JP2002151474A - Apparatus for manufacturing semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce particles deposited onto a substrate being processed in the micromachining process or film deposition process. SOLUTION: Forward end part of piping for supplying gas into a carrying chamber is coated with a corrosion resistant material. Alternatively, a nozzle made of a corrosion resistant material is fixed to the forward end part of a nozzle in order to prevent corrosion of a material composing the carrying chamber thus suppressing generation of particles. Since contamination is reduced on the substrate, trouble is reduced in the film deposition process and micromachining process. Consequently, the yield of manufacture is increased while reducing the production cost of semiconductor device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device manufacturing apparatus and, more particularly, to prevention of generation of particles in a semiconductor device manufacturing apparatus used for etching or forming a film on a substrate. is there.

[0002]

2. Description of the Related Art In recent semiconductor manufacturing apparatuses, a chamber for processing a substrate (hereinafter referred to as a processing chamber) and a vacuum state are changed from an atmospheric state in order to transfer a substrate stored in the air to the processing chamber. A room (hereinafter, referred to as a load lock chamber) and a room for changing a vacuum state to an atmospheric state (hereinafter, referred to as an unload lock chamber) in order to take the substrate into the atmosphere after the processing of the substrate is completed. The chamber is configured to take out a substrate from the load lock chamber and transfer it to the processing chamber, or to take out the substrate from the post-processing processing chamber and transfer it to the unload lock chamber (hereinafter, referred to as a transfer chamber).

In manufacturing a semiconductor device using the above-described apparatus, if an unnecessary natural oxide film is formed on a substrate by oxygen or particles adhere thereto, the device will be defective. For example, in the case of performing fine processing such as etching, a portion where a natural oxide film is formed and a portion where particles are attached remain without being etched, resulting in a short defect. Further, in the case of forming a film, the film quality and the like of the portion where the particles are attached are different, which affects the electrical characteristics.
Oxygen that causes the formation of a natural oxide film is considered to be caused by mixing with the atmosphere. The particles are generated from reaction products formed in the processing chamber when the substrate is processed, and are considered to have flowed from the processing chamber to the transfer chamber, the load lock chamber, and the unload lock chamber.

Japanese Patent Application Laid-Open No. Hei 10-335407 discloses a method of supplying an inert gas in order to suppress the inflow of oxygen and particles from the outside. JP
The disclosed example of Japanese Patent Publication No. 10-335407 is characterized in that an inert gas is supplied to each room with a pressure difference. According to the disclosed example, it is possible to efficiently discharge oxygen remaining in each room and to prevent particles from flowing from a processing chamber into a transfer chamber, a load lock chamber, or the like.

[0005]

SUMMARY OF THE INVENTION The present inventors have analyzed the composition of particles attached to a substrate in various semiconductor manufacturing apparatuses. As a result, in addition to particles having the composition of the reaction product formed when processing the substrate, particles that are not used in the processing chamber and have the composition of the components used in the transfer chamber are also detected. Was done. In other words, it was found that particles were generated in the transfer chamber, and that the dust was generated from the corroded parts of the transfer chamber. This is because the corrosive gas used for processing the substrate flows into the transfer chamber,
This is probably due to the gradual corrosion over a long period of time. The corrosive gas flows into the transfer chamber in two cases. One is a case where the corrosive gas flows in from the processing chamber by diffusion. When unloading a substrate after processing in the processing chamber, the processing chamber is evacuated to about 10 ^-5 Torr and corrosive gas is exhausted from the processing chamber.However, the substrate cannot be completely exhausted. When it flows in by diffusion. The other is when the substrate itself is brought in. Since the corrosive gas is adsorbed on the substrate after the treatment, the substrate itself is brought in when passing through the transfer chamber.

When the corrosive gas flows into the transfer chamber, the entire transfer chamber is corroded. However, the generation of particles is particularly affected when the piping of the gas supply line is corroded. This is because the particles generated from the corroded portion along with the blowing of the gas follow the flow and spread throughout the transfer chamber.

That is, in order to prevent the generation of particles in the transfer chamber, it is necessary to make parts in the transfer chamber resistant to corrosive gas flowing from the processing chamber into the transfer chamber. This is not taken into account.

An object of the present invention is to provide a method for reducing the generation of particles even when a corrosive gas flows.

