JPH06208958A - Thin film forming equipment - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a thin film forming apparatus capable of forming a thin film of good quality with little contamination by foreign matter on a substrate, such as a semiconductor substrate, and forming a uniform thin film thickness. To do. A thin film forming apparatus 100 for forming a thin film on a substrate 40 in a heating atmosphere by introducing a gas containing a reaction gas onto a substrate, wherein a sealed container 110 and a sealed container 11 are provided.
Gas discharge means 110h which is provided in the lower part of 0 and discharges the above gas introduced onto the substrate 40 to the outside of the sealed container 110,
111, a reaction tube 120 that is housed in the sealed container 110 and that houses the substrate 40, gas introduction units 120i and 121 that directly introduce the gas into the reaction tube 120, and the reaction tube 1
Gas guide means 120a for guiding the above-mentioned gas introduced into the upper part 20 into the space 130 formed by the sealed container 110 and the reaction tube 120, and provided in the reaction tube 120,
A gas supply head unit 180 is provided that is connected to the gas introduction unit 120i and that uniformly supplies the gas onto the substrate 40.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film forming apparatus,
In particular, the present invention relates to a thin film forming apparatus capable of forming a good quality thin film on a substrate, such as a semiconductor substrate, which is less contaminated by foreign matter, and capable of forming a uniform thin film on the substrate.

[0002]

2. Description of the Related Art There are various types of thin film forming apparatuses used for producing semiconductor devices and the like. As such a thin film forming apparatus, there are a thermal diffusion apparatus, a low pressure CVD apparatus and the like.

A thermal diffusion device usually introduces oxidizing species such as water vapor or oxygen onto a wafer, for example, a semiconductor substrate such as a silicon substrate, under normal pressure to oxidize the wafer itself in a heating atmosphere, For example, an oxide diffusion device used to form an oxide film such as SiO ₂ (hereinafter referred to as an oxide film) in the depth direction of the wafer itself, or ions or the like on a wafer, for example, a semiconductor substrate such as a silicon substrate. There is a thermal diffusion device after ion implantation for implanting and forming an ion diffusion layer on the wafer itself in a heating atmosphere.

Further, the low pressure CVD apparatus usually introduces a raw material gas onto a wafer, for example, a semiconductor substrate such as a silicon substrate, under a reduced pressure and emits a gas which is a chemical reaction species of the raw material gas in a heating atmosphere. This is an apparatus for performing a thermochemical reaction to deposit and form, for example, SiO ₂ , a polysilicon film, a nitride film such as Si ₃ N ₄ or the like on a wafer.

In the present specification, simply, "forming a thin film on a substrate" means a case where a thin film such as an oxide film or a thermal diffusion layer after ion implantation is formed on the wafer itself in the depth direction of the wafer. And the case of depositing a thin film on the surface of the wafer.

The term "thermal diffusion film" means a thin film such as an oxide film formed on the wafer itself in the depth direction of the wafer or a thermal diffusion layer after ion implantation.

FIG. 12 is a partial sectional view schematically showing a conventional thin film forming apparatus. With reference to FIG. 12, this thin film forming apparatus 400 shows a conventional heat diffusion apparatus, and includes a cylindrical heater 401, a cylindrical heat equalizing tube 402 provided inside the heater 401, and a heat equalizing tube 402. A cylindrical hermetically sealed container (outer tube) 410 provided inside the
10 includes a reaction tube 420 that accommodates a substrate that forms a heat diffusion film. For the heater wire of the heater 401, for example, tantalum is used, but this heater wire contains a large amount of impurities. Further, a soaking tube 4 for ensuring soaking properties
02 is made of, for example, silicon carbide or umlite, but the material of the soaking tube 402 has a large amount of impurities. For example, the soaking tube 402 is silicon carbide containing impurities such as iron (Fe) in the ppm order. As the material of the sealed container 410, for example, quartz or the like is used, and the reaction tube 42
As a material of 0, for example, quartz or the like is used.

A thin film forming apparatus 400 shown in FIG.
Is called a vertical heat spreader. The reaction tube 420 is provided at its upper portion with an opening 420a for allowing gas to flow between the inside of the sealed container 410 and the inside of the reaction tube 420. The opening 420a is usually provided with a circular cap 425 having a plurality of holes 425a.
Inside the reaction tube 420, a thermocouple (not shown) is installed in the thermocouple protection tube 450 as a temperature measuring means for measuring the temperature inside the reaction tube 420. The thermocouple (not shown) may be provided directly in the reaction tube 420 in a state of being exposed. The sealed container 410 and the reaction tube 420 are integrally molded, for example. Sealed container 4
A gas introduction port 4 for introducing a gas containing a reactive species that directly reacts with the substrate and / or an atmospheric gas is provided in a lower portion of the substrate 10.
10i is provided.

The reaction tube 4 is provided below the reaction tube 420.
A gas discharge port 420h for discharging the gas containing the reactive species that directly reacts with the substrate and / or the ambient gas introduced into the inside of the film 20 to the outside of the thin film forming apparatus 400 is provided. A gas introduction pipe 411 for introducing a gas containing a reactive species that directly reacts with the substrate and / or an atmospheric gas is connected to the gas introduction port 410i, and the gas discharge port 42i.
At 0 h, the gas exhaust pipe 421 is inserted through the sealed container 410.
Are connected. A gas rectifier 470 for rectifying a gas containing a reactive species that directly reacts with the substrate and / or an atmospheric gas, which is introduced into the reaction tube 420, is provided in the gap 430 formed by the sealed container 410 and the reaction tube 420. Is provided.

FIG. 13 is a partially enlarged perspective view of the gas rectifier 470. In addition, FIG.
FIG. 14 is a cross-sectional view of the gas rectifier 470 shown in FIG. 13 taken along the line XIV-XIV. 13 and 14, the gas rectifier 470 includes a plurality of plate-shaped gas rectification plates 470a formed on the outer wall of the reaction tube 420, for example, made of quartz or the like.
Are provided so as to project in the circumferential direction of the outer circumference of the reaction tube 420 toward the sealed container 410. Such a gas straightening plate 47
As shown in FIG. 14, 0a is densely provided on the side where the gas introduction port 410i is provided and sparsely provided on the opposite side.
The gas containing the reactive species that directly reacts with the substrate and / or the ambient gas introduced into the gap 430 formed by the sealed container 410 and the reaction tube 420 are uniformly mixed in the reaction tube 42.
It can be introduced into 0.

Referring to FIG. 12, when a thermal diffusion film is formed on a substrate using such a thin film forming apparatus 400,
A plurality of wafers 40 are placed on the boat 41, and the boat 41 is housed in the reaction tube 420. The end cap 42 of the boat 41 includes a sealed container 410 and a reaction tube 42 that are integrally molded.
The outer wall of the bottom portion 420b with 0 is pressed from below. When the boat 41 on which the wafer 40 is placed is accommodated in the reaction tube 420, the atmospheric gas is introduced from the gas introduction tube 411 and the gas introduction port 410i into the sealed container 410 and the reaction tube 420.
Install inside. Then, the wafer 40 is heated by the heater 401.
Are preheated at the processing temperature. Next, a gas containing a reactive species that directly reacts with the wafer 40 is introduced into the sealed container 410 and the reaction tube 4 through the gas introduction pipe 411 and the gas introduction port 410i.
Introduce into 20. The wafer 4 introduced into the sealed container 410 through the gas introduction pipe 411 and the gas introduction port 410i.
The gas containing the reactive species that directly reacts with 0 and / or the atmospheric gas rises in the gap 430 formed by the sealed container 410 and the reaction tube 420, and enters the opening 420a provided in the upper portion of the reaction tube 420. Reach At this time, the gap 4
The gas and / or the atmospheric gas, which rises in the chamber 30 and contains the reactive species that directly reacts with the wafer 40, is rectified uniformly and evenly by the gas rectifier 470 provided in the gap 430, and reaches the opening 420a. Next, the gas containing the reactive species that directly reacts with the wafer 40 and / or the ambient gas, which is rectified by the gas rectifier 470, is supplied to the opening portion 4.
After being introduced into the reaction tube 420 from 20a and forming a thermal diffusion film such as a thermal oxide film in the depth direction of the wafer 40 on the wafer 40 itself, the gas exhaust port 420h and the gas exhaust pipe 421 are formed.
As a result, the film is discharged to the outside of the thin film forming apparatus 400. In the thin film forming apparatus 400 for forming a thermal diffusion film, a gas containing a reactive species that directly reacts with the wafer 40 and / or an atmospheric gas is first introduced into the gap 430 and then into the reaction tube 420. That is, the gas containing the reactive species that directly reacts with the wafer 40 and / or the atmospheric gas is uniformly heated before reaching the wafer 40, and the heat diffusion film formed in the depth direction of the wafer 40 is formed on the wafer itself. This is to improve the uniformity of the film thickness. Further, the heat conduction from the heater 401 uniformly gives radiant heat to the wafer 40 through the soaking tube 402 and the gap portion 430.

Next, the gas containing the reactive species that directly reacts with the wafer 40 is purged, and the atmospheric gas is introduced into the gas inlet 410i.
In the further introduced state, the boat 41 is taken out from the reaction tube 420, and the wafer 40 on which the heat diffusion film is formed is taken out.

As described above, the heat diffusion film is usually formed on the substrate at normal pressure. Note that, in FIG. 12, the arrow indicated by the solid line indicates the flow direction of the gas containing the reactive species that directly reacts with the substrate, and the arrow indicated by the broken line indicates the flow direction of the atmospheric gas.

FIG. 15 is a partial sectional view schematically showing a conventional thin film forming apparatus. Referring to FIG. 15, this thin film forming apparatus 500 shows a conventional heat diffusion apparatus, and includes a cylindrical heater 501, a cylindrical heat equalizing tube 502 provided inside the heater 501, and a heat equalizing tube 502. Reaction tube (inner tube) for accommodating a cylindrical outer tube 510 provided inside the tube and a substrate provided inside the outer tube 510 and forming a heat diffusion film.
Including 520. The material of the heater wire of the heater 510,
The material of the soaking tube 502, the material of the outer tube 510, and the material of the reaction tube 520 are the material of the heater wire of the heater 401 and the soaking tube 40 of the thin film forming apparatus 400 shown in FIG. 12, respectively.
2 material, sealed container (outer tube) 410 material, reaction tube 40
Since it is the same as the material of No. 2, its explanation is omitted.

