JP2002016008A - Method and device for vapor phase growth of thin film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve utilization efficiency deposition gases, particularly a gaseous starting material at formation of a thin film on a semiconductor substrate by vapor phase growth, and in addition, to reduce the clogging of an exhaust pipe with an unreacted gaseous starting material by improving the utilization efficiency of the gaseous starting material. SOLUTION: In a vapor phase growth method for the thin film, a reaction furnace in which the space between the internal wall surface of the top section of the furnace and a straightening plate is divided into at least two concentric zones, by using the center of a wafer substrate 3 as a center of effort and gas supply ports 6 and 7 are respectively installed to the zones is used, and of the deposition gases, the gaseous starting material and a dopant-containing gas are made to nearly vertically flow down, from the inner most zone of the concentric zones and only a carrier gas is made to flow down from the outermost zone.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film vapor deposition method and a thin film vapor deposition apparatus, and more particularly, to an excellent utilization of a film forming gas such as a source gas and a dopant gas, and The present invention relates to an improved thin film vapor phase growth method which does not cause inconvenience such as exhaust pipe blockage, and a thin film vapor phase growth apparatus used in the method.

[0002]

2. Description of the Related Art In general, a thin film vapor phase growth apparatus used for a CVD method for vapor phase growth of a thin film on a semiconductor substrate surface is roughly divided into a thin film growth furnace system and a gas supply system. For example, as shown in FIG. 3 as an example of a schematic sectional view of an epitaxial thin film vapor phase growth apparatus, a thin film growth furnace system includes a gas rectifying plate 4, a heater (not shown), and a semiconductor substrate 3 in a quartz chamber 1. It comprises a susceptor 2 to be held and a gas exhaust pipe (not shown). In addition, the susceptor 2 is usually provided with a rotation mechanism, on which the semiconductor substrate 3 to be processed is placed and rotated at a predetermined rotation speed about the center thereof.

The thin film growth furnace system is provided with a plurality of gas supply ports 6 connected to a gas supply system above the quartz chamber 1, and supplies a film forming gas 9 a such as a source gas from the gas supply ports 6. Is done. In thin film vapor phase growth,
A source gas containing a thin film component to be grown and a dopant diluted with a hydrogen gas as a carrier for controlling a specific resistance of a formed thin film are supplied into a thin film growth furnace.

[0004]

By the way, in the thin film vapor deposition using the conventional apparatus as shown in FIG. 3, the source gas supplied from the top of the thin film vapor deposition furnace is smaller than the area of the semiconductor substrate surface. Is also supplied to a wide area, usually the entire furnace. For this reason, the utilization efficiency of the source gas supplied to the outer peripheral portion of the semiconductor substrate is low, which causes a reduction in the utilization efficiency of all the source gases. Unused gas reacts on the inner wall surface of the furnace or in the exhaust pipe to generate particles or block the exhaust pipe.

SUMMARY OF THE INVENTION The present invention has been made to solve the above technical problems, and it is an object of the present invention to improve the utilization efficiency of a film forming gas, in particular, a raw material gas in vapor phase growth of a thin film on a semiconductor substrate. It is an object of the present invention to provide a thin film vapor phase growth method and a thin film vapor phase growth apparatus capable of performing the above. It is another object of the present invention to provide a thin film vapor phase growth method and a thin film vapor phase growth apparatus capable of reducing clogging of an exhaust pipe due to unreacted raw material gas by improving utilization efficiency of a raw material gas.

[0006]

In order to solve the above-mentioned technical problems, a thin film vapor phase growth method comprises a source gas containing a component of a thin film to be grown, and a dopant for controlling the resistivity of the thin film layer. The gas for film formation comprising the gas containing the carrier gas and the carrier gas flows down from a plurality of gas supply ports provided at the top of the cylindrical reactor through a straightening plate, and is mounted on a rotary susceptor provided below. In the method of vapor-phase growing a thin film on the substrate surface by contacting the semiconductor substrate,
As the reaction furnace, a gap between the top inner wall surface and the rectifying plate is divided into at least two sections concentrically with the center point of the wafer substrate as a corresponding center, and a gas supply port is provided in each section. A gas containing a raw material gas and a dopant among the film forming gases is allowed to flow substantially vertically from the innermost section of the concentric section, and the carrier gas is discharged from the outermost section. It is characterized by only flowing down.

