JPH0265233A - Device for removing moisture of semiconductor wafer - Google Patents

Abstract

PURPOSE:To enable the moisture to be removed at the low heating temperature around 100 deg.C by a method wherein a hot plate to heat a semiconductor wafer, a chamber to maintain the ambient atmosphere of said semiconductor wafer to be heated in the pressure-reduced state and a means to purge the gas in said chamber are provided. CONSTITUTION:When a wafer 2 is carried to a hot plate 1, a chamber 3 is lowered to closely adhere to the outer peripheral of the hot plate 1 while the gap between them is sealed with a sealing member 4 to isolate the wafer 2 from the air. The atmospheric gas in the chamber is exhausted from an exhaust port 6. The chamber 3 is pressure-reduced while the moisture of the wafer 2 heated by the hot plate 1 is evaporated to be exhausted. A trap 9 cools down the exhausted steam to be trapped. A nozzle 7 to purge dry air or N2 is fixed to the upper part of the chamber 3 so that a vacuum exhausting valve 8 may be closed for stopping the exhaustion after the lapse of specified time to purge gas from the nozzle 7 for restoring the pressure in chamber 3 to the atmospheric pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the manufacture of semiconductor wafers, and more particularly to an apparatus for removing moisture from the wafer surface.

[Conventional technology]

Conventionally, this type of moisture removal equipment includes a day hydration hot plate type in which a wafer is placed on a hot plate in an atmosphere of dry air or inert gas, especially nitrogen (hereinafter referred to as N2), and is heated to evaporate moisture. This method is integrated in-line with other process equipment.

As shown in FIG. 2, the day hydration hot plate system includes a hot plate 1 for heating a semiconductor wafer (hereinafter referred to as wafer) 2, a double heat insulating cover 10 that covers the upper space of the hot plate 1, and It has a nozzle 7 that sprays purge gas toward the semiconductor wafer 2.

[Problem to be solved by the invention]

The conventional moisture removal equipment described above evaporates moisture only by heating under atmospheric pressure, so in order to remove moisture sufficiently, it is necessary to increase the heating temperature or increase the heating time. be.

In order to raise the heating temperature, it is necessary to take measures such as heat resistance of the heating part of the device, insulation from the outside, heat radiation, etc., and the limit for in-line hot plates and the like is around 350°C.

Also, depending on the surface condition of the wafer, it may be coated with an organic film, and in some cases it may not be possible to heat it above 150-200°C, so the only option is to remove moisture by increasing the heating time, and the processing capacity is low. There was a drawback.

SUMMARY OF THE INVENTION An object of the present invention is to provide a moisture removal device for a semiconductor device (c) that solves the above-mentioned problems.

[Differences between the invention and the prior art]

The present invention differs from the conventional moisture removal apparatus described above in that the wafer is heated under reduced pressure to evaporate the moisture.

[Means to solve the problem]

In order to achieve the above object, an apparatus for removing water from a semiconductor wafer according to the present invention includes: a hot plate for heating a semiconductor wafer; a chamber for maintaining an atmosphere surrounding the heated semiconductor wafer in a reduced pressure state; and means for purging gas.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention.

In the figure, the present invention includes a hot plate 1 that heats a wafer 2, a chamber 3 that maintains the atmosphere surrounding the wafer 2 in a reduced pressure state, and a chamber 3 and hot plates 1 to 1.
1, and a vacuum pump 5 for evacuating the inside of the chamber 3. Trap 9. It has an exhaust valve 8 and a nozzle 7.

In the embodiment, when the wafer 2 is transferred onto the hot plate 1, the chamber 3 is lowered and comes into close contact with the outer periphery of the hot plate 1, and the gap therebetween is sealed by the sealing material 4.
The wafer 2 is isolated from the outside air.

The atmospheric gas in the chamber 3 is exhausted from an exhaust port 6 by a vacuum pump 5. The pressure inside the chamber 3 is reduced, and the moisture in the wafer 2 heated by the hot plate 1 is evaporated and exhausted. Trap 9 cools and captures the exhausted water vapor. The upper part of chamber 3 is filled with dry air or N2.
It is equipped with a nozzle 7 that purges the water after a certain period of time.
The evacuation valve 8 is closed to stop evacuation, and the gas is purged from the nozzle 7 to return the inside of the chamber 3 to atmospheric pressure. Also,
It is also possible to constantly purge gas under reduced pressure and use it as a carrier gas for water vapor to quickly exhaust the water vapor in the chamber 3 and replace it with gas.

After drying the wafer, the chamber 3 is raised and the wafer 2 on the hot plate 1 is transported to the outside.

The present invention can be incorporated as an in-line type by docking with a coating machine or a developing machine, such as a dehydration bake before resist coating or a bake after development in a photolithography process in semiconductor wafer manufacturing.

〔Effect of the invention〕

As explained above, the present invention can quickly remove moisture at a low heating temperature of around 100°C by heating the wafer under reduced pressure. The countermeasures are very advantageous compared to conventional methods. Furthermore, since the water removal rate is also improved, it has the effect of being able to remove water in a short time.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view showing the structure of a conventional day hydration hot plate system. 1... Hola 1 ~ Plate 2... Wafer 3...
...Chamber 5...Vacuum pump 7...Nozzle 9...Trap

Claims (1)

[Claims] (1) A semiconductor wafer characterized by having a hot plate for heating a semiconductor wafer, a chamber for maintaining an atmosphere surrounding the heated semiconductor wafer in a reduced pressure state, and means for purging gas into the chamber. Moisture removal equipment.