A thermocouple (not shown) is provided in the reaction tube 520 as a temperature measuring means for measuring the temperature in the reaction tube 520.
Is installed in the thermocouple protection tube 550. The thermocouple (not shown) may be provided in the reaction tube 520 in a state of being directly exposed. The reaction tubes 520 of the outer tube 501 are each formed of independent members, and the lower end portion 510e of the outer tube 510 and the lower end portion 520e of the reaction tube 520 are fixed by a flange 506. A gas containing a reactive species that directly reacts with the substrate and / or an atmosphere gas is provided on the upper part of the reaction tube 520.
20 is provided with a gas introduction port 520i for directly introducing the gas into the reaction tube 520, and a gas containing reactive species directly reacting with the substrate, which is introduced into the reaction tube 520, and /
Alternatively, a gas discharge port 520h for discharging the atmospheric gas to the outside of the thin film forming apparatus 500 is provided. A gas introduction pipe 5 for introducing a gas containing a reactive species that directly reacts with the substrate and / or an atmosphere gas into the gas introduction port 520i.
60 is connected, and a gas exhaust pipe 521 is connected to the gas exhaust port 520h by inserting an outer pipe 510. Gap portion 53 formed by outer tube 510 and reaction tube 520
The inside of 0 is sealed. Then, in the upper part of the outer tube 510, Fe generated from the heater 501 and the soaking tube 502
Is provided with an active gas inlet port 510i for introducing an active gas such as HCl gas into the gap portion 530, and the active gas introduced into the gap portion 530 is discharged. Active gas discharge port 510 for
h is provided. Since the boat and the like housed in the reaction tube 520 are the same as the boat and the like used in the thin film forming apparatus 400 shown in FIG. 12, the same reference numerals are given to the corresponding members and the description thereof will be omitted. .

Using such a thin film forming apparatus 500,
When forming the thermal diffusion film on the substrate, the plurality of wafers 40 are placed on the boat 41, and the boat 41 is housed in the reaction tube 520. The end cap 42 of the boat 41 presses the outer wall side of the flange 506 from below. When the boat 41 on which the wafer 40 is placed is housed in the reaction tube 520,
Atmosphere gas is introduced into the reaction tube 520 through the gas introduction tube 560. Further, from the active gas inlet 510i, the gap 5
An active gas is introduced into 30. Next, the heater 501 preheats the wafer 40 at the processing temperature. Next, the gas containing the reactive species that directly reacts with the wafer 40 is introduced into the gas introduction pipe 5
From 60, it is introduced into the reaction tube 520. Gas introduction pipe 50
The gas and / or the atmosphere gas containing the reactive species that directly reacts with the wafer 40, which is directly introduced into the reaction tube 520 from the No. 6, is applied to the wafer 40 itself in the depth direction of the wafer 40 such as a thermal diffusion film such as a thermal oxide film. After forming, the gas is discharged from the thin film forming apparatus 500 through the gas discharge port 520h and the gas discharge port 521.

Next, the boat 41 is taken out from the reaction tube 520 in a state where the gas containing the reactive species that directly reacts with the wafer 40 is purged and the atmospheric gas is introduced from the gas introduction tube 560, and the wafer on which the thermal diffusion film is formed. Take out 40.

As described above, the heat diffusion film is usually formed on the substrate at normal pressure. Note that in FIG. 15, arrows indicated by solid lines indicate the flow direction of gas containing a reactive species that directly reacts with the substrate, arrows indicated by broken lines indicate the direction of flow of atmospheric gas, and arrows indicated by alternate long and short dash lines indicate The direction of the flow of active gas is shown.

In the thin film forming apparatus 500, an active gas for removing foreign matters generated from the heater 501 and the heat equalizing tube 502 is caused to flow in the gap 530, and as a result, the thin film forming apparatus 500 is formed on the substrate. The heat diffusion film formed by using the thin film forming apparatus 400 is
Less likely to be contaminated by foreign matter.

FIG. 16 is a partial sectional view schematically showing a conventional thin film forming apparatus. With reference to FIG. 16, this thin film forming apparatus 600 shows a conventional low pressure CVD apparatus,
A cylindrical heater 601, a cylindrical heat equalizing tube 602 provided inside the heater 501, a cylindrical pressure vessel (outer tube) 610 provided inside the heat equalizing tube 602, and a housing inside the pressure vessel 610. , A reaction tube (inner tube) 620 containing a substrate on which a thin film is deposited. The material of the heater wire of the heater 610, the material of the soaking tube 602, the material of the pressure vessel 610, and the material of the reaction tube 620 are the material of the heater wire of the heater 401 and the material of the soaking tube 402 of the thin film forming apparatus 400 shown in FIG. 12, respectively. Since the material is the same as the material of the sealed container (outer tube) 410 and the material of the reaction tube 420, description thereof will be omitted.

The reaction tube 620 is provided at its upper portion with an opening 620a for allowing gas to flow between the pressure vessel 610 and the reaction tube 620. Reaction tube 62
A thermocouple (not shown) as a temperature measuring means for measuring the temperature in the reaction tube 620 is installed in the inside of 0 in a state of being housed in the thermocouple protection tube 650. The thermocouple (not shown) may be installed in the reaction tube 620 in a state of being directly exposed. In addition, the pressure vessel 610 and the reaction tube 620
Are formed of independent members, and the lower end portion 610e of the pressure vessel 610 and the lower end portion 6 of the reaction tube 620 are
20e is fixed by the flange 606. The flange 606 is connected to the flange 608 via an O-ring 607. A gas injector 622 is provided for inserting the reaction gas and / or the carrier gas directly into the reaction tube through the outer wall of the flange 606. One such gas injector 622 is provided for each chemical reaction species of the reaction gas that is the raw material of the thin film deposited and formed on the substrate. The outlet 622i of the reaction gas and / or the carrier gas of the gas injector 622 is provided with a soaking tube 6
It is provided below the soaking zone A formed by 02. The reaction gas and / or carrier gas outlet 622i of the gas injector 622 is provided below the soaking zone A so that the reaction gas, which is a chemically reactive species taken out from each gas injector 622, is kept in the soaking zone A. This is because they are mixed below without causing a reaction and are introduced onto the substrate. The reaction gas and / or carrier gas outlet 622i of the gas injector 622 is provided in the reaction tube 620 to prevent the reaction gas from undergoing a thermochemical reaction before being introduced onto the substrate and becoming a powder. This is because the above-mentioned thermochemical reaction is efficiently carried out and the thin film is efficiently deposited, that is, deposited on the substrate. Further, on the outer wall of the flange 606, the pressure vessel 610 and the reaction tube 620 were introduced.
The reaction vessel and / or the atmosphere gas are supplied to the pressure vessel 61.
A gas discharge port 610h for discharging to the outside is provided. A gas exhaust pipe 611 is connected to the gas exhaust port 610h. Further, the clearance 6 formed by the pressure vessel 610 and the reaction tube 620 is inserted through the outer wall of the flange 606.
An atmosphere gas introduction pipe 660 is provided below the inside of 30. Atmosphere gas outlet 6 of atmosphere gas introduction pipe 660
60i is usually provided below the gap 630 formed by the pressure vessel 610 and the reaction tube 620. Further, an O-ring 609 is provided on the lower surface of the outer wall of the flange 608.
Is installed.

Since the boat and the like housed in the reaction tube 601 are the same as the boat and the like used in the thin film forming apparatus 400 shown in FIG. 12, the same reference numerals are used for the corresponding members, and the description thereof is omitted. Is omitted.

Using such a thin film forming apparatus 600,
When depositing a thin film on a substrate, a plurality of wafers 40
Is placed on the boat 41, and the boat 41 is housed in the reaction tube 620. The end cap 42 of the boat 41 is connected to the flange 608 via an O-ring 609. This is to prevent a leak at the connecting portion. When the boat 41 on which the wafer 40 is placed is housed in the reaction tube 620,
Atmosphere gas is supplied from the atmosphere gas introduction pipe 660 to the pressure vessel 6
10 and into reaction tube 620. Next, the inside of the pressure vessel 610 and the inside of the reaction tube 620 are evacuated through the gas discharge port 610h and the gas discharge pipe 611 by a vacuum pump (not shown) or the like. Next, the atmosphere gas is introduced into the pressure vessel 610 and the reaction tube 620 from the atmosphere gas introduction pipe 660, and the heater 60 is maintained while maintaining a reduced pressure state.
1, the wafer 40 is preheated at the processing temperature. next,
The reaction gas, which is the raw material of the thin film deposited on the wafer 40, is supplied to each gas injector 62 for each chemical reaction species.
2 is introduced directly into the reaction tube 620. The reaction gas directly introduced into the reaction tube 620 by the gas injector 622 is mixed below the soaking zone A, rises in the reaction tube 620, is introduced onto the wafer 40, and is thermochemically reacted.
After depositing a thin film on the wafer 40, the opening 620a is formed.
Reach Next, the reaction gas and / or the atmospheric gas is lowered in the gap 630 by a vacuum pump (not shown) or the like, and is discharged to the outside of the pressure vessel 610 through the gas discharge port 610h and the gas discharge pipe 611. It

Next, the reaction gas is purged and the pressure vessel 61 is
After returning the inside of 0 and the inside of the reaction tube 620 to normal pressure, the boat 41 is taken out from the reaction tube 620 and the wafer 40 on which the thin film is adhered is taken out while the atmospheric gas is introduced from the atmosphere gas introduction tube 660.

In FIG. 16, the arrow shown by the solid line shows the direction of the flow of the reaction gas, and the arrow shown by the broken line shows the direction of the flow of the atmospheric gas.

