JPS63226028A - steam drying equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a steam drying apparatus, and particularly to a technique that is effective when applied to remove water adhering to various objects after washing with water.

[Prior art]

In the manufacturing process of a semiconductor device, for example, after a semiconductor wafer is treated with a chemical solution, the chemical solution is removed by washing with water, and following the washing process, a process of drying and removing water adhering to the wafer is performed.

In recent years, a steam drying apparatus has been used as an apparatus for drying semiconductor wafers.

In this steam drying apparatus, isopropyl alcohol (IPA), for example, is injected as a volatile chemical into the bottom of the drying chamber. A heater is provided below this drying chamber, and the drying chamber is filled with IPA vapor that is evaporated by heating the IPA with this heater. Drying to remove water adhering to the semiconductor wafer is performed by introducing the semiconductor wafer into a drying chamber filled with IPA vapor. In this case, the wafer is at room temperature at this point because it has been washed with pure water kept at room temperature in the pretreatment process.

Therefore, when the wafer is introduced into the drying chamber, IPA vapor is condensed and liquefied on the surface of the wafer. Then, the liquefied IPA dissolves the water adhering to the wafer surface, and then drops from the wafer surface and is removed, thereby drying the wafer.

Incidentally, as a prior art document related to this type of steam drying apparatus, for example, Japanese Patent Application Laid-Open No. 57-89664 can be cited.

[Problems to be Solved by the Invention] However, the above-mentioned conventional steam drying apparatus has many problems as follows. That is, immediately after a semiconductor wafer at room temperature is introduced into the drying chamber, the temperature inside the drying chamber, especially the temperature at the top of the wafer, drops below the liquefaction temperature of IPA.By the way, cooling pipes are arranged at the top of the drying chamber. Therefore, an IPA mist is generated in the upper part of the drying chamber, and there is a boundary between this mist and IPA vapor (hereinafter referred to as a vapor surface). Therefore, when a low-temperature (room temperature) wafer is introduced into the drying chamber, the IPA vapor level decreases, exposing the upper part of the wafer to the outside of the IPA vapor, and then the wafer recovers to be surrounded by IPA vapor again. As the temperature of the wafer rises during this time, the temperature difference between it and the IPA vapor becomes small.As a result, a sufficient amount of IPA is not liquefied on the wafer surface, resulting in a situation close to natural drying, which causes drying. This will result in defects.

Additionally, if the heating with a heater is strengthened to prevent the IPA vapor level from dropping when introducing a semiconductor wafer, the IPA will boil and create droplets, and foreign matter mixed in these droplets will adhere to the wafer surface. , resulting in poor drying.

An object of the present invention is to provide a technique that can effectively dry an object to be dried.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Means for solving problems]

A brief overview of one typical invention disclosed in this application is as follows.

That is, the steam generation source is connected to the first
and a second steam generation source provided on the inner wall of the drying chamber.

[Effect]

According to the above-mentioned means, it is possible to generate a large amount of steam by providing the second steam generation source, so even if the steam level drops immediately after introducing the object to be dried into the drying chamber, it is possible to generate a large amount of steam in a short period of time. The initial steam level can be recovered and the object to be dried can be completely surrounded by steam, and a large amount of steam can be generated without boiling the chemical, which reduces the amount of chemical splash. can be prevented. Thereby, the object to be dried can be dried well.

〔Example〕

An embodiment of the present invention will be specifically described below with reference to the drawings.

Note that throughout the description of the embodiments, parts having the same functions are given the same reference numerals, and repeated explanations thereof will be omitted.

FIG. 1 is a sectional view showing a steam drying apparatus according to an embodiment of the present invention.

As shown in FIG. 1, in the steam drying apparatus according to the present embodiment, a volatile chemical solution such as IPA2 (a first steam generation source) is injected. A heater 3 is provided below this drying chamber 1, and by heating the IPA 2 with this heater 3, the IP
It is now possible to generate steam A.

Furthermore, in the steam drying apparatus according to this embodiment.

A gutter 4 is spirally provided along the inner wall of the drying chamber 1. Further, a circulation pump 5 is provided outside the drying chamber 1, and the circulation pump 5 can pump up the drying agent PA2 accumulated at the bottom of the drying chamber 1 through a conduit C and flow it into the gutter 4. There is. IPA2 in this gutter 4
While flowing downward through this gutter 4, it is heated by a heater 6 provided on the outer periphery of the drying chamber 1. Therefore, the IPA2 (second steam generation i) in this gutter 4 is
IPA vapor can also be generated from [). IPA vapor generated from IPA2 at the bottom of drying chamber 1 and IPA generated from IPA2 in gutter 4.
For example, the semiconductor wafer 8 housed in the carrier 7 can be dried with the PA vapor.

