摘要:
The present invention provides a method for producing a compound single crystal that can improve a growth rate and grow a large single crystal with high crystal uniformity in a short time, and a production apparatus used for the method. The compound single crystal is grown while stirring a material solution to create a flow from a gas-liquid interface in contact with a source gas toward the inside of the material solution. With this stirring, the source gas can be dissolved easily in the material solution, and supersaturation can be achieved in a short time, thus improving the growth rate of the compound single crystal. Moreover, the flow formed by the stirring goes from the gas-liquid interface where a source gas concentration is high to the inside of the material solution where the source gas concentration is low, so that dissolution of the source gas becomes uniform. Accordingly, it is possible not only to suppress nonuniform nucleation at the gas-liquid interface, but also to improve the quality of the compound single crystal produced.
摘要:
A method for producing Group-III-element nitride crystals by which an improved growth rate is obtained and large high-quality crystals can be grown in a short time, a producing apparatus used therein, and a semiconductor element obtained using the method and the apparatus are provided. The method is a method for producing Group-III-element nitride crystals that includes a crystal growth process of subjecting a material solution containing a Group III element, nitrogen, and at least one of alkali metal and alkaline-earth metal to pressurizing and heating under an atmosphere of a nitrogen-containing gas so that the nitrogen and the Group III element in the material solution react with each other to grow crystals. The method further includes, prior to the crystal growth process, a material preparation process of preparing the material solution in a manner that under an atmosphere of a nitrogen-containing gas, at least one of an ambient temperature and an ambient pressure is set so as to be higher than is set as a condition for the crystal growth process so that the nitrogen is allowed to dissolve in a melt containing the Group III element and the at least one of alkali metal and alkaline-earth metal. The method according to the present invention can be performed by using, for example, the producing apparatus shown in FIG. 7.
摘要:
A manufacturing apparatus of Group III nitride crystals and a method for manufacturing Group III nitride crystals are provided, by which high quality crystals can be manufactured. For instance, crystals are grown using the apparatus of the present invention as follows. A crystal raw material (131) and gas containing nitrogen are introduced into a reactor vessel (120), to which heat is applied by a heater (110), and crystals are grown in an atmosphere of pressure applied thereto. The gas is introduced from a gas supplying device (180) to the reactor vessel (120) through a gas inlet of the reactor vessel, and then is exhausted to the inside of a pressure-resistant vessel (102) through a gas outlet of the reactor vessel. Since the gas is introduced directly to the reactor vessel (120) without passing through the pressure-resistant vessel (102), the mixture of impurities attached to the pressure-resistant vessel (102) and the like into the site of the crystal growth can be prevented. Further, since the gas flows through the reactor vessel (120), there is no aggregation of an evaporating alkali metal, etc., at the gas inlet or the like, and such an alkali metal does not flow into the gas supplying device (180). As a result, the quality of Group III nitride crystals obtained can be improved.
摘要:
A method for manufacturing Group III nitride crystals with high quality is provided. By the method, a crystal raw material solution and gas containing nitrogen are introduced into a reactor vessel, which is heated, and crystals are grown in an atmosphere of pressure applied thereto. The gas is introduced from a gas supplying device to the reactor vessel through a gas inlet of the reactor vessel, and then is exhausted to the inside of a pressure-resistant vessel through a gas outlet of the reactor vessel. Since the gas is introduced directly to the reactor vessel, impurities attached to the pressure-resistant vessel and the like into the crystal growing site can be prevented. Further, the gas flows through the reactor vessel, to suppress aggregation of an evaporating alkali metal, etc., at the gas inlet and reduce flow of the metal vapor into the gas supplying device.
摘要:
A manufacturing apparatus of Group III nitride crystals and a method for manufacturing Group III nitride crystals are provided, by which high quality crystals can be manufactured. For instance, crystals are grown using the apparatus of the present invention as follows. A crystal raw material (131) and gas containing nitrogen are introduced into a reactor vessel (120), to which heat is applied by a heater (110), and crystals are grown in an atmosphere of pressure applied thereto. The gas is introduced from a gas supplying device (180) to the reactor vessel (120) through a gas inlet of the reactor vessel, and then is exhausted to the inside of a pressure-resistant vessel (102) through a gas outlet of the reactor vessel. Since the gas is introduced directly to the reactor vessel (120) without passing through the pressure-resistant vessel (102), the mixture of impurities attached to the pressure-resistant vessel (102) and the like into the site of the crystal growth can be prevented. Further, since the gas flows through the reactor vessel (120), there is no aggregation of an evaporating alkali metal, etc., at the gas inlet or the like, and such an alkali metal does not flow into the gas supplying device (180). As a result, the quality of Group III nitride crystals obtained can be improved.
