JPH05198515A - Semiconductor treatment device and semiconductor pretreatment device - Google Patents

Abstract

PURPOSE:To reduce a quantity of dust generated in a treatment chamber by installing the treatment chamber for treating a substrate to be treated, a device for heating the inside of the treatment chamber and an exhaustion system for eliminating water apart from an exhaustion system to be used in the treatment chamber and by eliminating water from the treatment chamber before starting a process. CONSTITUTION:Before starting a process, a gate valve 5 for exhaustion in the process is closed and gases excluding sedimentary material (Ar, Cl2, NF3, etc.) are brought into the inside of a treatment chamber 1 through a gas bring-in port 3 for heating the inside of the treatment chamber and the gas is exhausted through an exhaust port for water elimination 6 and then RF power is applied to generate a plasma of these gases in the treatment chamber 1. At that time, water which detaches from an inner wall is eliminated through the exhaust port for water elimination 6. This means that the inner wall of the treatment chamber is shocked by electrons or ions and the temperature of the inner wall sharply rises. On the other hand, water which still remains in the treatment chamber repeatedly attaches to and detaches from mainly the inner wall of the treatment chamber. However, water attaching to the inner wall detaches from the inner wall due to the plasma and then is exhausted. After that, the process is started.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor processing apparatus used for vapor phase epitaxy (CVD), dry etching and the like and a pretreatment method thereof.

In recent years, with the high integration of semiconductor devices, suppression of dust generation during processing and dust generation from devices has become a major issue. In particular, in the CVD and etching processes that use chemical reactions, plasma processes have come to be used more frequently as the process temperature has become lower to respond to device miniaturization.

In the case of plasma of reactive gas, reaction products are deposited on the inner wall of the processing chamber, and the deposit is the largest dust source. For example, the CVD film deposited on other than the wafer was peeled off due to the difference in expansion coefficient from the material of the inner wall of the processing chamber, and dust was generated. In the etching apparatus, a reaction product having a high vapor pressure adheres to and grows on the inner wall of the processing chamber having a relatively low temperature. As with CVD, the grown reaction product peeled off when it grew thick and generated dust.

[0004]

2. Description of the Related Art In any case of plasma CVD and etching, reaction products are deposited on the inner wall of a processing chamber, and these deposits serve as a dust source, so it is necessary to clean them regularly. Generally, cleaning includes wet cleaning and dry cleaning.

The dry cleaning employs a method in which plasma of a gas capable of etching reaction products is generated and removed. In this case, complete cleaning cannot be performed, but there is an advantage that it can be performed frequently because it can be performed easily.

In wet cleaning, the processing chamber is brought to atmospheric pressure and the processing chamber is disassembled for cleaning. The disassembled processing chamber has its inner wall cleaned with water, organic solvent, acid, etc., and also internal jigs and parts are cleaned in the same way. In some cases, ultrasonic cleaning is also used. In this way, wet cleaning requires disassembly, which lowers the operating rate of the equipment and may impair the reliability of the equipment.

Usually, the above-mentioned dry cleaning and wet cleaning are used together to reduce the burden of wet cleaning.

[0008]

As described above, in the plasma processing apparatus, the deposition of the reaction products on other than the wafer is a factor of dust generation, and therefore the dry cleaning and the wet cleaning are performed. As a result, the operating rate and reliability of the equipment have declined, so it is necessary to devise ways to extend the cleaning cycle and reduce the amount of dust generation.

An object of the present invention is to reduce the amount of dust generation, improve the manufacturing yield and reliability of devices, and improve the operating rate and reliability of processing equipment.

[0010]

[Means for Solving the Problems] 1)
A semiconductor processing apparatus having a processing chamber for processing a substrate to be processed, a means for heating the processing chamber, and an exhaust system for removing water different from an exhaust system used for processing, or 2) deposition, etching, etc. A step of heating the inside of the processing chamber before starting the processing,
A pretreatment method for a semiconductor processing apparatus including a step of removing water in the processing chamber by using an exhaust system different from an exhaust system used for processing during the heating, or 3) the heating generates a reaction product. 2) The pretreatment method for a semiconductor processing apparatus according to 2), which is performed by generating a plasma of a gas having a property that does not occur, or 4) the gas is a rare gas, a fluorine-based gas,
This is achieved by the pretreatment method for a semiconductor processing apparatus according to the above 3), which is a chlorine-based gas.

[0011]

As a result of studying dust generation in the plasma processing apparatus, the present inventor has found that moisture remaining in the processing chamber has a great influence on the generation process of fine particles and the peeling process of reaction products adhering to the inner wall of the processing chamber. I discovered that (Figs. 3-5)
reference).

FIG. 3 is a diagram showing a water peak before etching. This figure shows that the processing chamber has been cleaned and 5 × 10 ^-5 Torr
2 is a mass spectrometric result showing the partial pressure of water at the time when the ultimate vacuum of is reached. The number of generated fine particles at this time is A.

FIG. 4 is a diagram showing peaks of water after etching. Here, the processing chamber is cleaned and 5 × 10 ^-5 Torr
Shows the partial pressure of water after reaching the ultimate vacuum of 10 and etching 10 wafers. The number of generated fine particles at this time is B.

