JPH09227298A - Carbon nitride single crystal film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a carbon nitride single crystal film having excellent crystallinity useful as tools, wear resistant parts, etc., by forming a single crystal film of AlN, etc., as an intermediate layer on a single crystal substrate, and forming the carbon nitride single crystal film having a specified crystalline structure thereon. SOLUTION: The single crystal film 2 of a solid soln. consisting of hexagonal gallium nitride, aluminum nitride, indium nitride, hexagonal silicon carbide, zinc oxide or materials consisting of >=2 kinds thereof is formed as the intermediate layer on the single crystal substrate 1. The carbon nitride single crystal film 3 which has a crystalline structure of β-Si3 N4 type or α-Si3 N4 type and is expressed by the chemical formula C3 N4 is formed on the single crystal film 2. The single crystal film 2 of the intermediate layer is preferably so formed that the (0001) face parallels with the substrate face of the single crystal substrate 1 and that the (0001) face of the carbon nitride single crystal film 3 parallels with the (0001) face of the single crystal film 2. The resulted carbon nitride single crystal film 3 has the excellent crystallinity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carbon nitride film used for tools, wear resistant parts, high thermal conductivity heat sinks, high temperature operating devices, environment resistant devices, light emitting devices and the like.

[0002]

2. Description of the Related Art Diamond has been known as a material having the highest hardness among the materials, but in 1989, Cohen et al. Calculated that carbon nitride β-C ₃ N ₄ is a superhard material that exceeds diamond. Predicted by. β-C ₃ N ₄ is sp3
It is a new substance having a β-Si ₃ N ₄ type crystal structure with a CN bond by a hybrid orbital. Similarly, α-C ₃ N ₄ having an α-Si ₃ N ₄ type crystal structure is also expected to be an ultra-hard material exceeding diamond. Since computer prediction by Cohen et al.
Many attempts have been made to synthesize a thin film of crystalline carbon nitride, that is, β-C ₃ N ₄ or α-C ₃ N ₄ , but most of them were amorphous and crystalline thin films were obtained. Almost never. As a method for synthesizing a crystalline carbon nitride thin film, for example, a method using a sputtering method has been proposed in US005110679A. In this method, a graphite target is sputtered in an atmosphere gas containing nitrogen.A thin film of β-C ₃ N ₄ is deposited on a Si (100) single crystal substrate and α-C ₃ N _{4 is} deposited on a Ge (111) single crystal substrate. Forming a thin film of.

Further, in WO95 / 02709, a method using laser ablation is proposed. This is a method of supplying C atoms by laser ablation of a graphite target on the substrate and N atoms by an atomic nitrogen beam formed by RF plasma, and β-C on Si (100) single crystal substrate and polycrystalline Ni substrate. A thin film of ₃ N ₄ is formed. In addition, Dong.Li et al. Created a laminated film of β-C ₃ N ₄ and TiN on a Si substrate and M ₂ steel by using the sputtering method (Appl.Phys.Lett., 67 (2), 203 (1995)). This is TiN
And C ₃ N ₄ ultra-thin films are alternately laminated, and TiN (111)
By taking advantage of the fact that the lattice mismatch of the atomic arrangement period of β-C ₃ N ₄ (0001) is twice as small as about 7%,
We have succeeded in converting the ₃ N ₄ layer into a β-type crystal.

[0004]

[Problems to be Solved by the Invention] β-C ₃ N ₄ or α-C ₃
When N ₄ is used as a tool or wear resistant part by utilizing its ultra-high hardness, or when it is used as a heat sink by utilizing high thermal conductivity, it must have good crystallinity for the best performance. If possible, a single crystal having no grain boundaries is desirable. Further, when it is used as a semiconductor material for a light emitting device or a high temperature operating device, it is essential that a single crystal film can be synthesized on a substrate. However, all the carbon nitride films obtained in the above-mentioned prior art are polycrystalline films, and no method for obtaining a single crystal film is described.

[0005]

The present invention provides a hexagonal silicon carbide (h-SiC) single crystal having good lattice matching with the (0001) planes of β-C ₃ N ₄ and α-C ₃ N ₄ , and oxidation. Zinc (ZnO) single crystal (0001)
Plane, a (111) plane of magnesium oxide (MgO) single crystal is used as a substrate, and a β-C ₃ N ₄ or α-C ₃ N ₄ is grown on it to obtain a carbon nitride single crystal film That is what was realized. In addition, hexagonal gallium nitride (hG) with good lattice matching with β-C ₃ N ₄ and α-C ₃ N ₄ on a single crystal substrate
aN), aluminum nitride (AlN), indium nitride (In
N), hexagonal silicon carbide (h-SiC), zinc oxide (ZnO), or a solid solution of two or more of these substances, cubic gallium nitride (c-GaN), cubic silicon carbide (c)
-SiC), titanium nitride (TiN), magnesium oxide (M
gO) or a solid solution single crystal film consisting of two or more of these substances and growing β-C ₃ N ₄ or α-C ₃ N ₄ on it to grow a carbon nitride single crystal. It was realized to obtain a film.

