JPH10154702A - Manufacturing method of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the yield of semiconductor wafer fors reducing the the maintenance frequency, by a method wherein after processing the semiconductor wafer in a vacuum vessel, the vessel is fed with purge gas so as to form the sublimation atmosphere in the vessel for sublimating a reaction sub-product to be exhausted together with the purge gas. SOLUTION: A vacuum processing vessel 2 cut off from the outside air is provided with a processing part 2a for film-forming a semiconductor wafer 1 while a gas feeder 4 feeds the processing part 2a with purge gas through the intermediary of a gas leading in part 2b communicated with the processing part 2a. On the other hand, a vacuum pump 7 exhausts the purge gas 3 out of the vacuum vessel 2 through an exhaust pipe 2c communicated with the processing part 2a while a control part 10 controls the atmosphere in the vacuum processing vessel 2 to be sublimated atmosphere for sublimating ammonium chloride as a reaction sub-product produced in the vessel 2. In such a constitution, after finishing the film-forming step on the semiconductor wafer 1, the ammonium chloride is sublimated by the control part 10 to be exhausted together with the purge gas 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor manufacturing technique, and more particularly to a semiconductor manufacturing method and apparatus for removing a reaction by-product in a CVD (Chemical Vapor Deposition) apparatus.

[0002]

2. Description of the Related Art The technology described below studies the present invention,
Upon completion, they were examined by the inventor, and the outline is as follows.

In a silicon nitride film forming technique using a dichlorosilane gas and an ammonia gas, especially when a low-pressure CVD apparatus is used, the silicon nitride film is deposited on an inner wall of a reaction furnace (also called a vacuum processing vessel) or a jig for supporting a semiconductor wafer. When the accumulated thickness of the silicon nitride film reaches about 1 μm, the exhaust pipe (exhaust portion)
It is known that ammonium chloride, which is a reaction by-product, adheres to the inside of the wafer, diffuses back into the furnace, and adheres as foreign matter on the wafer.

The hot wall type CVD apparatus is disclosed in “Industrial Research Institute, Inc., published on November 22, 1991,“ Electronic Materials November Issued Separate Volume, Ultra LSI Manufacturing / Testing Equipment Guidebook <1992 Edition> ”, It is described on pages 29-34.

[0005]

However, in the low-pressure CVD apparatus according to the above-mentioned technique, since the reaction by-product adheres to the inside of the exhaust pipe, there is a problem that maintenance of the exhaust pipe takes time.

Further, since ammonium chloride adheres to the surface of the semiconductor wafer when the semiconductor wafer is carried in and out, there is a problem that the yield of the semiconductor wafer (product) is reduced.

An object of the present invention is to provide a semiconductor manufacturing method and apparatus which improve the yield of semiconductor wafers and reduce the frequency of maintenance.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0009]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows.

That is, in the semiconductor manufacturing method according to the present invention, a predetermined processing is performed on the semiconductor wafer by the processing unit of the vacuum processing container including the processing unit for processing the semiconductor wafer and the gas introduction unit and the exhaust unit communicating with the processing unit. After performing the process, supplying a purge gas into the vacuum processing container; and controlling at least one or both of the degree of vacuum in the vacuum processing container and the temperature of the exhaust unit, and controlling the vacuum processing container. Forming a sublimation atmosphere therein to sublimate the reaction by-product generated in the vacuum processing container, and exhausting the reaction by-product together with the purge gas.

As a result, the reaction by-product generated in the vacuum processing vessel can be sublimated, that is, converted into a gas. As a result, the reaction by-product converted into the gas is exhausted together with the purge gas, whereby the vacuum processing is performed. Reaction by-products can be removed from the container.

Therefore, it is possible to prevent the reaction by-product from staying inside the exhaust part of the vacuum processing vessel.
The frequency of maintenance in the semiconductor manufacturing device can be reduced.

Further, the semiconductor manufacturing method according to the present invention includes:
A step of introducing the purge gas from a gas introduction unit on one side of the vacuum processing container and flowing the purge gas to an exhaust unit on the other side of the vacuum processing container through the processing unit, and from the gas introduction unit on the other side. Introducing the purge gas and flowing the purge gas to the one-side exhaust unit via the processing unit, wherein each step is performed at least once.

Further, the semiconductor manufacturing apparatus according to the present invention provides a vacuum processing container having a processing section for shutting off the outside air and performing a predetermined processing on a semiconductor wafer, and a process through a gas introducing section communicating with the processing section. A gas supply unit for supplying a gas or a purge gas to the processing unit; an exhaust unit for exhausting the process gas or the purge gas to the outside of the vacuum processing container via an exhaust unit communicating with the processing unit; and heating the processing unit. And a control unit for controlling the inside of the vacuum processing vessel to a sublimation atmosphere for sublimating a reaction by-product generated therein, and after the predetermined processing on the semiconductor wafer is completed, the control The reaction by-product can be sublimated by a unit, and the reaction by-product can be exhausted together with the purge gas.