摘要:
The present invention provides a method for producing a compound single crystal that can improve a growth rate and grow a large single crystal with high crystal uniformity in a short time, and a production apparatus used for the method. The compound single crystal is grown while stirring a material solution to create a flow from a gas-liquid interface in contact with a source gas toward the inside of the material solution. With this stirring, the source gas can be dissolved easily in the material solution, and supersaturation can be achieved in a short time, thus improving the growth rate of the compound single crystal. Moreover, the flow formed by the stirring goes from the gas-liquid interface where a source gas concentration is high to the inside of the material solution where the source gas concentration is low, so that dissolution of the source gas becomes uniform. Accordingly, it is possible not only to suppress nonuniform nucleation at the gas-liquid interface, but also to improve the quality of the compound single crystal produced.
摘要:
A method for producing Group-III-element nitride crystals by which an improved growth rate is obtained and large high-quality crystals can be grown in a short time, a producing apparatus used therein, and a semiconductor element obtained using the method and the apparatus are provided. The method is a method for producing Group-III-element nitride crystals that includes a crystal growth process of subjecting a material solution containing a Group III element, nitrogen, and at least one of alkali metal and alkaline-earth metal to pressurizing and heating under an atmosphere of a nitrogen-containing gas so that the nitrogen and the Group III element in the material solution react with each other to grow crystals. The method further includes, prior to the crystal growth process, a material preparation process of preparing the material solution in a manner that under an atmosphere of a nitrogen-containing gas, at least one of an ambient temperature and an ambient pressure is set so as to be higher than is set as a condition for the crystal growth process so that the nitrogen is allowed to dissolve in a melt containing the Group III element and the at least one of alkali metal and alkaline-earth metal. The method according to the present invention can be performed by using, for example, the producing apparatus shown in FIG. 7.
摘要:
A manufacturing apparatus of Group III nitride crystals and a method for manufacturing Group III nitride crystals are provided, by which high quality crystals can be manufactured. For instance, crystals are grown using the apparatus of the present invention as follows. A crystal raw material (131) and gas containing nitrogen are introduced into a reactor vessel (120), to which heat is applied by a heater (110), and crystals are grown in an atmosphere of pressure applied thereto. The gas is introduced from a gas supplying device (180) to the reactor vessel (120) through a gas inlet of the reactor vessel, and then is exhausted to the inside of a pressure-resistant vessel (102) through a gas outlet of the reactor vessel. Since the gas is introduced directly to the reactor vessel (120) without passing through the pressure-resistant vessel (102), the mixture of impurities attached to the pressure-resistant vessel (102) and the like into the site of the crystal growth can be prevented. Further, since the gas flows through the reactor vessel (120), there is no aggregation of an evaporating alkali metal, etc., at the gas inlet or the like, and such an alkali metal does not flow into the gas supplying device (180). As a result, the quality of Group III nitride crystals obtained can be improved.
摘要:
The present invention provides a manufacturing method that allows a Group III nitride substrate with a low dislocation density to be manufactured, and a semiconductor device that is manufactured using the manufacturing method. The manufacturing method includes, in an atmosphere including nitrogen, allowing a Group III element and the nitrogen to react with each other in an alkali metal melt to cause generation and growth of Group III nitride crystals. In the manufacturing method, a plurality of portions of a Group III nitride semiconductor layer are prepared, selected as seed crystals, and used for at least one of the generation and the growth of the Group III nitride crystals, and then surfaces of the seed crystals are brought into contact with the alkali metal melt.
摘要:
The present invention provides a Group III nitride crystal substrate whose surface has concavities and convexities reduced in size. The surfaces with concavities and convexities, such as hillocks, pits and facets, of Group III nitride crystals are brought into contact with a melt and thereby the surfaces are subjected to meltback etching or mechanochemical polishing. The melt includes at least one of alkali metal and alkaline-earth metal. Thus a Group III nitride crystal substrate that has reduced strain and a reduced number of defects, which are caused through the processing, and is excellent in surface flatness is manufactured. Furthermore, by the use of the Group III nitride crystal substrate of the present invention, for instance, semiconductor devices of high performance can be obtained.