Generally, as a method for growing a single crystal film,
Although homoepitaxial growth is often used in which a single crystal of the same substance is used as a substrate and a single crystal film is grown on it, when a large single crystal that can be used as a substrate such as nitride cannot be synthesized, Heteroepitaxial growth is used in which a different material is used as a substrate and a single crystal film is grown thereon. Since carbon nitride cannot also synthesize a large single crystal, a method of synthesizing a single crystal film by heteroepitaxial growth can be considered. As a result of repeated studies and experiments on a base for growing a carbon nitride single crystal film by heteroepitaxial growth, the inventors have found that the following materials are excellent as a base for growing a carbon nitride single crystal film.

1) A solid solution composed of h-GaN, AlN, InN, h-SiC, ZnO, and two or more kinds of these substances. 2) c-GaN, c-SiC, TiN, MgO or 2 of these
Solid solution consisting of more than one type of substance. Generally, the substrate conditions for forming a single crystal film by heteroepitaxial growth are (a) that the rotational symmetry of the atomic arrangement period of the substrate and the film is the same at the interface between the substrate and the film,
And (b) It is important that the difference between the atomic arrangement period of the substrate and the atomic arrangement period of the film is very small, that is, the lattice mismatch is small. The material shown in 1) is carbon nitride (β-C
₃ N ₄ , α-C ₃ N ₄ ) has a hexagonal crystal structure, and its (0001) plane is the same as the (0001) plane of β-C ₃ N ₄ , α-C ₃ N _4. It has an atomic arrangement with 3-fold symmetry. The material shown in 2) has a cubic crystal structure, the (111) plane of which is β-C ₃ N ₄ , α-C ₃ N ₄
It has the same three-dimensional symmetry as the (0001) plane. That is, all of the materials 1) and 2) satisfy the above-mentioned condition (a) for heteroepitaxial growth.

The atomic arrangement period of the (0001) plane of the material 1) is 2
Table 1 shows the lattice mismatch between the atomic number and the atomic arrangement period of the (0001) plane of β-C ₃ N ₄ and α-C ₃ N ₄ . Similarly (2) material (111)
Table 2 shows the lattice mismatch between twice the atomic arrangement period of the plane and the atomic arrangement period of the (0001) plane of β-C ₃ N ₄ and α-C ₃ N ₄ . As is clear from Tables 1 and 2, the materials 1) and 2) both have a double atomic arrangement period and a lattice mismatch between β-C ₃ N ₄ and α-C ₃ N ₄ (0001) planes. It satisfies the condition (b) described above.

[0009]

[Table 1]

[0010]

[Table 2]

Therefore, the single crystal (0001) of the material 1)
If β-C ₃ N ₄ and α-C ₃ N ₄ are grown on the plane, a single crystal film is obtained by epitaxial growth so that the (0001) planes are parallel to each other. Also, β-C ₃ on the (111) plane of the single crystal of the material of 2)
If N ₄ and α-C ₃ N ₄ are grown, a single crystal film is obtained by epitaxial growth so that the (111) plane and the (0001) plane are parallel to each other.
The hexagonal silicon carbide (h-SiC) contained in 1) contains 2H-Si.
There are polytypes of C, 4H-SiC, 6H-SiC, but (0001)
Since all the atomic arrangement periods of the plane are the same, they can all be used in the present invention.

Among 1), it is a solid solution of InN and h-GaN.
In _x Ga _(1-x) N and In _x Al _(1-x) N, which is a solid solution of InN and AlN
And (InN) _x (SiC) _(1-x), which is a solid solution of InN and SiC, makes it possible to reduce the lattice mismatch with carbon nitride to 0 by selecting the optimum composition, and a film with good crystallinity can be obtained. It is particularly desirable because it can be obtained. Theoretically, for In _x Ga _(1-x) N, the lattice mismatch with β-C ₃ N ₄ is 0 at x = 0.087, and the lattice mismatch with α-C ₃ N ₄ is 0 at x = 0.340. Therefore, it is most desirable to grow carbon nitride on In _x Ga _(1-x) N having these compositions, but when growing β-C ₃ N ₄ , x = 0.001 to 0.2.
3. When growing α-C ₃ N ₄ , a carbon nitride single crystal film having sufficiently good crystallinity can be grown if x = 0.19 to 0.48 is used.

