JPH10177959A - Vapor thin film growth device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent particles from attaching themselves to or a thin film component from depositing on the peripheral wall of the reaction oven by a method wherein the reaction oven is separated into an upper part of small diameter and a lower part of large diameter, the lower edge of the upper part and the upper edge of the lower part are joined together to connect their hollow inner spaces together, and flow regulating gas outlets are provided to a joint between the upper and the lower part of the oven. SOLUTION: A reaction oven 10 is partitioned into an upper part 1 and a lower part 2, where the upper part 1 is thinner than the lower part 2. That is, the inner diameter D1 of the upper part 1 is smaller than the inner diameter D2 of the lower part (D2 /D1 is not less than 1.2). The upper edge U of the lower part 2 is joined to the lower edge B of the upper part 1 at a joint 18 into the reaction oven 10 with an inner hollow space. Flow-regulating gas (carrier gas) is introduced into the reaction oven 10 through flow regulating gas outlet holes 18a bored in the joint 18 so as to make gas flow smooth toward an unreacted gas outlet. By this setup, reaction gas reaches to a wafer substrate 11 to grow a thin film and then discharged out through an exhaust vent 15 flowing smooth from outside a rotating substrate holder 12 located below the lower end B of the upper part 1 of the oven 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vapor phase thin film growth apparatus and a vapor phase thin film growth method, and more particularly, to a vapor phase thin film with less generation of contaminants applied to a process of manufacturing a semiconductor wafer substrate requiring high quality. The present invention relates to a growth apparatus and a vapor phase thin film growth method for forming a thin film having a uniform thickness with few crystal defects.

[0002]

2. Description of the Related Art FIG. 8 is a schematic explanatory view showing an example of a conventional vapor phase growth apparatus. 8, a rotary substrate holder 82 on which a wafer substrate 81 such as a silicon wafer is mounted, a rotary shaft 83 for rotating the rotary substrate holder 82, and a heating A heater 84 is provided, and a rotating motor (not shown) is connected to the rotating shaft 83. Also, the reactor 8
A plurality of exhaust ports 85 for exhausting unreacted gas etc.
85 is provided and connected to an exhaust control device (not shown). On the other hand, a plurality of gas supply pipes 86, 86 for supplying a raw material gas and a carrier gas into the furnace and a disk-shaped current plate 87 are disposed at the top of the reaction furnace 80. Many holes 87a are formed to adjust the height. The conventional vapor phase growth apparatus is configured as described above, and the substrate 81 placed on the rotating substrate holder 82 that rotates at a predetermined rotation speed by the rotation of the motor is heated to a predetermined temperature by the heater 84 while rotating. Is done. At the same time, the reactor 80
A reaction gas such as a raw material gas or a carrier gas is introduced into the inside of the reactor through a plurality of gas supply pipes 86 to make the gas momentum and pressure distribution uniform, and then a rectifying plate so that the gas flow velocity distribution in the reaction furnace becomes uniform. The reaction gas is uniformly supplied to the wafer substrate 81 on the rotary substrate holder 82 by passing through a large number of holes 87 a of the substrate 87, and the thin film is vapor-phase grown.

In the vapor phase growth apparatus for forming a thin film on a semiconductor wafer as described above, in order to prevent the generation of particles due to the gas for forming the thin film and the deposition of deposits on the inner wall of the reaction furnace, it is necessary to prevent Various proposals have been made so that crystal defects are not caused by inconvenience and a thin film-formed wafer having a uniform thin film and a uniform film thickness can be obtained. For example, in Japanese Patent Application Laid-Open No. Hei 5-74719, the crystal flow is prevented by preventing the temperature change in the reaction furnace by controlling the supply flow rate of the raw material gas to a predetermined value. JP 5
In JP-A-90167, the amount of the source gas, the pressure in the furnace, the number of rotations of the rotating substrate holder, and the like are controlled to a predetermined value so as to make the in-plane temperature distribution of the wafer substrate uniform during thin film formation, thereby preventing slip. . In Japanese Patent Application Laid-Open No. 6-216045, a shielding tube is provided on a part of the inner wall of the reactor where precipitates are liable to be formed, while keeping the inner peripheral surface smooth, and the reactor is easily cleaned after performing a thin film forming operation. In addition, the gas flow is maintained in a laminar state to form a uniform thin film. In addition, Japanese Patent Application Laid-Open
In Japanese Patent No. 50260, the source gas and carrier gas are supplied to the substrate at a uniform flow rate by uniformizing the gas momentum and the gas pressure by making the method of introducing the source gas and the carrier gas into the reaction furnace to be uniform. This is to achieve uniformity.

[0004]

However, even in the conventional vapor phase growth apparatuses proposed in the above-mentioned various proposals, it is possible to sufficiently prevent crystal defects and inconveniences such as particle adhesion on a wafer substrate on which a thin film is grown. Not really,
In particular, with the recent increase in the degree of integration of semiconductors, the quality of wafer substrates has been required to be higher and higher. Has become. SUMMARY OF THE INVENTION The present invention has been made in view of the deterioration of the quality of a wafer substrate in the formation of a vapor-growth thin film by such a conventional vapor-phase growth apparatus, and has been made for the purpose of solving them. The inventors first studied in detail the phenomenon occurring in a conventional vapor phase growth apparatus. as a result,
A phenomenon in which a large amount of particles adhere to the reactor wall has been observed.
It has been found that the particles adhered to the reaction furnace wall adhere to the wafer substrate and cause crystal defects, or directly cause deterioration of wafer quality as adhered particles.

