JP2001244203A - Method for cleaning semiconductor manufacturing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the ClF3 gas left in a semiconductor manufacturing device after the device is cleaned by shortening the time required until a process becomes normal. SOLUTION: A semiconductor manufacturing device is provided with a reaction chamber 11, a holder 13 positioned in the chamber 11 to support a wafer, a cylindrical shield ring 15 positioned on the outside of the holder 13 in the chamber 11, gas introducing pipes 16a and 16b through which a reactive gas and an inert gas are respectively introduced to the chamber 11, and an exhaust pipe 17 through which gases are exhausted from the chamber 11. The reactive gas is made to flow to a section proposed for installing an object to be treated and its vicinity at the time of cleaning the inside of the chamber 11, after a sufficient amount of inert gas is made to flow in the chamber 11 before cleaning. When the reactive gas is made to flow in the chamber 11, the inert gas is simultaneously made to continuously flow to the chamber 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cleaning a semiconductor manufacturing apparatus, and more particularly to a method for removing a film remaining on a support member near a wafer or the like during a reaction or removing the film remaining in a reaction vessel after the removal of the film. The present invention relates to a semiconductor manufacturing apparatus cleaning method for cleaning a reaction container by removing a reactive gas.

[0002]

2. Description of the Related Art Conventionally, a semiconductor manufacturing apparatus such as a CVD (C
chemical Vapor Deposition
n) As a device, a device having a configuration shown in FIG. 3 is known.

[0003] Reference numeral 1 in the figure denotes a reaction vessel. In this reaction vessel 1, a holder 3 for supporting a wafer 2 is arranged. A heater 4 for heating the wafer 2 is disposed inside the holder 3. A cylindrical shielding ring 5 is disposed outside the holder 3 and inside the reaction vessel 1. Here, although not shown, the shielding ring 5 is composed of a cylindrical metal ring and a quartz ring provided so as to cover the metal ring.
The quartz ring is for protecting the metal ring from a reactive gas. A gas for introducing a reactive gas such as ClF ₃ into the reaction vessel 1 is provided on the side wall of the reaction vessel 1 located at a position higher than the top of the shielding ring 5 and on the side wall of the reaction vessel 1 located below the shielding ring 5. Introductory pipe 6
a, a gas introduction pipe 6b for introducing an inert gas such as N ₂ gas into the reaction vessel 1 is provided. At the bottom of the reaction vessel located between the shielding ring 5 and the inner wall of the reaction vessel 1, exhaust pipes 7 for exhausting the reactive gas and the inert gas in the reaction vessel are provided. Here, although not shown in detail, the plurality of exhaust pipes 7 are connected on the way to a common pipe via an exhaust valve.

[0004] In such a conventional CVD apparatus, when a film is formed on the wafer 2, a material gas such as SiH ₄ is supplied into the reaction vessel 1.
The film also adheres to the shielding ring 5 and the like. So, conventionally,
In order to remove this film, ClF ₃ gas and N ₃ gas were simultaneously flowed from the gas introduction pipes 6a and 6b at the start of cleaning. FIGS. 5A to 5D are characteristic diagrams (FIG. 5A) showing the relationship between the time and the pressure of the reaction vessel at the time of cleaning, respectively, and the relationship between the time and the opening of the exhaust valve. 5B, a characteristic diagram showing the relationship between time and the flow rate of the N ₂ gas (FIG. 5C), and a characteristic diagram showing the relationship between time and the flow rate of the ClF ₃ gas (FIG. 5). (D)).

However, in the conventional cleaning, to flow simultaneously a large amount of N ₂ gas into the reaction in one container with respect to the ClF ₃ gas and ClF ₃ gas, a long unstable pressure in the reaction vessel . Specifically, FIG.
As shown in (A), the pressure in the reaction vessel takes a long time until the valve opens, and gradually increases, and it takes a lot of time until the pressure in the reaction vessel becomes a constant pressure.

