer drying apparatus, and IPA gas is supplied into the hoods 150. Thus, a supply means for supplying such IPA gas, for example, a supply nozzle 305 is introduced onto the inner tank 110 in the hood 150. Therefore, the IPA gas is distributed in the inner space of the inner tank 110 and the hood 150.

When the IPA gas is supplied, the wafers 200 immersed in the pure water supplied to the inner tank 110 are lifted and raised to induce a drying action due to the marangoni effect at the interface between the IPA gas and the pure water. This drying process may be performed by gradually raising the wafer support 200 supporting the wafers 200. After performing the drying process, the cleaning liquid in the inner tank 110 may be drained through the outlet and discharged to the outside.

The IPA gas supplied in the drying process is distributed in the inner space of the inner tank 110 and the hood 150, and is also distributed in the outer tank 130 because the inner tank 110 and the outer tank 130 are connected to each other. . The outer tank 130 may be installed to surround the inner tank 110 to overflow the pure water supplied to the inner tank 110. Accordingly, the inner tank 110 and the outer tank 130 are to communicate with each other.

An extraction port 401 for extracting the IPA gas may be installed on the inner wall of the outer tub 130 to be connected to the outside. The IPA gas extracted from the IPA gas extraction port 401 is delivered to the IPA concentration detector 400. In this case, the IPA concentration detector 400 may be installed behind the liquid tanks 110 and 130 in consideration of the installation space. The IPA concentration detector 400 detects the IPA concentration in the IPA gas extracted as a sample using a chemical detection method or the like and notifies the operator. It may also be configured to generate an alert when an IPA concentration is detected below a certain concentration.

The IPA gas used for the concentration check is exhausted through a separate exhaust line without being returned to the drying unit. This exhaust line can be connected to an exhaust line installed in the drying apparatus to exhaust the IPA gas used for the concentration test. This is because when the concentration-tested IPA gas is returned to the drying apparatus, it may adversely affect the concentration of the IPA gas present in the inner tank 110 and the hood 150.

The detected IPA concentration may be fed back to an operator or a controller (not shown) that controls the drying process in real time, and the drying process may be more effectively controlled based on the detected concentration information. In addition, it is possible to improve the drying efficiency by the IPA concentration information. In addition, when the leakage of the IPA gas is naturally accompanied by a change in the IPA concentration, if it detects such a change in the IPA concentration it can be alerted to prevent the leakage of the IPA gas in advance.

In order to detect the IPA concentration of the IPA gas, it is very important to establish an extraction port for extracting the IPA gas. In detecting the concentration of the IPA gas, it may be most effective to verify in the supply line or the supply tube immediately before the IPA gas is supplied to the processing liquid tanks 110 and 130.

However, this extraction method involves the vulnerability of exhausting the IPA gas generated in the IPA gas supplier 301 before reaching the processing liquid tanks 110 and 130, and also substantially the IPA supplied on the wafer 200. There is a possibility of changing the concentration or / and amount of gas. Accordingly, this extraction method may act as a factor that destroys the IPA layer participating in the drying of the wafer 200.

In the embodiment of the present invention, by installing the IPA gas extraction port 401 on the inner wall of the outer tank 130, it is possible to effectively prevent the actual drying process is affected by the extraction of the IPA gas for concentration detection.

According to the present invention described above, it is possible to detect in real time the IPA concentration of the IPA gas that is substantially supplied to the drying liquid tank of the IPA drying apparatus and participates in the drying action. Accordingly, the IPA drying process can be more effectively controlled based on the detected IPA gas concentration. In addition, it is possible to prevent the occurrence of a process accident due to the IPA gas leakage in advance.

As mentioned above, although this invention was demonstrated in detail through the specific Example, this invention is not limited to this, It is clear that the deformation | transformation and improvement are possible by the person of ordinary skill in the art within the technical idea of this invention.

Claims (3)

A treatment bath in which the wafer is dried by supply of a cleaning liquid and isopropyl alcohol (IPA) gas; And And an isopropyl alcohol concentration detector for extracting the isopropyl alcohol concentration by extracting the isopropyl alcohol gas supplied into the processing tank. The method of claim 1, The treatment tank An inner bath in which the wafer is mounted and supplied with the cleaning liquid and isopropyl alcohol (IPA) gas; And Installed to surround the inner tank and includes an outer tank in which the washing liquid overflows the inner tank, The detector is An extraction port installed on the inner wall of the outer tub and connected to the outside to extract the isopropyl alcohol gas; And And exhaust means for exhausting the isopropyl alcohol gas detected by the detector to the outside. An inner tank to which a cleaning liquid and an isopropyl alcohol (IPA) gas are supplied; An outer tub installed to surround the inner tub such that the cleaning liquid supplied to the inner tank overflows; A wafer support for mounting the wafers to be dried in the inner tank and raising the wafers into the isopropyl alcohol gas in a cleaning liquid such that the wafers are dried by a Marangoni effect; An extraction port installed on the inner wall of the outer tub and connected to the outside to extract the isopropyl alcohol gas; A detector for detecting an isopropyl alcohol concentration of the isopropyl alcohol gas extracted from the extraction port; And And exhaust means for exhausting the isopropyl alcohol gas detected by the detector to the outside.

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