JPH0358418A - Wafer vacuum drying device - Google Patents

Abstract

PURPOSE:To make it possible to cut down the drying time by a method wherein a cover, which is closely fixed to a supporting stand when the stand moves up, is provided, a recessed part of small volume covering a wafer is formed in the rear surface of the cover, and the recessed part is communicated with a source of vacuum. CONSTITUTION:A wafer supporting stand 4 freely movably vertically and a cover 7, which is closely fixed to the supporting stand when the stand moves up, are provided. A recessed part 8 of small volume covering the wafer A is formed in the rear surface of the cover 7, and the recessed part 8 is communicated with a source of vacuum. The wafer A washed in a washing process is carried on a conveyer, and it is placed on a protruding mount 5 of the supporting stand. Then, the supporting stand moves up, the cover 7 is closely fixed to the supporting stand through a sealing material 6. When a switching valve 10 is switched to the side of a vacuum pump under the above-mentioned state, quick evaporation takes place in the recessed part 8 of small volume, and the steam is forcibly discharged. As a result, the wafer is dried up in short time, and productivity can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vacuum drying apparatus for disc-shaped wafers that serve as substrates for ICs and transistors. Here, the wafer is formed by thinly slicing a cylindrical single crystal (of silicon or the like) called an ingot.

[Prior Art] Such a conventional device uses centrifugal force to shake off cleaning liquid and the like. Alternatively, a vacuum drying device was known.

[Problems to be Solved by the Invention] In the above-mentioned apparatus that uses centrifugal force to shake off cleaning liquid, etc., there is a drawback that the shaken-off cleaning liquid scatters and adheres to the wafer, bringing in contamination from the surrounding area. .

On the other hand, vacuum drying equipment theoretically has the double effect of evaporating the cleaning liquid and forcing the steam out. It is possible to prevent the above-mentioned drawbacks. For this reason, vacuum drying equipment is partially used for cleaning circuit parts and the like.

However, in conventional vacuum drying apparatuses, no particular improvements have been made to the vacuum mechanism. That is, in the conventional vacuum drying apparatus, there is a problem in that it takes time to draw a vacuum, making it difficult to improve productivity.

In response, a technique has been proposed in which a load lock mechanism is used in combination to shorten the time required for evacuation, but even when such a load lock mechanism is used, the time required for evacuation is relatively long. Drying time is also longer
Another problem is that the entire vacuum drying apparatus becomes huge.

The present invention was proposed in view of the problems of the prior art described above, and an object of the present invention is to provide a wafer vacuum drying apparatus that can shorten drying time.

[Means for Solving the Problems] A wafer vacuum drying apparatus according to the present invention includes a support base that supports a wafer and is movable up and down, and a lid body that is brought into close contact with the support base when the support base is raised. A small-volume recess is formed on the lower surface of the body to cover the wafer, and the recess is connected to a vacuum source.

It is preferable to interpose a sealing member such as an O-ring between the support base and the lid.

Further, it is preferable that a plurality of cone-shaped wafer placement protrusions on which wafers are placed protrude from the upper surface of the support base.

Further, it is preferable that the vacuum source is constituted by a vacuum pump, and a switching valve for selectively switching the recess to the vacuum pump side or the atmosphere side is interposed in the pipeline connecting the pump and the recess.

Further, it is preferable to provide the lid with a heating device to promote evaporation and further shorten the drying time.

Although it is preferable to place one wafer on the support stand, it is also possible to place a plurality of wafers on the support stand.

[Function] In the wafer vacuum drying apparatus of the present invention configured as described above, during drying, the wafer cleaned in the cleaning step is first conveyed by the conveyor and placed on the mounting protrusion of the support table. be placed. Next, the support base is raised, and the lid body is brought into close contact with the support base via the sealing material.

When the switching valve is switched to the vacuum pump (operating) side in this state, the inside of the small volume recess is rapidly evacuated, the cleaning liquid adhering to the wafer is rapidly evaporated, and the vapor is forcibly exhausted. As a result, the wafer dries in a short time.

Thereafter, the switching valve is switched to the atmosphere (inside the clean room), the support stage is lowered, and the dried wafers are stored or transported to the next processing facility.

[Example" Embodiments of the present invention will be described below with reference to the drawings.

In FIGS. 1 and 2, an air cylinder 2 is erected on a fixing member l by bolt connection or the like. A disk-shaped wafer support 4, which is a support member, is fixed to the upper end of the piston rod 3, and a plurality of (three in the illustrated example) cone-shaped wafer mounting protrusions are provided on the upper surface of the support 4. Section 5 is set up. Further, an O-ring 6, which is a sealing member, is provided near the peripheral edge.

On the other hand, a cover 7 which is a lid body faces the wafer support 4.
is provided, and four parts 8 are formed on the lower surface thereof. Here, the inner volume of the recess 8 is set to be small so as to cover the cover while providing a narrow gap between the wafer A and the cover 8.

The recess 8 is selectively connected to a vacuum pump (not shown) serving as a vacuum source or to the atmosphere via an exhaust pipe 9 via a switching valve 10 .

When drying the wafer A, the wafer A, which has been completely cleaned in the cleaning process, is transported by a wafer transport machine (not shown) and placed on the wafer mounting projections 5 .

Next, the air cylinder 2 is extended and the wafer support 4 is raised via the piston rod 3, and the O-ring 6 is raised.
The cover 7 and the wafer support 4 are brought into close contact with each other via.

Then, operate the switching valve 10 to switch to the vacuum pump side,
The air in the small volume four parts 8 is evacuated. As a result, the inside of the recess 8 is rapidly evacuated, the cleaning liquid adhering to the wafer A is rapidly evaporated, the vapor is forcibly evacuated by the vacuum pump, and the wafer A is dried in a short time.

Finally, the switching valve 10 is switched to the atmosphere side (inside the clean room) to release the vacuum state within the recess 8.

Then, the air cylinder 2 is contracted to lower the wafer support 4, and the dried wafer A is transported to the next process by the wafer transport machine. Therefore, extremely clean gas air can be used during the vacuum break.

[Effects of the Invention] Since the present invention is configured as described above, the inside of the small volume recess is rapidly evacuated using a vacuum pump, the cleaning liquid adhering to the wafer is rapidly evaporated, and the vapor is released. Forced exhaust can be performed.

Thereby, the wafer can be dried in a short time and productivity can be improved. At the same time, it is possible to achieve a reduction in size and weight compared to conventional vacuum drying equipment.

[Brief explanation of drawings]

FIG. I is a partially sectional side view showing one embodiment of the present invention, and FIG. 2 is a top view of a wafer support. 2●...Air cylinder 4●●●Wafer support
7・●・Cover 8●・・Part 4'J Diagram

Claims (1)

[Claims] The device includes a support stand that supports a wafer and is movable up and down, and a lid that comes into close contact with the support when the support is raised, and a small-volume recess is formed on the lower surface of the lid so as to cover the wafer. A wafer drying apparatus characterized in that the recess is connected to a vacuum source.