Further, conventionally, when removing the film remaining in the reaction vessel using a ClF ₃ gas and also after removal of the film ClF ₃ gas into the reaction vessel remains in the reaction vessel, the following Such a problem arises. That is, since ClF ₃ gas has high reactivity, SiH ₄ , AsH ₃ , H
May react violently with ₂ , dangerous. Furthermore,
When heated during film formation, a reaction with the metal member in the reaction vessel occurs, and the parts are deteriorated, and the metal parts in the reaction vessel and Cl
F ₃ product made by the reaction of the gas (Contaminatio
n, contamination). Therefore, conventionally, as a measure against the ClF ₃ gas, vacuum evacuation was performed immediately after the cleaning to remove the ClF ₃ gas.

FIGS. 7 (A) to 7 (C) show conventional Cl
FIG. 7 (A) is a characteristic diagram showing the relationship between time and pressure of the reaction vessel after cleaning with the F ₃ gas, and FIG. 7 (B) is a characteristic diagram showing the relationship between time and the opening of the exhaust valve. ), A characteristic diagram showing the relationship between time and the flow rate of N ₂ gas (FIG. 7).
(C)). That is, in the conventional case, the flow rate of the N ₂ gas and the pressure in the reaction vessel are 0, and only the evacuation is performed by opening the evacuation valve. However, conventionally, ClF ₃
Gas could not be sufficiently removed.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above circumstances, and has been described in detail. At the same time as flowing the gas to the portion where the object is to be installed and the vicinity thereof, the inert gas is continuously flowed to improve the purging performance and reduce the pressure fluctuation in the reaction vessel to achieve a steady state until the process reaches a steady state. An object of the present invention is to provide a method for cleaning a semiconductor manufacturing apparatus, which can reduce the time.

In addition, the present invention provides (1) a step of introducing only an inert gas into the reaction vessel immediately after the completion of the cleaning process in the reaction vessel, and (2) a step of introducing 50 Torr in the reaction vessel.
(3) raising the pressure in the reaction vessel to 1
(1) to (3) of the step of evacuating to Torr or less
It is an object of the present invention to provide a method of cleaning a semiconductor manufacturing apparatus capable of suppressing residual ClF ₃ gas after cleaning by sequentially performing the steps of at least once.

[0010]

According to a first aspect of the present invention, there is provided a reaction vessel, a support member disposed in the reaction vessel and supporting an object to be processed, and a support member disposed in the reaction vessel outside the support member. Cylindrical shielding ring, and gas introduction means for introducing a reactive gas and an inert gas into the reaction vessel,
A method for cleaning a semiconductor manufacturing apparatus, comprising: an exhaust means for exhausting gas in the reaction vessel, wherein a sufficient amount of an inert gas is flowed into the reaction vessel before cleaning the inside of the reaction vessel, A cleaning method for a semiconductor manufacturing apparatus, characterized in that a gas is caused to flow to a portion where an object to be processed is to be installed and in the vicinity thereof, while simultaneously flowing an inert gas.

According to a second aspect of the present invention, there is provided a reaction vessel, a support member disposed in the reaction vessel and supporting an object to be processed, and a cylindrical shielding ring disposed in the reaction vessel outside the support member. And a gas introducing means for introducing a reactive gas and an inert gas into the reaction vessel, and an exhaust means for exhausting the gas in the reaction vessel. Immediately after the completion of the cleaning process, (1) a step of introducing only an inert gas into the reaction vessel, (2) a step of increasing the pressure inside the reaction vessel to 50 Torr or more, and (3) a pressure of 1 T inside the reaction vessel.
A method for cleaning a semiconductor manufacturing apparatus, comprising sequentially performing at least one of the steps (1) to (3) of evacuating to orr or less.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. In the first invention, “sufficient amount” means about 10 times the amount of the reactive gas in relation to the reactive gas.

In the second invention, the pressure in the reaction vessel is raised to a pressure of 50 Torr or more (step (2)), but preferably in the range of 50 to 400 Torr. The reason for this is that if the pressure is less than 50 Torr, the degree of cleaning in the reaction vessel becomes low, and if the pressure exceeds 400 Torr, the time until pressure stabilization becomes long.

In the second invention, the above steps (1) to (4)
(3) is preferably repeated several times sequentially, but even once, the cleaning performance can be improved as compared with the conventional case. The cleaning performance also varies depending on the pressure in the reaction vessel, and the relationship between the number of repetitions of each step and the pressure is preferably set as appropriate.

