JPH0722376A - Wafer treatment equipment - Google Patents

Abstract

PURPOSE:To enable a wafer of large diameter to be uniformly treated through a wet manner with a small amount of treatment liquid and dried out in a short time by a method wherein a laminar flow of gas is provided between the wafer and a treatment chamber. CONSTITUTION:A cleaning chamber is of double-structure or composed of an inner chamber 11 and an outer chamber 12, and a load/unload chamber 13, a transfer robot chamber 14, and the cleaning chamber can be exhausted by a vacuum pump 15. Nitrogen is fed to the inner chamber 11, a heating means 21 is fixed to a nitrogen gas line so as to feed heated nitrogen to the inner chamber 11. A gas jet nozzle 22 is formed round, whereby a uniform laminar flow can be formed. In this case, it is effective that the product of the velocity and thickness of a laminar flow is set larger than 0.1m<2>/s. Or, a laminar flow of gas may be made to blow against the inner wall of a chamber. Furthermore, an aspirator 23 is provided to an exhaust/drainage system so as to carry out an exhaust/drain action at a high speed by suction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor cleaning / drying apparatus, and more particularly to a wafer processing apparatus which has good in-plane uniformity and can process a wafer with a small amount of liquid when cleaning a large-diameter wafer.

[0002]

2. Description of the Related Art A conventional batch type washing and drying apparatus is disclosed in
As disclosed in Japanese Laid-Open Patent Application No. 56-168072 and Japanese Utility Model Laid-Open No. 59-138232, a vapor dryer for washing a wafer with water and then replacing the moisture with alcohol to dry the wafer;
No. 7, as described in JP-A-61-267230,
There is a warm air drying device that blows warm air onto the substrate to dry it. Further, the conventional single-wafer cleaning device is disclosed in Japanese Patent Laid-Open No. 4-100231.
As described in the official gazette, after cleaning, the wafer is rotated by a rotary stage to blow gas to dry it, or as described in JP-A-2-237029, the wafer is ramped after being cleaned. It had a structure of drying by heating.

[0003]

The conventional batch-type cleaning / drying apparatus has a problem that a large amount of processing liquid is required when the diameter of the wafer is large and the cost is high.
Further, in the single-wafer cleaning / drying apparatus, the liquid cannot be uniformly etched when performing wet etching due to the splashing of the liquid from the chamber, and when the wafer is rotated and dried, the liquid on the wafer remains in the chamber. There is a problem that the liquid cannot be dried in a short time because the liquid adheres to the upper part and the liquid adheres to the wafer to cause liquid dripping. further,
In the heating and drying apparatus, there is a problem that a watermark is generated due to a liquid such as pure water remaining on the wafer surface.

It is an object of the present invention to provide a wafer processing apparatus capable of uniformly performing wet etching or cleaning with a small amount of processing liquid even on a large-diameter wafer and drying it in a short time.

[0005]

The above objective is accomplished by providing a laminar flow of gas between the wafer and the processing chamber during wet processing of the wafer. FIG. 1 is a diagram showing a processing chamber of a wafer processing apparatus according to the present invention.
The processing chamber 1 has an oval shape as shown in the figure, and a nozzle 2 for radially injecting gas is provided on the upper portion of the chamber. In this case, the egg shape includes a spherical shape, a spheroid, etc., and may be any shape that does not particularly generate turbulence. In this processing chamber, the wafer 3 is rotated by a rotating stage 4 equipped with a rotating mechanism for cleaning and drying. At this time, the wafer 3
Is fixed by a wafer chuck 5 which fixes the end portion by sandwiching it. With such a structure, a laminar flow of gas always exists between the processing chamber and the wafer.
Therefore, when the liquid is jetted from the front surface jet nozzle 6 and the back surface jet nozzle 7 while the wafer is rotated for processing, the liquid dispersed from the wafer is removed downward by the gas and splashes from the processing chamber to the wafer. There is no. Further, the liquid does not adhere to the chamber. Further, the same effect can be obtained even if the gas is blown to the inner wall of the chamber.

[0006]

According to the present invention, when cleaning or wet etching is performed, all the liquid scattered from the rotating wafer can be eliminated by the gas flow, so that the liquid does not splash back to the wafer and is uniformly distributed within the wafer surface. Cleaning or wet etching can be performed with good controllability. Further, since the liquid does not adhere to the processing chamber and can be dried in a short time, for example, the natural oxide film growing on the Si surface can be controlled to the minimum. Further, since there is no liquid left on the wafer surface and there is no need to heat and dry, there is an advantage that no watermark is generated.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 is a block diagram of a wet processing apparatus to which the present invention is applied. In consideration of airtightness and safety, the cleaning chamber has a double structure of an inner chamber 11 and an outer chamber 12 made of Teflon. Each of the load / unload chamber 13, the transfer robot chamber 14, and the cleaning chamber has a structure capable of being evacuated by the vacuum pump 15, so that gas replacement can be performed in a short time. At this time, a vacuum valve 16 is provided in the exhaust pipe of each chamber and a gate valve 17 separates each chamber from each other so that each chamber can be evacuated independently. In addition, measurement room 1
8 is provided so that infrared spectroscopy, X-ray photoelectron spectroscopy and the like can be performed without exposing the surface state of the processed wafer to the atmosphere.
The chemical solution is supplied from the chemical solution tank 19, and the supply pipe is shared with pure water. A valve 20 is attached to each of the chemical liquid and pure water supply systems in order to prevent mixing of the liquid and to purge the inside of the pipe with nitrogen after cleaning.

