WO2015194068A1

WO2015194068A1 - Vapor phase growth apparatus and film-forming method

Info

Publication number: WO2015194068A1
Application number: PCT/JP2014/082936
Authority: WO
Inventors: 正志水田; 哲也松原
Original assignee: 古河機械金属株式会社
Priority date: 2014-06-17
Filing date: 2014-12-12
Publication date: 2015-12-23
Also published as: JP2017157577A; TW201600624A

Abstract

A vapor phase growth apparatus (1) is provided with a film-forming chamber (4), a first supply unit (2), a second supply unit (3), a transfer means (5), and a first gas release means (6). At least one substrate (S) is disposed in the film-forming chamber (4), and a III-V compound semiconductor film is formed on the substrate (S). The transfer means (5) is provided with a susceptor (51) that rotates about a rotation axis (L). Furthermore, the vapor phase growth apparatus (1) is provided with a second gas release means (7) that releases, independently from the first gas release means (6), gas from the film-forming chamber (4). The second gas release means (7) releases a remaining gas which is generated on the rotation axis (L) of the transfer means (5), said remaining gas being close to an upper surface of the susceptor (51).

Description

Vapor phase growth apparatus and film forming method

The present invention relates to a vapor phase growth apparatus and a film forming method.

Light emitting elements such as light emitting diode elements and semiconductor laser elements are manufactured as follows, for example. Sapphire, SiC, GaN, AlN or the like is used as a substrate, and a semiconductor layer is stacked thereon using a metal organic chemical vapor deposition (MOCVD) method. As the semiconductor layer, for example, an underlayer such as an undoped GaN layer, an n-type semiconductor layer, a light emitting layer, and a p-type semiconductor layer are grown.

In recent years, in order to reduce defects during crystal growth caused by lattice mismatch and further remove a substrate such as a sapphire substrate, it is required to increase the thickness of an underlayer such as an undoped GaN layer to, for example, 30 μm to 50 μm. It has been. However, the film formation rate in the MOCVD method is generally 1 μm / h to 3 μm / h, and the film formation rate is slow, so it takes a very long time to form a thick underlayer.

Therefore, a method of forming a thick underlayer by hydride vapor phase epitaxy (HVPE) having a high growth rate and then forming an upper semiconductor layer by MOCVD is conceivable. The film formation rate in the HVPE method is generally about 100 μm / h to 300 μm / h, and it is considered that the time required for manufacturing the device is remarkably shortened by using the HVPE method.

As a film forming apparatus for meeting such a demand, for example, Patent Document 1 and Patent Document 2 disclose an apparatus capable of continuously performing film formation by the HVPE method and film formation by the MOCVD method in one film formation chamber. Is disclosed.

JP 2011-114196 A JP 2013-222848 A

However, with the techniques described in Patent Document 1 and Patent Document 2, the production yield of the fabricated elements and laminated substrates may not be good. Then, when this inventor earnestly examined, it discovered newly that dispersion | variation has arisen in the average film thickness between batches. As a result of further investigations, the in-plane film thickness may be non-uniform for each substrate, and new knowledge has been obtained that the degree of non-uniformity varies between batches and film formation conditions. It was.

The present invention provides a vapor phase growth apparatus and a film forming method capable of forming a group III-V compound semiconductor film in which in-plane film thickness non-uniformity and batch-to-batch variation are reduced.

As a method for forming such a film, there has been a method of rotating (spinning) the substrate during film formation around a straight line that is perpendicular to the main surface of the substrate and passes through the center of the substrate, but it is not sufficient. It was. For example, in this method, the film thickness is made uniform in the circumferential direction of rotation, but the non-uniformity in the radial direction cannot be eliminated, and the in-plane film thickness non-uniformity is a film forming condition. Depended on.

According to the present invention,
A deposition chamber in which at least one substrate is disposed, and a group III-V compound semiconductor film is formed on the substrate;
A first supply unit that introduces a first source gas containing a halogen element and a group III element into the film formation chamber, and a second source gas that reacts with the first source gas to form a film on the substrate;
A second supply unit for introducing a third source gas containing an organic metal into the film formation chamber and a fourth source gas that reacts with the third source gas to form a film on the substrate;
Transport means for transporting the substrate in the film forming chamber;
A first exhaust means for exhausting and evacuating the gas in the film forming chamber;
The first supply unit includes:
A first supply port for supplying the first source gas toward the substrate;
A second supply port for supplying the second source gas toward the substrate;
Without mixing the first source gas and the second source gas with each other, each led to the first supply port and the second supply port,
The second supply unit includes:
A third supply port for supplying the third source gas toward the substrate;
A fourth supply port for supplying the fourth source gas toward the substrate;
Without mixing the third source gas and the fourth source gas with each other, led to the third supply port and the fourth supply port,
The transport means includes a susceptor that rotates around a rotation axis;
The first supply port, the second supply port, the third supply port, and the fourth supply port are provided near the upper surface of the susceptor, and are opposed to the upper surface.
The transfer means includes a first arrangement in which the substrate arranged on the susceptor is opposed to the first supply port and the second supply port, and a first arrangement in which the substrate is opposed to the third supply port and the fourth supply port. 2 between the first and second supply ports, the second supply port, the third supply port, and the fourth supply port.
A second exhaust means for exhausting the film formation chamber independently of the first exhaust means;
The second exhaust means is provided with a vapor phase growth apparatus that exhausts a staying gas generated on the rotating shaft of the transport means and in the vicinity of the upper surface of the susceptor.

According to the present invention,
Disposing at least one substrate in the film formation chamber, evacuating the film formation chamber by a first exhaust means, and evacuating;
A first source gas containing a halogen element and a III element, and a second source gas for reacting with the first source gas to form a film on the substrate are simultaneously supplied into the film formation chamber; A hydride vapor phase growth step of forming a film on at least one of the substrates;
A third source gas containing an organic metal and a fourth source gas for reacting with the third source gas to form a film on the substrate are simultaneously supplied into the film formation chamber, A metal organic chemical vapor deposition step of forming a film on one of the substrates,
In the hydride vapor phase growth step and the organometallic vapor phase growth step,
The substrate disposed on the susceptor is transported in the film forming chamber by a transport unit including a susceptor that rotates around a rotation axis.
A method of forming a group III-V compound semiconductor film, which is a second exhaust unit independent of the first exhaust unit, and exhausts stagnant gas generated on the rotating shaft of the transport unit and in the vicinity of the upper surface of the susceptor. Provided.

According to the present invention, it is possible to provide a vapor phase growth apparatus and a film forming method capable of forming a group III-V compound semiconductor film in which in-plane film thickness non-uniformity and variation between batches are reduced.

The above-described object and other objects, features, and advantages will be further clarified by a preferred embodiment described below and the following drawings attached thereto.

It is a figure which shows the structure of the vapor phase growth apparatus which concerns on 1st Embodiment. It is a figure which shows the arrangement | positioning relationship of the principal part in the vapor phase growth apparatus which concerns on 1st Embodiment. It is a figure which shows the structure of the 1st supply part of the vapor phase growth apparatus which concerns on 1st Embodiment. It is a figure which shows the positional relationship of a susceptor, a board | substrate, a 1st supply part, a 2nd supply part, a rotating shaft, and a 2nd exhaust means. It is a figure which shows the modification of the structure of the exhaust pipe of the 2nd exhaust means which concerns on 1st Embodiment. It is a figure which shows the modification of the structure of the vapor phase growth apparatus which concerns on 1st Embodiment. It is a figure which shows the arrangement | positioning relationship of the principal part in the modification of the vapor phase growth apparatus which concerns on 1st Embodiment. It is a figure for demonstrating control of a 2nd exhaust means. It is a figure for demonstrating control of a 1st exhaust means. It is a figure which shows the modification of control of a 2nd exhaust means. It is a figure which shows the structure of the exhaust pipe and 5th supply pipe | tube of the 2nd exhaust means which concern on 2nd Embodiment. The positional relationship of the rotating shaft of the 1st supply part which concerns on 2nd Embodiment, a 2nd supply part, a susceptor, the exhaust pipe of a 2nd exhaust means, a 5th supply pipe, the supply port of a 5th supply pipe, a board | substrate is shown. FIG. FIG. 4 is a diagram showing a film thickness distribution of a GaN film according to Example 1. 6 is a diagram showing a film thickness distribution of a GaN film according to Example 2. FIG. It is a figure which shows the film thickness distribution of the GaN film | membrane which concerns on a comparative example.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate.

In the following description, the storage unit 91, the appropriate exhaust flow rate calculation unit 92, the exhaust flow rate control unit 93, and the pressure control unit 95 indicate functional unit blocks instead of hardware units. The storage unit 91, the appropriate exhaust flow rate calculation unit 92, the exhaust flow rate control unit 93, and the pressure control unit 95 are an arbitrary computer CPU, memory, a program that realizes the components shown in FIG. It is realized by an arbitrary combination of hardware and software, mainly a storage medium such as a hard disk to be stored and a network connection interface. There are various modifications of the implementation method and apparatus.

(First embodiment)
FIG. 1 is a diagram showing a structure of a vapor phase growth apparatus 1 according to the first embodiment. FIG. 2 is a diagram showing an arrangement relationship of main parts in the vapor phase growth apparatus 1. Here, in this figure, the first supply unit 2, the second supply unit 3, the film formation chamber 4, and the second exhaust unit 7 as viewed from the direction in plan view of the substrate S attached to the vapor phase growth apparatus 1. The arrangement relationship is shown. FIG. 1 is a cross-sectional view taken along the line AA ′ of FIG. FIG. 3 is a diagram showing the structure of the first supply unit 2 of the vapor phase growth apparatus 1 according to this embodiment. In FIG. 1, the structure of the 1st supply part 2 is simplified and drawn.

According to the present embodiment, the vapor phase growth apparatus 1 includes a film forming chamber 4, a first supply unit 2, a second supply unit 3, a transfer unit 5, and a first exhaust unit 6. At least one substrate S is disposed inside the film forming chamber 4, and a III-V group compound semiconductor film is formed on the substrate S. The first supply unit 2 introduces a first source gas containing a halogen element and a group III element into the film forming chamber 4 and a second source gas that reacts with the first source gas to form a film on the substrate S. To do. The second supply unit 3 introduces into the film forming chamber 4 a third source gas containing an organic metal and a fourth source gas that forms a film on the substrate S by reacting with the third source gas. The transport unit 5 transports the substrate S in the film forming chamber 4. The first exhaust means 6 exhausts the gas in the film forming chamber 4 and evacuates it. The first supply unit 2 includes a first supply port 214 that supplies the first source gas toward the substrate S, and a second supply port 215 that supplies the second source gas toward the substrate S. The first supply unit 2 guides the first source gas and the second source gas to the first supply port 214 and the second supply port 215, respectively, without mixing each other. The second supply unit 3 includes a third supply port 311 that supplies the third source gas toward the substrate S, and a fourth supply port 312 that supplies the fourth source gas toward the substrate S. Then, the second supply unit 3 guides the third source gas and the fourth source gas to the third supply port 311 and the fourth supply port 312 without mixing each other. The transport means 5 includes a susceptor 51 that rotates around the rotation axis L. The first supply port 214, the second supply port 215, the third supply port 311, and the fourth supply port 312 are provided near the upper surface of the susceptor 51 and face the upper surface of the susceptor 51. The transport means 5 includes a first arrangement in which the substrate S arranged on the susceptor 51 is opposed to the first supply port 214 and the second supply port 215, and a third arrangement in which the substrate S is opposed to the third supply port 311 and the fourth supply port 312. 2 and the third arrangement that does not oppose any of the first supply port 214, the second supply port 215, the third supply port 311, and the fourth supply port 312. The vapor phase growth apparatus 1 further includes a second exhaust unit 7 that exhausts the inside of the film forming chamber 4 independently of the first exhaust unit 6. The second exhaust unit 7 exhausts the staying gas generated on the rotation axis L of the transport unit 5 and in the vicinity of the upper surface of the susceptor 51. This will be described in detail below.

