JP3485285B2 - Vapor phase growth method and vapor phase growth apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vapor phase growth apparatus, and more particularly to a group III-nitrogen compound semiconductor vapor phase growth apparatus.

[0002]

2. Description of the Related Art In recent years, studies have been conducted on blue light emitting devices using II-VI group, SiC, and gallium nitride compound semiconductors as constituent materials. Among such constituent materials, gallium nitride compound semiconductor is
Recently, it has been announced that it exhibits excellent emission characteristics at room temperature, a blue LED using the same has been developed, and a blue laser has also been developed.

By the way, the current growth method of gallium nitride-based compound semiconductors is mainly vapor phase growth methods such as MOCVD and MBE. However, gallium nitride-based compound semiconductors have an extremely high equilibrium vapor pressure of nitrogen as a constituent element. , Nitrogen vacancies are likely to occur in the growth in an ultrahigh vacuum. Therefore, at the present time, research and development are actively conducted because MOCVD growth is relatively easy to obtain a high-quality crystal than MBE.

For example, Japanese Patent Application Laid-Open No. 60-207332 discloses a crystal growth method for growing a gallium nitride crystal as a constituent material of a blue light emitting element.

In the method disclosed in this publication, the growth of the GaN crystal is divided into a first stage and a second stage. That is, in the first step, the GaN crystal is grown by the MOCVD method in which the stress at the film-forming interface is small, and in the second step, the GaN crystal is grown by the CVD method that can obtain good crystallinity. In the first step by the MOCVD method, a vertical reaction furnace is used to flow a film forming gas in a direction perpendicular to the substrate surface with respect to the substrate placed on the susceptor,
Further, in the second step by the CVD method, a horizontal reaction furnace in which a film forming gas is caused to flow in a direction parallel to the surface of the substrate is used. In each of the reaction furnaces, the group III organic metal and the nitrogen hydride compound raw material are adapted to be supplied from separate gas introduction paths, and particularly in the vertical reactor, the group III organic metal gas outlet is provided. Independently, an outlet for the gas raw material of the hydrogenated compound of nitrogen is provided.

Japanese Unexamined Patent Publication (Kokai) No. 4-238890 discloses a group III-nitrogen compound semiconductor MOCVD growth method in which a group III organometallic gas and a nitrogen hydride compound gas are provided respectively. There is disclosed a method in which a vapor phase growth apparatus in which the both gas introduction paths are joined immediately before the reaction tube is used and the both film forming gases are alternately supplied to the reaction chamber.

As described above, in MOCVD growth of the group III-nitrogen compound semiconductors disclosed in the above publications, in order to avoid a gas phase reaction between the group III organic metal and the hydrogenated compound of nitrogen, a hydrogenated compound of the group III organic metal and nitrogen is avoided. A method of separating and supplying the raw material is adopted.

However, in both the methods disclosed in the above publications, since the vertical furnace is used as the MOCVD growth apparatus, the source gas and the carrier gas flow in a direction perpendicular to the substrate surface, and the gas collides with the substrate. Due to the turbulence of the gas flow due to, there is a problem that a large-area homogeneous film cannot be obtained.

Therefore, as a solution to such a problem in the vertical reaction furnace, there is provided a MOCVD apparatus having a horizontal reaction furnace configured to flow a film forming gas in the reaction chamber in a direction substantially parallel to the surface of the substrate. Has already been developed.

FIG. 4 shows a MOC having a conventional horizontal reactor.
It is a figure for explaining a VD device, and Drawing 4 (a) is a figure showing the structure typically. In the figure, 201 is M
The OCVD apparatus has a quartz reaction tube 1 configured to flow a source gas in a direction substantially parallel to the substrate surface. The peripheral wall of the reaction tube 1 parallel to the longitudinal direction has a double structure, and the reaction tube 1 can be cooled by cooling water. Further, a high frequency induction heating coil 2 is attached around the reaction tube 1, and a carbon susceptor for mounting a substrate 4 inside the reaction tube 1 corresponding to the high frequency induction heating coil 2. 3 is provided.

The opening at the gas introduction side end and the opening at the gas discharge side end of the reaction tube 1 are each provided with a flange 8
a, 8b, and three gas introduction pipes 5, 6, 7 are provided on the gas introduction side end flange 8a.
a is penetrated and attached, and each gas introduction pipe 5,
The gas outlets 5a, 6a, and 7a of 6 and 7 are located in the vicinity of the substrate placed on the susceptor 4 so as to be distant from the substrate surface in the vertical direction in this order. Here, the width W of the substrate 4 is 50 mm, and the distance D in the longitudinal direction of the reaction tube from the outlet of each gas introduction pipe to the substrate is 30 mm.

Here, the hydrogen compound of nitrogen is supplied from the gas introducing pipe 5, the organometallic gas is supplied from the gas introducing pipe 6, and the mixed gas of hydrogen and nitrogen is supplied from the gas introducing pipe 7. There is.

Further, a gas discharge opening 9 is formed near the gas discharge side end of the peripheral wall of the reaction tube 1.

In the MOCVD apparatus 201 having such a structure, the film-forming gas supplied from each gas introduction tube flows along the surface of the substrate 1 placed on the susceptor 3, and therefore the substrate surface. There is almost no disturbance of the gas flow due to collision with.

