JP2017200862A - Method and apparatus for manufacturing group iii nitride crystal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and apparatus for manufacturing a group III nitride crystal, capable of achieving improved production efficiency.SOLUTION: A method for manufacturing a group III nitride crystal comprises the steps of:: activating a reactive gas (H) in a reactive gas supply pipe 103 by a coil 104; reacting the activated reactive gas (H) with a group III element-containing source (GaO) 106 to form a group III oxide gas (GaO) being the oxide gas of the group III element containing source; and reacting the group III oxide gas (GaO) with a nitrogen element-containing gas (ammonia) supplied from a nitrogen element-containing gas supply port 113 to form a group III nitride crystal on a seed substrate 116. The apparatus for manufacturing the group III nitride crystal uses the method.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a method and an apparatus for manufacturing a group III nitride crystal.

As a Group III nitride crystal manufacturing apparatus, a manufacturing method using Group III oxide as a raw material has been devised (for example, see Patent Document 1).
A reaction system in this production method will be described. Ga ₂ O ₃ is heated, and H ₂ gas is introduced in this state. The introduced H ₂ gas reacts with Ga ₂ O ₃ to generate Ga ₂ O gas (the following formula (I)). The produced Ga ₂ O gas is reacted with ammonia gas to produce a GaN crystal on the seed substrate (the following formula (II)).
Ga ₂ O ₃ + 2H ₂ → Ga ₂ O + 2H ₂ O (I)
Ga ₂ O + 2NH ₃ → 2GaN + H ₂ O + 2H ₂ (II)

JP 2009-234800 A

However, conventionally, since the reactivity of Ga ₂ O ₃ which is a group III element-containing source and H ₂ which is a reactive gas is low, the supply amount of Ga ₂ O gas which is a group III oxide gas is increased. It was difficult.

  Accordingly, the present invention provides a group III nitride capable of realizing improved production efficiency by increasing the supply amount of group III oxide gas by improving the reactivity between the group III element-containing source and the reactive gas. It is an object of the present invention to provide a crystal manufacturing method and a manufacturing apparatus.

A method for producing a group III nitride crystal according to the present disclosure includes:
Activating a reactive gas;
Reacting the activated reactive gas with a group III element-containing source to generate a group III oxide gas that is an oxide gas of the group III element-containing source;
Reacting the Group III oxide gas with a nitrogen element-containing gas to form a Group III nitride crystal;
Have

In addition, a group III nitride crystal manufacturing apparatus according to the present disclosure includes:
A raw material reaction chamber for installing a group III element-containing source;
A first heater for heating the raw material reaction chamber;
An activation mechanism for activating the reactive gas;
A reactive gas supply pipe for supplying the activated reactive gas into the raw material reaction chamber;
A growth chamber for producing a group III nitride crystal;
A second heater for heating the growth chamber;
A connecting pipe for connecting the raw material reaction chamber and the growth chamber, and introducing a gas obtained by reacting the group III element-containing source and the reactive gas into the raw material reaction chamber;
Is provided.

  According to the method and apparatus for producing a group III nitride crystal according to the present disclosure, the reactivity between the group III element-containing source and the reactive gas can be improved by activating the reactive gas. Thereby, the supply amount of group III oxide gas can be increased, and the improved production efficiency can be realized.

It is a figure which shows an example of a structure of the manufacturing apparatus of the group III nitride crystal of this indication. It is a figure which shows the flowchart of the manufacturing method of the group III nitride crystal of this indication. It is a figure which shows the thermodynamic analysis result of the III group oxide gas production amount of this indication.

The method for producing a group III nitride crystal according to the first aspect includes:
A method for producing a group III nitride crystal comprising:
Activating a reactive gas;
Reacting the activated reactive gas with a group III element-containing source to generate a group III oxide gas that is an oxide gas of the group III element-containing source;
Reacting the Group III oxide gas with a nitrogen element-containing gas to form a Group III nitride crystal;
Have

  The method for producing a group III nitride crystal according to a second aspect is the process of accelerating the flow rate of the activated reactive gas before the step of generating the group III oxide gas in the first aspect. May further be included.