An opening provided in the film forming chamber 4 or on the inner wall of the film forming chamber 4 and supplying gas into the film forming chamber 4 is referred to as a “supply port”, and is formed in the film forming chamber 4 or the inner wall of the film forming chamber 4. An opening that is provided and exhausts gas from the film forming chamber 4 is called an “exhaust port” to be distinguished.

The film forming chamber 4 is composed of a chamber made of stainless steel, for example. A substrate S is disposed in the film forming chamber 4, and a III-V group compound semiconductor film is formed on the substrate S. Although it does not specifically limit as the board | substrate S, For example, any of a sapphire substrate, a SiC substrate, a ZnO substrate, and a silicon substrate can be used. A template substrate can also be used. The size of the substrate S is not particularly limited, but is 2 to 6 inches, for example. The group III element in the group III-V compound semiconductor film is at least one of Ga, Al, In, and B, for example. The V element in the III-V compound semiconductor film is, for example, one or more of N, As, and P. The group III-V compound semiconductor is, for example, any one of GaN, AlN, InN, BN, GaAlN, InGaN, GaBN, AlBN, InBN, GaNAs, InNAs, AlNAs, BNAs, and mixed crystals thereof. In the following embodiment, an example will be described in which nitrogen is a group V element, Ga is a group III element, and a GaN film is formed. However, it is not limited to this example.

The vapor phase growth apparatus 1 according to the present embodiment performs hydride vapor phase epitaxy (HydrideapVapor Phase Epitaxy: HVPE) and metal organic vapor phase epitaxy (Metal Organic Chemical VaporＭＯDeposition: MOCVD) in one film formation chamber 4. It is a device that can implement both. After the film is formed on the substrate S by one growth method, the film can be continuously formed by the other growth method without removing the substrate S from the film formation chamber 4. For this reason, a semiconductor device or the like can be manufactured with high manufacturing efficiency without requiring cooling or transporting time. In addition, after the film formation by one growth method and before the film formation by the other growth method, the surface of the substrate S is not contaminated, and a semiconductor device having excellent crystal quality is obtained. Can be manufactured.

The first supply unit 2 is a gas supply unit for performing hydride vapor phase growth (hereinafter referred to as “HVPE”) in the film forming chamber 4. FIG. 3 is a cross-sectional view showing the structure of the first supply unit 2. The first supply unit 2 includes a first supply pipe 21, a heating means 27 provided outside the first supply pipe 21, and a heat shield means 22 provided outside the heating means 27. The first supply unit 2 is a part for supplying the first source gas and the second source gas toward the substrate S. Here, the first source gas is a gas containing a halogen element and a group III element, for example, GaCl gas. The first source gas is preferably a halogenated gas of a group III element. The second source gas is a reactive gas containing a group V element, for example, ammonia gas. When film formation by HVPE is performed, the first source gas and the second source gas are simultaneously supplied into the film formation chamber 4 to form a III-V group compound semiconductor film on the substrate S. The first source gas and the second source gas can be supplied together with the carrier gas.

The first supply pipe 21 includes three pipes, that is, an outer pipe 211, a first inner pipe 212, and a second inner pipe 213, and is configured as a triple pipe structure. The first inner tube 212 has a smaller inner diameter than the outer tube 211 and is inserted into the outer tube 211. The second inner tube 213 has a smaller inner diameter than the first inner tube 212 and is inserted into the first inner tube 212.

The first supply pipe 21 is connected to the first supply port 214, the second supply port 215, and the non-reactive gas supply port 216 at its end. Here, a non-reactive gas that does not react with either the first source gas or the second source gas is supplied into the film forming chamber 4 from the non-reactive gas supply port 216. The non-reactive gas is, for example, hydrogen gas. The second source gas passes through the space inside the outer tube 211 and outside the first inner tube 212 and is supplied into the film forming chamber 4 from the second supply port 215. The non-reactive gas passes through the space inside the first inner pipe 212 and outside the second inner pipe 213, and is supplied into the film forming chamber 4 from the non-reactive gas supply port 216. The first source gas is generated inside the second inner pipe 213 and supplied into the film forming chamber 4 from the first supply port 214.

In the first supply unit 2 according to this embodiment, a non-reactive gas supply port 216 is provided between the first supply port 214 and the second supply port 215, and a non-reactive gas is supplied. Since these supply ports are located immediately above the substrate S transported by the susceptor 51, the first source gas and the second source gas are supplied onto the substrate S without being mixed. As described above, the vapor phase growth apparatus 1 according to the present embodiment is configured such that the first source gas and the second source gas are mixed for the first time in the vicinity of the substrate S, so that the reaction occurs in the supply pipe. Thus, no film is deposited and a good film can be formed on the substrate S.

Here, a configuration for generating the first source gas will be described. Inside the second inner pipe 213, a raw material source for generating a first raw material gas, for example, a raw material container (source boat) 24 containing a raw material 20 containing a group III element is arranged. Here, the raw material 20 is, for example, Ga. A pipe 25 and a pipe 26 are connected to the raw material container 24, and a gas for generating the first raw material gas is supplied into the raw material container 24 through the pipe 25. Here, the gas for generating the first source gas is a gas containing a halogen element, for example, HCl gas. A gas for generating the first source gas supplied into the source container 24 reacts with the source 20 to generate a first source gas. When the source material 20 is Ga and the gas for generating the first source gas is HCl, GaCl is generated as the first source gas. The generated first source gas is discharged from the pipe 26 and supplied into the film forming chamber 4 from the first supply port 214.

A heating means 27 for heating the inside of the first supply pipe 21, for example, a heater, is provided around the first supply pipe 21, particularly around the raw material container 24. By heating the inside of the first supply pipe 21 with the heating means 27, the first source gas is efficiently generated.

Furthermore, a heat shielding means 22 is provided around (outer circumference) the heating means 27. The heat shield means 22 according to the present embodiment includes a metal member 223 provided so as to surround the first supply pipe 21, particularly the heating means 27, and a cooling means 224 disposed around the metal member 223. It is comprised including. The metal member 223 has a triple tube structure, for example. A pipe constituting the cooling means 224 is disposed around the metal member 223. The cooling fluid passes through the inside of the pipe, and the heat generated by the heating means 27 is transmitted to the outside of the first supply unit 2. prevent. In FIG. 3, the internal structure of the metal member 223 and the cooling means 224 is omitted. The fluid is for example water. As described above, by preventing the heat generated by the heating means 27 from being transmitted to the outside of the first supply unit 2, the influence of the heat is generated on the components outside the first supply unit 2 in the vapor phase growth apparatus 1. Therefore, stable film formation on the substrate S can be performed, and the degree of freedom in designing the vapor phase growth apparatus 1 is increased.

The first source gas may be introduced through the inside of the outer pipe 211 and the outside of the first inner pipe 212, and the second source gas may be introduced through the inside of the second inner pipe 213. In that case, the raw material container 24, the pipe 25, and the pipe 26 are arranged in a space inside the outer pipe 211 and outside the first inner pipe 212.

Next, returning to FIG. 1, the structure of the second supply unit 3 will be described in detail. The second supply unit 3 is a gas supply unit for performing metal organic chemical vapor deposition (hereinafter referred to as “MOCVD”) in the film forming chamber 4. The second supply unit 3 includes a second supply pipe 31, a shower head 32, a pipe 33, and a pipe 34. The second supply unit 3 is a part for supplying the third source gas and the fourth source gas toward the substrate S. Here, the third source gas is a gas containing an organic metal, for example, trimethylgallium gas. The third source gas is preferably an organometallic gas containing a group III element. The fourth source gas is a reactive gas containing a group V element, such as ammonia gas. When film formation by MOCVD is performed, the third source gas and the fourth source gas are simultaneously supplied into the film formation chamber 4 to form a III-V group compound semiconductor film on the substrate S. The third source gas and the fourth source gas can be supplied together with the carrier gas.

A pipe 34 and a pipe 33 are connected to the second supply pipe 31. A shower head 32 is provided at the end of the second supply pipe 31. The second supply pipe 31 has a double structure, and is configured such that the gas introduced from the pipe 34 and the gas introduced from the pipe 33 are guided to the hole of the shower head 32 without being mixed with each other.

The third source gas passes through a predetermined space in the pipe 34 and the second supply pipe 31 and is supplied into the film forming chamber 4 from a third supply port 311 provided in the shower head 32. The fourth source gas passes through a space in the pipe 33 and the second supply pipe 31 that is different from the space through which the third source gas passes, and enters the film formation chamber 4 from the fourth supply port 312 provided in the shower head 32. Supplied.

Here, the shower head 32 has a plurality of holes that are the third supply ports 311 and a plurality of holes that are the fourth supply ports 312. That is, the third source gas and the fourth source gas are supplied into the film forming chamber 4 through different holes of the shower head 32. These supply ports are located immediately above the substrate S transported by the susceptor 51. As described above, the vapor phase growth apparatus 1 according to the present embodiment is configured such that the third source gas and the fourth source gas are mixed for the first time in the vicinity of the substrate S, and thus a reaction occurs in the supply pipe. Thus, good film formation on the substrate S can be performed.

In addition, unlike the 1st supply part 2, the 2nd supply part 3 which concerns on this embodiment is not provided with the mechanism which heats the raw material gas in a supply pipe | tube.

In the vapor phase growth apparatus 1 according to this embodiment, a non-reactive gas such as hydrogen gas is supplied from the third supply port 311 and the fourth supply port 312 during film formation by HVPE. Further, during film formation by MOCVD, a non-reactive gas such as hydrogen gas is supplied from the first supply port 214 and the second supply port 215. This is to prevent the raw material gas from flowing into the supply port.

Next, the conveying means 5 according to this embodiment will be described.

The susceptor 51 according to the present embodiment has a disk shape, the rotation axis L passes through the center of the susceptor 51 and is perpendicular to the upper surface of the susceptor 51, and the exhaust port of the first exhaust means 6 is on the susceptor 51. It is provided along the outer edge of the susceptor 51 when the substrate S is viewed in a plan view. This will be described in detail below.