FIG. 4B shows an M having the horizontal reaction tube.
When the GaN film is grown on the substrate by the OCVD device 201, the film forming rate (μm / h) at each portion on the substrate is shown in a graph, the vertical axis indicates the film forming rate, and the horizontal axis indicates the substrate surface. The distance from the end of the gas introduction pipe on the outlet side is taken. From FIG. 4B, it can be seen that the GaN film hardly grows in the portion directly below the outlet of the substrate, and the amount of the group III organic metal that contributes to the growth is small, resulting in a poor raw material yield. .

FIG. 5 shows an MOC having a horizontal reaction tube.
5 is a diagram for explaining another configuration example of the VD device, and FIG.
(A) schematically shows the cross-sectional structure. In the figure, 202 is an MOCVD apparatus having a quartz reaction tube 1 configured to flow a source gas in a direction substantially parallel to the surface of the substrate. This apparatus is the hydride compound in the MOCVD apparatus 201 shown in FIG. Gas introduction pipe 5 for supplying gas and gas introduction pipe 6 for supplying organometallic compound gas
It is the reverse of the upper and lower layout relationship. That is, in the reaction tube 1 of this MOCVD apparatus 202, the gas introduction pipe 5 for introducing the hydrogen compound of nitrogen is located above the gas introduction pipe 6 for introducing the organic metal, and its gas outlet 5a. Also, the upper and lower relations of 6a and 6a are the same as those in the MOCVD.
It is the opposite of device 201.

FIG. 5B shows the film forming rate (μ) at each portion on the substrate when the GaN film is grown on the substrate by the MOCVD apparatus 202 with the same coordinates as FIG. 4B.
m / h) is shown in the graph, and it can be seen from this figure that the growth of GaN is concentrated in the portion directly below the outlet of the substrate.

[0018]

As described above, the conventional techniques have the following problems.

That is, in both of the methods disclosed in the above publications, the vertical furnace is used as the MOCVD growth apparatus, so that the direction in which the source gas and the carrier gas flow is perpendicular to the substrate surface, and the gas collides with the substrate. Due to the turbulence of the gas flow due to, there is a problem that a large-area homogeneous film cannot be obtained.

The diffusion constant of the group III organic metal for hydrogenated compounds of nitrogen is extremely smaller than the diffusion constant of group III organic metal for hydrogen. Further, in the MOCVD growth of the group III-nitrogen compound semiconductor, a normal GaAs MOC is used.
The V / III ratio is as large as 10 times or more as compared with the VD growth, and the poor mixing of the group III organic metal and the nitrogen hydride compound greatly affects the crystallinity, composition and uniformity of the group III-nitrogen compound semiconductor.

Therefore, MOCVD having a horizontal reaction tube
Also in the apparatus, there is a problem that a uniform film thickness cannot be formed with a configuration in which a blowout port for the group III organometallic gas and a blowout port for the nitrogen hydride compound gas are separately provided.

That is, as shown in FIG. 4 (a), the blowing port 5a for the hydrogenated compound gas of nitrogen is set at a low position on the surface of the susceptor so as to be close to the substrate, and the blowing port 6a for the group III organometallic gas is placed. When GaN is placed at a high position on the surface of the susceptor far from the substrate, as shown in FIG. 4 (b), GaN hardly grows directly under the blowing port, and the amount of group III organic metal contributing to the growth is small. However, the yield of raw materials will deteriorate.

On the other hand, as shown in FIG. 5A, the blowing port 6a for the group III organometallic gas is installed at a low position on the surface of the susceptor so as to be close to the substrate, and the blowing port 5a for the hydrogenated compound gas of nitrogen is formed. When GaN is placed at a high position on the surface of the susceptor far from the substrate, GaN grows as shown in FIG.
As shown in (b), it will be concentrated on the portion directly below the outlet of the substrate.

Therefore, no matter whether the growth apparatus of the MOCVD apparatus having the vertical reaction tube or the MOCVD apparatus having the horizontal reaction tube is used, a large-area GaN having a uniform film thickness is used.
There is a problem that it is extremely difficult to obtain a film.

In the MOCVD apparatus, the susceptor on which the substrate is placed is configured to be rotatable, and the substrate is rotated at the time of film formation to make the film thickness and composition uniform.
In the growth of the GaN film, the group III organometallic gas and the nitrogen hydride compound source gas are blown out from different gas outlets, and the growth of the GaN film is performed at a high temperature of 1000 ° C. or higher. Therefore, the variation in film thickness is Ga
There is a problem in that it is extremely large compared to the As system, and it is quite difficult to obtain a large-area GaN film with a uniform film thickness only by rotation.

The present invention has been made to solve the above problems, and has a large area with a uniform film thickness and mixed crystal ratio.
An object is to obtain a vapor phase growth apparatus capable of forming a Group III-nitrogen compound semiconductor thin film.