In the first and second aspects of the present invention, the reactive gas refers to, for example, a highly reactive ClF ₃ gas. The inert gas refers to a gas that does not contribute to the reaction, such as N ₂ gas, Ar gas, and He gas.

In the first and second inventions, the inert gas flows from the bottom of the reaction vessel located below the support member,
It is preferable to flow the reactive gas from the side of the reaction vessel higher than the object to be processed. With this configuration, the reactive gas can be intensively flown to the holder around the portion where the wafer is to be installed. However, the position is not limited to this configuration as long as the reactive gas can be intensively supplied to the holder around the portion where the wafer is to be installed.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) Reference is made to FIGS. 1A, 1B and 2. FIG.
Here, FIG. 1 is an explanatory view of a CVD apparatus before cleaning, FIG. 1 (A) is an overall view of the apparatus, and FIG. 1 (B) is a cross-sectional view of a main part of a shielding ring which is one configuration of the apparatus. FIG. 2 is an explanatory view of a CVD apparatus during cleaning.

Reference numeral 11 in the figure denotes a reaction vessel. In the reaction vessel 11, a support member (holder) 13 for supporting the wafer 12 is arranged. This holder 13
A heater 14 for heating the wafer 12 is arranged inside the wafer. A cylindrical shielding ring 15 is disposed outside the holder 13 and inside the reaction vessel 11. Here, as shown in FIG. 1 (B), the shielding ring 15 includes a cylindrical metal ring 15a and a metal ring 1a.
And a quartz ring 15b provided so as to cover 5a. The quartz ring 15b is for protecting the metal ring 15a from reaction gas.

A reactive gas such as ClF ₃ is supplied into the reaction vessel 1 on the side wall of the reaction vessel 11 located above the top of the shielding ring 15 and on the side wall of the reaction vessel 11 located below the shielding ring 15. A gas introduction pipe (gas introduction means) 16a for introducing, a gas introduction pipe (gas introduction means) 16b for introducing an inert gas such as N ₂ gas into the reaction vessel 11.
Are provided respectively. An exhaust pipe (exhaust means) 17 for exhausting the reactive gas and the inert gas in the reaction vessel is provided at the bottom of the reaction vessel located between the shielding ring 15 and the inner wall of the reaction vessel 11.

The exhaust pipe 17 is provided at two locations facing each other when viewed from above. Although not shown in detail, the plurality of exhaust pipes 17 are connected to a common pipe via an exhaust valve on the way, and this pipe is connected to a vacuum pump (not shown). The reaction vessel 11
Is provided with a pressure gauge (not shown) for measuring the pressure in the reaction vessel 11.

In such a CVD apparatus, the wafer
Cleaning after film formation on C is performed as follows. this
During cleaning, the relationship between time and pressure in the reaction vessel,
Relationship between time and opening of exhaust valve, time and N₂Gas
Relationship with flow rate, time and ClF ₃The relationship with the gas flow rate is
This is as shown in FIGS.

1) First, a purge N₂Gas
The same amount as for leaning (for example, 6 liters / min), gas
Into the reaction vessel 11 through the inlet pipe 16b,
Before the reaction, the inside of the reaction vessel 11 was filled. At this time, the reaction volume
The pressure in the vessel 11 is maintained at, for example, about 400 Torr.
However, it may be approximately 100 to 600 Torr.
FIG. 1 shows a CVD apparatus before cleaning, particularly in a reaction vessel.
Indicates the status, N ₂Gas spreads throughout the reaction vessel
ing. The hatched portion in FIG. 1 is N₂Indicates gas.

2) Subsequently, while continuing to flow the same amount of N ₂ gas, ClF ₃ gas, which is a reactive gas, is introduced into the gas introduction pipe 1.
From 6a, the N ₂ gas was flown to about 1/10 of the N ₂ gas, that is, 0.6 liter / min. Thereby, C
The IF ₃ gas is supplied to the upper portion of the holder 13 and its periphery, moves between the shielding ring 15 and the inner wall of the reaction vessel, and is exhausted to the outside through the exhaust pipe 17. On the other hand, the N ₂ gas is supplied from the bottom of the reaction vessel 11 to a region located inside the shielding ring 15, but is pushed by the ClF ₃ gas, and as shown by an arrow A, from the upper end of the shielding ring 15. The gas moves between the inner wall 15 and the inner wall of the reaction vessel and is exhausted to the outside through the exhaust pipe 17. The shaded portion in FIG. 2 indicates N ₂ gas during cleaning,
₃ shows a region of ClF ₃ gas.