Here, the diameter of the innermost section of the concentric section is 0.2D, where D is the diameter of the semiconductor substrate.
It is desirably in the range of １．１1.17D. Further, it is desirable that the difference in the supply amount per unit area of the film-forming gas supplied from each of the sections at each supply portion is 25% or less.

Further, a thin film vapor phase growth apparatus made to solve the above technical problem has a plurality of gas supply ports at the top of a cylindrical reactor, an exhaust port at the bottom, and a rotary for mounting a wafer substrate inside. A gas rectifying plate in the upper part of the inside, a film forming gas composed of a source gas, a dopant gas and a carrier gas is allowed to flow down the furnace from the gas supply port through the rectifying plate, and the lower rotary susceptor In the thin film vapor phase epitaxy apparatus for vapor-phase growing a thin film on a wafer substrate mounted thereon, in the reactor, a gap between a top inner wall and a rectifying plate has a center corresponding to a center point of the mounted wafer substrate by a partition wall. It is characterized in that it is concentrically divided into at least two sections, and a gas supply port is provided in each section.

Here, the diameter of the innermost section of the concentric section is 0.2D, where D is the diameter of the semiconductor substrate.
It is desirably in the range of １．１1.17D. Further, it is desirable that the difference in the supply amount per unit area of the film-forming gas supplied from each of the sections at each supply portion is 25% or less.

Further, the partition extends downward from between the inner wall of the reactor top and the straightening plate further beyond the straightening plate, so that the film forming reaction gas from a different section is not immediately mixed even after flowing out of the straightening plate. It is desirable to be constituted. Furthermore, it is desirable that a means for adjusting and changing the flow rate of the film forming reaction gas be supplied to the gas supply port.

According to the present invention, a film forming gas such as a reaction gas, a dopant gas, and a carrier gas is caused to flow downward from a top of a thin film vapor phase growth furnace toward a semiconductor substrate surface mounted on a rotating susceptor below. In the thin film vapor phase growth in which a predetermined thin film is formed on the substrate surface by the reaction, the film forming gas supply unit at the top of the cylindrical furnace is concentrically divided into two or more sections by, for example, providing partition walls. Then, a reaction gas such as SiH ₄ is supplied from the innermost compartment (central portion), and only the carrier gas flows down from the outermost compartment, so that the reaction gas is used as efficiently as possible for the reaction. In addition, it is characterized in that the unreacted gas remaining in the furnace is reduced as much as possible, thereby suppressing an exhaust pipe system blockage trouble.

That is, in the present invention, a reaction gas containing an active ingredient, for example, SiH ₄ , is substantially vertical from above in the furnace,
It flows down toward the center of the rotating semiconductor substrate surface and collides with the center of the surface. Here, the direction is changed by 90 ° and the peripheral portion is moved from the center of the surface by the centrifugal force to the peripheral portion. And react during this time to form a thin film on the surface.

Therefore, unlike the conventional thin film vapor phase growth apparatus, the reaction gas is not supplied to a wider area than the semiconductor substrate, usually to the whole inside of the furnace, and the utilization efficiency of the source gas can be improved. In addition, it is possible to suppress the occurrence of inconvenience such as the unreacted gas reacting in the lower part of the furnace, the exhaust pipe, or the like, and the reactant adheres to the inner surface of the pipe wall, thereby closing the exhaust pipe or the like.

In particular, when the diameter of the innermost section of the concentric section is D, the diameter of the semiconductor substrate is 0.2D to 0.2D.
It is desirable to be in the range of 1.17D. If the diameter of the innermost section of the concentric section is less than 0.2D, the reaction gas does not spread over the entire surface of the semiconductor substrate, which is not preferable. It is not preferable because it occurs.

Further, it is desirable that the difference in the supply amount per unit area of each film-forming gas supplied from each of the sections at each supply portion is 25% or less. If this difference is too large, the difference between the film forming speeds at each site becomes large, and the film thickness distribution becomes non-uniform. When the difference is 25% or less, the film thickness distribution is also within an allowable range, which is preferable. Desirably, this difference is not more than 10%.

