Gas mixer

A gas mixer comprising:

• a first gas channel configured to supply a first gas to a reaction chamber;
• a first distribution channel having a cylindrical shape, wherein the first distribution channel surrounds the first gas channel and is configured to uniformly distribute a second gas within the first distribution channel;
• a second gas channel configured to supply the second gas to the first distribution channel;
• a plurality of first connection channels, wherein the first distribution channel is in fluid communication with the first gas channel via the plurality of first connection channels;
• a second distribution channel having a cylindrical shape, wherein the second distribution channel surrounds the first distribution channel and is configured to uniformly distribute a third gas within the second distribution channel;
• a third gas channel configured to supply the third gas to the second distribution channel;
• and
• a plurality of second connection channels, wherein the second distribution channel is in fluid communication with the first gas channel via the plurality of second connection channels.

A gas mixer comprising:

• a first gas channel configured to supply a first gas to a reaction chamber;
• a first distribution channel extending around the first gas channel;
• a second gas channel configured to supply a second gas to the first distribution channel;
• and
• a plurality of first connection channels, wherein the first distribution channel is in fluid communication with the first gas channel via the plurality of first connection channels such that the second gas in the first distribution channel mixes with the first gas in the first gas channel, and wherein the plurality of the first connection channels are uniformly spaced apart from each other.