From the above findings, the inventors have further attempted to find the cause of the phenomenon of large amount of particles adhering to the reactor wall.
The raw material gas flow in the reactor was studied. As a result, it has been further clarified that the following phenomenon occurs in the reactor. That is, the reaction gas such as the silicon source gas introduced from the top of the reaction furnace and supplied onto the wafer substrate 81 at a uniform flow rate as described above is heated by the heater 84 and becomes lower in the temperature in the lower part of the reaction furnace 80 than in the upper part. Reaches the vicinity of the wafer substrate 81 and is heated. As a result, as shown by an arrow in FIG. 8, a rising gas flow is generated, a rising phenomenon of the reaction gas is generated along the reactor wall, and a gas vortex is generated. Further, since the heated reaction gas rises, the reaction furnace 8
The temperature of the entire region within 0 also increases, so that uniform nucleation of the thin film forming raw material gas in the gas phase increases, and particle generation in the gas phase increases. Further, when the gas vortex flows, the dopant in the reaction gas may be re-introduced at the outer peripheral portion of the wafer substrate 81 on the rotating substrate holder 82, and the in-plane resistance value distribution of the obtained wafer substrate may be uneven. It may also cause the transformation. Further, the rising phenomenon of the reactant gas flowing down near the wafer substrate to the upper part of the reaction furnace is generated separately from the generation of the gas vortex, on the outer peripheral side of the rotating substrate holder 82, by the so-called "roughness of gas flow". A turbulence resulting in a complicated flow will occur. When the gas flow becomes rough, the unreacted gas to be discharged from the exhaust port 85 reacts to deposit a thin film component on the outer peripheral surface of the rotating substrate holder 82 or the reaction furnace facing the outer peripheral surface of the rotating substrate holder 82. Particles may adhere to walls.

The generation of the gas vortex and the roughening of the gas flow which cause the various inconveniences described above can be suppressed to some extent by setting the gas flow velocity in the axial direction of the rotating substrate holder to an extremely high speed of about 1 m / s or more in the conventional method. It is possible. However, for that purpose, it is necessary to flow a large amount of carrier gas. In addition, in order to suppress the generation of the gas vortex, the diameter of the upper part of the reactor was narrowed down compared to the lower part, so as to block the space where the high temperature reaction gas rises, and to prevent the generation of the gas vortex. Was. However, in this case, it is possible to prevent particles from adhering to the upper part of the reactor and the like, but FIG. 7 is a schematic explanatory view of a vapor phase thin film growing apparatus having a smaller upper part of the reactor used in the comparative example described below. ,
As shown by the arrow, it was found that a gas vortex or a rough gas flow was generated in the enlarged portion of the reactor diameter located outside the rotary substrate holder. If this gas vortex or gas flow becomes rough in the area where the diameter increases, the reactor also causes problems such as particles adhering to the lower peripheral wall of the reactor and deposition of thin film components due to the reaction of unreacted gas. It has also been clarified that inconveniences such as shortening of the maintenance cycle also occur when only the area is changed.

On the basis of the above findings, the inventors have found that the above-mentioned inconveniences, such as deterioration of the quality of the thin-layer-formed wafer substrate and shortening of the maintenance cycle of the reactor, are caused by the gas flow of the upward flow of the gas in the reactor. In addition to finding that there is turbulence, not only eliminating or closing the upper space where the gas flow is inconvenient, but also providing straightening gas outflow holes at the connection between the upper and lower reactors with different diameters to enlarge the diameter Actively introduce rectifying gas to rectify the gas flow to the part,
By setting the ratio of the upper diameter of the reaction furnace, the lower diameter and the diameter of the rotating substrate holder to a predetermined value, a large amount of particles to the outer peripheral surface at the reactor wall or the lower portion of the rotating substrate holder in the conventional vapor phase growth apparatus described above. The inventors have found that it is possible to prevent adhesion, deposition of thin film components, and incorporation of dopants at the outer peripheral portion of the wafer, thereby preventing deterioration in the quality of the wafer substrate, and completed the present invention. That is, the present invention provides a vapor phase thin film growth apparatus that prevents particles generated by uniform nucleation of silicon source gas from adhering on the peripheral wall of the reaction furnace and preventing deposition of thin film components on the outer periphery of the rotating substrate holder and the inner peripheral wall of the furnace. The present invention also provides a method for vapor-phase growing a high-quality and uniform thin film on a wafer substrate with few defects.

[0008]

According to the present invention, a plurality of reactant gas supply ports are provided at the top of a hollow reactor, and an exhaust port is provided at a bottom thereof.
A rotating substrate holder on which a wafer substrate is placed, and a rectifying plate having a plurality of holes formed in an upper portion of the inside, and a reaction gas is supplied to the inside of the rotating substrate holder to cover the surface of the wafer substrate on the rotating substrate holder. In a vapor phase growth apparatus for vapor-phase growing a thin film, the hollow interior of the reaction furnace is divided into upper and lower portions having considerably different inner diameters,
An upper inner diameter is smaller than a lower lower inner diameter, and an upper lower end and a lower upper end are connected by a connecting portion to form a continuous hollow interior, and the connecting portion has a rectifying gas outflow hole; Is provided below the lower end of the reactor with a predetermined height difference from the lower end of the upper part of the reactor.

[0009] In the vapor phase thin film growth apparatus of the present invention,
Further, it is preferable that a space portion surrounding the rectification gas outlet hole in an airtight manner is provided on the connection portion, and the space portion has a rectification gas supply port. Further, it is preferable that the upper side surface is perpendicular to the upper surface of the rotating substrate holder, and the space portion and the upper portion are formed in a double annular shape,
It is preferable that an outer side surface of the space portion is continuous with the upper end of the lower portion via a connection portion. Furthermore, the horizontal cross section of the inside of the reactor hollow is circular, the upper diameter (D ₁ ) is larger than the diameter of the wafer substrate, and the rotating substrate holder is circular and has a diameter ( _DS). preferably) the ratio of (D ₁ / D _S) is 0.7 to 1.2, the upper diameter (D
₁ ) and the ratio (D ₂ / D ₁ ) of the lower diameter (D ₂ ) to 1.2
Preferably or more, it is preferable the ratio of the lower diameter (D ₂₎ and the rotating substrate holder diameter _{(D S) (D 2 /} D S) is 1.2 or more. Furthermore, the height difference (H) between the upper and lower ends and the rotating substrate holder is larger than the transition layer thickness (T) of the gas flow on the upper surface of the rotating substrate holder, and the transition layer thickness (T) is 3.22 (ν / ω) ^1/2 (where ν indicates the kinematic viscosity coefficient (mm ² / s) of the atmosphere gas in the reactor and ω indicates the angular velocity of rotation (rad / s), respectively) It is preferable that a part of the connecting portion and the upper surface of the rotating substrate holder are in the same horizontal plane.