In the semiconductor manufacturing apparatus according to the present invention, a plurality of the gas introduction sections and a plurality of the exhaust sections corresponding to the plurality of the gas introduction sections may be configured such that the process gas or the purge gas introduced from the gas introduction section serves the processing section. The vacuum processing container is provided on one side and the other side of the vacuum processing vessel so that the vacuum processing vessel flows through the exhaust section.

Further, the semiconductor manufacturing apparatus according to the present invention comprises:
An exhaust unit heating means controlled by the control unit and heating the exhaust unit is provided.

[0017]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a conceptual view showing the structure of a semiconductor manufacturing apparatus according to an embodiment of the present invention in partial cross section.
FIG. 2 is a control block diagram showing one embodiment of the structure of the control system of the semiconductor manufacturing apparatus according to the present invention, and FIG. 3 is a sublimation condition of a reaction by-product (ammonium chloride) generated in the semiconductor manufacturing apparatus of the present invention. FIG. 4 is a control flow chart showing an example of an embodiment of a sequence control procedure in a semiconductor manufacturing method according to the present invention.

The semiconductor manufacturing apparatus according to the present embodiment is a hot-wall type two-transfer simultaneous-deposition-type low-pressure CVD apparatus for performing a film forming process (predetermined process) on the semiconductor wafer 1,
In the present embodiment, a case where a silicon nitride film is formed on a semiconductor wafer 1 using a dichlorosilane gas and an ammonia gas, which are process gases, will be described.

Therefore, the reaction by-product formed in this case is ammonium chloride (3SiH ₂ Cl _2).
+ 10NH ₃ → Si ₃ N ₄ + 6NH ₄ Cl + 6H ₂ ).

The structure of the low-pressure CVD apparatus will be described below. A vacuum processing vessel 2 having a processing section 2a for shielding the outside air and performing a film forming process on the semiconductor wafer 1;
a gas supply unit 4 for supplying a process gas or a purge gas 3 to the processing unit 2a via a gas introduction unit 2b communicating with the processing unit 2a.
A vacuum pump 7 (exhaust means) for exhausting the process gas or the purge gas 3 to the outside of the vacuum processing vessel 2 via an exhaust pipe 2c (exhaust section) communicating with the processing section 2a; and a main heating for heating the processing section 2a. And a control unit 10 for controlling the inside of the vacuum processing vessel 2 to a sublimation atmosphere for sublimating ammonium chloride, which is a reaction by-product generated therein, for forming a film on the semiconductor wafer 1. After the end,
The ammonium chloride is sublimated by the control unit 10,
The ammonium chloride is exhausted together with the purge gas 3.

That is, the vacuum processing vessel 2 in the low-pressure CVD apparatus according to the present embodiment comprises a gas introduction section 2b and a processing section 2a.
And an exhaust pipe 2c, and a film forming process on the semiconductor wafer 1 is performed in the processing unit 2a.

Here, the processing section 2a is formed by a tubular member 2d (also referred to as a reaction furnace) made of quartz, silicon carbide, or the like, which is a prismatic (or cylindrical) tubular member. Is provided with a heater 5.

That is, since the low-pressure CVD apparatus of the present embodiment is of a hot wall type, the semiconductor wafer 1 is heated by the heater 5 via the pipe member 2d during the film forming process (for example, the processing unit 2a and the semiconductor 6 wafers 1
Heat to about 00 to 900 ° C).

The gas inlet 2b is provided with a flange member 2e.
And the exhaust pipe 2c is formed by the flange member 2
e and protrudes outward from the flange member 2e.

Further, the vacuum processing vessel 2 is provided with a gate valve 8 for carrying in and out the semiconductor wafer 1 and an opening / closing valve 9 for opening / closing when performing maintenance of the pipe member 2d. Thus, the vacuum processing container 2 can be sealed and cut off from the atmosphere of the outside air.

The gate valve 8 and the opening / closing valve 9
Each has a flange surface 8a or a flange surface 9a for maintaining airtightness on each inner surface.

Here, the gate valve 8 is opened and closed by the driving member 6, and the semiconductor wafer 1 is transferred by the transfer robot 15.

Further, in the vacuum processing vessel 2 of the present embodiment, two gas inlets 2b and two corresponding exhaust pipes 2c are used for the process gas or purge gas 3 introduced from the gas inlet 2b. One side 2f of the vacuum processing vessel 2 so as to flow to the exhaust pipe 2c via the processing section 2a.
And the other side 2g are provided as a pair.

That is, the vacuum processing vessel 2 of the low-pressure CVD apparatus according to the present embodiment comprises a process gas and a purge gas 3.
And two gas flow paths.