[0026]

However, when a thermal diffusion film is formed on a substrate by using the conventional thin film forming apparatus 400, foreign matter such as Fe generated from the heater 401 and the heat equalizing tube 402 is made of quartz and is a sealed container 410. Gas and / or ambient gas containing a reactive species that directly reacts with the substrate.

That is, even if the sealed container 410 made of high-purity quartz is used, when the heater 401 or the soaking tube 402 is heated to a high temperature, atoms or ions contained as impurities in the heater 401 or the soaking tube 402. In this state, metallic impurities such as Fe contaminate the outer wall side of the sealed container 410.
Then, metallic impurities such as Fe thermally diffuse from the outer wall side of the sealed container 410 to the inner wall side. Then, the sealed container 410
The metal impurities such as Fe that have reached the inner wall of the sealed container 41
Gas that contains reactive species that reacts directly with the substrate and / or atmosphere gas that rises in the gap 430 from the inner wall surface of 0 (Nagasawa et al., 38th Society of Applied Physics (1991, Spring)) Proceedings, Volume 2, p.702,3
0p-X-14).

Then, when ascending in the clearance 430,
Since the gas containing the reactive species that directly reacts with the substrate and / or the atmosphere gas contaminated by the foreign matter is introduced into the reaction tube 420, the heat diffusion film formed on the substrate is contaminated by the foreign matter such as Fe. There was a problem that

Recently, there has been known a technique for coating a soaking tube in order to prevent generation of metallic impurities such as Fe from the soaking tube, but the coating cost per thin film forming apparatus is expensive. It has not become popular.

Further, in the conventional thin film forming apparatus 500, an active gas such as HCl is caused to flow into the gap 530 so that the heater 5
01 or foreign matter generated from the heat equalizing tube 502 and having passed through the outer tube 510 is reacted with the active gas in the gap portion 530 and is discharged to the outside of the outer tube 510 again.
The thermal diffusion film formed on the substrate by using the thin film forming apparatus 4
As compared with a heat diffusion film formed on a substrate by using No. 00, the degree of contamination by foreign substances generated from a heater or a heat equalizing tube is less.

However, it is difficult to collect and reuse the active gas used to remove the foreign matter. Therefore, as a result of using the active gas in the thin film forming apparatus 500, the manufacturing cost of forming the thermal diffusion film on the substrate using the thin film forming apparatus 500 is the same as the manufacturing cost of forming the thermal diffusion film on the substrate using the thin film forming apparatus 400. There was an economic problem that the running cost was increased by the cost of the active gas as compared with the manufacturing cost in the case of forming.

Further, when a thin film is formed on the substrate by using the conventional thin film forming apparatus 600, there is a problem that the thickness of the thin film formed on the substrate is not uniform.

The present invention has been made in order to solve the above problems and provides a substrate, for example, a semiconductor substrate or the like with a good film quality with less contamination by foreign substances without using an active gas or the like. It is an object of the present invention to provide a thin film forming apparatus capable of forming a thin film and forming a uniform thin film on a substrate.

[0034]

A thin film forming apparatus according to a first aspect of the present invention is a thin film forming apparatus for introducing a gas containing a reaction gas onto a substrate to form a thin film on the substrate under a heating atmosphere, and is a hermetically sealed device. A container and a gas discharge means provided under the sealed container for discharging the gas introduced onto the substrate to the outside of the sealed container, a reaction tube housed in the sealed container for housing the substrate, and a gas directly into the reaction tube. Gas introducing means for introducing the gas, gas guiding means for guiding the gas introduced into the reaction tube upward in the gap formed by the sealed container and the reaction tube, and provided in the reaction tube and connected to the gas introducing means. And a gas supply head means for uniformly supplying the gas onto the substrate.

A thin film forming apparatus according to a second aspect of the present invention is a thin film forming apparatus for introducing a gas containing a reactive species that directly reacts with a substrate onto the substrate to form a thermal diffusion film on the substrate in a heating atmosphere. A hermetically sealed container, a gas discharge means provided below the hermetically sealed container, for discharging the gas introduced onto the substrate to the outside of the hermetically sealed container, a reaction tube housed in the hermetically sealed container and housing the substrate, and directly into the reaction tube. A gas introducing unit for introducing gas and a gas guiding unit for guiding the gas introduced into the reaction tube upward in a gap formed by the sealed container and the reaction tube are provided.

[0036]

In the first aspect of the invention, the gas containing the reaction gas is directly introduced into the reaction tube by the gas introducing means to form a thin film on the substrate. Therefore, the gas containing the reaction gas introduced onto the substrate is not contaminated by the foreign matter, and a thin film of good quality with little contamination by the foreign matter is formed on the substrate. After forming the thin film on the substrate, the gas containing the reaction gas is guided by the gas guiding means upward in the gap formed by the sealed container and the reaction tube, and the gas in the gap formed by the sealed container and the reaction tube is introduced. From above, the gas is discharged from the gas discharge means provided at the bottom of the sealed container to the outside of the sealed container.
Therefore, the foreign matter generated from the heater or the heat equalizing tube and passing through the hermetically sealed container is again discharged outside the hermetically sealed container together with the gas containing the reaction gas in the gap. Therefore, the inside of the reaction tube is unlikely to be contaminated by the foreign matter generated from the heater or the soaking tube.

In addition, since the gas containing the reaction gas flows from the upper part to the lower part in the gap, the quartz fine particles deposited on the inner wall of the bottom of the gap, the powder generated by the reaction gas, etc. Since it is difficult for foreign matter to be rolled up,
The inside of the reaction tube is unlikely to be contaminated with such foreign matter.

Therefore, when a thin film is formed on a substrate using the thin film forming apparatus according to the first aspect of the invention, the thin film has a good quality with less contamination by foreign matter.

Further, since the thin film forming apparatus according to the first invention is provided with the gas supply head means for uniformly supplying the gas containing the reaction gas onto the substrate, the thin film forming apparatus according to the first invention. When a thin film is formed on the substrate by using, the film thickness of the thin film becomes uniform.

In the second aspect of the invention, the gas containing the reactive species that directly reacts with the substrate is directly introduced into the reaction tube by the gas introducing means to form the heat diffusion film on the substrate. Therefore, the gas containing the reactive species that directly reacts with the substrate, which is introduced onto the substrate, is not contaminated by the foreign matter, and a good quality thermal diffusion film with less contamination by the foreign matter is formed on the substrate. After forming the thermal diffusion film on the substrate, the gas containing the reactive species that directly reacts with the substrate is guided by the gas guiding means above the gap formed by the sealed container and the reaction tube, and the gas is introduced between the sealed container and the reaction tube. From above in the gap formed by
The gas is discharged to the outside of the sealed container from a gas discharge means provided in the lower part of the sealed container. Therefore, the foreign matter generated from the heater or the heat equalizing tube and passing through the sealed container is
The gas containing the reactive species that reacts directly with the substrate is discharged again to the outside of the sealed container. Therefore, the inside of the reaction tube is unlikely to be contaminated by the foreign matter generated from the heater or the soaking tube.

Further, in the gap, the gas containing the reactive species that directly reacts with the substrate flows from the upper side to the lower side in the gap, so that foreign matter such as quartz fine particles accumulated on the inner wall of the bottom of the gap is rolled up. Because it is hard to be caught, inside the reaction tube,
Less likely to be contaminated by such foreign matter.

Therefore, when the heat diffusion film is formed on the substrate using the thin film forming apparatus according to the second aspect of the invention, the heat diffusion film becomes a thin film having a good quality with less contamination by foreign matters.

[0043]

EXAMPLES Preferred examples will be shown below, but the following examples are merely for explaining the invention according to the present application, and the invention according to the present application is not limited by the following examples. There is no such thing.

Example 1 FIG. 1 is a partial sectional view schematically showing a thin film forming apparatus according to the present invention. Referring to FIG. 1, this thin film forming apparatus 10
Reference numeral 0 denotes a thin film forming apparatus for forming a heat diffusion film on a substrate, which has a cylindrical heater 101, a cylindrical heat equalizing tube 102 provided inside the heater 101, and a heat equalizing tube 10.
A cylindrical hermetically sealed container (outer tube) 110 provided inside 2
And a reaction tube (inner tube) 120 that is housed in the sealed container 110 and that houses the substrate that forms the heat diffusion film. The material of the heater wire of the heater 101, the material of the soaking tube 102, the material of the sealed container 110, and the material of the reaction tube 120 are
Any material can be used as long as it is a material used for a conventional heat diffusion device, and is not particularly limited.

The sealed container 110 and the reaction tube 120 are formed of, for example, quartz. Thin film forming apparatus 100
The sealed container 110 and the reaction tube 120 are integrally molded.

At the upper part of the reaction tube 120, an opening is provided between the inside of the sealed container 110 and the inside of the reaction tube 120 for passing a gas containing a reactive species that directly reacts with the substrate and / or an atmosphere gas. A section 120a is provided. A thermocouple (not shown) as a temperature measuring means for measuring the temperature in the core portion 140 formed of the sealed container 110 and the reaction tube 120 is provided in the gap 130 formed by the sealed container 110 and the reaction tube 120. ) Is installed inside the thermocouple protection tube 150. The thermocouple (not shown) may be directly exposed in the gap 130.

At the bottom of the sealed container 110, the sealed container 11
The gas and / or the atmosphere gas containing the reactive species that directly reacts with the substrate, which are introduced into the chamber 0 and the reaction tube 120,
Gas discharge port 110h for discharging outside the sealed container 110
Is provided. The gas outlet 110h has a gas outlet pipe 1
11 is connected. In addition, a gas inlet 120 i for directly introducing a gas containing a reactive species that directly reacts with the substrate into the reaction tube 120 is provided in the lower portion of the reaction tube 120.
Insert the sealed container 110 into the gas inlet 120i,
A gas introduction pipe 121 for introducing a gas containing a reactive species that directly reacts with the substrate is connected.