Further, according to the present invention, in the above-described vapor phase growth apparatus, the transition layer thickness (T) of the gas flow in the upper part of the rotating substrate holder is higher or lower than the lower end of the upper part and the upper surface of the rotating substrate holder. At the same time, a reaction gas composed of a thin film forming raw material gas and a carrier gas is supplied from the plurality of reaction gas supply ports so as to be smaller than the difference (H), and is passed through the holes of the rectifying plate to flow on the wafer substrate. A gas phase thin film forming method is characterized in that a gas for flow straightening is introduced through a flow straightening gas outlet of the connecting portion. Further, in the vapor phase thin film growth method of the present invention, the transition layer thickness (T) is:
3.22 (ν / ω) ^1/2 (where ν is the kinematic viscosity coefficient (mm ² / s) of the reaction gas and ω is the angular velocity of rotation (rad /
s) respectively, the rotation of the rotating substrate holder can be controlled so as to be smaller than the height difference (H), and the carrier gas flow rate (G _C ) and the rectifying gas outlet of the connecting portion can be controlled. Gas flow rate (G
It is preferred ratio of _{I) (G I / G C} ) is 0.05 to 2.

The vapor phase thin film growth apparatus of the present invention is configured as described above, and suppresses generation of a gas vortex caused by a reaction gas rising phenomenon generated along a reaction furnace wall in a conventional vapor phase thin film growth apparatus. It can be suppressed by changing the furnace shape to make it smaller than the lower diameter to eliminate the generation space, and at the same time, it can prevent the rise of the gas phase temperature in the upper part of the reactor, so the uniform nucleus of the raw material gas for thin film formation such as silicon Generation is suppressed and particles generated in the gas phase are reduced. Therefore, it is possible to prevent the particles from adhering to the reaction furnace wall and shortening the maintenance cycle, from adhering to the wafer to cause crystal defects, and from directly adhering particles and deteriorating the quality of the wafer. Further, the generation of the gas vortex is suppressed uniformly without obstructing the flow of the gas just above the wafer placed on the rotating substrate holder from flowing from the center of the wafer to the outer periphery in parallel with the wafer surface. Therefore, a high-quality thin-layer-formed wafer substrate having a uniform in-plane resistance value distribution can be obtained without re-uptake of the dopant in the gas phase at the outer peripheral portion of the substrate. Furthermore, since the upper part of the reactor is made thinner, the gas flow velocity in the axial direction of the rotating substrate holder can be increased with a relatively small amount of carrier gas, and the amount of carrier gas is reduced as compared with the conventional apparatus.

In addition, a rectifying gas outflow hole may be provided at a connecting portion connecting the lower end of the upper portion of the small diameter and the upper end of the lower portion of the large diameter of the reactor, so that a rectifying gas such as hydrogen flows out at a predetermined flow rate. Since it is possible, the gas flow from the center to the outer periphery generated on the rotating substrate holder is rectified, and the so-called lower portion in which the diameter of the outer periphery of the rotating substrate holder is increased by making the reactor upper diameter smaller than the lower portion. Roughness of the gas flow can be suppressed. As a result, it is possible to prevent particles from adhering to the inner wall of the enlarged diameter connecting portion or the lower part of the reactor and the deposition of thin film forming components. Furthermore, the reactor upper diameter,
Since the ratio of the lower diameter of the reactor and the diameter of the rotating substrate holder is set to a predetermined value, it is possible to prevent the upward flow of gas in the reactor to reduce the generation of particles, and to prevent the generation of gas vortex and rough gas flow. Further, it is possible to prevent the particles attached to the furnace wall from dropping on the wafer substrate on the rotating substrate holder.

Further, the rotating substrate holder is disposed with a difference in height below the lower end of the reaction furnace, which is the upper end of the connecting portion, at the lower part of the reactor, and is particularly formed on the upper surface of the rotating substrate holder. Since the height difference is larger than the transition layer thickness of the gas flow, the upper and lower ends do not obstruct the smooth gas flow,
Further, by preventing the upward flow of the gas, a gas vortex or a rough gas flow does not occur, and a high-quality thin film-formed wafer substrate having no crystal defects can be obtained. In addition, the vapor phase thin film growth method of the present invention uses the above-described apparatus and controls the rotation speed of the rotating substrate holder by controlling the flow velocity of the reaction gas, the flow velocity of the rectifying gas from the connection part, and the rotation speed. Since the height difference between the upper surface of the rotating substrate holder and the lower part of the reactor is larger than the transition layer thickness of the gas flow formed on the substrate holder, a high-quality thin film with no crystal defects is similarly deposited on the wafer substrate. Vapor phase growth. In the present invention, the transition layer refers to a gas layer in which the source gas flow supplied via the current plate flows with a vector from the center to the outer peripheral direction on the rotating substrate holder. The thickness refers to the thickness of the gas flow having the above vector on the rotating substrate holder.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. However, the present invention is not limited by the following examples. FIG. 1 is a schematic sectional explanatory view of one embodiment of a vapor phase thin film growth apparatus of the present invention. In FIG. 1, a reactor 10 is divided into an upper part 1 and a lower part 2, and the upper part 1 is formed thinner than the lower part 2. That is, the upper inner diameter D ₁ is D ₁ <D ₂ smaller than the lower inner diameter D _2. The ratio between the heights H ₁ and H ₂ of the upper and lower parts of the reactor 10, that is, the division ratio is not particularly limited, as long as a rotating substrate holder or the like is provided in the lower part 2 in a predetermined manner. Good. Usually, H ₁ / H ₂ =
0.5 to 2.0. In the reactor 10, the upper end U of the large-diameter lower portion 2 and the lower end B of the small-diameter upper portion 1 are connected by a connecting portion 18, and the inner space of the reactor is continuous although the upper and lower portions have different diameters. Also, the side wall surface of the reactor upper part 1 is usually
The lower substrate 2 is formed perpendicular to the side wall surface and perpendicular to the upper surface of the rotating substrate holder. The connecting portion 18 between the upper lower end B and the lower upper end U is usually formed horizontally,
It is not particularly limited, and may be formed in an inclined shape or a curved shape. In the reactor of the vapor phase thin film growth apparatus of the present invention, a plurality of rectification gas outlet holes 18a for rectifying gas to flow out are formed in the connecting portion 18.