FIG. 5 is a diagram showing the relationship between the number of processed wafers and the number of fine particles (pieces / 6 inch wafer). From the figure, it can be seen that the numbers A and B of the fine particles are related to the peak value of water, and the larger the value, the larger the number of fine particles.

Therefore, the present invention provides an apparatus for removing moisture remaining in the processing chamber in a short time before the start of a process such as CVD or etching. That is, before starting the process, a gas that does not generate reaction products is introduced into the processing chamber,
RF power is applied to generate the plasma. Due to this plasma, the inner wall of the processing chamber is bombarded with electrons and ions, and the temperature rises rapidly. On the other hand, the water remaining in the processing chamber is repeatedly adsorbed and desorbed mainly on the inner wall of the processing chamber, but the adsorbed water is desorbed and exhausted by this plasma. However, if the exhaust system used in the normal process is used, this exhaust will have a large adverse effect on the exhaust pipes and the deposits adsorbed inside the equipment. Therefore, in the present invention, an exhaust system different from the exhaust system used for the process to remove water is used to remove water without side effects (see FIGS. 6 to 7 described later).

At this time, instead of using plasma for removing water, preheated gas may be purged in vacuum to raise the temperature of the inner wall of the processing chamber. Alternatively, an infrared lamp may be used as a heating method for the processing chamber.

[0017]

EXAMPLE 1 FIG. 1 is a sectional view for explaining Example 1 of the present invention. In the figure, 1 is a processing chamber, 2 is a process gas inlet, 3 is an internal heating gas inlet according to the present invention, 4 is a process exhaust port, 5 is a process exhaust gate valve, and 6 is water removal according to the present invention. An exhaust port, 7 is a gate valve for removing water, 8 is an electrode on the wafer side (wafer stage), 9 is a capacitor, and 10 is an RF power supply.

Before starting the process, the process exhaust gate valve 5 is closed, and a gas (Ar, Cl ₂ , NF ₃ , ..., Etc.) containing no deposition raw material is supplied from the internal heating gas inlet 3 to the processing chamber 1.
The gas is introduced into the chamber, exhausted through the moisture removing exhaust port 6, and RF power is applied to generate plasma of these gases in the processing chamber. At this time, the moisture separated from the inner wall is removed from the moisture removing exhaust port 6. After that, the original process is performed.

An example of conditions for generating plasma for removing water is shown below. Gas used: Ar, 100 SCCM Gas pressure: 0.53 to 1.0 Torr RF power: 1500 W Fig. 6 is a diagram showing the relationship between the partial pressure of water and the heating time when the processing chamber is heated by Ar plasma.

The case of Ar discharge (internal heating) of the embodiment is indicated by a, and the plasma generation conditions in this case are as described above. As a comparative example, the dotted line b shows the change over time in the partial pressure of water without Ar discharge (internal heating). In the embodiment, the partial pressure of water can be 1/100 or less of the total pressure.

FIG. 2 is a sectional view for explaining the second embodiment of the present invention. In this example, instead of the plasma of FIG. 1, nitrogen (N ₂ ) preheated to about 250 ° C. from the internal heating gas inlet 3 was used.
Alternatively, flow the air through 1 SLM to remove the water in the processing chamber and then perform the original process.

The internal heating may be performed by introducing an infrared or far infrared lamp into the processing chamber as described above.
FIG. 7 is a diagram showing the effect of the embodiment.

The figure shows the relationship between the number of fine particles and the number of processed wafers, which is indicated by a for internal heating in the embodiment and b for internal heating in the conventional example.

[0024]

According to the present invention, the amount of dust generated in the processing chamber can be reduced by removing the water in the processing chamber before the start of the process. As a result, it was possible to improve the manufacturing yield and reliability of the device and improve the operating rate and reliability of the processing equipment.

[Brief description of drawings]

FIG. 1 is a sectional view illustrating a first embodiment of the present invention.

FIG. 2 is a sectional view illustrating a second embodiment of the present invention.

FIG. 3 is a diagram showing a water peak before etching.

FIG. 4 is a diagram showing water peaks after etching.

FIG. 5 is a diagram showing a relationship between the number of processed wafers and the number of fine particles.

FIG. 6 is a diagram showing the relationship between the partial pressure of water and the heating time for Ar plasma heating.

FIG. 7 is a diagram showing the effect of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 processing chamber 2 process gas inlet 3 gas inlet for internal heating according to the present invention 4 exhaust port for process 5 gate valve for process exhaust 6 exhaust port for removing moisture according to the present invention 7 gate valve for removing moisture 8 wafer side electrode (wafer Stage) 9 Capacitor 10 RF power supply

Claims (4)

[Claims] 1. A semiconductor processing comprising a processing chamber for processing a substrate to be processed, a means for heating the processing chamber, and an exhaust system for removing water, which is different from an exhaust system used for the processing. apparatus. 2. A step of heating the inside of the processing chamber before the start of processing such as deposition and etching, and an exhaust system different from the exhaust system used for the processing during the heating to remove water in the processing chamber. A pretreatment method for a semiconductor processing apparatus, comprising: 3. The pretreatment method for a semiconductor processing apparatus according to claim 2, wherein the heating is performed by generating plasma of a gas that does not generate a reaction product in the processing chamber. 4. The pretreatment method for a semiconductor processing apparatus according to claim 3, wherein the gas is a rare gas, a fluorine-based gas, or a chlorine-based gas.