Here, the first gas inlet 2b on one side 2f of the vacuum processing vessel 2 is provided with a first on-off valve 11a.
The pipe 11 is connected, and the other side 2g of the gas introduction section 2
b, a second pipe 12 provided with a second on-off valve 12a is connected, and further, an exhaust pipe 2c on one side 2f is connected to a third pipe 13 provided with a third on-off valve 13a.
A fourth on-off valve 14 is provided in the exhaust pipe 2c on the other side 2g.
The fourth pipe 14 in which a is installed is connected.

Accordingly, by controlling the opening and closing of the four on-off valves by the control unit 10, the process gas or the purge gas 3 taken in from the gas introduction unit 2b on one side 2f is exhausted to the exhaust pipe 2g on the other side via the processing unit 2a. 2c, and the process gas or purge gas 3 taken in from the gas inlet 2b on the other side 2g can be flowed to the exhaust pipe 2c on one side 2f via the processing section 2a.

That is, the process gas or purge gas 3
Gas from the gas inlet 2b on one side 2f
When the gas flows into the exhaust pipe 2c, the first on-off valve 11a and the fourth on-off valve 14a are opened, and the second on-off valve 12a and the third on-off valve 13a are closed.

When the gas flows from the gas inlet 2b on the other side 2g to the exhaust pipe 2c on the one side 2f, the second on-off valve 12a and the third on-off valve 13a are opened, and the first on-off valve 11a and the The fourth on-off valve 14a is closed.

The first pipe 11 and the first on-off valve 11a connected to the gas inlet 2b, and the second pipe 12 and the second
The on-off valves 12a are provided in the same number as the types of the process gas.

That is, in the present embodiment, since there are two types of process gas (dichlorosilane gas and ammonia gas), each of the gas introduction portions 2b has two process gases.
Two first pipes 11 and two first opening / closing valves 11a installed therein, and two second pipes 12 and two second opening / closing valves 12a installed therein are attached.

In the low-pressure CVD apparatus of the present embodiment, an exhaust heater 16 which is controlled by the control unit 10 and serves as an exhaust heating means for heating the exhaust pipe 2c includes an exhaust pipe 2c on one side 2f and the other. 2g and the exhaust pipe 2c on the side 2g.

The exhaust heater 16 is provided, for example, outside each exhaust pipe 2c and heats the exhaust pipe 2c from outside the exhaust pipe 2c. In the present embodiment, the heating temperature is: It is controlled by the control unit 10.

The control unit 10 included in the low-pressure CVD apparatus according to the present embodiment includes a gas supply unit 4, a vacuum pump 7, a heater 5, an exhaust unit heater 16, a first on-off valve 11a, a second on-off valve 12a, The third on-off valve 13a, the fourth on-off valve 14a, and the transfer robot 15 can be controlled.

Thus, the control unit 10 controls the vacuum processing vessel 2
And the temperature of the exhaust pipe 2c, and the kind of the gas to be supplied, can be controlled to predetermined values.

That is, under the control of the controller 10, a sublimation atmosphere for sublimating ammonium chloride can be formed in the vacuum processing vessel 2.

The sublimation condition of ammonium chloride can be derived from the sublimation curve shown in FIG. 3 by using the degree of vacuum (pressure) and the temperature in the vacuum processing vessel 2 as parameters.

The purge gas 3 according to the present embodiment
Is an inert gas, and a case of N ₂ gas will be described as an example, but a gas such as He, Ar, or NH ₃ may be used depending on the type of a film formed on the semiconductor wafer 1.

The semiconductor manufacturing method according to the present embodiment will be described.

In the semiconductor manufacturing method, a film forming process is performed on the semiconductor wafer 1 by using the low-pressure CVD apparatus of the present embodiment shown in FIG. This is for removing a reaction by-product generated in the vacuum processing vessel 2 of the low-pressure CVD apparatus.

In this embodiment, two kinds of process gases (dichlorosilane gas and ammonia gas) are used.
A case will be described in which a silicon nitride film is formed on a semiconductor wafer 1 by using the method described above, and thereafter, ammonium chloride generated in the vacuum processing vessel 2 during film formation is removed.

Further, with respect to the vacuum processing container 2 of the low-pressure CVD apparatus described here, the processing unit 2a and the gas introduction unit 2
b and an exhaust pipe 2c (exhaust section), in which the two gas introduction sections 2b and the two exhaust pipes 2c corresponding thereto are introduced from the gas introduction section 2b in the vacuum processing vessel 2. Gas or purge gas 3
The vacuum processing container 2 is provided on one side 2f and the other side 2g of the vacuum processing vessel 2 so as to flow to the exhaust pipe 2c via the line a. That is, this is a low-pressure CVD apparatus having two flow path systems for the gas such as the process gas and the purge gas 3.

First, under the control of the control unit 10 shown in FIG. 2, the gate valve 8 of the vacuum processing vessel 2 is opened by the driving member 6, and the two semiconductor wafers 1 are processed by the transfer robot 15 in the pipe member 2d. The wafer loading 20 (see FIG. 4) to be loaded into the section 2a is performed, and then the gate valve 8 is closed.

