Method for cooling a furnace, and furnace provided with a cooling device

A furnace assembly, comprising:

• a furnace having an outer casing, a core tube located within the outer casing and a cooling chamber existing between the outer casing and the core tube, the core tube having an elongate boundary wall and being configured to accommodate wafers for processing in a treatment atmosphere, wherein the outer casing includes a heating element and has first lateral, cirucumferentially spaced openings in proximity of a first end of the outer casing and second lateral, circumferentially spaced openings in proximity of a second end of the outer casing;
• a gas line coupled to said first and second lateral, circumferentially spaced openings to provide for communication with the cooling chamber at a first end and a second end of the furnace to supply and to discharge a cooling gas that cools the boundary wall of the core tube and that has a uniform distribution of flow within the cooling chamber, the gas line including valves that comprise diverter valves to direct the cooling gas alternately in one direction along the boundary wall and then in an opposite direction along the boundary wall;
• and
• a liquid-gas heat exchanger in communication with the diverter valves forming a closed circuit for the cooling gas so that the cooling gas is preserved and so that the cooling atmosphere is separated from the treatment atmosphere.

A method for cooling a core tube of a furnace, the core tube having an elongate boundary wall and being configured to accommodate wafers for processing the wafers in a treatment atmosphere, the furnace having a cooling chamber defined between the elongate boundary wall and an outer casing of the furnace, wherein the outer casing includes a heating element and has at least one first opening in proximity of a first end of the outer casing and at least one second opening in proximity of a second end of the outer casing, wherein the cooling chamber is closed at the first and second ends, comprising:

• supplying a cooling gas through one of said first and second openings to a region of one end of said cooling chamber, wherein said cooling gas provides for a cooling atmosphere;
• guiding said cooling gas along said cooling chamber, wherein said cooling gas has a uniform distribution of flow;
• discharging said cooling gas through one of said first and second openings from a region of an opposite end of the cooling chamber;
• periodically reversing a direction of flow of said cooling gas during cooling;
• guiding said cooling gas along a closed circuit so that the cooling gas is preserved and so that the cooling atmosphere is separated from the treatment atmosphere;
• and
• cooling said cooling gas through a liquid-gas heat exchanger.

A furnace assembly, comprising:

• a furnace having an outer casing, a core tube located within the outer casing and a cooling chamber existing between the outer casing and the core tube, the core tube having an elongate boundary wall and being configured to accommodate wafers for processing in a treatment atmosphere, wherein the outer casing includes a heating element and has at least one opening in proximity of a first end of the outer casing and at least one second opening in proximity of a second end of the outer casing, wherein the cooling chamber is closed at the first and second ends;
• a gas line coupled to said first and second openings to provide for communication with the cooling chamber at a first end and a second end of the furnace to supply and to discharge a cooling gas that cools the boundary wall of the core tube and that has a uniform distribution of flow within the cooling chamber, the gas line including valves that comprise diverter valves to direct the cooling gas alternately in one direction along the boundary wall and then in an opposite direction along the boundary wall;
• and
• a liquid-gas heat exchanger in communication with the diverter valves forming a closed circuit for the cooling gas so that the cooling gas is preserved and so that the cooling atmosphere is separated from the treatment atmosphere.