  In the method for producing a group III nitride crystal according to a third aspect, in the second aspect, the step of accelerating the flow rate of the reactive gas may include a step of heating the activated reactive gas. .

  In the method for producing a Group III nitride crystal according to a fourth aspect, in any one of the first to third aspects, the step of generating the Group III oxide gas oxidizes the Group III element-containing source. The group III oxide gas may be produced.

  In the method for producing a Group III nitride crystal according to a fifth aspect, in any one of the first to third aspects, the step of generating the Group III oxide gas reduces the Group III element-containing source. The group III oxide gas may be produced.

In the fourth aspect of the method for producing a Group III nitride crystal according to a sixth aspect, the Group III element-containing source may be Ga ₂ O ₃ .

  In the method for producing a Group III nitride crystal according to a seventh aspect, in the fifth aspect, the Group III element-containing source may be Ga.

In the method for producing a group III nitride crystal according to an eighth aspect, in any one of the first to seventh aspects, the step of generating the group III oxide gas is a step of activating the reactive gas. Performed at a higher temperature than
The step of generating the group III nitride crystal may be performed at a higher temperature than the step of generating the group III oxide gas.

An apparatus for producing a group III nitride crystal according to a ninth aspect includes a raw material reaction chamber for installing a group III element-containing source,
A first heater for heating the raw material reaction chamber;
An activation mechanism for activating the reactive gas;
A reactive gas supply pipe for supplying the activated reactive gas into the raw material reaction chamber;
A growth chamber for producing a group III nitride crystal;
A second heater for heating the growth chamber;
A connecting pipe for connecting the raw material reaction chamber and the growth chamber, and introducing a gas obtained by reacting the group III element-containing source and the reactive gas into the raw material reaction chamber;
Is provided.

  In the ninth aspect, the group III nitride crystal manufacturing apparatus according to the tenth aspect may be configured such that the activation mechanism is a coil that applies a high-frequency electric field to the reactive gas supply pipe.

  In the method for producing a group III nitride crystal according to an eleventh aspect, in any of the ninth and tenth aspects, the second heater may perform heating at a temperature higher than that of the first heater. .

  Hereinafter, a method and an apparatus for producing a group III nitride crystal according to an embodiment will be described with reference to the accompanying drawings. In the drawings, substantially the same members are denoted by the same reference numerals.

(Embodiment 1)
<Group III nitride crystal production apparatus>
Hereinafter, Embodiment 1 of the present disclosure will be described with reference to FIG.
1 is a diagram showing an example of the configuration of a group III nitride crystal production apparatus according to Embodiment 1. FIG. In FIG. 1, the size, ratio, and the like of each component are different from actual ones.
The apparatus for producing a group III nitride crystal in the present disclosure includes a raw material chamber 100 including a raw material reaction chamber 101 and a growth chamber 112 for generating a group III nitride crystal. The raw material chamber 100 and the growth chamber 112 are connected by a connecting pipe 110. A reactive gas supply pipe 103 that supplies a gas that reacts with the starting Ga source 106 is connected to the raw material reaction chamber 101 on the upstream side.

  According to this group III nitride crystal production apparatus, the reactivity between the group III element-containing source and the reactive gas can be improved by activating the reactive gas. Thereby, the supply amount of group III oxide gas can be increased, and the improved production efficiency can be realized.

<Reactive gas supply pipe>
The reactive gas supply pipe 103 is provided with a coil 104. A high frequency electric field is applied to the coil 104 to activate the gas passing through the reactive gas supply pipe 103. The coil 104 is disposed outside and upstream of the raw material reaction chamber 101. Therefore, after the reaction, the reactive gas is introduced into the raw material reaction chamber 101.

<Raw material chamber>
A raw material reaction chamber 101 is arranged in the raw material chamber 100. In the raw material reaction chamber 101, a raw material boat 105 on which a starting Ga source 106 that is a group III element-containing source is placed is disposed. A first heater 107 is provided on the outer periphery of the raw material reaction chamber 101. The starting Ga source 106 is heated by the first heater 107. By supplying a reactive gas to the heated starting Ga source 106, the starting Ga source 106 and the reactive gas react to generate a Group III oxide gas that is an oxide gas of a Group III element-containing source. To do. This group III oxide gas is discharged from a group III oxide gas outlet 108 provided on the downstream side of the raw material reaction chamber 101.

