JP2000144431A - Method cleaning for chemical vapor depositing chamber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for cleaning metallic contaminants in a chamber of a chemical vapor deposition system. SOLUTION: A gaseous mixture contg. a medium gas and a cleaning gas is introduced into a chamber 100. This gaseous mixture is excited by electric power 102 to form plasma in the chamber, and by this plasma, the chamber is cleaned for a prescribed time. The medium gas may be gaseous argon or nitrogen, and the cleaning gas may be nitrogen trifluoride. This method is suitable particularly for cleaning a CVD chamber after the execution of a metal chemical vapor deposition stage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method of cleaning a chamber of a chemical vapor deposition apparatus, and more particularly to a method of removing metal contaminants from a chamber of a chemical vapor deposition apparatus.

[0002]

2. Description of the Related Art Chemical vapor deposition (CVD) includes atmospheric pressure CVD,
There are low pressure CVD, plasma enhanced CVD and the like. In general,
All CVD equipment has a reactor, a gas transport system,
It comprises a ventilation system and a process control system. Since plasma-enhanced CVD (PECVD) is a main component of the thin film deposition method, the present invention uses the PEC
This will be described using VD as an example. In PECVD, a reactive gas is excited by radio frequency (RF) and is deposited on a substrate at a low temperature. When a metal thin film is formed using CVD, CV
It is difficult to avoid the generation of metal contaminants in the chamber of the D apparatus.

[0003] At present, as a method of removing metal contaminants from a chamber of a PECVD apparatus, a method of placing a dummy wafer on a wafer holder in a chamber of the PECVD apparatus has been used. In this case, the cleaning gas is then CV
The cleaning gas is sent to the D chamber, and the cleaning gas is excited by the RF power to form cleaning plasma, and the cleaning plasma cleans the CVD chamber. Thereafter, the dummy wafer is removed and the cleaning of the CVD chamber is completed.

When a metal contaminant such as a tungsten contaminant is too thick in a CVD chamber, a cleaning gas such as nitrogen trifluoride cannot be excited to generate a cleaning plasma. Therefore, metal contaminants cannot be removed from the CVD chamber, so that subsequent CVD
The process will be contaminated.

[0005]

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a method for cleaning a chamber of a chemical vapor deposition apparatus which makes it possible to remove metal contaminants from a CVD chamber. The present invention provides a method for cleaning a chamber of a chemical vapor deposition apparatus, as described herein, as a means of achieving the above and other benefits.

[0006]

That is, the present invention provides a method suitable for cleaning a chamber of a chemical vapor deposition apparatus after performing a metal chemical vapor deposition step. And a step of introducing a mixed gas containing a cleaning gas and exciting the mixed gas with electric power to form a plasma in the chamber, and cleaning the chamber with the plasma for a predetermined time. is there. This medium gas can accelerate the ionization rate of the mixed gas. Therefore, the mixed gas can be easily excited to form plasma.

[0007] The above general description and the following detailed description are merely exemplary, and are intended to provide further explanation of the claims.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Preferred Embodiment: First, a first preferred embodiment of the present invention will be described in detail with reference to the drawings. In the drawings and text, the same reference numerals are used for the same members wherever possible.

FIG. 1 schematically illustrates a cross section of a PECVD apparatus. First, as shown in FIG.
The VD apparatus includes a chamber 100, a power supply 102, and an electrode 1
04, a heater 106, a wafer holder 108,
It comprises a gas introduction valve 110 and a ventilation valve 112.
The method of cleaning the CVD chamber includes a step of introducing a mixed gas into the chamber 100 via the gas introduction valve 110. This mixed gas contains a medium gas and a cleaning gas. This medium gas may be argon or nitrogen gas. The cleaning gas is, for example, nitrogen trifluoride.
The flow ratio of the medium gas to the cleaning gas and the pressure in the chamber are adjusted to predetermined levels. As an example, the flow ratio is about 1/4 and the pressure in the chamber is about 6
torr. The flow rate of the cleaning gas can vary widely depending on the actual conditions. For example, a preferred flow rate of the cleaning gas is about 200 standard cm ³ / min (SCCM). The flow rate of the medium gas can also vary over a wide range depending on the actual conditions. For example, a preferred flow rate of the medium gas is about 50 SCCM.
It is. The argon or nitrogen gas in the medium gas promotes the ionization rate of the mixed gas. That is, in the presence of the medium gas, the mixed gas can be easily excited to form plasma. The chamber 100 is very efficiently cleaned by this plasma, even if the tungsten contaminants are very thick.

A power supply 102 is used to excite the gas mixture and form a clean plasma in the chamber 100. The power in this case is about 100-600 W and the gas mixture is excited for about 10-300 seconds. The cleaning plasma induced by the mixed gas is used to clean the inside of the chamber 100, and the chamber 100 is cleaned by the cleaning plasma for about 10 to 300 seconds.