[0027]

Therefore, the inventor of the present invention,
In order to obtain a group III-nitrogen compound semiconductor crystal having a larger area than that of the conventional group III-nitrogen compound semiconductor crystal by a vapor phase growth method using a group III organometallic compound and a hydrogenated compound of nitrogen as raw materials,
Diffusion constants of Group II organometallic compounds with respect to hydrogenated compounds of nitrogen were measured, and various reactor shapes based on the constants were measured.
Regarding the gas outlet position and flow rate, we performed a flow simulation considering the chemical reaction and derived the optimum value.
The following invention was completed by actually performing crystal growth and determining the optimum value of the conditions.

The vapor phase growth apparatus according to the present invention (Claim 1) has a reaction chamber having a mounting portion for mounting a substrate therein, and the organometallic compound gas introduced into the reaction chamber. And a hydride compound gas to vapor-deposit a compound semiconductor film on the surface of a substrate mounted on the mounting portion. The reaction chamber has two or more first outlets that are independently provided in the reaction chamber and blow out the organometallic compound gas as a raw material gas, and the individual first chambers in the reaction chamber. And one or a plurality of second blowout ports that blow out the hydride compound gas as a raw material gas, provided independently of the blowout ports, and the raw material gas blown out from each of the blowout ports The structure is such that it flows substantially parallel to the surface of the substrate above the parts. In addition, the number of first and second outlets provided inside the reaction chamber is 6 or less. Thereby, the above object is achieved.

According to the present invention (claim 2), in the vapor phase growth apparatus according to claim 1, the reaction chamber is defined by the substrate mounting surface of the mounting part of the first and second blowing ports. Is provided on the upper side of the blowout port farthest from the plane including, and has a blowout port for blowing out nitrogen gas or hydrogen gas, or a mixed gas of nitrogen gas and hydrogen gas.

According to the present invention (claim 3), in the vapor phase growth apparatus according to claim 1, the organometallic compound gas is used.
An organometallic compound of Group III element is supplied into the reaction chamber.

According to a fourth aspect of the present invention, in the vapor phase growth apparatus according to the first aspect, a hydride compound of nitrogen as the hydride compound gas is supplied into the reaction chamber.

The operation of the present invention will be described below.

In the present invention (claim 1), the organometallic compound gas outlet and the nitrogen hydride compound gas outlet are provided independently, so that the organometallic compound gas and the hydride compound gas are provided. The gas phase reaction with can be avoided.

Further, since the source gas blown out from each of the outlets flows in the reaction chamber substantially in parallel to the surface of the substrate placed on the substrate placing portion, the source gas and the carrier gas It is possible to prevent the gas flow from being disturbed due to the gas hitting the substrate.

Further, since two or more organometallic compound gas outlets are independently provided in the reaction chamber, the organometallic compound gas reaching the substrate surface is dispersed, and the film formation on the substrate surface. Will be performed more uniformly. Therefore, a group III-nitrogen compound semiconductor crystal having a large area and a uniform film thickness can be obtained by optimizing the concentration of raw materials and the flow rate.

In the present invention (claim 2), the reaction chamber is defined by a blowout port farthest from the plane including the substrate mounting surface of the mounting portion of the first and second blowout ports. Since it is provided on the upper side and has a blowout port for blowing out nitrogen gas, hydrogen gas, or a mixed gas thereof as a barrier gas, it is possible to prevent the upper part of the reaction chamber from being contaminated by the barrier gas.

In the present invention (claim 3), a compound semiconductor containing a group III element can be grown on the substrate by supplying an organometallic compound of the group III element as the organometallic compound gas into the reaction chamber. it can.

In the present invention (claim 4), a compound semiconductor containing nitrogen can be grown on the substrate by supplying a hydrogenated compound of nitrogen as the hydride compound gas into the reaction chamber.

[0039]

DETAILED DESCRIPTION OF THE INVENTION

(Embodiment 1) FIG. 1 shows a second embodiment II of the present invention.
It is a figure which shows notionally the vapor-phase growth apparatus of a group I-nitrogen compound semiconductor crystal. In the figure, the same reference numerals as those in FIG.
From the group III element organometallic compound gas and nitrogen hydride compound gas introduced into the reaction tube 1,
This is a vapor phase growth apparatus for vapor-depositing a group III-nitrogen compound semiconductor film on the surface of a substrate 4 placed thereon.

In addition to the structure of the conventional vapor phase epitaxy apparatus 202 shown in FIG. 5A, the vapor phase epitaxy apparatus 100 according to the first embodiment includes the above organometallic compound gas (hereinafter referred to as the first organometallic compound). Gas introduction pipe (hereinafter referred to as gas)
This is called the first MO gas introduction pipe. ) 6 independent, second
Is provided with a second MO gas introduction pipe 26 for introducing the organometallic compound gas, and the gas ejection port 26a thereof has a blowout port 5a of the gas introduction pipe 5 for introducing the hydrogenated compound gas of nitrogen, It is arranged at a height position between the gas inlet pipe 7 and the outlet 7a for introducing the mixed gas of hydrogen and nitrogen. That is, in this vapor phase growth apparatus 100,
The source gas outlets are arranged in the order of a first organometallic compound gas outlet 6a, an ammonia gas outlet 5a, and a second organometallic compound gas outlet 26a in the height direction from the substrate. Has been done. Further, a barrier gas (a mixture of hydrogen and nitrogen) outlet 7a for preventing the contamination of the upper portion of the inner surface of the growing reaction tube is disposed above the outlet 26a. Here, each of the outlets is separated from the edge of the substrate by 30 mm in the horizontal direction (left and right direction on the paper), and the outlet 6a closest to the substrate and the substrate are 4 mm in the vertical direction (vertical direction on the paper).
Installed separately, each outlet is 4mm from each other
They are located vertically apart from each other. As the barrier gas, hydrogen gas or nitrogen gas may be used alone instead of the mixed gas of nitrogen gas and hydrogen gas.

