JPH07249584A - Chemical vapor growth device and film formation method using it - Google Patents

Abstract

PURPOSE:To provide a chemical vapor growth device and film formation method with less amount of generated particles and a high productivity which are especially suited for the case when film formation gas contains a silane compound. CONSTITUTION:The chemical vapor growth device for forming a film with a specific thin film on the surface of a substrate 5 using a film formation gas introduced into a reaction chamber 1 for housing the substrate 5 is provided with a piping 6 for supplying purge gas with an opening near a substrate carry- out entrance 1d of a reaction chamber 1. At this time, the chemical vapor growth device may be provided with a purge gas heating mechanism for heating purge gas or a heating mechanism for heating before introducing the film formation gas into the reaction chamber 1. At this time, the film formation gas may contain a feed gas and a dilute gas for giving the constituents of a thin film and the heating mechanism may heat the dilution gas or a load lock chamber 3 may be provided with at least either of a heater for heating the substrate 5 or a piping for supplying heated purge gas for supplying the heated purge gas.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chemical vapor deposition apparatus (hereinafter referred to as a CVD apparatus) and a film forming method using the same.
The present invention relates to a CVD apparatus and a film forming method that are suitable for forming an iN thin film, a polysilicon thin film, or the like and that suppress the generation of particles.

[0002]

2. Description of the Related Art A CVD apparatus supplies one or several kinds of gases (hereinafter, these gases are collectively referred to as "film forming gas") consisting of elements constituting a thin film material onto a substrate to form a gas phase. Alternatively, it is an apparatus for forming a desired thin film by a chemical reaction on the substrate surface.

The above CVD apparatus, especially the low pressure CVD apparatus,
It is widely used for forming thin films of Si, SiN, SiO, SiON and the like.

The above-mentioned low pressure CVD apparatus is a CVD apparatus for reducing the pressure in the reaction chamber where a thin film is formed to form a film. In the low pressure CVD apparatus, since the mean free path of the film forming gas and the diffusion constant are large, the film thickness and the film quality are more uniform and the step coverage (thin film) is higher than that in the atmospheric pressure CVD apparatus in which the reaction is performed in the atmospheric pressure space. It is possible to form a film having a good state in which the film is adhered at the minute step portion on the surface of the.

An example of the CVD apparatus will be described below. C
As shown in FIG. 9, the VD device mainly includes a reaction chamber 21, a heater 22, a load lock chamber 23, and a boat 24.

The reaction chamber 21 is tubular and has a double structure, and is composed of an outer outer tube 21a for heat insulation and an inner inner tube 21b for process.
A substrate loading / unloading port 21d having a valve for opening / closing the reaction chamber 21 is provided in the lower portion. There is a hole 21c in the upper part of the inner tube 21b, and the space inside the inner tube 21b and the space between the outer tube 21a and the inner tube 21b communicate with each other through the hole 21c. The inside of the reaction chamber 21 is the outer tube 2
It is cut off from the outside air by 1a. Further, the film forming gas inlet 28 for introducing the film forming gas into the inner tube 21b, the outer tube 21a and the inner tube 2 are formed.
1b is provided with an exhaust port 29 for exhausting the inside of the reaction chamber 21. The film forming gas is introduced into the reaction chamber 21 and the inside of the reaction chamber 21 is exhausted. Then, the substrate 25 is housed inside the inner tube 21b, a film forming gas is introduced, and a thin film is formed on the surface of the substrate 25.

The heater 22 is arranged so as to surround the reaction chamber 21, and is used for heating the substrate 25 to a temperature necessary for forming a thin film during film formation.

The load lock chamber 23 is a so-called preliminary vacuum chamber that is evacuated to a reduced pressure or a vacuum by an exhaust device (not shown), and is the reaction chamber 2 through the substrate loading / unloading port 21d.
Connected under 1. And this load lock chamber 23
The substrate 25 is carried into the reaction chamber 21 or is carried out of the apparatus from the reaction chamber 21 via the.

The boat 24 has about 100 substrates 25.
Is a substrate support tool capable of horizontally supporting each substrate 25 at a constant interval, and is arranged so as to be able to reciprocate between the reaction chamber 21 and the load lock chamber 23 by a transport mechanism (not shown). It Then, with the substrate 25 placed on the boat 24 and supported, the substrate 25 is carried into the reaction chamber 21 from the load lock chamber 23, or the substrate 25 is carried out from the reaction chamber 21 to the load lock chamber 23, or inside the reaction chamber 21. Then, a thin film is formed on the surface of the substrate 25.

When a thin film is formed on the surface of the substrate by the above-described CVD apparatus, the substrate 25 is placed on the boat 24 in the load lock chamber 23 and is loaded into the reaction chamber 21 from the load lock chamber 23. . At this time, in order to prevent oxygen and water in the atmosphere from entering the reaction chamber 21 and causing an unintended gas phase reaction, the substrate 25 is carried into the load lock chamber 23, and then the load lock chamber 23 is depressurized. Or, the substrate 25 is carried into the reaction chamber 21 from the load lock chamber 23 after evacuating to vacuum and removing oxygen and water in the atmosphere. Then, a film forming gas is introduced into the reaction chamber 21 and the substrate 25
A thin film is formed on the surface of. Then, when the thin film formation is completed, the substrate 25 is carried out together with the boat 24 from the reaction chamber 21 to the load lock chamber 23. Then, the substrate 25 is taken out from the load lock chamber 23.