  The raw material chamber 100 is provided with a first carrier gas supply port 102 for supplying the first carrier gas to the raw material reaction chamber 101. The group III oxide gas and the first carrier gas flow from the group III oxide gas and carrier gas discharge port 109 through the connection pipe 110 to the growth chamber 112.

<Growing chamber>
The growth chamber 112 has a group III oxide gas and carrier gas supply port 118, a nitrogen element-containing gas supply port 113, a second carrier gas supply port 114, and an exhaust port 119, and a substrate susceptor 117 on which the seed substrate 116 is installed. Prepare. The substrate susceptor 117 is rotatable. The growth chamber 112 is provided with a nitrogen element-containing gas supply port 113 for introducing a nitrogen element-containing gas. A second heater 115 is provided around the growth chamber 112. The inside of the growth chamber 112 is heated by the second heater 115. The gas introduced from the group III oxide gas and the carrier gas supply port 118 passes through the seed substrate 116 and reaches the exhaust port 119. A second carrier gas supply port 114 is provided to facilitate this flow. The second carrier gas is supplied from the second carrier gas supply port 114. This second carrier gas is substantially the same as the first carrier gas introduced from the first carrier gas supply port 102.

  In the growth chamber 112, the group III oxide gas and the nitrogen element-containing gas meet and react to generate a group III nitride crystal on the seed substrate 116.

<Method for Producing Group III Nitride Crystal>
FIG. 2 is a flowchart of the method for producing a group III nitride crystal of the present disclosure. As shown in FIG. 2, this Group III nitride crystal manufacturing method includes a reactive gas activation step, a Group III oxide gas generation step, and a Group III nitride crystal generation step.
(1) In the reactive gas activation step, the reactive gas that reacts with the group III element-containing source is activated.
(2) In the group III oxide gas generation step, the activated reactive gas and the group III element-containing source are reacted to generate a group III oxide gas.
(3) In the group III nitride crystal generation step, the generated group III oxide gas and the nitrogen element-containing gas are reacted to generate a group III nitride crystal.

  According to this method for producing a group III nitride crystal, since the reactive gas activation step of activating the reactive gas is included, the reaction between the group III element-containing source and the reactive gas is promoted, and a larger amount of III Group oxide gas can be generated. Thereby, the supply amount of group III oxide gas can be increased, and the improved production efficiency can be realized.

<Activation of reactive gas>
First, activation of the reactive gas will be described. The activated reactive gas deactivates with time, and radicals and active oxygen disappear. For this reason, it is desirable to use the activated reactive gas in the Group III oxide gas generation step as soon as possible. In this case, it is preferable to accelerate the flow rate of the reactive gas after activation. As a means for accelerating the flow rate of the reactive gas, heating is preferable. That is, it is desirable to provide an activation gas heating step after the activation step and before the group III oxide gas generation step. At this time, when the activation step is performed, the temperature can be lowered, that is, the flow rate of the reactive gas can be decreased, so that more reactive gas can be activated.

Here, an example of the configuration of a group III nitride crystal manufacturing apparatus for carrying out the above group III nitride crystal manufacturing method will be described with reference to FIG. Here, the case where Ga ₂ O ₃ is used as the group III element-containing source will be described.

  Examples of means for activating the reactive gas include activating means such as a catalyst, direct current discharge, and high frequency discharge. When a catalyst is used, the catalyst material must be disposed in the reactive gas supply pipe 103. When direct current discharge is used, the electrode material must be disposed in the reactive gas supply pipe 103. In those cases, there is a concern that impurities derived from each material are mixed. On the other hand, in the case of activation using high-frequency discharge, there is no need to arrange an electrode material in the reactive gas supply pipe 103, the coil 104 is installed outside the reactive gas supply pipe 103, and the coil 104 has high-frequency power. This can be realized by applying. Thus, the reactive gas is activated in the reactive gas supply pipe 103 by applying a high-frequency electric field to the reactive gas in the reactive gas supply pipe 103 by the coil 104.