Next, GaN is formed by the vapor phase growth apparatus 100.
A method for growing a film will be described.

First, trimethylgallium (hereinafter referred to as TMG) was used as an organometallic compound gas, and a GaN buffer layer was grown to a thickness of 30 mm on a sapphire (0001 plane) 2-inch substrate at a substrate temperature of 550 ° C., and then the substrate temperature was set to 1100. C., and a GaN film was grown to 4 .mu.m.

Here, the growth of GaN is performed under normal pressure, and the supply amount of the first organometallic compound gas blown out from the blow-out port 6a is 1 with H2 gas as a carrier gas.
6 μmol / min. And the flow velocity is 3.5 m / se
c. In addition, the second blown out from the outlet 26a
The supply amount of the organometallic compound gas is 40 μmol / min. And the flow velocity was 3.5 m / sec. As the ammonia gas, the ratio of the supply amount (H2: NH3 = 0.65: 0.3
The mixed gas of 5) was used and the flow rate was 2.3 m / sec. The above growth was performed without rotating the substrate.

When X-ray diffraction measurement was performed on the obtained GaN film, the full width at half maximum of the rocking curve (Δω: swing width of X-ray) was about 5 min. It was found that a small and good crystalline film was obtained. The full width at half maximum of the rocking curve is about 5 min. Met. It was also confirmed that strong band edge emission was obtained at room temperature in photoluminescence measurement (hereinafter abbreviated as PL measurement), and that a favorable GaN film was obtained in PL measurement.

Finally, the substrate on which the GaN film was grown was cut, and the film thickness distribution of the GaN film obtained by cross-section SEM was measured. The result is shown in FIG.

Here, the position 0 mm indicates the position on the most upstream side of the substrate, and in the direction perpendicular to the flow (in the horizontal plane), the center of the substrate was set as the reference position (0 mm), and the measurement was performed at the reference position. FIG. 1C shows the GaN film thickness distribution in the direction perpendicular to the flow.

From these results, the thickness of 4
GaN film grown to μm (deposition time 4 hours) is 2 in
The film thickness distribution on the ch substrate is within ± 2%, which shows that the GaN film is extremely uniform.

As described above, in the first embodiment, the raw material gas is blown out from the substrate in the height direction by the first organometallic compound gas blowing port 6a, the hydride compound gas blowing port 5a, Since the second metal-organic compound gas outlet 26a and the barrier gas outlet 7a are arranged in this order, the nitrogen hydride compound source outlet 5a is located close to the substrate as in the conventional vapor phase growth apparatus 201. Ga on the substrate obtained when the blowout port 6a of the group III organometallic gas is arranged at a position far from the substrate.
When the film thickness distribution of the N film and the height positions of the nitrogen hydride compound gas outlet and the group III organic metal outlet like the vapor phase growth apparatus 202 are reversed from those of the vapor phase growth apparatus 201. A film thickness distribution obtained by superimposing the film thickness distribution of GaN obtained in the above is obtained.

Thus, by optimizing the concentration of raw materials and the flow rate, a large-area group III-nitrogen compound semiconductor crystal having a uniform film thickness can be obtained.

Further, an organometallic compound gas outlet 6
Since a and 26a are independently provided with the nitrogen hydride compound gas outlet 5a, the gas phase reaction between the organometallic compound gas and the hydride compound gas can be avoided.

Further, since the source gas blown out from each of the outlets flows in the reaction chamber substantially in parallel with the surface of the substrate placed on the substrate placing part, the source gas and the carrier gas It is possible to prevent the gas flow from being disturbed due to the gas hitting the substrate.

Further, since the outlet port 7a for blowing out the barrier gas is provided further above the uppermost one 26a of the source gas outlet port, it is possible to prevent the upper part of the reaction chamber from being contaminated.

(Second Embodiment) Next, a second embodiment of the present invention will be described.

In the second embodiment, TMG is used as the organometallic compound gas by the vapor phase growth apparatus 100 shown in FIG.
And trimethylaluminum (hereinafter referred to as TMA) were used to grow a compound semiconductor.

That is, TM as an organometallic compound gas
Using G, a GaN buffer layer of 30 nm was formed on a sapphire (0001 plane) 2-inch substrate at a substrate temperature of 550 ° C.
After the growth, the substrate temperature was raised to 1100 ° C. and the GaN film was grown to 2 μm. In the growth up to this point, only TMG is used as the organometallic compound gas.

Thereafter, TM was used as an organometallic compound gas.
TMA was added to G to grow an AlGaN film with a thickness of 2 μm.