The thin film vapor phase growth apparatus used in the method of the present invention includes a supply amount of a source gas, a supply amount of a dopant gas, and a supply amount of a hydrogen gas supplied from each of two or more divided regions. It is preferable to provide an adjustment changing means for adjusting the supply amount of the carrier gas, whereby a uniform thin film having a desired uniform thickness can be formed on the semiconductor substrate.

In particular, for the above-mentioned reason, when the diameter of the innermost section of the concentric section is D, the diameter of the innermost section is preferably in the range of 0.2D to 1.17D. It is preferable that the difference (variation width) of the supply amount per unit area of each film-forming gas supplied from each of the sections at each supply portion is controllable to 25% or less.

Further, the gas supplied from the different compartments is
The compartments, for example, partitions, are placed between the reactor top inner wall and the rectifying plate so that they are not mixed immediately after the rectifying plate flows out, and desirably do not mix with each other until reaching the vicinity on the semiconductor substrate surface. It is more preferable to further extend downward beyond the current plate. Further, it is desirable that a means for adjusting and changing the flow rate of the film forming reaction gas be supplied to the gas supply port, so that the fluctuation width can be minimized.

The thin-film vapor deposition method of the present invention using the thin-film vapor-phase growth apparatus of the present invention having the above-mentioned structure can be performed under the same conditions as those of the ordinary method, for example, under reduced pressure conditions of about 10 to 500 Torr. The present invention can be suitably applied to a single crystal film forming reaction including the formation of an epitaxial crystal film.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below more specifically with reference to the drawings. FIG. 1 is a schematic view showing a cross-sectional structure of an embodiment of a thin film vapor phase growth apparatus used in the thin film vapor phase growth method of the present invention, and FIG. 2 is a schematic view showing another embodiment.

In the apparatus shown in FIGS. 1 and 2 which is a thin film vapor phase growth apparatus of the present invention, a reaction furnace which constitutes a main part of the apparatus comprises an almost cylindrical chamber 1 usually made of quartz, and a furnace Gas supply ports 6, 7, 8 for supplying a film forming gas such as a source gas, a dopant gas, and a carrier gas therein.
And a rectifying plate 4 having a plurality of through-holes for adjusting the flow of gas, a susceptor 2 having a seat on the top surface on which a semiconductor substrate 3 is mounted, and a susceptor 2 for rotating the susceptor 2. A heating heater (not shown) for heating the rotating shaft 2a and the wafer substrate 3 placed on the seat is provided, and a motor (rotationally driving the rotating shaft 2a) is provided below the chamber 1 (usually near the bottom). (Not shown), an exhaust port (not shown) for exhaust gas containing unreacted gas in the chamber 1 and a control device (not shown) for the exhaust gas.

The feature of the apparatus used in the thin film vapor phase growth method of the present invention is that the gap between the top inner wall of the reactor chamber 1 and the rectifying plate 4 is set to correspond to the center point of the mounted semiconductor substrate 3 by the partition wall 5. It is divided into a plurality of sections concentrically, and gas supply ports 6, 7, 8 and the like are provided in each section, and preferably, at least one of the flow rate and the composition of the film forming reaction gas is adjusted in the gas supply ports. The point is that the means that can be changed and supplied is connected.

In the thin film vapor deposition of the present invention, FIG.
In the case of the apparatus shown in FIG. 2, a gas supply port 6 supplies a source gas containing a component of a thin film to be grown and a gas 9b containing a dopant for controlling the resistivity of the thin film layer.

As an effective component of the source gas, specifically, in the case of forming a silicon (Si) single crystal thin film, silane gas (SiH ₄ ) or dichlorosilane gas (SiH ₂ C
l ₂ ) and the like are used. As the dopant gas, for example, a gas obtained by diluting diborane (B ₂ H ₆ ) or the like with a carrier gas such as hydrogen gas to a concentration of about 50 to 200 ppm is used. Then, the source gas and the dopant gas are rectified by the rectifying plate 4 provided in the innermost partitioned area, flow down almost vertically toward the center of the semiconductor substrate 3 from above, and reach the center of the substrate surface, On the surface of the substrate, it flows while changing its direction in the outer peripheral direction.

At this time, since the semiconductor substrate 3 mounted on the susceptor 2 is rotated together with the susceptor at a rotation speed of usually 500 to 3000 rpm, the source gas and the source gas reaching the center of the substrate surface are removed. The dopant gas flows along the surface of the semiconductor substrate while being uniformly diffused in the outer peripheral direction by the centrifugal force, and forms a thin film layer on the surface by the reaction.