Similarly, for In _x Al _(1-x) N, β-C ₃ N at x = 0.251
With _4, the lattice mismatch with alpha-C ₃ N ₄ with x = 0.459 is 0, it is most desirable to use these compositions,
When β-C ₃ N ₄ is grown, x = 0.13 to 0.37 is used, and when α-C ₃ N ₄ is grown, x = 0.34 to 0.57 is used. A carbon single crystal film can be grown. Similarly, in (InN) _x (SiC) _(1-x) , x = 0.300 and β-C ₃ N ₄
, The lattice mismatch with α-C ₃ N ₄ is 0 at x = 0.494, so it is most desirable to use these compositions,
When β-C ₃ N ₄ is grown, x = 0.19 to 0.41 is used, and when α-C ₃ N ₄ is grown, x = 0.38 to 0.60 is used. A carbon single crystal film can be grown.

Not only the above-mentioned combinations but also elemental systems such as In-Ga-Al-N can grow C ₃ N ₄ of α and β by appropriately adjusting the composition ratio. This combination can be selected from all the base materials described in this invention. In the present invention, it is most preferable to use a bulk single crystal of the substance shown in 1) or 2) as a substrate and to grow a carbon nitride single crystal film on it as a crystalline carbon nitride single crystal film. Although it is desirable, a single crystal film of the substance shown in 1) or 2) may be formed as an intermediate layer on a single crystal substrate, and a carbon nitride single crystal film may be grown thereon. Of the substances 1) and 2), h-SiC, ZnO, MgO, etc. are available as bulky single crystals, but other substances are difficult to obtain. It is desirable to use it in the form of being grown as an intermediate layer on a single crystal substrate. The suitable thickness of the intermediate layer is 1 nm or more and 1 μm or less. If it is thinner than this, it is equivalent to the absence of an intermediate layer, and if it is thicker, distortions and defects occur in the intermediate layer itself, and the crystallinity of C ₃ N ₄ formed thereon deteriorates.

When a single crystal film of the substances 1) and 2) is grown on a single crystal substrate, the single crystal substrate may be, for example, sapphire, h-SiC, ZnO (0001) plane, c-SiC, diamond, The (111) plane of Si, BN, MgO, etc. can be used.
As a synthesis method for growing a single crystal film of the substances 1) and 2) on these single crystal substrates, there are thermal CVD method, plasma CVD method, sputtering method, ion plating method, reactive vapor deposition method, MBE method. A known method such as a method or a laser ablation method can be used. GaN, A on single crystal substrate
When growing a single crystal film of lN, InN, or a solid solution of these, in order to grow a film with excellent crystallinity and surface smoothness, a low temperature growth buffer layer of these substances is first formed on the single crystal substrate. It is also possible to use a method in which a single crystal film is grown by growing the single crystal film on the substrate.

For growing a carbon nitride single crystal film on the single crystal substrate of the substances 1) and 2) or on the single crystal film of the substances 1) and 2) formed as an intermediate layer on the single crystal substrate. As the synthesis method, thermal CVD method, plasma CVD method, laser
Known methods such as the CVD method, the sputtering method, the ion beam sputtering method, the ion plating method, the reactive vapor deposition method, the MBE method, and the laser ablation method can be used. In any of the synthesis methods, it is necessary to heat the substrate to a high temperature in order to grow the carbon nitride single crystal film, and the temperature is 600 ° C to 2000 ° C, though it depends on the synthesis method.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 4 shows a thermal CVD apparatus, FIG. 5 shows a plasma CVD apparatus, and FIG. 6 shows a laser CVD apparatus.
In the thermal CVD device, the raw material gas is decomposed by heat to grow carbon nitride on the substrate. Although the substrate is heated at a high frequency in FIG. 4, resistance heating, infrared heating, or the like can be used as a method for heating the substrate. In a plasma CVD device, raw material gas is decomposed by plasma. Figure 5 shows high frequency (RF)
Although a plasma CVD device is shown, a DC plasma CVD device,
A plasma CVD apparatus such as an ECR plasma CVD apparatus or a μ wave plasma CVD apparatus can also be used. Figure 6 shows Laser C
5 shows a VD device. In a laser CVD device, a source gas is decomposed by laser light.

FIG. 7 shows an RF sputtering device. DC sputtering can also be used as the sputtering method. FIG. 8 shows an ion beam sputtering apparatus. While the target is sputtered by the ion source of 50, the substrate is irradiated with ions containing a nitrogen element by the ion source of 42 to grow a carbon nitride film on the substrate. ECR as an ion source
An ion source such as an ion source, an RF ion source, or a Kalfman type ion source can be used.

FIG. 9 shows an ion plating device. Although FIG. 9 shows a high frequency type device, a direct current type device can also be used. As an evaporation source for evaporating raw materials,
Besides the method using the electron beam shown in FIG. 9, resistance heating or high frequency heating can also be used.

