Vapor phase epitaxial growth device

A method for controlling vapor phase epitaxial growth device configured to grow a compound semiconductor,

• the vapor phase epitaxial growth device comprising:
• a reactor vessel;
• a wafer holder arranged within the reactor vessel;
• a first material gas supply pipe;
• a second material gas supply pipe;
• and
• a gas exhaust pipe,
• the method comprising:
• holding a wafer by the wafer holder such that a wafer surface is oriented substantially vertically downward;
• supplying, by using the first material gas supply pipe, a first material gas into the reactor vessel from below the wafer surface;
• supplying, by using the second material gas supply pipe, a second material gas which reacts with the first material gas into the reactor vessel from below the wafer surface;
• and
• exhausting, by using the gas exhaust pipe, gases in the reactor vessel from below the wafer surface,
• wherein a distance between the gas exhaust pipe and an axis line passing through a center of the wafer surface and vertical to the wafer 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.

A compound semiconductor substrate comprising:

• a base substrate;
• and
• a grown crystal layer disposed on a surface of the base substrate and constituted of a compound semiconductor monocrystal, an end surface at a peripheral portion of the grown crystal layer being formed vertical to the surface of the base substrate,
• wherein the grown crystal layer is grown by:
• holding the base substrate by a wafer holder;
• moving at least one of the wafer holder and a ring unit along an axis line vertical to the surface of the base substrate, the ring unit including a hole corresponding to the wafer held by the wafer holder;
• and
• maintaining a constant distance between a surface of the ring unit and a surface of the grown crystal layer.