By the way, in chemical vapor deposition, it is a major problem to prevent particles from adhering to the surface of the thin film. There are roughly two types of causes of the particles.

The first cause of particle generation is the film forming gas. Specifically, for example, a reaction product or a side reaction product in the gas phase may serve as a particle source.
In particular, if a concentration gradient occurs in the film forming gas in the reaction chamber, a gas phase reaction is likely to occur in a region where the film forming gas is rich, and particles are likely to occur. Alternatively, the film grown in a region other than the substrate surface in the reaction chamber may peel off to become particles. Alternatively, when the film-forming gas and the reaction by-products that remain with the substrate during the unloading of the substrate are released to the outside of the reaction chamber, these released substances may react with oxygen or water in the atmosphere, or may be cooled. , May solidify into particles. Alternatively, if a temperature gradient occurs in the film forming gas in the reaction chamber, an unintended vapor phase reaction may occur and particles may be generated.

The film-forming gas or reaction by-product reacts with oxygen or water in the atmosphere to be solidified into particles, for example, a silane-based film forming gas for chemical vapor deposition such as Si. This is the case where the gas reacts with oxygen in the atmosphere to become SiO or the like and solidifies into particles. Further, the film forming gas and the reaction by-product are cooled and solidified into particles, for example, when ammonium chloride, which is a reaction by-product of chemical vapor deposition such as SiN, is cooled to about room temperature. This is the case where it solidifies into particles. Further, a temperature gradient occurs in the film forming gas in the reaction chamber and an unintended vapor phase reaction occurs and becomes particles, for example, when the temperature of the film forming gas is lower than the gas phase reaction temperature It is a case where particles react with a sensitivity to abnormal growth and become particles.

The second cause of particle generation is a transfer mechanism for loading and unloading the substrate into and from the reaction chamber. That is, when the transport mechanism operates, particles are generated due to sliding of the transport mechanism or the like.

In order to prevent the particles generated as described above from adhering to the surface of the substrate, the load lock chamber and the reaction chamber are set to atmospheric pressure when the substrate is carried into and out of the reaction chamber. The transport mechanism is operated on. This is because the average flight distance of particles is shortened to prevent diffusion and reduce the number of particles adhering to the substrate surface.

That is, when the substrate is loaded into the reaction chamber, first, the substrate loading / unloading port between the load lock chamber and the reaction chamber is closed, and then the load lock chamber is preliminarily replaced with an inert gas at atmospheric pressure. Bring in the board and place it on the boat. And
The substrate loading / unloading port between the load lock chamber and the reaction chamber is opened, and the substrate is loaded into the reaction chamber together with the boat. Then, the substrate loading / unloading port between the load lock chamber and the reaction chamber is closed. Also,
When unloading the substrate from the reaction chamber, first replace the load lock chamber with an inert gas at atmospheric pressure, then open the substrate loading / unloading port between the load lock chamber and the reaction chamber, and load the substrate with the boat into the load lock chamber. Carry out. Then, the substrate loading / unloading port between the load lock chamber and the reaction chamber is closed. Then, the substrate is taken out from the load lock chamber.

[0017]

The above-described method of operating the substrate transfer mechanism while keeping the load lock chamber and the reaction chamber at atmospheric pressure only prevents particles from adhering to the substrate surface. Generation of particles is not prevented. For this reason, particles are cumulatively increased as the film forming process is repeated, and the particles are likely to adhere to the substrate surface. Therefore, it is desired not only to prevent the particles from adhering to the surface of the substrate but also to prevent the particles themselves from being generated.

The present invention has been proposed in view of such a conventional situation, and provides a CVD apparatus and a film forming method in which the amount of particles generated is small, the yield is good, and the productivity is high. With the goal.

[0019]

The present inventor has completed the following invention as a result of intensive studies in order to suppress the generation of particles.

That is, the apparatus of the present invention is a CVD apparatus adapted to form a predetermined thin film on the surface of a substrate by using a film forming gas introduced into a reaction chamber containing the substrate. A purge gas supply pipe having an opening near the substrate loading / unloading port of the chamber is provided. Hereinafter, this type of CVD apparatus is referred to as a "purge gas supply type CVD apparatus".

The purge gas supply type CVD apparatus may be equipped with a purge gas heating mechanism for heating the purge gas. Hereinafter, this type of CVD apparatus is referred to as a "heating purge gas supply type CVD apparatus".

Alternatively, the apparatus of the present invention is a CVD apparatus adapted to form a predetermined thin film on the surface of a substrate by using a film forming gas introduced into a reaction chamber containing the substrate, A heating mechanism for heating the film-forming gas before introduction into the reaction chamber is provided. Below, this type of CV
The D device is referred to as a "film forming gas heating type CVD device".

In this film-forming gas heating type CVD apparatus, the film-forming gas includes a raw material gas for providing the constituents of the thin film and a diluent gas, and the heating mechanism is adapted to heat the diluent gas. Good. Hereinafter, this type of CVD apparatus is referred to as a "dilution gas heating type CVD apparatus".

