Plasma generator and substrate processing apparatus including the same

A plasma generator comprising:

• a first outer wall extending in a first direction from a first area to a second area;
• a second outer wall parallel to the first outer wall and extending in from a third area to a fourth area;
• a third outer wall extending in a second direction from the first area to the third area, wherein the second direction intersects the first direction;
• a gas nozzle in an inner space formed by the first, the second, and the third outer walls, wherein the gas nozzle is configured to inject a processing gas into the inner space;
• a first plasma electrode on an outer surface of the first outer wall and a second plasma electrode on an outer surface of the second outer wall, wherein a voltage is applied to the first and the second plasma electrodes;
• a first floating electrode on the outer surface of the first outer wall and a second floating electrode on the outer surface of the second outer wall, wherein the first floating electrode is adjacent to the first plasma electrode and the second floating electrode is adjacent to the second plasma electrode;
• and
• a gas guide on inner surfaces of the first outer wall and the second outer wall.

A substrate processing apparatus comprising:

• a reaction vessel;
• a wafer boat in the reaction vessel and configured to hold one or more wafers;
• and
• a plasma generator configured to generate plasma, wherein the plasma generator comprises:
• a housing comprising an internal space and an opening through which the plasma is emitted into the reaction vessel;
• a gas nozzle in the internal space, wherein the gas nozzle is configured to inject a processing gas into the internal space;
• a plurality of plasma electrodes on an outer surface of the housing and to which a voltage is applied;
• and
• a plurality of floating electrodes on an outer surface of the housing and adjacent to the plurality of plasma electrodes.