In FIG. 1, a large-diameter reactor lower part 2
A rotating substrate holder 12 on which a wafer substrate 11 is placed is rotatably supported by a rotating shaft 13 and disposed below the rotating substrate holder 12 and a wafer substrate 11 placed thereon. Is provided. The rotating substrate holder 12 is disposed so that the upper surface is located below the lower end B of the reactor with a predetermined height difference (H). The rotating shaft 13 is connected to a motor (not shown) for rotationally driving. Further, a plurality of exhaust ports 15 for exhausting unreacted gas and the like are provided at the bottom of the reactor 10. On the other hand, a plurality of reaction gas supply ports 16 and 16 are provided at the top of the upper part of the reaction furnace 1, for example, a raw material gas such as silane (SiH ₄ ) and dichlorosilane (SiH ₂ Cl ₂ ) and hydrogen (H ₂ ). , Helium (He), argon (Ar), or other carrier gas. Above the upper part of the reactor upper part 1, a disk-shaped rectifying plate 17 having a plurality of holes 17a formed therein while holding a top part and a predetermined space area S reacts so that the supply gas does not form a deviated flow path. It is arranged close to the inner peripheral surface of the furnace upper part.

A rectifying gas is discharged from a rectifying gas outlet hole 18a formed in the connecting portion 18 in order to smoothly flow the unreacted gas to the exhaust ports 15, 15. As the rectifying gas, the above-mentioned carrier gas is generally used, and usually, the same gas as the carrier gas supplied from the gas supply ports 16 at the top of the reactor is discharged. As a result, after the reaction gas reaches the wafer substrate 11 and is provided for thin film growth,
The unreacted gas flows smoothly from the outer peripheral side of the rotating substrate holder 12 without causing a gas swirl or a rough gas flow, and the exhaust port 1
5 and 15 can be discharged. Rectifying gas outlet 1
The rectifying gas is introduced into each rectifying gas outlet 18a.
There is no particular limitation as long as the rectifying gas flows out of the tank uniformly. For example, an introduction pipe can be provided for each rectifying gas outlet 18a, and rectifying gas can be separately introduced. Further, as shown in FIG. 1, a rectifying gas introduction space 19 having a rectification gas supply port I is provided on the connecting portion 18 so as to hermetically surround the rectification gas outlet 18a. A rectifying gas may be supplied to 19. in this case,
Rectifying gas introduction space 19 'having a rectifying gas supply port I'
The upper portion of the reactor 10 is formed in a double ring shape surrounding the entire outer peripheral surface of the upper portion 1 of the reactor as described above, the hollow interior is defined as the reactor upper portion 1, and the hollow annular portion is defined as the rectifying gas introduction space. You can also. This double ring shape is preferable because it is simple in the production of the reactor.

In the vapor phase thin film growth apparatus of the present invention, the upper surface of the rotary substrate holder 12 has a predetermined height difference H below the lower end B of the upper part 1 of the reactor as described above. This height difference H
Is a transition layer of the gas flow supplied to the upper part of the rotating substrate holder 12, that is, the current plate 1 as shown by the arrow in FIG.
The gas flow of the source gas or the like supplied through 7 is made larger than the thickness (T) of the gas layer having a vector from the center to the outer peripheral portion on the rotating substrate holder 12. If the height difference H is smaller than the transition layer thickness T, the rotating substrate holder 12
The gas flow from the center of the upper wafer substrate 11 to the outer periphery is
It is obstructed by the lower end B of the upper part 1 of the reactor, and a rising phenomenon occurs along the inner wall of the reactor to promote the generation of a gas vortex, so that a large amount of precipitates are formed on the connecting part 18 and the inner wall of the lower part 2 of the reactor. This is because Further, it is preferable that the upper surface of the rotating substrate holder 12 be in the same horizontal plane as the connecting portion 18 between the upper part 1 and the lower part 2 of the reactor.

The transition layer thickness T of the gas flow on the rotating substrate holder 12 is mainly determined by the type of atmospheric gas in the reactor, the pressure in the reactor, Although it changes depending on the number of rotations of the rotating substrate holder, it can be calculated by the following equation (1). Equation (1) below is generally expressed in hydrodynamics. T = 3.22 (ν / ω) ^1/2 (1) (where ν is the kinematic viscosity coefficient of the reaction gas in the reactor (mm ² /
s) and ω represents the angular velocity of rotation (rad / s). In this case, ω takes the minimum value during the operation of forming a thin film in the vapor phase thin film growth apparatus. For example, the source gas is a silane gas, the carrier gas is a hydrogen gas, and the rotation speed of the rotating substrate holder is 500 to 2000 rpm (52 to 2 rpm).
09 rad / s), the transition layer thickness T is about 5 to 5
0 mm. Therefore, it is preferable that the upper surface of the rotating substrate holder is located at a height difference H larger than the T value from the lower end B of the upper portion 1 of the small diameter reactor. As a result, the gas flow from the center to the outer periphery on the wafer substrate is smooth, and there is no adhesion of the particles of the thin film forming raw material on the inner wall of the furnace, and the obtained thin film forming wafer has no defects in the crystal phase and a uniform thin film is formed. You.

Further, in the vapor phase thin film growth apparatus according to the present invention, in the reactor having upper and lower parts having different diameters, the small diameter D _{1 of the} upper part of the reactor, the large diameter D _{2 of the} lower part ₂ , the rotating substrate holder 12
The diameter D _S of, preferably in the respective proportional relationship as follows. For example, D ₁ is larger than the wafer diameter, and (1) the D ₂ / D ₁ ratio is 1.2 or more (D ₂ / D ₁ ≧
1.2). If D ₁ is smaller than the wafer diameter, particles that have fallen from the inner wall surface of the furnace upper part 1 are likely to adhere to the wafer substrate placed on the rotating substrate holder 12, and as a result, LPD (wafer surface laser scatterer (particles This is because the number of crystal defects measured as (included)) increases. Another reason is that it is difficult to measure the non-contact temperature of the peripheral portion of the wafer substrate using infrared rays, which is usually performed in the vapor phase thin film growth step. On the other hand, when the ratio D ₂ / D ₁ is smaller than 1.2, a gas flow upwards along the reactor wall and a gas vortex is generated, thereby reducing the diameter of the upper portion of the reactor and causing the gas to rise. This is because the phenomenon is prevented and the effect of suppressing the generation of the gas vortex is reduced.