In any of the above-mentioned CVD apparatuses, a load dock chamber may be connected to the reaction chamber via the substrate loading / unloading port.

Alternatively, the apparatus of the present invention is adapted to form a predetermined thin film on the surface of the substrate by using the film forming gas introduced into the reaction chamber containing the substrate, and to form the substrate in the reaction chamber. A CVD apparatus in which a load dock chamber is connected via a loading / unloading port, wherein the load lock chamber comprises:
At least one of a heater for heating the substrate and a heated purge gas supply pipe for supplying a heated purge gas is provided. Hereinafter, this type of CVD apparatus will be referred to as "load lock chamber heating type CVD
Device.

On the other hand, according to the film forming method of the present invention, when a predetermined thin film is formed on the substrate in the reaction chamber by using the purge gas supply type CVD apparatus or the heating purge gas supply type CVD apparatus, When the substrate is carried out, the purge gas is blown toward the substrate from the purge gas supply pipe. Hereinafter, this film forming method is referred to as a "purge type film forming method".

Alternatively, when a film forming gas heating type CVD apparatus or a dilution gas heating type CVD apparatus is used, the film forming gas is introduced into the reaction chamber while being heated by the heating mechanism to a temperature lower than the gas phase reaction start temperature. To do. Hereinafter, this film forming method is referred to as a “film forming gas heating type film forming method”.

In this film-forming gas heating type film-forming method, in order to further reduce the temperature gradient in the reaction chamber, the temperature of the film-forming gas may be heated to near the gas phase reaction start temperature before being introduced into the reaction chamber. Particularly preferred. However, if the film formation gas is heated to a temperature above the gas phase reaction start temperature, a gas phase reaction will occur before the film formation gas is introduced into the reaction chamber, so it is necessary to set the temperature lower than the gas phase reaction start temperature. is there.

In the film-forming gas heating type film-forming method using the dilution gas heating type CVD apparatus, the diluent gas is heated and then the raw material gas and the diluent gas are mixed immediately before being introduced into the reaction chamber. , As a film forming gas.

Alternatively, when a load lock chamber heating type CVD apparatus is used, when the substrate is unloaded from the reaction chamber, a heater provided in the load lock chamber or a heating purge gas supply unit provided in the load lock chamber is supplied. The substrate is heated by at least one of the heated purge gases supplied from the pipe. Hereinafter, this film forming method is referred to as a "load lock chamber heating type film forming method".

Alternatively, a CV of any of the above types
In the case of using the D apparatus, which is a CVD apparatus in which the load dock chamber is connected to the reaction chamber through the substrate loading / unloading port,
At least when carrying out the substrate from the reaction chamber,
It is also preferable to make the pressure in the load lock chamber higher than the pressure in the reaction chamber. Hereinafter, this film forming method is referred to as a "pressure control type film forming method".

The film-forming gas used in the film-forming method of the present invention is not particularly limited as long as it is a gas that may generate particles when itself or reaction by-products come into contact with the atmosphere. In particular, the merit of the present invention can be remarkably obtained when a film forming gas containing a silane compound is used. Hereinafter, the film forming method of the present invention, which uses a film forming gas containing a silane compound, will be referred to as a “film forming method using a silane compound”.

The present invention is not particularly limited to the thin film to be formed, but in particular, a polysilicon-based thin film, a silicon oxide-based thin film, and a silicon nitride-based thin film using a silane-based gas as a film-forming gas are used. It is suitable to be applied to the formation of a thin film, a silicon oxynitride-based thin film, or the like.

The load lock chamber connected to the reaction chamber through the substrate loading / unloading port is not particularly limited. For example, a load lock chamber in which the inside is replaced with an inert gas such as nitrogen, or a reduced pressure or A load lock chamber for evacuating is used.

[0035]

In the purge type film forming method using the purge gas supply type CVD apparatus, when the substrate is carried out of the reaction chamber, the purge gas blown from the purge gas supply pipe toward the substrate causes the residual gas from the reaction chamber to remain. Emission of membrane gas and reaction by-products is prevented. Therefore, it is possible to prevent the film forming gas and the reaction by-products from being released and reacting with oxygen, water, etc. in the atmosphere, or being cooled to be solidified into particles.

Further, in the purge type film forming method using the heated purge gas supply type CVD apparatus, when the substrate is unloaded from the reaction chamber, the heated purge gas blown from the purge gas supply pipe toward the substrate causes the above-mentioned phenomenon. In addition to the action of the purge type film forming method using the purge gas supply type CVD apparatus, it is further prevented that the film forming gas and the reaction by-products remaining from the reaction chamber are released and cooled to become particles. . That is, since the vapor pressure of the film forming gas and the reaction by-product is increased by heating, it becomes easy to exhaust and remove the film forming gas and the reaction by-product as a gas before they become particles.

Further, in the film-forming gas heating type film-forming method using the film-forming gas heating type CVD apparatus, the film-forming gas is heated to a temperature lower than the gas phase reaction start temperature by the heating mechanism, and then is introduced into the reaction chamber. Since it is introduced, the temperature gradient of the film forming gas in the reaction chamber is reduced, an unintended vapor phase reaction is prevented, and the generation of particles is suppressed.

