Substrate processing apparatus, method of manufacturing semiconductor device, and baffle structure of the substrate processing apparatus

A substrate processing apparatus comprising:

• a reaction vessel having a tubular shape;
• a cover installed at a first end of the reaction vessel;
• a resonance coil wound on an outer circumference of the reaction vessel;
• a first baffle installed between the cover and an upper end of the resonance coil with a first gap between an outer circumference of the first baffle and an inner circumference of the reaction vessel along the outer circumference of the first baffle;
• a second baffle installed between the first baffle and the upper end of the resonance coil with a second gap between an outer circumference of the second baffle and the inner circumference of the reaction vessel along the outer circumference of the second baffle, wherein a lower surface of the second baffle is at a height that is higher than that of the upper end of the resonance coil;
• a gas introduction port installed at the cover and having a conical shape with a diameter thereof increasing toward a lower surface of the cover;
• and
• a gas exhaust pipe connected to the reaction vessel,
• wherein the first baffle and the second baffle are free from a hole allowing a gas to flow therethrough.