[0020] (2) D ₁ / D _S ratio is 0.7 to 1.2
(0.7 ≦ D ₁ / D _S ≦ 1.2). When the D ₁ / D _S ratio is smaller than 0.7, the particles that have fallen off from the inner wall of the furnace adhere to the wafer substrate because the wall surface of the upper part 1 is too close to the wafer substrate placed on the rotating substrate holder 12. It will be easier. Therefore, because the above-mentioned D ₁ is as if smaller than the wafer substrate diameter, the quality of the increased crystal defects measured as LPD film formed wafer substrate is reduced. On the other hand, when the D ₁ / D _S ratio is larger than 1.2, the gas flow rises upward along the inner wall of the reactor as in the case where the D ₂ / D ₁ ratio is smaller than 1.2. This is because there is a disadvantage such as generation of a gas vortex. (3) The D ₂ / D _S ratio is 1.2 or more (D ₂ / D _S ≧ 1.2). D ₂ / D
_{If the S} ratio is less than 1.2, the roughness of the gas flow outside the rotating substrate holder 12 cannot be suppressed.
This is because particles adhere to the inner wall of the reaction furnace facing the outside or unreacted gas reacts below the rotating substrate holder 12 to deposit a thin film forming component on the inner wall of the lower part 2 of the reaction furnace.

As described above, in the vapor phase thin film growth apparatus of the present invention, the reaction furnace is a continuous hollow cylindrical body having different diameters divided into upper and lower portions, and rectifying gas is connected to the upper and lower connecting portions of different diameters. Except for having an outflow hole and arranging the respective members in the above-described predetermined manner, the design and manufacture are performed in substantially the same manner as the reaction furnace having the same diameter hollow cylinder of the conventional vapor phase thin film growth apparatus described above. be able to. A vapor phase growth method using the vapor phase thin film growth apparatus of the present invention can be similarly performed. In the vapor phase thin film growth apparatus of the present invention configured as described above, the inside of the reaction furnace 10 is evacuated by the exhaust control device connected to the exhaust ports 15, 15, and the pressure in the furnace, for example, the source gas or carrier gas. The reaction gas is adjusted to 20 to 50 torr. On the other hand, the rotating substrate holder 12 is rotated by the rotation of the rotating shaft 13 by operating the motor, and the wafer substrate 11 thereon is simultaneously rotated. At the same time, the wafer substrate 11 on the rotating substrate holder 12 is For example, about 900-1
Heat to 200 ° C. At the same time, a reaction gas composed of a source gas and a carrier gas is supplied into the reaction furnace 10 from the plurality of reaction gas supply ports 16 while controlling the flow rate to a predetermined value. The gas flow supplied to the space region S from the plurality of reaction gas supply ports 16 and 16 has a uniform momentum and pressure distribution, and furthermore, a gas flow distribution in the reaction furnace is obtained by passing through the holes 17 a of the current plate 17. Is supplied onto the substrate so that the thin film can be uniformly vapor-phase grown on the substrate. In the vapor phase thin film growth apparatus of the present invention, the rectifying gas outlet 18a
As a rectifying gas, the same gas as the normal carrier gas flows out.

In this case, the ratio (G _I / G _C ) of the flow rate (G _C ) of the reaction gas from the reaction gas supply port 16 to the flow rate (G _I ) of the rectifying gas introduced from the rectifying gas outlet of the connecting portion 18. There it is preferable to flow out so that _{0.05~2 (0.05 ≦ G I / G} C ≦ 2). If G _I / G _C is less than 0.05, the gas flow becomes rough at a portion where the diameter of the lower portion of the reactor located outside the rotary substrate holder 12 is increased, which is not preferable. If G _I / G _C exceeds 2, the gas flow rate at the enlarged diameter portion on the outside of the rotary substrate holder 12 is similarly too high, and the center of the rotary substrate holder 12 on the rotary substrate Since a smooth gas flow to the substrate is hindered, a uniform thickness and uniform thin film cannot be grown, which is not preferable. The rectifying gas flows out of the rectifying gas outlet hole 18a of the connecting portion 18 when the ratio G _I / G _C with the reactive gas from the reactive gas supply port is within the above range. In addition, the flow of the unreacted gas from the outer periphery of the rotating substrate holder to the lower space in the reactor is smoothly performed without causing gas vortex or gas flow roughness. This makes it possible to obtain a uniform high-quality thin-film-formed wafer substrate having few crystal defects.

The arrangement of the straightening gas outflow holes provided in the above-mentioned connecting portion is only required to prevent generation of a gas vortex due to rising of the gas upward and generation of a rough gas flow in the enlarged diameter portion of the reactor. It can be appropriately selected according to reaction conditions such as the capacity of the furnace, the type of the reaction gas, the flow rate of the reaction gas, the rotation speed of the rotating substrate holder, and is not particularly limited. Normally, like the rectified gas flow indicated by the arrow in FIG. 1, outflow holes having the same diameter are uniformly arranged over the entire connecting portion 18 so that the gas outflow speed is evenly distributed. Further, in order to provide a gradient in the outflow velocity distribution of the rectifying gas, the rectifying gas outflow holes may be arranged so that the hole diameters are changed in a predetermined distribution. For example, in the schematic diagram of another embodiment of the vapor phase thin film growth apparatus shown in FIG. 2, the flow of the rectifying gas from the rectifying gas outlet hole 28a of the connecting portion 28 is indicated by an arrow, as shown by an arrow. The flow can be discharged so as to have a gradient in the flow velocity distribution so that the flow velocity is high on the inner peripheral wall side of the lower part of the reactor 2 and slow on the central side. In FIG. 2, the same members as those in the apparatus shown in FIG. 1 are given the same numerical values in the first place, or are denoted by the same reference numerals (the same applies hereinafter). In order to give a gradient to the rectifying gas flow whose flow velocity becomes slower from the inner peripheral wall side toward the center as described above, for example, the connecting portion 28 shown in FIG.
As shown in the schematic plan view of FIG.
Can be arranged. In other words, a method is used in which a large number of outflow holes are provided on the inner peripheral wall side and less provided on the center side. By flowing the rectifying gas in such a manner as to have a predetermined flow velocity gradient, it is possible to prevent the generation of a gas vortex or a rough gas flow, rectify the flow of the reaction gas, and smoothly flow the unreacted gas from the lower part of the reactor. It is effective for exhausting.