The growth of the compound semiconductor here is carried out at normal pressure, and the supply amount of the first organometallic compound gas blown out from the blow-out port 6a is T2 using H2 gas as a carrier gas.
For MG, 16 μmol / min. , TMA was 2.8 μmol / min. And That is, the ratio of the supply amounts of these gases when TMA is added to TMG is TMG: TMA = 0.85: 0.15. The flow rate of the gas supplied from the outlet 6a to the reaction tube was 2.3 m / sec both when TMG was used alone and when TMA was added to TMG.

Further, the supply amount of the second organometallic compound gas blown out from the blow-out port 26a is 40 μmol / min. ,
For TMA, 7 μmol / min. And That is, the ratio of the supply amounts of these gases when TMA is added to TMG is TMG: TMA = 0.85: 0.15.
The flow rate of the gas supplied from the outlet 26a to the reaction tube was 3.5 m / sec both when TMG was used alone and when TMA was added to TMG.

As the NH3 gas, a mixed gas having a supply amount ratio of H2: NH3 = 0.65: 0.35 was used, and the flow rate was 2.3 m / sec. Also here
The compound semiconductor was grown without rotating the substrate.

When the X-ray diffraction measurement was performed on the obtained GaN film, the full width at half maximum (Δω) of the rocking curve was about 7.
min. It was found that a small and good crystalline film was obtained. The full width at half maximum of the rocking curve is about 7 min. Met. Further, the Al concentration of the AlGaN film was determined from the lattice constant obtained by X-ray diffraction measurement.
It was found to be a _0.15 Ga _0.85 N film. Cross section SE
When the film thickness distribution was determined by M, the film thickness distribution of the AlGaN film was within ± 2% on the 2-inch substrate, and a very uniform AlGaN film was obtained.

(Third Embodiment) In the third embodiment,
By the vapor phase growth apparatus 100 shown in FIG. 1, TMG and trimethylindium (hereinafter referred to as TMI) as an organometallic compound gas are used.
Was used to grow a compound semiconductor.

That is, TM as an organometallic compound gas
G was used to grow a GaN buffer of 30 nm on a sapphire (0001 plane) 2-inch substrate at a substrate temperature of 550 ° C., and subsequently the substrate temperature was raised to 1100 ° C.
An aN film was grown to 2 μm. In the growth up to this point, only TMG is used as the organometallic compound gas.

After that, the substrate temperature is lowered to 800 ° C. and TM
TMI was added to G to grow an InGaN film with a thickness of 5 nm.

The growth of the compound semiconductor here is carried out at normal pressure, and the supply amount of the first organometallic compound gas blown out from the blow-out port 6a is T2 with H2 gas as the carrier gas.
For MG, 0.7 μmol / min. , TMI was 14 μmol / min. And The flow rate of the gas supplied from the outlet 6a to the reaction tube was set to 1.5 m / sec both when TMG was used alone and when TMI was added to TMG. The supply amount of the second organometallic compound gas blown out from the blowout port 26a is H2.
2 μmol for TMG with gas as carrier gas
/ Min. , TMI was set to 40 μmol / min. The flow rate of the gas supplied from the outlet 26a to the reaction tube was 2 m / sec both when TMG was used alone and when TMI was added to TMG.

As the NH3 gas, a mixed gas having a supply amount ratio of H2: NH3 = 0.65: 0.35 was used, and the flow rate was 2.3 m / sec. Also here
The above compound semiconductor layers were grown without rotating the substrate.

When PL measurement was performed on the obtained film, sharp light emission was observed at around 380 nm. From this, the concentration of In in the InGaN film was calculated to be 0.0
It turned out to be 6. Moreover, when the film thickness distribution was obtained by the cross-sectional SEM, the total film thickness of the GaN film and the InGaN film was within ± 5% on the 2-inch substrate, and a very uniform InGaN film was obtained. Was given.

(Embodiment 4) FIG. 2 is a diagram conceptually showing a vapor phase growth apparatus for a group III-nitrogen compound semiconductor crystal according to Embodiment 4 of the present invention. In the figure, the same reference numerals as those in FIG. 1A indicate the same parts as those of the vapor phase growth apparatus 100 of the first embodiment, and 101 is a group III element organometallic compound gas and nitrogen introduced into the reaction tube 1. Of the hydride compound gas from the substrate 3 mounted on the mounting portion 3 on the surface of the substrate 4.
A vapor phase growth apparatus for performing vapor phase growth of a group-nitrogen compound semiconductor film.

The vapor phase growth apparatus 101 of the fourth embodiment includes a vapor phase growth apparatus 10 of the first embodiment shown in FIG.
In addition to the configuration of 0, a gas introduction pipe (hereinafter, referred to as a first ammonia gas) for introducing the ammonia gas (hereinafter, referred to as a first ammonia gas)
This is called the first NH ₃ gas introduction pipe. ) 5, a second NH ₃ gas introducing pipe 25 for introducing a second ammonia gas is provided, and the gas ejection port 25a has a second NH ₃ gas introducing pipe 25
It is arranged at a height position between the blow-out port 26a of the MO gas introduction pipe 26 and the blow-out port 7a of the gas introduction pipe 7 for introducing the mixed gas of hydrogen and nitrogen.