As a result, the inside of the vacuum processing container 2 is shut off from the outside air, that is, hermetically sealed.

Thereafter, the heater 5 is controlled, and a wafer heating 21 for heating the processing section 2a of the vacuum processing vessel 2 to a predetermined temperature via the pipe member 2d is performed.

In the present embodiment, for example, the temperature is detected by the temperature sensor 17 provided in the processing section 2a, whereby the processing section 2a and the semiconductor wafer 1 are detected by the temperature sensor 600 to 9-9.
Heat to 00 ° C.

Subsequently, the gas supply means 4 and the vacuum pump 7 are controlled and the first on-off valve 11a of the first pipe 11 is controlled.
And the fourth on-off valve 14a of the fourth pipe 14 is opened, and the second
The first on / off valve 12a of the pipe 12 and the third on / off valve 13a of the third pipe 13 are closed, and the first process gas introduction 22 is performed.

That is, using the gas flow meter 19, the two types of process gas, each controlled to a predetermined flow rate, are separately introduced into the gas introduction section 2b on one side 2f. Thereafter, the introduced two types of process gas flow through the processing unit 2a to the exhaust pipe 2c on the other side 2g.

At this time, the gas flow meter 19 and the vacuum processing vessel 2
The inside of the vacuum processing vessel 2 is maintained at a predetermined degree of vacuum (pressure) by using the pressure sensor 18 for detecting the internal pressure and controlling the gas supply means 4 and the vacuum pump 7 by the control unit 10.

In this state, by flowing the process gas for a predetermined time, a silicon nitride film having a desired thickness can be formed on the semiconductor wafer 1.

Thereafter, the first on-off valve 11a of the first pipe 11
By closing the second on-off valve 12a of the second pipe 12 and the introduction of the process gas, the third on-off valve 13a of the third pipe 13 and the fourth on-off valve 14a of the fourth pipe 14 are opened. A vacuum pump 23 is performed to control the vacuum pump 7 to adjust the inside of the vacuum processing container 2 to a predetermined degree of vacuum.

Subsequently, the gas supply means 4 and the vacuum pump 7 are controlled and the second on-off valve 12a of the second pipe 12 is controlled.
And the third on-off valve 13a of the third pipe 13 is opened, and the first
The first on-off valve 11a of the pipe 11 and the fourth on-off valve 14a of the fourth pipe 14 are closed, and the second process gas introduction 24 is performed.

That is, using the gas flow meter 19, the two kinds of process gases, each controlled to a predetermined flow rate, are separately introduced into the gas introduction section 2b on the other side 2g.
Thereafter, the introduced process gas flows through the processing section 2a to the exhaust pipe 2c on one side 2f.

At this time, similarly to the first process gas introduction 22, the gas flow meter 19 and the pressure sensor 18 for detecting the pressure in the vacuum processing vessel 2 are used, and the gas supply means 4 and the vacuum pump 7 are controlled. The inside of the vacuum processing container 2 is maintained at a predetermined degree of vacuum (pressure) by controlling by the unit 10.

In this state, the first process gas introduction 2
By flowing the process gas for a predetermined time as in the case of 2, a silicon nitride film having a desired thickness can be further formed on the semiconductor wafer 1.

The second process gas introduction 24
This is for uniformly depositing the silicon nitride film on the semiconductor wafer 1. In the processing section 2 a, the process gas is caused to flow in opposite directions at the first time and the second time so that a uniform film is formed on the semiconductor wafer 1. It can be performed.

However, the number of times the process gas is introduced is
The number of times is not limited to two, but can be changed as needed.

Thereafter, a film formation process end determination 25 is executed.

That is, when a silicon nitride film having a desired thickness can be formed, the film forming process is terminated, and when the silicon nitride film cannot be formed, the film forming process is repeated.

When the silicon nitride film is formed, ammonium chloride, which is a reaction by-product, adheres to the inside of the vacuum processing vessel 2, particularly to the inner wall of the exhaust pipe 2 c which is the exhaust part.

Subsequently, after the film forming process is completed, the gate valve 8 is opened by the control unit 10, and further, the semiconductor wafer 1 is taken out 26 from the vacuum processing container 2 by using the transfer robot 15, and the semiconductor wafer 1 is removed. It is transported to a predetermined location.

Further, after unloading the semiconductor wafer 1 from the vacuum processing container 2, a purge process in the vacuum processing container 2 is performed.

The purge gas 3 according to the present embodiment
Is N ₂ gas.

First, the control section 10 shown in FIG. 2 controls the exhaust section heater 16 while detecting the temperature of the temperature sensor 17 provided in the exhaust pipe 2c, whereby the temperature of the exhaust pipe 2c is raised to 80 to 180 ° C. Preferably, it is heated to 150 ° C.