In the present invention, the flow direction of the rectifying gas is not particularly limited. Usually, as shown in FIG. 1 and FIG. But,
If necessary, it can flow out in a direction other than the vertical direction. In other words, by rectifying gas outflow holes in the connecting portion so as to have an angle instead of a vertical direction parallel to the rotation axis of the rotating substrate holder, the rectifying gas flows out of the rectifying gas outflow holes of the rotating substrate holder. It can be discharged at a predetermined angle with respect to the rotation axis. For example, FIG. 4 is an enlarged partial cross-sectional explanatory view of an example of the connecting portion region. In FIG. 4, the straightening gas outlet hole 48a of the connecting portion 48 is formed so as to be inclined at a predetermined angle toward the inner peripheral wall of the reactor. The rectifying gas from the rectifying gas outlet hole 48a flows away from the rotation axis in the direction of the inner peripheral wall. Such a straightening gas outlet hole structure is preferable because the gas flow near the rotating body is not roughened. In this case, the inclination angle is usually about 1 to the rotation axis of the rotating substrate holder.
It is inclined at 0 to 80 degrees toward the inner peripheral wall of the reactor. It is not preferable to incline in the direction of the rotation axis because the gas flow swept out from the vicinity of the rotating body is roughened.

The rectifying gas may be caused to flow out in the same direction as the rotating direction of the rotating substrate holder. For example, FIG. 5 is a schematic perspective view in which an example of a connection portion formed by inclining a straightening gas outlet hole 58a of the annular connection portion 58 at a predetermined angle in a circumferential direction is partially cut away. In FIG. 5, a hole is formed in the gas inflow surface 58A of the rectifying gas outflow hole 58a so as to be inclined in the circumferential direction so as to communicate with the hole 58Y of the gas outflow surface on the back surface. The rectifying gas from the rectifying gas outlet hole 58a flows out in the same circumferential direction as the rotation of the rotating substrate holder.
This straightening gas outlet hole structure is preferable because the gas flow near the rotating body is not roughened. The inclination angle in this case is also generally inclined in the circumferential direction at about 10 to 80 degrees with respect to the gas inflow surface of the connecting portion. Further, the rectifying gas outflow hole can be inclined in the circumferential direction and at the same time in the center direction of the diameter so that the rectifying gas can flow out in the rotating direction of the rotating substrate holder. FIG. 6 is a schematic plan view showing an example of a connecting portion in which the straightening gas outflow hole 68a of the annular connecting portion 68 is inclined at a predetermined angle in the circumferential direction and the center of the annular shape. In FIG. 6, a hole is formed in the gas inflow surface 6F so as to be inclined from the opening 68X of the rectifying gas outflow hole 68a in the circumferential direction and the center of the annular shape so as to communicate with the opening 68Y in the gas outflow surface on the back surface. The rectifying gas flows out from the rectifying gas outlet hole 68a so as to rotate in the same direction as the rotation direction of the rotating substrate holder. This straightening gas outlet hole structure is preferable because the gas flow near the rotating body is not roughened. In this case, the inclination angle is usually about 10 to 80 degrees with respect to the gas inflow surface of the connecting portion, and about 10 degrees with respect to the circumferential direction.
Tilt to ~ 80 degrees.

[0026]

【Example】

Examples 1 to 3 are formed in a hollow cylinder similarly to the reaction furnace shown in FIG.
The upper inner diameter D ₁ , lower inner diameter D _2, and rotating substrate holder diameter D _{S of the} reactor have the diameters shown in Table 1, respectively, and the upper lower end B and the upper surface of the rotating substrate holder have the heights shown in Table 1. Difference H
The vapor phase growth apparatus provided so that it may have was used. SiH ₄ gas is used as a source gas, H ₂ gas is used as a carrier gas, and diborane (B ₂ H ₆ ) is used as a dopant.
Table 1 lists the gases contained in the _two gases at 0.1 ppm.
And the same H ₂ gas as the carrier gas was flowed out of the connection portion in the vertical direction at the flow rate shown in Table 1 as a rectifying gas. Reaction gas flow rate (m / s)
Table 1 also shows the ratio (G _I / G _c ) of the flow rate to the rectifying gas (m / s), the reaction temperature, the reaction pressure, and the number of rotations of the rotating substrate holder.

A B ₂ H ₆ dopant silicon thin film was grown on a silicon wafer under the vapor growth conditions shown in Table 1. After the vapor-phase growth thin film was formed, the adhesion of particles to the connection part of the vapor-phase growth apparatus used and the inner peripheral wall of the lower part of the reactor were visually observed. Further, the properties of the crystal phase on the surface of the obtained thin film-formed wafer substrate were measured at 0.135 using a Surfscan 6200 manufactured by Tencor Corporation.
The number of LPDs (laser scatterers on the wafer surface) of μm or more was measured, and the results are shown in Table 1 as the number per wafer. The thickness of the formed thin film was measured by an infrared interference thickness meter, and the maximum thickness (F _max ) and the minimum thickness (F _max ) were measured.
_min ) and determine the uniformity of the thin film thickness by ( _{Fmax- Fmin} ).
/ Calculated as _{(F max + F min) ×} 100 are shown in Table 1. The resistance value of the obtained thin film-formed wafer substrate is represented by C
The maximum value (R _max ) and the minimum value (R _min ) are determined using the -V method, and the uniformity of the resistance value due to the incorporation of the dopant is determined by (R _max -R _min ) / (R _max + R _min ) × 1
The calculated values are shown in Table 1.

[0028]

[Table 1]

Comparative Examples 1 and 2 Same as the reactor of Example 1 except that the rectifying gas was discharged from the connection part in a very small amount (Comparative Example 1) or a large amount (Comparative Example 2) as shown in Table 1. Using a vapor phase thin film growth apparatus configured as described above, B ₂ H
Vapor-phase growth of _6- dopant silicon thin film was performed. Thereafter, the results of observation in the apparatus and measurement of the obtained thin film-formed wafer substrate in the same manner are shown in Table 1.

Comparative Examples 3 to 13 In the same manner as in Example 1, a silicon thin film was vapor-phase-grown on a wafer substrate using a reaction furnace 70 of a vapor-phase thin-film growth apparatus whose schematic sectional explanatory view is shown in FIG. Referring to FIG.
The vapor phase thin film growth of Example 1 except that the inner diameter of the upper and lower portions of the upper portion 1 'of the small diameter and the lower portion 2' of the large diameter are different, and the connecting portion 78 connecting the upper and lower portions is not provided with a rectifying gas outflow hole. It is configured exactly like the reactor of the device. The same members as those in the apparatus shown in FIG. 1 are indicated by the same numeral of the first digit or by the same reference numeral. In the reaction furnace 70,
The ratio of the upper inner diameter D ₁ , lower inner diameter D _2, and rotating substrate holder diameter D _S of the reactor was changed as shown in Tables 2 and 3, and B ₂ H ₆ was deposited on the silicon wafer in the same manner as in Example 1.
Vapor-phase growth of a dopant silicon thin film was performed. afterwards,
Tables 2, 3 and 4 show the results of observations in the apparatus and the same measurements performed on the obtained thin film-formed wafer substrates.

