JPS6221227A - Drying device - Google Patents

Abstract

PURPOSE:To prevent the readhesion of scattering liquid, dust and the like by a method wherein the materials to be dried up such as a semiconductor wafer and the like are placed in a drying chamber, and before drying them up by blowing gas against them, an air intake hole for drying process and an air- intake hole for exhaust of the gas of different kind for a forcible evacuation of the drying chamber are provided. CONSTITUTION:A shaft 10 driven by a motor 11 located outside a drying chamber is penetrated the flat cylindrical drying chamber 3, a circular flat plate- formed rotor 4 is attached to the upper end of said chamber 3, and the semiconductor wafer to be dried up is adhered on the rotor 4. According to this constitution, an intake hole 6 wherein N2 gas for drying is provided directly above the rotor 4, and a plurality of intake holes 8 for blowing of clean air going to the direction of the outer circumference are provided on the outer circumference of the chamber 3. Thus, a wet wafer is dried up by N2 gas and after the wafer is dried up, clean air 7 is exhausted from an exhaust hole 9 provided on the lower surface of the chamber 3, and all the foreign substances are removed completely.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a drying technique, particularly to a technique that is effective when applied to drying wafers in the manufacture of semiconductor devices.

[Background Art] For example, in a semiconductor device manufacturing process, liquid treatment, cleaning treatment, and drying treatment are repeated in a wafer treatment step.

Here, when drying a wafer, a so-called spin drying apparatus is known, in which the wafer is held on a rotor, and an inert gas such as nitrogen gas is sprayed from the upper center of the rotor while rotating the rotor at high speed.

This spin drying device dries the wafer surface using the centrifugal force generated by the rotation of the rotor and the spraying of gas. However, in the spin drying device with the above structure, foreign matter such as liquid or dust that is scattered due to the high speed rotation of the rotor is transferred to the rotor. When the rotor's rotation decelerates, these foreign particles re-adhere to the wafer and form so-called water marks, which cause local abnormal oxidation of the wafer and lead to defective semiconductor devices. The present inventor has clarified that there is a possibility that

Regarding this point, it may be possible to increase the supply amount of nitrogen gas, which is a gas for drying processing, to improve exhaust efficiency and prevent the foreign matter from re-adhering to the wafer. The inventor further revealed that the cost is high.

An example of a wafer drying technique that describes wafer drying technology is "Electronic Materials 4, March 1983 issue, pages 68 to 71, published by Kogyo Kenkyukai Co., Ltd., March 1, 1983.

[Object of the Invention] An object of the present invention is to provide a drying technique that prevents foreign matter such as liquid and dust scattered from the object to be dried from re-adhering to the object to be dried.

Another object of the present invention is to provide a drying apparatus that improves exhaust efficiency without increasing the amount of drying gas supplied and has a low cost and highly reliable drying capacity.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Summary of the Invention] A brief overview of typical inventions disclosed in this application is as follows.

In other words, by opening an inlet that supplies drying gas and an inlet that supplies exhaust gas for forced exhaust, liquids, dust, etc. that are scattered by the drying gas that has passed through the surface of the object to be dried are removed. Since the foreign matter is immediately discharged to the outside by the flow of exhaust gas without floating around the object to be dried, it is possible to prevent foreign objects such as scattered liquid and dust from re-adhering to the object to be dried. [Example] Fig. 1 is a sectional view of a drying device which is an embodiment of the present invention, Fig. 2 is a perspective view showing a rotor used in this embodiment, and Fig.
The figure is a partial sectional view showing a state in which a wafer guide holding plate and a lid body are attached to the rotor.

The drying apparatus 1 of this embodiment is a so-called spin drying apparatus for drying semiconductor wafers 2 after liquid processing such as cleaning, and a rotor 4 rotatably mounted in a flat cylindrical drying chamber 3. It is something that you have.

At the center of the upper surface of the drying chamber 3 is a drying gas inlet 6 that vertically supplies nitrogen gas 5 as a drying gas.
Further, on the outer periphery of the drying processing gas inlet 6, there are a plurality of rows of exhaust gas inlets 8 in the circumferential direction for supplying clean air 7 as an exhaust gas toward the outer circumference inside the drying chamber 3. It is set up. At the bottom near the outer periphery of the drying chamber 3, a plurality of exhaust ports 9 are provided in the circumferential direction for exhausting nitrogen gas 5 and clean air 7 together with liquid, dust, and the like.

A disk-shaped rotor 4 (rotating body) is attached to the center of the inside of the drying chamber 3 so as to be freely rotatable by a motor 11 via a shaft 10 . The rotor 4 has a pair of wafer guides 13 for holding a semiconductor wafer 2 to be dried on a disc-shaped base 12, and further has a wafer guide holding plate 14 and a lid 15 on top of the pair of wafer guides 13. There is. The semiconductor wafer 2 is held by a wafer guide 13 and is connected to the base 12 and the wafer guide 1.
4 with a slight gap as a nitrogen gas passage 16 between them.

