KR100223331B1 - Wafer cleaning method and apparatus therefor - Google Patents

Abstract

The present invention relates to a wafer cleaning apparatus and a wafer cleaning method, wherein, in a wafer cleaning method for removing organic matter from a wafer surface, the wafer is cleaned by a wet cleaning method using ozone water in an ozone water spray chamber and the wafer is washed with ultrapure water. After drying the wafer, the wafer is moved to the HF vapor chamber to remove the oxide film generated during the cleaning process in the ozone water spray chamber by dry cleaning to remove the organic material on the wafer surface and the oxide film generated on the wafer surface. As a result, the semiconductor device manufacturing process, which is a subsequent process, can be easily performed, thereby improving characteristics and reliability of the semiconductor device.

Description

Wafer Cleaning Equipment and Wafer Cleaning Method

1 is a cross-sectional view of an ozone water spray chamber according to the present invention.

2 is a schematic view showing the cleaning equipment according to the present invention.

* Explanation of symbols for main parts of the drawings

11,13,17: chamber door 15: robot part

21: ozone water spray chamber 23: rinse chamber

25: wafer holder 27: wafer

29: ozone water spray nozzle 31: ultrapure water nozzle

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer cleaning apparatus and a wafer cleaning method, and more particularly, to a technology for removing organic matter present on an enlarged wafer surface.

Currently, wafers with a diameter of 200 mm or less are mainly used for wet cleaning. However, large diameter wafers with a diameter of 300 mm or more increase the specific gravity of dry cleaning, and the cleaning method performs a plurality of wafers at once as the size of the wafer increases. It changes from a batch form to a single sheet type wafer to be cleaned one by one.

However, the dry cleaning alone is not as effective as the conventional wet cleaning, and thus does not completely remove contaminants present on the surface of the way surface.

In particular, sulfuric acid cleaning, which is a conventional wet cleaning method for removing organic matter, has to be performed at a high temperature process of 100 ° C. or more, and it is not easy to control the temperature and takes a considerable time to reach an appropriate temperature.

In order to solve the above disadvantages, dry cleaning using ozone gas or wet cleaning is performed.

However, in the case of dry cleaning using the ozone gas, the concentration of the ozone gas is very high, but the activity of oxygen radicals generated from the ozone is reduced, so that a substantial cleaning process effect cannot be obtained. There is a problem of deteriorating characteristics and reliability.

Table 1 shows the reduction effect of carbon when ozone gas was flowed for 20 seconds at a flow rate of 3 lpm (liter / min) on the surface of a carbon-based organic material contaminated wafer. There was little effect.

TABLE 1

In addition, in the case of the wet cleaning, there is a problem in that a large-sized wafer and a large amount of compounds are required to clean the large-diameter wafer, thereby increasing productivity and cost of additional equipment and production.

Therefore, in order to solve the above problems, the present invention provides an ozone spray chamber for spraying ozone water dissolved in ultrapure water on a wafer by a spray method and an HF vapor chamber for removing unnecessary oxide film. A second object is to provide a connected wafer cleaning apparatus, and a second object is to provide a large-diameter wafer cleaning method using the two kinds of chambers.

Features of the wafer cleaning apparatus to achieve the above first object,

A robot unit capable of moving the wafer between chambers;

An ozone water spray chamber connected to one side of the robot unit, a rinse chamber provided at a lower side thereof, and an ozone water spray nozzle disposed at an upper side thereof;

An HF vapor chamber connected to the other side of the robot unit;

It is configured to include a chamber for forming a semiconductor device connected to the other side of the robot.

In addition, the wafer cleaning method for achieving the second object is a feature,

In the wafer cleaning method for removing organic matter on the wafer surface,

Cleaning the wafer by a wet cleaning method using ozone water in an ozone water spray chamber;

Washing the wafer with ultrapure water and drying the wafer;

And moving the wafer to the HF vapor chamber to remove the oxide film generated during the cleaning process in the ozone water spray chamber by a dry cleaning method.

The principle of the present invention for achieving the above first and second objects is to remove the organic matter on the surface of the wafer by a wet cleaning method using ozone water in the ozone spray chamber, and dry cleaning using HF vapor in the HF wafer chamber continuously The cleaning effect is improved by removing the oxide film generated during the wet cleaning process.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 and 2 are schematic diagrams of a wafer cleaning apparatus according to the present invention.