FIG. 10 shows a vacuum vapor deposition apparatus used in the reactive vapor deposition method. Evaporate C raw material by electron beam,
A carbon nitride film is grown by reacting with the N source material supplied as a gas on the substrate.

FIG. 11 shows an MBE device. An electron beam evaporation source, a Knudsen cell, or the like is used as the C evaporation source, an ion source such as an ECR ion source, an RF ion source, or a Karfman type ion source is used as the N source, or a gas containing an N element is used as the ion source. Supply directly without.

FIG. 12 shows a laser ablation device. While ablating the target of the C source with laser light, ions containing a nitrogen element are supplied onto the substrate using an ion source. ECR ion source, R as ion source
An ion source such as an F ion source or a Kalfman type ion source can be used. The gas containing the N element may be directly supplied without using the ion source.

In CVD methods such as thermal CVD method, plasma CVD method and laser CVD method, hydrocarbons such as CH ₄ , C ₂ H ₆ and C ₃ H ₈ are used as C raw materials, and N ₂ and NH ₃ are used as N raw materials. Can be used. Plasma such as RF plasma, μ wave plasma, and ECR plasma can be used in plasma CVD. In the sputtering method, the ion beam sputtering method, the ion plating method, the reactive vapor deposition method, the MBE method, and the laser ablation method, carbon solid such as graphite is used as the C raw material, and N ₂ , NH _{3 and the} like are used as the N raw material. Since the carbon nitride synthesized in this way is a single crystal film, it does not contain an extremely large number of grain boundaries and defects like a polycrystalline film and is extremely excellent in crystallinity. It can make the most of the unique properties of C ₃ N ₄ and exhibits excellent properties as a tool, wear resistant parts, and high heat conductivity heat sink.

Further, in the present invention, since a carbon nitride single crystal film having excellent crystallinity can be formed on the substrate, the valence electrons can be controlled by doping an appropriate impurity, and the light emitting element, the high temperature operation element, It can be used as a semiconductor for environmental elements. At this time, Be, B, Mg, Al, Ca, Zn, G
The p-type conductivity is improved by doping a, etc. with O, S,
N-type conductivity can be provided by doping Se or the like. The impurity doping can be performed by supplying impurities as a raw material during film formation or by ion implantation after film formation.

[0025]

【Example】

Example 1 A sapphire (0001) plane was used as a single crystal substrate, an h-GaN single crystal film was grown as an intermediate layer, and a carbon nitride film was formed thereon. The sapphire single crystal substrate is cleaned and then h-Ga is formed by MOCVD (CVD method using organic metal).
An N single crystal film was grown. The cleaning of the substrate was performed by the steps of 1) ultrasonic cleaning with acetone, 2) rinse with pure water, 3) cleaning with 10% hydrogen chloride aqueous solution, and 3) rinse with pure water. H ₂ as a carrier gas at a flow rate of 10 l / min, NH ₃ as a raw material,
TMG (trimethylgallium) 4.0l / min, 30μm
It is introduced into the reaction chamber at a flow rate of ol / min and the substrate temperature is 500 ° C
-The low temperature buffer layer of GaN was grown to 25 nm. Next, with the introduced gas as it was, the substrate temperature was raised to 1000 ° C. and an h-GaN film was grown on the buffer layer for 0.5 minutes to 0.5 μm. When the grown thin film was evaluated by X-ray diffraction, it was confirmed that it was h-GaN, and by RHEED it was a single crystal film in which the (0001) plane was epitaxially grown parallel to the substrate surface.

Further, a carbon nitride film was grown on this h-GaN single crystal film by a sputtering method. Using the RF magnetron sputtering apparatus shown in FIG. 7, using graphite as a target and Ar + N ₂ gas as a film forming gas, film forming pressure of 5 mTorr,
The N ₂ partial pressure was 2.5 mTorr, the RF power was 500 W, the substrate temperature was 1500 ° C., and the substrate bias was 300 V. In the figure, the magnet in the cathode 39 is omitted. When the sample after film formation was evaluated by X-ray diffraction, it was found that it was β-C ₃ N ₄ by β-C ₃ N ₄ (000 for the h-GaN (0001) plane by RHEED.
It was confirmed that the 1) plane was a single crystal film grown in parallel. Results The hardness of the β-C ₃ N ₄ film produced was measured using a micro hardness tester, Knoop hardness have a substantially comparable hardness 5000~7000kg / mm ² of is CVD diamond is 6800kg / mm ² There was found.