Subsequently, the gas supply means 4 and the vacuum pump 7 are controlled and the first on-off valve 11a of the first pipe 11 is controlled.
And the fourth on-off valve 14a of the fourth pipe 14 is opened, and the second
The second on-off valve 12a of the pipe 12 and the third on-off valve 13a of the third pipe 13 are closed to perform the first purge gas introduction 27.

In this embodiment, the gas flow meter 19
And N ₂ gas (purge gas 3) controlled at 1 l / min or more, preferably 4 l / min by the control unit 10 is flowed for 5 minutes.

This is because the amount of the purge gas 3 is reduced by the pipe member 2d.
The flow rate and the flow time of the N ₂ gas per unit time are set so as to be at least three times the internal volume of the (reactor). For example, the semiconductor wafer 1 having a diameter of up to 200 mm is set.
4l / mi in the case of the pipe member 2d used for the film forming process of
This is because it is appropriate to flow n for 5 minutes.

Thus, one side 2f of the vacuum processing vessel 2
Purge gas 3 introduced from the gas introduction section 2b of the processing section 2
Through (a) into the exhaust pipe 2c on the other side 2g.

At this time, the gas flow meter 19 and the vacuum processing vessel 2
By controlling the gas supply means 4 and the vacuum pump 7 by the control unit 10 using the pressure sensor 18 for detecting the pressure in the vacuum processing chamber 2, the pressure in the vacuum processing vessel 2 is reduced to 80 Pa
To keep.

Thereafter, the first on-off valve 11a of the first pipe 11
And the second on-off valve 12a of the second pipe 12 are closed to stop the introduction of the purge gas 3, and the third on-off valve 13a of the third pipe 13 and the fourth on-off valve 14a of the fourth pipe 14 are opened and the vacuum is opened. The pump 7 is controlled to perform vacuum evacuation 28 for adjusting the pressure in the vacuum processing container 2 to about 0.1 Pa.

That is, the inside of the vacuum processing vessel 2 is about 0.1 Pa
To form a sublimation atmosphere of ammonium chloride in the vacuum processing vessel 2.

At this time, the temperature of the exhaust pipe 2c is 150 ° C.
Or a temperature other than this.

The time for performing the pressure reduction is, for example, 5
The time may be on the order of minutes, but may be other times.

That is, using the ammonium chloride sublimation curve diagram shown in FIG. 3, the pressure and temperature in the vacuum processing vessel 2 (particularly, the temperature of the exhaust pipe 2c) satisfy the conditions for sublimating ammonium chloride. I just need.

For example, as shown in FIG. 3, when the pressure in the vacuum processing vessel 2 is set to 60 Pa, it is necessary to adjust the temperature of the exhaust pipe 2c to about 150 ° C. or more.
When the internal pressure is set to 200 Pa, it is necessary to adjust the temperature of the exhaust pipe 2c to about 170 ° C. or more.

As a result, the ammonium chloride adhering to the exhaust pipe 2c on the other side 2g can be sublimated,
In addition, the sublimated ammonium chloride can be exhausted together with the purge gas 3.

Thereafter, the control unit 10 shown in FIG. 2 controls the gas supply means 4 and the vacuum pump 7, and opens the second on-off valve 12a of the second pipe 12 and the third on-off valve 13a of the third pipe 13, And the first on-off valve 1 of the first pipe 11
1a and the fourth on-off valve 14a of the fourth pipe 14 are closed, and the second purge gas introduction 29 is performed.

In the second purge gas introduction 29, the control section 10 also uses the gas flow meter 19 to control the purge gas to 1 l.
/ Min, preferably 4 l / min, for 5 minutes.

As a result, the other side 2 g of the vacuum processing container 2
The purge gas 3 introduced from the gas introduction unit 2b is passed through the processing unit 2a to the exhaust pipe 2c on one side 2f, and the pressure inside the vacuum processing vessel 2 is again increased to 80 Pa.

After the pressure increase, the first on-off valve 11a of the first pipe 11
And the second on-off valve 12a of the second pipe 12 are closed to stop the introduction of the purge gas 3, and the third on-off valve 13a of the third pipe 13 and the fourth on-off valve 14a of the fourth pipe 14 are opened and the vacuum is opened. A vacuum evacuation 30 for controlling the pressure of the vacuum processing vessel 2 to about 0.1 Pa by controlling the pump 7 is performed.

That is, as in the case of the vacuum evacuation 28, the pressure in the vacuum processing vessel 2 is reduced to about 0.1 Pa, thereby forming a sublimation atmosphere of ammonium chloride in the vacuum processing vessel 2.

At this time, as in the case of the vacuum evacuation 28, the temperature of the exhaust pipe 2c may be 150 ° C. or any other temperature. For example, about 5 minutes may be used, but other times may be used.

That is, using the ammonium chloride sublimation curve diagram shown in FIG. 3, the pressure and temperature in the vacuum processing vessel 2 (particularly, the temperature of the exhaust pipe 2c) satisfy the conditions for sublimating ammonium chloride. I just need.