The transport unit 5 includes a susceptor 51 that holds the substrate S and a driving unit 52 that rotationally drives the susceptor 51. The susceptor 51 has a disk shape, and has a recess (not shown) for holding the substrate S on one surface (hereinafter referred to as “upper surface”, which is the upper side in FIG. 1). A rotational axis L for rotational driving of the susceptor 51 is orthogonal to the upper surface of the susceptor 51. The driving means 52 is connected to the surface opposite to the upper surface of the susceptor 51 (hereinafter referred to as “lower surface”). The transport means 5 is configured such that when the substrate S is held in the recess of the susceptor 51, the main surface on which the substrate S is to be formed faces the first supply unit 2 and the second supply unit 3. In other words, the transport unit 5 is configured such that the main surface of the substrate S and the supply direction of the source gas from the first supply unit 2 and the second supply unit 3 are orthogonal to each other. Hereinafter, “source gas” refers to one or more of the first source gas, the second source gas, the third source gas, and the fourth gas.

A heating means 53 (for example, a heater) is disposed on the lower surface side of the susceptor 51. The heating means 53 heats the substrate S from the lower surface side during film formation.

Note that the susceptor 51 according to the present embodiment is provided with a plurality of recesses for holding the substrate S, and the plurality of substrates S are held. For example, the rotation axis L passes through the center of the disk of the susceptor 51, and the plurality of substrates S are arranged on the same circle with the rotation axis L as the center.

The driving means 52 includes a shaft portion 521 that supports the susceptor 51 from the lower surface side, and a motor 522 connected to the shaft portion 521. As the motor 522 operates, the shaft portion 521 rotates about the rotation axis L.

FIG. 4 is a diagram showing the positional relationship among the susceptor 51, the substrate S, the first supply unit 2, the second supply unit 3, the rotating shaft L, and the second exhaust means 7. Here, this figure has shown the arrangement | positioning relationship seen from the direction which planarly views the board | substrate S hold | maintained at the susceptor 51 from the main surface side which is going to form into a film. That is, it is the figure which looked at the susceptor 51 from the 1st supply part 2 and the 2nd supply part 3 side. The parts with different heights and the parts that are actually hidden are shown by solid lines. The first supply unit 2 and the second supply unit 3 are positioned on the circumference drawn by the substrate S by rotationally driving the susceptor 51. That is, the first supply port 214, the second supply port 215, the third supply port 311, and the fourth supply port 312 are positioned on the circumference drawn by the substrate S by rotationally driving the susceptor 51.

Here, the susceptor 51 rotates by the driving means 52. As a result, the substrate S held by the susceptor 51 moves on one circumference around the rotation axis L and revolves around the rotation axis L. By the revolution of the substrate S, the substrate S repeats the arrangement of “first arrangement”, “second arrangement”, and “third arrangement” in order. Here, in the first arrangement, the first supply port 214 and the second supply port 215 and the substrate S are opposed to each other, and the substrate S is positioned in the film formation region immediately below the first supply port 214 and the second supply port 215. It is arrangement to do. The second arrangement is an arrangement in which the third supply port 311 and the fourth supply port 312 are opposed to the substrate S, and the substrate S is located in the film formation region immediately below the third supply port 311 and the fourth supply port 312. is there. The third arrangement is an arrangement in which the substrate S is not positioned in the first arrangement or the second arrangement. Note that the third arrangement is not limited to once while the substrate S goes around the circumference. In particular, since the third arrangement can be taken between the first arrangement and the second arrangement, for example, the substrate S repeatedly moves the first arrangement, the third arrangement, the second arrangement, and the third arrangement in this order.

Film formation is performed while moving the substrate S as described above, and a time for supplying the source gas to the substrate S, that is, a time for taking the first arrangement or the second arrangement, and a time for not supplying it, that is, a time for taking the third arrangement are provided. Thus, there is a time for migrating the substrate after the reactive species reaches the substrate. As a result, a stable film quality with excellent crystal quality can be obtained.

In addition, the distance between the substrate S of the first arrangement and the first supply port 214 and the second supply port 215 is sufficiently short, and the first source gas and the second source gas are mixed in the vicinity of the substrate S for the first time. Has been. Further, the distance between the substrate S in the second arrangement and the third supply port 311 and the fourth supply port 312 is sufficiently close, and the second source gas and the third source gas are mixed for the first time in the vicinity of the substrate S. Has been.

In addition, a region on the susceptor 51 that faces the first supply port 214 and the second supply port 215 and a region that faces the third supply port 311 and the fourth supply port 312 are a single substrate S in plan view. The size of the plurality of substrates S does not fit.

In the vapor phase growth apparatus 1 according to this embodiment, the susceptor 51 is rotated during film formation, whereby the film can be efficiently formed on the substrate S. The reason will be described below. During film formation, the temperature in the vicinity of the first supply port 214 and the second supply port 215 or in the vicinity of the third supply port 311 and the fourth supply port 312 is lower than the temperature around the substrate S. From this, a gas flow that rises toward these supply ports may occur. When such a gas flow is strong, the flow of the gas supplied from each supply port to the substrate S is hindered. Here, by rotating the susceptor 51 and applying a centrifugal force to the gas on the susceptor 51 during film formation, the flow of gas rising from the substrate S toward the supply port can be weakened. Thereby, a film can be efficiently formed on the substrate S.

The appropriate rotational speed of the susceptor 51 may differ between HVPE and MOCVD, but is preferably 1 rpm or more. Further, although the appropriate rotation speed of the susceptor 51 may be different between HVPE and MOCVD, the rotation speed is increased from the substrate S toward the supply port side of the first supply pipe 21 because the rotation mechanism can be simply constructed. From the viewpoint of appropriately suppressing the flow of gas, for example, it is preferably 2000 rpm or less, and more preferably 100 rpm or less. By using such a rotational speed, the centrifugal force is not sufficiently generated, the gas distribution on the substrate S is uneven, and the thickness of the film formed in the plane of the substrate S is not uniform. Can be prevented. In addition, since the rotation is not too fast, the source gas can sufficiently stay on the substrate S, and the film can be formed at a sufficient speed.

Here, the flow of the raw material gas generated when the susceptor 51 is rotationally driven will be further described. As an example, a case where film formation by MOCVD is performed will be described. While the third source gas and the fourth source gas are supplied to the film formation chamber 4 and the film is formed on the substrate S, the susceptor 51 is rotationally driven. By this rotational drive, a gas flow in a direction from the rotation axis L toward the outer periphery of the susceptor 51 occurs in the film forming chamber 4, particularly in the upper part of the susceptor 51 and around the substrate S. The gas here includes the third source gas, the fourth source gas, and other gases in the film forming chamber 4. Due to the rotation, the gas above the susceptor 51 receives a centrifugal force in a direction away from the rotation axis L and moves toward the outer periphery of the susceptor 51. Here, since this centrifugal force is understood to be stronger as it moves away from the rotation axis L and weaker in the vicinity of the rotation axis L, etc., the inventor of the present invention stagnates a certain amount of gas in the vicinity of the rotation axis L. Newly found that there is a possibility of hangups. In this way, the gas stagnating in a specific region is called a staying gas. The staying gas may include a third source gas, a fourth source gas, a non-reactive gas, a carrier gas, and the like. In addition, although the case where the film formation by MOCVD was demonstrated here, when the film formation by HVPE was performed, the same gas flow was found, and it discovered that a certain amount of residence gas might arise. In this case, the staying gas may include a first source gas, a second source gas, a non-reactive gas, a carrier gas, and the like.

In the vapor phase growth apparatus 1 according to this embodiment, the rotation axis L and the substrate S are sufficiently close. Therefore, the effect of the staying gas reaches the substrate S. As will be described later, in the vapor phase growth apparatus 1 according to the present embodiment, the second exhaust unit 7 is provided to exhaust the staying gas, so that the film can be uniformly formed on the substrate S.

Next, the exhaust from the film forming chamber 4 of the vapor phase growth apparatus 1 according to the present embodiment will be described. A second exhaust means 7 and a first exhaust means 6 for exhausting the gas in the film formation chamber 4 are connected to the film formation chamber 4. The exhaust port of the second exhaust unit 7 is located at the upper part of the rotation center of the susceptor 51, and the exhaust port of the first exhaust unit 6 is located at the outer periphery of the susceptor 51.

The tip of the exhaust pipe of the second exhaust means 7 extends in parallel with the rotation axis L. In the present embodiment, the exhaust pipe of the second exhaust means 7 extends on the rotation axis L in the film forming chamber 4. Further, the distal end portion of the second exhaust means 7 extends in the vertical direction in parallel with the first supply pipe 21 and the second supply pipe 31. Since the exhaust port of the second exhaust means 7 is located in the upper part of the rotation center of the susceptor 51, that is, in the region where the gas stays, the second exhaust means 7 exhausts the staying gas generated when the susceptor 51 rotates. be able to. The second exhaust means 7 exhausts the staying gas in the vicinity of the upper surface of the susceptor 51 on the rotating shaft L. In addition, the staying gas around the rotating shaft L and above the susceptor 51 may be exhausted. In the vapor phase growth apparatus 1 according to the present embodiment, the concentration of the source gas on the substrate S is made uniform by exhausting the staying gas by the second exhaust means 7, and a film is formed with a uniform thickness in the surface. The For example, when film formation is performed by further supplying a doping gas, the doping concentration of the film becomes uniform in the plane.

Although the reason is not clear, the exhaust of the stagnant gas reduces the non-uniformity such that the concentration of the source gas on the substrate S increases toward the rotation axis L, or the source gas is on the surface of the substrate S. The non-uniformity of the flow velocity flowing through the substrate is reduced in-plane, and the non-uniformity of the time during which Group III atoms and Group V atoms contained in the source gas stay on the surface of the substrate S is reduced. It is presumed that it is acting on.

In the case where the vapor phase growth apparatus 1 includes the transport unit 5 in which the driving unit 52 is not positioned at the center of the lower surface side of the susceptor 51, the exhaust pipe of the second exhaust unit 7 extends from below the susceptor 51, You may comprise so that 51 may be penetrated and the residence gas of an upper surface side may be exhausted.

The exhaust port of the first exhaust means 6 is provided on the bottom surface of the film forming chamber 4 on the lower surface side of the outer peripheral portion of the susceptor 51. The gas that has flowed to the outer peripheral side of the susceptor 51 is mainly exhausted out of the film forming chamber 4 by the first exhaust means 6.

Here, the second exhaust means 7 can be configured to exhaust at an exhaust flow rate corresponding to the amount of staying gas generated. In addition, the first exhaust unit 6 can exhaust the interior of the film forming chamber 4 to a predetermined pressure independently of the second exhaust unit 7.

Here, a modified example of the structure of the second exhaust means 7 will be described. Specifically, the structure of the exhaust pipe.
FIG. 5 is a view showing the structure of the exhaust pipe of the second exhaust means 72 according to this modification. This figure is a cross-sectional view of the distal end portion of the exhaust pipe of the second exhaust means 72 as seen from the direction orthogonal to the rotation axis L. Moreover, in this figure, the direction in which the staying gas discharged | emitted from the film-forming chamber 4 flows is shown by the arrow.
The exhaust pipe of the second exhaust means 72 according to this modification is the same as the second exhaust means 7 except that at least a part thereof has a double pipe structure. A vacuum is formed between the outer tube 712 and the inner tube 711 of the double structure, and the staying gas is exhausted through the inside of the inner tube 711.