Example 2 A sapphire (0001) plane was used as a single crystal substrate, and In _x Ga _(1-x) N (x = 0.1 ₎ was used as an intermediate layer.
0) A single crystal film was grown and a carbon nitride film was formed on it. The sapphire single crystal substrate was washed in the same manner as in Example 1, and an In _x Ga _(1-x) N single crystal film was grown by the MOCVD method.
First, the low temperature buffer layer of h-GaN was formed in the same manner as in Example 1.
It was grown to 5 nm. Next, N ₂ gas as a carrier gas was 10 l / m
At a flow rate of in, NH ₃ , TMI (trimethylindium), and TMG as raw materials were 4.0 l / min, 35 μmol / min, and 1.0 μmol, respectively.
It is introduced into the reaction chamber at a flow rate of / min and the substrate temperature is 800 ° C.
It was grown for 0.25 μm per minute. The grown thin film was In _x Ga _(1-x) N when evaluated by X-ray diffraction, and it was confirmed by RHEED that it was a single crystal film in which the (0001) plane was epitaxially grown parallel to the substrate surface. From the composition analysis result by SIMS, it was confirmed that the composition was x = 0.10.
Further, a carbon nitride film was grown on the In _x Ga _(1-x) N single crystal film by the sputtering method in the same manner as in Example 1. When the sample after film formation was evaluated by X-ray diffraction, it was found to be β-C ₃ N ₄ , which was confirmed by RHEED to be β-C ₃ N ₄ relative to the In _x Ga _(1-x) N (0001) plane.
It was confirmed that the ₃ N ₄ (0001) plane was a single crystal film grown in parallel.

Example 3 A diamond (111) plane was used as a single crystal substrate, and In _x Ga _(1-x) N (x = 0.3 ₎ was used as an intermediate layer.
6) A single crystal film was grown and a carbon nitride film was formed on it. The diamond single crystal substrate was washed in the same manner as in Example 1, and an In _x Ga _(1-x) N single crystal film was grown by the MOCVD method. First, in the same manner as in Example 1, a low-temperature buffer layer of h-GaN was grown to 25 nm. Next, N ₂ gas is used as a carrier gas.
At a flow rate of 10 l / min, NH ₃ , TMI (trimethylindium), and TMG were used as raw materials at 4.0 l / min, 130 μmol / min, and
Introduced into the reaction chamber at a flow rate of 1.0 μmol / min, substrate temperature 800
0.5 μm was grown at 120 ° C. for 120 minutes. The grown thin film is X
In _x Ga _(1-x) N evaluated by line diffraction, R
It was confirmed by HEED that it was a single crystal film in which the (0001) plane was epitaxially grown parallel to the substrate surface, and it was confirmed from the composition analysis result by SIMS that the composition was x = 0.36. Further, a carbon nitride film was grown on the In _x Ga _(1-x) N single crystal film by a sputtering method. The film forming conditions were the same as in Example 1 except that the substrate temperature was 1200 ° C. It was grown for 1 hour to obtain a film thickness of 0.2 μm. When the sample after film formation was evaluated by X-ray diffraction, it was found to be α-C ₃ N ₄ , which was confirmed by RHEED to be α-C ₃ N ₄ (0001) for the In _x Ga _(1-x) N (0001) plane. It was confirmed that the surface was a single crystal film grown in parallel. Results The hardness of the α-C ₃ N ₄ film produced was measured using a micro hardness tester, Knoop hardness have a substantially comparable hardness 5000~7000kg / mm ² of is CVD diamond is 6400kg / mm ² There was found.

Example 4 Si (111) as a single crystal substrate
Using the surface, an In _x Al _(1-x) N (x = 0.24) single crystal film was grown as an intermediate layer, and a carbon nitride film was formed thereon. The Si single crystal substrate was cleaned and an In _x Al _(1-x) N single crystal film was grown by the MOCVD method. The cleaning of the substrate was carried out in the procedure of 1) ultrasonic cleaning with acetone, 2) pure water rinse, 3) oxide film removal with 1.5% hydrogen fluoride aqueous solution for 1 minute, and 3) pure water rinse.
First, the low temperature buffer layer of h-GaN was formed in the same manner as in Example 1.
It was grown to 5 nm. Next, N ₂ gas as a carrier gas was 10 l / m
at a flow rate of in, NH ₃ as a raw material, TMI (trimethyl indium), TMA and (trimethyl aluminum) are 4.0 l /
It was introduced into the reaction chamber at flow rates of min, 80 μmol / min, and 2.0 μmol / min, and 0.5 μm was grown at a substrate temperature of 800 ° C. for 120 minutes.
When the grown thin film was evaluated by X-ray diffraction, In _x Al
_(1-x) N, RHEED confirmed that the (0001) plane was a single crystal film epitaxially grown parallel to the substrate surface, SIMS composition analysis results, x = 0.24 composition Was confirmed. Furthermore, this In _x Al _(1-x) N
A carbon nitride film was grown on the single crystal film by the sputtering method in the same manner as in Example 1. When the sample after film formation was evaluated by X-ray diffraction, it was found to be β-C ₃ N ₄ by RHEED.
It was confirmed that the β-C ₃ N ₄ (0001) plane was a single crystal film grown in parallel to the In _x Al _(1-x) N (0001) plane.