According to the cleaning method of the first embodiment, a sufficient amount (6 l / min) of N ₂ gas is flowed into the reaction vessel 11 before cleaning the inside of the reaction vessel 11, and then ClF _{3 is used for} cleaning. A small amount of gas (0.6 liter / min) flows into the holder 3 where the wafer is to be installed and the shielding ring near the periphery thereof, and at the same time, the same amount of N ₂ gas flows continuously, so before and after the introduction of ClF ₃ gas. Thus, the pressure in the reaction vessel 11 hardly fluctuates, and the state can be quickly shifted to the steady state. Therefore, the purging performance can be improved, and the time required for the process to reach a steady state can be significantly reduced as compared with the related art.

(Embodiment 2) In Embodiment 2 as well, FIG.
Is used. However, the same members as those in FIG. In Example 2, the reaction vessel 1
After cleaning inside 1, ClF used for cleaning
It is for removing _three gases. In the second embodiment,
The cleaning is performed as follows.

That is, immediately after the completion of the cleaning process in the reaction vessel 11, (1) a step of introducing only N ₂ gas into the reaction vessel 11, and (2) a pressure of 300 Torr in the reaction vessel 11.
and (3) a step of evacuating the reaction vessel to 1 Torr or less.
Step (3) was sequentially performed once. FIG. 6 is a characteristic diagram (FIG. 6A) showing the relationship between time and the pressure in the reaction vessel, and a characteristic diagram showing the relationship between time and the opening of the exhaust valve (FIG. 6A) in the CVD apparatus of Example 2. FIG. 6B shows a characteristic diagram (FIG. 6C) showing the relationship between time and the flow rate of the N ₂ gas.

According to the second embodiment, immediately after the completion of the cleaning process in the reaction vessel 11, the step of introducing only N ₂ gas into the reaction vessel 11, and the inside of the reaction vessel 11 at 50 Torr.
r, and the step of evacuating the reaction vessel 11 to 1 Torr or less in order, thereby leaving the reaction vessel 11 remaining in the reaction vessel 11 immediately after cleaning, as compared with the conventional method of performing only vacuum evacuation. ClF ₃
The gas can be reduced quickly, and the safety and the performance of the film forming process can be improved. That is, since the amount of ClF ₃ gas can be considerably reduced, a reaction with a metal component in the reaction container occurs when heated during film formation, and the cause of component deterioration and contamination can be eliminated.

In the second embodiment, the above (1) to (1)
Although the case where each step of (3) is sequentially performed once has been described, the present invention is not limited to this, and these steps may be sequentially repeated a plurality of times.

In the above embodiment, the gas introduction pipe 16
Although a case has been described in which a and 16b are provided one by one, the present invention is not limited to this, and a plurality may be provided. Furthermore, in the above embodiment, one kind of inert gas is introduced into the reaction vessel from the gas introduction pipe 16b. However, different kinds of inert gases are introduced into the reaction vessel from a plurality of gas introduction pipes. Is also good.

[0030]

As described above in detail, according to the first aspect of the present invention, a sufficient amount of an inert gas is flowed into the reaction vessel before cleaning the inside of the reaction vessel, and then the reactive gas is treated during cleaning. By purging the inert gas at the same time as the product is to be installed and its vicinity, the purging performance is improved, and the pressure fluctuation in the reaction vessel is reduced to shorten the time until the process reaches a steady state. Thus, it is possible to provide a method for cleaning the obtained semiconductor manufacturing apparatus.

According to the second aspect of the present invention, immediately after the completion of the cleaning process in the reaction vessel, (1) a step of introducing only an inert gas into the reaction vessel, and (2) a pressure of 50 Torr or more in the reaction vessel. The process of raising the pressure to
(3) The step of evacuating the reaction vessel to 1 Torr or less, the steps (1) to (3) are sequentially performed at least once, thereby cleaning the semiconductor manufacturing apparatus capable of suppressing the residual ClF ₃ gas after the cleaning. We can provide you with the method.