The wafer guide holding plate 14 transfers the nitrogen gas 5 to the semiconductor wafer 2.
As shown in FIG. 3, nitrogen gas 5 is blown onto the held semiconductor wafer 2 from an obliquely upward direction. Also, the lid body 15
is provided with an intake port 18 for taking in nitrogen gas, and this is located at a position corresponding to the drying process gas intake port 6 of the drying chamber 3.

The operation of this embodiment will be explained below.

The semiconductor wafer 2 is horizontally inserted into one of the wafer guides 13 on the base by a mass loader (not shown) to hold the wafer, and then the pop-out prevention pins 19 are made to protrude from the bottom of the base.

Next, while the rotor 4 is rotated by the motor 11, nitrogen gas 5 is supplied from the drying gas intake port 6, and at the same time, clean air 7 is supplied from the exhaust gas intake port 8. Nitrogen gas 5 is supplied to the intake port 18 as shown in FIGS. 1 and 3.
The opening 17 of the wafer guide holding plate 14 inside the rotor 4
It passes over the semiconductor wafer 2 via the nitrogen gas passage 16 and scatters water droplets and the like on the semiconductor wafer 2 toward the outer circumference.

On the other hand, the scattered water droplets and dust J in the drying chamber 3 are forcibly exhausted to the outside from the exhaust port 9 by the clean air 7 supplied from the exhaust gas intake port 8 .

The semiconductor wafer 2 that has been dried in this way is stored in an unloader (not shown), and the drying process is completed.

As described above, according to the present embodiment, in addition to the drying process intake 06 which is the intake port for the nitrogen gas 5, the exhaust gas intake port 8 as the clean air intake port is provided, so that the semiconductor Liquid, dust, etc. scattered from the surface of the wafer 2 are immediately discharged to the outside from the exhaust port 9 by the flow of clean air 7 without floating in the drying chamber.

Therefore, even if the rotor 4 rotates at a low speed, the drying process of the semiconductor wafer 2 can be completed without the scattered liquid, dust, etc. re-adhering to the semiconductor wafer 2.

In addition, by using nitrogen gas 5 as the drying gas and clean air 7 as the exhaust gas, it is possible to increase exhaust efficiency without using a large amount of nitrogen gas 5.
It becomes possible to reduce the cost of drying processing.

[Effects] (1) A structure in which a drying processing gas inlet for supplying the gas into the drying chamber and an exhaust gas inlet for supplying exhaust gas for forcibly exhausting the drying chamber are provided. As a result, foreign matter such as scattered liquid and dust is forcibly exhausted by the flow of the exhaust gas without floating in the drying chamber, thereby preventing the foreign matter from adhering to the wafer again.

(2) By using different types of gases as the drying gas and the exhaust gas, the exhaust efficiency can be increased without using a large amount of the drying gas, thereby reducing the cost of the drying process.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the Examples and can be modified in various ways without departing from the gist thereof. Nor.

For example, the wafer holding portion of the rotor is not limited to the one described in the embodiment, and a single holding portion may be used to hold a large diameter wafer.

In this case, even large diameter wafers can be dried with high reliability.

Furthermore, the wafer holding section may have a structure that holds a plurality of wafers in parallel.

Furthermore, it is needless to say that the gas is not limited to the nitrogen gas and clean air described in the embodiments, but may also be nitrogen gas, clean air, and other gases whose temperature has been appropriately adjusted.

[Field of Application] In the above explanation, the invention made by the present inventor was explained as a field of application, which is the background of the invention, which is the application to the so-called drying of semiconductor wafers, but the present invention is not limited to this. However, it is an effective technique that can be widely applied to drying other semiconductor-related parts such as photomasks, or other articles.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a drying device that is an embodiment of the present invention, Fig. 2 is a perspective view showing a rotor used in the embodiment, and Fig. 3 is a rotor used in the embodiment with a wafer guide holding plate and a lid. It is a partial sectional view showing the state where the body is attached.

Claims (1)

[Scope of Claims] 1. A drying device having a drying chamber for drying an object by blowing gas onto it, comprising: a drying gas inlet for supplying the gas into the drying chamber; A drying device characterized by having an exhaust gas inlet for supplying exhaust gas for forced exhaust. 2. The drying apparatus according to claim 1, wherein the drying gas and the exhaust gas are different types of gas. 3. The drying apparatus according to claim 2, wherein the drying gas is nitrogen gas and the exhaust gas is clean air. 4. The drying apparatus according to claim 1, wherein the drying process is performed while rotating the material to be dried at high speed.