Further, in the film forming gas heating type film forming method using the dilution gas heating type CVD apparatus, the film forming gas is introduced into the reaction chamber while being heated to a temperature lower than the gas phase reaction start temperature by the heating mechanism. Therefore, the above film forming gas heating type CVD
In addition to the function of the film-forming gas heating type film-forming method using an apparatus,
The concentration gradient of the film forming gas in the reaction chamber is reduced, and an unintended vapor phase reaction in a region where the film forming gas is high is prevented.
This suppresses the generation of particles. Furthermore, by heating the diluent gas and then mixing the raw material gas and the diluent gas, the film forming gas can be easily heated.

Further, in the load lock chamber heating type film forming method using the load lock chamber heating type CVD apparatus, when the substrate is carried out from the reaction chamber, the heater provided in the load lock chamber or the load lock chamber is provided. The substrate is heated by at least one of the heated purge gases supplied from the heated purge gas supply pipe. This prevents the remaining film-forming gas and reaction by-products discharged from the reaction chamber from cooling and becoming particles. That is, the vapor pressures of the film forming gas and the reaction by-product are increased by heating, and the film forming gas and the reaction by-product are easily exhausted and removed as gas before becoming particles. Further, when the substrate is heated by the heating purge gas, the remaining film forming gas and reaction by-products discharged from the reaction chamber are prevented from being cooled and turned into particles, and the film forming gas and The reaction by-product can be quickly removed by evacuation.

In the pressure control type film forming method, since the pressure in the load lock chamber is made higher than the pressure in the reaction chamber at least when the substrate is carried out from the reaction chamber, the film forming gas remaining from the reaction chamber is And the release of reaction by-products is prevented. Therefore, these film forming gases and reaction byproducts are released to the outside of the reaction chamber to react with oxygen and water in the atmosphere,
Alternatively, when cooled, it is prevented from solidifying and becoming particles.

The above-mentioned effects can be obtained also in the film forming method using a silane compound, but particularly when the film forming gas heating type film forming method is applied, the effect of suppressing the generation of particles is remarkably obtained. . This is because when a film-forming gas containing a silane-based compound is used, it is particularly important to keep the temperature of the film-forming gas appropriately in order to suppress the generation of particles. For example, dichlorosilane, which is a silane-based compound used for forming a silicon nitride-based thin film, has a low boiling point and is easily liquefied. It reacts to generate particles. However, in the film-forming gas heating type film-forming method, since the temperature of the film-forming gas is appropriately maintained, the above-mentioned generation of particles can be suppressed.

[0042]

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

Example 1 An example of a purge gas supply type CVD apparatus and a purge type film forming method using the same will be described with reference to FIGS. 1 and 2.

The purge gas supply type CVD apparatus of this embodiment is a low pressure CVD apparatus, and as shown in FIG. 1, mainly from the reaction chamber 1, the heater 2, the load lock chamber 3, the boat 4, and the purge gas supply pipe 6. Composed.

The reaction chamber 1 is tubular and has a double structure, and is composed of an outer heat-insulating outer tube 1a and an inner process inner tube 1b, and a valve for opening and closing the reaction chamber 1 at the lower part. It has a substrate loading / unloading port 1d. The hole 1c is formed in the upper part of the inner tube 1b.
The space inside the inner tube 1b and the space between the outer tube 1a and the inner tube 1b communicate with each other through the hole 1c. The inside of the reaction chamber 1 is isolated from the outside air by the outer tube 1a. Further, it is provided with a film forming gas inlet 8 for introducing the film forming gas into the inner tube 1b, and an exhaust port 9 for exhausting the reaction chamber 1 from the space between the outer tube 1a and the inner tube 1b. The deposition gas is introduced into the reaction chamber 1, and the inside of the reaction chamber 1 is exhausted. Then, the substrate 5 is housed inside the inner tube 1b,
A film forming gas is introduced to form a thin film on the surface of the substrate 5.

The heater 2 is arranged so as to surround the reaction chamber 1, and is used for heating the substrate 5 to a temperature necessary for forming a thin film during film formation.

The load lock chamber 3 is a so-called preliminary vacuum chamber that is evacuated to a reduced pressure or a vacuum by an exhaust device (not shown), and is connected below the reaction chamber 1 via the substrate loading / unloading port 1d. Then, the substrate 5 is carried into or out of the reaction chamber 1 via the load lock chamber 3.

The boat 4 is a substrate support tool capable of supporting about 100 substrates 5 horizontally at regular intervals and by a transport mechanism (not shown).
It is arranged so as to be able to reciprocate between the reaction chamber 1 and the load lock chamber 3. Then, with the substrate 5 placed on the boat 4 and supported, the substrate 5 is carried into the reaction chamber 1 from the load lock chamber 3, or the substrate 5 is moved from the reaction chamber 1 to the load lock chamber 3
Or to form a thin film on the surface of the substrate 5 in the reaction chamber 1.

