JPH04352424A - Drying apparatus - Google Patents

Abstract

PURPOSE:To sufficiently dry in a shorter time. CONSTITUTION:A heating wire 10 is disposed out of an IPA vapor tank in which isopropyl alcohol vapor is fully filled, a wire fault is irradiated in a lower direction of a vapor cooling tube 4 through a window 9, and even if a semiconductor wafer 1 and a carrier 2 of low temperature are inserted, a decrease in a temperature of a region to be irradiated is prevented.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drying device, and more particularly to a drying device that replaces moisture adhering to the surface of an object to be cleaned with isopropyl alcohol (hereinafter abbreviated as IPA) and evaporates it by heating to dry it.

0002

[Prior Art] Generally, since IPA is compatible with water, it can be directly applied to semiconductor wafers or exposure masks that are wet with water.
It can be exposed to PA vapor, and moisture adhering to the semiconductor substrate or exposure mask surface is replaced by condensed IPA. Therefore, if the surface temperature of the semiconductor substrate or exposure mask whose moisture has been replaced with IPA rises to the vapor temperature of IPA, it can be easily dried.

FIG. 2 is a schematic cross-sectional view of a drying device showing an example of the conventional method. Conventionally, this type of drying apparatus has been used, for example, as shown in FIG.
As shown in the figure, there is an IPA steam tank 3 that stores IPA 6, a heater 8 that heats the IPA steam tank 3 and evaporates the IPA, an evaporative cooling pipe 4 that cools the evaporated IPA, and a carrier that stores the semiconductor wafer 1. A carrier elevator 11 that raises and lowers IPA 2 in the IPA steam tank 3, and an IP that condenses and drops
It was equipped with a condensate receiver 7 for collecting A.

[0004] In the operation of this drying apparatus, first, IPA 6 placed in an IPA steam tank 3 is heated by a heater 8 and becomes steam. Next, this IPA vapor is liquefied again through the vapor cooling pipe 4. And in the area where the steam cooling pipe 4 is located,
A vapor line 5 is formed in which the IPA vapor concentration is high in the lower part and the atmosphere is in the upper part. Next, the carrier 2 and the semiconductor wafer 1 wetted with water are inserted from above by a carrier elevator 9 through the vapor line 5 into an area where the IPA vapor concentration is high. As a result, semiconductor wafer 1 and IPA
IPA condenses on the surfaces of the carrier and semiconductor wafer 1 due to the temperature difference and concentration difference of the steam, and dissolves in water. Then, it becomes a drop and drips into the condensate receiver 7.

[0005] By repeating the condensation and falling of the condensed drops in this way, the adhering water is replaced with IPA. After a certain period of time has elapsed, the carrier 2 is raised by the carrier elevator 9, passed through the vapor line 5, and exposed to the atmosphere above the vapor line 5, and the replaced I
The PA was evaporated and dried.

[0006]

[Problems to be Solved by the Invention] In the conventional drying apparatus described above, when a low-temperature semiconductor wafer, exposure mask, or carrier is inserted into an IPA vapor bath, condensation of IPA starts and the semiconductor wafer or The temperature near the exposure mask rapidly decreases, and the IPA vapor concentration also decreases rapidly. For this reason, the amount of condensation is extremely reduced, and IPA
This has resulted in insufficient replacement, which in turn lengthens the drying time, resulting in insufficient drying.

SUMMARY OF THE INVENTION An object of the present invention is to provide a drying device capable of sufficiently drying in a shorter time in order to solve this problem.

[0008]

[Means for Solving the Problems] The drying apparatus of the present invention includes: a steam tank containing isopropyl alcohol and the object to be dried filled with the vapor thereof; a steam cooling mechanism disposed above the steam tank; A heating means is provided for externally heating a region of the steam tank below the steam cooling mechanism.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a schematic sectional view of a drying apparatus showing an embodiment of the present invention. As shown in FIG. 1, this drying device is equipped with a heat-resistant glass window 9 on the outer wall of the IPA steam tank 3 facing the lower part of the evaporative cooling pipe 4, and through this window 9 radiant heat is transferred to the IPA steam tank 3. It is equipped with a heating wire 10 that projects inside.

By providing a mechanism for heating the materials to be dried in this manner, the heating wire 10 starts heating the inside of the tank immediately before the semiconductor wafer 1 and the carrier 2 are lowered into the tank from above by the carrier elevator 11. When the low-temperature semiconductor wafer 1, carrier 2, and carrier elevator 11 are inserted into the tank, the temperature in the tank starts to drop, and the vapor line 5 also starts to drop, but because the tank is heated, it quickly stops. Vapor line 5 returns to normal. Therefore, the semiconductor wafer 1 and carrier 2 can be exposed to IPA vapor at a sufficient temperature.

After a certain period of time, the heating of the heating wire 10 is finished, and then the carrier elevator 11 is raised to the atmosphere to finish the drying.

[0013] In this way, even if the semiconductor wafer 1 and the carrier 2, which have a low temperature, are inserted into the IPA steam tank 3, the temperature inside the IPA steam tank 3 will not be lowered, so the IPA vapor concentration will not drop and the temperature will gradually increase. The moisture is well replaced with IPA, and when the semiconductor wafer 1 and carrier 2 are lifted up by the carrier elevator 11, the IPA evaporates, resulting in drying in a shorter time.

In this embodiment, a heating wire was simply used as the heating source, but an infrared lamp or an incandescent lamp may also be used. The window materials that allow these heat rays to pass through include
It is necessary to select a material that transmits the wavelength of heat rays.

Furthermore, according to the present invention, since the region in the lower part of the steam cooling pipe is heated, the heat capacity of this lower region can be estimated to be large, so the heat capacity absorbed by the material to be dried that is inserted is taken into consideration. If the volume of the lower area of the IPA steam tank is set so that the temperature can be maintained above the specified temperature,
There is an advantage that the IPA steam tank can be made smaller.

[0016]

As explained above, the present invention provides a mechanism for heating the lower region of the evaporative cooling pipe of the IPA vapor tank from outside the IPA vapor tank, thereby allowing low-temperature semiconductor substrates or exposed Even if the mask is inserted, the temperature can be prevented from decreasing, so that the IPA vapor concentration does not decrease. Therefore, there is an effect that a drying device that can perform sufficient drying in a shorter time can be obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of a drying device showing one embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view of a drying device showing a conventional example.

[Explanation of symbols]

1 Semiconductor wafer 2　　　　Career 3 IPA steam tank 4 Evaporative cooling pipe 5 Vapor line 6 IPA 7 Condensate receiver 8 Heater 9 Window 10 Heating wire 11 Carrier elevator

Claims (2)

[Claims] Claim 1: A drying device that dries the object by replacing moisture adhering to the object to be dried with isopropyl alcohol and evaporating the isopropyl alcohol. It is characterized by comprising a steam tank in which dry matter is placed, a steam cooling mechanism disposed above the steam tank, and a heating means for externally heating a region of the steam tank below the steam cooling mechanism. drying equipment. 2. The drying apparatus according to claim 1, wherein the heating means comprises a window provided on an outer wall of the steam tank, and a heat source that generates heat rays passing through the window.