(Example 5) As a single crystal substrate, 6H-SiC (0
An In _x Al _(1-x) N (x = 0.48) single crystal film was grown as an intermediate layer using the ₍ 001) plane, and a carbon nitride film was formed thereon. 6H
-SiC single crystal substrate was washed in the same manner as in Example 4, and MO
An In _x Al _(1-x) N single crystal film was grown by the CVD method. First, in the same manner as in Example 1, a low-temperature buffer layer of h-GaN was grown to 25 nm. Next, N ₂ gas as a carrier gas at a flow rate of 10 l / min and NH ₃ as a raw material, TMI (trimethylindium), and TMA (trimethylaluminum) at 4.0 l / min, respectively.
It was introduced into the reaction chamber at a flow rate of min, 160 μmol / min, and 2.0 μmol / min, and the substrate was grown at a substrate temperature of 800 ° C. for 240 minutes to 1.0 μm. When the grown thin film was evaluated by X-ray diffraction, In _x
Al _(1-x) N, (0001) to the substrate surface by RHEED
It was confirmed that the surface was a single crystal film epitaxially grown in parallel, and it was confirmed from the composition analysis result by SIMS that the composition was x = 0.48. This In _x Al _(1-x)
A carbon nitride film was grown on the N single crystal film by the sputtering method in the same manner as in Example 3. When the sample after film formation was evaluated by X-ray diffraction, it was found to be α-C ₃ N ₄ , which was confirmed by RHEED to be α-C ₃ N ₄ (0001) against the In _x Al _(1-x) N (0001) plane. It was confirmed that the surface was a single crystal film grown in parallel.

Example 6 As a single crystal substrate, 6H-SiC (0
(InN) _x (SiC) _(1-x) (x = 0.3
0) A single crystal film was grown and a carbon nitride film was formed on it. The 6H-SiC single crystal substrate was washed in the same manner as in Example 4, and the (InN) _x (SiC) _(1-x) single crystal film was grown by the MOCVD method. N ₂ gas as a carrier gas at a flow rate of 10 l / min,
NH ₃ as raw materials, TMI (trimethyl indium), SiH
₄ (silane) and C ₃ H ₈ (propane) at 4.0 l / min and 2 respectively
It was introduced into the reaction chamber at a flow rate of 00 μmol / min, 10 μmol / min, 50 μmol / min, and grown at a substrate temperature of 900 ° C. for 0.5 minutes to 0.5 μm. The grown thin film was (InN) _x (SiC) _(1-x) evaluated by X-ray diffraction, and it was a single crystal film in which the (0001) plane was epitaxially grown parallel to the substrate surface by RHEED. Confirmed, from the composition analysis results by SIMS,
It was confirmed to have a composition of x = 0.30. Furthermore this
A C ₃ N ₄ film was grown on the (InN) _x (SiC) _(1-x) single crystal film by the laser ablation method shown in FIG. Pulse YAG
While ablating a graphite target at 100 mJ using a laser, the substrate was irradiated with a 100 eV N ion beam and grown at a substrate temperature of 1500 ° C. for 1 hour to obtain a film thickness of 400 nm. When the sample after film formation was evaluated by X-ray diffraction, it was found to be β-C ₃ N ₄ by RHEED (InN) _x (SiC)
It was confirmed that the β-C ₃ N ₄ (0001) plane was a single crystal film grown in parallel to the _(1-x) (0001) plane.

Example 7 As a single crystal substrate, 6H-SiC (0
(InN) _x (SiC) _(1-x) (x = 0.5
2) A single crystal film was grown and a carbon nitride film was formed on it. The 6H-SiC single crystal substrate was washed in the same manner as in Example 4, and the (InN) _x (SiC) _(1-x) single crystal film was grown by the MOCVD method. N ₂ gas as a carrier gas at a flow rate of 10 l / min,
NH ₃ as raw materials, TMI (trimethyl indium), SiH
₄ (silane) and C ₃ H ₈ (propane) 5.0 l / min,
It was introduced into the reaction chamber at a flow rate of 300 μmol / min, 8 μmol / min, 40 μmol / min, and grown at a substrate temperature of 900 ° C. for 0.5 minutes for 0.5 μm. The grown thin film was (InN) _x (SiC) _(1-x) evaluated by X-ray diffraction, and it was a single crystal film in which the (0001) plane was epitaxially grown parallel to the substrate surface by RHEED. Confirmed, from the composition analysis results by SIMS,
It was confirmed that the composition was x = 0.52. Furthermore this
A C ₃ N ₄ film was grown on the (InN) _x (SiC) _(1-x) single crystal film by a laser ablation method. Substrate temperature is 12
Same as Example 6 except that the temperature was set to 00 ° C. It was grown for 1 hour to obtain a film thickness of 400 nm. When the sample after film formation was evaluated by X-ray diffraction, it was found to be α-C ₃ N ₄ by RHEED.
It was confirmed that the α-C ₃ N ₄ (0001) plane was grown in parallel with the (nN) _x (SiC) _(1-x) (0001) plane to be a single crystal film.