  In order to activate the reactive gas in a larger amount, it is desired to lengthen the residence time of the gas in the activation region (region to which the high-frequency electric field is applied). When the temperature is raised, the reactive gas expands, thereby increasing the flow rate of the reactive gas and shortening the residence time in the activated region. For example, compared with the case where the gas temperature is 25 ° C., the flow rate is increased about five times when the gas temperature is 1200 ° C. Therefore, it is preferable to further include a step of activating at a low temperature and then accelerating the flow rate of the activated reactive gas. Specifically, from the viewpoint of efficiency, it is desirable that the temperature of the reactive gas in the activation step is lower than room temperature and higher than the temperature of the condensation point of the reactive gas. In addition, room temperature is 1 degreeC or more and 30 degrees C or less. At this time, it is preferable to provide a heat insulating material between the reactive gas supply pipe 103 and the raw material chamber 100 so that the temperature of the region where the reactive gas is activated is not increased by the heat of the first heater 107.

  In addition, since the flow rate of the reactive gas is inversely proportional to the cross-sectional area of the pipe that passes through at the same flow rate, the cross-sectional area of the flow path of the reactive gas supply pipe 103 is set so that the residence time in the activation region can be prolonged. It is preferable to make it larger than the cross-sectional area of the flow path of the raw material reaction chamber 101.

Furthermore, it is desirable to increase the flow rate by heating the activated reactive gas by the first heater 107 so that the reactive gas can reach the starting Ga source 106 while maintaining the activated state. Since the first heater 107 used in the group III oxide generation process can be diverted to the activated reactive gas acceleration process, the size of the equipment is not increased and the process is complicated. Therefore, the group III oxide gas can be generated more efficiently. A desired amount of group III oxide gas (here, Ga ₂ O gas) can be generated by the reaction between the starting Ga source 106 and the activated reactive gas.

<Production of Group III Oxide Gas>
Next, the method for generating the group III oxide gas is roughly classified into a method for reducing the starting Ga source 106 and a method for oxidizing the starting Ga source 106.

For example, in the reduction method, a Group III element oxide (for example, Ga ₂ O ₃ ) is used for the starting Ga source 106 and a reducing gas (for example, H ₂ gas) is used as the reactive gas. The reducing gas is not limited to H ₂ gas, and for example, hydrocarbon gas such as carbon monoxide gas, methane gas, ethane gas, hydrogen sulfide gas, or sulfur dioxide gas can be used. Note that an oxide of a group III element such as Ga ₂ O ₃ has an advantage that it is easy to handle because it is a stable material in the air.

A reaction system when Ga ₂ O ₃ is used as the starting Ga source and H ₂ gas is used as the reducing gas will be described. The Ga ₂ O ₃ that is the starting Ga source 106 is heated, and in this state, H ₂ gas that is a reducing gas is introduced. The introduced H ₂ gas reacts with Ga ₂ O ₃ to generate Ga ₂ O gas (the following formula (III)). The formula (III) is substantially the same as the above formula (I).
Ga ₂ O ₃ + 2H ₂ → Ga ₂ O + 2H ₂ O (III)

On the other hand, in the oxidation method, a metal (for example, liquid Ga) is used for the starting Ga source 106, and an oxidizing gas (for example, H ₂ O gas or O ₂ gas) is used as the reactive gas. Only when the starting Ga source 106 is liquid Ga, H ₂ gas, which is a reducing gas, may be used as the reactive gas. As the oxidizing gas, CO ₂ gas, CO gas, and the like can also be used. Note that a Group III element metal such as Ga has an advantage that a high-purity material is generally available at a lower cost than a Group III element oxide. Furthermore, since the group III element metal such as Ga becomes a liquid at a low temperature, there is an advantage that it is easy to provide a mechanism for continuously supplying the material.

A reaction system in which Ga is used as the starting Ga source and O ₂ gas is used as the oxidizing gas will be described. Ga which is the starting Ga source 106 is heated, and in this state, O ₂ gas which is an oxidizing gas is introduced. The introduced O ₂ gas reacts with Ga to generate Ga ₂ O gas (the following formula (IV)).
2Ga + 1 / 2O ₂ → Ga ₂ O (IV)

In addition to the starting Ga source 106, an In source and an Al source can be employed as the group III element-containing source. In either case, a group III oxide gas (eg, Ga ₂ O) is generated.