Next, GaN is formed by the vapor phase growth apparatus 101.
A method for growing a film will be described.

First, using TMG as an organometallic compound gas, a GaN buffer was grown to a thickness of 30 nm on a sapphire (0001 plane) 2-inch substrate at a substrate temperature of 550 ° C.,
Subsequently, the substrate temperature was raised to 1100 ° C. and a GaN film was grown to 4 μm.

Here, the growth of GaN is performed under normal pressure, and the supply amount of the first organometallic compound gas blown out from the blowout port 6a is 1 with H2 gas as a carrier gas.
6 μmol / min. And the flow velocity was 2.3 m / sec. Further, the supply amount of the _second organometallic compound gas blown out from the blowout port 26a is 40 μmol / min. With H ₂ gas as a carrier gas. And its flow rate is 3.5
It was set to m / sec.

As the first ammonia gas, a mixed gas having a supply amount ratio of H2: NH3 = 0.65: 0.35 was used, and the flow rate was 2.3 m / sec. As the second ammonia gas, the supply amount ratio is H2: N.
A mixed gas of H3 = 0.65: 0.35 was used, and the flow rate was 3.5 m / sec. The above growth was performed without rotating the substrate.

When the X-ray diffraction measurement was performed on the obtained GaN film, the full width at half maximum of the rocking curve was about 5 min. Met. It was also confirmed that strong band edge emission was obtained at room temperature in photoluminescence (hereinafter referred to as PL) measurement, and that a favorable GaN film was obtained in PL measurement. When the finally obtained film (substrate) was cut and observed by a cross-section SEM, Ga having a thickness of 4 μm was grown.
The film thickness distribution of the N film was within ± 2% on the 2-inch substrate, and it was found that a very uniform GaN film was obtained.

In the fourth embodiment, the first embodiment described above is adopted.
In addition to the above effect, since two independent outlets for ammonia gas are provided, there is an effect that the distribution of ammonia gas on the substrate surface can be made more uniform.

(Fifth Embodiment) FIG. 3 is a diagram conceptually showing a vapor phase growth apparatus for a group III-nitrogen compound semiconductor crystal according to a fifth embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 2 designate the same parts as those of the vapor phase growth apparatus 101 of the fourth embodiment, and 102 is a group III element organometallic compound gas and nitrogen hydride introduced into the reaction tube 1. From the compound gas, the group III-based compound on the surface of the substrate 4 mounted on the mounting part 3
It is a vapor phase growth apparatus for vapor phase growing a nitrogen compound semiconductor film.

In addition to the structure of the vapor phase growth apparatus 101 of the fourth embodiment shown in FIG. 2, the first and second organometallic compound gases are introduced into the vapor phase growth apparatus 102 of the fifth embodiment. A third MO for introducing a third organometallic compound gas, which is independent of the first and second MO gas introduction pipes 6, 26
A gas introduction pipe 36 is provided, and the gas ejection port 36 thereof is provided.
a is an outlet 25a of the second NH ₃ gas introducing pipe 25
And the outlet 7a of the gas introduction pipe 7 for introducing the barrier gas. Next, a method of growing a GaN film by the vapor phase growth apparatus 102 will be described.

First, using TMG as an organometallic compound, a GaN buffer was grown to 30 nm on a sapphire (0001 plane) 3 inch substrate at a substrate temperature of 550 ° C., and then the temperature was raised to 1100 ° C. to grow GaN to 4 μm. .

Here, the growth of GaN is performed under normal pressure, and the supply amount of the first organometallic compound gas blown out from the blowout port 6a is H ₂ gas as a carrier gas.
12 μmol / min. And the flow velocity is 2.3 m / sec
And Further, the supply amount of the _second organometallic compound gas blown out from the blowout port 26a is 35 μmol / min. And the flow velocity is 3.5
It was set to m / sec. Furthermore the supply amount of the third organic metal compound gas blown out from the air outlet 36a is, 35 [mu] mol / min of H ₂ gas as a carrier gas. And the flow velocity was 5 m / sec.

As the first ammonia gas, a mixed gas having a supply amount ratio of H2: NH3 = 0.65: 0.35 was used, and the flow rate was 2.3 m / sec. As the second ammonia gas, the supply amount ratio is H2:
A mixed gas of NH3 = 0.65: 0.35 was used, and the flow rate was 3.5 m / sec. The above growth was performed without rotating the substrate.

When the X-ray diffraction measurement was performed on the obtained GaN film, the half width (Δω) of the toking curve was about 5
min. It was found that a film having good crystallinity was obtained. The half width of the rocking curve is about 5 min. Met. It was also confirmed that strong band edge emission was obtained at room temperature in photoluminescence (hereinafter referred to as PL) measurement, and that a favorable GaN film was obtained in PL measurement. When the finally obtained film (substrate) was cut and observed with a cross-section SEM, the GaN film grown to 4 μm had a film thickness distribution within ± 5% on a 3 inch substrate, and a very uniform GaN film was obtained. I understood that it was done.

[0081]

As described above, according to the vapor phase growth apparatus according to the present invention, since two or more organometallic compound gas outlets are independently provided in the reaction chamber, the organic compound reaching the substrate surface is Since the metal compound gas is dispersed, the film formation on the substrate surface can be performed more uniformly. Therefore, a group III-nitrogen compound semiconductor crystal having a large area and a uniform film thickness can be obtained by optimizing the concentration of raw materials and the flow rate.