In this way, the IP in the gutter 4 provided on the inner wall of the drying chamber 1
Since IPA vapor can also be generated from A2,
The total surface area of IPA2 in the drying chamber 1 is increased, for example, by about 10 times compared to a conventional steam drying device in which IPA2 is injected only into the bottom of the drying chamber 1, and therefore a large amount of IPA vapor can be obtained. . Therefore, even if the IPA vapor level V (indicated by the broken line) decreases immediately after the semiconductor wafer 8, which is at approximately room temperature and has been subjected to pretreatment such as washing with water, is introduced into the drying chamber 1 together with the carrier 7, the process will be completed in an extremely short time. That is, the vapor surface V recovers to its initial position while the temperature of the semiconductor wafer 8 hardly rises. As a result, a sufficient amount of IPA is liquefied on the entire surface of the semiconductor wafer 8, so that the semiconductor wafer 8 can be dried satisfactorily. Also 1
, drying room 1 without heating IPA2 to high temperature and boiling it.
Since a sufficient amount of IPA vapor can be supplied within the wafer 8, the droplets generated by the IPA2 conductor can be applied to the semiconductor wafer 8.
The semiconductor wafer 8 can be properly dried. In fact, a tray (not shown) is provided below the semiconductor wafer 8, and this tray stores the IPA that liquefies on the surface of the semiconductor wafer 8 and falls downward, and transfers it to the drying chamber 1. can be discharged to the outside.

On the other hand, in the upper part of the drying chamber 1, a cooling pipe 9, for example, water-cooled, is provided along the inner wall thereof.

After the IPA vapor is cooled and liquefied by the cooling pipe 9, it falls into the gutter 4 and is collected. Therefore, the IPA cooled and liquefied by the cooling pipe 9 does not fall downward in the drying chamber 1, so that generation of turbulent flow of IPA vapor in the drying chamber 1 can be prevented. Therefore, it is possible to prevent the semiconductor wafer 8 from being contaminated by the mist of the process PA or the entrainment of foreign matter.
Thereby, the semiconductor wafer 8 can be dried well.

As described above, according to the steam drying apparatus according to this embodiment, the semiconductor wafer 8 can be dried well.
It is possible to improve the yield of highly integrated LSI.

The present invention has been specifically explained above based on examples, but
It goes without saying that the present invention is not limited to the embodiments described above, and can be modified in various ways without departing from the spirit thereof.

For example, the a4 does not necessarily need to be provided continuously in a spiral shape, but a large number of gutter 4 may be provided in parallel to the bottom of the drying chamber 1 and separated from each other, and IPA2 can be applied to each type of 4 through holes provided in these gutter 4. In addition, in the above-mentioned embodiment, the case where the present invention is applied to drying the semiconductor wafer 8 has been described, but the present invention
For example, it can be applied to drying various objects such as optical tissues, magnetic disks, photomasks, and lenses.

〔Effect of the invention〕

A brief explanation of the effects obtained by typical inventions disclosed in this application is as follows.

That is, the object to be dried can be dried satisfactorily.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a steam drying apparatus according to an embodiment of the present invention. In the figure, 1... drying room, 2... IPA (chemical solution), 3.
6... Heater, 4... Gutter, 8... Semiconductor wafer (object to be dried), 9... Cooling pipe. Figure 1

Claims (1)

[Claims] 1. A steam generator comprising a steam generation source for generating steam by evaporating a volatile chemical solution, and a drying chamber for accommodating an object to be dried and drying it with the steam. The drying device is characterized in that the steam generation source includes a first steam generation source provided at the bottom of the drying chamber and a second steam generation source provided on the inner wall of the drying chamber. Steam drying equipment. 2. The steam drying apparatus according to claim 1, wherein the second steam generation source is comprised of the chemical solution flowing in a spiral gutter provided on the inner wall of the drying chamber. 3. The steam drying device according to claim 2, characterized in that a cooling pipe is provided above the gutter. 4. The steam drying apparatus according to any one of claims 1 to 3, wherein the chemical liquid is alcohol. 5. The steam drying apparatus according to any one of claims 1 to 4, wherein the object to be dried is a semiconductor wafer.