JP2657955B2 - Wafer vacuum drying equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum drying apparatus for a disk-shaped wafer serving as a substrate of an IC or a transistor. Here, the wafer is formed by thinly cutting a columnar single crystal (such as silicon) called an ingot.

[Prior Art] In such a conventional apparatus, a washing liquid or the like is shaken off by centrifugal force. Alternatively, vacuum drying devices have been known.

[Problems to be Solved by the Invention] In the apparatus of the above-mentioned system in which the cleaning liquid or the like is shaken off by the centrifugal force, there is a disadvantage that the washed-off cleaning liquid or the like scatters and adheres to the wafer again in a manner that brings in surrounding contamination. .

On the other hand, the vacuum drying apparatus has the dual effects of evaporation of the cleaning liquid and the above-described forced exhaust,
Theoretically, it is possible to prevent the above-mentioned drawbacks in a device of a system in which a washing solution or the like is shaken off by centrifugal force.
Therefore, the vacuum drying apparatus is partially implemented for cleaning circuit components and the like.

However, in the conventional vacuum drying apparatus, the vacuum mechanism was not particularly devised. That is, the conventional vacuum drying apparatus has a problem that it takes a long time to evacuate, and it has been difficult to improve the productivity. On the other hand, a technique of shortening the time required for evacuation by using a load lock mechanism or the like has been proposed, but even when the load lock mechanism is used, the time required for evacuation is relatively long. There is a problem that the drying time becomes long and the entire vacuum drying apparatus becomes huge.

As another prior art, Japanese Patent Application Laid-Open No. Sho 63-102234 discloses a wafer drying apparatus configured to perform drying under reduced pressure in a closed structure. However, JP-A-63-102234
In the wafer drying apparatus disclosed in Japanese Patent Application Laid-Open Publication No. H10-157, there is a problem that a relatively long time is required before the internal wafer is dried because the internal volume of the closed structure is relatively large. In addition, since it takes a long time to dry, there is a problem that the production efficiency of semiconductor products such as ICs is deteriorated, and that the entire apparatus is enlarged.

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above-described problems of the related art, and has as its object to provide a wafer vacuum drying apparatus capable of shortening a drying time and achieving downsizing of the entire apparatus.

[Means for Solving the Problems] A wafer vacuum drying apparatus according to the present invention includes a disk-shaped wafer support, which is a support member fixed on a lower fixing member, and a plurality of cones erected on the upper surface of the support. Wafer mounting projection, a seal member provided near the periphery of the wafer support, an exhaust pipe opening at the center of the wafer support, and a vacuum source side interposed in the exhaust pipe. A switching valve configured to be selectively connected to the clean room side, and a lid provided opposite to the wafer support, wherein a concave portion is formed on a lower surface of the lid, and the concave portion is formed. Is set small enough to cover the wafer while providing a narrow gap between the wafer and the lid, and the lid is fixed to a piston rod of an air cylinder suspended from an upper fixing member.

In practicing the present invention, the vacuum source is constituted by a vacuum pump, and a switching valve for selectively switching the concave portion to the vacuum pump side or the atmospheric side is interposed in an exhaust pipe connecting the pump and the concave portion. preferable.

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

Further, it is preferable that one wafer is placed on the support, but a plurality of wafers can be placed.

[Operation] In the wafer vacuum drying apparatus of the present invention configured as described above, in drying, first, the wafer cleaned in the cleaning step is transported by the transporter and placed on the mounting projection of the support base. Is placed. Next, by extending the piston rod of the air cylinder suspended from the upper fixing member and lowering the lid, the lid is brought into close contact with the support base (wafer support) via the sealing material.

In this state, when the switching valve is switched to a vacuum pump (during operation), which is a vacuum source, the inside of the small-volume concave portion is rapidly evacuated, the cleaning liquid attached to the wafer evaporates rapidly, and the wafer is short-lived. Dry with. Then, since the vapor of the cleaning liquid is forcibly discharged to the vacuum pump side, there is a small possibility that the component of the vapor adheres to the drying device and adheres to the semiconductor product.