The present apparatus is most suitable for an apparatus for vapor-depositing a group III-nitrogen compound semiconductor crystal, and a light emitting diode and a laser having excellent optical characteristics can be produced by using the apparatus. Moreover, because it is possible to grow a large area,
It is possible to obtain a larger number of diodes and lasers than the conventional one growth, and it is possible to reduce the cost of manufacturing the diodes and lasers.

[Brief description of drawings]

FIG. 1 is a group III according to embodiments 1, 2, and 3 of the present invention.
FIG. 1 is a diagram for explaining a vapor phase growth apparatus for a nitrogen compound semiconductor crystal, and FIG. 1 (a) conceptually shows the configuration thereof.
(B) is a GaN film formed by the vapor phase growth apparatus,
The film thickness distribution in the flow direction of the gas flow is shown in FIG.
The film thickness distribution of the aN film in the direction perpendicular to the gas flow direction is shown.

FIG. 2 is a diagram conceptually showing the structure of a group III-nitrogen compound semiconductor crystal vapor phase growth apparatus in accordance with Embodiment 4 of the present invention.

FIG. 3 is a diagram conceptually showing the structure of a vapor phase growth apparatus for group III-nitrogen compound semiconductor crystals according to a fifth embodiment of the present invention.

4A and 4B are views for explaining a conventional MOCVD apparatus having a horizontal reaction furnace, FIG. 4A schematically shows the structure, and FIG. 4B is a MOCV having the horizontal reaction tube.
When the GaN film is grown on the substrate by the D device 201, the film forming rate (μm / h) at each portion on the substrate is shown in the graph.

5A and 5B are views for explaining another configuration example of a conventional MOCVD apparatus having a horizontal reaction tube, FIG. 5A schematically shows the cross-sectional structure thereof, and FIG. 5B shows the MOCVD apparatus.
When a GaN film is grown on a substrate by the device 202,
The film forming rate (μm / h) at each portion on the substrate is shown in a graph.

[Explanation of symbols]

1 Quartz Reaction Tube 2 High-Frequency Induction Heating Coil 3 Carbon Susceptor 4 Substrate 5,25 NH ₃ Gas Introducing Tubes 5a, 25a Nitrogen Hydrogen Compound Outlet 6,26,36 MO Gas Introducing Tubes 6a, 26a, 36a Organic Metal Injecting Port 7 Mixed gas introduction pipe 7a Barrier gas outlets 8a, 8b Flange 9 Gas outlet 100, 101, 102 Vapor growth apparatus

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Claims (17)