The stagnant gas exhausted during film formation becomes a high temperature of about 1000 ° C., for example. When such a staying gas is exhausted, the exhaust pipe becomes high temperature, and thus heat resistance is required for the structure around the exhaust pipe. Here, in the second exhaust means 72 according to this modification, the pipe has a double pipe structure, and the vacuum part functions as a heat insulating material, so that there is no influence on the structure part around the exhaust pipe. Specifically, as shown in FIG. 5, the high-temperature staying gas taken in from the exhaust port 713 of the second exhaust means 72 passes through the inner pipe 711 and is exhausted. The outer tube 712 is closed near the exhaust port 713, and the space inside the outer tube 712 and outside the inner tube 711 is in a vacuum. This vacuum portion has a heat insulating effect, and the heat of the staying gas flowing in the inner tube 711 can be prevented from being transmitted to the outside of the outer tube 712. For this reason, the structure around the exhaust pipe of the second exhaust means 72 is not greatly affected by heat, and heat resistance is not required. Therefore, stable film formation can be performed, and the design freedom of the vapor phase growth apparatus 1 can be increased.

Hereinafter, another modification of the present embodiment will be described.
FIG. 6 is a view showing the structure of the vapor phase growth apparatus 11 according to this modification. FIG. 7 is a diagram showing an arrangement relationship of main parts in the vapor phase growth apparatus 11. Here, in FIG. 7, the first supply unit 2, the second supply unit 3, the film formation chamber 4, and the second exhaust unit 73 are viewed from the direction in which the substrate S attached to the vapor phase growth apparatus 11 is viewed in plan. The arrangement relationship is shown. 6 is a cross-sectional view taken along the line BB ′ of FIG.

The vapor phase growth apparatus 11 according to this modification is the same as the vapor phase growth apparatus 1 except that a second exhaust means 73 having an L-shaped exhaust pipe is provided instead of the second exhaust means 7. . The exhaust port of the second exhaust means 73 is provided at the tip of an L-shaped exhaust pipe.

In this modification, as shown in FIGS. 6 and 7, the exhaust pipe of the second exhaust means 73 is inserted from the side surface of the film forming chamber 4, and the upper surface side of the susceptor 51 extends to the center in parallel with the upper surface of the susceptor 51. is doing. The exhaust pipe of the second exhaust means 73 is bent in an L shape so that only its tip extends to the rotation axis L, and the exhaust port faces the susceptor 51 side. At this time, the exhaust pipe is disposed between the side surface of the film forming chamber 4 and the center of the susceptor 51 so as not to interfere spatially with the first supply unit 2 and the second supply unit 3. Further, the exhaust pipe is arranged between the side surface of the film forming chamber 4 and the center of the susceptor 51 so as not to affect the supply of the source gas.

Also in this modified example, the exhaust port of the second exhaust means 73 is located in the upper part of the rotation center of the susceptor 51, that is, in the region where the gas stays, and the second exhaust means 73 is used when the susceptor 51 rotates. The resulting stagnant gas can be exhausted. In addition, the front-end | tip part of the 2nd exhaustion means 73 does not necessarily need to be bent at right angle, and may be bent at another angle. Even in this case, it is preferable that the exhaust port of the second exhaust means 73 is disposed on the rotation axis L and in the vicinity of the upper surface of the susceptor 51.

Next, control of the second exhaust unit 7 and the first exhaust unit 6 of the vapor phase growth apparatus 1 according to the present embodiment will be described.
FIG. 8 is a diagram for explaining the control of the second exhaust unit 7, and FIG. 9 is a diagram for explaining the control of the first exhaust unit 6.

The vapor phase growth apparatus 1 according to the present embodiment further includes a storage unit 91, an appropriate exhaust flow rate calculation unit 92, an exhaust flow rate control unit 93, and a pressure control unit 95. The storage unit 91 holds appropriate exhaust reference information in advance. Here, the appropriate exhaust reference information refers to the supply flow rate of the gas supplied from the first supply port 214, the supply flow rate of the gas supplied from the second supply port 215, and the gas supplied from the third supply port 311. This is information indicating the relationship among the supply flow rate, the supply flow rate of the gas supplied from the fourth supply port 312, the rotational speed of the susceptor 51, and the appropriate exhaust flow rate of the staying gas by the second exhaust means 7. The appropriate exhaust flow rate calculation unit 92, the appropriate exhaust reference information read from the storage unit 91, the supply flow rate of the gas supplied from the first supply port 214, respectively measured when forming a film on the substrate, The supply flow rate of the gas supplied from the second supply port 215, the supply flow rate of the gas supplied from the third supply port 311, the supply flow rate of the gas supplied from the fourth supply port 312, and the rotational speed of the susceptor 51 Based on the above, an appropriate exhaust flow rate by the second exhaust means 7 is calculated. The exhaust flow rate control unit 93 controls the second exhaust unit 7 so as to exhaust at an appropriate exhaust flow rate by the second exhaust unit 7 calculated by the appropriate exhaust flow rate calculation unit 92. The pressure control unit 95 controls the first exhaust unit 6 so that the inside of the film forming chamber 4 has a predetermined pressure. This will be described in detail below.

The vapor phase growth apparatus 1 according to the present embodiment includes a rotational speed detection unit 901, a first flow rate detection unit 902, a second flow rate detection unit 903, a third flow rate detection unit 904, a fourth flow rate detection unit 905, and a pressure detection unit. 907 and a pressure input unit 94 are further provided. The second exhaust means 7 and the first exhaust means 6 have an exhaust pump (not shown). Both exhaust pumps may be independent, or one exhaust pump may be shared. The rotational speed detection unit 901 is attached to the driving unit 52 and detects the rotational speed of the substrate S, that is, the rotational speed of the susceptor 51. For example, a tachometer.

The first flow rate detector 902 detects the flow rate of the gas supplied from the first supply port 214. The second flow rate detector 903 detects the flow rate of the gas supplied from the second supply port 215. The third flow rate detector 904 detects the flow rate of the gas supplied from the third supply port 311. The fourth flow rate detection unit 905 detects the flow rate of the gas supplied from the fourth supply port 312. Each flow rate detection unit is a flow meter provided in the piping of the first supply unit 2 or the second supply unit 3 so as to detect the flow rate of gas supplied from each supply port, for example. In the present embodiment, the gas supplied from the first supply port 214 can be either the first source gas or the non-reactive gas. The gas supplied from the second supply port 215 can be either the second source gas or the non-reactive gas. The gas supplied from the third supply port 311 can be either the third source gas or the non-reactive gas. The gas supplied from the fourth supply port 312 can be either the fourth source gas or the non-reactive gas. Specifically, when film formation is performed by HVPE, the first source gas is supplied from the first supply port 214, the second source gas is supplied from the second supply port 215, the third supply port 311 and the fourth supply port 312. The non-reactive gas is supplied from and the flow rate thereof is detected. When film formation is performed by MOCVD, the non-reactive gas from the first supply port 214 and the second supply port 215, the third source gas from the third supply port 311, and the fourth source material from the fourth supply port 312. Gases are supplied and their flow rates are detected. When the source gas is supplied together with the carrier gas, each detected flow rate is a combined flow rate of the carrier gas.

The pressure detector 907 measures the pressure in the film forming chamber 4. For example, a vacuum gauge attached to the film forming chamber 4. The user of the vapor phase growth apparatus 1 inputs information indicating a predetermined value to be maintained as the pressure of the film forming chamber 4 to the pressure control unit 95 via the pressure input unit 94.

First, the control of the second exhaust means 7 will be described with reference to FIG. The storage unit 91 holds appropriate exhaust reference information in advance. The supply flow rate of the gas supplied from the first supply port 214, the supply flow rate of the gas supplied from the second supply port 215, the supply flow rate of the gas supplied from the third supply port 311, and the fourth supply port 312. If the supply flow rate of the gas supplied from 1 and the rotation speed of the substrate S are known, the appropriate exhaust gas reference flow information can be used to derive the appropriate exhaust gas flow rate of the stagnant gas. Here, the appropriate exhaust reference information refers to the supply flow rate of the gas supplied from the first supply port 214, the supply flow rate of the gas supplied from the second supply port 215, and the gas supplied from the third supply port 311. This is information indicating the relationship between the supply flow rate, the supply flow rate of the gas supplied from the fourth supply port 312, the rotational speed of the substrate S, and the appropriate exhaust flow rate of the stagnant gas by the second exhaust means 7. Coefficients, tables, etc. The appropriate exhaust reference information can be obtained based on fluid calculation, fluid simulation, or preliminary experiment. The appropriate exhaust flow rate of the staying gas can be determined so that, for example, the amount of staying gas generated is discharged equally. Alternatively, the appropriate exhaust flow rate of the staying gas can be an appropriate value based on a prior experiment, or can be a value obtained by weighting a theoretically obtained value according to conditions.

In the vapor phase growth apparatus 1 according to the present embodiment, during film formation, information indicating the rotation speed of the susceptor 51 is input from the rotation speed detection unit 901 to the appropriate exhaust flow rate calculation unit 92 and from the first supply port 214. Information indicating the supply flow rate of the supplied gas is input from the first flow rate detection unit 902 to the appropriate exhaust flow rate calculation unit 92, and information indicating the supply flow rate of the gas supplied from the second supply port 215 is the second flow rate. Information indicating the supply flow rate of the gas supplied from the detection unit 903 to the appropriate exhaust flow rate calculation unit 92 and supplied from the third supply port 311 is input from the third flow rate detection unit 904 to the proper exhaust flow rate calculation unit 92, and Information indicating the supply flow rate of the gas supplied from the 4 supply ports 312 is input from the fourth flow rate detection unit 905 to the appropriate exhaust flow rate calculation unit 92. In addition, the appropriate exhaust flow rate calculation unit 92 reads appropriate exhaust reference information from the storage unit 91. Then, the appropriate exhaust flow rate calculation unit 92 obtains information indicating the rotation speed of the susceptor 51, information indicating the supply flow rate of the gas supplied from the first supply port 214, and supply flow rate of the gas supplied from the second supply port 215. On the basis of the information indicating, the information indicating the supply flow rate of the gas supplied from the third supply port 311, the information indicating the supply flow rate of the gas supplied from the fourth supply port 312, and the appropriate exhaust reference information 7 to calculate an appropriate exhaust flow rate. The appropriate exhaust flow rate calculated by the appropriate exhaust flow rate calculation unit 92 is input to the exhaust flow rate control unit 93. The exhaust flow rate controller 93 controls the exhaust flow rate of the second exhaust unit 7 so that the second exhaust unit 7 exhausts the gas in the film forming chamber 4 at the input appropriate exhaust flow rate.

The appropriate exhaust flow rate calculation unit 92 may be configured to calculate an appropriate exhaust flow rate by the second exhaust means 7 by further taking into account the supply flow rate of the gas supplied from the non-reactive gas supply port 216. At that time, the storage unit 91 supplies the supply flow rate of the gas supplied from the first supply port 214, the supply flow rate of the gas supplied from the second supply port 215, and the gas supplied from the third supply port 311. , The supply flow rate of the gas supplied from the fourth supply port 312, the supply flow rate of the gas supplied from the non-reactive gas supply port 216, the rotational speed of the substrate S, and the retention by the second exhaust means 7. Information indicating the relationship with the appropriate exhaust flow rate of gas is stored in advance as appropriate exhaust reference information.