The purge gas supply pipe 6 is for blowing the purge gas toward the substrate 5 when the substrate 5 is carried out from the reaction chamber 1, and the substrate carry-in / out port 1 of the reaction chamber 1 is provided.
It is arranged in the vicinity of d so as to surround the substrate loading / unloading port 1d. As shown in FIG. 2, the purge gas supply pipe 6 includes a pipe portion 6a for guiding the purge gas from the outside and a circular pipe portion 6b. This circular pipe part 6b
Is a tube with a diameter of about 10 mm, and the diameter of the circle is such that the boat 4 on which the substrate 5 is placed can pass through it. Then, a large number of circular purge gas ejection ports 6c having a diameter of about 1 mm are opened at equal intervals inside the circular pipe portion 6b. The substrate 5 is the purge gas supply pipe 6
When passing through the circular pipe portion 6b of, the purge gas is blown toward the substrate 5 from the purge gas jet port 6c.

When a thin film is formed on the surface of the substrate 5 by using the above-mentioned low pressure CVD apparatus, it is carried out as follows. First,
The substrate 5 is placed on the boat 4 in the load lock chamber 3 and loaded into the reaction chamber 1 from the load lock chamber 3. And
A film forming gas is introduced into the reaction chamber 1 to form a thin film on the surface of the substrate 5. After the thin film is formed, the substrate 5 is carried out from the reaction chamber 1 together with the boat 4 to the load lock chamber 3 while spraying the purge gas toward the substrate 5 from the purge gas ejection port 6c of the purge gas supply pipe 6. Then, the substrate 5 is taken out from the load lock chamber 3.

In the above film forming method, since the remaining film forming gas and reaction by-products are prevented from diffusing into the load lock chamber 3, these film forming gas and reaction by-products are released outside the reaction chamber. Particles are prevented by cooling, or by reacting with oxygen or water in the atmosphere. As a result, the amount of particles attached to the substrate 5 is reduced.

As an example of the above film forming method, when forming a SiN film, for example, the following conditions are used. Temperature: 760 ° C. Pressure: 50 Pa Film forming gas: NH ₃ / SiH ₂ Cl ₂ / N ₂ = 600/50 /
2000SCCM

In the film formation of the above SiN film, as a reaction by-product, it solidifies into particles when the temperature decreases,
NH ₄ Cl is produced. However, when the substrate 5 is carried out together with the boat 4 from the reaction chamber 1 to the load lock chamber 3 after the formation of the SiN film is completed, the purge gas is discharged from the purge gas ejection port 6c of the purge gas supply pipe 6 (for example, 50
By spraying 00 SCCM N ₂ ) toward the substrate 5, the diffusion of NH ₄ Cl into the load lock chamber 3 is prevented, the generation of particles is suppressed, and the amount of particles adhering to the substrate 5 is reduced.

Example 2 An example of a heated purge gas supply type CVD apparatus and a purge type film forming method using the same will be described with reference to FIG.

The heating purge gas supply type CVD apparatus of this embodiment is a low pressure CVD apparatus and has the same structure as that of the first embodiment. However, before the purge gas is blown toward the substrate 5, a purge gas heating mechanism for heating the purge gas is provided in advance.

The heating mechanism is constructed, for example, as shown in FIG. 3, so that the pipe portion 6a for guiding the purge gas from the outside of the purge gas supply pipe 6 passes between the reaction chamber 1 and the heater 2. . Then, the purge gas passes through the pipe portion 6a passing between the reaction chamber 1 and the heater 2 and is heated, and then is led to the circular pipe portion 6b for blowing the purge gas toward the substrate 5.

When a thin film is formed on the surface of the substrate 5 by using the above-mentioned low pressure CVD apparatus, it is carried out as follows. First,
The substrate 5 is placed on the boat 4 in the load lock chamber 3 and loaded into the reaction chamber 1 from the load lock chamber 3. And
A film forming gas is introduced into the reaction chamber 1 to form a thin film on the surface of the substrate 5. Then, when the thin film formation is completed, the substrate 5 together with the boat 4 is moved from the reaction chamber 1 to the load lock chamber 3 while blowing the heated purge gas toward the substrate 5 from the purge gas jet port 6c of the purge gas supply pipe 6.
Carry out. Then, the substrate 5 is taken out from the load lock chamber 3.

In addition to the effects of the first embodiment, in the above film forming method, since the purge gas is preheated by the heater 2, the film forming gas and reaction by-products remaining from the reaction chamber are released and cooled. It is further prevented from becoming particles. That is, since the vapor pressure of the film forming gas and the reaction by-product is increased by heating, it becomes easy to exhaust and remove the film forming gas and the reaction by-product as a gas before they become particles. As a result, the amount of particles attached to the substrate 5 is reduced.

Example 3 An example of a purge gas supply type CVD apparatus and a film forming method using the purge type film forming method and the pressure control type film forming method using the same will be described.

A thin film is formed in the same manner as in Example 1. However, when the substrate 5 is carried out together with the boat 4 from the reaction chamber 1 to the load lock chamber 3, the purge gas is ejected from the purge gas ejection port 6c of the purge gas supply pipe 6 toward the substrate 5 and the inside of the load lock chamber 3 is blown. Is set to be higher than the pressure inside the reaction chamber 1.

The pressure inside the load lock chamber 3 and the pressure inside the reaction chamber 1 are set as follows, for example. Pressure inside the load lock chamber 3: About 2000 Pa Pressure inside the reaction chamber 1: About 500 Pa or less

In addition to the effects of the first embodiment, the above film forming method further prevents the residual film forming gas and the reaction by-products from being discharged from the reaction chamber. It is further prevented that the substance is released to the outside of the reaction chamber and reacts with oxygen or water in the atmosphere or is cooled to be solidified and become particles. As a result, the amount of particles attached to the substrate 5 is reduced.