(57) [Claims] 1. A method for vapor phase growth of a compound semiconductor layer, comprising: a first step of placing a substrate on a placing part provided inside a reaction chamber; and a second step of forming a compound semiconductor film on the surface of the substrate. In the second step, the first outlet and the second outlet provided in the reaction chamber
While blowing out an organometallic compound gas as a raw material gas from the blow-out port of the raw material gas from the at least one third blow-out port provided in the reaction chamber between the first blow-out port and the second blow-out port. A vapor-phase growth method, characterized in that a hydride compound gas of nitrogen is blown out as said. 2. A vapor phase growth method for a compound semiconductor layer, comprising: a first step of mounting a substrate on a mounting part provided inside a reaction chamber; and a second step of forming a compound semiconductor film on the surface of the substrate. In the second step, the first outlet and the second outlet provided in the reaction chamber
While blowing out an organometallic compound gas as a source gas from the blow-out port of the raw material gas from the at least one third blow-out port provided in the reaction chamber between the first blow-out port and the second blow-out port. As a hydride gas, the hydride gas is discharged from any of the first, second, and third discharge ports.
No. 4, the fourth blowout located far from the substrate
From the mouth, hydrogen gas or nitrogen gas, or nitrogen and water
A vapor phase growth method characterized by blowing out a mixed gas of oxygen . 3. The vapor phase growth method according to claim 1, wherein the first blowing port is arranged so that a distance from the substrate is shorter than that of the second blowing port. Vapor growth equipment. 4. The organic metal compound gas according to claim 1 or 2, wherein the organic metal compound gas is an organic metal compound of a group III element.
Vapor-phase growth method of mounting. 5. A mounting section for mounting a substrate has a reaction chamber inside, and the mounting section is placed on the mounting section from the organometallic compound gas and hydride compound gas introduced into the reaction chamber. An apparatus for vapor-depositing a compound semiconductor film on a surface of a substrate placed on a substrate, wherein the reaction chamber comprises a first introduction pipe for introducing the organometallic compound gas as a source gas, and a source gas as a source gas. a second introduction pipe for introducing the hydride compound gas having independently the interior of the reaction chamber, further, to the reaction chamber portion, said first and said second inlet tube 1 independently provided for introducing the organometallic compound gas as a raw material gas
And more third introduction pipe, the first, independently of the said second and said third inlet
The hydride compound gas provided as a source gas is provided.
A vapor phase growth apparatus comprising: one or more fourth introduction pipes for entering . 6. A are introduced into the reaction chamber portion, characterized in that the concentration or flow rate of the organometallic compound gas is independently controlled by each of the third inlet pipe and the first inlet tube The vapor phase growth apparatus according to claim 5 . 7. is introduced into the reaction chamber portion, the hydrogen
Concentration or flow rate of the product compound gas, the second inlet pipe and the fourth vapor deposition apparatus according to claim 5, wherein the independently be controlled in each of the inlet tube. 8. above the substrate platform, said organometallic compound outlet of the introduction pipe of the gas, and outlet of the introduction pipe of the hydrogenated compound gas, and being disposed alternately The vapor phase growth apparatus according to any one of claims 5 to 7 . 9. A vapor phase growth method for a compound semiconductor layer, comprising: a first step of mounting a substrate on a mounting part provided inside a reaction chamber; and a second step of forming a compound semiconductor film on the surface of the substrate. a is, in the above-described second step, the independently provided in a reaction chamber part, and the outlet of the first inlet pipe for introducing an organometallic compound gas, nitrogen
Each raw material gas is blown out from the blowout port of one or a plurality of second introduction pipes for introducing the elementary hydride compound gas.
Together to further the first and the at least one or more third outlet or <br/> et al introduction pipe provided independently of the second inlet tube, characterized in that for blowing organic metal compound gas Vapor phase growth method for compound semiconductors. 10. A method for vapor phase growth of a compound semiconductor layer, comprising: a first step of mounting a substrate on a mounting part provided inside a reaction chamber; and a second step of forming a compound semiconductor film on the surface of the substrate. In the second step, a blow-out port of a first introduction pipe, which is independently provided in the reaction chamber, for introducing an organometallic compound gas, and water.
One or more second for introducing a hydride compound gas
Of <br/> from the outlet of the introduction pipe and the blows of each raw material gas monitor further comprises at least one or more of the 3 provided independently of said first and said second outlet of the inlet pipe The organometallic compound gas is blown out from the blow-out port of the introduction pipe of the above-mentioned first, second, and third blow-out ports.
In addition, a fourth introduction tube located far from the substrate
From the outlet of, hydrogen gas or nitrogen gas, or
A vapor phase growth method for a compound semiconductor, which comprises blowing out a mixed gas of nitrogen and hydrogen . And wherein said first inlet tube into the reaction chamber portion
Said third introduced by inlet pipe, the concentration or flow rate of the organometallic compound gases, or claim 9 crystals are controlled independently for each inlet tube is characterized in that it is grown
Or the vapor phase growth method of a compound semiconductor according to 10 . 12. introduced by a plurality of said <br/> second introduction pipe which is independent of the reaction chamber portion, the concentration or flow rate of the hydride compound gas is controlled independently for each inlet tube 10. A crystal is grown by the method of claim 9 or
11. The vapor phase growth method of a compound semiconductor according to 10 . 13. The raw material blown out from each of the outlets.
The source gas flows almost parallel to the surface of the substrate on the mounting part.
It is constituted so that it may be constituted.
Or the compound semiconductor vapor phase growth method according to any one of 9 to 12 . 14. A mounting part for mounting a substrate is provided inside the reaction chamber, and the mounting part is placed on the mounting part from the organometallic compound gas and the hydride compound gas introduced into the reaction chamber. An apparatus for vapor-depositing a compound semiconductor film on the surface of a substrate placed on a substrate, wherein the reaction chambers are independently provided in the reaction chamber, and the organometallic compound gas is blown out as a source gas. Two or more first
And one or a plurality of second outlets that are provided inside the reaction chamber independently of the individual first outlets to blow out the hydride compound gas as a source gas. The total number of the first and second outlets provided in the reaction chamber is 6 or less , and the reaction chamber is provided in the first and second outlets. ,
Blowing farthest from the plane including the substrate mounting surface of the mounting unit
Provided on the upper side of the outlet, nitrogen gas or hydrogen gas,
Or outlet for blowing out a mixed gas of nitrogen gas and hydrogen
A vapor phase growth apparatus further comprising: 15. A mounting chamber for mounting a substrate is provided inside the reaction chamber, and an organometallic compound gas and a hydride compound gas introduced into the reaction chamber are used to mount on the mounting unit. An apparatus for vapor-depositing a compound semiconductor film on the surface of a substrate placed on a substrate, wherein the reaction chambers are independently provided in the reaction chamber, and the organometallic compound gas is blown out as a source gas. Two or more first
And one or a plurality of second outlets that are provided inside the reaction chamber independently of the individual first outlets to blow out the hydride compound gas as a source gas. The total number of the first and second outlets provided inside the reaction chamber is 6 or less, and the hydrogenated compound of nitrogen is used as the hydride compound.
A vapor phase growth apparatus characterized by being supplied to the reaction chamber . 16. III as the organometallic compound gas
According supplying organometallic compound of group elements into the reaction chamber
Item 16. The vapor phase growth apparatus according to Item 14 or 15 . 17. The raw material blown out from each of the outlets
The source gas flows almost parallel to the surface of the substrate on the mounting part.
It is constituted so that it may be constituted.
Or any one of claims 14 to 16.
Vapor growth equipment .