In addition, FIG. 10 is a figure which shows the modification of a structure of the control system of the 2nd exhaust means 7 which concerns on this embodiment. As shown in the figure, the vapor phase growth apparatus 1 may further include a film formation information input unit 96. A user of the vapor phase growth apparatus 1 inputs film formation information indicating film formation conditions to the appropriate exhaust flow rate calculation unit 92 via the film formation information input unit 96. The film formation information includes, for example, information on a film formation method indicating which film formation method is used, HVPE or MOCVD, and indicates which III-V compound semiconductor material film is to be formed. Information and other information relating to film formation. The film formation information may be one of these or a combination of a plurality of information.

The storage unit 91 holds in advance appropriate exhaust reference information for each film formation condition indicated by the film formation information, and the appropriate exhaust flow rate calculation unit 92 is based on the film formation information input from the film formation information input unit 96. Then, the appropriate exhaust reference information corresponding to the film forming conditions is read from the storage unit 91, and the appropriate exhaust flow rate by the second exhaust means 7 is calculated in the same manner as described above.

Next, control of the first exhaust means 6 according to the present embodiment will be described with reference to FIG. The first evacuation unit 6 evacuates the film formation chamber 4 to a predetermined pressure independently of the second evacuation unit 7. The amount of gas to be exhausted by the first exhaust means 6 depends on the exhaust flow rate by the second exhaust means 7 in addition to each gas supplied to the film forming chamber 4. First, target pressure information indicating the pressure in the film forming chamber 4 to be maintained is input from the pressure input unit 94 to the pressure control unit 95. During film formation, detected pressure information indicating the pressure in the film formation chamber 4 detected by the pressure detection unit 907 is input to the pressure control unit 95. The pressure control unit 95 controls the first exhaust unit 6 based on the input target pressure information and the detected pressure information. Specifically, when the pressure value related to the detected pressure information is higher than the pressure value related to the target pressure information, the exhaust flow rate of the first exhaust means 6 is increased, and the pressure value related to the detected pressure information is the pressure related to the target pressure information. If it is lower than the value, the exhaust flow rate of the first exhaust means 6 is reduced.

As described above, the vapor phase growth apparatus 1 according to the present embodiment has the two independent exhaust units, the second exhaust unit 7 and the first exhaust unit 6, so that the generated staying gas is appropriately exhausted. The film forming chamber 4 can be maintained at a desired pressure. Therefore, the film can be formed with high stability and a uniform film thickness.

Below, the film-forming method which concerns on this embodiment is demonstrated. In the film forming method according to the present embodiment, film formation is performed using the vapor phase growth apparatus 1.
In the film forming method according to the present embodiment, at least one substrate S is disposed in the film forming chamber 4, the inside of the film forming chamber 4 is evacuated and vacuumed by the first exhaust means 6, and the HVPE step ( A hydride vapor phase growth step) and an MOCVD step (metal organic vapor phase growth step). In the HVPE process, the first source gas and the second source gas are supplied into the film forming chamber 4 to form a film on at least one substrate S in the film forming chamber 4. In the MOCVD process, the third source gas and the fourth source gas are supplied into the film forming chamber 4 to form a film on at least one substrate S in the film forming chamber 4. Here, in the HVPE process and the MOCVD process, the substrate S disposed on the susceptor 51 is transported in the film forming chamber 4 by the transport means 5 including the susceptor 51 rotating around the rotation axis L. In addition, the second exhaust means 7 independent of the first exhaust means 6 exhausts the staying gas generated on the rotation axis L of the transport means 5 and in the vicinity of the upper surface of the susceptor 51.

In the film formation method according to the present embodiment, a case will be described in which film formation is first performed by HVPE (HVPE process), and then film formation is performed by MOCVD (MOCVD process). However, the present invention is not limited to this, and film formation by MOCVD may be performed after film formation by MOCVD first.

First, a plurality of substrates S are installed on the susceptor 51. Next, the substrate S is heated from the lower surface side by the heating means 53, the same gas as the second source gas (for example, ammonia gas) is supplied into the film forming chamber 4, and the second source gas atmosphere is formed in the film forming chamber 4. And The temperature of the substrate S is preferably 1000 ° C. or higher, for example, and more preferably 1040 ° C. or higher. Note that the inside of the film forming chamber 4 may be a gas atmosphere containing a group V (for example, a nitrogen gas atmosphere). These gases may be supplied from any supply port.

Also, heating is performed until the temperature of the raw material 20 in the raw material container 24 reaches a predetermined temperature, for example, 850 ° C. Thereafter, a gas for generating the carrier gas and the first raw material gas is supplied into the raw material container 24 through the pipe 25, and the gas for generating the first raw material gas and the raw material 20 in the raw material container 24 are reacted. The first source gas is generated. Here, for example, the carrier gas is hydrogen gas, the gas for generating the first source gas is HCl gas, the source 20 is Ga, and the first source gas is GaCl gas. The generated first source gas is discharged from the source container 24 through the pipe 26, passes through the inside of the second inner pipe 213, and is supplied into the film forming chamber 4 from the first supply port 214.

Also, the second source gas is supplied from the second supply port 215 into the film forming chamber 4 through the inside of the outer tube 211 and the outside of the first inner tube 212. At this time, the non-reactive gas is supplied from the non-reactive gas supply port 216 into the film forming chamber 4 through the inside of the first inner tube 212 and the outside of the second inner tube 213, and near the supply port of the first supply tube 21. The contact between the first source gas and the second source gas is suppressed.

In the HVPE process according to the present embodiment, a non-reactive gas (for example, hydrogen gas) is supplied to the film forming chamber 4 from the supply port of the second supply pipe 31, that is, from the third supply port 311 and the fourth supply port 312.

Here, during film formation by HVPE, the susceptor 51 in the film formation chamber 4 is rotationally driven by the driving means 52. Therefore, each substrate S on the susceptor 51 revolves around the rotation axis L of the susceptor 51, and the supply port of the first supply pipe 21, that is, the first supply port 214, the second supply port 215, and the non-reactive gas supply port. The first arrangement facing 216 and the other arrangements (second arrangement and third arrangement) are alternately repeated. Then, the plurality of substrates S on the susceptor 51 sequentially take the first arrangement.

The rotational speed of the susceptor 51 in the HVPE process is preferably 1 rpm or more. Further, the rotational speed of the susceptor 51 in the HVPE process is preferably 2000 rpm or less, and more preferably 100 rpm or less. This is because the flow of gas that rises from the substrate S toward the supply port side of the first supply pipe 21 is appropriately suppressed.

The first source gas supplied from the first supply port 214 and the second source gas supplied from the second supply port 215 are supplied onto the substrate S in the first arrangement and reacted to react with the substrate S. A film is formed on the main surface. As the substrate S repeatedly takes the first arrangement by the rotation of the susceptor 51, the film on the substrate S grows and the film thickness increases. In the HVPE step, the region immediately below the supply port of the first supply pipe 21 (first arrangement) is a film formation region where film formation proceeds mainly, and the other regions (second arrangement and third arrangement) are non-film formation regions. Become. In the HVPE process, the film growth mainly proceeds on the substrate having the first arrangement, and basically the film formation does not advance on the second arrangement and the third arrangement. However, the growth of the film on the substrate S does not always occur only while the substrate S is in the first arrangement. For example, the first raw material gas and the second raw material gas supplied to the substrate S in the first arrangement pass after the substrate S passes just below the supply port of the first supply pipe 21 (that is, in the second arrangement or the third arrangement). The reaction process may proceed on the main surface of the substrate S even during the placement. Further, even when the substrate S is not in the first arrangement, the first source gas and the second source gas remaining in the film formation chamber 4 reach the main surface of the substrate S, and the film growth proceeds. There is.

In the film forming method according to the present embodiment, the staying gas generated along with the rotation of the susceptor 51 is exhausted by the second exhaust means 7 during the film formation. Here, as described above, the second exhaust means 7 is controlled by the exhaust flow rate control unit 93 to discharge gas at an appropriate flow rate. By exhausting the staying gas in the vicinity of the substrate S by the second exhaust means 7, it is possible to form a film with a uniform thickness in the surface.

On the other hand, the first exhaust means 6 exhausts the inside of the film forming chamber 4 to a predetermined pressure. The first exhaust means 6 is controlled by the pressure controller 95 as described above. In the present embodiment, the pressure in the film forming chamber 4 is set to 660 hPa, for example. By providing the first exhaust means 6 that is controlled independently of the second exhaust means 7, the inside of the film forming chamber 4 can be maintained at a desired pressure, and film formation with high film quality is stably performed. be able to.

As described above, after the film formation with a desired thickness by HVPE is completed, the supply of the first source gas and the second source gas from the first supply pipe 21 is stopped, and the first supply pipe by the heating unit 27 is stopped. 21 stops heating.

Next, the MOCVD process is performed. At this time, the MOCVD process can be started without waiting for the first supply pipe 21 of the first supply unit 2 to be cooled.

First, the heating conditions of the heating means 53 are switched as necessary so that the substrate S has a predetermined temperature in the MOCVD process.

The same gas as the fourth source gas (for example, ammonia gas) is supplied, and the film forming chamber 4 is set as the fourth source gas atmosphere. Note that the inside of the film forming chamber 4 may be a gas atmosphere containing a group V (for example, a nitrogen gas atmosphere). These gases may be supplied from any supply port. Subsequently, the third source gas and the fourth source gas are supplied into the film formation chamber 4 through the shower head 32 of the second supply unit 3 and film formation is performed. The third source gas is, for example, trimethyl gallium gas.

In the MOCVD process according to this embodiment, a non-reactive gas (for example, hydrogen gas) is supplied into the film forming chamber 4 from the supply port of the first supply pipe 21, that is, the first supply port 214 and the second supply port 215. .

Here, during film formation by MOCVD, the susceptor 51 in the film formation chamber 4 is rotationally driven by the driving means 52. Accordingly, each substrate S on the susceptor 51 revolves around the rotation axis L of the susceptor 51 and has a second arrangement facing the supply ports of the second supply unit 3, that is, the third supply port 311 and the fourth supply port 312. The other arrangements (the first arrangement and the third arrangement) are alternately repeated. And the some board | substrate S on the susceptor 51 will take 2nd arrangement | sequence sequentially.

Rotational speed of the susceptor 51 in the MOCVD process is preferably 1 rpm or more. Further, the rotation speed of the susceptor 51 in the MOCVD process is preferably 2000 rpm or less, and more preferably 100 rpm or less. This is to appropriately suppress the flow of gas that rises from the substrate S toward the supply port side of the second supply pipe 31.

