摘要:
The present invention provides a self-supporting substrate obtained by the steps of: forming an Al-based group-III nitride thin-layer having a thickness in the range of 3-200 nm on a base substrate made of a single crystal of an inorganic substance which substantially does not decompose at 800° C. in an inert gas atmosphere and which does produce volatiles by decomposition when contacting with a reducing gas in a temperature range of 800-1600° C., for example sapphire; forming voids along the interface between the base substrate and the Al-based group-III nitride thin-layer of the obtained laminated substrate by thermally treating the laminated substrate in a temperature range of 800-1600° C. in a reducing gas atmosphere containing ammonia gas; forming a group-III nitride single crystal thick-layer on the Al-based group-III nitride thin-layer; and separating these formed layers. The self-supporting substrate is a self-supporting substrate of the group-III nitride single crystal such as AlN, which is suitably used for forming a semiconductor device such as ultraviolet light emitting device and of which crystal plane shows a large radius of curvature.
摘要:
The present invention is a method for producing a laminated body, comprising the steps of: (1) preparing a base substrate having a surface formed of a single crystal which is different from the material constituting the Al-based group-III nitride single crystal layer to be formed; (2) forming an Al-based group-III nitride single crystal layer having a thickness of 10 nm to 1.5 μm on the single crystal surface of the prepared base substrate; (3) forming on the Al-based group-III nitride single crystal layer a non-single crystal layer being 100 times or more thicker than the Al-based group-III nitride single crystal layer without breaking the previously-obtained Al-based group-III nitride single crystal layer; and (4) removing the base substrate. The method provides a substrate which can be suitably used as a base substrate for producing an Al-based group-III nitride single crystal self-supporting substrate, of which surface is formed of a single crystal of an Al-based group-III nitride, and which is free from cracking and warpage.
摘要:
There is provided a method capable of obtaining an aluminum-based group III nitride crystal layer having a smooth surface and high crystallinity by employing only HVPE in which inexpensive raw materials can be used to reduce production costs and high-speed film formation is possible without employing MOVPE.To produce a group III nitride crystal by HVPE comprising the step of growing a group III nitride crystal layer by vapor-phase growth on a single crystal substrate by contacting the heated single crystal substrate with a raw material gas containing a group III halide and a compound having a nitrogen atom, the group III nitride crystal is grown by vapor-phase growth on the single crystal substrate heated at a temperature of 1,000° C. or more and less than 1,200° C. to form an intermediate layer and then, a group III nitride crystal is further grown by vapor-phase growth on the intermediate layer on the substrate heated at a temperature of 1,200° C. or higher.
摘要:
There is provided a method capable of obtaining an aluminum-based group III nitride crystal layer having a smooth surface and high crystallinity by employing only HVPE in which inexpensive raw materials can be used to reduce production costs and high-speed film formation is possible without employing MOVPE.To produce a group III nitride crystal by HVPE comprising the step of growing a group III nitride crystal layer by vapor-phase growth on a single crystal substrate by contacting the heated single crystal substrate with a raw material gas containing a group III halide and a compound having a nitrogen atom, the group III nitride crystal is grown by vapor-phase growth on the single crystal substrate heated at a temperature of 1,000° C. or more and less than 1,200° C. to form an intermediate layer and then, a group III nitride crystal is further grown by vapor-phase growth on the intermediate layer on the substrate heated at a temperature of 1,200° C. or higher.
摘要:
This invention provides a self supporting substrate which consists of a n-type conductive aluminum nitride semiconductor crystal and is useful for manufacturing the vertical conductive type AlN semiconductor device. The n-type conductive aluminum nitride semiconductor crystal, by which the self supporting substrate is made up, contains Si atom at a concentration of 1×1018 to 5×1020 cm−3 is substantially free of halogen atoms and substantially does not absorb the light having the energy of not more than 5.9 eV. The self supporting substrate can be obtained by a method comprising the steps of forming an AlN crystal layer on a single crystal substrate such as a sapphire by the HVPE method, preheating the obtained substrate having the AlN crystal layer to a temperature of 1,200° C. or more, forming a second layer consisting of the n-type conductive aluminum nitride semiconductor crystal is formed on the AlN crystal layer in high rate by the HVPE method and separating the second layer from the obtained laminate.
摘要:
This invention provides a selfsupporting substrate which consists of a n-type conductive aluminum nitride semiconductor crystal and is useful for manufacturing the vertical conductive type AlN semiconductor device.The n-type conductive aluminum nitride semiconductor crystal, by which the selfsupporting substrate is made up, contains Si atom at a concentration of 1×1018 to 5×1020 cm−3, is substantially free from halogen atoms, and substantially does not absorb the light having the energy of not more than 5.9 eV. The selfsupporting substrate can be obtained by a method comprising the steps of forming an AlN crystal layer on a single crystal substrate such as a sapphire by the HVPE method, preheating the obtained substrate having the AlN crystal layer to a temperature of 1,200° C. or more, forming a second layer consisting of the n-type conductive aluminum nitride semiconductor crystal is formed on the AlN crystal layer in high rate by the HVPE method and separating the second layer from the obtained laminate.
摘要:
The invention provides highly transparent single crystalline AlN layers as device substrates for light emitting diodes in order to improve the output and operational degradation of light emitting devices. The highly transparent single crystalline AlN layers have a refractive index in the a-axis direction in the range of 2.250 to 2.400 and an absorption coefficient less than or equal to 15 cm-1 at a wavelength of 265 nm. The invention also provides a method for growing highly transparent single crystalline A1N layers, the method including the steps of maintaining the amount of Al contained in wall deposits formed in a flow channel of a reactor at a level lower than or equal to 30% of the total amount of aluminum fed into the reactor, and maintaining the wall temperature in the flow channel at less than or equal to 1200° C.
摘要:
The present invention relates to a single-crystalline aluminum nitride wherein a carbon concentration is 1×1014 atoms/cm3 or more and less than 3×1017 atoms/cm3, a chlorine concentration is 1×1014 to 1×1017 atoms/cm3, and an absorption coefficient at 265 nm wavelength is 40 cm−1 or less.
摘要:
The invention provides highly transparent single crystalline AlN layers as device substrates for light emitting diodes in order to improve the output and operational degradation of light emitting devices. The highly transparent single crystalline AlN layers have a refractive index in the a-axis direction in the range of 2.250 to 2.400 and an absorption coefficient less than or equal to 15 cm-1 at a wavelength of 265 nm. The invention also provides a method for growing highly transparent single crystalline AlN layers, the method including the steps of maintaining the amount of Al contained in wall deposits formed in a flow channel of a reactor at a level lower than or equal to 30% of the total amount of aluminum fed into the reactor, and maintaining the wall temperature in the flow channel at less than or equal to 1200° C.
摘要:
The present invention relates to a single-crystalline aluminum nitride wherein a carbon concentration is 1×1014 atoms/cm3 or more and less than 3×1017 atoms/cm3, a chlorine concentration is 1×1014 to 1×1017 atoms/cm3, and an absorption coefficient at 265 nm wavelength is 40 cm−1 or less.