Example 8 Si (111) as a single crystal substrate
A TiN single crystal film was grown as an intermediate layer using the surface, and a carbon nitride film was formed thereon. The Si single crystal substrate was washed in the same manner as in Example 4, and a TiN single crystal film was grown by the sputtering method. Using RF magnetron sputtering equipment, Ti as target, Ar + N ₂ gas as film forming gas, film forming pressure 5 mTorr, N ₂ gas partial pressure 2.5 mTorr, RF power 500 W, substrate temperature 800 ° C. for 60 minutes 0.5 μm. The grown thin film was TiN as evaluated by X-ray diffraction, RH
It was confirmed by EED that the (111) plane was a single crystal film epitaxially grown parallel to the substrate surface. Furthermore this
A carbon nitride film was grown on the TiN single crystal film in the same manner as in Example 1 by the sputtering method. When the sample after film formation was evaluated by X-ray diffraction, it was found to be β-C ₃ N ₄ by RHEED.
As a result, it was confirmed that the β-C ₃ N ₄ (0001) plane was a single crystal film grown in parallel to the TiN (111) plane.

Example 9 As a single crystal substrate, 6H-SiC (0
The 001) surface was used, and a carbon nitride film was formed thereon. 6H-S
The iC single crystal substrate was washed in the same manner as in Example 4, and a carbon nitride film was grown by the laser ablation method in the same manner as in Example 6. When the sample after film formation was evaluated by X-ray diffraction, it was found to be β-C ₃ N ₄ by RHEED.
It was confirmed that the β-C ₃ N ₄ (0001) plane was a single crystal film grown in parallel with the -SiC (0001) plane.

Example 10 As a single crystal substrate, ZnO (00
The (01) surface was used and a carbon nitride film was formed thereon. The ZnO single crystal substrate was washed in the same manner as in Example 1 to obtain Example 6
A carbon nitride film was grown by the laser ablation method in the same manner as in. When the sample after film formation was evaluated by X-ray diffraction, it was found that it was β-C ₃ N ₄ by ZnO (00
It was confirmed that the β-C ₃ N ₄ (0001) plane was a single crystal film grown parallel to the (01) plane.

Example 11 As a single crystal substrate, MgO (11
1) surface was used and a carbon nitride film was formed on it. The MgO single crystal substrate was washed in the same manner as in Example 1 to obtain Example 1.
A carbon nitride film was grown by the sputtering method in the same manner as in. When the sample after film formation was evaluated by X-ray diffraction, it was found to be β-C ₃ N ₄ , and a single crystal in which the β-C ₃ N ₄ (0001) plane was grown parallel to the MgO (111) plane by RHEED. It was confirmed to be a film.

[0037]

As described above, according to the present invention, a carbon nitride single crystal film can be formed on a substrate.

[Brief description of drawings]

FIG. 1 is a diagram showing a structure according to claim 1 of the present invention.

FIG. 2 is a diagram showing a structure according to claim 3 of the present invention.

FIG. 3 is a diagram showing a structure according to claim 6 of the present invention.

FIG. 4 is a schematic sectional view of a thermal CVD apparatus.

FIG. 5 is a schematic sectional view of a plasma CVD apparatus.

FIG. 6 is a schematic sectional view of a laser CVD apparatus.

FIG. 7 is a schematic sectional view of a sputtering apparatus.

FIG. 8 is a schematic sectional view of an ion beam sputtering apparatus.

FIG. 9 is a schematic cross-sectional view of an ion plating device.

FIG. 10 is a schematic cross-sectional view of a vacuum vapor deposition device.

FIG. 11 is a schematic sectional view of an MBE device.