The third source gas supplied from the third supply port 311 and the fourth source gas supplied from the fourth supply port 312 are supplied onto the substrate S in the second arrangement and reacted to react with the substrate S. A film is formed on the main surface. When the substrate S repeatedly takes the second arrangement by the rotation of the susceptor 51, the film on the substrate S grows and the film thickness increases. In the MOCVD process, the area immediately below the supply port of the second supply pipe 31 (second arrangement) is a film formation area where film formation proceeds mainly, and the other areas (first arrangement and third arrangement) are non-film formation areas. Become. In the MOCVD process, the growth of the film mainly proceeds on the substrate having the second arrangement, and basically the film formation does not proceed on the substrates having the first arrangement and the third arrangement. However, the growth of the film on the substrate S does not always occur only while the substrate S is in the second arrangement. For example, the third source gas and the fourth source gas supplied to the substrate S in the second arrangement are passed after the substrate S passes directly under the supply port of the second supply pipe 31 (that is, the first arrangement or the third arrangement). The reaction process may proceed on the main surface of the substrate S even during the placement. Further, even when the substrate S is not in the second arrangement, the third source gas and the fourth source gas remaining in the film forming chamber 4 reach the main surface of the substrate S, and the film growth proceeds. There is.

As described above, after film formation with a desired thickness by MOCVD is completed, the supply of the third source gas and the fourth source gas from the second supply pipe 31 is stopped.

Thus, on the substrate S, a semiconductor device such as a semiconductor light emitting element such as a laser or a light emitting diode can be manufactured.

Next, the effect of this embodiment is demonstrated.
The vapor phase growth apparatus 1 of the present embodiment exhausts the staying gas generated in the vicinity of the rotation axis L at the upper part of the susceptor by the second exhaust means 7, thereby reducing the thickness of the film formed on the surface of the substrate S. Uniformity can be reduced, and as a result, in-plane variation in in-plane film thickness non-uniformity can be reduced.

In the vapor phase growth apparatus 1 of the present embodiment, the first supply pipe 21 of the first supply unit 2 and the second supply pipe 31 of the second supply unit 3 are connected in the same film formation chamber 4. In the film forming chamber 4, gas is supplied from each of the first supply unit 2 and the second supply unit 3. Therefore, for example, after the gas supply from the second supply unit 3 is stopped, the gas is supplied from the first supply unit 2 to form a film on the substrate S, and then the gas from the first supply unit 2 is supplied. The supply of gas from the second supply unit 3 can be started and film formation can be performed on the substrate S without stopping the supply and waiting for the cooling of the first supply unit 2. For example, in an apparatus having a separate chamber for HVPE and a chamber for MOCVD, a cooling time of 2 to 3 hours is required to move the substrate S to the other chamber after film formation in one chamber. The vapor phase growth apparatus 1 according to the present embodiment does not require such a cooling time, and can form a film efficiently.

In the present embodiment, the gas supply port to the film formation chamber 4 of the first supply pipe 21 and the gas to the film formation chamber 4 of the second supply pipe 31 are viewed from the top view of the upper surface of the susceptor 51. Is provided on the circumference drawn by the substrate S by rotationally driving the susceptor 51. Therefore, a film can be formed on the substrate S by the gas from the supply port of the first supply pipe 21 or the supply port of the second supply pipe 31 only by rotationally driving the susceptor 51.

Further, in the present embodiment, during the film formation by HVPE and during the film formation by MOCVD, a state where the substrate S is in a position facing the supply port from which the source gas is discharged and a state where the substrate S is not in this position are alternately displayed. As shown in FIG. Thereby, it is possible to alternately perform the process of supplying the source gas to the surface of the substrate S and the process of not supplying the source gas. In the step in which the raw material is not supplied, the diffusion of atoms as the raw material of the film on the substrate S can be promoted, and a III-V group compound semiconductor with high crystallinity can be obtained.

In the present embodiment, the susceptor 51 holding a plurality of substrates S is rotated, and each substrate S is sequentially deposited to face the source gas supply port. That is, the distance and the positional relationship between the supply port and the substrate S are the same for all the substrates S. Thereby, the film quality and film thickness of the formed film do not differ for each substrate S.

In the present embodiment, when the gas is supplied from the first supply unit 2, the first source gas is supplied from the second inner pipe 213, and the first source gas is supplied through the inner side of the outer pipe 211 and the outer side of the first inner pipe 212. Two source gases are supplied, and a non-reactive gas is supplied through the inside of the first inner pipe 212 and the outside of the second inner pipe 213. As a result, contact between the first source gas and the second source gas in the vicinity of the supply port of the first supply pipe 21 is suppressed. Since the first source gas and the second source gas are mixed and reacted for the first time in the vicinity of the substrate S, a film can be efficiently formed on the substrate S.

In the present embodiment, the heating means 27 for heating the inside of the first supply pipe 21 is arranged around the first supply pipe 21, and the heat from the heating means 27 is cut off around the heating means 27. A heat shield 22 is arranged. By doing in this way, the influence of the heat to structure parts other than the 2nd supply part 3 and the 2nd supply part 3 can be suppressed. Furthermore, since the heat shield means 22 includes the cooling means 224, heat can be more reliably cut off.

In this embodiment, the number of substrates S that can be formed by HVPE is the same as the number of substrates S that can be formed by MOCVD. Therefore, for example, since all the substrates S formed in the HVPE process can be processed in the MOCVD process, the manufacturing efficiency is good. Furthermore, since the film formation process can be continuously performed by HVPE and MOCVD without removing the substrate S from the film formation chamber 4, for example, after the HVPE process, the film formation process is started by MOCVD. It can be suppressed that S is contaminated or crystallinity is deteriorated by evaporation of surface atoms.

In this embodiment, the example in which the GaN film is formed as the III-V compound semiconductor film has been described, but the present invention is not limited to this. For example, as another example, when forming a GaAlN film, an Al source may be disposed in the second inner tube 213 of the first supply unit 2 in addition to the Ga source. Further, the second supply unit 3 may supply trimethylaluminum in addition to trimethylgallium as the third source gas.

The vapor phase growth apparatus 1 stores various information related to conditions suitable for the HVPE process and the MOCVD process in the storage unit, and the film is automatically formed when the user inputs a signal requesting the start of each process. May be configured. For example, the vapor phase growth apparatus 1 can be configured as described in Japanese Patent Application Laid-Open No. 2013-222284 and film formation can be performed.

In the present embodiment, the exhaust flow rate control unit 93 controls the exhaust flow rate of the second exhaust unit 7 based on the proper exhaust flow rate by the second exhaust unit 7 input from the appropriate exhaust flow rate calculation unit 92. Although the configured example has been described, the present invention is not limited to this. For example, the exhaust flow rate control unit 93 may be configured to control the second exhaust unit 7 based on information input by the user instead of the appropriate exhaust flow rate input from the appropriate exhaust flow rate calculation unit 92. Good. The information input by the user is, for example, information indicating the flow rate to be exhausted by the second exhaust means 7 that is arbitrarily set, or information indicating the value that the pressure inside the pipe provided in the second exhaust means 7 should take. sell.

In the present embodiment, the vapor phase growth apparatus 1 includes one first supply pipe 21 and one second supply pipe 31, but includes a plurality of first supply pipes 21 and a plurality of second supply pipes 31. May be.

In the present embodiment, the example in which the substrate S is transported in the film forming chamber 4 by the rotation of the susceptor 51 and the staying gas is generated in the vicinity of the rotation axis L is described, but the present invention is not limited to this. For transporting the substrate S, linear driving or the like is also possible. In this case, the region where the gas can be accumulated differs depending on the arrangement of the gas supply port, the exhaust port, the configuration of the transfer means, etc. in the film forming chamber 4, and the position where the exhaust port of the second exhaust means 7 is to be arranged is also different. Different. The region where the gas can be accumulated can be known using, for example, a fluid simulation. The second exhaust means 7 may be provided so as to exhaust the staying gas generated in the vicinity of the substrate S.

In the present embodiment, an example in which the exhaust port of the first exhaust unit 6 is provided on the bottom surface of the film forming chamber 4 on the lower surface side of the outer peripheral portion of the susceptor 51 has been described. However, the present invention is not limited to this. It may be provided so as not to affect the exhaust of the staying gas by the second exhaust means 7 and the supply of the raw material gas to the substrate S.

In the film forming method using the vapor phase growth apparatus 1 according to the present embodiment, the staying gas is exhausted by the second exhaust means 7 in the HVPE process or the MOCVD process. Do not mean. Under the condition that a uniform film can be formed without exhausting the staying gas, the film can be formed by appropriately evacuating the second exhaust means 7.

(Second Embodiment)
The vapor phase growth apparatus 1 according to the second embodiment has the same configuration as the vapor phase growth apparatus 1 according to the first embodiment except that a fifth supply pipe 722 is further provided. The fifth supply pipe 722 supplies an auxiliary gas containing a group V element to the non-film-deposited substrate S. This will be described in detail below.

FIG. 11 is a view showing the structure of the exhaust pipe 721 and the fifth supply pipe 722 of the second exhaust means 74 according to the present embodiment. This drawing is a cross-sectional view of the exhaust pipe 721 and the tip of the fifth supply pipe 722 as seen from the direction orthogonal to the rotation axis L. Further, in this drawing, the flow direction of the staying gas discharged from the film formation chamber 4 and the auxiliary gas supplied to the film formation chamber 4 is indicated by arrows. The fifth supply pipe 722 and the exhaust pipe 721 of the second exhaust means 74 form a double pipe structure.

FIG. 12 shows the first supply unit 2, the second supply unit 3, the susceptor 51, the exhaust pipe 721 of the second exhaust means 74, the fifth supply pipe 722, the supply port 724, the rotating shaft L, and the substrate according to the present embodiment. It is a figure which shows the positional relationship of S. This figure shows a positional relationship when the susceptor 51 is viewed from the top surface in a plan view. The direction in which the auxiliary gas is supplied from the supply port 724 is indicated by an arrow. The parts with different heights and the parts that are actually hidden are shown by solid lines.

A fifth supply pipe 722 is connected to the film forming chamber 4 of the vapor phase growth apparatus 1 according to the present embodiment. The tip of the fifth supply pipe 722 is inserted into the film forming chamber 4. The fifth supply pipe 722 supplies an auxiliary gas containing a group V element to the substrate S not facing the supply port to which the source gas is supplied during film formation. Here, the auxiliary gas only needs to contain a group V element contained in the second source gas and the fourth source gas, and examples thereof include any one or more of ammonia gas, nitrogen gas, and hydrazine gas. . Of these, ammonia gas is preferred from the viewpoint of good decomposability.

When the group V element contained in the second source gas supplied from the second supply port 215 and the group V element contained in the fourth source gas supplied from the fourth supply port 312 are different, A gas containing the same group V element as the group V element contained in the source gas supplied during the film formation is supplied from the fifth supply pipe 722 into the film formation chamber 4. That is, the gas contains the same group V element as the group V element contained in the second source gas in the HVPE process and in the fourth source gas in the MOCVD process.

The exhaust pipe 721 is inserted into the fifth supply pipe 722 to form a double pipe structure in which the exhaust pipe 721 is an inner pipe and the fifth supply pipe 722 is an outer pipe. The fifth supply pipe 722 and the exhaust pipe 721 have at least tip portions extending in parallel with the rotation axis L. In the present embodiment, the fifth supply pipe 722 and the exhaust pipe 721 extend on the rotation axis L.