Second Preferred Embodiment: Next, a second preferred embodiment of the present invention will be described in detail with reference to the drawings.
In the drawings and text, the same reference numerals are used for the same members wherever possible. FIG. 2 schematically illustrates a cross section of a PECVD apparatus in which a dummy wafer is placed on a wafer holder. FIG. 3 is a flowchart of a method for cleaning a PECVD apparatus according to the second embodiment of the present invention.

First, as shown in FIGS.
The method of cleaning the chamber includes a step of arranging a dummy wafer 212 in a wafer holder 208 in the chamber 200.
06 is used to protect the surface from direct plasma bombardment. The mixed gas is introduced into the chamber 200 via the gas introduction valve 210. This mixed gas contains a medium gas and a cleaning gas. This medium gas is argon,
Alternatively, it may be nitrogen gas. The cleaning gas is, for example, nitrogen trifluoride. The flow ratio of the medium gas to the cleaning gas is about 1/4, and the pressure in the chamber is about 6 torr.
r. The preferred flow rate of the cleaning gas is about 200 SCC
M and the preferred flow rate of the medium gas is about 50 SCCM. The argon or nitrogen gas in the medium gas promotes the ionization rate of the mixed gas.
That is, the mixed gas can be easily excited to form plasma. The chamber 200 is very efficiently cleaned by this plasma, even if the tungsten contaminants are very thick.

A power supply 202 is used to excite the gas mixture and form a clean plasma in the chamber 200. The power is about 100-600W and the mixed gas is about 1
Excited for 0-300 seconds. The cleaning plasma induced by the mixed gas is used to clean the inside of the chamber 200, and the chamber 200 is cleaned by the cleaning plasma for about 10 to 300 seconds.

Thereafter, the dummy wafer 212 is removed, and the cleaning of the CVD chamber is completed. As will be apparent from the above description, the method of the present invention has a specific CV as shown.
It is not limited to the configuration of the D chamber.

[0015]

As described above in detail, the present invention has the following advantages. 1. In the present invention, argon or nitrogen gas in the medium gas can accelerate the ionization rate of the mixed gas, and the mixed gas can be easily excited to form plasma. The chamber is cleaned with this plasma, even if the tungsten contaminants are very thick.

2. The device of the present invention is compatible with conventional devices, and thus the present invention is suitable for use by manufacturers. It will be apparent to those skilled in the art that the present invention can be variously modified without departing from the spirit thereof.
Therefore, the present invention intends to include such modifications in the scope of the invention.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically illustrating a PECVD apparatus.

FIG. 2 is a cross-sectional view of the PECVD apparatus in a state where a dummy wafer is mounted on a wafer holder.

FIG. 3 is a flowchart of a method for cleaning a PECVD apparatus according to a second embodiment of the present invention.

[Description of Signs] 100: Chamber 102: Power supply 104: Electrode 106: Heater 108: Wafer holder 110: Gas introduction valve 112: Ventilation valve 200: Chamber 202: Power supply 204: Electrode 206: Heater 208: Wafer holder 210: Gas introduction Valve 212: dummy wafer

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Guo Jingyi, No.16, No. 188, 188 Southeast Street, Hsinchu City, Taiwan F Term (Reference) 4K030 BA01 CA12 DA06 FA01 FA03 JA09 JA11 JA16 KA08 KA30

Claims (14)

[Claims] 1. A method for cleaning a chamber of a chemical vapor deposition apparatus contaminated by a metal chemical vapor deposition process, comprising: introducing a mixed gas containing a medium gas and a cleaning gas into the chamber; Exciting the plasma to form a plasma in the chamber; and cleaning the chamber with the plasma for a predetermined time. 2. The method according to claim 1, wherein said medium gas is argon. 3. The method according to claim 1, wherein said medium gas is nitrogen gas. 4. The method according to claim 1, wherein said cleaning gas comprises nitrogen trifluoride. 5. A flow rate ratio of said medium gas to said cleaning gas is about 1/4, and a pressure in said chamber is about 6%.
2. The method of claim 1 wherein the method is torr. 6. The method of claim 1 wherein said gas mixture is excited by a power source of about 100-600W. 7. The method of claim 1, wherein said predetermined time is about 10-300 seconds. 8. A method for cleaning a chamber of a chemical vapor deposition apparatus suitable for applying after performing a metal chemical vapor deposition process, comprising: placing a dummy wafer in the chamber; A step of introducing a mixed gas containing a cleaning gas; a step of exciting the mixed gas to form plasma in the chamber; a step of cleaning the chamber with the plasma for a predetermined time; and removing a dummy wafer from the chamber. Removing. 9. The method of claim 8, wherein said medium gas comprises argon. 10. The method according to claim 8, wherein said medium gas includes nitrogen gas.
The described method. 11. The method according to claim 8, wherein said cleaning gas comprises nitrogen trifluoride. 12. The method of claim 8, wherein a flow ratio of said medium gas to said cleaning gas is about 1/4 and a pressure in said chamber is about 6 torr. 13. The method of claim 8 wherein said gas mixture is excited by a power source of about 100-600W. 14. The method of claim 8, wherein said predetermined time is about 10-300 seconds.