Thus, the ammonium chloride adhering to the inside of the exhaust pipe 2c on the one side 2f can be sublimated.
In addition, the sublimated ammonium chloride can be exhausted together with the purge gas 3.

Thereafter, a purge process end determination 31 is executed.

Here, in the operation shown in FIG. 4, the operation from the first purge gas introduction 27 to the vacuum evacuation 30, ie, the purging process, is performed until the operator instructs the completion of the purging process.

In the present embodiment, in the low-pressure CVD apparatus, after the film formation processing is completed, until the next film formation processing is started, that is, the low-pressure CVD apparatus forms a silicon nitride film (composition). At times other than when the vacuum processing container 2 is used for performing the film processing, the purging processing is continuously performed until the operator instructs the completion of the purging processing.

However, even when the low-pressure CVD apparatus is not performing the film forming process, if the ammonium chloride does not adhere to the vacuum processing vessel 2, the purging process is not necessarily performed. Needless to say.

Further, the purge gas 3 is introduced from the gas introduction section 2b on one side 2f of the vacuum processing vessel 2 and the purge gas 3
Through the processing unit 2a to the exhaust pipe 2c on the other side 2g of the vacuum processing vessel 2, and the gas introduction unit 2b on the other side 2g.
Purge gas 3 is introduced from the
It is preferable that the flow through the exhaust pipe 2c on the one side 2f via a is intermittently repeated a plurality of times as a pair.

It goes without saying that the number of intermittent repetitions can be changed depending on the degree of adhesion of ammonium chloride.

According to the semiconductor manufacturing method and apparatus of the present embodiment, the following operation and effect can be obtained.

That is, after the film forming process is performed on the semiconductor wafer 1, the purge gas 3 is supplied into the vacuum processing container 2, and the degree of vacuum in the vacuum processing container 2 or the temperature of the exhaust pipe 2c is controlled to control the vacuum processing container. By forming a sublimation atmosphere of ammonium chloride (reaction by-product) in 2, the ammonium chloride generated in the vacuum processing vessel 2 can be sublimated, that is, changed from a solid to a gas.

As a result, it is possible to remove ammonium chloride from the inside of the vacuum processing vessel 2 by exhausting the ammonium chloride converted into a gas together with the purge gas 3.

Therefore, it is possible to prevent the ammonium chloride from remaining in the exhaust pipe 2c of the vacuum processing container 2, thereby reducing the frequency of maintenance in the low-pressure CVD device (semiconductor manufacturing device).

In the present embodiment, the cumulative thickness of the silicon nitride film on the pipe member 2d is set to about 2.5 μm (about 1 μm in the conventional low-pressure CVD apparatus), which is a guideline for maintenance of the low-pressure CVD apparatus. As a result, the frequency of maintenance can be greatly reduced.

Further, ammonium chloride is supplied to the exhaust pipe 2c.
Since it can be prevented from continuing to adhere to the inside, it is possible to prevent ammonium chloride from adhering to the semiconductor wafer 1 when the semiconductor wafer 1 is carried in and out.

As a result, the yield of the semiconductor wafer 1 can be improved.

When the purge gas 3 flows in the vacuum processing container 2, the gas introduction section 2 f on one side 2 f of the vacuum processing container 2
b, the purge gas 3 is introduced from the exhaust pipe 2 on the other side 2g of the vacuum processing vessel 2 through the processing section 2a.
c and flowing the purge gas 3 from the gas introduction unit 2b on the other side 2g and flowing the purge gas 3 to the exhaust pipe 2c on the one side 2f via the processing unit 2a a plurality of times (at least once for both). By doing so, the back diffusion of ammonium chloride into the vacuum processing vessel 2 can be prevented.

As a result, adhesion of ammonium chloride and other foreign substances in the vacuum processing vessel 2 can be prevented, and the produced ammonium chloride can be diluted.

Thus, the amount of ammonium chloride generated in the vacuum processing vessel 2 can be reduced, and as a result, the adhesion of ammonium chloride to the vacuum processing vessel 2 can be reduced.

After the film forming process on the semiconductor wafer 1 is completed, the processing unit 2 connects the gas introducing unit 2b to the exhaust pipe 2c.
a through the purge gas 3 through the processing unit 2a.
The heated purge gas 3 reaches the exhaust pipe 2c.
Can be heated.

As a result, the exhaust pipe 2c can be efficiently heated when it is heated.

Although the invention made by the inventor has been specifically described based on the embodiments of the present invention, the present invention is not limited to the embodiments of the invention, and does not depart from the gist of the invention. It is needless to say that various changes can be made.

For example, in the above embodiment, when controlling or reducing the degree of vacuum in the vacuum processing vessel, the first on-off valve and the second on-off valve are closed to introduce the purge gas from the gas introduction section. Has been described, but when controlling the degree of vacuum in the vacuum processing vessel or reducing the pressure in the vacuum processing vessel, the first on-off valve and the second on-off valve are opened, and the The control of the degree of vacuum or the control of the pressure reduction may be performed by controlling the amount of introduction of the purge gas or the amount of evacuation.