[0031]

[Table 2]

[0032]

[Table 3]

Comparative Examples 14 and 15 As in the case of the reactor of the conventional vapor phase thin film growth apparatus shown in FIG. Using the reactor thus constructed, a B ₂ H ₆ dopant silicon thin film was formed on the silicon wafer surface under the same gas phase growth reaction conditions as in Example 1 shown in Table 4. Thereafter, the results of observation in the apparatus and measurement of the obtained thin film-formed wafer substrate in the same manner are shown in Table 4.

[0034]

[Table 4]

As is clear from the above Examples and Comparative Examples, the thin film obtained by dividing the reaction furnace into upper and lower portions having different diameters and allowing the rectifying gas to flow out from the connecting portion where the diameters of the upper and lower portions are increased is obtained. LP of the crystalline phase on the surface of the formed wafer substrate
It can be seen that the number of D is also reduced to about 1/300 or less as compared with Comparative Example 14 using the conventional vapor phase growth apparatus under the same conditions at 100 or less. Further, it is clear that a very uniform thin film is formed when the uniformity of the formed thin film is 1 or less. Further, it can be seen that the uniformity of the resistance value is 4.4 or less, and there is no defect in the crystal phase, and also the re-incorporation of the dopant is prevented and a uniform thin film is formed. Also, when a large amount of carrier gas is circulated by the conventional apparatus as in Comparative Example 15, the film thickness is relatively uniform, the LPD is small and the crystal phase is relatively good, but the uniformity of the resistance value is low. Inferiorly, it can be estimated that the gas flow was rough on the outer peripheral side of the rotating substrate holder. Further, it can be predicted that the amount of precipitates is large at the lower part of the reactor, and the maintenance cycle of the reactor is shortened.

On the other hand, even in the case of using a reaction furnace in which the diameters of the upper and lower portions are different from each other as in Comparative Examples 3 to 13, when the outflow of the rectifying gas from the connecting portion is not performed, the same as in the example. In Comparative Example 3 having a diameter ratio of (1), all of the film uniformity, the uniformity of the resistance value, the number of LPDs, and the amount of deposits in the lower part of the reactor are superior to the case of the conventional normal carrier gas flow rate (Comparative Example 14). However, it is clear that it is lower than the embodiment in which the rectifying gas is discharged. Also,
It can be seen that even when the ratio between the diameter of the furnace upper and lower portions and the diameter of the rotating substrate holder is variously changed, good results cannot be obtained as compared with the embodiment. In Comparative Examples 8 and 9 in which the lower diameter was increased three to four times as compared with the upper diameter, a relatively good thin film was formed. However, there were inconveniences such as an excessively large device size. This is not preferable because there are precipitates in the part, the defects in the crystal phase slightly increase, and the maintenance cycle of the reactor is shortened. The height difference between the upper lower end B of the reaction furnace and the upper surface of the rotating substrate holder is 5 mm.
It can be seen that in Comparative Example 12, where the number of LPDs was significantly increased, the number of LPDs was significantly increased, and the defects of the crystal phase, the uniformity of the thin film thickness, and the uniformity of the resistance value were significantly impaired.

Further, according to Comparative Examples 1 and 2, when the flow rate of the rectifying gas from the connecting portion is smaller than the flow rate of the reaction gas using the reactor of the vapor phase thin film growth apparatus of the present invention, , While the resulting thin film is relatively good,
It can be seen that at twice the outflow, the number of LPDs increases remarkably, and there is no precipitate at the connection portion, but the amount of deposition at the lower part of the reactor increases, and the properties of the obtained thin film also decrease. Note that the transition layer thickness T in the above Examples and Comparative Examples is ω by the above equation (1).
= 209 rad / s, v = 6608-8811 mm ² /
The calculated value in which s was introduced was 18 to 21 mm.

[0038]

According to the vapor phase thin film growth apparatus of the present invention, the reactor is divided into an upper part and a lower part with a small-diameter upper part and a large-diameter lower part. And
Since the rising space of the reaction gas is omitted, the upward rising phenomenon of the reaction gas can be prevented. In addition, temperature rise of the reaction gas can be suppressed, uniform nucleation of the source gas is suppressed, and particles generated in the gas phase are reduced. Therefore, a high-quality thin-film-formed wafer substrate can be manufactured because particles that adhere to the reaction furnace wall and shorten the maintenance cycle or particles that adhere to the wafer and cause crystal defects are reduced. In addition, a gas outlet hole is provided at the connection part of the upper and lower joints, and a rectifying gas flows out simultaneously with the reaction gas, stabilizing the gas flow to the exhaust port at the bottom of the reactor, so that the wafer substrate is placed. In addition to preventing the generation of gas vortices on the rotating substrate holder, the reaction gas flow becomes turbulent on the outer peripheral side and the gas flow can be prevented from becoming rough, and the connection part can prevent precipitation at the bottom of the reactor. The maintenance cycle of the reactor can be maintained for a long time. After all, the vapor phase thin film growth by the vapor phase thin film growth apparatus of the present invention maintains the gas flow in the reactor stably without generation of particles, turbulence and drift, and particles on the furnace inner wall. It is possible to obtain a high-quality, uniform-thickness thin-film-formed wafer substrate without crystal defects without adhesion, preventing an increase in particles attached to the wafer, and obtaining a wafer suitable for high integration. .

[Brief description of the drawings]

FIG. 1 is a schematic sectional explanatory view of one embodiment of a vapor phase thin film growth apparatus of the present invention.

FIG. 2 is a schematic sectional view showing a gas flow of another embodiment of the vapor phase thin film growth apparatus of the present invention.

FIG. 3 is a schematic plan view of a connecting portion in the vapor phase thin film growth apparatus of FIG. 2;

FIG. 4 is a schematic cross-sectional view of a connection region in another embodiment of the vapor phase thin film growth apparatus of the present invention.