An atmosphere gas introduction pipe 160 for introducing the atmosphere gas into the reaction tube 120 is provided in the gap 130. One end 160a of the atmosphere gas introduction pipe 160
Is provided outside the sealed container 110 by inserting the sealed container 110, and the other end 160b of the atmospheric gas introduction pipe 160 is provided.
Is provided in the vicinity of the opening 120a provided in the upper portion of the reaction tube 120.

In the gap 130 formed by the hermetically sealed container 110 and the reaction tube 120, the gas is introduced directly into the reaction tube 120, and the hermetically sealed container 11 is introduced from above in the gap 130.
The gas is discharged to the gas discharge port 110h provided at the bottom of 0.
A gas rectifier 170 is provided for rectifying a gas containing a reactive species that directly reacts with the substrate and / or an atmospheric gas.

FIG. 2 is a perspective view schematically showing the gas rectifier 170 in a partially enlarged manner. In addition, FIG.
3 is a cross-sectional view of the gas rectifier 170 shown in FIG. 2 and 3, in the gas rectifier 170, a plurality of plate-shaped gas rectification plates 170a made of, for example, quartz are provided on the outer wall of the reaction tube 120 in the circumferential direction of the outer circumference of the reaction tube 120. Further, it is provided so as to project toward the sealed container 110. Such a gas straightening plate 170a
3, as shown in FIG. 3, they are densely provided on the side where the gas outlet 110h is provided and sparsely provided on the opposite side, and the gap 130 formed by the sealed container 110 and the reaction tube 120 is formed. The gas containing the reactive species that directly reacts with the substrate and / or the atmosphere gas, which is discharged from the upper part inside to the gas discharge port 110h provided in the lower part of the sealed container 110, is uniformly formed in the gap 130. The gas is rectified and exhausted so that such gas does not form a stagnation part.

FIG. 4 is a perspective view schematically showing another embodiment of the gas rectifier. 4, the gas rectifier 171 is provided instead of the gas rectifier 170 shown in FIG. Further, FIG. 5 is a cross-sectional view taken along the line VV of the gas rectifier 171 shown in FIG.

Referring to FIGS. 4 and 5, this gas rectifier 171 has a donut shape for shutting upward and downward inside the gap 130 formed by the sealed container 110 and the reaction tube 120. Flat plate 172 made of quartz or the like
And a pipe 173 having a plurality of hollows provided on the flat plate 172. The pipe 173 is fixedly provided by being fitted into a plurality of holes 174 formed in the flat plate 172. The plurality of holes 174 are formed in the sealed container 11 as shown in FIG.
0 is provided sparsely on the side where the gas outlet 110h is provided at the lower part and densely on the opposite side, and from above in the gap 130 formed by the sealed container 110 and the reaction tube 120. A gas containing a reactive species that directly reacts with the substrate and / or an atmospheric gas, which is discharged to a gas discharge port 110h provided in the lower portion of the sealed container 110, is uniformly distributed
Further, in the gap 130, such gas is rectified and exhausted so that such a gas does not form a stagnation portion.

Referring to FIG. 1, in the reaction tube 120, the gas supply head 1 is connected to the gas inlet 120i.
80 is provided.

FIG. 6 is a partially enlarged perspective view schematically showing the gas supply head 180. FIG. 7 is a cross-sectional view of the gas supply head 180 shown in FIG. 6 taken along the line VII-VII.

With reference to FIGS. 6 and 7, this gas supply head 180 is provided with a tube 182 having a donut-shaped hollow portion 181 provided along the wall surface of the inner peripheral leather of the reaction tube 120. On the inner peripheral side of the tube 182, a plurality of gas ejection holes 182h distributed in the circumferential direction are provided as gas ejection means for ejecting a gas containing a reactive species that directly reacts with the substrate into the reaction tube 120. Gas ejection hole 182
h is sparsely provided on the gas introduction port 120i side and densely provided on the opposite side. The inner wall of the tube 182 and the reaction tube 12
In the hollow portion 181 formed by the inner wall surface of the reaction tube 1, the gas straightening plate 183 that divides the inside of the hollow portion 181 into the upper portion 181a and the lower portion 181b is formed from the inner wall of the tube 182.
It is provided so as to project in the direction of the inner wall surface of 20. As shown in FIG. 5, the gas straightening plates 183 are densely provided on the gas introduction port 120i side and sparsely provided on the opposite side. With reference to FIG. 6, the gas inlet 120 i is located at the lower part 181 of the hollow part 181.
It is connected to the b side. The gas containing the reactive species that directly reacts with the substrate, introduced into the lower portion 181b side of the hollow portion 181 of the gas supply head 180 through the gas introduction port 120i, moves in the lower portion 181b of the hollow portion 181 in the circumferential direction. next,
The gas that has moved in the circumferential direction inside the lower portion 181b of the hollow portion 181 is removed from the hollow portion 184 between the gas straightening plate 183 and the inner wall of the reaction tube 120 and the gap portion 185 between the gas straightening plates 183. It moves into the upper part 181a of 181 and is uniformly introduced into the reaction tube 120 through the gas ejection hole 182h.

Further, referring to FIG. 1, the gas ejection holes 182
h is provided in a soaking zone A formed by the heater 101 and the soaking tube 102.

The material of the gas supply head 180 is formed of a material usually used for the sealed container 110 and the reaction tube 120, such as quartz or SiC.

Further, since the boat and the like housed in the reaction tube 120 are the same as the boat and the like used in the thin film forming apparatus 400 shown in FIG. 12, the same reference numerals are used for the corresponding members, and The description is omitted.

Referring to FIG. 1, when a thermal diffusion film is formed on a substrate using such a thin film forming apparatus 100, a plurality of wafers 40 are placed on a boat 41 and the boat 41 is used as a reaction tube. It is accommodated in 110. The end cap 42 of the boat 41 includes a sealed container 110 and a reaction tube 120 that are integrally formed.
And the outer wall of the bottom portion 120b is pressed from below. When the boat 41 on which the wafer 40 is mounted is housed in the reaction tube 110, an atmospheric gas is introduced into the reaction tube 120 from the atmospheric gas introduction tube 160 through the opening 120a provided in the upper portion of the reaction tube 120. To do. Next, with the heater 101,
The wafer 40 is preheated at the processing temperature. Next, wafer 4
The gas containing the reactive species that directly reacts with 0 is introduced into the gas introduction pipe 121.
Further, it is directly introduced into the reaction tube 120 through the gas introduction port 120i. The gas containing the reactive species that directly reacts with the wafer 40 introduced into the reaction tube 120 is, as described above of the gas supply head 180, the inner wall of the tube 182 and the reaction tube 12.
It is temporarily stored in the other part 181b of the hollow part 181 formed by the inner wall of 0 and the gas rectifying plate 183, and is diffused in the circumferential direction in the lower part 181b of the hollow part 181 in the gas supply head 180.

The gas containing the reactive species that directly reacts with the wafer 40, which is introduced into the lower portion 181b of the hollow portion 181 of the gas supply head 180, is heated by the heat in the reaction tube 120, and the inner wall of the reaction tube 120 is removed. A hollow portion 181 is formed by a slit-shaped gap portion 184 with the gas straightening plate 183 and a gap portion between the gas straightening plates 183 (the gap portion 185 shown in FIG. 7).
Is introduced into the upper part 181a. Next, the gas containing the reactive species that directly reacts with the wafer 40 is supplied to the gas supply head 18.
0 through a plurality of gas ejection holes 182h introduced into the reaction tube 120 at a uniform and uniform pressure to form a thermal diffusion film on the wafer 40, and then from the opening 120a to inside the gap 130. It is discharged upward.

The gas containing reactive species that directly reacts with the wafer 40 and / or the atmosphere gas discharged above the gap 130 is discharged from the gas discharge port 110h and the gas discharge pipe 111 provided in the lower portion of the sealed container 110. Sealed container 11
It is discharged to the outside. At this time, the gas containing reactive species that directly reacts with the wafer 40 and / or the atmospheric gas discharged into the gap 130 is rectified by the gas rectifier 170.

Next, the gas containing the reactive species that directly reacts with the wafer 40 is purged, and the atmospheric gas is replaced with the atmospheric gas introducing pipe 1.
From 60, the opening 12 provided in the upper part of the reaction tube 120
In the state of being introduced from 0a, the boat 41 is taken out from the reaction tube 120, and the wafer 40 on which the heat diffusion film is formed is taken out.

In FIG. 1, solid arrows indicate the flow direction of the gas containing the reactive species that directly reacts with the substrate, and broken arrows indicate the flow direction of the atmospheric gas.

The thin film forming apparatus 100 directly introduces a gas containing a reactive species that directly reacts with the wafer 40 into the reaction tube 120. As a result, the gas containing the reactive species that directly reacts with the wafer 40 is less likely to be contaminated by foreign matter such as Fe generated from the heater 101 or the heat equalizing tube 102, so that the thermal diffusion film formed on the wafer 40 is Less likely to be contaminated by foreign matter.

After the thermal diffusion film is formed on the wafer 40, the gas containing the reactive species that directly reacts with the wafer 40 and / or the atmospheric gas is introduced into the sealed container 11 from above in the gap 130.
The gas is discharged to the outside of the hermetically sealed container 110 through a gas discharge port 110h provided at the lower part of 0.

Therefore, the heater 101 and the soaking tube 10
The foreign matter such as Fe generated from No. 2 and passed through the sealed container 110 is discharged again to the outside of the sealed container 110 together with the gas containing the reactive species that directly reacts with the wafer 40 and / or the atmospheric gas. Therefore, the heater 101 and the soaking tube 10
The inside of the reaction tube 120 is unlikely to be contaminated by foreign matter such as Fe generated from No. 2. In the gap 130, the wafer 4
Since the gas containing the reactive species that directly reacts with 0 and / or the atmospheric gas flows from the upper side to the lower side in the gap 130, foreign matters such as quartz particles accumulated on the inner wall of the bottom 120b of the gap 130 are rolled up. Since it is difficult to be prevented, the inside of the reaction tube 120 is unlikely to be contaminated with such foreign matter.

Therefore, when a thermal diffusion film is formed on the wafer 40 using the thin film forming apparatus 100, the thermal diffusion film has a good quality with less contamination by foreign matter.