On the other hand, a carrier gas 10 such as hydrogen gas is supplied from gas supply ports 7 and 8, and the gas is similarly rectified by rectifying plates 4 provided in the corresponding sections, and the wafer is supplied from above. It flows down toward the outer peripheral portion of the substrate and its outer side.

In the thin film vapor phase growth apparatus of the present invention, as shown in FIGS. 1 and 2, the partition wall 5 extends downward from the space between the inner wall of the reactor top and the straightening plate further beyond the straightening plate 4. It is particularly preferable to provide the portion 5a. In particular, in the embodiment shown in FIG. 2, gases from different compartments, that is, each film-forming gas having a different component supplied from the supply port 6 and the supply ports 7 and 8 are supplied immediately after flowing out of the current plate 4. Are never mixed. Therefore, when forming a thin film, not only an excellent effect of uniformizing the film thickness and the in-plane resistivity is obtained, but also the turbulence of the gas flow hanging down in the furnace is suppressed, and as a result, particle generation can be reduced. It also has advantages.

In the present invention, when the diameter of the innermost partitioned area is D, where D is the diameter of the semiconductor substrate to be processed.
2D to 1.17D, more preferably 0.2 to
It is preferable to be in the range of 0.5D from the viewpoint of improving the effective utilization of the raw material gas and the like. When the diameter of the innermost section of the concentric section is less than 0.2D, the reaction gas does not spread over the entire surface of the semiconductor substrate, which is not preferable.
If it exceeds D, it is not preferable because unused reaction gas is generated.

Further, in the thin film vapor phase growth apparatus of the present invention, the partitioning area can be changed by exchanging the partition walls. It is more preferable from the viewpoint that optimum film forming conditions can be appropriately set in accordance with various desired requirements such as a type of a thin film, a desired film thickness, and desired formed film characteristics.

Further, the adjusting and changing means for adjusting the supply amount of the source gas supplied from the two or more divided supply ports, the adjusting and changing means for adjusting the supply amount of the dopant gas, and the supply amount of the carrier gas such as hydrogen gas. It is more preferable to provide an adjustment changing means for adjusting, so that a more uniform thin film having a more uniform thickness can be formed on the semiconductor substrate. In particular, the difference (variation width) of the supply amount per unit area of the film formation gas supplied from each of the sections at each supply portion is adjusted by the adjustment changing means for adjusting the supply amount of each film formation gas. It is preferable to control it to 25% or less.

In the method of the present invention, the substrate used for forming the thin film is typically a silicon wafer, but a semiconductor substrate other than silicon, such as a silicon carbide substrate, can also be used. Furthermore, the thin film formed on the semiconductor substrate is most commonly a silicon film, but other thin films, for example, GaAs
An s film or the like may be used, and the thin film may be applied to any of a single crystal film, a polycrystalline film, and an epitaxial crystal film without any trouble. As a film forming gas used in the vapor phase growth in the present invention, a film forming gas used for forming a thin film by a normal CVD thin film growth method can be used without particular limitation. As such a film forming gas, for example, In the case of forming a silicon thin film, a film forming reaction gas composed of a source gas containing a silicon component, a dopant, and a carrier gas can be used.

The silicon component of the source gas is Si
H ₄ , Si ₂ H ₆ , SiHCl ₃ , SiCl ₄ , and the like can be exemplified. As the dopant gas, a boron compound of B ₂ H ₆ , a phosphorus compound of PH ₃ , and AsH ₃ can be exemplified.
In addition, a hydrogen gas Ar or the like is generally used as a carrier gas. The thin film vapor phase growth method of the present invention using the thin film vapor phase growth apparatus of the present invention configured as described above can be suitably applied to the same conditions as ordinary methods, for example, under reduced pressure conditions of about 10 to 500 Torr. it can.

