JPH0574754A - Etching system - Google Patents

Abstract

PURPOSE:To prevent a natural oxide film which deteriorates a semiconductor element in characteristics from being formed in and after an etching process. CONSTITUTION:Nitrogen gas is made to flow nearly in parallel with a direction in which chemical liquid and cleansing water are made to drip, nitrogen gas inside an etching chamber 2 and a cleaning chamber 6 is enhanced in gas pressure to stop air from penetrating into an opening, the wafer subjected to etching is housed in a container 10 filled with nitrogen gas.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention rotates a wafer, which is a semiconductor substrate, drops a chemical solution on the surface of the wafer to scatter the chemical solution on the surface for etching, and cleans the etched wafer by dropping pure water or the like. , An etching apparatus for rotating a wafer at a high speed to dry the wafer.

[0002]

2. Description of the Related Art Conventionally, although not shown in the drawings, an etching apparatus of this type includes a first stage on which a wafer is placed and rotated, and a first nozzle for dropping a chemical solution onto the surface of the rotating wafer. It has a second stage on which the etched wafer is placed and which rotates, and a second nozzle which drops pure water onto the wafer surface.

When etching a wafer using the etching apparatus as described above, first, the wafer is loaded from the first stage to the second stage by the loader.
Next, while rotating the first stage at high speed, the chemical liquid is dropped onto the wafer surface by the first nozzle. As a result, the chemical spreads on the wafer surface and is etched.
Next, the wafer is moved from the first stage to the second stage by the loader.
Will be transferred to the stage. Next, the second stage is rotated and pure water is dropped onto the wafer surface from the second nozzle. This spreads the pure water on the wafer surface,
The adhering drug solution is poured out and washed. Next, the wafer is sped up to scatter the water remaining on the wafer and dried.

This etching apparatus has been widely used in the semiconductor device manufacturing process because it can be processed more rapidly than other etching apparatuses. Further, a series of operations from etching processing to drying has been performed in a normal atmosphere in a room.

[0005]

However, in the conventional etching apparatus, since this series of operations is performed in the atmosphere of air, there is a drawback that a natural oxide film is formed on the wafer after etching. Further, when this natural oxide film is formed, for example, the film quality of the gate oxide film of the transistor formed on the wafer surface is deteriorated and the gate breakdown voltage is deteriorated.

An object of the present invention is to provide an etching apparatus capable of etching a wafer without forming an unnecessary natural oxide film in order to solve such a problem.

[0007]

An etching apparatus of the present invention comprises a first stage on which a wafer is placed and the wafer on which a chemical solution is dropped is rotated, and a wafer which is subjected to etching treatment is placed on a cleaning solution. An etching apparatus having a second stage for rotating the wafer to be dropped, in the etching chamber and the cleaning chamber surrounding the first and second stages, respectively, in substantially the same direction as the dropping direction of the chemical liquid and the cleaning liquid. It is characterized by comprising a detachable wafer storage box which is formed adjacent to the cleaning chamber and which forms a nitrogen gas inlet and a gas outlet.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a partially cutaway perspective view of an etching apparatus showing an embodiment of the present invention. As shown in FIG. 1, this etching apparatus is provided with an etching chamber 2 surrounding a stage 3 and a stage 7 and a cleaning chamber separately, and introducing nitrogen gas into the chambers 4 and 8 and an exhaust pipe 5 for discharging the nitrogen gas. , 9 and a detachable storage box 10 for storing the cleaned wafers.

The inlets 4 and 8 are provided above each chamber, and the exhaust pipes 5 and 9 are provided at the bottom of each chamber so that the flow of nitrogen gas does not hinder the dropping of the chemical liquid and pure water. That is, the nitrogen gas pressure in each chamber is set to about 1.1 to 1.3 atm so as to prevent the atmosphere from entering through the opening of the etching chamber 2 in contact with the loader 1. That is, the direction in which the chemical liquid and the pure water are dropped is made substantially parallel to the gas flow direction.

Next, the operation of this etching apparatus will be described. First, nitrogen gas is introduced into the etching chamber 2 through the inlet 4, and the wafer is transferred to the stage 3 by the loader 1 while increasing the pressure in the etching chamber 2. Next, the stage 3 is rotated to drop the chemical liquid on the wafer. Next, nitrogen gas is introduced into the cleaning chamber 6 through the inlet 8 to increase the pressure in the cleaning chamber 6. Next, the wafer is transferred from the stage 3 to the stage 7 by the loader 1. Next, the introduction of nitrogen gas into the cleaning chamber 6 is stopped, the stage 7 is rotated, and the wafer is cleaned with pure water. Next, the stage 7 is rotated at high speed to dry the wafer. Next, the loader 1 stores the wafer from the stage 7 in the storage box 10 filled with nitrogen gas. In this way, etching cleaning and drying are sequentially performed, and when all the wafers are stored in the storage box 10, the storage box 10 is removed from the apparatus and transported to the subsequent process.

As described above, since the atmosphere is not exposed at all from the etching process to the drying, a natural oxide film is not formed on the wafer. In addition, nitrogen gas is used because it is inexpensive, and other inert gases can be used.

[0012]

In addition to the above-described effects, the present invention prevents the chemical solution and pure water from being dripped by the gas flow through the inlet and the outlet of the nitrogen gas in the etching chamber for etching the wafer and the cleaning chamber for rinsing and drying. So that the gas pressure in each room rises above the atmospheric pressure and air is blocked from opening.
In addition, by filling the storage box for storing processed wafers with nitrogen gas, which is easy to attach and detach, there is no contact with air during the series of processing such as etching, cleaning and drying of the wafers. The effect is to obtain an etching apparatus that can perform processing without forming an oxide film.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view of an etching apparatus showing an embodiment of the present invention.

[Explanation of symbols]

 1 Loader 2 Etching Chamber 3,7 Stage 4,8 Inlet Port 5,9 Exhaust Pipe 6 Cleaning Room 10 Storage Box

Claims (1)

[Claims] 1. A first stage for placing a wafer and rotating the wafer on which a chemical solution is dropped, and a second stage for placing the wafer to be etched and rotating the wafer on which a cleaning solution is dropped. In the etching apparatus having the stage of 1., a nitrogen gas inlet and a gas outlet are formed in the etching chamber and the cleaning chamber surrounding the first and second stages, respectively, in substantially the same direction as the dropping directions of the chemical liquid and the cleaning liquid. An etching apparatus comprising a removable wafer storage box disposed adjacent to the cleaning chamber.