In the thin film forming apparatus 100, the reaction tube 1
The gas containing the reactive species that directly reacts with the wafer 40 and is directly introduced into the reaction chamber 20 is uniformly supplied into the reaction tube 120 by the gas supply head 180. Since the gas containing the reactive species that directly reacts with the wafer 40 is uniformly supplied into the reaction tube 120, the uniformity of the film thickness of the thermal diffusion film formed on the wafer 40 is improved.

In the thin film forming apparatus 100, the wafer 4
A gas ejection hole 182h for taking out a gas containing a reactive species that directly reacts with 0 is installed in a soaking zone A formed by the heater 101 and the soaking tube 102. Therefore, the reaction tube 12
The gas containing the reactive species that directly reacts with the wafer 40, which is introduced into 0, is preheated in the gas supply head 180 before being introduced into the reaction tube 120. Therefore, the gas containing the reactive species that directly reacts with the wafer 40 is generated in the reaction tube 120.
Since the temperature difference between the temperature inside the reaction tube 120 and the temperature inside the reaction tube 120 is small, the uniformity of the temperature distribution in the reaction tube 120 is improved. Since the temperature controllability inside the reaction tube 120 is improved,
The uniformity of the film thickness of the heat diffusion film formed on the wafer 40 is improved.

In the thin film forming apparatus 100, the sealed container 110 and the reaction tube 120 are integrally formed. 14
As in the conventional thin film forming apparatus 500 as shown in FIG. 5, the connection between the sealed container 510 and the flange 506 and the reaction tube 520
The problematic leak does not occur at the connection portion between the flange 506 and the flange 506. Therefore, in the thin film forming apparatus 100, since the above-mentioned leak does not occur, the thermal diffusion film formed on the wafer 40 is less contaminated by foreign substances caused by the leak, and the temperature unevenness in the reaction tube 120 due to the leak does not occur. The uniformity of the film thickness is improved.

Further, since the hermetically sealed container 110 and the reaction tube 120 are integrally formed as a single body, the hermetically sealed container 110 and the reaction tube 120 may be cleaned as one body, and the work at the time of cleaning the hermetically sealed container 110 and the reaction tube 120. Will be easier. Further, after cleaning, as in the conventional thin film forming apparatus 500, the sealed container 5
Since it is not necessary to inspect whether or not there is a leak in the connection between the flange 10 and the flange 506 or the connection between the reaction tube 520 and the flange 506, maintenance of the thin film forming apparatus during cleaning and the like is improved.

In the thin film forming apparatus 100, the heater 1
01 or the heat equalizing tube 102 and the foreign matter that has passed through the sealed container 110 and has been removed, a gas containing a reactive species that directly reacts with the wafer 40 and / or an atmospheric gas is used. Therefore, it is necessary to use an active gas. There is no. Therefore, if the thin film forming apparatus 100 is used, the running cost for forming the thermal diffusion film on the wafer 40 can be reduced.

Further, in the thin film forming apparatus 100, the thermocouple protection tube 150 and / or the thermocouple (not shown) is not directly installed in the reaction tube 120 but is installed in the gap 130. Therefore, contamination in the reaction tube 120 is suppressed by the foreign substances generated from the thermocouple itself, the insulating tube used for the thermocouple, or the thermocouple protection tube 150 made of ceramics or the like, and the film quality of the heat diffusion film formed on the wafer 40 is reduced. The quality of the film is high with less contamination by such foreign matter.

Further, by introducing the atmospheric gas through the opening 120a provided in the upper portion of the reaction tube 120,
It is possible to prevent particles such as fine quartz powder accumulated on the inner wall of the bottom portion 120a of the gap 130 formed by the sealed container 110 and the reaction tube 120 from being rolled up.

At the time of loading (loading) the wafer 40 into the reaction tube 120 or unloading (unloading) the wafer 40 from the reaction tube 120, an atmosphere gas such as N ₂ gas or Ar gas is used as a gap. As a result of introducing from the upper side to the lower side into the reaction tube 120 using the atmospheric gas introducing tube 160 provided in the portion 130, entrainment oxidation and the like can be controlled, and the film thickness of the thermal diffusion film formed on the wafer 40. Uniformity is improved. Further, the quality of the thermal oxide film formed on the wafer 40 is also improved.

Further, in the thin film forming apparatus 100, the gap 130 formed by the sealed container 110 and the reaction tube 120.
By providing the gas rectifier 170 inside, the gap 1
Rectification of the gas and / or the atmosphere gas containing the reactive species that directly reacts with the wafer 40, which is discharged into the wafer 30, is performed.
As described above, in the thin film forming apparatus 100, by providing the gas rectifier 170 in the gap 130, the gap 130 is formed.
As a result of being able to rectify the above-mentioned gas discharged into the interior of the reaction tube 120, the flow of the gas containing the reactive species that directly reacts with the wafer 40 and / or the atmosphere gas near the wafer 40 in the reaction tube 120 is also rectified. As a result, the uniformity of the film thickness of the thermal diffusion film formed on the wafer 40 is improved.

Further, in the thin film forming apparatus 100, the atmospheric gas introducing pipe 160 is provided in the gap 130 formed by the sealed container 110 and the reaction pipe 120. Therefore, as a result of the atmospheric gas in the atmospheric gas introducing pipe 160 being protected by the double wall of the hermetically sealed container 110 and the atmospheric gas introducing pipe 160, foreign substances generated from the heater 101 and the heat equalizing pipe 102 are contained in the atmospheric gas. It can be prevented from being mixed. Further, such foreign matter that has passed through the sealed container 110 due to the gas containing the reactive species that directly reacts with the wafer 40 and / or the atmospheric gas flowing through the gap 130 is removed before reaching the atmospheric gas introduction pipe 160. To be done. Therefore, since the atmospheric gas introduced into the reaction tube 120 from the atmospheric gas introduction tube 160 is less contaminated by foreign matter, the reaction tube 120 is less likely to be contaminated by such foreign matter.

Using the thin film forming apparatus 100, a thermal oxide film made of SiO _{2 in} the range of 100Å to 200Å was formed on a Si substrate.

When the obtained thermal oxide film was used as the capacitor dielectric film, the withstand voltage was improved as compared with the conventional capacitor dielectric film. That is, the withstand voltage of the capacitor dielectric film using the thermal oxide film made of SiO ₂ formed using the conventional thin film forming apparatus is 8 MeV / cm to 10 Me.
V / cm, whereas thin film forming apparatus 1 according to the present invention
The dielectric breakdown voltage of the capacitor dielectric film using the thermal oxide film made of SiO ₂ formed of 100 is about 11 MeV /
cm or more, and the insulation pressure was improved by about 15 to 20% as compared with the conventional capacitor dielectric film.

Using the thin film forming apparatus 100, a thermal oxide film made of SiO _{2 in} the range of 100Å to 200Å was formed on a Si substrate.

The uniformity of the film thickness of the thermal oxide film made of SiO ₂ formed on the Si substrate was measured. The film thickness of the thermal oxide film made of SiO ₂ formed on the Si substrate was measured by an ellipsometer. The film thickness of SiO ₂ formed on the Si substrate is measured at a plurality of places, and the maximum film thickness D _max and the minimum film thickness D are obtained.
_min and the average film thickness D _ave of the SiO ₂ film thickness,
The uniformity of the film thickness was measured according to Formula 1.

[0082]

[Equation 1] S formed on a Si substrate using the thin film forming apparatus 100
The uniformity of the thickness of the thermal oxide film made of iO ₂ was improved by about 5% to 20% as compared with the uniformity of the thickness of the thermal oxide film formed on the Si substrate by using the conventional thin film forming apparatus.

Further, when the number of particles of foreign matter such as quartz fine particles taken into the thermal oxide film made of SiO ₂ per unit area was measured, the conventional SiO ₂
The number of particles was reduced by about 8 to 10% as compared with the number of particles incorporated in the thermal oxide film made of.

Further, the work efficiency at the time of cleaning the hermetically sealed container and the reaction tube is
The work efficiency is improved by about 20% compared with the conventional thin film forming apparatus. The working efficiency was measured by the average time required for the work including the removal process, the mounting process, and the leak inspection process when cleaning the sealed container and the reaction tube. The work required for the conventional thin film forming apparatus was about 6 hours on average, and the work required for the thin film forming apparatus according to the present invention was about 4 hours.

Example 2 FIG. 8 is a partial sectional view schematically showing a thin film forming apparatus according to the present invention.

Referring to FIG. 8, this thin film forming apparatus 200
Shows a thin-film forming apparatus for forming a heat diffusion film on a substrate, and includes a cylindrical heater 201, a cylindrical heat equalizing tube 202 provided inside the heater 201, and a heat equalizing tube 202.
Cylindrical sealed container (outer tube) 210 provided inside the container
And a reaction tube (inner tube) 220 that is housed in the sealed container 210 and that houses a substrate that forms a heat diffusion film. The material of the heater wire of the heater 201, the material of the soaking tube 202, the material of the sealed container 210, and the material of the reaction tube 220 are
Any material can be used as long as it is a material used for a conventional heat diffusion device, and is not particularly limited.

The sealed container 210 and the reaction tube 220 are made of, for example, quartz. The sealed container 210 and the reaction tube 220 are integrally molded.

In the gap 230 formed by the sealed vessel 210 and the reaction tube 220, a thermocouple (as a temperature measuring means for measuring the temperature of the core portion 240 formed by the sealed vessel 210 and the reaction tube 220) is used. (Not shown) is installed inside the thermocouple protection tube 250. The thermocouple (not shown) may be provided directly in the gap 230 in a state of being exposed. A gas inlet 220i for directly introducing a gas containing a reactive species that directly reacts with the substrate and / or an atmospheric gas into the reaction tube 220 is provided in the upper portion of the reaction tube 220, and a lower portion of the reaction tube 220 is provided with The gas containing the reaction species that directly reacts with the substrate and / or the atmospheric gas introduced into the reaction tube 220 is filled with the gap 23 formed by the sealed container 210 and the reaction tube 220.
A gas exhaust port 220h is provided for exhausting into 0.