[0033]

[Example 1] A gas supply port 6 (innermost section: inner diameter D350m) using the thin film vapor phase growth apparatus shown in FIG.
m) to 50 liter / min of film forming gas (source gas; S
iH ₄ 1.5 l / min, dopant: B ₂ H ₆
0.4 ppb, the remaining carrier gas: H ₂ ), and the carrier gas (H ₂ ) 2 from the gas supply port 8 (intermediate section).
4 liter / min and carrier gas (H ₂ ) 30 liter / min were supplied from the gas supply port 7 (outermost section). At this time, the flow velocity in the innermost section (flow velocity immediately below the current plate 4) is 0.052 liter / cm ² · mi.
n, the flow velocity in the middle section (flow velocity just below the current plate 4)
Was 0.057 l / cm ² · min, and the flow rate in the outermost section (flow rate immediately below the current plate 4) was 0.052 l / cm ² · min. In addition, vapor phase growth temperature 1
The operation of growing a thin film on a silicon wafer substrate having a diameter of 300 mm was repeated (about 3000 times, for a period of 3 months) under the operating conditions of 000 ° C., a vapor growth pressure of 20 torr, and a holder rotation speed of 1500 rpm. During this period, the average film forming rate, the raw material gas use efficiency, and the number of maintenance times were measured and recorded. Table 1 shows the obtained results.

The average film forming speed (μm / min) is
It is obtained by measuring the film thickness in the wafer surface, obtaining an average, and dividing the average value by the film formation time. Further, in order to obtain the source gas utilization efficiency, first, the deposition rate is obtained by the following equation. Deposition rate (μm ³ / min) = wafer area (mm ² )
/ 10 ⁻⁶ × film formation (growth) rate (μm / min) The deposition rate determined from this equation is expressed in units (mol / mi).
n) Convert and calculate the source gas utilization efficiency from the following equation. Source gas utilization efficiency = unit of deposition rate (mol / mi)
n) / Amount of raw material gas used (mol / min) × 100 Further, the number of maintenance means the number of times of decomposition and cleaning in the furnace, and maintenance is required when the exhaust pressure falls outside the control value due to deposits. And the number was counted.

Embodiment 2 and Embodiment 4 In Embodiment 1, except that the flow rate of each gas supplied from the gas supply ports 6, 8, and 7 (see FIG. 1) was changed to the values shown in Table 1. A thin film growth operation was performed in the same manner as in Example 1, and evaluation was performed in the same manner as in Example 1. Table 1 shows the results. At this time,
The flow rate of the innermost section (flow rate immediately below the current plate 4) in Example 2 was 0.051 liter / cm ² · min,
The flow velocity in the middle section (flow velocity immediately below the current plate 4) is 0.05
1 liter / cm ² · min, and the flow rate in the outermost section (flow rate immediately below the current plate 4) is 0.051 liter / cm.
It was ² min.

Similarly, the flow rate in the innermost section (flow rate immediately below the current plate 4) in Example 3 is 0.064 liter / c.
m ² · min, the flow rate in the middle section (flow rate immediately below the current plate 4) is 0.045 liter / cm ² · min, and the flow rate in the outermost section (flow rate immediately below the current plate 4) is 0. .
It was 050 liter / cm ² · min. In Example 4, the flow rate in the innermost section (flow rate immediately below the flow straightening plate 4) was 0.035 liter / cm ² · min, and the flow rate in the middle section (flow rate immediately below the flow straightening plate 4) was 0. 015
Liter / cm ² · min, and the flow rate in the outermost section (flow rate immediately below the current plate 4) is 0.036 liter / cm 2
It was ² min.

REFERENCE EXAMPLE 1 The same procedures as in Reference Example 1 were carried out except that the flow rates of the respective gases supplied from the gas supply ports 6, 8, and 7 (see FIG. 1) were changed to the values shown in Table 2. A thin film growth operation was performed in the same manner, and evaluation was performed in the same manner as in Example 1. Table 2 shows the results. At this time, the flow velocity in the innermost section (the flow velocity immediately below the current plate 4) in Reference Example 1 is 0.5.
142 liters / cm ² · min, and the flow rate in the middle section (flow rate immediately below the current plate 4) is 0.028 liters / cm ² · min.
cm ² · min, and the flow rate in the outermost section (flow rate immediately below the current plate 4) was 0.027 liter / cm ² · min.

