JP2904307B2 - Organic solvent regeneration equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] In a semiconductor manufacturing process, a pervaporation for removing water introduced into an organic solvent in a washing and drying apparatus using an organic solvent after water washing of a wafer or the like. The present invention relates to a membrane (hereinafter abbreviated as PV membrane module) device.

[Prior Art] Isopropanol (hereinafter referred to as IP) performed in the course of semiconductor manufacturing, for example, after processing a wafer, followed by washing with water.
(Abbreviated as A) In drying combined with washing with steam, IPA used at this time is 100% pure at the beginning of use.
Is charged in an organic solvent evaporation tank (hereinafter abbreviated as evaporation tank). As the IPA once charged is used repeatedly, moisture adhering to the dried material to be washed is brought into the IPA. Gradually decreases in purity. Generally, the I
If the purity of the PA is 93% or less, a stain due to impurities called a watermark occurs on a wafer surface or the like, and the probability of a defect as a semiconductor increases.

For this reason, IPA for washing and drying is usually replaced with 100% purity, with a limit of 93% purity. A technique has been developed to provide a solvent regenerating device for removing water in the IPA and maintain the required purity of the IPA.

[Problems to be Solved by the Invention] Fig. 1 shows the minimum components of the conventional solvent regenerating apparatus. As shown in this figure, the regenerating apparatus is always provided with a pump 8 for feeding a solvent to the PV membrane module. The pump 8 is provided with a solvent for preventing a trace amount of metal or metal ions from being mixed into the solvent. No metal can be used for the contacting parts.

Further, the pump must be provided with a safety measure because the solvent to be handled is easily ignited by static electricity or the like. That is, the pump actually has various problems in selection or safety. In addition, in the case where the above-mentioned solvent regenerating device is to be added to an existing evaporating tank, it is sometimes difficult to install the solvent regenerating device due to a small installation space, and there is a demand for downsizing of the solvent regenerating device.

[Means for Solving the Problems] In the present invention, the pervaporation method applies pressure to the stock solution side of the membrane as in a general reverse osmosis method in order to solve the above-mentioned problems and to satisfy the demand. Instead, the pump is omitted by focusing on the fact that the minimum components are a PV membrane module and a vacuum generator in principle, since the water is removed by applying a negative pressure to the permeate side. It is. That is, since the pump merely supplies a solvent to the PV membrane module and does not require pressure for permeation on the stock solution side, the PV membrane module is directly immersed in the evaporation tank,
The pump is omitted by inventing a system for removing the water in the IPA in the evaporation tank by making the permeate side of the membrane module a negative pressure.

That is, in the present invention, when a solvent regenerating apparatus using a pervaporation membrane module for removing water is attached to an organic solvent evaporating tank, part or all of the module is directly immersed in the organic solvent in the evaporating tank. The present invention relates to an organic solvent regenerating apparatus characterized in that: The organic solvent evaporation tank is used for a system for washing a semiconductor material with water, and then washing and drying the semiconductor material with an organic solvent vapor.

The present invention will be described in detail with reference to FIG. 1 and FIG.
FIG. 1 is a diagram showing a flow sheet when a conventional evaporation tank and a solvent regeneration device are combined, and FIG. 2 is a diagram showing an example of a flow sheet combining an evaporation tank and a solvent regeneration device according to the present invention. It is. In FIGS. 1 and 2,
1 is a solvent supply pipe, 2 is a solvent, 3 is an evaporation tank, 4 is a heater, 5 is a cooler, 6 is an object to be cleaned, for example, a wafer,
7 is a liquid feed pump suction pipe, 8 is a liquid feed pump, 9
Is a PV membrane module, 10 is a solvent return pipe, 11 is a vacuum pump suction pipe, 12 is a condenser, 13 is a cooling water pipe, 14 is a drain pipe, 15 is a vacuum pump, and 16
Indicates an exhaust pipe. That is, as can be easily understood by comparing FIGS. 1 and 2, in the present invention, the PV membrane module 9 is immersed in the evaporation tank 3 as shown in the example of FIG. The pump 8 and the liquid supply pump suction pipe 7 of the piping related to the liquid supply pump 8
In addition, it is understood that the solvent return pipe 10 and the like are not provided, so that the size of the entire apparatus can be inevitably reduced.