In the lower part of the pressure vessel 210, the gas containing the reactive species that directly reacts with the substrate and / or the atmospheric gas introduced into the reaction tube 220 and the sealed vessel 210 is discharged to the outside of the sealed vessel 210. Gas outlet 2 for
10h is provided.

In the gap 230 formed by the sealed container 210 and the reaction tube 220, the reaction tube 220 is filled with a gas containing a reactive species that directly reacts with the substrate and / or an atmospheric gas.
A gas introducing pipe 260 for introducing the gas into the inside is provided. One end 260 a of the gas introduction pipe 260 is provided by inserting the sealed container 210, and the other end 2 a of the gas introduction pipe 260 is provided.
60b is connected to a gas inlet 220i provided in the upper part of the reaction tube 220.

In the gap 230 formed by the sealed container 210 and the reaction tube 220, the gas containing the reactive species and / or the atmospheric gas introduced into the reaction tube 220, which directly reacts with the substrate, is introduced. Sealed container 210 and reaction tube 22
A gas guide tube 290 is provided as a gas guide unit that guides the inside of the gap 230 formed by 0 and 0. One end 290a of the gas introduction pipe 290 is connected to the gas exhaust port 220h provided in the lower portion of the reaction pipe 220, and the other end 290b of the gas guide pipe 290 is provided above the gap 230 and the other end thereof is provided. A gas containing a reactive species that directly reacts with the substrate and / or an atmospheric gas is supplied from 290b to the gap 2
It can be discharged upward in 30.

Further, in the gap 230 formed by the sealed container 210 and the reaction tube 220, the gas guide tube 290 is provided.
From the other end 290b of the gas discharge port 21 provided in the lower portion of the hermetically sealed container 210.
A gas rectifier 270 is provided for rectifying the gas containing the reactive species that directly reacts with the substrate and / or the atmospheric gas exhausted to 0 h.

Since the structure of the gas rectifier 270 is the same as that of the gas rectifier 170 shown in FIGS. 3 and 4 and the gas rectifier 171 shown in FIGS. 5 and 6, the description thereof will be omitted.

Since the boat and the like housed in the reaction tube 220 are the same as the boat and the like used in the thin film forming apparatus 400 shown in FIG. 12, the same reference numerals are given to the corresponding members, and The description is omitted.

Using such a thin film forming apparatus 200,
When forming the thermal diffusion film on the substrate, the plurality of wafers 40 are placed on the boat 41, and the boat 41 is housed in the reaction tube 220. The end cap of the boat 41 presses the outer walls of the bottom 220b of the integrally molded hermetic container 210 and the reaction tube 220 from below. When the boat 41 on which the wafer 40 is mounted is housed in the reaction tube 220, the atmospheric gas is introduced into the reaction tube 220 from the gas introduction tube 260 through the gas introduction port 220i provided in the upper portion of the reaction tube 220. .

Then, the heater 40 preheats the wafer 40 at the processing temperature. Next, a gas containing a reactive species that directly reacts with the substrate is introduced into the gas introduction pipe 260 and the gas introduction port 2.
It is directly introduced into the reaction tube 220 from 20i. Reaction tube 22
The gas and / or the atmosphere gas, which is introduced into 0 and contains the reactive species that directly reacts with the substrate, forms a thermal diffusion film on the wafer 40, and then the gas exhaust port 220h and the gas exhaust port 220h provided in the lower portion of the reaction tube 220. It is discharged upward in the gap 230 through the guide tube 290. The gas and / or the atmospheric gas containing the reactive species that directly reacts with the substrate, which is discharged upward in the gap 230, is discharged to the outside of the sealed container 210 through the gas discharge port 210h provided in the lower portion of the sealed container 210. It At this time, the gas containing the reactive species that directly reacts with the substrate and / or the atmospheric gas discharged into the gap 230 is rectified by the gas rectifier 270.

Next, the gas containing the reactive species that directly reacts with the substrate is purged, and the atmospheric gas is introduced from the gas introduction pipe 260 through the gas introduction port 220i provided in the upper portion of the reaction pipe 220, and the boat 41 Is taken out from the reaction tube 220, and the wafer 40 on which the heat diffusion film is formed is taken out.

In FIG. 8, the arrow shown by the solid line shows the direction of the flow of the gas containing the reactive species that directly reacts with the substrate, and the arrow shown by the broken line shows the direction of the flow of the atmospheric gas.

The thin film forming apparatus 200 directly introduces the gas containing the reactive species that directly reacts with the wafer 40 into the reaction tube 220. As a result, the gas containing the reactive species that directly reacts with the wafer 40 is less likely to be contaminated by foreign substances such as Fe generated from the heater 201 and the heat equalizing tube 202, and thus the thermal diffusion film formed on the wafer 40 is Less likely to be contaminated by foreign matter.

After the thermal diffusion film is formed on the wafer 40, the gas containing the reactive species that directly reacts with the wafer 40 and / or the atmospheric gas is introduced into the sealed container 21 from above in the gap 230.
The gas is discharged to the outside of the hermetically sealed container 210 through the gas discharge port 210h provided in the lower part of 0.

Therefore, the heater 201 and the soaking tube 20
The foreign matter such as Fe generated from No. 2 and passed through the sealed container 210 is again discharged to the outside of the sealed container 210 together with the gas containing the reactive species that directly reacts with the wafer 40 and / or the atmospheric gas. Therefore, the heater 201 and the soaking tube 10
The inside of the reaction tube 220 is unlikely to be contaminated by foreign matter such as Fe generated from 2. Further, in the gap 230, the gas containing the reactive species that directly reacts with the wafer 40 and / or the atmospheric gas flows from the upper side to the lower side in the gap 230, and therefore is deposited on the inner wall of the bottom 220 b of the gap 230. Since foreign matter such as quartz fine particles that are present is less likely to be rolled up, the inside of the reaction tube 220 is less likely to be contaminated by such foreign matter.

Therefore, when a thermal diffusion film is formed on the wafer 40 using the thin film forming apparatus 200, the thermal diffusion film has a good quality with less contamination by foreign matter.

Further, in the thin film forming apparatus 200, the sealed container 210 and the reaction tube 220 are integrally formed. Therefore, in the thin film forming apparatus 200, since the above-mentioned leak does not occur, the thermal diffusion film formed on the wafer 40 is less contaminated by foreign substances caused by the leak, and the temperature unevenness in the reaction tube 220 due to the leak does not occur. Therefore, the uniformity of the film thickness is improved.

Further, since the sealed container 210 and the reaction tube 220 are integrally molded, it is sufficient to clean the sealed container 210 and the reaction tube 220 as one body, and the work at the time of cleaning the sealed container 210 and the reaction tube 220. Will be easier. Further, after cleaning, as in the conventional thin film forming apparatus 500, the sealed container 5
Since it is not necessary to inspect whether or not there is a leak in the connection between the flange 10 and the flange 506 or the connection between the reaction tube 520 and the flange 506, maintenance of the thin film forming apparatus during cleaning and the like is improved.

In the thin film forming apparatus 200, the heater 2
01 or the soaking tube 202 and the foreign matter that has passed through the hermetically sealed container 210 is removed, a gas containing a reactive species that directly reacts with the wafer 40 and / or an atmospheric gas is used. Therefore, it is necessary to intentionally use an active gas. There is no. Therefore, the running cost for forming the thermal diffusion film on the wafer 40 using the thin film forming apparatus 200 can be reduced.

Further, in the thin film forming apparatus 200, the thermocouple protection tube 250 and / or the thermocouple (not shown) is not directly installed in the reaction tube 220, but is installed in the gap 230.

Therefore, contamination in the reaction tube 220 is suppressed by foreign matter generated from the thermocouple itself, the insulating tube used for the thermocouple, the thermocouple protection tube 250 such as ceramics,
The film quality of the heat diffusion film formed on the wafer 40 is a good film quality with less contamination by foreign matter.

In the thin film forming apparatus 200, the gap 230 formed by the sealed container 210 and the reaction tube 220.
By providing the gas rectifier 270 inside, the gap 2
Rectification of the gas and / or the atmosphere gas containing the reactive species that directly reacts with the wafer 40, which is discharged into the wafer 30, is performed.
As described above, in the thin film forming apparatus 200, by providing the gas rectifier 270 in the gap 230, the gap 230
As a result of being able to rectify the above-mentioned gas discharged into the interior of the reaction tube 220, the flow of the gas containing the reactive species that directly reacts with the wafer 40 and / or the atmosphere gas near the wafer 40 in the reaction tube 220 is also rectified. As a result, the uniformity of the film thickness of the thermal diffusion film formed on the wafer 40 is improved.

Further, in the thin film forming apparatus 200, the gas introduction pipe 260 is provided in the gap 230 formed by the sealed container 210 and the reaction pipe 220. For this reason,
The gas containing the reactive species that directly reacts with the substrate and / or the atmospheric gas in the gas introduction pipe 260 is protected by the double wall of the sealed container 210 and the gas introduction pipe 260, and as a result, the heater 201 and the heat equalizing pipe 202. It is possible to prevent foreign matter generated from the above from being mixed into the gas containing the reactive species that directly reacts with the substrate and / or the atmospheric gas. In addition, the hermetically sealed container 2 is provided by the gas containing the reactive species that directly reacts with the wafer 40 and / or the atmospheric gas flowing in the gap 230.
Such foreign matter that has passed through 10 is removed before reaching the gas introduction pipe 260. Therefore, the gas introduction pipe 26
The gas and / or the atmosphere gas containing the reactive species that directly reacts with the wafer 40, which is introduced into the reaction tube 220 from inside 0, has a small degree of contamination by foreign matter, and therefore the reaction tube 22
The inside of 0 is unlikely to be contaminated by such foreign matter.

Embodiment 3 FIG. 9 is a partial sectional view schematically showing a thin film forming apparatus according to the present invention.