FIG. 5 is a partially cutaway perspective schematic view of a connecting portion in another embodiment of the vapor phase thin film growth apparatus of the present invention.

FIG. 6 is a schematic plan view of a connecting portion in another embodiment of the vapor phase thin film growth apparatus of the present invention.

FIG. 7 is a schematic sectional explanatory view of a vapor phase thin film growth apparatus used in a comparative example of the present invention.

FIG. 8 is a schematic cross-sectional explanatory view of an example of a conventional vapor phase thin film growth apparatus.

[Explanation of symbols]

10, 20, 70, 80 Reactor 11, 21, 41, 51, 71, 81 Wafer substrate 12, 22, 42 52, 72, 82 Rotating substrate holder 13, 23, 43, 73, 83 Rotating shaft 14, 24 , 44 74, 84 Heater 15, 25, 75, 85 Exhaust port 16, 26, 76, 86 Gas supply port 17, 27, 77, 87 Rectifier plate 17a, 27a, 77a, 87a Rectifier hole 18, 28, 78 Connecting portion 18a, 28a, 78a Rectifying gas outlets 19, 19 ', 29 Rectifying gas introduction space 1, 1' Reactor upper part 2, 2 'Reactor lower part S Space part B Upper lower end U Lower upper end I, I' Rectifying gas inlet D ₁ inner diameter of reactor upper part D ₂ inner diameter of lower reactor DS _S diameter of rotating substrate holder

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shindaira 30 Soya, Hadano-shi, Kanagawa Toshiba Ceramics Co., Ltd. (72) Inventor Tatsuo Fujii 8231-5 Eguchi Kaisaku Tokuyama, Tokuyama City, Tokuyama City, Yamaguchi Prefecture Tokuyama Toshiba Ceramics Co., Ltd. (72) Inventor Katsuyuki Iwata Tokuyama City, Yamaguchi Prefecture Tokuyama, Eguchi Kaisaku 8231-5 Tokuyama Toshiba Ceramics Co., Ltd. (72) Inventor Shinichi Mitani 2068-3 Ooka, Numazu City, Shizuoka Prefecture Toshiba Machine Co., Ltd. Numazu Office (72) Inventor Yasuaki Honda 2068-3 Ooka, Numazu City, Shizuoka Prefecture Toshiba Machine Corporation Numazu Office

Claims (13)

[Claims] 1. A hollow reaction furnace having a plurality of reaction gas supply ports at the top, an exhaust port at the bottom, a rotating substrate holder on which a wafer substrate is placed, and a plurality of holes at the top inside. In a vapor phase growth apparatus having a rectifying plate and supplying a reaction gas to the inside to vapor-grow a thin film on the surface of a wafer substrate on a rotating substrate holder, the hollow interior of the reaction furnace has upper and lower portions having substantially different inner diameters. The upper equivalent diameter is smaller than the lower equivalent diameter, and the upper lower end and the lower upper end are connected by a connecting portion, the hollow interior is continuous, and the connecting portion has a rectifying gas outflow hole, An apparatus for growing a vapor phase thin film, wherein a rotating substrate holder is disposed below a lower end of the upper portion of the lower portion of the reactor with a predetermined height difference. 2. The gas-phase thin film according to claim 1, further comprising a space portion airtightly surrounding the rectifying gas outlet hole on the connecting portion, and having a rectifying gas supply port in the space portion. Growth equipment. 3. The vapor phase thin film growth apparatus according to claim 1, wherein the upper side surface is perpendicular to the upper surface of the rotating substrate holder. 4. The vapor phase thin film forming apparatus according to claim 3, wherein the space portion and the upper portion are formed in a double annular shape, and an outer surface of the space portion is connected to the upper end of the lower portion via a connecting portion. 5. The horizontal cross section of the inside of the reactor hollow is circular, the upper diameter (D ₁ ) is larger than the diameter of the wafer substrate, and the rotating substrate holder is circular and has a diameter (D _S) and the ratio of (D ₁ / D _S) is 0.7 to 1.2
The apparatus for growing a vapor phase thin film according to any one of claims 1 to 4, wherein 6. The vapor phase thin film growth apparatus according to claim 5, wherein a ratio (D ₂ / D ₁ ) between the upper diameter (D ₁ ) and the lower diameter (D ₂ ) is 1.2 or more. 7. The vapor phase thin film of the lower diameter (D ₂₎ and the rotating substrate holder diameter (D _S) and the ratio of (D ₂ / D _S) is according to claim 5 or 6, wherein at least 1.2 Growth equipment. 8. The method according to claim 1, wherein a height difference (H) between the upper and lower ends and the rotating substrate holder is larger than a transition layer thickness (T) of a gas flow on the upper surface of the rotating substrate holder. Or a vapor phase thin film growth apparatus according to any one of the preceding claims. 9. The transition layer thickness (T) is 3.22 (ν /
ω) ^1/2 (where ν represents the kinematic viscosity coefficient (mm ² / s) of the atmosphere gas in the reactor and ω represents the angular velocity of rotation (rad / s), respectively). The vapor phase thin film growth apparatus according to the above. 10. The vapor phase thin film growth apparatus according to claim 1, wherein a part of the connecting portion and an upper surface of the rotating substrate holder are in the same horizontal plane. 11. The vapor-phase growth apparatus according to any one of 1 to 7, wherein a transition layer thickness (T) of a gas flow above the rotary substrate holder is between a lower end of the upper portion and an upper surface of the rotary substrate holder. A reactant gas composed of a thin film forming raw material gas and a carrier gas is supplied from the plurality of reactant gas supply ports so as to be smaller than the height difference (H), and is passed through the holes of the rectifying plate to flow on the wafer substrate. At the same time, a rectifying gas is introduced through the rectifying gas outlet of the connecting portion to introduce a rectifying gas. 12. The transition layer thickness (T) is 3.22 (ν
/ Ω) ^1/2 (where ν is the kinematic viscosity coefficient of the reaction gas (mm ²
/ S), and ω denotes the angular velocity of rotation (rad / s), respectively), and controls the rotation of the rotating substrate holder so as to be smaller than the height difference (H). Growth method. 13. A ratio (G _I / G _C ) of the carrier gas flow rate (G _C ) to the flow rate (G _I ) of the rectification gas introduced from the rectification gas outlet of the connecting portion is 0.05 to 2. The method for growing a vapor phase thin film according to claim 11 or 12.