Patent ID: 8043431

Claim:
A substrate processing apparatus comprising: a reaction furnace for processing a substrate; a seal cap for sealing an opening of the reaction furnace hermetically; a first cover installed within the hermetically sealed furnace so as to be separate from the seal cap so as to cover at least a section of the surface of the seal cap which faces the inner side of the reaction furnace; a first small chamber formed by the seal cap and the first cover, a first feed opening for supplying a first gas to the first small chamber; a first flow outlet provided in the first small chamber for making the first gas flow into the reaction furnace; a second cover installed within the hermetically sealed furnace so as to be separate from the inner wall surface of the lower section of the reaction furnace so as to cover at least a portion of the inner wall surface of the lower part of the reaction furnace; a second small chamber formed by the second cover and the inner wall surface of the lower part of the reaction furnace; a second feed opening for supplying a second gas that is different from the first gas to the second small chamber; and a second flow outlet provided in the second small chamber for allowing the second gas to flow into the reaction chamber, wherein the first flow outlet is configured to substantially prevent inflow of the second gas into the first small chamber, and wherein the first gas and the second gas are simultaneously supplied into the reaction furnace.