Referring to FIG. 9, this thin film forming apparatus 300
Shows a low pressure CVD apparatus, in which a gas containing a reaction gas is introduced onto a substrate, and under reduced pressure and under a heating atmosphere,
It is a thin film forming apparatus for depositing and forming a thin film on a substrate.

This thin film forming apparatus 300 has the same structure as the thin film forming apparatus 100 shown in FIG. 1 except for the following points. That is, in the thin film forming apparatus 300, in the thin film forming apparatus 100, the heater 101 is the heater 301, the soaking tube 102 is the soaking tube 302, the reaction tube (inner tube) 120 is the reaction tube (inner tube) 320, and the gap 130. In the gap 330,
The core part 140 is the core part 340, the thermocouple protection pipe 150 is the thermocouple protection pipe 350, the atmosphere gas introduction pipe 160 is the atmosphere gas introduction pipe 360, the gas rectifier 170 is the gas rectifier 370, and the gas outlet 110h is gas. Outlet 310h
The opening 120a to the opening 320a and the bottom 120b.
Is at the bottom 320b, and the gas exhaust pipe 111 is at the gas exhaust pipe 31.
Each corresponds to 1. In addition, the thermocouple (not shown),
It may be provided in a state of being directly exposed in the gap 330.

The thin film forming apparatus 300 is different from the thin film forming apparatus 100 in the following points.

In the thin film forming apparatus 300, the core portion 340
Since, in general, is used in a reduced pressure state, a pressure vessel 310 that is a hermetically sealed vessel and has pressure resistance characteristics is used instead of the hermetically sealed vessel 110 of the thin film forming apparatus 100. As such a pressure vessel 310, a normal decompression C
A material used for the VD device, such as quartz, is used.

Further, in the thin film forming apparatus 300, the gas injector 322 is provided as a gas introducing means for directly introducing the gas containing the reaction gas into the reaction tube 320. One gas injector 322 is provided for each chemical reaction species of the gas that is the raw material of the thin film deposited on the substrate.

FIG. 10 is a perspective view schematically showing a partially enlarged gas supply head 380 provided with a plurality of gas injectors 322. Further, FIG. 11 is a cross-sectional view of the gas supply head 380 taken along the line XI-XI.

With reference to FIGS. 10 and 11, this gas supply head 380 is provided for each gas injector 322.
It is provided separately and independently. In the gas supply head 380,
This is to prevent the chemically reactive species from mixing with each other.
Each gas supply head 380 is provided separately for each gas injector 322, except for FIG.
Since it has the same configuration as the gas supply head shown in FIG. 7, the corresponding members are designated by the same reference numerals,
The description is omitted.

Further, referring to FIG. 9, an O-ring 319 is provided on the lower surface of the pressure vessel 310 and the bottom portion 320b of the reaction tube 320, which are integrally molded, on the outer wall side.

Since the boat and the like housed in the reaction tube 320 are the same as the boat and the like used in the thin film forming apparatus 400 shown in FIG. 12, the same reference numerals are given to the corresponding members and the description thereof is omitted. Is omitted.

Using such a thin film forming apparatus 300,
When a gas containing a reaction gas is introduced onto the substrate to deposit a thin film on the substrate, a plurality of wafers 40 are attached to the boat 41.
The boat 41 is housed in the reaction tube 320. The end cap 42 of the boat 41 presses the lower surface of the outer wall of the bottom 320b of the integrally molded pressure vessel 310 and the reaction tube 320 from below through the O-ring 319. When the boat 41 on which the wafer 40 is placed is housed in the reaction tube 320, the atmospheric gas is introduced into the reaction tube 320 from the atmosphere gas introduction tube 360 through the opening 320 a provided in the upper portion of the reaction tube 320. .

Next, using a vacuum pump (not shown) or the like,
Via the gas outlet 310h and the gas outlet pipe 311
The inside of the pressure vessel 310 and the inside of the reaction tube 320 are evacuated. Next, the atmosphere gas is introduced from the atmosphere gas introduction pipe 360,
From the opening 320a provided in the upper part of the reaction tube 320,
It is introduced into the reaction tube 320. Next, the heater 301 preheats the wafer 40 at the processing temperature. Next, wafer 4
The reaction gas, which is the raw material of the thin film to be deposited and formed on No. 0, is directly introduced into the reaction tube 320 from each gas injector 322 for each chemical reaction species. Gas injector 322
The reaction gas for each chemical reaction species introduced directly into the reaction tube 320 by means of the inner wall of the tube 182 of the gas supply head 380 and the inner wall of the reaction tube 320, which are connected to the respective gas injectors 322, and the gas. Lower part 1 of hollow part 181 formed by flow straightening plate 183
The gas supply head 380 is temporarily stored in 81b.
Inside the lower part 181b of the hollow part 181 inside, it is diffused in the circumferential direction.

The reaction gas introduced into the lower portion 181b of the hollow portion 181 of the gas supply head 380 is the reaction tube 32.
The space 184 on the slit between the inner wall of the reaction tube 320 and the gas straightening plate 183 and the space between the gas straightening plates 183 (the space 18 shown in FIG.
From 5), it is introduced into the upper part 181a of the hollow part 181.

Next, the reaction gas is supplied to the gas supply head 380.
After being introduced into the reaction tube 320 through the gas ejection holes 182h provided in the inside of the reaction tube 320 and onto the wafer 40, a thin film is formed on the wafer 40 by a thermochemical reaction. , Reaches the opening 320a. Next, by a vacuum pump (not shown) or the like, the reaction gas / or the atmosphere gas descends in the gap 330 and the gas exhaust port 310h.
Then, the gas is discharged to the outside of the pressure vessel 610 through the gas discharge pipe 311. At this time, the reaction gas and / or the atmospheric gas discharged into the gap 330 is rectified by the gas rectifier 370.

Next, the reaction gas is purged and the pressure vessel 31
0 and the inside of the reaction tube 320 are returned to normal pressure, and then the atmospheric gas is introduced from the atmosphere gas introduction tube 360 through the opening 320a provided in the upper part of the reaction tube 320, and the boat 41 is set in the reaction tube 320. Then, the wafer 40 having the thin film deposited thereon is taken out.

In FIG. 9, the arrow indicated by the solid line indicates the flow direction of the gas containing the reaction gas, and the arrow indicated by the broken line indicates
The direction of the flow of atmospheric gas is shown.

The thin film forming apparatus 300 supplies the reaction tube 3 with a gas containing a reaction gas as a raw material of a thin film to be deposited on a wafer.
Directly introduced into 20. As a result, the gas containing the reaction gas, which is the raw material of the thin film deposited on the wafer 40, is less likely to be contaminated by foreign substances such as Fe generated from the heater 301 and the heat equalizing tube 302, and therefore the gas on the wafer 40 is reduced. The deposited thin film is less likely to be contaminated by foreign matter.

After depositing the thin film on the wafer 40, the gas containing the reaction gas and / or the atmospheric gas, which is the raw material of the thin film deposited on the wafer 40, is introduced into the sealed container 310 from above in the gap 330. The gas is exhausted to the outside of the hermetically sealed container 310 through a gas exhaust port 310h provided in the lower part of the. Therefore, foreign matter such as Fe generated from the heater 301 or the heat equalizing tube 302 and passing through the sealed container 310 is re-established together with the gas containing the reaction gas and / or the atmospheric gas which is the raw material of the thin film deposited on the wafer 40. It is discharged to the outside of the sealed container 310. Therefore, the reaction tube 320 is caused by foreign matter such as Fe generated from the heater 301 and the soaking tube 302.
The inside is not easily contaminated. In the gap 330,
The gas containing the reaction gas and / or the atmospheric gas, which is a raw material of the thin film to be deposited on the wafer 40, is formed in the gap 330.
Since it flows from the upper side to the lower side inside, the bottom portion 3 of the gap 330 is
Since foreign matter such as quartz fine particles deposited on the inner wall of 20b and fine particles formed by the reaction gas are not easily rolled up, the inside of the reaction tube 320 is less likely to be contaminated by such foreign matter.

Therefore, when a thin film is deposited on the wafer 40 by using the thin film forming apparatus 300, the thin film is
A good quality film with less contamination by foreign matter.

In addition, in the thin film forming apparatus 300, the reaction tube 3
The gas containing the reaction gas, which is directly introduced into the wafer 20 and serves as a raw material of the thin film deposited on the wafer 40, is uniformly supplied into the reaction tube 320 by the gas supply head 380. Since the gas containing the reaction gas, which is the raw material of the thin film deposited on the wafer 40, is uniformly supplied into the reaction tube 320,
The uniformity of the thickness of the thin film deposited on the wafer 40 is improved.

Further, in the thin film forming apparatus 300, the wafer 4
A gas ejection hole 182h for taking out a gas containing a reaction gas, which is a raw material of a thin film to be deposited on the surface of 0, is installed in a soaking zone A formed by the heater 301 and the soaking tube 302.
Therefore, the gas containing the reaction gas, which is the raw material of the thin film deposited on the wafer 40 and is placed in the reaction tube 320, is heated in advance in the gas supply head 380 before being introduced into the reaction tube 320. To be done. Therefore, the gas containing the reaction gas, which is the raw material of the thin film deposited on the wafer 40, becomes
Since there is little difference between the temperature at the time of being introduced into the reaction tube 20 and the temperature in the reaction tube 320, the uniformity of the temperature distribution in the reaction tube 320 is improved. Since the temperature controllability in the reaction tube 320 is improved, the film thickness uniformity of the thin film deposited on the wafer 40 is improved.

In the thin film forming apparatus 300, the pressure vessel 310 and the reaction tube 320 are integrally formed. Therefore, like the conventional thin film forming apparatus 600, the pressure vessel 6
No problematic leak occurs at the connection between the No. 10 and the flange 606 or at the connection between the reaction tube 620 and the flange 606.

Therefore, in the thin film forming apparatus 300, since the above-mentioned leak does not occur, the thin film deposited on the wafer 40 is less contaminated by foreign matter caused by the leak,
Further, since the temperature in the reaction tube 320 does not become uneven due to the leak, the uniformity of the film thickness is improved.

