JP3372840B2 - Dry etching apparatus and gas flow control inspection method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dry etching apparatus and a gas flow rate control inspection method, and more particularly to a dry etching apparatus having a gas flow rate measuring function and a gas flow rate control inspection method thereof.

[0002]

2. Description of the Related Art Conventionally, in a dry etching apparatus used for manufacturing a semiconductor device or the like, when a gas is supplied to a reaction chamber, a mass flow controller (hereinafter referred to as MFC) is used to accurately control a gas flow rate. ) Is used.

And, the dry etching apparatus has its MF
It is necessary for C to have a function of checking whether the gas flow rate is accurately controlled (hereinafter referred to as MFC verification), and improving the accuracy of MFC verification is important for reproducibility of dry etching. Play a role.

The MFC described above with reference to the drawings
An example of the test will be described.

FIG. 3 shows a conventional dry etching apparatus,
It shows a reaction chamber and peripheral equipment. A pressure gauge 2 is provided in a reaction chamber 1 for performing a dry etching process on an object to be processed such as a semiconductor wafer, and a gas supply system 20 having an MFC 7 for controlling a gas flow rate of a gas 13 (shown by an arrow) necessary for the process. Is connected to the reaction chamber 1 through valves 6 and 5, and the pipe of the vacuum exhaust system 30 having the pump 4 is connected to the reaction chamber 1 through the valve 3.

When performing the MFC test, it is confirmed by the pressure gauge 2 that the reaction chamber 1 which is evacuated by the pump 4 with the valve 3 opened and the valve 5 closed is in a high vacuum state. Then, the valve 3 is closed and the reaction chamber 1 is vacuum-stored.

Next, the valve 5 is opened, and a gas having a constant flow rate is introduced into the reaction chamber 1 from the MFC 7 in which the attached valve 6 is opened, and the increase in the pressure in the reaction chamber 1 at that time is monitored by the pressure gauge 2. , Measure the pressure rise rate and convert the flow rate.

[0008]

The first problem is that in the prior art, the performance of the MFC cannot be accurately checked because the reaction chamber is used for the MFC assay.

The reason for this is that the products produced by etching are accumulated in the reaction chamber, and the outgas generated from the products causes an error in the pressure increase during MFC verification.

The second problem is that in the prior art, the MF
It is that the result is not accurately reflected in the actual etching process because the temperature control is not taken into consideration in the C test.

The reason is that since the temperature of the reaction chamber is not controlled at a constant level, the result of MFC test performed by utilizing the property of Boyle-Charles' law changes depending on the temperature change of the environment where the etching apparatus is placed. This is because it will end up.

Therefore, an object of the present invention is to provide a dry etching apparatus and a gas flow rate control inspection method capable of improving the reproducibility of dry etching by improving the accuracy of MFC verification.

[0013]

A feature of the present invention is a dry etching apparatus having a reaction chamber for performing dry etching on an object to be processed, a gas supply system provided with MFC, and a vacuum exhaust system. A vacuum chamber dedicated to measuring the gas flow rate is installed in parallel with the reaction chamber between it and the vacuum exhaust system.
Only, in the vacuum chamber is in a dry etching apparatus heater is provided to the temperature constant. Alternatively, the feature of the present invention is that in a dry etching apparatus having a reaction chamber for performing dry etching on an object to be processed, a gas supply system provided with MFC, and a vacuum exhaust system, a gas is provided between the MFC and the reaction chamber. the vacuum chamber of the flow measurement only provided, wherein the vacuum chamber is in a dry etching apparatus capable of gas flow measurement at high during a given temperature than the outside air has a heater.

Another feature of the present invention is to check the characteristics of the MFC by supplying a gas to the vacuum chamber through an MFC and measuring the pressure with a pressure gauge provided in the vacuum chamber , and in the inspection method for a gas flow rate control in the dry etching apparatus for controlling the temperature of the vacuum chamber under examination by the heater provided in the vacuum chamber.

According to the present invention as described above, since the MFC test can be performed in the vacuum chamber controlled to a constant temperature, the influence of the change of the outside air of the chamber (the temperature change of the environment in which the etching apparatus is placed) is influenced. MFC certification can be done without receiving. Further, since foreign matters such as products generated during etching do not exist in the vacuum chamber, MFC verification can be performed without being affected by outgas in the chamber.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described with reference to the drawings.

FIG. 1 is a schematic view showing a dry etching apparatus according to the first embodiment of the present invention. A pressure gauge 2 is provided in a processing chamber 1 for dry-etching an object to be processed such as a semiconductor wafer, and an MFC 7 for accurately controlling a gas flow rate of an etching gas 13 necessary for the etching process is provided. The pipe of the gas supply system 20 having the valve 6 is connected to the reaction chamber 1 through the valve 5, and the pipe of the vacuum exhaust system 30 having the pump 4 is connected to the reaction chamber 1 through the valve 3.