Nitrogen is supplied to the inner chamber 11, and a heating device 21 is attached to the nitrogen gas line so that heated nitrogen can be supplied. At this time, an inert gas or dry air may be used instead of the nitrogen gas. By making the gas injection nozzle 22 circular, a uniform laminar flow can be formed. In this case, it is effective to set the product of the flow velocity of the laminar flow and the layer thickness to be 0.1 m ² / s or more. Further, the structure may be such that gas is blown against the inner wall of the chamber. further,
An aspirator 23 is attached to the exhaust / drainage system so that high-speed waste liquid and exhaust can be performed by suction. The wafer stage 24 has a structure capable of rotating up to 2000 times per minute. In addition, if the load / unload chamber has a removable structure and is also used as another process device, an oxide film, a metal film, or the like can be formed without being exposed to the atmosphere after cleaning.

In this embodiment, the wafer chuck portion of the transfer robot 25 has a structure that can be easily removed, and Teflon is used as the material so that cleaning can be performed easily. further,
A sampling tube 26 for measuring the water concentration in the gas inside the inner chamber was provided. The structure of the inner chamber was an egg type as shown in FIG. When adsorption of fine particles due to generation of static electricity becomes a problem in this apparatus, it may be combined with other static electricity removing apparatus.

FIG. 3 shows the cleaning of a Si wafer by this apparatus.
It is the figure which showed the water | moisture density in nitrogen gas at the time of drying at the time of drying with respect to drying time. The wafer was rotated at 100 rpm to supply pure water, cleaning was performed for 30 seconds, and then the wafer was dried at 1000 rpm. In this experiment, the product of the flow velocity of the laminar flow and the layer thickness was set to 0.3 m ² / s, and the amount of water with and without the flow of nitrogen gas for forming the laminar flow was measured. In either case, nitrogen is blown onto the front and back surfaces of the wafer. If laminar nitrogen is formed,
It can be seen that the water concentration decreases faster than when it is not formed. In this experiment, the drying time could be reduced to about 1/3 by forming the laminar flow nitrogen as compared with the case where the nitrogen was not formed.

[0011]

According to the present invention, even a large-diameter wafer can be uniformly wet-processed in a plane with a small amount of liquid, and the drying time can be shortened. Specifically, the drying time after washing with pure water can be improved to about 1/3.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a processing chamber of a wet processing apparatus of the present invention.

FIG. 2 is a system diagram of a single wafer cleaning apparatus using the present invention.

FIG. 3 is a characteristic diagram showing the time dependence of the water content in the chamber after cleaning with pure water by the apparatus to which the present invention is applied.

[Explanation of symbols]

1 ... Processing chamber, 2 ... Gas injection nozzle, 3 ... Wafer,
4 ... Rotary stage.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Osamu Okura Inventor, Osamu Ogukeku 1-280, Higashi Koikeku, Kokubunji, Tokyo Inside the Central Research Laboratory, Hitachi, Ltd.

Claims (6)

[Claims] 1. A single wafer processing apparatus for processing wafers one by one, having a mechanism for rotating the wafer and a mechanism for supplying a liquid to the wafer, and between the wafer to be processed and a processing chamber. A wafer processing apparatus comprising a gas supply device for generating a laminar flow of gas. 2. A single wafer processing apparatus for processing wafers one by one, having a mechanism for rotating the wafer and a mechanism for supplying a liquid to the wafer, and generating a gas flow over the entire surface of the inner wall of the processing chamber. A wafer processing apparatus comprising a gas supply device for performing the operation. 3. A single wafer processing apparatus for processing wafers one by one, having a mechanism for rotating the wafer and a mechanism for supplying a liquid to the wafer, and simultaneously supplying gas to the entire inner wall of the processing chamber. A wafer processing apparatus comprising a supply device for spraying the wafer. 4. The wafer processing according to claim 1, wherein at least one of a measurement chamber, a heat treatment chamber, and a film formation chamber is provided, and the transfer between these chambers and the processing chamber can be performed in a non-atmosphere atmosphere. apparatus. 5. The wafer processing apparatus according to claim 1, wherein the gas that causes the laminar flow is nitrogen or an inert gas, or dry air. 6. The wafer processing apparatus according to claim 1, wherein the material of the processing chamber is an acid-resistant resin or a metal subjected to an inner surface treatment with an acid-resistant resin.