Here, FIG. 3 shows the relationship between the heating temperature of the first heater 107 obtained by thermodynamic analysis and the theoretical generation amount of the group III oxide gas. The supply amount of the reactive gas is 4 slm. The broken line in FIG. 3 indicates that the reactive gas is activated, and the solid line indicates that there is no activation. The vertical axis of the graph indicates the amount of Ga ₂ O produced [g / h], and the horizontal axis indicates the reaction temperature [° C.] between the reactive gas and Ga ₂ O ₃ . From FIG. 3, it can be understood that the activation effect is greatly reduced in a high temperature region of 1900 ° C. or higher.

  Here, the relationship between the first heater 107 and the second heater 115 in FIG. 1 will be described. Impurities (oxygen, carbon, silicon, chlorine, hydrogen, sodium, magnesium, aluminum, titanium, chromium, iron, nickel, molybdenum mixed in the group III nitride crystal in the group III nitride crystal generation step using the second heater 115 , Tantalum, etc.) from the viewpoint of reduction, the second heater 115 needs to be set to 1200 ° C. or higher and lower than 1800 ° C. from the viewpoint of decomposition of the group III nitride crystal.

On the other hand, when the raw material chamber 100 is heated to a temperature higher than that of the growth chamber 112, a reverse reaction of the reaction for generating the group III oxide gas occurs in the growth chamber 112. Therefore, the temperature of the raw material chamber 100 must be less than 1800 ° C. at the highest. Moreover, since the lower limit of the temperature of the 1st heater 107 is conveyed as gas, it is necessary to make it higher than the boiling point of group III oxide gas. Specifically, the boiling point of the Ga ₂ O gas is set to 800 ° C. or higher. That is, the second heater 115 is heated at a temperature of 1200 ° C. or higher and lower than 1800 ° C., and the first heater 107 is heated at a temperature of 800 ° C. or higher and lower than the second heater.

The starting Ga source 106 is placed in the raw material boat 105.
Here, the group III oxide gas is generated in the raw material reaction chamber 101 and then discharged from the group III oxide gas outlet 108. The group III oxide gas is diluted and transported by the first transport gas supplied from the first transport gas supply port 102. Accordingly, the flow rate of the group III oxide gas supplied from the group III oxide gas and the carrier gas discharge port 109 to the growth chamber 112 is adjusted. As the first carrier gas, an inert gas such as Ar or N ₂ or H ₂ gas is used.

<Transportation of group III oxide gas>
The group III oxide gas generated in the raw material reaction chamber 101 is transported to the growth chamber 112 via a connecting pipe 110 that connects the raw material chamber 100 and the growth chamber 112. When the temperature of the connecting pipe 110 that connects the raw material chamber 100 and the growth chamber 112 is lower than the temperature of the raw material chamber 100, the reverse reaction of the reaction that generates the group III oxide gas occurs, and the starting Ga source 106 is connected to the connecting pipe 110. Precipitates within. Accordingly, the connection pipe 110 is heated to a temperature higher than that of the first heater 107 by the third heater 111 so as not to drop below the temperature of the raw material chamber 100.

<Reaction between Group III Oxide Gas and Nitrogen Element-Containing Gas>
The growth chamber 112 is heated to a temperature at which the group III oxide gas and the nitrogen element-containing gas react with each other by the second heater 115. At this time, the temperature of the growth chamber 112 is heated so as not to be lower than the temperature of the raw material chamber 100 in order to prevent the reverse reaction of the reaction for generating the group III oxide gas from occurring. In addition, the temperature of the second heater 115 and the temperature of the third heater 111 are the same because the temperature variation of the growth chamber 112 caused by the Ga ₂ O gas generated in the raw material chamber 100 and the first carrier gas is suppressed. .

  The group III oxide gas is generated in the raw material chamber 100, then passes through the connection pipe 110, and is supplied to the growth chamber 112 that has been heated. On the other hand, the nitrogen element-containing gas is supplied from the nitrogen element-containing gas supply port 113 to the growth chamber 112. By mixing the group III oxide gas and the nitrogen element-containing gas upstream of the seed substrate 116, a group III nitride crystal can be grown on the seed substrate 116.