FIG. 1 is a cross-sectional view showing a multichamber in which an ozone water spray chamber 21 is positioned on an upper side and a rinse chamber 23 is positioned on a lower side, and is for removing organic matter on a large diameter wafer surface.

First, the wafer 27 is fixed to the wafer holder 25 and the wafer holder 25 is raised to the ozone water spray chamber 21 so as to be positioned at ⓐ. The wafer 27 is rotated by rotating the holder 25 and the ozone water is sprayed through the ozone water nozzle 29 by spraying to clean the surface of the wafer 27 for a time of about 5 to 10 minutes. .

Here, the ozone water is formed by dissolving ozone gas in ultrapure water at a concentration of 10 to 20 ppm. The holder is rotated at a speed of 20 to 100 rpm (revoltion / min).

Next, move the adjuster 25 to the lower rinse chamber 23 to be located at ⓑ. Ultrapure water is injected through the ultrapure water nozzle 31 to wash the wafer 27, and the wafer 27 is rotated at a high speed to dry.

The above process removes the carbon-based organic matter attached to the surface of the wafer 27, and then oxidizes the surface of the wafer 27, in particular, the surface where silicon is exposed, thereby forming an oxide film formed in the form of a silicon oxide film having a thickness of 5 to 10 Å. To form. In addition, in the gate oxide film process using the thin dielectric film or the electrode deposition process for connecting the electrodes, the oxide film causes problems such as deterioration of the gate oxide film property or increase of contact resistance between the electrodes.

(Figure 1)

2 is a robot part for moving the wafer to D, which is a chamber for forming a semiconductor device on a wafer which has been processed in the ozone water spray chamber, B is an HF vapor chamber, and C is an ozone water spray chamber and an HF vapor chamber. It is a schematic diagram showing.

After the process in the ozone water spray chamber A as shown in FIG. 1, dry cleaning is performed in the HF vapor chamber B to remove the oxide film formed on the surface of the wafer 27. At this time, the dry cleaning process is carried out continuously by moving from the A to the B part by the robot of C which is the robot part.

Then, the wafer 27 is moved from the B portion, which is the HF vapor chamber, to the D portion, and a subsequent process is performed to form a semiconductor device.

Here, 11, 13 and 17 show each chamber door. (Figure 2)

Table 2 shows that when ozone gas is dissolved in ultrapure water, the carbon reduction effect is very excellent despite the low concentration of ozone gas dissolved in ultrapure water. (Table 2) Thickness reduction effect of ozone water treatment on photoresist (carbon-containing film)

TABLE 2

Table 2 shows the results of oxygen radicals generated from ozone dissolved in ultrapure water, which is highly active due to the influence of ultrapure water, and reacts with carbon to match the washing effect by ultrapure water.

As described above, the wafer cleaning equipment and the wafer cleaning method are characterized in that the semiconductor device is subjected to a subsequent process by cleaning the wafer by a wet cleaning method using ozone water in an ozone water spray chamber and a dry cleaning method in an HF vapor chamber. There is an advantage in improving reliability.

Claims (6)

A robot unit capable of moving the wafer between chambers; An ozone water spray chamber connected to one side of the robot unit, a rinse chamber provided at a lower side thereof, and an ozone water spray nozzle disposed at an upper side thereof; An HF vapor chamber connected to the other side of the robot unit; And a chamber for forming a semiconductor device connected to the other side of the robot unit. A wafer cleaning method for removing organic matter on a wafer surface, the method comprising: cleaning the wafer by a wet cleaning method using ozone water in an ozone water spray chamber; Moving the wafer to a rinse chamber, washing with ultrapure water, and drying the wafer; Moving the wafer to the HF vapor chamber to remove the oxide film caused during the cleaning process in the ozone water spray chamber by a dry cleaning method. The method of claim 2, The ozone water is a wafer cleaning method, characterized in that formed by dissolving ozone gas in ultrapure water. The method of claim 2 or 3, The ozone water is a wafer cleaning method, characterized in that the ozone concentration of 10 to 20 ppm. The method of claim 2 or 3, The warm water spray cleaning process is a wafer cleaning method, characterized in that performed for 5 to 10 minutes while rotating the wafer at 20 ~ 100rpm. The method of claim 2, And the dry cleaning process is performed continuously after the wet cleaning process.