A vapor phase epitaxial growth device comprises a reactor vessel and a wafer holder arranged within the reactor vessel. The wafer holder includes a wafer holding surface configured to hold a wafer with a wafer surface oriented substantially vertically downward. The device comprises a first material gas supply pipe configured to supply a first material gas and arranged below the wafer holding surface. The device comprises a second material gas supply pipe configured to supply a second material gas and arranged below the wafer holding surface. The device comprises a gas exhaust pipe configured to exhaust gases and arranged below the wafer holding surface. A distance between the gas exhaust pipe and an axis line passing through a center of the wafer holding surface is greater than distances between the axis line and each of the first material gas supply pipe and the second material gas supply pipe.

There is provided a method for manufacturing a nitride semiconductor template constituted by forming a nitride semiconductor layer on a substrate, comprising: (a) forming a first layer by epitaxially growing a nitride semiconductor containing aluminum on the substrate; (b) applying annealing to the first layer in an inert gas atmosphere; and (c) forming a second layer by epitaxially growing a nitride semiconductor containing aluminum on the first layer by a vapor phase growth after performing (b), and constituting the nitride semiconductor layer by the first layer and the second layer.

There is provided a method for manufacturing a nitride semiconductor template constituted by forming a nitride semiconductor layer on a substrate, comprising: (a) forming a first layer by epitaxially growing a nitride semiconductor containing aluminum on the substrate; (b) applying annealing to the first layer in an inert gas atmosphere; and (c) forming a second layer by epitaxially growing a nitride semiconductor containing aluminum on the first layer by a vapor phase growth after performing (b), and constituting the nitride semiconductor layer by the first layer and the second layer.

A group Ill nitride crystal manufacturing apparatus includes a raw material chamber generating a group Ill elemental oxide gas, and a growth chamber allowing the group Ill element oxide gas supplied from the raw material chamber to react with a nitrogen element-containing gas to generate a group III nitride crystal on a seed substrate, and the growth chamber incudes a decomposition promoting part promoting decomposition of the unreacted nitrogen element- containing gas between the seed substrate and an exhaust port for discharging the unreacted group Ill oxide gas and the nitrogen element-containing gas.

A group Ill nitride crystal manufacturing apparatus includes a raw material chamber generating a group Ill elemental oxide gas, and a growth chamber allowing the group Ill element oxide gas supplied from the raw material chamber to react with a nitrogen element-containing gas to generate a group III nitride crystal on a seed substrate, and the growth chamber incudes a decomposition promoting part promoting decomposition of the unreacted nitrogen element- containing gas between the seed substrate and an exhaust port for discharging the unreacted group Ill oxide gas and the nitrogen element-containing gas.

A crystal substrate 1 includes an underlying layer 2 and a thick film 3. The underlying layer 2 is composed of a crystal of a nitride of a group 13 element and includes a first main face 2a and a second main face 2b. The thick film 3 is composed of a crystal of a nitride of a group 13 element and provided over the first main face of the underlying layer. The underlying layer 2 includes a low carrier concentration region 5 and a high carrier concentration region 4 both extending between the first main face 2a and the second main face 2b.

A crystal substrate 1 includes an underlying layer 2 and a thick film 3. The underlying layer 2 is composed of a crystal of a nitride of a group 13 element and includes a first main face 2a and a second main face 2b. The thick film 3 is composed of a crystal of a nitride of a group 13 element and provided over the first main face of the underlying layer. The underlying layer 2 includes a low carrier concentration region 5 and a high carrier concentration region 4 both extending between the first main face 2a and the second main face 2b.

A method for manufacturing a compound semiconductor substrate comprises: a step to form an SiC (silicon carbide) layer on a Si (silicon) substrate, a step to form a LT (Low Temperature)-AlN (aluminum nitride) layer with a thickness of 12 nanometers or more and 100 nanometers or less on the SiC layer at 700 degrees Celsius or more and 1000 degrees Celsius or less, a step to form a HT (High Temperature)-AlN layer on the LT-AlN layer at a temperature higher than the temperature at which the LT-AlN layer was formed, a step to form an Al (aluminum) nitride semiconductor layer on the HT-AlN layer, a step to form a GaN (gallium nitride) layer on the Al nitride semiconductor layer, and a step to form an Al nitride semiconductor layer on the GaN layer.

A method for manufacturing a compound semiconductor substrate comprises: a step to form an SiC (silicon carbide) layer on a Si (silicon) substrate, a step to form a LT (Low Temperature)-AlN (aluminum nitride) layer with a thickness of 12 nanometers or more and 100 nanometers or less on the SiC layer at 700 degrees Celsius or more and 1000 degrees Celsius or less, a step to form a HT (High Temperature)-AlN layer on the LT-AlN layer at a temperature higher than the temperature at which the LT-AlN layer was formed, a step to form an Al (aluminum) nitride semiconductor layer on the HT-AlN layer, a step to form a GaN (gallium nitride) layer on the Al nitride semiconductor layer, and a step to form an Al nitride semiconductor layer on the GaN layer.

A nitride laminate, in which contamination in the nitride layer is suppressed and crystallinity is improved, is provided. A nitride laminate includes a polymer substrate, and a nitride layer provided on at least one of the surfaces of the polymer substrate. The nitride layer has a wurtzite crystal structure. The atomic proportion of oxygen in the nitride layer is 2.5 atm. % or less, and the atomic proportion of hydrogen in the nitride layer is 2.0 atm. % or less. The FWHM of the X-ray rocking curve of the nitride layer is 8 degree or less.