FIG. 12 is a schematic sectional view of a laser ablation device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Single crystal substrate 2 ... Single crystal film 3 ... Carbon nitride single crystal film 4 ... Single crystal substrate 5 ... Single crystal film 6 ... Carbon nitride single crystal film 7 ... Single crystal substrate 8 ... Carbon nitride single crystal film 9 ... Quartz tube 10 ... Exhaust port 11 ... High frequency coil 12 ... Substrate 13 ... Susceptor 14 ... Raw material gas supply port 15. ..High frequency power supply 16 ... exhaust port 17 ... high frequency power supply 18 ... raw material gas supply port 19 ... quartz tube 20 ... high frequency coil 21 ... substrate 22 ... substrate heater 23 ...・ Substrate holder 24 ・ ・ ・ Laser 25 ・ ・ ・ Lens 26 ・ ・ ・ Vacuum tank 27 ・ ・ ・ Material gas supply port 28 ・ ・ ・ Exhaust port 29 ・ ・ ・ Substrate 30 ・ ・ ・ Substrate heater 31 ・ ・ ・ Substrate holder 32 ... Film forming gas supply port 33 ... Vacuum chamber 34 ... Exhaust 35 ... Substrate heater 36 ... Substrate 37 ... Substrate holder 38 ... Target 39 ... Cathode 40 ... High frequency power source 41 ... Raw material gas supply port 42 ... Ion source 43 ... Exhaust port 44 ... Substrate 45 ... Target 46 ... Target holder 47 ... Substrate heater 48 ... Substrate holder 49 ... Vacuum chamber 50 ... Sputtering ion source 51 ... Sputtering Gas supply port 52 ... Vacuum chamber 53 ... Exhaust port 54 ... Substrate heater 55 ... High frequency coil 56 ... Shutter 57 ... Raw material 58 ... Crucible 59 ... Substrate bias DC Power source 60 ... Substrate holder 61 ... Substrate 62 ... Electron gun 63 ... Source gas supply port 64 ... Source gas supply port 65 ... Vacuum chamber 66 ... Exhaust port 7 ... Substrate heater 68 ... Substrate 69 ... Raw material 70 ... Substrate holder 71 ... Shutter 72 ... Crucible 73 ... Electron gun 74 ... Vacuum tank 75 ... Substrate holder 76 ... ECR ion source 77 ... Raw material gas supply port 78 ... Substrate heater 79 ... Substrate 80 ... Shutter 81 ... Knudsen cell 82 ... Raw material 83 ... Exhaust port 84. ..Laser 85 ... Lens 86 ... Vacuum chamber 87 ... Target 88 ... Target holder 89 ... Exhaust port 90 ... Substrate heater 91 ... Substrate holder 92 ... Substrate 93 ... ..Source gas supply port 94 ... Ion source

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location H01L 21/205 H01L 21/205

Claims (6)

[Claims] 1. Hexagonal gallium nitride (h-GaN), aluminum nitride (AlN), as an intermediate layer on a single crystal substrate (1),
The single crystal film (2) of indium nitride (InN), hexagonal silicon carbide (h-SiC), zinc oxide (ZnO), or a solid solution composed of two or more kinds of these materials is formed. It has a structure in which a carbon nitride single crystal film (3) is formed thereon, and the carbon nitride single crystal film is β-Si ₃ N ₄ type or α-S.
A carbon nitride single crystal film having an i ₃ N ₄ type crystal structure and represented by the chemical formula C ₃ N ₄ . 2. An intermediate-layer single crystal film is formed such that a (0001) plane is parallel to a substrate surface of a single crystal substrate, and a carbon nitride single crystal is formed on a (0001) plane of the single crystal film. The carbon nitride single crystal film according to claim 1, wherein the (0001) planes of the film are formed to be parallel to each other. 3. A cubic crystal gallium nitride (c-GaN), a cubic crystal silicon carbide (c-SiC) as an intermediate layer on a single crystal substrate (4),
A solid solution single crystal film (5) made of titanium nitride (TiN), magnesium oxide (MgO) or two or more kinds of these materials is formed, and a carbon nitride single crystal film (6) is formed on the single crystal film. The carbon nitride single crystal film having a formed structure has a β-Si ₃ N ₄ type or α-Si ₃ N ₄ type crystal structure, and is represented by the chemical formula C ₃ N _4. Carbon nitride single crystal film. 4. A single crystal film of an intermediate layer is formed such that a (111) plane is parallel to a substrate surface of a single crystal substrate, and a carbon nitride single crystal is formed on a (111) plane of the single crystal film. The carbon nitride single crystal film according to claim 3, wherein the (0001) planes of the film are formed to be parallel to each other. 5. A sapphire (α-Al ₂
O ₃ ), hexagonal silicon carbide (h-SiC), zinc oxide (ZnO) single crystal (0001) plane, or silicon (Si), diamond, magnesium oxide (MgO) single crystal (111) 4. The carbon nitride single crystal film according to claim 1, wherein one of the surfaces is used. 6. Hexagonal silicon carbide (h-SiC), zinc oxide (Z
(0001) plane of each single crystal of nO) or (111) plane of magnesium oxide (MgO) single crystal is used as a single crystal substrate (7), and a carbon nitride single crystal film (8) is formed on the single crystal substrate. Are formed so that the (0001) plane is parallel to the substrate surface, and the carbon nitride single crystal film has a β-Si ₃ N ₄ type or α-Si ₃ N ₄ type crystal structure, and C ₃ N ₄ A carbon nitride single crystal film having the following chemical formula.