Thereafter, the switching valve is switched to the atmosphere side (inside the clean room), and the piston rod of the air cylinder is contracted to raise the lid. Then, the dried wafer may be stored or transported to the next processing facility.

As described above, according to the present invention, the inside of the small volume concave portion is rapidly evacuated by the vacuum pump, the cleaning liquid attached to the wafer is rapidly evaporated, and the vapor can be forcibly exhausted.

Here, the inner volume of the concave portion formed on the lower surface of the lid is set small enough to cover the wafer while providing a narrow gap between the wafer and the lid, so that compared to the related art,
The time spent for evacuation or the time until the cleaning liquid remaining in the recess completely evaporates becomes very short.
Therefore, the wafer can be dried in a short time as compared with the related art, and the productivity is improved.

Further, in connection with the fact that the volume of the concave portion is set to be small, the wafer vacuum drying apparatus of the present invention is smaller and lighter than the conventional apparatus.

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

In FIGS. 1 and 2, a disk-shaped wafer support 2 as a support member is fixed on a fixing member 1. On the upper surface of the support 2, a plurality of (three in the illustrated example) cone-shaped wafer mounting projections 3 are erected, and an O-ring 4 as a sealing member is provided near the periphery. . Further, it is selectively connected to a vacuum pump (not shown) or an atmosphere (clean room) side, which is a vacuum source, via an exhaust pipe 5 and a switching valve 6 opened at the center of the upper surface of the support 2.

On the other hand, a cover 7 serving as a lid is provided facing the wafer support 2, and a concave portion 8 is formed on the lower surface thereof. Here, the inner volume of the recess 8 is set small so as to cover the wafer while providing a narrow gap between the wafer A and the cover 7. The cover 7 is fixed to a piston rod 8 of an air cylinder 9 suspended from a fixing member 10.

At the time of drying the wafer A, the wafer A that has been cleaned in the cleaning step is transferred by a wafer transfer device (not shown),
It is mounted on the wafer mounting protrusions 3. Next, the air cylinder 9 is extended and the cover 7 is lowered via the piston rod 8, and is brought into close contact with the support 2 via the O-ring 4.

Next, the switching valve 6 is operated to switch to the vacuum pump side,
The air in the small volume recess 8 is exhausted. As a result, the inside of the concave portion 8 is rapidly evacuated, the cleaning liquid adhering to the wafer A is rapidly evaporated, and the vapor is forcibly exhausted by a vacuum pump, thereby drying the wafer A in a short time.

Finally, the switching valve 6 is switched to the atmosphere (in a clean room), the air cylinder 9 is contracted, the cover 7 is raised, and the dried wafer A is transferred to the next step by the wafer transfer device. Therefore, extremely clean gas air can be used during a vacuum break.

[Effects of the Invention] Since the present invention is configured as described above,
The inside of the small volume concave portion is rapidly evacuated by a vacuum pump, the cleaning liquid adhering to the wafer is rapidly evaporated, the vapor is forcibly exhausted, and the wafer is dried in a short time, thereby improving the productivity. . At the same time, a reduction in size and weight can be achieved as compared with a conventional vacuum drying apparatus.

[Brief description of the drawings]

FIG. 1 is a side view showing a part of an embodiment of the present invention in cross section, and FIG. 2 is a top view of a wafer support. 2 ... Wafer support, 7 ... Cover 8 ... Recess, 9 ... Air cylinder

Claims (1)

(57) [Claims] 1. A disk-shaped wafer support as a support member fixed on a lower fixing member, a plurality of cone-shaped wafer mounting projections erected on the upper surface of the support, A seal member provided in the vicinity of the peripheral portion, an exhaust pipe opening at the center of the wafer support, and an exhaust pipe interposed to selectively connect to the vacuum source side and the clean room side. Switching valve, and a lid provided opposite to the wafer support, a concave portion is formed on the lower surface of the lid, and the internal volume of the concave portion is narrow between the wafer and the lid. A wafer drying apparatus characterized in that it is set small enough to cover the wafer while providing a gap, and a lid is fixed to a piston rod of an air cylinder suspended from the fixing member.