[Comparative Example 1 and Comparative Example 2] The conventional thin film growth apparatus (Comparative Example 1) shown in FIG. 3 has an inner diameter of a gas supply port 6 of 450 mm as shown in FIG. Each of the thin film growth apparatuses (Comparative Example 2) was used, and a gas having a flow rate described in the column of Comparative Example 1 and Comparative Example 2 of Table 1 was supplied from the supply port under the same conditions as in Example 1. A thin film growth reaction was performed. Table 2 shows the results. At this time, the flow velocity of the innermost section (the flow rate immediately below the current plate 4) in Comparative Example 1 was 0.051 liter / cm ² · min, and the flow rate of the innermost section (the current plate 4 Was just 0.050 liter / cm ² · min, and the flow rate of the outermost section (the flow rate just below the current plate 4) was 0.054 liter / cm ² · min.

[0039]

[Table 1]

[0040]

[Table 2]

From Tables 1 and 2, it was confirmed that the raw material gas utilization in Examples 1 to 4 and Reference Example 1 was improved as compared with the comparative example using the conventional apparatus. In particular, in the innermost section area, when the diameter of the wafer to be processed is D,
It was recognized that it was preferable to be in the range of 0.2D to 1.17D (Examples 1 to 4) from the viewpoint of improving the effective utilization of the raw material gas and the like. Further, in consideration of the film forming rate, it was recognized that the diameter is preferably in the range of 0.2D to 0.5D when the diameter of the wafer is D as in Examples 3 and 4.

Example 4 Next, based on the conditions of Example 2, variations in the flow velocity of the gas supplied from each gas supply section (flow velocity distribution) and variations in the thickness of the formed film (thickness distribution). And examined the relationship. The supply amounts of the respective gases are as shown in Table 3, and the flow rates of the respective sections in Example 2 and Reference Example 1 at this time are as described above. In Reference Example 2, the flow rate in the innermost section (flow rate immediately below the current plate 4) was 0.051 liter / cm ² · min, and the flow rate in the middle section (flow rate immediately below the current plate 4) was 0. 0.051 liter / cm ² · min, and the flow rate in the outermost section (flow rate immediately below the current plate 4) is 0.051 liter / cm ² · mi.
n.

Similarly, in Reference Example 3, the flow rate in the innermost section (flow rate immediately below the current plate 4) was 0.051 liter /
cm ² · min, the flow rate in the middle section (flow rate immediately below the current plate 4) is 0.047 liter / cm ² · min, and the flow rate in the outermost section (flow rate immediately below the current plate 4) is 0. 0.038 liter / cm ² · min. Also,
In Reference Example 4, the flow rate in the innermost section (flow rate immediately below the current plate 4) was 0.0510 liter / cm ² · min, and the flow rate in the middle section (flow rate immediately below the current plate 4) was 0.
0679 l / cm ² · min, and the flow rate in the outermost section (flow rate immediately below the current plate 4) was 0.0400 l / cm ² · min. The film thickness was measured by an apparatus using a Fourier transform infrared spectrometer (FTIR).

From the obtained measurement results, the gas flow velocity distribution and the film thickness distribution were calculated based on the following equations (1) and (2). Gas flow rate distribution = (Maximum value of each section gas flow rate−Minimum value) / (Maximum value of each section gas flow rate + Minimum value) × 100 (1) Film thickness distribution = (Maximum value of film thickness−Minimum value of film thickness) / ( (Film thickness maximum value + film thickness minimum value) (2) The results are shown in Table 3.

[0045]

[Table 3]

From Example 2, Reference Example 2, and Reference Example 3 in Table 3, it is recognized that a good uniform film can be obtained when there is no flow velocity distribution (variation) of the supplied gas. As shown in Reference Examples 1 and 4, when the flow rate distribution of scum exceeds 25%, the film thickness distribution exceeds 5% (standard value), and is regarded as defective. Therefore, the gas flow rate portion is preferably 25% or less.

[0047]

As described in detail above, the source gas and the raw material gas are used by using a thin film vapor phase growth apparatus having a structure in which two or more sections are concentrically divided and a gas supply port is provided in each section. By causing the gas containing the dopant to flow almost vertically from the innermost section of the concentric section toward the center of the surface of the semiconductor substrate to be processed, and from the outermost section to flow only the carrier gas, the source gas The utilization efficiency can be remarkably improved and troubles such as clogging of an exhaust pipe can be reduced due to a decrease in unreacted gas.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a cross-sectional structure of one embodiment of a thin film vapor phase growth apparatus used in a thin film vapor phase growth method of the present invention.