Example 4 An example of a load lock chamber heating type CVD apparatus and a load lock chamber heating type film forming method using the same will be described with reference to FIG.

The load lock chamber heating type CVD apparatus of this embodiment is a low pressure CVD apparatus and has the same structure as that of the first embodiment. However, the purge gas supply pipe 6 for blowing the purge gas toward the substrate 5 when the substrate 5 is carried out from the reaction chamber 1 is not provided. Then, a mechanism for heating the substrate 5 inside the load lock chamber 3 is provided.

The substrate 5 inside the load lock chamber 3 described above.
For example, as shown in FIG. 4, the mechanism for heating is configured by arranging a heater 2a so as to surround the load lock chamber 3. When the substrate 5 is unloaded from the reaction chamber 1 to the load lock chamber 3, the heater 5 a heats the substrate 5 unloaded to the load lock chamber 3.

When a thin film is formed on the surface of the substrate 5 by using the above-mentioned low pressure CVD apparatus, it is carried out as follows. First,
The substrate 5 is placed on the boat 4 in the load lock chamber 3 and loaded into the reaction chamber 1 from the load lock chamber 3. And
A film forming gas is introduced into the reaction chamber 1 to form a thin film on the surface of the substrate 5. After the thin film is formed, after heating the heater 2a surrounding the load lock chamber 3,
The substrate 5 is carried out together with the boat 4 from the reaction chamber 1 to the load lock chamber 3. Then, the substrate 5 is taken out from the load lock chamber 3.

In the above film forming method, since the substrate 5 is heated even when being carried out, it is possible to prevent the film forming gas and reaction by-products remaining from the reaction chamber from being released and cooled to become particles. . That is, the vapor pressures of the film forming gas and the reaction by-product are increased by heating, and the film forming gas and the reaction by-product are easily exhausted and removed as gas before becoming particles. As a result, the amount of particles attached to the substrate 5 is reduced.

Embodiment 5 Another embodiment of a load lock chamber heating type CVD apparatus and a load lock chamber heating type film forming method using the same will be described with reference to FIGS. 5 and 6.

The load lock chamber heating type CVD apparatus of this embodiment is a low pressure CVD apparatus and has the same structure as that of the first embodiment. However, the purge gas supply pipe 6 for blowing the purge gas toward the substrate 5 when the substrate 5 is carried out from the reaction chamber 1 is not provided. Then, a mechanism for introducing the heated purge gas into the load lock chamber 3 is provided.

The mechanism for introducing the heated purge gas into the load lock chamber 3 is constructed by providing a purge gas supply pipe 7 below the load lock chamber 3 as shown in FIG. Then, the purge gas is heated outside the load lock chamber 3, and the heated purge gas is introduced into the load lock chamber 3 from the purge gas supply pipe 7.

When a thin film is formed on the surface of the substrate 5 by using the above-mentioned low pressure CVD apparatus, it is carried out as follows. First,
The substrate 5 is placed on the boat 4 in the load lock chamber 3 and loaded into the reaction chamber 1 from the load lock chamber 3. And
A film forming gas is introduced into the reaction chamber 1 to form a thin film on the surface of the substrate 5. After the thin film is formed, the heated purge gas is introduced into the load lock chamber 3 from the purge gas supply pipe 7, and then the substrate 5 is carried out together with the boat 4 from the reaction chamber 1 to the load lock chamber 3. Then, the substrate 5 is taken out from the load lock chamber 3.

In the above film forming method, since the substrate 5 is heated even when being carried out, it is possible to prevent the film forming gas and reaction by-products remaining from the reaction chamber from being released and cooled to form particles. . That is, the vapor pressures of the film forming gas and the reaction by-product are increased by heating, and the film forming gas and the reaction by-product are easily exhausted and removed as gas before becoming particles. Further, since the substrate is heated by the heating purge gas, it is possible to prevent the film forming gas and the reaction by-products remaining from the reaction chamber from being released and cooled to become particles, and at the same time, to form the film forming gas and the reaction. By-products can be quickly removed by evacuation. As a result,
The amount of particles adhering to the substrate 5 is reduced.

In this embodiment, the purge gas was heated and then introduced into the load lock chamber 3. However, even if the temperature is lowered, the remaining film forming gas and the reaction by-product are not easily turned into particles. When used, the purge gas may be introduced into the load lock chamber 3 at room temperature without heating the purge gas. Also in this case, the flow of the purge gas promptly exhausts and removes the film forming gas and the reaction by-products, and the amount of particles adhering to the substrate 5 is reduced.

Further, in the present embodiment, the heated purge gas was introduced into the load lock chamber 3 to heat the substrate. However, even if the purge gas is introduced at room temperature and the substrate is heated as in Example 4. The same effect can be obtained. That is, as shown in FIG. 6, when the purge gas supply pipe 7 and the heater 2a surrounding the load lock chamber 3 are arranged, when the substrate 5 is carried out from the reaction chamber 1 to the load lock chamber 3, the purge gas at room temperature is supplied. It is introduced from the purge gas supply pipe 7 into the load lock chamber 3, and the load lock chamber 3 is surrounded by the heater 2a arranged so as to surround the load lock chamber 3.
The substrate 5 carried out may be heated.