That is, when the sublimation atmosphere of ammonium chloride is formed in the vacuum processing vessel 2 in the above embodiment, the gas introduction section 2b on one side 2f or the other side 2g is formed.
The purge gas 3 is introduced from the
a, the first on-off valve 11a and the second on-off valve 12a
And the third on-off valve 13a and the fourth on-off valve 14a are also opened to set the flow rate of the purge gas 3 to 0 to 2 l / min.
For example, it flows for about 5 minutes (however, a time other than 5 minutes may be used).

Further, by heating the temperature of the exhaust pipe 2c to 150 ° C. or higher, it becomes possible to form a sublimation atmosphere of ammonium chloride in the vacuum processing vessel 2.

In the above embodiment, the case where the semiconductor manufacturing apparatus is a low-pressure CVD apparatus has been described. However, the semiconductor manufacturing apparatus may be a silicon nitride film, a polycrystalline silicon film, an epitaxial silicon film, a silicon oxide film, or a tantalum oxide film. It may be another film forming apparatus capable of forming a film, or may be an oxidizing apparatus for performing a heat treatment or an oxidizing treatment on a semiconductor wafer, or a doping apparatus for injecting impurities from a gas phase into the semiconductor wafer. .

That is, when the semiconductor manufacturing apparatus shown in FIG. 1 is used, the process gas is exchanged for a predetermined gas, and the predetermined processing is performed under the processing conditions for the semiconductor wafer, the vacuum processing is performed. The reaction by-product generated in the container is formed by the same method as the semiconductor manufacturing method of the above-described embodiment (however, the conditions for forming the sublimation atmosphere in the vacuum processing container are each time the semiconductor wafer is processed or the reaction is performed). The reaction by-product can be sublimated and exhausted (depending on the type of by-product).

The semiconductor manufacturing method in this case is such that a predetermined processing is performed on the semiconductor wafer by the processing section of the vacuum processing vessel comprising a processing section for processing the semiconductor wafer and a gas introducing section and an exhaust section communicating with the processing section. After performing, a step of supplying a purge gas into the vacuum processing container, and controlling at least one or both of the degree of vacuum in the vacuum processing container and the temperature of the exhaust unit into the vacuum processing container. A step of forming a sublimation atmosphere to sublimate a reaction by-product generated in the vacuum processing container; and a step of exhausting the reaction by-product together with the purge gas.

[0115]

The effects obtained by typical ones of the inventions disclosed in the present application will be briefly described as follows.

(1). After performing a predetermined process on the semiconductor wafer, the sublimation atmosphere is formed in the vacuum processing container by controlling at least one of the degree of vacuum in the vacuum processing container and the temperature of the exhaust unit, so that the inside of the vacuum processing container is Can be sublimated. As a result, by exhausting the reaction by-products together with the purge gas, it is possible to prevent the reaction by-products from remaining in the vacuum processing vessel, thereby reducing the frequency of maintenance in the semiconductor manufacturing apparatus.

(2). Since reaction by-products can be prevented from continuing to adhere to the inside of the exhaust unit, reaction by-products can be prevented from adhering to the semiconductor wafer when the semiconductor wafer is loaded or unloaded. Thereby, the yield of the semiconductor wafer can be improved.

(3). When the purge gas flows in the vacuum processing container, the purge gas is introduced from the gas introduction unit on one side of the vacuum processing container, and the purge gas flows to the exhaust unit on the other side of the vacuum processing container via the processing unit. Preventing the back-diffusion of reaction by-products into the vacuum processing vessel by at least once introducing a purge gas from the gas introduction section and flowing the purge gas to one exhaust section via the processing section. Can be. As a result, the amount of the reaction by-product generated in the vacuum processing container can be reduced, and thereby, the adhesion of the reaction by-product in the vacuum processing container can be reduced.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a partial cross section of an example of an embodiment of the structure of a semiconductor manufacturing apparatus according to the present invention.

FIG. 2 is a control block diagram showing an example of an embodiment of a control system structure of the semiconductor manufacturing apparatus according to the present invention.

FIG. 3 is a sublimation curve diagram showing an example of an embodiment of sublimation conditions of a reaction by-product (ammonium chloride) generated in the semiconductor manufacturing apparatus of the present invention.