Returning to FIG. 11, an exhaust port 723 is provided at the tip of the exhaust pipe 721. The exhaust port 723 faces the upper surface of the susceptor 51 and is located above the center of rotation of the susceptor 51. The staying gas generated by the rotation of the susceptor 51 passes through the exhaust pipe 721 through the exhaust port 723 and is exhausted outside the film forming chamber 4.

A supply port 724 is provided near the tip of the fifth supply pipe 722. An end surface in the extending direction of the fifth supply pipe 722 is closed in the film forming chamber 4, and a plurality of supply ports 724 are provided on the side surface near the tip of the fifth supply pipe 722 so as to be spaced apart in the circumferential direction. ing. The auxiliary gas passes through the inside of the fifth supply pipe 722 and the outside of the exhaust pipe 721, and is supplied into the film forming chamber 4 from the plurality of supply ports 724. The auxiliary gas that has passed through the fifth supply pipe 722 is released in a direction parallel to the upper surface of the susceptor 51. Further, the auxiliary gas is supplied radially as shown in FIG. 12 from the center of the susceptor 51 toward the outer periphery. Therefore, the auxiliary gas is supplied toward the top of the plurality of substrates S. Note that the distance between the supply port 724 and the susceptor 51 is longer than the distance between the exhaust port 723 and the susceptor 51.

Here, the auxiliary gas is supplied only to the plurality of substrates S that are not opposed to the supply port of the first supply pipe 21 and the supply port of the second supply pipe 31, that is, in the third arrangement. Specifically, a straight line connecting the center of the supply port of the first supply pipe 21 and the center of the fifth supply pipe 722, and the center of the second supply pipe 31 and the center of the fifth supply pipe 722 are arranged. The supply port 724 is not formed on the connecting straight line. The auxiliary gas may be supplied to the surface of the substrate S to which no source gas is supplied. That is, the auxiliary gas is supplied toward the plurality of substrates S having the second arrangement and the third arrangement in the HVPE process, and toward the plurality of substrates S having the first arrangement and the third arrangement in the MOCVD process. , It may be configured to be switchable.

In the present embodiment, the example in which the plurality of supply ports 724 are provided on the side surface in the vicinity of the tip of the fifth supply pipe 722 so as to be spaced apart in the circumferential direction has been described, but the supply port 724 and the susceptor 51 The distances may all be the same or different. However, from the viewpoint of keeping the gas concentration on the surface of the substrate S as constant as possible regardless of the arrangement, the distance is preferably the same for all the supply ports 724.

Next, the flow rate for supplying the auxiliary gas will be described.
For example, in the HVPE process, when the substrate S is located in the film formation region immediately below the supply port of the first supply pipe 21 (first arrangement), the group III atom concentration and the group V atom concentration on the surface of the substrate S are high. Become. On the other hand, while the substrate S revolves around the rotation axis L, the substrate S is temporarily located in another region that is not the film formation region, and the group III atom concentration on the surface of the substrate S becomes approximately zero. .

Here, an auxiliary gas containing a group V element is supplied from the fifth supply pipe 722. The supply flow rate of auxiliary gas from the fifth supply pipe 722 (V group atom supply amount per unit time) is the supply flow rate of the second source gas from the second supply port 215 (V group atom supply amount per unit time). Less than. For example, the supply flow rate of the auxiliary gas from the fifth supply pipe 722 is 1/100 to 1/2 the supply flow rate of the second source gas from the second supply port 215. As described above, since the gas containing the group V element is supplied from the fifth supply pipe 722, the group V atom concentration on the surface of the substrate S located in another region that is not the film formation region is located in the film formation region. Although it is lower than the group V atom concentration on the surface of the substrate S, it does not become zero. For this reason, it is possible to apply a certain pressure to the group V atoms on the surface of the substrate S, and to prevent the group V atoms from separating from the surface of the substrate S. On the other hand, when the group V atom concentration on the surface of the substrate S is lowered, the pressure applied to the group III atom is lowered, the group III atom is diffused on the surface, and reaches the kink or step formed on the growth surface. By growing crystals in this manner, a good crystal film that inherits the crystallinity of the underlayer can be obtained.

Here, the HVPE process has been described as an example, but the same applies to the MOCVD process. Note that the optimal auxiliary gas supply flow rate may differ between the HVPE process and the MOCVD process.

Note that the appropriate exhaust flow rate calculation unit 92 of the vapor phase growth apparatus 1 according to the present embodiment may be configured to calculate the appropriate exhaust flow rate by the second exhaust unit 74 by further taking into account the supply flow rate of the auxiliary gas. good. At that time, the storage unit 91 supplies the supply flow rate of the gas supplied from the first supply port 214, the supply flow rate of the gas supplied from the second supply port 215, and the gas supplied from the third supply port 311. The relationship between the supply flow rate of the gas, the supply flow rate of the gas supplied from the fourth supply port 312, the supply flow rate of the auxiliary gas, the rotation speed of the substrate S, and the appropriate exhaust flow rate of the stagnant gas by the second exhaust means 74. The indicated information is held in advance as appropriate exhaust reference information.

Next, the operation and effect of this embodiment will be described. In this embodiment, the same operation and effect as in the first embodiment can be obtained. In addition, the following actions and effects can be obtained.

The vapor phase growth apparatus 1 according to this embodiment includes a fifth supply pipe 722 that supplies a gas containing a group V element to the substrate S located in another region that is not a film formation region. By supplying the auxiliary gas containing the group V element from the fifth supply pipe 722, a constant pressure can be applied to the group V atoms on the surface of the substrate S in a state where the source gas is not supplied. The group V atoms can be prevented from leaving from the surface of S. In particular, the supply flow rate of the auxiliary gas from the fifth supply pipe 722 is set to the driving gas supply unit, that is, the second source gas or the fourth source gas supplied from the first supply unit 2 or the second supply unit 3. By reducing the flow rate below the supply flow rate, a certain pressure can be applied to the group V atoms on the surface of the substrate S while promoting the diffusion of the group III atoms on the surface of the substrate S, and the group V atoms are desorbed. Can be prevented. Therefore, a group III-V compound semiconductor film with good crystal quality can be formed.

Further, the fifth supply pipe 722 according to the present embodiment is provided separately from the first supply pipe 21 and the second supply pipe 31 and is an independent pipe different from these supply pipes. In addition to the amount of gas supplied from the second supply pipe 31, the amount of auxiliary gas supplied can be controlled independently. Thereby, the pressure on the surface of the substrate S can be set to a desired pressure, and the optimum pressure is applied to the group V atoms on the surface of the substrate S while promoting the diffusion of the group III atoms on the surface of the substrate S on the surface of the substrate S. Can be granted. Therefore, a group III-V compound semiconductor film with good crystal quality can be formed.

In the vapor phase growth apparatus 1 according to the present embodiment, the auxiliary gas is supplied from the fifth supply pipe 722 toward the upper portion of the substrate S in the region other than the growth region. The group V atom concentration on the surface of a certain substrate S can be kept relatively constant.

Further, in the present embodiment, the fifth supply pipe 722 is configured to supply gas toward an area excluding the film formation area directly below the first supply pipe 21 and the second supply pipe 31. Specifically, a supply port 724 is formed at the distal end portion of the fifth supply pipe 722. This supply port 724 is viewed in a plan view from the direction of the rotation axis, that is, viewed from a direction in which the susceptor 51 is viewed in a plan view. And not formed on the straight line connecting the center of the first supply pipe 21 and the center of the fifth supply pipe 722 and on the straight line connecting the center of the second supply pipe 31 and the center of the fifth supply pipe 722. . By using the fifth supply pipe 722 having such a structure, the flow of the raw material gas supplied from the supply port of the first supply pipe 21 and the flow of the raw material gas supplied from the supply port of the second supply pipe 31 Is prevented from being disturbed by the gas supplied from the fifth supply pipe 722. In addition, the value of the V / III ratio (the group V atom concentration with respect to the group III atom concentration) in the gas supplied from the first supply tube 21 or the second supply tube 31 varies depending on the gas supplied from the fifth supply tube 722. Can also be prevented.

Further, in the present embodiment, one fifth supply pipe 722 is disposed inside the circumference drawn by the substrate S, and gas is discharged radially from the fifth supply pipe 722. This eliminates the need to provide a large number of supply pipes. Furthermore, in this embodiment, since the tip of the fifth supply pipe 722 is located on the rotation axis L, the substrate S is located at any position on the circumference drawn by the substrate S revolving around the rotation axis L. Even in some cases, the distance between the fifth supply pipe 722 and the substrate S is constant. An auxiliary gas containing a group V element is supplied from the fifth supply pipe 722 toward the upper portion of the substrate S. However, the concentration of the auxiliary gas on the revolving substrate S can be kept relatively constant.

Further, in the vapor phase growth apparatus 1 according to this embodiment, the exhaust pipe 721 and the fifth supply pipe 722 of the second exhaust means 74 are arranged on the rotation axis L in a double pipe structure, It is possible to achieve both the exhaust of the accumulated gas and the supply of the auxiliary gas at the upper part of the rotation center of the susceptor 51. In particular, the exhaust port 723 of the second exhaust unit 74 is provided to face the surface of the susceptor 51, and the supply port 724 of the fifth supply pipe 722 emits auxiliary gas in a direction orthogonal to the side surface of the exhaust pipe 721. For this reason, the flow of the staying gas discharged and the supplied auxiliary gas are not hindered from each other. Therefore, a film with good crystal quality can be formed with a uniform film thickness in the in-plane direction.

Further, in the vapor phase growth apparatus 1 according to the present embodiment, since the exhaust pipe 721 and the fifth supply pipe 722 of the second exhaust means 74 have a double pipe structure, a heat shielding effect is obtained. That is, since the auxiliary gas flows through the outer peripheral portion of the exhaust pipe 721, it is possible to suppress the heat of the high-temperature staying gas passing through the exhaust pipe 721 from being transmitted to the structure portion outside the fifth supply pipe 722. . For this reason, the structure around the fifth supply pipe 722 is not greatly affected by heat, and heat resistance is not required. Therefore, the degree of freedom in design can be increased. In addition, stable film formation can be achieved.

In addition, although this embodiment demonstrated the case where the 5th supply pipe 722 and the exhaust pipe 721 of the 2nd exhaust means 74 comprised a double pipe structure, it is not limited to this. The fifth supply pipe 722 and the exhaust pipe 721 may be provided as a single pipe, or may be provided at different locations. In that case, the fifth supply pipe 722 may be provided so as to supply the auxiliary gas to the substrate S not in the growth region, and the exhaust pipe 721 may be provided so as to exhaust the staying gas.

In this embodiment, an example in which gas is supplied radially from one fifth supply pipe 722 has been described, but the present invention is not limited to this. For example, a plurality of fifth supply pipes 722 may be provided. In this case, each fifth supply pipe 722 is positioned on the circumference drawn by the revolving substrate S, and can be configured to face the substrate S in the third arrangement. Thereby, a gas containing a group V element may be supplied onto the substrate S.

As described above, the embodiments of the present invention have been described with reference to the drawings. However, these are exemplifications of the present invention, and various configurations other than the above can be adopted.