In addition, since there is almost no difference in the water removal performance between the case where the PV membrane module is immersed in the IPA solution and the case where the PV membrane module is exposed to the IPA vapor, a part of the PV membrane module protrudes into the IPA vapor. May be. FIG.
FIG. 2 is a view showing an example in which only an effective portion of the PV membrane module 9 is immersed in a solvent, and includes a condenser and a vacuum pump.
15 is omitted.

As the PV membrane module, a hollow fiber membrane module, a flat membrane tank type module, a tubular type module, a pleated type module, a spiral type module and the like are used.

[Effect of the Invention] In contrast to the downsizing of the apparatus, in the combination of the evaporation tank and the solvent regenerating apparatus in the prior art, when the condenser 12 and the vacuum pump 15 which may be installed at positions away from the evaporation tank 3 are removed, the PV The size of the case accommodating the membrane module 9 and the liquid feed pump 8 needs to be 55 cm × 35 cm × 15 cm, whereas in the case of the present invention, the PV membrane module 9 is incorporated in the evaporation tank 3. Since no liquid feed pump is required, no storage case is required. This greatly contributes particularly when it is desired to attach a solvent regenerating device to an existing evaporation tank.

On the other hand, saying that there is no liquid feed pump,
There is no fear of safety against ignition of the solvent and no contamination of the solvent with foreign matter, which greatly contributes to safety and quality. Regarding the effect of removing water from the PV membrane module, IPA in the evaporation tank
Is constantly heated by the heater 4, so the IP is constantly
Since A was flowing, it was found that there was no difference in the effect of removing water from the case using the external PV membrane module with the liquid sending pump.

[Brief description of the drawings]

FIG. 1 is a diagram showing a flow sheet when a solvent regenerating device is attached to a conventional evaporation tank, and FIG. 2 is a diagram showing an example of a flow sheet when a solvent regenerating device is attached to an evaporation tank according to the present invention. FIG. 3 is a view showing an example in which only the effective portion of the PV membrane module according to the present invention is immersed in a solvent. DESCRIPTION OF SYMBOLS 1 ... Solvent supply pipe 2 ... Solvent 3 ... Evaporation tank 4 ... Heater 5 ... Cooler, 6 ... Cleaning object 9 ... PV membrane module 11 ... Vacuum pump suction pipe 12 ... Condenser, 13 ... Cooling water pipe 14 ... Drain pipe , 15… Vacuum pump 16… Exhaust pipe

──────────────────────────────────────────────────続 き Continuing on the front page (72) Yoshiro Shinmura 5-20-1, Josuihoncho, Kodaira-shi, Tokyo Inside the Musashi Factory, Hitachi, Ltd. (72) Masashi Yamamoto 5-chome, Josuihoncho, Kodaira-shi, Tokyo No. 20 in the Musashi Factory, Hitachi, Ltd. (72) Inventor Toshihiko Sakurai 5-2-1, Kamimizu Honcho, Kodaira-shi, Tokyo Inside the Musashi Factory in Hitachi, Ltd. Machi 29-16 (58) Field surveyed (Int.Cl. ⁶ , DB name) B01D 61/36 H01L 21/304 647 H01L 21/304 648

Claims (2)

(57) [Claims] When a solvent regenerating apparatus using a pervaporation membrane module for removing moisture is attached to an organic solvent evaporating tank, a part or all of the module is directly immersed in the organic solvent in the evaporating tank. An organic solvent regenerating device, comprising: 2. The organic solvent regenerating apparatus according to claim 1, wherein the organic solvent evaporating tank is used in a system for washing the semiconductor material with water, and then washing and drying the semiconductor material with vapor of the organic solvent.