FIG. 2 is a schematic diagram showing a cross-sectional structure of another embodiment of a thin film vapor phase growth apparatus used in the thin film vapor phase growth method of the present invention.

FIG. 3 is a schematic view showing a cross-sectional structure of a conventional thin film vapor deposition apparatus.

FIG. 4 is a schematic sectional view showing a thin film vapor phase growth apparatus used in Comparative Example 2.

[Explanation of symbols]

 Reference Signs List 1 chamber 2 susceptor 3 semiconductor substrate 4 gas rectifying plate 5 partition 6 gas supply port 7 gas supply port 8 gas supply port 9a deposition gas 9b source gas and dopant gas 10 carrier gas

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tadashi Ohashi, 30 Soya, Hadano-shi, Kanagawa Toshiba Ceramics Co., Ltd. (72) Inventor Katsuyuki Iwata 30 Soya, Hadano-shi, Kanagawa Toshiba Ceramics Co., Ltd. In-house (72) Inventor Shinichi Mitani 2068-3 Ooka Numazu-shi, Shizuoka Toshiba Machine Co., Ltd. (72) Inventor Kunihiko Suzuki 2068-3 Ooka, Numazu-shi, Shizuoka Toshiba Machine Co., Ltd. (72) Inventor Hidenori Takahashi Shizuoka 2068-3 Ooka, Numazu-shi F-term (reference) 4K030 AA06 AA17 BA29 CA04 EA03 FA10 GA06 JA01 JA05 KA05 LA15 5F045 AA06 AB02 AB10 AC01 AC05 AF02 AF03 BB02 BB10 BB15 DP03 DP28 DQ04 EE17 EE20 EF15

Claims (7)

[Claims] A film forming gas comprising a source gas containing a component of a thin film to be grown, a gas containing a dopant for controlling the resistivity of a thin film layer, and a carrier gas is provided at the top of a cylindrical reactor. A method of causing a thin film to flow down from a plurality of gas supply ports through a rectifying plate and contacting a semiconductor substrate mounted on a rotary susceptor provided below to vapor-phase grow a thin film on the substrate surface. As a reaction furnace, the gap between the top inner wall surface and the rectifying plate is divided into at least two sections concentrically with the center point of the wafer substrate described above as a corresponding center, and a gas supply port is provided in each section. Of the film forming gas, a gas containing a source gas and a dopant is allowed to flow almost vertically from the innermost section of the concentric section, and only the carrier gas flows from the outermost section. Let down Thin film vapor-phase growth method, characterized in that. 2. The diameter of the innermost section of the concentric section is:
When the diameter of the semiconductor substrate is D, 0.2D-1.
The method of claim 1, wherein the thickness is in the range of 17D. 3. The difference between the supply amount of each film-forming gas supplied from each of the sections and the supply amount per unit area at each supply portion is 25% or less. 3. The thin film vapor phase growth method according to item 1. 4. A source gas, a dopant gas, comprising a plurality of gas supply ports at the top of a cylindrical reactor, an exhaust port at the bottom, a rotary susceptor for mounting a wafer substrate inside, and a gas rectifying plate at the top inside. And a film forming gas comprising a carrier gas flowing down the furnace from the gas supply port via a flow straightening plate, and vapor-phase growing a thin film on a wafer substrate mounted on a rotary susceptor below. In the apparatus, the reaction furnace may be divided into at least two sections in a concentric circle having a center corresponding to a center point of the wafer substrate, wherein a gap between a top inner wall and a rectifying plate is separated by a partition, and a gas supply port is provided for each section. A thin film vapor phase growth apparatus, wherein: 5. The diameter of the innermost section of the concentric section is:
When the diameter of the semiconductor substrate is D, 0.2D-1.
The apparatus according to claim 3, wherein the apparatus is in a range of 17D. 6. The difference in the supply amount per unit area of each film-forming gas supplied from each of the sections at each supply portion is 25% or less. 3. The thin-film vapor deposition apparatus according to item 1. 7. The partition wall extends downward from between the inner wall of the reactor top and the straightening plate further beyond the straightening plate, so that the film forming reaction gas from a different section is not immediately mixed even after flowing out of the straightening plate. 7. The thin-film vapor deposition apparatus according to claim 4, wherein the apparatus is configured as follows.