SiC epitaxial growth apparatus having purge gas supply ports which surround a vicinity of a raw material gas supply port

1. A SiC epitaxial growth apparatus comprising:

a mounting stand on which a SiC wafer is mounted; and

a furnace body which is configured to cover the mounting stand and includes a growth space therein,

wherein the furnace body includes

a raw material gas supply port which is positioned so as to face the mounting stand and is configured to supply a raw material gas to the growth space,

a first purge gas supply port which surrounds the raw material gas supply port and is configured to supply a purge gas to the growth space, and

a second purge gas supply port which surrounds a vicinity of the first purge gas supply port and is configured to supply a purge gas to the growth space;

the raw material gas supply port comprises a plurality of raw material gas supply ports,

the first purge gas supply port comprises a plurality of first purge gas supply ports, each of the plurality of first purge gas supply ports comprises an opening that entirely surrounds an outer periphery of one of the plurality of the raw material gas supply ports in a concentric circle,

the raw material gas supply port is a first end of a raw material gas supply pipe for supplying the raw material gas to the growth space,

the first purge gas supply port is a first end of a first purge gas supply pipe for supplying the purge gas to the growth space,

the first end of the raw material gas supply pipe is positioned above the first end of the first purge gas supply pipe in a +z direction that is perpendicular to the mounting stand on which the SiC wafer is mounted, and

the second purge gas supply port comprises a plurality of second purge gas supply ports, and each of the plurality of second purge gas supply ports is arranged in a concentric circle surrounding only one of the plurality of first purge gas supply ports.

2. The SiC epitaxial growth apparatus according to claim 1 , wherein the SiC epitaxial growth apparatus is configured such that a flow velocity of the purge gas supplied from the second purge gas supply port becomes lower than a flow velocity of the purge gas supplied from the first purge gas supply port.

3. The SiC epitaxial growth apparatus according to claim 1 , wherein

the first purge gas supply port is configured so as to supply a purge gas to the growth space at a flow velocity of greater than 10 m/s and equal to or less than 100 m/s, and

the second purge gas supply port is configured so as to supply a purge gas to the growth space at a flow velocity of equal to or greater than 0.1 m/s and equal to or less than 10 m/s.

4. The SiC epitaxial growth apparatus according to claim 1 , wherein the second purge gas supply port is positioned on a side outward from an outer periphery of the first purge gas supply port at a distance of 0.5 mm or more therefrom.

5. The SiC epitaxial growth apparatus according to claim 1 , wherein

the second purge gas supply port is a through hole formed in a partition wall that separates the growth space and a processing front chamber from each other.

6. The SiC epitaxial growth apparatus according to claim 1 ,

wherein the plurality of raw material gas supply ports include a Si-based gas supply port and a C-based gas supply port, and

the plurality of second purge gas supply ports are arranged in a concentric circle surrounding the Si-based gas supply port.

7. The SiC epitaxial growth apparatus according to claim 1 , wherein

the first end of the raw material gas supply pipe has a diameter that increases in a downward −z direction.