[0009]

According to the present invention, in order to achieve the above object, the inside and outside of the tip of the pipe of the gas supply line are coated with a corrosion-resistant material. Alternatively, a nozzle made of a corrosion-resistant material is attached to the tip of the pipe. Accordingly, the corrosive gas does not directly contact the pipe of the gas supply line, so that corrosion does not occur and generation of particles can be prevented.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment to which the present invention is applied will be described below in detail with reference to the drawings.

FIG. 1 is a schematic configuration diagram of a dry etching apparatus to which the present invention is applied, and FIG. 2 shows a leading end portion of a gas supply line of a transfer chamber, which is a feature of the present invention.

In FIG. 1, in a dry etching apparatus, two load lock chambers capable of storing a substrate and switching the inside between a vacuum state and an atmospheric state, here, a load lock chamber 1 used for carrying in a substrate, Unload lock chamber 2 used for unloading, processing chamber 3 for processing substrates, and transfer robot for transferring substrates from load lock chamber 1 to processing chamber 3 and from processing chamber 3 to unload lock chamber 2 4 comprises a transfer chamber 5 in which is installed. Here, the case where the processing chamber 3 in which the substrate processing is performed is illustrated as one is illustrated, but there are some dry etching apparatuses provided with a plurality thereof, and in such a case, the processing chamber 3 is installed around the transfer chamber 5. Is done. Gate valves 6 to 8 are provided between the transfer chamber 5 and the load lock chamber 1, the unload lock chamber 2, and the processing chamber 3. 3 and the same atmosphere or isolated state. The load lock chamber 1, the unload lock chamber 2, the processing chamber 3, and the transfer chamber 5 are provided with gas supply lines 9 to 12 for supplying gas. The transfer chamber 5, the load lock chamber 1, the unload lock chamber 2, and the processing chamber 3 are each provided with a vacuum exhaust system for vacuum exhaust and a vacuum gauge for measuring pressure (not shown).

Next, the operation of the apparatus will be described.

The substrate 13 is loaded into the load lock chamber 1 while the load lock chamber 1 is in the atmospheric state with the gate valve 6 closed. After loading the substrate 13, the load lock chamber 1
The inside is evacuated to a vacuum. When the load lock chamber 1 drops to a predetermined pressure, the gate valve 6 opens, and the substrate 13 is carried out by the transfer robot 4. When the substrate 13 is transferred to the transfer chamber 5, the gate valve 6 is closed and the gate valve 7 is opened at the same time, and the substrate 13 is transferred to the processing chamber 3 and set on the table 14. When the substrate 13 is placed on the table 14, the gate valve 7 is closed, and the substrate 13 is subjected to a predetermined etching process. The gas used for the processing is introduced from the gas supply line 10 into the processing chamber 3, and the predetermined processing is performed by adjusting the pressure and the like. Here, a highly corrosive gas such as Cl ₂ gas or HBr gas is used for the etching process. When the predetermined processing is completed, the introduction of the gas from the gas supply line 10 is stopped, the processing chamber 3 is evacuated, and the gas used for the processing is discharged. When the gas is exhausted to a predetermined pressure, the gate valve 7 opens and the substrate 13 is carried out. When the substrate 13 is transferred to the transfer chamber 5, the gate valve 7 is closed, and at the same time, the gate valve 8 is opened and transferred to the unload lock chamber 2. When the transfer of the substrate 13 is completed, the gate valve 8 closes. Then, the substrate 13 is supplied with gas from the gas supply line 11, brought into an atmospheric state, and taken out.

Here, the inside of the processing chamber 3 after the substrate 13 is subjected to the predetermined processing is evacuated to a predetermined pressure upon completion of the processing. Can not exhaust. Therefore, the corrosive gas used for the processing of the substrate 13 remains without being completely exhausted, for example, by being adsorbed on the wall of the processing chamber 3. In this state, when the gate valve 8 is opened and the substrate 13 is carried out and carried in, the corrosive gas is transferred from the processing chamber 3 to the transfer chamber 5 and through the transfer chamber 5 to the load lock chamber 1 and the unloading chamber. It will flow into the lock chamber 2. When the corrosive gas flows into the transfer chamber 5 or the like, there arises a problem that the components in the transfer chamber 5 or the like are gradually corroded with the use of the apparatus for a long time, and particles are generated.

In the present invention, as shown in FIG.
It is characterized in that the surface of the pipe tip 201 of the gas supply line 9 of the transfer chamber 5 is coated with a corrosion resistant material 202. Examples of the corrosion-resistant material include a fluorine resin. Further, as shown in FIG. 2B, it is effective to attach a nozzle 203 made of a corrosion-resistant material to the pipe tip 201 of the gas supply line 9.