Further, since the pressure vessel 310 and the reaction tube 320 are integrally formed as a single body, it is sufficient to wash the pressure vessel 310 and the reaction tube 320 as one body, and the work at the time of washing the pressure vessel 310 and the reaction tube 320. Will be easier. Further, after cleaning, as in the conventional thin film forming apparatus 600, the sealed container 6
Since it is not necessary to inspect for a leak or the like at the connection between the No. 10 and the flange 606 and at the connection between the reaction tube 620 and the flange 606, the maintainability of the thin film forming apparatus at the time of cleaning or the like is improved.

In the thin film forming apparatus 300, the heater 3
01 and the soaking tube 302, and to remove foreign matter that has passed through the pressure vessel 310, a gas containing a reaction gas and / or an atmospheric gas as a raw material of a thin film deposited on the wafer 40 is used. There is no need to use active gas. Therefore, using the thin film forming apparatus 300,
It is possible to reduce the running cost when forming a thin film on the wafer 40.

Further, in the thin film forming apparatus 300, the thermocouple protection tube 350 and / or the thermocouple (not shown) is not directly installed in the reaction tube 320 but is installed in the gap 330.

Therefore, contamination in the reaction tube 320 is suppressed by foreign substances generated from the thermocouple itself, an insulating tube used for the thermocouple, and a thermocouple protection tube 350 made of ceramics or the like, and the reaction tube 320 is adhered and formed on the wafer 40. The film quality of the thin film is a good quality film with less contamination by foreign matter.

The atmosphere gas is introduced into the atmosphere gas introduction pipe 3
A space 33 formed by the pressure vessel 310 and the reaction tube 320 by being introduced from the other end 360b of 60 through an opening 320a provided above the reaction tube 320.
It is possible to prevent the particles such as the fine quartz powder deposited on the inner wall of the bottom portion 320b of No. 0 and the powder formed by the reaction gas from being rolled up.

At the time of loading (loading) the wafer 40 into the reaction tube 320 or when unloading (unloading) the wafer 40 from the reaction tube 320, an atmospheric gas such as N ₂ gas or Ar gas is used. As a result of being introduced into the reaction tube 320 from the upper side to the lower side, entrainment oxidation and the like can be controlled, and the film thickness uniformity of the thin film formed on the wafer 40 is improved. In addition, the quality of the thermal oxide film formed on the wafer 40 is also improved.

Further, in the thin film forming apparatus 300, the gap 330 formed by the pressure vessel 310 and the reaction tube 320.
By providing the gas rectifier 370 inside, the gap 3
The gas containing the reaction gas and / or the atmospheric gas, which is the raw material of the thin film to be deposited on the wafer 40, discharged into 30 is rectified. FIG. 17 schematically shows a portion of the conventional thin film forming apparatus 600 where a stagnation 630a of a gas containing a reaction gas and / or an atmospheric gas, which is a raw material of a thin film to be deposited and formed on a wafer 40, is generated in a gap 630. FIG. In the conventional thin film forming apparatus 600, since the gas rectifying means is not provided in the gap portion 630,
A stagnation 630a of a gas containing a reaction gas and / or an atmospheric gas, which is a raw material of a thin film to be deposited and formed on a substrate, is generated in the gap 630 as shown in FIG. This stagnation 63
In the portion where 0a is generated, the gas containing the reaction gas and / or the atmospheric gas, which is the raw material of the thin film to be deposited on the substrate, does not flow, so that the foreign matter generated from the heater 601 or the heat equalizing pipe 602 and the pressure vessel 610 react It may pass through the tube 620 and contaminate the inside of the reaction tube 620. On the other hand, in the thin film forming apparatus 300, the gas rectifier 3 is provided in the gap 330.
As a result of providing 70, the stagnation does not occur and the reaction tube 3
The inside of 20 is less likely to be contaminated by foreign matter generated from the heater 301 or the heat equalizing tube 302. Therefore, when a thin film is formed on the wafer 40 by using the thin film forming apparatus 300, the quality of the thin film becomes a good quality with less contamination by foreign matter.

In the thin film forming apparatus 300, the gap 3
By disposing the gas rectifier 370 inside 30, the above-mentioned gas discharged into the gap 330 can be rectified,
The flow of the gas containing the reaction gas and / or the atmospheric gas, which is the raw material of the thin film deposited on the wafer 40, in the vicinity of the wafer 40 in the reaction tube 320 is also rectified, and as a result, deposited on the wafer. The uniformity of the film thickness of the thin film is improved.

Further, in the thin film forming apparatus 300, the atmospheric gas introducing pipe 360 is provided in the gap 330 formed by the pressure vessel 310 and the reaction pipe 320. Therefore, as a result of the atmospheric gas in the atmospheric gas introducing pipe 360 being protected by the double wall of the pressure vessel 310 and the atmospheric gas introducing pipe 360, foreign substances generated from the heater 301 and the heat equalizing pipe 302 are contained in the atmospheric gas. It can be prevented from being mixed.

Further, the wafer 4 flowing in the gap 330
Such a foreign matter that has passed through the pressure vessel 310 is removed by the gas containing the reaction gas and / or the atmospheric gas that is the raw material of the thin film to be deposited and formed on the surface 0 before reaching the atmospheric gas introduction pipe 360. Therefore, since the atmosphere gas introduced into the reaction tube 320 from the atmosphere gas introduction tube 360 is less contaminated by foreign matter, the reaction tube 32
The inside of 0 is unlikely to be contaminated by such foreign matter.

In the first embodiment, the case where the thermal oxide film is formed on the Si substrate is illustrated, but this is merely for the purpose of explanation, and the present invention is applied to the Si substrate. It should be additionally noted that the present invention is not limited to the apparatus for forming the.

[0144]

As described above, according to the thin film forming apparatus according to the first aspect of the invention, the gas containing the reaction gas is directly introduced into the reaction tube, and the gas is introduced from above in the gap formed by the sealed container and the reaction tube. Since the gas containing the reaction gas is made to flow downward, the thin film formed on the substrate is a good quality thin film with less contamination by foreign matter.

Further, in the thin film forming apparatus according to the first aspect of the present invention, since the gas supply head means for uniformly supplying the gas containing the reaction gas is provided, the film thickness uniformity of the thin film formed on the substrate is improved. To do.

Further, according to the thin film forming apparatus of the second invention, the gas containing the reactive species that directly reacts with the substrate is directly introduced into the reaction tube, and the gas is introduced from above in the gap formed by the sealed container and the reaction tube. Since the gas containing the reactive species that directly reacts with the substrate and / or the atmospheric gas is made to flow downward, the thermal diffusion film formed on the substrate is a good quality thin film with less contamination by foreign matter.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view schematically showing a thin film forming apparatus according to the present invention.

FIG. 2 is a partially enlarged schematic perspective view of the gas rectifier 170 shown in FIG.

3 is a III-III of the gas rectifier 170 shown in FIG.
It is a cross-sectional view taken along the line.

FIG. 4 is a perspective view schematically showing an embodiment of a gas rectifier.

5 is a cross-sectional view taken along the line VV of the gas rectifier 171 shown in FIG.

6 is a perspective view schematically showing a partially enlarged gas supply head 180 shown in FIG. 1. FIG.

7 is a VII-V of the gas supply head 180 shown in FIG.
It is a cross-sectional view taken along the line II.

FIG. 8 is a partial cross-sectional view schematically showing a thin film forming apparatus according to the present invention.

FIG. 9 is a partial cross-sectional view schematically showing a thin film forming apparatus according to the present invention.

FIG. 10 is a partially enlarged perspective view schematically showing the gas supply head 380 shown in FIG.

11 is a XI- of the gas supply head 380 shown in FIG.
It is a cross-sectional view taken along the line XI.

FIG. 12 is a partial cross-sectional view schematically showing a conventional thin film forming apparatus.

13 is a partially enlarged perspective view schematically showing the gas rectifier 470 shown in FIG.

14 is an XIV-X of the gas rectifier 470 shown in FIG.
It is a cross-sectional view taken along the line IV.

FIG. 15 is a sectional view schematically showing a conventional thin film forming apparatus.

FIG. 16 is a sectional view schematically showing a conventional thin film forming apparatus.

17 is a diagram for explaining a state of stagnation of gas generated in a gap formed by the pressure vessel and the reaction tube of the thin film forming apparatus shown in FIG.

[Explanation of symbols]

 100 thin film forming apparatus 110 hermetically sealed container (outer tube) 110h gas outlet 111 gas outlet 120 reaction tube (inner) 120i gas inlet 120a opening 121 gas inlet 130 130 gap 180 gas supply head

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kiyoki Kobayashi 4-1-1 Mizuhara, Itami City, Hyogo Prefecture Mitsubishi Electric Corp.

Claims (2)

[Claims] 1. A thin film forming apparatus for introducing a gas containing a reaction gas onto a substrate to form a thin film on the substrate under a heating atmosphere, the device comprising: a hermetically sealed container; and a lower part of the hermetically sealed container. Gas discharging means for discharging the gas introduced onto the substrate to the outside of the sealed container, a reaction tube housed in the sealed container for housing the substrate, and a gas introduction for directly introducing the gas into the reaction tube. Means, a gas guiding means for guiding the gas introduced into the reaction tube upward in a gap formed by the sealed container and the reaction tube, and provided in the reaction tube, and in the gas introducing means A thin film forming apparatus comprising: a gas supply head unit which is connected to the substrate and uniformly supplies the gas onto the substrate. 2. A thin film forming apparatus for forming a thermal diffusion film on a substrate in a heating atmosphere by introducing a gas containing a reactive species that directly reacts with the substrate into a sealed container, A gas discharge means provided below the sealed container for discharging the gas introduced onto the substrate to the outside of the sealed container; a reaction tube housed in the sealed container for housing the substrate; A thin film forming apparatus comprising: a gas introducing unit that directly introduces the gas into the reaction tube; and a gas guiding unit that guides the gas introduced into the reaction tube upward in a gap formed by the sealed container and the reaction tube.