Provided are: a GaN crystal used in a substrate for a nitride semiconductor device having a horizontal device structure, such as a GaN-HEMT; and a GaN substrate used for the production of a nitride semiconductor device having a horizontal device structure, such as a GaN-HEMT. The GaN crystal and the GaN substrate each include a surface having an inclination of 10° or less from a (0001) crystal plane and an area of 5 cm.sup.2 or more, and have an Mn concentration of 1.0 × 10.sup.16 atoms/cm.sup.3 or higher but lower than 1.0 × 10.sup.19 atoms/cm.sup.3 and a total donor impurity concentration of lower than 5.0 × 10.sup.16 atoms/cm.sup.3.

Provided are: a GaN crystal used in a substrate for a nitride semiconductor device having a horizontal device structure, such as a GaN-HEMT; and a GaN substrate used for the production of a nitride semiconductor device having a horizontal device structure, such as a GaN-HEMT. The GaN crystal and the GaN substrate each include a surface having an inclination of 10° or less from a (0001) crystal plane and an area of 5 cm.sup.2 or more, and have an Mn concentration of 1.0 × 10.sup.16 atoms/cm.sup.3 or higher but lower than 1.0 × 10.sup.19 atoms/cm.sup.3 and a total donor impurity concentration of lower than 5.0 × 10.sup.16 atoms/cm.sup.3.

A vapor phase growth system includes a process chamber that includes a susceptor lifting mechanism that raises and lowers the susceptor between a first position and a second position. With the susceptor in the first position, the top surface of the susceptor is above the bottom surface of the preheating ring, and a source gas distribution space with a predetermined height dimension is secured between the top surface of the susceptor and the bottom surface of a ceiling plate of the reaction vessel body. With the susceptor in the second position, the top surface of the susceptor is located below the bottom surface of a preheating ring, and a substrate loading/unloading space, which has a greater height dimension than that of the source gas distribution space, is secured between the top surface of the susceptor and the bottom surface of the preheating ring.

A vapor phase growth system includes a process chamber that includes a susceptor lifting mechanism that raises and lowers the susceptor between a first position and a second position. With the susceptor in the first position, the top surface of the susceptor is above the bottom surface of the preheating ring, and a source gas distribution space with a predetermined height dimension is secured between the top surface of the susceptor and the bottom surface of a ceiling plate of the reaction vessel body. With the susceptor in the second position, the top surface of the susceptor is located below the bottom surface of a preheating ring, and a substrate loading/unloading space, which has a greater height dimension than that of the source gas distribution space, is secured between the top surface of the susceptor and the bottom surface of the preheating ring.

A reactor system may comprise a first reaction chamber and a second reaction chamber. The first and second reaction chambers may each comprise a reaction space enclosed therein, a susceptor disposed within the reaction space, and a fluid distribution system in fluid communication with the reaction space. The susceptor in each reaction chamber may be configured to support a substrate. The reactor system may further comprise a first reactant source, wherein the first reaction chamber and the second reaction chamber are fluidly coupled to the first reactant source at least partially by a first reactant shared line. The reactor system may be configured to deliver a first reactant from the first reactant source to the first reaction chamber and a second reaction chamber through the first reactant shared line.

A reactor system may comprise a first reaction chamber and a second reaction chamber. The first and second reaction chambers may each comprise a reaction space enclosed therein, a susceptor disposed within the reaction space, and a fluid distribution system in fluid communication with the reaction space. The susceptor in each reaction chamber may be configured to support a substrate. The reactor system may further comprise a first reactant source, wherein the first reaction chamber and the second reaction chamber are fluidly coupled to the first reactant source at least partially by a first reactant shared line. The reactor system may be configured to deliver a first reactant from the first reactant source to the first reaction chamber and a second reaction chamber through the first reactant shared line.

Provided is a method of manufacturing an epitaxial wafer, which includes vapor-phase growing an epitaxial layer on a substrate W placed on a susceptor 3 in a state where an upper surface 4b1 of a lift pin 4 inserted in a through-hole H of the susceptor 3 retracts or projects with respect to an upper opening H1a of the through-hole H. A level difference D from the upper surface 4b1 of the lift pin 4 to the opening H1a of the through-hole H is measured with laser light, and outputs, during epitaxial growth, of heaters 9 located above and beneath the susceptor 3 are adjusted on the basis of the measured level difference D. Thus, a method of manufacturing an epitaxial wafer, which facilitates adjustment of the outputs of the heat sources during epitaxial growth, is provided.

Provided is a method of manufacturing an epitaxial wafer, which includes vapor-phase growing an epitaxial layer on a substrate W placed on a susceptor 3 in a state where an upper surface 4b1 of a lift pin 4 inserted in a through-hole H of the susceptor 3 retracts or projects with respect to an upper opening H1a of the through-hole H. A level difference D from the upper surface 4b1 of the lift pin 4 to the opening H1a of the through-hole H is measured with laser light, and outputs, during epitaxial growth, of heaters 9 located above and beneath the susceptor 3 are adjusted on the basis of the measured level difference D. Thus, a method of manufacturing an epitaxial wafer, which facilitates adjustment of the outputs of the heat sources during epitaxial growth, is provided.

A method and an apparatus for depositing an epitaxial layer on a substrate wafer made of semiconductor material. The method comprises the arrangement of the substrate wafer and a susceptor in a deposition device such that the substrate wafer rests on the susceptor and the susceptor is held by arms of a support shaft; monitoring whether a misalignment of the susceptor exists with respect to its position relative to the position of a pre-heating ring surrounding it; monitoring whether a misalignment of the support shaft exists with respect to its position relative to the position of the pre-heating ring; if at least one of the misalignments is present, elimination of the respective misalignment; and the deposition of the epitaxial layer on the substrate wafer.

A method and an apparatus for depositing an epitaxial layer on a substrate wafer made of semiconductor material. The method comprises the arrangement of the substrate wafer and a susceptor in a deposition device such that the substrate wafer rests on the susceptor and the susceptor is held by arms of a support shaft; monitoring whether a misalignment of the susceptor exists with respect to its position relative to the position of a pre-heating ring surrounding it; monitoring whether a misalignment of the support shaft exists with respect to its position relative to the position of the pre-heating ring; if at least one of the misalignments is present, elimination of the respective misalignment; and the deposition of the epitaxial layer on the substrate wafer.