If the length L1 to be coated and the length L2 of the nozzle are designed as follows, the inner diameter portion of the gas supply line 9 where the coating is not applied, the nozzle 203
Corrosive gas reaching deeper inside diameter can be reduced. Therefore, the progress of corrosion of the gas supply line 9 can be suppressed, and the generation of particles can be reduced.

The length L1 to be coated and the length L2 of the nozzle are set to be about five times or more the mean free path determined by the kind of gas supplied to the transfer chamber 5, pressure and temperature.

The mean free path λ is obtained from the following equation.

[0020]

Λ = 3.11 × 10 ⁻²⁴ × T / P / σ ₂ (Equation 1) where T is temperature, P is pressure (Pa), and σ is molecular diameter (m).

The probability P (x) that a gas molecule of the mean free path λ flies without colliding with another molecule at least up to x can be obtained from the following equation.

[0022]

(Equation 2) P (x) = exp (−x / λ) From both equations, when the length L1 to be coated and the length L2 of the nozzle are the same as the mean free path, The probability of collision between the supply gas and the corrosive gas is 60%. 2
The probability of doubling is 86%, and the probability of doubling is 95%. On the other hand, when the average free path is about five times or more, it becomes 99% or more. That is, as the coating length L1 and the nozzle length L2 are increased,
Since the rate of collision between the supply gas and the corrosive gas in the coated inner diameter portion and the nozzle 203 increases, the inner diameter portion not coated and the nozzle 2
Corrosive gas that reaches the inner diameter portion deeper than 03 can be reduced.

For example, room temperature nitrogen gas 10P
a, a nozzle 203 of 4 mm, which is about five times the mean free path, is connected to the pipe tip of the gas supply line 9.
After attaching to 201, even if we started 30,000 substrates,
No corrosion was observed at the pipe tip 201 of the gas supply line 9 in the transfer chamber. The effect was almost the same even when the length of the nozzle 203 was set to 35 mm, which was about 10 times the mean free path.

Therefore, if the length L1 to be coated and the length L2 of the nozzle are set to be about five times or more the mean free path determined by the kind of gas supplied to the transfer chamber 5, the pressure and the temperature, the gas supply line 9 The progress of corrosion can be suppressed, and the generation of particles can be reduced.

[0025]

As described above, the corrosion of the piping section of the gas supply line of the transfer chamber is prevented by coating the tip of the pipe of the gas supply line of the transfer chamber with a corrosion-resistant material or attaching a nozzle. And generation of particles can be suppressed. Thus, contamination on the substrate is reduced, and defects during the film formation process and the fine processing are reduced. This leads to an improvement in the yield and a reduction in the production cost of the semiconductor device.

[Brief description of the drawings]

FIG. 1 is a diagram showing a system of a semiconductor manufacturing apparatus according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a tip portion of a pipe in the embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Load lock chamber, 2 ... Unload lock chamber, 3 ... Processing chamber, 4 ... Transport robot, 5 ... Transport chamber, 6 ... Gate valve, 7 ... Gate valve, 8 ... Gate valve, 9 ... Gas supply line, 10 ... gas supply line, 11 ... gas supply line, 12 ... gas supply line, 13 ... substrate, 14 ... unit, 2
01 ... Piping tip, 202 ... Corrosion resistant material, 203 ...
nozzle.

Continued on the front page (72) Inventor Osamu Takahashi 6-16-16 Shinmachi, Ome-shi, Tokyo F-term in the Device Development Center, Hitachi, Ltd. 4K030 CA04 CA12 DA06 EA04 KA47 5F004 AA15 BB30 BC03 BC05 BC06 DA00 DA04 5F031 MA28 MA32 NA04 PA26 5F045 BB08 BB15 EB08 EB09 EC08 EF02 EF11 EN04 GB06

Claims (1)

[Claims] A load lock chamber for evacuating and transferring a substrate in the atmosphere to a processing chamber; a processing chamber for processing the substrate;
In the meantime, a transfer chamber for transferring the substrate from the load lock chamber to the processing chamber is provided, the transfer chamber has a gas supply line, and in a semiconductor device manufacturing apparatus for processing a substrate using a corrosive gas, a gas is used. An apparatus for manufacturing a semiconductor device, characterized in that a tip portion of a supply line is coated with a corrosion-resistant material.