Example 6 An example of a film forming gas heating type CVD apparatus and a film forming gas heating type film forming method using the same will be described with reference to FIGS. 7 and 8.

The film-forming gas heating type CVD apparatus of this embodiment is a low pressure CVD apparatus and has the same structure as that of the first embodiment. However, the purge gas supply pipe 6 for blowing the purge gas toward the substrate 5 when the substrate 5 is carried out from the reaction chamber 1 is not provided. Then, before introducing the film forming gas into the reaction chamber 1, a heating mechanism for heating the film forming gas to a temperature lower than the gas phase reaction start temperature is provided in advance.

The heating mechanism is, for example, as shown in FIG. 7, a sheath heater 10 in which a heating wire 10b is inserted into a rubber plate 10a having a thickness of about 1 mm and a width of about 10 mm.
As shown in FIG. 8, it is configured by being wound around the film forming gas pipe 8 immediately before the reaction chamber 1. Then, by heating the sheath heater 10 to about 400 ° C. and introducing the film-forming gas into the reaction chamber 1, the film-forming gas is introduced into the reaction chamber 1 in advance to a temperature higher than the gas phase reaction start temperature. Heat to low temperature. The sheath heater 10 is used because other heaters may affect the reaction. A heat-resistant seal 11, for example, F-based rubber is used for the sealing portion of the pipe.

When a thin film is formed on the surface of the substrate 5 using the above-mentioned low pressure CVD apparatus, it is carried out as follows. First,
The substrate 5 is placed on the boat 4 in the load lock chamber 3 and loaded into the reaction chamber 1 from the load lock chamber 3. And
The heated film forming gas is introduced into the reaction chamber 1 to generate the substrate 5
A thin film is formed on the surface of. Then, when the thin film formation is completed, the substrate 5 is carried out together with the boat 4 from the reaction chamber 1 to the load lock chamber 3. Then, the substrate 5 is taken out from the load lock chamber 3.

In the above film forming method, since the temperature gradient in the reaction chamber is reduced, the temperature gradient of the film forming gas in the reaction chamber is reduced, an unintended vapor phase reaction is prevented, and the generation of particles is suppressed. As a result, the amount of particles attached to the substrate 5 is reduced.

Since the film-forming gas is heated in order to prevent the temperature gradient in the reaction chamber as much as possible, it is necessary to heat the film-forming gas to at least about 300 ° C. or higher. It is recommended to heat to near the starting temperature.

As an example of film formation by the low pressure CVD apparatus,
The SiN film is formed under the following conditions, for example. Temperature: 760 ° C. Pressure: 50 Pa Film forming gas: NH ₃ / SiH ₂ Cl ₂ / N ₂ = 600/90 /
1000 SCCM

Even in the conventional CVD apparatus, in order to prevent the film-forming gas from adsorbing to the pipe, the film-forming gas is set to 50%.
In some cases, the temperature of the film forming gas when introduced into the reaction chamber is considerably lower than the gas phase reaction start temperature of the film forming gas. It has almost no effect on reducing the temperature gradient of the film forming gas.

EXAMPLE 7 An example of a dilution gas heating type CVD apparatus and a film forming gas heating type film forming method using the same will be described.

The dilution gas heating type CVD apparatus of this embodiment is a low pressure CVD apparatus and has the same structure as that of the first embodiment. However, the purge gas supply pipe 6 for blowing the purge gas toward the substrate 5 when the substrate 5 is carried out from the reaction chamber 1 is not provided. Then, before introducing the film forming gas into the reaction chamber 1, a raw material gas that provides the constituents of the thin film and a diluent gas that is an inert gas are mixed so that the diluent gas is equal to or more than the raw material gas. In addition to providing a mechanism for using as a film forming gas, a heating mechanism for heating the dilution gas in advance is provided before the mixing.

The heating of the diluting gas and the mixing of the heated diluting gas with the raw material gas may be carried out in any manner as long as the heating and the mixing are carried out when they are introduced into the reaction chamber. In the present example, after the diluent gas was heated externally, the diluent gas and the source gas were mixed so that the diluent gas was equal to or more than the source gas, thereby forming a film forming gas. The dilution gas is heated such that the temperature of the film forming gas as a result of mixing the diluent gas and the source gas is equal to or lower than the gas phase reaction start temperature of the film forming gas and near the gas phase reaction start temperature.

When the thin film is formed on the surface of the substrate by using the above-mentioned low pressure CVD apparatus, it is carried out as follows. First, the substrate is placed on a boat in the load lock chamber and loaded into the reaction chamber from the load lock chamber. Then, the film forming gas is introduced into the reaction chamber to form a thin film on the surface of the substrate. Then, when the thin film formation is completed, the substrate is carried out together with the boat from the reaction chamber to the load lock chamber. Then, the substrate is taken out from the load lock chamber.

In the above film forming method, the temperature gradient of the film forming gas in the reaction chamber is reduced, an unintended vapor phase reaction is prevented, and the concentration gradient of the film forming gas in the reaction chamber is reduced. Since the unintended gas phase reaction in the dark region is prevented, the generation of particles is suppressed. As a result, the amount of particles attached to the substrate is reduced. Further, since the diluent gas is heated and then the source gas and the diluent gas are mixed, the film forming gas can be easily heated.