FIG. 4 is a control flow showing an example of an embodiment of a sequence control procedure in the semiconductor manufacturing method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor wafer 2 Vacuum processing container 2a Processing part 2b Gas introduction part 2c Exhaust pipe (exhaust part) 2d Tube member 2e Flange member 2f One side 2g The other side 3 Purge gas 4 Gas supply means 5 Heater (main heating means) 6 Drive member 7 Vacuum pump (exhaust means) 8 Gate valve 8a Flange surface 9 Open / close valve 9a Flange surface 10 Control unit 11 First pipe 11a First open / close valve 12 Second pipe 12a Second open / close valve 13 Third pipe 13a Third open / close valve 14th 4 piping 14a Fourth on-off valve 15 Transfer robot 16 Exhaust part heater (exhaust part heating means) 17 Temperature sensor 18 Pressure sensor 19 Gas flow meter 20 Wafer loading 21 Wafer heating 22 First process gas introduction 23 Vacuum exhaust 24 Second time Introducing process gas 25 Determining completion of film forming process 26 Unloading wafer 27 First pass Introduction of vacuum gas 28 evacuation 29 introduction of second purge gas 30 evacuation 31 end of purge processing

Claims (9)

[Claims] After performing a predetermined process on the semiconductor wafer in the processing section of a vacuum processing container including a processing section for processing a semiconductor wafer and a gas introduction section and an exhaust section communicating with the processing section, Supplying a purge gas into the processing container, forming at least one or both of the degree of vacuum in the vacuum processing container and the temperature of the exhaust unit to form a sublimation atmosphere in the vacuum processing container; A semiconductor manufacturing method, comprising: a step of sublimating a reaction by-product generated in the vacuum processing container; and a step of exhausting the reaction by-product together with the purge gas. 2. The semiconductor manufacturing method according to claim 1, wherein said purge gas is introduced from a gas inlet on one side of said vacuum processing vessel, and said purge gas is supplied to said other side of said vacuum processing vessel via said processing section. Flowing to the side exhaust part,
Introducing the purge gas from the gas introduction section on the other side and flowing the purge gas to the exhaust section on the one side via the processing section, wherein each step is performed at least once. Semiconductor manufacturing method. 3. A film forming process is performed on the semiconductor wafer in the processing unit of the vacuum processing container including a processing unit for processing the semiconductor wafer and a plurality of gas introduction units and a plurality of exhaust units communicating with the processing unit. Thereafter, a step of introducing a purge gas from a gas inlet on one side of the vacuum processing vessel and flowing the purge gas to an exhaust section on the other side of the vacuum processing vessel via the processing section; Or a step of forming a sublimation atmosphere in the vacuum processing vessel by performing one or both of heating of the exhaust unit and sublimating a reaction by-product generated in the vacuum processing vessel; A step of introducing the purge gas from a gas introduction unit and flowing the purge gas to the one-side exhaust unit through the processing unit to increase the pressure inside the vacuum processing container; and after increasing the pressure, the vacuum processing container Forming a sublimation atmosphere in the vacuum processing container by performing one or both of decompression of the inside or heating of the exhaust unit, and sublimating a reaction by-product generated in the vacuum processing container; Exhausting the reaction by-products together with the purge gas. 4. The method of manufacturing a semiconductor device according to claim 1, wherein the control of the degree of vacuum in the vacuum processing vessel or the reduction of the pressure in the vacuum processing vessel is stopped. Alternatively, the method is performed by controlling the amount of introduction of the purge gas or the amount of evacuation. 5. A vacuum processing container provided with a processing unit for performing a predetermined processing on a semiconductor wafer while shutting off a process gas or a purge gas through a gas introduction unit communicating with the processing unit. A gas supply unit that supplies the process gas or the purge gas to the outside of the vacuum processing container via an exhaust unit that communicates with the processing unit; a main heating unit that heats the processing unit; A control unit for controlling the inside of the vacuum processing vessel to a sublimation atmosphere for sublimating a reaction by-product generated therein, and after the predetermined processing on the semiconductor wafer is completed, the control unit controls the reaction by-product. Wherein the reaction by-product is exhausted together with the purge gas. 6. The semiconductor manufacturing apparatus according to claim 5, wherein the plurality of gas introduction units and the plurality of exhaust units corresponding to the plurality of gas introduction units are configured so that the process gas or the purge gas introduced from the gas introduction unit is used. A semiconductor manufacturing apparatus provided on one side and the other side of the vacuum processing container so as to flow to the exhaust unit via the processing unit. 7. The semiconductor manufacturing apparatus according to claim 5, further comprising an exhaust unit heating means controlled by said control unit and heating said exhaust unit. . 8. The semiconductor manufacturing apparatus according to claim 5, wherein the control unit controls the gas supply unit and the exhaust unit, and the control unit controls the degree of vacuum in the vacuum processing vessel. A semiconductor manufacturing apparatus characterized by being adjustable. 9. The semiconductor manufacturing apparatus according to claim 5, wherein a silicon nitride film, a polycrystalline silicon film, an epitaxial silicon film, a silicon oxide film or a tantalum oxide film is formed on the semiconductor wafer. A semiconductor manufacturing apparatus, which is a film forming apparatus, an oxidizing apparatus for performing a heat treatment or an oxidizing process on the semiconductor wafer, or a doping apparatus for injecting impurities from a gas phase into the semiconductor wafer.