[Brief description of the drawings]

FIG. 1 is a CV showing a state before cleaning according to the present invention.
Explanatory drawing of D apparatus.

FIG. 2 is a CV showing a state during cleaning according to the present invention.
Explanatory drawing of D apparatus.

FIG. 3 is an explanatory view of a conventional CVD apparatus.

FIG. 4 is a characteristic diagram showing a relationship among a time during cleaning, a pressure in a reaction vessel, an opening of an exhaust valve, a flow rate of N ₂ gas, and a flow rate of ClF ₃ gas in the CVD apparatus of FIG.

FIG. 5 is a characteristic diagram showing a relationship among a time during cleaning, a pressure in a reaction vessel, an opening of an exhaust valve, a flow rate of N ₂ gas, and a flow rate of ClF ₃ gas in the CVD apparatus of FIG.

FIG. 6 is a graph showing the relationship between the time after cleaning, the pressure in the reaction vessel, the opening of the exhaust valve, and N in the CVD apparatus of FIG.
FIG. 4 is a characteristic diagram showing a relationship between the flow rate of _two gases.

FIG. 7 shows the time after cleaning, the pressure in the reaction vessel, the opening of the exhaust valve, and the N
FIG. 4 is a characteristic diagram showing a relationship with a gas flow rate.

[Explanation of symbols]

 11: reaction vessel, 12: wafer, 13: holder (supporting member), 14: heater, 15: shielding ring, 16a, 16b: gas introduction pipe, 17: exhaust pipe.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4K030 AA03 AA04 AA16 AA18 CA12 DA06 GA01 JA09 KA23 5F004 AA15 BB16 BB17 BB18 BC03 BD04 CA01 CA02 DA00 DA22 DA23 DA24 DA25 5F045 AA06 AC01 AC15 AC16 AC17 AE23 AE25 BB10 EB14 EB10 EB10 BB23 HA03 HA13

Claims (5)

[Claims] 1. A reaction vessel, a support member disposed in the reaction vessel and supporting an object to be processed, a cylindrical shielding ring disposed in the reaction vessel outside the support member, and the reaction vessel A method for cleaning a semiconductor manufacturing apparatus, comprising: a gas introducing means for introducing a reactive gas and an inert gas into the inside; and an exhaust means for exhausting the gas in the reaction vessel. After flowing a sufficient amount of gas into the reaction vessel, at the same time as flowing the reactive gas to the portion where the object to be processed is to be installed and the vicinity thereof at the time of cleaning, the inert gas is continuously flowed. Cleaning method. 2. The method according to claim 1, wherein the inert gas flows from the bottom of the reaction vessel located below the support member, and the reactive gas flows from the side of the reaction vessel located higher than the object to be processed. A cleaning method for a semiconductor manufacturing apparatus according to the above. 3. The reactive gas is ClF.₃Gas,
The inert gas is N ₂Gas, Ar gas, He gas
2. The method according to claim 1, wherein at least one of them is selected.
Cleaning method of the semiconductor manufacturing apparatus described above. 4. A reaction vessel, a support member disposed in the reaction vessel and supporting an object to be processed, a cylindrical shielding ring disposed in the reaction vessel outside the support member, and the reaction vessel A method for cleaning a semiconductor manufacturing apparatus, comprising: a gas introducing means for introducing a reactive gas and an inert gas into the inside; and an exhaust means for exhausting a gas in the reaction vessel. (1) a step of introducing only an inert gas into the reaction vessel, (2) a step of increasing the pressure in the reaction vessel to 50 Torr or more, and (3) a step of evacuating the reaction vessel to 1 Torr or less. A method for cleaning a semiconductor manufacturing apparatus, wherein the steps (1) to (3) are sequentially performed at least once. 5. The reactive gas is ClF.₃Gas,
The inert gas is N ₂Gas, Ar gas, He gas
5. The method according to claim 4, wherein at least one of them is selected.
Cleaning method of the semiconductor manufacturing apparatus described above.