Further, in the present embodiment, a vacuum chamber 9 provided with a heater 12 capable of setting an arbitrary temperature and a pressure gauge 10 and exclusively for measuring a gas flow rate is provided between a gas supply system 20 and a vacuum exhaust system 30. And are connected in parallel.

That is, the pipe from one side of the vacuum chamber 9 is connected to the pipe between the valve 5 and the valve 6 through the valve 11, and the pipe from the other side is connected between the valve 3 and the pump 4 through the valve 8. It is connected to the pipe between.

Next, the operation of the embodiment of the present invention will be described with reference to FIG.

When the dry etching apparatus is in the standby state, the valves 5, 6, 11 and 8 are closed, the valve 3 is opened, and the reaction chamber 1 is evacuated by the pump 4.

When the MFC verification is started, the valve 3
Is closed, and the gas flow into the reaction chamber 1 is blocked. Next, the valve 8 is opened, and the vacuum chamber 9 controlled to a constant temperature by the heater 12 and a temperature control system (not shown).
The pump 4 is evacuated to a high vacuum state.

The controlled set temperature is, for example, 30 degrees. This set temperature differs depending on the environment in which the dry etching apparatus is placed, and is set higher than the temperature of the outside air of the apparatus.

The vacuum chamber 9 is, for example, 1.0 × 10 ^-5
When a high vacuum state equal to or less than Torr is reached, the valve 8 is closed and vacuum storage is performed.

At this time, the high vacuum is confirmed by the pressure gauge 10. When the vacuum chamber 9 is in a vacuum storage state, the valves 6 and 11 are opened, and the MFC 7 introduces a constant flow rate of the etching gas 13 (indicated by an arrow) into the vacuum chamber 9. The pressure gauge 1 measures the increase in pressure in the chamber 9 at that time.
Monitor at 0, measure the pressure rise rate, and perform flow rate conversion.

Next, a dry etching apparatus according to a second embodiment of the present invention will be described with reference to FIG. 2 that are the same as or similar to those in FIG. 1 are designated by the same reference numerals.

In the second embodiment, the vacuum chamber 9 is provided in series with the reaction chamber 1. That is, the vacuum chamber 9 is provided between the reaction chamber 1 and the gas supply system 20.

When the dry etching apparatus is on standby, the valves 3 and 5 are opened, the valve 6 is closed, and the reaction chamber 1
And the vacuum chamber 9 is evacuated.

When the MFC verification is started, the valve 5 is closed after the pressure gauge 10 confirms that the vacuum chamber 9 is in a high vacuum state, and the vacuum chamber 9 is vacuum-stored.

Since the subsequent operation is the same as that of the first embodiment, its explanation is omitted.

[0031]

The first effect of the present invention is that the accuracy of the MFC assay is improved because the reaction chamber is not used in the MFC assay.

The reason is that it is not affected by the outgas from the products deposited in the reaction chamber.

The second effect is that since the temperature of the MFC assay chamber can be controlled, the accuracy of the MFC assay is further improved in this case.

The reason is that it is not affected by the temperature change of the air outside the chamber.

[Brief description of drawings]

FIG. 1 is a schematic view showing a dry etching apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic view showing a dry etching device according to a second embodiment of the present invention.

FIG. 3 is a schematic view showing a conventional dry etching apparatus.

[Explanation of symbols]

1 reaction chamber 2 pressure gauge 3 valves 4 pumps 5 valves 6 valves 7 MFC 8 valves 9 vacuum chamber 10 pressure gauge 11 valves 12 heater 13 Etching gas 20 gas supply system 30 vacuum exhaust system

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01L 21/3065 C23F 4/00

Claims (3)

(57) [Claims] 1. A reaction for performing dry etching on an object to be processed.
A chamber and a gas supply system provided with a mass flow controller,
In a dry etching apparatus having a vacuum exhaust system,
Between the mass flow controller and the vacuum exhaust system
A vacuum chamber dedicated to gas flow measurement is parallel to the reaction chamber
To provided, and a dry etching apparatus, wherein the heater is provided in the vacuum chamber. 2. A reaction chamber for performing dry etching on an object to be processed, a gas supply system provided with a mass flow controller,
In a dry etching apparatus having a vacuum exhaust system,
And wherein said mass flow controller and the vacuum chamber of a dedicated gas flow measurement provided between the reaction chamber, the vacuum chamber that enables gas flow measurement at high during a given temperature than the outside air has a heater Dry etching equipment. 3. The mass flow controller is provided in the vacuum chamber.
Gas is supplied through the controller and the vacuum chamber
By measuring the pressure with a pressure gauge installed in
Check the characteristics of the mass flow controller,
One, the heater provided in the vacuum chamber
Claim 1 or claim 2 inspection method for a gas flow rate control in the dry etching apparatus, wherein the controlling the temperature of the vacuum chamber under examination Ri.