A reaction system in which Ga ₂ O gas is used as the group III oxide gas and ammonia gas is used as the nitrogen element-containing gas will be described. A Ga ₂ O gas, which is a group III oxide gas, is reacted with ammonia gas, which is a nitrogen element-containing gas, to generate a GaN crystal on the seed substrate (the following formula (V)). The formula (V) is substantially the same as the above formula (II).
Ga ₂ O + 2NH ₃ → 2GaN + H ₂ O + 2H ₂ (V)

  At this time, in order to prevent the nitrogen element-containing gas from being decomposed by the heat from the growth chamber 112, it is preferable to cover the nitrogen element-containing gas supply port 113 and the outer wall of the growth chamber 112 with a heat insulating material.

  In addition, parasitic growth of a group III nitride crystal on the furnace wall of the growth chamber 112 and the substrate susceptor 117 is a problem. Therefore, the occurrence of this problem can be suppressed by controlling the concentration of the group III oxide gas and the nitrogen element-containing gas with the second carrier gas supplied from the second carrier gas supply port 114 to the growth chamber 112.

As the seed substrate 116, for example, gallium nitride, gallium arsenide, silicon, sapphire, silicon carbide, zinc oxide, gallium oxide, or ScAlMgO ₄ can be used.

As the nitrogen element-containing gas, NH ₃ gas, NO gas, NO ₂ gas, N ₂ H ₂ gas, N ₂ H ₄ gas, or the like can be used. Unreacted group III oxide gas, nitrogen element-containing gas, first carrier gas and second carrier gas are exhausted from the exhaust port 119.

  With the above apparatus configuration, the step of generating the group III oxide gas is performed at a higher temperature than the step of activating, and the step of generating the group III nitride crystal generates the group III oxide gas. Performed at a higher temperature than the process.

  Control of each heater, coil 104, gas flow rate, and the like are performed by a control unit (not shown). A circuit board is mounted on the control unit, and a processor or a separate device is provided on the circuit board. A predetermined program is stored in these processors or devices, a predetermined process is executed by the program, and the above-described method is performed.

  As described above, since the group III oxide-containing source and the reactive gas can be efficiently reacted, the generation efficiency of the group III oxide gas can be improved, and the growth rate of the group III nitride crystal can be improved.

Example 1
In Example 1, the Group III nitride crystal was manufactured by specifically setting each condition of the Group III nitride crystal manufacturing method according to Embodiment 1 as follows.
First, the area of the material boat 105 was 300 mm × 150 mm, and the depth was 10 mm. The floor area of the raw material reaction chamber 101 was 450 mm × 170 mm and the height was 12 mm. A carbon heater was used as the first heater 107. The region where the reactive gas is activated in the reactive gas supply pipe 103 by the coil 104 is 10 cm. _Ga 2 _{O 3} in the starting Ga source 106, 4 slm of _{H 2} into the reaction gas, and the _{N 2} using 1slm as a first conveying gas. Electric power with a frequency of 0.5 MHz and 50 W was supplied to the coil 104. The reactive gas was kept at 25 ° C. outside the raw material chamber 100. The heating temperature of the first heater 107 was 1250 ° C. The 3rd heater 111 was 1350 degreeC. NH ₃ gas 10 slm was supplied from the nitrogen element-containing gas supply port 113 to the growth chamber 112, and N ₂ was supplied as the second carrier gas from the second carrier gas supply port 114 for 1 slm. A GaN single crystal substrate was used as the seed substrate 116, the diameter of the seed substrate 116 was 170 mm, and the diameter of the substrate susceptor 117 was 171 mm. A carbon heater was used as the second heater 115. The second heater 115 was set to 1350 ° C. Moreover, a GaN single crystal was produced as a group III nitride crystal.

(Comparative Example 1)
Compared with Example 1, the comparative example 1 is characterized in that the coil 104 provided in the reactive gas supply pipe 103 is eliminated. That is, in Comparative Example 1, a group III nitride crystal was produced under the same conditions as in Example 1 except that the reactive gas was not activated.