In this embodiment, the film forming gas can be heated easily. This is because in this embodiment, since the diluent gas, which is an inert gas that is stable even at high temperatures, is heated, it is cooled in the pipe, or even when cooled by mixing with the raw material gas, to the extent that the required temperature is maintained. This is because it is possible to heat the dilution gas. Further, since the heating is performed outside the device, it is not necessary to consider the influence on the reaction of the heater used for heating the diluent gas, and any heater can be used, for example, a lamp or a resistance heating device. It can be used.

As an example of film formation by the low pressure CVD apparatus,
The SiN film is formed under the following conditions, for example. Temperature: 760 ° C. Pressure: 50 Pa Film forming gas: NH ₃ / SiH ₂ Cl ₂ / N ₂ = 600/90 /
1000 SCCM

[0090]

As is apparent from the above description, in the CVD apparatus and the film forming method using the same of the present invention, not only the particles are prevented from adhering to the surface of the substrate, but also the generation of the particles itself is prevented. Since it is possible to prevent this and the amount of particles generated is reduced, the yield can be improved and the productivity can be improved.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a configuration example of a purge gas supply type CVD apparatus.

FIG. 2 is a schematic top view showing a configuration example of a purge gas supply pipe of a purge gas supply type CVD apparatus.

FIG. 3 is a schematic cross-sectional view showing a configuration example of a heating purge gas supply type CVD apparatus.

FIG. 4 is a schematic cross-sectional view showing a configuration example of a load lock chamber heating type CVD apparatus.

FIG. 5 is a schematic cross-sectional view showing another configuration example of the load lock chamber heating type CVD apparatus.

FIG. 6 is a schematic cross-sectional view showing another configuration example of the load lock chamber heating type CVD apparatus.

FIG. 7 is a schematic cross-sectional perspective view showing an example of a sheath heater.

FIG. 8 is a schematic sectional view showing a configuration example of a film forming gas heating type CVD apparatus.

FIG. 9 is a schematic cross-sectional view showing a configuration example of a conventional CVD apparatus.

[Explanation of symbols]

 1 Reaction Chamber 2 Heater 3 Load Lock Chamber 4 Boat 5 Substrate 6 Purge Gas Supply Pipe 7 Purge Gas Supply Pipe 8 Film Forming Gas Inlet 9 Exhaust 10 Sheath Heater 11 Seal

Claims (11)

[Claims] 1. A chemical vapor deposition apparatus adapted to form a predetermined thin film on a surface of a substrate by using a film forming gas introduced into a reaction chamber containing the substrate, wherein the substrate in the reaction chamber A chemical vapor deposition apparatus comprising a purge gas supply pipe having an opening near the carry-in / out port. 2. The chemical vapor deposition apparatus according to claim 1, further comprising a purge gas heating mechanism for heating the purge gas. 3. A chemical vapor deposition apparatus adapted to form a predetermined thin film on the surface of a substrate by using a film forming gas introduced into the reaction chamber containing the substrate, A chemical vapor deposition apparatus comprising a heating mechanism for heating the film-forming gas before introduction. 4. The chemical vapor deposition according to claim 3, wherein the film forming gas includes a raw material gas that provides the constituents of the thin film and a diluent gas, and the heating mechanism is configured to heat the diluent gas. apparatus. 5. The load dock chamber is connected to the reaction chamber via the substrate loading / unloading port.
The chemical vapor deposition apparatus according to any one of 1. 6. A film forming gas introduced into a reaction chamber containing a substrate is used to form a predetermined thin film on the surface of the substrate, and the reaction chamber is loaded through a substrate loading / unloading port. In a chemical vapor deposition apparatus in which a dock chamber is connected, the load lock chamber includes at least one of a heater for heating the substrate or a heated purge gas supply pipe for supplying a heated purge gas. A chemical vapor deposition apparatus characterized by: 7. A film forming method for forming a predetermined thin film on a substrate in the reaction chamber using the chemical vapor deposition apparatus according to claim 1 or 2, wherein the substrate is removed from the reaction chamber. When carrying out, a purge gas is sprayed from the purge gas supply pipe toward the substrate. 8. A film forming method for forming a predetermined thin film on a substrate in the reaction chamber by using the chemical vapor deposition apparatus according to claim 3 or 4, wherein the film forming gas is heated. A film forming method, wherein the film is introduced into the reaction chamber while being heated to a temperature lower than a gas phase reaction start temperature by a mechanism. 9. A film forming method for forming a predetermined thin film on a substrate in the reaction chamber using the chemical vapor deposition apparatus according to claim 6, wherein the substrate is unloaded from the reaction chamber. A method for forming a film, wherein the substrate is heated by at least one of the heater, and the heating purge gas. 10. A film forming method for forming a predetermined thin film on a substrate in the reaction chamber using the chemical vapor deposition apparatus according to claim 5 or 6, wherein at least the substrate is provided in the reaction chamber. When carrying out from
A film forming method, wherein the pressure in the load lock chamber is made higher than the pressure in the reaction chamber. 11. The film forming gas according to claim 7, wherein the film forming gas contains a silane-based compound.
The film forming method as described in the item.