Example 1
Using a vapor phase growth apparatus as described in the second embodiment, a gallium nitride (GaN) film was formed on a sapphire substrate by MOCVD. A sapphire substrate was placed on the susceptor, and the chamber (film formation chamber 4) was evacuated to a vacuum. During the film formation, the rotational speed of the susceptor was driven at 30 rpm. In addition, ammonia (NH ₃ ) gas is supplied at 2 L / min from the periphery of the double pipe (the supply port 724 of the fifth supply pipe 722) disposed at the upper center of the susceptor during film formation. Exhaust was performed from the center pipe (exhaust pipe 721 of the second exhaust means 74). The central tube was connected to an exhaust pump via a needle valve. As a source gas, first, trimethylgallium gas is supplied from the third supply port 311 at a flow rate of 4.8 cc / min, and ammonia gas is supplied from the fourth supply port 312 at a flow rate of 8 L / min. The film was formed for 5 minutes. Next, the flow rate of trimethylgallium gas supplied from the third supply port 311 is switched to 10 cc / min, the flow rate of ammonia gas supplied from the fourth supply port 312 is switched to 12 L / min, and the substrate temperature is 1000 ° C. for 15 minutes. Then, film formation was performed. The exhaust flow rate from the central tube was controlled based on the pressure so as to be 600 hPa immediately before the needle valve. Further, the chamber was evacuated by the evacuation means (first evacuation means 6) so that the pressure in the chamber was 666 hPa.

FIG. 13 is a diagram showing the film thickness distribution of the GaN film according to this example. The film thickness distribution was measured with an optical non-contact film thickness measuring device. This figure also shows the measurement results of three substrates (depicted by different markers in the figure) on which film formation has been performed at once. In this figure, the horizontal axis indicates the distance from the center of the susceptor (rotation axis L), and the vertical axis indicates the film thickness of the formed GaN film. From this figure, it can be seen that the film was formed with a uniform film thickness. In addition, even when the same film formation was repeated, or when the same film formation was performed under a plurality of different conditions, the in-plane film thickness non-uniformity was suppressed from batch to batch. And the improvement in yield was confirmed.

(Example 2)
Using a vapor phase growth apparatus as described in the second embodiment, a gallium nitride (GaN) film was formed on a GaN template by HVPE. The GaN template was placed on the susceptor, and the chamber (film formation chamber 4) was evacuated to a vacuum. During the film formation, the rotational speed of the susceptor was driven at 5 rpm. In addition, ammonia (NH ₃ ) gas was supplied at a rate of 0.5 L / min from the periphery of the double pipe (the supply port 724 of the fifth supply pipe 722) disposed at the upper center of the susceptor during film formation. Here, the exhaust flow rate from the central pipe (exhaust pipe 721 of the second exhaust means 74) of the same double pipe was controlled based on the pressure so as to be 600 hPa immediately before the needle valve. Further, the chamber was evacuated by the evacuation means (first evacuation means 6) so that the pressure in the chamber was 666 hPa. As source gases, GaCl gas is supplied from the first supply port 214 at a flow rate of 300 cc / min, ammonia gas is supplied from the second supply port 215 at a flow rate of 6 L / min, and the substrate temperature is 1000 ° C. for 5 minutes. Film formation was performed.

FIG. 14 is a diagram showing the film thickness distribution of the GaN film according to this example. In this figure, the horizontal axis indicates the distance from the center of the susceptor (rotation axis L), and the vertical axis indicates the film thickness of the formed GaN film. From this figure, it can be seen that in HVPE, the film was formed with a uniform film thickness without exhausting from the central tube.

In addition, in the film formation by HVPE, even when the exhaust from the central tube is not performed, the film formation with a uniform film thickness may be possible. On the other hand, in particular, when the raw material gas flow rate was increased and the film growth rate was increased, there was a high tendency for non-uniform film thickness distribution without exhaust from the central tube. By exhausting from the central tube, even when the raw material gas flow rate was increased, a film having a uniform film thickness could be stably formed.
In addition, even if the same film is formed repeatedly by exhausting from the central tube, or even if the film is formed in the same way under different conditions, the in-plane film thickness non-uniformity varies from batch to batch. Was suppressed. And the improvement in yield was confirmed.

(Comparative example)
Using a vapor phase growth apparatus as described in the second embodiment, a gallium nitride (GaN) film was formed on a sapphire substrate by MOCVD. A sapphire substrate was placed on the susceptor, and the chamber (film formation chamber 4) was evacuated to a vacuum. During the film formation, the rotational speed of the susceptor was driven at 5 rpm. In addition, ammonia gas was supplied at a rate of 2 L / min from around the double pipe (the supply port 724 of the fifth supply pipe 722) disposed at the upper center of the susceptor during film formation. Here, no exhaust was performed from the central pipe (exhaust pipe 721 of the second exhaust means 74) of the same double pipe. As a source gas, first, trimethylgallium gas is supplied from the third supply port 311 at a flow rate of 4.8 cc / min, and ammonia gas is supplied from the fourth supply port 312 at a flow rate of 8 L / min. The film was formed for 5 minutes. Next, the flow rate of trimethylgallium gas supplied from the third supply port 311 is switched to 10 cc / min, the flow rate of ammonia gas supplied from the fourth supply port 312 is switched to 12 L / min, and the substrate temperature is 1000 ° C. for 15 minutes. Then, film formation was performed. The first exhaust means 6 was controlled so that the pressure in the chamber was 660 hPa.

FIG. 15 is a view showing the film thickness distribution of the GaN film according to this comparative example. In this figure, the horizontal axis indicates the distance from the center of the susceptor (rotation axis L), and the vertical axis indicates the film thickness of the formed GaN film. This figure also shows the measurement results of three substrates (depicted by different markers in the figure) on which film formation has been performed at once. From this figure, it can be seen that the film thickness of the GaN film formed on the substrate is non-uniform and is thicker as it is closer to the center of the susceptor (rotation axis L). In addition, when the same film formation was repeated, or when the same film formation was performed under a plurality of different conditions, the in-plane film thickness non-uniformity was large between batches.

This application claims priority based on Japanese Patent Application No. 2014-122402 filed on June 17, 2014, the entire disclosure of which is incorporated herein.

Claims

A deposition chamber in which at least one substrate is disposed, and a group III-V compound semiconductor film is formed on the substrate;
A first supply unit that introduces a first source gas containing a halogen element and a group III element into the film formation chamber, and a second source gas that reacts with the first source gas to form a film on the substrate;
A second supply unit for introducing a third source gas containing an organic metal into the film formation chamber and a fourth source gas that reacts with the third source gas to form a film on the substrate;
Transport means for transporting the substrate in the film forming chamber;
A first exhaust means for exhausting and evacuating the gas in the film forming chamber;
The first supply unit includes:
A first supply port for supplying the first source gas toward the substrate;
A second supply port for supplying the second source gas toward the substrate;
Without mixing the first source gas and the second source gas with each other, each led to the first supply port and the second supply port,
The second supply unit includes:
A third supply port for supplying the third source gas toward the substrate;
A fourth supply port for supplying the fourth source gas toward the substrate;
Without mixing the third source gas and the fourth source gas with each other, led to the third supply port and the fourth supply port,
The transport means includes a susceptor that rotates around a rotation axis;
The first supply port, the second supply port, the third supply port, and the fourth supply port are provided near the upper surface of the susceptor, and are opposed to the upper surface.
The transfer means includes a first arrangement in which the substrate arranged on the susceptor is opposed to the first supply port and the second supply port, and a first arrangement in which the substrate is opposed to the third supply port and the fourth supply port. 2 between the first and second supply ports, the second supply port, the third supply port, and the fourth supply port.
A second exhaust means for exhausting the film formation chamber independently of the first exhaust means;
The second exhaust unit is a vapor phase growth apparatus that exhausts a staying gas generated on the rotating shaft of the transport unit and in the vicinity of the upper surface of the susceptor.
The vapor phase growth apparatus according to claim 1,
The susceptor has a disk shape,
The rotation axis passes through the center of the susceptor and is perpendicular to the top surface of the susceptor;
The exhaust port of the first exhaust means is a vapor phase growth apparatus provided along the outer edge of the susceptor when viewed from a plan view of the substrate on the susceptor.
The vapor phase growth apparatus according to claim 1 or 2,
A supply flow rate of gas supplied from the first supply port, a supply flow rate of gas supplied from the second supply port, a supply flow rate of gas supplied from the third supply port, and the fourth supply port A storage unit in which appropriate exhaust reference information indicating a relationship between a supply flow rate of the gas supplied from, a rotation speed of the susceptor, and an appropriate exhaust flow rate of the staying gas by the second exhaust unit is held;
An appropriate exhaust flow rate calculation unit for calculating an appropriate exhaust flow rate by the second exhaust means;
An exhaust flow rate control unit that controls the second exhaust unit so as to exhaust at an appropriate exhaust flow rate calculated by the second exhaust unit calculated by the appropriate exhaust flow rate calculation unit;
A pressure control unit for controlling the first exhaust means so that the film forming chamber has a predetermined pressure;
The appropriate exhaust flow rate calculation unit includes the appropriate exhaust reference information read from the storage unit, and a supply flow rate of gas supplied from the first supply port, which is measured when a film is formed on the substrate. A supply flow rate of the gas supplied from the second supply port, a supply flow rate of the gas supplied from the third supply port, a supply flow rate of the gas supplied from the fourth supply port, and the rotational speed. Based on the above, a vapor phase growth apparatus for calculating an appropriate exhaust flow rate by the second exhaust means.
The vapor phase film forming apparatus according to any one of claims 1 to 3,
A vapor phase growth apparatus further comprising a fifth supply pipe for supplying an auxiliary gas containing a group V element to the substrate in the third arrangement.
The vapor phase growth apparatus according to claim 4.
A vapor phase growth apparatus in which the fifth supply pipe and the exhaust pipe of the second exhaust means form a double pipe structure.
In the vapor phase film forming apparatus according to any one of claims 1 to 4,
The exhaust pipe of the second exhaust means has a double pipe structure at least in part, a vacuum is formed between the outer pipe and the inner pipe of the double pipe structure, and the staying gas passes through the inside of the inner pipe. Vapor phase growth equipment exhausted.
In the vapor phase growth apparatus according to any one of claims 1 to 6,
The exhaust pipe of the second exhaust means is a vapor phase growth apparatus that extends on the rotating shaft in the film forming chamber.
Disposing at least one substrate in the film formation chamber, evacuating the film formation chamber by a first exhaust means, and evacuating;
A first source gas containing a halogen element and a III element, and a second source gas for reacting with the first source gas to form a film on the substrate are simultaneously supplied into the film formation chamber; A hydride vapor phase growth step of forming a film on at least one of the substrates;
A third source gas containing an organic metal and a fourth source gas for reacting with the third source gas to form a film on the substrate are simultaneously supplied into the film formation chamber, A metal organic chemical vapor deposition step of forming a film on one of the substrates,
In the hydride vapor phase growth step and the organometallic vapor phase growth step,
The substrate disposed on the susceptor is transported in the film forming chamber by a transport unit including a susceptor that rotates around a rotation axis.
A method of forming a group III-V compound semiconductor film, wherein a second exhaust unit independent of the first exhaust unit exhausts stagnant gas generated on the rotating shaft of the transport unit and in the vicinity of the upper surface of the susceptor.