In Example 1 and Comparative Example 1, the supply amount of Ga ₂ O gas and the growth rate of the GaN single crystal were evaluated. The amount of Ga ₂ O gas supplied was estimated from the amount of decrease in Ga ₂ O ₃ . The growth rate of the GaN single crystal was estimated from the weight change of the seed substrate before and after the growth. The results are shown in Table 1. Table 1 shows Ga ₂ O supply amounts and GaN growth rates of Example 1 and Comparative Example 1. In Example 1, it was confirmed that the supply amount of Ga ₂ O increased from Comparative Example 1. In addition, with respect to the growth rate of the GaN single crystal, Example 1 improved more than twice as much as Comparative Example 1.

  It should be noted that the present disclosure includes appropriately combining any of the various embodiments and / or examples described above, and each of the embodiments and / or examples. The effect which an Example has can be show | played.

  According to the method and apparatus for producing a group III nitride crystal according to the present disclosure, the reactivity between the group III element-containing source and the reactive gas can be improved by activating the reactive gas. Thereby, the supply amount of group III oxide gas can be increased, and the improved production efficiency can be realized. Therefore, a group III nitride crystal can be obtained with high productivity. Group III nitride crystals are used in optical devices such as LEDs and lasers, and power devices such as transistors and diodes.

100 Raw material chamber 101 Raw material reaction chamber 102 First carrier gas supply port 103 Reactive gas supply pipe 104 Coil 105 Raw material boat 106 Starting Ga source 107 First heater 108 Group III oxide gas outlet 109 Group III oxide gas and carrier gas Discharge port 110 Connection tube 111 Third heater 112 Growth chamber 113 Nitrogen element-containing gas supply port 114 Second carrier gas supply port 115 Second heater 116 Seed substrate 117 Substrate susceptor 118 Group III oxide gas and carrier gas supply port 119 Exhaust port

Claims (11)

A method for producing a group III nitride crystal comprising:
Activating a reactive gas;
Reacting the activated reactive gas with a group III element-containing source to generate a group III oxide gas that is an oxide gas of the group III element-containing source;
Reacting the Group III oxide gas with a nitrogen element-containing gas to form a Group III nitride crystal;
A method for producing a group III nitride crystal comprising:   The method for producing a group III nitride crystal according to claim 1, further comprising a step of accelerating a flow rate of the activated reactive gas before the step of generating the group III oxide gas.   The method for producing a group III nitride crystal according to claim 2, wherein the step of accelerating the flow rate of the reactive gas includes a step of heating the activated reactive gas.   4. The group III nitride crystal according to claim 1, wherein the step of generating the group III oxide gas includes oxidizing the group III element-containing source to produce the group III oxide gas. Manufacturing method.   The group III nitride crystal according to any one of claims 1 to 3, wherein the step of generating the group III oxide gas comprises reducing the group III element-containing source to produce the group III oxide gas. Manufacturing method. The method for producing a group III nitride crystal according to claim 4, wherein the group III element-containing source is Ga ₂ O ₃ .   6. The method for producing a group III nitride crystal according to claim 5, wherein the group III element-containing source is Ga. The step of generating the group III oxide gas is performed at a higher temperature than the step of activating the reactive gas,
The method for producing a group III nitride crystal according to any one of claims 1 to 7, wherein the step of generating the group III nitride crystal is performed at a higher temperature than the step of generating the group III oxide gas. . A raw material reaction chamber for installing a group III element-containing source;
A first heater for heating the raw material reaction chamber;
An activation mechanism for activating the reactive gas;
A reactive gas supply pipe for supplying the activated reactive gas into the raw material reaction chamber;
A growth chamber for producing a group III nitride crystal;
A second heater for heating the growth chamber;
A connecting pipe for connecting the raw material reaction chamber and the growth chamber, and introducing a gas obtained by reacting the group III element-containing source and the reactive gas into the raw material reaction chamber;
An apparatus for producing a group III nitride crystal.   The group III nitride crystal manufacturing apparatus according to claim 9, wherein the activation mechanism includes a coil that applies a high-frequency electric field to the reactive gas supply pipe.   11. The apparatus for producing a group III nitride crystal according to claim 9, wherein the second heater performs heating at a temperature higher than that of the first heater.

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